Banding

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Banding

  • adjustable gastric banding
  • gastric banding
  • laparoscopic adjustable gastric banding
  • shear banding

  • Terms modified by Banding

  • banding pattern

  • Selected Abstracts


    Coarse-Grained Simulations of Elongational Viscosities, Superposition Rheology and Shear Banding in Model Core,Shell Systems

    MACROMOLECULAR THEORY AND SIMULATIONS, Issue 8 2007
    A. van den Noort
    Abstract A recently developed coarse-grain model is used to investigate nonlinear rheological properties of model core,shell systems. The influence of several model parameters on the stresses and shear rates is investigated. Continuous planar elongational flow and superposition rheology are studied and compared to simple shear flow results. With particular values of the model parameters, an initially linear velocity profile splits into many bands with different shear rates and different densities, which finally merge into just two bands stacked along the gradient direction. With the box sizes used in our simulations, stick and Lees,Edwards boundary conditions lead to qualitatively similar results, with the stick boundary simulations showing better quantitative agreement with experiments. [source]


    Late Presenters with Dextro-transposition of Great Arteries and Intact Ventricular Septum: To Train or Not to Train the Left Ventricle for Arterial Switch Operation?

    CONGENITAL HEART DISEASE, Issue 6 2009
    Noor Mohamed Parker MBChB
    ABSTRACT Objective., We report our experience in managing late presenters (older than 4 weeks) with dextro-transposition of great arteries and intact ventricular septum (d-TGA/IVS) in an effort to achieve successful arterial switch operation (ASO) in a third world setting. Design., We retrospectively reviewed the charts of all late presenters with d-TGA/IVS. Patients were divided into two groups: left ventricular training (LVT) group and non-left ventricular training (non-LVT) group. LVT group underwent pulmonary artery banding and Blalock-Taussig Shunt prior to ASO. Results., Twenty-one late presenters were included in the study. In LVT group, 11 patients with median age of 6 months (range, 1,72 months) underwent LVT. Later, 8 patients with median age of 9.25 months (range, 1.33,84 months) underwent ASO. Prior to ASO, left ventricle (LV) collapse resolved in all and left ventricle to systemic pressure (LV/SP) ratio was 0.81 (range, 0.76,0.95) in 4 patients. Two patients who had LVT for ,14 days required postoperative extracorporeal membrane oxygenation (ECMO) support due to LV dysfunction. Seven patients survived to discharge. In non-LVT group, 10 patients with median age of 2.5 months (range, 1,98 months) underwent ASO. Five patients had LV collapse, and median LV/SP ratio was 0.67 (range, 0.56,1.19) in 5 patients. Seven patients needed ECMO support. Seven patients survived to discharge. Conclusion., Late presenters with d-TGA/IVS, who have LV collapse on echocardiography and/or a LV/SP ratio <0.67 on cardiac catheterization, should be subjected to LVT preferably for duration of longer than 14 days in order to avoid potential ECMO use. [source]


    Balloon Debanding the Pulmonary Artery: In Vitro Studies and Early Clinical Experience

    CONGENITAL HEART DISEASE, Issue 4 2009
    Gareth J. Morgan MPhil
    ABSTRACT Despite increasing corrective procedures for children with congenital heart disease, there remains a place for surgical banding of the main pulmonary artery (PA). In the vast majority of cases, these bands eventually need to be removed. We examined three cases of percutaneous disruption of PA bands using balloon catheters at our institution. We also performed an in vitro study of PA band disruption mechanism and disruption pressure. Our in vitro study suggested a predictable burst pressure for PA bands over the range of diameters routinely used in pediatric practice. Of three patients who underwent interventional debanding, two patients had successful disruption of their PA bands with no reintervention at 19 months and 23 months follow up. Balloon disruption of surgical PA bands may offer a less invasive alternative to surgical band removal. In vitro analysis suggests that the burst pressure required and mechanism of disruption are predictable. [source]


    Dystrophin upregulation in pressure-overloaded cardiac hypertrophy in rats

    CYTOSKELETON, Issue 1 2003
    Masato Maeda
    Abstract Dystrophin is a cytoskeletal protein localized to the sarcolemma of skeletal and cardiac muscle, and neurons. We have recently demonstrated that a significant cardiac damage including myocytes injury, inflammation, and fibrosis, was found in dystrophin-deficient myocardium during pressure overload [Kamogawa et al., 2001: Cardiovasc Res 50:509,515]. However, little is known about how the cardiac sarcolemmal cytoskeleton produces qualitative and quantitative changes in response to pressure overload. Accordingly, we investigated dystrophin gene expression and protein accumulation during cardiac hypertrophy. Cardiac hypertrophy was produced by banding of the abdominal aorta of rats. Total RNA from the left ventricle of the heart was used for a quantitative reverse transcription-polymerase chain reaction (RT-PCR). Dystrophin mRNA expression significantly increased by 33 ± 18% at 1 day (P < 0.05) and 45 ± 19% at 2 days (P < 0.01) after banding, while G3PDH mRNA showed no significant change. RT-PCR for dystrophin tissue-specific exon 1 revealed that only muscle type promoter, but not non-muscle type promoter (brain and Purkinje-cell type), was activated immediately after banding. Immunohistochemistry for dystrophin showed intense cellular membrane staining with an increase in the perimeter of the myocytes by 14% at 3 days (46.3 ,m, P < 0.01) and 19% at 7 days (51.2 ,m, P < 0.01) after banding. Western blotting also showed dystrophin protein increased by 14 ± 6% at 2 days (P < 0.05) and by 32 ± 10% at 3 days (P < 0.01) after aortic banding. In conclusion, upregulation of dystrophin mRNA expression and protein accumulation occurs in response to cardiac hypertrophy. These data and the vulnerability of dystrophin-deficient myocardium to pressure overload suggest that dystrophin could play an important role in maintaining the integrity of the sarcolemma. Cell Motil. Cytoskeleton 55:26,35, 2003. © 2003 Wiley-Liss, Inc. [source]


