bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal response of a surface flashover on a velvet cathode in a relativistic diode
Authors: Coleman J. E. , Moir D. C. , Crawford M. T. , Welch D. R. , Offermann D. T.
Published: March 2015

Surface flashover of a carbon fiber velvet cathode generates a discharge from which electrons are relativistically accelerated to γ ranging from 4.9 to 8.8 through a 17.8 cm diode. This discharge is assumed to be a hydrocarbon mixture. The principal objective of these experiments is to quantify the dynamics over the ∼100 ns pulse of the plasma discharge generated on the surface of the velvet cathode and across the anode-cathode (A-K) gap. A qualitative comparison of calculated and measured results is presented, which includes time resolved measurements with a photomultiplier tube and charge-coupled device images. In addition, initial visible spectroscopy measurements will also be presented confirming the ion species are dominated by hydrogen.
Solitary structures in a spatially nonuniform degenerate plasma in the presence of quantizing magnetic field
Authors: Masood W. , Shaukat Muzzamal I. , Shah H. A. , Mirza Arshad M.
Published: March 2015

In the present investigation, linear and nonlinear propagation of low frequency (ω≪Ωci) electrostatic waves have been studied in a spatially inhomogeneous degenerate plasma with one dimensional electron trapping in the presence of a quantizing magnetic field and finite temperature effects. Using the drift approximation, formation of 1 and 2D drift ion solitary structures have been studied both for fully and partially degenerate plasmas. The theoretical results obtained have been analyzed numerically for the parameters typically found in white dwarfs for illustrative purpose. It is observed that the inclusion of Landau quantization significantly changes the expression of the electron number density of a dense degenerate plasma which affects the linear and nonlinear propagation of drift acoustic solitary waves in such a system. The present work may be beneficial to understand the propagation of drift solitary structures with weak transverse perturbation in a variety of physical situations, such as white dwarfs and laser-induced plasmas, where the quantum effects are expected to dominate.
Anomalous law of cooling
Authors: Lapas Luciano C. , Ferreira Rogelma M. S. , Rubí J. Miguel , Oliveira Fernando A.
Published: March 2015

We analyze the temperature relaxation phenomena of systems in contact with a thermal reservoir that undergoes a non-Markovian diffusion process. From a generalized Langevin equation, we show that the temperature is governed by a law of cooling of the Newton’s law type in which the relaxation time depends on the velocity autocorrelation and is then characterized by the memory function. The analysis of the temperature decay reveals the existence of an anomalous cooling in which the temperature may oscillate. Despite this anomalous behavior, we show that the variation of entropy remains always positive in accordance with the second law of thermodynamics.
Ferroelectric polarization relaxation in Au/Cu2O/ZnO/BiFeO3/Pt heterostructure
Authors: Fan Zhen , Xiao Juanxiu , Yao Kui , Zeng Kaiyang , Wang John
Published: March 2015

The stability of polarization in ferroelectric BiFeO3 thin film stacked with a p-n junction of Cu2O/ZnO was studied in the Au/Cu2O/ZnO/BiFeO3/Pt heterostructure. It was observed that the downward ferroelectric polarization of BiFeO3 gradually relaxes once the external electric field is removed, which is driven by the depolarization effect induced by the reduction of compensating charges due to the charge redistribution within Cu2O/ZnO. This work contributes to an improved understanding on the polarization behavior in multilayer thin film structures comprising ferroelectrics and p-n junctions for guiding relevant device design and performance analysis.
Effect of epitaxial strain on small-polaron hopping conduction in Pr0.7(Ca0.6Sr0.4)0.3MnO3 thin films
Authors: Wang Jing , Hu Feng-xia , Zhao Ying-ying , Liu Yao , Wu Rong-rong , Sun Ji-rong , Shen Bao-gen
Published: March 2015

We investigated the epitaxial strain effect on the small-polaron hopping conduction properties in Pr0.7(Ca,Sr)0.3MnO3 (PCSMO) films. An increase in the carrier localization, as evidenced by the enhancement of the small-polaron activation energy EA in the high temperature region, was obtained by increasing the epitaxial lattice strain in either the tensile or compressive strained film. Furthermore, it was found that the magnitude of EA, and thus the carrier localization, strongly depends on the sign of the lattice strain, which explains the diverse percolative transport behaviors in PCSMO films with different types of strains. Meanwhile, similar dependencies on the strain of the films were also obtained for the electron-phonon interaction, characterized by the calculated small-polaron coupling constant. Our results reveal that the type of lattice strain plays a crucial role in determining the degree of localization of charge carriers and the electron-phonon coupling strength, which is important for understanding the lattice strain-induced various novel properties related to phase separation and percolation behaviors.
Solution processing of transparent conducting epitaxial La:BaSnO3 films with improved electrical mobility
Authors: Wei R. H. , Tang X. W. , Hui Z. Z. , Luo X. , Dai J. M. , Yang J. , Song W. H. , Chen L. , Zhu X. G. , Zhu X. B. , Sun Y. P.
Published: March 2015

