bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of a “V” Notch on the Tensile Creep Behavior of Cr-Mo Steel
Authors: Suezawa Yoshitada , Ho¯jo¯ Hidemitsu
Published: November 2011

The effect of a “V” notch on the tensile creep behavior of Cr-Mo steel at elevated temperature was studied to elucidate the reasons for notch strengthening or notch weakening. Special attention was paid to changes in notch profile and dimensions, as well as to structural changes of the notched portion of the specimens with the lapse of time up to rupture. Some interesting results were obtained which are different from those of an ordinary tensile test or a creep test on smooth bars, and which are useful to the complete analysis of the stress distribution at the notch-root section of the notched specimens at any time after loading and, in turn, to clarify reasons for notch strengthening.
Notched-Bar Creep Rupture of a Cast Heat-Resistant Alloy at Temperatures Where Ductility Is Limited
Authors: Hanink Dean K. , Voorhees Howard R.
Published: November 2011

Rupture life of a cast nickel-base alloy was increased by the presence of a mild notch even for test temperatures and nominal stresses at which unnotched specimens had fracture elongations of only about 0.5 per cent.
On Cavitation Produced by a Vortex Trailing From a Lifting Surface
Authors: McCormick B. W.
Published: November 2011

An experimental and analytical study is made of cavitation produced by the vortex system trailing from elliptic, rectangular, and delta wings. It is found that the inception of this type of cavitation depends upon the boundary-layer thickness of the lower surface of the wing tip. The thickness of the vortex core is apparently not determined by the induced drag of the wing. For a given wing shape, the critical cavitation index was found to: Increase with increasing Reynolds number; increase nearly linearly with angle of attack; be almost independent of aspect ratio; and, depend significantly upon the undissolved air content.
The Simulation of Bearing Whirl on an Electronic-Analog Computer
Authors: Jennings U. D. , Ocvirk F. W.
Published: November 2011

Journal bearing whirl is simulated on an electronic-analog computer and typical whirl paths of the journal center are presented as obtained from the computer and recorded on an x-y plotter. Transient and steady-state paths of the journal of a rigid rotor are shown. Families of steady paths indicate the changes in orbital size of whirl from nearly zero to very large as influenced by load, journal speed, journal mass, bearing diameter, bearing length, clearance, and viscosity.
Oil Flow in a Full Journal Bearing
Authors: Hays Donald F.
Published: November 2011

An analysis was made of the oil flows occurring in a full journal bearing with a continuous oil film. The flow rate into the bearing was determined at the section of greatest clearance and the rate of outflow was determined at the section of least clearance. The rate of side flow or leakage rate was determined by considering the flow across the boundary of the positive pressure area only and is the flow resulting from the hydrodynamic pressure gradients. It does not include the effects of any specific oil feed mechanism.
Inlet and Exit-Header Shapes for Uniform Flow Through a Resistance Parallel to the Main Stream
Authors: Perlmutter Morris
Published: November 2011

An analytical and experimental study of flow in headers with a resistance parallel to the turbulent and incompressible main stream has been made. The purpose was to shape the inlet and exit headers, which had a large length-to-height ratio, so that the fluid would pass through the resistance uniformly. Analytical wall shapes and estimated total pressure drop through the headers were compared with experimental results. Good agreement between analysis and experiment was found for the cases compared.
Journal Bearings With Arbitrary Position of Source—II
Authors: Fedor J. V.
Published: November 2011

A complete oil film solution of Reynolds equation is found that takes into account the presence of a point source. The solution gives integrated journal bearing characteristics in finite form. With the load in a vertical plane and the source at the top or bottom of the bearing, two simple universal relationships have emerged between the angle indicating the line of centers (α) and the eccentricity (b). With the source at the base of the bearing and −cos α = b, the plot of coefficient of friction versus the Sommerfeld variable goes through the origin and is essentially independent of bearing length to diameter ratio. Also, lubricant end flow becomes vanishingly small as the Sommerfeld variable approaches zero. With the source at the top of the bearing a friction axis intercept can be obtained depending upon a source parameter, q. With cos α ≈ b/2, a rapid rise in the co-efficient of friction can also be simulated by properly varying the source parameter. Also, lubricant end flow increases monotonically as the Sommerfeld variable approaches zero.
Performance Characteristics of Lubricating Oil Film Between Rotating Disks
Authors: El-Sisi S. I. , Shawki G. S. A.
Published: November 2011

A testing machine has been designed to investigate the performance of the lubricating oil film between two independently driven circular disks in line contact under conditions of combined rolling and sliding, in an endeavor to study the behavior of meshing gear teeth with adequate supply of lubricant. Test results show that the ratio of sliding to rolling velocity is a prime factor in the behavior of rotating disks. Values of this ratio equal to zero and unity (conditions of pure rolling and pure sliding, respectively) give rise to critical changes in the performance of the disks, being most favorable, from a lubrication viewpoint, at pure rolling (i.e., at the gear pitch line) and least favorable at pure sliding where scuffing of surfaces may well be expected Recent theoretical investigations do not seem to be able yet to account for salient results obtained in the present study. Further work on the subject is proceeding.
A Thermocouple System for Measuring Turbine-Inlet Temperatures
Authors: Ihnat M. E. , Hagel W. C.
Published: November 2011

