bluuebunny/crossref_metadata_2025_split huggingface dataset:
Addressing non‐uniqueness in linearized multichannel surface wave inversion
Authors: Cercato Michele 
Published: May 2008

ABSTRACTThe multichannel analysis of the surface waves method is based on the inversion of observed Rayleigh‐wave phase‐velocity dispersion curves to estimate the shear‐wave velocity profile of the site under investigation. This inverse problem is nonlinear and it is often solved using ‘local’ or linearized inversion strategies. Among linearized inversion algorithms, least‐squares methods are widely used in research and prevailing in commercial software; the main drawback of this class of methods is their limited capability to explore the model parameter space. The possibility for the estimated solution to be trapped in local minima of the objective function strongly depends on the degree of nonuniqueness of the problem, which can be reduced by an adequate model parameterization and/or imposing constraints on the solution.In this article, a linearized algorithm based on inequality constraints is introduced for the inversion of observed dispersion curves; this provides a flexible way to insert a priori information as well as physical constraints into the inversion process. As linearized inversion methods are strongly dependent on the choice of the initial model and on the accuracy of partial derivative calculations, these factors are carefully reviewed. Attention is also focused on the appraisal of the inverted solution, using resolution analysis and uncertainty estimation together with a posteriori effective‐velocity modelling. Efficiency and stability of the proposed approach are demonstrated using both synthetic and real data; in the latter case, cross‐hole S‐wave velocity measurements are blind‐compared with the results of the inversion process.
Gastrointestinal Kaposi’s sarcoma: CD117 expression and the potential for misdiagnosis as gastrointestinal stromal tumour
Authors: Parfitt J R , Rodriguez‐Justo M , Feakins R , Novelli M R 
Published: May 2008

Aims:  Gastrointestinal Kaposi’s sarcoma (KS) may mimic gastrointestinal stromal tumours (GISTs) histologically. Studies have shown that KS outside the gastrointestinal (GI) tract may express CD117, an antibody usually used to support a diagnosis of GIST. The aim was to evaluate the clinicopathological features of GI KS, including the expression of CD117 with and without antigen retrieval.Methods and results:  Fourteen GI KS were assessed histologically, 12 of which were also subjected to immunohistochemistry for CD34, human herpesvirus (HHV) 8, DOG1 and CD117. CD117 immunohistochemistry was performed with and without antigen retrieval. All cases showed an infiltrative spindle cell tumour. Lamina propria infiltration, lymphoplasmacytic inflammation, extravasated red blood cells and haemosiderin were typical histological features. In all cases tumour cells were positive for CD34 and HHV8, but negative for DOG1. CD117 was positive in four of 12 cases without antigen retrieval and 10 of 12 cases with antigen retrieval.Conclusions:  The microscopic distinction of GI KS from GIST can be difficult. Clues that raise the possibility of GI KS include young patient age, a history of immunosuppression, lamina propria infiltration, lymphoplasmacytic inflammation, extravasated red blood cells and haemosiderin deposition. Use of the immunomarkers CD117 (without antigen retrieval), HHV8 and DOG1 may aid in the distinction between GI KS and GIST.
Riverine effects on mitochondrial structure of Bornean orang‐utans (Pongo pygmaeus) at two spatial scales
Authors: JALIL M. F. , CABLE J. , SINYOR J. , LACKMAN‐ANCRENAZ I. , ANCRENAZ M. , BRUFORD M. W. , GOOSSENS B. 
Published: May 2008

AbstractWe examined mitochondrial DNA control region sequences of 73 Kinabatangan orang‐utans to test the hypothesis that the phylogeographical structure of the Bornean orang‐utan is influenced by riverine barriers. The Lower Kinabatangan Wildlife Sanctuary contains one of the most northern populations of orang‐utans (Pongo pygmaeus) on Borneo and is bisected by the Kinabatangan River, the longest river in Sabah. Orang‐utan samples on either side of the river were strongly differentiated with a high ΦST value of 0.404 (P < 0.001). Results also suggest an east–west gradient of genetic diversity and evidence for population expansion along the river, possibly reflecting a postglacial colonization of the Kinabatangan floodplain. We compared our data with previously published sequences of Bornean orang‐utans in the context of river catchment structure on the island and evaluated the general relevance of rivers as barriers to gene flow in this long‐lived, solitary arboreal ape.
Prospective community‐based cluster census and case‐control study of stillbirths and neonatal deaths in the West Bank and Gaza Strip
Authors: Kalter Henry D. , Khazen Reem Rahil , Barghouthi Mustafa , Odeh Mohammed 
Published: May 2008

