bluuebunny/crossref_metadata_2025 huggingface dataset:
Mycobacteria and the Intraphagosomal Environment: Take It With a Pinch of Salt(s)!
Authors: Soldati Thierry , Neyrolles Olivier
Published: April 2012

Ancient protozoan phagocytes and modern professional phagocytes of metazoans, such as macrophages, employ evolutionarily conserved mechanisms to kill microbes. These mechanisms rely on microbial ingestion, followed by maturation of the phagocytic vacuole, or so‐called phagosome. Phagosome maturation includes a series of fusion and fission events with the host cell endosomes and lysosomes, leading to a rapid increase of the degradative properties of the vacuole and to the destruction of the ingested microbe within a very hostile intracellular compartment, the phagolysosome. Historically, the mechanisms and weapons used by phagocytes to kill microbes have been separated into different classes. Phagosomal acidification, together with the production of reactive oxygen and nitrogen species, the selective manipulation of various ions in the phagosomal lumen, and finally the engagement of a battery of acidic hydrolases, are well‐recognized players in this process. However, it is relatively recently that interconnections among these mechanisms have become apparent. In this review, we will focus on some emerging concepts about these interconnected aspects of the warfare at the host–pathogen interface, using mostly Mycobacterium tuberculosis as an example of intracellular pathogen. In particular, recent discoveries on the role of phagosomal ions and other chemicals in the control of pathogens, as well as mechanisms evolved by intracellular pathogens to circumvent or even exploit the weapons of the host cell will be discussed.
Initial resuscitation for Australasian Triage Scale 2 patients in a Nepalese emergency department
Authors: Basnet Bibhusan , Bhandari Rabin , Moore Malcolm
Published: April 2012

Objectives: Triage is recognized as important in providing timely care to emergency patients. However, systematic triage is only practised in two EDs in Nepal. The first objective of this study was to assess the performance of one of these departments in seeing triaged patients in a timely fashion. Second, an epidemiological survey of patients presenting to the ED was performed to describe the conditions seen and initial resuscitation undertaken.

Methods: We performed a descriptive cross‐sectional study in the ED of B.P. Koirala Institute of Health Sciences, eastern Nepal where the Australasian Triage Scale (ATS) is used. One hundred and sixty patients triaged as ATS 2 were recruited. The time taken for the duty doctor to see the patient was noted. The presenting problems, vital signs and level of consciousness were measured at presentation. The resuscitation measures were recorded.

Results: The mean waiting time was 2.1 ± 1.7 min with a range of 1–10 min, which meets the benchmark for ATS 2. At triage, the most common presenting problems were circulatory shock (23.1%), altered consciousness (21%), respiratory difficulty (16.9%) and poisoning (15%). Oxygen, i.v. fluids and antibiotics were the most common therapies used in the initial resuscitation of patients.

Conclusion: Patients triaged as ATS 2 were seen in a timely fashion. Seriously ill patients requiring resuscitation present commonly to this ED. This is a big challenge for junior doctors. Improved training, treatment protocols and equipment are needed to help manage this burden.
Development of competence scale for senior clinical nurses
Authors: AKAMINE Itsuko , UZA Miyoko , SHINJO Masaki , NAKAMORI Eri
Published: April 2012

Aim:  The aim of this study was to develop a new scale, the Competence Scale for Senior Clinical Nurses (CS‐SCN), to assess and evaluate senior clinical nurses in hospitals, and to confirm the validity and reliability of the scale.

Method:  A cross‐sectional questionnaire survey was undertaken at a hospital in Japan, using an anonymous self‐administered questionnaire administered to clinical nurses (n = 374). A useable sample of 218 was achieved, which was used in the analysis. Statistical analysis examined exploratory/confirmatory factor analysis, internal consistency, and construct validity.

Results:  A five factor solution with 22 items was extracted for nursing competence in senior clinical nurses, which was the interpretable questionnaire. In the confirmatory factor analysis, the indices of fitness supported these results. Cronbach's alpha coefficient was 0.93 for the total score and varied between 0.63 and 0.90 in the five factors. Five factors emerged from an oblique factor analysis, with a cumulative variance of 66.7%: “role accomplishment”; “self‐management”; “research”; “practice and coordination”; and “work implementation”. The five factors had only a moderate correlation (0.30–0.77, P < 0.001) with each other, which indicated construct validity.

Conclusion:  The CS‐SCN, a concise scale to measure and evaluate the competence of senior clinical nurses, was developed. Results suggest initial support for the new instrument as a measure of competence of senior clinical nurses, but it must be further refined, tested, and evaluated. Both the validity and reliability of the scale were verified. Future studies using the CS‐SCN might lead to improvement in the competence of senior clinical nurses.
The Etiological Relationship Between Anxiety Sensitivity, Sexual Distress, and Female Sexual Dysfunction is Partly Genetically Moderated
Authors: Burri Andrea , Spector Timothy , Rahman Qazi
Published: April 2012

Introduction

Presence of sexual distress is diagnostic requirement for female sexual dysfunction (FSD). However, previous correlational research indicates that sexual distress in women may be related to general anxiety per se rather than being an outcome of FSD.

Aim

In this exploratory study, we test, for the first time, whether the correlation between anxiety sensitivity, sexual distress, and FSD can be explained by shared genetic and nongenetic factors using multivariate twin modeling.

