bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simplified method for determining acceleration amplitude of prestressed concrete floor under individual jumping load
Authors: Liu Jiepeng , Cao Liang , Zhou Zikai 
Published: March 2018

SummaryModern long‐span prestressed concrete (PC) floors typically possess low damping and low natural frequency, presenting a potential vibration sensitivity problem induced by human activities. Field test and numerical analysis methods are available to study this kind of problems but would be inconvenient for design engineers. This paper proposes a simplified method to determine the acceleration amplitude of a PC floor subjected to individual jumping load, carrying out through a mix of analytical and experimental techniques. To theoretically analyze the acceleration response, the PC floor was simplified as an anisotropic rectangular plate and the mode decomposition method was used. To facilitate the calculation of the acceleration amplitude aP, a frequency‐dependent coefficient βJ is introduced, which depends on the geometry and support condition of the PC floor and dynamic amplification factor KJ. Field tests on 7 PC floors with various boundary conditions and fundamental natural frequencies were conducted to determine βJ coefficient. Based on the test results, practical formulas for βJ coefficient is first proposed, followed by that for acceleration amplitude aP. The proposed simplified method is easy for practical use and will yield safe and conservative structural designs.
Localized buckling of laminated cylindrical shells with low reduced shear modulus under non‐uniform axial compression
Authors: Mikhasev Gennadi , Mlechka Ihnat 
Published: March 2018

AbstractThe problem on buckling of a thin laminated non‐circular cylindrical shell under action of axial compressive forces non‐uniformly distributed along edges is considered. It is assumed that some layers are made of a “soft” material so that the reduced (effective) shear modulus for the entire package is much less than the reduced Young's modulus. The differential equations based on the generalized hypotheses of Timoshenko and including the effect of transverse shears are used to predict the buckling of laminated cylinders regardless a number of layers and their mechanical properties. Using the asymptotic method, the buckling modes are constructed in the form of functions rapidly decaying far away from some generatrix at the reference surface. It is shown that accounting transverse shears strongly effect on the buckling modes and corresponding critical buckling forces. In particular, the preferable buckling form for a medium‐length thin laminated cylinder with a low reduced shear modulus (as compared with the reduced Young's modulus) is found to be a system of small dents in the axial direction, whose amplitudes decay in the circumferential direction without oscillations; whereas the buckling of a shell with a relatively large reduced shear modulus may occur with formation of waves in both the axial and circumferential directions. As an example, the buckling of cylindrical sandwiches assembled from the ABS‐plastic and magnetorheological elastomer with variable shear modulus under different levels of an applied magnetic field is examined
Preoperative Smoking Cessation is Integral to the Prevention of Postoperative Morbidities in Minimally Invasive Esophagectomy
Authors: Yoshida Naoya , Nakamura Kenichi , Kuroda Daisuke , Baba Yoshifumi , Miyamoto Yuji , Iwatsuki Masaaki , Hiyoshi Yukiharu , Ishimoto Takatsugu , Imamura Yu , Watanabe Masayuki , Baba Hideo 
Published: March 2018

AbstractBackgroundPreoperative smoking cessation is considered integral to decreasing postoperative morbidities after esophagectomy. To our knowledge, the association of the duration of smoking cessation with the occurrence of postoperative morbidity has never been investigated in minimally invasive esophagectomy (MIE).MethodsA total of 198 consecutive MIEs for esophageal cancer between June 2011 and December 2017 were eligible for the study. According to the length of smoking cessation, patients were separated into three groups: ≤ 30, 31–90, and ≥ 91 days. Incidence of postoperative morbidities was retrospectively analyzed among the groups.ResultsIn patients with smoking cessation ≤ 30 days, morbidities of Clavien–Dindo classification (CDc) ≥ II, severe morbidities of CDc ≥ IIIb, pneumonia, and any pulmonary morbidities were frequently observed. Morbidities of CDc ≥ II, pneumonia, and any pulmonary morbidities increased as the length of cessation became shorter. Smoking cessation ≤ 30 days was a significant risk factor for severe morbidity (hazard ratio [HR] 4.89, 95% confidence interval [CI] 1.993–12.011; P < 0.001). Smoking cessation ≤ 90 days (HR 3.98, 95% CI 1.442–10.971; P = 0.008), past smoking (per 100 increase in Brinkman index), and cardiovascular comorbidity were significant risk factors for pneumonia. Smoking cessation ≤ 30 days (HR 3.13, 95% CI 1.351–7.252; P = 0.008) and past smoking were significant risk factors for any pulmonary morbidity.ConclusionsPreoperative smoking cessation is considerably important to prevent postoperative morbidities, even in MIE. At least, preoperative cessation ≥ 31 days is preferable to decrease considerable morbidities after MIE.
Preparation of ultrafine grained copper nanoparticles via immersion deposit method
Authors: Abbasi-Kesbi Fatemeh , Rashidi Ali Mohammad , Astinchap Bandar 
Published: March 2018