As a type of perovskite transparent conducting oxides, La-doped BaSnO3 is considered as a very important material to construct all transparent perovskite devices. The difficulty in achievement of large-area films with high electrical mobility has hindered the development of La-doped BaSnO3 films. Here, we report the results about chemical solution deposition of Ba0.92La0.08SnO3−δ (BLSO) films. The post-annealing and atmosphere as well as lattice mismatch have been investigated. Post-annealing at 1000 °C can obviously improve the performance due to the enhanced crystallization. Under post-annealing in N2 atmosphere the room-temperature resistivity and electrical mobility can achieve 3.25 mΩ cm and 11.09 cm2 V−1 s−1, respectively, for the BLSO on LaAlO3 single crystal substrates due to the enhanced oxygen deficiencies. BLSO films with different orientation can be easily obtained by selection of the substrates, showing isotropic physical properties. Furthermore, the room-temperature resistivity and mobility are optimized to 1.8 mΩ cm and 23.04 cm2 V−1 s−1 when SrTiO3 single crystal substrates with smaller lattice mismatch are used due to the decreased dislocation density. The results will provide an alternative route to fabricate large-area transparent conducting alkaline-earth stannate films with high performance using low-cost chemical solution deposition.
Vickers-indentation-induced crystallization in a metallic glass
Authors: Yan Zhijie , Hu Yong , Song Kaikai , Dai Fuping , He Jie , Eckert Jürgen
Published: March 2015

Crystallization preferentially occurs on the compressive sides of some metallic glasses due to bending, implying that stress state is a critical factor affecting the mechanically induced crystallization. However, the role of stress state in mechanically induced crystallization in metallic glasses is poorly understood. Here, we report on the crystallization kinetics in different deformed regions during Vickers indentation of Zr65Al7.5Ni10Cu12.5Ag5 metallic glass. Our results indicate that the nucleation rate beneath the indenter tip is much higher than that under an indenter edge. It is revealed that the nucleation rate I (m−3 s−1) and the effective compressive stress P (MPa) follow an expression I = exp(3.81 + 0.044 P), which agrees well with our experimental results. Our findings reduce the role of stress state in mechanically induced crystallization in metallic glasses, which is helpful in understanding the mechanism of mechanically induced crystallization.
Contactless heat flux control with photonic devices
Authors: Ben-Abdallah Philippe , Biehs Svend-Age
Published: March 2015

The ability to control electric currents in solids using diodes and transistors is undoubtedly at the origin of the main developments in modern electronics which have revolutionized the daily life in the second half of 20th century. Surprisingly, until the year 2000 no thermal counterpart for such a control had been proposed. Since then, based on pioneering works on the control of phononic heat currents new devices were proposed which allow for the control of heat fluxes carried by photons rather than phonons or electrons. The goal of the present paper is to summarize the main advances achieved recently in the field of thermal energy control with photons.
Investigating the properties of interfacial layers in planar Schottky contacts on hydrogen-terminated diamond through direct current/small-signal characterization and radial line small-signal modelling
Authors: Cappelluti F. , Ghione G. , Russell S. A. O. , Moran D. A. J. , Verona C. , Limiti E.
Published: March 2015

Large-area Schottky diodes on hydrogen-terminated diamond are investigated through DC and small-signal characterization and physics-based equivalent circuit modeling. Measured current- and capacitance-voltage characteristics suggest significant distributed resistance effects induced by the relatively low mobility of the 2D hole gas in the diamond sub-surface. A distributed equivalent circuit model of the device is proposed aimed at correlating the device physics with the observed electrical behavior. It is shown that a heterostructure-like model of H-diamond Schottky contacts, including a thin non-conductive interfacial layer that separates the 2D hole channel from the Schottky barrier, enables an accurate description of both the device DC and AC behaviour and the extraction of relevant quantitative information on the physical parameters of the interface, channel charge control, and carrier mobility.
Sperm rescue in wild African elephants
Authors: Saragusty Joseph , Prieto María Teresa , Courtiol Alexandre , Potier Romain , Göritz Frank , Hildebrandt Thomas B. , Hermes Robert
Published: March 2015

This study investigated ways of improving the usefulness of ~1700 mL of poor-quality frozen semen collected from wild African elephant (Loxodonta africana) bulls. Ten semen samples from six bulls, frozen with 5% glycerol in Berliner cryomedium, with or without prior removal of the seminal plasma by centrifugation, were tested. All samples were subjected to the following density-gradient centrifugation treatments: no centrifugation (control), sham centrifugation, Percoll, OptiPrep, Isolate and PureSperm. Sample evaluation included motility, concentration, viability, acrosome integrity and normal morphology after thawing and after gradient centrifugation. Motility was also evaluated 3 h after thawing. While all treatments were similar to the Control in acrosome integrity and normal morphology, significant differences were noted in concentration, viability and motility. Samples treated by Percoll showed the best motility, which was maintained unchanged over 3 h of incubation (37°C). Correlations between manual and automated evaluations of concentration were high (cytometer; rho = 0.92), but were lower for viability (cytometer; rho = 0.57) and motility (computer-aided sperm analysis; rho = 0.66). By performing density centrifugation, the quality of these sperm samples may be improved to a level suitable for artificial insemination in elephants. Although a sizeable proportion of cells are lost in the process, combining samples may still allow for multiple inseminations.
Morphometric Contribution to the Detection of Introgressive Hybridization in the Endangered Owens Tui Chub in California
Authors: Galicia David , Leunda Pedro M. , Miranda Rafael , Madoz Javier , Parmenter Steve
Published: March 2015

