bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress influence on band-edge luminescence properties of 4H-AlN
Authors: Cheng Y. C. , Wu X. L. , Li S. H. , Chu Paul K.
Published: September 2009

The band-edge luminescence properties of 4H-AlN under biaxial and uniaxial stress are studied using the first-principle method. In equilibrium, excitons B and C have energies 92 and 14 meV lower than exciton A, respectively. When the uniaxial tensile strain exceeds ∼0.95%, the top valence band is the B exciton state. Its band-edge emission is no longer prohibited and changes to E⊥c. The shift in the A exciton energy is similar to that of 2H-AlN under stress of −5 to 5 GPa. When the compressive biaxial strain is larger than 5 GPa, the band structure of 4H-AlN becomes indirect.
The effect of spin polarization on zero field splitting parameters in paramagnetic π-electron molecules
Authors: van Gastel Maurice
Published: September 2009

Spin polarization effects play an important role in the theory of isotropic hyperfine interactions for aromatic protons. The spin polarization gives rise to significant isotropic proton hyperfine interactions—spin-dependent one-electron properties—smaller than 0 MHz and the effect has been theoretically described [H. M. McConnell and D. B. J. Chesnut, Chem. Phys. 28, 107 (1958)]. The influence of spin polarization on the zero field splitting parameters, which are spin-dependent two-electron properties, has not been clearly identified yet. A phenomenological equation is proposed here for the contribution of spin polarization to the zero field splitting parameter D in analogy to McConnell’s equation for hyperfine interactions. The presence of the effect is demonstrated in a series of calculations on polyacenes in the triplet state and turns out to be responsible for up to 50% of the D parameter in the case of naphthalene! It is found that spin-unrestricted single-determinant methods, including the widely used density functional theory methods, do not accurately reproduce the two-electron reduced electron density required for the evaluation of two-electron spin-dependent properties. For the accurate calculation of zero field splitting parameters by quantum chemical methods, it thus seems necessary to resort to correlated ab initio methods which do not give rise to spin contamination and which do provide an accurate description of the two-electron reduced electron density.
Time-resolved photoluminescence analysis of two-peak emission behavior in Sr2Si5N8:Eu2+
Authors: Sohn Kee-Sun , Lee Sangjun , Xie Rong-Jun , Hirosaki Naoto
Published: September 2009

Sr 2 Si 5 N 8 : Eu 2 + , one of the most recently developed phosphors for use in white light emitting diodes, exhibits a two-peak emission. Namely, the emission band of Sr2Si5N8:Eu2+ is deconvoluted into two Gaussian peaks irrespective of the Eu2+ concentration. We examined the two-peak emission of Sr2Si5N8:Eu2+ by analyzing the time-resolved photoluminescence spectra. We revealed that the two-peak emission was closely associated with the energy transfer taking place between Eu2+ activators located at two different crystallographic sites in the Sr2Si5N8 structure. The experimental results coincided well with the rate equation model involving the crystallographic information of the host.
On the saturation in the average transmitted current in two-dimensional planar diodes
Authors: Kumar Raghwendra , Biswas Debabrata
Published: September 2009

The relation between average transmitted current density (JTR) and injected current density (JIN) in a two-dimensional planar diode is investigated using particle-in-cell simulation. Beyond the space charge limited value of injected current density, JTR is found to increase slowly with JIN and finally saturate for higher values. The physics of gradual increase in JTR to the saturation value is explained using the electric field profile at the cathode surface.
Al
13
H
−
: Hydrogen atom site selectivity and the shell model
Authors: Grubisic A. , Li X. , Stokes S. T. , Vetter K. , Ganteför G. F. , Bowen K. H. , Jena P. , Kiran B. , Burgert R. , Schnöckel H.
Published: September 2009

Using a combination of anion photoelectron spectroscopy and density functional theory calculations, we explored the influence of the shell model on H atom site selectivity in Al13H−. Photoelectron spectra revealed that Al13H− has two anionic isomers and for both of them provided vertical detachment energies (VDEs). Theoretical calculations found that the structures of these anionic isomers differ by the position of the hydrogen atom. In one, the hydrogen atom is radially bonded, while in the other, hydrogen caps a triangular face. VDEs for both anionic isomers as well as other energetic relationships were also calculated. Comparison of the measured versus calculated VDE values permitted the structure of each isomer to be confirmed and correlated with its observed photoelectron spectrum. Shell model, electron-counting considerations correctly predicted the relative stabilities of the anionic isomers and identified the stable structure of neutral Al13H.
Monte Carlo calculation of the methane-water interfacial tension at high pressures
Authors: Biscay F. , Ghoufi A. , Lachet V. , Malfreyt P.
Published: September 2009

Monte Carlo simulations have been performed in the NpNAT statistical ensemble to study the methane-water mixture as a function of pressure. The interfacial tensions are calculated with different definitions and are reported for pressures from 1 to 50 MPa. The interfacial tensions, coexisting densities, and composition of the methane and water phases are shown to be in good agreement with the corresponding experimental properties. The interfacial region has been described through the profiles of the number of hydrogen bonds, the coordination number of each species, and the different energy contributions. We complete this study by a theoretical investigation of the thermal and mechanical equilibria in the binary mixture. We have also examined the profile of the intrinsic and long range correction parts of the interfacial tension along the normal to the water surface.
Structural relaxation and crystallization of NiTi thin film metallic glasses
Authors: Huang Xu , Ramirez A. G.
Published: September 2009