    The Corset Platysma Repair: A Technique Revisited

    DERMATOLOGIC SURGERY, Issue 3 2002
    Carolyn I. Jacob MD
    background. Platysma banding along with excess submental adipose tissue and sagging skin can lead to an aged appearance. Several methods for improving neck and submental contours exist, including neck liposuction, bilateral platysma plication, midline platysma plication with transection of distal fibers, necklift with skin excision, and botulinum toxin injection for platysma relaxation. With the current interest in minimally invasive procedures, surgeons and patients are searching for techniques that produce maximal improvement with minimal intervention. objective. To present a modified technique for maximizing neck contouring, discuss possible complications of the procedure, and describe appropriate candidates for the corset platysmaplasty. methods. We performed a retrospective analysis of 10 consecutive patients who underwent neck liposuction with concomitant corset platysmaplasty at our institution. results. All 10 patients achieved good to excellent submental and jawline contouring, determined by both physician and patient assessment, with no visible platysma banding at 6 months follow-up. No major complications were noted. conclusion. Use of corset platysmaplasty is a safe and effective method for neck rejuvenation. This variation of platysmaplasty can be used in conjunction with neck liposuction to maximize jawline and neck contour enhancement. [source]


    Improvements in insulin sensitivity and ,-cell function (HOMA) with weight loss in the severely obese

    DIABETIC MEDICINE, Issue 2 2003
    J. B. Dixon
    Abstract Aims To examine the effect of weight loss on insulin sensitivity and ,-cell function in severely obese subjects of varying glycaemic control. Patients and methods Subjects were 254 (F:M 209:45) patients having adjustable gastric banding for severe obesity, with paired biochemical data from before operation and at 1-year follow up. The homeostatic model assessment method was used to calculate insulin sensitivity (HOMA%S) and ,-cell function (HOMA%B). Subjects were grouped by diabetic status and by pre-weight loss HbA1c. Results Initial mean (sd) weight and body mass index were 128 (26) kg and 46.2 (7.7) kg/m2, respectively, and at 1-year were 101 (22) kg and 36.4 (6.7) kg/m2. The percentage of excess weight lost (%EWL) was 44.3 (14)%. HOMA%S improved from 37.5 (16)% presurgery to 62 (25)% (P < 0.001). %EWL was the only predictor of HOMA%S improvement (r = 0.28, P < 0.001). Subjects with normal fasting glucose, impaired fasting glucose and Type 2 diabetes had a fall, no change and increase in HOMA%B, respectively. The improvement in HOMA%B in subjects with diabetes (n = 39) was inversely related to the time with diabetes (r = ,0.36, P = 0.02). In non-diabetic subjects the HOMA%S,HOMA%B relationship was favourably altered with weight loss, so that for any given HOMA%S there was an increase in HOMA%B (f = 11.8, P = 0.001). This improvement in HOMA%B was positively related to %EWL (r = 0.25, P = 0.019). Discussion There are beneficial changes in both insulin sensitivity and ,-cell function with weight loss. Modern laparoscopic obesity surgery may have an important early role in the management of Type 2 diabetes in obese subjects. [source]


    Effect of bariatric surgery on circulating chemerin levels

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2010
    C. Ress
    Eur J Clin Invest 2010; 40 (3): 277,280 Abstract Background, Subclinical inflammation in obesity is critical for development of several obesity-associated disorders. We set out to investigate the effect of pronounced weight loss on circulating chemerin levels, a chemoattractant protein that also influences adipose cell function by paracrine and autocrine mechanisms. Material and methods, Thirty-two obese patients undergoing bariatric surgery were tested before and on an average of 18 months after gastric banding or gastric bypass surgery. Results, Pronounced weight loss after bariatric surgery was accompanied by improvements in parameters of lipid and glucose metabolism and increased adiponectin levels. Chemoattractant chemerin significantly decreased from 175·91 ± 24·50 to 145·53 ± 26·44 ng mL,1 after bariatric surgery (P , 0·01). Concomitantly, hs-CRP as a marker of subclinical inflammation was significantly reduced after weight reduction (P , 0·01). Conclusions, We hypothesize that weight-loss induced reduction in circulating chemerin might in conjunction with other factors be associated with diminished recruitment of macrophages in adipose tissue and reduction of subclinical inflammation, which again could partly explain beneficial long-term effects of weight reduction in obese subjects. [source]


    Transition of Failure Mode and Enhanced Plastic Deformation of Metallic Glass by Multiaxial Confinement,