SummaryObstetric complications and newborn illnesses amenable to basic medical interventions underlie most perinatal deaths. Yet, despite good access to maternal and newborn care in many transitional countries, perinatal mortality is often not monitored in these settings. The present study identified risk factors for perinatal death and the level and causes of stillbirths and neonatal deaths in the West Bank and Gaza Strip. Baseline and follow‐up censuses with prospective monitoring of pregnant women and newborns from September 2001 to August 2002 were conducted in 83 randomly selected clusters of 300 households each. A total of 113 of 116 married women 15–49 years old with a stillbirth or neonatal death and 813 randomly selected women with a surviving neonate were interviewed, and obstetric and newborn care records of women with a stillbirth or neonatal death were abstracted.The perinatal and neonatal mortality rates, respectively, were 21.2 [95% confidence interval (CI) 16.5, 25.9] and 14.7 [95% CI 10.2, 19.2] per 1000 livebirths. The most common cause (27%) of 96 perinatal deaths was asphyxia alone (21) or with neonatal sepsis (5), while 18/49 (37%) early and 9/19 (47%) late neonatal deaths were from respiratory distress syndrome (12) or sepsis (9) alone or together (6). Constraint in care seeking, mainly by an Israeli checkpoint, occurred in 8% and 10%, respectively, of 112 pregnancies and labours and 31% of 16 neonates prior to perinatal or late neonatal death. Poor quality care for a complication associated with the death was identified among 40% and 20%, respectively, of 112 pregnancies and labour/deliveries and 43% of 68 neonates. (Correction added after online publication 5 June 2008: The denominators 112 pregnancies, labours, and labour/deliveries, and 16 and 68 neonates were included; and 9% of labours was corrected to 10%.) Risk factors for perinatal death as assessed by multivariable logistic regression included preterm delivery (odds ratio [OR] = 11.9, [95% CI 6.7, 21.2]), antepartum haemorrhage (OR = 5.6, [95% CI 1.5, 20.9]), any severe pregnancy complication (OR = 3.4, [95% CI 1.8, 6.6]), term delivery in a government hospital and having a labour and delivery complication (OR = 3.8, [95% CI 1.2, 12.0]), more than one delivery complication (OR = 4.4, [95% CI 1.8, 10.5]), mother's age >35 years (OR = 2.9, [95% CI 1.3, 6.8]) and primiparity in a full‐term pregnancy (OR = 2.6, [1.1, 6.3]). Stillbirths are not officially reportable in the West Bank and Gaza Strip and this is the first time that perinatal mortality has been examined. Interventions to lower stillbirths and neonatal deaths should focus on improving the quality of medical care for important obstetric complications and newborn illnesses. Other transitional countries can draw lessons for their health care systems from these findings.
Maternal smoking, demographic and lifestyle factors in relation to daughter's age at menarche
Authors: Windham Gayle C. , Zhang Lixia , Longnecker Matthew P. , Klebanoff Mark 
Published: May 2008

SummaryA previous study suggested a younger age at menarche (AAM) among daughters of heavy prenatal smokers, especially among non‐Whites. The present study was designed to evaluate that association in another population and to examine other factors that may be related to AAM. We analysed data from the Collaborative Perinatal Project, a nationwide longitudinal study of pregnant women and their children conducted in 1959–66. At three sites, with a predominance of Black participants (80%), AAM was ascertained in the offspring when they were young adults. We included data on 1556 daughters who had a mean AAM of 12.7 years (standard deviation 1.8). Amount smoked by the mothers was obtained from a baseline interview and subsequent prenatal visits. Regression models were run including maternal smoking and other covariates, for only the prenatal period, as well as in models with some childhood characteristics.In the prenatal factor model, younger mean AAM in daughters was found with maternal characteristics of earlier AAM, being married, and of lower parity. Examining childhood variables, earlier AAM was found among girls with few or no siblings or with higher socio‐economic status. Unlike our previous findings, mean AAM was later in daughters of heavy smokers (20+ cigarettes/day), with a delay of 0.31 years [95% confidence interval (CI) 0.008, 0.61], or about 3.7 months in the prenatal model, and 0.34 years [95% CI −0.02, 0.66] in the model with childhood variables included. The pattern was consistent by race. A number of prenatal and childhood factors related to AAM were identified that should be considered when examining exogenous exposures in relation to pubertal onset.
Dental caries in 3‐year‐old children and smoking status of parents
Authors: Hanioka Takashi , Nakamura Etsuko , Ojima Miki , Tanaka Keiko , Aoyama Hitoshi 
Published: May 2008

