bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive self‐calibrating iterative GRAPPA reconstruction
Authors: Park Suhyung , Park Jaeseok
Published: October 2011

Parallel magnetic resonance imaging in k‐space such as generalized auto‐calibrating partially parallel acquisition exploits spatial correlation among neighboring signals over multiple coils in calibration to estimate missing signals in reconstruction. It is often challenging to achieve accurate calibration information due to data corruption with noises and spatially varying correlation. The purpose of this work is to address these problems simultaneously by developing a new, adaptive iterative generalized auto‐calibrating partially parallel acquisition with dynamic self‐calibration. With increasing iterations, under a framework of the Kalman filter spatial correlation is estimated dynamically updating calibration signals in a measurement model and using fixed‐point state transition in a process model while missing signals outside the step‐varying calibration region are reconstructed, leading to adaptive self‐calibration and reconstruction. Noise statistic is incorporated in the Kalman filter models, yielding coil‐weighted de‐noising in reconstruction. Numerical and in vivo studies are performed, demonstrating that the proposed method yields highly accurate calibration and thus reduces artifacts and noises even at high acceleration. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
A novel augmented Lagrangian‐based formulation for upper‐bound limit analysis
Authors: Vicente da Silva M. , Antão A. N.
Published: October 2011

This paper describes a novel upper‐bound formulation of limit analysis. This formulation is an innovative variant of an existing two‐field mixed formulation based on the augmented Lagrangian method also developed by the authors. A natural approach is used to describe the deformation of each finite element. Furthermore, and in contrast to the previous formulation, two independent field approximations are now both used to define the velocity field, defined globally and at element level. It is shown that this feature allows a governing system of uncoupled linear equations to be obtained. Some numerical examples in plane strain conditions are presented in order to illustrate the current model performance. In conclusion, the potential and advantages of this new approach are discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Application of spectral filtering to discontinuous Galerkin methods on triangulations
Authors: Meister A. , Ortleb S. , Sonar Th.
Published: October 2011

We adapt the spectral viscosity (SV) formulation implemented as a modal filter to a discontinuous Galerkin (DG) method solving hyperbolic conservation laws on triangular grids. The connection between SV and spectral filtering, which is undertaken for the first time in the context of DG methods on unstructured grids, allows to specify conditions on the filter strength regarding time step choice and mesh refinement. A crucial advantage of this novel damping strategy is its low computational cost. We furthermore obtain new error bounds for filtered Dubiner expansions of smooth functions. While high order accuracy with respect to the polynomial degree N is proven for the filtering procedure in this case, an adaptive application is proposed to retain the high spatial approximation order. Although spectral filtering stabilizes the scheme, it leaves weaker oscillations. Therefore, as a postprocessing step, we apply the image processing technique of digital total variation (DTV) filtering in the new context of DG solutions and prove conservativity in the limit for this filtering procedure. Numerical experiments for scalar conservation laws confirm the designed order of accuracy of the DG scheme with adaptive modal filtering for polynomial degrees up to 8 and the viability of spectral and DTV filtering in case of shocks. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2011
Cell–matrix interactions in muscle disease
Authors: Carmignac Virginie , Durbeej Madeleine
Published: October 2011

The extracellular matrix (ECM) provides a solid scaffold and signals to cells through ECM receptors. The cell–matrix interactions are crucial for normal biological processes and when disrupted they may lead to pathological processes. In particular, the biological importance of ECM–cell membrane–cytoskeleton interactions in skeletal muscle is accentuated by the number of inherited muscle diseases caused by mutations in proteins conferring these interactions. In this review we introduce laminins, collagens, dystroglycan, integrins, dystrophin and sarcoglycans. Mutations in corresponding genes cause various forms of muscular dystrophy. The muscle disorders are presented as well as advances toward the development of treatment. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The cellular pathology of lysosomal diseases
Authors: Cox Timothy M , Cachón‐González M Begoña
Published: October 2011

With a constitutive recycling function and the capacity to digest exogenous material as well as endogenous organelles in the process of autophagy, lysosomes are at the heart of the living cell. Dynamic interactions with other cellular components ensure that the lysosomal compartment is a central point of convergence in countless diverse diseases. Inborn lysosomal (storage) diseases represent about 70 genetically distinct conditions, with a combined birth frequency of about 1 in 7500. Many are associated with macromolecular storage, causing physical disruption of the organelle and cognate structures; in neurons, ectopic dendritogenesis and axonal swelling due to distension with membraneous tubules and autophagic vacuoles are observed. Disordered autophagy is almost universal in lysosomal diseases but biochemical injury due to toxic metabolites such as lysosphingolipid molecules, abnormal calcium homeostasis and endoplasmic reticulum stress responses and immune‐inflammatory processes occur. However, in no case have the mechanistic links between individual clinico‐pathological manifestations and the underlying molecular defect been precisely defined. With access to the external fluid‐phase and intracellular trafficking pathways, the lysosome and its diseases are a focus of pioneering investment in biotechnology; this has generated innovative orphan drugs and, in the case of Gaucher's disease, effective treatment for the haematological and visceral manifestations. Given that two‐thirds of lysosomal diseases have potentially devastating consequences in the nervous system, future therapeutic research will require an integrative understanding of the unitary steps in their neuro pathogenesis. Informative genetic variants illustrated by patients with primary defects in this organelle offer unique insights into the central role of lysosomes in human health and disease. We provide a conspectus of inborn lysosomal diseases and their pathobiology; the cryptic evolution of events leading to irreversible changes may be dissociated from the cellular storage phenotype, as revealed by the outcome of therapeutic gene transfer undertaken at different stages of disease. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Microtubule‐binding protein CLIP‐170 is a mediator of paclitaxel sensitivity
Authors: Sun Xiaodong , Li Dengwen , Yang Yunfan , Ren Yuan , Li Jingyu , Wang Zaizhu , Dong Bin , Liu Min , Zhou Jun
Published: October 2011