The Owens Tui Chub Siphateles bicolor snyderi has become endangered by introgressive hybridization with the Lahontan Tui Chub S. bicolor obesa since the 1960s. Adequate conservation strategies require prior identification of pure populations, which is usually difficult because the diagnostic features presented in the formal subspecies description do not always allow unequivocal determination of populations. In the present study, the shape and some meristic features of the scales, along with the shape of other bones with taxonomic value, were analyzed to distinguish both parental subspecies and their hybrids in samples diagnosed in a previous work using microsatellite DNA. Scales, pharyngeal arches, dentaries, cleithra, and opercula of 211 individuals from 16 localities across the Owens River and neighbouring basins in California and Nevada were compared. The results show that the meristic parameters of the scales were in agreement with values provided by Miller (1973) for the parental subspecies. Shape analyses were based on landmark or Fourier methods, depending on the shape characteristic of each structure. Geometric morphometric analyses provided variable discriminatory power between subspecies depending on the studied bone. In scales, pharyngeal arches, and dentaries, the derived morphological patterns matched the shape descriptions set forth by Miller (1973) for both parental subspecies. In all cases, the observed morphometric variability of hybrids was too high to separate them from parental subspecies. However, joint analysis of the five structures produced groupings that were concordant with the genetic analyses: localities of parental subspecies in separate groups and an intermediate group with the hybrid swarm localities that was morphologically closer to Lahontan. Finally, a new derived parameter (the ratio between scale lengths from the anterior and posterior body) is suggested as a promising tool for rapid discrimination of Owens Tui Chub from Lahontan Tui Chub and their hybrid populations.

Received August 5, 2014; accepted December 4, 2014
Angolan civil society activism since the 1990s: reformists, confrontationists and young revolutionaries of the ‘Arab spring generation’
Authors: Vidal Nuno
Published: March 2015

Aiming for regime transformation, post-transition Angolan civil society activism moved from reformism and confrontationism to ultra-confrontationism. Reformism and confrontationism evolved until the 2008 elections, influenced by development thinking (neoliberalism/institutionalism vs neo-Marxism/world-system thinking), in two opposing strategies: ‘constructive engagement’ vs political defiance. The dispute ended with ultra-confrontationism gaining impetus with the Arab spring, with a younger generation resorting to new methods (information and communications technology and demonstrations). Despite the lack of funding or international links, the newer methods caused more concern to the regime. Nevertheless, they suffer from the same shortfalls as their predecessors: they are confined to an urban/suburban social segment, and unable to attract the majority of the population.
ER network formation and membrane fusion by atlastin1/SPG3A disease variants
Authors: Ulengin Idil , Park John J. , Lee Tina H.
Published: March 2015

At least 38 distinct missense mutations in the neuronal atlastin1/SPG3A GTPase are implicated in an autosomal dominant form of hereditary spastic paraplegia (HSP), a motor-neurological disorder manifested by lower limb weakness and spasticity and length-dependent axonopathy of corticospinal motor neurons. Because the atlastin GTPase is sufficient to catalyze membrane fusion and required to form the ER network, at least in nonneuronal cells, it is logically assumed that defects in ER membrane morphogenesis due to impaired fusion activity are the primary drivers of SPG3A-associated HSP. Here we analyzed a subset of established atlastin1/SPG3A disease variants using cell-based assays for atlastin-mediated ER network formation and biochemical assays for atlastin-catalyzed GTP hydrolysis, dimer formation, and membrane fusion. As anticipated, some variants exhibited clear deficits. Surprisingly however, at least two disease variants, one of which represents that most frequently identified in SPG3A HSP patients, displayed wild-type levels of activity in all assays. The same variants were also capable of co-redistributing ER-localized REEP1, a recently identified function of atlastins that requires its catalytic activity. Taken together, these findings indicate that a deficit in the membrane fusion activity of atlastin1 may be a key contributor, but is not required, for HSP causation.
On the birth and death of ideas in marine science†
Authors: Rothschild Brian J.
Published: March 2015

In this essay, I review six decades of my career in marine science and fisheries, considering the ideas that came and went in the period as “food for thought”. I describe my inspirations and successes, and my disappointments and failures. My activities were both administrative and research-oriented. As regards the former, I was part of major changes in ocean policy and new ocean research programmes that gave me a unique perspective. For example, I was responsible for the implementation of the US extended jurisdiction in fisheries under National Oceanic and Atmospheric Administration. Also I conceived and led the creation of the Global Ocean Ecosystem Dynamics Programme (GLOBEC) and guided it in many international contexts, including its integration with the International Geosphere Biosphere Programme (IGBP). From a research standpoint, my efforts leading up to GLOBEC strongly influenced the introduction of ocean physics into biological oceanography. This led me into plankton dynamics, food signals, small-scale turbulence and physical forcing, even into the stochastic geometry of the plankton. My life-long interest in the dynamics of marine fish populations was strongly influenced by the seminal thinkers in fisheries and my research explored population regulation processes as well as practical applications of statistics and operations research to fisheries management. In my last academic post, I became founding Dean of the School for Marine Science and Technology (SMAST) at the University of Massachusetts. This position required integrating administrative and research (both pure and applied) perspectives to create an institution of academic excellence which was at the same time actively responsive to issues arising in our local, nationally prominent fisheries. I end the essay with a consideration of “what has changed”.
Practice Improvements Based on Participation in Simulation for the Maintenance of Certification in Anesthesiology Program
Authors: Steadman Randolph H. , Burden Amanda R. , Huang Yue Ming , Gaba David M. , Cooper Jeffrey B.
Published: March 2015

AbstractAbstract

In a review of 634 Maintenance of Certification in Anesthesiology Program simulation course participants, 94% successfully implemented some or all of their planned practice improvements, which focused mostly around environment or systems changes, teamwork skills, and personal knowledge.

