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Quantitative Study (quantitative + study)
Selected AbstractsLimitations of Right Internal Thoracic Artery to Left Anterior Descending Artery Bypass: A Comparative Quantitative Study of Postoperative Angiography of the Bilateral Internal Thoracic Artery Bypass GraftsJOURNAL OF CARDIAC SURGERY, Issue 4 2008Mizuho Imamaki M.D. Methods: The 111 subjects underwent graft angiography after bypass grafting of the left or right internal thoracic artery (ITA) to the LAD. The vascular caliber was measured at the origin of the ITA, at an ITA site adjacent to the anastomotic site, and at an LAD site immediately below the anastomotic site, regarding the outer diameter of the catheter as a reference. Results: The caliber of the ITA immediately above the anastomotic site of the LAD was significantly lower in the RITA group. In the left internal thoracic artery (LITA) group, no patient showed a caliber of less than 1.25 mm, but five patients (7.8%) did in the RITA group. The preoperative cardio-thoracic ratio was significantly higher than that in patients in whom the caliber of the ITA immediately above the anastomotic site was 1.25 mm or more, and the height was significantly lower. Conclusions: In many patients, the RITA is appropriate as a graft material to the LAD. However, in patients with a high cardio-thoracic ratio and those with a low height, the RITA may not reach the LAD in a favorable state, and the LITA should be anastomosed to the LAD in some patients. [source] The "Cross" Signs in Patients With Multiple System Atrophy: A Quantitative StudyJOURNAL OF NEUROIMAGING, Issue 1 2006Kazuo Abe MD ABSTRACT Patients with multiple system atrophy (MSA) may show the "cross" sign in the pontine base that has been considered as an expression of the degeneration of pontine neurons and transverse pontocerebellar fibers. However, correlations between pontine base atrophy and existence of "cross" sign have not been fully investigated. The authors studied 68 patients with MSA (47 MSA-C [predominantly cerebellar ataxia], 21 MSA-P [predominantly parkinsonism], mean [±SD ] 58.7 ± 10.9 years). T1-weighted (T1W) sagittal and axial images and T2-weighted (T2W) axial images were obtained for all patients and controls. To measure the areas of pontine basis and cerebellar vermis, the authors used midsagittal T1W images and analyzed a bit map transformed on a computer. They classified atrophy in the pontine base into 3 grades. There is significant correlation between atrophies of pontine base and existence of the cross sign. All patients with a smaller area of pontine base 2 standard deviations below those of normal controls had the cross sign. This supports that existence of the cross sign depends only on the extent of pontine base atrophies. [source] A Quantitative Study of the Medial Surface Dynamics of an In Vivo Canine Vocal Fold during Phonation,THE LARYNGOSCOPE, Issue 9 2005Michael Doellinger PhD Abstract Objectives/Hypothesis: The purpose of this study was to measure the medial surface dynamics of a canine vocal fold during phonation. In particular, displacements, velocities, accelerations, and relative phase velocities of vocal fold fleshpoints were reported across the entire medial surface. Although the medial surface dynamics have a profound influence on voice production, such data are rare because of the inaccessibility of the vocal folds. Study Design: Medial surface dynamics were investigated during both normal and fry-like phonation as a function of innervation to the recurrent laryngeal nerve for conditions of constant glottal airflow. Methods: An in vivo canine model was used. The larynx was dissected similar to methods described in previous excised hemilarynx experiments. Phonation was induced with artificial airflow and innervation to the recurrent laryngeal nerve. The recordings were obtained using a high-speed digital imaging system. Three dimensional coordinates were computed for fleshpoints along the entire medial surface. The trajectories of the fleshpoints were preprocessed using the method of Empirical Eigenfunctions. Results: Although considerable variability existed within the data, in general, the medial-lateral displacements and vertical displacements of the vocal fold fleshpoints were large compared with anterior-posterior displacements. For both normal and fry-like phonation, the largest displacements and velocities were concentrated in the upper medial portion. During normal phonation, the mucosal wave propagated primarily in a vertical direction. Above a certain threshold of subglottal pressure (or stimulation to the recurrent laryngeal nerve), an abrupt transition from chest-like to fry-like phonation was observed. Conclusions: The study reports unique, quantitative data regarding the medial surface dynamics of an in vivo canine vocal fold during phonation, capturing both chest-like and fry-like vibration patterns. These data quantify a complex set of dynamics. The mathematical modeling of such complexity is still in its infancy and requires quantitative data of this nature for development, validation, and testing. [source] A Quantitative Study of the Neural Changes Underlying Pyloric Stenosis in DogsANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2002R. M. Abel Summary This study aimed to quantify the neural changes in congenital pyloric stenosis in dogs and to study the comparative anatomy between this condition