    ADVANCED ENGINEERING MATERIALS, Issue 11 2009
    Fu-Fa Wu
    Multiple shear bands are formed in a confined metallic-glass specimen under small-punch loading. The intersecting of shear bands and the formation of profuse secondary shear bands are promoted under this confinement; accordingly, the failure mode changes from catastrophic fracture to stable multiple shear banding. Multiaxial confinement is an effective method to stabilize shear banding and further enhance the mechanical performance, especially the plastic deformation capability of metallic glass. These results present a simple step for making shear banding more stable and exploiting the shear-deformation capability of metallic glasses, leading to the toughening of brittle metallic glasses and potentially broadening their applications. [source]


    Effects of Temperatures on Inhomogeneous Plastic Flows of a Bulk-Metallic Glass,

    ADVANCED ENGINEERING MATERIALS, Issue 11 2008
    H. Jiang
    The effects of temperatures on plastic flow and shear banding of a bulk-metallic glass in compression were investigated. Temperature significantly affects the plastic-flow and shear-banding behaviors. With increasing temperatures from the ambient, the plastic deformation tends to become homogeneous both in time and space; while decreasing temperature from the ambient, it tends to be less inhomogeneous in time, but more inhomogeneous in space. Plastic flow is related to shear banding. [source]


    Cardioventilatory Coupling in Resting Human Subjects

    EXPERIMENTAL PHYSIOLOGY, Issue 6 2003
    Y. C. Tzeng
    In 48 conscious resting subjects we examined the temporal coupling of heart beat timing and the onset of inspiration (cardioventilatory coupling), and the relationship between coupling and spectral indices of autonomic function. Using the proportional Shannon entropy (SH,) of the RI -1 interval (interval between inspiration and the preceding ECG R wave) as a measure of coupling we detected statistically significant coupling in 32 of the 48 subjects. This was confirmed by visual inspection of time series plots of RI intervals, in which coupling was evident as horizontal banding. Coupling resulted in a significant preference for whole number heart rate/respiratory frequency ratios. The strongest coupling was associated with low ventilatory frequency and high heart rate variability in the high (0.15-0.40 Hz) and low (0.04-0.15 Hz) frequency ranges, but was not related to blood pressure variability, or to a spectral measure of baroreflex sensitivity (,-index, low frequency range). There was no difference in coupling strength between males and females. We have previously described cardioventilatory coupling in spontaneously breathing anaesthetised subjects. The current study extends those observations by demonstrating that the qualitative features of coupling seen during anaesthesia are also observed in the conscious state. We conclude that the role of coupling in normal physiological respiratory control needs to be more widely explored. [source]


    Hereditary gastrointestinal stromal tumors sharing the KIT Exon 17 germline mutation p.Asp820Tyr develop through different cytogenetic progression pathways

    GENES, CHROMOSOMES AND CANCER, Issue 2 2010
    Isabel Veiga
    Hereditary gastrointestinal stromal tumor (GIST) syndrome is a rare autosomal dominant genetic disorder originated by germline mutations in the KIT or PDGFRA genes. We report the third family with hereditary predisposition to GIST due to the KIT Exon 17 germline mutation p.Asp820Tyr and characterize the cytogenetic progression pathways followed by different GIST sharing the same primary genetic event, using a combination of chromosome banding, comparative genomic hybridization (CGH), and fluorescence in situ hybridization (FISH) analyses. The missense mutation p.Asp820Tyr was detected in the proband's rectal and gastric GIST, as well as in his aunt's GIST epiplon metastasis. The mutation p.Asp820Tyr was subsequently also found in the proband's peripheral blood DNA, as well as in that of 4 of 10 relatives thus far analyzed. CGH analysis revealed loss of 14q and 15q in the proband's gastric lesion, whereas FISH analysis of the proband's rectal GIST did not detect loss of 14q and 15q, but instead loss of 4q and 22q and gain of 20q, indicating that the two tumors were independent GIST. Chromosome banding and CGH analyses of the aunt's GIST epiplon metastasis revealed multiple cytogenetic alterations, including 1p loss, but none in common with the two proband's GIST. We conclude that, although the patients share the same KIT Exon 17 germline mutation, the multiple GIST analyzed followed different pathogenetic progression pathways, each of which did not significantly differ from what has been described in sporadic GIST. © 2009 Wiley-Liss, Inc. [source]


    Detection of a t(1;22)(q23;q12) translocation leading to an EWSR1-PBX1 fusion gene in a myoepithelioma

    GENES, CHROMOSOMES AND CANCER, Issue 7 2008
    Petter Brandal
    Chromosome banding as well as molecular cytogenetic methods are of great help in the diagnosis of mesenchymal tumors. Myoepithelial neoplasms of soft tissue including myoepitheliomas, mixed tumors, and parachordomas are diagnoses that have been increasingly recognized the last few years. It is still debated which neoplasms should be included in these morphologically heterogeneous entities, and the boundaries between them are not clear-cut. The pathogenetic mechanisms behind myoepithelial tumors are unknown. Only five parachordomas and one mixed tumor have previously been karyotyped, and nothing is known about their molecular genetic characteristics. We present a mesenchymal tumor classified as a myoepithelioma that had a balanced translocation t(1;22)(q23;q12) as the sole karyotypic change. A novel EWSR1-PBX1 fusion gene consisting of exons 1,8 of the 5,-end of EWSR1 and exons 5,9 of the 3,-end of PBX1 was shown to result from the translocation. Both genes are known to be targeted also by other neoplasia-specific translocations, PBX1 in acute lymphoblastic leukemia and EWSR1 in several solid tumors, most of which are malignant. Based on the structure of the novel fusion gene detected, its transforming mechanism is thought to be the same as for other fusion genes involving EWSR1 or PBX1. © 2008 Wiley-Liss, Inc. [source]


