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(11/09/12 12:48am)
This month marked the first phase culmination of “The 1,000 Genomes Project,” an extensive five-year study that sought to determine the gene sequences of 1,092 individuals. The project’s well-represented research team comprised of about 400 researchers from around the world including Aravinda Chakravarti, a member of the Institute of Genetic Medicine at the Hopkins School of Medicine.
(10/05/12 3:37am)
A recent study conducted at the Hopkins School of Medicine provides renewed optimism for the treatment of sickle cell disease. Researchers have demonstrated that bone marrow transplants only partially matched to a patient’s tissues can successfully eradicate the disease and the need for lifelong treatment.
(03/07/12 5:00am)
Ron Weasley's high-pitched squeals demonstrate all too well how the dire fear of spiders can manifest itself. Recent psychological research demonstrates that individuals who fear spiders tend to overestimate the size of these creatures and perceive them as physically larger than their actual size.
(02/29/12 5:00am)
The auditory system connects us to the outside world through sounds. Ranging from the musical tone of an orchestra performance to the annoying tapping noises your neighbor won't stop making in class, every sound is translated into the complex language neurons used to communicate. Hopkins researchers have recently discovered another explanation for why hearing loss can lead to everyday challenges. Their new study demonstrates that hearing loss increases one's risk of falling by nearly three times. The finding exposes a major public health concern that may potentially save the US billions of dollars in health care costs if addressed properly. In a normal ear, an external structure known as the pinna reflects sound waves in our surroundings and directs them to the auditory canal. The main function of the pinna is to help the brain determine the direction of the sound source. Once they reach the ear, sound waves travel through the auditory canal and eventually encounter the tympanic membrane, commonly known as the eardrum. Subsequently, the waves go through three bones - malleus, incus and stapes, that serve to increase the pressure of the waves. At a higher pressure, sound waves are able to transmit through the fluid, as they pass the oval window. At this point, the sound waves have already reached the inner ear, which consists of the cochlea and various vestibular system structures. The basilar membrane in the cochlea is arranged such that lower frequency sound waves travel further and stimulate hair cells closer to the apex of the membrane, while higher frequency sounds activate hair cells closer to the base. Stimulated hair cells depolarize, which means that there is an increase in intracellular voltage. The hair cells then transmit the signal to neurons that make up the auditory nerve, eventually leading to the temporal lobe in the brain. The temporal lobe is the cortical area primarily responsible for receiving and processing auditory stimuli. Deafness can occur when any point of this pathway is disrupted. In general, hearing loss can be separated into two categories: conductive hearing loss and sensorineural hearing loss. Conductive hearing impairment occurs when the sound wave is unable to reach the inner ear, often because of damage to the eardrum or to bones in the middle ear. Sensorineural hearing impairment occurs when the inner ear isn't functioning properly. Damage to hair cells, for example, is the most common cause of sensorineural hearing impariment. Patients subjected to hearing loss may have an increased risk of falling because they are less aware of their surroundings. Additionally, these patients can experience cognitive load, which occurs when the brain is overwhelmed by limited resources, such as reduced functioning of one of its senses. In the study, the researchers tested the hearing ability of 2,017 subjects between the ages of 40-69. The subjects were asked questions about their age, sex and demographic background. They were also asked to report the number of falls they had experienced within the past year. Upon analyzing the data, the researchers found that people suffering from mild hearing loss were nearly three times more likely to fall. Other factors known to cause falls, such as increased age and cardiovascular disease, were taken into account but did not affect the findings. Hearing loss is measured using a unit called the decibel. A mild hearing loss is characterized by a measure of 25-decibel. Subjects with 25-decibel hearing loss showed a threefold increase in falls. Each subsequent 10-decibel increase raised the chances of falling by another 1.4 fold. With such a high risk of falling, researchers are hoping to develop ways of securing the safety of patients subject to hearing loss. The study will hopefully inspire new methods of preventing falls and reducing subsequent injuries.
