Arsenic Irradiation Induced Atomic Interdiffusion of InxGa1-xAs/InP Quantum Well Structures

The atomic intermixing of InxGa1-xAs/InP quantum well structures induced by arsenic irradiation has been investigated using photoluminescence (PL) measurement. The ion doses used were varried from 5x1011 As/cm2 to 1x1013 As/cm2. Also, the irradiation temperature were carried out from -200oC to 300oC. The samples were annealed under Argon flow in rapid thermal annealer (RTA) at 750oC for 60 second. The photoluminescence result showed that there was increase in energy shift at lower doses. However, the energy shift was saturated at higher dose. At elevated temperature implantation showed that the energy shift did not change significantly for all the samples (LM, TS, CS). In additon to this, the higher energy shift was observed in the Compressive Strain (CS) samples, but the lower of the energy shift was experienced in the Tensile Strain (TS) samples. Received: 06 September 2012; Revised: 27 November 2012; Accepted: 03 December 201

Molecular biology of amitraz resistance in cattle ticks of the genus Rhipicephalus

Amitraz is an important product for the control of cattle ticks around the world. In comparison with other products for the control of ticks, it is quite affordable and it has a rapid knock-down effect. It binds with and activates adrenergic neuro-receptors of animals and it inhibits the action of monoamine oxidases (MAO). Resistance to amitraz has been documented in Rhipicephalus microplus, R. decoloratus and R. appendiculatus. Four mechanisms of resistance have been proposed, each of which is supported by evidence but none of which has been definitively confirmed as the cause of resistance in the field. The proposed mechanisms include genetic target site insensitivity in two G protein-coupled receptors, the beta-adrenergic octopamine receptor (BAOR) and the octopamine/tyramine receptor (OCT/Tyr), increased expression or activity of monoamine oxidases and increased expression or activity of the ATP binding cassette transporter

Evolution of miniaturization and the phylogenetic position of Paedocypris, comprising the world's smallest vertebrate

10.1186/1471-2148-7-38BMC Evolutionary Biology7

Dissecting the genetic components of a quantitative trait locus for blood pressure and renal pathology on rat chromosome 3

Background: We have previously confirmed the importance of rat chromosome 3 (RNO3) genetic loci on blood pressure elevation, pulse pressure (PP) variability and renal pathology during salt challenge in the stroke-prone spontaneously hypertensive (SHRSP) rat. The aims of this study were to generate a panel of RNO3 congenic sub-strains to genetically dissect the implicated loci and identify positional candidate genes by microarray expression profiling and analysis of next-generation sequencing data. Method and results: A panel of congenic sub-strains were generated containing Wistar-Kyoto (WKY)-introgressed segments of varying size on the SHRSP genetic background, focused within the first 50 Mbp of RNO3. Haemodynamic profiling during salt challenge demonstrated significantly reduced systolic blood pressure, diastolic blood pressure and PP variability in SP.WKYGla3a, SP.WKYGla3c, SP.WKYGla3d and SP.WKYGla3e sub-strains. Only SBP and DBP were significantly reduced during salt challenge in SP.WKYGla3b and SP.WKYGla3f sub-strains, whereas SP.WKYGla3g rats did not differ in haemodynamic response to SHRSP. Those sub-strains demonstrating significantly reduced PP variability during salt challenge also demonstrated significantly reduced renal pathology and proteinuria. Microarray expression profiling prioritized two candidate genes for blood pressure regulation (Dnm1, Tor1b), localized within the common congenic interval shared by SP.WKYGla3d and SP.WKYGla3f strains, and one candidate gene for salt-induced PP variability and renal pathology (Rabgap1), located within the region unique to the SP.WKYGla3d strain. Comparison of next-generation sequencing data identified variants within additional positional genes that are likely to affect protein function. Conclusion: This study has identified distinct intervals on RNO3-containing genes that may be important for blood pressure regulation and renal pathology during salt challenge

Phylogenetics of Archerfishes (Toxotidae) and Evolution of the Toxotid Shooting Apparatus

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Archerfishes (Toxotidae) are variously found in the fresh- and brackish-water environments of Asia Pacific and are well known for their ability to shoot water at terrestrial prey. These shots of water are intended to strike their prey and cause it to fall into the water for capture and consumption. While this behavior is well known, there are competing hypotheses (blowpipe vs. pressure tank hypothesis) of how archerfishes shoot and which oral structures are involved. Current understanding of archerfish shooting structures is largely based on two species, Toxotes chatareus and T. jaculatrix. We do not know if all archerfishes possess the same oral structures to shoot water, if anatomical variation is present within these oral structures, or how these features have evolved. Additionally, there is little information on the evolution of the Toxotidae as a whole, with all previous systematic works focusing on the interrelationships of the family. We first investigate the limits of archerfish species using new and previously published genetic data. Our analyses highlight that the current taxonomy of archerfishes does not conform to the relationships we recover. Toxotes mekongensis and T. siamensis are placed in the synonymy of T. chatareus, Toxotes carpentariensis is recognized as a species and removed from the synonymy of T. chatareus, and the genus Protoxotes is recognized for T. lorentzi based on the results of our analyses. We then take an integrative approach, using a combined analysis of discrete hard- and soft-tissue morphological characters with genetic data, to construct a phylogeny of the Toxotidae. Using the resulting phylogenetic hypothesis, we then characterize the evolutionary history and anatomical variation within the archerfishes. We discuss variation in the oral structures and the evolution of the mechanism with respect to the interrelationships of archerfishes, and find that the oral structures of archerfishes support the blowpipe hypothesis but soft-tissue oral structures may also play a role in shooting. Finally, by comparing the morphology of archerfishes to their sister group, we find that the Leptobramidae has relevant shooting features in the oral cavity, suggesting that some components of the archerfish shooting mechanism are examples of co-opted or exapted traits

Porphyrin ‘‘Mille-Feuilles” photo-electrodes

A porphyrin ‘‘Mille-Feuilles” photo-electrode is fabricated layer-by-layer by deposition of anionic [zinc meso-tetrakis(p-sulfonato phenyl) porphyrin]4- (ZnTPPS4−) and positively charged polypeptides on a 11-mercaptoundecanoic acid-modified gold electrode to form a photoactive film. This work demonstrates that it is possible to form 3D structures having regularly spaced layers of redox molecules. UV–visible spectra of the multilayer films display the characteristic absorption bands of the porphyrins and the absorbance increases linearly with the number of bilayers. The cyclic voltammetric response of the films in contact with 1,2-dichloroethane (DCE) varies from that of a modified electrode to that of a supported liquid film. Under illumination, a large photocurrent response for oxygen reduction with a maximum for a 5-bilayer film is observed

Protoporphyrin IX sensitized titanium oxide gel electrode

Titanium oxide (Ti(O)) xerogel films functionalized by protoporphyrin IX (PPIX) and ferrocene carboxylic acid (FCA) were deposited on indium tin oxide (ITO) electrodes following a sol–gel synthesis. PPIX and FCA were first complexed to titanium oxide precursors, which were then subjected to hydrolysis to obtain a homogenous Ti(O) polymeric network gel doped with PPIX and FCA. The Ti(O) film cast on the ITO electrode has been characterized by UV–Vis absorption, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy and cyclic voltammetry. Illumination of the PPIX doped Ti(O) films on the ITO electrode immersed in aqueous electrolytes onsets photoinduced electron transfer reactions, and a cathodic photocurrent was observed in most cases. This photocurrent response was investigated in detail using a kinetic model. Preliminary investigations of oxygen reduction, lithium and proton insertion into the Ti(O) film have also been carried out