bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Overloading and Crack Closure Effects on Fatigue Crack Growth in an Aircraft 7075-T7351 Al-Alloy
Authors: Černý Ivo , Mikulová Dagmar
Published: September 2013

Al 7075 alloy is a high strength material usually used for highly stressed components in lightweight structures, typically in aircraft, aerospace and defence applications. It can be applied in different heat treatment conditions, but the T7351 temper state is most widely used because of improved stress-corrosion cracking resistance. An investigation of effects of overloads on fatigue crack growth (FCG) and retardation in Al 7075-T7351 alloy was carried out. FCG rates were measured at load asymmetry R = Fmin / Fmax = 0.1, in quite wide region of growth between 10-8 and 10-5 m/cycle (stress intensity factor range ΔK between 6 and 40 MPa m1/2). Retardation effects of overloads of the magnitudes 2.7-times and 3.0-times of the maximum load in the constant range fatigue loading were significant. Crack mouth opening displacement was evaluated at numerous stages of crack growth including pre-cracking with so called load shedding method. The overloads resulted in substantial crack closure effects, which, however, did not occur immediately after the overloading, but after further fatigue crack extension. Results are discussed considering both theoretically and experimentally estimated plastic zone size and considering crack closure issues recently published in the literature
Modelling Porosity in Quasi-Brittle Reactor Core Graphite
Authors: Smith G.E. , Flewitt Peter E.J. , Hodgkins A.
Published: September 2013

Some designs of nuclear reactors involve a graphite moderator within their core. Different forms of graphite have been adopted in the UK gas-cooled reactors but all have a complex structure of filler particles, matrix and pores. Changes occur in the graphite during service and in particular, porosity increases from that found in the virgin material. As part of a structural assessment, it is important to analyse the effects of this change in porosity. Software has been developed to represent the microstructure of pile grade A (PGA) and Gilsocarbon graphite with a range of porosities, to support finite element determination of material properties. The models are three dimensional geometric and voxel models based on the observed microstructures of these different graphites. Creating a sequence of model specimens with increasing porosities while holding other parameters constant, provides a representative microstructure to test the effect of increasing porosity on mechanical and physical properties.
Bi-Material Notches under Various Normal-Shear Loading Modes
Authors: Klusák Jan , Kopp D. , Profant Tomáš
Published: September 2013

In the range of linear elastic fracture mechanics, the critical loading assessment of structures made of two dissimilar materials is usually based on the assumptions of the prevailing normal mode of loading. However, in engineering practice there are cases of loading and failure close to the shear mode of loading. The aim of the work is to study the stress distribution in the vicinity of a bi-material notch subjected to a combination of normal and shear modes of loading. Then the stability criteria use knowledge of common fracture mechanics properties for normal I and shear II modes of loading. The assessment of crack initiation conditions is shown on a specimen with two different bi-material notches under loading of a varying direction.
Ultrasonic Corrosion Fatigue Behaviorof Duplex Stainless Steel
Authors: Ebara Ryuichiro , Miyoshi Yuya
Published: September 2013

Ultrasonic Corrosion Fatigue Tests were Conducted for SUS329J3L in Air and 3%NaCl Aqueous Solution. Reduction of Giga-Cycle Corrosion Fatigue Strength was 12.5%. Corrosion Pit was Observed on Corrosion Fatigue Crack Initiation Area. Striation was Predominantly Observed on Crack Propagation Area both in Air and 3% Nacl Aqueous Solution. it can be Concluded that the Reduction of Corrosion Fatigue Strength of SUS329J3L is due to the Corrosion Pit Formation at Corrosion Fatigue Crack Initiation Area.
A Unified Model for Micromechanics Damage in the Asphalt Concrete
Authors: Buonsanti Michele , Leonardi Giovanni , Scoppelliti Francesco
Published: September 2013

The particles distinct element model has the consistency to model the mechanical behavior of the microscopic structures inside an asphalt mixture. The model assumes that the schematized granular constituents are in a contact point, considering the thin asphalt films as the binding elements. In this paper, we will model (at micro-scale) the damage to a surface in asphalt concrete under an impulsive load, considering binding, interface, viscosity and friction. Our aim is to reproduce the micro-damage due to detachment among the elementary components of the concrete in airports pavements.The proposed approach is mainly from a mechanical point of view, and a general model describing adhesive contact between rigid bodies is proposed. The intensity of adhesion is supposed to decrease under prescribed shear and normal displacement fields and comes by energy reduction, where the viscosity and friction contributes are taken in account.A numerical implementation by finite element procedures has been performed, and the outcome is presented.
Thermo-Mechanical Investigation of Ultra-High Molecular Weight Polyethylene for High Strain-Rate Applications
Authors: Ashcroft I.A. , Gorwade C.V. , Alghamdi A.S. , Silberschmidt V.V. , Song M.
Published: September 2013