CLIP‐170 is a microtubule‐binding protein and participates in diverse microtubule‐associated cellular activities by regulating microtubule dynamics. Here we provide evidence that CLIP‐170 is a mediator of the sensitivity of the anti‐microtubule drug paclitaxel in breast cancer. In vitro cell proliferation assays reveal that CLIP‐170 expression in breast cancer cell lines correlates with their sensitivity to paclitaxel. In addition, CLIP‐170 expression in clinical samples of breast cancer correlates with the pathological response of tumours to paclitaxel‐containing chemotherapy. Mitotic index and caspase‐3 activity analyses reveal that CLIP‐170 increases the abilities of paclitaxel to block cell cycle progression at mitosis and to induce apoptosis in breast cancer cells. By microtubule sedimentation assay and binding affinity analysis, we further find that CLIP‐170 promotes paclitaxel binding to microtubules. In vitro tubulin polymerization assay shows that CLIP‐170 enhances the activity of paclitaxel to promote microtubule assembly. These results demonstrate that CLIP‐170 mediates paclitaxel sensitivity in breast cancer via a microtubule‐dependent mechanism. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Activated growth signaling pathway expression in Ewing sarcoma and clinical outcome
Authors: Mora Jaume , Rodríguez Eva , de Torres Carmen , Cardesa Teresa , Ríos José , Hernández Teresa , Cardesa Antonio , de Alava Enrique
Published: October 2011

Background

In Ewing sarcoma (EWS) most of the research on signaling pathways has been performed on cell lines or animal models. The objective of the current study was to determine the relation between clinical outcome and the expression of proteins involved in active growth signaling pathways.

Methods

A paraffin‐embedded microarray of 45 human primary EWS tissue specimens was stained with the antibodies against c‐KIT, AKT, p‐AKT, p‐mTOR, IGF‐1R, IGFBP‐3, MAPK, p27KIP1, and p70S6 kinase. Immunohistochemical staining was correlated with patient overall survival (OS).

Results

In the univariate analysis 3 variables showed statistical significance to predict survival: presence of metastasis, p‐mTOR, and p27KIP1. A positive stain for p‐mTOR (hazard ratio of 4.74 [95% CI (57, 121)]) was significantly (log‐rank test with a P = 0.029) associated with better OS. Also, a positive stain for p27KIP1 (hazard ratio of 6.87 [95% CI (77, 136)] was significantly (log‐rank test with a P = 0.009) associated with better OS. Multivariate analysis showed metastasis (HR: 4.3; 95% CI: 0.99, 19; P = 0.05), p‐mTOR (HR: 4.8 with 95% CI: 0.6, 38; P = 0.13) and p27 (HR: 5.3; 95% CI: 1.37, 20; P = 0.01) as independent prognostic factors of outcome.

Conclusions

In our series, p‐mTOR and p27KIP1 protein overexpression were independently associated with better survival. Pediatr Blood Cancer 2012; 58: 532–538. © 2011 Wiley Periodicals, Inc.
Aggressive peripheral CD70‐positive t‐cell lymphoma associated with severe chronic active EBV infection
Authors: Shaffer Donald R. , Sheehan Andrea M. , Yi Zhongzhen , Rodgers Cheryl C. , Bollard Catherine M. , Brenner Malcolm K. , Rooney Cliona M. , Heslop Helen E. , Gottschalk Stephen
Published: October 2011

Severe chronic active Epstein–Barr virus infection (CAEBV) in T or NK cells is a rare complication of latent EBV infection. CAEBV associated T‐cell lymphoproliferative disease (LPD) consists of polyclonal lesions as well as aggressive lymphomas. Here, we report such a patient. In addition, we show that this primary CAEBV associated T‐cell lymphoma expresses CD70 and is sensitive to killing by CD70‐specific T cells, identifying CD70 as a potential immunotherapeutic target for CAEBV‐associated T‐cell lymphoma. Pediatr Blood Cancer 2012;59:758–761. © 2011 Wiley Periodicals, Inc.
Correlation between processing conditions and fiber breakage during compounding of glass fiber‐reinforced polyamide
Authors: Inceoglu Funda , Ville Julien , Ghamri Nessim , Pradel Jean Laurent , Durin Audrey , Valette Rudy , Vergnes Bruno
Published: October 2011

The inter‐relationship between processing conditions and fiber breakage has been studied for glass fiber‐reinforcedpolyamide 12, prepared using (i) an internal batch mixer, (ii) a laboratory scale corotating twin screw extruder, and (iii) an industrial scale twin screw extruder. The average fiber lengths and fiber length distributions were measured for various compounding conditions (screw or rotor speed, mixing time, feed rate). Experimental results have shown that fiber breakage depends on both screw speed and mixing time, the later being controlled, in an extruder, by the feed rate. For a given compounding system (batch mixer or twin screw extruder), the energy input (specific mechanical energy, SME) during the compounding process is found to be a reliable parameter, which governs fiber length (average, minimal, and maximal) evolution. Experimental data are correctly described with a model defining change in fiber length as a function of SME. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Amphiphilic poly(acrylonitrile‐co‐acrylic acid)/silver nanocomposite additives for the preparation of antibiofouling membranes with improved properties
Authors: Jewrajka Suresh K. , Haldar Soumya
Published: October 2011