A fast-response, unique thermoelement combination of platinum-15 per cent iridium and palladium, whose emf output is about three fourths that of Chromel/Alumel at 2000 F (1093 C), has been found reliable from 1800 to 2300 F (982 to 1260 C) for more than 400 hours in a combustion atmosphere. A new, stable nickel-4.3 per cent silicon matching-lead-wire alloy was prepared for use up to an ambient temperature of 1400 F (760 C). Additional tests provided the best choice of insulation, thermocouple dimensions, sheath material, connectors, and harness design for aircraft jet engines. While it has heretofore been impractical or very difficult to determine turbine-inlet temperatures above 1600 F (871 C), this system is capable of measuring directly the most critical of all operational variables and accordingly allows safe potential increases in engine performance.
Analysis of Axially Loaded Annular Shells With Applications to Welded Bellows
Authors: Hetenyi M. , Timms R. J.
Published: November 2011

A method is presented for the calculation of stresses and deflections in ring-shaped shells of circular cross section, subjected to axial forces. The solution is derived without the restriction imposed for toroidal shells by previous investigators, that the radius of curvature of the cross section is to be small in comparison with the mean radius of the torus. The range of applicability of the method is extended hereby to include the slightly arched convolutions used in the construction of welded bellows. By a rational reduction of the general solution approximate design formulas are obtained for the maximum stresses and deflections in bellows under axial forces and the calculated values are compared with experimental data.
Assessment of Hindlimb Locomotor Strength in Spinal Cord Transected Rats through Animal-Robot Contact Force
Authors: Nessler Jeff A. , Moustafa-Bayoumi Moustafa , Soto Dalziel , Duhon Jessica , Schmitt Ryan
Published: November 2011

Robotic locomotor training devices have gained popularity in recent years, yet little has been reported regarding contact forces experienced by the subject performing automated locomotor training, particularly in animal models of neurological injury. The purpose of this study was to develop a means for acquiring contact forces between a robotic device and a rodent model of spinal cord injury through instrumentation of a robotic gait training device (the rat stepper) with miniature force/torque sensors. Sensors were placed at each interface between the robot arm and animal’s hindlimb and underneath the stepping surface of both hindpaws (four sensors total). Twenty four female, Sprague-Dawley rats received mid-thoracic spinal cord transections as neonates and were included in the study. Of these 24 animals, training began for 18 animals at 21 days of age and continued for four weeks at five min/day, five days/week. The remaining six animals were untrained. Animal-robot contact forces were acquired for trained animals weekly and untrained animals every two weeks while stepping in the robotic device with both 60 and 90% of their body weight supported (BWS). Animals that received training significantly increased the number of weight supported steps over the four week training period. Analysis of raw contact forces revealed significant increases in forward swing and ground reaction forces during this time, and multiple aspects of animal-robot contact forces were significantly correlated with weight bearing stepping. However, when contact forces were normalized to animal body weight, these increasing trends were no longer present. Comparison of trained and untrained animals revealed significant differences in normalized ground reaction forces (both horizontal and vertical) and normalized forward swing force. Finally, both forward swing and ground reaction forces were significantly reduced at 90% BWS when compared to the 60% condition. These results suggest that measurement of animal-robot contact forces using the instrumented rat stepper can provide a sensitive and reliable measure of hindlimb locomotor strength and control of flexor and extensor muscle activity in neurologically impaired animals. Additionally, these measures may be useful as a means to quantify training intensity or dose-related functional outcomes of automated training.
Stereoscopically Observed Deformations of a Compliant Abdominal Aortic Aneurysm Model
Authors: Meyer Clark A. , Bertrand Eric , Boiron Olivier , Deplano Valérie
Published: November 2011

A new experimental setup has been implemented to precisely measure the deformations of an entire model abdominal aortic aneurysm (AAA). This setup addresses a gap between the computational and experimental models of AAA that have aimed at improving the limited understanding of aneurysm development and rupture. The experimental validation of the deformations from computational approaches has been limited by a lack of consideration of the large and varied deformations that AAAs undergo in response to physiologic flow and pressure. To address the issue of experimentally validating these calculated deformations, a stereoscopic imaging system utilizing two cameras was constructed to measure model aneurysm displacement in response to pressurization. The three model shapes, consisting of a healthy aorta, an AAA with bifurcation, and an AAA without bifurcation, were also evaluated with computational solid mechanical modeling using finite elements to assess the impact of differences between material properties and for comparison against the experimental inflations. The device demonstrated adequate accuracy (surface points were located to within 0.07 mm) for capturing local variation while allowing the full length of the aneurysm sac to be observed at once. The experimental model AAA demonstrated realistic aneurysm behavior by having cyclic strains consistent with reported clinical observations between pressures 80 and 120 mm Hg. These strains are 1–2%, and the local spatial variations in experimental strain were less than predicted by the computational models. The three different models demonstrated that the asymmetric bifurcation creates displacement differences but not cyclic strain differences within the aneurysm sac. The technique and device captured regional variations of strain that are unobservable with diameter measures alone. It also allowed the calculation of local strain and removed rigid body motion effects on the strain calculation. The results of the computations show that an asymmetric aortic bifurcation created displacement differences but not cyclic strain differences within the aneurysm sac.
Properties of double-layered Ga-doped Al-zinc-oxide/titanium-doped indium–tin-oxide thin films prepared by dc magnetron sputtering applied for Si-based thin film solar cells
Authors: Wang Chao-Chun , Wuu Dong-Sing , Lin Yang-Shih , Lien Shui-Yang , Huang Yung-Chuan , Liu Chueh-Yang , Chen Chia-Fu , Nautiyal Asheesh , Lee Shuo-Jen
Published: November 2011