in dogs and that in infantile hypertrophic pyloric stenosis. Eight specimens from the pylorus of dogs with pyloric stenosis and six control specimens were examined using conventional histology and immunohistochemistry for a range of neural antigens. The changes in the proportion of nerves immunoreactive for each antigen were quantified and analysed statistically. The morphology of the nerves in the diseased dogs was similar to that in controls. Only vasoactive intestinal peptide was reduced in expression in dogs (median proportion in control dogs 0.57, in diseased dogs 0.17; P = 0.065). This study demonstrates both morphological similarities and significant differences between closely related conditions in dogs, humans and other species. [source] Judicial Interaction on the Latham Court: A Quantitative Study of Voting Patterns on the High Court 1935-1950AUSTRALIAN JOURNAL OF POLITICS AND HISTORY, Issue 3 2001Russell Smyth This article examines voting patterns in two sub-periods of the Latham Court (1935-1940 and 1940-1950), where voting is defined as a decision (and associated judgements) by the Justices participating in the disposition of a particular case. There are two main findings. First, from 1935 to 1940 there was a clear four-Justice core consisting of Justices Sir George Rich, Sir Owen Dixon, Herbert Vere Evatt and Sir Edward McTiernan. Over this period, both Chief Justice Sir John Latham and Justice Sir Hayden Starke were outside the core. Second, with the retirement of Justice Evatt, and appointment of Justice Sir Dudley Williams in 1940, the decision-making structure of the Court changed. From 1940 to 1950 there was a loose five-Justice core consisting of Chief Justice Latham, Justices Rich, Dixon, McTiernan and Williams with Justice Starke on the outside. The article argues that observed voting patterns can be explained in terms of personal relationships and ideological differences between the Justices. [source] A Quantitative Study of Fault Zone SealingACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2010Yang LI Abstract: A fault is not simply a plane, but a zone consisting of a series of broken planes or lower faults. The greater the scale of faults, the wider and more complex the fault zone is. Fault-sealing properties are influenced by the fault zone itself, whose fault displacement, depth, net-to-gross-ratio of mudstone, fault plane angle, and fault mechanical properties play important controlling roles. The sealing of hydrocarbon by the fault zone depends on whether the fault zone can form a continuous sealing zone and if the pore throats connecting those fault zones are small enough. The concept of fault zone-sealing potential is proposed here, and a quantitative formula is established by using a great amount of practical statistical data as well as the fuzzy comprehensive evaluation method, which is a comprehensive characterization parameter to judge whether or not fault zones could seal oil hydrocarbon. The greater the value of the fault zone-sealing potential, the better sealed the fault is. For example, with increasing depth, the sealing degree of the Xin 68 Fault in the Dongxin 1 oilfield changes greatly, reflecting the complexity of fault-sealing properties. [source] Quantitative study of bite force during sleep associated bruxismJOURNAL OF ORAL REHABILITATION, Issue 5 2001K. Nishigawa Nocturnal bite force during sleep associated bruxism was measured in 10 subjects. Hard acrylic dental appliances were fabricated for the upper and lower dentitions of each subject. Miniature strain-gauge transducers were mounted to the upper dental appliance at the right and left first molar regions. In addition, thin metal plates that contact the strain-gauge transducers were attached to the lower dental appliance. After a 1-week familiarization with the appliances, nocturnal bite force was measured for three nights at the home of each subject. From the 30 recordings, 499 bruxism events that met the definition criteria were selected. The above described system was also used to measure the maximum voluntary bite forces during the daytime. The mean amplitude of detected bruxism events was 22·5 kgf (s.d. 13·0 kgf) and the mean duration was 7·1 s (s.d. 5·3 s). The highest amplitude of nocturnal bite force in individual subjects was 42·3 kgf (15·6,81·2 kgf). Maximum voluntary bite force during the daytime was 79·0 kgf (51·8,99·7 kgf) and the mean ratio of nocturnal/daytime maximum bite force was 53·1% (17·3,111·6%). These data indicate that nocturnal bite force during bruxism can exceed the amplitude of maximum voluntary bite force during the daytime. [source] The anterior olfactory nucleus: Quantitative study of dendritic morphologyTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 9 2010Peter C. Brunjes Abstract The anterior olfactory nucleus (AON) occupies a crucial position within the olfactory circuit, as it is able to influence function in nearly every major synaptic processing stage of both the ipsilateral and the contralateral pathways. Nevertheless, very little is known about the region's internal organization and circuitry. The present study provides basic quantitative and qualitative data on the morphology of several cell types within the two major regions of the AON, pars externa and pars principalis. In pars externa two types of cells are analyzed, the "classical" cell (type I), containing only apically directed dendrites with large spines, and a previously unreported cell with basilar dendrites and complex, spiny apical processes (type II). In pars principalis the characteristic pyramidal cell is described both on the basis of the depth of the cell bodies in the cell layer comprising the structure and on the basis of their radial location. Several other nonpyramidal neurons are also described. The findings provide useful basic information necessary for understanding and modeling the circuitry of the AON. J. Comp. Neurol. 