bluuebunny/crossref_metadata_2025_split huggingface dataset:
A magnetar powering the ordinary monster GRB 130427A?
Authors: Bernardini M. G. , Campana S. , Ghisellini G. , D'Avanzo P. , Calderone G. , Covino S. , Cusumano G. , Ghirlanda G. , La Parola V. , Maselli A. , Melandri A. , Salvaterra R. , Burlon D. , D'Elia V. , Fugazza D. , Sbarufatti B. , Vergani S. D. , Tagliaferri G. 
Published: January 2014

Abstract
We present the analysis of the extraordinarily bright gamma-ray burst (GRB) 130427A under the hypothesis that the GRB central engine is an accretion-powered magnetar. In this framework, initially proposed to explain GRBs with precursor activity, the prompt emission is produced by accretion of matter on to a newly born magnetar, and the observed power is related to the accretion rate. The emission is eventually halted if the centrifugal forces are able to pause accretion. We show that the X-ray and optical afterglow is well explained as the forward shock emission with a jet break plus a contribution from the spin-down of the magnetar. Our modelling does not require any contribution from the reverse shock, that may still influence the afterglow light curve at radio and mm frequencies, or in the optical at early times. We derive the magnetic field (B ∼ 1016 G) and the spin period (P ∼ 20 ms) of the magnetar and obtain an independent estimate of the minimum luminosity for accretion. This minimum luminosity results well below the prompt emission luminosity of GRB 130427A, providing a strong consistency check for the scenario where the entire prompt emission is the result of continuous accretion on to the magnetar. This is in agreement with the relatively long spin period of the magnetar. GRB 130427A was a well-monitored GRB showing a very standard behaviour and, thus, is a well-suited benchmark to show that an accretion-powered magnetar gives a unique view of the properties of long GRBs.
Cold stream stability during minor mergers
Authors: Wang Liang , Zhu Weishan , Feng Long-Long , Macciò Andrea V. , Chang Jiang , Kang Xi 
Published: January 2014

Abstract
We use high-resolution Eulerian simulations to study the stability of cold gas flows in a galaxy size dark matter halo (1012 M⊙) at redshift z = 2. Our simulations show that a cold stream penetrating a hot gaseous halo is stable against thermal convection and Kelvin–Helmholtz instability. We then investigate the effect of a satellite orbiting the main halo in the plane of the stream. The satellite is able to perturb the stream and to inhibit cold gas accretion towards the centre of the halo for 0.5 Gyr. However, if the supply of cold gas at large distances is kept constant, the cold stream is able to re-establish itself after 0.3 Gyr. We conclude that cold streams are very stable against a large variety of internal and external perturbations.
Event‐Related Potential Responses to the Acute and Chronic Effects of Alcohol in Adolescent and Adult Wistar Rats
Authors: Ehlers Cindy L. , Desikan Anita , Wills Derek N. 
Published: January 2014

BackgroundThis study explored the hypothesis that adolescent ethanol (EtOH) exposure may cause long‐lasting changes in EtOH sensitivity by exploring the age‐related effects of acute alcohol on intoxication and on event‐related potential (ERP) responses to acoustic stimuli in EtOH‐naïve adolescent and adult male Wistar rats and in adult rats that were exposed to chronic EtOH/control conditions during adolescence.MethodsEtOH‐naïve adolescent (postnatal day 32 [PD32]) and adult male rats (PD99) were included in the first study. In a second study, rats were exposed to 5 weeks of EtOH vapor (blood EtOH concentrations at 175 mg%) or air from PD24 to 59 and allowed to mature until PD90. In both studies, rats were implanted with cortical recording electrodes, and the effects of acute EtOH (0.0, 1.5, and 3.0 g/kg) on behavioral and ERP responses were assessed.ResultsAdolescents were found to have higher amplitude and longer latency P3a and P3b components at baseline as compared to adult rats, and EtOH was found to produce a robust dose‐dependent increase in the latency of the P3a and P3b components of the auditory ERP recorded in cortical sites in both adolescents and adults. However, EtOH produced significantly larger delays in P3a and P3b latencies in adults as compared to adolescents. Acute EtOH administration was also found to produce a robust dose‐dependent increase in the latency of the P3a and P3b components in adult animals exposed to EtOH vapor as adolescents and air exposed controls; however, larger acute EtOH‐induced increases in P3a and P3b latencies were seen in controls as compared to adolescent vapor exposed rats.ConclusionsAdolescent rats have a less intense P3 latency response to acute EtOH administration when compared to adult rats. Exposure to chronic EtOH during adolescence can cause “retention” of the adolescent phenotype of reduced P3 latency sensitivity to EtOH.
Aggravation of Seizure‐like Events by Hydrogen Sulfide: Involvement of Multiple Targets that Control Neuronal Excitability
Authors: Luo Yi , Wu Peng‐Fei , Zhou Jun , Xiao Wen , He Jin‐Gang , Guan Xin‐Lei , Zhang Jie‐Ting , Hu Zhuang‐Li , Wang Fang , Chen Jian‐Guo 
Published: January 2014

