animal – Lightsources.org

Monitoring food safety of marine fishes

2019/08/282019/09/19

Research investigates ways to convert titanium dioxide into a new photoactive material in the visible light range.

The search for clean and renewable energy sources has intensified in recent years due to the increase in atmospheric concentration of greenhouse gases and the consequent increase in the average temperature of the planet. One such alternative source is the conversion of sunlight into electricity through photovoltaic panels. The efficiency in this conversion depends on the intrinsic properties of the materials used in the manufacturing of the panels, and it increases year by year with the discovery of new and better materials. As such, solar energy is expected to become one of the main sources of electric energy by the middle of this century, according to the International Energy Agency (IEA).

Titanium dioxide ( $T i O_{2}$ ) is an abundant, nontoxic, biologically inert and chemically stable material, known primarily as a white pigment used in paints, cosmetics and even toothpastes. $T i O_{2}$ is also often used in sunscreens since it is especially capable of absorbing radiation in the ultraviolet region. However, this same property severely limits the use of $T i O_{2}$ for solar energy conversion, since the ultraviolet emission comprises only 5 to 8% of the total energy of the solar light. Can this $T i O_{2}$ property be extended to the visible light region to increase the conversion of sunlight into electricity? To answer this question, Maria Pilar de Lara-Castells et al. [1] conducted an innovative research in which they discuss how a special treatment can change the optical properties of $T i O_{2}$ .

>Read more on the LNLS website

Image: Joakant (Pixabay)

Research on shark vertebrae could improve bone disease treatment

2019/07/262019/07/31

The U.S. Department of Energy’s Advanced Photon Source (APS) at Argonne National Laboratory has facilitated tens of thousands of experiments across nearly every conceivable area of scientific research since it first saw light more than two decades ago.
But it wasn’t until earlier this year that the storied facility was used to study shark vertebrae in an experiment that one Northwestern University researcher hopes will shed light on the functionality of human bone and cartilage. Shark spines constantly flex when they swim, said Stuart R. Stock, a materials scientist and faculty member of Northwestern’s Feinberg School of Medicine. Yet they remain surprisingly resilient throughout the fish’s lifetime, he said.

Human bones, however, cannot endure the same kind of bending and become more fragile as people age. Stock is using the APS to better understand shark vertebrae’s formation and strength. He wants to know how the animal’s tissue develops and how it functions when the animal swims.

Natural defense against red tide toxin found in bullfrogs

2019/06/262019/06/27

A team led by Berkeley Lab faculty biochemist Daniel Minor has discovered how a protein produced by bullfrogs binds to and inhibits the action of saxitoxin, the deadly neurotoxin made by cyanobacteria and dinoflagellates that causes paralytic shellfish poisoning.
The findings, published this week in Science Advances, could lead to the first-ever antidote for the compound, which blocks nerve signaling in animal muscles, causing death by asphyxiation when consumed in sufficient quantities.
“Saxitoxin is among the most lethal natural poisons and is the only marine toxin that has been declared a chemical weapon,” said Minor, who is also a professor at the UCSF Cardiovascular Research Institute. About one thousand times more potent than cyanide, saxitoxin accumulates in tissues and can therefore work its way up the food chain – from the shellfish that eat the microbes to fish, turtles, marine mammals, and us.

>Read more on the ALS website

Image: A photo illustration showing the atomic structures of saxiphilin and saxitoxin, a red tide algal bloom, and an American bullfrog (R. catesbeiana).
Credit: Daniel L. Minor, Jr., and Deborah Stalford/Berkeley Lab.

Coelacanth reveals new insights into skull evolution

2019/04/172019/04/29

A team of researchers, in conjunction with the National Museum of Natural History in Paris, presents the first observations of the development of the skull and brain in the living coelacanth Latimeria chalumnae.

The study, published in Nature, uses data from beamline ID19 and provides new insights into the biology of this iconic animal and the evolution of the vertebrate skull.
The coelacanth Latimeria is a marine fish closely related to tetrapods, four-limbed vertebrates including amphibians, mammals and reptiles. Coelacanths were thought to have been extinct for 70 million years, until the accidental capture of a living specimen by a South African fisherman in 1938. Eighty years after its discovery, Latimeria remains of scientific interest for understanding the origin of tetrapods and the evolution of their closest fossil relatives – the lobe-finned fishes.

Image: Overall anterolateral view of the skull of the coelacanth foetus imaged on beamline ID19. The brain is in yellow.
Credit: H. Dutel et al.

