991 resultados para Quantitative micrographic parameters
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Selostus: Ayrshire-ensikoiden koelypsykohtaisen maidontuotannon perinnölliset tunnusluvut laktaation eri vaiheissa
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The cichlids of East Africa are renowned as one of the most spectacular examples of adaptive radiation. They provide a unique opportunity to investigate the relationships between ecology, morphological diversity, and phylogeny in producing such remarkable diversity. Nevertheless, the parameters of the adaptive radiations of these fish have not been satisfactorily quantified yet. Lake Tanganyika possesses all of the major lineages of East African cichlid fish, so by using geometric morphometrics and comparative analyses of ecology and morphology, in an explicitly phylogenetic context, we quantify the role of ecology in driving adaptive speciation. We used geometric morphometric methods to describe the body shape of over 1000 specimens of East African cichlid fish, with a focus on the Lake Tanganyika species assemblage, which is composed of more than 200 endemic species. The main differences in shape concern the length of the whole body and the relative sizes of the head and caudal peduncle. We investigated the influence of phylogeny on similarity of shape using both distance-based and variance partitioning methods, finding that phylogenetic inertia exerts little influence on overall body shape. Therefore, we quantified the relative effect of major ecological traits on shape using phylogenetic generalized least squares and disparity analyses. These analyses conclude that body shape is most strongly predicted by feeding preferences (i.e., trophic niches) and the water depths at which species occur. Furthermore, the morphological disparity within tribes indicates that even though the morphological diversification associated with explosive speciation has happened in only a few tribes of the Tanganyikan assemblage, the potential to evolve diverse morphologies exists in all tribes. Quantitative data support the existence of extensive parallelism in several independent adaptive radiations in Lake Tanganyika. Notably, Tanganyikan mouthbrooders belonging to the C-lineage and the substrate spawning Lamprologini have evolved a multitude of different shapes from elongated and Lamprologus-like hypothetical ancestors. Together, these data demonstrate strong support for the adaptive character of East African cichlid radiations.
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Pedotransfer functions (PTF) were developed to estimate the parameters (α, n, θr and θs) of the van Genuchten model (1980) to describe soil water retention curves. The data came from various sources, mainly from studies conducted by universities in Northeast Brazil, by the Brazilian Agricultural Research Corporation (Embrapa) and by a corporation for the development of the São Francisco and Parnaíba river basins (Codevasf), totaling 786 retention curves, which were divided into two data sets: 85 % for the development of PTFs, and 15 % for testing and validation, considered independent data. Aside from the development of general PTFs for all soils together, specific PTFs were developed for the soil classes Ultisols, Oxisols, Entisols, and Alfisols by multiple regression techniques, using a stepwise procedure (forward and backward) to select the best predictors. Two types of PTFs were developed: the first included all predictors (soil density, proportions of sand, silt, clay, and organic matter), and the second only the proportions of sand, silt and clay. The evaluation of adequacy of the PTFs was based on the correlation coefficient (R) and Willmott index (d). To evaluate the PTF for the moisture content at specific pressure heads, we used the root mean square error (RMSE). The PTF-predicted retention curve is relatively poor, except for the residual water content. The inclusion of organic matter as a PTF predictor improved the prediction of parameter a of van Genuchten. The performance of soil-class-specific PTFs was not better than of the general PTF. Except for the water content of saturated soil estimated by particle size distribution, the tested models for water content prediction at specific pressure heads proved satisfactory. Predictions of water content at pressure heads more negative than -0.6 m, using a PTF considering particle size distribution, are only slightly lower than those obtained by PTFs including bulk density and organic matter content.