Methods

Questionnaire data were available on a representative final sample of 930 Caucasian British female twin individuals (119 monozygotic twin pairs, 67 dizygotic twin pairs, and 558 single twins; aged 18–85 years). Validated scales assessed anxiety sensitivity, sexual distress, and FSD and included the Female Sexual Function Index, the Female Sexual Distress Scale, and the Anxiety Sensitivity Index.

Main Outcome Measures

Questionnaire responses were subject to trivariate heritability analyses to assess common genetic and environmental influences underlying specific trait variance and the covariance between the phenotypes.

Results

Heritability for FSD was 28%, 48% for anxiety sensitivity, and 44% for sexual distress. The phenotypic associations among anxiety sensitivity, sexual distress, and FSD were all significant. Trivariate analysis indicated that additive genetic factors accounted for approximately 75% of the covariance between anxiety sensitivity and FSD 35% of the covariance between anxiety sensitivity and sexual distress, and 11% between sexual distress and FSD.

Conclusions

The association between anxiety sensitivity and FSD has a common genetic component. There is a weaker genetic link between anxiety sensitivity and sexual distress and between sexual distress and FSD. These data, while silent on direction of causality, suggest a role for pleiotropic genetic factors influencing anxiety sensitivity and FSD. They also highlight a need to refine the inclusion of distress in classifications of disorders of female sexual functioning.
Age at reproductive maturity and effect of age and time of day on sex attraction in the potato psyllid Bactericera cockerelli
Authors: Guédot Christelle , Horton David R. , Landolt Peter J.
Published: April 2012

Abstract  The potato psyllid, Bactericera (= Paratrioza) cockerelli (Šulc) (Hemiptera: Triozidae), is a major pest of potato. Studies were conducted to determine the age at which both males and females reach reproductive maturity and the effect of age and time of day on sex attraction. Adult B. cockerelli reach reproductive maturity within 48 h post‐eclosion, with females being mature on the day of eclosion and males at 1 day post‐eclosion. Oviposition generally began 2 days after mating but was delayed when females mated within 2 days post‐eclosion. In laboratory olfactometer assays, the age of females used as odor sources and the age of males assayed to these odors did not affect sex attraction, with both younger (1–4‐day‐old) and older (8–10‐day‐old) males being attracted to females, regardless of female age (1–4‐day‐old or 8–10‐day‐old). Males assayed to live females at different times during the photophase (between 8:00 and 20:00 hours) were attracted to females between 11:00 and 17:00 hours, showing a temporal periodicity in sex attraction with B. cockerelli at least during the photophase.
No snowplough mechanism during the rapid hardening of supermassive black hole binaries
Authors: Baruteau Clément , Ramirez-Ruiz Enrico , Masset Frédéric
Published: April 2012

We present 2D hydrodynamical simulations of the tidal interaction between a supermassive black hole binary with moderate mass ratio and the fossil gas disc where it is embedded. Our study extends previous 1D height-integrated disc models, which predicted that the density of the gas disc between the primary and the secondary black holes should rise significantly during the ultimate stages of the binary's hardening driven by the gravitational radiation torque. This snowplough mechanism, as we call it, would lead to an increase in the bolometric luminosity of the system prior to the binary merger, which could be detected in conjunction with the gravitational wave signal. We argue here that the snowplough mechanism is unlikely to occur. In 2D, when the binary's hardening time-scale driven by gravitational radiation becomes shorter than the disc's viscous drift time-scale, fluid elements in the inner disc get funnelled to the outer disc through horseshoe trajectories with respect to the secondary. Mass leakage across the secondary's gap is thus found to be effective and, as a result, the predicted accretion disc luminosity will remain at roughly the same level prior to merger.
Current guidelines for cervical cancer screening
Authors: Schwaiger Constance , Aruda Mary , LaCoursiere Sheryl , Rubin Richard
Published: April 2012

Purpose: To provide evidence‐based information that will guide nurse practitioners in instituting the most current cervical cancer screening recommendations.

Data sources: A literature search covering the years 2006 to the present conducted through Medline, CINAHL, and OVID.

Conclusions: Human papillomavirus (HPV) cervical infections are highly prevalent among females under 21 years, yet this age group has a low incidence of cervical cancer. For young women, 90% of HPV infections regress in 24 months, and, in longitudinal studies, no invasive cervical cancer was detected. HPV co‐testing is effective for women age 30 and over.

Implications for practice: Current scientific evidence supports initiating cervical cancer screening for immunocompetent women at age 21, biennial screening between ages 21 and 29, and HPV DNA co‐testing for women over 30. Nurse practitioners play an important role in integrating the newest guidelines into practice and improving the quality of healthcare regarding women's cervical health and cancer prevention.
Effectiveness of reforestation in erosion mitigation and implications for future sediment yields, East Coast catchments, New Zealand: A review
Authors: Marden Michael
Published: April 2012

This paper argues that reforestation of unstable and degraded parts of the East Coast region, predominantly with exotic pines, has successfully stabilised existing erosion forms and prevented the initiation of new ones. Effectiveness is often assessed by capturing erosion scars on aerial photography taken before and after reforestation and any change in scar size is measured in a geographic information system (GIS). Combined with forest age data, modelled reforestation scenarios indicate that sediment generation from earth flows and shallow landslides would be negligible within eight to 10 years after planting, and if all remaining gullies were to be reforested before 2020, sediment yield could halve by 2030 and remain constant thereafter. In a similar time frame, the risk to infrastructure by sedimentation and flooding would likely decrease.
Progressive Lacunar Stroke: Review of Mechanisms, Prognostic Features, and Putative Treatments
Authors: Del Bene Alessandra , Palumbo Vanessa , Lamassa Maria , Saia Valentina , Piccardi Benedetta , Inzitari Domenico
Published: April 2012