518:1603,1616, 2010. © 2009 Wiley-Liss, Inc. [source] Quantitative study on cerebral blood volume determined by a near-infrared spectroscopy during postural change in childrenACTA PAEDIATRICA, Issue 3 2009Yasuko Taeja Kim Abstract Aim: To investigate changes in cerebral blood volume during standing in healthy children with or without abnormal cardiovascular responses. Methods: We studied 53 children (age, 10,15 years). Cerebral oxygenated haemoglobin (oxy-Hb) and deoxygenated Hb (deoxy-Hb) were non-invasively and continuously measured using near-infrared spectroscopy (NIRS) (NIRO 300, Hamamatsu Photomedics, Shizuoka, Japan) during active standing. Beat-to-beat arterial pressure was monitored by Portapres. Results: Of 49 children with complete data acquisition, 33 had a normal cardiovascular response to the test (Group I) and 16 showed an abnormal response (Group II); nine with instantaneous orthostatic hypotension, three with postural tachycardia syndrome, three with neutrally mediated syncope and one with delayed orthostatic hypotension. At the onset of standing, Group II showed a significantly larger fall of oxy-Hb than Group I did (,2.9 ± 2.8 ,mol/L vs. ,6.4 ± 7.2 ,mol/L, respectively, p < 0.05). During min 1 to 7 of standing, with one exception, changes in oxy-Hb were normally distributed over the level of ,4 ,mol/L in Group I. Group II also showed a significantly marked decrease in oxy-Hb compared to Group I. Decreases in oxy-Hb were not correlated with blood pressure changes. Conclusion: This study shows that precise change in cerebral blood volume caused by orthostatic stress can be determined by NIRS in children in a quantitative manner of NIRS. Children with abnormal circulatory responses to standing showed a significant reduction of oxy-Hb compared with normal counterparts, suggesting impairment of cerebral autoregulation in these children. [source] Six Factors Fostering Protest: Predicting Participation in Locally Unwanted Land Uses MovementsPOLITICAL PSYCHOLOGY, Issue 6 2009Terri Mannarini In two studies we analyzed the predictors of participation in an Italian Lulu mobilization, rooted in the Susa Valley, a North-Western Italian valley where a high speed railway (HSR) should be sited. Based on the data of qualitative Study 1, performed interviewing 12 anti-HSR militants and 12 non anti-HSR militants, we hypothesized that Klandermans' (1997) model on participation (centered on group identification, sense of injustice, and collective efficacy) is suitable to predict the Lulu mobilization we studied, and that three contextual variables (community involvement, the perception of the existence of a vast majority in the community favoring the mobilization, and place attachment) may be added to Klandermans' to predict such a mobilization. We formally tested such hypotheses in quantitative Study 2 (representative sample of the people living in the Susa Valley, N = 250). Results supported the role of Klandermans' (1997) variables and confirmed the influence exerted by our contextual variables, thus suggesting that an integration of the two models would be fruitful in the analysis of Lulu mobilizations. Limits and future developments of this research are discussed. [source] A quantitative study of the optic nerve in diabetic mutant, Otsuka Long-Evans Tokushima Fatty (OLETF) ratsCONGENITAL ANOMALIES, Issue 4 2001Kazuhiko Sawada ABSTRACT, Optic nerves of the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, an animal model of non-insulin dependent diabetes mellitus, were examined using quantitative stereological procedures. At 67 weeks of age, OLETF rats showed a mild hyperglycemia: their blood glucose level was 196 ± 93 mg/dl, significantly higher than that of non-diabetic control Long-Evans Tokushima Otsuka (LETO) rats (110 ± 24 mg/dl). However, there were no differences in the cross sectional area of optic nerves (the mean minimum diameter), the total number and mean diameter of both myelinated and non-myelinated fibers, or the thickness of the myelin sheath between OLETF and LETO rats. The results suggested that a mild hyperglycemia in OLETF rats could not cause any morphological changes in the optic nerve. [source] Spatial utilisation of fast-ice by Weddell seals Leptonychotes weddelli during winterECOGRAPHY, Issue 3 2005Samantha Lake This study describes the distribution of Weddell seals Leptonychotes weddelli in winter (May,September 1999) at the Vestfold Hills, in Prydz Bay, East Antarctica. Specifically, we describe the spatial extent of haul-out sites in shore,fast sea-ice, commonly referred to as fast-ice. As winter progressed, and the fast-ice grew thick (ca 2 m), most of the inshore holes closed over, and the seals' distribution became restricted to ocean areas beyond land and islands. Using observations from the end of winter only, we fitted Generalised Additive Models (GAMs) to generate resource selection functions, which are models that yield values proportional to the probability