SummaryAn association has been suggested between environmental tobacco smoke and oral disease. The present study examined the relationship between early childhood caries (ECC) and parental smoking, particularly paternal smoking, using records of 711 36‐month‐old children. The smoking status of parents as an independent variable was entered in the multivariable logistic regression model for caries experience as the dependent variable with confounders: sex, residential location, and possible risks of ECC such as order of birth, type of main drink, frequency of daily intake of sugar‐containing snacks, daily toothbrushing by parents and use of fluoridated toothpaste.About 65% of children were caries free. Children whose parents did not smoke (CN), those in whom only the father smoked (CF), and those whose mother smoked regardless of the smoking status of the father (CM) comprised 33%, 33% and 34% respectively. The adjusted mean number [95% CI] of decayed teeth and caries experience prevalence for CN, CF and CM were 1.2 [0.8, 1.6], 1.6 [1.2, 2.0] and 2.1 [1.7, 2.5], and 25.6%, 35.3% and 45.7% respectively. The relationship between caries experience and parental smoking was significant on multivariable analysis. The adjusted OR [95% CI] of CF and CM relative to CN was 1.52 [1.01, 2.30] and 2.25 [1.51, 3.37] respectively. These results indicate the association of ECC with parental smoking, although the association with paternal smoking was weaker than with maternal smoking.
Three‐dimensional modelling and sequence stratigraphy of a carbonate ramp‐to‐shelf transition, Permian Upper San Andres Formation
Authors: PHELPS RYAN M. , KERANS CHARLES , SCOTT SAM Z. , JANSON XAVIER , BELLIAN JEROME A. 
Published: May 2008

AbstractThis study highlights three‐dimensional variability of stratigraphic geometries in the ramp crest to basin of mixed carbonate–siliciclastic clinoforms in the Permian San Andres Formation. Standard field techniques and mapping using ground‐based lidar reveal a high degree of architectural complexity in channellized, scoured and mounded outer ramp stratigraphy. Development of these features was a function of location along the ramp profile and fluctuations in relative sea‐level. Deposition of coarse‐grained and fine‐grained turbidites in the distal outer ramp occurred through dilute and high‐density turbidity flows and was the result of highstand carbonate shedding within individual cycles. In this setting, high‐frequency cycles of relative sea‐level are interpreted on the basis of turbidite frequency, lateral extent and composition. Submarine siliciclastic sediment bypass during lowstand cycles resulted in variable degrees of siliciclastic preservation. Abundant siliciclastic material is preserved in the basin and distal outer ramp as point‐sourced lowstand wedges and line‐sourced early transgressive blankets. In mounded topography of the outer ramp, siliciclastic preservation is minimal to absent, and rare incised channels offer the best opportunity for recognition of a sequence boundary. Growth of mounded topography in the outer ramp began with scouring, followed by a combination of bioherm construction, fusulinid mound construction and isopachous draping. Intermound areas were then filled with sediment and continued mound growth was prevented by an accommodation limit. Mound growth was independent of high‐frequency cycles in relative sea‐level but was dependent on available accommodation dictated by low‐frequency cyclicity. Low‐angle ramp clinoforms with mounded topography in the outer ramp developed during the transgressive part of a composite sequence. Mound growth terminated as the ramp transformed into a shelf with oblique clinoform geometries during the highstand of the composite sequence. This example represents a ramp‐to‐shelf transition that is the result of forcing by relative sea‐level fluctuations rather than ecologic or tectonic controls.
Incidence and Distribution of Grapevine Leafroll‐associated viruses in Tunisian Vineyards
Authors: Mahfoudhi Naima , Digiaro Michele , Dhouibi Mohamed Habib 
Published: May 2008

