“Somewhere, something incredible is waiting to be known.” ― Carl Sagan Current Biology

21st October 2014

Photo with 13 notes

On Eagle’s Wings, a Revelation About Flight (NY Times)
When an aircraft hits turbulence, bad things can happen. At the very least, passengers may feel an unpleasant lurch in their stomachs.
But soaring birds, however they may feel, seem better able to deal with sudden gusts, said Graham K. Taylor, a mathematical biologist at the University of Oxford.
And the way they do it, he and his colleagues Kate V. Reynolds and Adrian L.R. Thomas have found, is by momentarily pulling in their wings — a maneuver called a wing tuck.

Check out the video of the maneuver!

On Eagle’s Wings, a Revelation About Flight (NY Times)

When an aircraft hits turbulence, bad things can happen. At the very least, passengers may feel an unpleasant lurch in their stomachs.

But soaring birds, however they may feel, seem better able to deal with sudden gusts, said Graham K. Taylor, a mathematical biologist at the University of Oxford.

And the way they do it, he and his colleagues Kate V. Reynolds and Adrian L.R. Thomas have found, is by momentarily pulling in their wings — a maneuver called a wing tuck.

Check out the video of the maneuver!

Tagged: eaglebirdswing tuckturbulenceflightbiologyscience

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20th October 2014

Photo with 536 notes

Tagged: crowsmurderpunhumorbiologyscience

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20th October 2014

Photoset reblogged from Great British Bioscience with 297 notes

bbsrc:

Tagged: imagingartbiologyscience

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20th October 2014

Photo with 279 notes

Mitochondria may have once been energy parasites

"We believe this study has the potential to change the way we think about the event that led to mitochondria," said U.Va. biologist Martin Wu, the study’s lead author. "We are saying that the current theories — all claiming that the relationship between the bacteria and the host cell at the very beginning of the symbiosis was mutually beneficial — are likely wrong.
"Instead, we believe the relationship likely was antagonistic — that the bacteria were parasitic and only later became beneficial to the host cell by switching the direction of the ATP transport."

Zhang Wang, Martin Wu. Phylogenomic Reconstruction Indicates Mitochondrial Ancestor Was an Energy Parasite. PLOS ONE, 2014 DOI: 10.1371/journal.pone.0110685

Mitochondria may have once been energy parasites

"We believe this study has the potential to change the way we think about the event that led to mitochondria," said U.Va. biologist Martin Wu, the study’s lead author. "We are saying that the current theories — all claiming that the relationship between the bacteria and the host cell at the very beginning of the symbiosis was mutually beneficial — are likely wrong.

"Instead, we believe the relationship likely was antagonistic — that the bacteria were parasitic and only later became beneficial to the host cell by switching the direction of the ATP transport."

Zhang Wang, Martin Wu. Phylogenomic Reconstruction Indicates Mitochondrial Ancestor Was an Energy Parasite. PLOS ONE, 2014 DOI: 10.1371/journal.pone.0110685

Tagged: Mitochondriaparasitesymbiosisenergycellbiologyscience

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19th October 2014

Photo with 77 notes

Silverberry scaly hair whole mount (400x)
Dr. Jonathan Eisenback
North Carolina State UniversityRaleigh, North Carolina, USA
Technique: Brightfield

Silverberry scaly hair whole mount (400x)

Dr. Jonathan Eisenback

North Carolina State UniversityRaleigh, North Carolina, USA

Technique: Brightfield

Tagged: Silverberryimagingbiologyscience

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19th October 2014

Photo with 75 notes

Sperm wars
Why do male animals need millions of sperms every day in order to reproduce? And why are there two sexes anyway? These and related questions are the topic of the latest issue of the research journal Molecular Human Reproduction published today (Oct. 16th, 2014). The evolutionary biologist Steven Ramm from Bielefeld University Bielefeld has compiled this special issue on sperm competition. In nature, it is not unusual for a female to copulate with several males in quick succession – chimpanzees are one good example. ‘The sperm of the different males then compete within the female to fertilize the eggs,’ says Ramm. ‘Generally speaking, the best sperm wins. This may involve its speed or also be due to the amount of sperm transferred. It can also be useful for the seminal fluid to be viscous, meaning it sticks inside the female reproductive tract to try to keep other sperm at bay.’
Caption: Sperm come in all shapes and sizes: the sperm cell of the flatworm Macrostomum lignano (picture) has a frontal “feeler” (right) and two lateral bristles that may function to anchor the sperm inside the female sperm-receiving organ. Credit: Photo: Bielefeld University

Sperm wars

Why do male animals need millions of sperms every day in order to reproduce? And why are there two sexes anyway? These and related questions are the topic of the latest issue of the research journal Molecular Human Reproduction published today (Oct. 16th, 2014). The evolutionary biologist Steven Ramm from Bielefeld University Bielefeld has compiled this special issue on sperm competition. In nature, it is not unusual for a female to copulate with several males in quick succession – chimpanzees are one good example. ‘The sperm of the different males then compete within the female to fertilize the eggs,’ says Ramm. ‘Generally speaking, the best sperm wins. This may involve its speed or also be due to the amount of sperm transferred. It can also be useful for the seminal fluid to be viscous, meaning it sticks inside the female reproductive tract to try to keep other sperm at bay.’

