[CENTRAAL] Wetenschap & Technologie in het Nieuws 3

Mij Reflex, wat doe je?

quote:

Op woensdag 19 november 2014 09:14 schreef ExperimentalFrentalMental het volgende:
18-11-2014

Leven programmeren

[ afbeelding ]

Stel je voor: onderzoekers bouwen compleet nieuwe levensvormen op basis van bestaand DNA. Dat lijkt nu erg ver weg, maar het is dichterbij dan je denkt. Wetenschappers zijn op dit moment druk bezig in het lab met het programmeren van nieuw leven, nog geen compleet nieuwe organismen, maar wel hele nieuwe eigenschappen voor bestaande soorten. Deze nieuwe technologie noemen we synthetische biologie.
door Joy Kerklaan

Wat is synthetische biologie?
Er is geen eenduidige definitie die de synthetische biologie beschrijft. Om een idee te geven wat synthetische biologie precies is, kun je hieronder bekijken hoe verschillende bedrijven, wetenschappers en studenten synthetische biologie beschrijven

Geschiedenis van de synthetische biologie
Synthetische biologie bouwt voort op technologieën die zich in de loop der tijd ontwikkeld hebben, zoals genetische modificatie. Bij genetische modificatie haal je handige eigenschappen van het ene organisme en plak je deze in het genetische bouwplan van een ander organisme. Synthetische biologie gaat nog een stap verder: wetenschappers bouwen organismen met compleet nieuwe functies door stukken DNA zelf aan elkaar te plakken en die in te bouwen. Ze maken allerlei stukjes DNA die voor verschillende functies coderen. Bijvoorbeeld een stukje dat de groeisnelheid bepaalt of een stukje dat zorgt dat een lichtgevend eiwit wordt gemaakt. Zo krijgen ze een gereedschapsdoos gevuld met allerlei eigenschappen waar ze op voort kunnen bouwen.

[ afbeelding ]
Het verschil tussen Genetische Modificatie en synthetische biologie
Rathenau Instituut Bericht aan het parlement. Den Haag september 2007

Wat kun je met synthetische biologie?
Wetenschappers beweren dat synthetische biologie problemen als klimaatverandering, energie- en watertekorten en de gezondheidszorg kan oplossen in de toekomst. Echter, er kleven ook nadelen aan de toepassingen. Zo spelen ethische aspecten mee: mag je zomaar knutselen aan het leven? Mag je elke eigenschap zomaar van het ene organisme naar het andere verplaatsen? Weten we wel genoeg over de gevolgen en risico’s op lange termijn?

Wil jij meepraten over de voor-en nadelen van synthetische biologie? Welke toepassingen je wel en niet aan staan? In hoeverre deze techniek onze toekomst zou mogen veranderen? Discussieer bijvoorbeeld mee over vragen als Wil je lichtgevende bomen langs je fietspad?, willen we met z’n allen langer leven en hebben we behoefte aan pillen die maken dat we lekkerder ruiken op het toilet?.

[ afbeelding ]
De ontwikkeling van de synthetische biologie
Rathenau Instituut Bericht aan het parlement. Den Haag september 2007, p.4.
Bron:
van Est, R. e.a., Synthetische biologie: Nieuw leven in het biodebat, Rathenau Instituut (september 2007).

(Kennislink)

Dank je voor dit bericht, ik wist dat men gisten gebruikt voor het maken van allerlei zaken, maar dat men nu ook het malariamedicijn Artemisinezuur kan produceren op grote schaal is heel erg positief, het werd tot voor kort nog uit zomeralsem gewonnen, een complex en niet voorspelbaar proces, te veel onbekende variabelen die de opbrengst beïnvloeden.

ff gegoegeld
http://www.kennislink.nl/(...)-van-malariamedicijn
Met 800 reactoren voldoende produceren om alle malaria patienten wereldwijd te behandelen.
Dat is heel erg goed nieuws

quote:

Op dinsdag 25 november 2014 10:12 schreef ExperimentalFrentalMental het volgende:
24-11-2014

Recent ontdekte mammoet maakt klonen wellicht mogelijk

(scientias.nl)

Opvallend dat dit net voordat er een nieuwe Jurassic film uitkomt gepubliceerd wordt, waar ook het klonen van Mammoeten een belangrijke rol speelt

quote:

Op donderdag 27 november 2014 12:56 schreef ExperimentalFrentalMental het volgende:
26-11-2014

Menselijke hersencellen verwerken informatie veel beter en sneller dan muizenhersencellen

Denken, concentreren, onthouden, en herinneren worden in onze hersenen geregeld door hersencellen die met elkaar ‘praten’. NWO Vici-laureaat prof. Huib Mansvelder en zijn team VU-onderzoekers hebben voor het eerst dat communiceren tussen menselijke hersencellen in levend menselijk hersenweefsel onderzocht. De onderzoekers laten zien dat de contactpunten (of: synapsen) tussen hersencellen tot wel tien keer efficiënter zijn en veel meer informatie over kunnen dragen dan werd aangenomen. Dat is belangrijke nieuwe kennis over de elementaire bouwstenen van de menselijke hersenen. Een artikel daarover verscheen 25 november in het open access tijdschrift PLoS Biology.

[ afbeelding ]
Beeld: Rademaker/Hollandse Hoogte

Betere ‘conditie’ vergroot informatieoverdracht

Hersencellen ‘praten’ met elkaar met elektrische en chemische signalen via synapsen. Deze synapsen zorgen dat informatie wordt verwerkt. De onderzoekers voerden metingen uit aan ‘pratende’ levende menselijke hersencellen en concludeerden dat deze minder snel moe worden én informatie kunnen blijven overdragen, waar muizencellen allang uitgeput zouden zijn. Bovendien kunnen menselijke hersencellen op veel kleinere details in de elektrische signaaloverdracht reageren dan muizencellen waardoor veel meer informatie kan worden overgedragen. Het is alsof muizenhersencellen door een heel smal telefoonlijntje communiceren en een hele kleine batterij hebben, terwijl menselijke hersencellen via een breedbandige glasvezel verbinding communiceren met een grote accu.

Nieuwe onderzoeksmethode voor levend hersenweefsel

Tot nu toe was kennis over de werking van het menselijk brein gebaseerd op cellen uit o.a. knaagdieren, omdat de wetenschap er vanuit gaat dat menselijke cellen grofweg hetzelfde werken. Door te kijken naar levend hersenweefsel, verkregen uit tumor- en epilepsie-operaties van nog levende patiënten, is het functioneren van menselijke hersencellen direct te bestuderen.

Daarvoor heeft Mansvelder een unieke samenwerking met neurochirurgen in het VUmc geïnitieerd. Hersenweefsel dat voor behandeling van tumoren en epilepsie is verwijderd, wordt in leven gehouden en in het lab onderzocht. Slechts bij een enkel laboratorium ter wereld diedat de technische expertise hebben om deze analyse te kunnen doen, lukt zo’n technisch zeer lastige ’transfer’. Daarom is er nagenoeg niets over de werking van menselijke hersencellen bekend.
Mansvelder: ‘De meerwaarde van onze aanpak zit hem in de kwaliteit van het weefsel dat de neurochirurg aanlevert en de state-of-the-art neurowetenschappelijke aanpak om de kleine elektrische signalen die twee cellen elkaar sturen, direct te meten.

Grote investeringen voor verdere puzzel

De afgelopen jaren zijn veel grootschalige investeringen in de VS en in de EU gedaan om menselijke hersenen in kaart te brengen. Zoals het Human Brain Project, waar dit onderzoek ook deels uit gefinancierd is. De resultaten van ons huidige onderzoek vormen weer een stukje van de grotere puzzel. Ze laten o.a. zien dat menselijke hersenen opgebouwd zijn uit hoogwaardige onderdelen die zeer snel en efficiënt zijn. Een computer die samengesteld is uit onderdelen die sneller functioneren, zal als geheel sneller zijn. Misschien is dat bij onze hersenen ook zo. Een volgende stap is onderzoeken of communicatie tussen menselijke hersencellen kan verklaren waarom menselijke hersenen zoveel meer kunnen dan andere diersoorten met hersenen van vergelijkbare grootte. Het zijn de elementaire, slimme bouwstenen van onze hersenen.

Het artikel is beschikbaar via het open access tijdschrift PLOS Biology.

Over NWO

De Nederlandse Organisatie voor Wetenschappelijk Onderzoek is een van de belangrijkste wetenschapsfinanciers in Nederland en zorgt voor kwaliteit en vernieuwing in de wetenschap. NWO investeert jaarlijks ruim 650 miljoen in nieuwsgierigheidsgedreven onderzoek en onderzoek rond maatschappelijke uitdagingen. Op basis van adviezen van deskundige wetenschappers en relevante experts uit binnen- en buitenland selecteert en financiert NWO onderzoeksvoorstellen. NWO stimuleert nationale en internationale samenwerking, investeert in grote onderzoeksfaciliteiten, bevordert kennisbenutting en beheert onderzoeksinstituten. NWO financiert meer dan 5.600 onderzoeksprojecten aan universiteiten en kennisinstellingen.
Bron: NWO

(nwo.nl)

Vet van mij: zeer hinderlijke taalfouten.
Maar dan nog: wat zegt weefsel dat bij tumoren en epilepsie is verwijderd over gezond weefsel?

New Analysis Suggests Earth's Magnetic Field Is Destabilizing

November 26, 2014 | by Lisa Winter



Photo credit: US Department of Energy



Earth’s magnetic field is generated by an interaction between rotation in the planet’s core and electrical currents. The field then creates the magnetosphere, which acts sort of like a force field, protecting the planet from the brunt of the sun's solar wind. This field has both a North and South pole, which can be used for navigational purposes, and they are not static. Variations in the electric current have caused the poles to migrate as much as 16 km (10 miles) per year.

The field itself is not fixed either, and about every 450,000 years or so, the poles actually reverse. This puts the magnetic North where the South was, and vice versa. Last month, a team from the University of California, Santa Cruz was able to determine that the last pole reversal occurred roughly 786,000 years ago over the course of less than 100 years -- within a single human lifetime. Typically, these events take place over the course of thousands of years.

The planet seems to be long overdue for a field reversal: there is evidence that these events happen more frequently than they used to hundreds of millions of years ago. This could be due to the inner core growing larger, which is obstructing the outer core, resulting in a magnetic field that isn’t quite as solid.

Evidence of magnetic field reversals can be seen in rocks. When molten rock cools, the metal components are oriented toward the field. By looking at layers of rock, geologists are able to observe where the metallic molecules are pointing, and thus, determine the direction of the magnetic field.

