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Trailblazing: Royal Society’s 350th anniversary

30 Novembre 2009,

Publié par JMB

La Royal Society (Angleterre) fêtera ses 350 ans d'existance en 2010. Pour saluer l'évènement, la Royal Society met à la disposition du publique plusieurs articles scientifiques couvrant la période de 1664 à 2010. Un trésor fabuleux à découvrir sur le site "Trailbazing".

In English:
Trailblazing
is an online, interactive timeline launched to commemorate the Royal Society’s 350th anniversary in 2010. 

Welcome to Trailblazing, an interactive timeline for everybody with an interest in science. Compiled by scientists, science communicators and historians – and co-ordinated by Professor Michael Thompson FRS – it celebrates three and a half centuries of scientific endeavour and has been launched to commemorate the Royal Society’s 350th anniversary in 2010.

Trailblazing is a user-friendly, ‘explore-at-your-own-pace’, virtual journey through science. It showcases sixty fascinating and inspiring articles selected from an archive of more than 60,000 published by the Royal Society between 1665 and 2010.

Olympus BioScapes International Digital Imaging Competition Website

26 Novembre 2009,

Publié par JMB

Olympus America Inc. is in the seventh year of sponsoring a dynamic international photo competition that honors the world's most extraordinary microscope images of life science subjects.

More informations
here


Olympus BioScapes
2009 Winners Gallery

Thumbnail images of the Olympus BioScapes 2009 winners and honorable mentions are displayed in this gallery. In order to view a larger version of the images (or to play videos), please click on the individual thumbnails.

2009 Winners  |  2008 Winners  |  2007 Winners  |  2006 Winners  |  2005 Winners  |  2004 Winners

2009 Winning Entries


1st Place
Jan Michels

2nd Place
Chung-Ju Rachel Wang

3rd Place
Jeremy Pickett-Heaps

4th Place
Charles Krebs

5th Place
David Domozych

6th Place
Alvaro Migotto

7th Place
Albert Pan

8th Place
Heiti Paves

9th Place
Haruka Fujimaki

10th Place
Croft / Weygandt

2009 Honorable Mentions


N. Barker

H. Berg

S. Boyle

K. Bruun

M. Clarke

M. Clemente

S. Coccoris

M. Dadpour

A. Doni

F. Federici

F. Federici

R. Fink

U. Ganesan

R. Grimm

M. Guervos

M. Hajihosseini

P. Hickey

M. Jurna

Kasischke / Gelbard

D. Kirilly

C. Krebs

E. Lamm

O. Leroux

M. Letellier

A. Lomakin

J. Mellott

J. Michels

A. Migotto

A. Migotto

D. Millard

L. Millet

M. Mis

E. Myburgh

S. Nagy

S. Nagy

M. Nemethova

J. Nicholson

J. Nicholson

S. Nishimura

D. Paquet

F. Parais

H. Paves

H. Paves

J. Peloquin

M. Peres

J. Pickett-Heaps

S. Pintscher

F. Poulain

M. Ramírez

G. Rogers

Rounsevell / Lam

R. Sandoval

N. Sanjana

S. Schirmer

M. Sivaguru

J. Spacek

V. Sýkora

T. Viney

Wakazaki / Toyooka

S. Walker

S. Walker

Y. Wang

D. Ward

M. Zappia

B. Zobiak

All image copyrights belong to the individual contestants.
Olympus BioScapes Digital Imaging Competition® | © Olympus Corporation of the Americas

Richard Dawkins

23 Novembre 2009,

Publié par JMB

Le biologiste Richard Dawkins nous encourage à "penser l'improbable" en examinant la manière dont le cadre de référence humain nous limite dans notre compréhension de l'univers (Biologist Richard Dawkins makes a case for "thinking the improbable" by looking at how the human frame of reference limits our understanding of the universe).




Pour insérer un sous titrage, dans la langue de votre choix, cliquez sur "View subtitles" (cliquez sur le "triangle" pour démarrer la vidéo. )

Source : Ted.com

Le piège à poils : un outil de détection de la faune

17 Novembre 2009,

Publié par JMB

Un article de Cécile Regazzi; 27 avril 2007 (source : site Internet "Objectif Science International")

"Détecter la présence (ou l’absence) d’espèces animales dans leur environnement naturel n’est pas toujours chose évidente pour l’observateur de terrain. La nature discrète et cryptique qui caractérise certains mammifères, les faibles densités de population et l’accessibilité parfois difficile par l’homme de certains milieux, tels que les massifs montagneux, sont autant d’obstacles qui entravent le travail de prospection et de détection de la faune dans une aire déterminée. Ces difficultés in situ sont rencontrées notamment dans l’étude des grands mammifères comme les félins et les ours ainsi que pour des espèces plus petites comme les blaireaux et le carcajou (ou glouton, Gulo gulo)."

