893 resultados para Quantitative structure property relationships
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Senior thesis written for Oceanography 445
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Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção do grau de Mestre em Intervenção Precoce
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A liderança e a motivação são aspetos essenciais no alcance do sucesso das organizações. Os líderes alcançaram um papel de destaque nas organizações, quer através da tomada de decisões estratégicas, quer na motivação dos colaboradores. Os conceitos e o entendimento da liderança têm vindo a mudar no decurso do tempo. E sugere que, provavelmente, a liderança adquirirá novos significados e será alvo de novas abordagens no futuro. Porque as sociedades, as organizações e as pessoas mudam, é presumível que novas janelas de compreensão venham a ser abertas. Atendendo a que vivemos numa era de globalização, em que a tecnologia, as estratégias e a estrutura das organizações são quase uniformes, a verdadeira vantagem competitiva só poderá surgir das competências dos recursos humanos. Os líderes também alcançaram um papel de destaque nas organizações, quer através da tomada de decisões estratégicas, quer na motivação dos colaboradores, motivação esta que é o motor que potencia capacidade para que os colaboradores sejam persistentes visando alcançar os seus objetivos. Na indústria hoteleira, objeto de estudo da presente investigação, um dos desafios permanentes é proporcionar níveis consistentes de qualidade de serviço. Esse segmento é profundamente afetado pelo comportamento dos seus líderes e das suas características pessoais e especialmente pela maneira como influenciam os seus colaboradores a alcançarem um resultado. Sendo assim, a presente dissertação tem como objetivo geral conhecer, identificar e analisar os estilos e comportamentos de liderança praticados pelos líderes dos vários departamentos de uma unidade hoteleira do Grande Porto. Para isso, recorremos ao estudo de caso, que inclui as metodologias quantitativa e qualitativa, por forma a identificar o(s) estilo(s) de liderança presente(s) no hotel. As conclusões que resultaram da aplicação das entrevistas e do inquérito por questionário mostram que o líder atual da unidade hoteleira em estudo é o líder democrático.
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Abstract: Selection among broilers for performance traits is resulting in locomotion problems and bone disorders, once skeletal structure is not strong enough to support body weight in broilers with high growth rates. In this study, genetic parameters were estimated for body weight at 42 days of age (BW42), and tibia traits (length, width, and weight) in a population of broiler chickens. Quantitative trait loci (QTL) were identified for tibia traits to expand our knowledge of the genetic architecture of the broiler population. Genetic correlations ranged from 0.56 +/- 0.18 (between tibia length and BW42) to 0.89 +/- 0.06 (between tibia width and weight), suggesting that these traits are either controlled by pleiotropic genes or by genes that are in linkage disequilibrium. For QTL mapping, the genome was scanned with 127 microsatellites, representing a coverage of 2630 cM. Eight QTL were mapped on Gallus gallus chromosomes (GGA): GGA1, GGA4, GGA6, GGA13, and GGA24. The QTL regions for tibia length and weight were mapped on GGA1, between LEI0079 and MCW145 markers. The gene DACH1 is located in this region; this gene acts to form the apical ectodermal ridge, responsible for limb development. Body weight at 42 days of age was included in the model as a covariate for selection effect of bone traits. Two QTL were found for tibia weight on GGA2 and GGA4, and one for tibia width on GGA3. Information originating from these QTL will assist in the search for candidate genes for these bone traits in future studies.
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A PhD is like a box of chocolates, …… and in this thesis I will present what I got. My work has been focused on a cellular structure that is essential for accurate genome inheritance: the centromere. Centromeres are chromosomal domains that do not rely on the presence of any specific DNA sequence. Rather, they are determined by the presence of a histone variant called CENP-A. Stable transmission of CENP-A containing chromatin is accomplished through 1) an unusually high level of protein stability, 2) selfdirected recruitment of nascent CENP-A near existing molecules, and 3) strict cell cycle regulation of assembly. Together, these features lead to a self-sustaining loop that allows for epigenetic maintenance of centromeres.(...)