This work focuses the preparation of polymer‐silver nanocomposite (Ag‐Nc) dense free standing films and nonwoven fabric supported porous ultrafiltration membranes with improved membrane performance and long‐term antibiofouling properties. New polyacrylonitrle‐based Ag‐Ncs, poly(acrylonitrle‐co‐acrylic acid)‐silver (PAN‐co‐PAA‐Ag) containing 35 wt% of PAA and 0.35–0.65 wt% of Ag‐nanoparticles (Nps) were synthesized and used as additives for the fabrication of PAN‐based (PAN/PAN‐co‐PAA‐Ag) Ag‐Nc porous membranes and dense‐free standing films. The Ag‐Nps were homogeneously dispersed into the PAN‐co‐PAA random copolymer matrix. The prepared membranes (PAN/PAN‐co‐PAA‐Ag) showed combination of properties such as excellent antimicrobial activity towards both Gram Negative and Gram Positive bacteria (prevent biofilm formation), improved protein antifouling properties, and enhanced water flux when compared to neat PAN‐based membrane. The antimicrobial properties, hydrophilicity, and the water flux of various membranes follow the following order for the membranes PAN < PAN/PAN‐co‐PAA < PAN/PAN‐co‐PAA‐Ag. Extraneous addition of small amount of polyethylene glycol (PEG) during preparation of additive i.e. [PEG + PAN‐co‐PAA]‐Ag further improved the protein antifouling properties of the PAN‐based membranes (PAN/[PEG+PAN‐co‐PAA‐Ag]). The dispersed Ag‐Nps were stable on the surface of phase inverted membranes for long period of time and PAN/PAN‐co‐PAA‐Ag membranes are therefore suitable for long‐term water treatment under bacterial environment. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Are all quantitative postmarketing signal detection methods equal? Performance characteristics of logistic regression and Multi‐item Gamma Poisson Shrinker
Authors: Berlin Conny , Blanch Carles , Lewis David J. , Maladorno Dionigi D. , Michel Christiane , Petrin Michael , Sarp Severine , Close Philippe
Published: October 2011

Purpose

The detection of safety signals with medicines is an essential activity to protect public health. Despite widespread acceptance, it is unclear whether recently applied statistical algorithms provide enhanced performance characteristics when compared with traditional systems. Novartis has adopted a novel system for automated signal detection on the basis of disproportionality methods within a safety data mining application (Empirica™ Signal System [ESS]). ESS uses two algorithms for routine analyses: empirical Bayes Multi‐item Gamma Poisson Shrinker and logistic regression (LR).

Methods

A model was developed comprising 14 medicines, categorized as “new” or “established.” A standard was prepared on the basis of safety findings selected from traditional sources. ESS results were compared with the standard to calculate the positive predictive value (PPV), specificity, and sensitivity. PPVs of the lower one‐sided 5% and 0.05% confidence limits of the Bayes geometric mean (EB05) and of the LR odds ratio (LR0005) almost coincided for all the drug‐event combinations studied.

Results

There was no obvious difference comparing the PPV of the leading Medical Dictionary for Regulatory Activities (MedDRA) terms to the PPV for all terms. The PPV of narrow MedDRA query searches was higher than that for broad searches. The widely used threshold value of EB05 = 2.0 or LR0005 = 2.0 together with more than three spontaneous reports of the drug‐event combination produced balanced results for PPV, sensitivity, and specificity.

Conclusions

Consequently, performance characteristics were best for leading terms with narrow MedDRA query searches irrespective of applying Multi‐item Gamma Poisson Shrinker or LR at a threshold value of 2.0. This research formed the basis for the configuration of ESS for signal detection at Novartis. Copyright © 2011 John Wiley & Sons, Ltd.
Turn‐on chemosensors for silver ions based on oligomers with diaza‐16‐crown 6‐ether receptors and aromatic fluorophore end groups
Authors: Yamaguchi Isao , Shingai Saki
Published: October 2011

The reaction of N‐(2,4‐dinitrophenyl)pyridinium chloride (1), diaza‐18‐crown 6‐ether (DA18C6) and 2,5‐bis(aminophenyl)‐1,3,4‐oxadiazole (2) caused the opening of the pyridinium ring and yielded an ionic oligomer (oligomer‐1) comprising a 5‐DA18C6‐penta‐2,4‐dienylideneammonium chloride main chain and 2‐(4‐aminophenyl)‐5‐phenyl‐1,3,4‐oxadiazole or 2‐(4‐N‐phenylpyridinium)‐5‐phenyl‐1,3,4‐oxadiazole end groups. Accordingly, the reaction of 1, DA18C6 and 2,7‐diaminofluorene (3) yielded oligomer‐2. The structures of oligomer‐1 and oligomer‐2 were determined by comparing their 1H NMR spectra with those of model compounds, which were synthesized by the 1:1 reaction of 1 with 2 or 3. Oligomer‐1 and oligomer‐2 exhibited weak bluish‐green photoluminescence (PL) before the inclusion of Ag+ in the DA18C6 receptor, after which they exhibited strong bluish‐green PL. These observations can be explained by the occurrence of photoinduced electron transfer in the oligomers. Copyright © 2011 Society of Chemical Industry
Predicting nucleic acid binding interfaces from structural models of proteins
Authors: Dror Iris , Shazman Shula , Mukherjee Srayanta , Zhang Yang , Glaser Fabian , Mandel‐Gutfreund Yael
Published: October 2011