    Intrachromosomal amplification of chromosome 21 (iAMP21) may arise from a breakage,fusion,bridge cycle

    GENES, CHROMOSOMES AND CANCER, Issue 4 2007
    Hazel M. Robinson
    Intrachromosomal amplification of chromosome 21 (iAMP21), involving amplification of the RUNX1 gene and duplication of chromosome 21, dup(21q), defines a new cytogenetic subgroup in B-lineage acute lymphoblastic leukemia (ALL) with a poor prognosis. Characterization of this abnormality has become vital to ensure that the most accurate detection method is used. We have previously defined common regions of amplification and deletion of chromosome 21 in these patients, although the level and extent of amplification within the amplicon was highly variable. This study, using interphase fluorescence in situ hybridization (FISH) with chromosome 21 locus specific probes, substantiated these findings in a large series of patients and confirmed that the amplicon always included RUNX1. Thus, FISH with probes directed to the RUNX1 gene remains the most reliable detection method. Metaphase FISH, supported by G- and multiple color chromosomal banding (mBAND) revealed the patient specific morphology and genetic profile of the dup(21q) chromosomes, as well as the complexity of the intrachromosomal changes giving rise to them. These findings suggested that iAMP21 had arisen from a breakage,fusion,bridge cycle: a mechanism previously described in tumors, which we report for the first time in ALL. © 2007 Wiley-Liss, Inc. [source]


    Outcomes of a patient-to-patient outbreak of genotype 3a hepatitis C,

    HEPATOLOGY, Issue 2 2009
    Mark E. Mailliard
    Between March 2000 and July 2001, at least 99 persons acquired a hepatitis C virus genotype 3a (HCV-3a) infection in an oncology clinic. This nosocomial HCV outbreak provided an opportunity to examine the subsequent clinical course in a well-defined cohort. This was a retrospective/prospective observational study of the short-term significant health outcomes of a large, single-source, patient-to-patient HCV-3a outbreak. Outbreak patients or their legal representatives consenting to study were enrolled between September 2002 and December 2007. We measured history and physical examinations, medical records, HCV serology, HCV RNA and genotype, liver enzymes, histology, response to antiviral therapy, and liver-related morbidity and mortality. Sixty-four of the 99 known HCV-3a outbreak patients participated. During a 6-year period, six patients developed life-threatening complications from liver disease, three died, one received a liver transplant, and two were stable after esophageal variceal banding or diuretic therapy of ascites. Thirty-three patients underwent antiviral therapy, with 28 achieving a sustained viral remission. One patient acquired HCV-3a infection sexually from an outbreak patient and was successfully treated. Eleven study patients died of malignancy, including two that had achieved a sustained viral remission after antiviral therapy. Conclusion: Our patient cohort had a nosocomial source and an oncologic or hematologic comorbidity. Compared with previous HCV outcome studies, a patient-to-patient HCV outbreak in an oncology clinic exhibited significant morbidity and mortality. Attention is needed to the public health risk of nosocomial HCV transmission, emphasizing infection control, early diagnosis, and therapy. (HEPATOLOGY 2009.) [source]


    Of squeezers and skippers: factors determining the age at moult of immature African Penguins Spheniscus demersus in Namibia

    IBIS, Issue 2 2005
    JESSICA KEMPER
    We used banding and resighting records of 391 African Penguins Spheniscus demersus banded as chicks and later resighted during immature moult to explain the roles of date of fledging and age at moult in determining the season of moult and its timing within the season. Breeding was continuous, but immature moult occurred mainly during spring and summer. Age at immature moult extended over 11 months, from 12 to 23 months after hatching. Birds that fledged during summer and early autumn generally moulted during the next moult season (squeezers), whereas birds that fledged in late autumn, winter and spring skipped the next moult season to moult only the following season (skippers). There was a significant relationship between age at moult and moult date, with young birds moulting later in the season than older birds. The age at moult of immature birds appears to be constrained by minimum age, moult seasonality and plumage wear. Birds that fledged over nearly 2 years moult during one season. Counts of moulting immature African Penguins have not been used to estimate year-class strength and post-fledging survival owing to the wide range of ages at immature moult. Our results provide the means of assigning recruits to specific age groups. [source]


    Micromechanical analysis of failure propagation in frictional granular materials

    INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 15 2009
    Antoinette Tordesillas
    Abstract The extent to which the evolution of instabilities and failure across multiple length scales can be reproduced with the aid of a bifurcation analysis is examined. We adopt an elastoplastic micropolar constitutive model, recently developed for dense cohesionless granular materials within the framework of thermomicromechanics. The internal variables and their evolution laws are conceived from a direct consideration of the dissipative mechanism of force chain buckling. The resulting constitutive law is cast entirely in terms of the particle scale properties. It thus presents a unique opportunity to test the potential of micromechanical continuum formulations to reproduce key stages in the deformation history: the development of material instabilities and failure following an initially homogeneous deformation. Progression of failure, initiating from frictional sliding and rolling at contacts, followed by the buckling of force chains, through to macroscopic strain softening and shear banding, is reproduced. Bifurcation point, marking the onset of shear banding, occurred shortly after the peak stress ratio. A wide range of material parameters was examined to show the effect of particle scale properties on the progression of failure. Model predictions on the thickness and angle of inclination of the shear band and the structural evolution inside the band, namely the latitudinal distribution of particle rotations and the angular distributions of contacts and the normal contact forces, are consistent with observations from numerical simulations and experiments. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    A discrete model for the dynamic propagation of shear bands in a fluid-saturated medium

    INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 2 2007
    Julien Réthoré
    Abstract The first part of this manuscript discusses a finite element method that captures arbitrary discontinuities in a two-phase medium by exploiting the partition-of-unity property of finite element shape functions. The fluid flow away from the discontinuity is modelled in a standard fashion using Darcy's relation, and at the discontinuity a discrete analogy of Darcy's relation is used. Subsequently, dynamic shear banding is studied numerically for a biaxial, plane-strain specimen. A Tresca-like as well as a Coulomb criterion is used as nucleation criterion. Decohesion is controlled by a mode-II fracture energy, while for the Coulomb criterion, frictional forces are transmitted across the interface in addition to the cohesive shear tractions. The effect of the different interface relations on the onset of cavitation is studied. Finally, a limited quantitative study is made on the importance of including a so-called dynamic seepage term in Darcy's relation when considering dynamic shear banding. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Assessment of test data for selection of 3-D failure criterion for sand

    INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 4 2006
    Poul V. Lade
    Abstract Data from three-dimensional experiments performed on sand in true triaxial equipment have been reviewed to sort out apparent disarray resulting from their interpretation. This has been done based on analyses made possible by recent developments and understanding of factors influencing sand behaviour: occurrence of shear banding, boundary conditions and/or specimen slenderness ratio, cross-anisotropy, and stability of experimental technique. These factors are reviewed and test data from the literature are evaluated. Experimental data are divided into three groups in which: (a) homogeneous behaviour controls the sand strength; (b) shear banding affects the shape of the three-dimensional failure surface in the midrange of values of b=(,2,,3)/(,1,,3), and (c) the data has been misinterpreted. Appropriate interpretation of three-dimensional strength data for sand exhibiting isotropic, homogeneous behaviour is represented by a smoothly rounded triangular failure surface expressible in terms of the first and third stress invariants. Shear banding effects will cause the failure surface to be ,indented' in the midrange of b -values in all sectors of the octahedral plane. Effects of cross-anisotropy will result in lower strengths in sector III than in sector I of the octahedral plane, and the failure surface will appear as rotated around the stress origin in principal stress space. Copyright © 2005 John Wiley & Sons, Ltd. [source]


    Kinematic modelling of shear band localization using discrete finite elements

    INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 4 2003
    X. Wang
    Abstract Modelling shear band is an important problem in analysing failure of earth structures in soil mechanics. Shear banding is the result of localization of deformation in soil masses. Most finite element schemes are unable to model discrete shear band formation and propagation due to the difficulties in modelling strain and displacement discontinuities. In this paper, a framework to generate shear band elements automatically and continuously is developed. The propagating shear band is modelled using discrete shear band elements by splitting the original finite element mesh. The location or orientation of the shear band is not predetermined in the original finite element mesh. Based on the elasto-perfect plasticity with an associated flow rule, empirical bifurcation and location criteria are proposed which make band propagation as realistic as possible. Using the Mohr,Coulomb material model, various results from numerical simulations of biaxial tests and passive earth pressure problems have shown that the proposed framework is able to display actual patterns of shear banding in geomaterials. In the numerical examples, the occurrence of multiple shear bands in biaxial test and in the passive earth pressure problem is confirmed by field and laboratory observations. The effects of mesh density and mesh alignment on the shear band patterns and limit loads are also investigated. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    A novel approach to the analysis of distributed shear banding in polymer blends

    INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 5 2003
    K. G. W. Pijnenburg
    Abstract The toughness of glassy polymers can be enhanced by blending with rubber particles. The consensus is that this toughening is due to massive plastic deformation of the matrix that takes place once the particles have cavitated. Micromechanical studies of regular stackings of particles in a polymer matrix have provided much insight into the localized plastic flow in blends at the microscale of individual particles (or voids, once cavitated). Even some steps towards macroscopic constitutive models have been made. However, at intermediate length scales (i.e. larger than several particles, but smaller than the scale at which the material may be regarded as homogeneous) the situation is unclear. It is this length scale that becomes important around crack tips, for example, where a thorough understanding of the toughening effect has to be derived from. In this paper, we therefore present a novel approach to the analysis of distributed shear banding in polymer,rubber blends. A coarse-grain description, in which much of the morphology is retained but the local shear banding is idealized into ,shear surfaces', will enable us to analyse ensembles with large numbers of particles. The parameters of this model will be validated with results from detailed cell analyses. Copyright © 2003 John Wiley Sons, Ltd. [source]


    Binge eating and exercise behavior after surgery for severe obesity: A structural equation model

    INTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 5 2006
    Junilla K. Larsen PhD
    Abstract Objective: The current study sought to find indications for the appropriateness of a model in which eating patterns and exercise beliefs influence binge eating and physical exercise, respectively, that, in turn, influence outcome after gastric banding for severe obesity. Method: Participants were 157 patients (144 females, 13 males) who completed questionnaires approximately 34 months (range = 8,68 months) after laparoscopic adjustable gastric banding (LAGB). Results: Our data showed a well-fitting model in which external and emotional eating were associated with outcome through binge eating. Several exercise beliefs were associated with physical exercise, but physical exercise was not associated with weight loss or physical health. Conclusion: Binge eating was related more strongly to the outcome after gastric banding than physical exercise. Future research should examine whether a strong focus on the management of binge eating and external and emotional eating could improve the outcome of morbidly obese patients with unsuccessful weight outcome after obesity surgery. © 2006 by Wiley Periodicals, Inc. Int J Eat Disord 2006. [source]


    Digital cementum luminance analysis (DCLA): a tool for the analysis of climatic and seasonal signals in dental cementum

    INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 1 2008
    C. M. Wall-Scheffler
    Abstract Cementum banding patterns have been used by archaeozoologists and wildlife managers for a number of decades to assess the season and age at death of mammalian populations. However, the observation and measurement of the nature of cementum banding, especially that of the final band, has proved to be difficult except under conditions of excellent preservation and advanced microscopy. The research presented here details a method for extracting luminance data from the banding patterns of cementum in order to quantify the optical properties of cementum tissue. By doing so, analysis of the relationship between cementum deposition and environmental variables is achieved. We present the results of a digital cementum luminance analysis (DCLA) on a sample of first molars from two species, Ovis aries, Soay and Capra ibex. The results indicate that significant relationships occur between seasonal temperature changes and cementum histology. Furthermore, we show that luminance values can be used to assess the geographical range of genetically similar populations. Our results demonstrate that the study of luminance is a vital tool for the quantitative study of dental cementum for both archaeological and ecological studies. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Field Pea Seeding Management for Semi-arid Mediterranean Conditions

    JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 2 2004
    A. M. Tawaha
    Abstract The effects of seeding rate (30, 60 and 90 seeds m,2), seeding date (14 January, 28 January and 12 February), seed weight (0.18 and 0.25 g seed,1), seeding depth (3 and 6 cm), and phosphorus fertilization rate (17.5, 35.0 and 52.5 kg P ha,1) and placement method (banded or broadcasted) on field pea (Pisum sativum L.) development and seed yields were investigated in irrigated field experiments conducted in northern Jordan in 2000 and 2001. Results and treatment responses were consistent in both years. Seeding rate, seeding date, seed weight and rate and method of phosphorus fertilization had significant effects on most traits measured; planting depth however did not affect any of the traits. Generally a positive correlation was observed between each factor and seed yield and yield components, with the exception of a negative correlation between seeding rate and yield components, and seeding date and yield and yield components. Increase in seeding rate from 30 to 90 seeds m,2, and increase in P fertilization from 17.5 to 52.5 kg ha,1 alone increased seed yields by 50 and 41 %, respectively. Each delay of 2 weeks for seeding from mid-January resulted in reductions of 12 % in seed yields. Overall, the results revealed that a combination of early seeding (14 January), of large seeds at an high seeding rate (90 seeds m,2), with P fertilizer banding (52.5 kg P ha,1) maximize field pea yields in irrigated fields in semi-arid Mediterranean environments. With such management pea seed yields can be as high as 2800 kg ha,1. [source]


    The Roles of Gender and Affirmative Action Attitude in Reactions to Test Score Use Methods,

    JOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 9 2000
    Donald M. Truxillo
    The present study explored the effects of 2 variables, affirmative action (AA) attitude and gender, on reactions to 3 test score use (TSU) methods: top-down selection. banding with random selection, and banding with preferences. In a study of 94 upper-division and graduate business students, AA attitude was associated with different reactions to TSU methods in terms of fairness and organizational attractiveness. Moreover, women with negative AA attitudes and men rated banding with preferences lower than the other two methods, but women with positive AA attitudes did not Results are discussed in terms of applicant reactions models, implications for organizations and future research. [source]


    TRANSPLANTATION AND MECHANICAL SUPPORT Original Articles: Heart Transplantation Techniques after Hybrid Single-Ventricle Palliation

    JOURNAL OF CARDIAC SURGERY, Issue 5 2010
    Vinod A. Sebastian M.D.
    The hybrid palliative strategy of pulmonary artery banding and ductal stenting has emerged as an alternative treatment for neonates with HLHS. Neonates who have undergone a hybrid Norwood but are not candidates for the three-stage single-ventricle pathway may need heart transplantation. Patients who have undergone hybrid Norwood or those with visceral heterotaxy who have undergone ductal stenting and bilateral PA bands represent a technically challenging group of patients for heart transplantation, but it appears to be a favorable approach and we describe our experience with three patients who underwent heart transplant after a hybrid Norwood procedure. (J Card Surg 2010;25:596-600) [source]


    Cellular repressor of E1A-stimulated genes attenuates cardiac hypertrophy and fibrosis

    JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 7 2009
    Zhouyan Bian
    Abstract Cellular repressor of E1A-stimulated genes (CREG) is a secreted glycoprotein of 220 amino acids. It has been proposed that CREG acts as a ligand that enhances differentiation and/or reduces cell proliferation. CREG has been shown previously to attenuate cardiac hypertrophy in vitro. However, such a role has not been determined in vivo. In the present study, we tested the hypothesis that overexpression of CREG in the murine heart would protect against cardiac hypertrophy and fibrosis in vivo. The effects of constitutive human CREG expression on cardiac hypertrophy were investigated using both in vitro and in vivo models. Cardiac hypertrophy was produced by aortic banding and infusion of angiotensin II in CREG transgenic mice and control animals. The extent of cardiac hypertrophy was quantitated by two-dimensional and M-mode echocardiography as well as by molecular and pathological analyses of heart samples. Constitutive over-expression of human CREG in the murine heart attenuated the hypertrophic response, markedly reduced inflammation. Cardiac function was also preserved in hearts with increased CREG levels in response to hypertrophic stimuli. These beneficial effects were associated with attenuation of the mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase 1 (MEK-ERK1)/2-dependent signalling cascade. In addition, CREG expression blocked fibrosis and collagen synthesis through blocking MEK-ERK1/2-dependent Smad 2/3 activation in vitro and in vivo. Therefore, the expression of CREG improves cardiac functions and inhibits cardiac hypertrophy, inflammation and fibrosis through blocking MEK-ERK1/2-dependent signalling. [source]


    Silibinin attenuates cardiac hypertrophy and fibrosis through blocking EGFR-dependent signaling,

    JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 5 2010
    Wen Ai
    Abstract Cardiac hypertrophy is a major determinant of heart failure. The epidermal growth factor receptor (EGFR) plays an important role in cardiac hypertrophy. Since silibinin suppresses EGFR in vitro and in vivo, we hypothesized that silibinin would attenuate cardiac hypertrophy through disrupting EGFR signaling. In this study, we examined this hypothesis using neonatal cardiac myocytes and fibroblasts induced by angiotensin II (Ang II) and animal model by aortic banding (AB) mice. Our data revealed that silibinin obviously blocked cardiac hypertrophic responses induced by pressure overload. Meanwhile, silibinin markedly reduced the increased generation of EGFR. Moreover, these beneficial effects were associated with attenuation of the EGFR-dependent ERK1/2, PI3K/Akt signaling cascade. We further demonstrated silibinin decreased inflammation and fibrosis by blocking the activation of NF-,B and TGF-,1/Smad signaling pathways in vitro and in vivo. Our results indicate that silibinin has the potential to protect against cardiac hypertrophy, inflammation, and fibrosis through blocking EGFR activity and EGFR-dependent different intracellular signaling pathways. J. Cell. Biochem. 110: 1111,1122, 2010. Published 2010 Wiley-Liss, Inc. [source]


    Colored plastic and metal leg bands do not affect survival of Piping Plover chicks

    JOURNAL OF FIELD ORNITHOLOGY, Issue 3 2010
    Erin A. Roche
    ABSTRACT Leg bands are commonly used to mark shorebird chicks as young as 1-d old, but little is known about the possible impacts of bands on survival of prefledging shorebirds. We used a mark-recapture framework to assess the impact of bands and banding-related disturbance on prefledging survival in a federally endangered population of Piping Plovers (Charadrius melodus) breeding in the Great Lakes region from 2000 to 2008. We banded approximately 96% of all surviving chicks hatched prior to fledging, typically between 5 and 15 d of age. We used a multistate approach in program MARK whereby individuals contributed data as unbanded chicks before capture (N= 1073) and as banded chicks afterward (N= 780). The cumulative probability of surviving through 24 d of age was 0.63 and did not differ between banded and unbanded chicks. In addition, we found a positive effect of banding-related disturbance on survival up to 3 d following banding (,= 0.60 CI: 0.17,1.02), possibly due to increased postbanding vigilance on the part of chicks and adults. Our results indicate that banding has no detrimental effect on survival of Piping Plover chicks prior to fledging and that current capture and banding methods are appropriate for this endangered species. RESUMEN Los anillos son comúnmente utilizados para marcar los polluelos de aves playeras desde edades tempranas como un día de eclosionados, pero poco se conoce sobre los posibles impactos que estos anillos puedan tener sobre la supervivencia antes de abandonar el nido en aves playeras. Usamos técnicas de marca recaptura para estimar el impacto de los anillos y disturbios asociados a este proceso en la supervivencia antes de abandonar el nido en una población federal en peligro de Charadrius melodus anidando en la región de los grandes lagos desde el 2000 hasta el 2008. Anillamos aproximadamente 96% de todos los polluelos que sobrevivieron después de la eclosión y antes de abandonar el nido, normalmente entre 5,15 días de nacidos. Usamos una aproximación de estado múltiple en el programa MARK en el cual se dividieron los datos en polluelos sin anillar antes de la captura (N= 1073) y polluelos después de ser anillados (N= 780). La probabilidad acumulada de supervivencia a través de 24 días de edad fue 0.63 y no existieron diferencias entre polluelos anillados y no anillados. Adicionalmente, encontramos un efecto positivo relacionado con el disturbio creado durante le anillamiento en la supervivencia hasta tres días después del anillamiento (,= 0.60 CI: 0.17,1.02), posiblemente debido al incremento de vigilancia después del anillamiento por parte de los polluelos y adultos. Nuestros resultados indican que el anillamiento no tiene efectos negativos sobre la supervivencia de polluelos de Charadrius melodus antes de abandonar el nido y que los métodos de anillamiento y captura actualmente utilizados son apropiados para esta especie en peligro. [source]