Background:

This study describes anesthesiologists’ practice improvements undertaken during the first 3 yr of simulation activities for the Maintenance of Certification in Anesthesiology Program.

Methods:

A stratified sampling of 3 yr (2010–2012) of participants’ practice improvement plans was coded, categorized, and analyzed.

Results:

Using the sampling scheme, 634 of 1,275 participants in Maintenance of Certification in Anesthesiology Program simulation courses were evaluated from the following practice settings: 41% (262) academic, 54% (339) community, and 5% (33) military/other. A total of 1,982 plans were analyzed for completion, target audience, and topic. On follow-up, 79% (1,558) were fully completed, 16% (310) were partially completed, and 6% (114) were not completed within the 90-day reporting period. Plans targeted the reporting individual (89% of plans) and others (78% of plans): anesthesia providers (50%), non-anesthesia physicians (16%), and non-anesthesia non-physician providers (26%). From the plans, 2,453 improvements were categorized as work environment or systems changes (33% of improvements), teamwork skills (30%), personal knowledge (29%), handoff (4%), procedural skills (3%), or patient communication (1%). The median word count was 63 (interquartile range, 30 to 126) for each participant’s combined plans and 147 (interquartile range, 52 to 257) for improvement follow-up reports.

Conclusions:

After making a commitment to change, 94% of anesthesiologists participating in a Maintenance of Certification in Anesthesiology Program simulation course successfully implemented some or all of their planned practice improvements. This compares favorably to rates in other studies. Simulation experiences stimulate active learning and motivate personal and collaborative practice improvement changes. Further evaluation will assess the impact of the improvements and further refine the program.
Hippocampal Spine Head Sizes Are Highly Precise
Authors: Bartol Thomas M , Bromer Cailey , Kinney Justin , Chirillo Michael A. , Bourne Jennifer N. , Harris Kristen M. , Sejnowski Terrence J
Published: March 2015

Hippocampal synaptic activity is probabilistic and because synaptic plasticity depends on its history, the amount of information that can be stored at a synapse is limited. The strong correlation between the size and efficacy of a synapse allowed us to estimate the precision of synaptic plasticity. In an electron microscopic reconstruction of hippocampal neuropil we found single axons making two or more synaptic contacts onto the same dendrites which would have shared histories of presynaptic and postsynaptic activity. The postsynaptic spine heads, but not the spine necks, of these pairs were nearly identical in size. The precision is much greater than previous estimates and requires postsynaptic averaging over a time window many seconds to minutes in duration depending on the rate of input spikes and probability of release.

One Sentence Summary

Spine heads on the same dendrite that receive input from the same axon are the same size.
An evolutionarily conserved DNA architecture determines target specificity of the TWIST family bHLH transcription factors
Authors: Chang Andrew T. , Liu Yuanjie , Ayyanathan Kasirajan , Benner Chris , Jiang Yike , Prokop Jeremy W. , Paz Helicia , Wang Dong , Li Hai-Ri , Fu Xiang-Dong , Rauscher Frank J. , Yang Jing
Published: March 2015

Basic helix–loop–helix (bHLH) transcription factors recognize the canonical E-box (CANNTG) to regulate gene transcription; however, given the prevalence of E-boxes in a genome, it has been puzzling how individual bHLH proteins selectively recognize E-box sequences on their targets. TWIST is a bHLH transcription factor that promotes epithelial–mesenchymal transition (EMT) during development and tumor metastasis. High-resolution mapping of TWIST occupancy in human and Drosophila genomes reveals that TWIST, but not other bHLH proteins, recognizes a unique double E-box motif with two E-boxes spaced preferentially by 5 nucleotides. Using molecular modeling and binding kinetic analyses, we found that the strict spatial configuration in the double E-box motif aligns two TWIST–E47 dimers on the same face of DNA, thus providing a high-affinity site for a highly stable intramolecular tetramer. Biochemical analyses showed that the WR domain of TWIST dimerizes to mediate tetramer formation, which is functionally required for TWIST-induced EMT. These results uncover a novel mechanism for a bHLH transcription factor to recognize a unique spatial configuration of E-boxes to achieve target specificity. The WR–WR domain interaction uncovered here sets an example of target gene specificity of a bHLH protein being controlled allosterically by a domain outside of the bHLH region.
Effect of minichromosome maintenance protein 2 deficiency on the locations of DNA replication origins
Authors: Kunnev Dimiter , Freeland Amy , Qin Maochun , Leach Robert W. , Wang Jianmin , Shenoy Rajani M. , Pruitt Steven C.
Published: March 2015