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Anaemia is a chief determinant of global ill health, contributing to cognitive impairment, growth retardation and impaired physical capacity. To understand further the genetic factors influencing red blood cells, we carried out a genome-wide association study of haemoglobin concentration and related parameters in up to 135,367 individuals. Here we identify 75 independent genetic loci associated with one or more red blood cell phenotypes at P < 10(-8), which together explain 4-9% of the phenotypic variance per trait. Using expression quantitative trait loci and bioinformatic strategies, we identify 121 candidate genes enriched in functions relevant to red blood cell biology. The candidate genes are expressed preferentially in red blood cell precursors, and 43 have haematopoietic phenotypes in Mus musculus or Drosophila melanogaster. Through open-chromatin and coding-variant analyses we identify potential causal genetic variants at 41 loci. Our findings provide extensive new insights into genetic mechanisms and biological pathways controlling red blood cell formation and function.
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The aim of this article is to show the classical parameters of Shadowlands by R. Attenborough, with a screenplay by W. Nicholson, on C. S. Lewis's life and work. Based upon an accurate reading of Lewis's works, the author of this article proposes to interpret the opposition Lewis / Gresham as the translation into the real life of the opposition between the Platonic or idealistic and the Aristotelian or materialistic temperaments which was already maintained by Coleridge. In any case, there are many classical references which must be taken into account in order to understand to what extent C. S. Lewis's Christianity is also a classic Christianity, that is, a Greek and Latin one.
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The dynamics of N losses in fertilizer by ammonia volatilization is affected by several factors, making investigation of these dynamics more complex. Moreover, some features of the behavior of the variable can lead to deviation from normal distribution, making the main commonly adopted statistical strategies inadequate for data analysis. Thus, the purpose of this study was to evaluate the patterns of cumulative N losses from urea through ammonia volatilization in order to find a more adequate and detailed way of assessing the behavior of the variable. For that reason, changes in patterns of ammonia volatilization losses as a result of applying different combinations of two soil classes [Planossolo and Chernossolo (Typic Albaqualf and Vertic Argiaquolls)] and different rates of urea (50, 100 and 150 kg ha-1 N), in the presence or absence of a urease inhibitor, were evaluated, adopting a 2 × 3 × 2 factorial design with four replications. Univariate and multivariate analysis of variance were performed using the adjusted parameter values of a logistic function as a response variable. The results obtained from multivariate analysis indicated a prominent effect of the soil class factor on the set of parameters, indicating greater relevance of soil adsorption potential on ammonia volatilization losses. Univariate analysis showed that the parameters related to total N losses and rate of volatilization were more affected by soil class and the rate of urea applied. The urease inhibitor affected only the rate and inflection point parameters, decreasing the rate of losses and delaying the beginning of the process, but had no effect on total ammonia losses. Patterns of ammonia volatilization losses provide details on behavior of the variable, details which can be used to develop and adopt more accurate techniques for more efficient use of urea.
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INTRODUCTION: Quantitative sensory testing (QST) is widely used in human research to investigate the integrity of the sensory function in patients with pain of neuropathic origin, or other causes such as low back pain. Reliability of QST has been evaluated on both sides of the face, hands and feet as well as on the trunk (Th3-L3). In order to apply these tests on other body-parts such as the lower lumbar spine, it is important first to establish reliability on healthy individuals. The aim of this study was to investigate intra-rater reliability of thermal QST in healthy adults, on two sites within the L5 dermatome of the lumbar spine and lower extremity. METHODS: Test-retest reliability of thermal QST was determined at the L5-level of the lumbar spine and in the same dermatome on the lower extremity in 30 healthy persons under 40 years of age. Results were analyzed using descriptive statistics and intraclass correlation coefficient (ICC). Values were compared to normative data, using Z-transformation. RESULTS: Mean intraindividual differences were small for cold and warm detection thresholds but larger for pain thresholds. ICC values showed excellent reliability for warm detection and heat pain threshold, good-to-excellent reliability for cold pain threshold and fair-to-excellent reliability for cold detection threshold. ICC had large ranges of confidence interval (95%). CONCLUSION: In healthy adults, thermal QST on the lumbar spine and lower extremity demonstrated fair-to-excellent test-retest reliability.
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The statistical theory of signal detection and the estimation of its parameters are reviewed and applied to the case of detection of the gravitational-wave signal from a coalescing binary by a laser interferometer. The correlation integral and the covariance matrix for all possible static configurations are investigated numerically. Approximate analytic formulas are derived for the case of narrow band sensitivity configuration of the detector.