of use. The models showed that seal distribution was defined mainly by distance to ice-edge and distance to land. Distance to ice-bergs was also selected for models of some regions. We present the results as maps of the fitted probability of seal presence, predicted by the binomial GAM for offshore regions, both with and without autocorrelation terms. The maps illustrate the expected distribution encompassing most of the observed distribution. On this basis, we hypothesise that propensity for the fast-ice to crack is the major determinant of Weddell seal distribution in winter. Proximity to open water and pack-ice habitats could also influence the distribution of haul-out sites in fast-ice areas. This is the first quantitative study of Weddell seal distribution in winter. Potential for regional variation is discussed. [source] Consequences of dispersal for the quantitative study of adaptation in small-scale plots: a case study of an avian island populationECOGRAPHY, Issue 5 2000M. M. Lambrechts Lifetime recruitment of breeding offspring estimated in small-scale study plots (i.e. local recruitment) is considered to be the best available ecological measure of contributions to following generations, and sufficient for the quantitative study of adaptation in natural populations. Recent investigations suggest that local recruitment of breeding offspring does not always reflect the total recruitment in the whole population, especially in small-scale plots where the majority of locally-born offspring leave these plots to breed elsewhere. We examined in an avian island population whether study plot size has an important impact on different population and fitness measures. We defined around a central nestbox seven plots, varying in radius from 100 to 700 m. We show that in the smallest plots, the local replacement rate of adults by breeding offspring is low, the number of locally-born offspring settling beyond the limits of a plot is high, and relationships between local and total recruitment are weak. This is especially true for daughters as more daughters than sons settle beyond the limits of local plots for breeding. Our interpretation is that the lifetime recruitment of breeding offspring in local plots does not necessarily reflect the lifetime recruitment of breeding offspring in the whole population, especially when plots do not cover the natal dispersal distance. Consequences of dispersal for the quantitative study of adaptation are discussed. [source] Structure and vertical stratification of plant galler,parasitoid food webs in two tropical forestsECOLOGICAL ENTOMOLOGY, Issue 3 2009MIGUEL R. PANIAGUA Abstract 1.,Networks of feeding interactions among insect herbivores and natural enemies such as parasitoids, describe the structure of these assemblages and may be critically linked to their dynamics and stability. The present paper describes the first quantitative study of parasitoids associated with gall-inducing insect assemblages in the tropics, and the first investigation of vertical stratification in quantitative food web structure. 2.,Galls and associated parasitoids were sampled in the understorey and canopy of Parque Natural Metropolitano in the Pacific forest, and in the understorey of San Lorenzo Protected Area in the Caribbean forest of Panama. Quantitative host,parasitoid food webs were constructed for each assemblage, including 34 gall maker species, 28 host plants, and 57 parasitoid species. 3.,Species richness was higher in the understorey for parasitoids, but higher in the canopy for gall makers. There was an almost complete turnover in gall maker and parasitoid assemblage composition between strata, and the few parasitoid species shared between strata were associated with the same host species. 4.,Most parasitoid species were host specific, and the few polyphagous parasitoid species were restricted to the understorey. 5.,These results suggest that, in contrast to better-studied leaf miner,parasitoid assemblages, the influence of apparent competition mediated by shared parasitoids as a structuring factor is likely to be minimal in the understorey and practically absent in the canopy, increasing the potential for coexistence of parasitoid species. 6.,High parasitoid beta diversity and high host specificity, particularly in the poorly studied canopy, indicate that tropical forests may be even more species rich in hymenopteran parasitoids than previously suspected. [source] Quantitative evaluation of sample application methods for semipreparative separations of basic proteins by two-dimensional gel electrophoresisELECTROPHORESIS, Issue 19-20 2003Richard C. Barry Abstract The use of cup-loading for sample application has become widely used in two-dimensional electrophoresis (2-DE) for resolution of basic proteins, but no side-by-side quantitative study has been published which compares cup-loading with the alternative passive and active rehydration methods to fully promote one type of loading method over another. Replicate 2-D gels from each loading method were quantitatively evaluated for gel-to-gel reproducibility using IPG 6,11 strips and semipreparative protein loads (300 ,g). Gels were stained with SYPRO Ruby and analyzed with PDQuest. An inexpensive home-made assembly for cup-loading was used with the Protean IEF Cell for separation of whole cell extracts from the archaeon, Sulfolobus solfataricus. Cup-loading was determined to be far superior for IPG 6,11 