[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 ]