902 resultados para Small Sample
Resumo:
Recent advances in molecular biology have made it possible to use the trace amounts of DNA in faeces to non-invasively sample endangered species for genetic studies. Here we use faeces as a source of DNA and mtDNA sequence data to elucidate the relationship among Spanish and Moroccan populations of great bustards. 834 bp of combined control region and cytochrome-b mtDNA fragments revealed four variable sites that defined seven closely related haplotypes in 54 individuals. Morocco was fixed for a single mtDNA haplotype that occurs at moderate frequency (28%) in Spain. We could not differentiate among the sampled Spanish populations of Caceres and Andalucia but these combined populations were differentiated from the Moroccan population. Estimates of gene flow (Nm = 0.82) are consistent with extensive observations on the southern Iberian peninsular indicating that few individuals fly across the Strait of Gibraltar. We demonstrate that both this sea barrier and mountain barriers in Spain limit dispersal among adjacent great bustard populations to a similar extent. The Moroccan population is of high ornithological significance as it holds the only population of great bustards in Africa. This population is critically small and genetic and observational data indicate that it is unlikely to be recolonised via immigration from Spain should it be extirpated. In light of the evidence presented here it deserves the maximum level of protection.
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A new method is presented which allows the separation of the soil aggregate exterior from the aggregate core. The method employs a combination of aggregate freezing with rapid separation of aggregate exteriors using ultrasonic energy. The factors influencing the thickness of the removed aggregate surface layer include water content of the aggregate prior to freezing, temperature difference between that of the frozen aggregate and that of the liquid it is submerged in during sonification, sonification time and energy, and the type of the immersion liquid. The success of the method and the thickness of the removed aggregate surface were examined using barium ( Ba2+) as a tracer. Barium ( as BaCl2) is rapidly absorbed by soil and is present at only very low levels in natural soils. Surface layers of 0.2 - 0.4 cm thickness were successfully removed from aggregates of 1 - 4 cm diameter. Two examples are given from soils in northern NSW to demonstrate the occurrence of small- scale heterogeneity in soil chemical properties. Compared with the surface fraction, a 4 - 7% higher calcium concentration was found in the core fraction of a clay loam soil ( Dermosol). Conversely, on a cracking clay soil ( Vertosol), atrazine concentration was around 15 times greater in the aggregate surface fractions compared with core fractions. Compared with the traditional estimation of soil chemical properties on homogenised bulk soil samples, it is suggested that separate analysis of aggregate surface and core fractions could provide useful additional information on the relationships between soil properties and environmental responses.
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The potential applications of macrocycles in chemistry and at its interfaces with biology and physics continue to emerge, one of which is as receptors for small molecules and ions. This review illustrates these applications with examples from the last ten years employing complexation as the binding mechanism; some of the systems presented have already found real-world sensor applications. In any case, the challenges remain to design more selective and sensitive receptors for guests.
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Ouabain increases vascular resistance and may induce hypertension by inhibiting the Na+ pump. The effects of 0.18 and 18 µg/kg, and 1.8 mg/kg ouabain pretreatment on the phenylephrine (PHE; 0.1, 0.25 and 0.5 µg, in bolus)-evoked pressor responses were investigated using anesthetized normotensive (control and uninephrectomized) and hypertensive (1K1C and DOCA-salt treated) rats. Treatment with 18 µg/kg ouabain increased systolic and diastolic blood pressure in all groups studied. However, the magnitude of this increase was larger for the hypertensive 1K1C and DOCA-salt rats than for normotensive animals, while the pressor effect of 0.18 µg/kg ouabain was greater only in DOCA-salt rats. A very large dose (1.8 mg/kg) produced toxic effects on the normotensive control but not on uninephrectomized or 1K1C rats. Rat tail vascular beds were perfused to analyze the effects of 10 nM ouabain on the pressor response to PHE. In all animals, 10 nM ouabain increased the PHE pressor response, but this increase was larger in hypertensive DOCA-salt rats than in normotensive and 1K1C rats. Results suggested that a) increases in diastolic blood pressure induced by 18 µg/kg ouabain were larger in hypertensive than normotensive rats; b) in DOCA-salt rats, smaller ouabain doses had a stronger effect than in other groups; c) hypertensive and uninephrectomized rats were less sensitive to toxic doses of ouabain, and d) after treatment with 10 nM ouabain isolated tail vascular beds from DOCA-salt rats were more sensitive to the pressor effect of PHE than those from normotensive and 1K1C hypertensive rats. These data suggest that very small doses of ouabain, which might produce nanomolar plasma concentrations, enhance pressor reactivity in DOCA-salt hypertensive rats, supporting the idea that endogenous ouabain may contribute to the increase and maintenance of vascular tone in hypertension.