The European Space Agency’s Swarm constellation uses three satellites to study the Earth’s magnetic field as well as the oceans and the planet’s inner structure. At a Swarm science meeting held in Copenhagen this past summer, it was announced that the magnetic field has been weakening by roughly 5% every 10 years. A weakening or unstable magnetic field could be a sign that a reversal is about to occur. The strength of the magnetic field normally does fluctuate a little bit, but the rate that this appears to be happening is larger than normal. The field appears to be weakening about ten times faster than previously predicted, indicating that an event could be coming sooner rather than later.

If the poles flip, having a compass that points South instead of North doesn’t seem like too big of a deal to humans, but there is a question of what will happen other animals. Certain migratory animals like sea turtles and birds use the magnetic field in order to orient themselves. A reversal of the poles could interfere with their ability to do so.

Another concern about the reversal is that the weakening of the magnetic field which precedes the flipping event will mean that it will not be able to adequately shield us from the sun’s radiation. Though there is no evidence in the fossil record of a mass extinction correlating with a field reversal or an influx of radiation, this could potentially be problematic to power grids and satellites.

http://www.iflscience.com(...)tic-field-about-flip

http://www.spacedaily.com(...)above_Earth_999.html

Star Trek-like invisible shield found thousands of miles above Earth

A team led by the University of Colorado Boulder has discovered an invisible shield some 7,200 miles above Earth that blocks so-called "killer electrons," which whip around the planet at near-light speed and have been known to threaten astronauts, fry satellites and degrade space systems during intense solar storms.

<...>

RESEARCHERS HAVE DISCOVERED COMET DUST ON EARTH FOR THE FIRST TIME EVER

Particles of comet dust have been discovered preserved in the ice and snow of Antarctica, and could provide new insight into how our Solar System formed.

FIONA MACDONALD 6 DEC 2014


Scientists have uncovered a relatively large amount of comet dust preserved in Antarctica. Comet dust represents the oldest astronomical particles we have access to, and up until now it was believed that the material couldn't survive on Earth's surface.

“It’s very exciting for those of us who study these kinds of extraterrestrial materials, because it opens up a whole new way to get access to them,” Larry Nittler, a planetary scientist at the Carnegie Institution for Science in Washington DC, who wasn’t involved with the research, told Ilima Loomis from Science. “They’ve found a new source for something that’s very interesting and very rare.”

Comest dust is extraordinary because it can give us clues about the materials that helped form the Solar System, but until now it’s been pretty difficult to access. Scientists currently need to fly research planes high up into the stratosphere in order to collect tiny amounts of the dust - usually several hours of flying time will only result in one particle being collected.

This small sample size means that scientists haven’t been able to do as much research on the dust as they'd like to. But now a relatively huge amount - more than 40 comet dust particles - has been found right here on Earth’s surface.

“Two to four more orders of magnitude mass of material is potentially collectible this way,” John Bradley, an astromaterials scientists at the University of Hawaii, who worked on the discovery, told Science. “I think it could precipitate a paradigm shift in the way these kinds of materials are collected.”

Comet dust, also known as “chondritic porous interplanetary dust particles”, is highly porous and extremely fragile, and prior to this discovery scientists thought the particles couldn’t survive here on Earth. Back in 2010, French scientists reported that they’d found evidence of dense, unusually carbon-rich comet particles in the Antarctic snow, but it’s only now that researchers have been able to confirm that the discovery of comet dust itself.

The researchers found the dust in snow and ice collected from two different Antarctic sites. After melting the ice, they filtered out more than 3,000 micormeteorites - tiny space particles that were 10 microns in diameter or larger. Over five years they analysed these micrometeorites individually under the microscope to work out which could be classified as comet dust.

In the end they found more than 40 particles with the characteristics of comet dust - these particles were indistinguishable from the comet dust collected in the stratosphere, and also matched samples collected from the coma that surrounds a comet by NASA’s Stardust mission in 2006.

Publishing their discovery in Earth and Planetary Science Letters, the researchers also report that the comet dust they’ve found in Antarctica is cleaner than the dust they collect from the stratosphere. This is because in order to capture the dust at the moment, they use plates coated with silicon oil - sort of in the same way you use flypaper to trap flies. Not only is this not super effective, it also means that the few comet dust particles they collect end up contaminated with oil and the organic compounds used to later clean them. So it’s hard to scientists to narrow down exactly what organic materials the dust actually contains.

Now the scientists will compare their Antarctic comet particles with the ones collected using planes, and work our which organic materials are contaminants and which are naturally occuring. This will provide some insight into the material that led to the birth of our Solar System.

“The study of these cometary particles will help shed more light on the material that served for planetary formation,” meteorite researcher Cécile Engrand from Paris-Sud University in Orsay, co-author of the 2010 French research, told Loomis over at Science. “They are the best witnesses that we have of that period of time.”

But importantly, this discovery also suggests that there could be even more sources of comet dust right here on Earth - something we previously thought was impossible.

“Our result shows that such fragile particles can be preserved not only in … snow, but also in ice,” said the study’s lead author, Takaaki Noguchi, a meteorite researcher at Kyushu University in Fukuoka, Japan.

Bron: http://www.sciencealert.c(...)-the-first-time-ever

THE WORLD'S MOST EFFICIENT PARTICLE ACCELERATOR HAS JUST SET A NEW ENERGY RECORD

A tabletop-sized device has accelerated electrons at a rate 1,000 times greater than the Large Hadron Collider.

FIONA MACDONALD 9 DEC 2014

Using one of the most powerful lasers in the world, researchers in the US have accelerated electrons to the highest energies ever recorded from a compact accelerator.

The team from Lawrence Berkeley National Laboratory in the US has managed to speed subatomic particles to an energy of 4.25 giga-electron volts inside a 9-cm-long tube of plasma.

This represents 1,000 times greater acceleration than traditional particle accelerators, including the 27-km-long Large Hadron Collider (LHC) at CERN, and marks a world record energy for laser-plasma accelerators.
Because subatomic particles zoom around accelerators so quickly, they're measured by the amount of energy they gain rather than a kilometres per hour measurement. In comparison, the LHC can achieve maximum energy gains of around 100 mega-electron volts per metre.

Published in Physical Review Letters, the results were achieved using a new breed of particle accelerator, known as laser-plasma accelerators.

These accelerators rely on lasers and plasma - a charged-particle gas - to speed up subatomic particles extremely rapidly. Traditional particle accelerators instead speed up electrons inside a metal vacuum using changing electromagnetic fields.

"This result requires exquisite control over the laser and the plasma," said Wim Leemans, lead author of the paper, in a press release.

The laser in this case was called BELLA (Berkeley Lab Laser Accelerator) and it’s one of the most powerful lasers in the world, capable of producing a quadrillion watts of power (a petawatt).

Their “tunnel” was a 9-cm-long tube of plasma, and the system relies on a type of acceleration first propose in the ‘70s, known as plasma wakefield acceleration.

The press release explains:

“In the case of this experiment, a pulse of laser light is injected into a short and thin straw-like tube that contains plasma. The laser creates a channel through the plasma as well as waves that trap free electrons and accelerate them to high energies. It's similar to the way that a surfer gains speed when skimming down the face of a wave.”

A computer simulation of the plasma wakefield over the 9-cm-long tube is below.



Because they’re working with such high energies, the researchers used computer simulations to test the set up before they ever turned on the laser.

Small changes in the setup give you big perturbations,” said Eric Esarey, who led the theoretical side of the project, in the release. “We’re homing in on the regions of operation and the best ways to control the accelerator.”

The team now hopes to achieve energies of 10 giga-electron volts with their accelerator. In order to do this, they will need to more precisely control the density of the plasma channel through with the laser beam flows. In theory, they need to create a tunnel for the light pulse that’s the right shape to handle more-energetic electrons.

But for now, they’ve proved that condense laser-plasma accelerators definitely have the potential to conduct scientific experiments that currently require far larger machines.

“It is an extraordinary achievement for Dr. Leemans and his team to produce this record-breaking result in their first operational campaign with BELLA," said James Symons, a physicist at Berkeley who didn’t work on the project, in the release.

Source: http://www.sciencealert.c(...)-a-new-energy-record

(met dank aan PeZu)

[ Bericht 0% gewijzigd door Kijkertje op 10-12-2014 13:31:10 ]

quote:

Op dinsdag 25 november 2014 11:06 schreef Pietverdriet het volgende:

[..]

Opvallend dat dit net voordat er een nieuwe Jurassic film uitkomt gepubliceerd wordt, waar ook het klonen van Mammoeten een belangrijke rol speelt

Broodje aap / marketing idd

SCIENTISTS RECREATE FIRST SPARK OF LIFE

December 9, 2014 | by Justine Alford



Photo credit: Don Davis, via Wikimedia Commons.

Although we will probably never know precisely how life started on Earth, scientists have a few different ideas that attempt to answer this intriguing but challenging question. Some believe that an asteroid or comet slamming into primordial Earth could have provided the right conditions to spark the formation of the chemical building blocks of life. And now, researchers have some tantalizing evidence to back up this idea.

Using a high-power laser to simulate a collision, scientists from the Academy of Sciences in the Czech Republic created the four essential ingredients of RNA, a close relative of DNA, from a chemical soup. While the work can’t prove how life started on Earth, it is the first time that these four molecules have all been made under one set of experimental conditions. The work has been published in Proceedings of the National Academy of Sciences.

The mystery of how life sprung from non-living matter has long eluded scientists. Since we have some understanding of the conditions present on early Earth, scientists have been recreating this environment for decades to see if they can produce some of the molecules that could have led to life.

Life appeared on our planet around 4 billion years ago, a period that coincided with a dramatic, 150-million-year event called the Late Heavy Bombardment in which Earth was pummeled with debris. While some scientists believe these collisions could have wiped out any existing early life forms, others believe they could have provided the necessary conditions for the building blocks of life to emerge.

To simulate a space rock collision, scientists fired a high-power laser at a chemical soup containing clay and a molecule called formamide. Formamide, a simple chemical produced when hydrogen cyanide reacts with water, was first postulated as a possible parent compound of the molecules needed for life back in 2001 by a duo of Italian researchers. The chemical would have been abundantly available on early Earth and has even been identified in the tail of comets. Furthermore, previous experiments have shown it is possible to create genetic building blocks using this molecule and other ingredients.

The laser pulses generated intense pressure, high temperatures exceeding 4200oC and also X-rays and extreme UV radiation; the kind of conditions we would expect if space debris slammed into Earth. When the researchers examined the resulting molecules, they found all four precursor chemicals to the building blocks of RNA: adenine, guanine, cytosine and uracil—the first three are also found in DNA. Although DNA is the molecule of life on Earth, many believe that RNA could have been the first molecule to encode genetic information.

While this work is certainly interesting, not everyone is convinced and its relevance has been called into question. Some have argued that pure formamide wouldn’t have existed on prebiotic Earth, while others have suggested that there would have been too much water to allow formamide-rich pools to exist. Furthermore, the experiments can’t tell us how these building blocks united with other molecules to form RNA. But the researchers recognize this and are planning to conduct more experiments to see if the other basic RNA ingredients can be made under similar conditions.

