bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetically controlled single-electron shuttle
Authors: Ilinskaya O. A. , Kulinich S. I. , Krive I. V. , Shekhter R. I. , Jonson M.
Published: January 2015

A theory of single-electron shuttling in an external magnetic field in nanoelectromechanical system with magnetic leads is presented. We consider partially spin-polarized electrons in the leads and electron transport in both the Coulomb blockade regime and in the limit of large bias voltages when the Coulomb blockade is lifted. The influence of the degree of spin polarization on shuttle instability is considered. It is shown that there is certain degree of spin polarization above which the magnetic field ceases to control electron transport. In the Coulomb blockade regime the dependence of the threshold magnetic field, which separates the “shuttle” and vibron regimes, on the degree of polarization is evaluated. The possibility of re-entrant transitions to the shuttle phase is discussed.
Comments on the cross-relaxation effect between adsorbed 3He and PrF3 nanoparticles
Authors: Alakshin E. M. , Gazizulin R. R. , Gazizulina A. M. , Klochkov A. V. , Orlinskii S. B. , Rodionov A. A. , Safin T. R. , Safiullin K. R. , Tagirov M. S. , Zakharov M. Yu.
Published: January 2015

The spin kinetics data of 3He in contact with PrF3 and LaF3 nanosized powders are reported. All experiments have been carried out by pulse NMR methods at temperature 1.5 K. The analysis of obtained data testifies in favor of cross-relaxation presence in the nuclear spin–lattice relaxation data, which takes place between 3He and 141Pr nuclei.
Molecular alignment dependent electron interference in attosecond ultraviolet photoionization
Authors: Yuan Kai-Jun , Bandrauk André D.
Published: January 2015

We present molecular photoionization processes by intense attosecond ultraviolet laser pulses from numerical solutions of time-dependent Schrödinger equations. Simulations preformed on a single electron diatomic H2+ show minima in molecular photoelectron energy spectra resulting from two center interference effects which depend strongly on molecular alignment. We attribute such sensitivity to the spatial orientation asymmetry of the photoionization process from the two nuclei. A similar influence on photoelectron kinetic energies is also presented.
Coexistence of spin crossover and magnetic ordering in a dendrimeric Fe(III) complex
Authors: Vorobeva V. E. , Domracheva N. E. , Pyataev A. V. , Gruzdev M. S. , Chervonova U. V.
Published: January 2015

The magnetic properties of a new dendrimeric spin crossover Fe(III) complex, [Fe(L)2]+PF6−, where L = 3,5-di[3,4,5-tris(tetradecyloxy) benzoyloxy]benzoyl-4-salicylidene-N-ethyl-N-ethylene-diamine, are reported for the first time. EPR studies show that this compound undergoes a gradual spin transition in the temperature range 70–300 K and has antiferromagnetic ordering below 10 K. Mössbauer spectroscopy at 5 K confirms the presence of magnetic ordering in the dendrimeric iron complex.
Anomalous magnetization dynamics near the spin-reorientation transition temperature in ε-In0.24Fe1.76O3 nanowires
Authors: Dmitriev A. I. , Tokoro H. , Ohkoshi S. , Morgunov R. B.
Published: January 2015

It is found that increasing the frequency of an alternating magnetic field leads to an anomalous shift in the temperature maximum of the dynamic magnetic susceptibility in ε-In0.24Fe1.76O3 nanowires in a direction opposite to theoretical predictions for thermally activated processes. This unusual effect can be explained in terms of a redistribution of the contributions to the dynamic magnetic susceptibility from the high- and low-temperature phases, each of which is described by a cluster glass model. The contributions of these phases to the electron spin resonance spectra are identified.
Competition of Peierls relief and structural defects in the damping of domain walls in [Mn{(R/S)-pn}]2[Mn{(R/S)-pn}2(H2O)][Cr(CN)6]2 ferrimagnet
Authors: Talantcev A. D. , Koplak O. V. , Kirman M. V. , Morgunov R. B.
Published: January 2015

A reverse ordering of changes in the modes of domain wall movement in the molecular ferrimagnet [Mn{(R/S)-pn}]2[Mn{(R/S)-pn}2(H2O)][Cr(CN)6]2 is observed with rising temperature in ac magnetic fields with frequencies of 0.04–1400 Hz. The appearance of a relaxation mode against the background of domain wall creep during heating of the crystals indicates that these modes apply to two different types of barriers. The existence of a threshold amplitude for the ac magnetic field confirms that the periodic Peierls relief contributes to the damping of domain walls along with the traditional contribution from pinning of the walls on structural defects.
Oscillation of the multiferroic/ferroelectric GdMnO3/SrTiO3 and YbMnO3/SrTiO3 interfaces in the EPR spectrum
Authors: Eremina R. M. , Gavrilova T. P. , Fazlizhanov I. I. , Yatsyk I. V. , Mamedov D. V. , Sukhanov A. A. , Chichkov V. I. , Andreev N. V. , Krug von Hidda H.-A. , Loidl A.
Published: January 2015

