982 resultados para Physiological Implications


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The aim of this experiment was to evaluate the effect of storage temperature on the viability and vigour of A. peregrina seeds. Seeds of A. peregrina harvested in Viçosa-MG, in September 2005 were used. The seeds were stored in the Laboratory of Forest Seeds Analysis (LASF) of the Universidade Federal de Viçosa (UFV), in a cold chamber, under approximately 5ºC over150 days. The seeds were stored under 20ºC for 150 days more. Seed moisture was determined after oven-drying at 105 ± 3ºC for 24 hours. The seeds were analyzed monthly using germination, tetrazolium and electrical conductivity tests and Osmopriming during 300 days, with four repetitions of 25 seeds. A. peregrina seeds kept a constant percentage of germination and viable seeds under the tetrazolium test for five months of storage, under either 5ºC and 20ºC. The electrical conductivity test showed significant differences in relation to the storage period, proving to be more sensitive than the standard germination test. Seed priming in PEG -0,4 MPa solution was not efficient in recovering the viability and vigor of the stored seeds at 5ºC and 20ºC.

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Physiological and biochemical aspects of assai palm during seed germination and early seedling growth were investigated. Seeds collected from plants growing in flooded and upland forests were used to determine the influence of normoxic (aerobic) and anoxic (anaerobic) conditions in germination and the initial and average time of development in the roots and shoots. After 75 days, seedlings germinated under normoxia were transferred to trays and submitted to flooding. Seed reserves (lipids, proteins, soluble sugars and starch) were monitored for quiescent and germinated seeds maintained under normoxic and anoxic conditions, as well as after 5, 10 and 20 days of seedling growth. Alcohol dehydrogenase (ADH) activity was quantified in roots and leaves of seedlings without or with flooding (partial and total). Seeds were not able to germinate under anoxia. Different strategies of storage mobilization of lipids, proteins, soluble sugars and starch were observed in seeds of each environment. ADH activity was induced by anoxia, with the highest level observed in the leaves. This study showed that, under normoxic conditions, the best developmental performance of assai palm seeds, from flooded or upland forest areas, during germination was associated with primary metabolites mobilization and seedling flooding tolerance with increased ADH activity. We conclude that the assai palm is well adapted to the anoxic conditions provoked by flooding.

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Studies of seed physiological processes represent the starting point for the sustainable utilization of native or cultivated plant species from the caatinga biome for which germination studies are still scarce. In order to determine adequate methods for the conservation of Gliricidia sepium seeds, the physiological quality of propagules exposed to different conditions and times of storage were examined. Recently collected seeds of G. sepium were analyzed immediately, while the other sample was stored for three, six, nine, or twelve months in plastic or paper bags under refrigeration or at room temperature for further analysis. The germination rates of seeds from each storage regime were determined and these rates compared to their water content. It was observed that germination capacity was directly related to changes in seed humidity. Storing seeds in plastic bags yielded the best conservation, mainly when they were stored at low temperatures. However, even at temperatures near 25°C it was possible to prolong seed viability when their water content was controlled through the use of impermeable packing.

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More and more innovations currently being commercialized exhibit network effects, in other words, the value of using the product increases as more and more people use the same or compatible products. Although this phenomenon has been the subject of much theoretical debate in economics, marketing researchers have been slow to respond to the growing importance of network effects in new product success. Despite an increase in interest in recent years, there is no comprehensive view on the phenomenon and, therefore, there is currently incomplete understanding of the dimensions it incorporates. Furthermore, there is wide dispersion in operationalization, in other words, the measurement of network effects, and currently available approaches have various shortcomings that limit their applicability, especially in marketing research. Consequently, little is known today about how these products fare on the marketplace and how they should be introduced in order to maximize their chances of success. Hence, the motivation for this study was driven by the need to increase our knowledge and understanding of the nature of network effects as a phenomenon, and of their role in the commercial success of new products. This thesis consists of two parts. The first part comprises a theoretical overview of the relevant literature, and presents the conclusions of the entire study. The second part comprises five complementary, empirical research publications. Quantitative research methods and two sets of quantitative data are utilized. The results of the study suggest that there is a need to update both the conceptualization and the operationalization of the phenomenon of network effects. Furthermore, there is a need for an augmented view on customers’ perceived value in the context of network effects, given that the nature of value composition has major implications for the viability of such products in the marketplace. The role of network effects in new product performance is not as straightforward as suggested in the existing theoretical literature. The overwhelming result of this study is that network effects do not directly influence product success, but rather enhance or suppress the influence of product introduction strategies. The major contribution of this study is in conceptualizing the phenomenon of network effects more comprehensively than has been attempted thus far. The study gives an augmented view of the nature of customer value in network markets, which helps in explaining why some products thrive on these markets whereas others never catch on. Second, the study discusses shortcomings in prior literature in the way it has operationalized network effects, suggesting that these limitations can be overcome in the research design. Third, the study provides some much-needed empirical evidence on how network effects, product introduction strategies, and new product performance are associated. In general terms, this thesis adds to our knowledge of how firms can successfully leverage network effects in product commercialization in order to improve market performance.