separations than active or passive rehydration methods. Cup-loading consistently produced the greatest number of detectable spots, the best spot matching efficiency (56%), lowest spot quantity variations (28% coefficient of variation, CV), and the best-looking gels qualitatively. The least satisfactory results were obtained with active rehydration, followed closely by passive rehydration in off-line tubes. Passive rehydration experiments, performed using an on-line isoelectric focusing (IEF) tray, produced comparable spot numbers to cup-loading (84%), with 55% of the spots having higher intensity but 10% more spot quantity variance than cup-loading. [source] ON THE OPPORTUNITY FOR SEXUAL SELECTION, THE BATEMAN GRADIENT AND THE MAXIMUM INTENSITY OF SEXUAL SELECTIONEVOLUTION, Issue 7 2009Adam G. Jones Bateman's classic paper on fly mating systems inspired quantitative study of sexual selection but also resulted in much debate and confusion. Here, I consider the meaning of Bateman's principles in the context of selection theory. Success in precopulatory sexual selection can be quantified as a "mating differential," which is the covariance between trait values and relative mating success. The mating differential is converted into a selection differential by the Bateman gradient, which is the least squares regression of relative reproductive success on relative mating success. Hence, a complete understanding of precopulatory sexual selection requires knowledge of two equally important aspects of mating patterns: the mating differential, which requires a focus on mechanisms generating covariance between trait values and mating success, and the Bateman gradient, which requires knowledge of the genetic mating system. An upper limit on the magnitude of the selection differential on any sexually selected trait is given by the product of the standard deviation in relative mating success and the Bateman gradient. This latter view of the maximum selection differential provides a clearer focus on the important aspects of precopulatory sexual selection than other methods and therefore should be an important part of future studies of sexual selection. [source] A quantitative study on the use of converted waves for sub-basalt imagingGEOPHYSICAL PROSPECTING, Issue 3 2003Peter Hanssen ABSTRACT The idea of imaging beneath a high-velocity layer using converted waves has been popular since 1990. Because these wave types have their maximum amplitudes at mid- to far-offsets, the search for pure P-waves at the highly multiple-contaminated near-offsets can be avoided. For the Atlantic Margin, with buried thin-layered basalts, our quantitative study shows that the initial single-layered approach is not viable. Even in an unrealistic ideal geological setting, the amplitude of the symmetrical PSP-mode is far too weak to be recognized on towed streamer data. Furthermore, in the far-offset window, where locally converted waves have their strongest amplitudes, there is a multitude of other reflections, refractions and interbedded multiples, which have similar moveouts and, often, higher amplitudes. Without the removal of these events, a reliable image of the subsurface cannot be produced. We show that even if this problem were solved, it would be far easier to use the P-wave reflection from beneath the basalt at near-offsets. Our study shows that this wave type is by far the strongest response. A borehole-derived model using a thin-layered basalt sequence reveals that the strongest locally converted wave has an asymmetrical path and is 10 times weaker. All our results indicate that the pure P-modes provide the best chance of imaging sub-basalt sedimentary interfaces. [source] Neuropsychological correlates of hippocampal and rhinal cortex volumes in patients with mesial temporal sclerosisHIPPOCAMPUS, Issue 8 2003Catherine E. O'Brien Abstract Considerable progress has been made toward understanding the function of the primate rhinal cortex, comprising the entorhinal (ErC) and perirhinal (PrC) cortices. However, translating animal models to human memory has been limited by the technological problems associated with characterizing neural structures in vivo. Functional correlates of hippocampal and rhinal cortex volume changes were examined in a sample of 61 temporal lobe epilepsy patients with mesial temporal sclerosis (MTS; 33 left, 28 right). Patients were administered the Wechsler Adult Intelligence Scale (revised or third edition), the Wechsler Memory Scale (revised or third edition), and a spatial maze task. Neuropsychological data, together with rhinal cortex and hippocampal volumes, collected in our earlier study (O'Brien CE, Bowden SC, Whelan G, Cook MJ, unpublished observations), were analyzed using multiple regression. The only significant predictor of verbal memory function was the difference score between the volume of left hippocampus and the left PrC. Spatial maze scores were predicted by the bilateral sum of ErC volume. The difference score between the left hippocampus and left PrC volumes was the most powerful predictor of verbal episodic memory. Right hippocampal volume was not a significant predictor of nonverbal episodic memory. Verbal and nonverbal semantic memory were not significantly predicted by any combination of rhinal cortex structures. This quantitative study suggests a lateralized or material-specific memory function for the left hippocampus and left PrC, in contrast to the bilateral