The electron paramagnetic resonance (EPR) method was used to study thin manganite ytterbium YbMnO3 and gadolinium GdMnO3 films, with a thickness of 100 nm, deposited on a SrTiO3 virtual ferroelectric backing (GdMnO3/SrTiO3 and YbMnO3/SrTiO3). The most interesting results are obtained in the 40–100 K temperature interval for GdMnO3/SrTiO3, and 40–150 K for YbMnO3/SrTiO3. In these temperature ranges, in addition to the exchange-narrowed line from all film material, absorbed power oscillations were observed in the EPR spectra, with the amplitude of the oscillations depending on both the temperature and the magnitude of the external magnetic field.
Proton NMR of water colloidal solutions of nanosized crystalline LaF3 and LaF3:Gd3+ particles
Authors: Alakshin E. M. , Gizatullin B. I. , Zakharov M. Yu. , Klochkov A. V. , Salikhov T. M. , Skirda V. D. , Tagirov M. S.
Published: January 2015

A study of the nuclear magnetic relaxation of water protons in a series of colloidal solutions of nanosized lanthanum trifluoride and lanthanum fluoride particles, doped with gadolinium (0.5%). The proton NMR signal was recorded by a “Proton-20 M (Chromatech)” spectrometer. It is established that the rate of longitudinal relaxation depends on the nanoparticle concentration in the water solution, and on their dimension. It is demonstrated that the proton relaxation rate in the LaF3:Gd3+ solution increases with paramagnet concentration in the nanoparticles, and decreases with increasing particle size.
Influence of intermediate-heat treatment on the structure and magnetic properties of iron-rich Sm(CoFeCuZr)Z sintered magnets
Authors: Horiuchi Yosuke , Hagiwara Masaya , Endo Masaki , Sanada Naoyuki , Sakurada Shinya
Published: January 2015

In this study, we investigated intermediate-heat treatment (IHT) at temperatures between those of sintering and solution treatment, and evaluated the effects on the macrostructure, microstructure, and magnetic properties of Sm(Cobal.Fe0.35Cu0.06Zr0.018)7.8. We found that squareness was clearly improved by adopting the IHT, which promotes grain growth. These results indicate that reducing the fraction of grain boundaries by increasing the grain size affects the behavior of domain-wall motion. Magnetic properties of Mr 1.22 T, HcJ 1580 kA/m, and (BH)max 282 kJ/m3 (>35 MGOe) were obtained for Sm(Cobal.Fe0.35Cu0.06Zr0.018)7.8 subjected to IHT at 1453 K.
The search for an underground nuclear test
Authors: Kramer David
Published: January 2015

In a month-long exercise, the on-site inspection capabilities of the Comprehensive Nuclear-Test-Ban Treaty Organization were put to the test.
Taking the next steps in fusion ignition quest
Authors: Kramer David
Published: January 2015

Researchers focus on improving the hohlraum, the cylinder that surrounds the fusion fuel capsule.
Energetics and forces in living cells
Authors: Dunn Alexander R. , Price Andrew
Published: January 2015

Proteins can act as exquisite nanomachines to produce or sense the motion associated with cell division, intercellular trafficking, muscle contraction, and countless other activities.
Turning nuclear waste into glass
Authors: Pegg Ian L.
Published: January 2015

Vitrification has emerged as the treatment option of choice for the most dangerous radioactive waste. But dealing with the nuclear waste legacy of the Cold War will require state-of-the-art facilities and advanced glass formulations.
The oceans’ accumulating plastic garbage
Authors: van Sebille Erik
Published: January 2015

A piece of plastic discarded into the sea travels far and wide, carried by complex currents. Eventually, the material settles into one of five distinct garbage patches in the subtropical oceans.
Age and size compositions, habitats, growth and reproductive characteristics of a terapontid (Pelates octolineatus) in coastal waters
Authors: Veale Lauren , Coulson Peter , Hall Norman , Hesp Alex , Potter Ian C.
Published: January 2015

This study of Pelates octolineatus is the first to use individually aged fish to describe the life cycle of a terapontid, a speciose and abundant Indo-West Pacific family. On the lower west Australian coast, this species uses dense seagrass as a nursery area and, after ~1 year of life when approaching 100mm in total length (TL), moves into deeper waters over sparser seagrass where it matures at the end of its second year at ~140–170mm. The maximum TL and age were 256mm and 10 years. A modified von Bertalanffy curve, allowing for a linear increase in the growth coefficient with age, improved the fit to the lengths at age of older P. octolineatus. Growth was even better described by extending this model to allow for seasonality through incorporating a sine-based curve. This model described well the seasonality exhibited by modal progressions in monthly length–frequency distributions. Instantaneous growth rates, particularly of the youngest age classes, peaked in the warm, summer months and the amplitude of seasonal change in these rates declined with increasing age. Gonadal recrudescence occurred in early spring as temperature and day length increased and spawning peaked in late-spring to mid-summer when temperatures were approaching their maxima.
Derivation of a Screening Tool to Identify Patients with Right Ventricular Dysfunction or Tricuspid Regurgitation after Negative Computerized Tomographic Pulmonary Angiography of the Chest
Authors: Kline Jeffrey A. , Russell Frances M. , Lahm Tim , Mastouri Ronald A.
Published: January 2015

