SciTech Briefs
Genetic researchers identify four distinct species of giraffe
Researchers have recently discovered that there are four genetically distinct species of giraffes. The findings, which were published in the journal Current Biology, were unexpected; all giraffes are quite similar in appearance, which had previously led to the conclusion that all giraffes were part of a single species.
Axel Janke, a geneticist at the Senckenberg Biodiversity and Climate Research Centre and the Goethe University in Germany, along with a team of researchers, took DNA samples from 190 giraffes. The subjects the study were from a variety of regions in Africa and included samples from all nine previously recognized giraffe subspecies.
DNA testing of the samples indicates that giraffes should be split into four genetically distinct species: the Southern giraffe (Giraffa giraffa), the Masai giraffe (G. tippelskirchi), the Reticulated giraffe (G. reticulata), and the Northern giraffe (G. camelopardalis). The study also suggested that these four species of giraffes do not mate with each other in the wild.
These findings could have a severe impact on giraffe conservation efforts. Giraffe numbers have been severely declining in the past 30 years, and the researchers hope that these findings will bolster support for giraffes.
Source: Science Daily
Device visualizes bacterial resistivity to antibiotics
Michael Baym, a research fellow in systems biology at Harvard Medical School, along with a team of researchers has developed a device that allows researchers to visualize how microbes become antibiotic-resistant. “Inside that flask, in order for a new strain to evolve, the new mutant has to be more fit than everything around it,” says Baym.
The research team used a dish over a meter long that was coated with different concentrations of antibiotics — low concentrations at the edges and high concentrations in the middle. The team added E. coli bacteria to the plate and let it multiply for a week and a half. With this setup, the bacteria mutated over time in order to handle higher levels of antibiotics, and were able to move onto new portions of the plate.
This setup allowed researchers to see differences in movement — highly resistant bacteria spread across the plate more slowly than bacteria with low resistance levels. The team believes that this new setup could also help researchers study how microbial colonies evolve under other conditions such as nutrient availability or spatial constraints.
Source: Science News
Improving PTSD brain function with near-infrared light
Researchers at the University of Texas (UT) at Arlington have discovered that light could potentially be used to improve the cognitive function of patients with PTSD.
The research team shined near-infrared light (NIR) on a human forearm and discovered that this treatment promoted the production of cytochrome-c-oxydase, a protein that stimulates blood flow in neurons. Hanli Liu, a bioengineer at UT Arlington, was the principle investigator of the research and explained that “this is the first time that effects of light stimulation have been quantified on living human tissue.” Liu also noted that the next step is to “apply what was learned in a simpler system to the brain, where the light must pass through the scalp and the skull, as well as the brain.”
The research team had previously found that patients with PTSD had decreased blood flow in the left side of the dorsal lateral prefrontal cortex. The team believes that by using light to promote increased blood flow, they could potentially treat this component of PTSD.
The research team is now moving towards transcranial NIR stimulation in the hope of confirming their initial findings.
Source: Science Daily
Wilderness reduced by 10 percent since 1990s
World Conservation Society researchers have recently shown that a tenth of the world’s wilderness has been destroyed in the past twenty years. The findings, which were published in Current Biology, show that the most alarming losses are occurring in South America and Africa.
The research team created a map of wilderness areas around the world and compared their findings to a similar map that was made in the early 1990s. They discovered that approximately 3.3 million square kilometers had been lost since the original map was made.
The researchers argue that this loss demonstrates the need for focused attention on nature preservation and active reversal of industrial landscapes to natural settings.
James Watson, an associate professor of geography planning and environmental management at the University of Queensland, noted that wilderness areas are “completely ignored in environmental policy.” He argues that “international policy mechanisms must recognize the actions needed to maintain wilderness areas before it is too late … we probably have one to two decades to turn this around.”
Source: BBC News
NASA launches probe to retrieve asteroid sample
On Sept. 9, NASA launched Osiris-Rex, a probe that is being sent to collect a rock sample from an asteroid called Bennu. The probe will spend approximately 2.5 years on Bennu, and will take seven years total to complete its journey and collect the rock sample. If all goes as planned, the sample will be delivered to Earth in a capsule on Sept. 24, 2023 somewhere in the Utah desert.
Researchers hope that the rock sample will provide clues to understanding how the sun and the planets were created. “For primitive, carbon-rich asteroids like Bennu, materials are preserved from over 4.5 billion years ago. We’re talking about the formation of our Solar System,” said Christina Richey, NASA’s Osiris-Rex deputy program scientist. “And these primitive materials could contain organic molecules that may be the precursors to life here on Earth or elsewhere within our Solar System.”
Scientists in Japan have already completed a similar mission, although the U.S. mission hopes to bring back a larger sample — approximately a couple hundred grams. Scientists in Europe are also hoping to complete a similar mission to return in the late 2020s.
Source: BBC News
Trilobites show early example of mass migration
Blazej Blazejowski, a paleobiologist from the Polish Academy of Sciences, along with a team of researchers, has discovered that trilobites, a type of extinct marine invertebrate animal, could be one of the earliest examples of mass animal migration.
Blazejowski’s team of researchers investigated a fossil from a quarry located in central Poland along with 80 others, all of which showed trails of trilobites moving in single file. Blazejowski explained that the animals “may have migrated periodically to shallow marine areas for mass mating and spawning.”
Since trilobites are blind, the researchers believe that they used chemical cues in order to form their single file lines. This process can be seen in other animals such as lobsters, which also migrate in single file. It is believed that trilobites were eventually killed by toxic amounts of carbon dioxide and hydrogen sulfide in the ocean floor.
Source: New York Times