Advanced polymeric materials, such as ultra-high molecular weight polyethylene (UHMWPE) are used in lightweight body armour because of their combination of good impact resistance with light weight. However, a broader use of such materials is limited by the complexity and cost of the manufacturing processes and the lack of experimental data on their behaviour and failure evolution under high strain-rate loading conditions. The current study deals with an investigation of the internal heat generation during the tensile testing of UHWMPE and polymer nano-composite blends at various strain rates. A 3D finite element (FE) model of the tensile test is developed and validated with the experimental work. An elastic-plastic material model is used with adiabatic heat generation. The temperature and stresses obtained with the FE analysis are found to be in a good agreement with the experimental results for UHMWPE materials. The model can be used as a simple and cost effective tool to predict the thermo-mechanical behaviour of parts made from these materials under various loading conditions.
An Estimation on the Performance of High Fluidity Anti-Washout Underwater Concrete
Authors: Park Jung Jun , Moon Jae Heum , Park Jun Hyoung , Kim Sung Wook
Published: September 2013

The placing of anti-washout underwater concrete for the increasing construction of offshore foundations of long-span bridges at relatively deep sea is accompanied with significant loss of the quality of concrete as well as of the durability and reliability of the structure due to limitations brought by the workability of the high-pressure pump and the performance of the anti-washout agent. Therefore, the improvement of the performance of the underwater anti-washout agent and the development of high fluidity anti-washout underwater concrete exhibiting improved packing ability and fluidity should be implemented. Accordingly, this study focuses on the concrete for foundations applied in the RCD (Reverse Circulation Drill) method. The adequate mix proportions of a high fluidity anti-washout underwater concrete satisfying a design compressive strength of 35 MPa, slump flow larger than 600 mm and with less than 50 mg/ℓ of suspended solids is derived and the corresponding characteristics are evaluated.
3D Global-Local Analysis Using Mesh Superposition Method
Authors: Sellitto Andrea , Borrelli Rosario , Caputo Francesco , Ludwig T. , Riccio Aniello , Scaramuzzino Francesco
Published: September 2013

One of the main issue in a FEM analysis is to determine and minimizing discretization errors. This kind of errors assume a critical importance especially where the solution, in terms of displacement and stress, quickly changes inside the finite element. This issue can be overcame adopting a very refined element discretization in those regions.Hence, for this kind of simulations, it is common practice to use global-local methods rather than adopt a refined discretization over the entire domain. Indeed, global-local methods allow to define very refined elements distributions in some regions of interest, which can be coupled with coarser element distributions in the rest of the domain.A global-local approach based on the superposition technique is presented in this work. This approach allows the coupling of two different meshed domain by superimposing the refined local mesh on the global mesh for the region of interest. The coupling takes place without introducing multi-point constraints or transition regions; the mesh continuity and the well-conditioning of the stiffness matrix are satisfied by appropriate boundary conditions. This approach allows to obtain accurate solutions in the areas of interest while keeping the computational time within satisfactory limits. Several numerical applications are presented which allow to assess the effectiveness of the proposed approach for 3D linear static simulations.
An Experimental-Numerical Hybrid Method to Determine Dynamic Elastic-Plastic Fracture Toughness
Authors: Zhu Shi Fan , Cao Yang , Guo Chun Huan , Jiang Feng Chun
Published: September 2013

The dynamic fracture behavior of 7075-T6 aluminum alloy was studied by finite element method to simulate a cracked three-point bending specimen loaded by stress wave loading. In order to determine the elastic-plastic dynamic fracture toughness using quasi-static fracture mechanics theory, the nominal load measured by Hopkinson pressure bar loaded fracture testing system was input into a finite element program to calculate the loading point displacement, and then this displacement was employed to obtain the load-displacement field in the vicinity of the crack tip without the inertia effect, the variation of J-integral as a function of time was established using the load-displacement parameters determined by finite element analysis. The critical J-integral corresponding to crack initiation time detected by a small strain gauge mounted on the three-point bending fracture specimen is determined as an elastic-plastic dynamic fracture toughness (JId). The comparison between the equivalent dynamic fracture toughness(KId) given by the aforementioned procedures and the value measured in previous studies was made to verify the validation of the proposed procedure.
Evaluation of Interlaminar Shear Strength of Longitudinal GRP Railway Bogie Frames Considering Microstructure Aspects
Authors: Černý Ivo
Published: September 2013

The paper contains results of a comprehensive research and development programme aimed at an evaluation of static strength of a GRP railway bogie of a new advanced design. The works were carried out as one of the essential phases of the implementation of a EUREKA project EUROBOGIE, which is aimed at development of advanced vehicle bogies and has a great potential to lead to more efficient movement of freight and passengers with lower environmental impact. The GRP bogie design consists of three main load carrying parts, namely two quite massive longitudinal side frames connected by a central transom plate which are manufactured in a single moulding operation using the resin transfer moulding (RTM) method. Since the component is unusually thick, all parameters of the RTM method have to be well balanced. One of the critical issues in the design and manufacture is the connection area of the transom with the side frames. Therefore, testing of this subcomponent was an important part of the bogie development. Results of the experimental programme provided necessary feedback for the optimization of the manufacture technology.
Micromechanical Modelling of Advanced Ceramics Using Statistically Representative Microstructures
Authors: Alveen Patricia , McNamara Declan , Carolan Declan , Murphy Neal , Ivanković Alojz
Published: September 2013