Lacunar stroke is generally considered to have a fair outcome. However 20–30% of patients with lacunar stroke worsen neurologically in hours or days after onset, reaching eventually an unexpectedly severe disability status. In the field of acute stroke, progressive lacunar stroke remains an important unresolved practice problem, because as yet no treatment does exist proven to prevent or halt progression. Pathophysiology of progression is yet incompletely understood. Hemodynamic factors, extension of thrombosis, excitotoxicity, and inflammation, have been proposed as possible mechanisms of progression. A few clinical studies also aimed at establishing presentation features that may help identifying patients at risk of deterioration. In this paper, we review hypothesized mechanisms of lacunar stroke progression and possible markers of early deterioration. Moreover, based on putative mechanisms and suggestions from reported evidence, we propose a few treatments that seem worthy to be tested by randomized clinical trials.
Identifying the last supper: utility of the DNA barcode library for bloodmeal identification in ticks
Authors: GARIEPY T. D. , LINDSAY R. , OGDEN N. , GREGORY T. R.
Published: April 2012

Ticks are among the most important vectors of disease in the Northern Hemisphere, and a better understanding of their feeding behaviour and life cycle is critical to the management and control of tick‐borne zoonoses. DNA‐based tools for the identification of residual bloodmeals in hematophagous arthropods have proven useful in the investigation of patterns of host use in nature. Using a blind test approach, we challenged the utility of the DNA barcode library for the identification of vertebrate bloodmeals in engorged, field‐collected Ixodes scapularis. Universal vertebrate primers for the COI barcode region successfully amplified DNA from the host bloodmeal and only rarely amplified tick DNA. Of the 61 field‐collected ticks, conclusive genus‐ and species‐level identification was possible for 72% of the specimens. In all but two cases, barcode‐based identification of the bloodmeal was consistent with the morphological identification of the vertebrate host the ticks were collected from. Possible explanations for mismatches or ambiguities are presented. This study validates the utility of the DNA barcode library as a valuable and reliable resource for the identification of unknown bloodmeals in arthropod vectors of disease. Future directions aimed at the refinement of these techniques to gain additional information and to improve the amplification success of digested vertebrate DNA in tick bloodmeals are discussed.
Bioenergy production and Skylark (Alauda arvensis) population abundance – a modelling approach for the analysis of land‐use change impacts and conservation options
Authors: Engel Jan , Huth Andreas , Frank Karin
Published: April 2012

Bioenergy production is seen as one way of meeting future energy needs. The growing demand for biomass for energy production induces the cultivation of a few fast growing and high‐yielding energy crops on vast areas of arable land. This land‐use change has been found associated with the reduction of habitat suitability for farmland birds and a decline in farmland biodiversity in general. A large number of studies have assessed the ecological effects of energy crop cultivation at the local scale of a single field. This study focuses on regional landscape changes caused by increased energy crop cultivation, which includes reduction of crop‐type richness and spatial concentration of single crop‐types. We present a spatially explicit ecological model to assess the population‐level consequences of these effects on the abundance of the farmland bird species Skylark (Alauda arvensis). We also investigate the impacts of different land‐use scenarios and aim to identify adaptive conservation options. We show that (1) the impacts of increased energy crop cultivation on Skylark population abundance depend strongly on the landscape structure; (2) impacts could be tolerated as long as a certain minimum level of crop‐type heterogeneity is retained at the landscape level and (3) conservation actions are required and effective especially on landscapes where crop‐field size is large.
Improving Algebra Preparation: Implications From Research on Student Misconceptions and Difficulties
Authors: Welder Rachael M.
Published: April 2012

Through historical and contemporary research, educators have identified widespread misconceptions and difficulties faced by students in learning algebra. Many of these universal issues stem from content addressed long before students take their first algebra course. Yet elementary and middle school teachers may not understand how the subtleties of the arithmetic content they teach can dramatically, and sometimes negatively, impact their students' ability to transition to algebra. The purpose of this article is to bring awareness of some common algebra misconceptions, and suggestions on how they can be averted, to those who are teaching students the early mathematical concepts they will build upon when learning formal algebra. Published literature discussing misconceptions will be presented for four prerequisite concepts, related to symbolic representation: bracket usage, equality, operational symbols, and letter usage. Each section will conclude with research‐based practical applications and suggestions for preventing such misconceptions. The literature discussed in this article makes a case for elementary and middle school teachers to have a deeper and more flexible understanding of the mathematics they teach, so they can recognize how the structure of algebra can and should be exposed while teaching arithmetic.
Using Similarities and Differences: A Meta‐Analysis of Its Effects and Emergent Patterns
Authors: Apthorp Helen S. , Igel Charles , Dean Ceri
Published: April 2012