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Soil characteristics related to the genesis, land use and management are important factors in water dynamics in watersheds. This study evaluated physical, morphological and pedogenetic attributes related to water yield potential in small watersheds in Guarapari, ES, Brazil. The following representative profiles were selected, morphologically described and sampled in area of Atlantic Forest domain: Lithic Udifolists, Oxyaquic Udifluventes, Typic Paleudults, Typic Hapludults, Typic Hapludox, Oxic Dystrudepts and Typic Endoaquents. Samples were collected in the soil profiles for physical analysis. Measurements of field-saturated hydraulic conductivity and soil penetration resistance were perfomed in some profiles, which were under different uses. The Endoaquents of Limão Creek can be considered efficient as temporary water reservoirs. However, the use of artificial drainage tends to reduce this effect. Differential erosion was detected by the sand texture on the surface of the Typic Paleudults due to the low degree of clay flocculation, slope, high resistance to the penetration and low hydraulic conductivity of the Bt horizon, making it necessary to adopt soil management practices to increase the water infiltration. Under pasture, mainly in the cattle trails where the trampling is more intense, there was high resistance to penetration in the superficial layers of the Typic Hapludults. The Typic Hapludox have the greatest potential for water yield in the small watersheds because of its greater extent in the headwaters and their morphological and physical characteristics, which can result in increased aquifer recharge.
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The purpose of this study is to characterise the environmental management systems (EMS) certification process (International Organization for Standardization (ISO) 14001) in Portuguese small and medium enterprises (SMEs) following quality management system (QMS) certification (ISO 9001). The study is based on a sample from Portuguese SMEs which characterise the local reality in terms of companies certified in accordance with ISO 14001 after ISO 9001 certification. Some Portuguese SMEs have the EMS implemented but not certified, mainly given the lack of investment support and because it is considered merely a form of marketing. As such, they do not feel motivated to certificate an EMS in the company since they consider that it is a form of advertising and not a way to protect the environment. Nonetheless, it is already evident form other Portuguese SMEs that gained EMS certification that gains supersede marketing benefits and allow for evermore enduring benefits such as prevention of environmental risks, environment protection, improved company image, compliance with legislation and efficient use of natural resources. This paper also presented the main difficulties in achieving an EMS certification, including high certification costs, human resources, motivation issues and difficulties in changing the company’s culture.
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This study examines the relationship between the environmental performance and the financial performance of Portuguese corporations, based on a sample of 35 stocks listed in the Euronext Lisbon stock exchange, for the period from 2000 to 2004. Corporate environmental performance is measured by an analysis of the environmental information disclosed in 2003 corporate annual financial reports. Stock market-based measures, such as return, risk and risk-adjusted return measures, are used to evaluate corporate financial performance, for the 5 years observation period. We use the portfolio studies and contingency tables methodology to evaluate the relationship between corporate environmental disclosures and corporate stock market performance. The empirical results suggest that companies that do not disclose environmental information have a superior financial performance – as measured by return, risk and risk-adjusted return – than those that disclose environmental information. In particular, companies with better environmental reporting, which disclose qualitative and quantitative environmental information, are the ones with worse financial performance. Nevertheless the differences found in financial performance are not statistically significant. The empirical results are thus adverse to the more recent view of environmental performance as a competitive advantage, maybe due to the still relatively small importance of environmental issues to companies and investors.
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Although postal questionnaires, personal interviewing, and telephone interviewing are the main methods of survey-based research, there is an increasing use of e-mail as a data collection medium. However, little, if any, published Western research in general and that of Turkish in particular have investigated e-mail survey technique from pure survey research perspective. Attempting to develop a framework to assess e-mail as a data collection mean, the purpose of this study is to explore e-mail-based questionnaire technique from complementary angles. To this goal, sample representativeness, data quality, response rates, and advantages and disadvantages of e-mail surveying are discussed.
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Category management (CM) is an important tool to strengthen the relationship between manufacturers and retailers. This process has been associated with large corporate retailers; however, some recent researches show that CM is open to companies of any type or size. This possibility is important in emerging markets, where neighborhood supermarkets are still representative and are often considered an alternative for manufacturers to achieve higher margins compared to big chains. In this context, the aim of this research was to analyze the results of a CM initiative in small neighborhood supermarkets from a manufacturer perspective. Data for the study comes from a food manufacturer in Brazil that implemented a CM process with 180 small retailers. A quantitative analysis was conducted in order to analyze the effect of the program on the food manufacturer' s sales and market share. Our analysis suggests an overall positive effect of the program on both, sales and market share.
