3D imaging of shark embryos reveals evolution of pelvic fins

Photo Credit: Marcelo Cidrack

Curtin University researchers have revealed how the pelvic fins of fish such as sharks and chimaeras have evolved from their sudden appearance in the fossil record over 410 million years ago.

The team used CT scanning and 3D modelling to study the growth of pelvic fins in fish embryos to help us understand how the skeleton of these fins changed over evolutionary history.

Lead author and PhD candidate Jacob Pears from Curtin’s School of Molecular and Life Sciences said the research showed what the development of modern animals can tell us about their evolution.

“Our work focused on cartilaginous fish and in particular looked at the pelvic fins of elephant sharks. The fine detail from our imaging revealed the basipterygium (pelvic fin bar), which like the femur and tibia in humans, were formed by the fusion of fin radials during early embryonic development,” Mr. Pears said.

Early humans may have first walked upright in the trees

Photo Credit: Alexa

Human bipedalism – walking upright on two legs – may have evolved in trees, and not on the ground as previously thought, according to a new study involving UCL researchers.

In the study, published in the journal Science Advances, researchers from UCL, the University of Kent, and Duke University, USA, explored the behaviors of wild chimpanzees - our closest living relative - living in the Issa Valley of western Tanzania, within the region of the East African Rift Valley.

Known as ‘savanna-mosaic’ – a mix of dry open land with few trees and patches of dense forest - the chimpanzees’ habitat is very similar to that of our earliest human ancestors and was chosen to enable the scientists to explore whether the openness of this type of landscape could have encouraged bipedalism in hominins.

The study is the first of its kind to explore if savanna-mosaic habitats would account for increased time spent on the ground by the Issa chimpanzees, and compares their behavior to other studies on their solely forest-dwelling cousins in other parts of Africa.

Overall, the study found that the Issa chimpanzees spent as much time in the trees as other chimpanzees living in dense forests, despite their more open habitat, and were not more terrestrial (land-based) as expected.

Scientists Have Figured Out How to Use Silicone to Protect against Radiation

Scientists plan to investigate a broader set of materials that can attenuate radiation.
Photo Credit: Anastasia Farafontova

An international team of scientists has developed a material that can be used in the future as radiation protection against gamma radiation, in particular, it can be used to create radiation protection for Nuclear Power Station workers. The new material is based on silicone using zinc oxide nano powder additions. The results of research on the new material and its properties have been published in the journal Optical Materials. Physicists from Russia (Ural Federal University), Jordan, and Turkey took part in the work.

"Gamma radiation is widespread in the health care, food and aerospace industries. Excessive exposure can be harmful to human health. Gamma radiation is now attenuated or absorbed using lead, concrete, lead-oxide, tungsten, or tin-based materials. These protective materials are not always convenient to use as protection against gamma rays. In addition, they are expensive, too heavy and highly toxic to humans and the environment. This is why it is important to find new materials and optimize their composition for radiation protection, which will ensure human and environmental safety," says Oleg Tashlykov, Associate Professor at the Department of Nuclear Power Plants and Renewable Energy Sources at UrFU.

Quenchbody Immunosensors Pave the Way to Quick and Sensitive COVID-19 Diagnostics

A new immunosensor based on Quenchbody technology shows great potential as a fast, inexpensive, and convenient tool to detect SARS-CoV-2. Developed by scientists at Tokyo Institute of Technology (Tokyo Tech) and Tokyo Medical and Dental University (TMDU), this highly efficient diagnostic approach will be useful not only for point-of-care testing, but also for high-throughput epidemiological studies of COVID-19 and other emerging infectious diseases.

The double-tagged Quenchbody immunosensor becomes fluorescent when its target antigen—the nucleocapsid protein from SARS-CoV-2—binds at the antigen-binding region of the antibody fragments. This approach is fast, cost-effective, and convenient to use in practice, making it ideal for point-of-care testing as well as batch processing of patient samples. 

The incredibly fast spread of COVID-19 throughout the world brought to light a very important fact: we need better methods to diagnose infectious diseases quickly and efficiently. During the early months of the pandemic, polymerase chain reaction (PCR) tests were one of the most widely used techniques to detect COVID-19. However, these viral RNA-based techniques require expensive equipment and reaction times longer than an hour, which renders them less than ideal for point-of-care testing.

Early green, early brown – climate change leads to earlier senescence in alpine plants

Alpine plants that start to grow earlier also start to age earlier. As is the case with the alpine vegetation in these containers, which were exposed to summer weather several months before the snow melted photograph taken in July
Photo Credit: P. Möhl

Global warming is leading to longer growing seasons worldwide, with many plants growing earlier in spring and continuing longer in autumn thanks to warmer temperatures—so is the general opinion. Now, however, plant ecologists at the University of Basel have been able to show that this is not the case for the most common type of alpine grassland in the European Alps, where an earlier start leads to earlier aging and leaves the grassland brown for months.

Spring 2022 was extremely warm, giving many plants an early start to the growing season. And the Swiss Alps were no exception, with the snow cover melting early and the underlying vegetation being quickly roused into growth. Researchers at the Department of Environmental Sciences at the University of Basel have investigated how such an early start affects the plants’ further development.

For their study, they removed intact blocks of alpine grassland and placed them in walk-in climate chambers at Basel’s Botanical Institute. Here, they left the vegetation to overwinter artificially in cold darkness, and then switched some of the blocks to summer conditions in February. A second group was left in the cold dark until April, before summer was introduced here as well. The researchers compared the growth and aging of these plants with their neighbors growing naturally at an elevation of 2,500 meters, which did not emerge from the snow until late June.