In this article, Ga-doped Al-zinc-oxide (GAZO)/titanium-doped indium–tin-oxide (ITIO) bi-layer films were deposited onto glass substrates by direct current (dc) magnetron sputtering. The bottom ITIO film, with a thickness of 200 nm, was sputtered onto the glass substrate. The ITIO film was post-annealed at 350 °C for 10-120 min as a seed layer. The effect of post-annealing conditions on the morphologies, electrical, and optical properties of ITIO films was investigated. A GAZO layer with a thickness of 1200 nm was continuously sputtered onto the ITIO bottom layer. The results show that the properties of the GAZO/ITIO films were strongly dependent on the post-annealed conditions. The spectral haze (Tdiffuse/Ttotal) of the GAZO/ITIO bi-layer films increases upon increasing the post-annealing time. The haze and resistivity of the GAZO/ITIO bi-layer films were improved with the post-annealed process. After optimizing the deposition and annealing parameters, the GAZO/ITIO bi-layer film has an average transmittance of 83.20% at the 400–800 nm wavelengths, a maximum haze of 16%, and the lowest resistivity of 1.04 × 10−3 Ω cm. Finally, the GAZO/ITIO bi-layer films, as a front electrode for silicon-based thin film solar cells, obtained a maximum efficiency of 7.10%. These encouraging experimental results have potential applications in GAZO/ITIO bi-layer film deposition by in-line sputtering without the wet-etching process and enable the production of highly efficient, low-cost thin film solar cells.
Entorhinal Cortex Layer III Input to the Hippocampus Is Crucial for Temporal Association Memory
Authors: Suh Junghyup , Rivest Alexander J. , Nakashiba Toshiaki , Tominaga Takashi , Tonegawa Susumu
Published: November 2011

A specific neural circuit integrates temporally dispersed stimuli into a coherent memory episode.
Systematic Phosphorylation Analysis of Human Mitotic Protein Complexes
Authors: Hegemann Björn , Hutchins James R. A. , Hudecz Otto , Novatchkova Maria , Rameseder Jonathan , Sykora Martina M. , Liu Sihan , Mazanek Michael , Lénárt Péter , Hériché Jean-Karim , Poser Ina , Kraut Norbert , Hyman Anthony A. , Yaffe Michael B. , Mechtler Karl , Peters Jan-Michael
Published: November 2011

Analysis of the phosphorylation of mitotic protein complexes suggests that specific members of the complexes relay regulatory signals to these molecular machines.
In VitroPhenotypic Susceptibility of HIV-2 Clinical Isolates to CCR5 Inhibitors
Authors: Visseaux Benoit , Charpentier Charlotte , Hurtado-Nedelec Margarita , Storto Alexandre , Antoine Romain , Peytavin Gilles , Damond Florence , Matheron Sophie , Brun-Vézinet Françoise , Descamps Diane ,   the French ANRS HIV-2 Cohort (ANRS CO 05 VIH-2)
Published: November 2011

HIV-2 is naturally resistant to nonnucleoside reverse transcriptase inhibitors, to a fusion inhibitor, and to some of the protease inhibitors. Maraviroc is the first drug of the new anti-CCR5 drug class and is effective only on CCR5-tropic (R5) HIV-1. No previous studies concerning HIV-2 susceptibility to maraviroc have been reported yet. We developed a phenotypic maraviroc susceptibility test using a peripheral blood mononuclear cell (PBMC) model. We analyzed the maraviroc susceptibility of 13 R5 HIV-2, 2 X4R5 (dual) HIV-2, and 2 CXCR4-tropic (X4) HIV-2 clinical isolates. We also tested, with the same protocol, 1 X4 HIV-1 and 4 R5 HIV-1 clinical isolates. For the R5 HIV-2 clinical isolates, the 50% effective concentration (EC50) for maraviroc was 0.80 nM (interquartile range [IQR], 0.48 to 1.39 nM), similar to that observed for the R5 HIV-1 isolates. The median maximum percentage of inhibition in the R5 HIV-2 isolates was 93% (IQR, 84 to 98%), similar to that observed in the R5 HIV-1 isolates. As expected, both X4 HIV-1 and HIV-2 were highly resistant to maraviroc. Our study showed for the first time that maraviroc is activein vitroagainst R5 HIV-2. The new tools we developed will allow identification of HIV-2-infected patients eligible for CCR5 inhibitor use and management of virological failure when receiving a maraviroc-based regimen.
Hospital emergency management research in China: trends and challenges
Authors: Xin Yantao T , Xu Keyi Y
Published: November 2011

