bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct observation of bias-dependence potential distribution in metal/HfO2 gate stack structures by hard x-ray photoelectron spectroscopy under device operation
Authors: Yamashita Y. , Yoshikawa H. , Chikyo T. , Kobayashi K.
Published: January 2014

Although gate stack structures with high-k materials have been extensively investigated, there are some issues to be solved for the formation of high quality gate stack structures. In the present study, we employed hard x-ray photoelectron spectroscopy in operating devices. This method allows us to investigate bias dependent electronic states, while keeping device structures intact. Using this method, we have investigated electronic states and potential distribution in gate metal/HfO2 gate stack structures under device operation. Analysis of the core levels shifts as a function of the bias voltage indicated that a potential drop occurred at the Pt/HfO2 interface for a Pt/HfO2 gate structure, while a potential gradient was not observed at the Ru/HfO2 interface for a Ru/HfO2 gate structure. Angle resolved photoelectron spectroscopy revealed that a thicker SiO2 layer was formed at the Pt/HfO2 interface, indicating that the origin of potential drop at Pt/HfO2 interface is formation of the thick SiO2 layer at the interface. The formation of the thick SiO2 layer at the metal/high-k interface might concern the Fermi level pinning, which is observed in metal/high-k gate stack structures.
Creep damage characterization using nonlinear ultrasonic guided wave method: A mesoscale model
Authors: Xiang Yanxun , Deng Mingxi , Xuan Fu-Zhen
Published: January 2014

The early deformations in materials such as creep, plasticity, and fatigue damages have been proved to have a close relationship with the nonlinear effect of ultrasonic waves propagating in them. In the present paper, a theoretical mesoscale model of an ultrasonic non-destructive method has been proposed to evaluate creep deformed states based on nonlinear guided waves. The model developed here considers the nonlinear generation of Lamb waves response from precipitates variation in the dislocation network, which can be applicable to all precipitate stages including coherent and semi-coherent precipitates in the metallic alloy undergoing creep degradation. To verify the proposed model, experiments of titanium alloy Ti60 plates were carried out with different creep strains. An “increase-decrease” change of the acoustic nonlinearity of guided wave versus the creep life fraction has been observed. Based on microscopic images analyses, the mesoscale model was then applied to these creep damaged Ti60 specimens, which revealed a good accordance with the measured results of the nonlinear guided waves. It is shown that the change of the nonlinear Lamb wave depends on the variations of the α2 precipitation volume fraction, the dislocation density, the growth of the creep-voids, and the increasing mismatch of the phase velocities during the creep deformation process. The results indicate that the effect of the precipitate-dislocation interactions on the nonlinear guided wave is likely the dominant mechanism responsible for the change of nonlinear guided wave propagation in the crept materials.
Mechanical property improvement by texture control of magnetron co-sputtered Zr-Ti films
Authors: Wang Weipeng , Zhan Peng , Xie Zheng , Li Zhengcao , Zhang Zhengjun
Published: January 2014

The present work studies the effect of substrate temperature and film composition on the structural and mechanical properties evolution of magnetron sputtered Zr-Ti films. As-deposited films show a monotonically strengthening (0002) crystallographic texture ranging from ambient temperature to 523 K, while then reveal a (0002) texture to randomly orientated structure transition at higher temperature. High Resolution TEM observations reveal a competitive and reconstruction growth mechanism which is in good agreement with the well-known Structure Zone Model. Nano-indentation measurements revealed that texture strengthening contribute to the improvement of mechanical properties. These results suggest that by establishing a semi-quantitative phase diagram based on the Structure Zone Model, structure and structure-related properties modification can be easily realized and precisely controlled by modifying the TS/Tm region during deposition.
Free-space cavity optomechanics in a cryogenic environment
Authors: Kuhn A. G. , Teissier J. , Neuhaus L. , Zerkani S. , van Brackel E. , Deléglise S. , Briant T. , Cohadon P.-F. , Heidmann A. , Michel C. , Pinard L. , Dolique V. , Flaminio R. , Taïbi R. , Chartier C. , Le Traon O.
Published: January 2014