Minichromosome maintenance (MCM) proteins are loaded onto chromatin during G1-phase and define potential locations of DNA replication initiation. MCM protein deficiency results in genome instability and high rates of cancer in mouse models. Here we develop a method of nascent strand capture and release and show that MCM2 deficiency reduces DNA replication initiation in gene-rich regions of the genome. DNA structural properties are shown to correlate with sequence motifs associated with replication origins and with locations that are preferentially affected by MCM2 deficiency. Reduced nascent strand density correlates with sites of recurrent focal CNVs in tumors arising in MCM2-deficient mice, consistent with a direct relationship between sites of reduced DNA replication initiation and genetic damage. Between 10% and 90% of human tumors, depending on type, carry heterozygous loss or mutation of one or more MCM2-7 genes, which is expected to compromise DNA replication origin licensing and result in elevated rates of genome damage at a subset of gene-rich locations.
Unraveling determinants of transcription factor binding outside the core binding site
Authors: Levo Michal , Zalckvar Einat , Sharon Eilon , Dantas Machado Ana Carolina , Kalma Yael , Lotam-Pompan Maya , Weinberger Adina , Yakhini Zohar , Rohs Remo , Segal Eran
Published: March 2015

Binding of transcription factors (TFs) to regulatory sequences is a pivotal step in the control of gene expression. Despite many advances in the characterization of sequence motifs recognized by TFs, our ability to quantitatively predict TF binding to different regulatory sequences is still limited. Here, we present a novel experimental assay termed BunDLE-seq that provides quantitative measurements of TF binding to thousands of fully designed sequences of 200 bp in length within a single experiment. Applying this binding assay to two yeast TFs, we demonstrate that sequences outside the core TF binding site profoundly affect TF binding. We show that TF-specific models based on the sequence or DNA shape of the regions flanking the core binding site are highly predictive of the measured differential TF binding. We further characterize the dependence of TF binding, accounting for measurements of single and co-occurring binding events, on the number and location of binding sites and on the TF concentration. Finally, by coupling our in vitro TF binding measurements, and another application of our method probing nucleosome formation, to in vivo expression measurements carried out with the same template sequences serving as promoters, we offer insights into mechanisms that may determine the different expression outcomes observed. Our assay thus paves the way to a more comprehensive understanding of TF binding to regulatory sequences and allows the characterization of TF binding determinants within and outside of core binding sites.
X-ray investigation of lateral hetero-structures of inversion domains in LiNbO3, KTiOPO4and KTiOAsO4
Authors: Lyford Thomas S. , Collins Stephen P. , Fewster Paul F. , Thomas Pamela A.
Published: March 2015

In this paper periodically domain-inverted (PDI) ferroelectric crystals are studied using high-resolution X-ray diffraction. Rocking curves and reciprocal-space maps of the principal symmetric Bragg reflections in LiNbO3(LN) (Λ = 5 µm), KTiOPO4(KTP) (Λ = 9 µm) and KTiOAsO4(KTA) (Λ = 39 µm) are presented. For all the samples strong satellite reflections were observed as a consequence of the PDI structure. Analysis of the satellites showed that they were caused by a combination ofcoherentandincoherentscattering between the adjacent domains. Whilst the satellites contained phase information regarding the structure of the domain wall, this information could not be rigorously extracted withouta prioriknowledge of the twinning mechanism. Analysis of the profiles reveals strain distributions of Δd/d= 1.6 × 10−4and 2.0 × 10−4perpendicular to domain walls in KTP and LN samples, respectively, and lateral correlation lengths of 63 µm (KTP), 194 µm (KTA) and 10 µm (LN). The decay of crystal truncation rods in LN and KTP was found to support the occurrence of surface corrugations.
First report of L1014F kdr mutation in Culex quinquefasciatus in Mexico
Authors: Ponce Gustavo , Sanchez Iram P. , García Selene M. , Torrado Jose M. , Lozano‐Fuentes Saúl , Lopez‐Monroy Beatriz , Flores Adriana E.
Published: March 2015

The L1014F mutation in the voltage‐sodium channel gene has been associated with resistance to DDT and pyrethroids in various arthropod species including mosquitoes. We determined the frequency of the L1014F kdr mutation in 16 field populations of Culex quinquefasciatus from Northeastern Mexico collected between 2008 and 2013. The L1014F was present in all populations analyzed with the lowest frequency (3.33%) corresponding to the population from Monclova collected in 2012, and the highest frequency (63.63%) from the Monterrey population collected in 2012. The presence of a kdr mutation in populations of Cx. quinquefasciatus from northeastern Mexico provides evidence of pyrethroid resistance. This requires a special attention, considering that pyrethroid‐based insecticides are commonly used in vector‐control campaigns, especially against Aedes aegypti (L.).
Comparison of endoscopic balloon dilation with metal stent placement in the treatment of achalasia
Authors: Zhao Hang , Wan Xin Jian , Yang Chang Qing
Published: March 2015

Objective

To compare the outcomes of endoscopic balloon dilation and metal stent placement in patients with achalasia.

Methods

The patients with newly diagnosed achalasia between July 2001 and December 2011 were retrospectively studied. A total of 88 patients underwent either balloon dilation (n = 41) or metal stent placement (n = 47), their global symptom score and esophageal kinetics index were determined before, one week after and one month after the treatment. All the patients were followed up in the Outpatient Clinics or with a telephone interview every 6 months.

