Category Archives: Students

Items for students and others, interested in learning about science and engineering and the application of science in our lives. We post many of the general interest items here.

Curious Platypus Genome is No Surprise

Platypus Genome Found Fittingly Strange by Rick Weiss

a team of scientists has determined the platypus’s entire genetic code. And right down to its DNA, it turns out, the animal continues to strain credulity, bearing genetic modules that are in turn mammalian, reptilian and avian.

There are genes for egg laying — evidence of its reptilian roots. Genes for making milk, which the platypus does in mammalian style despite not having nipples. Genes for making snake venom, which the animal stores in its legs. And there are five times as many sex-determining chromosomes as scientists know what to do with.

“It’s such a wacky organism,” said Richard Wilson, director of the Genome Sequencing Center at Washington University in St. Louis, who with colleague Wesley Warren led the two-year effort, described today in the journal Nature.

Yet in its wackiness, Wilson said, the platypus genome offers an unprecedented glimpse of how evolution made its first stabs at producing mammals. It tells the tale of how early mammals learned to nurse their young; how they matched poisonous snakes at their venomous game; and how they struggled to build a system of fertilization and gestation that would eventually, through relatives that took a different tack, give rise to the first humans.

“As we learn more about things like platypuses,” Wilson said, “we also learn more about ourselves and where we came from and how we work.”

Very cool stuff. Related: Platypus genome explains animal’s peculiar features; holds clues to evolution of mammals – Platypus genome mapping boon for human and livestock researchers – Platypus genetic code unravelled – Weird Creatures – Evolution is Fundamental to Science – Long-Eared Jerboa – Cat Joins Exclusive Genome Club – Your Inner Fish

Elephants Classify Human Ethnic Groups that Hunt Them by Odor

Wash Your Clothes: Elephants Can Smell You a Mile Away

…in Amboseli National Park in Kenya. Elephants in the region encounter different ethnic groups, including the Maasai, whose young men spear elephants, and the Kamba, agricultural villagers who pose no threat at all.

The researchers observed elephants exposed to the scent from identical cloth garments, some worn by Maasai men, others by Kamba men and some that were unworn. The Maasai scent produced the strongest reactions, with elephants moving farther and faster to distance themselves from the odor source, often not stopping until reaching tall grass. The elephants also took far longer to calm down than those exposed to scents from the Kamba and unworn cloths.

Pioneers of the Pacific

how could a Neolithic people with simple canoes and no navigation gear manage to find, let alone colonize, hundreds of far-flung island specks scattered across an ocean that spans nearly a third of the globe?

Answers have been slow in coming. But now a startling archaeological find on the island of Ã‰fatÃ©, in the Pacific nation of Vanuatu, has revealed an ancient seafaring people, the distant ancestors of today’s Polynesians, taking their first steps into the unknown. The discoveries there have also opened a window into the shadowy world of those early voyagers.
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While the Lapita left a glorious legacy, they also left precious few clues about themselves. What little is known or surmised about them has been pieced together from fragments of pottery, animal bones, obsidian flakes, and such oblique sources as comparative linguistics and geochemistry. Although their voyages can be traced back to the northern islands of Papua New Guinea, their language—variants of which are still spoken across the Pacific—came from Taiwan. And their peculiar style of pottery decoration, created by pressing a carved stamp into the clay, probably had its roots in the northern Philippines.

Breastfeeding Linked to More Intelligent Kids

McGill study links breastfeeding to increased intelligence

The largest randomized study of breastfeeding ever (14,000 children for 6.5 years) conducted reports that breastfeeding raises children’s IQs and improves their academic performance, a McGill researcher and his team have found.

“Our study provides the strongest evidence to date that prolonged and exclusive breastfeeding makes kids smarter,” said Kramer, a Professor of Pediatrics and of Epidemiology & Biostatistics in the McGill University Faculty of Medicine and lead investigator in the study.

Kramer and his colleagues evaluated the children in 31 Belarusian hospitals and clinics. Half the mothers were exposed to an intervention that encouraged prolonged and exclusive breastfeeding. The remaining half continued their usual maternity hospital and outpatient pediatric care and follow-up. This allowed the researchers to measure the effect of breastfeeding on the children’s cognitive development without the results being biased by differences in factors such as the mother’s intelligence or her way of interacting with her baby.

The children’s cognitive ability was assessed by IQ tests administered by the children’s pediatricians and by their teachers’ ratings of their academic performance in reading, writing, mathematics and other subjects. Both sets of measures were significantly higher in the group randomized to the breastfeeding promotion intervention.

“The effect of breastfeeding on brain development and intelligence has long been a popular and hotly debated topic,” says Dr. Kramer. “While most studies have been based on association, however, we can now make a causal inference between breastfeeding and intelligence – because of the randomized design of our study.”

Molecular Action May Help Keep Birds on Course

Four decades after scientists showed that migratory birds use Earth’s magnetic field to orient themselves during their seasonal journeys, researchers have at last found a molecular mechanism that may explain how they do it.

If the hypothesis is true, the planet’s magnetic field lines — which arch around Earth from north to south — may be plainly visible to birds, like the dashed line in the middle of a road.

The work, described online yesterday in the journal Nature, was conducted in a test tube and does not prove that birds actually use the mechanism. And researchers aligned with a competing model say they are not convinced.

But by identifying for the first time a molecule that reacts to very weak magnetic fields, the experiments prove the plausibility of a long-hypothesized method of avian navigation that has had a credibility problem because no one had ever found a molecule with the required sensitivity.

