Another perceptive in DNA expressing

Now there is one of the biggest challenges currently facing the fields of genomics and genetics, which Scientists from Australia and the United States bring into our concept of the three-dimensional structure of the genome.

DNA, roughly 3 metres is tightly folded into the nucleus of every cell in our body. This folding facilitates some genes to be ‘expressed’, or activated, while excluding others.

Genes consist of ‘exons’ and ‘introns’ the former being the sequences that code for protein and are expressed, and the latter being stretches of noncoding DNA in-between. As the genes are copied, or ‘transcribed’, from DNA into RNA, the intron sequences are cut or ‘spliced’ out and the remaining exons are strung together to form a sequence that encodes a protein. Depending on which exons are strung together, the same gene can generate different proteins.

Referring vast amounts of data from the ENCODE project*, Dr Tim Mercer and colleagues have examined the folding of the genome, finding that even within a gene, selected exons are easily exposed.

There will be new device to detect disease with drop of blood

Professor Eginald Farrow and his partners’ cutting-edge work with carbon nanotubes is the fore path to a new device, a prototype lab-on-a-chip that would someday enable a physician to detect disease or virus from just one drop of liquid, including blood.

The article entitled “Scalable nano-bioprobes with sub-cellular resolution for cell detection” will publish on July 15, 2013 but is available now online, describes how NJIT research professors Reginald Farrow and Alokik Kanwal, his former postdoctoral fellow, and their team have created a carbon nanotube-based device to noninvasively and quickly detect mobile single cells with the potential to maintain a high degree of spatial resolution.

In the article, the NJIT researchers evaluated three different types of cells using three different electrical probes. "It was an exploratory study and we don't want to say that we have a signature," Farrow added. "What we do say here is that these cells differ based on electrical properties. Establishing a signature, however, will take time, although we know that the distribution of electrical charges in a healthy cell changes markedly when it becomes sick."

Two Mutations produced an Evolutionary Leap 500 Million Years Ago

In a feat of "molecular time travel" the researchers resurrected and analyzed the functions of the ancestors of genes that play key roles in modern human reproduction, development, immunity and cancer. By re-creating the same DNA changes that occurred during those genes' ancient history, the team showed that two mutations set the stage for hormones like estrogen, testosterone and cortisol to take on their crucial present-day roles.

"Changes in just two letters of the genetic code in our deep evolutionary past caused a massive shift in the function of one protein and set in motion the evolution of our present-day hormonal and reproductive systems," said Joe Thornton, PhD, professor of human genetics and ecology & evolution at the University of Chicago, who led the study.

"If those two mutations had not happened, our bodies today would have to use different mechanisms to regulate pregnancy, libido, the response to stress, kidney function, inflammation, and the development of male and female characteristics at puberty," Thornton said.

The findings were published online June 24 in the Proceedings of the National Academy of Sciences.

Understanding how the genetic code of a protein determines its functions would allow biochemists to better design drugs and predict the effects of mutations on disease. Thornton said the discovery shows how evolutionary analysis of proteins' histories can advance this goal, Before the group's work, it was not previously known how the various steroid receptors in modern species distinguish estrogens from other hormones.

The team, which included researchers from the University of Oregon, Emory University and the Scripps Research Institute, studied the evolution of a family of proteins called steroid hormone receptors, which mediate the effects of hormones on reproduction, development and physiology. Without receptor proteins, these hormones cannot affect the body's cells.

Thornton's group traced how the ancestor of the entire receptor family -- which recognized only estrogens -- evolved into descendant proteins capable of recognizing other steroid hormones, such as testosterone, progesterone and the stress hormone cortisol.

To do so, the group used a gene "resurrection" strategy. They first inferred the genetic sequences of ancient receptor proteins, using computational methods to work their way back up the tree of life from a database of hundreds of present-day receptor sequences. They then biochemically synthesized these ancient DNA sequences and used molecular assays to determine the receptors' sensitivity to various hormones.
Thornton's team narrowed down the time range during which the capacity to recognize non-estrogen steroids evolved, to a period about 500 million years ago, before the dawn of vertebrate animals on Earth. They then identified the most important mutations that occurred during that interval by introducing them into the reconstructed ancestral proteins. By measuring how the mutations affected the receptor's structure and function, the team could re-create ancient molecular evolution in the laboratory.

They found that just two changes in the ancient receptor's gene sequence caused a 70,000-fold shift in preference away from estrogens toward other steroid hormones. The researchers also used biophysical techniques to identify the precise atomic-level mechanisms by which the mutations affected the protein's functions. Although only a few atoms in the protein were changed, this radically rewired the network of interactions between the receptor and the hormone, leading to a massive change in function.

"Our findings show that new molecular functions can evolve by sudden large leaps due to a few tiny changes in the genetic code," Thornton said. He pointed out that, along with the two key changes in the receptor, additional mutations, the precise effects of which are not yet known, were necessary for the full effects of hormone signaling on the body to evolve.

via DailyScience 

Puya chilensis

Puya chilensis is a kind of plant in very large bromeliad, native to the mountains of Chile. Bromeliads are spiky, mostly tropical, commonly New-World plants, the best-known of which is probably the pineapple. But while the pineapple is delicious, Puya chilensis is a bit more harmful.