AbstractToday, the exploration about synthesis of nanoparticles is much of interest to materials scientists. In this work, copper nanoparticles have been successfully synthesized by immersion deposit method in the absence of any stabilizing and reducing agents. Copper (II) sulfate pentahydrate as precursor salt and distilled water and Ethylene glycol as solvents were used. The copper nanoparticles were deposited on plates of low carbon steel. The effects of copper sulfate concentrations and solvent type were investigated. X-ray diffraction, scanning electron microscopy and UV–Visible spectroscopy were taken to investigate the crystallite size, crystal structure, and morphology and size distribution and the growth process of the nanoparticles of obtained Cu particles. The results indicated that the immersion deposit method is a particularly suitable method for synthesis of semispherical copper nanoparticles with the crystallites size in the range of ~22 to 37 nm. By increasing the molar concentration of copper sulfate in distilled water solvent from 0.04 to 0.2 M, the average particles size is increased from 57 to 81 nm. The better size distribution of Cu nanoparticles was achieved using a lower concentration of copper sulfate. By increasing the molar concentration of copper sulfate in water solvent from 0.04 to 0.2, the location of the SPR peak has shifted from 600 to 630 nm. The finer Cu nanoparticles were formed using ethylene glycol instead water as a solvent. Also, the agglomeration and overlapping of nanoparticles in ethylene glycol were less than that of water solvent.
It’s all about relationships: A&nbsp;qualitative study of family physicians’ teaching experiences in rural longitudinal clerkships
Authors: Cuncic Cary , Regehr Glenn , Frost Heather , Bates Joanna 
Published: March 2018

Introduction The relationship between preceptor and trainee is becoming recognized as a critical component of teaching, in particular in the negotiation of feedback and in the formation of professional identity. This paper elaborates on the nature of the relationships between preceptor and student that evolve in the context of rural longitudinal integrated clerkships (LICs).
Methods We drew on constructivist grounded theory for the research approach. We interviewed nine LIC family practice preceptors from three sites at one educational institution. We adapted the interview framework based on early findings. We analyzed the data through a constant comparative process. We then drew on concepts of relationship-based learning as sensitizing concepts in a secondary analysis.
Results We constructed three themes from the data. First, preceptors developed trusting professional and personal relationships with students over time. These relationships expanded to include friendship, advocacy, and ongoing contact beyond the clerkship year. Second, preceptors’ approach to teaching was anchored in the relationship with an understanding of the individual student. Third, preceptors set learning goals collaboratively with their students, based not only on program objectives, but also with the student as a future physician in mind.
Discussion Our findings suggest that rural family medicine preceptors developed engaged and trusting relationships with their students over time. These relationships imbued all activities of teaching and learning with an individual and personal focus. This orientation may be a key factor in supporting the learning outcomes demonstrated for students studying in rural LICs.
Beneficial effects of environmental enrichment on behavior, stress reactivity and synaptophysin/BDNF expression in hippocampus following early life stress
Authors: Dandi Εvgenia , Kalamari Aikaterini , Touloumi Olga , Lagoudaki Rosa , Nousiopoulou Evangelia , Simeonidou Constantina , Spandou Evangelia , Tata Despina A. 
Published: March 2018