Emergency management is a relatively new research field in China. The severe acute respiratory syndrome epidemic in 2003 caused research and papers on emergency management to increase by leaps and bounds. This review summarises the progress of hospital emergency management research in China, highlights trends and challenges, and discusses likely solutions for research improvement. Articles were identified from a systematic search of Wanfang Med Online and PubMed, from reviews of bibliographic reference lists and by consultation with experts in the field. The search identified 2548 articles potentially involving hospital emergency management. By reviewing the titles and abstracts, we narrowed the list to 253. Reading the texts resulted in the inclusion of 85 articles in the review. Two additional articles were included from the references cited in articles that were reviewed. Research progress was summarised in terms of basic concepts and principles, system development, emergency response plan, preparedness and response, training and exercise, and management evaluation. Based on this study we suggest that hospital emergency management research in China should make efforts to (1) establish a universally accepted theory framework and terminology, (2) create a structure for further studies, (3) integrate research of different disciplines, and (4) avoid or minimise confusion. More attention should be paid on the evolvement mechanism of main public health incidents and disasters, and the key functional systems related to hospital's emergency response resiliencies. Focus should also be placed on practical guidelines and tools.
Characteristics and capabilities of emergency departments in Abuja, Nigeria
Authors: Wen Leana S , Oshiomogho John I , Eluwa George I , Steptoe Anne P , Sullivan Ashley F , Camargo Carlos A
Published: November 2011

Objectives

Emergency departments (ED) are the basic unit of international emergency medicine, but often differ in fundamental features. This study sought to describe and characterise ED in the capital city of Nigeria, Abuja.

Methods

All ED open 24 h/day 7 days/week to the general public were surveyed using the national ED inventories survey instrument (http://www.emnet-nedi.org). ED staff were asked about ED characteristics with reference to calendar year 2008.

Results

Twenty-four ED participated (83% response). All were located in hospitals, which ranged in size from six to 250 beds. The majority (92% CI 73% to 100%) had a contiguous layout with medical and surgical care provided in one area. All ED saw both adults and children, with a median of 1500 annual visits (IQR 648–2328). Almost half of respondents (46%; CI 26% to 67%) thought their ED operated under capacity, none thought that their ED was over capacity. Only 4% of ED surveyed had dedicated CT scanners, 25% had cardiac monitoring and none had negative-pressure rooms. There was wide variation in the types of emergencies that were identified as being treatable 24 h/day 7 days/week; these appeared to correlate with ED consultant availability.

Conclusions

Although ED location and layout in Abuja do not differ greatly from that in a typical US city, ED utilisation was lower and fewer resources and capabilities were available. The lack of technological and human resources raise questions about what critical technologies are needed in resource-limited settings, and whether Nigeria should consider training emergency medicine physicians to meet its workforce needs.
Epidemiological transition in a rural community of northern India: 18-year mortality surveillance using verbal autopsy
Authors: Kumar Rajesh , Kumar Dinesh , Jagnoor J , Aggarwal Arun K , Lakshmi P V M
Published: November 2011

Background

Information on causes of death is vital for planning of health services. However, vital events registration systems are weak in developing countries. Therefore, verbal autopsy (VA) tools were incorporated in a community-based surveillance system to track causes of death.

Method and Findings

Trained fieldworker identified all deaths and interviewed a living relative of those who had died during 1992–2009, using VA, in eight villages of Haryana (11 864 populations). These field reports detailing events preceding death were reviewed by two trained physicians, who independently assigned an International Classification of Disease-10 code to each death. Discrepancies were resolved through reconciliation and, if necessary, adjudication. Non-communicable conditions were the leading causes of death (47.6%) followed by communicable diseases including maternal, perinatal and nutritional conditions (34.0%), and injuries (11.4%). Cause of death could not be determined in 6.9% cases. Deaths due to cardiovascular diseases showed a significant rise, whereas deaths due to diarrhoeal diseases have declined (p<0.01). Majority (90.0%) of the deceased had contacted a healthcare provider during illness but only 11.5% were admitted in hospital before death.

Conclusion

Rising trend of cardiovascular diseases observed in a rural community of Haryana in India calls for reorientation of rural healthcare delivery system for prevention and control of chronic diseases.
Controversies and advances in non-steroidal anti-inflammatory drug (NSAID) analgesia in chronic pain management
Authors: Shah Seema , Mehta Vivek
Published: November 2011

Chronic pain can lead to significant disability with social and economic implications in the community. Traditional non-steroidal anti-inflammatory drugs (NSAIDs) have been part of the management of chronic pain. The risk of adverse events with traditional NSAIDs has led to the development of alternative therapeutic options. Differential blockade of the enzymes involved in pain and inflammation can offer therapeutic options without the gastrointestinal side effects. However, this may be at the expense of other major cardiovascular side effects. Pain pathways that involve peripheral transmission may be altered by local application of analgesia to the skin overlying the painful area. Recent guidelines for osteoarthritis treatment from the National Institute for Health and Clinical Excellence highlight the importance of topical NSAIDs in the armamentarium of pain management. NSAID combination drugs with gastric protection have provided alternatives to traditional NSAIDs, but the long term sequelae are unknown.
Environmental determinants of threespine stickleback species pair evolution and persistence
Authors: Ormond Chad I. , Rosenfeld Jordan S. , Taylor Eric B.
Published: November 2011