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OBJECTIVE: Evaluation of the quantitative antibiogram as an epidemiological tool for the prospective typing of methicillin-resistant Staphylococcus aureus (MRSA), and comparison with ribotyping. METHODS: The method is based on the multivariate analysis of inhibition zone diameters of antibiotics in disk diffusion tests. Five antibiotics were used (erythromycin, clindamycin, cotrimoxazole, gentamicin, and ciprofloxacin). Ribotyping was performed using seven restriction enzymes (EcoRV, HindIII, KpnI, PstI, EcoRI, SfuI, and BamHI). SETTING: 1,000-bed tertiary university medical center. RESULTS: During a 1-year period, 31 patients were found to be infected or colonized with MRSA. Cluster analysis of antibiogram data showed nine distinct antibiotypes. Four antibiotypes were isolated from multiple patients (2, 4, 7, and 13, respectively). Five additional antibiotypes were isolated from the remaining five patients. When analyzed with respect to the epidemiological data, the method was found to be equivalent to ribotyping. Among 206 staff members who were screened, six were carriers of MRSA. Both typing methods identified concordant of MRSA types in staff members and in the patients under their care. CONCLUSIONS: The quantitative antibiogram was found to be equivalent to ribotyping as an epidemiological tool for typing of MRSA in our setting. Thus, this simple, rapid, and readily available method appears to be suitable for the prospective surveillance and control of MRSA for hospitals that do not have molecular typing facilities and in which MRSA isolates are not uniformly resistant or susceptible to the antibiotics tested.
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A Strontium ranelate appears to influence more than alendronate distal tibia bone microstructure as assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT), and biomechanically relevant parameters as assessed by micro-finite element analysis (mu FEA), over 2 years, in postmenopausal osteoporotic women.Introduction Bone microstructure changes are a target in osteoporosis treatment to increase bone strength and reduce fracture risk.Methods Using HR-pQCT, we investigated the effects on distal tibia and radius microstructure of strontium ranelate (SrRan; 2 g/day) or alendronate (70 mg/week) for 2 years in postmenopausal osteoporotic women. This exploratory randomized, double-blind trial evaluated HR-pQCT and FEA parameters, areal bone mineral density (BMD), and bone turnover markers.Results In the intention-to-treat population (n = 83, age: 64 +/- 8 years; lumbar T-score: -2.8 +/- 0.8 [DXA]), distal tibia Cortical Thickness (CTh) and Density (DCort), and cancellous BV/TV increased by 6.3%, 1.4%, and 2.5%, respectively (all P < 0.005), with SrRan, but not with alendronate (0.9%, 0.4%, and 0.8%, NS) (P < 0.05 for all above between-group differences). Difference for CTh evaluated with a distance transformation method was close to significance (P = 0.06). The estimated failure load increased with SrRan (+2.1%, P < 0.005), not with alendronate (-0.6%, NS) (between-group difference, P < 0.01). Cortical stress was lower with SrRan (P < 0.05); both treatments decreased trabecular stress. At distal radius, there was no between-group difference other than DCort (P < 0.05). Bone turnover markers decreased with alendronate; bALP increased (+21%) and serum-CTX-I decreased (-1%) after 2 years of SrRan (between-group difference at each time point for both markers, P < 0.0001). Both treatments were well tolerated.Conclusions Within the constraints of HR-pQCT method, and while a possible artefactual contribution of strontium cannot be quantified, SrRan appeared to influence distal tibia bone microstructure and FEA-determined biomechanical parameters more than alendronate. However, the magnitude of the differences is unclear and requires confirmation with another method.