SummaryAimsEpileptic seizures are well‐known neurological complications following stroke, occurring in 3% of patients. However, the intrinsic correlation of seizures with stroke remains largely unknown. Hydrogen sulfide (H2S) is a gas transmitter that may mediate cerebral ischemic injury. But the role of H2S in seizures has not been understood yet. We examined the effect of H2S on seizure‐like events (SLEs) and underlying mechanisms.Methods and ResultsPentylenetetrazole (PTZ)‐ and pilocarpine‐induced rat epileptic seizure models were tested. Low‐Mg2+/high‐K+‐ and 4‐aminopyridine (4‐AP)‐induced epileptic seizure models were examined using patch‐clamp recordings in brain slices. It was found that NaHS aggravated both PTZ‐ and pilocarpine‐induced SLEs in rats, while both low‐Mg2+/high‐K+‐ and 4‐AP‐induced SLEs were also exacerbated by NaHS in brain slices, which may be due to its regulation on the voltage‐gated sodium channel, N‐methyl‐D‐aspartic acid receptor (NMDAR), and α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor (AMPAR) function. Furthermore, these effects were reversed by blocking voltage‐gated sodium channel, NMDAR, and AMPAR.ConclusionsThese results suggest a pathological role of increased H2S level in SLEs in vivo and in vitro. Enzymes that control H2S biosynthesis could be interesting targets for antiepileptic strategies in poststroke epilepsy treatment.
Rapamycin inhibits acrolein‐induced apoptosis by alleviating ROS‐driven mitochondrial dysfunction in male germ cells
Authors: He X. , Song W. , Liu C. , Chen S. , Hua J. 
Published: January 2014

AbstractObjectivesAcrolein (Acr) is a highly reactive α, β‐unsaturated aldehyde, which can induce reactive oxygen species (ROS) generation. Several factors, including lipid peroxidation, clinical use of cyclophosphamide, fried foods, automobile exhausts, smoking and aging can increase its concentration in blood serum. Mounting evidence has suggested that Acr‐induced ROS might reduce quality of sperm. Thus, the aim of this study was to examine reproductive toxicity of Acr‐caused ROS in vitro and find a means to alleviate it.Materials and methodsWe investigated the effects of Acr on male germ cell (MGC)‐derived GC‐1 cells in vitro. Dihydroethidium and DCFH‐DA fluorescent dyes were used to determine generation of intracellular ROS.ResultsWe found that Acr induced ROS generation, which was accompanied by reduced Bcl2/Bax ratio, substantial decline in mitochondrial membrane potential, and further promoted apoptosis of MGCs. Furthermore, Rapamycin was capable of alleviating Acr‐induced ROS, reducing ROS‐induced apoptosis by increasing ratio of Bcl2/Bax mRNA and proteins, and protecting MGC mitochondrial membranes.ConclusionRapamycin inhibited Acr‐induced apoptosis by alleviating ROS‐driven mitochondrial dysfunction in MGCs.
The relationship between sleep habits and academic performance in dental students in Croatia
Authors: Valic M. , Pecotic R. , Lusic L. , Peros K. , Pribudic Z. , Dogas Z. 
Published: January 2014

