Thursday, May 1, 2014

Trusting Your Nose

Humans carry more secretion and sweat glands in their skin than any other primate, yet 70% of people lack a vomeronasal organ. Vomeronasal is a crescent-shaped bundle of neurons at the base of each nostril that allows a variety of species—from reptiles to nonprimate mammals—to pick up on pheromones. Still, scientists have continued to search for examples of pheromones that humans might sense.
Two strong pheromones are androstadienone (andro) and estratetraenol (estra). Men secrete andro in their sweat and semen, while estra is primarily found in female urine. Researchers have found hints that both trigger arousal in the opposite sex. Yet to be true pheromones, it is said that these chemicals must shape how people view different genders.
A study in the Chinese Academy of Sciences in Beijing split men and women into groups of 24 and then had them watch virtual simulations of a human figure walking. The head, pelvis, and major joints in each figure were replaced with moving dots. Patrons in prior studies had previously ranked the videos as being feminine or masculine.
In this study, three videos were shown. On the leftmost frame, a video was shown that included a female gauged as having a quintessential female strut. Patrons noticed a distinctive swagger in the “hip” dots and how they compared with the flat pace of the “male” prototype in a video shown in the right frame. An unbiased walk was featured in the middle frame of the video, but when the subjects inhaled andro or estra, they judged the walk as either more masculine or more feminine.
The results depended on the viewer’s sexuality. Heterosexual women and gay men perceived the gender- neutral stride as more masculine after smelling andro, whereas estra had no effect on them. In contrast, study leader and behavioral psychologist Wen Zhou, pointed out that smelling estra influenced heterosexual males, but not females, toward perceiving the walkers as more feminine. Gender judgments of the simulated figures shifted on average by 8% for heterosexual men and women as well as gay men. 
It's very interesting to see how influential smells can be, especially when it comes to sexual arousal. I feel as though i'm going to pay attention to smells more after reading about this study.
Posted by Samuel Ustayev (Group C)

Tuesday, April 29, 2014

Bacteria on the Skin

Our skin is filled with bacteria from head to toe. Arecent study suggests that the bacteria living on our skin may actually influence how quickly a wound may heal. These new discoveries may help treat patients with chronic wounds (cuts or lesions that just never seem to heal), which affect about 1 in 20 elderly people. Researchers from the University of Manchester Healing Foundation Center says “It’s our hope that these insights could help lead to better treatments to promote wound healing that are based on sound biology”. Chronic wounds are a serious problem because they may even lead to diabetes, poor blood circulation or even result in a person being confined to a bed or wheelchair. 

The findings of bacteria in the gut have made it clear that not all bacteria cause harm and diseases, some bacteria are very beneficial to our health. In their recent study, the researchers compared the skin bacteria from people who heal and don't heal with chronic wounds. The results showed many different bacterial families, which suggests that there must be a bacteria that causes wounds to refuse to heal. The researchers also conducted a series of studies on mice to figure out why some wounds heal while others do not. They found that mice who lacked a single gene had a completely different array of skin microbiota. This made some bacteria harmful and slowed the mice's healing process. Researchers conclude that  "Presumably, the mice's defect in the ability to identify bacteria means that they aren't able to mount the right type of response". 

After these studies, the researchers concluded that there has to be link between skin microbiome and how we heal. This may help discover more treatments for people with chronic wounds. 

Posted by Amber Vien (Group C)

Monday, April 28, 2014

Brain Trauma Linked to Homelessness in Males, New Study Shows

In a new study done by St. Michael’s Hospital, results showed that almost half of all homeless men who partook had suffered at least one traumatic brain injury in their life.  87% of those injuries occurred before the men lost their homes.  The study, led by Dr. Jane Topolovec-Vranic, who works in the hospital’s Neuroscience Research Program, was published in the journal CMAJ OPEN. 

The study showed that assaults were a major cause of the traumatic brain injuries (TBI’s for short), accounting for about 60%.  There were also other non-violent ways that the men received these injuries, such as sports and recreation, which made up 44% of the injuries as well as motor vehicle collisions and falls, which compiled 42% of the TBI’s.  The findings in this study suggest that such injuries could be a risk factor for becoming homeless, according to Topolovec-Vranic.  The doctor looked at data on 111 homeless men between the ages of 27-81.  They all were recruited from a downtown Toronto men’s homeless shelter.  Her findings also included 45% of these men experiencing a traumatic brain injury, and of these, 70% were injured during childhood or teenage years.  Interestingly enough, in men under 40 years old, falls from drug/alcohol blackouts were the most common cause of TBI.  In men over 40 years old, assault was the most common cause.

The article concluded by talking about the fact that a TBI could predispose someone to homelessness, and that this thought may challenge assumptions that homelessness is a conscious choice made by individuals in a given situation, or the result of their addictions or mental illnesses.  I think that this is a good question to ponder.  There are a number of reasons why a person may be in his or her situation, and who are we to judge them for how they are living their life at any given moment?