The function of DNA‐ and RNA‐binding proteins can be inferred from the characterization and accurate prediction of their binding interfaces. However, the main pitfall of various structure‐based methods for predicting nucleic acid binding function is that they are all limited to a relatively small number of proteins for which high‐resolution three‐dimensional structures are available. In this study, we developed a pipeline for extracting functional electrostatic patches from surfaces of protein structural models, obtained using the I‐TASSER protein structure predictor. The largest positive patches are extracted from the protein surface using the patchfinder algorithm. We show that functional electrostatic patches extracted from an ensemble of structural models highly overlap the patches extracted from high‐resolution structures. Furthermore, by testing our pipeline on a set of 55 known nucleic acid binding proteins for which I‐TASSER produces high‐quality models, we show that the method accurately identifies the nucleic acids binding interface on structural models of proteins. Employing a combined patch approach we show that patches extracted from an ensemble of models better predicts the real nucleic acid binding interfaces compared with patches extracted from independent models. Overall, these results suggest that combining information from a collection of low‐resolution structural models could be a valuable approach for functional annotation. We suggest that our method will be further applicable for predicting other functional surfaces of proteins with unknown structure. Proteins 2012. © 2011 Wiley Periodicals, Inc.
Engineered interface using a hydroxyl group‐free polymeric buffer layer onto a TiO2 nanocomposite film for improving the electrical properties in a low‐voltage operated organic transistor
Authors: Bae Jin‐Hyuk , Choi Yoonseuk
Published: October 2011

We demonstrate the effect of engineered interfaces by introducing different classes of polymeric buffer layers onto a titanium oxide (TiO2) nanocomposite film on the density of interfacial trap sites and corresponding mobility in low‐voltage‐operated organic field‐effect transistors. The organic field‐effect transistors were fabricated using pentacene as an organic semiconductor layer and a high dielectric TiO2 nanocomposite film for low‐voltage operation stacked with two different kinds of thin polymers, one of which is hydroxyl group‐existing polyvinyl phenol and the other is hydroxyl group‐free polyvinyl cinnamate. By using the hydroxyl group‐free buffer layer, the interfacial trap density is found to be much decreased than that for the hydroxyl group‐existing buffer layer. In addition, the mobility for the polyvinyl cinnamate used case, shows significantly increased value by at least one of magnitude compared to the case of no buffer layer. It is found that a hydroxyl group‐free polymeric layer produces a more effective surface, which leads to high electrical properties and less electrochemical traps at the interface in the organic devices. Copyright © 2011 John Wiley & Sons, Ltd.
Mathematical Simulation of Flow Field for Molten Steel in an 80–ton Single Snorkel Vacuum Refining Furnace
Authors: Yang Xue‐Min , Zhang Meng , Wang Fei , Duan Jian‐Ping , Zhang Jian
Published: October 2011

The three–dimensional flow field of molten steel in an 80–ton single snorkel vacuum refining furnace has been mathematically simulated to attain the optimal configuration and operation parameters, such as the bottom blowing Ar flow rate, the eccentric position of bottom blowing Ar port at ladle bottom, the single snorkel inner diameter, and the single snorkel immersion depth into molten steel. The mathematical simulation results show that a stable flow field of molten steel can be achieved in 70–second; meanwhile, the maximal circulation intensity of molten steel in the 80–ton single snorkel vacuum refining furnace can be found on a cross–section with y as 0 mm based on the middle of ladle bottom as circular point of the Cartesian space coordinate under the condition of injecting Ar gas on x coordinate considering the asymmetry of flow field for molten steel in the single snorkel vacuum refining furnace. The recommended parameters of the 80–ton single snorkel vacuum refining furnace with ideal circulation intensity as 970.1 kg/s are the bottom blowing Ar flow rate as 450–500 Nl/min, the eccentric position of bottom blowing Ar port as 250 mm, the single snorkel inner diameter as 1000 mm, and the single snorkel immersion depth as 500 mm.
Clusters in irregular areas and lattices
Authors: Wieczorek William F. , Delmerico Alan M. , Rogerson Peter A. , Wong David W.S.
Published: October 2011

Geographic areas of different sizes and shapes of polygons that represent counts or rate data are often encountered in social, economic, health, and other information. Often political or census boundaries are used to define these areas because the information is available only for those geographies. Therefore, these types of boundaries are frequently used to define neighborhoods in spatial analyses using geographic information systems and related approaches such as multilevel models. When point data can be geocoded, it is possible to examine the impact of polygon shape on spatial statistical properties, such as clustering. We utilized point data (alcohol outlets) to examine the issue of polygon shape and size on visualization and statistical properties. The point data were allocated to regular lattices (hexagons and squares) and census areas for zip‐code tabulation areas and tracts. The number of units in the lattices was set to be similar to the number of tract and zip‐code areas. A spatial clustering statistic and visualization were used to assess the impact of polygon shape for zip‐ and tract‐sized units. Results showed substantial similarities and notable differences across shape and size. The specific circumstances of a spatial analysis that aggregates points to polygons will determine the size and shape of the areal units to be used. The irregular polygons of census units may reflect underlying characteristics that could be missed by large regular lattices. Future research to examine the potential for using a combination of irregular polygons and regular lattices would be useful. WIREs Comp Stat 2012, 4:67–74. doi: 10.1002/wics.196