AbstractIntroductionIt is well accepted that sleep and lifestyle habits affect academic success in students. However, sleep patterns and sleep problems amongst dental students have been insufficiently addressed in the literature. The purpose of this study was to evaluate sleep habits of dental students and the relationship between sleep habits and academic performance.Materials and methodsA self‐administered questionnaire on sleep habits, academic performance and lifestyle was administered. The participants were 447 dental students from Split University Dental Medicine School and Zagreb University Dental Medicine School from the six academic years. The subjects were classified into two groups based on academic success (high‐performing vs. low‐performing students) for comparison of sleep and lifestyle habits.ResultsAmongst the whole group of students, average bedtime and wake time during weekday was significantly earlier compared with weekend. Main findings indicate that students with high academic performance had earlier bedtimes during weekdays and weekends, earlier wake times during weekends and shorter sleep latency compared with low academic performing students.ConclusionSelf‐reported academic performance of dental students in Croatia is associated with timing of sleep and wakefulness, rather than with total sleep time duration.
The use of acoustic cameras in shallow waters: new hydroacoustic tools for monitoring migratory fish population. A review of DIDSON technology
Authors: Martignac François , Daroux Aurélie , Bagliniere Jean‐Luc , Ombredane Dominique , Guillard Jean 
Published: January 2014

AbstractEuropean Union legislation, through the Water Framework Directive (2000/60/EC), as well as national legislation, such as the ‘Grenelle Environnement’ (2007) in France, requires restoration of ecological connectivity in streams to improve free circulation of migratory fish. Different methods (e.g. capture by trap or net, telemetry, hydroacoustics) are used to evaluate the efficiency of fish passes to estimate the migratory species abundance and analyse changes in their within‐river distributions. Among these methods, hydroacoustics is non‐intrusive, allowing long‐term observation and description of fish populations based on physical properties of sound in water. However, the main limit to hydroacoustic tools is their difficulty in identifying species. Initially designed for military purposes, dual‐frequency identification sonar (DIDSON) has been used in environmental management for a decade. This acoustic camera uses higher frequencies and more sub‐beams than common hydroacoustic tools, which improves image resolution and then enables observation of fish morphology and swimming behaviour. The ability to subtract static echoes from echograms and directly measure fish length improve the species‐identification process. However, some limits have been identified, such as automatic dataset recording and the low range of the detection beam, which decreases accuracy, but efficient tools are now being developed to improve the accuracy of data recording (morphology, species identification, direction and speed). The new technological properties of acoustic cameras, such as the video‐like visualization of the data, have greatly improved monitoring of diadromous fish populations (abundance, distribution and behaviour), helping river and fisheries managers and researchers in making decisions.
Larval dispersal of intertidal organisms and the influence of coastline geography
Authors: Adams Thomas P. , Aleynik Dmitry , Burrows Michael T. 
Published: January 2014

The dispersal stages of organisms with sessile adults must be able to select habitats with suitable environmental conditions for establishment and survival, and also must be able to reach those locations. For marine planktonic larvae, movement due to currents is often orders of magnitude greater than movement due to swimming behaviour.Current patterns are determined by interactions between underlying geography and tidal forces, modified by meteorological conditions. These linkages impose an area‐specific focus to connectivity studies. Yet, how geographical features and meteorological forcing combine to produce specific current patterns and resultant connectivity among populations remains unclear.In this study of a complex fjordic region (the Firth of Lorn, Scotland), we followed tracks of generic particles driven by modelled hydrodynamic currents to investigate how connectivity between evenly spaced habitat sites varies in relation to coastal topography. We studied a range of larval durations (1–28 d), and two different but typical meteorological forcing scenarios. Particles released from regions of high current velocity, open coastline and low local habitat availability travelled furthest but were less likely to disperse successfully to other coastal sites. Extensive natal habitat in the vicinity of a site generally had a positive impact on the number of arriving particles, as did low current velocities. However, relationships between numbers of arriving particles and local geographical indices were complex, particularly at longer larval durations.Local geography alone explained up to 50% of the variance in success of particles released and closer to 10% of the variation in the number of particles arriving at each site. General patterns are evident, but coastline properties fall short of predicting dispersal measures for particular locations. The study shows that meteorological variation and broad scale current patterns interact strongly with local geography to determine connectivity in coastal areas.
Electromechanical Properties of Acceptor‐Doped Lead‐Free Piezoelectric Ceramics
Authors: Taghaddos Elaheh , Hejazi Mehdi , Safari Ahmad 
Published: January 2014