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Summary : International comparisons in the area of victimization, particularly in the field of violence against women, are fraught with methodological problems that previous research has not systematically addressed, and whose answer does not seem to be agreed up~n. For obvious logistic and financial reasons, international studies on violence against women (i.e. studies that administer the same instrument in different countries). are seldom; therefore, researchers are bound to resort to secondary comparisons. Many studies simply juxtapose their results to the ones of previous wòrk or to findings obtained in different contexts, in order to offer an allegedly comparative perspective to their conclusions. If, most of the time, researchers indicate the methodological limitations of a direct comparison, it is not rare that these do not result in concrete methodological controls. Yet, many studies have shown the influence of surveys methodological parameters on findings, listing recommendations fora «best practice» of research. Although, over the past decades, violence against women surveys have become more and more similar -tending towards a sort of uniformization that could be interpreted as a passive consensus -these instruments retain more or less subtle differences that are still susceptible to influence the validity of a comparison. Yet, only a small number of studies have directly worked on the comparability of violence against women data, striving to control the methodological parameters of the surveys in order to guarantee the validity of their comparisons. The goal of this work is to compare data from two national surveys on violence against women: the Swiss component of the International Violence Against Women Survey [CH-IVAWS] and the National Violence Against Women Survey [NVAWS] administered in the United States. The choice of these studies certainly ensues from the author's affiliations; however, it is far from being trivial. Indeed, the criminological field currently endows American and Anglo-Saxon literature with a predominant space, compelling researchers from other countries to almost do the splits to interpret their results in the light of previous work or to develop effective interventions in their own context. Turning to hypotheses or concepts developed in a specific framework inevitably raises the issue of their applicability to another context, i.e. the Swiss context, if not at least European. This problematic then takes on an interest that goes beyond the particular topic of violence against women, adding to its relevance. This work articulates around three axes. First, it shows the way survey characteristics influence estimates. The comparability of the nature of the CH-IVAWS and NVAWS, their sampling design and the characteristics of their administration are discussed. The definitions used, the operationalization of variables based on comparable items, the control of reference periods, as well as the nature of the victim-offender relationship are included among controlled factors. This study establishes content validity within and across studies, presenting a systematic process destined to maximize the comparability of secondary data. Implications of the process are illustrated with the successive presentation of comparable and non-comparable operationalizations of computed variables. Measuring violence against. women in Switzerland and the United-States, this work compares the prevalence of different forms (threats, physical violence and sexual violence) and types of violence (partner and nonpartner violence). Second, it endeavors to analyze concepts of multivictimization (i.e. experiencing different forms of victimization), repeat victimization (i.e. experiencing the same form of violence more than once), and revictimization (i.e. the link between childhood and adulthood victimization) in a comparative -and comparable -approach. Third, aiming at understanding why partner violence appears higher in the United States, while victims of nonpartners are more frequent in Switzerland, as well as in other European countries, different victimization correlates are examined. This research contributes to a better understanding of the relevance of controlling methodological parameters in comparisons across studies, as it illustrates, systematically, the imposed controls and their implications on quantitative data. Moreover, it details how ignoring these parameters might lead to erroneous conclusions, statistically as well as theoretically. The conclusion of the study puts into a wider perspective the discussion of differences and similarities of violence against women in Switzerland and the United States, and integrates recommendations as to the relevance and validity of international comparisons, whatever the'field they are conducted in. Résumé: Les comparaisons internationales dans le domaine de la victimisation, et plus particulièrement en ce qui concerne les violences envers les femmes, se caractérisent par des problèmes méthodologiques que les recherches antérieures n'ont pas systématiquement adressés, et dont la réponse ne semble pas connaître de consensus. Pour des raisons logistiques et financières évidentes, les études internationales sur les violences envers les femmes (c.