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The primary goal of this paper is to comprehend the fundamental organizational differences between Brazilian franchise chains that only operate in the home market and Brazilian franchise chains that operate internationally. The sample chosen for this study comprehends 96 Brazilian franchises operating in the home market and 67 franchises with international operations; logistic regression was used to analyze data obtained from these sources. Our findings suggest that the development of a brand in international operations can be strategic for certain Brazilian franchise chains; this seems to be, however, a scarce resource for many franchises and it could be developed through international operations. With regard to the fees charged, the outcomes demonstrate that Brazilian franchises with international operations tend to charge lower fees from its franchisees to install new units. Regarding the monitoring and control of franchises, there is evidence that the monitoring capability is one of the determining factors in the development of Brazilian franchises international operations.
Resumo:
RESUMO: Com a globalização e as mudanças provenientes da mesma, o ser humano vem sofrendo com o estresse ao tentar se adaptar e acompanhar tais acontecimentos seja no âmbito familiar, social, afetivo e profissional. Para desempenhar as funções docentes do ensino superior, são exigidas diversas condições, e o professor sofre um desgaste físico e psicológico ao tentar suprir determinadas demandas, o que em muitos casos, ocasiona o estresse ocupacional. Com o propósito de aprofundar conhecimentos sobre a relação existente entre o estresse e a atividade docente, fizemos o seguinte questionamento: quais os sintomas de estresse apresentados em professores do ensino superior? Com Objetivo geral de estudar os sintomas e níveis de estresse, relacionando-os à carreira docente do ensino superior, com as variáveis: regime de trabalho, vínculo institucional, idade, sexo, tempo de trabalho, tipo de IES, em uma população específica pertencente a duas Instituições de Ensino Superior -IES da cidade de Teresina, Estado do Piauí- Brasil, sendo uma pública e uma privada. Visando atingir os objetivos propostos, utilizamos da metodologia de caráter exploratório e descritivo, com abordagem quantitativa dos dados recorrendo à estatística descritiva. O instrumento de coleta de dados utilizado foi o “Inventário de Sintomas de Stress Lipp – ISSL” da autora Marilda Lipp (2000), aplicado em uma amostra de cem (100) professores, com idade entre 22 e 55 anos de idade. Mediante a análise dos dados, pode-se verificar que apesar das diferenças existentes entre IES públicas e privadas, a maioria dos resultados foram semelhantes. Em ambas as IES houve presença de estresse nos docentes, prevalecendo a fase de alerta, logo após a fase de resistência, em seguida a fase de quase-exaustão,Houve um predomínio de sintomas psicológicos, onde na IES privada se destacam: aumento súbito de motivação e entusiasmo súbito. E como sintomas físicos: boca seca e nó no estômago. Na IES públicas os sintomas psicológicos foram: entusiasmo súbito e aumento súbito de motivação. E físicos: tensão muscular e nó no estômago. Em relação as co-variáveis que apresentaram maior relação com o estresse pode-se apresentar na IES privada o sexo masculino e feminino possuem a mesma representatividade, a faixa etária de 31 a 39 anos, estado civil casado, tempo de serviço de 7 a 13 anos, jornada de trabalho integral e vínculo efetivo. Já na IES pública verifica-se relação com o sexo feminino, idade variando de 31 a 39 anos, estado civil solteiro, tempo de serviço de 7 a 13 anos, jornada de trabalho parcial e vínculo substituto. De acordo com o que foi analisado, percebe-se que os docentes do ensino superior, independente do tipo de IES ao qual estão vinculados, estão sujeitos ao estresse e que estes não devem ser responsabilizados pelo mesmo, nem por adoção de medidas preventivas, visto que toda a IES sofre as conseqüências, e tem condições de auxiliar o professor com situações preventivas, de controle a partir do conhecimento, interpretação e mudança de hábitos do professor no ambiente universitário. ABSTRACT: With globalization and its changes, the human being has suffered from stress while trying to adapt and monitor such events, within family, social, emotional or professional scope. To play as teacher in higher education, they are required various conditions and the teacher suffers physical and psychological wear trying to meet certain demands, which in many cases leads to occupational stress.Aiming to deepen knowledge about the relationship between stress and teaching activities, we made the following question: what are the symptoms of stress presented by higher education teachers? With the general objective of study the symptoms and the stress levels, linking them to the teaching career in higher education, using the following variables: working regime, institutional link, age, sex, working