La suite
ici

Des exemples d'application de la technique des pièges à poil pour recenser les chats sauvages, les lynx (2), les cougars, les ours (2),...

17 Novembre 2009,

Publié par JMB

"Next time you go for a hike, keep an eye out for the hidden cameras. The first sign that you're under surveillance might be a plastic or metal case, about the size of a hefty hardcover book, strapped to a tree and painted to blend into the bark. If you're listening carefully, you might even hear the click of the shutter or the whirr of the film advancing.

The cameras are not meant for you, and you'll probably have to get off the trail—at least, off human trails—to find them. They are designed to capture images of wild animals, and in recent years their use by hunters and wildlife biologists has been increasing exponentially. According to one
study, there has been a 50 percent increase in the number of scientific papers involving data from camera traps every year for the past decade; at any given time, there may be about 10,000 deployed in research projects. And that's just the tip of the iceberg. Exact figures are hard to come by, but industry sources say that as many as 300,000 are sold every year, mostly to hunters.

In fact, camera traps are so useful for science, fund-raising, and conservation that few researchers or conservationists have paused to consider the unintended side effects of this massive deployment. The cameras may be hurting the animals they're used to study—and they may be affecting humans, too.

Related in
Slate
Juliet Lapidos explained
how they use camera traps to count tigers, and Brendan I. Koerner explained how to count right whales. Ed Finn assessed the best way to raise and train a tiger. C. Josh Donlan argued that we should let elephants, cheetahs, and lions out of captivity to run free in North America."

More informations here

Remote camera

17 Novembre 2009,

Publié par JMB

Michael Nichols is a wildlife photographer. Some animals are so afraid of humans that it’s nearly impossible to photograph them up close. In 1993, Michael first experimented with remote cameras (or camera traps) triggered by the animal breaking an invisible beam. The trick is to have the animal make the kind of image that you would do if you were there.

Giant Beach Worms

12 Novembre 2009,

Publié par JMB

Giant Beach Worms (Australonuphis teres) are long and thin. They can grow up 2.5 m long. They have hundreds of body segments. They have short tentacles near their head.

They live around eastern and southern Australia, and are found in sandy beaches at the low water mark. The worms live under the sand.

Giant Beach Worms eat dead fish, seaweed, dead octopuses and Pipis. They come out of the sand only to feed. They poke their heads out of the sand and grab the food in their jaws and eat it.

Fish and birds eat Giant Beach Worms. People fishing collect Giant Beach Worms for bait.

Giant Beach Worms are rarely seen as they only come out of the sand to feed. They live hidden in the sand in burrows or in tubes that they make.

La photo de nuit : une nouvelle révolution

9 Novembre 2009,

Publié par JMB

Eté 2009. Vincent Munier, photographe animalier professionel, a été choisi par Nikon Corporation pour tester le boitier D3s. Une mission réalisée en Scandinavie. Surtout de nuit. Une vidéo en haute définition, et des photos prises de nuits à 12 800 iso (quelques exemples ci-dessous), d'une qualité époustouflante ! Une nouvelle voie vient de s'ouvrir.


 

Voici la vidéo "Summer Variations" tournée par Vincent Munier avec son appareil photo, le Nikon D3s :


Dans l'interview ci-dessous, Vincent Munier nous raconte son expérience avec le D3s :




Bacteria 'invest' wisely to survive uncertain times, scientists report

3 Novembre 2009,

Publié par JMB

Like savvy Wall Street money managers, bacteria hedge their bets to increase their chances of survival in uncertain times, strategically investing their biological resources to weather unpredictable environments.

In a new study available online and featured on the cover of today's issue of Cell, UT Southwestern Medical Center researchers describe how bacteria play the market so well. Inside each bacterial cell are so-called genetic circuits that provide specific survival skills. Within the bacteria population, these genetic circuits generate so much diversity that the population as a whole is more tolerant of - and is more likely to survive - a wide range of variability in the environment.

