Pony Express Protein: Protein Found That Rallies Biological Clock

A biologist at Washington University in St. Louis and his collaborators have identified the factor in mammalian brain cells that keeps cells in synchrony so that functions like the wake-sleep cycle, hormone secretion and loco motor behaviors are coordinated daily.
Erik Herzog, Ph.D., Washington University associate professor of Biology in Arts & Sciences, Sara Aton, Ph.D., a graduate student in Herzog's lab who is now a postdoctoral researcher at the University of Pennsylvania, James Huettner, Ph.D., associate professor in cell biology and physiology at the Washington University School of Medicine, and Martin Straume, a biostatistician, have determined that VIP — vasoactive intestinal polypeptide — is the rallying protein that signals the brain's biological clock to coordinate daily rhythms in behavior and physiology.
The finding clarifies the roles that both VIP and a neurotransmitter GABA play in synchronizing biological clocks, and sheds light on how mammals, in this case mice and rats, regulate circadian rhythm. Results were published in the Nov. 27- Dec. 1 online issue of the Proceedings of the National Academy of Sciences.
Neurons in the biological clock, an area called the suprachiasmatic nucleus (SCN), located at the base of the brain right across the optic nerve, keep 24-hour time and are normally highly synchronized. The SCN is composed of 10,000 neurons on one side of the hypothalamus, and 10,000 on the other. Together these neurons are intrinsic clocks in communication with each other to keep 24-hour time.
It had been thought that GABA was the prime candidate for the rallying role. All SCN neurons make this inhibitory neurotransmitter, and it had been shown that giving GABA daily at 8 a.m. to SCN cells synchronizes them.
"The surprise was that GABA was not needed," said Herzog. "VIP synchronizes even when we block all GABA signaling. When we blocked GABA, synchrony was perfectly fine. Instead, the oscillations got bigger."
Herzog likens VIP to the Pony Express rider telling all the SCN cells to synchronize their watches; GABA, he says, is like the marshal that prevents the cells from being too active.
Herzog and Aton recorded neuron activity from the SCN using a multielectrode array with 60 electrodes upon which they place SCN cells, a "clock in a dish." They also recorded gene expression in real-time using a bioluminescent reporter of gene activity.
Using drugs or genetic knock out mice, they negated the role of GABA and recorded the electrical activity of many neurons, what Herzog calls the "hands of the clock," and the gene activities, "the cogs of the clock," of many SCN cells.
They found that, without GABA, the cells marched together, but without VIP, they lost synchrony, indicating that VIP is the coordinator.
Source : Washington University in St. Louis

Why Do Leaves Change Color In The Fall?

Many of the colors we see in fall are always present, but normally they’re hidden from view, says UW-Madison Arboretum native plant gardener Susan Carpenter.
The leaves of trees and other plants contain three main pigments: carotene, anthocyanin, and the photosynthetic pigment, chlorophyll, which captures the sun’s energy to make food for plants. As the most abundant pigment, chlorophyll is what gives leaves their green hue in spring and summer.
Another chemical in leaves, auxin, controls a special band of cells at the base of each leaf stem, called the abscission layer. During the growing season, auxin prevents this layer from fully developing and blocking the tiny, internal tubes that connect each leaf to the rest of the tree’s circulatory system.
In fall, however, cooler and shorter days trigger an end to auxin production, allowing the abscission layer to grow and cut off the circulation of water, nutrients and sugar to the leaves. When this happens, chlorophyll disintegrates rapidly, letting carotene shine through as the yellow in maple, aspen and birch leaves. Anthocyanin, meanwhile, provides the oranges and reds of maples, sumacs and oaks. When there’s less sun, anthocyanin isn’t as chemically active and leaves are more orange or yellow than red.