This letter demonstrates the effects of structural relaxation on the crystallization and phase transformation behavior of NiTi thin films. Heat treatments below the glass transformation temperature produce films with a greater hardness than as-deposited films. The reduction in free volume occurring during film relaxation plays a role. Using scanning electron microscopy, structural relaxation was found to decrease the overall crystallization time and increase the nucleation rate, thus modifying the resulting microstructures. Structural relaxation had little effect on the phase transformation temperatures of fully crystallized films, but slightly increased the resulting actuation force during transformation.
Measurements on thermodiffusion in ternary hydrocarbon mixtures at high pressure
Authors: Srinivasan S. , Saghir M. Z.
Published: September 2009

Experimental investigations on thermodiffusion have been conducted for five different ternary mixtures of methane, n-butane, and n-dodecane at a high temperature and pressure. While the mole fraction of methane was fixed at 0.2 the mole fraction of n-dodecane was varied from 0.7 to 0.2. The experiments were performed in a microgravity environment on board the satellite FOTON-M3. It was found that in all mixtures, n-dodecane separated to the cold side whereas methane segregated to the hot side. n-butane, the species with an intermediate density, showed a change in sign as its mole fraction was increased. At low concentrations it collected on the cold side but moved in the opposite direction with an increase in its mole fraction. The role of the relative density coupled with the species concentrations has been used to explain the thermodiffusion factor in each mixture. Computational investigations showed a similar behavior. However, the theoretical model was not able to capture the sign change of n-butane accurately. The inadequate representation of the significance of the relative densities and the mole fraction of the species has been found as the reason for this.
Adsorption-induced magnetic properties and metallic behavior of graphene
Authors: Zhou Y. G. , Zu X. T. , Gao F. , Lv H. F. , Xiao H. Y.
Published: September 2009

Magnetic properties and electronic structures of graphene with Cl, S, and P adsorption have been investigated using ab initio calculations. The adsorption of Cl leads to Fermi level shifting to valence band, which results in metallic graphene. A band gap of 0.6 eV emerges in a S-absorbed graphene, leading to the semiconducting graphene. The unpaired electrons in the absorbed P atom are polarized and thus exhibit a magnetic moment of 0.86μB, while no magnetic moment has been observed after Cl and S adsorption. This demonstrates that the magnetic properties and conductive behavior of graphene can be modified via atom adsorption. Specially, P-absorbed graphene may be useful for spintronic applications, such as tunneling magnetoresistance.
Coupled cluster benchmarks of water monomers and dimers extracted from density-functional theory liquid water: The importance of monomer deformations
Authors: Santra Biswajit , Michaelides Angelos , Scheffler Matthias
Published: September 2009

To understand the performance of popular density-functional theory exchange-correlation (xc) functionals in simulations of liquid water, water monomers and dimers were extracted from a PBE simulation of liquid water and examined with coupled cluster with single and double excitations plus a perturbative correction for connected triples [CCSD(T)]. CCSD(T) reveals that most of the dimers are unbound compared to two gas phase equilibrium water monomers, largely because monomers within the liquid have distorted geometries. Of the three xc functionals tested, PBE and BLYP tend to predict too large dissociation energies between monomers within the dimers. We show that this is because the cost to distort the monomers to the geometries they adopt in the liquid is systematically underestimated with these functionals. PBE0 reproduces the CCSD(T) monomer deformation energies very well and consequently the dimer dissociation energies much more accurately than PBE and BLYP. Although this study is limited to water monomers and dimers, the results reported here may provide an explanation for the overstructured radial distribution functions routinely observed in BLYP and PBE simulations of liquid water and are of relevance to water in other phases and to other associated molecular liquids.
Low temperature hydrothermal epitaxy and Raman study of heteroepitaxial BiFeO3 film
Authors: Rout Dibyaranjan , Han Seung Ho , Moon Kyoung-Seok , Kim Ho Gi , Cheon Chae Il , Kang Suk-Joong L.
Published: September 2009

By hydrothermal epitaxy, a heteroepitaxial BiFeO3 (BFO) film of ∼2.5 μm thickness was grown on a (100)-oriented single-crystalline SrTiO3 (STO) substrate at 200 °C, which is at least 250 °C lower than the conventional techniques used thus far. The x-ray diffraction pattern indicated the formation of a single-phase perovskite structure that was highly oriented along the (00l) lattice plane. Pole-figure and Φ-scan results confirmed the cube-on-cube epitaxial relationship of BFO∥STO. The Raman active vibrational modes showed anomalous changes in the vicinity of the Neel temperature (TN), which was attributed to spin-phonon coupling.
Nitridating r-plane sapphire to improve crystal qualities and surface morphologies of a-plane GaN grown by metalorganic vapor phase epitaxy
Authors: Ma Bei , Hu Weiguo , Miyake Hideto , Hiramatsu Kazumasa
Published: September 2009

Effects of the nitridation of the r-plane sapphire were investigated on the growth of a-plane GaN. Surface morphology and crystal quality were very sensitive to the nitridated time. A high quality a-plane GaN with a pit free-surface was obtained with nitridation at 1100 °C for 5 min, compared with under- or overnitridation. Nitridated layer were identified as AlN grains with ⟨112¯0⟩ preferred orientation, which acted as the nuclearation layers for a-plane GaN growth. Moreover, the qualities improvements were attributed to enhancing grain uniformity and size with 5 min nitridation.
Diffraction of spin waves from a submicrometer-size defect in a microwaveguide
Authors: Birt Daniel R. , O’Gorman Brian , Tsoi Maxim , Li Xiaoqin , Demidov Vladislav E. , Demokritov Sergej O.
Published: September 2009