Bron: http://www.iflscience.com(...)g-asteroid-collision

(met dank aan PeZu)

[ Bericht 0% gewijzigd door Kijkertje op 10-12-2014 13:31:46 ]

NEW THEORY SUGGESTS THAT TWO PARALLEL UNIVERSES WERE PRODUCED BY THE BIG BANG

New research suggests our Universe could be moving forwards in time, while a parallel one moves backwards on the “other side” of the Big Bang.

FIONA MACDONALD 10 DEC 2014

Physicists have performed an experiment that suggests time in our Universe may be directed by gravity, not thermodynamics, and that the Big Bang could have created two parallel universes - our own, in which time runs forwards, and a mirror one where time runs backwards.

Although the idea sounds pretty out there, the new theory could help physicists solve some of their biggest issues with time - mainly the fact that they still can’t work out why it runs in only one direction.

In fact, this single “arrow of time” is one of the biggest conceptual problems of modern physics and has puzzled physicists for more than a century.

The root of the dilemma is the fact that all of the fundamental laws of physics - such as Einstein’s special and general relativity and Newton’s gravitation - work just as well if time is flowing forwards or backwards.

In models of physical systems, which physicists use to mimic our Universe, a preferred direction of time does sometimes arise, but this typically only happens when researchers tinker with the system and set specific starting conditions.

So why then does our Universe only move forwards in time? Why are stars emitting light rather than sucking it up and why do we remember the past and not the future?

Currently, the leading theory is that the direction of time’s arrow is controlled by the laws of thermodynamics - more specifically, entropy.

Entropy is a measure of disorder within a thermodynamic system - a system with low entropy is extremely organised and predictable, whereas a high entropy system is more random. Thermodynamic law states that the entropy of an isolated system, such as our Universe, will only ever move from a state of low entropy to a state of high entropy.

Most physicists generally accept that this is why time moves forward - because at the birth of our Universe everything was extremely ordered, and so the direction of time is the same as the direction of increasing entropy.

As Lee Billings explains for Scientific American, this is “a product of the universal tendency for all things to settle toward equilibrium with one another”.

But this theory relies on those highly organised, low entropy conditions being present at the start of the Universe in order to give time a direction. Which is something we simply can’t prove, much to the frustration of many physicists.

Now new theories are emerging that suggest this idea of time being governed by entropy isn’t the only possibility.

And the new work, led by Julian Barbour from the University of Oxford in the UK, suggests it may in fact be gravity, not thermodynamics, that controls the direction of time’s arrow.

The research, which also involved Tim Koslowski from the University of New Brunswick and Flavio Mercati of the Perimeter Institute for Theoretical Physics, both in Canada, and was published in October in Physical Review Letters.

Their model suggests that the Universe doesn’t need a special, low-entropy initial state in order for it to define an arrow of time - instead, the flow of time is just the inevitable result of gravity.

They came to this conclusion after studying a very simple model of our Universe comprised of just 1,000 particles. Using computer simulations, they tested how these particles interacted under nothing but the influence of the laws of Newtonian gravity.

What they found was that, no matter how the system was originally arranged, the particles would all eventually end up in these tightly packed, low-complexity states without any tinkering, simply through the sheer force of gravity.

This means that in order to set the direction of time’s arrow, we don’t need any perfect low-entropy conditions, we just need gravity.

But perhaps most interesting is what happened next in their model. From that highly condensed place, the system expanded outwards - but in two separate directions, each with their own time arrow travelling in a different direction.

Along both time pathways the particles were pulled by gravity into larger, more ordered and complex structures. As Billings writes for Scientific American, these are our equivalent of the Universe forming galaxies, stars and planetary systems.

Of course, we are a long way from knowing if this is what occurred in our own Universe - the system that Barbour and his team tested was extremely simple, and didn’t factor in general relativity or the effects of quantum mechanics.

But if it’s true, it means that what we perceive as the future would really be the distant past for any life that exists in the parallel universe.

“This two-futures situation would exhibit a single, chaotic past in both directions, meaning that there would be essentially two universes, one on either side of this central state,” Barbour told Billings for Scientific American.

“If they were complicated enough, both sides could sustain observers who would perceive time going in opposite directions. Any intelligent beings there would define their arrow of time as moving away from this central state. They would think we now live in their deepest past.”

Which is extremely trippy to think about. Even more mind-blowing is how Tim de Chant from PBS NOVA puts it:

“From that perspective, maybe George Lucas’s Star Wars didn’t take place a long time ago in a galaxy far, far away, but in the far future - our deepest past - of our mirror universe.”

However, devotees to the idea that entropy controls the direction of time, such as cosmologist Sean Caroll from California Institute of technology, will need much more proof before they subscribe to the theory.

“This paper by Barbour, Koslowski and Mercati is good because they roll up their sleeves and do the calculations for their specific model of particles interacting via gravity, but I don’t think it’s the model that is interesting—it’s the model’s behaviour being analysed carefully,” Caroll, who wasn’t involved in the research, told Scientific American.

“I think basically any time you have a finite collection of particles in a really big space you’ll get this kind of generic behaviour they describe. The real question is, is our Universe like that? That’s the hard part.”

If we could answer that question, then not only would it change our entire perspective on the Universe, but, importantly, it could help us properly explain the expansion and growth of the Universe that we observe - which is something we still struggle with.

If you’re as fascinated by all of this as we are, read the amazing account of how this theory emerged and other theories that are out there in Billings' piece for Scientific American.

Bron: http://www.sciencealert.c(...)uced-by-the-big-bang

(met dank aan PeZu)

[ Bericht 0% gewijzigd door Kijkertje op 10-12-2014 13:32:24 ]

HISTORIC DISCOVERY: HUGE ELECTRIC FIELD OCCURS SPONTANEOUSLY IN LAUGHING GAS
December 22, 2014 - 06:30

Scientists have discovered a new, astonishing electric phenomenon.
By: Lise Brix

Danish scientists thought they had made a mistake when they discovered a huge electric field in a thin layer of solid nitrous oxide, commonly known as laughing gas.

As it transpires, however, they had discovered a new and astounding electrical phenomenon.

It was one of those ordinary days in the lab in the basement beneath Aarhus University. Two young physicists were examining how electrons pass through nitrous oxide.

They had frozen the gas to minus 233 °C making the molecules of the gas settle as an extremely thin film above a metal surface.

There wasn't supposed to be anything special about the ice-cold laughing gas, but the young researchers' measurements indicated something else - something completely different.

"They came upstairs and knocked on my door, saying ‘David, there's something not right’. At first we thought the experiment had gone wrong, because it wasn't supposed to be possible for a current to pass through the film and be detected. No external voltage was applied," remembers David Field, Professor at the Department of Physics and Astronomy at Aarhus University.

During the next few days, however, the scientists continued to see huge electric fields across the thin film of laughing gas, and it soon became clear that they had discovered an entirely new electrical phenomenon.

The findings have recently been published in Physical Chemistry Chemical Physics.


The picture shows part of the apparatus used by scientists at Aarhus University in their discovery of the electric spontelectric phenomenon. At the top there is a thin piece of gold. On the surface of the gold the scientists condensed laughing gas, creating a huge electrical field within the thin film. (Photo: David Field)

No one had discovered it before

Professor Field has dubbed the phenomenon ‘spontelectric'.

The illustration shows an example of how spontelectrics can occur: a thin film of laughing gas (N2O) is condensed on top of the surface of gold. In the large circle, the film of laughing gas has been enlarged in order to see the individual laughing gas molecules (blue = nitrogen, red = oxygen). The positively charged nitrogen end of the laughing gas molecule sticks out from the surface, creating a positive potential. (Illustration by post-doc Andrew Cassidy from Aarhus University, who is involved with research into spontelectrics).

Since it’s first discovery in 2009, the scientists have discovered that the laughing gas is by no means the only material which shows the spontelectric phenomenon.

The electric field can reach more than 100 million volts per metre – i.e. enormous strength.

Professor Field and his colleagues have now examined more than 12 different materials and established that similar enormous electric fields occur spontaneously in common or garden materials such as carbon monoxide, propane, toluene and methyl formate.

All materials are frozen to extremely low temperatures in the form of a microscopically thin layer.

"In some cases, quite a few layers are necessary before the spontelectric effect manifests itself," says Field.

"When the experiment is conducted with toluene at 75 Kelvin, minus 198° C, more than a hundred layers are necessary for the effect to occur".

He believes that the spontelectric phenomenon happens because of a special interplay, in which the whole layer of molecules behave as much more than the sum of its parts, “in much the way as a beehive is much more than the sum of individual bees,” says Professor Field.


The illustration shows an example of how spontelectrics can occur: a thin film of laughing gas (N2O) is condensed on top of the surface of gold. In the large circle, the film of laughing gas has been enlarged in order to see the individual laughing gas molecules (blue = nitrogen, red = oxygen). The positively charged nitrogen end of the laughing gas molecule sticks out from the surface, creating a positive potential. (Illustration by post-doc Andrew Cassidy from Aarhus University, who is involved with research into spontelectrics).


Researcher: an important discovery

One of the scientists who is researching 'spontelectrics' is Martin McCoustra from Heriot-Watt University in Scotland.

"Spontelectrics are an extremely important discovery. I think masses of exciting new theories will result from attempting to explain the phenomenon in the years to come," says McCoustra, head of the Department of Chemical Physics at Heriot-Watt University.

"This is the first time since the 1920s that anyone has discovered a new electrical form of solid material. The incredible thing is that work has been done on thin layers of materials -including laughing gas films - for more than half a century. Even so, no one has discovered this powerful electrical phenomenon" says Field.

The molecules are dipolar

Laughing gas consists of dipolar molecules.

This means that one end of a laughing gas molecule has a slightly more negative electric charge than the other end.

The great majority of molecules are dipolar. For example, in laughing gas (N2O), the oxygen end of the molecule is negative compared with the positive nitrogen end.

When the spontelectric effect occurs, scientists have observed something unusual happening with the dipolar molecules:

Keeping to experiments conducted with a thin layer of laughing gas, the laughing gas molecules in the upper layer will arrange themselves in such a way that the positive end of the molecule pokes up towards the surface, creating a voltage on the surface of the film, Professor Field explains.

"Spontelectrics goes against our intuition. It doesn't seem to make any sense when you consider what we normally learn in physics and chemistry. The molecules arrange themselves entirely spontaneously - in a way that you would think they would not like. Fundamentally, we don't know what it is that makes them do it," says McCoustra

Strange behaviour of molecules

The behaviour of dipolar molecules can be compared to magnets.

The opposite ends of the magnet will normally repel each other. In the same way, dipolar molecules attempt to position themselves in such a way that one molecule has its 'north pole' facing the 'south pole' of the other.