Threespine stickleback ( Gasterosteus aculeatus ) species pairs are found in four watersheds in southwestern British Columbia, Canada, and are listed as Endangered under the federal Species at Risk Act. Their origin is thought to be through a double-invasion process followed by character displacement; however, this hypothesis does not consider whether speciation is dependent on unique environmental factors necessary to support two species with separate habitat and resource requirements, which may be essential both for their evolution and persistence. To test whether species pair lakes have unique attributes, we compared abiotic and biotic factors of species pair lakes to lakes with only a single population of stickleback. There were no clear environmental differences between species pair and non-species pair lakes, but species pairs were only present in lakes with low fish species diversity, suggesting that evolution and persistence of species pairs requires a simplified fish community. Our study suggests that colonization history rather than unique lake attributes (related to either physical habitat or trophic resources) facilitated the evolution of stickleback species pairs and that the fish assemblage in lakes may affect resource availability and speciation potential as strongly as the limnological attributes of the lakes themselves.
Molecular evolution of candidate sour taste receptor gene PKD1L3 in mammals
Authors: Chen Dazhi , Li Ping , Guo Wenhu , Ye Fang , Wu Jian , Wei Damu , Guo Zhiyun , Ye Chun
Published: November 2011

The PKD1L3 gene encodes an ion channel protein that can interact with the PKD2L1 protein to form a candidate sour taste receptor. In the present study, we have analyzed the evolutionary patterns of PKD1L3 genes from 10 mammalian species. The results showed that PKD1L3 genes have evolved under a dominant purifying selection force. However, for some branches and sites, PKD1L3 genes were detected to have been operated by positive selection. Moreover, some of these positive evolutionary sites are likely to participate in acid stimulus recognition. In rodents, PKD1L3 genes evolved more rapidly than other mammalian lineages. Combined with other functional research reports, our results suggest that rodents may not be the most appropriate model for functional research on the PKD1L3 gene.
High-throughput prediction of physical and mechanical properties of paper from Raman chemometric analysis of pulp fibres1This article is a contribution to the series The Role of Sensors in the New Forest Products Industry and Bioeconomy.
Authors: Chen D. , Trung T. , Jang H.-F. , Francis D.W. , Grant E.R.
Published: November 2011

Better pulp quality control, especially relating to product sheet strength, can offer an important means to improve the market superiority of a pulp. However, aside from lignin content, few pulp properties can be easily measured in a timely manner for process control. The present report proves a principle on a novel Raman system and a systematic chemometric approach, allowing for rapid spectral data acquisition and definitive spectrochemical analysis of wet pulp under harsh manufacturing conditions. By incorporating sophisticated chemometrics strategies that combine wavelet transform with a template-oriented genetic algorithm feature selection and partial least squares multivariate classification, this instrument system extracts maximum analytical information from raw Raman spectra to accurately predict the physicomechanical properties of sheet products. Our work has tested and refined these routines by drawing upon the systematic analysis of 26 bleached softwood kraft pulps formulated to yield challenges representative of those encountered in common pulp fibre and sheet analyses. Satisfactory calibration results suggest that a Raman gauge can be developed that has the capacity to continuously assay pulp to predict the physicomechanical properties of sheet paper in real time.
Linear window correlation: new image processing based approach to strain distribution analysis of wood1This article is a contribution to the series The Role of Sensors in the New Forest Products Industry and Bioeconomy.
Authors: Yang Yin , Gong Meng , Leblon Brigitte , Chui Ying Hei
Published: November 2011

An in-depth understanding of the response of wood under compression/densification calls for characterization of strain distribution over the wood. Recently, an image processing technique has been used for strain evaluation on wood, as the traditional devices are not able to measure irregularly distributed strain field. Unfortunately, the classic image correlation algorithm is rather time consuming and could take up to days to compute the final result. In this paper, an improved image correlation algorithm with linearly changed searching region during the correlation seeking is presented. The processing speed is increased by over 1800 times while keeping the high accuracy of the displacement measurement. In addition, full feasibility tests were conducted on balsam fir ( Abies balsamea (L.) Mill.) and eastern white pine ( Pinus strobus L.) samples. The results demonstrate the high robustness, efficiency, and accuracy of the proposed method.
Concentrations of mercury and polychlorinated biphenyls in blood of Southern Beaufort Sea polar bears (Ursus maritimus) during spring: variations with lipids and stable isotope (δ15N, δ13C) values
Authors: Knott Katrina K. , Boyd Daryle , Ylitalo Gina M. , O’Hara Todd M.
Published: November 2011