We have experimentally studied the diffraction of spin waves propagating in a Permalloy-film microwaveguide from a submicrometer-sized circular defect. For microwave excitation above the cutoff frequency of the fundamental transverse mode, the defect leads to a frequency dependent reflection of the spin wave. The efficiency of the reflection appears to be dependent on the wavelength of the incident spin wave in a nonmonotonous way. The observed two-dimensional spin wave distribution pattern after the defect can be understood based on the interference of several copropagating modes, suggesting that the defect couples the fundamental mode with higher order modes.
Quantum recoil and Bohm diffusion
Authors: Melrose D. B. , Mushtaq A.
Published: September 2009

It is argued that the inclusion of the Bohm potential in quantum fluid equations is equivalent to inclusion of a nonrelativistic form of the quantum recoil in plasma kinetic theory. The Bohm term is incorrect when applied to waves with phase speed greater than the speed of light.
Modernisation and the Practices of Contemporary Food Shopping
Authors: Everts Jonathan , Jackson Peter
Published: September 2009

This paper examines the relationship between modernisation, consumption, and society, challenging received ideas about the distinction between ‘modern’ and ‘premodern’ geographies of food consumption. While conventional accounts posit a historical progression from premodern to modern forms of consumption, associated with the rise of the supermarket and the demise of the corner store, we argue that such distinctions may, in fact, refer less to a historical process of transition than to a contrast between different forms of contemporary sociality, experienced simultaneously in different sites of consumption. By drawing critically on the work of Augé and his contrast between places and nonplaces, these ideas are then put to work empirically in an examination of contemporary food shopping in Germany, focusing particularly on notions of consumer trust. A practice-based and ethnographically informed account of food shopping in Germany shows how distinctions between ‘traditional’ and ‘modern’ forms of consumption involve historicised accounts of contemporary consumption spaces and their associated socialities rather than referring to historical differences per se.
How effective are minimally trained/experienced volunteer mental health counsellors? Evaluation of CORE outcome data
Authors: Armstrong Joe
Published: September 2009

Background: Existing research findings indicate that minimally trained/experienced paraprofessional counsellors can be as effective as professionally trained and experienced counsellors. More research into the effectiveness of paraprofessionals with specific client populations is required to determine the conditions under which they can be most effective. Aims: To evaluate the effectiveness of a group of 12 minimally trained/experienced volunteer mental health counsellors. Method: Data were collected over a one year period on 118 clients referred to a voluntary sector counselling agency. The CORE‐OM was used to measure clients' levels of distress on a session‐by‐session basis. Clients and counsellors also completed a range of additional self‐report measures. A benchmarking strategy was used to evaluate the outcomes achieved by participants in this study against three benchmark studies selected from published literature. Results: Paraprofessionals in this study were less effective than their professional counterparts. Results showed that participants in this study achieved an effect size of .70 compared to effect sizes of 1.36, 1.39 and 1.42 in the selected benchmark studies. Implications: Findings suggest that minimally trained/experienced paraprofessional counsellors working in mental health settings may benefit from longer and more targeted training programmes before engaging in practice. Conclusions: The benchmarking strategy provided a valuable and practical means of evaluating the comparative effectiveness of paraprofessional and professional counsellors. Findings should be interpreted cautiously as the selected benchmarks are not precise measurements and may not reflect the organisational factors operating within voluntary sector counselling agencies.
Regulation of ClC-1 and KATP channels in action potential–firing fast-twitch muscle fibers
Authors: Pedersen Thomas Holm , de Paoli Frank Vincenzo , Flatman John A. , Nielsen Ole Bækgaard
Published: September 2009

Action potential (AP) excitation requires a transient dominance of depolarizing membrane currents over the repolarizing membrane currents that stabilize the resting membrane potential. Such stabilizing currents, in turn, depend on passive membrane conductance (Gm), which in skeletal muscle fibers covers membrane conductances for K+ (GK) and Cl− (GCl). Myotonic disorders and studies with metabolically poisoned muscle have revealed capacities of GK and GCl to inversely interfere with muscle excitability. However, whether regulation of GK and GCl occur in AP-firing muscle under normal physiological conditions is unknown. This study establishes a technique that allows the determination of GCl and GK with a temporal resolution of seconds in AP-firing muscle fibers. With this approach, we have identified and quantified a biphasic regulation of Gm in active fast-twitch extensor digitorum longus fibers of the rat. Thus, at the onset of AP firing, a reduction in GCl of ∼70% caused Gm to decline by ∼55% in a manner that is well described by a single exponential function characterized by a time constant of ∼200 APs (phase 1). When stimulation was continued beyond ∼1,800 APs, synchronized elevations in GK (∼14-fold) and GCl (∼3-fold) caused Gm to rise sigmoidally to ∼400% of its level before AP firing (phase 2). Phase 2 was often associated with a failure to excite APs. When AP firing was ceased during phase 2, Gm recovered to its level before AP firing in ∼1 min. Experiments with glibenclamide (KATP channel inhibitor) and 9-anthracene carboxylic acid (ClC-1 Cl− channel inhibitor) revealed that the decreased Gm during phase 1 reflected ClC-1 channel inhibition, whereas the massively elevated Gm during phase 2 reflected synchronized openings of ClC-1 and KATP channels. In conclusion, GCl and GK are acutely regulated in AP-firing fast-twitch muscle fibers. Such regulation may contribute to the physiological control of excitability in active muscle.
Photodynamic therapy using light‐emitting diodes for the treatment of viral warts
Authors: OHTSUKI Akiko , HASEGAWA Toshio , HIRASAWA Yusuke , TSUCHIHASHI Hitoshi , IKEDA Shigaku
Published: September 2009