time, type of HEI, in a specific population belongs to two Higher Education Institutions HEI - of Teresina, Piauí, Brazil, one public and one private. Aiming to achieve the proposed objectives, we used a exploratory - descriptive study, with quantitative approach of data using graphs and tables. The data collection instrument used was the "Lipp Stress Symptoms Inventory - ISSL" by the author Marilda Lipp (2000), applied to a sample of a hundred (100) teachers, between 22 and 55 years of age. Through data analysis, despite the differences between public and private HEIs, we can see that the most results were similar. In both HEIs, the results revealed that the alert phase of stress had prevailed, followed by resistance and almost-exhaustion phases. A small number presented stress in exhaustion phase and another group did not present stress. There was a predominance of psychological symptoms, which in private HEIs stands out: increase of motivation and enthusiasm suddenly. And as physical symptoms: dry mouth and stomached. In public HEI, psychological symptoms were sudden enthusiasm and increse of motivation. And physical symptoms: muscle tension and stomached. In relation to the co-variables that showed a greater relationship with stress, in private HEIs males and females have the same representation, between 31-39 years, married, working time of 7-13 years, full working day and effective link. Already in public HEIs, female, between 31-39 years, unmarried, working time of 7-13 years, partial working day and substitute link had prevailed. According to analysis, we find that teachers in higher education, regardless of the HEI to which they are linked, are subject to stress. And they should not be blamed for the onset of stress, neither by adopting preventive measures, since all the HEI suffers the consequences, and it is able to help teachers with preventive measures based on the knowledge, interpretation and change habits of the teacher in the university environment.
Resumo:
RESUMO: A organização militar é uma das mais importantes para qualquer , é uma instituição com regras e valores muito bem definidos, em que factores como a personalidade e o stress terão de ser muito bem avaliados para que se possa integrar uma carreira militar. A amostra estudada foi constituída por 200 militares da Força Aérea Portuguesa, com idade compreendidas entre os 19 e os 52 anos sendo a média de idades 26,3 anos (DP= 5,9). Em estudos anteriores verifiou-se que as diferenças entre géneros são uma condicionante no dia-a-dia de um militar (Lorenzi-Cioldi, 1994). Contudo, Eagly (1987), afirma que a diferença entre géneros tem uma pequena percentagem (5%) contra os 95 % de variabilidade explicada por outros factores na vida militar. Com esta investigação pretendeu-se verificar se existem diferenças entre géneros em relação aos factores básicos da personalidade, stress, afectividade e desejabilidade social, para além de outros aspectos relacionados com estes factores. Utilizaram-se as seguintes medidas de avaliação: o Big Five Factory, BFI (Benet-Martínez & John, 1998), a Paulhus Deception Scale, PDS (Paulhus, 1998), a Positive and Negative Affect Shedule, PANAS (Watson, Clark e Tellenger, 1998) e o Daily Stress Inventory, DSI (Brantley e Glenn, 1989). Conclui-se que ao nível da personalidade, nos factores de extroversão e conscienciosidade as mulheres apresentam valores mais elevados que os homens, em relação ao stress, nos factores competências pessoais, factores ambientais e stressores variados as mulheres obtêm valores mais baixos que os homens. ABSTRACT: The military institution is one of the most important in any country, it has very strict rules and values and therefore factors such as personality and stress must be thoroughly evaluated in order to integrate a military career. The sample under study is constituted by 200 militaries of the Portuguese Air Force, with ages between 19 and 52 years old, being the average 26,3 (DP=5,9). From previous studies it is know that differences in gender constitute a special condition in military personnel day to day life (Lorenzi-Cioldi, 1994). On the other hand, Eagly (1987) states that gender differences represents a small percentage (5%) against 95 % of variance explained by other military life factors. The main focus of this investigation was to determine if there were differences in gender in personality, stress, affect, social desirability and also to study other aspects related to these factors. The measures used were: the Big Five Factory, BFI (Benet-Martínez & John, 1998), the Paulhus Deception Scale, PDS (Paulhus, 1998), the Positive and Negative Affect Schedule, PANAS (Watson, Clark e Tellenger, 1998), the Daily Stress Inventory, DSI (Brantley e Glenn, 1998). It was concluded that on the personality level, women present higher scores on factors such as extroversion and consciousness. On the stress level, when considering factors such as personal competences, environmental factors and varied stressors, women present lower scores than men.