AbstractExposure to environmental enrichment can beneficially influence the behavior and enhance synaptic plasticity. The aim of the present study was to investigate the mediated effects of environmental enrichment on postnatal stress‐associated impact with regard to behavior, stress reactivity as well as synaptic plasticity changes in the dorsal hippocampus. Wistar rat pups were submitted to a 3 h maternal separation (MS) protocol during postnatal days 1–21, while another group was left undisturbed. On postnatal day 23, a subgroup from each rearing condition (maternal separation, no‐maternal separation) was housed in enriched environmental conditions until postnatal day 65 (6 weeks duration). At approximately three months of age, adult rats underwent behavioral testing to evaluate anxiety (Elevated Plus Maze), locomotion (Open Field Test), spatial learning and memory (Morris Water Maze) as well as non‐spatial recognition memory (Novel Object Recognition Test). After completion of behavioral testing, blood samples were taken for evaluation of stress‐induced plasma corticosterone using an enzyme‐linked immunosorbent assay (ELISA), while immunofluorescence was applied to evaluate hippocampal BDNF and synaptophysin expression in dorsal hippocampus. We found that environmental enrichment protected against the effects of maternal separation as indicated by the lower anxiety levels and the reversal of spatial memory deficits compared to animals housed in standard conditions. These changes were associated with increased BDNF and synaptophysin expression in the hippocampus. Regarding the neuroendocrine response to stress, while exposure to an acute stressor potentiated corticosterone increases in maternally‐separated rats, environmental enrichment of these rats prevented this effect. The current study aimed at investigating the compensatory role of enriched environment against the negative outcomes of adverse experiences early in life concurrently on emotional and cognitive behaviors, HPA function and neuroplasticity markers.
The interaction of Matrix Reasoning and Social Motivation as predictors of Separation anxiety in boys with Autism Spectrum Disorder
Authors: Bitsika Vicki , Sharpley Christopher F. 
Published: March 2018

AbstractBackgroundIt has been suggested that higher cognitive functioning based in the pre‐frontal cortex is implicated in the ability of people with Autism Spectrum Disorder (ASD) to understand and communicate in social situations. Low motivation to engage in social interaction may also be influential in this process. Although both of these factors have been argued to influence the levels of comorbid anxiety in young people with ASD, no detailed examination of those relationships has been reported to date.MethodsA sample of 90 boys with ASD (aged 6 to 12 yr) and 29 of their non‐ASD peers, matched for age and IQ, completed tests of cognitive function and anxiety.ResultsOnly one form of anxiety—fear of being separated from their parents– was significantly associated with cognitive function, at the Full Scale IQ and Matrix Reasoning levels, plus motivation to engage in social interactions, and only for the ASD boys.ConclusionThese data represent a complex interaction between the neurobiological aspects of ASD, fluid reasoning, social motivation, and Separation Anxiety in boys with ASD. As such, they bring a new perspective to understanding and treating anxious behaviour in these boys.
Flow topology of helical vortices
Authors: Velasco Fuentes Oscar 
Published: March 2018

Equal coaxial symmetrically located helical vortices translate and rotate steadily while preserving their shape and relative position if they move in an unbounded inviscid incompressible fluid. In this paper, the linear and angular velocities of this set of vortices ($U$ and $\unicode[STIX]{x1D6FA}$ respectively) are computed as the sum of the mutually induced velocities found by Okulov (J. Fluid Mech., vol. 521, 2004, pp. 319–342) and the self-induced velocities found by Velasco Fuentes (J. Fluid Mech., vol. 836 2018). Numerical computations of the velocities using the Helmholtz integral and the Biot–Savart law, as well as numerical simulations of the flow evolution under the Euler equations, are used to verify that the theoretical results are accurate for $N=1,\ldots ,4$ vortices over a broad range of values of the pitch and radius of the vortices. An analysis of the flow topology in a reference system that translates with velocity $U$ and rotates with angular velocity $\unicode[STIX]{x1D6FA}$ serves to determine the capacity of the vortices to transport fluid.
Palaeolatitudinal distribution of lithologic indicators of climate in a palaeogeographic framework
Authors: CAO WENCHAO , WILLIAMS SIMON , FLAMENT NICOLAS , ZAHIROVIC SABIN , SCOTESE CHRISTOPHER , MÜLLER R. DIETMAR 
Published: March 2018