However, in experiments in which spontelectrics occur, the molecules do the exact opposite," says McCoustra.

“Under normal circumstances, the molecules will arrange themselves with the positive end towards the negative end. Instead, we see that they suddenly arrange themselves in unfavourable positions,”.

What can we use it for?

"Right now the discovery of the phenomenon is pure fundamental science, which contributes to our understanding of how solid substances behave," says Field.

Field is particularly interested in finding out whether the phenomenon plays a role when new stars are born.

Stars are created in huge clouds of dust and gas. In the middle of the clouds it is so cold that spontelectric carbon monoxide could potentially form. This would change the chemistry inside the cloud of dust and the way in which it would collapse to form a star.

"Spontelectrics may prove to have a big impact on our understanding of how stars are born," says Field.

"What can we use it for? To be frank, we don't know,” says McCoustra. “But that could have been said about many other scientific discoveries when they were made. It often takes a long time before we find out how to use a discovery”.

The spontelectric phenomenon was first seen in the ASTRID synchrotron laboratory (ISA) in the basement of Aarhus University.

Bron: http://sciencenordic.com/(...)neously-laughing-gas

NEUROSCIENTISTS USE FLASHES OF LIGHT TO BOTH 'READ' AND 'WRITE' BRAIN SIGNALS

By University College London on December 22, 2014

UCL researchers have developed an innovative way to understand how the brain works by using flashes of light, allowing them to both ‘read’ and ‘write’ brain signals.


The new technique, described in Nature Methods, combines two cutting-edge technologies for reading and writing electrical activity in the brain. First, genetically encoded activity sensors enable neuroscientists to engineer nerve cells to visibly light up when they are active. Expressing light-sensitive proteins in the same nerve cells then allows these cells to be activated with flashes of light. By combining these two techniques, the team was able to both observe and control brain activity in mice.

“Combining reading and writing of activity in the same neurons in the intact brain could revolutionize how neuroscientists can interact with and understand brain activity,” explains Professor Michael Hausser (UCL Wolfson Institute for Biomedical Research), senior author of the study. “One of the best things about having an extended conversation with someone is that you can really get to know them. With time, their responses can give you a feel for the key questions to ask in order to understand their character. Just as we combine specific words into sentences that elicit a reply from someone we talk to, we used light to activate specific combinations of nerve cells in the intact brain and record how the other cells respond. In this way, we hope to be able to ask the brain questions and, from its answers, better understand how it works.”

To activate multiple brain cells simultaneously, the researchers split up the incoming beam of light using a holographic technique to direct smaller beamlets to individual cells of their choosing. The team selected a group of neurons in the cortex that are specifically responsive to the sensation of touch, reliably activating them while recording the flashes of activity in both the activated neurons and in hundreds of neighbouring neurons. This allowed them to ‘interrogate’ the circuit in a precise way, activating selected brain cells in different patterns and measuring how the circuit responds.

These experiments could be repeated in the same sets of neurons in the same animals over days and even weeks, allowing an extended ‘conversation’ with the circuit. In future, the team hope that by replacing a physical stimulus with precise, holographically controlled brain activity, the ‘neural code’ of sensory perception can be cracked.

“We are very excited to use this technology to probe the basis of how groups of neurons and ultimately the brain stores and processes information from the world around us,” says first author Dr Adam Packer (UCL Wolfson Institute for Biomedical Research). “This work provides a new way for neuroscientists to have a long-term and engaging conversation with the cerebral cortex in the brain of a mouse. Crucially, since the methods of both recording and activation rely on light, this technique is flexible and non-invasive.”

The nature of the ‘conversation’ depends only on where and when the researchers choose to point the light. Insights gained using this approach will be useful not only for understanding the ‘neural code’, but also for understanding how neural activity goes awry in neurological conditions such as autism and dementia.

http://www.psypost.org/20(...)-brain-signals-30415

Voor de liefhebbers de W&T nieuws hoogtepunten van 2014 van phys.org:
http://m.phys.org/news/20(...)hnology-stories.html

Hubble takes the biggest image ever of Andromeda at 1.5 billion pixels

January 06, 2015


The Hubble Space Telescope's image of the Andromeda Galaxy is the sharpest and biggest image ever taken of it. Click to expand but for an even closer view go to the Hubble website and use the zoom tool.


NASA and the European Space Agency (ESA) have released the sharpest and biggest image ever taken of the Andromeda galaxy. The image taken by the Hubble Space Telescope has an amazing 1.5 billion pixels that would require 600 HD television screens to display in full.

This panorama is the product of the Panchromatic Hubble Andromeda Treasury (PHAT) program. Images were obtained from viewing the galaxy in near-ultraviolet, visible, and near-infrared wavelengths, using the Advanced Camera for Surveys aboard Hubble.

The view shows the galaxy in its natural visible-light color as photographed in red and blue filters.

This image is too large to display at full resolution and is best viewed here, using the zoom tool.

Andromeda Galaxy, otherwise known as Messier 31, is a large spiral galaxy that lies "just" 2.5 million light years from Earth. Hubble's detailed view captures more than 100 million stars and thousands of star clusters embedded in a section of the galaxy’s pancake-shaped disc stretching across over 40,000 light-years.

The whole galaxy contains over one thousand billion stars.

But the image represents just a third of the giant galaxy. It traces the galaxy from its central galactic bulge on the left of the image, where stars are densely packed together, across lanes of stars and dust to the sparser outskirts of its outer disc on the right.

Imagery of this sophistication has more than a "wow" factor. It will help astronomers interpret the light from the many galaxies that have a similar structure but lie much further away from us than Andromeda.

http://blog.cosmosmagazin(...)at-15-billion-pixels

William Fowle/Northeastern University
The newly discovered bacterium Eleftheria terrae makes an antibiotic that could be a new weapon against resistant infections.

MICROBE FOUND IN GRASSY FIELD CONTAINS POWERFUL ANTIBIOTIC

By Kelly Servick 7 January 2015 2:00 pm

For much of the last decade, a team of researchers in Boston has eagerly exhumed and reburied dirt. It’s part of a strategy to access an untapped source of new antibiotics—the estimated 99% of microbes in the environment that refuse to grow in laboratories. Now, their technique has yielded a promising lead: a previously unknown bacterium that makes a compound with infection-killing abilities. What’s more, the team claims in a report out today, the compound is unlikely to fall prey to the problem of antibiotic resistance. That suggestion has its skeptics, but if the drug makes it through clinical trials, it would be a much needed weapon against several increasingly hard-to-treat infections.

Many existing antibiotics, including penicillin, were identified by cultivating naturally occurring microorganisms—bacteria often try to kill each other with chemical warfare, it turns out. But the supply of novel microbes that will grow in a lab has been largely tapped out. In 2002, microbiologist Kim Lewis, along with his colleague at Northeastern University in Boston, microbial ecologist Slava Epstein, described a new technique for coaxing bacteria to grow: Put soil samples into tiny chambers sandwiched between permeable membranes and return these contraptions to the ground. The bacterial strains confined in the chambers will form colonies—thanks in part, the team suspects, to growth factors from neighboring organisms that cross the membranes. The resulting “domesticated” colony can then be removed from the chamber and sometimes will more readily call a petri dish home.

The researchers used a version of this approach to isolate and grow new bacterial colonies—many scooped out of soil in the backyard of microbiologist Losee Ling, who leads research and development at the startup company NovoBiotic Pharmaceuticals, formed to commercialize their approach. To test the antibacterial properties of these soil microbes, the team let each of them duel in a lab dish with Staphylococcus aureus, a cause of serious skin and respiratory infections. Then they isolated and tested individual compounds—10,000 in all—from the bacteria that most effectively killed the staph bacteria.

One bacterium, from a grassy field in Maine, produced a compound with powerful abilities to kill a variety of other bacterial species, including many human pathogens. Moreover, these pathogens failed to develop resistance to the compound: There were no surviving individuals that had evolved to withstand its attack. (Resistance usually develops when a small percentage of microbes escape an antibiotic because of a mutation and then those bacteria multiply.) Lewis initially took this total devastation as a discouraging sign—the mark of “another boring detergent.” (Bleach, after all, is a strong antibiotic, but it’s a little too effective at killing any surrounding cells.) However, it turned out that the new compound, which the group named teixobactin, was not toxic to human cells in a dish.

And it showed other qualities of a good antibiotic, the team reports online in Nature. On bacteria growing in lab dishes, it outperformed vancomycin, a drug long relied upon to treat the obstinate methicillin-resistant Staphylococcus aureus (MRSA), by a factor of 100, Lewis says. In mice infected with MRSA, injections of teixobactin led to a 100% survival rate at lower doses than vancomycin.

The compound isn’t effective against so-called Gram-negative bacteria, increasingly feared in hospitals for their resistance to existing drugs. But the authors suggest it could be of great value to people fighting MRSA, tuberculosis, and infections with rare-but-nasty Enterococcus bacterial strains that aren’t responding to available drugs.

These results offer hope that other promising agents await discovery in the soil, says Helen Zgurskaya, a biochemist at the University of Oklahoma, Norman, who studies how bacteria become susceptible to antibiotics. “This study demonstrates that unculturable bacteria … have new, previously unrecognized, biologically active compounds,” she says. “We now have proof of principle, and I hope more people will follow this path.”

But will teixobactin, like so many promising agents before it, eventually meet its match in a resistant strain? Lewis and his co-authors believe it’s unlikely. Collaborators at the University of Bonn in Germany figured out that teixobactin works by interfering with two important lipids that bacteria use to build their cell walls. (A few other known compounds work in a similar way, including vancomycin.) The authors suggest that bacteria are unlikely to evolve ways to resist teixobactin because it acts on two different targets that are highly conserved across many bacterial species and are not easily changed.

Bacteria did eventually develop resistance to vancomycin, though Lewis points out that it took 30 years. And he thinks this compound may have even better odds than vancomycin. Based on the team’s screens of soil, the compound seems to be relatively rare, so Lewis doubts that many bacteria have evolved to produce an enzyme that could destroy it.

That’s a logical argument, says Michael Fischbach, a microbiologist at the University of California, San Francisco. But there are many paths to developing resistance, and if any bacterium out there makes a substance with even limited activity against teixobactin, that could be “the starting point for evolution,” he says. “The results that they got were promising, no doubt about it,” he concludes, but “I would never underestimate the wiliness of bacteria.”

Posted in Biology, Health

http://news.sciencemag.or(...)ful-antibiotic?rss=1

EXTRAORDINARY GENE TRANSFER BETWEEN CELLS

07 January 2015, Cancer

A team led by Professor Mike Berridge from the Malaghan Institute has become the first in the world to demonstrate mitochondrial DNA movement between cells in an animal tumour. Their paper was published today in the leading biological journal Cell Metabolism.