The purpose of the study was to update previous meta‐analytic findings on the effectiveness of using similarities and differences as an instructional strategy. The strategy includes facilitating student comparison, classification, use of analogies, and use of metaphors. Previously, Marzano, Pickering, and Pollock reported a mean effect size of 1.61. For the present meta‐analysis, literature was searched to locate experimental studies meeting the following inclusion criteria: published between 1998 and 2008; examined effects of facilitating student comparison, classification, use of analogies, and use of metaphors; measured student academic achievement as an outcome; involved students in kindergarten through grade 12; and provided data necessary to compute effect sizes. Based on the eligible research, the overall mean effect size (Hedges' g) was .65, confirming earlier results indicating that using similarities and differences positively influences student achievement. Type of control group, however, moderated the effect. Larger effect sizes were associated with control groups receiving textbook‐guided instruction versus those receiving interactive instruction. Emergent patterns were observed for the positive influence of long‐term instruction, systematic instruction, supportive cuing, and opportunity for reflection and discussion. Results support recommendations to guide students through analogical reasoning about, and classification of, important concepts and relationships in content‐area instruction.
Calculator Use on NAEP: A Look at Fourth‐ and Eighth‐Grade Mathematics Achievement
Authors: Walcott Crystal , Stickles Paula R.
Published: April 2012

This article summarizes research conducted on calculator block items from the 2007 fourth‐ and eighth‐grade National Assessment of Educational Progress Main Mathematics. Calculator items from the assessment were categorized into two categories: problem‐solving items and noncomputational mathematics concept items. A calculator has the potential to be used as a problem‐solving tool for items categorized in the first category. On the other hand, there are no practical uses for calculators for noncomputational mathematics concept items. Item‐level performance data were disaggregated by student‐reported calculator use to investigate the differences in achievement of those fourth‐ and eighth‐grade students who chose to use calculators versus those who did not, and whether or not the nation's fourth and eighth graders are able to identify items where calculator use serves as an aide for solving a given mathematical problem. Results from the analysis show that eighth graders, in particular, benefit most from the use of calculators on problem‐solving items. A small percentage of students at both grade levels attempted to use a calculator to solve problems in the noncomputational mathematics concept category (items in which the use of a calculator does not serve as a tool to solve the problem).
How the Hodgkin–Huxley equations inspired the Cardiac Physiome Project
Authors: Noble Denis , Garny Alan , Noble Penelope J.
Published: April 2012

Abstract  Early modelling of cardiac cells (1960–1980) was based on extensions of the Hodgkin–Huxley nerve axon equations with additional channels incorporated, but after 1980 it became clear that processes other than ion channel gating were also critical in generating electrical activity. This article reviews the development of models representing almost all cell types in the heart, many different species, and the software tools that have been created to facilitate the cardiac Physiome Project.
The chemokine CXCL12 and the HIV‐1 envelope protein gp120 regulate spontaneous activity of Cajal–Retzius cells in opposite directions
Authors: Marchionni Ivan , Beaumont Michael , Maccaferri Gianmaria
Published: April 2012

Key points

The CXC chemokine ligand 12 (CXCL12) modulates spontaneous firing of Cajal–Retzius cells via the CXC chemokine receptor 4 (CXCR4). However, the underlying mechanism(s) are poorly understood. CXCR4 also binds the human immunodeficiency virus type 1 (HIV‐1) envelope glycoprotein 120 (gp120), but the functional effects of this interaction on Cajal–Retzius cell excitability remain unknown.

We show that CXCL12 reduces spontaneous firing in Cajal–Retzius cells by opening a BK‐type calcium‐activated potassium conductance, whereas gp120 increases their excitability via a calcium‐ and chloride‐dependent mechanism.

Our data suggest that, depending on the use of CXCL12 or gp120 as ligands, partial agonism at the CXCR4 receptor generates calcium responses of different strengths, which lead to the recruitment of either calcium‐activated potassium or chloride channels.

We propose that HIV infection disrupts a signalling pathway important for the regulation of the excitability of Cajal–Retzius cells, and alters their functions.

Abstract  Activation of the CXC chemokine receptor 4 (CXCR4) in Cajal–Retzius cells by CXC chemokine ligand 12 (CXCL12) is important for controlling their excitability. CXCR4 is also a co‐receptor for the glycoprotein 120 (gp120) of the envelope of the human immunodeficiency virus type 1 (HIV‐1), and binding of gp120 to CXCR4 may produce pathological effects. In order to study CXCR4‐dependent modulation of membrane excitability, we recorded in cell‐attached configuration spontaneous action currents from hippocampal stratum lacunosum‐moleculare Cajal–Retzius cells of the CXCR4‐EGFP mouse. CXCL12 (50 nm) powerfully inhibited firing independently of synaptic transmission, suggesting that CXCR4 regulates an intrinsic conductance. This effect was prevented by conditioning slices with BAPTA‐AM (200 μm), and by blockers of the BK calcium‐dependent potassium channels (TEA (1 mm), paxilline (10 μm) and iberiotoxin (100 nm)). In contrast, exposure to gp120 (pico‐ to nanomolar range, alone or in combination with soluble cluster of differentiation 4 (CD4)), enhanced spontaneous firing frequency. This effect was prevented by the CXCR4 antagonist AMD3100 (1 μm) and was absent in EGFP‐negative stratum lacunosum‐moleculare interneurons. Increased excitability was prevented by treating slices with BAPTA‐AM or bumetanide, suggesting that gp120 activates a mechanism that is both calcium‐ and chloride‐dependent. In conclusion, our results demonstrate that CXCL12 and gp120 modulate the excitability of Cajal–Retzius cells in opposite directions. We propose that CXCL12 and gp120 either generate calcium responses of different strength or activate distinct pools of intracellular calcium, leading to agonist‐specific responses, mediated by BK channels in the case of CXCL12, and by a chloride‐dependent mechanism in the case of gp120.
Modulation of synaptic input by GABAB receptors improves coincidence detection for computation of sound location
Authors: Fischl Matthew J. , Combs T. Dalton , Klug Achim , Grothe Benedikt , Burger R. Michael
Published: April 2012

Key points

Organisms localise low frequencies using interaural time disparities (ITDs) in which specialized neurones in the medial superior olive (MSO) compute submillisecond differences in arrival time of sounds to each ear, a value that varies systematically with sound location.