New Evidence Debunks 'Stupid' Neanderthal Myth

Research by UK and American scientists has struck another blow to the theory that Neanderthals (Homo neanderthalensis) became extinct because they were less intelligent than our ancestors (Homo sapiens). The research team has shown that early stone tool technologies developed by our species, Homo sapiens, were no more efficient than those used by Neanderthals.
Published in the Journal of Human Evolution, their discovery debunks a textbook belief held by archaeologists for more than 60 years.
The team from the University of Exeter, Southern Methodist University, Texas State University, and the Think Computer Corporation, spent three years flintknapping (producing stone tools). They recreated stone tools known as 'flakes,' which were wider tools originally used by both Neanderthals and Homo sapiens, and 'blades,' a narrower stone tool later adopted by Homo sapiens. Archaeologists often use the development of stone blades and their assumed efficiency as proof of Homo sapiens' superior intellect. To test this, the team analysed the data to compare the number of tools produced, how much cutting-edge was created, the efficiency in consuming raw material and how long tools lasted.
Blades were first produced by Homo sapiens during their colonization of Europe from Africa approximately 40,000 years ago. This has traditionally been thought to be a dramatic technological advance, helping Homo sapiens out-compete, and eventually eradicate, their Stone Age cousins. Yet when the research team analysed their data there was no statistical difference between the efficiency of the two technologies. In fact, their findings showed that in some respects the flakes favoured by Neanderthals were more efficient than the blades adopted by Homo sapiens.
The Neanderthals, believed to be a different species from Homo sapiens, evolved in Ice Age Europe, while the latter evolved in Africa before spreading out to the rest of the world around 50-40,000 years ago. Neanderthals are thought to have died out around 28,000 years ago, suggesting at least 10,000 years of overlap and possible interaction between the two species in Europe.
Many long-held beliefs suggesting why the Neanderthals went extinct have been debunked in recent years. Research has already shown that Neanderthals were as good at hunting as Homo sapiens and had no clear disadvantage in their ability to communicate. Now, these latest findings add to the growing evidence that Neanderthals were no less intelligent than our ancestors.
Metin Eren, an MA Experimental Archaeology student at the University of Exeter and lead author on the paper comments: "Our research disputes a major pillar holding up the long-held assumption that Homo sapiens were more advanced than Neanderthals. It is time for archaeologists to start searching for other reasons why Neanderthals became extinct while our ancestors survived. Technologically speaking, there is no clear advantage of one tool over the other. When we think of Neanderthals, we need to stop thinking in terms of 'stupid' or 'less advanced' and more in terms of 'different.'"
Now that it is established that there is no technical advantage to blades, why did Homo sapiens adopt this technology during their colonization of Europe? The researchers suggest that the reason for this shift may be more cultural or symbolic. Eren explains: "Colonizing a continent isn't easy. Colonizing a continent during the Ice Age is even harder. So, for early Homo sapiens colonizing Ice Age Europe, a new shared and flashy-looking technology might serve as one form of social glue by which larger social networks were bonded. Thus, during hard times and resource droughts these larger social networks might act like a type of 'life insurance,' ensuring exchange and trade among members on the same 'team.'"
The University of Exeter is the only university in the world to offer a degree course in Experimental Archaeology. This strand of archaeology focuses on understanding how people lived in the past by recreating their activities and replicating their technologies. Eren says: "It was only by spending three years in the lab learning how to physically make these tools that we were able to finally replicate them accurately enough to come up with our findings."
This research was funded by the National Science Foundation of the USA and the Exeter Graduation Fund.
Source : University of Exeter

Standard DNA Barcodes For Plants?

Two University of British Columbia researchers are part of an international team recommending standards for the DNA barcoding of land plants, a step they hope will lead to a universal system for identifying over 400,000 species, and ultimately boost conservation efforts.
Barcodes based on portions of DNA – the taxonomical equivalent to UPC barcodes on products – have already emerged as a viable solution for uniquely identifying species in many animal groups. However, because DNA varies less between plant species, determining which portions of plant DNA to use as a unique identifier has been a thorny issue.
The research team, which included scientists from more than 20 institutions around the world, selected two genomic regions – genes referred to as rbcL and matK – as the best candidates from which to generate barcode data.
Results of the four-year study were recently published in the Proceedings of the National Academy of Sciences.
"It's a pragmatic first step in solving a complex issue," says UBC botanist and Associate Professor Sean Graham, who conducted research on the project and helped author the study. "We've selected areas of DNA that are available in the vast majority of plants, could easily and accurately be sequenced, and when combined, provide a near-unique signature for barcoding."
Limiting the barcode to information generated from two DNA sites should help cut costs associated with sequencing and retrieving the correct information.
The researchers used 400 land plant samples to test the two-site solution. In 72% of cases they were immediately able to determine the correct species of plant, and in the rest of the cases were able to place the plant in a group of congeneric species.
"There's no doubt this will be refined in the future, but there is a need for a core barcoding standard now," says Graham, with the UBC Botanical Garden and Centre for Plant Research, and the Department of Botany. "Particular research projects with special needs could augment the system by adding a third DNA locus to their barcode if required."
Theoretically, any DNA barcoding standard would have to accommodate over 400,000 species of plants, and would be a key step toward establishing a central barcode database for taxonomy, agriculture and conservation.
The 2008 International Union for Conservation of Nature Red List categorized, 8,457 out of an evaluated 12,055 species of plants as endangered, but notes only four per cent of total plant species have been evaluated. Those evaluations tend to focus on areas losing biodiversity and plants families that are endangered. Estimates of the total number of endangered plants vary from 13 per cent to 37 per cent.
Graham worked with UBC post-doctoral fellow Diana Percy on the project, and the international research team included scientists from the universities of Guelph and Toronto, along with scientists from the United Kingdom, the United States, Europe, South and Central America, South Africa and South Korea.