Photodynamic therapy with topical 5‐aminolevulinic acid is an effective and safe treatment for actinic keratosis and superficial non‐melanoma skin cancer. Further, some studies have reported good efficacy when using photodynamic therapy to treat viral warts. The light‐emitting diode is an incoherent, narrow‐spectrum light source. The purpose of this study is to evaluate the efficacy of photodynamic therapy using a light‐emitting diode for viral warts. Six patients with a total of 41 foot and hand warts were recruited in this study. They were treated with 20% 5‐aminolevulinic acid cream under occlusion for 5 h. Thereafter, the treated area was irradiated with the light from a red light‐emitting diode (633 ± 6 nm) with a dose of 126 J/cm2. This treatment was repeated at 2‐ or 3‐week intervals. The rate of improvement observed in patients was 68.3%. The adverse effects included mild to moderate pain and erythema, which was well‐tolerated by all six patients. No patients withdrew from the study due to the adverse effects. Photodynamic therapy with topical 5‐aminolevulinic acid using the light from a red light‐emitting diode has the advantage of non‐invasiveness, minimal associated adverse reactions, and production of good results in a significant proportion of cases: therefore, it is an alternative treatment for recalcitrant viral warts.
Skin barrier function recovery after diamond microdermabrasion
Authors: KIM Hei Sung , LIM Sook Hee , SONG Ji Youn , KIM Mi‐Yeon , LEE Ji Ho , PARK Jong Gap , KIM Hyung Ok , PARK Young Min
Published: September 2009

Microdermabrasion is a popular method for facial rejuvenation and is performed worldwide. Despite its extensive usage, there are few publications on skin barrier change after microdermabrasion and none concerning diamond microdermabrasion. Our object was to see changes in transepidermal water loss (TEWL), hydration and erythema of the face following diamond microdermabrasion. Twenty‐eight patients were included in this spilt face study. TEWL, stratum corneum hydration and the degree of erythema were measured from the right and left sides of the face (forehead and cheek) at baseline. One side of the face was treated with diamond microdermabrasion and the other side was left untreated. Measurements were taken right after the procedure and repeated at set time intervals. Diamond microdermabrasion was associated with a statistically significant increase in TEWL immediately after the procedure and at 24 h. However, on day 2, levels of TEWL were back to baseline. An increase in hydration and erythema was observed right after microdermabrasion, but both returned to baseline on day 1. The results show that skin barrier function of the forehead and cheek recovers within 2 days of diamond microdermabrasion. Diamond microdermabrasion performed on a weekly basis, as presently done, is expected to allow sufficient time for the damaged skin to recover its barrier function in most parts of the face.
Exclusion of livestock grazing and wood collection in dryland savannah: an effect on long‐term vegetation succession
Authors: Hejcmanová Pavla , Hejcman Michal , Camara Abdoul Aziz , Antonínová Markéta
Published: September 2009

Sahelian savannah faces increasing pressure from human activities, leading to its degradation. The aim of this study was to investigate the possibility of restoration of dryland savannah vegetation by the elimination of disturbance factors on the ecosystem. Is degraded dryland savannah vegetation able to be restored by means of natural succession? What is the timescale for its recovery? The study took place in the Bandia Reserve, 65 km south‐east of Dakar (Senegal), a unique site with two successional stages due to the elimination of uncontrolled exploitation. The vegetation structure of 15 years (15YRS) and 5 years (5YRS) after fencing was compared with vegetation exposed to continuous livestock grazing and wood collection outside the fenced area. Calculated by redundancy analysis, a significant effect of selected areas on the cover of all species was revealed and successional stage explained more than 45% of data variability. Perennial forbs, annual forbs and perennial grasses achieved the highest cover in 5YRS, woody species in 15YRS and annual grasses in the area outside of the fenced reserve. The dominant woody species Acacia seyal, A. ataxacantha, A. nilotica subsp. adstringens and Balanites aegyptiaca reconstituted the dense formation of Acacia bushland by means of natural succession in the 15YRS area.
Age, growth and reproduction of Marcusenius pongolensis, Oreochromis mossambicus and Schilbe intermedius in an oligotrophic impoundment in Swaziland
Authors: Booth Anthony J. , Khumalo Nokuthula
Published: September 2009

The age, growth and reproductive biology of Marcusenius pongolensis, Oreochromis mossambicus and Schilbe intermedius were investigated in the Mnjoli Dam, Swaziland. Otolith annulus formation occurred in winter for M. pongolensis, and in spring/summer for O. mossambicus and S. intermedius. Maximum ages of 8, 6 and 8 years were recorded for M. pongolensis, O. mossambicus and S. intermedius, respectively. Growth was described by the von Bertalanffy growth model as Lt = 238.73(1 − exp−0.27(t+2.27) mm fork length (FL) for M. pongolensis, Lt = 226.83(1 − exp−0.45(t+2.02)) mm total length (TL) for O. mossambicus, and Lt = 214.59(1 − exp−0.60(t+1.20)) mm FL for S. intermedius. Sexual maturity was estimated for male and female M. pongolensis at 134 mm FL and 119 mm FL, respectively. Marcusenius pongolensis matured within their first year. Female O. mossambicus and S. intermedius matured at 239 mm TL and 205 mm FL, corresponding to 2 and 4 years of age, respectively. Extended spawning periods, with two spawning peaks was observed for M. pongolensis, one in spring (September) and the second in autumn (March) and one peak over late‐summer for S. intermedius.
Intra‐lake stable isotope ratio variation in selected fish species and their possible carbon sources in Lake Kyoga (Uganda): implications for aquatic food web studies
Authors: Mbabazi Dismas , Makanga B. , Orach‐Meza F. , Hecky R. E. , Balirwa J.S. , Ogutu‐Ohwayo R. , Verburg P. , Chapman L. , Muhumuza E.
Published: September 2009