Polar bears ( Ursus maritimus Phipps, 1774) are exposed to heavy metal and lipophilic contaminants that are known to bioaccumulate and biomagnify. Few studies concurrently report both chemical classes in the same individuals and are thus unable to assess drivers of observed tissue concentrations, and the potential adverse biological responses to combined exposures. We examined blood concentrations of mercury (Hg) and the sum of seven polychlorinated biphenyls (Σ7PCB) from free-ranging Southern Beaufort Sea polar bears to assess which factors contributed to variations among cohorts (adult males, adult females, young) during spring. Concentrations of Hg ranged from 10.3 to 228.0 ng/g wet mass, but mean concentrations were similar between males and females independent of age. Concentrations of Σ7PCB (range 2.0–132.8 ng/g wet mass) were greater among females and young than among males. Toxicant concentrations were related to packed cell δ15N, an estimate of trophic position, after the inclusion of packed cell δ13C. Concentrations of Σ7PCB were also positively correlated with concentrations of neutral lipids (triglycerides and free fatty acids) and inversely correlated to body condition indices. Elevated concentrations of toxicants and lower body condition indices in females and young compared with males may be a sentinel to a changing arctic environment. Further assessment of the potential adverse health impacts of contaminants and nutritional stress in these cohorts is warranted.
Effect of gonadal hormones and sexual experience on vocalizations and behavior of male bank voles (Myodes glareolus)
Authors: Kapusta J. , Pochroń E.
Published: November 2011

This study investigated the influence of gonadal hormones and sexual experience on behavior, especially vocalizations, of male bank voles ( Myodes glareolus (Schreber, 1780)) during same-sex encounters in a neutral arena. Interactions within pairs of castrated males, castrated but testosterone-treated males, and sham-operated intact males were studied in the first experiment and within pairs of sexually experienced males and sexually inexperienced males in the second experiment. Castration reduced the number of ultrasonic vocalizations emitted and androgen treatment restored it to levels seen in intact males. Ultrasounds were emitted more frequently during amicable encounters than during aggressive ones, but ultrasonic calling was reduced during interactions between sexually experienced males, possibly because of the high level of aggression seen in such encounters. In contrast, audible sounds were associated with aggressive behavior and were positively affected by social experience, but they were not testosterone dependent. Neither testosterone nor sexual experience appeared to have any effect on the spectral and temporal characteristics of either audible or ultrasonic calls. The results indicate that emission of ultrasounds during same-sex encounters of male bank voles is regulated by hormonal and social factors and seems to be correlated with type of behavior shown.
Body length and mass growth of the brown bear (Ursus arctos) in northern Canada: model selection based on information theory and ontogeny of sexual size dimorphism
Authors: Bartareau T.M. , Cluff H.D. , Larter N.C.
Published: November 2011

We compared four nonlinear growth functions in modeling body length and mass size-at-age data for the brown bear ( Ursus arctos L., 1758) in northern Canada of wide-ranging body sizes and ages. Then, we analyzed the sex differences in patterns of growth and ontogeny of sexual dimorphism in this species revealed by the best model from these alternatives. The von Bertalanffy function proved to be the most parsimonious model because it was easy to fit, with higher fitting degrees, lower root mean squared standard deviation of data points about fitted growth curve, larger Akaike weight, and fewer parameters derived directly from metabolic laws that accurately estimated the observed body length and mass growth profiles. Our growth models indicated an association between sexual growth divergence and the onset of reproduction in females, together with more rapid and prolonged male growth. These findings suggest that sexual size dimorphism develops in part by constraints on female growth from high energetic costs of reproduction. In contrast, males do not experience a comparable energetic trade-off after reaching sexual maturity and apparently allocate available energetic resources to growing faster and longer to produce larger body size, which benefits more competitive males in terms of increased reproductive success.
ANALYSIS OF THE Y(4274) WITH QCD SUM RULES
Authors: WANG ZHI-GANG
Published: November 2011

In this paper, we assume that there exists a pseudoscalar [Formula: see text] molecular state and study its mass with the molecule-type interpolating current in details using the QCD sum rules. The numerical result disfavors identifying the charmonium-like state Y(4274) as the [Formula: see text] molecule.
SUPERSYMMETRIC YANG–MILLS THEORIES WITH EXACT SUPERSYMMETRY ON THE LATTICE
Authors: JOSEPH ANOSH
Published: November 2011

Inspired by the ideas from topological field theory it is possible to rewrite the supersymmetric charges of certain classes of extended supersymmetric Yang–Mills (SYM) theories in such a way that they are compatible with the discretization on a Euclidean space–time lattice. Such theories are known as maximally twisted SYM theories. In this review we discuss the construction and some applications of such classes of theories. The one-loop perturbative renormalization of the four-dimensional lattice [Formula: see text] SYM is discussed in particular. The lattice theories constructed using twisted approach play an important role in investigating the thermal phases of strongly coupled SYM theories and also the thermodynamic properties of their dual gravitational theories.
STRUCTURAL, ELECTRONIC STRUCTURE, TRANSPORT AND MAGNETIC STUDIES OF NdFe1-xNixO3(x = 0.4, 0.5)
Authors: BASHIR ABIDA , IKRAM MOHD , KUMAR RAVI
Published: November 2011

The structural, transport, electronic structure and magnetic properties of NdFe 1-x Ni x O 3(x = 0.4, 0.5) samples are studied. Both the samples are in single phase with orthorhombic Pbnm structure. The transport properties show the semiconducting nature of the system and no transition is seen on the application of magnetic field. The electronic structure studies verify the chemical states of the ions in the embedded system and the symmetry of the interacting ions. The magnetic properties show the transition from ferromagnetic to paramagnetic phase and which is studied through the Mossbauer studies. The paramagnetic doublet in the x = 0.5 system clearly shows the phase transition from ferromagnetic to paramagnetic.
AB INITIO STUDY OF ELECTRONIC AND MAGNETIC STRUCTURE OF INTERMETALLIC RE5Ge3 COMPOUNDS
Authors: DJERMOUNI M. , BELHADJ M. , KACIMI S. , ZAOUI A.
Published: November 2011