Posted by Taylor Schille (Group C)

Friday, April 25, 2014

Trillion Different Smells

The human nose can detect more than a trillion different scents.There had been a long-standing claim that people could detect 10,000 different scents. That estimate was way small. The new research suggests the real number is 10,000 times bigger. “We are visual animals, but this new report highlights humans’ superb sense of smell,” Noam Sobel told Science News. This neuroscientist at the Weizmann Institute of Science in Rehovot, Israel, did not work on the new study. Our sense of smell may be even more refined than sight or sound. People can see million different colors and hear about 340,000 tones, Leslie Vosshall, geneticist at Rockefeller University told Science News. She and her coworkers recruited 26 men and women to visit a lab and perform an experiment which involved a lot of sniffing. Each person completed 264 different smell tests. Each time, the volunteers sniffed a trio of vials. Two contained the same odor. A third differed. The participants had to identify which one wasn't like the others.
Scientist performing sniffing experiment 

Most odors in the real world contain a mix of molecules, each of which contributes some part of the final scent. Here, the scientists combined a selection of molecules to create the different scents. They chose various amounts from a group of 128 different chemicals to concoct the odors. People could generally tell the difference between two scents that had been made from two completely different groups of molecules. Most people could even tell the difference between scents that shared half of the same molecules. But as the scents’ number of shared ingredients increased, people found it harder to tell scents apart. No one in the study could tell the difference between two smells that shared 90 percent of the same molecules. Based on those results, the scientists estimate that the average person can identify about a trillion different smells, each made from 30 separate odor molecules. However, the most sensitive smeller in the group could probably identify many more, the scientists say. Someone with a relatively insensitive nose would probably detect only about 80 million, they now suspect. The study only used 128 odor molecules, far fewer than the number that exist in the real world.

Posted by Chelcie C.

Thursday, April 24, 2014

Predicting the next Flu Season

It happens every year; either you or someone you know gets the flu. And then it spreads. Suddenly every second person seems to be feeling sick, having passed their illness on to those around them. Wouldn’t it be great if we could predict which virus was causing the problem and tailor the flu vaccine to preemptively protect you? Up until recently this sort of prediction was done by humans who made logical guesses as to which strain of the virus was most likely to rear its ugly head.

A new paper by two computational biologists from the University of Columbia explains how they hope to change that. Their approach was to outline all the different families of the flu virus and create predictive models of their potency and compare their genetic drift. Using this model they were able to predict with 93 percent accuracy which families will be the most widespread in the upcoming year. As the article in Popular Mechanics explains this is not a cure for the flu, nor does it solve problems of unknown mutations appearing in variants of the virus, however it does help to improve the vaccine and increase its effectiveness.

While mutations in flu viruses certainly pose a problem, knowing which family to target should be more effective as similar strains are still vulnerable to the same vaccine. The biggest challenge with new mutations is when they affect the shell proteins of the virus, allowing them to hide within an organism that doesn’t recognize their markings. This too is taken into account by the model as certain families of viruses are more likely to mutate in this way compared to others.

Nonetheless there is still a long way to go with the model. It demonstrates a strong proof of concept, especially considering how volatile the real world can be, but it still fell short in a number of areas. Particularly in estimating the seasonal decline of a flu family, where it was only correct three out of four times. This new model for predicting the strength and likelihood of a particular virus is an exciting new tool for scientists as they continue to fight against seasonal outbreaks.

Posted by: Kirk MacKinnon (B)

Wednesday, April 23, 2014

Gene Therapy, A New Door for Neurological Conditions

Hearing loss is the third most common health problem in the United States with increasing rate. To the date, there are at least 36 million Americans reported lost hearing according to WebMD.
Patients who suffer from hearing loss usually wear a hearing aid or have cochlear implant. Hearing aids amplify sounds so that damaged ears can detect them. Comparing to hearing aids, cochlear implant is very different and much more powerful. A cochlear implant is a complex electronic device that can help to provide a sense of sound to patients who are profoundly deaf. It consists of an external portion and an internal portion. The external part is where a microphone and a speech processor are located right above the ear. The microphone can pick up sound and send to the speech process, which selects and arranges the sounds. Signals of the sounds then were passed to the stimulator of the internal part and were converted into electric impulses. Another part of the internal part, electrode array, collects the impulses from stimulator to its position in the cochlear and sends the impulses to the auditory nerve.

 According to ScienceDaily, researchers at University of New South Wales, Australia have successfully regrew auditory nerves by delivering electrical pulses from a cochlear implant to deliver gene therapy. The principle behind this method is using electrical pulses delivered from the cochlear implant to deliver the DNA to the cells close to the array of implanted electrodes. And then these cells produce neurotrophins. After a couple months the neurotrophins were generated, the hearing nerve maybe maintained by ongoing neural activity made by the cochlear implant.

This result is an important breakthrough of gene therapy for possible treating different kinds of neurological disorders, such as Alzheimer’s disease, Parkinson’s and other psychiatric conditions. With advanced technology nowadays, it seems that we are able to cure devastating disorders in the soon future.

