Biologists propose to sequence the DNA of all life on Earth“The entire eukaryotic effort would likely cost about the same as it did to sequence that first human genome, estimate Lewin, Robinson, and EBP co-organizer John Kress, an evolutionary biologist at the Smithsonian National Museum of Natural History here. It took about $2.7 billion to read and order the 3 billion bases composing the human genome, about $4.8 billion in today’s dollars. With a comparable amount of support, the EBP’s eukaryotic work might be done in a decade, its organizers suggest.”
Bumble bees are surprisingly innovative“Bumble bees have already proven themselves remarkable animals. They possess complex navigational skills, rudimentary culture, and emotions. They can even use tools: Scientists have shown that the insects can learn to pull a string—and so get a sugary reward—by watching another bee perform the task. Although bees don’t pull strings in the wild, they do sometimes pull or push aside flower petals and parts that may resemble strings.”“This flexibility could help bumble bees in the wild, which face widespread population declines. “It suggests that bees may be able to respond quickly to novel problems that arise in their environment,” such as the introduction of new flowering plants and the loss of familiar ones, says Daniel Papaj, an evolutionary biologist at the University of Arizona in Tucson.”“Most importantly for the study’s researchers, “It puts the final nail in the coffin of the idea that small brains constrain insects’” cognitive abilities, says co-author Lars Chittka, a behavioral ecologist also at Queen Mary University of London. There’s more going on beneath that exoskeleton than we think.”
Herpes virus may be a trigger for autismThere are a number of known viral antibodies that are known to damage a fetus including Cytomegalovirus, Toxoplasma gondii, rubella, HSV-1, and HSV-2. Only HSV-2 was discussed to be correlated to the development of ASD and we do not know why the other antibodies did not induce similar effects. This however, is only a correlation, not causation as being an HSV-2 carrier is not determinate of the child developing ASD.“In the new paper, the researchers posit that a subgroup of women is genetically predisposed to develop intense immune responses to certain disease-causing organisms—like HSV-2—and that the inflammatory molecules and antibodies generated by the mother’s vigorous immune response cross the placenta and damage the fetal brain.”Unlike studies that suggest vaccines cause autism (coughcough Wakefield 1997) this article suggests that the new study examined the cause of the ASD development to be en utero and not post natal.
“What do our results imply about how the brain encodes an olfactory percept? We speculate that, for each molecular feature, there must be some quantitative mapping, possibly one to many, between the magnitude of that feature and the spatiotemporal pattern and activation magnitude of the associated olfactory receptors. If features rarely or never interact to produce perception, as suggested by the strong relative performance of linear models in this challenge, then these feature-specific patterns must sum linearly at the perceptual stage (19). Peripheral events in the olfactory sensory epithelium, including receptor binding and sensory neuron firing rates might have nonlinearities, but the numerical representation of perceptual magnitude must be linear in these patterns. It is possible that stronger nonlinearity will be discovered when odor mixtures or the temporal dynamics of odor perception are investigated. Many questions regarding human olfaction remain that may be successfully addressed by applying this method to future data sets that include more specific descriptors; more molecules that represent different olfactory percepts than those studied here; and subjects of different genetic, cultural, and geographic backgrounds.”This is so cool! When I read these kind of articles though I wish I would’ve come up with the idea!
The Term, ‘Heart Strings’ Isn’t Just For Love Songs.
It turns out that we’ve all got Heart Strings, diligently strumming along inside our chests…and not the kind you hear about in poetry and song lyrics.
The Chordae Tendineae (tendinous chords), or heart strings, are cord-like tendons that connect the papillary muscles to the outer edges of the Tricuspid Valve and the Mitral Valve in the heart. Chordae tendineae are approximately 80% collagen, while the remaining 20% is made up of elastin and endothelial cells.
During atrial systole (contraction of the atria), blood flows from the atria to the ventricles down the pressure gradient. The chordae tendineae are relaxed because the atrioventricular valves are forced open.
When the ventricles of the heart contract in ventricular systole, the increased blood pressures in both chambers push the AV valves to close simultaneously, preventing backflow of blood into the atria. Since the blood pressure in atria is much lower than that in the ventricles, the flaps attempt to evert to the low pressure regions. The chordae tendineae prevent this eversion by becoming tense thus pulling the flaps, holding them in closed position.
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