Many dyspneic patients who undergo computerized tomographic pulmonary angiography (CTPA) for presumed acute pulmonary embolism (PE) have no identified cause for their dyspnea yet have persistent symptoms, leading to more CTPA scanning. Right ventricular (RV) dysfunction or overload can signal treatable causes of dyspnea. We report the rate of isolated RV dysfunction or overload after negative CTPA and derive a clinical decision rule (CDR). We performed secondary analysis of a multicenter study of diagnostic accuracy for PE. Inclusion required persistent dyspnea and no PE. Echocardiography was ordered at clinician discretion. A characterization of isolated RV dysfunction or overload required normal left ventricular function and RV hypokinesis, or estimated RV systolic pressure of at least 40 mmHg. The CDR was derived from bivariate analysis of 97 candidate variables, followed by multivariate logistic regression. Of 647 patients, 431 had no PE and persistent dyspnea, and 184 (43%) of these 431 had echocardiography ordered. Of these, 64 patients (35% [95% confidence interval (CI): 28%–42%]) had isolated RV dysfunction or overload, and these patients were significantly more likely to have a repeat CTPA within 90 days (P =. 02, χ2 test). From univariate analysis, 4 variables predicted isolated RV dysfunction: complete right bundle branch block, normal CTPA scan, active malignancy, and CTPA with infiltrate, the last negatively. Logistic regression found only normal CTPA scanning significant. The final rule (persistent dyspnea + normal CTPA scan) had a positive predictive value of 53% (95% CI: 37%–69%). We conclude that a simple CDR consisting of persistent dyspnea plus a normal CTPA scan predicts a high probability of isolated RV dysfunction or overload on echocardiography.
An RPTPα/Src family kinase/Rap1 signaling module recruits myosin IIB to support contractile tension at apical E-cadherin junctions
Authors: Gomez Guillermo A. , McLachlan Robert W. , Wu Selwin K. , Caldwell Benjamin J. , Moussa Elliott , Verma Suzie , Bastiani Michele , Priya Rashmi , Parton Robert G. , Gaus Katharina , Sap Jan , Yap Alpha S.
Published: January 2015

Cell–cell adhesion couples the contractile cortices of epithelial cells together, generating tension to support a range of morphogenetic processes. E-cadherin adhesion plays an active role in generating junctional tension by promoting actin assembly and cortical signaling pathways that regulate myosin II. Multiple myosin II paralogues accumulate at mammalian epithelial cell–cell junctions. Earlier, we found that myosin IIA responds to Rho-ROCK signaling to support junctional tension in MCF-7 cells. Although myosin IIB is also found at the zonula adherens (ZA) in these cells, its role in junctional contractility and its mode of regulation are less well understood. We now demonstrate that myosin IIB contributes to tension at the epithelial ZA. Further, we identify a receptor type-protein tyrosine phosphatase alpha–Src family kinase–Rap1 pathway as responsible for recruiting myosin IIB to the ZA and supporting contractile tension. Overall these findings reinforce the concept that orthogonal E-cadherin–based signaling pathways recruit distinct myosin II paralogues to generate the contractile apparatus at apical epithelial junctions.
SFA-SPA: a suffix array based short peptide assembler for metagenomic data
Authors: Yang Youngik , Zhong Cuncong , Yooseph Shibu
Published: January 2015

Summary: The determination of protein sequences from a metagenomic dataset enables the study of metabolism and functional roles of the organisms that are present in the sampled microbial community. We had previously introduced algorithm and software for the accurate reconstruction of protein sequences from short peptides identified on nucleotide reads in a metagenomic dataset. Here, we present significant computational improvements to the short peptide assembly algorithm that make it practical to reconstruct proteins from large metagenomic datasets containing several hundred million reads, while maintaining accuracy. The improved computational efficiency is achieved using a suffix array data structure that allows for fast querying during the assembly process, and a significant redesign of assembly steps that enables multi-threaded execution.

Availability and implementation: The program is available under the GPLv3 license from sourceforge.net/projects/spa-assembler.

Contact:  syooseph@jcvi.org

Supplementary information:  Supplementary data are available at Bioinformatics online.
Computational identification of MoRFs in protein sequences
Authors: Malhis Nawar , Gsponer Jörg
Published: January 2015

Motivation: Intrinsically disordered regions of proteins play an essential role in the regulation of various biological processes. Key to their regulatory function is the binding of molecular recognition features (MoRFs) to globular protein domains in a process known as a disorder-to-order transition. Predicting the location of MoRFs in protein sequences with high accuracy remains an important computational challenge.

Method: In this study, we introduce MoRF CHiBi , a new computational approach for fast and accurate prediction of MoRFs in protein sequences. MoRF CHiBi combines the outcomes of two support vector machine (SVM) models that take advantage of two different kernels with high noise tolerance. The first, SVM S , is designed to extract maximal information from the general contrast in amino acid compositions between MoRFs, their surrounding regions (Flanks), and the remainders of the sequences. The second, SVM T , is used to identify similarities between regions in a query sequence and MoRFs of the training set.

Results: We evaluated the performance of our predictor by comparing its results with those of two currently available MoRF predictors, MoRFpred and ANCHOR. Using three test sets that have previously been collected and used to evaluate MoRFpred and ANCHOR, we demonstrate that MoRF CHiBi outperforms the other predictors with respect to different evaluation metrics. In addition, MoRF CHiBi is downloadable and fast, which makes it useful as a component in other computational prediction tools.

Availability and implementation:  http://www.chibi.ubc.ca/morf/ .

Contact:  gsponer@chibi.ubc.ca .