We present a free-space optomechanical system operating in the 1-K range. The device is made of a high mechanical quality factor micropillar with a high-reflectivity optical coating atop, combined with an ultra-small radius-of-curvature coupling mirror to form a high-finesse Fabry-Perot cavity embedded in a dilution refrigerator. The cavity environment as well as the cryostat have been designed to ensure low vibrations and to preserve micron-level alignment from room temperature down to 100 mK.
A tunable metamaterial dependent on electric field at terahertz with barium strontium titanate thin film
Authors: Bian Yanlong , Wu Chao , Li Hongqiang , Zhai Jiwei
Published: January 2014

A tunable metamaterial with resonance frequency at terahertz (THz) was developed. Electromagnetic response of the metamaterial was characterized with THz time domain spectrometer at various direct current electric fields. The resonance frequency increased monotonously with increasing electric field. The finite difference time domain method was used to simulate the transmission spectra of the metamaterial at THz frequencies. By comparing the simulated resonance frequency with the experimental curve, dielectric property of the Ba0.6Sr0.4TiO3 (BST60) thin film at THz, over 0–33 kV/cm, was evaluated.
Imaging of free carriers in semiconductors via optical feedback in terahertz quantum cascade lasers
Authors: Mezzapesa F. P. , Columbo L. L. , Brambilla M. , Dabbicco M. , Vitiello M. S. , Scamarcio G.
Published: January 2014

To monitor the density of photo-generated charge carriers on a semiconductor surface, we demonstrate a detectorless imaging system based on the analysis of the optical feedback in terahertz quantum cascade lasers. Photo-excited free electron carriers are created in high resistivity n-type silicon wafers via low power (≅40 mW/cm2) continuous wave pump laser in the near infrared spectral range. A spatial light modulator allows to directly reconfigure and control the photo-patterned intensity and the associated free-carrier density distribution. The experimental results are in good agreement with the numerical simulations.
Microjetting from grooved surfaces in metallic samples subjected to laser driven shocks
Authors: de Rességuier T. , Lescoute E. , Sollier A. , Prudhomme G. , Mercier P.
Published: January 2014

When a shock wave propagating in a solid sample reflects from a free surface, geometrical effects predominantly governed by the roughness and defects of that surface may lead to the ejection of tiny jets that may breakup into high velocity, approximately micrometer-size fragments. This process referred to as microjetting is a major safety issue for engineering applications such as pyrotechnics or armour design. Thus, it has been widely studied both experimentally, under explosive and impact loading, and theoretically. In this paper, microjetting is investigated in the specific loading conditions associated to laser shocks: very short duration of pressure application, very high strain rates, small spatial scales. Material ejection from triangular grooves in the free surface of various metallic samples is studied by combining transverse optical shadowgraphy and time-resolved velocity measurements. The influences of the main parameters (groove angle, shock pressure, nature of the metal) on jet formation and ejection velocity are quantified, and the results are compared to theoretical estimates.
Surface-plasmons lasing in double-graphene-layer structures
Authors: Dubinov A. A. , Aleshkin V. Ya. , Ryzhii V. , Shur M. S. , Otsuji T.
Published: January 2014

We consider the concept of injection terahertz lasers based on double-graphene-layer (double-GL) structures with metal surface-plasmon waveguide and study the conditions of their operation. The laser under consideration exploits the resonant radiative transitions between GLs. This enables the double-GL laser room temperature operation and the possibility of voltage tuning of the emission spectrum. We compare the characteristics of the double-GL lasers with the metal surface-plasmon waveguides with those of such laser with the metal-metal waveguides.
Friction force microscopy studies on SiO2 supported pristine and hydrogenated graphene
Authors: Fessler Gregor , Eren Baran , Gysin Urs , Glatzel Thilo , Meyer Ernst
Published: January 2014