A series of binary rare-earth metal germanides RE 5 Ge 3 ( RE = La , Ce , Pr and Nd ) adopting the Mn 5 Si 3-type hexagonal structure is studied. These intermetallic phases show a complex magnetic behavior. Using a modification of the local density approximation (LSDA + U) the magnetic and electronic properties of these compounds are calculated. The spin-orbit coupling (SOC) was included using a full relativistic basis. Besides the structural parameters, bonding characters, total and partial densities of state and band structures are analyzed and compared with the experimental findings.
ASSOCIATED HYPERON–KAON PRODUCTION VIA NEUTRINO–NUCLEUS SCATTERING
Authors: ADERA G. B. , VAN DER VENTEL B. I. S.
Published: November 2011

We present the investigation of the neutrino-induced strangeness associated production on nuclei in the relativistic plane wave impulse approximation (RPWIA) framework at the intermediate neutrino energies. In this study, the elementary hadronic weak amplitudes are embedded inside the nuclear medium for the description of the exclusive channels of neutrino–nucleus interactions. These amplitudes are extracted using a model-dependent evaluation of the hadronic vertex using the Born term approximation in which the application of the Cabibbo V–A theory and SU(3) symmetry are assumed to be valid. The nuclear effects are included via the bound state wave functions of the nucleon obtained from the relativistic mean field (RMF) models. Two kinematics settings are used to examine various distributions of the differential cross-section in the rest frame of the target nuclei. The numerical results are obtained for the neutrino-induced charged-current (CC) K +Λ-production on bound neutrons in 1s1/2 and 1p3/2 orbitals of 12 C . The angular distributions are forward peaked under both kinematic settings, whereas under the quasifree setting, the cross-sections tend to mimic the missing momentum distribution of the bound nucleon inside the nucleus.
Developmental Patterns in Mesozoic Evolution of Mammal Ears
Authors: Luo Zhe-Xi
Published: November 2011

Complex structures with significant biological function can arise multiple times in evolution by common gene patterning and developmental pathways. The mammalian middle ear, with its significant hearing function, is such a complex structure and a key evolutionary innovation. Newly discovered fossils have now shown that the detachment of the ear from the jaw, an important transformation of the middle ear in early mammals, has major homoplasies; the morphogenesis of these homoplasies is also illuminated by new genetic studies of ear development in extant mammals. By extrapolating the developmental morphogenesis of genetic studies into the early mammal fossil record, evolution of the middle ear in early mammals provides an integrated case study of how development has impacted, mechanistically, the transformation of a major structural complex in evolution.
Diabetes-induced vascular dysfunction involves arginase I
Authors: Romero Maritza J. , Iddings Jennifer A. , Platt Daniel H. , Ali M. Irfan , Cederbaum Stephen D. , Stepp David W. , Caldwell Ruth B. , Caldwell Robert W.
Published: November 2011

Arginase can cause vascular dysfunction by competing with nitric oxide synthase for l-arginine and by increasing cell proliferation and collagen formation, which promote vascular fibrosis/stiffening. We have shown that increased arginase expression/activity contribute to vascular endothelial cell (EC) dysfunction. Here, we examined the roles of the two arginase isoforms, arginase I and II (AI and AII, respectively), in this process. Experiments were performed using streptozotocin-induced diabetic mice: wild-type (WT) mice and knockout mice lacking the AII isoform alone (AI+/+AII−/−) or in combination with partial deletion of AI (AI+/−AII −/−). EC-dependent vasorelaxation of aortic rings and arterial fibrosis and stiffness were assessed in relation to arginase activity and expression. Diabetes reduced mean EC-dependent vasorelaxation markedly in diabetic WT and AI+/+AII−/− aortas (53% and 44% vs. controls, respectively) compared with a 27% decrease in AI+/−AII −/− vessels. Coronary fibrosis was also increased in diabetic WT and AI+/+AII−/− mice (1.9- and 1.7-fold vs. controls, respectively) but was not altered in AI+/−AII −/− diabetic mice. Carotid stiffness was increased by 142% in WT diabetic mice compared with 51% in AI+/+AII−/− mice and 19% in AI+/−AII −/− mice. In diabetic WT and AI+/+AII−/− mice, aortic arginase activity and AI expression were significantly increased compared with control mice, but neither parameter was altered in AI+/−AII −/− mice. In summary, AI+/−AII −/− mice exhibit better EC-dependent vasodilation and less vascular stiffness and coronary fibrosis compared with diabetic WT and AI+/+AII−/− mice. These data indicate a major involvement of AI in diabetes-induced vascular dysfunction.
Impact of repeated daily exposure to intermittent hypoxia and mild sustained hypercapnia on apnea severity
Authors: Yokhana Sanar S. , Gerst David G. , Lee Dorothy S. , Badr M. Safwan , Qureshi Tabarak , Mateika Jason H.
Published: November 2011