role of the ErC. The left hippocampus and left PrC appear to act on verbal memory function through an opposing relationship. Finally, differentiation between hippocampal and subhippocampal components in terms of episodic and semantic memory, respectively, could not be supported by the current data. © 2003 Wiley-Liss, Inc. [source] Neural network approach to stereoscopic correspondence of three-dimensional particle tracking velocimetryIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 6 2008Achyut Sapkota Student Member Abstract Particle tracking velocimetry (PTV) is a reliable measurement technique for the quantitative study of fluid flows by observing the motion of the particles seeded in them and is widely used in several industrial applications. The nature of the flow can be precisely observed only if all the three components of the velocity are computed. In 3-D PTV system, particles viewed by two (or more than two) stereoscopic cameras with a parallax have to be correctly paired at every synchronized time step. This is important because the 3-D coordinates of individual particles cannot be computed without the knowledge of the correct stereo correspondence of the particles. In the present work, a neural network,based algorithm has been proposed for the stereoscopic particle pairing process. The correspondence between the particle pairs is modeled as a constrained optimization problem. The constraints are provided on the basis of the epipolar geometry of the particle images and on the basis of the uniqueness of the matched pairs. The results are tested with various standard images. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] A discrete model for the dynamic propagation of shear bands in a fluid-saturated mediumINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 2 2007Julien 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] A quantitative study of epidermal Langerhans cells in cutaneous leishmaniasis caused by Leishmania tropicaINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 11 2004Simin Meymandi MD Objective, The purpose of this study was to characterize the number and distribution of epidermal Langerhans cells in different clinical forms of dry-type cutaneous leishmaniasis (CL). Methods, Sixteen cases of dry-type cutaneous leishmaniasis caused by Leishmania tropica were studied. These cases were classified clinically as five cases of acute leishmaniasis with indurated papules, nodules and plaques with central crust formation and duration < 2 years, six cases of lupoid leishmaniasis with characteristic papules around previous scars of cutaneous leishmaniasis with duration > 2 years, and five cases of chronic nonlupoid type with nonhealing lesions of duration > 2 years. Paraffin-embedded blocks were stained with hematoxylin and eosin (H&E) and stained immunohistochemically for CD1a. Results, The number of Langerhans cells per millimeter length of epidermis was increased in acute cases compared to chronic and lupoid cases. Conclusions, Lesions of acute leishmaniasis contain the greatest amounts of antigen for presentation, so Langerhans cells increase in number and in trafficking to present antigens derived from Leishman bodies to the cellular immune system. In chronic leishmaniasis, the Langerhans cell population is reduced, perhaps because of exhaustion of the source of Langerhans cells, or because of reduced response to modified antigen. [source] The impact of brand orientation on managerial practice: a quantitative study of the UK's top 500 fundraising managersINTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 1 2002Philippa Hankinson This paper explores the impact of brand orientation on the managerial practices of fundraising managers in the top 500 UK charities and, in particular, on their ability to attract voluntary income. A series of hypotheses was tested including whether level of brand orientation is associated with different patterns of influence within charities, with the range and type of brand communicators used and with the extent to which organisational objectives are fulfilled. A key finding of the research was that high brand-oriented fundraising managers attract significantly more voluntary income than low brand-oriented fundraisers, but that level of brand orientation was not related to statutory income. Such findings are consistent with current theory and practice of branding in which a brand is perceived as a product or organisation plus, where the plus indicates a unique set of values which allows differentiation and hence, donor choice, within competitive environments. Copyright © 2002 Henry Stewart Publications [source] Digital cementum luminance analysis (DCLA): a tool for the analysis of climatic and seasonal signals in dental cementumINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 1 2008C. 