X-ray fluorescence sheds light on the growth patterns of extinct hyaena

2019/03/152019/03/18

A novel synchrotron technique examines growth patterns in fossil bones

Until recently, it was thought that warm-blooded animals experienced uninterrupted high rates of growth, whilst cold-blooded animals showed zonal growth – alternating periods of fast and slow growth. The identification of zonal growth in a range of mammals and birds disproved that theory, but as yet we don’t know how widespread zonal growth is in vertebrates, or which factors affect the speed of bone growth. Conventional techniques lack the resolution to correlate variations in bone chemistry with histological features, but in work recently published in the Journal of Analytical Atomic Spectrometry, an international team of researchers carried out the first direct comparison between optical histology (bone tissue identification) and synchrotron-based chemical mapping, quantification, and characterisation of trace elements (biochemistry) within cyclic growth tissues, and reported the first case of zonal tissue within the Hyaenidae.

Image: Lead author Jennifer Anné with a spotted hyaena mount.

What keeps spiders on the ceiling?

2019/02/042019/02/26

DESYs X-ray source PETRA III reveals details of adhesive structures of spider legs

Hunting spiders easily climb vertical surfaces or move upside down on the ceiling. A thousand tiny hairs at the ends of their legs make sure they do not fall off. Like the spider’s exoskeleton, these bristle-like hairs (so-called setae) mainly consist of proteins and chitin, which is a polysaccharide. To find out more about their fine structure, an interdisciplinary research team from the Biology and Physics departments at Kiel University and the Helmholtz-Zentrum Geesthacht (HZG) examined the molecular structure of these hairs in closer detail at DESY’s X-ray light source PETRA III and at the European Synchrotron Radiation Facility ESRF. Thanks to the highly energetic X-ray light, the researchers discovered that the chitin molecules of the setae are specifically arranged to withstand the stresses of constant attachment and detachment. Their findings could be the basis for highly resilient future materials. They have been published in the current issue of the Journal of the Royal Society Interface.

Image: In order to find out why the hunting spider Cupiennius salei adheres so well to vertical surfaces, the interdisciplinary research team investigates the tiny adhesive hairs on the spider legs.
Credit: Universität Kiel, Julia Siekmann

Megachirella -the mother of all lizards

2018/06/062018/06/08

A new international research rewrites the history of reptiles starting from a fossil found in the Dolomites.

The origin of lizards and snakes should be pushed back by about 75 million years, as documented by a small reptile, Megachirella wachtleri, found almost 20 years ago in the Dolomites and rediscovered today thanks to cutting-edge techniques in the field of 3D analysis and the reconstruction of evolutionary relationships. Evidence to this effect has been provided by an international paleontological research with the participation of the MUSE Science Museum of Trento, in collaboration with the “Abdus Salam” International Centre of Theoretical Physics of Trieste, the Enrico Fermi Centre of Rome and Elettra Sincrotrone Trieste. The results have been published in the prestigious science journal Nature, which has also dedicated its cover image to research.

The international team has identified Megachirella wachtleri – a small reptile which lived approximately 240 million years ago in what are today the Dolomites – the most ancient lizard in the world thereby providing key insight into the evolution of modern lizards and snakes.
The data – obtained by 3D X-ray imaging techniques and the analysis of DNA sequences – suggest that the origin of “squamates”, i.e. the group comprising lizards and snakes,is older than previously thought and that it can be dated to approximately 250 million years ago, before the most extensive mass extinction in history.

Image: Megachirellawandering amidst the lush vegetation that approximately 240 million years ago surrounded the dolomitic beaches.
Credit: Davide Bonadonna

Synchrotron X-rays reveal identity of 1.5 million-year-old Tuscan big cat

2018/05/292018/05/31

The identity of a mysterious fossil felid found in central Italy has been revealed thanks to synchrotron techniques.

Scientists used X-ray tomography to virtually extract the fossil from its rock encasing and describe decisive anatomical details for the first time. Previously thought to be an extinct Eurasian jaguar, this new study concluded by identifying the felid as Acinonyx pardinensis, one of the most intriguing extinct carnivores of the Old World Plio-Pleistocene. The study is published in Scientific Reports.

The team of physicists and palaeontologists from the University of Perugia, the University of Verona and the University of Rome Sapienza, in collaboration with the European Synchrotron, ESRF, scanned the partial skull of the specimen, still embedded in the rock. The analysis of images and 3D models obtained revealed a mosaic of cheetah-like teeth and Panthera-like features leading to a reconsideration of the ecological role of this species.

Image: Dawid Iurino with the Acinonyx pardinensis skull from Monte Argentario, on the set-up of ESRF ID17 beamline.
Credit: Marco Cherin