This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Clustering and Classification

Statistical Learning and Exploratory Methods of the Data Sciences > Exploratory Data Analysis
Schizophrenia: A five-year follow-up of patient outcome following psycho-education for caregivers
Authors: McWilliams S. , Hill S. , Mannion N. , Fetherston A. , Kinsella A. , O’Callaghan E.
Published: October 2011

Introduction

There is evidence that psycho-education courses for caregivers of individuals with schizophrenia improve the short-term outcome of the condition. However, most of the outcome studies are limited to two-year follow-up.

Materials and methods

This study is a five-year retrospective case-control follow-up of an original cohort of 63 patients and their 101 caregivers who completed a six-week Caregiver Psycho-education Programme (CPP) for schizophrenia and psychosis between 2002 and 2005, and 60 controls, matched for age, gender and severity of their psychotic illness.

Results

Patients whose caregivers learned more from the six-week psycho-education course had a significantly longer time to relapse (P = 0.04) and a significantly shorter length of stay during their first relapse (P < 0.05). Patients whose caregivers attended the six-week psycho-education course (regardless of how much the caregivers learned) had a significantly better outcome than controls. This included a significantly smaller number of relapses (P < 0.01), longer time to relapse (P < 0.01), shorter length of stay during their first relapse (P < 0.01) and smaller number of bed days over five years (P < 0.01). The odds ratio of controls relapsing, although insignificant at one year, was 4.13 (1.85–9.21) at five years. Outcome was not affected by either the numbers of caregivers attending for each patient, or caregiver gender.

Discussion and conclusions

This study, which is among the first to examine outcome over five years, supports the efficacy of psycho-education for caregivers in improving outcome for patients. Caregivers should be encouraged to take up psycho-education where it is available.
Neurites outgrowth and amino acids levels in goldfish retina under hypo‐osmotic or hyper‐osmotic conditions
Authors: Cubillán Lisbeth , Obregón Francisco , Lima Lucimey
Published: October 2011

Amino acids are known to play relevant roles as osmolytes in various tissues, including the retina. Taurine is one of these active molecules. In addition, taurine stimulates outgrowth from the goldfish retina by mechanisms that include extracellular matrix, calcium fluxes and protein phosphorylation. The present report aims to explore the effect of medium osmolarity on goldfish retinal outgrowth and the possible modifications produced by changing eye osmolarity on amino acid levels in the retina. Goldfish retinal explants were obtained 10 days after crush of the optic nerve and cultured under iso‐, hypo‐ or hyper‐osmotic conditions. Hypo‐osmotic medium was prepared by diluting the solutions 10% twice, preserving fetal calf serum concentration. Hyper‐osmotic medium was done by adding 50 or 100 mM urea or mannitol. Evaluation of length and density of neurites was performed 5 days after plating. Outgrowth was reduced in hypo‐ and in hyper‐osmotic conditions. Taurine, 4 mM, increased length and density of neurites in iso‐osmotic, and produced stimulatory effects under both hyper‐osmotic conditions. The in vivo modification of osmolarity by intraocular injection of water or 100 mM urea modified levels of free amino acids in the retina. Taurine and aspartate retinal levels increased in a time‐dependent manner after hypo‐ and hyper‐osmotic solution injections. Serine, threonine, arginine, γ‐aminobutyric acid, alanine and tyrosine were elevated in hyper‐osmotic conditions. Outgrowth in vitro, after in vivo osmolarity changes, was higher in the absence of taurine, but did not increase in the presence of the amino acid. The fact that certain outgrowth took place in these conditions support that the impairment was not due to tissue damage. Rather, the effects might be related to the cascade of kinase events described during osmolarity variations. The time course under these conditions produced adjustments in ganglion cells probably related to taurine transporter, and phosphorylation of specific proteins.
Miscible displacements in Hele-Shaw cells: three-dimensional Navier–Stokes simulations
Authors: Oliveira Rafael M. , Meiburg Eckart
Published: October 2011

Three-dimensional Navier–Stokes simulations of viscously unstable, miscible Hele-Shaw displacements are discussed. Quasisteady fingers are observed whose tip velocity increases with the Péclet number and the unfavourable viscosity ratio. These fingers are widest near the tip, and become progressively narrower towards the root. The film of resident fluid left behind on the wall decreases in thickness towards the finger tip. The simulations reveal the detailed mechanism by which the initial spanwise vorticity of the base flow, when perturbed, gives rise to the cross-gap vorticity that drives the fingering instability in the classical Darcy sense. Cross-sections at constant streamwise locations reveal the existence of a streamwise vorticity quadrupole along the length of the finger. This streamwise vorticity convects resident fluid from the wall towards the centre of the gap in the cross-gap symmetry plane of the finger, while it transports injected fluid laterally away from the finger centre within the mid-gap plane. In this way, it results in the emergence of a longitudinal, inner splitting phenomenon some distance behind the tip that has not been reported previously. This inner splitting mechanism, which leaves the tip largely intact, is fundamentally different from the familiar tip-splitting mechanism. Since the inner splitting owes its existence to the presence of streamwise vorticity and cross-gap velocity, it cannot be captured by gap-averaged equations. It is furthermore observed that the role of the Péclet number in miscible displacements differs in some ways from that of the capillary number in immiscible flows. Specifically, larger Péclet numbers result in wider fingers, while immiscible flows display narrower fingers for larger capillary numbers. Furthermore, while higher capillary numbers are known to promote tip-splitting, inner splitting is delayed for larger Péclet numbers.
Correlation of a feline muscle mass score with body composition determined by dual-energy X-ray absorptiometry
Authors: Michel Kathryn E. , Anderson Wendy , Cupp Carolyn , Laflamme Dorothy P.
Published: October 2011