Supplementary information:  Supplementary data are available at Bioinformatics online.
Use of Clinical and Neuroimaging Characteristics to Distinguish Temporal Lobe Herpes Simplex Encephalitis From Its Mimics
Authors: Chow Felicia C. , Glaser Carol A. , Sheriff Heather , Xia Dongxiang , Messenger Sharon , Whitley Richard , Venkatesan Arun
Published: January 2015

Background.  We describe the spectrum of etiologies associated with temporal lobe (TL) encephalitis and identify clinical and radiologic features that distinguish herpes simplex encephalitis (HSE) from its mimics.

Methods.  We reviewed all adult cases of encephalitis with TL abnormalities on magnetic resonance imaging (MRI) from the California Encephalitis Project. We evaluated the association between specific clinical and MRI characteristics and HSE compared with other causes of TL encephalitis and used multivariate logistic modeling to identify radiologic predictors of HSE.

Results.  Of 251 cases of TL encephalitis, 43% had an infectious etiology compared with 16% with a noninfectious etiology. Of infectious etiologies, herpes simplex virus was the most commonly identified agent (n = 60), followed by tuberculosis (n = 8) and varicella zoster virus (n = 7). Of noninfectious etiologies, more than half (n = 21) were due to autoimmune disease. Patients with HSE were older (56.8 vs 50.2 years; P = .012), more likely to be white (53% vs 35%; P = .013), more likely to present acutely (88% vs 64%; P = .001) and with a fever (80% vs 49%; P < .001), and less likely to present with a rash (2% vs 15%; P = .010). In a multivariate model, bilateral TL involvement (odds ratio [OR], 0.38; 95% confidence interval [CI], .18–.79; P = .010) and lesions outside the TL, insula, or cingulate (OR, 0.37; 95% CI, .18–.74; P = .005) were associated with lower odds of HSE.

Conclusions.  In addition to HSE, other infectious and noninfectious etiologies should be considered in the differential diagnosis for TL encephalitis, depending on the presentation. Specific clinical and imaging features may aid in distinguishing HSE from non-HSE causes of TL encephalitis.
A novel mutation, D404N, in the connection subdomain of reverse transcriptase of HIV-1 CRF08_BC subtype confers cross-resistance to NNRTIs
Authors: Zhang Xiao-Min , Wu Hao , Zhang Qiwei , Lau Terrence Chi-Kong , Chu Hin , Chen Zhi-Wei , Jin Dong-Yan , Zheng Bo-Jian
Published: January 2015

Objectives

Growing evidence suggests that mutations in the connection domain of the HIV-1 reverse transcriptase (RT) can contribute to viral resistance to RT inhibitors. This work was designed to determine the effects of a novel mutation, D404N, in the connection subdomain of RT of HIV-1 CRF08_BC subtype on drug resistance, viral replication capacity (RC) and RT activity.

Methods

Mutation D404N, alone or together with the other reported mutations, was introduced into an HIV-1 CRF08_BC subtype infectious clone by site-directed mutagenesis. Viral susceptibility to nine RT inhibitors, viral RC and the DNA polymerase activity of viral RT of the constructed virus mutants were investigated. A modelling study using the server SWISS-MODEL was conducted to explore the possible structure-related drug resistance mechanism of the mutation D404N.

Results

Single mutations D404N and H221Y conferred low-level resistance to nevirapine, efavirenz, rilpivirine and zidovudine. Double mutations Y181C/D404N and Y181C/H221Y significantly reduced susceptibility to NNRTIs. The most pronounced resistance to NNRTIs was observed with the triple mutation Y181C/D404N/H221Y. Virus containing D404N as the only mutation displayed ∼50% RC compared with the WT virus. The modelling study suggested that the D404N mutation might abolish the hydrogen bonds between residues 404 and K30 in p51 or K431 in p66, leading to impaired RT subunit structure and enhanced drug resistance.

Conclusions

These results indicate that D404N is a novel NNRTI-associated mutation in the HIV-1 subtype CRF08_BC and provides information valuable for the monitoring of clinical RTI resistance.
Multicentre evaluation of the Check-Direct CPE® assay for direct screening of carbapenemase-producing Enterobacteriaceae from rectal swabs
Authors: Huang Te-Din , Bogaerts Pierre , Ghilani Enes , Heinrichs Amélie , Gavage Pierre , Roisin Sandrine , Willems Elise , Verbruggen Anne-Marie , Francart Hugo , Denis Olivier , Senterre Jean-Marc , Glupczynski Youri
Published: January 2015

Objectives

The objective of this study was to evaluate in a multicentre survey the analytical performance of the Check-Direct CPE® assay (CDCPE), a multiplex PCR assay for the detection of carbapenemase-producing Enterobacteriaceae (CPE), directly from rectal swabs.

Methods

Adult patients admitted to a high-risk unit in four participating centres were prospectively screened for CPE carriage by rectal swabbing. Samples were cultured on chromogenic CPE-selective media in the local laboratories. All growing Enterobacteriaceae strains were transferred for confirmation of carbapenemase production by multiplex PCR, together with the faecal swabs for CDCPE, to the coordinating laboratory.