These neurones compute sound location over a 1012 fold range in sound intensities, despite large intensity‐dependent changes in input strength. Modulation of synaptic gain has been suggested as a mechanism to maintain accurate ITD processing.

Here we show that activation of GABAB receptors suppresses both the excitatory and inhibitory inputs to the MSO and alters the kinetics of inhibitory synaptic currents.

Using in vitro physiological methods and computational modelling, we show that the modulation by GABAB receptor activation contributes to spatial tuning of MSO neurones.

These results contribute to the understanding of how neurones maintain computational stability under widely varying input conditions.

Abstract  Interaural time disparities (ITDs) are the primary cues for localisation of low‐frequency sound stimuli. ITDs are computed by coincidence‐detecting neurones in the medial superior olive (MSO) in mammals. Several previous studies suggest that control of synaptic gain is essential for maintaining ITD selectivity as stimulus intensity increases. Using acute brain slices from postnatal day 7 to 24 (P7–P24) Mongolian gerbils, we confirm that activation of GABAB receptors reduces the amplitude of excitatory and inhibitory synaptic currents to the MSO and, moreover, show that the decay kinetics of IPSCs are slowed in mature animals. During repetitive stimuli, activation of GABAB receptors reduced the amount of depression observed, while PSC suppression and the slowed kinetics were maintained. Additionally, we used physiological and modelling approaches to test the potential impact of GABAB activation on ITD encoding in MSO neurones. Current clamp recordings from MSO neurones were made while pharmacologically isolated excitatory inputs were bilaterally stimulated using pulse trains that simulate ITDs in vitro. MSO neurones showed strong selectivity for bilateral delays. Application of both GABAB agonists and antagonists demonstrate that GABAB modulation of synaptic input can sharpen ITD selectivity. We confirmed and extended these results in a computational model that allowed for independent manipulation of each GABAB‐dependent effect. Modelling suggests that modulation of both amplitude and kinetics of synaptic inputs by GABAB receptors can improve precision of ITD computation. Our studies suggest that in vivo modulation of synaptic input by GABAB receptors may act to preserve ITD selectivity across various stimulus conditions.
Influence of process parameters on properties of reactively sputtered tungsten nitride thin films
Authors: Addonizio Maria L. , Castaldo Anna , Antonaia Alessandro , Gambale Emilia , Iemmo Laura
Published: April 2012

Tungsten nitride (WNx) thin films were produced by reactive dc magnetron sputtering of tungsten in an Ar–N2 gas mixture. The influence of the deposition power on the properties of tungsten nitride has been analyzed and compared with that induced by nitrogen content variation in the sputtering gas. A combined analysis of structural, electrical and optical properties on thin WNx films obtained at different deposition conditions has been performed. It was found that at an N2 content of 14% a single phase structure of W2N films was formed with the highest crystalline content. This sputtering gas composition was subsequently used for fabricating films at different deposition powers. Optical analysis showed that increasing the deposition power created tungsten nitride films with a more metallic character, which is confirmed with resistivity measurements. At low sputtering powers the resulting films were crystalline whereas, with an increase of power, an amorphous phase was also present. The incorporation of an excess of nitrogen atoms resulted in an expansion of the W2N lattice and this effect was more pronounced at low deposition powers. Infrared analysis revealed that in WNx films deposited at low power, chemisorbed N2 molecules did not behave as ligands whereas at high deposition power they clearly appeared as ligands around metallic tungsten. In this study, the influence of the most meaningful deposition parameters on the phase transformation reaction path was established and deposition conditions suitable for producing thermally stable and highly crystalline W2N films were found.
Astrocytes Modulate Neural Network Activity by Ca
2+
-Dependent Uptake of Extracellular K
+
Authors: Wang Fushun , Smith Nathan A. , Xu Qiwu , Fujita Takumi , Baba Akemichi , Matsuda Toshio , Takano Takahiro , Bekar Lane , Nedergaard Maiken
Published: April 2012

Astrocytes modulate synaptic activity by changing the local concentration of extracellular K
+
.
Influence of Antituberculosis Drug Resistance and Mycobacterium tuberculosis Lineage on Outcome in HIV-Associated Tuberculous Meningitis
Authors: Tho Dau Quang , Török M. Estée , Yen Nguyen Thi Bich , Bang Nguyen Duc , Lan Nguyen Thi Ngoc , Kiet Vo Sy , van Vinh Chau Nguyen , Dung Nguyen Huy , Day Jeremy , Farrar Jeremy , Wolbers Marcel , Caws Maxine
Published: April 2012