The stable isotopes of nitrogen (δ15N) and carbon (δ13C) provide powerful tools for quantifying trophic relationships and carbon flow to consumers in food webs; however, the isotopic signatures of organisms vary within a lake. Assessment of carbon and nitrogen isotopic signatures in a suite of plants, invertebrates, and fishes in Lake Kyoga, indicated significant variation between two sites for δ13C (paired t = 6.305; df = 14, P < 0.001 and δ15N paired t = 1.292; df = 14; P < 0.05). The fish fauna in Bukungu was generally more 13C enriched (mean δ13C = –16.37 ± 1.64‰) than in Iyingo (mean δ13C = –20.80 ± 2.41‰) but more δ15N depleted (mean δ15N = 5.57 ± 0.71‰) than in Iyingo (mean δ15N = 6.92 ± 0.83‰). The simultaneous shifts in phytoplankton and consumer signatures confirmed phytoplankton as the major source of carbon for the food chain leading to fish. Limited sampling coverage within lakes may affect lake wide stable isotope signatures, and the same error is transferred into trophic position estimation. Consideration of potential intra‐lake spatial variability in isotope ratios and size is essential in evaluating the spatial and trophic structure of fish assemblages.
Synthesis of a seismic virtual reflector*
Authors: Poletto Flavio , Farina Biancamaria
Published: September 2009

We describe a method to process the seismic data generated by a plurality of sources and registered by an appropriate distribution of receivers, which provides new seismic signals as if in the position of the receivers (or sources) there was an ideal reflector, even if this reflector is not present there. The data provided by this method represent the signals of a virtual reflector. The proposed algorithm performs the convolution and the subsequent sum of the real traces without needing subsurface model information. The approach can be used in combination with seismic interferometry to separate wavefields and process the reflection events. The application is described with synthetic examples, including stationary phase analysis and with real data in which the virtual reflector signal can be appreciated.
Drill‐bit seismic interferometry with and without pilot signals*
Authors: Poletto Flavio , Corubolo Piero , Comelli Paolo
Published: September 2009

We use different interferometry approaches to process the seismic signals generated by a drill‐bit source in one well and recorded by seismic receivers located both in a second borehole and at the surface near the source well. We compare the standard interferometry results, obtained by using the raw drill‐bit data without a pilot signal, with the new interferometry results obtained by using the drill‐bit seismograms correlated with a reference pilot signal. The analysis of the stationary phase shows that the final results have different S/N levels and are affected by the coherent noise in the form of rig arrivals. The interferometry methods are compared by using different deconvolution approaches. The analysis shows that the results agree with the conventional drill‐bit seismograms and that using the reference pilot signal improves the quality of the drill‐bit wavefields redatumed by the interferometry method.
Carry‐over effect of larval settlement cue on postlarval gene expression in the marine gastropod Haliotis asinina
Authors: WILLIAMS ELIZABETH A. , DEGNAN SANDIE M.
Published: September 2009

The drastic shift from pelagic larvae to benthic adult form that occurs during marine invertebrate metamorphosis is often induced by intimate interactions between settling larvae and their benthic environment. Larval experience prior to and during metamorphosis can significantly affect adult fitness, but it is presently unknown whether the exact nature of the inductive cue is an experience that matters, or by what mechanism such carry‐over effects are mediated. Here we test for carry‐over effects of the specific nature of inductive cues on gene expression in metamorphosing postlarvae of the tropical abalone, Haliotis asinina. Postlarvae induced by three different species of coralline algae all successfully undergo metamorphosis, yet the expression profiles of 11 of 17 metamorphosis‐related genes differ according to which species of algae the larvae settled upon. Significantly, several genes continue to be differentially expressed for at least 40 h after removal of the algae from the postlarvae, clearly demonstrating a carry‐over effect of inductive cue on gene expression. We observe a carryover effect in several genes with varying functions and spatial expression patterns, indicating that each algal species impacts global gene expression in a unique manner. These data unexpectedly reveal that transcriptional modulation of metamorphosis‐related genes is contingent upon the precise composition of the benthic microenvironment experienced directly at induction of settlement, and highlight transcription as a mechanism that can mediate between larval and postlarval experiences. For new recruits into an abalone population, metamorphosis clearly does not represent a new transcriptional beginning.
Molecular systematics and phylogeny of the ‘Marbled Whites' (Lepidoptera: Nymphalidae, Satyrinae, Melanargia Meigen)
Authors: NAZARI VAZRICK , HAGEN WOLFGANG TEN , BOZANO GIAN CHRISTOFORO
Published: September 2009