Advanced ceramics are a class of materials used as cutting tools in some of the most demanding material removal operations. Their high hardness makes them extremely suited for use at these extreme conditions. However they have a relatively low fracture toughness when compared to other conventional tool materials.
A combined experimental-numerical method was used to investigate the role of microstructure on the fracture of advanced ceramics. In particular, the effect of grain size and matrix content were examined. Representative finite volume (FV) microstructures were created using Voronoi tessellation. It is shown, by comparing with real micrographs, that the method captures the features of real microstructures in terms of grain size distribution and grain aspect ratio. It was found that the underlying microstructure significantly affects the failure of this class of materials. Furthermore, it was found that by altering the microstructural parameters in the numerical model, such as grain size and matrix content, it is possible to specify material improvements.
Probability Distribution Analysis of Rock Salt Creep Parameters Based on Comprehensive Optimal Acceptance Criteria
Authors: Ma Ji Wei , Wang Zhi Yin , Wu Jin Peng
Published: September 2013

According to salt rock creep test data and strain variation regulation of a salt mine, salt rock creep parameters are obtained based on Burgers creep model fitting. Statistical study of the probability distribution of the salt rock Burgers model creep parameters is carried out by K-S, A-D and C-M test method, from which probability model for each creep parameters is obtained. To achieve the purpose of determining the optimal probability model for each creep parameters, considering the acceptable level of various test method to different hypothesis probability model, the author put forward the comprehensive optimal acceptance criteria on the basis of limited comparison method, the correctness of which is proved by test result.
Numerical Simulation on the Oblique Penetration of Ceramic Particles Reinforced Metal Matrix Functional Gradient Armor
Authors: Wang Zhen Qing , Tang Xiao Jun , Wang Xin Tao , Meng Xiang Nan , Lv Hong Qing
Published: September 2013

Ceramic particles reinforced metal matrix functional gradient armor is a terrific protective material for helicopter gunship armor to gain light weight and improve anti-penetration performance. However, the anti-penetration mechanism is still not understood. In view of this fact, this paper aims to investigate the penetration mechanism of functional gradient armor. LS-DYNA software is used to simulate the processes of armor-piercing projectile oblique penetrating an optimal ceramic particles reinforced metal matrix functional gradient armor. The armor’s geometry of the calculation model considered is a four-sides-fixed supported round plate whose side length is far longer than its thickness. The penetrator considered is a long rod projectile. The results show that: when the oblique angle is relatively small, the projectile will turn to the vertical direction, that is to say, the oblique angle will diminish during the oblique penetration, and this phenomenon will do harm to the anti-penetration performance of the armor; when the oblique angle increases to a certain degree, the oblique angle will be enlarged during the oblique penetration, and this phenomenon will be beneficial to the anti-penetration performance of the armor. The bigger the oblique angle is, the easier the ricochet phenomenon will become. When design armors, the oblique angles of 0~15 degree should be avoided, and the oblique angles greater than 35 degree are preferred.
Damage and Fracture during Contact between a Spherical Indenter and Ice: Experimental Results and Finite Element Simulations
Authors: Taylor Rocky S. , Jordaan Ian J.
Published: September 2013

Effective modeling of ice material behavior requires treatment of both damage and fracture. In this paper, a discussion of local ice damage and fracture processes observed during laboratory-scale indentation experiments conducted on unconfined polycrystalline ice using a spherical indenter is provided. Particular emphasis is placed on the interplay between fracture and extrusion processes corresponding to the failure of ice under a single zone of high contact pressure. Simulations have been conducted using a continuum damage mechanics user-material routine in conjunction with element removal techniques to simulate pressure-softening and discrete fracture processes, respectively. Simulation results provide good agreement with test data and provide important insights into interplay between damage and fracture mechanisms associated with compressive ice failure. Finite element modeling was found to work well for modeling pressure softening effects and for replicating the effects of discrete fracture events. For interactions involving multiple failure events, further work is needed to develop models that account for random aspects of fracture associated with flaw structure, contact geometry and the geometry of individual spalls.
Evaluating the Critical Temperature of Creep-Fatigue Interaction a Nickel-Based Powder Metallurgy Superalloy
Authors: Liu Hao , Bao Rui , Lei Wei Ming , Fei Bin Jun
Published: September 2013

For the components working in high temperature and enduring fatigue loading, the fatigue fracture properties will be reduced remarkably when the working temperature is higher than the critical temperature of creep-fatigue interaction Tc of the material. In consequence, the damage mechanism from creep-fatigue interaction becomes more complex. A method is presented in this paper to determine the Tc of a nickel-based powder metallurgy superalloy. Pure fatigue crack growth and creep-fatigue crack growth tests were conducted in several different elevated temperatures. The fracture mechanism was investigated via observing the fractographic characteristics using scanning electron microscope (SEM). The test results show that the Tc of this superalloy is a little bit lower than a half of the melting temperature Tm.
Dynamic Behavior to Fatigue Crack Initiation of a Glass/Epoxy Laminate
Authors: Lecheb S. , Nour A. , Chellil A. , Lechani R. , Kebir H.
Published: September 2013

