journal club
grrlscientist | August 7, 2007tags: researchblogging.org, coffee, memory, cognition, women, aging
Recent research has shown that women older than 65 years old who drink more than three cups of coffee per day were protected from some types of age-related memory declines.
"The more coffee one drank, the better the effects seemed to be on (women's) memory functioning in particular," reported Karen Ritchie, epidemiological and clinical researcher at La Colombiere Hospital and at the French National Institute of Medical Research (INSERM), in Montpellier, France.
To do this research, the researchers studied more than 4,197…
grrlscientist | August 1, 2007tags: researchblogging.org, white-crowned sparrow, Zonotrichia leucophrys, steroids, brain growth
White-crowned sparrow, Zonotrichia leucophrys [song and other information].
Image: Birds of Oklahoma.
The first thing that most people think of when they hear the word "steroids" is baseball players who rely on these chemicals to increase their muscle mass and thereby improve their athletic performance. But recently, a small songbird that I studied for my dissertation work, Gambel's white-crowned sparrow, Zonotrichia leucophrys gambelii, has shown scientists that steroids trigger the growth…
grrlscientist | July 27, 2007tags: researchblogging.org, animals, predict death, Oscar the cat, New England Journal of Medicine
Oscar the cat provides comfort to the dying.
According to an article that was just published in the New England Journal of Medicine, a two-year-old cat that lives in Steere House Nursing and Rehabilitation Center in Providence, Rhode Island, can correctly predict impending death among the residents. Oscar the cat has a habit of curling up next to patients who are in their final hours, and so far, he has been observed to be correct in 25 cases.
"He doesn't make many mistakes. He seems to…
grrlscientist | July 18, 2007tags: researchblogging.org, flight speed, birds, ornithology, aerodynamics, evolution
Not Bad, But Not Perfect
A peregrine falcon keeps a close eye as she circles her nest in St. Louis.
A new survey of 138 species of birds finds that closely-related birds fly at roughly the same speeds and that no birds are perfect flying specimens.
Image: Tom Gannam (AP) [larger]
When it comes to flight speeds, human-made contraptions, such as airplanes, conform to basic aerodynamic scaling rules, which generate predictions based on how much an object weighs and how large its wings are. However, those…
grrlscientist | July 17, 2007tags: researchblogging.org, birds, ornithology, evolution, radiation, Chernobyl
Normal Barn Swallow (a),
while the other pictures show signs of albinism (white feathers; b & c),
unusually colored feathers (d), deformed beaks (e & f), deformed air sacs (g),
and bent tail feathers (h & i).
Images: Tim Mousseau.
Twenty years after the Chernobyl reactor disaster, which released clouds of radioactive particles in April 1986, the uninhabited forests within the 19 mile (30 kilometer) "exclusion zone" around the disaster site are lush and teeming with wildlife, giving the appearance…
grrlscientist | July 16, 2007
A male Blue Moon or Great Eggfly butterfly, Hypolimnas bolina.
A butterfly-killing bacteria that is only lethal to males has given rise to skewed sex ratios in populations of this species on two islands in the South Pacific, but researchers have found that male butterflies on one island have bounced back, thanks to the rise of a suppressor gene. [larger].
In a dramatic demonstration of how quickly evolution can occur, a butterfly species that is found on two adjacent islands in the South Pacific Ocean has rapidly evolved genetic defenses against a bacterial parasite that is lethal only…
grrlscientist | June 20, 2007tags: researchblogging.org, superb starling, Spreo superbus, Lamprotornis superbus, birds, behavior, infidelity
Superb starling, Lamprotornis (Spreo) superbus.
These small birds are commonly found in open woodlands and savannahs throughout Northeast Africa.
Image: Hogle Zoo, Utah.
While it is widely known that males of many species seek out extra-pair copulations in order to produce as many offspring as possible, the reasons for female "infidelity" are much more complex. For example, a study was recently published that showed how a bird species uses sexual politics to ensure maximal…
grrlscientist | June 15, 2007tags: researchblogging.org, global warming, climate change, ornithology, birds, avian biodiversity, habitat destruction
White-crested hornbill, Tropicranus albocristatus, also confined to African rainforests, may see more than half of its geographic range lost by 2100.
Image: Walter Jetz, UCSD. [larger]
Thanks to the combined effects of global warming and habitat destruction, bird populations will experience significant declines and extinctions over the next century, according to a study conducted by ecologists at the University of California, San Diego and Princeton University. This…
grrlscientist | June 13, 2007tags: researchblogging.org, dinosaur, bird, fossil, Gigantoraptor erlianensis, China
An artist's painting of the newly discovered Gigantoraptor dinosaur, depicted with other smaller dinosaurs. Fossilized bones uncovered in the Erlian Basin of northern China's Inner Mongolia region show the Gigantoraptor erlianensis was about 26 feet in length and weighed 3,000 pounds. The discovery of the giant, birdlike dinosaur indicates a more complicated evolutionary process for birds than originally thought.
Image: Institute of Vertebrate Paleontology & Paleoanthropology (Beijing, China) [larger…
grrlscientist | June 7, 2007tags: researchblogging.org, archaeopteryx, dinosaurs, mammals, fossils
Archaeopteryx fossil showing the distinctive head-back death pose of many articulated fossilized birds, dinosaurs and early mammals. Archaeopteryx is an ancient feathered dinosaur. This specimen is at the Humboldt Museum, Berlin. The skull is approximately two inches long.
