Search results for "horseshoe"

News from an Ancient World: Two Novel Astacin Metalloproteases from the Horseshoe Crab

2008

In this work, we report the cloning, heterologous expression, and characterization of two novel astacin proteases from the chelicerate Limulus polyphemus (horseshoe crab), designated as LAST (Limulus astacin) and LAST_MAM (Limulus astacin containing a MAM domain), respectively. The expression pattern showed ubiquitous occurrence of LAST_MAM, while LAST was predominantly restricted to the eyes and brain, indicating a function in the nervous system. Both enzymes contain the characteristic metzincin-type zinc-binding region and Met turn. While LAST is made up only of the typical prodomain and astacin-like protease domain, LAST_MAM contains an additional MAM (meprin A5 protein tyrosine phosphat…

Vortex diffusion and vortex-line hysteresis in radial quantum turbulence

2014

Abstract We study the influence of vortex diffusion on the evolution of inhomogeneous quantized vortex tangles. A simple hydrodynamical model to describe inhomogeneous counterflow superfluid turbulence is used. As an illustration, we obtain solutions for these effects in radial counterflow of helium II between two concentric cylinders at different temperatures. The vortex diffusion from the inner hotter cylinder to the outer colder cylinder increases the vortex length density everywhere as compared with the non-diffusive situation. The possibility of hysteresis in the vortex line density under cyclical variations of the heat flow is explored.

The diversity and evolution of chelicerate hemocyanins

2012

Abstract Background Oxygen transport in the hemolymph of many arthropod species is facilitated by large copper-proteins referred to as hemocyanins. Arthropod hemocyanins are hexamers or oligomers of hexamers, which are characterized by a high O2 transport capacity and a high cooperativity, thereby enhancing O2 supply. Hemocyanin subunit sequences had been available from horseshoe crabs (Xiphosura) and various spiders (Araneae), but not from any other chelicerate taxon. To trace the evolution of hemocyanins and the emergence of the large hemocyanin oligomers, hemocyanin cDNA sequences were obtained from representatives of selected chelicerate classes. Results Hemocyanin subunits from a sea s…

Spatial variability of biological and chemical contaminants in nurseries of lesser horseshoe bat : preliminary results in Franche-Comté (Eastern Fran…

2011

Molecular Structure of the Arthropod Hemocyanins

1992

Hemocyanin is an extracellular, blue protein that occurs in high concentrations in the blood of many arthropods, including spiders, scorpions, horseshoe crabs, crustaceans, and at least two centipedes. Serving as an ### oxygen carrier, it is functionally equivalent to hemoglobin, but performs reversible oxygen binding between two copper ions. Hemocyanin is composed of a number of subunits that assemble in an extremely large macro-molecular entity. These particles, which are similar in size to viruses or ribosomes, exhibit a complex allosteric behavior during oxygen binding. There is growing evidence that this functional plasticity has evolved upon, and answers to, ecophysiological constrain…

Phylogenetic relationships of the Italian populations of Horseshoe Whip Snake Hemorrhois hippocrepis (Serpentes, Colubridae)

2020

Hemorrhois hippocrepis is a colubrid snake with a West Mediterranean distribution. It is widespread in the Iberian Peninsula and Northwest Africa. The only Italian populations are found on the islands of Sardinia and Pantelleria. The phylogenetic relationships of these insular populations have been analysed for the first time on the basis of the mitochondrial DNA cytochrome b gene. The sequences were compared with those available from the geographic range of this species. The analyses showed that the Italian samples are part of a lineage that groups Tunisian and East Algerian samples, with which they share the same haplotype. These results strongly support the hypothesis of a recent origin …

The Horseshoe whip snake (Hemorrhois hippocrepis) on Ibiza: predator release in an invasive population

2020

Abstract The key to fighting a biological invasion may lie in understanding every variable that can explain its success. The Enemy Release Hypothesis (ERH) states that when an invader arrives to a new environment, the absence of its common enemies (predators, parasites and competitors) facilitates the invasion success. The Horseshoe whip snake (Hemorrhois hippocrepis) has been recently introduced from the Iberian Peninsula to the island of Ibiza, and it is currently threatening the only endemic vertebrate, the Ibiza wall lizard (Podarcis pityusensis). We hypothesized that the snake invasion success is caused by the absence of natural predators, and we checked the ERH by relating the tail br…

Uwarunkowania mikroklimatyczne Sztolni w Łomie Buchmana (Sławniowice) podkowca małego Rhinolphus hiposideros podczas hibernacji

2018

Percutaneous Nephrostomy Catheter Misplacement into Inferior Vena Cava in a Patient with a Horseshoe Kidney

2020

Background: Percutaneous nephrostomy (PCN) is commonly indicated for upper urinary tract drainage in case of obstruction or fistula. Only a few cases of PCN catheter misplacement into the inferior vena cava (IVC) have been published. Case Presentation: We report a case of a PCN catheter misplaced into the IVC through a fistula between the urinary tract and an ipsilateral renal vein in a patient with horseshoe kidney, after bedside urgent replacement for hemorrhage and hemorrhagic shock. Conclusion: Although a nephrostomy Foley catheter can be used for adequate urinary drainage and hemostatic purposes after percutaneous nephrolithotomy, its placement should be always verified through antegra…