We examined whether exposure to intermittent hypoxia (IH) during wakefulness impacted on the apnea/hypopnea index (AHI) during sleep in individuals with sleep apnea. Participants were exposed to twelve 4-min episodes of hypoxia in the presence of sustained mild hypercapnia each day for 10 days. A control group was exposed to sustained mild hypercapnia for a similar duration. The intermittent hypoxia protocol was completed in the evening on day 1 and 10 and was followed by a sleep study. During all sleep studies, the change in esophageal pressure (ΔPes) from the beginning to the end of an apnea and the tidal volume immediately following apneic events were used to measure respiratory drive. Following exposure to IH on day 1 and 10, the AHI increased above baseline measures ( day 1: 1.95 ± 0.42 fraction of baseline, P ≤ 0.01, vs. day 10: 1.53 ± 0.24 fraction of baseline, P < 0.06). The indexes were correlated to the hypoxic ventilatory response (HVR) measured during the IH protocol but were not correlated to the magnitude of ventilatory long-term facilitation (vLTF). Likewise, ΔPes and tidal volume measures were greater on day 1 and 10 compared with baseline (ΔPes: −8.37 ± 0.84 vs. −5.90 ± 1.30 cmH20, P ≤ 0.04; tidal volume: 1,193.36 ± 101.85 vs. 1,015.14 ± 119.83 ml, P ≤ 0.01). This was not the case in the control group. Interestingly, the AHI on day 10 (0.78 ± 0.13 fraction of baseline, P ≤ 0.01) was significantly less than measures obtained during baseline and day 1 in the mild hypercapnia control group. We conclude that enhancement of the HVR initiated by exposure to IH may lead to increases in the AHI during sleep and that initiation of vLTF did not appear to impact on breathing stability. Lastly, our results suggest that repeated daily exposure to mild sustained hypercapnia may lead to a decrease in breathing events.
Similar changes of gene expression in human skeletal muscle after resistance exercise and multiple fine needle biopsies
Authors: Friedmann-Bette Birgit , Schwartz Fides Regina , Eckhardt Holger , Billeter Rudolf , Bonaterra Gabriel , Kinscherf Ralf
Published: November 2011

Repeated biopsy sampling from one muscle is necessary to investigate muscular adaptation to different forms of exercise as adaptation is thought to be the result of cumulative effects of transient changes in gene expression in response to single exercise bouts. In a crossover study, we obtained four fine needle biopsies from one vastus lateralis muscle of 11 male subjects (25.9 ± 3.8 yr, 179.2 ± 4.8 cm, 76.5 ± 7.0 kg), taken before (baseline), 1, 4, and 24 h after one bout of squatting exercise performed as conventional squatting or as whole body vibration exercise. To investigate if the repeated biopsy sampling has a confounding effect on the observed changes in gene expression, four fine needle biopsies from one vastus lateralis muscle were also taken from 8 male nonexercising control subjects (24.5 ± 3.7 yr, 180.6 ± 1.2 cm, 81.2 ± 1.6 kg) at the equivalent time points. Using RT-PCR, we observed similar patterns of change in the squatting as well as in the control group for the mRNAs of interleukin 6 (IL-6), IL-6 receptor, insulin-like growth factor 1, p21, phosphofructokinase, and glucose transporter in relation to the baseline biopsy. In conclusion, multiple fine needle biopsies obtained from the same muscle region can per se influence the expression of marker genes induced by an acute bout of resistance exercise.
Cerebral circulation during mild +Gz hypergravity by short-arm human centrifuge
Authors: Iwasaki Ken-ichi , Ogawa Yojiro , Aoki Ken , Yanagida Ryo
Published: November 2011

We examined changes in cerebral circulation in 15 healthy men during exposure to mild +Gz hypergravity (1.5 Gz, head-to-foot) using a short-arm centrifuge. Continuous arterial pressure waveform (tonometry), cerebral blood flow (CBF) velocity in the middle cerebral artery (transcranial Doppler ultrasonography), and partial pressure of end-tidal carbon dioxide (ETco2) were measured in the sitting position (1 Gz) and during 21 min of exposure to mild hypergravity (1.5 Gz). Dynamic cerebral autoregulation was assessed by spectral and transfer function analysis between beat-to-beat mean arterial pressure (MAP) and mean CBF velocity (MCBFV). Steady-state MAP did not change, but MCBFV was significantly reduced with 1.5 Gz (−7%). ETco2 was also reduced (−12%). Variability of MAP increased significantly with 1.5 Gz in low (53%)- and high-frequency ranges (88%), but variability of MCBFV did not change in these frequency ranges, resulting in significant decreases in transfer function gain between MAP and MCBFV (gain in low-frequency range, −17%; gain in high-frequency range, −13%). In contrast, all of these indexes in the very low-frequency range were unchanged. Transfer from arterial pressure oscillations to CBF fluctuations was thus suppressed in low- and high-frequency ranges. These results suggest that steady-state global CBF was reduced, but dynamic cerebral autoregulation in low- and high-frequency ranges was improved with stabilization of CBF fluctuations despite increases in arterial pressure oscillations during mild +Gz hypergravity. We speculate that this improvement in dynamic cerebral autoregulation within these frequency ranges may have been due to compensatory effects against the reduction in steady-state global CBF.