Posted by Yim Hui (B)

News About the Y Chromosome

Humans have 23 pairs of chromosomes, but only one pair determines our sex: the X and Y chromosome. The Y-chromosome differentiates between male and females; males have the Y-chromosome, females do not. However, this may not have always been the case. The Y-chromosome is substantially smaller than the X-chromosome, in terms of base pairs and functional genes. The Y-chromosome has about two hundred functional genes, while the X-chromosome has over a thousand genes.

A recently study conducted by a team of scientist composed of Henrik Kaessmann, Associate Professor at the CIG (UNIL) and group leader at the SIB Swiss Institute of Bioinformatics, and their collaborators in Australia released findings that the X and Y chromosomes were once identical and around 180 million years ago the Y chromosome began to lose non-essential genes and became unique to eutherian males. They compared the three types of mammals; egg-laying mammals such as the platypus, marsupials like the opossum, and eutherians, which include humans. They sequenced DNA from non-determining chromosome in both platypuses and opossums, and sex-determining chromosomes in eutherian mammals and found the Y-chromosome splits about 180 million years back. Through evolution, elements common between the X and Y chromosomes, not related to sex, became functionless and lost in the Y chromosome. This caused the chromosome to shrink and made it the sole factor in determining sex in eutherian mammals. The scientist predict that, at its current rate of evolution, the Y-chromosome might eventual disappear completely. However, this wouldn’t be the end of males..They predict another split would have to occur in order to maintain sex determination.

The Y sex-chromosome evolved from the X non-sex-determining chromosome. The SRY gene, found on the Y chromosome, is one of the major genes responsible for the development of testes. Its expression is present in both platypuses and eutherians. This is one of the essential elements that survived the split and was a useful gene in tracing the split between chromosomes.

Posted by 
Maxwell Liner (B)

High CO2 Affects the Growing Season of Plants

Plants respond to their outside environment much more than people usually think. Day to day they can modulate a variety of variables from their leaf shape to the angle at which their stem is bent. Over the course of the year however much more is modulated, changing enough about the behavior of the plant to distinguish a discrete "Growing Season" during spring and summer and relative hibernation in the other half of the year. These changes are controlled by a variety of signals, but a paper published in Nature describes the significant effect that increasing CO2 levels have on the growing season.

Elevated CO2 levels have been attributed with a slight lengthening of the growing season already, and the experiment detailed in this paper hopes to determine what the growing season will look like in the future. Since a lot of water is lost by plants during CO2 uptake, increased CO2 concentrations allow the plants to lose less water per unit of CO2 taken in. Desiccation is a major threat to plants, so they will be more effective at growing as well as growing for longer. In plots of plants with raised CO2 levels, growing season was lengthened by 6.2 days. However, growing season is controlled by more than CO2 levels. The other main factor is temperature, and when the experimenters changed this as well the plot growing season lengthened by 14.2 days. Since temperatures are poised to rise as well as CO2 levels, this is an important metric.

While increased growing season may sound like a good thing at first, it can have very disruptive effects on the distribution and biodiversity of an area. In areas where freezing resistance is important, disruption of growing season can mean plants stay vulnerable for too long and end up taking freezing damage. Drastic changes in competitive advantage mean some plants will outcompete others quickly, decreasing biodiversity and increasing ecosystem fragility later.

-Stephen O'Brien

The Power of Space!

You and I usually don’t think much of our pee, we just dispose of it in a toilet (or wherever nature calls in a boy’s case) and let the sewers deal with it. but astronauts on the International Space Stations are seeing it as a bit more valuable than most. To date, it costs NASA about $33,000 per kilogram to launch materials into low-Earth orbit (LEO) or to be able to reach the International Space Station; but the final frontier does not end in LEO, and the amount of money it would cost to get materials outside of Earth’s orbit would reach staggering amounts.
Turning to urine is one the the possible solutions to the problem, made mostly of water, urine can be reclaimed for nutrients and also electrical power. Water from urine is currently recovered at a rate of 75%, but with the efforts now underway, recovery rate could increase to 85% by next year, and eventually 100%. Crews on extended space missions recycle the water used, the biggest source being from their urine, an individual astronaut producing more than 1.5 liters per day, making up 81% of the space stations waste-water. Urea, the nitrogen rich compound found in urine, is currently disposed of on space stations, but can be converted into ammonia and inserted into a fuel cell producing a small charge. Urea is produced through the process of osmosis, separating the molecules of water and urea as well as other small dissolved molecules. The resulting solution containing urea, is put through a device called a bioreactor, which contains charcoal soaked with urease, an enzyme that breaks down urea.
About 86% of that solution is actually converted into ammonia, which is packed into a battery like fuel cell, and can convert the ammonia into nitrogen and water, emitting power. The power emitted is not much, about 0.2 volts, and a current of 2 milliamps, but again there is room for improvement.  This small output places skepticism on the project, or so believes Layne Carter, a systems engineer at NASA’s Marshall Space Flight Center in Huntsville, Alabama, “the limited amount of power that might be harvested from the team’s new process might not recoup the effort or expense.” So the question remains, is all this effort really worth drinking your own pee?

Posted By Thomas Flores (11)