This paper based to study of the dynamic and fatigue behaviors with numerical and experimental parts of a composite material manufactured by stacking two layers of E-glass fiber in different angle orientations (0°/90°) immersed in polyester resin with total thickness 1.39mm. In Finite Element Analysis (FEA) using ABAQUS was used to evaluate the maximal (displacement, strain and stress) and the natural frequencies (mode shapes) of composite behavior under crack initiation condition. In the experimental part the laminate plate specimen with two layers is tested under one types of cyclic load in fully reversible tensile at (R=0), the fast fracture occur phenomenon and the fatigue life are presented , the fatigue testing exerted in INSTRON 8801 machine.
Fatigue Strength of Aluminum Cast Alloy in Plant Oil
Authors: Kawagoishi Norio , Kariya K. , Maeda Y. , Kinoshita E. , Chen Q. , Goto Masahiro
Published: September 2013

Effect of plant oil on the fatigue strength of a squeeze cast Al-Si-Mg alloy was investigated. Crack growth rate was higher in plant oil than in air, inducing a decrease in fatigue strength. The reason included is explained from the viewpoint of high water absorbency of plant oils, on basis of hydrogen enhanced localized plasticity.
The doctor and the patient: doing too much or too little
Authors: D'Amore Francesco
Published: September 2013

In his work, the doctor walks a narrow line between doing too much or doing too little. This is a difficult terrain requiring a sense of balance, of solidarity and the knowledge that, in the near future, the doctor will be the main actor in changing the relationships between the medical profession and society...
Doctor or junk man? What we wouldn’t do to have the personal books of Cesare Frugoni or Vincenzo Monaldi
Authors: Sgambato Francesco , Sgambato Ester
Published: September 2013

It all began when I was browsing through the advertisements in the magazine Famiglia Cristiana and I came across: For sale: academic and personal texts of Prof. Cesare Frugoni. There was a Rome phone number...
Complexity in hospital internal medicine departments: what are we talking about?
Authors: Nardi Roberto , Berti Franco , Greco Antonio , Scanelli Giovanni , Leandri Paolo , Reta Massimo , Mazzetti Magda , Pasquale Angelo , Belmonte Gelorma , Magnani Mirco , Frasson Stefania , Baldo Concetta , Gussoni Gualberto , Vescovo Giorgio , La Regina Micaela , Campanini Mauro , Iori Ido , Mathieu Giovanni , Mazzone Antonino , Nozzoli Carlo
Published: September 2013

Internal medicine (IM) patients are mostly elderly, with multiple complex co-morbidities, usually chronic. The complexity of these patients involves the intricate entanglement of two or more systems (e.g. body and disease, family-socio-economic and environmental status, coordination of care and therapies) and this requires comprehensive, multi-dimensional assessment (MDA). Despite attempts to improve management of chronic conditions, and the availability of several MDA tools, defining the complex patient is still problematic. The complex profile of our patients can only be described through the best assessment tools designed to identify their characteristics. In order to do this, the Federation of Associations of Hospital Doctors on Internal Medicine FADOI has created its own vision of IM. This involves understanding the different needs of the patient, and analyzing diseases clusters and the possible relationships between them. By exploring the real complexity of our patients and selecting their real needs, we can exercise holistic, anthropological and appropriate choices for their treatment and care. A simpler assessment approach must be adopted for our complex patients, and alternative tools should be used to improve clinical evaluation and prognostic stratification in a hierarchical selection of priorities. Further investigation of complex patients admitted to IM wards is needed.
Beware erysipelas: renal disease is just around the corner
Authors: Lagi Alfonso , Lagi Filippo
Published: September 2013

We describe a case of erysipelas caused by Streptococcus Group G to draw attention to organ and systemic complications that may be associated with this disease. Group G streptococcal infection affected a 70-year old woman following a small skin wound at the base of her second left toe. On admittance to the emergency department, the patient’s urine was dark from macrohematuria. She later developed septic shock. Cutaneous and renal symptoms were kept in check with antibiotic therapy, and she fully recovered from the septic shock after receiving specific therapies. This case shows that erysipelas is not just a disease of the skin and soft tissues, but one that may be associated with organ diseases and systemic complications. The patient completely recovered from both the cutaneous and kidney pathologies after antibiotic therapy.
Echocardiography in heart failure patients admitted onto internal medicine wards: when? Data from the CONFINE-FADOI study
Authors: Biagi Paolo
Published: September 2013

Nor required
Cognition and closed systems
Authors: Bota Robert G.
Published: September 2013