Abstract. We investigated genetic divergence and phylogenetic relationships amongst all known species of Palaearctic butterflies of the genus Melanargia using sequence information from three genes [mitochondrial cox1 barcode region (658 bp), ribosomal 16S rRNA (c. 518 bp), and nuclear wg (404 bp)]. Results show a lack of DNA divergence among several poorly characterized taxa, as well as deep divergences within and between others. We corroborated the molecular information with morphological and genitalic characters as well as with geographic data. We revise the taxonomy of Melanargia, and propose a new systematic scheme for the group. We revive some previous synonymies (M. lucasi meadwaldoistat. rev., M. ines fathmestat. rev., M. ines jahandiezistat. rev., M. meridionalis tapaishanensisstat. rev.), revise the status of some subspecies into species (M. transcaspicastat. nov., M. lucidastat. nov., M. wiskottistat. nov.) and of several species into subspecies of other taxa (M. evartianae sadjadiistat. nov., M. larissa hylatastat. nov., M. larissa grumistat. nov., M. larissa syriacastat. nov., M. larissa titeastat. nov., M. lugens montanastat. nov., M. epimede ganymedesstat. nov.), revise the status of subspecies and transfer them to other species (M. larissa lorestanensisstat. nov., M. larissa iranicastat. nov., M. larissa karabagistat. rev., M. larissa kocakistat. nov., M. transcaspica ebertistat. nov.), and propose new synonymies (M. larissa titea = M. titea standfussisyn. nov. = M. titea titaniasyn. nov., M. leda leda = M. leda yunnanasyn. nov., M. lugens lugens = M. lugens ahyouisyn. nov., M. lugens hengshanensis = M. lugens hoeneisyn. nov., M. halimede halimede = M. halimede gratianisyn. nov., M. asiatica asiatica = M. asiatica dejeanisyn. nov., = M. asiatica elisasyn. nov., = M. asiatica sigbertisyn. nov.).
Invasive non‐typhoidal Salmonella in Mozambican children
Authors: Mandomando Inácio , Macete Eusébio , Sigaúque Betuel , Morais Luis , Quintó Llorenç , Sacarlal Jahit , Espasa Mateu , Vallès Xavier , Bassat Quique , Aide Pedro , Nhampossa Tacilta , Machevo Sonia , Ruiz Joaquim , Nhacolo Ariel , Menéndez Clara , Kotloff Karen L. , Roca Anna , Levine Myron M. , Alonso Pedro L.
Published: September 2009

Objective  To describe the epidemiology and clinical presentation of invasive non‐typhoidal Salmonella (NTS) in Mozambique.

Methodology  We analysed the epidemiology, clinical presentation and serotype distribution of invasive NTS among Mozambican children admitted to the Manhiça District Hospital between May 2001 and April 2006.

Results  A total of 401 NTS cases were analysed; the median age was 16 months [interquartile range (IQR): 10–24]. Fever, cough and increased respiratory rate were the most common symptoms reported, while diarrhoea was present in only 29%. In the univariate analysis, invasive NTS was associated with age, fever, diarrhoea, increased respiratory rate, splenomegaly, hepatomegaly, severe malnutrition, and severe anaemia. Young age, severe malnutrition, diarrhoea and pneumonia were independent risk factors of death. S. typhimurium (66%), and S. enteritidis (25%) were the most frequent serotypes, with incidence rates of 240.4 and 108.6 per 100 000 child years among infants for S. typhimurium and S. enteritidis, respectively; and no significant differences were found regarding their clinical presentation. Resistance to ampicillin, chloramphenicol and trimethoprim‐sulfamethoxazole was high for both S. typhimurium and S. enteritidis.

Conclusions  Clinical presentation of invasive NTS was non‐specific and similar to that of other infections, with some factors being associated with NTS. Antibiotic resistance was very common to currently recommended and available antibiotics for suspected sepsis.
China’s new strategy to block Schistosoma japonicum transmission: experiences and impact beyond schistosomiasis
Authors: Wang Long‐De , Guo Jia‐Gang , Wu Xiao‐Hua , Chen Hong‐Gen , Wang Tian‐Ping , Zhu Shao‐Ping , Zhang Zhi‐Hai , Steinmann Peter , Yang Guo‐Jing , Wang Shi‐Ping , Wu Zhong‐Dao , Wang Li‐Ying , Hao Yang , Bergquist Robert , Utzinger Jürg , Zhou Xiao‐Nong
Published: September 2009

Despite sustained efforts for its control made over the past 50+ years, the re‐emergence of schistosomiasis in China was noted around the turn of the new millennium. Consequently, a new integrated strategy was proposed to stop the contamination of schistosome eggs to the environment, which emphasizes health education, access to clean water and adequate sanitation, mechanization of agriculture and fencing of water buffaloes, along with chemotherapy. Validation of this integrated control strategy in four pilot counties in the provinces of Anhui, Hubei, Hunan and Jiangxi revealed significant reductions in the rate of Schistosoma japonicum infection in humans and intermediate host snails. Importantly, this strategy showed an impact on diseases beyond schistosomiasis, signified by concomitant reductions in the prevalence of soil‐transmitted helminth infections. In view of China’s new integrated strategy for transmission control of schistosomiasis showing an ancillary benefit on other helminthic diseases, we encourage others to investigate the scope and limits of integrated control of neglected tropical diseases.
Chapter 1: Key ethical requirements and progress toward the definition of an international regulatory framework
Authors: Cozzi Emanuele , Tallacchini Mariachiara , Flanagan Enda B. , Pierson III Richard N. , Sykes Megan , Vanderpool Harold Y.
Published: September 2009