Results

There were significant improvements in the global symptom scores and esophageal kinetics indices in all patients. No major complications were encountered in either group. There were no significant differences with regard to overall treatment failure or long‐term outcome.

Conclusion

Balloon dilation and removable stents can effectively relieve clinical manifestations in patients with achalasia.
Gut symptoms in diabetics correlate with components of the rectoanal inhibitory reflex, but not with pudendal nerve motor latencies or systemic autonomic neuropathy
Authors: Thiruppathy Kumaran , Bajwa Adeel , Kuan Kean Guan , Murray Charles , Cohen Richard , Emmanuel Anton
Published: March 2015

Objective

Fecal incontinence (FI) occurs in up to 20% of diabetes mellitus (DM) patients. Rectoanal inhibitory reflex (RAIR) is an enteric anorectal reflex that reflects the integrity of mechanisms in the physiology of FI. We aimed to investigate whether diabetic patients with FI, not constipation, had prolongation of RAIR and altered gut‐specific autonomic tone.

Methods

In this prospective case‐matched study 31 type I DM (19 FI and 12 constipation) and 42 type II DM (26 FI and 16 constipation). Another 21 participants were included as controls. Patients underwent the following assessments: cardiovagal autonomic tone (Modified Mayo Clinic composite autonomic severity score), rectal mucosal blood flow (RMBF) (assessment of gut‐specific autonomic tone) and RAIR. Three phases of RAIR and the amplitude of maximal reflex relaxation were compared between groups. All participants completed symptom scores for FI and constipation.

Results

RAIR recovery time back to resting pressure was slower in diabetic patients with FI than controls (8.7 s vs 3.6 s, P < 0.05) and was an independent variable correlating with symptoms of FI (P < 0.05). RAIR recovery time was correlated with RMBF (r = 0.58, P = 0.04).

Conclusion

RAIR is correlated with anorectal symptoms of FI and was associated with gut‐specific autonomic neuropathy.
Comparison between two types of confocal laser endomicroscopy in gastrointestinal tract
Authors: Li Chang Qing , Zuo Xiu Li , Guo Jing , Zhang Jing Yuan , Liu Jian Wei , Li Yan Qing
Published: March 2015

Objectives

Confocal laser endomicroscopy (CLE) consists of endoscope‐based CLE (eCLE) and probe‐based CLE (pCLE). This study aimed to compare eCLE and pCLE in their diagnostic yield in different parts of the gastrointestinal (GI) tract.

Methods

Consecutive patients were scheduled for CLE examination due to GI symptoms. All patients were randomly assigned to eCLE or pCLE group and underwent a programmed procedure using one type of CLE. Differences in procedure time, complication rate, CLE image quality and image acquisition feasibility between these two types of CLE for esophagogastroduodenoscopy (EGD) and colonoscopy were calculated.

Results

Altogether 513 CLE procedures were performed, including 324 EGD and 189 colonoscopy. The procedure time of pCLE was significantly shorter than that of eCLE both in EGD and colonoscopy (16.78 min vs 18.13 min for EGD, P = 0.027; 32.48 min vs 39.89 min for colonoscopy, P < 0.001). No significant difference was found between these two types of CLE in diagnostic utility, including the detection and prediction of histopathological results of the lesions. The CLE image quality of both eCLE and pCLE were comparable in the stomach and colon, but eCLE seemed to be superior to pCLE in examining the esophagus. Colonoscopy using pCLE had a higher complete rate than that of eCLE, although the difference was not statistically significant (P = 0.065).

Conclusions

pCLE is more flexible in diagnosing GI diseases with a shorter procedure time than eCLE regardless of comparable diagnostic yields, except the diagnosis of esophageal diseases in which eCLE provides better image quality.
Paediatric ventilation treatment of acute lung injury in Nordic intensive care units
Authors: JENSEN L. L. , BARATT‐DUE A. , ENGLUND P. N. , HARJU J. A. , SIGURÐSSON T. S. , LIBERG J.‐P.
Published: March 2015

Background

Treatment of acute respiratory distress syndrome (ARDS) in children is largely based on extrapolated knowledge obtained from adults and which varies between different hospitals. This study explores ventilation treatment strategies for children with ARDS in the Nordic countries, and compares these with international practice.

Methods

In October 2012, a questionnaire covering ventilation treatment strategies for children aged 1 month to 6 years of age with ARDS was sent to 21 large Nordic intensive care units that treat children with ARDS. Pre‐terms and children with congenital conditions were excluded.

Results

Eighteen of the 21 (86%) targeted intensive care units responded to the questionnaire. Fifty per cent of these facilities were paediatric intensive care units. Written guidelines existed in 44% of the units. Fifty per cent of the units frequently used cuffed endotracheal tubes. Ventilation was achieved by pressure control for 89% vs. volume control for 11% of units. Bronchodilators were used by all units, whereas steroids usage was 83% and surfactant 39%. Inhaled nitric oxide and high frequency oscillation were available in 94% of the units. Neurally adjusted ventilator assist was used by 44% of the units. Extracorporeal membrane oxygenation could be started in 44% of the units.