We have studied the processing and electromechanical properties of Mn and Fe‐doped 0.88[Bi0.5Na0.5TiO3]–0.08[Bi0.5K0.5TiO3]–0.04[Bi0.5Li0.5TiO3] piezoelectric ceramics prepared by the mixed oxide route. Different amounts of Mn (0.01, 0.014, 0.015, 0.016, 0.017, 0.02, 0.022) or Fe (0.0125, 0.015, 0.0175) were doped to this lead‐free piezoelectric composition. Ceramics were sintered at different temperatures (1075°C–1150°C) to achieve the highest density and mechanical quality factor. Mn or Fe doping resulted in a considerable enhancement ofQmin both planar and thickness resonance modes. In 1.5 mol% Mn‐doped ceramics sintered at 1100°C, a planarQmof about 970 and tanδ of 0.88% were obtained. In Fe‐doped ceramics, a planarQmas high as 900 was achieved. Acceptor dopants also resulted in decreasing the coupling coefficients, the piezoelectric charge coefficient, and the dielectric constant.
Older diabetic patients' attitudes and beliefs about health and illness
Authors: Ağralı Hatice , Akyar İmatullah 
Published: January 2014

Aims and objectivesTo determine older diabetic patients' attitudes and beliefs about illness and health.BackgroundPrevention of metabolic complications and treatment for cardiovascular risk factors are the main aims of the care and treatment of older diabetic patients. For the effective management of diabetes, it is crucial to recognise patients' beliefs and attitudes about and behaviours towards their health and illness.DesignA descriptive study.MethodsThe sample included 70 diabetic patients aged 65 and older. Data were collected using a socio‐demographic form and the Health Belief Model Scale. The data were analysed using descriptive statistics, Mann–Whitney U‐test, t‐test, Kruskal–Wallis test, Welch variance analysis and Spearman correlation.ResultsResults showed that older diabetic patients' attitudes about illness and health were negative. Among individuals aged 65–70 years with more than secondary education and previous employment, mean perceived severity scores were found to be significantly higher than in other groups. The mean perceived barriers scores were found to be higher than in other groups, and this difference was statistically significant for older participants who declared a good economic status, who exhibited good/very good adherence to nutritional therapy and who were exercising and checking their blood sugar regularly. The perceived benefits and recommended activities scores of patients needing more education were significantly higher.ConclusionsPatients who were female, aged 70 and older, and of low educational and economic statuses; who showed poor adherence to treatment and medical nutrition therapy; and who needed diabetes‐related training had negative health beliefs and were particularly at risk.Relevance to clinical practiceDetermining the personal factors that influence health behaviours can support the development of educational activities for diabetes management, complication prevention and treatment adherence improvement.
DEVELOPING RENAL NURSES' BUTTONHOLE CANNULATION SKILLS USING E‐LEARNING
Authors: Blackman Ian R. , Mannix Trudi , Sinclair Peter M. 
Published: January 2014

SUMMARYBackgroundIt has previously been shown that nurses can learn clinical nursing skills by e‐learning (online), and that many variables will influence how well nurses adopt learned clinical skills using distance education.ObjectivesThis study aimed to identify and measure the strength of those factors which would simultaneously influence registered nurses' (RNs') beliefs about their own learning about buttonhole cannulation, using e‐learning.DesignAn online Likert style survey consisting of a list of statements related to knowledge and skill domains considered crucial in the area of buttonhole cannulation was distributed to 101 RNs before and after completing an e‐learning programme. Participants were required to identify their current level of self‐confidence in relationship to each of the statements.MeasurementsMeasures of RNs' self‐rated abilities to assess and implement buttonhole cannulation after completing a related e‐learning program were tested using a Partial Least Squares Analysis (PLS‐PATH) programme.ResultsThe study's results strongly identify that the nurses' ability to meet both clinical and educational outcomes of the renal e‐learning module can be predicted by six variables, none of which are directly related to the participants' demographic or clinical backgrounds.ConclusionThese findings support the use of e‐learning to teach clinical skills to RNs, and demonstrate the value of Partial Least Squares Analysis in determining influential learning factors.
Preliminary pharmacokinetics of morphine and its major metabolites following intravenous administration of four doses to horses
Authors: Knych H. K. , Steffey E. P. , McKemie D. S. 
Published: January 2014