(02/22/12 5:00am)
Evolutionary biologists may as well ditch their books and race to Russia, where they can now observe the live-action speciation of a single-celled microbe population known as Sulfolobus islandicus. Speciation is the evolutionary process by which new species form, and in this case, it means that Sulfolobus islandicus is on its way to becoming two distinct, new species. Differentiating between species is a challenging business. In sexually reproducing organisms, a species is primarily defined by the ability of its members to mate with one another and exchange genetic information. For instance, humans and chimpanzees are considered two separate species because their members cannot produce viable offspring. Although evolution holds that these two species once shared a common ancestor, significant genetic differences now render them as separate. Classifying species becomes more tricky when one ventures into domains of life that reproduce asexually or by cloning. These species do not mate with other organisms in their population and are, therefore, difficult to distinguish from one other. Scientists classify asexual species using other criteria, including morphological (or structural) differences, behavior observation and DNA sequencing.Sulfolobus islandicus falls into this "difficult to classify" category because it belongs to the domain known as Archaea, whose organisms reproduce asexually. In addition to being asexual, archaeons are single-celled microbes that live in extreme environments. Scientists found Sulfolobus islandicus living on a Russian volcano, in a spring full of boiling, acidic water. Although they live in the same water, some organisms belonging to Sulfolobus islandicus began to show marked genetic changes, and scientists noticed that the shared portions of their genome were decreasing with time. This led them to believe that Sulfolobus islandicus is diverging into two species, which they termed the Red and Blue groups. The scientists concluded that the microbes were structurally identical. However, after observing the archeon behavior, they noticed that organisms belonging to the Blue group grew less rapidly than those in the Red and that Blue group's colonies were subsequently less dense. After collecting strains of Sulfolobus islandicus from the hot spring, they sequenced the microbes' genome and examined their evolutionary relationships. They noticed that the highest difference between the genomes of any two strains totaled to a mere 0.35 percent. Despite being so similar, the strains were telling of a clear movement towards two species, with each individual analyzed bearing a resemblance toward only some of the members. Furthermore, the scientists found that microbes only shared their DNA with some of the members of Sulfolobus islandicus. Namely, they observed that the Blue group began to donate less DNA to the Red one. This was another clue that led them to believe that speciation was indeed taking place. It may seem surprising that microbes can share DNA despite being unable to sexually reproduce. Unlike organisms, who share genetic information through sexual reproduction, however, microbes exchange DNA through a process known as lateral gene transfer. This method of gene transfer stands in contrast to vertical gene transfer, where genes are passed from parents to offspring. Scientists are perplexed as to why Sulfolobus islandicus is rapidly evolving into two separate species. The most common reason for speciation is that organisms become separated by a geographic barrier, such as a mountain or a river, and are subsequently subjected to different selection pressures, thus causing them to evolve. The quintessential example of this phenomenon, known as allotropic speciation, concerns Darwin's finches of the Galapagos Islands. The finches used to share a common ancestor but evolved into separate species after migrating to different islands where they experienced selection pressures like new food sources. In contrast to the finches that underwent allotropic speciation, Sulfolobus islandicus is evolving in one geographic region under the same environmental conditions. This form of speciation, called sympatric speciation, is more difficult to account for and is undergoing further scientific investigation. According to Rachel Whitaker, lead author of the study from the University of Illinois, this is the first known example of sympatric speciation in a microorganism. She believes that the study highlights the extensive genetic diversity that occurs in microbial populations.
(02/01/12 5:00am)
The scientific community was significantly shaken this past December when, for the very first time in history, the US government requested that research journals withhold details of a study from the public. The study concerns a highly pathogenic avian influenza strain known as H5N1, whose transmissibility features have been genetically altered by a team of Dutch scientists, leaving the virus highly contagious and a threat to global security.
(11/07/11 5:00am)
An age-old collegiate concern and the one deterrent from eating too many FFC cookies is the daunting Freshman 15. Do we have reason to fear its effects?
(10/26/11 5:00am)
In response to the growing number of pedestrian accidents in Charles Village, three seniors from the Department of Civil Engineering were inspired to write a proposal for the construction of a pedestrian bridge across Charles Street. The team includes Erin Kelly, Charlotte Healy and Alison Ignatowski, with project advisor Dr. Rachel Sangree, a lecturer in the Department of Civil Engineering.
(10/05/11 5:00am)
A wave of excitement and pride reverberated throughout the Hopkins community on Tuesday when Hopkins Physics and Astronomy professor Adam Riess received the Nobel Prize in Physics for discovering that a mysterious force known as dark energy causes the universe to accelerate and expand.
(09/28/11 5:00am)
Einstein's theory of relativity, which states that particles cannot travel faster than the speed of light, has been a bedrock of our understanding of modern physics for the last 100 years. However, recent research suggests that particles known as neutrinos are potentially capable of exceeding this speed.
(09/07/11 5:00am)
Colon cleansing, colonic irrigation, or colonic hydrotherapy all refer to the practice of flushing the large intestine with a combination of water and dietary fibers, laxatives, or herbs. The practice aims to remove toxins from the colon and essentially cleanse the end of the intestinal tract.
(04/07/11 8:48pm)
Researchers recently revisited Stanley Miller’s work and discovered that hydrogen sulfide released from volcanoes contributed to the formation of some of the most primitive amino acids on earth.
(03/31/11 4:03pm)
For centuries, biologists have been fascinated with studying the role of animal sounds. In many animal species, sounds play a crucial role in communication and behavior. A recently introduced field of science known as soundscape ecology calls to study not just individual animal sounds, but the collective sounds of ecosystems.
(03/11/11 4:12am)
In a recent study conducted at Hopkins, researchers found that childhood cancers are linked to an internal cellular clock which regulates the timing of genetic exchange in dividing immune cells.
(02/03/11 6:42pm)
A new dinosaur species was recently named for Hopkins postdoctoral student Marina Suarez and her twin sister Celina Suarez. Its name, Geminiraptor suarezarum, or “Twin Predatory Thief of the Suarezes,” honors the 29-year-old twins whose geology work led to the discovery of a rich bone site near Green River, Utah.
(11/11/10 11:24pm)
Despite the numerous studies that have shown favorable conditions for microbial life on Mars, there still has not been direct evidence to suggest that the planet ever supported life. In a recent study, planetary geologists at Brown University found mounds of hydrated silica that were left on a volcanic cone in an area of Mars called the Nili Patera three billion years ago.
(09/23/10 11:33pm)
A recent study by the Hopkins Children’s Center reveals the mechanism that puts obese women at a higher risk for infertility.
(09/09/10 11:42pm)
Two Hopkins professors, Peter Searson and Steve Desiderio, were recently appointed by Maryland Governor Martin O’Malley to join the Governor’s Task Force in an effort to study the emerging advantages of nanobiotechnology.
(01/27/10 5:00am)
If you've ever wondered what it is like to be a bornavirus, you may not have to for much longer. A recent study published in Nature found that the bornavirus genome comprises parts of the human genome, and has been a part of our ancestry for the past 40 million years.
(11/19/09 5:00am)
In the midst of this fresh explosion of health care debate, a striking study released by Hopkins researchers may provide another support pillar for advocates of government-funded insurance coverage.