Abstract:  The outstanding results recently obtained in islet xenotransplantation suggest that porcine islet clinical trials may soon be scientifically appropriate. Before the initiation of such clinical studies, however, it is essential that a series of key ethical and regulatory conditions are satisfied. As far as ethics is concerned, the fundamental requirements have been previously reported in a position paper of the Ethics Committee of the International Xenotransplantation Association. These include aspects related to the selection of adequately informed, appropriate recipients; animal breeding and welfare; safety issues and the need for a favorable risk/benefit assessment based on strong efficacy data in relevant xenotransplantation studies in the primate. As most diabetic patients are not at risk of short‐term mortality without islet transplantation, only a small subset of patients could currently be considered for any type of islet transplant. However, there are potential advantages to xenotransplantation that could result in a favorable benefit‐over‐harm determination for islet xenotransplantation in this subpopulation and ultimately in a broader population of diabetic patients. With regard to regulatory aspects, the key concepts underlying the development of the regulatory models in existence in the United States, Europe and New Zealand are discussed. Each of these models provides an example of a well‐defined regulatory approach to ensure the initiation of well‐regulated and ethically acceptable clinical islet xenotransplantation trials. At this stage, it becomes apparent that only a well‐coordinated international effort such as that initiated by the World Health Organization, aimed at harmonizing xenotransplantation procedures according to the highest ethical and regulatory standards on a global scale, will enable the initiation of clinical xenotransplantation trials under the best auspices for its success and minimize any risk of failure.
Leptin mRNA and Protein Immunoreactivity in Adipose Tissue and Liver of Rainbow Trout (Oncorhynchus mykiss) and Immunohistochemical Localization in Liver
Authors: Pfundt B. , Sauerwein H. , Mielenz M.
Published: September 2009

Leptin is an important modulator of energy balance and metabolism in mammals, but for evolutionary older vertebrates like fish, the first reports on leptin expression were only recently characterized and the functional role scarcely. In this study, we demonstrated leptin immunoreactivity in liver tissue of rainbow trout (Oncorhynchus mykiss) by immunohistochemistry using three different polyclonal antibodies against mammalian leptin. Immunoreactivity was observed in hepatocytes and also in parts of the biliary system. Using Western blot, we detected an immunoreactive band of about 16 kDa in serum and visceral adipose tissue (AT) of rainbow trout. The presence of leptin in fish AT has been doubted in other studies. Besides the immunoreactivity, leptin mRNA was detected in trout AT albeit not in all animals sampled. Our observations add further evidence to the concept of AT being a source of leptin in trouts. Moreover, the cellular localization of leptin immunoreactivity in liver opens up new vistas for understanding the functional role of leptin in teleosts.
Pax‐3 and Pax‐7 Label Muscle Progenitor Cells During Myotomal Myogenesis in Coregonus lavaretus (Teleostei: Coregonidae)
Authors: Kacperczyk A. , Jagla T. , Daczewska M.
Published: September 2009

In Coregonus lavaretus, prior the mesoderm segmentation, in cells adjacent to the notochord called adaxial cells MyoD and slow myosin heavy chain (MyHC‐slow) proteins were observed. After somite formation, adaxial cells migrate towards the lateral part of the myotome and form a layer of red muscles. Deeper cells differentiate into white muscle fibres. In situ hybridization using Pax‐3 molecular probe revealed, that after somitogenesis, Pax‐3 is expressed in a layer of cells superficial to the myotome resembling the “external cells” (found in many teleosts species) or dermomyotome described in Amniota. During later developmental stages Pax‐3 gene is expressed in cells in intermyotomal space and then in myoblasts between myotubes. In these cells Pax‐7 protein was also observed. Pax‐3/7 positive cells which have migrated into the myotomes differentiate into satellite cells/secondary myoblasts and participate in hypertrophic and hyperplastic growth of muscles.
Adenosine A1 receptor activation reduces opening of mitochondrial permeability transition pores in hypoxic cardiomyocytes
Authors: Xiang Fei , Huang Yue‐sheng , Zhang Dong‐xia , Chu Zhi‐gang , Zhang Jia‐ping , Zhang Qiong
Published: September 2009

1. Adenosine A1 receptors (A1R) play an important role in cardioprotection against hypoxic damage and the opening of mitochondrial permeability transition pores (MPTP) is central to the regulation of cell apoptosis and necrosis. However, it is still unclear whether A1R open MPTP in hypoxic cardiomyocytes.

2. The present study used primary cardiomyocyte cultures from neonatal rats to investigate the mechanisms of A1R activation and the effects of A1R on MPTP opening under hypoxic conditions.

3. Hypoxia increased both MPTP opening and the production of reactive oxygen species (ROS), while decreasing cell viability and mitochondrial membrane potential (Δψ). The A1R agonist 2‐chloro‐N6‐cyclopentyladenosine (CCPA; 500 nmol/L) blocked the increase in MPTP opening and ROS production and maintained cell viability and Δψ under hypoxic conditions.

4. The protective effects of CCPA were eliminated by both the protein kinase C (PKC) inhibitor chelerythine (2 μmol/L) and the mitochondrial ATP‐sensitive K+ channel (mitoKATP) inhibitor 5‐hydroxydecanoate (500 μmol/L). Moreover, CCPA significantly increased the PKC content in both total protein and membrane protein of cardiomyocytes. 5‐Hydroxydecanoate did not prevent these CCPA‐induced increases in PKC.