A graphene sample supported on SiO2 with pristine and plasma-hydrogenated parts is investigated by friction force microscopy. An initial contrast in friction is apparent between the two regions. A tip induced cleaning of the surface in the course of continuous scanning results in a very clean surface accompanied with a reduction of the friction force by a factor of up to 4. The contamination is adhering stronger to hydrogenated regions, but once cleaned, the frictional behavior is the same on pristine and hydrogenated graphene. Raman imaging demonstrates that the hydrogenation remains intact under the mechanical treatment.
Mechanical switching of ferroelectric polarization in ultrathin BaTiO3 films: The effects of epitaxial strain
Authors: Wen Zheng , Qiu Xiangbiao , Li Chen , Zheng Chunyan , Ge Xiaohui , Li Aidong , Wu Di
Published: January 2014

Electrical switching of spontaneous polarizations has been intensively studied for decades in ferroelectric thin films for non-volatile memory applications. Recent advances have shown that the polarization in ultrathin ferroelectric films can also be switched by a mechanical loading force owing to the flexoelectric effect. In this work, we report the strain effects on the mechanical switching in 12-unit-cell-thick BaTiO3 ultrathin films grown coherently on SrRuO3-buffered SrTiO3, DyScO3, and GdScO3 substrates. The mechanical threshold for polarization reversal increases with increasing in-plane compressive strain, associated with the increased coercive field for electrical polarization switching. These are ascribed to the increase of switching barrier in BaTiO3 thin films as the compressive strain increases.
Trace inequalities for products of positive definite matrices
Authors: Bhatia Rajendra
Published: January 2014

It is shown that for positive definite matrices A and B the inequality ‖ApBq + BpAq‖2 ⩽ ‖ApBq + AqBp‖2 holds for all positive real number p and q for which p/(p + q) is in [1/4, 3/4]. This is a significant improvement on a recent result of Hayajneh and Kittaneh [“Lieb-Thirring trace inequalities and a question of Bourin,” J. Math. Phys. 54, 033504 (2013)].
Estimating the indirect impact of wind farms on breeding bird assemblages: a case study in the central Apennines
Authors: Battisti Corrado , Franco Daniel , Norscia Claudio , Santone Pasquale , Soccini Christiana , Ferri Vincenzo
Published: January 2014

In 2011 and 2012 we carried out a monitoring study to evaluate the indirect impacts of a wind farm on the breeding bird assemblages in a high-altitude secondary prairie area of the central Apennines (Italy). We used the point count method to compare the breeding birds at species and assemblage level, using the wind farm area (36 windmills) as treatment and an equivalent habitat surface as control. We did not observe any significant difference between treatment and control areas at species level (25 species detected, seven of conservation concern at European level), in terms of species abundance frequency, and at assemblage level, in terms of species richness or assemblage structure (k-dominance plots), even if lower evenness values were detected in the control sites. Our preliminary results gave no evidence of an indirect impact of the wind farm on breeding bird assemblages, mainly composed of small passerines, in these mountain ecosystems. However, further studies should be performed to deepen the relationships between indirect impact of wind farms and site-specific characteristics.
Risk Factors of Surgical Site Infection after Hepatic Resection
Authors: Yang Tian , Tu Ping-An , Zhang Han , Lu Jun-Hua , Shen Yi-Nan , Yuan Shou-Xin , Lau Wan Yee , Lai Eric C. H. , Lu Chong-De , Wu Meng-Chao , Li Jie-Wei , Shen Feng
Published: January 2014

A study of 7,388 consecutive patients after hepatic resection between 2011 and 2012 identified hepatolithiasis, cirrhosis, and intraoperative blood transfusion as the only independent risk factors of both incisional and organ/space surgical site infection (SSI). Patients with these conditions should be cared for with caution to lower SSI rates.
The Effect of Leadership on Hand Hygiene: Assessing Hand Hygiene Adherence prior to Patient Contact in 2 Infectious Disease Units in Tuscany
Authors: Lieber Sarah R. , Mantengoli Elisabetta , Saint Sanjay , Fowler Karen E. , Fumagalli Carlo , Bartolozzi Dario , Magistri Lea , Niccolini Fabrizio , Bartoloni Alessandro
Published: January 2014