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Abstract: This article presents both a brief systemic intervention method (IBS) consisting in 6 sessions developed in an ambulatory service for couples and families, and two research projects done in collaboration with the Institute for Psychotherapy of the University of Lausanne. The first project is quantitative and it aims at evaluating the effectiveness of ISB. One of its main feature is that outcomes are assessed at different levels of individual and family functioning: 1) symptoms and individual functioning; 2) quality of marital relationship; 3) parental and co-parental relationships; 4) familial relationships. The second project is a qualitative case study about a marital therapy which identifies and analyses significant moments of the therapeutic process from the patients' perspective. Methodology was largely inspired by Daniel Stem's work about "moments of meeting" in psychotherapy. Results show that patients' theories about relationship and change are important elements that deepen our understanding of the change process in couple and family therapy. The interest of associating clinicians and researchers for the development and validation of a new clinical model is discussed.
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In the framework of health services research sponsored by the Swiss National Science Foundation, a research was undertaken of the activity of the large majority of the public health nurses working in the Swiss cantons of Vaud and Fribourg (total population 700,000). During one week, 130 nurses gathered, with a specially devised instrument, data on 4165 patient visits. Studying the duration of the contacts, one has distinguished contact duration per se (DC), duration of the travel time preceding the contact (DD), and total duration in relation with the contact (DTC-addition of the first two). It was noted that the three durations increased significantly with patient age (as regard travel time, this is explained by the higher proportion of home visits in higher age groups, as compared with visits at a health center). Examined according to location of the visit, contact duration per se (without travel) is higher for visits at home and in nursing homes than for those taking place at a health center. Looked at in respect to the care given (technical care, or basic nursing care, or both simultaneously), our data show that the provision of basic nursing care (alone or with technical care) doubles contact duration (from 20 to 42-45'). The analyses according to patient age shows that, at an advanced age (beyond 80 years particularly), there is an important increase of the visits where both types of care are given. However, contact duration per se shows a significant raise with age only for the group "technical care only"; it can be demonstrated that this is due to the fact that older patients require more complex technical acts (e.g., bladder care, as compared with simpler acts such as injection). A model of the relationships between patient age and contact duration is proposed: it is because of the increase in the proportions of home visits, of visits including basic nursing care, and of more complex technical acts that older persons require more of the working time of public health nurses.
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The dentate gyrus is one of only two regions of the mammalian brain where substantial neurogenesis occurs postnatally. However, detailed quantitative information about the postnatal structural maturation of the primate dentate gyrus is meager. We performed design-based, stereological studies of neuron number and size, and volume of the dentate gyrus layers in rhesus macaque monkeys (Macaca mulatta) of different postnatal ages. We found that about 40% of the total number of granule cells observed in mature 5-10-year-old macaque monkeys are added to the granule cell layer postnatally; 25% of these neurons are added within the first three postnatal months. Accordingly, cell proliferation and neurogenesis within the dentate gyrus peak within the first 3 months after birth and remain at an intermediate level between 3 months and at least 1 year of age. Although granule cell bodies undergo their largest increase in size during the first year of life, cell size and the volume of the three layers of the dentate gyrus (i.e. the molecular, granule cell and polymorphic layers) continue to increase beyond 1 year of age. Moreover, the different layers of the dentate gyrus exhibit distinct volumetric changes during postnatal development. Finally, we observe significant levels of cell proliferation, neurogenesis and cell death in the context of an overall stable number of granule cells in mature 5-10-year-old monkeys. These data identify an extended developmental period during which neurogenesis might be modulated to significantly impact the structure and function of the dentate gyrus in adulthood.
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Exploratory and confirmatory factor analyses reported in the French technical manual of the WISC-IV provides evidence supporting a structure with four indices: Verbal Comprehension (VCI), Perceptual Reasoning (PRI), Working Memory (WMI), and Processing Speed (PSI). Although the WISC-IV is more attuned to contemporary theory, it is still not in total accordance with the dominant theory: the Cattell-Horn-Carroll (CHC) theory of cognitive ability. This study was designed to determine whether the French WISC-IV is better described with the four-factor solution or whether an alternative model based on the CHC theory is more appropriate. The intercorrelations matrix reported in the French technical manual was submitted to confirmatory factor analysis. A comparison of competing models suggests that a model based on the CHC theory fits the data better than the current WISC-IV structure. It appears that the French WISC-IV in fact measures six factors: crystallized intelligence (Gc), fluid intelligence (Gf), short-term memory (Gsm), processing speed (Gs), quantitative knowledge (Gq), and visual processing (Gv). We recommend that clinicians interpret the subtests of the French WISC-IV in relation to this CHC model in addition to the four indices.
