Saturday, January 30, 2016
The Bluebottle or Portuguese Man of War
The Bluebottle or Portuguese Man of War is not a single animal but a colony of four kinds of highly modified individuals (zooids). The zooids are dependent on one another for survival. The float (pneumatophore) is a single individual and supports the rest of the colony. The tentacles (dactylozooids) are polyps concerned with the detection and capture of food and convey their prey to the digestive polyps (gastrozooids). Reproduction is carried out by the gonozooids, another type of polyp.
The float is a bottle or pear-shaped sac that can exceed 15 cm. It is mainly blue, though its upper margin may show delicate shades of green or pink. It is a living, muscular bag that secretes its own gas, which is similar to air. The float has aerodynamic properties and it seems likely that sailing characteristics may be modified by muscular contraction of the crest.
Know more:http://australianmuseum.net.au/bluebottle#sthash.0q5PADZl.dpuf
Photo credit: Matty Smith
Photo via HousingCamerahttp://www.housingcamera.com/blog/featured-photographers/weekly-featured-underwater-photographer-matthew-smith#.Vqm3Qbnn671
More of his work:http://www.mattysmithphoto.com/
Prehistoric violence among nomadic hunter-gatherer communities
A pregnant woman with her hands and feet bound. A man with an obsidian blade embedded in his skull. Men and women with arrow wounds to the head and neck.
That’s the grisly scene archaeologists describe at Nataruk, in modern-day Kenya, where they say they’ve uncovered unique evidence of violence in prehistoric, nomadic hunter-gatherer communities.
The massacre they’ve uncovered is striking, they say, because it pushes back against a theory that warfare didn’t become a feature of human culture until communities settled down.
Archaeologists from Cambridge University excavated the remains of 27 people, including at least eight women and six children, in a region that was once the edge of a lagoon, near modern-day Lake Turkana. The remains included 12 skeletons that were fairly complete, “preserved by the particular conditions of the lagoon,” the researchers write in Nature.
Source & further reading:http://www.npr.org/sections/thetwo-way/2016/01/21/463835225/discovery-of-ancient-massacre-suggests-war-predated-settlements
Paper:http://www.nature.com/articles/nature16477.epdf
That’s the grisly scene archaeologists describe at Nataruk, in modern-day Kenya, where they say they’ve uncovered unique evidence of violence in prehistoric, nomadic hunter-gatherer communities.
The massacre they’ve uncovered is striking, they say, because it pushes back against a theory that warfare didn’t become a feature of human culture until communities settled down.
Archaeologists from Cambridge University excavated the remains of 27 people, including at least eight women and six children, in a region that was once the edge of a lagoon, near modern-day Lake Turkana. The remains included 12 skeletons that were fairly complete, “preserved by the particular conditions of the lagoon,” the researchers write in Nature.
Source & further reading:http://www.npr.org/sections/thetwo-way/2016/01/21/463835225/discovery-of-ancient-massacre-suggests-war-predated-settlements
Paper:http://www.nature.com/articles/nature16477.epdf
Friday, January 29, 2016
Mom’s in control – even before you’re born
Researchers have uncovered previously unappreciated means by which epigenetic information contained in the egg influences the development of the placenta during pregnancy. The research, which was performed in mice, indicates that a mother’s health, even before conception, may influence the health of her fetus, and opens questions on how a mother’s age may influence placental development.
Epigenetic information is not encoded within the DNA sequence but is critical for determining which genes are on or off. One of the ways this is achieved is via DNA methylation, a biological process where the DNA is chemically tagged to silence genes. DNA methylation marks are laid down in each egg during their development in the ovaries and, after fertilization, some of these marks are passed onto the fetus and placenta.
In exploring the purpose of this maternal information in fetal development, focus so far has been on a small number of genes termed ‘imprinted genes’. However, there are nearly one thousand other genomic regions where methylation in the egg cell is passed onto the early embryo. The researchers set out to explore the importance of this type of methylation on the development of the placenta, a vital organ in pregnancy, and their findings are presented in the latest issue of the journal Developmental Cell.
Source & further reading:http://www.eurekalert.org/pub_releases/2016-01/bi-mic012116.php
Thursday, January 28, 2016
Film Studio Scorecard: How Much Diversity Is There at the Very Top? (Chart)
There are more
women than persons of color among the leading executives at the six majors.
This story first appeared in the
Feb. 5 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.
While the power structure is
different at each studio, THR has identified the production, marketing
and distribution heads most directly responsible for the creative decisions
that determine which movies get made. Hence, this chart excludes executives
from business affairs, legal, etc. Also not represented here are the ranks of
female and ethnically diverse EVPs and SVPs making waves, which means a future
census surely will be a more colorful affair.
The Hollywood Reporter by THR Staff 1/28/2016
5:55am PST
The physics of snowflakes
One could say that snowflakes are simply frozen water — but if you compare a snowflake to an ice cube, you’ll notice a big difference. Why are all snowflakes six-sided? Why are none of them exactly the same? And how do we ski on them?
Though we know that their shapes have to do with the many possible branching points in snowflake formation and the differences in temperature and humidity, it is true that no matter how hard you look, you’re almost definitely not going to find two identical snowflakes.
Watch & learn from TED-Ed Lesson :http://ed.ted.com/lessons/the-science-of-snowflakes-marusa-bradac
Animation: bottomless well films
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