Results

Overall, 38 of the 394 samples analysed (9.6%; range 3%–20% per centre) yielded a positive signal for a carbapenemase gene with CDCPE, including 17 samples (4.3%; range 0%–15% per centre) that grew a total of 25 CPE-confirmed isolates (all OXA-48-like producers, including one isolate that simultaneously harboured a VIM-type carbapenemase). No CPE culture-positive samples were missed by CDCPE. Among the 21 samples that were CPE-positive with CDCPE but negative on culture, five were collected from previously known CPE carriers and 6/9 OXA-48-positive signals were detected at one participating centre that was undergoing a hospital-wide outbreak of OXA-48 CPE. When compared with the selective culture, the sensitivity and specificity of CDCPE were 100% and 94%, respectively.

Conclusions

This study showed the value of CDCPE as a tool for screening CPE carriage in an epidemiological setting with a high prevalence of OXA-48 CPE. However, the potential added value for infection control management remains to be demonstrated.
1D accretion discs around eccentric planets: observable near-infrared variability
Authors: Dunhill A. C.
Published: January 2015

I present the results of 1D models of circumplanetary discs around planets on eccentric orbits. I use a classical viscous heating model to calculate emission fluxes at the wavelengths targeted by the NIRCam instrument on JWST, and compare the variability of this signal with the published NIRCam sensitivity specifications. This variability is theoretically detectable by JWST for a sufficiently viscous disc (α ∼ 10−2) around a sufficiently eccentric planet (e ∼ 0.1–0.2) and if the circumplanetary disc accretes material from its parent disc at a rate $\skew4\dot{M} \gtrsim 10^{-7}\,\mathrm{M}_{\odot }$ yr−1. I discuss the limitations of the models used, and the implications of the result for probing the effectiveness of disc interactions for growing a planet's orbital eccentricity.
Education and Human Capital Externalities: Evidence from Colonial Benin
*
Authors: Wantchekon Leonard , Klašnja Marko , Novta Natalija
Published: January 2015

Using a unique data set on students from the first regional schools in colonial Benin, we investigate the effect of education on living standards, occupation, and political participation. Since both school locations and student cohorts were selected with very little information, treatment and control groups are balanced on observables. We can therefore estimate the effect of education by comparing the treated to the untreated living in the same village, as well as those living in villages where no schools were set up. We find a significant positive treatment effect of education for the first generation of students, as well as their descendants: they have higher living standards, are less likely to be farmers, and are more likely to be politically active. We find large village-level externalities—descendants of the uneducated in villages with schools do better than those in control villages. We also find extended family externalities—nephews and nieces directly benefit from their uncle’s education—and show that this represents a “family tax,” as educated uncles transfer resources to the extended family.
A New Approach to Assess Early Progressive Loss Across Multiple Visual Channels In the Natural History of Glaucoma
Authors: Mateus Catarina , Raimundo Miguel , Oliveiros Bárbara , Faria Pedro , Reis Aldina , Castelo-Branco Miguel
Published: January 2015

Purpose:

We aimed to evaluate the ability of new psychophysical discrimination tests, based on readily available hardware, to probe motion, achromatic, and chromatic contrast sensitivity, across the natural history of glaucoma. We assessed the sensitivity of these tests to detect functional damage at ocular hypertension stage, using receiver operating characteristic analysis. We also explored whether eccentricity-related patterns of damage change with disease progression.

Patients and Methods:

We studied a cohort of 43 participants, who were divided between different groups: ocular hypertension (n=16 eyes), glaucoma suspects (n=15), and primary open-angle glaucoma (n=12). These patients were compared with an age-matched control group (n=15 eyes). We tested distinct subsets of retinal ganglion cell populations using 3 novel 2-alternative forced choice psychophysical discrimination tests (independent variables: motion, achromatic, and chromatic L, M, and S-cone contrasts) between 2 separated peripheral, small moving single dots at 4 distinct meridians. Notably these tests were implemented in relatively standard hardware.

Results:

All tests showed significant correlation with disease progression (mean ρ±SD=0.708±0.075; P<0.0001) and had sufficient power to discriminate glaucoma subgroups. Most tests using this design had large sensitivity (above 90% for 80% specificity) to detect functional damage at the ocular hypertensive stage. Disease-related eccentricity patterns of damage were also found, matching the expected pattern of progression.

Conclusions:

Our new psychophysical discrimination tests are capable of probing disease progression and to detect functional damage at ocular hypertension stage. It is therefore possible to customize psychophysical test software to detect early changes and monitor disease progression, including progressive loss of functional reserve, using relatively simple hardware.
Chlorpyrifos Exposure During Perinatal Period Affects Intestinal Microbiota Associated With Delay of Maturation of Digestive Tract in Rats
Authors: Joly Condette Claire , Bach Véronique , Mayeur Camille , Gay‐Quéheillard Jérôme , Khorsi‐Cauet Hafida
Published: January 2015

Objectives:

Pesticide exposure via residues in food may be especially harmful when it takes place in the developing child. The present study was designed to assess the impact of perinatal exposure to chlorpyrifos (CPF, an insecticide known to cross the placental barrier).

Methods:

Female rats were exposed to oral CPF (1 or 5 mg kg−1 day−1 vs vehicle controls) from gestation onset up to weaning of the pups that were individually gavaged (CPF or vehicle) thereafter. Two developmental time points were studied: weaning (day 21) and adulthood (day 60). After sacrifice, samples from the intestinal tract and other organs underwent microbiological and histological analyses.