HIV-associated tuberculous meningitis (TBM) has high mortality. Aside from the devastating impact of multidrug resistance (MDR) on survival, little is understood about the influence of other bacterial factors on outcome. This study examined the influence of
Mycobacterium tuberculosis
drug resistance, bacterial lineage, and host vaccination status on outcome in patients with HIV-associated TBM.
Mycobacterium tuberculosis
isolates from the cerebrospinal fluid of 186 patients enrolled in two studies of HIV-associated TBM in Ho Chi Minh City, Vietnam, were tested for resistance to first-line antituberculosis drugs. Lineage genotyping was available for 122 patients. The influence of antituberculosis drug resistance and
M. tuberculosis
lineage on 9-month mortality was analyzed using Kaplan-Meier survival analysis and Cox multiple regression models. Isoniazid (INH) resistance without rifampin resistance was associated with increased mortality (adjusted hazard ratio [HR], 1.78, 95% confidence interval [CI], 1.18 to 2.66;
P
= 0.005), and multidrug resistance was uniformly fatal (
n
= 8/8; adjusted HR, 5.21, 95% CI, 2.38 to 11.42;
P
< 0.0001). The hazard ratio for INH-resistant cases was greatest during the continuation phase of treatment (after 3 months; HR, 5.05 [95% CI, 2.23 to 11.44];
P
= 0.0001). Among drug-susceptible cases, patients infected with the “modern” Beijing lineage strains had lower mortality than patients infected with the “ancient” Indo-Oceanic lineage (HR, 0.29 [95% CI, 0.14 to 0.61];
P
= 0.001). Isoniazid resistance, multidrug resistance, and
M. tuberculosis
lineage are important determinants of mortality in patients with HIV-associated TBM. Interventions which target these factors may help reduce the unacceptably high mortality in patients with TBM.
Antischistosomal Activities of Mefloquine-Related Arylmethanols
Authors: Ingram Katrin , Ellis William , Keiser Jennifer
Published: April 2012

Interesting antischistosomal properties have been documented for the antimalarial mefloquine, a 4-quinolinemethanol. We evaluated the antischistosomal activities of nine mefloquine-related compounds belonging to the 4-pyridinemethanols, 9-phenanthrenmethanols, and 4-quinolinemethanols. Eight compounds revealed high activities against
Schistosoma mansoni in vitro
, with two drugs (the 4-quinolinemethanols WR7573 and WR7930) characterized by significantly lower half-maximal inhibitory concentrations (IC
50
s) (2.7 and 3.5 μM, respectively) compared to mefloquine (11.4 μM). Mefloquine and WR7930 showed significantly decreased IC
50
s when incubated in the presence of hemoglobin. High worm burden reductions (WBR) were obtained with enpiroline (WBR, 82.7%; dosage, 200 mg/kg of body weight) and its
threo
isomers (+)-
threo
(WBR, 100%) and (−)-
threo
(WBR, 89%) and with WR7930 (WBR, 87%; dosage, 100 mg/kg) against adult
S. mansoni
in mice. Furthermore, excellent
in vitro
and
in vivo
antischistosomal activity was observed for two WR7930-related structures (WR29252 and WR7524). In addition, mefloquine (WBR, 81%), enpiroline (WBR, 77%), and WR7930 (WBR, 100%) showed high activities against
S. haematobium
harbored in mice following single oral doses of 200 mg/kg. These results provide a deeper insight into the structural features of the arylmethanols that rule antischistosomal activity. Further studies should be launched with enpiroline and WR7930.
Contribution of Bordetella Filamentous Hemagglutinin and Adenylate Cyclase Toxin to Suppression and Evasion of Interleukin-17-Mediated Inflammation
Authors: Henderson Michael W. , Inatsuka Carol S. , Sheets Amanda J. , Williams Corinne L. , Benaron David J. , Donato Gina M. , Gray Mary C. , Hewlett Erik L. , Cotter Peggy A.
Published: April 2012

Bordetella pertussisandBordetella bronchisepticaestablish respiratory infections with notorious efficiency. Our previous studies showed that thefhaBgenes ofB. pertussisandB. bronchiseptica, which encode filamentous hemagglutinin (FHA), are functionally interchangeable and provided evidence that FHA-deficientB. bronchisepticainduces more inflammation in the lungs of mice than wild-typeB. bronchiseptica. We show here that the robust inflammatory response to FHA-deficientB. bronchisepticais characterized by the early and sustained influx of interleukin-17 (IL-17)-positive neutrophils and macrophages and, at 72 h postinoculation, IL-17-positive CD4+T cells, suggesting that FHA allows the bacteria to suppress the development of an IL-17-mediated inflammatory response. We also show that thecyaAgenes ofB. pertussisandB. bronchiseptica, which encode adenylate cyclase toxin (ACT), are functionally interchangeable and that ACT, specifically its catalytic activity, is required forB. bronchisepticato resist phagocytic clearance but is neither required for nor inhibitory of the induction of inflammation if bacteria are present in numbers sufficient to persist during the first 3 days postinoculation. Incubation of bone marrow-derived macrophages with a ΔcyaAstrain caused decreased production of IL-1β and increased production of tumor necrosis factor alpha (TNF-α) and IL-12, while incubation with a ΔcyaAΔfhaBstrain caused increased production of IL-23. These data suggest that FHA and ACT both contribute to suppress the recruitment of neutrophils and the development of an IL-17-mediated immune response. To our knowledge, this is the first demonstration of a microbial pathogen suppressing IL-17-mediated inflammationin vivoas a strategy to evade innate immunity.
Entamoeba histolytica Cell Surface Calreticulin Binds Human C1q and Functions in Amebic Phagocytosis of Host Cells
Authors: Vaithilingam Archana , Teixeira Jose E. , Miller Peter J. , Heron Bradley T. , Huston Christopher D.
Published: April 2012