The research lays important groundwork for understanding human diseases other than cancer, since defective mitochondrial DNA is known to account for around 200 diseases and is implicated in many more. It could also usher in a new field where synthetic mitochondrial DNA is custom-designed to replace defective genes.

In mouse models of breast cancer and melanoma that had had their mitochondrial DNA removed, replacement DNA was acquired from surrounding normal mouse tissue. After adopting this new DNA, the cancer cells went on to form tumours that spread to other parts of the body.

Professor Berridge says the landmark discovery could open up whole new areas of research.

“Our findings overturn the dogma that genes of higher organisms are usually constrained within cells except during reproduction. It may be that mitochondrial gene transfer between different cells is actually quite a common biological occurrence.”

Although other research groups have seen mitochondrial DNA move between cells in the laboratory, the Malaghan team is the first to demonstrate the transfer in an animal tumour model.


The dark field image on the left highlights the transfer of fluorescent mitochondria. The bright field on the right has sufficient light to see the connecting nanotube.


Professor Berridge says the research wouldn’t have happened without the extraordinary patience of his research colleague, An Tan.

“A normal person would have terminated the experiment after a week, before this effect was observed, thinking that the tumour cells without mitochondrial DNA weren’t going to grow. But Tan kept monitoring them for more than a month and eventually saw tumours starting to grow.”

The next challenge for the team was to find out how this was possible.

“Initially we thought the cells had learned to grow without needing mitochondrial DNA. But when we presented the research at a conference, a well-known scientist asked if we had tested the growing cells to see if they contained mitochondrial DNA. We hadn’t.”

A simple experiment confirmed the presence of mitochondrial DNA and extensive molecular, biochemical and protein analysis with international collaborators established that the mitochondrial DNA had, in fact, been obtained from non-tumour cells. The latest genetic sequencing technologies were used to confirm that the adopted mitochondrial DNA was distinct from that of the original tumour, but identical to surrounding non-tumour cells.

“This appears to be a basic physiological mechanism in the body that no one has seen before because they lacked the exploratory tools. Whether this new phenomenon is important in tumour formation is still unclear, but we are interested in pursuing the research to see if the transfer occurs more widely in the body. Preliminary evidence indicates it may be a common occurrence in the brain.”

Many copies of mitochondrial DNA, a small circular bacterial-like genome, are found inside each mitochondria. This DNA encodes key proteins in the mitochondrial machinery that converts energy from food into a form of chemical energy that is particularly important for brain and muscle function.

Mitochondrial DNA is unrelated to nuclear DNA, which encodes a person’s primary genetic instructions, including characteristics such as hair colour, height and sex. Mitochondrial DNA is inherited solely from a person’s mother – a trait that has been used to trace all living humans back to a common ancestor who lived in Africa 60 –70,000 years ago.

http://www.malaghan.org.n(...)ween-cells-observed/

[ Bericht 6% gewijzigd door Molurus op 22-01-2015 20:47:05 ]

WORLD FIRST: MASSIVE COSMIC RADIO BURST DETECTED IN REAL TIME

For the first time, scientists in Australia have detected a gigantic burst of radio waves from outside our galaxy in real time. Called blitzars, these bursts generate as much energy as the Sun does in a day, but they do it in mere milliseconds.

BEC CREW 20 JAN 2015

Astronomers manning the Parkes radio telescope in New South Wales have detected the first real-time burst of radio waves from outside our Milky Way galaxy. Unlike similar cosmic events, such as gamma ray bursts or supernovae, which emit energy across several wavelengths, all the energy given off by blitzars is contained within the single band of the radio light spectrum.

The source of these ‘blitzars’ has so far remained a mystery, but finds like this could help scientists figure out what’s causing them.

Blitzars were first discovered by researchers at Swinburne University of Technology in Melbourne using the Parkes telescope. Also known as ‘fast radio bursts’ (FRB’s), seven more were discovered - six more using the Parkes telescope, and one using Arecibo telescope in Puerto Rico - but each of these were found up to several years, after the actual event. That’s what makes this latest discovery so special - the Swinburne researchers were able to detect the blitzar as soon as the resulting radiation reached Earth.

“These bursts were generally discovered weeks, months or even more than a decade after they happened,” PhD student Emily Petroff, who witnessed the event, said in a university press release. “We are the first to catch one in real time.”

Petroff has gotten to know these bursts of radio waves so well, that once she was confident she’d see a ‘live’ one, she let astronomers around the world know so they could make follow-up observations as soon as it was detected. So the aftermath was watched by scientists manning 12 telescopes in Australia, California, the Canary Islands, Chile, Germany, Hawaii, and India, plus the Swift Gamma Ray Burst Explorer in space, who captured it at wavelengths ranging from radio to X-ray.

Michael Slezek reports at New Scientist that the fact that, several hours after the explosion, no one saw an afterglow, makes it less likely that long gamma-ray bursts or supernovae were the source.

"Nobody knows what to make of it,” astronomer Keith Bannister from Australia's national science agency, the CSIRO, told Slezek. "All the ideas are very exotic so ruling them out is all you can do at the moment."

“We can rule out some ideas because no counterparts were seen in the optical, infrared, ultraviolet or X-ray,” Head of Astrophysics at CSIRO, Simon Johnston, added in the press release. "However, the neat idea that we are seeing a neutron star imploding into a black hole remains a possibility.”

So the team is thinking that perhaps an oversized neutron star - which has the strongest magnetic field of anything in the known universe - collapsed. Normally, this would see it be consumed by a black hole, but perhaps it was spinning so fast, says Slezek, that relativity made it appear light enough to avoid that particular fate. “Other possibilities include a flare from a magnetar, a type of neutron star with an extremely strong magnetic field,” he says.

Publishing their findings in The Monthly Proceedings of the Royal Astronomical Society, the team says they’ve calculated the blitzar to be up to 5.5 billion light-years away from Earth. “This means it could have given off as much energy in a few milliseconds as the Sun does in a day,” she said in the press release.

Now that they’ve managed it once, Petroff thinks it’s only a matter of time before they detect another ‘real time' blitzar. “We’ve set the trap. Now we just have to wait for another burst to fall into it.”

http://www.sciencealert.c(...)etected-in-real-time

Ook op nu.nl

http://www.nu.nl/wetensch(...)ngen-telescoop-.html

GM MICROBES CREATED THAT CAN'T ESCAPE THE LAB

Engineered bacteria kept in check with a designer diet.



Synthetic biologists hope to treat disease in the gut by making Lactobacillus bacteria (pictured) that are dependent on an artificial amino acid.

Critics of genetic engineering have long worried about the risk of modified organisms escaping into the environment. A biological-containment strategy described this week in Nature1, 2 has the potential to put some of those fears to rest and to pave the way for greater use of engineered organisms in areas such as agriculture, medicine and environmental clean-up.

Two US teams have produced genetically modified (GM) bacteria that depend on a protein building block — an amino acid — that does not occur in nature. The bacteria thrive in the laboratory, growing robustly as long as the unnatural amino acid is included in their diet. But several experiments involving 100 billion or more cells and lasting up to 20 days did not reveal a single microbe capable of surviving in the absence of the artificial supplement.

“Our strains, to the extent that we can test them, won’t escape,” says Dan Mandell, a synthetic biologist at Harvard Medical School in Boston, Massachusetts, and an author on one of the two studies describing the strategy.

The microbes also do not swap their engineered DNA with natural counterparts because they no longer speak life’s shared biochemical language. “Establishing safety and security from the get-go will really enable broad and open use of engineered organisms,” says Farren Isaacs, a synthetic biologist at Yale University in New Haven, Connecticut, who led the other study.

Biocontainment could provide added safety in the biological production of drugs or fuels, where microbes can be kept separate from their surroundings. But the modified bacteria could also permit controlled release into the human body or the environment. “Containment might no longer be of the physical kind,” says Tom Ellis, a synthetic biologist at Imperial College London who was not involved in the research.

The new technique originated in the laboratory of George Church, a geneticist at Harvard Medical School. Two years ago, Church and his team (which included Isaacs) reported the synthesis of a strain of Escherichia coli that had a reprogrammed genetic code3. Instead of recognizing a particular DNA triplet known as the amber stop codon as an order to terminate protein synthesis, the recoded bacterium read the same instruction as a directive to incorporate a new kind of amino acid into its proteins.

Church and Isaacs have independently made this engineered microbe reliant on unnatural amino acids. The Isaacs team used genomic sequencing to identify sites in essential bacterial proteins where the microbes could incorporate synthetic amino acids without affecting overall function, whereas Church’s group started with the protein structures and added elements to help integrate and accommodate the artificial amino acids.

“This is really the culmination of a decade of work,” says Church.

These organisms are also more resistant to viruses than their natural counter­parts because of the mismatch between the genetic code of the virus and that of its host3. Looking ahead, Church and his team are working to co-opt seven different codons, instead of just one. “That would be more than enough to be resistant to all viruses and to create a lot of opportunity for safety,” Church says.

Isaacs has also developed a different safeguarding system, in which E. coli can grow only in environments containing synthetic chemicals needed for gene expression. He described the work this month in Nucleic Acids Research4. Another research team led by Jef Boeke at the New York University Langone Medical Center and Patrick Yizhi Cai at the University of Edinburgh, UK, has been working on a similar strategy in yeast. Commonly used in industry and biotechnology, yeast has its genetic mater­ial packaged in chromosomes similarly to animals and plants rather than bacteria.

“That’s a strategy that is going to be more easily adaptable to other organisms beyond E. coli,” says Isaacs. His team is now engineering a bacterium that is dependent on synthetic chemicals as well as on artificial protein building blocks. “I think ultimate solutions for robust biocontainment will involve multiple approaches that are deployed at the same time in a single organism,” he says.

Such a beast will present a real challenge for regulators, says Todd Kuiken, senior research associate for the Science and Technology Innovation Program at the Woodrow Wilson International Center for Scholars in Washington DC. “What we’re now starting to talk about is a really, completely synthetic organism,” Kuiken says. “How do you evaluate that once you put it out into the field?”

http://www.nature.com/new(...)cape-the-lab-1.16758

SCIENTISTS MAY HAVE FOUND THE PART OF THE BRAIN THAT ENABLES LUCID DREAMING

People who are aware, and often in control, during their dreams have one thing in common, researchers have found.

FIONA MACDONALD 26 JAN 2015

Do a quick Google search for lucid dreaming - the phenomenon where someone is aware during their dreams - and you'll quickly be overwhelmed with tips and techniques for unlocking the ability.

Despite lucid dreaming being relatively rare in most people, knowing when you're dreaming and potentially even being able to change the course of your dreams is clearly desirable to a lot of people.

Now scientists from Germany believe they may have found the neurological key to the ability. After scanning the brains of regular dreamers and those who are frequently lucid, they've found that the region of the brain that enables self reflection is larger among lucid dreamers.