-à-d. les études utilisant un même instrument dans différents pays) sont rares, aussi les chercheurs sont-ils contraints de se tourner vers des comparaisons secondaires. Beaucoup de recherches juxtaposent alors simplement leurs résultats à ceux de travaux antérieurs ou à des résultats obtenus dans d'autres contextes, afin d'offrir à leurs conclusions une perspective prétendument comparative. Si, le plus souvent, les auteurs indiquent les limites méthodologiques d'une comparaison directe, il est fréquent que ces dernières ne se traduisent pas par des contrôles méthodologiques concrets. Et pourtant, quantité de travaux ont mis en évidence l'influence des paramètres méthodologiques des enquêtes sur les résultats obtenus, érigeant des listes de recommandations pour une «meilleure pratique» de la recherche. Bien que, ces dernières décennies, les sondages sur les violences envers les femmes soient devenus de plus en plus similaires -tendant, vers une certaine uniformisation que l'on peut interpréter comme un consensus passif-, il n'en demeure pas moins que ces instruments possèdent des différences plus ou moins subtiles, mais toujours susceptibles d'influencer la validité d'une comparaison. Pourtant, seules quelques recherches ont directement travaillé sur la comparabilité des données sur les violences envers les femmes, ayant à coeur de contrôler les paramètres méthodologiques des études utilisées afin de garantir la validité de leurs comparaisons. L'objectif de ce travail est la comparaison des données de deux sondages nationaux sur les violences envers les femmes: le composant suisse de l'International Violence Against Women Survey [CHIVAWSj et le National Violence Against Women Survey [NVAWS) administré aux États-Unis. Le choix de ces deux études découle certes des affiliations de l'auteure, cependant il est loin d'être anodin. Le champ criminologique actuel confère, en effet, une place prépondérante à la littérature américaine et anglo-saxonne, contraignant ainsi les chercheurs d'autres pays à un exercice proche du grand écart pour interpréter leurs résultats à la lumière des travaux antérieurs ou développer des interventions efficaces dans leur propre contexte. Le fait de recourir à des hypothèses et des concepts développés dans un cadre spécifique pose inévitablement la question de leur applicabilité à un autre contexte, soit ici le contexte suisse, sinon du moins européen. Cette problématique revêt alors un intérêt qui dépasse la thématique spécifique des violences envers les femmes, ce qui ajoute à sa pertinence. Ce travail s'articule autour de trois axes. Premièrement, il met en évidence la manière dont les caractéristiques d'un sondage influencent les estimations qui en découlent. La comparabilité de la nature du CH-IVAWS et du NVAWS, de leur processus d'échantillonnage et des caractéristiques de leur administration est discutée. Les définitions utilisées, l'opérationnalisation des variables sur la base d'items comparables, le contrôle des périodes de référence, ainsi que la nature de la relation victime-auteur figurent également parmi les facteurs contrôlés. Ce travail établit ainsi la validité de contenu intra- et inter-études, offrant un processus systématique destiné à maximiser la comparabilité des données secondaires. Les implications de cette démarche sont illustrées avec la présentation successive d'opérationnalisations comparables et non-comparables des variables construites. Mesurant les violences envers les femmes en Suisse et aux États-Unis, ce travail compare la prévalence de plusieurs formes (menaces, violences physiques et violences sexuelles) et types de violence (violences partenaires et non-partenaires). 11 s'attache également à analyser les concepts de multivictimisation (c.-à-d. le fait de subir plusieurs formes de victimisation), victimisation répétée (c.-à.-d. le fait de subir plusieurs incidents de même forme) et revictimisation (c.-à-d. le lien entre la victimisation dans l'enfance et à l'âge adulte) dans une approche comparative - et comparable. Dans un troisième temps, cherchant à comprendre pourquoi la violence des partenaires apparaît plus fréquente aux États-Unis, tandis que les victimes de non-partenaires sont plus nombreuses en Suisse, et dans d'autres pays européens, différents facteurs associés à la victimisation sont évalués. Cette recherche participe d'une meilleure compréhension de la pertinence du contrôle des paramètres méthodologiques dans les comparaisons entre études puisqu'elle illustre, pas à pas, les contrôles imposés et leurs effets sur les données quantitatives, et surtout comment l'ignorance de ces paramètres peut conduire à des conclusions erronées, tant statistiquement que théoriquement. La conclusion replace, dans un contexte plus large, la discussion des différences et des similitudes observées quant à la prévalence des violences envers les femmes en Suisse et aux États-Unis, et intègre des recommandations quant à la pertinence et à la validité des comparaisons internationales, cela quel que soit le domaine considéré.