Body condition scoring (BCS) systems primarily assess body fat. Both overweight and underweight animals may have loss of lean tissue that may not be noted using standard BCS systems. Catabolism of lean tissue can occur rapidly, may account for a disproportionate amount of body mass loss in sick cats and can have deleterious consequences for outcome. Therefore, along with evaluation of body fat, patients should undergo evaluation of muscle mass. The aims of the present study were first to evaluate the repeatability and reproducibility of a 4-point feline muscle mass scoring (MMS) system and second to assess the convergent validity of MMS by dual-energy X-ray absorptiometry (DXA). MMS was as follows: 3, normal muscle mass; 2, slight wasting; 1, moderate wasting; 0, severe wasting. For the first aim, forty-four cats were selected for evaluation based on age and BCS, and for the second aim, thirty-three cats were selected based on age, BCS and MMS. Cats were scored by ten different evaluators on three separate occasions. Body composition was determined by DXA. Inter- and intra-rater agreement were assessed using kappa analysis. Correlation between MMS and BCS, age, percentage lean body mass and lean body mass (LBM) was determined using Spearman's rank-order correlation. The MMS showed moderate inter-rater agreement in cats that scored normal or severely wasted (κ = 0·48–0·53). Intra-rater agreement was substantial (κ = 0·71–0·73). The MMS was significantly correlated with BCS (r0·76,P < 0·0001), age (r− 0·75,P < 0·0001), LBM (g) (r0·62,P < 0·0001) and percentage LBM (r− 0·49,P < 0·0035). Additional investigation is needed to determine whether the MMS can be refined and to assess its clinical applicability.
Increased antioxidant capacity in the plasma of dogs after a single oral dosage of tocotrienols
Authors: Raila Jens , Rohn Sascha , Schweigert Florian J. , Abraham Getu
Published: October 2011

The intestinal absorption of tocotrienols (TCT) in dogs is, to our knowledge, so far unknown. Adult Beagle dogs (n 8) were administered a single oral dosage of a TCT-rich fraction (TRF; 40 mg/kg body weight) containing 32 % α-TCT, 2 % β-TCT, 27 % γ-TCT, 14 % δ-TCT and 25 % α-tocopherol (α-TCP). Blood was sampled at baseline (fasted), 1, 2, 3, 4, 5, 6, 8 and 12 h after supplementation. Plasma and chylomicron concentrations of TCT and α-TCP were measured at each time point. Plasma TAG were measured enzymatically, and plasma antioxidant capacity was assessed by the Trolox equivalent antioxidant capacity assay. In fasted dogs, levels of TCT were 0·07 (sd 0·03) μmol/l. Following the administration of the TRF, total plasma TCT peaked at 2 h (7·16 (sd 3·88) μmol/l; P < 0·01) and remained above baseline levels (0·67 (sd 0·44) μmol/l; P < 0·01) at 12 h. The TCT response in chylomicrons paralleled the increase in TCT in plasma with a maximum peak (3·49 (sd 2·06) μmol/l; P < 0·01) at 2 h post-dosage. α-TCP was the major vitamin E detected in plasma and unaffected by TRF supplementation. The Trolox equivalent values increased from 2 h (776 (sd 51·2) μmol/l) to a maximum at 12 h (1130 (sd 7·72) μmol/l; P < 0·01). The results show that TCT are detected in postprandial plasma of dogs. The increase in antioxidant capacity suggests a potential beneficial role of TCT supplementation in the prevention or treatment of several diseases in dogs.
Faecal IgA concentration is influenced by age in dogs
Authors: Zaine Leandro , Ferreira Chayanne , de O. S. Gomes Marcia , Monti Mariana , Tortola Leticia , Vasconcellos Ricardo S. , Carciofi Aulus C.
Published: October 2011

Data comparing age-related alterations in faecal IgA concentrations of dogs are not available in the literature. The present study aimed to compare the faecal concentrations of IgA in puppies, mature and senior dogs. A total of twenty-four beagle dogs were used, including eight puppies (5 months old, four females and four males), eight mature (4·6 years old, eight males) and eight senior dogs (10·6 years old, three males and five females). Fresh faecal samples were collected from each dog for three consecutive days and pooled by animal. After saline extraction, IgA content was measured by ELISA. Data were analysed by one-way ANOVA, and means were compared with Tukey's test (P < 0·05). Results showed that puppies have lower faecal IgA concentrations than mature dogs (P < 0·05); senior animals presented intermediary results. The reduced faecal IgA concentration in puppies is consistent with the reduced serum and salivary IgA concentrations reported previously, suggesting a reduced mucosal immunity in this age group. Although some studies have found an increased serum IgA concentration in older dogs, this may differ from the intestinal secretion of IgA, which appears to be lower in some senior animals (four of the eight dogs studied).
Five-week dietary exposure to dry diets alters the faecal bacterial populations in the domestic cat (Felis catus)
Authors: Bermingham Emma N. , Kittelmann Sandra , Henderson Gemma , Young Wayne , Roy Nicole C. , Thomas David G.
Published: October 2011