"Our results indicate that self-reflection in everyday life is more pronounced in persons who can easily control their dreams," said Elisa Filevich, a research at the Centre for Lifespan Psychology at the Max Planck Institute for Human Development, who was one of the leaders of the research, in a press release.

Although research has previously shown that people who lucid dream appear to have more pronounced awareness of their own thought processes, known as metacognition, this is one of the first studies to explore the link between the two at a neural level.

To do this, the team asked volunteers to complete a questionnaire on their lucid dreaming ability, and then split them into two groups depending on whether they were highly lucid, or never or rarely lucid during dreams.

The team then performed structural and functional MRI scans on the two different groups to compare the volume of different regions of their brains.

What they found was that participants who were highly lucid during dreams had larger anterior prefrontal cortexes, which is the region of the brain that controls conscious cognitive processes and plays an important role in our ability to self reflect.

The team also took scans while the participants were solving waking self awareness tests. The scans revealed that lucid dreamers also had more brain activity happening in their prefrontal cortex than regular dreamers. This suggests that the same brain region is connected to both abilities. Their research has now been published in The Journal of Neuroscience.

"Our results indicate that self-reflection in everyday life is more pronounced in persons who can easily control their dreams," said Filevich in the release.

The researchers are now eager to find out whether these self awareness skills can be taught. Their next study will attempt to teach volunteers to lucid dream, and then see whether their self-reflection also improves as a result.

As someone who’s had plenty of lucid dreams myself, I’m still not entirely sure of the appeal. All the dreams that I'm lucid during, and particularly those I have some control over, are frustrating and exhausting and feel more like a mental marathon than rest.

But I can’t deny that it’s fascinating to discover more about how our brains work - both when we’re awake, and during sleep. Even if it is occasionally nice to have a little escape from awareness.

You can find out more about the science of lucid dreaming thanks to the guys over at AsapSCIENCE.

http://www.sciencealert.c(...)ables-lucid-dreaming

quote:

'Vogels in V-formatie werken onbaatzuchtig samen'

Vogels werken onbaatzuchtig samen bij het vliegen in een V-formatie. Dat blijkt uit een nieuwe studie met noordelijke kale ibissen.

Deze trekvogels vliegen in een zwerm allemaal net zo lang op de koppositie als in de slipstream van anderen.

Zo'n eerlijk verdeelde samenwerking is bijzonder zeldzaam in de dierenwereld.

Dat melden onderzoekers in het wetenschappelijk tijdschrift Proceedings of the National Academy of Sciences.
Vliegtuigje

De wetenschappers kwamen tot hun bevindingen door een uniek Oostenrijks project, waarbij noordelijke kale ibissen van jongs af aan hebben geleerd om te migreren door achter een vliegtuigje aan te vliegen.

Een zwerm van veertien van deze getrainde vogels werd door de wetenschappers van Oostenrijk naar Italië geleid. Elke ibis was uitgerust met een GPS-tag, zodat de posities van de vogels ten opzichte van elkaar zeer nauwkeurig in de gaten konden worden gehouden.

Na afloop van de tocht bleek uit een analyse van de GPS-gegevens dat er geen profiteurs in de zwerm zaten. "We vonden voor alle vogels een sterke correlatie tussen de tijd dat ze op kop vlogen en de tijd dat ze andere vogels volgden", verklaart hoofdonderzoeker Bernhard Voelkl op BBC News.
Evolutie

Dat gedrag is opmerkelijk, vooral omdat acht van de veertien vogels geen familieband hadden. Vanuit evolutionair oogpunt zouden dieren alleen gericht moeten zijn op hun eigen welzijn of dat van hun nakomelingen.

De wetenschappers vermoeden dat de vogels in zwermen onbaatzuchtig gedrag vertonen omdat positiewisselingen onmiddellijk invloed hebben op hun energieverbruik.

Als ze verzaken om de kop over te nemen, valt de formatie uit elkaar en moeten ze meer krachten verspillen. "Door hun energieverbruik te verminderen, verbeteren ze hun overlevingskansen", aldus Voelkl.http://www.nu.nl/wetensch(...)tzuchtig-samen-.html

SCIENTISTS HAVE FIGURED OUT HOW TO STOP THE COMMON COLD IN ITS TRACKS


1 billion infections per year - in the US alone
Plus Ebola, hepatitis C, HIV, polio, and many others.

BEC CREW 9 FEB 2015

We're still a long way off developing new drugs to combat them, but scientists have finally cracked the code used by a major group of virus to spread infections such as the common cold, Ebola, hepatitis C, HIV, and polio around the body.

This newly discovered code has been hiding inside the sequence of ribonucleic acid (RNA) - a nucleic acid involved in the coding, decoding, regulation, and expression of genes - that makes up the genome of the single-stranded RNA viruses group, which is considered one of the most potent and debilitating of groups of infectious pathogens. And once the scientists found it, they were able to decipher it.

“We have understood for decades that the RNA carries the genetic messages that create viral proteins, but we didn’t know that, hidden within the stream of letters we use to denote the genetic information, is a second code governing virus assembly,” one of the team, biophysicist Roman Tuma from the University of Leeds in the UK, told Laura Donnelly at The Telegraph. “It is like finding a secret message within an ordinary news report and then being able to crack the whole coding system behind it.”

Single-stranded RNA viruses are the most simple type of viruses known to science, and it’s thought that they were probably one of the first to evolve. And being around for a long time means they’re super-effective at what they do. Rhinovirus, which is the predominant cause of the common cold, is responsible for 1 billion infections per year - in the US alone.

The discovery has taken the team several years to complete, the first big step occurring in 2012, when Tuma and his colleagues published the first observations taken at a single-molecule level of how a single-stranded RNA virus fit its core into its outer shell. And it’s not just a case of stuffing it in like vacation wear into a suitcase - the core has to be very precisely folded in order to fit within the shape of the shell, made from a protective protein coating, and the virus has figured out how to do this in mere milliseconds. But how?

The next step involved mathematicians at the University of York in the UK, who worked with the Leeds group to come up with algorithms that could read the encrypted code that controls the complex folding process. Computer models were then built to replicate this coding system so the team had a better chance of cracking it.

The team compared these computer models to the Enigma machine, used famously during the 20th century to encipher and decipher secret messages, particularly during World War II.

Now, publishing in the Proceedings of the National Academy of Sciences, the team reports that they’ve finally done it. Using a visualising technique called single-molecule fluorescence spectroscopy, they watched the common plant disease - a single stranded RNA plant virus called the tobacco necrosis virus - use the code to replicate itself.

“The Enigma machine metaphor is apt,” says one of the team, Reidun Twarock from the University of York, in a press release. "The first observations pointed to the existence of some sort of a coding system, so we set about deciphering the cryptic patterns underpinning it using novel, purpose-designed computational approaches. We found multiple dispersed patterns working together in an incredibly intricate mechanism and we were eventually able to unpick those messages. We have now proved that those computer models work in real viral messages.”

Not only can the team read these coded messages within the genomes of the viruses, but they now know how to jam them and stop the spread of the virus in its tracks. The way to do this, says Tuma, is by designing molecules that can interfere with this secret code and scramble it, so the virus cannot fold its core properly and replicate. The team plans to work on this and start testing the method out on animal viruses.

http://www.sciencealert.c(...)n-cold-in-its-tracks

Alien star system buzzed the Sun



An alien star passed through our Solar System just 70,000 years ago, astronomers have announced.

No other star is known to have approached this close to us.

An international team of researchers says it came five times closer than our current nearest neighbour - Proxima Centauri.

The object, a red dwarf known as Scholz's star, cruised through the outer reaches of the Solar System - a region known as the Oort Cloud.

Scholz's star was not alone; it was accompanied on its travels by an object known as a brown dwarf. These are essentially failed stars that lacked the necessary mass to get fusion going in their cores.

The findings are published in Astrophysical Journal Letters.

Observations of the dim star's trajectory suggest that 70,000 years ago this cosmic infiltrator passed within 0.8 light years of the Sun. By comparison, Proxima Centauri is 4.2 light years away.

Close encounter

In the paper, astronomers led by Eric Mamajek at the University of Rochester, New York, say they are 98% certain that Scholz's star travelled through what is known as the "outer Oort Cloud" - a region at the edge of the Solar System filled with trillions of comets a mile or more across.

This region is like a spherical shell around the Solar System and may extend out to as much as 100,000 Astronomical Units, or AU (one AU is the distance between the Earth and the Sun).



The Oort Cloud is thought to give rise to long-period comets that can swing past the Sun when their orbits are disturbed.

Oort Cloud The Oort Cloud in perspective: 1 Astronomical Unit (AU) represents the distance from the Earth to the Sun
To determine the trajectory of the star, the researchers needed two pieces of information: the change in distance from the Sun to the star (its radial velocity) and the star's motion across the sky (its tangential velocity).

Scholz's star currently lies 20 light years away - making it a fairly nearby system. But it showed very slow tangential motion for a star this close. This indicated that it was either moving away from us or towards a future close encounter with the Solar System.

The radial velocity measurements confirmed that the binary star system was actually speeding away from us. By tracing its movements back in time, they found its close shave with the Sun occurred some 70,000 years ago.

Grand theft Oort-o?

A star passing through the Oort Cloud could potentially play gravitational havoc with the orbits of comets there, sending them on trajectories into the inner Solar System. But Dr Mamajek believes the effects of Scholz's star on our cosmic neighbourhood were "negligible".

"There are trillions of comets in the Oort cloud and likely some of them were perturbed by this object," he told BBC News.

"But so far it seems unlikely that this star actually triggered a significant 'comet shower'."

The effect of a passing star on the Oort Cloud is a function of the star's mass, speed and proximity. The worst case scenario for stirring up comets would be a slow-moving, massive star that came close to the Sun.

Scholz's star came relatively close, but the binary system (the red dwarf and its brown dwarf companion) has a low mass and it was speeding by. These factors conspired to make its effect on the Oort Cloud very small.

While this is the closest flyby detected so far, Dr Mamajek thinks it's not uncommon for alien stars to buzz the Sun. He says a star probably passes through the Oort Cloud every 100,000 years, or so.

But he suggests an approach as close - or closer - than that made by Scholz's star is somewhat rarer. Dr Mamajek said mathematical simulations show such an event occurs on average about once every nine million years.

"So it is a bit of a strange coincidence that we happen to have caught one that passed so close within the past 100,000 years or so," he said.

bron

20 February 2015 Last updated at 00:02 GMT

EVOLUTION 'FAVOURS BIGGER SEA CREATURES'

By Jonathan Webb
Science reporter, BBC News


Whales and other modern sea animals tend to be much larger than Cambrian sea creatures

The animals in the ocean have been getting bigger, on average, since the Cambrian period - and not by chance.

That is the finding of a huge new survey of marine life past and present, published in the journal Science.

It describes a pattern of increasing body size that cannot be explained by random "drift", but suggests bigger animals generally fare better at sea.