Caption: Sperm come in all shapes and sizes: the sperm cell of the flatworm Macrostomum lignano (picture) has a frontal “feeler” (right) and two lateral bristles that may function to anchor the sperm inside the female sperm-receiving organ. Credit: Photo: Bielefeld University

Tagged: spermcompetitionbiologyscience

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18th October 2014

Photo with 5,250 notes


These Bacteria Are Wired to Hunt Like a Tiny Wolf Pack
There is an elaborate stealth communication network in the Earth beneath your feet. This smart web acts like a superorganism, fortifying defensive capabilities and coordinating deadly attacks on unsuspecting targets. But it’s not run by the NSA, the CIA, or the military. This web is made of bacteria.
A team of scientists led by Manfred Auer at Lawrence Berkeley National Laboratory have used cutting-edge 3-D microscopy to identify a new mechanism for bacterial networking. They observed elaborate webs of a common soil bacterium, Myxococcus xanthus, connected by thread-like membranes. This system of cellular pipelines suggests that some bacteria have evolved complex ways to deliver molecular cargo out of sight from snooping neighbors. Their work appears in the journal Environmental Microbiology.


Myxococcus xanthus biofilm devouring a colony of Escherichia coli. Credit: James Berlemanc

These Bacteria Are Wired to Hunt Like a Tiny Wolf Pack

There is an elaborate stealth communication network in the Earth beneath your feet. This smart web acts like a superorganism, fortifying defensive capabilities and coordinating deadly attacks on unsuspecting targets. But it’s not run by the NSA, the CIA, or the military. This web is made of bacteria.

A team of scientists led by Manfred Auer at Lawrence Berkeley National Laboratory have used cutting-edge 3-D microscopy to identify a new mechanism for bacterial networking. They observed elaborate webs of a common soil bacterium, Myxococcus xanthus, connected by thread-like membranes. This system of cellular pipelines suggests that some bacteria have evolved complex ways to deliver molecular cargo out of sight from snooping neighbors. Their work appears in the journal Environmental Microbiology.

Myxococcus xanthus biofilm devouring a colony of Escherichia coli. Credit: James Berlemanc

Tagged: MyxococcusEscherichia colibiofilmcommunicationbiologyscience

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18th October 2014

Video with 67 notes

Bacterial nanowires are really wires, not hairs

Some bacteria shoot out tendrils that conduct electricity. Researchers have determined the structure of one variety of bacterial nanowire, and found the wires are distinct from common bacterial hairs that they closely resemble.

The results will help scientists understand how bacteria build up or break down minerals, and help researchers harness the bacteria to make microbial fuel cells, batteries, or to turn waste into electricity.

Appearing online at the Proceedings of the National Academy of Sciences Early Edition, the work was led by Moh El-Naggar at the University of Southern California. Contributors included researchers from the Department of Energy’s Pacific Northwest National Laboratory, Penn State, the University of Wisconsin-Milwaukee and Renssalaer Polytechnic Institute.

To determine what the nanowires are made of, researchers used genetics and molecular biology to narrow down the proteins involved. They found that rather than the expected bacterial hair proteins, the nanowires comprised specialized proteins called cytochromes that shuttle electrons. PNNL researchers helped make the cytochromes fluoresce in cells, allowing the team to show they are located in the wires.

Read more at USC’s Pressroom.

Tagged: nanowiresbacteriacytochromeselectricitybiologyscience

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18th October 2014

Photo with 70 notes

Foraminifera fossil (30x)
Christian Richer
Saran, France
Technique: Kohler Illumination

Foraminifera fossil (30x)

Christian Richer

Saran, France

Technique: Kohler Illumination

Tagged: Fossilimagingbiologyscience

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18th October 2014

Photo with 238 notes

The Evolution of Sleep: 700 Million Years of Melatonin (NY Times)
To explore the evolution of sleep, scientists at the European Molecular Biology Laboratory in Germany study the activity of genes involved in making melatonin and other sleep-related molecules. Over the past few years, they have compared the activity of these genes in vertebrates like us with their activity in a distantly related invertebrate — a marine worm called Platynereis dumerilii.
A highly-magnified view of young larva of the marine worm Platynereis dumerilii.  Credit Harald Hausen

The Evolution of Sleep: 700 Million Years of Melatonin (NY Times)

To explore the evolution of sleep, scientists at the European Molecular Biology Laboratory in Germany study the activity of genes involved in making melatonin and other sleep-related molecules. Over the past few years, they have compared the activity of these genes in vertebrates like us with their activity in a distantly related invertebrate — a marine worm called Platynereis dumerilii.

A highly-magnified view of young larva of the marine worm Platynereis dumerilii. Credit Harald Hausen

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