The effects of wet (canned) or dry (kibbled) diets on faecal bacterial populations in the cat were investigated in eight domestic short-haired cats (four males and four females; averaging 6 years of age and 3·4 kg) in a nested design. The cats were fed ad libitum a commercially available wet diet (moisture 82·0 %, crude protein 51·7 %, fat 28·9 %, carbohydrate (CHO) 8·9 % and ash 10·6 % DM) for 5 weeks. On the fifth week, individual feed intakes and faecal outputs were determined. Fresh faecal samples were collected twice daily, mixed for homogeneity, subsampled and stored at − 85°C until analysis. The cats were then switched to a commercially available dry diet (moisture 8·5 %, crude protein 33·0 %, fat 11·0 %, CHO 49·4 % and ash 6·6 % DM) for 5 weeks, and fresh faeces were sampled as described previously. Energy intake tended to be higher in cats fed dry diets (P < 0·10), but body weight was similar between the two feeding periods (P>0·05). Denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA genes amplified from DNA extracted from faeces was performed. The unweighted pair group method with arithmetic mean cluster analysis of bacterial community profiles using Pearson's correlation revealed diet-specific clustering when the same cats were fed on either a dry or a wet diet (dissimilarity between the groups, 88·6 %; P < 0·001). Subsequent cloning and sequencing of five selected distinct DGGE bands indicated that members of the Pelomonas and Fusobacteriaceae were influenced by a short-term change in diet format. This suggests that 5-week dietary exposure is sufficient to alter gastrointestinal microflora.
Do feeding practices of obese dogs, before weight loss, affect the success of weight management?
Authors: German Alexander J. , Holden Shelley L. , Gernon Lucy J. , Morris Penelope J. , Biourge Vincent
Published: October 2011

Dietary factors (e.g. feeding treats and table scraps) can predispose to obesity in dogs, but it is not known whether they also influence success of weight loss. Therefore, the aim of the present study was to determine which pre-weight-loss factors were associated with outcome of their weight management regimen in dogs. Information from ninety-five dogs attending the Royal Canin Weight Management Clinic, University of Liverpool (Wirral, UK), was reviewed. The effect of different food types (e.g. dry, wet and home-prepared), feeding practices (e.g. method of portion size calculation and number of meals per day) and use of treats was assessed on outcome measures of the weight management regimen. Before weight loss, most owners (sixty-three out of ninety-five, 66 %) fed twice daily, used complete dry food (seventy-two out of ninety-five, 76 %) and calculated portion size either by measuring cup (thirty-six out of ninety-five, 38 %) or by visual estimation (thirty-seven out of ninety-five, 39 %). Feeding treats was common and included purchased treats (forty-one out of ninety-five, 43 %), table scraps (twenty-four out of ninety-five, 25 %), pet food (eighty-three out of ninety-five, 87 %) and human food (eighty-one out of ninety-five, 85 %). The majority of feeding practices did not influence any outcome measure for the weight-loss period (P>0·05 for all). However, metabolisable energy intake during weight loss was significantly higher in dogs fed dry food (P = 0·047) and lower in dogs fed purchased snacks before weight loss (P = 0·036). Thus, most pre-weight-loss factors have limited effect on outcomes of weight loss. The significance of the associations identified between feeding of dried food and purchased treats, and weight-loss energy intake, requires further study.
Water content of faeces is higher in the afternoon than in the morning in morning-fed dogs fed diets containing texturised vegetable protein from soya
Authors: Hill Richard C. , Burrows Colin F. , Ellison Gary W. , Finke Mark D. , Huntington Jennifer L. , Bauer John E.
Published: October 2011

Faecal moisture content can determine whether faeces appear soft or firm, and faecal character can influence whether owners are satisfied with a dog food. In a previous study, dogs appeared to produce softer faeces after noon. The purpose of the present study was to determine whether time of defecation affected canine faecal water content. A total of eight hound dogs were fed one of four canned diets as a single meal each morning for 1 week per diet in a Latin square design. All four diets contained approximately 77 % moisture and, on a DM basis, 24 MJ/kg gross energy, 23 % crude protein, 32 % crude fat, 31 % N-free extract and 1 % crude fibre. The proportion of dietary protein from soya-derived texturised vegetable protein (TVP):beef was 0:100, 14:86, 29:71 and 57:43, respectively. Soya carbohydrate partially replaced maize starch as TVP increased. Faeces were collected by direct catch during the sixth morning and afternoon of each diet period. Mean faecal moisture content was greater in the afternoon than in the morning (79 v. 71 %; P = 0·01) and increased with dietary TVP (P ≤ 0·0001), and there was an interaction between time of day and percentage TVP (P = 0·003). Faecal moisture content differed from morning to afternoon only with TVP in the diet. Faecal wet weight was similar from morning to afternoon. This suggests that time of day and presence of TVP from soya should be taken into account when evaluating the effect of a diet on faecal form and moisture content in dogs fed once daily.
Management of struvite uroliths in dogs
Authors: Calabrò Serena , Tudisco Raffaella , Bianchi Sergio , Grossi Micaela , De Bonis Antonio , Isabella Cutrignelli Monica
Published: October 2011