5. These results demonstrate that CCPA reduces MPTP opening in hypoxic cardiomyocytes, possibly by activating PKC, stabilizing Δψ and reducing ROS production following the opening of mitoKATP. Consequently, fewer MPTP open.
Neuronal network properties underlying the generation of gasping
Authors: Peña Fernando
Published: September 2009

1. The pre‐Bötzinger complex (PreBötC) generates different inspiratory rhythms. Under control normoxic conditions, a mixture of intrinsic and synaptic properties underlies the generation of eupnoea by the PreBötC. Under hypoxia, those network properties change and modify the respiratory rhythm pattern. Hypoxia can be caused by a reduction in oxygen availability in the environment, inadequate oxygen transport, an inability of tissues to use oxygen or several pathological conditions.

2. During severe hypoxia, the network properties within the PreBötC are reconfigured whereby the network no longer generates eupnoea, but instead generates a new rhythm, named gasping. Such reconfiguration includes changes in synaptic and intrinsic properties triggered by hypoxia itself, as well as the influence of different neuromodulators released during hypoxia. Gasping has been considered an important arousal mechanism that triggers autoresuscitation. Dysregulation of gasping has been proposed to result in failure to autoresuscitate and has been hypothesised to contribute to Sudden Infant Death Syndrome.

3. Precisely which synaptic and/or neuronal intrinsic membrane properties are critical to central respiratory rhythmogenesis, in either normoxia or hypoxia, is still the subject of considerable debate. In the present article I review how hypoxia alters the respiratory network and discuss my hypotheses regarding the cellular and network mechanisms involved in gasping rhythm generation. Finally, I review changes in the hypoxic response during postnatal development and the contribution of several neuromodulators to such a response.
Upregulation of angiotensin‐converting enzyme (ACE) 2 in hepatic fibrosis by ACE inhibitors
Authors: Huang Mao‐liang , Li Xu , Meng Ying , Xiao Bing , Ma Qiang , Ying Song‐song , Wu Ping‐sheng , Zhang Zhen‐shu
Published: September 2009

1. The role of angiotensin‐converting enzyme (ACE) 2 is likely to balance the status of the renin–angiotensin system (RAS) by degrading angiotensin (Ang) II and generating Ang‐(1–7). Earlier demonstrations that ACE2 is insensitive to ACE inhibitors prompted us to evaluate the effect of ACE inhibitors on ACE2 expression.

2. Liver fibrosis was induced in rats with 40% CCl4 (2.5 mL/kg, s.c., twice per week). Half the rats were further treated with perindopril (2 mg/kg, p.o., daily). After 2 and 4 weeks treatment, ACE2 immunoreactivity was assessed by immunohistochemical staining, ACE2 protein expression was determined by western blot and mRNA expression of ACE2 and the Ang‐(1–7) receptor Mas was determined by reverse transcription–polymerase chain reaction (RT‐PCR).

3. As an in vitro study, hepatic stellate cells (HSC) were treated with AngII (0.1–10 μmol/L) alone or in combination with the synthesized peptide ACEI (Sigma‐Aldrich). Western blot and RT‐PCR were used to evaluate ACE2 expression and Mas mRNA levels. Furthermore, after treatment of HSC with the Mas antagonist A779 (1 μmol/L), the protein expression of connective tissue growth factor (CTGF) was detected to evaluate the interaction between AngII, ACEI and the ACE2–Mas axis.

4. Expression of both ACE2 mRNA and protein and Mas mRNA was markedly upregulated in both CCl4‐injured rat liver and AngII‐treated HSC. Further significant upregulation was observed following additional administration of ACEI. In addition, ACEI treatment of HSC inhibited AngII–induced overexpression of connective tissue growth factor and this effect was ameliorated by blockade of the Mas receptor with A779.

5. The findings of the present study suggest that ACE inhibitors are able to upregulate ACE2 under conditions of liver injury both in vivo and in vitro, which may indicate potential benefits of ACE inhibitors in the therapeutic treatment of liver fibrosis.
The hypotensive effect of intravenous amiodarone is sustained throughout the maintenance infusion period
Authors: Cushing Daniel J , Cooper Warren D , Gralinski Michael R , Lipicky Raymond J
Published: September 2009

1. Hypotension frequently occurs with use of intravenous amiodarone and is managed by slowing the rate of administration. This response has been attributed to the cosolvents in the formulation and is believed to be solely related to the initial loading dose. The present study was performed to determine whether intravenous amiodarone‐induced hypotension persists beyond the loading dose and into the maintenance infusion period and also whether hypotension occurs with maintenance level dosing alone.

2. Anaesthetized beagle dogs (n = 7/group) were instrumented to assess haemodynamics. Animals were treated with the human‐equivalent dosing regimen (loading dose followed by maintenance infusion) of intravenous amiodarone or control (5% dextrose in water).

3. No haemodynamic changes were observed in the control group during the 6 h study. In contrast, administration of the standard intravenous amiodarone regimen produced rapid and significant decreases in mean aortic pressure, cardiac output and maximum rate of change of left ventricular pressure that persisted throughout the 6 h maintenance infusion period. Administration of amiodarone as the maintenance infusion dose alone produced haemodynamic changes that were similar in magnitude to those observed with administration of the full dosing regimen, but were delayed in onset by approximately 60 min.

4. Dosing with a cosolvent‐free formulation of amiodarone (PM101) caused no haemodynamic effects during the 6 h dosing period, indicating that the cardiodepressant effects of intravenous amiodarone were due to its cosolvents.

5. These data suggest that consideration should be given to intravenous amiodarone as a potential cause for sustained hypotension during prolonged infusion.