We assessed hand hygiene adherence in 2 infectious disease units. In one unit, adherence declined slightly from year 1 (84.2%) to year 4 (71.0%) after a multimodal intervention but remained much higher than before intervention. Adherence dropped in the second unit after a loss of leadership (from 50.7% to 5.7%). Strong leadership presence may improve hand hygiene adherence.
Age-specific natural mortality rates in stock assessments: size-based vs. density-dependent
Authors: Powers Joseph E.
Published: January 2014

Natural mortality (M) rates are difficult to measure empirically and are often specified in stock assessments based on life history characteristics. More recently, these specifications have included M as a function of the size or age of a fish. However, natural mortality is a dynamic parameter that will change with the suite of predators and, thus, indirectly with cohort size and age. As an alternative, a density-dependent M rate function is derived and compared with the commonly used Lorenzen model, where M at age forms an allometric relationship with weight-at-age. The density-dependent model expresses M as a function of two parameters: one density dependent and one density independent. Properties of the two models (size-based vs. density-dependent) were explored to indicate conditions where the results are and are not similar. Associated catch equations, equilibrium analyses, and non-linear replacement lines in stock–recruitment theory are examined. Just as with density-independent values of M, most assessment data are not sufficient to provide precise estimates of density-dependent M parameters. However, the density-dependent model provides a basis for incorporating ecological variability into single-species assessments, noting the differing dynamics between short- and long-lived species. The incorporation of dynamic natural mortality has implications when estimating abundance trends and stock status, and ultimately setting management reference points.
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

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

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

Background

This 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.

Methods

EtOH‐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.

Results

Adolescents 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.

Conclusions

Adolescent 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

Aims

Epileptic 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 Results

Pentylenetetrazole (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.

Conclusions

These 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

Objectives

Acrolein (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 methods

We 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.

Results

We 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.

Conclusion

Rapamycin 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

Introduction

It 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 methods

A 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.

Results

Amongst 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.

Conclusion

Self‐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

European 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.
Number Density and Diameter Control of Chemical Bath Deposition of ZnO Nanorods on FTO by Forced Hydrolysis of Seed Crystals
Authors: Manthina Venkata , Patel Tulsi , Agrios Alexander G.
Published: January 2014

ZnO nanorods have been studied extensively due to facile synthesis and useful optoelectronic properties for applications in nanoscale devices. In a common two‐step procedure, an ethanolic Zn2+ precursor solution is used to deposit ZnO seed crystals on a substrate, which is then immersed in an aqueous Zn2+ precursor solution to grow the nanorods. Here, a forced hydrolysis technique was employed based on additions of water and heat to the seed precursor solution before depositing the seeds on commercial fluorine‐doped tin oxide (FTO)/glass substrates. ZnO nanorods were then grown from these seeds by chemical bath deposition. Analyses showed that the forced hydrolysis resulted in an increase in seed crystallite size and a decrease in the number of seeds deposited. With increasing seed size, the number density of nanorods decreased, while the length and diameter of each rod increased. These findings offer a simple method for exerting control over the number density of ZnO nanorods that is compatible with the rough FTO surface, unlike other methods that require smoother substrates.
Older diabetic patients' attitudes and beliefs about health and illness
Authors: Ağralı Hatice , Akyar İmatullah
Published: January 2014

Aims and objectives

To determine older diabetic patients' attitudes and beliefs about illness and health.

Background

Prevention 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.

Design

A descriptive study.

Methods

The 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.

Results

Results 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.

Conclusions

Patients 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 practice

Determining 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

Background

It 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.

Objectives

This 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.

Design

An 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.

Measurements

Measures 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.

Results

The 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.