Urolithiasis is a common clinical problem in dogs. Struvite and calcium oxalate are the predominant mineral types in dog urolithiasis. The aim of the present study was to compare the effect of two commercial dry foods formulated for the management of struvite urolithiasis with different anion–cation balance on urinary pH. For the trial, twelve privately owned adult dogs showing struvite urolithiasis were studied. The dogs were randomly divided into two groups (A and B) and fed two dissolving diets for 3 months. The analyses of urine were repeated six times. In both diets, the anion–cation balance was negative ( − 203 and − 192 for diets A and B, respectively). At the first urine analysis, pH values of all the dogs were close to 8·0, and bacteria were present in about 70 % of the samples and thus an antimicrobial was administered for 1 week. Both groups showed a progressive decrease in pH values, and after 2 months, in both cases, the recommended pH values for stone dissolution were achieved. From the sampling at 30 d, group A showed pH values significantly (P < 0·05) lower than group B, probably due to the lower anion–cation balance of diet A. The combination of antimicrobial and dietary therapy allowed the dissolution of struvite uroliths in both groups, even if the utilisation of the diet characterised by the lower anion–cation balance seems to decrease the urinary pH more rapidly. In this case, it seems necessary to interrupt the dietary treatment in order to avoid the risk of other diseases.
A pilot study of the body weight of pure-bred client-owned adult cats
Authors: Kienzle Ellen , Moik Katja
Published: October 2011

A total of 539 pure-bred and seventy-five cats without a pedigree were weighed and scored at cat shows or in veterinary surgeries. Data from normal-weight cats with a body condition score (BCS) of 5 (ideal) were only used. Breeds were grouped into five classes. For female cats, the mean weight for these groups were as follows: very light (2·8 kg); light (3·2 kg); medium (3·5 kg); large (4·0 kg); giant (4·9) kg. For male cats, the corresponding values were 3·6, 4·2, 4·3, 5·1 and 6·1 kg. Siamese/Oriental Shorthair were identified as a very light breed, the Norwegian Forest and the Siberian Cat as a large breed and the Maine Coon as a giant breed. Males and females of the same breed did not always belong to the same class. In some breeds, individuals of the same sex were found in two different classes. The percentage of intact overweight cats (BCS >5) was low (7 % of intact males, 3 % of intact females). Incidence of overweight in neutered cats was 50 % in males and 38 % in females. Among pedigreed cats, there were differences in the incidence of overweight in neutered cats: high in Norwegian Forest Cats (males 75 %, females 50 %) and low in Siamese/Oriental Shorthair Cats (males 25 %, females 1 %). Cats with a BCS of 6, 7 and 8 had on average 120, 154 and 214 % of the normal weight of their breed, respectively.
Physical activity level of adult cats with varied feeding frequency
Authors: Deng Ping , Grant Ryan W. , Swanson Kelly S.
Published: October 2011

The prevalence of feline obesity is influenced by numerous factors, including inactivity and overconsumption of food. The objective of the present study was to evaluate the effect of feeding frequency on physical activity in adult cats. A total of twelve healthy adult cats were used in a cross-over study consisting of 32 d. In each of the two periods, six cats were fed either two meals or four meals daily. Throughout the study, cats were fed the same diet at amounts to maintain body weight and body condition score. Cats were individually housed 4 h/d at each scheduled feeding time, while for the other 20 h, cats were group-housed to allow for voluntary physical activity in the room with a 16 h light–8 h dark cycle. Voluntary activity levels were evaluated using Actical activity collars for seven consecutive days in each period. Daily average activity level for two-meal-fed cats (20·04 (sem 2·19), activity counts/epoch (15 s)) was not different from four-meal-fed cats (20·14 (sem 2·15), activity counts/epoch (15 s); P>0·05). In conclusion, when group-housed cats are fed to maintain their body weight and body condition score, varied feeding frequency between twice and four times daily may not affect activity levels.
Maintenance energy requirement determination of cats after spaying
Authors: Mitsuhashi Yuka , Chamberlin Amy J. , Bigley Karen E. , Bauer John E.
Published: October 2011

Neutering is often associated with obesity in companion animals. However, the maintenance energy requirement (MER) for these animals has not been clearly defined. The present study investigated the MER for spayed cats whose body weights (BW) began to increase shortly after ovariohysterectomy. A total of twenty-two shorthair adult female cats were fed complete and balanced diets in amounts to maintain their BW and body condition score (BCS) before the present study. All cats were spayed and the diet was fed for 11 weeks using the same MER as previously. During these weeks, all cats gained weight. Beginning with week 12, a weight-loss regimen was initiated until each cat achieved a BCS of 5 out of 9. After each cat obtained a BCS of 5, an appropriate amount of diet was fed to maintain its BW for at least 4 weeks to determine a modified MER. Daily food consumption, weekly BW and BCS were monitored. Blood was collected before and after weight loss for plasma biochemistry profiles. BW and BCS increased by 16 % and one point (P < 0·01), respectively, during the first 11 weeks after surgery, although food consumption was constant both pre- and post-surgery. The mean MER after obtaining a BCS of 5 was 313·6 (sem23·6) kJ/BW0·67, which is 25 % lower than the current National Research Council recommendation and lower than the cat's requirement before surgery (P < 0·05). In conclusion, spaying significantly increased BW when using MER values for intact cats. Thus, 313·6 × ideal BW0·67 kJ is proposed for the MER of spayed adult cats.