Phagocytosis of host cells is characteristic of tissue invasion by the intestinal amebaEntamoeba histolytica, which causes amebic dysentery and liver abscesses.Entamoeba histolyticainduces host cell apoptosis and uses ligands, including C1q, on apoptotic cells to engulf them. Two mass spectrometry analyses identified calreticulin in amebic phagosome preparations, and, in addition to its function as an endoplasmic reticulum chaperone, calreticulin is believed to be the macrophage receptor for C1q. The purpose of this study was to determine if calreticulin functions as anE. histolyticaC1q receptor during phagocytosis of host cells. Calreticulin was localized to the surface ofE. histolyticaduring interaction with both Jurkat lymphocytes and erythrocytes and was present in over 75% of phagocytic cups during amebic erythrophagocytosis. Presence of calreticulin on the cell surface was further demonstrated using a method that selectively biotinylated cell surface proteins and by flow cytometry using trophozoites overexpressing epitope-tagged calreticulin. Regulated overexpression of calreticulin increasedE. histolytica's ability to phagocytose apoptotic lymphocytes and calcium ionophore-treated erythrocytes but had no effect on amebic adherence to or destruction of cell monolayers or surface expression of the GalNAc lectin and serine-richE. histolyticaprotein (SREHP) receptors. Finally,E. histolyticacalreticulin bound specifically to apoptotic lymphocytes and to human C1q. Collectively, these data implicate cell surface calreticulin as a receptor for C1q duringE. histolyticaphagocytosis of host cells.
Reactive Oxygen Species-Triggered Trophoblast Apoptosis Is Initiated by Endoplasmic Reticulum Stress via Activation of Caspase-12, CHOP, and the JNK Pathway in Toxoplasma gondii Infection in Mice
Authors: Xu Xiucai , Liu Tingting , Zhang Aimei , Huo Xingxing , Luo Qingli , Chen Zhaowu , Yu Li , Li Qing , Liu Lili , Lun Zhao-rong , Shen Jilong
Published: April 2012

Toxoplasma gondii
infection in pregnant women may result in abortion or in fetal teratogenesis; however, the underlying mechanisms are still unclear. In this paper, based on a murine model, we showed that maternal infection with RH strain
T. gondii
tachyzoites induced elevated production of reactive oxygen species (ROS), local oxidative stress, and subsequent apoptosis of placental trophoblasts. PCR array analysis of 84 oxidative stress-related genes demonstrated that 27 genes were upregulated at least 2-fold and that 9 genes were downregulated at least 2-fold in the
T. gondii
infection group compared with levels in the control group. The expression of NADPH oxidase 1 (Nox1) and glutathione peroxidase 6 (Gpx6) increased significantly, about 25-fold. The levels of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) increased significantly with
T. gondii
infection, and levels of glutathione (GSH) decreased rapidly.
T. gondii
infection increased the early expression of endoplasmic reticulum stress (ERS) markers, followed by cleavage of caspase-12, activation of ASK1/JNK, and increased apoptosis of trophoblasts, both
in vivo
and
in vitro
. The apoptosis of trophoblasts, the activation of caspase-12 and the ASK1/JNK pathway, and the production of peroxides were dramatically inhibited by pretreatment with
N
-acetylcysteine (NAC). The upregulation of Nox1 was contact dependent and preceded the increase in levels of ERS markers and the activation of the proapoptosis cascade. Thus, we concluded that apoptosis in placental trophoblasts was initiated predominantly by ROS-mediated ERS via activation of caspase-12, CHOP, and the JNK pathway in acute
T. gondii
infection. Elevated ROS production is the central event in
T. gondii
-induced apoptosis of placental trophoblasts.
Retrospective study of 155 cases of prolapse of the nictitating membrane gland in dogs
Authors: Mazzucchelli S. , Vaillant M. D. , Wéverberg F. , Arnold‐Tavernier H. , Honegger N. , Payen G. , Vanore M. , Liscoet L. , Thomas O. , Clerc B. , Chahory S.
Published: April 2012

A retrospective study of 155 cases (114 dogs). The breed, sex and age at the time of the first and opposite onset of nictitans gland prolapse were recorded. Long‐term follow‐up with a minimum of one‐year duration was performed by telephone conversations. One hundred and fourteen dogs representing 155 nictitans gland prolapses were included. 75.4 per cent of the first prolapse occur before one year of age. Unilateral nictitans gland prolapse was observed in 64 per cent of cases. When the condition was bilateral, it occurred simultaneously in 41.4 per cent. When it was bilateral but not simultaneous (24/41), the opposite gland prolapse occurred within three months in 70.8 per cent of the cases. Five breeds were most commonly affected by the bilateral condition: French bulldog, shar pei, great dane, English bulldog and cane corso.
OPERA SUPERLUMINAL NEUTRINOS AND KINEMATICS IN FINSLER SPACETIME
Authors: CHANG ZHE , LI XIN , WANG SAI
Published: April 2012

The OPERA collaboration recently reported that the muon neutrinos could be superluminal. More recently, Cohen and Glashow pointed that such superluminal neutrinos would be suppressed since they lose their energies rapidly via bremsstrahlung. Here, we propose that the Finslerian nature of the spacetime could account for the superluminal phenomena of particles. The Finsler spacetime permits the existence of the superluminal behavior of particles while the causality still holds. A new dispersion relation is obtained in a class of Finsler spacetimes. It is shown that the superluminal speed is linearly dependent on the energy per unit mass of the particle. We find that such a superluminal speed formula is consistent with the data of the OPERA, MINOS and Fermilab-1979 neutrino experiments as well as the observations on the neutrinos from the SN1987A.
SUPERLUMINAL NEUTRINOS IN THE MINIMAL STANDARD MODEL EXTENSION
Authors: QIN NAN , MA BO-QIANG
Published: April 2012