AbstractWhether the latitudinal distribution of climate-sensitive lithologies is stable through greenhouse and icehouse regimes remains unclear. Previous studies suggest that the palaeolatitudinal distribution of palaeoclimate indicators, including coals, evaporites, reefs and carbonates, has remained broadly similar since the Permian period, leading to the conclusion that atmospheric and oceanic circulation control their distribution rather than the latitudinal temperature gradient. Here we revisit a global-scale compilation of lithologic indicators of climate, including coals, evaporites and glacial deposits, back to the Devonian period. We test the sensitivity of their latitudinal distributions to the uneven distribution of continental areas through time and to global tectonic models, correct the latitudinal distributions of lithologies for sampling- and continental area-bias, and use statistical methods to fit these distributions with probability density functions and estimate their high-density latitudinal ranges with 50% and 95% confidence intervals. The results suggest that the palaeolatitudinal distributions of lithologies have changed through deep geological time, notably a pronounced poleward shift in the distribution of coals at the beginning of the Permian. The distribution of evaporites indicates a clearly bimodal distribution over the past ~400 Ma, except for Early Devonian, Early Carboniferous, the earliest Permian and Middle and Late Jurassic times. We discuss how the patterns indicated by these lithologies change through time in response to plate motion, orography, evolution and greenhouse/icehouse conditions. This study highlights that combining tectonic reconstructions with a comprehensive lithologic database and novel data analysis approaches provide insights into the nature and causes of shifting climatic zones through deep time.
COMPLEX PRODUCT STRUCTURES ON HOM-LIE ALGEBRAS
Authors: NOURMOHAMMADIFAR L. , PEYGHAN E. 
Published: March 2018

AbstractIn this paper, we introduce the notion of complex product structures on hom-Lie algebras and show that a hom-Lie algebra carrying a complex product structure is a double hom-Lie algebra and it is also endowed with a hom-left symmetric product. Moreover, we show that a complex product structure on a hom-Lie algebra determines uniquely a left symmetric product such that the complex and the product structures are invariant with respect to it. Finally, we introduce the notion of hyper-para-Kähler hom-Lie algebras and we present an example of hyper-para-Kähler hom-Lie algebras.
Community assembly of glass frogs (Centrolenidae) in a Neotropical wet forest: a test of the river zonation hypothesis
Authors: Rivera Nelson , Folt Brian 
Published: March 2018

Abstract:The river zonation hypothesis predicts that abiotic and biotic conditions along riparian gradients drive variation in animal communities. Glass frogs are a diverse group of Neotropical anurans that use riparian habitats exclusively for oviposition and larval development, but little is known about how glass frog communities are distributed across riparian gradients. Here, we measured glass frog community assembly across a gradient of riparian habitats from first- to fifth-order streams at La Selva Biological Station, Costa Rica. We performed repeated nocturnal frog calling surveys and built occupancy andN-mixture abundance models to test for varying patterns of species occupancy, community assembly, species richness (α-diversity) and species turnover (ß-diversity). We observed significant differences in patterns of species occupancy and community assembly across a stream-order gradient: occupancy of two species increased with stream order (Teratohyla pulverata,Hyalinobatrachium fleischmanni), one species decreased (Teratohyla spinosa), and one species did not vary (Espadarana prosoblepon). We evaluated four a priori hypotheses describing how α- and ß-diversity of centrolenids are shaped across the riparian gradient; our data were most consistent with a pattern of nested assemblages and increasing species richness along the riparian gradient. Species-specific patterns of occupancy and abundance resulted in assemblage-level differences consistent with theoretical predictions for highly aquatic organisms along riparian gradients.
Sustaining ecological and subsistence functions in conservation areas: eider habitat and access by Native hunters along landfast ice
Authors: LOVVORN JAMES R. , ROCHA AARIEL R. , MAHONEY ANDREW H. , JEWETT STEPHEN C. 
Published: March 2018