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The structure of the brain as a product of morphogenesis is difficult to reconcile with the observed complexity of cerebral connectivity. We therefore analyzed relationships of adjacency and crossing between cerebral fiber pathways in four nonhuman primate species and in humans by using diffusion magnetic resonance imaging. The cerebral fiber pathways formed a rectilinear three-dimensional grid continuous with the three principal axes of development. Cortico-cortical pathways formed parallel sheets of interwoven paths in the longitudinal and medio-lateral axes, in which major pathways were local condensations. Cross-species homology was strong and showed emergence of complex gyral connectivity by continuous elaboration of this grid structure. This architecture naturally supports functional spatio-temporal coherence, developmental path-finding, and incremental rewiring with correlated adaptation of structure and function in cerebral plasticity and evolution.
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BackgroundBipolar disorder is a highly heritable polygenic disorder. Recent enrichment analyses suggest that there may be true risk variants for bipolar disorder in the expression quantitative trait loci (eQTL) in the brain.AimsWe sought to assess the impact of eQTL variants on bipolar disorder risk by combining data from both bipolar disorder genome-wide association studies (GWAS) and brain eQTL.MethodTo detect single nucleotide polymorphisms (SNPs) that influence expression levels of genes associated with bipolar disorder, we jointly analysed data from a bipolar disorder GWAS (7481 cases and 9250 controls) and a genome-wide brain (cortical) eQTL (193 healthy controls) using a Bayesian statistical method, with independent follow-up replications. The identified risk SNP was then further tested for association with hippocampal volume (n = 5775) and cognitive performance (n = 342) among healthy individuals.ResultsIntegrative analysis revealed a significant association between a brain eQTL rs6088662 on chromosome 20q11.22 and bipolar disorder (log Bayes factor = 5.48; bipolar disorder P = 5.85×10(-5)). Follow-up studies across multiple independent samples confirmed the association of the risk SNP (rs6088662) with gene expression and bipolar disorder susceptibility (P = 3.54×10(-8)). Further exploratory analysis revealed that rs6088662 is also associated with hippocampal volume and cognitive performance in healthy individuals.ConclusionsOur findings suggest that 20q11.22 is likely a risk region for bipolar disorder; they also highlight the informative value of integrating functional annotation of genetic variants for gene expression in advancing our understanding of the biological basis underlying complex disorders, such as bipolar disorder.
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A mycoparasite, Piptocephalis virginiana ^ shows a resemblance to fungal parasites of higher plants in the fine structure of hyphae and haustoria. The morphology and fine structure of host and parasitic fungi have been described. The mode of penetration of the host cell, Choanephora cucurbitarum , probably involves mechanical forces. Although the presence of cell wall degrading enzyme was not detected by conventional techniques, its role in penetration can't be ruled out. A collar around the haustorial neck is formed as an extension of the host cell wall. No papilla was detected although appressorixim was seen during penetration. The young haustorium is enclosed in highly invaginating plasmalemma of the host cell and n\imerous cisternae of endoplasmic reticulum. Appearance of an electron—dense sheath around the mature haustorium seems to coincide with the disappearance of cisternae of endoplasmic reticulum from the host cystoplasm in the vicinity of the haustorium. The role of host cytoplasm particularly of endoplasmic reticulum in the development of the sheath is discussed. Extensive accumulation of spherosomes-like bodies, containing lipids, is found in haustorium, parasite and host hypha. Electron microscope revealed the parasiticculture spore has more lipid content than the axenic culture spore of P. virginiana . The biochemical and cytochemical tests also support these results. The mature spore of C. cucurbitarum possesses a thick three-layered cell wall, different from the hyphal wall. Its germination is accompanied by the formation of an elastic thin inner layer which surrounds the emerging germ tube and the growing hypha. High resolution autoradiography showed that H N-acetyl-glucosamine , a precursor of chitin, was incorporated preferentially in the thin inner layer of the spore wall and also in the cell wall of the growing hypha. When the label was fed to the infected cells, at different intervals after inoculation, grains were observed on the sheath which developed around the haustorium of P. virginiana , 30 hours after inoculation. The significance of these results in relation to the origin and composition of the sheath is discussed.