If you've looked at the articulated 150-million-year-old Archaeopteryx fossils, you probably have noticed that they all have a weirdly similar pose; their heads are thrown over their backs, mouths open and tail curved upwards. Scientists have been…
grrlscientist | May 30, 2007tags: cheetahs, evolution
Researchers studied 47 litters of cheetah cubs over nine years. Nearly half contained cubs from multiple fathers.
Image: Sarah Durant [larger]
DNA technology has revealed that female cheetahs, Acinonyx jubatus, often produce litters that are comprised of cubs sired by multiple fathers. This research, recently published in the Proceedings of the Royal Society B, studied cheetahs found on that part of the Seregeti in the African nation, Tanzania.
"If the cubs are genetically more variable it may allow them to adapt and evolve to different circumstances," Dada…
grrlscientist | May 17, 2007tags: Antarctica, Weddell Sea, new species, ANDEEP, zoology
The scientists said an "astonishingly diverse" collection of isopods had been discovered. This young male isopod represents one of 674 isopod species found.
Image: W. Brokeland. [larger image]
According to a paper that was recently published, scientists have found more than 700 new species of marine creatures in seas surrounding Antarctica -- seas once thought too hostile to sustain such rich biodiversity. Fabulous creatures, such as carnivorous sponges, free-swimming worms, crustaceans and molluscs, were collected.
The…
grrlscientist | May 4, 2007tags: evolution, birds, orioles, Icterus, research
"Oriole."
Image appears here with the kind permission of the photographer, Pamela Wells.
[Larger image].
I often think about differences in morphological and behavioral traits in closely-related species and wonder whether the speed and character of changes in these traits reveal anything about the evolutionary relationships between taxa. For example, in birds, both visual and auditory cues, such as plumage and song patterns, are essential for identifying members of their own species. However, these phenomena have rarely been…
grrlscientist | May 4, 2007tags: Venus flytrap, plant, biology, mechanics
A Venus flytrap lies open, waiting for an insect to set off its trap. Lakshminarayanan Mahadevan and colleagues have shown that the plant uses stored elastic energy to operate its hinged leaves.
Image: Yoel Forterre.
How does the venus flytrap accomplish what most people cannot? How does a mere plant capture live flies? The mystery of the Venus flytrap's rapid movement lies in storing and releasing elastic energy, says Lakshminarayanan Mahadevan, who is the Gordon McKay Professor of Applied Mathematics and Mechanics at Harvard University.…
grrlscientist | May 2, 2007tags: ducks, birds, phallus, vagina, evolution, reproduction
An interesting article was published today by a group led by Patricia Brennan in the open-access journal, PLoS One, about the structural co-evolution of duck phalluses and vaginas. What, you ask? Ducks have phalluses? Yes, indeed they do. Further, ducks are also famous for forced copulations -- as many as 30% of all copulations are forced -- so it only makes evolutionary sense that females have co-evolved a method for excluding sperm they don't want fertilizing their precious eggs.
This paper examines the reproductive and…
grrlscientist | April 25, 2007tags: Solomon Islands Frogmouth, Rigidipenna inexpectatus, Podargus ocellatus inexpectatus, birds, birding, ornithology
Gone are the days when animals were classified to taxon based solely on bone structure (osteology), body structure (morphometrics) or behavior (ethology), or some combination of these characters. Currently, scientists have a suite of powerful tools for classifying creatures to taxon, and analyses using a combination of these methods is allowing us to come to a deeper understanding of all animal life. As a result of using these techniques, a new species of bird has been…
grrlscientist | April 13, 2007tags: researchblogging.org, Tyrannosaurus rex, dinosaurs, birds, fossils
Repeated analysis of proteins from a fossilized Tyrannosaurus rex reveal new evidence of a link between dinosaurs and birds: Of the seven reconstructed protein sequences, three were closely related to chickens.
Image: NYTimes
It was once thought impossible to obtain actual soft tissue, such as proteins, from fossils, but the impossible has happened and now, two research teams who published reports in this week's Science describe their findings: the closest relative to the fearsome Tyrannosaurus rex is .. a chicken.…
grrlscientist | April 11, 2007tags: bipolar disorder, mania, manic mouse, psychiatric research
Some of you, like me, suffer from bipolar disorder or might know someone who does, so I thought I'd take this opportunity to write a little about the creation of a mouse model to study the genetics that are thought to underlie the manic phase of bipolar disorder -- a phase that has not been well understood so far.
Bipolar disorder, or manic-depressive illness, is a psychiatric condition that affects a person's moods. Typically, a person who suffers from a classical bipolar disorder (Also known as bipolar affective disorder,…
grrlscientist | April 10, 2007tags: dog breeds, IGF1, insulin-like growth factor 1, cancer, growth disorders
One gene mutation makes all the difference in body size between a big dog and a little dog.
Image: NY Times.
There are several things that I think are amazing about dogs, Canis familiaris. First, there is a huge discrepancy in body size between different breeds -- greater than for any other mammal, in fact, and second, these vastly different dog breeds still recognize each other as being of the same species. Yet, according to a recently published research paper, this huge differential in the body size of dogs…
grrlscientist | January 23, 2007tags: Microraptor gui, microraptor, biplane, bird flight, evolution
The ancestors of modern birds are thought to have been small, feathered, dinosaurs, the theropods. One of these small feathered dinosaurs is Microraptor gui, a feathered dromaosaur that lived 125 million years ago in what is now China. According to the evidence, Microraptor gui was one of the earliest gliders. But unlike modern birds, it appears to have utilized four wings, like a biplane, because it had long and asymmetric flight feathers on both its hands and feet.
According to initial interpretations, Microraptor flew…