Most bromeliads have firm, hard leaves, but Puya chilensis is sort of an extreme sample. Its leaves look sort of like aloe leaves, but in between them are huge, sharp spines that jut out past them. Most plants that have spines, like cacti, use them for protection, but it's theorized that Puya chilensis actually uses them for hunting.

This plant is sometimes known as a "sheep-eating" plant, which is not, strictly speaking, accurate: it is not a carnivorous plant like the well-known pitcher plant or Venus flytrap, as it doesn't actually digest animal matter. Instead, scientists believe that the spikes trap animals with thick fur, like sheep, which then starve to death, fall to the ground, and decompose at the base of the plant, providing highly rich, localized food for the plant. It's gruesome as hell.

It's not a particularly rare plant; it's in the news now because for the first time, horticulturists in England have coaxed it to bloom, 15 years after planting it. They've been feeding it liquid fertilizer, because, says one of the horticulturists, "feeding it on its natural diet might prove a bit problematic.

Brain drain and brain circulation

According to an article, a brain drain or human capital flight is an emigration of trained and talented individuals ("human capital") to other nations or jurisdictions, due to conflicts, lack of opportunity, health hazards where they are living or other reasons. Spokesmen for the Royal Society of London coined the expression “brain drain” to describe the outflow of scientists and technologists to Canada and the United States in the early 1950s. Its counterpart is brain gain in the areas to which talent migrates. Brain drain can occur either when individuals who study abroad and complete their education do not return to their home country, or when individuals educated in their home country emigrate for higher wages or better opportunities. This phenomenon is perhaps most problematic for developing nations, where it is widespread. In these countries, higher education and professional certification are often viewed as the surest path to escape from a troubled economy or difficult political situation. Brain drain can be described as “soft brain drain” which is the non-availability of research results from a country where the study was carried out. This could be due to a publication of the findings in an international journal to which health practitioners from the study country have little access. This is different from the physical movement of persons from the developing countries to northern nations “hard brain drain2”. 

In the article published in Perspective, the author looked into the problem of brain drain and showed what caused it and how to avoid and improve it. It had been included into database of oalib: http://goo.gl/58bnF.

Oalib

Oalib, a simple tool to search for relating academic articles according to titles, abstracts, publication dates, authors, areas, journals and other clues, is now striving to create more service to meet the users’ need when they are using it.
It collects about 994,092 articles until now and all these articles are included in the database of oalib in the way of collaboration with well known publishers in the world and searching information on the internet, for example getting academic information on the base of google. Although it is not a perfect system containing multifunction such as searching academic information, intellectually alerting new outcomes, recording browsing history and so on, it is trying to provide a simplest way to search for articles generally in all disciplines, with no limitations.

A lot of colleges and universities have added oalib to its electronic academic resources for students. Anyone on the internet will enter to the database of oalib via one gate(http:\\www.oalib.com) Whether he or she get access through web links on the page of libraries or the entries which institutions create.

Oalib has its own facebook:
https://www.facebook.com/pages/Open-Access-Library/478189765581841


Users, authors or anyone can participate in it, talking about topics, communicating with someone that we have never met, sharing information with each other. Come on, enjoy it.

Home messages affect fluency of speaking another language

Sometimes there are moments when people blurt out homeland languages while they are speaking with foreigners using foreign languages. Why they happen make people confused.

Shu Zhang, a Chinese native, teamed up with Columbia social psychologist Michael Morris and colleagues to figure out the problem. In a new study, they show that reminders of one’s homeland can hinder the ability to speak a new language. The findings could help explain why cultural immersion is the most effective way to learn a foreign tongue and why immigrants who settle within an ethnic enclave acculturate more slowly than those who surround themselves with friends from their new country.

Previous studies have shown that cultural icons such as landmarks and celebrities act like “magnets of meaning,” instantly activating a web of cultural associations in the mind and influencing our judgments and behavior, Morris says. In an earlier study, for example, he asked Chinese Americans to explain what was happening in a photograph of several fish, in which one fish swam slightly ahead of the others. Subjects first shown Chinese symbols, such as the Great Wall or a dragon, interpreted the fish as being chased. But individuals primed with American images of Marilyn Monroe or Superman, in contrast, tended to interpret the outlying fish as leading the others. This internally driven motivation is more typical of individualistic American values, some social psychologists say, whereas the more externally driven explanation of being pursued is more typical of Chinese culture.

Understanding how these subtle cultural cues affect language fluency could help employers design better job interviews, Morris says. For example, taking a Japanese job candidate out for sushi, although a well-meaning gesture, might not be the best way to help them shine.

“It’s quite striking that these effects were so robust,” says Mary Helen Immordino-Yang, a developmental psychologist at the University of Southern California in Los Angeles. They show that “we’re exquisitely attuned to cultural context,” she says, and that “even subtle cues like the ethnicity of the person we’re talking to” can affect language processing. The take-home message? “If one wants to acculturate rapidly, don’t move to an ethnic enclave neighborhood where you’ll be surrounded by people like yourself,” Morris says. Sometimes, a familiar face is the last thing you need to see.