In the past 542 million years, the average size of a marine animal has gone up by a factor of 150.

It appears that the explosion of different life forms near the start of that time window eventually skewed decisively towards bulkier animals.

Today's tiniest sea critter is less than 10 times smaller than its Cambrian counterpart, measured in terms of volume; both are minuscule crustaceans. But at the other end of the scale, the mighty blue whale is more than 100,000 times the size of the largest animal the Cambrian could offer: another crustacean with a clam-like, hinged shell.

Big bias


The idea that natural selection might lead to animal lineages gradually gaining weight is far from new. It is set out in a proposal known as Cope's rule, after American fossil specialist Edward Drinker Cope.

19th-Century palaeontologists noticed that the ancient ancestors of modern mammals often tended to be smaller; horses, for example, can be traced to the dog-sized Eohippus genus of 50 million years ago.

The pattern is not consistent across the animal kingdom, however. Most groups of dinosaurs got bigger until they died out - but the birds that evolved from them grew smaller and lighter with the necessity of flight.

Dr Noel Heim, from Stanford University in California, set out to give Cope's rule its most thorough test yet - in the vast realm of the ocean.


One of the team's key sources was the 50-volume "Treatise on Invertebrate Paleontology"

He enlisted the help of colleagues, undergraduates and even high school interns, to scour the scientific record for body size data - including measuring countless illustrations from venerable palaeontological tomes.

"We've had at least 50 high school students working on it over the last five years," Dr Heim told BBC News.

"It would have taken many, many, many more years doing it on my own!"

Eventually the team had amassed information on more than 17,000 groups of species, called genera. This represents over 60% of all the animal genera ever to have lived.

It was detailed analysis of this formidable set of figures that revealed the trend towards increasing size.

But Dr Heim and his colleagues say the consistent trend does not mean that every single genus of animals evolved to grow larger.

Instead, the branches of the family tree that were populated by larger animals divided many more times - diversifying and expanding so that the ocean gradually built up a greater variety of bigger and bigger beasts.

Faster movers, better eaters

The team also wanted to work out whether this bigness bias was really driven by evolutionary advantage, or was simply a matter of chance.

To this end, they put their size data from the oldest animals into a computer model and ran multiple simulations of how the family tree might evolve. Each species could die out, stay the same, or get bigger or smaller.

In some simulations, the scientists allowed the animals' size to drift randomly without affecting each species' success; in others, they tweaked the rules so that bigger animals were more likely to survive and flourish.

The version that best matched the real fossil history was one with a genuine size advantage.

"The degree of increase in both mean and maximum body size just aren't well explained by neutral drift," said Dr Heim. "It appears that you actually need some active evolutionary process that promotes larger sizes."

As for what those benefits of extra bulk might be, the researchers cannot be sure - but larger species likely took advantage of being able to move faster, burrow better in sediment, or eat larger prey.

The changing chemistry of the ocean, including an increase in oxygen, may also have played a role, Dr Heim suggested.


Breathing air helped marine reptiles to maintain their extra body size

Dr Michael Berenbrink, an evolutionary physiologist at the University of Liverpool, said the US team had compiled "an incredible data set".

He cautioned that the results should be interpreted carefully, noting particularly that the size increase was not just the gradual progression that a straightforward application of Cope's rule might predict.

Certain key events, also highlighted by the study's authors, deliver an extra boost. Most obviously, at the stages when land animals like reptiles and, later, mammals returned to the water, the size graph lurched upward.

It was the return of mammals, after all, that eventually produced the modern giants of the sea: whales.

"You can see in the data, there is this trend to increasing size - but a real kick comes when you have these air-breathers re-entering the water," Dr Berenbrink told the BBC.

"Then you have a sort of a step change in size."

Breathing air delivers extra oxygen to an animal's tissues, he explained, allowing them to sustain bigger bodies beneath the waves.

Dr Heim agrees that these events are important, but emphasises the huge diversity of other life forms - the fish, molluscs and other invertebrates - which together continued on a trajectory of expanding size.

"[Marine mammals and reptiles] are not driving the trend," he said. "They're really big, but in terms of diversity there's just not that many of them.

"They actually have a fairly small impact on the mean size."

http://www.bbc.com/news/science-environment-31533744

INCREDIBLE DRONE FOOTAGE OF THE WORLD'S LARGETS CAVE

It's like its own little ecosystem.

http://www.sciencealert.c(...)world-s-largest-cave

SCIENTISTS CAN NOW TELL IF YOU'RE IN LOVE BY SCANNING YOUR BRAIN

And they know if you're faking it.

FIONA MACDONALD 16 MAR 2015

Love is one of the biggest human mysteries - people write songs about it, die for it and dedicate their lives to it. But what, exactly, is it? Scientists believe that they may finally have found the answer, after discovering the first evidence of changes in the love-struck brain.

The team scanned the brains of 100 students recruited from Southwest University in China and found clear changes in the areas of the brain involved in reward, motivation, emotion and social interactions when someone was in love. Their results have been published in Frontiers in Human Neuroscience, and you can see the full figure above here.

"The results shed light on the underlying neural mechanisms of romantic love, and demonstrate the possibility of applying a resting-state fMRI approach for investigating romantic love," the authors wrote in the paper.

The researchers used resting state functional magnetic resonance imaging (fMRI) to compare the brain activity of three different groups - 34 people who had been in love for between four and 18 months, 34 who had recently broken up with someone they loved, and 32 who had never been in love at all. Across the three groups there was no significant difference in age, personal monthly expenses, family income, or years of education.

During the scans, the participants were told to think of nothing in particular, so the scientists could get an understanding of how their brains worked overall.

They found that those who were "in love" had increased activity in several areas of their brains, including the dorsal anterior cingulate cortex, insula, caudate, amygdala, and nucleus accumbens, as well as the temporo-parietal junction, posterior cingulate cortex, medial prefrontal cortex, inferior parietal, precuneus, and temporal lobe.

In many of these brain regions, the amount of activity they saw was linked to the amount of time someone had been in love. So, the longer they'd loved someone, the more activity they experienced.

On the other hand, the longer the "ended love" group had been broken up, the lower activity in these regions. They also showed that one area of the brain, the caudate nucleus, seemed to be involved in helping people cope with the end of a love affair.

Of course, knowing this isn't really going to help you work out whether or not your boyfriend or girlfriend really loves you, or even whether your love is the kind of love that's going to last. But the researchers believe it could lead to a better understanding of the emotion, and could give scientists the ability to 'diagnose' whether someone really is in love or not.

However, before we get too carried away, there are a few flaws the study, the biggest being that its findings are all based on students self-classifying whether or not they were in love in the first place. And there's also not a clear base level of brain activity established. An interesting follow-up would be to compare people's brain activity between when they're in love to when they aren't to eliminate individual neural differences.

The researchers acknowledge this, and explain that longitudinal studies are now needed to verify their findings. And they also put forward another (slightly depressing) limitation of their study: "We do not know exactly whether love-related alterations are adaptation, or maladaptation in lovers." Which basically means they're not sure whether the brain-changing experience of falling head over heels in love is doing us more harm than good, and they suggest future studies determine this.

So there's still a lot to learn about love, but as far as taking steps towards understanding the biological basis of human emotions go, this is a pretty big one. We can't wait to find out more.

http://www.sciencealert.c(...)-scanning-your-brain

YOUR EYES ARE WIRED BACKWARDS: HERE'S WHY

Mystery SOLVED.

SCIENCEALERT STAFF

19 MAR 2015

This article was written by Erez Ribak from the Technion - Israel Institute of Technology, and was originally published at The Conversation.

The human eye is optimised to have good colour vision at day and high sensitivity at night. But until recently it seemed as if the cells in the retina were wired the wrong way round, with light travelling through a mass of neurons before it reaches the light-detecting rod and cone cells. New research presented at a meeting of the American Physical Society has uncovered a remarkable vision-enhancing function for this puzzling structure.

About a century ago, the fine structure of the retina was discovered. The retina is the light-sensitive part of the eye, lining the inside of the eyeball. The back of the retina contains cones to sense the colours red, green and blue. Spread among the cones are rods, which are much more light-sensitive than cones, but which are colour-blind.

Before arriving at the cones and rods, light must traverse the full thickness of the retina, with its layers of neurons and cell nuclei. These neurons process the image information and transmit it to the brain, but until recently it has not been clear why these cells lie in front of the cones and rods, not behind them. This is a long-standing puzzle, even more so since the same structure, of neurons before light detectors, exists in all vertebrates, showing evolutionary stability.

Researchers in Leipzig found that glial cells, which also span the retinal depth and connect to the cones, have an interesting attribute. These cells are essential for metabolism, but they are also denser than other cells in the retina. In the transparent retina, this higher density (and corresponding refractive index) means that glial cells can guide light, just like fibre-optic cables.

SELECTIVE VISION

In view of this, my colleague Amichai Labin and I built a model of the retina, and showed that the directional of glial cells helps increase the clarity of human vision. But we also noticed something rather curious: the colours that best passed through the glial cells were green to red, which the eye needs most for daytime vision. The eye usually receives too much blue – and thus has fewer blue-sensitive cones.

Further computer simulations showed that green and red are concentrated five to 10 times more by the glial cells, and into their respective cones, than blue light. Instead, excess blue light gets scattered to the surrounding rods.

This surprising result of the simulation now needed an experimental proof. With colleagues at the Technion Medical School, we tested how light crosses guinea pig retinas. Like humans, these animals are active during the day and their retinal structure has been well-characterised, which allowed us to simulate their eyes just as we had done for humans. Then we passed light through their retinas and, at the same time, scanned them with a microscope in three dimensions. This we did for 27 colours in the visible spectrum.

The result was easy to notice: in each layer of the retina we saw that the light was not scattered evenly, but concentrated in a few spots. These spots were continued from layer to layer, thus creating elongated columns of light leading from the entrance of the retina down to the cones at the detection layer. Light was concentrated in these columns up to 10 times, compared to the average intensity.

Even more interesting was the fact that the colours that were best guided by the glial cells matched nicely with the colours of the cones. The cones are not as sensitive as the rods, so this additional light allowed them to function better – even under lower light levels. Meanwhile, the bluer light, that was not well-captured in the glial cells, was scattered onto the rods in its vicinity.

These results mean that the retina of the eye has been optimised so that the sizes and densities of glial cells match the colours to which the eye is sensitive (which is in itself an optimisation process suited to our needs). This optimisation is such that colour vision during the day is enhanced, while night-time vision suffers very little. The effect also works best when the pupils are contracted at high illumination, further adding to the clarity of our colour vision.The Conversation

This article was originally published at The Conversation. Read the original article.

http://www.sciencealert.c(...)backwards-here-s-why

STAR'S BIRTH GLIMPSED 'IN REAL TIME'

3 April 2015



Data from 1996 - illustrated here as a 3D simulation - showed a compact, round blast of wind (in blue)

Astronomers have witnessed a key stage in the birth of a very heavy star, using two radio telescope views of the process taken 18 years apart.