Results:

Rat pups exposed to 5 mg kg−1 day−1 CPF were both significantly smaller (body length) and lighter than controls. Exposure to CPF was associated with changes in the histological structures (shorter and thinner intestinal villosities), an intestinal microbial dysbiosis, and increased bacterial translocation in the spleen and liver. These significant microbial changes in the gut were associated with impaired epithelium protection (mucin‐2) and microbial pattern recognition receptor (Toll‐like 2 and 4) gene expression.

Conclusions:

Exposure to CPF during gestation and development affected the pups' intestinal development, with morphological alteration of the structures involved in nutrient absorption, intestinal microbial dysbiosis, alteration of mucosal barrier (mucin‐2), stimulation of the innate immune system, and increased bacterial translocation. Perinatal exposure to CPF may therefore have short‐ and long‐term impacts on the digestive tract.
Lactose‐Free Milk or Soy‐Based Formulas Do Not Improve Caregivers' Distress or Perceptions of Difficult Infant Behavior
Authors: Sherman Amanda L. , Anderson Julia , Rudolph Colin D. , Walker Lynn S.
Published: January 2015

Objectives:

The aim of the study was to test the hypothesis that caregiver‐reported difficulties in infant behavior and caregivers' distress will significantly improve on lactose‐free (LF) milk‐based or LF soy–based formulas compared with a milk‐based, lactose‐containing formula.

Methods:

In this double‐blind randomized controlled trial, infants (mean age: 4.97 weeks) with caregiver‐reported feeding problems on a milk‐based lactose‐containing formula were randomized to receive either LF milk–based (n = 96), LF soy–based (n = 97), or milk‐based, lactose‐containing (n = 103) formula. Study formula was infants' sole item of diet for 14 days. Infants' caregivers completed measures of infant behavior and caregivers' distress for the week preceding baseline and again for the week preceding the 14‐day follow‐up.

Results:

Infants who received LF milk or LF soy–based formulas did not significantly differ from those who received milk‐based, lactose‐containing formula on follow‐up caregiver‐reported measures of infant difficultness from the Infant Characteristics Questionnaire, F(2, 277) = 0.83, nor on measures of caregivers' distress, assessed with measures of caregivers' mental health and parenting efficacy, F(2, 285) = 0.73–1.07. Across the 3 formula groups, scores on outcome measures significantly improved from baseline to follow‐up (P < 0.001).

Conclusions:

Our study does not support LF milk or LF soy–based formulas to alleviate common infant behaviors such as fussiness, crying, or need for attention. Moreover, the data suggest that some difficulties in infant behaviors, as well as caregivers' distress and perceived efficacy in parenting difficult infants, may improve within a couple weeks of reporting difficulties to the pediatrician.
The Evolution of Mechanisms Driving the Stomatal Response to Vapor Pressure Deficit
Authors: McAdam Scott A.M. , Brodribb Timothy J.
Published: January 2015

Stomatal responses to vapor pressure deficit (VPD) are a principal means by which vascular land plants regulate daytime transpiration. While much work has focused on characterizing and modeling this response, there remains no consensus as to the mechanism that drives it. Explanations range from passive regulation by leaf hydration to biochemical regulation by the phytohormone abscisic acid (ABA). We monitored ABA levels, leaf gas exchange, and water status in a diversity of vascular land plants exposed to a symmetrical, mild transition in VPD. The stomata in basal lineages of vascular plants, including gymnosperms, appeared to respond passively to changes in leaf water status induced by VPD perturbation, with minimal changes in foliar ABA levels and no hysteresis in stomatal action. In contrast, foliar ABA appeared to drive the stomatal response to VPD in our angiosperm samples. Increased foliar ABA level at high VPD in angiosperm species resulted in hysteresis in the recovery of stomatal conductance; this was most pronounced in herbaceous species. Increased levels of ABA in the leaf epidermis were found to originate from sites of synthesis in other parts of the leaf rather than from the guard cells themselves. The transition from a passive regulation to ABA regulation of the stomatal response to VPD in the earliest angiosperms is likely to have had critical implications for the ecological success of this lineage.
Webometrics as a method for identifying the most accredited free electronic journals
Authors: Isfandyari-Moghaddam Alireza , Danesh Farshid , Hadji-Azizi Nadia
Published: January 2015

Purpose

– The present study aims at determining the most accredited free English electronic journals (EJs) in Medical Sciences, as finding free scholarly EJs including medical ones is difficult in the web environment.

Design/methodology/approach

– The research population consisted of 700 free EJs of Medical Sciences, which were collected from two reputable websites, namely, Directory of Open Access Journals and Free Medical Journals. After first screening, 269 free EJs including 76 journals in health, 4 journals in nursing, 175 journals in medicine and 14 free EJs in dentistry remained for final investigation […].

Findings

– The most accredited journals in four medical disciplines studied here are health:New South Wales Public Health Bulletin,PLoS BiologyandEnvironmental Health Perspectives – National Institute of Environmental Health Sciences; nursing:Online Journal of Rural Nursing and Health CareandOnline Journal of Nursing Informatics[…].