Solving the mystery of how plants survive near Chernobyl

Twenty-two years after the Chernobyl nuclear power station accident in the Ukraine — the worst in history — scientists are reporting insights into the mystery of how plants have managed to adapt and survive in the radioactive soil near Chernobyl. Their research is the first to probe how production of key proteins in plants changes in response to the radioactive environment, according to the report. It is scheduled for the June 5 issue of ACS’ Journal of Proteome Research, a monthly publication.

Martin Hajduch and colleagues note in the new study that plants growing in the Chernobyl area following the April 26, 1986 disaster somehow adapted to the radioactive environment and thrived. But until now, nobody knew what biochemical changes in the plants accounted for this miracle and enabled plants to adapt.

The researchers found that soybean plant seeds exposed to radiation produced different amounts and types of protein than seeds from unexposed plants. The proteins protected the seeds from radio-contaminated environment. Interestingly, plants from contaminated fields produced one-third more of a protective protein called betaine aldehyde dehydrogenase — the same protein known to protect human blood from radiation damage. 

Life Forms May Have Evolved In Ancient Hot Springs On Mars

Data from the Mars Reconnaissance Orbiter (MRO) suggest the discovery of ancient springs in the Vernal Crater, sites where life forms may have evolved on Mars, according to a new report.
Hot springs have great astrobiological significance, as the closest relatives of many of the most ancient organisms on Earth can thrive in and around hydrothermal springs. If life forms have ever been present on Mars, hot spring deposits would be ideal locations to search for physical or chemical evidence of these organisms and could be target areas for future exploratory missions.
Carlton C. Allen and Dorothy Z. Oehler, from the Astromaterials Research and Exploration Science Directorate at the NASA Johnson Space Center, Houston, Texas, propose that new image data from the High Resolution Imaging Science Experiment (HiRISE) on MRO depict structures in Vernal Crater that appear to have arisen as part of a major area of ancient spring activity. The data suggest that the southern part of Vernal Crater has experienced episodes of water flow from underground to the surface and may be a site where martian life could have developed.
"Hot spring deposits are key target areas for future Mars missions," says Sherry L. Cady, PhD, Editor of Astrobiology and Associate Professor in the Department of Geology at Portland State University.
"Such deposits on Earth preserve evidence of the fossilized remains of the microbial communities that inhabited the hot springs over a wide range of spatial scales. The potential to find key evidence indicative of life––biofabrics, microbial remains, chemical fossils in minerals––is high when sedimentary deposits form from hydrothermal fluids. Hot spring fluids are typically laden with dissolved mineral ions that, when they precipitate out and create the hydrothermal deposit, enhance fossilization of all types of biosignatures."

Biophilia hypothesis

"Biophilia" is the term coined by Edward O. Wilson to describe what he believes is humanity's innate affinity for the natural world. In his landmark book Biophilia, he examined how our tendency to focus on life and lifelike processes might be a biologically based need, integral to our development as individuals and as a species. That idea has caught the imagination of diverse thinkers.The Biophilia Hypothesis brings together the views of some of the most creative scientists of our time, each attempting to amplify and refine the concept of biophilia. The variety of perspectives -- psychological, biological, cultural, symbolic, and aesthetic -- frame the theoretical issues by presenting empirical evidence that supports or refutes the hypothesis. Numerous examples illustrate the idea that biophilia and its converse, biophobia, have a genetic component: fear, and even full-blown phobias of snakes and spiders are quick to develop with very little negative reinforcement, while more threatening modern artifacts -- knives, guns, automobiles -- rarely elicit such a response people find trees that are climbable and have a broad, umbrella-like canopy more attractive than trees without these characteristics people would rather look at water, green vegetation, or flowers than built structures of glass and concrete The biophilia hypothesis, if substantiated, provides a powerful argument for the conservation of biological diversity. More important, it implies serious consequences for our well-being as society becomes further estranged from the natural world. Relentless environmental destruction could have a significant impact on our quality of life, not just materially but psychologically and even spiritually.