The measurement of the neutrino velocity with the OPERA detector in the CNGS beam shows unexpected indication, that the muon neutrino velocity, vν, exceeds the velocity of light in the vacuum, c, which is obviously in contradiction with the most basic hypothesis of modern physics. Within the framework of minimal Standard Model Extension (SME), we discuss the modified dispersion relation and consequently the velocity–energy relation of muon neutrinos. The simplified models are fitted to the OPERA data, Fermilab experiment and MINOS data. We find that minimal Standard Model Extension can describe these long baseline superluminal neutrinos to a good accuracy. For the well-known tension between the OPERA measurement and the Supernova 1987A neutrino observation, we discuss two ways out of the contradiction.
ROTATED WAVELET FILTERS-BASED FINGERPRINT RECOGNITION
Authors: BHARKAD SANGITA D. , KOKARE MANESH
Published: April 2012

A novel approach for feature extraction of fingerprint matching is proposed by using two-dimensional (2D) rotated wavelet filters (RWF). 2D RWF are used to capture the characterization of diagonally oriented information present in fingerprint image. Proposed method extracts the significant information from small area of fingerprint image. Experimental results conducted on standard database of Bologna University and FVC2002 indicate that the proposed method improves the genuine acceptance rate (GAR) from 92.14% to 96.12% and reduces false acceptance rate (FAR) from 25.2% to 21.2% on Bologna University database and it reduces FAR from 36.71% to 22.79% on FVC2002 database compared with discrete wavelet transform-based approach.
THE FATIGUE AND FRACTURE BEHAVIOR OF MICRON-RUBBER AND NANO-SILICA PARTICLES MODIFIED EPOXY POLYMER
Authors: MANJUNATHA C. M. , JAGANNATHAN N. , PADMALATHA K. , TAYLOR A. C. , KINLOCH A. J.
Published: April 2012

A thermosetting epoxy polymer was hybrid-modified by incorporating 9 wt.% of CTBN rubber microparticles and 10 wt.% of silica nanoparticles. The resin was poured into steel mould and cured to produce bulk epoxy polymer sheets from which fatigue test specimens were machined. The total fatigue life of the hybrid-modified epoxy polymer was determined by conducting constant amplitude fatigue tests with dog-bone shaped test specimens, at a stress ratio, R = σ min /σ max = 0.1, using a sinusoidal waveform at a frequency of 3 Hz. Further, the fatigue crack growth behavior of the hybrid-modified epoxy polymer, at a stress ratio, R = 0.1, was determined using a standard 50 mm wide compact tension specimen. The fatigue fracture surfaces were observed using a scanning electron microscope. The cyclic fracture toughness of the hybrid-modified epoxy polymer, estimated from the fracture surface analysis, correlated well with the reported values of the toughness; which was significantly greater than that of the neat epoxy polymer. The energy dissipating micromechanisms of, (i) rubber particle cavitation and plastic deformation of the surrounding material, and (ii) silica nanoparticle debonding followed by plastic void growth, were observed to be operative, resulting in an improved fracture toughness. The fatigue crack initiation and propagation lives were determined from the experimental data. The enhanced capability to withstand longer crack lengths, due to the improved toughness together with the retarded crack growth rate, were observed to enhance the total fatigue life of the hybrid-modified epoxy polymer.
GOLD SUPPORTED CALCIUM DEFICIENT HYDROXYAPATITE FOR ROOM TEMPERATURECOOXIDATION
Authors: REDDY E. LINGA , PRABHAKARN A. , KARUPPIAH J. , RAMESHBABU N. , SUBRAHMANYAM CH.
Published: April 2012

Gold supported hydroxyapatite (HA) and calcium deficient hydroxyapatite (CDHA) was studied for the room temperature CO oxidation. Nanostructured gold catalyst has been prepared by deposition precipitation method, whereas HA was synthesized by microwave synthesis. Inorder to understand the influence of surface properties of HA, support HA was synthesized with different Ca/P ratios (1.67, 1.62, 1.57, 1.534 and 1.5). The gold supported catalysts were characterized by XRD, BET, ICP-OES and TEM. Typical results indicate that gold supported 1.57 HA shows higher activity compared to other HA catalysts (1.67, 1.62, 1.534 and 1.5) which may be due to the presence of optimum number of acidic and basic sites.
EFFECT OF Al2O3-WATER NANOFLUIDS IN CONVECTIVE HEAT TRANSFER
Authors: PRAJAPATI OM SHANKAR , RAJVANSHI A. K.
Published: April 2012

Nanofluids are suspensions of metallic or nonmetallic nanopowders in base liquid and can be employed to increase heat transfer rate in various applications. In this work turbulent flow forced convection heat transfer of Al 2 O 3-water nanofluid inside an annular tube with variable wall temperature was investigated experimentally. The Nusselt numbers of nanofluid were obtained for various heat flux, Reynolds numbers and nanoparticle concentrations at atmospheric pressure. The addition of nanoparticle in water enhances heat transfer coefficient and enhancement increases with increase in the nanoparticle concentration, heat flux and flow rate. Experimental results emphasize the enhancement of heat transfer due to the nanoparticle presence in the fluid.