Conclusion

These 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

Question

How do soil fertility, neighbourhood host tree composition and bark characteristics influence community attributes of vascular epiphytes in a central Amazonian forest?

Location

Adolpho Ducke Forest Reserve, Amazonas, Brazil.

Methods

The 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.

Results

More 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.

Conclusion

Neighbourhood 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.
The origin of young mare basalts inferred from lunar meteorites Northwest Africa 4734, 032, and LaPaz Icefield 02205
Authors: Elardo Stephen M. , Shearer Charles K. , Fagan Amy L. , Borg Lars E. , Gaffney Amy M. , Burger Paul V. , Neal Clive R. , Fernandes Vera A. , McCubbin Francis M.
Published: January 2014

Northwest Africa (NWA) 4734 is an unbrecciated basaltic lunar meteorite that is nearly identical in chemical composition to basaltic lunar meteoritesNWA032 and LaPaz Icefield (LAP) 02205. We have conducted a geochemical, petrologic, mineralogic, and Sm‐Nd, Rb‐Sr, and Ar‐Ar isotopic study of these meteorites to constrain their petrologic relationships and the origin of young mare basalts.NWA4734 is a low‐Ti mare basalt with a low Mg* (36.5) and elevated abundances of incompatible trace elements (e.g., 2.00 ppm Th). The Sm‐Nd isotope system datesNWA4734 with an isochron age of 3024 ± 27 Ma, an initial εNdof +0.88 ± 0.20, and a source region147Sm/144Nd of 0.201 ± 0.001. The crystallization age ofNWA4734 is concordant with those ofLAP02205 andNWA032.NWA4734 andLAP02205 have very similar bulk compositions, mineral compositions, textures, and ages. Their source region147Sm/144Nd values indicate that they are derived from similar, but distinct, source materials. They probably do not sample the same lava flow, but rather are similarly sourced, but isotopically distinct, lavas that probably originate from the same volcanic complex. They may have experienced slightly different assimilation histories in route to eruption, but can be source‐crater paired.NWA032 remains enigmatic, as its source region147Sm/144Nd definitively precludes a simple relationship withNWA4734 andLAP02205, despite a similar bulk composition. Their high Ti/Sm, low (La/Yb)N, and Cl‐poor apatite compositions rule out the direct involvement ofKREEP. Rather, they are consistent with low‐degree partial melting of late‐formedLMOcumulates, and indicate that the geochemical characteristics attributed to urKREEPare not unique to that reservoir. These and other basaltic meteorites indicate that the youngest mare basalts originate from multiple sources, and suggest thatKREEPis not a prerequisite for the most recent known melting in the Moon.
Striga hermonthica MAX2 restores branching but not the Very Low Fluence Response in the Arabidopsis thaliana max2 mutant
Authors: Liu Qing , Zhang Yanxia , Matusova Radoslava , Charnikhova Tatsiana , Amini Maryam , Jamil Muhammad , Fernandez‐Aparicio Monica , Huang Kan , Timko Michael P. , Westwood James H. , Ruyter‐Spira Carolien , van der Krol Sander , Bouwmeester Harro J.
Published: January 2014

Seed germination of Striga spp. (witchweeds), one of the world's most destructive parasitic weeds, cannot be induced by light but is specifically induced by strigolactones. It is not known whether Striga uses the same components for strigolactone signaling as host plants, whether it has endogenous strigolactone biosynthesis and whether there is post‐germination strigolactone signaling in Striga.

Strigolactones could not be detected in in vitro grown Striga, while for host‐grown Striga, the strigolactone profile is dominated by a subset of the strigolactones present in the host.

Branching of in vitro grown Striga is affected by strigolactone biosynthesis inhibitors. ShMAX2, the Striga ortholog of Arabidopsis MORE AXILLARY BRANCHING 2 (AtMAX2) – which mediates strigolactone signaling – complements several of the Arabidopsis max2‐1 phenotypes, including the root and shoot phenotype, the High Irradiance Response and the response to strigolactones. Seed germination of max2‐1 complemented with ShMAX2 showed no complementation of the Very Low Fluence Response phenotype of max2‐1.