Conclusion

Ventilation treatment strategies for paediatric ARDS in the Nordic countries are relatively uniform and largely in accordance with international practice. The use of steroids and surfactant is more frequent than shown in other studies.
Genetic variation influences the risk of bleeding after cardiac surgery: novel associations and validation of previous findings
Authors: GREIFF G. , PLEYM H. , STENSETH R. , WAHBA A. , VIDEM V.
Published: March 2015

Background

Severe post‐operative bleeding in cardiac surgery is associated with increased morbidity and mortality. We hypothesized that variation in genetic susceptibility contributes to post‐operative bleeding in addition to clinical factors.

Methods

We included 1036 adults undergoing cardiac surgery with cardiopulmonary bypass. Two different endpoints for excessive post‐operative bleeding were used, either defined as blood loss exceeding 2 ml/kg/h the first 4 h post‐operatively or a composite including bleeding, transfusions, and reoperations. Twenty‐two single nucleotide polymorphisms (SNPs) central in the coagulation and fibrinolysis systems or in platelet membrane receptors were genotyped, focusing on replication of earlier non‐replicated findings and exploration of potential novel associations. Using logistic regression, significant SNPs were added to a model with only clinical variables to evaluate whether the genetic variables provided additional information.

Results

Univariate tests identified rs1799809 (located in the promoter region of the PROC gene), rs27646 and rs1062535 (in the ITGA2 gene), rs630014 (in the ABO gene), and rs6048 (in the F9 gene) as significantly associated with excessive post‐operative bleeding (P < 0.05, P‐values confirmed by permutation). The SNPs were significant also after adjustment with clinical variables, showing almost unchanged odds ratios except for rs1799809 (P = 0.06). Addition of the genetic covariates to a logistic regression model with clinical variables significantly improved the model (P < 0.01).

Conclusion

We identified five SNPs associated with post‐operative bleeding after cardiac surgery, of which two validated previously published associations. Addition of genetic information to models with only clinical variables improved the models. Our results indicate that common genetic variations significantly influence post‐operative bleeding after cardiac surgery.
Dry mouth and older people
Authors: Thomson WM
Published: March 2015

Dry mouth is more common among older people than in any other age group. Appropriate definition and accurate measurement of dry mouth is critical for better understanding, monitoring and treatment of the condition. Xerostomia is the symptom(s) of dry mouth; it can be measured using methods ranging from single questions to multi‐item summated rating scales. Low salivary flow (known as salivary gland hypofunction, or SGH) must be determined by measuring that flow. The relationship between SGH and xerostomia is not straightforward, but both conditions are common among older people, and they affect sufferers’ day‐to‐day lives in important ways. The major risk factor for dry mouth is the taking of particular medications, and older people take more of those than any other age group, not only for symptomatic relief of various age‐associated chronic diseases, but also in order to reduce the likelihood of complications which may arise from those conditions. The greater the number taken, the greater the associated anticholinergic burden, and the more likely it is that the individual will suffer from dry mouth. Since treating dry mouth is such a challenge for clinicians, there is a need for dentists, doctors and pharmacists to work together to prevent it occurring.
Improving the oral health of frail and functionally dependent elderly
Authors: Lewis A , Wallace J , Deutsch A , King P
Published: March 2015

The Australian Government endorsed a national evidence based oral health model when it introduced the first Nursing Home Oral and Dental Health Plan in 2010. Called Better Oral Health in Residential Care, it promotes a multidisciplinary approach with doctors, nurses, care workers and dental professionals sharing responsibility for the four key processes of oral health screening, oral health care planning, daily oral hygiene and access to dental treatment. Frail and dependent residents are most conveniently treated on‐site, hence an aged care/dental partnership is encouraged to facilitate the use of portable dental equipment in the delivery of dental care.

Currently, few dentists provide services to residential aged care facilities (RACFs), with loss of clinical time in practice, difficulty in providing clinical care in a non‐dental environment and lack of referral pathways from the RACFs to the dentists contributing to the problem. The need to establish a model of care involving dental hygienists/oral health therapists in RACFs has merit.

Minimal intervention treatment using glass ionomer cement (GIC) and silver fluoride is ideal in aged care. However, GIC has limitation in dry mouths with low pH caused by polypharmacy or disease. Palliative and definitive treatment techniques need to be individualized with consideration of a patient's ability to maintain their own mouths as well as their mental and physical competence.

The range of products available to address the oral diseases common to the frail elderly is growing. The oral health care provider is required to establish a preventive regime that is tailored to the patient's needs, is realistic and under revision as the patient's needs change.
The XX Sex Chromosome Complement is Required in Male and Female Mice for Enhancement of Immunity Induced by Exposure to 3,4‐Dichloropropionanilide
Authors: Holásková Ida , Franko Jennifer , Goodman Robert L. , Arnold Arthur P. , Schafer Rosana
Published: March 2015

Problem

The chemical propanil enhances antibody responses to a heat‐killed Streptococcus pneumoniae (HKSP) vaccine. The enhanced response is dependent on gonads in females, but independent of gonads in males. The sex differences in the immune response may be due to sexual differentiation of the immune system or sex chromosome complement.