"We have found that a particular genetic circuit is responsible for generating diversity within the bacteria population," said senior author Dr. Gürol Süel, assistant professor of pharmacology and in the Cecil H. and Ida Green Comprehensive Center for Molecular, Computational and Systems Biology
  at UT Southwestern.

This diversity, like a diversified investment portfolio, means that each bacterium has characteristics that allow it to survive under certain conditions, said Dr. Süel. "When conditions are highly variable, some individual bacteria are equipped to thrive in the highs or lows, while others tank," he said. "It's like the stock market. If you invest all your money in just one stock, and conditions change to lessen or completely eliminate its value, you won't survive financially. Similarly, in the case of these bacteria, if all the cells were adapted to only a small, rigid set of environmental factors, the population would be wiped out if conditions unexpectedly changed.

"There seems to be an optimization going on in these organisms," he added.

By generating diversity, genetic circuits ensure enough cells will survive to carry over the population, especially in times of variable conditions, Dr. Süel explained. Essentially, variability of bacterial cells appears to match the variability in the environment, thereby increasing the chances of bacterial survival, he said.

Genetic circuits are distinct sets of genes and proteins within cells that interact in a specific pattern, resulting in some biological process. In this study, the researchers focused on a genetic circuit within a bacterium that controls the transformation of bacteria cells in and out of a state called competence. Differences in the duration of the competence state have particular survival advantages, depending on the environmental conditions.

Biological "noise" in the genetic circuit, which comes from random fluctuations in the chemical reactions involved in the pattern of interactions, is similar to the undesirable noise - like static heard on AM radio - found in electrical circuits. In biological systems, however, biochemical "noise" is beneficial. In fact, it is the root mechanism that drives diversity within the bacteria population. Dr. Süel previously found that when noise reaches a certain level in some genetic circuits, it can prompt cells to transform from one cellular state to another.

For the current study, the researchers went beyond studying the native genetic circuit. Just as electronic maps can find alternate routes between two points, the UT Southwestern researchers also developed an alternative, synthetic genetic circuit that used a different architecture - or route - to accomplish the same function as the native circuit.

Dr. Süel believes his group is the first to insert such a synthetic genetic circuit into living bacterium and show that it can replace the biological function of the native version. He said his team was surprised to find that the behavior of the synthetic circuit was most precise, essentially generating less noise. The result was a population less diverse than the natural one. They were even more surprised to find that the lack of precision - or greater noisiness - in the native circuit ultimately allows bacteria to survive in a wider range of environments.

"It turns out that sometimes being sloppy can be good," Dr. Süel said. "For these bacteria, the more variable they are, the better they will be able to perform because they can adapt to a wider range of environments."

Dr. Süel said this approach of engineering alternative genetic circuits can in principle be applied even to human cells and possibly help explain why diseased cells have different survival capabilities than healthy ones.

Source: UT Southwestern Medical Center, and Physorg.com

Ecotoxicologie : Théorie et applications

3 Novembre 2009,

Publié par JMB

Ecotoxicologie
Théorie et applications
Valéry E. Forbes, Thomas L. Forbes
Traduit par Jean-Louis Rivière


L'écotoxicologie est un domaine scientifique en plein essor. Cet ouvrage en rappelle les fondements historiques, précise les champs d'application, traite des pratiques actuelles et des développements. Il fait une analyse pertinente et critique des méthodes utilisées pour tenter de donner une réponse à des questions difficiles : comment prévoir les phénomènes d'écotoxicité à différents niveaux d'organisation biologique ? Comment relier les prévisions du devenir et des effets des polluants dans une perspective réellement écologique ? L'ouvrage s'adresse en premier lieu aux spécialistes concernés par les problèmes de pollution, écotoxicologues de l'industrie, de la recherche et des agences gouvernementales, mais aussi à toute personne intéressée par ces questions d'actualité et pourvue de connaissances en biologie de niveau universitaire.

In English: Ecotoxicology in Theory and Practice
Ecotoxicology is a fast-expanding scientific field. This book outlines the historical background and the scope of this discipline and considers its current practices and developments. It proposes relevant and thought-provoking analyses of the methods currently used in an attempt to respond to difficult questions such as: Is it possible to predict ecotoxicological phenomena at different levels of biological organization? In an ecological context, how do predictions concerning the fate of the pollutants relate to their actual effects? This book is intended for specialists involved in pollution: scientists, engineers and governmental agencies, as well as those interested in this topical matter.