Konieczność ochrony środowiska

Często zagrożenia związane z globalnym skażeniem środowiska wydają się nam niezwykle odległe.Nie dostrzegamy tego, jako problemu, który bezpośrednio może nas dotyczyć.
W wielu programach dokumentalnych wymieniane są często hasła takie jak : efekt cieplarniany czy globalne ocieplenie. Od kilku ostatnich dekad stanowią one również zagadnienia, z którymi usiłuję się zmierzyć globalna polityka. Kraje, stany czy korporacje próbują wprowadzić i spropagować sposoby ograniczające niekorzystny wymiar tych zjawisk, a także przystosowujące do nich. Wiele stowarzyszeń ekologicznych wspiera inicjatywy skierowane przeciwko czynnikom wpływającym na ocieplanie się klimatu, realizowane zarówno poprzez indywidualne osoby, jak i przez organizacje lokalne i regionalne.

Wydaje nam się jednak, że jeśli bezpośrendio nie odczuwamy skutków owego skażenia to nie jestesmy zobligowania do podejmowania działań, które mogą nas przerastać. Czy my jednak, jako obywatele "globalnej wioski" możemy podejmować w życiu codziennym jakiekolwiek działania prewencyjne? Czy staramy się wziąć odpowiedzialność za własne postępowanie, którego konsekwencje mogą dotkliwie odczuwane już w nie tak bardzo odległej przyszłości przez kolejne pokolenia? Czy postrzegamy działania mające ratować nasze środowisko jako lokaty warte poświęcenia?

Obserwowane podwyższenie średniej temperatury przy powierzchni ziemi oraz oceanów, a także przewidywane ocieplenie w przyszłości wydają się być odległe dla jednostkowego obywatela. Dwutlenek węgla może powodować również tzw. zakwaszenie oceanów, czyli obniżenie stopnia pH. Organizmy morskie będące składnikami ekosystemów tolerują tylko specyficzny, wąski zakres zasadowości (pH), dlatego przez gwałtowne zmiany tego wskaźnika w oceanie mogą mieć one trudności w budowaniu szkieletów czy odżywianiu, może nawet dojść do ich zaniku,w przeszłości może i nie rozumieliśmy skutków naszych działań. Teraz jednak nie mamy już dłużej takiej wymówki, teraz potrafimy rozpoznać dokładnie konsekwencje naszych zachowań.

Dlatego też teraz z pewnością musimy podejmować działania na rzecz reformy: indywidualnie i kolektywnie, w skali narodowej i międzynarodowej - w przeciwnym razie doprowadzimy kolejne pokolenia do katastrofy.

Co to jest GMO ?

Organizmy zmodyfikowane genetycznie w skrócie GMO  i mikroorganizmy modyfikowane genetycznie można określić jako organizmy, w których materiał genetyczny (DNA) został zmieniony w taki sposób, w jakim nie występuje w warunkach naturalnych. Zamiennie używany jest również termin organizmy transgeniczne.

                     Zastosowanie  inżynierii genetycznej pozwala na wyselekcjonowanie pojedyńczych genów i przeniesienie ich za pomocą specjalnych technik z jednego organizmu do drugiego. Modyfikacje genetyczne dotyczą: mikroorganizmów , roślin, zwierząt i mogą zachodzić w obrębie tego samego gatunku, gatunków z tej samej rodziny, gatunków niespokrewnionych oraz z użyciem genów syntetycznych. Stopień pokrewieństwa między organizmem biorcy i dawcy może być bardzo wysoki  lub niski co może mieć wplyw na poziom akceptacji przez spoleczeństwo organizmów genetycznie zmodyfikowanych.
                     Ingerencja w materiał genwetyczny ma na celu głównie wprowadzenie genu kodującego pożądana cechę lub unieczynnienie genu kodującego niepożądaną cechę.
                      Wykorzystanie inzynierii genetycznej stwarza szerokie możliwości dla rozwoju gospodarczego: głównie rolnictwa, przemysłu spozywczego, farmaceutycznego -gwarantującego postęp w medycynie i weterynarii  w leczeniu chorób oraz nowych gałęzi przemysłu biotechnologicznego.
                      W rolnictwie modyfikacje genetyczne mogą być zastosowane zarówno w produkcji roślinnej jak i zwierzęcej. Celem zmian genetycznych organizmów roslinnych jest ulepszenie różnych właściwości roślin rolniczych takich jak wzrost odporności na mróz , suszę, zasolenie a także na szkodniki, choroby i herbicydy.  Rośliny o takich cechach mogą być uprawiane na nieurodzajnych glebach, a uprawa wiąże się z selektywnym stosowaniem środków ochrony roślin , co zmniejsza zanieczyszcznie środowiska i skażenie zywności pestycydami.