Method of study

To test the hypothesis that the immune system is sexually differentiated, newborn C57BL/6 pups were treated with testosterone propionate (TP) or placebo. The role of sex chromosome complement was investigated using the 4‐core genotypes (FCG) model of XXF and XYF gonadal females (ovaries), and XXM and XYM gonadal males (testes). For some experiments, mice were gonadectomized or sham gonadectomized. All mice were vaccinated with HKSP, treated with propanil, and the antibody response determined at day seven.

Results

Neonatal TP did not alter the response to HKSP. In FCG mice, propanil significantly enhanced the immune response in XXF females and XXM males, but not in XYF females or XYM males.

Conclusion

The immune system of females was not masculinized by neonatal TP treatment. Sex chromosome complement significantly contributes to the sexually dimorphic immune response after propanil exposure.
Low birthweight, gestational age, need for surgical intervention and gram‐negative bacteraemia predict intestinal failure following necrotising enterocolitis
Authors: Elfvin Anders , Dinsdale Elsa , Wales Paul W. , Moore Aideen M.
Published: March 2015

Aim

Necrotising enterocolitis (NEC) is associated with high morbidity and mortality. The aim of this study was to identify predictors of intestinal failure (IF), morbidity and mortality following NEC.

Methods

We performed a retrospective study of all neonates treated for NEC stage II or greater at a tertiary referral NICU between 2000 and 2009. Demographic data, need for surgery, residual bowel length and rates of bacteraemia, cholestasis, IF and mortality were analysed.

Results

During the 10‐year period, 301 patients were referred with NEC and 152 had surgical intervention. Overall mortality was 32%. Of the 230 infants who survived >42 days, 97 (42%) had IF at 42 days, decreasing to 15% at >90 days. The rate of IF was significantly higher in the surgical group than the medical group (OR 2.04, 95% CI, 1.25–3.35, p < 0.004), but 23% of the medically treated infants with NEC also developed IF. There was a significant relationship between IF and gram‐negative bacteraemia, the need for surgery, cholestasis, liver failure and mortality.

Conclusion

Intestinal failure occurred in a significant proportion of infants with NEC. Predictors for IF among infants with NEC were low birthweight, low gestational age, need for surgical intervention and gram‐negative bacteraemia.
Habitat restoration requires landscape‐scale planning
Authors: Helm Aveliina
Published: March 2015

Habitat restoration cannot be considered simply as an act of re‐creating the original environmental conditions and biota, neglecting the significance of the context of the surrounding landscape and overlooking the need to recreate metapopulation dynamics for target species. In this issue, Prach et al. show the importance of the availability of target species in the surrounding landscape to achieve successful restoration.
Interaction of platelets with endothelial progenitor cells in the experimental atherosclerosis: Role of transplanted endothelial progenitor cells and platelet microparticles
Authors: Alexandru Nicoleta , Andrei Eugen , Dragan Emanuel , Georgescu Adriana
Published: March 2015

Background information

Recent studies suggest that endothelial progenitor cells (EPCs) and platelets have an important role in repair following vascular injury. Although evidence suggest that platelets are essential in EPC attracting, homing and differentiation to the injury site; however, the platelet effects on EPC function in atherosclerosis have received less attention. In this context, we followed the consequences of circulating EPCs and platelet microparticles (PMPs) administration on platelet–EPC interaction in atherosclerosis and the involved mechanisms. The experiments were performed on Golden Syrian hamsters divided in five equal groups: control (C), hypertensive–hypercholesterolemic (HH), HH treated with EPCs (HH–EPCs) or PMPs (HH–PMPs) and HH treated with EPCs and PMPs (HH–EPCs–PMPs).

Results

Compared with C group, EPCs isolated from HH and HH–PMPs groups presented a reduction of endothelial nitric oxide synthase and vascular endothelial growth factor expressions and an increase in thrombospondin‐1 expression and inflammatory molecule secretion: interleukin 8 (IL)‐8, myeloperoxidase (MPO) and plasminogen activator inhibitor‐1 (PAI‐1). EPC administration had beneficial effects, the obtained results being similar with those from the C group, while the combination with PMPs did not improve the EPC influences. Static coincubation of EPCs from HH and HH–PMPs with analogous platelets resulted in an increased EPC adhesion/migration, and IL‐8, monocyte chemotactic protein‐1, regulated on activation, normal T expressed and secreted, MPO and PAI‐1 release, explained by the platelet hyperaggregability induced by pronounced distribution of vasodilator‐stimulated phosphoprotein and filamentous actin, and the secretion of proinflammatory factors: IL‐1β, ‐6, ‐8, CD40 ligand. EPC therapy alone revealed an impaired platelet–EPC interaction directly correlated with the reduction of inflammatory markers and platelet aggregability. Moreover, in a dynamic flow system, EPCs and platelets from HH and HH–PMPs exhibited weakened interplay abilities, while EPC transplantation reinforces them.

Conclusions

The present study demonstrates that HH animals revealed functional impairment of EPCs and platelets, which correlate with their reduced contribution to re‐endothelialisation at the injury site, although in vitro exposure to immobilised platelets promotes their adhesion and migration. EPC administration alone recovers EPC/platelet functions and consolidates their interaction under dynamic flow conditions. These findings disclose new advances in understanding the platelet–EPC interaction and its role in the vascular repair.