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] Screening for cervical cancer among Israeli lesbian womenINTERNATIONAL NURSING REVIEW, Issue 4 2009M. Ben-Natan rn Background:, The proportion of lesbian women who contract the human papilloma virus may reach 13% or even 21%; however, lesbian women were found to receive Pap smear tests less often or less regularly. Aim:, To explore factors influencing lesbian women to undergo Pap smear tests and to determine whether the Health Belief Model (HBM) is able to predict whether lesbian women would be willing to undergo the test. Method:, This is a correlational quantitative study guided by the HBM. A convenience sample of 108 Israeli lesbian women was recruited from local events in the lesbian community in the city of Tel Aviv, Israel. Data were collected using a self-administered questionnaire. Findings:, Findings indicate that only 22.2% of the women had undergone Pap smear tests in the past, but a slightly higher proportion, 30.8%, intended to be tested during the next year. Older women were found to be more compliant with the test. Model-based factors affecting actual testing were perceived benefits and barriers. Factors affecting women's intention to be tested were perceived susceptibility, perceived benefits and general health motivation. Conclusions:, Effective strategies for nurses promoting cervical cancer screening among lesbians should address ways to improve familiarity with Pap smear tests, raise physicians' awareness of offering the test to lesbians and emphasize the importance of women-based medical teams. [source] Awareness and determinants of family planning practice in Jimma, EthiopiaINTERNATIONAL NURSING REVIEW, Issue 4 2006A. T. Beekle rgn Background:, The continuing growth of the world population has become an urgent global problem. Ethiopia, like most countries in sub-Saharan Africa, is experiencing rapid population growth. Currently, the country's population is growing at a rate of 3%, one of the highest rates in the world and if it continues unabated, the population will have doubled in 23 years, preventing any gain in the national development effort. Aim:, To determine the level and determinants of family planning awareness and practice in one Ethiopian town. Methodology:, A quantitative study using a descriptive survey design was conducted in Jimma University Hospital. Discussion:, The findings revealed that the knowledge and practice of modern contraception methods was low. Most women's contraceptive knowledge and practice was influenced by socio-cultural norms such as male/husband dominance and opposition to contraception, and low social status of women. A lack of formal education for women was identified as a key factor in preventing change in the patterns of contraceptive knowledge and use by women in this part of Ethiopia. Conclusion:, The support and encouragement for women and men to enter and complete formal education is essential in bringing about a cultural and social change in attitude towards the economic and social value of family planning. This study and others suggest that education can address the imbalance in decision making about contraception and the role of women in society generally. [source] A quantitative study of day,night changes in the spatial distribution of insects in a stony streamJOURNAL OF ANIMAL ECOLOGY, Issue 1 2002J. M. Elliott Summary 1As many invertebrates are nocturnal, their spatial distribution may change from day to night. This behavioural aspect of their population dynamics has been ignored, but is now examined for the first time by testing the hypotheses: (i) a power function was a suitable model for the spatial distribution of common species of Ephemeroptera, Plecoptera and Trichoptera in a stony stream; (ii) the spatial distribution varied between species but was similar within species for larvae greater and smaller than half-size; (iii) diurnal and nocturnal spatial distributions were significantly different for each species. To ensure that the conclusions were consistent, large samples (n = 30) were taken near midday and midnight in April, June and November over 4 years. 2Twenty,one species were taken in sufficient numbers for the analyses; seven species were too sparse to be included. The first hypothesis was supported. A power function, relating spatial variance (s2) to mean (m), was an excellent fit in all the analyses (P < 0·001, r2 > 0·95), i.e. the spatial variance was density,dependent. The power b, often used as an ,index of aggregation', varied in the range 0·88,2·50. 3Most analyses supported the second hypothesis. For four species, the difference between the two size groups was just significant (P < 0·05), but was due to inadequate data for three species. Large larvae of the fourth species, the caddis Odontocerum albicorne, were less aggregated than small larvae at night, and were the only group with a b -value less than one. 4The third hypothesis was partially supported. The distribution did not change significantly (P > 0·05) for nine species; five burrowers in gravel, moss or mud, two highly mobile predators, one sedentary, case,building, Trichoptera species, and one net,spinning Trichoptera species. Aggregation was reduced significantly (P < 0·001) at night for four species, all case,building Trichoptera larvae. Aggregation increased significantly (P < 0·001) at night, except at low densities, for the remaining eight species, one being a nocturnal predator and the others being herbivorous species; all occurred frequently in night samples of invertebrate drift. Day,night changes in spatial distribution were therefore an essential part of the behavioural dynamics of 12 of the 21 species, and should be investigated in other species, including terrestrial species. [source] The Statistical Analysis of Judicial Decisions and Legal Rules with Classification TreesJOURNAL OF EMPIRICAL LEGAL STUDIES, Issue 2 2010Jonathan P. Kastellec A key question in the quantitative study of legal rules and judicial decision making is the structure of the relationship between