    Effect of count duration on abundance estimates of Black-capped Vireos

    JOURNAL OF FIELD ORNITHOLOGY, Issue 1 2009
    David A. Cimprich
    ABSTRACT Distance sampling applied to point count surveys (point transects) has become a common method for estimating the absolute abundance of birds. When conducting point transects, detections of focal species are typically recorded during a fixed time interval. However, count duration has varied among studies and the effect of such variation on the resulting abundance estimates is unclear. My objective was to examine the effect of count duration on abundance estimates of male Black-capped Vireos (Vireo atricapilla). The abundance of these vireos in a 349-ha area in central Texas was estimated using 3-, 5-, and 6-min point transects and results were then compared to actual number present as determined by banding and territory mapping. The 3-min counts provided an estimate that was 26% greater than the actual number of male Vireos present (N= 201), but this number was within the corresponding 95% confidence interval (N= 157,413). Confidence intervals for the 5- and 6-min counts did not include the actual number of vireos present. The shortest count duration may have provided the most accurate abundance estimate because male Black-capped Vireos are typically active, sing intermittently, and sometimes move tens of meters between songs. Thus, shorter-duration counts may also yield the most accurate abundance estimates for other species that exhibit similar behavior. However, because behavior varies among species, I recommend that investigators collect preliminary data to establish an appropriate count duration when accurate estimates of absolute, rather than relative, abundance are important. RESUMEN El muestreo a distancia aplicado a conteos de punto (transectos de punto) se ha convertido en un método común para estimar la abundancia absoluta de aves. Cuando se conducen conteos de punto, la detección de especies focales, típicamente, se lleva a cabo durante un periodo de tiempo definido. Sin embargo, la duración de tiempo del conteo, varía en diferentes estudios y el efecto de dicha variación, en los estimados de abundancia, no está definido. Mi objetivo fue examinar el efecto del periodo de tiempo usado en los conteos utilizando como objeto de estudio a Vireo atricapilla. La abundancia de dichas aves en 349 ha en la parte central de Texas, fue estimada utilizando periodos de 3, 5 y 6 minutos en cada punto del transecto. Los resultados fueron comparados a números obtenidos con recobro de animales anillados y mapas de territorios. Los conteos de 3 minutos dieron como resultado un 26% más alto que el número de machos presentes en la localidad (N= 201). Pero dichos resultados estuvieron dentro del intérvalo de confiabilidad de 95% (N= 157,413). Intérvalos de 5 y 6 minutos no estimaron adecuadamente el número de vireos presentes. El conteo más corto (3 minutos) suministró los números más exactos, aparentemente porque el ave estudiada, típicamente está activa, canta de forma intermitente y en ocasiones se mueve de lugar (decenas de metros) entre canciones. Por lo tanto los conteos más cortos deben de proveer los estimados de abundancia más precisos para otras especies de aves con hábitos similares. Sin embargo, dado el caso de que la conducta entre especies varía, recomendamos a otros investigadores, que tomen datos preliminares para establecer la duración más apropiada de conteos, cuando se necesiten estimados de absoluta exactitud, en vez de estimados relativos de abundancia. [source]


    Hypertrophied hearts: what of sevoflurane cardioprotection?

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009
    J. R. LARSEN
    Background: Recent studies have demonstrated that inhalation anaesthetics, like sevoflurane, confer cardioprotection both experimentally and clinically. However, coexisting cardiac disease might diminish anaesthetic cardioprotection and could partly explain why the clinical results of cardioprotection with anaesthetics remain controversial , in contrast to solid experimental evidence. Concomitant left ventricular hypertrophy is found in some cardiac surgery patients and could change cardioprotection efficacy. Hypertrophy could potentially render the heart less susceptible to sevoflurane cardioprotection and more susceptible to ischaemic injury. We investigated whether hypertrophy blocks sevoflurane cardioprotection, and whether tolerance to ischaemia is altered by left ventricular hypertrophy, in an established experimental animal model of ischaemia,reperfusion. Methods: Anaesthetized juvenile pigs (n=7,12/group) were subjected to 45 min distal coronary artery balloon occlusion, followed by 120 min of reperfusion. Controls were given pentobarbital, while sevoflurane cardioprotection was achieved by 3.2% inhalation throughout the experiment. Chronic banding of the ascending aorta resulted in left ventricular hypertrophy development in two further groups and these animals underwent identical ischaemia,reperfusion protocols, with or without sevoflurane cardioprotection. Myocardial infarct sizes were compared post-mortem. Results: The mean myocardial infarct size (% of area-at-risk) was reduced from mean 55.0 (13.6%) (±SD) in controls to 17.5 (13.2%) by sevoflurane (P=0.001). Sevoflurane reduced the infarct size in hypertrophied hearts to 14.6 (10.4%) (P=0.001); however, in hypertrophic controls, infarcts were reduced to 34.2 (10.2%) (P=0.001). Conclusion: Sevoflurane abrogated ischaemic injury to similar levels in both normal and left ventricular hypertrophied hearts. [source]