Originality/value

– This research can be treated as an addition to the webometrics literature.
Safeguarding vulnerable adults: learning from the reflective assignments of pre-registration students in the adult field of nursing practice
Authors: Stevens Emma L. , Cook Katie
Published: January 2015

Purpose

– The purpose of this paper was to identify safeguarding concerns for vulnerable adults, including exploring the implementation of safeguarding policy and procedures into practice. This was achieved by reviewing the content of reflective assignments written by pre-registration student nurses, identifying areas of concerns and proposing action plans.

Design/methodology/approach

– A qualitative approach was initially utilised to scrutinise a random 10 per cent sample of work, which was thematically analysed. From this, an audit tool was devised and then applied to evaluate a 35 per cent sample of work from the following cohort of students. Approval and consent was gained.

Findings

– From the initial 10 per cent sample, themes emerged around: practice issues; areas for student's development and marking or assessment issues. The standardised audit tool was devised and applied to a 35 per cent random sample of work. This determined that students identified local safeguarding policies and procedures were being followed in the majority of placement areas, although application of the Mental Capacity Act remained inconsistent.

Research limitations/implications

– The assessor feedback from the reflective assignments was not available to the reviewers, limiting the reviewers ability to identify if assessors had recognised and corrected any policy or practice issues that the student raised. Only assignments from the adult field of nursing were considered within the scope of this study. The authors recommend further empirical investigation into this area.

Practical implications

– This paper offers knowledge that can be applied in practice within both academic and health care provider services that deliver and facilitate nursing education. It has generated an audit tool that can be utilised to evaluate the knowledge of pre-registration students and has resulted in the implementation of safeguarding adults policies within an academic institution.

Originality/value

– Safeguarding adults concerns may be identified through studying pre-registration student assignments and promptly acting upon any concerns raised. Aspects of good practice can be acknowledged within health care provider services.
Characteristics of referrals and admissions to a medium secure ASD unit
Authors: O' Donoghue Therese , Shine John , Orimalade Olufunto
Published: January 2015

Purpose

– The purpose of this paper is to present preliminary data on a cohort of patients referred to a specialist forensic medium-secure autism spectrum disorder (ASD) service during its first two years of opening and to identify variables associated with admission to the service.

Design/methodology/approach

– Data on all referrals to the service (n=40) was obtained from clinical files on demographics, offending history, psychiatric history and levels of therapeutic engagement. The sample was divided into two groups: referred and admitted (n=23) and referred and not admitted (n=17). Statistical analysis compared the two groups on all variables.

Findings

– Totally, 94 per cent of all individuals assessed had a diagnosis of autism, however, structured diagnostic tools for ASD were used in a small minority of cases. About half the sample had a learning disability, almost four-fifths had at least one additional mental disorder and almost three-quarters had a history of prior supervision failure or non-compliance with treatment. The sample had a wide range of previous offences. No significant differences were found between the groups on any of the variables included in the study.

Research limitations/implications

– The present study presents a starting point to follow up in terms of response to treatment and characteristics associated with treatment outcome.

Practical implications

– The sample had a wide range of clinical and risk-related needs. Both groups shared many similarities.

Originality/value

– This highlights the need for comprehensive assessment looking at risk-related needs so that individuals are referred to an optimal treatment pathway.
The small business dilemma
Authors: Taylor Eunice , Al Yousuf Mariam , Nassar Eyad Saleh , Saleh Mohamed , Philip Jiji
Published: January 2015

Purpose

– This paper aims to explore the particular dilemma of achieving international best practice and regulatory compliance for food safety in small local restaurants with limited resources, low levels of literacy and no common language. It is the fourth article in a Worldwide Hospitality and Tourism Themes theme issue presenting a comprehensive government strategy for improving food safety management standards across the hospitality industry.

Design/methodology/approach

– The article outlines extensive industry fieldwork involving on-site observations and interviews, undertaken by researchers from the relevant cultural backgrounds to identify common practices and specific risks, and facilitate targeted interventions.

Findings

– As expected, the independent restaurant sub-sector in Abu Dhabi is similar to international norms, with the additional challenge of language and literacy. In-depth on-site observations reveal a range of high-risk situations and practices, which require specific solutions from government to raise food safety levels.

Practical implications

– This article clarifies the scale and nature of the independent restaurant sub-sector of hospitality businesses, and uses in-depth, culturally appropriate research to identify the reality of food safety practices, major risks and areas for improvement. It identifies a list of 18 practices found in small hospitality businesses, which if controlled would make a significant difference to food safety.

Originality/value

– The article will be of value to practitioners, researchers, policy makers and other stakeholders involved in the food industry.
Fitness consequences of indirect plant defence in the annual weed, Sinapis arvensis
Authors: Gols Rieta , Wagenaar Roel , Poelman Erik H. , Kruidhof H. Marjolein , van Loon Joop J.A. , Harvey Jeffrey A.
Published: January 2015

Plant traits that enhance the attraction of the natural enemies of their herbivores have been postulated to function as an ‘indirect defence’. An important underlying assumption is that this enhanced attraction results in increased plant fitness due to reduced herbivory. This assumption has been rarely tested.