Mathematics is a-priory knowledge, a closed and self-sufficient system which con- nections with the material world are incidental rather than definitory. To make mathematics applicable and useful in a pragmatic sense one has to give meanings to numbers. The interplay between a-priori and a-posteriori thinking leads to useful applications of the former.
Molecular detection of Yaba monkey tumour virus from a vervet monkey
Authors: Brettschneider Helene , Voster Johan H. , Lane Emily P. , Van Wilpe Erna , Biden Peter , Dalton Desire L. , Kotze Antoinette
Published: September 2013

Yaba monkey tumour virus (YMTV) was first diagnosed in a colony of captive rhesus monkeys (Macaca mulatta) in Yaba, Nigeria. It has been implicated as the cause of cutaneous nodules in wild baboons (Papio species), rhesus monkeys (Macaca mulatta) and cynomolgus monkeys (Macaca fascicularis). This article reports a case of cutaneous pox lesions caused by YMTV in a  free-ranging  adult  female  vervet  monkey  (Chlorocebus  pygerythrus)  from  the  Umkomaas coastal area in South Africa. The virus was identified by molecular sequencing from fragments of the insulin metalloprotease-like protein and intracellular mature virion membrane protein as well as the DNA polymerase genes. Phylogenetic analyses of these gene regions revealed a 99% similarity of the sample to YMTV. Although human disease caused by YMTV is normally mild,  it  is  recommended  that  persons  in  contact  with  non-human  primates  in  the  area  of Umkomaas who develop cutaneous lesions should inform their doctors of the possibility of this infection. The extent and significance of the virus to human and non-human primates in South Africa are not known. To the authors’ knowledge, this is the first diagnosis of YMTV in South Africa and in vervet monkeys.
Using XForms for interfaces to XML data
Authors: Pemberton Steven
Published: September 2013

XForms is a high-level tool for defining user interfaces to XML data. With a design based on years of experience with the simple forms of HTML, XForms systematically distinguishes between the model (the information structures being edited, in the form of sets of XML documents) and the user interface and its appearance. As an XML vocabulary, XForms is embeddable in arbitrary host document languages; its user interface widgets can easily be represented in different ways for different devices and users. Forms of arbitrarily complex fixed structure can be easily represented in XForms. Mixed content, variable-depth recursion, and structural modifications to the model are more challenging. This introduction to XForms provides an overview of its capabilities and current limits and the prospects for overcoming them.
Titanium Corrosion by a Hot Perfluoropolyether
Authors: CHANDLER WAYNE L. , LLOYD LINDSAY B. , FARROW MICHAEL M. , BURNHAM ROGER K. , EYRING EDWARD M.
Published: September 2013

The kinetics and mechanism of titanium corrosion by Krytox MLO-71-6 are reported. The rate of corrosion is found to be dependent on the presence of molecular oxygen in the environment. For titanium corrosion to occur, the lubricant chains must first break down into smaller reactive molecules. This degradation process is accelerated by TiF3 corrosion products on the metal surface, thus giving rise to a chain mechanism. The corrosion is not promoted by intense CW laser illumination at λ = 514nm.
Simulation of Coal Conversion Reactor Environments
Authors: COOKE RICHARD A. , DEVEREUX OWEN F.
Published: September 2013

Two models simulating the coal gasifier environment are described; Model 1 comprises coal gas components and a molten sodium salt phase, while Model 2 also includes a solid carbon phase. The use of equilibrium constants to compute the equilibrium state of an open system and the occurrence of multiple equilibrium states are detailed. Representative computations pertaining to the two models are shown in which dependent partial pressures and activity ratios are computed as function of temperature, total pressure, and the partial pressures of hydrogen, carbon monoxide, and hydrogen sulfide. The dominant anion in the liquid phase is mapped as a function of equilibrium gas phase composition.
Effect of Anions and Organic Corrosion Inhibitors on the Rate of Hydrogen Penetration of Iron
Authors: SAITO Y. , NOBE KEN
Published: September 2013

The rates of hydrogen penetration of annealed iron in different acids (pH 0.3), H2SO4, HCl, HClO4, and H3PO4, in the absence and presence of the organic compounds, benzotriazole, methylhydroxypentyne, and thiourea, have been measured. Although the differences in the hydrogen penetration rates of iron in the strong acids are not substantial, the penetration rate of iron in H3PO4 is significantly larger than that measured in the three strong acids. Both Benzotriazole (BTA) and methylhydroxypentyne (MHP) retard hydrogen penetration in all three strong acids. On the other hand, thiourea (TU) substantially accelerates penetration due to the presence of H2S. Anion effects on hydrogen penetration are small in the presence of BTA and MHP, while they are insignificant in the presence of TU.
Correcting basin-scale snowfall in a mountainous basin using a distributed snowmelt model and remote sensing data
Authors: Shrestha M. , Wang L. , Koike T. , Tsutsui H. , Xue Y. , Hirabayashi Y.
Published: September 2013