Fat Cell Count Set in Childhood

Fat cell number is set in childhood and stays constant in adulthood

As fat people have an abundance of fat tissue, the natural assumption is that fat people have more fat cells, or ‘adipocytes’. That’s only part of the story – it turns out that overweight and obese people not only have a surplus of fat cells, they have larger ones too.
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During adulthood, about 8% of fat cells die every year only to be replaced by new ones. As a result, adults have a constant number of fat cells, even those who lose masses of weight. Instead, it’s changes in the volume of fat cells that causes body weight to rise and fall.
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we couldn’t have a clearer indication of the importance of childhood as a window for preventing obesity and the chronic diseases affected by it – cancer, heart disease, diabetes and more.

The message is especially stark following the recent Foresight report, which estimated that if current trends are left unchecked, by 2050 a quarter of all UK children under the age of 16 will be obese. The knowledge that their fat cell count will then be set for life makes the cost of inaction even higher. Fortunately, it seems that the UK Government is taking appropriate steps and recently pledged over a third of a billion pounds on a concerted strategy to tackle childhood obesity.

Backyard Wildlife: Birds

photo of a bird

The last few days a bird like this one has been chasing a crow in my yard (unfortunately I have not been able to get an action picture of that). If you know what type of bird this is please add a comment.

When I see robins pecking away in the grass sometimes I see them get worms but my guess is they often are eating other stuff. I also see starlings feeding on my lawn. I found some online links that I quote below on what robins and starlings eat.

From the Yardener:

Next to beneficial insects, songbirds consume the most pest insects in your yard. Robins, blackbirds, flickers and starlings will eat a lot of webworms if they are in your lawn. Many seed-eating birds prey on caterpillars while raising their young. Encourage birds to settle in or near your yard and prey on fleas by offering them food, water, and shelter.

Cornell University: American Robin

The American Robin eats both fruit and invertebrates. Earthworms are important during the breeding season, but fruit is the main diet during winter. Robins eat different types of food depending on the time of day; they eat earthworms early in the day and more fruit later in the day.

History And Biology Of European Starlings In North America
Continue reading →

Colony Collapse Disorder Continues

1.1 Million Bee Colonies Dead This Year

The information provided here was generated by a survey conducted by the Apiary Inspectors of America. They took the survey in January and February this year, and in the process, gathered information from 18% of the colonies in the U.S.

The survey found that about 35% of all the colonies in the U.S. died last winter. Of those that died, 71% died of natural causes, 29% from symptoms that are suspect colony collapse disorder. Doing the math that comes to at least 10% of all the bees in the U.S. last year died of Colony Collapse Disorder.
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Considering all these factors, undue concern over IAPV detection is not warranted. While IAPV’s role in colony losses remains a priority in ongoing research, we do know that high levels of other common bee viruses, such as KBV, DWV, and ABPV, have also been linked with certain incidences of high colony mortality or decline in worker numbers. We also know that nearly all bee colonies are infected with at least one type of virus and that all these viruses are potentially pathogenic.

The research continues. As I have said before this is a great example of scientists in action trying to figure out what is happening.

Denzel Washington Marketing Science

Denzel Washington stressed the importance of illustrating to children that scientists are more important than entertainers.

Pauletta and Denzel Washington will presented two research scholarships at Mount Vernon High School in Denzel’s hometown of Mount Vernon, New York. The Pauletta and Denzel Washington Family Scholar in Neuroscience Awards have been given annually since 2004 by the Department of Neurosurgery at Cedars-Sinai Medical Center in Los Angeles. The program provides $2,500 in monthly support for a graduate-level researcher and $2,000 per month for an undergraduate. Recipients work during the summer months under the direction of renowned physicians, neurosurgeons and scientists, and prepare a scientific abstract or paper to submit to a national neuroscience, cancer or neurosurgery organization.

In addition to lending their name to the scholarships, the Washingtons take an active role in the program, meeting with applicants and announcing the annual awards. The scholarships are awarded in a different city each year to increase awareness of neuroscience research and encourage students from many geographic locations to apply. The Washingtons said they hope the Mount Vernon setting will persuade students from Denzel’s hometown to consider careers in the sciences because they offer the potential to change the world.

Yes I do see the irony of including a post on a celebrity saying we need to focus more on scientists and less on entertainers.

Vanishing Giant Nests of Yellow-jackets

Giant wasp nest

Vanishing Nests

Only a year ago, an Auburn University research entomologist encountered a phenomenon that beggared description – 16 super-sized yellow jacket nests throughout central and south Alabama.

By the end of the summer, the number of reported nests increased to more than 80. Auburn researcher Dr. Charles Ray speculates there probably were hundreds more undetected nests throughout the state. One nest collector spotted 10 of these nests in Lowndes County alone, while an Alabama Cooperative Extension System agent in Covington County reported as many as 25 nests.

Why were these gigantic nests considered such oddities? Because entomologists such as Ray could go an entire career without seeing scarcely one of these huge nests. This year, though, the nests seem to have vanished as quickly as dissipating clouds. Working closely with Alabama Extension agents and other monitors throughout the state, Ray hasn’t turned up so much as one nest this year.

“The summer of 2006 may prove to be a once in a lifetime opportunity,” say Ray, who considers the discovery of the nests one of the high points of his career. So what accounts for this once in a lifetime occurrence? Ray speculates it had to do with an unusually mild 2006 winter. “The mid-20s was about as cold as it got that year – only about a day or two of really cold weather,” says Ray, adding that this extremely mild winter probably established optimal conditions for the yellow jackets the following spring.