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One hundred and thirty four subjects participated in this survey. Quantitative data were obtained and correlational analyses were used to test a model to study the relationships among the achievement of work values and organizational commitment and job satisfaction and to identify the moderating effects of the meaningfulness of work and responsibility for work on these relationships. Part-time faculty in the Faculty of Continuing Education of a community college were mailed a questionnaire on all the variables of the model. Several reliable, valid instruments were used to test the variables. Data analysis through Pearson correlation and stepwise multiple regression analyses revealed that the achievement of the work values of recognition and satisfaction with promotions did predict organizational commitment and job satisfaction, although the moderating effects of the meaningfulness of work and responsibility for work was not supported in this study. This study suggests that the revised model may be used for determining the relationships between the achievement of work values and organizational commitment and job satisfaction in a community college setting.
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Changes in the configuration of a tree stern result insignificant differences in its total volume and in the proportion of that volume that is merchantable timber. Tree allometry, as represented by stem-fo~, is the result of the vertical force of gravity and the horizontal force of wind. The effect of wind force is demonstrated in the relationship between stem-form, standclosure and site-conditions. An increase in wind force on the individual tree due to a decrease in stand density should produce a more tapered tree. The density of the stand is determined by the conditions that the trees are growing under. The ability of the tree to respond to increased wind force may also be a function of these conditions . This stem-form/stand-closure/site-conditions relationship was examined using a pre-existing database from westcentral Alberta. This database consisted of environmental, vegetation, soils and timber data covering a wide range of sites. There were 653 sample trees with 82 variables that formed the basis of the analysis. There were eight tree species consisting of Pinus contorta, Picea mariana, Picea engelmannii x glauca, Abies lasiocarpa, Larix laricina, Populus tremuloides, Betula papyrifera and Populus balsamifera plus a comprehensive all-species data set. As the actual conformation of the stern is very individual, stem-fo~was represented by the diameter at breast height to total height r~tio. The four stand-closure variables, crown closure, total basal area, total volume and total number of stems were reduced to total basal area and total number of stems utilizing a bivariate correlation matrix by species. Site-conditions were subdivided into macro, meso and micro variables and reduced in number 3 using cross-tabulations, bivariate correlation and principal components analysis as screening tools. The stem-fo~/stand-closure relationship was examined using bivariate correlation coefficients for stem-fo~ with total number of stems and stem-fo~ with total basal area. The stem-fo~/site-conditions and the stand-closure/site- conditions relationships were examined using multiple correlation coefficients. The stem-form/stand-closure/site-conditions relationship was examined using multiple correlation coefficients in separate analyses for both total number of stems and total basal area. An increase in stand-closure produced a decrease in stem-form for both total number of stems and total basal area for most species. There was a significant relationship between stem-form and site-conditions and between stand-closure and site-conditions for both total number of stems and total basal area for most species. There was a significant relationship between the stemform and site-conditions, including the stand-closure, for most species; total number of stems was involved independently of the site-conditions in the prediction of stem-form and total basal area was not. Larix laricina and Betula papyrifera were the exceptions to the trends observed with most species. The influence of both stand-closure (total number of stems in particular) and site-conditions (elevation in particular) suggest that forest management practices should include these- ecological parameters in determining appropriate restocking levels.
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Chinese have unique perspectives on health and illness, which is mostly umecognized by western medicine. Immigration may contribute to problems with health consultations, inconvenience, and dissatisfaction. As the largest visible minority in Canada, Chinese- Canadians' perspectives on health should be studied in order to help Chinese immigrants adapt to a new health-care and health-promotion system, and keep them healthy. A quantitative questionnaire was designed based on the findings from a pilot study and previous literature. A hundred participants were recruited from Toronto, Vancouver, Halifax, and St. Catharines. Descriptive analysis and correlation analysis were used to investigate the structure of the variables. Findings indicated that most oftheir attitudes and corresponding practices to the different health aspects were positive. The relation between dietary practices and attitude was only found in small cities. Their attitudes were impacted by their length of stay in Canada. Their attitudes to regularly timed meals and psychological consultation were related to their acculturation level, as was the regularity of their practice of dental flossing. Their self-evaluated general health levels were also found to be affected by their medical history, education level, feeling to talk about • sexual health, and smoking, particularly in the male subjects of the study. In conclusion, they realized that each health aspect w~s important to their health. However, their practices did not bear a strong relation to their beliefs. Traditional thoughts about health reseeded with time. Acculturation level did not affect most of their attitudes or practices. Under pressure, the priority of the daily health practices decreased. Older persons, those with low incomes, lower education levels or families under stress need to pay more attention to their health level. In-depth future research was recommended.