Abstract. Adequate estimation of the spatial distribution of snowfall is critical in hydrologic modeling. However, this is a well-known problem in estimating basin-scale snowfall, especially in mountainous basins with data scarcity. This study focuses on correction and estimation of this spatial distribution, which considers topographic effects within the basin. A method is proposed that optimizes an altitude-based snowfall correction factor (Cfsnow). This is done through multi-objective calibration of a spatially distributed, multilayer energy and water balance-based snowmelt model (WEB-DHM-S) with observed discharge and remotely sensed snow cover data from the Moderate Resolution Imaging Spectroradiometer (MODIS). The Shuffled Complex Evolution – University of Arizona automatic search algorithm is used to obtain the optimal value of Cfsnow for minimum cumulative error in discharge and snow cover simulations. Discharge error is quantified by Nash–Sutcliffe efficiency and relative volume deviation, and snow cover error was estimated by pixel-by-pixel analysis. The study region is the heavily snow-fed Yagisawa Basin of the Upper Tone River in northeast Japan. First, the system was applied to one snow season (2002–2003), obtaining an optimized Cfsnow of 0.0007 m−1. For validation purposes, the optimized Cfsnow was implemented to correct snowfall in 2004, 2002 and 2001. Overall, the system was effective, implying improvements in correlation of simulated vs. observed discharge and snow cover. The 4 yr mean of basin-average snowfall for the corrected spatial snowfall distribution was 1160 mm (780 mm before correction). Execution of sensitivity runs against other model input and parameters indicated that Cfsnow could be affected by uncertainty in shortwave radiation and setting of the threshold air temperature parameter. Our approach is suitable to correct snowfall and estimate its distribution in poorly-gauged basins, where elevation dependence of snowfall amount is strong.
Iatrogenic Pneumothorax Associated with Inadvertent Intrapleural NGT Misplacement in Two Dogs
Authors: Gladden Juliet
Published: September 2013

This case report presents two cases of inadvertent intrapleural nasogastric tube (NGT) misplacement with consequent creation of a bronchopleural fistula and the development of an iatrogenic pneumothorax in dogs. Due to the simplicity and relative ease of NGT placement and the lack of reported life-threatening complications in the veterinary literature, the serious risks associated with this procedure are often overlooked. Although pulmonary complications with NGT misplacement have been previously reported in the human literature, serious and potentially fatal complications have not been currently described in veterinary patients. Both of the cases described herein were medically managed with successful outcomes; however, one case was associated with significant morbidity.
Influence of Helicobacter pylori Infection on the Small Intestinal Mucosa
Authors: Maeda Mitsunori , Nakano Masakazu , Hiraishi Hideyuki
Published: September 2013

Background/Aims. To investigate the role of Helicobacter pylori infection in the development of enteritis (small intestinal mucosal injury). Methodology. Between April 2007 and January 2013, 99 patients undergoing capsule endoscopy (CE) were tested for anti-H. pylori immunoglobulin G antibody (Hp-IgG) using an enzyme-linked immunosorbent assay (ELISA). None of the patients had been treated for H. pylori infection or diagnosed as having Crohn’s disease or any other clinically apparent small intestinal disorders prior to the CE. Results. The overall Hp-IgG-positive rate was 26.3%. The incidence of enteritis, as diagnosed by CE, tended to be lower in the Hp-IgG-positive patients (23.1%) than in the Hp-IgG-negative patients (38.4%) (). When patients receiving aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs), well-known causes of enteritis, were excluded, the incidence of enteritis in the Hp-IgG-positive patients (11.7%) was significantly lower than that in the Hp-IgG-negative patients (43.7%) (). A binomial logistic regression analysis revealed a significant negative relationship between Hp-IgG positivity and the presence of enteritis in patients receiving neither aspirin nor NSAIDs (). Conclusions. Our data indicated that H. pylori positivity was inversely associated with the prevalence of enteritis.
Membrane Guided Regeneration in Periodontal Tissues
Authors: Rajpal Jaisika , Arora Aakash , Prasad Ruchika , Gupta Madhav Mukund
Published: September 2013

Periodontal regeneration is the restoration of lost periodontium or supporting tissues and includes the formation of new alveolar bone, new cementum and new periodontal ligament. The concept of GTR is based on the exclusion of gingival connective tissue cells and prevention of epithelial down growth into the wound, thereby allowing cells with regenerative potential (PDL and bone cells) to enter the wound first. GTR consists of placing barriers of different types to cover the bone and periodontal ligament thus temporarily separating them from gingival epithelium. Excluding the epithelium and gingival connective tissue from the root surface during the post-surgical healing phase not only prevent epithelial migration into the wound but also favors repopulation of the area by cells from the periodontal ligament and bone. Purpose and Scope -This review discusses the rationale for using guided tissue regeneration therapy. The review not only attempts to clarify the concept of selective tissue regeneration using non-resorbable and resorbable barriers, but to discuss differences in healing events after treatment with the two types of barriers together with their significance in periodontal therapy. At present, barrier membranes have potential clinical use in promoting periodontal tissue regeneration if patients to be so treated are selected appropriately. Research is still necessary to determine the critical period for guiding the ingrowth of new attachment forming cells and also to further clarify the concept of GTR involving the "wrong cell type" which inhibits periodontal tissue regeneration.
Case report of ervical myelopathy due to ossification of the posterior longitudinal ligament in association with flavum ligament ossification: MRI and CT appearance
Authors: Boukobza Monique , Ušinskienė Jurgita , Letautienė Simona
Published: September 2013