Results provide indirect evidence for ShMAX2 functions in Striga. A putative role of ShMAX2 in strigolactone‐dependent seed germination of Striga is discussed.
The vacuolar calcium sensors CBL2 and CBL3 affect seed size and embryonic development in Arabidopsis thaliana
Authors: Eckert Christian , Offenborn Jan Niklas , Heinz Tobias , Armarego‐Marriott Tegan , Schültke Stefanie , Zhang Chunxia , Hillmer Stefan , Heilmann Mareike , Schumacher Karin , Bock Ralph , Heilmann Ingo , Kudla Jörg
Published: January 2014

Stimulus‐specific calcium (Ca2+) signals have crucial functions in developmental processes in many organisms, and are deciphered by various Ca2+‐binding proteins. In Arabidopsis thaliana, a signaling network consisting of calcineurin B‐like (CBL) protein calcium sensors and CBL‐interacting protein kinases (CIPKs) has been shown to fulfil pivotal functions at the plasma membrane in regulating ion fluxes and abiotic stress responses. However, the role of tonoplast‐localized CBL proteins and especially their function in regulating developmental programs remains largely unknown. In this study, we analyzed single and double mutants of the closely related tonoplast‐localized calcium sensors CBL2 and CBL3, which show either reduction of function (rf) or complete loss of function (lf). While single cbl2 or cbl3 mutants did not display discernable phenotypes, cbl2/cbl3 mutants exhibited defects in vegetative growth and were severely impaired in seed development and morphology. Seeds of the cbl2/3rf mutant were smaller in size and exhibited reduced weight and fatty acid content compared to wild‐type, but accumulation of sucrose was not altered. Moreover, accumulation of inositol hexakisphosphate (InsP6), the major storage form of phosphorus in seeds, was significantly reduced in mutant seeds. In addition, complete loss of CBL2 and CBL3 function in cbl2/3lf resulted in a high frequency of severe defects in embryonic development. Together, our findings reveal a crucial function of Ca2+‐controlled processes at the vacuolar membrane as determinants of seed yield and size, and demonstrate the importance of vacuolar CBL calcium sensors for plant embryogenesis.
Experimental Aerodynamic Characteristics of a Compound Wing in Ground Effect
Authors: Jamei Saeed , Abdul Malek Adi Maimun , Mansor Shuhaimi , Che Sidik Nor Azwadi , Priyanto Agoes
Published: January 2014

Wing configuration is a parameter that affects the performance of wing-in-ground effect (WIG) craft. In this study, the aerodynamic characteristics of a new compound wing were investigated during ground effect. The compound wing was divided into three parts with a rectangular wing in the middle and two reverse taper wings with anhedral angle at the sides. The sectional profile of the wing model is NACA6409. The experiments on the compound wing and the rectangular wing were carried to examine different ground clearances, angles of attack, and Reynolds numbers. The aerodynamic coefficients of the compound wing were compared with those of the rectangular wing, which had an acceptable increase in its lift coefficient at small ground clearances, and its drag coefficient decreased compared to rectangular wing at a wide range of ground clearances, angles of attack, and Reynolds numbers. Furthermore, the lift to drag ratio of the compound wing improved considerably at small ground clearances. However, this improvement decreased at higher ground clearance. The drag polar of the compound wing showed the increment of lift coefficient versus drag coefficient was higher especially at small ground clearances. The Reynolds number had a gradual effect on lift and drag coefficients and also lift to drag of both wings. Generally, the nose down pitching moment of the compound wing was found smaller, but it was greater at high angle of attack and Reynolds number for all ground clearance. The center of pressure was closer to the leading edge of the wing in contrast to the rectangular wing. However, the center of pressure of the compound wing was later to the leading edge at high ground clearance, angle of attack, and Reynolds number.