AbstractSurveys were carried out in Tunisian table grape vineyards for assessing the occurrence and distribution of grapevine leafroll‐associated viruses (GLRaVs). Leafroll symptoms were commonly observed in most of the surveyed vineyards. Samples were randomly collected from 712 individual vines for laboratory testing. Enzyme‐linked immunosorbent assay (ELISA) tests showed that 81.5% of the vines were infected by one (35.7%) or more (45.8%) viruses. GLRaV‐3 was the most widespread virus (76.3%), followed by GLRaV‐5 (38.5 %), GLRaV‐6 (13.2%), GLRaV‐1 (9.1%), GLRaV‐2 (6.3%), and GLRaV‐7 (0.9%). GLRaV‐3 and GLRaV–5, two mealybug‐transmissible Ampeloviruses, were present in mixture in 35.9% of samples. The highest infection rate was found in Cape Bon region (81.7 %), where cv. Italia had an infection rate of 79.5%. Superior seedless, the main cultivar in Sidi Bouzid, had 75% infection. GLRaV‐6 and ‐7 were detected for the first time in Tunisia.
Interaction of residual stress with mechanical loading in an austenitic stainless steel
Authors: MIRZAEE‐SISAN A. , TRUMAN C. E. , SMITH D. J. , SMITH M. C. 
Published: May 2008

ABSTRACTSingle edge notched bend, SEN(B), fracture specimens fabricated from AISI Type 316H austenitic stainless steel and containing a residual stress field were used to quantify the interaction of a residual stress field on subsequent fracture behaviour when the specimens were subjected to an applied load. Autogenous welding (where no additional filler material is used) was used to impart the residual stress field following a procedure which had been extensively characterised numerically and experimentally. Crack growth resistant curves were obtained for the specimens, and for similar specimens containing no residual stress field. It was observed that the residual stress field had negligible impact on the fracture behaviour of the specimens, in contrast to recently reported work which demonstrated a large influence of a residual stress field when the test specimens were fabricated from a ferritic steel. A numerical programme was conducted to consider the results in the context of a structural integrity assessment. The test results were assessed using both the procedures described in R6, a well‐known structural integrity assessment procedure, and by explicit calculation of a modified J‐integral via two‐dimensional cracked body finite element analysis. It was shown that the assessments were pessimistic, all predicting an influence of the residual stress field on fracture when none was observed experimentally.
Advanced methodology for assessing distribution characteristics of Paris equation coefficients to improve fatigue life prediction
Authors: RABINOWICZ Y. , ROMAN I. , RITOV Y. 
Published: May 2008

ABSTRACTThis paper offers a methodology for coping with information loss following consolidation of data on fatigue crack propagation rates derived from different experiments. It is customary, both in the literature and in standardization, to consolidate results of several experiments conducted under similar conditions, using identical materials. This reduces the ability to implement a probabilistic fracture mechanics approach in order to reliably calculate the distribution of the number of cycles needed to reach a critical value (CV; onset of instability or failure). Such reliable calculation requires, among other things, an estimation of the distribution characteristics of the crack progression curves coefficients represented by models such as Paris or NASGRO, and an estimation of joint distributions of equation coefficients representing such models. Consolidated data reduce the ability to estimate these required distribution characteristics. This work suggests an analytical approach that uses consolidated data, but enables the information to be treated as if it were possible to attribute the data to the various experimental specimens from which they were obtained. Consequently, information required for the evaluation of the distribution of the number of cycles needed to reach a CV can be obtained. The proposed approach is generic and can be applied in additional scientific fields that can benefit from separation of data obtained from different experiments.
Geometrical relationships between side necking and plastic zone size near a crack tip in ductile metals. Part I: Modified boundary layer solutions
Authors: KIM D. H. , KANG K. J. 
Published: May 2008