We investigated whether there are fitness consequences for the charlock mustard Sinapis arvensis, a short‐lived outcrossing annual weedy plant, when exposed to groups of large cabbage white (Pieris brassicae) caterpillars parasitized by either one of two wasp species, Hyposoter ebeninus and Cotesia glomerata, that allow the host to grow during parasitism. Hyposoter ebeninus is solitary and greatly reduces host growth compared with healthy caterpillars, whereas C. glomerata is gregarious and allows the host to grow approximately as large as unparasitized caterpillars. Both healthy and parasitized P. brassicae caterpillars initially feed on the foliage, but later stages preferentially consume the flowers.

In a garden experiment, plants damaged by parasitized caterpillars produced more seeds than conspecific plants damaged by unparasitized caterpillars. Reproductive potential (germination success multiplied by total seed number) was similar for plants that were not exposed to herbivory and those that were damaged by parasitized caterpillars and lower for plants that were damaged by healthy unparasitized caterpillars. However, these quantitative seed traits negatively correlated with the qualitative seed traits, individual seed size and germination success, suggesting a trade‐off between these two types of traits.

We show that parasitism of insect herbivores that feed on reproductive plant tissues may have positive fitness consequences for S. arvensis. The extent to which plant fitness may benefit depends on parasitoid lifestyle (solitary or gregarious), which is correlated with the amount of damage inflicted on these tissues by the parasitized host.
Ecological opportunity leads to the emergence of an alternative behavioural phenotype in a tropical bird
Authors: Touchton Janeene M. , Wikelski Martin
Published: January 2015

Loss of a dominant competitor can open ecological opportunities. Ecological opportunities are considered prerequisites for adaptive radiations. Nonetheless, initiation of diversification in response to ecological opportunity is seldom observed, so we know little about the stages by which behavioural variation either increases or coalesces into distinct phenotypes.

Here, a natural experiment showed that in a tropical island's guild of army ant‐following birds, a new behavioural phenotype emerged in subordinate spotted antbirds (Hylophylax naevioides) after the socially dominant ocellated antbird (Phaenostictus mcleannani) died out.

Individuals with this behavioural phenotype are less territorial; instead, they roam in search of ant swarms where they feed in locations from which dominant competitors formerly excluded them. Roaming individuals fledge more young than territorial individuals.

We conclude that ecological opportunity arising from species loss may enhance the success of alternative behavioural phenotypes and can favour further intraspecific diversification in life‐history traits in surviving species.
The path to host extinction can lead to loss of generalist parasites
Authors: Farrell Maxwell J. , Stephens Patrick R. , Berrang‐Ford Lea , Gittleman John L. , Davies T. Jonathan
Published: January 2015

Host extinction can alter disease transmission dynamics, influence parasite extinction and ultimately change the nature of host–parasite systems. While theory predicts that single‐host parasites are among the parasite species most susceptible to extinction following declines in their hosts, documented parasite extinctions are rare.

Using a comparative approach, we investigate how the richness of single‐host and multi‐host parasites is influenced by extinction risk among ungulate and carnivore hosts. Host–parasite associations for free‐living carnivores (orderCarnivora) and terrestrial ungulates (ordersPerissodactyla + Cetartiodactyla minus cetaceans) were merged with host trait data andIUCN RedList status to explore the distribution of single‐host and multi‐host parasites among threatened and non‐threatened hosts.

We find that threatened ungulates harbour a higher proportion of single‐host parasites compared to non‐threatened ungulates, which is explained by decreases in the richness of multi‐host parasites. However, among carnivores threat status is not a significant predictor of the proportion of single‐host parasites, or the richness of single‐host or multi‐host parasites.

The loss of multi‐host parasites from threatened ungulates may be explained by decreased cross‐species contact as hosts decline and habitats become fragmented. Among carnivores, threat status may not be important in predicting patterns of parasite specificity because host decline results in equal losses of both single‐host parasites and multi‐host parasites through reduction in average population density and frequency of cross‐species contact.

Our results contrast with current models of parasite coextinction and highlight the need for updated theories that are applicable across host groups and account for both inter‐ and intraspecific contact.
No apparent benefits of allonursing for recipient offspring and mothers in the cooperatively breeding meerkat
Authors: MacLeod Kirsty J. , McGhee Katie E. , Clutton‐Brock Tim H.
Published: January 2015

Cooperative behaviours by definition are those that provide some benefit to another individual. Allonursing, the nursing of non‐descendent young, is often considered a cooperative behaviour and is assumed to provide benefits to recipient offspring in terms of growth and survival, and to their mothers, by enabling them to share the lactation load. However, these proposed benefits are not well understood, in part because maternal and litter traits and other ecological and social variables are not independent of one another, making patterns hard to discern using standard univariate analyses.

Here, we investigate the potential benefits of allonursing in the cooperatively breeding Kalahari meerkat, where socially subordinate females allonurse the young of a dominant pair without having young of their own.

We use structural equation modelling to allow us to account for the interdependence of maternal traits, litter traits and environmental factors.

We find no evidence that allonursing provides benefits to pups or mothers. Pups that received allonursing were not heavier at emergence and did not have a higher survival rate than pups that did not receive allonursing. Mothers whose litters were allonursed were not in better physical condition, did not reconceive faster and did not reduce their own nursing investment compared to mothers who nursed their litters alone. These patterns were not significantly influenced by whether mothers were in relatively good, or poor, condition.

We suggest that allonursing may persist in this species because the costs to allonurses may be low. Alternatively, allonursing may confer other, more cryptic, benefits to pups or allonurses, such as immunological or social benefits.