The objective of the current study was to describe the pharmacokinetics of morphine and its metabolites following intravenous administration to the horse. A total of eight horses (two per dose group) received a single intravenous dose of 0.05, 0.1, 0.2, or 0.5 mg/kg morphine. Blood samples were collected up to 72 h postdrug administration, analyzed usingLC‐MS/MSand pharmacokinetic parameters determined. Behavior, step counts, and gastrointestinal activity were also assessed. The beta and gamma half‐life for morphine ranged from 0.675 to 2.09 and 6.70 to 18.1 h, respectively, following administration of the four different IV doses. The volume of distribution at steady‐state and systemic clearance ranged from 6.95 to 15.8 L/kg and 28.3 to 35.7 mL·min/kg, respectively. The only metabolites identified in blood samples were the primary metabolites identified in other species, 3‐morphine‐glucuronide and 6‐morphine‐glucuronide. Muscle fasciculations were observed at 0.2 and 0.5 mg/kg and ataxia noted at 0.5 mg/kg. Gastrointestinal activity was decreased in all dose groups (for up to 8 h in 7/8 horses and 24 h in one horse). This study extends previous studies and is the first report describing the metabolites of morphine in the horse. Plasma concentrations of morphine‐3‐glucuronide, a metabolite with demonstrated neuro‐excitatory activity in mice, far exceeded that of morphine‐6‐glucuronide. Further study is warranted to assess whether the high levels of the morphine‐3‐glucuronide contribute to the dose‐dependent excitation observed at high morphine doses.
A tangled web in tropical tree‐tops: effects of edaphic variation, neighbourhood phorophyte composition and bark characteristics on epiphytes in a central Amazonian forest
Authors: Boelter Carlos R. , Dambros Cristian S. , Nascimento Henrique E.M. , Zartman Charles E. 
Published: January 2014

AbstractQuestionHow do soil fertility, neighbourhood host tree composition and bark characteristics influence community attributes of vascular epiphytes in a central Amazonian forest?LocationAdolpho Ducke Forest Reserve, Amazonas, Brazil.MethodsThe abundances of all species of vascular epiphytes were recorded from 300 host trees with DBH >30 cm. Phorophytes were distributed among 30 sample plots established in lowland, slope and upland habitats, and bark characteristics were classified into five types (rough, peeling, fissured, smooth, rugose). The epiphytic species were also classified into three functional types (true epiphytes, hemi‐epiphytes and nomadic vines) for separate analyses in an effort to highlight differences in ecological constraints in relation to neighbourhood phorophyte composition and edaphic variation.ResultsMore than 21 000 individuals representing 122 species distributed in 66 genera and 20 families of vascular epiphytes were recorded from 300 phorophytes during the course of the study. Multiple regressions demonstrated that neighbourhood phorophyte composition and edaphic variables, nitrogen (N) and phosphorus (P), together explained 65% of the variation in epiphytic species composition. However, edaphic factors were the only significant predictors of epiphytic species richness, accounting for 70% of this variation. Nearly one‐third of the true epiphytes occurred only on phorophytes in soils with high P content. Null models demonstrate that a vast majority of the epiphyte species (76% in positive and 96% in negative associations) failed to exhibit a statistically significant preference for bark texture.ConclusionNeighbourhood phorophyte composition, in concert with N and P availability, accounts for the vast majority of the variation in vascular epiphyte composition and abundance in central Amazonian forests. However, only N and P were shown to be significant predictors of epiphyte richness. Such results suggest that both biotic and abiotic variables influence epiphyte community structure (composition, abundance and richness) at differing intensities. Weak associations between bark type and epiphyte taxa suggest that epiphyte community variation may also be influenced by other unmeasured physical and environmental factors such as phorophyte architecture or microclimatic differences. Nonetheless, these results corroborate with other studies which report significant changes in epiphyte composition and richness as a result of experimentally manipulated ground soil fertility.