ABSTRACTThe plastic zone size is regarded as the measure of a material's resistance, and it also determines the fracture behaviour. Recently, stereo digital speckle photography (SDSP) has been found to be useful for measuring in‐situ the side necking developed on the lateral surfaces of a specimen during a standard fracture test procedure forJIC. Because plastic deformation occurs without any volume change, the in‐plane plastic zone developed around a crack tip should be accompanied by out‐of‐plane deformation, that is, side necking. With the aid of the new measurement technique, side necking is expected to act as a gauge for indicating the plastic zone size. As a preliminary study, the geometrical relationships between side necking and the plastic zone size near a crack tip in ductile metals are explored by using a finite element model with modified boundary conditions. As parameters representing the geometrical similarity between side necking and the plastic zone, the shapes of each region, the distances from the crack tip to the boundaries of each region,rpandrsand the areas of each region,ApandAsare examined for their sensitivities to variables such as mode mixity, hardening exponent and so on. Among them, the areas,ApandAsseem to be the best for application because an excellent linearity between them is maintained in a wide range of mode mixity and load level regardless of the hardening exponent, specimen thickness and yield stress.
Multiaxial fatigue limits and material sensitivity to non‐zero mean stresses normal to the critical planes
Authors: SUSMEL L. 
Published: May 2008

ABSTRACTThis paper is concerned with an attempt to reformulate the so‐called Modified Wöhler Curve Method (MWCM) in order to more efficiently account for the detrimental effect of non‐zero mean stresses perpendicular to the critical planes. In more detail, by taking as a starting point the well‐established experimental evidence that engineering materials exhibit different sensitivities to superimposed tensile static stresses, an effective value of the normal mean stress relative to the critical plane was attempted to be calculated by introducing a suitable correction factor. Such a mean stress sensitivity index was assumed to be a material constant, i.e. a material parameter to be determined by running appropriate experiments. The accuracy of the novel reformulation of the MWCM proposed here was systematically checked by using several experimental data taken from the literature. In particular, in order to better explore the main features of the improved MWCM, its accuracy in estimating multiaxial high‐cycle fatigue damage was evaluated by considering fatigue results generated not only under non‐zero mean stresses but also under non‐proportional loading. Such a validation exercise allowed us to prove that the systematic use of the mean stress sensitivity index resulted in estimates falling within an error interval equal to about ±10%, and this held true independently of considered material and complexity of the investigated loading path. Finally, such a novel reformulation of the MWCM was also applied along with the Theory of Critical Distances (TCD) to predict the high‐cycle fatigue strength of notched samples tested under in‐phase bending and torsion with superimposed tensile and torsional static stresses: again our method was seen to be highly accurate, correctly predicting high‐cycle multiaxial fatigue damage also in the presence of stress concentration phenomena.
Potentiation of reflex erectile responses in the anaesthetized rat by the selective melanocortin receptor 4 agonist MB243
Authors: Allard Julien , Reynolds David S. , Edmunds Nicholas J. 
Published: May 2008

OBJECTIVETo assess the potentiation of erectile responses induced by electrical stimulation (ES) of the dorsal penile nerve (DPN) in the urethane‐anaesthetized rat by the selective melanocortin receptor 4 agonist MB243.MATERIALS AND METHODSIntracavernosal and blood pressures (ICP and BP, respectively) were monitored in urethane‐anaesthetized rats after complete spinal cord transection at the thoracic level. Erectile responses were induced by ES of the DPN (train of square wave pulses of 1 ms and 6 V for 20 s at 1, 2 and 5 Hz) after i.v. injection of either saline or MB243, 3 mg/kg, in two groups of six rats. The maximal and mean ICP, and the area under the curve (AUC) of the ICP response, corrected for the corresponding BP, were measured and used as an index of erectile function (ICPmax/BP, ICPmean/BP and AUC/BP, respectively).RESULTSMB243 increased the number of spontaneous erections between the injection and the first ES when compared with the vehicle group, but this difference was not statistically significant. ES of the DPN induced frequency‐dependent erectile responses, the mean (sem) ICPmean/BP was 0.26 (0.02), 0.34 (0.04) and 0.39 (0.05) after administration of saline (vehicle) at 1, 2 and 5 Hz, respectively. All the variables, except the ICPmax/BP at 5 Hz, were significantly increased in the group injected with MB243 when compared with the vehicle group (P < 0.05 for ICPmax/BP and ICPmean/BP; P < 0.01 for AUC/BP). The AUC/BP showed the greatest increases of (+79%, +60% and +44% at 1, 2 and 5 Hz, respectively) in the group injected with MB243 compared with the vehicle group.CONCLUSIONErectile responses induced by ES of the DPN in spinalized, urethane‐anaesthetized rat are suitable for evaluating the proerectile facilitator activity of selective peripherally restricted melanocortin receptor 4 agonists. This model represents a valuable alternative to the classically used cavernous/pelvic nerve stimulated model.