SUMMARYIn the Arctic, rapid climate change has kindled efforts to delineate and project the future of important habitats for marine birds and mammals. These animals are vital to subsistence economies and cultures, so including the needs of both animals and hunters in conservation planning is key to sustaining social-ecological systems. In the northeast Chukchi Sea, a nearshore corridor of open water is a major spring migration route for half a million eider ducks that are hunted along the landfast ice. Zoning areas for industrial activities or conservation should consider both eider habitat and hunter access to those habitats from the variable ice edge. Based on benthic sampling in 2010‒2012, a model of eider foraging energetics and satellite data on ice patterns in April and May 1997‒2011, we mapped the range of positions of the landfast ice edge relative to a given dispersion of habitat suitable for eider feeding. In some sectors, feeding areas were too limited or too far from landfast ice to provide regular hunting access. In other sectors, overlap of the ice edge with eider feeding habitat was quite variable, but often within a consistent geographic range. Areas accessible to hunters were a small fraction of total eider habitat, so areas adequate for conserving eiders would not necessarily include areas that meet the hunters’ needs. These results can inform spatial planning of industrial activities that yield cash income critical to subsistence hunting in less developed locations. Our study provides an approach for mapping ‘subsistence conservation areas’ throughout the Arctic and an example for such efforts elsewhere.
La traditionõrale comme source historique. Le « Livre II » du Ophir de Espanã de Fernando de Montesinos
Authors: Szemiński Jan 
Published: March 2018

RésuméL’article propose et développe un protocole d’étude appliqué à un texte andin composite. L’exercice devrait permettre d’aboutir à une reconstruction de la formation du texte depuis son ultime formulation indienne jusqu’à sa version préservée. Le texte se compose en réalité de faits de narration, restitués sous forme de phrases résumant l’action et reconstruites par l’historien d’après le texte – mais non déductibles de la stricte formulation du texte même –, d’une part, et, d’autre part, d’interpolations introduites par les rédacteurs successifs. Il s’avère que le « Livre II » de Montesinos pourrait contenir des traditions remontant aux VIe-Xe siècles, soit à l’horizon Wari-Tiahuanaco des Andes centrales.
Le versant brésilien de l’Atlantique-Sud : 1550-1850
Authors: de Alencastro Luiz Felipe 
Published: March 2018

RésuméL’histoire du Brésil moderne a toujours été interprétée à partir d’une question centrale : l’élevage du bétail dans la vallée de Saõ Francisco, les relations entre maîtres et esclaves, les structures de la dépendance générées par le capitalisme marchand, les privilèges bureaucratiques ou les enjeux de l’économie de l’or au XVIIIesiècle. De nouvelles recherches sur la traite négrière, sur l’asservissement des Indiens, sur les migrations internes et internationales, permettent d’élaborer un axe interprétatif d’une portée plus large : les transformations du travail dans le contexte colonial et national jusqu’au milieu du XIXesiècle. Ces transformations s’inscrivent dans un espace plus ample qui conditionne l’Amérique portugaise et le Brésil de 1550 à 1850 : l’Atlantique-Sud. Dès lors, la périodisation historique gagne une autre signification. La rupture avec l’ordre colonial intervient en 1850, lors de l’arrêt définitif de la traite des Noirs, et non pas en 1808 (ouverture des ports et arrivée de la Cour portugaise à Rio de Janeiro) ou en 1822, avec l’indépendance du Brésil.
L'historiographie des origines de la France: Genèse d'un imaginaire national
Authors: Burguière André 
Published: March 2018

RésumésDu VIIe siècle, quand les premières chroniques donnèrent à la Francia un ancêtre troyen fuyant sa cité en flammes, à la fin du XIXe siècle, quand Fustel de Coulanges réfuta définitivement la thèse d’une conquête franque, l’historiographie de la France n’a cessé d’osciller, dans son long périple, entre la thèse d’une origine franque et celle d’une origine gauloise. Un parcours historiographique particulièrement long mais nullement exceptionnel : la majorité des dynasties princières de l’Europe ont prétendu descendre d’un guerrier troyen ou d’un fils de Noé. La plupart des histoires nationales ont pensé leurs origines dans une opposition entre des indigènes et des conquérants. Reconstituer les étapes de ce discours des origines, c’est identifier les usages politiques successifs qui l’ont inspiré et sans cesse remanié. Mais on peut essayer aussi, pour rendre le cas français plus comparable à d’autres, d’isoler certains traits structurels de son imaginaire national et de la pensée historique qui s’est construite avec lui.