case facts and case outcomes. Legal doctrine and legal rules are general attempts to define this relationship. This article summarizes and utilizes a statistical method relatively unexplored in political science and legal scholarship,classification trees,that offers a flexible way to study legal doctrine. I argue that this method, while not replacing traditional statistical tools for studying judicial decisions, can better capture many aspects of the relationship between case facts and case outcomes. To illustrate the method's advantages, I conduct classification tree analyses of search and seizure cases decided by the U.S. Supreme Court and confession cases decided by the courts of appeals. These analyses illustrate the ability of classification trees to increase our understanding of legal rules and legal doctrine. [source] Altered osteoclast development and function in osteopontin deficient miceJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2008Ahnders Franzén Abstract The role of osteopontin in bone resorption was elucidated by studies of mice with knock out of the osteopontin gene generated by a different approach compared to previous models. Thus, a targeting vector with the promoter region as well as exons 1, 2, and 3 of the osteopontin gene was replaced by a loxP-flanked Neo-TK cassette, and this cassette was eliminated through transient expression of Cre recombinase. The recombined ES cells were used to create mice lacking expression of the osteopontin gene. Tissues from these mice were subjected structural and molecular analyses including morphometry and proteomics. The bone of the null mice contained no osteopontin but showed no significant alterations with regard to other bone proteins. The bone volume was normal in young null animals but in the lower metaphysis, the volume and number of osteoclasts were increased. Notably, the volume and length of the osteoclast ruffled border was several folds lower, indicating a lower resorptive capacity. The null mice did not develop the bone loss characteristic for osteoporosis demonstrated in old wild-type female animals. This quantitative study demonstrates a bone phenotype in the osteopontin null mice of all ages. The data provides further evidence for a role of osteopontin in osteoclast activity. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:721,728, 2008 [source] Effect of aging and degeneration on disc volume and shape: A quantitative study in asymptomatic volunteersJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2006Christian W. A. Pfirrmann Abstract Debate continues on the effect of disc degeneration and aging on disc volume and shape. So far, no quantitative in vivo MRI data is available on the factors influencing disc volume and shape. The objective of this MRI study was to quantitatively investigate changes in disc height, volume, and shape as a result of aging and/or degeneration omitting pathologic (i.e., painful) disc alterations. Seventy asymptomatic volunteers (20,78 years) were investigated with sagittal T1- and T2-weighted MR-images encompassing the whole lumbar spine. Disc height was determined by the Dabbs method and the Farfan index. Disc volume was calculated by the Cavalieri method. For the disc shape the "disc convexity index" was calculated by the ratio of central disc height and mean anterior/posterior disc height. Disc height, disc volume, and the disc convexity index measurements were corrected for disc level and the individuals age, weight, height, and sex in a multilevel regression analysis. Multilevel regression analysis showed that disc volume was negatively influenced by disc degeneration (p,<,0.001) and positively correlated with body height (p,<,0.001) and age (p,<,0.01). Mean disc height and the disc convexity index were negatively influenced by disc degeneration but not by gender, weight, and height. Disc height was positively correlated with age (p,<,0.01). From the results of this study, it can be concluded that disc degeneration generally results in a decrease of disc height and volume as well as a less convex disc shape. In the absence of disc degeneration, however, age tends to result in an inverse relationship on disc height, volume, and shape. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] CFD modeling of heat transfer in turbulent pipe flowsAICHE JOURNAL, Issue 9 2000S. S. Thakre Twelve versions of low Reynolds number k-, and two low Reynolds number Reynolds stress turbulence models for heat transfer were analyzed comparatively. Predictions of the mean axial temperature, the radial and axial turbulent heat fluxes, and the effect of Prandtl number on Nusselt number were compared with the experimental data. The model by Lai and So from the k-, group and Lai and So from the Reynolds stress group had the best overall predictive ability for heat transfer in turbulent pipe flow. The Lai and So model was attributed to its success in the predictions of flow parameters such as mean axial velocity, turbulent kinetic energy, eddy diffusivity, and the overall energy dissipation rate. The k-, models performed relatively better than the Reynolds stress models for predicting the mean axial temperature and the Nusselt number. This qualitative and quantitative study found the need for more sophisticated near-wall experimental measurements and the accuracy of the dissipation (of turbulent energy) and the pressure-scrambling models. [source] | |||||||||||||||||||||||||||||||