Background. Our objective is to analyze the cervical spinal cord damage and spinal canal stenosis due to OPLL which usually affects the cervical spine and leads to progressive myelopathy in 50–60s in Asian population; to demonstrate the mixed type OPLL and to show OPLL specific dural penetration signs: “double- layer” and “C-sign” on imaging.
Materials and methods. Subacute cord compression developed over a 3-month period in a 43-year-old Japanese patient. Severe spinal canal narrowing was related to the mixed type OPLL at C3–C4 through C6–C7 associated to flavum ligament ossification at T3–T4. Lateral radiograph of the cervical spine showed intraspinal ossification, CT demonstrated specific dural penetration signs, and MRI disclosed spinal cord compression. Laminectomy at C3–C7 was performed and decompression of the spinal cord was confirmed by postoperative MRI.
Conclusions. Absolute cervical stenosis and association with other diseases (like calcification of flavum ligament) predispose the patient to develop more severe deficit earlier in the clinical course. Specific CT signs, “double-layer” and “C-sign”, show dural involvement. MRI is a very useful modality to identify the precise level and extent of the spinal cord injury. OPLL must be included in the differential diagnosis of subacute cervical myelopathy.
Fibro-osseous lesions of craniofacial bones in children: case reports
Authors: Vankevičiūtė Rasa Aurelija , Neverauskienė Arijanda , Lukoševičius Evaldas
Published: September 2013

Background. The aim of this article is to present rare clinical cases of craniofacial fibro-osseous lesions in pediatric patients.
Materials and methods. In this report we present 3 cases of fibroosseous craniofacial lesions in pediatric patients. Lesions of bones resembled fibrous dysplasia, dysplastic fibroma and chronic osteomyelitis which were confirmed or suspected by clinical signs, radiographic visualization methods and histopathological investigations for these patients. The diagnostic workup, treatment, follow-up procedures and a literature review are presented.
Results and conclusions. Fibro-osseous lesions of the jaws and skull manifest in a similar pattern. Conditions are easily revealed upon examination and with the help of conventional diagnostics, however, differential diagnosis using only radiological imaging is impossible. Histological findings remain a tool of choice determining the treatment strategy and outcome of the patients but it is not always available due to anatomical and functional considerations. Treatment of fibro-osseous lesions of the face and skull is highly individualized and depends on various qualities of the lesion and the patient himself. All patients received palliative symptomatic treatment to alleviate their conditions and in all cases obtaining a histology specimen and surgical intervention for treatment of the lesion was considered as a treatment option only if it was seen being safe and as least traumatic as possible because of the functional and psychological importance of the craniofacial region.
Marques françaises de luxe : effets de la délocalisation de la fabrication et du design sur les évaluations des clients
Authors: Koromyslov Maxime , Walliser Björn , Roux Elyette
Published: September 2013

En comparant deux étapes de la chaine de valeur, deux niveaux de luxe, deux types de pays de délocalisation, cette recherche constitue une des premières validations empiriques des effets de la délocalisation pour les marques françaises du luxe. Menée sur un échantillon de 278 consommateurs de marques de luxe, les résultats montrent que le transfert du design ou de la fabrication de la France vers l’étranger affecte leur qualité perçue et leur évaluation globale. L’article permet aux gestionnaires des marques de luxe de savoir sous quelles conditions et dans quelle mesure leurs marques souffrent de la délocalisation.
La motivation à être bénévole des mentors influence-t-elle la relation de mentorat ? Une étude en dyade dans un contexte d’entrepreneurs novices
Authors: St-Jean Étienne , El Agy Majda
Published: September 2013

Cette recherche explore les motivations qui amènent les mentors bénévoles à s’engager dans les structures d’accompagnement pour entrepreneurs ainsi que leurs effets sur le processus de mentorat. Dans une enquête en dyade auprès de 78 mentors et mentorés du Réseau M, nous observons que trois des six motivations étudiées permettent de développer la confiance chez le mentoré à l’égard de son mentor alors qu’une autre est en lien avec une moins grande satisfaction de celui-ci. Sachant l’importance de la confiance dans le processus de mentorat, ces résultats suggèrent aux organismes de s’intéresser aux motivations lors de la sélection des mentors.
Lymphocytes: Antigen‐Induced Gene Activation
Authors: Suárez‐Fueyo Abel , Madrenas Joaquín , Criado Gabriel
Published: September 2013

Lymphocytes are activated upon antigen (Ag) recognition by their clonotypic surface Ag receptors, TCR in the case of T cells and BCR in the case of B cells. Lymphocyte activation triggers multiple signalling cascades that converge in the cell nucleus to cause significant changes in the pattern of gene expression that determine the phenotype of activated lymphocytes and, ultimately, the type of immune response. Primary activation in T cells is coupled to rapid T‐cell cycling and progressive epigenetic changes that guide the cell down distinct T‐cell lineages, either effector (T
H
1, T
H
2, T
H
17) or regulatory (Treg), characterised by the expression of specific transcription factors and cytokines. CD8 T cells and B cells also differentiate into cytotoxic thymus‐derived lymphocytes and plasma cells, respectively, driven by specific activation in the context of CD4 T
H
cells (helper) and the cytokine microenvironment.