The young star is 4,200 light-years from Earth and appears to be surrounded by a doughnut-shaped cloud of dust.

That cloud slows down the hot, ionised wind that the star blasts into space, causing it to form an elongated column perpendicular to the dusty ring.

The new results represent "before and after" glimpses of that column forming.

They were captured by the Very Large Array, a battery of 27 antennae in the New Mexico desert, and are published in the journal Science.

"The comparison is remarkable," said first author Carlos Carrasco-Gonzalez, from the National Autonomous University of Mexico. The compact, rounded wind indicated by data from 1996 transforms - just 18 years later in 2014 - into a "distinctly elongated outflow".

One to watch

The infant star is about 300 times brighter than the Sun and goes by the catchy name of W75N(B)-VLA2.

Being able to observe its dramatic growing pains in real time is unique, according to Prof Huib van Langevelde from Leiden University in the Netherlands, another of the study's authors.


The 2014 data revealed the wind to be much more elongated, emerging from the presumed ring of dust

"This object is providing us an exciting opportunity to watch the developments over the next few years, as this very young star develops the characteristic bipolar outflow morphology," said Prof van Langevelde, who also works at the Joint Institute for VLBI in Europe (JIVE).

VLBI - very long baseline interferometry - is the method of comparing signals between widely-spaced antennae, effectively simulating one massive telescope.

One of the major findings that has already emerged from studying W75N(B)-VLA2 relates to earlier work led by JIVE scientists, who in 2009 traced the large-scale magnetic field in that region of space and reported that the field surrounding the young star was neatly aligned with it.

Now, it seems the elongated outflow that has burst forth in just 18 years is also aligned with that magnetic field - suggesting that magnetism is playing a crucial role in the star's formation.

The team hopes to watch and learn more as the "protostar" continues its turbulent development.

"Our understanding of how massive young stars develop is much less complete than our understanding of how Sun-like stars develop," said Dr Gabriele Surcis, another co-author from JIVE.

"It's going to be really great to be able to watch one as it changes."

http://www.bbc.com/news/science-environment-32168507

quote:

Op donderdag 9 april 2015 08:47 schreef ExperimentalFrentalMental het volgende:
08-04-2015

Terminaal zieke man krijgt mogelijk eerste complete hoofdtransplantatie ooit

[ afbeelding ]
© Twitter, Daily Mail, Daily Mirror.

De 30-jarige Valery Spiridonov heeft zich aangemeld om de eerste mens ooit te worden die een complete hoofdtransplantatie zal ondergaan. Je hoort het goed, zijn hoofd wordt mogelijk integraal op het lichaam van iemand anders geplaatst. "Mijn beslissing is genomen en ik ben niet van plan om van gedacht te veranderen", zegt hij vastberaden.

De Russische Valery werd geboren met een ernstige genetische spierziekte. Hij wil de radicale operatie graag ondergaan omdat zijn toestand elk jaar verergert. "Als ik deze kans niet grijp, dan ziet mijn lot er heel triestig uit", zegt hij. "Ben ik bang? Natuurlijk. Maar het is niet alleen beangstigend, het is ook heel interessant."

[ afbeelding ]

De controversiële Italiaanse dokter Sergio Canavero, die de operatie zal uitvoeren, wordt door vele sceptici 'gestoord' genoemd. Maar hij is er rotsvast van overtuigd dat een complete hoofdtransplantatie wel degelijk mogelijk is.

[ afbeelding ]

Hij kreeg al heel wat aanvragen (?), maar staat erop dat de eerste patiënten, net zoals Valery, aan een spierziekte lijden en dus echt een nieuw lichaam kunnen gebruiken. Hij heeft Valery nu geïdentificeerd als eerste patiënt. De twee hebben elkaar nog niet in het echt ontmoet, maar hebben wel al contact gehad via Skype. De chirurg wil nu nog zeker twee jaar tijd om alle nodige voorbereidingen te treffen. In 2017 wil hij de operatie uitvoeren.

'Dr. Frankenstein' of wereldverbeterende pionier?
In 1970 onderging een aap voor het eerst een hoofdtransplantatie. Het aapje stierf acht dagen later omdat het lichaam het nieuwe hoofd afstootte. Voor de aap stierf bleek hij niet te kunnen bewegen omdat onder andere de ruggengraat niet voldoende verbonden was. De aap kon ook niet zelfstandig ademen. Volgens dokter Canavero staat hij met zijn plannen ondertussen al heel wat verder en bestaan nu ook alle technieken om een hoofd over te zetten op een donorlichaam.

Critici noemen Canavero 'Dr. Frankenstein' en vinden zijn plannen pure fictie. Moest dokter Canavero toch in dit huzarenstukje slagen, bezorgt hij met zijn pionierende operatie wel meteen voor hoop voor heel wat verlamde en gehandicapte mensen. "Voor de eerste man de ruimte in ging dacht men ook aan alles wat er fout kon gaan", zegt Valery. "Als je wil dat iets lukt, moet je er aan participeren", concludeert hij moedig.

Head transplantation -- The future is now | Dr. Sergio Canavero | TEDxLimassol

(HLN)

Ik geloof er geen fuck van

quote:

Op donderdag 9 april 2015 09:00 schreef ExperimentalFrentalMental het volgende:

[..]

Het is niks nieuws hoor, ze hebben al sinds de vorige eeuw experimenten gedaan met honden en apen, Ik ben echter ook sceptisch of het al binnen 2 jaar mogelijk zal zijn.bij een mens. En dan hebben we t nog niet over ethische implicaties...

Ze kunnen een dwarslesie nog steeds niet herstellen maar dit zou wel moeten lukken? Of neemt hij genoegen met een gevoelloos lichaam en leven in een rolstoel, weinig verschil met de huidige situatie behalve dat hij er langer mee kan leven.

13-04-2015

Universum dijt mogelijk toch niet zo snel uit als gedacht



Wetenschappers hebben ontdekt dat supernova’s die gebruikt worden om afstanden in het heelal te meten niet zo uniform zijn als gedacht. Het zou kunnen betekenen dat het universum toch niet zo snel uitdijt als gedacht.

Onderzoekers bestudeerden de supernova’s van type Ia. Aangenomen werd dat deze supernova’s allemaal evenveel licht geven. Door de helderheid van deze sterren te meten, kunnen onderzoekers dan ook vaststellen op welke afstand de supernova’s vanaf de aarde staan. Tenminste: dat dachten we. Nieuw onderzoek suggereert namelijk dat supernova’s van het type Ia helemaal niet zo uniform zijn.

Wetenschappers hebben ontdekt dat er verschillen zijn in de helderheid van deze supernova’s en dat de supernova’s op basis van die verschillen in twee groepen in te delen zijn. “De groep die nabij ons in de minderheid is, is op grotere afstanden – en dus toen het universum jonger was – in de meerderheid,” legt onderzoeker Peter Milne uit. “Er is sprake van verschillende populaties en dat hebben we niet eerder erkend. We namen altijd aan dat hoe ver ze ook van je verwijderd zijn, supernova’s van het type Ia altijd hetzelfde zijn. Maar dat blijkt niet zo te zijn.”

Het onderzoek heeft mogelijk implicaties voor de uitdijing van het heelal. Wetenschappers hebben namelijk onder meer supernova’s van het type Ia gebruikt om de snelheid waarmee het heelal uitdijt, vast te stellen. Uit hun onderzoek bleek dat veel supernova’s minder helder zijn, omdat ze door een versnelde uitdijing van het heelal tegenwoordig op grotere afstand van de aarde staan. “Het idee achter deze redenering was dat supernova’s van het type Ia allemaal dezelfde helderheid hebben en er dus – ongeacht waar ze ontploffen – hetzelfde uitzien. De verre supernova’s zouden er net zo uitzien als de supernova’s die dichtbij ons staan, maar omdat ze minder helder zijn dan verwacht gingen mensen ervan uit dat ze op een grotere afstand stonden. En dat heeft geleid tot de conclusie dat het universum nu sneller uitdijt dan in het verleden.”

(scientias.nl)

14-04-2015

Eerste gedetailleerde kaart van donkere materie is een feit

Onderzoekers hebben voor het eerst een gedetailleerde kaart afgeleverd waarop te zien is hoe donkere materie in het heelal verspreid is. Vooralsnog lijkt deze kaart onze ideeën over donkere materie te bevestigen.

Ongeveer een kwart van het universum bestaat naar schatting uit donkere materie. Maar donkere materie is onzichtbaar en dus niet zo gemakkelijk in kaart te brengen. Om een beeld te krijgen van de verdeling van donkere materie in het heelal, moeten onderzoekers dan ook kijken naar de zwaartekrachtsinvloed die donkere materie op de omgeving heeft. “We maten de bijna niet waarneembare verstoringen in de vormen van ongeveer twee miljoen sterrenstelsels om deze nieuwe kaarten te maken,” vertelt onderzoeker Vinu Vikram.


_{De kaart laat de verspreiding van donkere materie zien. De kleuren vertellen iets over de dichtheid: de dichtheid van de materie is groter in de rode en gele gebieden. De grijze stippen zijn clusters (hoe groter de stip, hoe groter het cluster). Afbeelding: Dark Energy Survey.}

Dark Energy Camera
De kaarten zijn gemaakt met behulp van de Dark Energy Camera. Deze camera bevindt zich op een telescoop in Chili. Vooralsnog hebben de onderzoekers één kaart vrijgegeven. Deze kaart beslaat ongeveer drie procent van het deel van het heelal dat de Dark Energy Camera tijdens zijn vijf jaar durende missie zal bestuderen.

Toets de theorie
Met behulp van de kaarten hopen onderzoekers te achterhalen of hun ideeën over de vrij mysterieuze donkere materie kloppen. Eén van die ideeën stelt bijvoorbeeld dat – omdat er veel meer donkere materie is dan zichtbare materie – sterrenstelsels zullen ontstaan op plekken waar de concentratie donkere materie groot is. Tot op heden lijkt de Dark Energy Camera dat idee te onderschrijven. De kaarten laten lange ‘slierten’ materie zien waarin zich veel sterrenstelsels en clusters bevinden en ‘lege gebieden’ waarin heel weinig sterrenstelsels te vinden zijn.

“Onze analyse is tot zover in lijn met wat we voorspelden,” stelt onderzoeker Chihway Chang. “Door in te zoomen op de kaarten hebben we kunnen meten hoe donkere materie sterrenstelsels van verschillende typen omwikkelt en hoe zij samen door de tijd heen evolueren. We kijken ernaar uit om de nieuwe gegevens die nu binnenkomen te gebruiken om theoretische modellen nog verder te beproeven.”

(scientias.nl)