With Discovery, Oxygen's Role in Growth of Tumors Reconsidered

Structure of the HIF1A protein. Based on PyMOL rendering of PDB 1h2k Illustration
Credit: Emw
CC BY-SA 3.0

Yale researchers have made a discovery that changes conventional thinking about the role that oxygen plays in the growth of tumors—an area of cancer research that has been intensely studied in recent years.

The results, from the lab of Andre Levchenko, the John C. Malone Professor of Biomedical Engineering, are published in Cell Systems. Other groups collaborating on this study were directed by Chi V. Dang (Johns Hopkins University) and Kshitiz (University of Connecticut).

When tumors start running out of oxygen, they can switch on hypoxia-inducible factor (HIF-1alpha)—a transcription factor, which is a protein that controls the activity of genes. As a result of HIF-1alpha activation, the expression of hundreds of genes can change and dramatically alter the behavior of cancer cells. Although the increase in HIF-1alpha is thought to be steady, the new study led by Levchenko discovered that the levels of this molecule can also repeatedly rise and fall in small groups of cells, particularly in areas of high cell density. The effects of this oscillation are profound, as it allows cancer cells starving for oxygen to resume division and growth. It can also promote pro-cancer genes and inhibit anti-cancer genes.

Paris Agreement temperature targets may worsen climate injustice for many island states

A comparison of global greenhouse gas emissions from 1990 – 2018 shows the low emissions contribution of AOSIS nations (blue) and increasing levels of total global emissions (red).
Illustration Credit: Sadai et al., 10.1029/2022EF002940

While the world focuses on limiting the rise in global temperature to 1.5 or 2 degrees Celsius over the preindustrial average, increasing meltwater from ice sheets presents an existential threat to the viability of island and coastal nations throughout the world. Now, research from the University of Massachusetts Amherst, recently published in the journal Earth’s Future, shows that even the most optimistic temperature targets can lead to catastrophic sea-level rise, which has already begun and will affect low-lying nations for generations to come.

While rising temperatures are having many deleterious effects on global ecosystems, economies and human wellbeing, an interdisciplinary team of researchers at the University of Massachusetts emphasize that temperature alone is not a sufficient basis for climate policy. 

Laser controls ultra-fast water switches

The water is fanned out by a specially developed nozzle. Then the laser is passed through.
Photo Credit: Adrian Buchmann

Researchers are introducing a completely new concept for switches with unprecedented speed.

Researchers at the Ruhr University Bochum have developed an ultra-fast circuit based on water. Thanks to a short but strong laser pulse, the water can be reached within less than a billionth of a second (10th-12 Seconds) in a conductive state and behaves almost like a metal during this time. This makes the circuit faster than the fastest known switching speed of a semiconductor to date. Adrian Buchmann, Dr. Claudius Hoberg and Dr. Fabio Novelli from the Ruhr Explores Solvation Cluster of Excellence, in short RESOLV, report in the journal APL Photonics December 2022.

Laser lets the water behave like a fast switch

All computer arithmetic operations are based on circuits. The speed at which a component can switch between states zero and one ultimately determines the speed of the computer. Semiconductors that enable electrical circuits are installed in current computers. "They are naturally limited in speed," explains Claudius Hoberg.

New Study Sheds Light on Boric Acid Transport and Excretion in Marine Fish

Seawater is known to contain a significant concentration of boric acid, which can be toxic and deadly to living systems. As such, fish living in marine habitats need to be able to excrete boric acid in order to maintain a healthy boron balance. Tokyo Tech researchers have now identified the gene and mechanism of boric acid transport in seawater fish and contrasted it to freshwater species.

Marine fishes live in highly saline environments with ionic concentrations that are vastly different from their blood plasma. Seawater contains a variety of toxic ion species that can build up in the body if the fish does not excrete them. One example of this is boric acid, which—in small amounts—is a vital micronutrient for animals but can prove toxic in excess. Hence, marine fish must develop physiologic means to excrete boric acid. However, how they do this is, as yet, unknown. Now, an international team led by researchers from Tokyo Institute of Technology (Tokyo Tech) has unveiled and demonstrated the molecular mechanisms underlying boric acid secretion in marine pufferfish.

Associate Professor Akira Kato of Tokyo Tech is the principal author of the study, which was published in the Journal of Biological Chemistry. He tells us more about it. "We compared euryhaline pufferfish (which are pufferfish that can survive in varying levels of salinity) accustomed to saltwater, brackish water, and freshwater. On comparing fish from these three habitats, we found that the urine of a seawater pufferfish (Takifugu pufferfish) contained 300 times more boric acid than pufferfish blood, and 60 times more boric acid than seawater." The urine of freshwater fish contained almost 1000 times less boric acid than that of seawater pufferfish. These findings established that Takifugu pufferfish living in seawater excrete boric acid in their urine. Just like in humans, the process of excretion via urine in pufferfish is mediated by the kidneys.

Researchers find the snake clitoris

A death adder snake, also known as acanthophis antarcticus.
Photo Credit: Luke Allen.

An international team of researchers, led by the University of Adelaide has provided the first anatomical description of the female snake clitoris, in a first-of-its-kind study.

PhD Candidate Megan Folwell from the School of Biological Sciences, University of Adelaide, led the research.

“Across the animal kingdom female genitalia are overlooked in comparison to their male counterparts,” said Ms Folwell.

“Our study counters the long-standing assumption that the clitoris (hemiclitores) is either absent or non-functional in snakes.”

The research involved examination of female genitalia in adult snake specimens across nine species, compared to adult and juvenile male snake genitalia.

Associate Professor Kate Sanders, School of Biological Sciences, University of Adelaide, said: “We found the heart-shaped snake hemiclitores is composed of nerves and red blood cells consistent with erectile tissue - which suggests it may swell and become stimulated during mating. This is important because snake mating is often thought to involve coercion of the female – not seduction.”