Key Concepts:

Lymphocyte stimulation leads to the activation of selected transcription factors depending on the type of signals.

Lymphocyte differentiation and function is directed by specific transcription factors that determine the cell lineage.

Interaction and/or collaboration of different transcription factors lead to expression or repression of different genes.

Alterations in the control of TFs activity lead to the development of autoimmune diseases and/or other pathologies.

Some TFs and the molecular pathways that control their activity are targets for the treatment of different diseases.
Relationships of Birds – Molecules versus Morphology
Authors: Torres Christopher , van Tuinen Marcel
Published: September 2013

Molecules and morphology frequently point to different phylogenies of modern birds, hence making birds unique models to study reasons for such conflicts. Molecules generally make a less biased tool for phylogenetic inference, but evolutionary interpretation of a phylogeny requires knowledge from both morphology and fossils. In the past decade, considerable progress has been made in reconciling molecular and morphological phylogenies, the examples of which are discussed here. Despite this progress and a wealth of new data now available, key features of the avian phylogenetic tree remain unresolved. This pattern more likely reflects the short time interval during which the majority of modern bird lineages diversified. Much improved insight about the early evolution of modern birds more likely will come from (1) genomic data, provided that biases at this scale are understood and (2) well‐preserved fossils that represent the stem of distinct bird lineages. At present, such data are too incomplete to resolve most key nodes in the diversification of modern birds.

Key Concepts:

Phylogenies represent the best interpretation of the evolutionary history of a chosen taxon set.

At increasing taxonomic level, both DNA sequence‐based and morphological variation are expected to increase.

DNA sequence variation at neutral markers is produced and enhanced by the process of random mutation; therefore, it is a function of time.

Morphological variation is enhanced by selection for certain phenotypes; therefore, it is a function of the environment.

Evolutionary convergence is less likely at the molecular level than at the morphological level.

If underlying changes at the molecular/morphological level are modelled appropriately (e.g. alignment, substitution bias and character weighting), reconstruction of phylogeny from either molecular or morphological data should yield the same result.

Rampant phylogenetic conflict at the ordinal level in modern birds can be explained by ordinal diversification taking place over a short time interval. During this interval, morphological key innovations were quickly selected for, but augmentation of molecular differences was small.

Phylogenetic conflict in modern birds is exacerbated by lack of molecular resolution, imperfect taxonomic sampling, uncertainty about extent of morphological homoplasy and paucity of well‐preserved fossils plesiomorphic for clades Palaeognathae, Neognathae and Neoaves.
Integrins: Signalling and Disease
Authors: Danen Erik HJ
Published: September 2013

Cell‐surface adhesion molecules of the integrin family are not a passive glue, but rather are dynamic molecules that mediate the transfer of information across the membrane in both directions. Integrin‐mediated adhesion can be regulated in response to signals by clustering and conformational changes triggered at their cytoplasmic tails. Vice versa, integrins probe chemical and physical aspects of the extracellular environment and, in concert with growth factor receptors, activate signalling pathways in response. Integrin signalling controls cell survival, cell cycle progression, and differentiation, and the dynamic regulation of integrin‐mediated adhesion structures is critical for many forms of cell migration. Lastly, integrins contribute to the pathogenesis of a diverse array of acquired and hereditary diseases, and hence represent major targets for therapeutic intervention.

Key Concepts:

Integrins are heterodimeric transmembrane receptors that mediate cell adhesion to extracellular matrix proteins and other cells.

Integrins cluster in cell–matrix or cell–cell adhesions where they assemble large multiprotein complexes including actin‐binding proteins.

Integrin‐containing adhesions contain enzymes such as FAK, Src, Rac and many others as well as their upstream activators and downstream effectors allowing local activation of cellular signalling cascades.

Through a series of conformational changes in mechanoresponsive proteins, integrin‐containing adhesions provide mechanical coupling between the environment and the cytoskeletal network.

Signalling through various growth factor receptors is amplified in response to integrin‐mediated adhesion.

The ability of integrins to modulate cellular shape and cytoarchitecture in accordance with environmental stiffness as well as their role in a variety of biochemical signal transduction cascades underlies their critical function in cell proliferation, survival, differentiation and motility.

Defective integrin function underlies several human diseases.

Integrins represent potential drug targets and therapeutic strategies based on interference with integrin‐mediated adhesion have entered clinical trials.