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The objective of this work was to determine the effect of environmental variables and supplementation levels on physiological parameters of Moxotó goats in confined and semi-confined rising systems, in the Brazilian semi-arid region. The semi-confined individuals were kept on a grass based diet during the day and arrested in the end of the afternoon. The confined animals were kept in a management center, receiving two diets composed by forage cactus and maniçoba hay into two different levels (0.5 and 1.5% of the body weight). Inside the management center and in the external environment the environmental comfort parameters were set high during the afternoon period characterizing a situation of thermal discomfort for the animals. During the morning the semi-confined animals presented an average respiratory frequency (69.5 mov min-1) and rectal temperature (39.5 ºC) higher than the confined ones (62.6 mov min-1 and 39.0 ºC, respectively). The confined and semi-confined animals were able to maintain their rectal temperature within normal limits, with increase in the cardiac beatings rate and respiratory frequency. The greater percentage of the used supplementations (1.5%) seemed to increase rectal temperature in the two studied rising systems.

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An experiment was conducted to evaluate the behavior, performance and physiological parameters of pigs in different production systems. Twenty four animals in the growth phase were distributed in a randomized block design in three treatments: T1 - concrete floor, T2 - deep bedding with wood shaving, and T3 - deep bedding with coffee husks. The behavioral study was carried out by observing the animal behavior for an uninterrupted period of eight hours throughout seven weeks. The proportions of time spent in each behavior were characterized using the frequency histogram composition. Environmental (IBGTH), physiological (rectal and skin temperature and respiratory rate) and performance (weight gain, feed intake and feed conversion) parameters were measured in animals during the period. The production systems of deep bedding showed higher values of IBGTH. There was no effect of production systems evaluated on the performance parameters. Rectal temperature was higher in animals reared on deep bedding with coffee husks in relation to the concrete floor. The use of deep bedding benefited the behavior of piglets in the growth phase and it reduced the agonistic behavior among individuals.

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In Tropical regions, the animal performance is often affected by climate conditions. This study aimed to evaluate covering materials in individual shelters, normally used to house dairy calves, and its influence on the calves physiology and performance. The design used was completely randomized, with a 2x3 factorial arrangement to compare the averages of 5% through the Tukey's test, i.e., both genders- and three types of covering in the shelters (Z - zinc; AC - asbestos cement; and WPAC - white-painted asbestos cement). Parameters evaluated included daily weight gain (DWG), dry matter intake (DMI), feed conversion (FC), rectal temperature (RT), and respiratory frequency (RF). Results showed significant differences (P < 0.05) among males (1.04kg/day) and females (0.74kg/day) for DWG and interaction between gender and treatment (P < 0.05) for zinc covering (0.562kg/day for females and 1.120kg/day for males). Significant differences were also observed in FI of animals housed under shelters with the covering of zinc (48.35kgDM/day for females and 96.91 kgDM/day for males). There were no significant differences (P > 0.05) in the FC and the RT, and there were significant differences (P < 0.05) for RF in the Z treatments (56.9 mov.min-1), WPAC (62.2 mov.min-1) and FC (70.25 mov.min-1). It was concluded that different covering materials did not affect performance and dry matter intake of dairy calves. However, the animals' physiology of thermoregulation was altered by the different covering materials used in individual shelters.

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Thermal discomfort inside facilities is one of the factors responsible for low productivity of caprines in the Brazilian Northeast region, because inadequate weather conditions can cause elevated rectal temperature, increased respiratory rate, decreased food ingestion and reduced production. The present paper aimed to study the behavior of physiological thermoregulation of the animals (respiratory rate - RR and rectal temperature - RT) at four different times of the day (8 a.m., 11 a.m., 2 p.m. and 5 p.m.) and their relation to bioclimatic indexes (Temperature Humidity Index - THI, Black Globe Humidity Index - BGHI and Radiant Heat Load - RHL) in order to determine whether the type of covering used in the animals facilities (ceramic covering - CC, asbestos cement covering - AC and straw covering - SC) interferes with the physiology of thermoregulation. The time of data collection was related to the values of environmental and physiological variables. At 2 p.m. it was found the highest values of Radiant Heat Load on the three types of covering. The values of RT and RR were higher at 11 a.m. and 2 p.m., and the straw tile provided better thermal conditions of microclimate for the animals. The increased RR maintained the caprines homeothermy.

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The purpose of this paper was to observe the use of bedding (wood shavings) in physiological variables that indicate thermal stress in gestating sows. The experiment was conducted in order to evaluate the effect of two types of floor (concrete and wood shavings). Worse microclimatic conditions were observed in bedding systems (P<0.05), with an increase in temperature and enthalpy of 1.14 ºC and 2.37 kJ.kg dry air-1, respectively. The floor temperature at the dirty area was higher in the bedding presence in comparison to its absence. In spite of the worse microclimatic conditions in the bedding, the rectal temperature did not differ significantly (P>0.05) but the skin surface temperature was higher in the bedding systems. The same occurred with the respiratory rates. The physical characteristics of the floor material influenced the rate of heat loss by conductance. Estimated values were 35.04 and 7.99 W m-2 for the conductive heat loss between the animal and floor for treatments with or without bedding, respectively. The use of bedding in sow rearing has a negative impact on microclimatic conditions, what implies in thermoregulatory damages.

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Intensive and critical care nursing is a speciality in its own right and with its own nature within the nursing profession. This speciality poses its own demands for nursing competencies. Intensive and critical care nursing is focused on severely ill patients and their significant others. The patients are comprehensively cared for, constantly monitored and their vital functions are sustained artificially. The main goal is to win time to cure the cause of the patient’s situation or illness. The purpose of this empirical study was i) to describe and define competence and competence requirements in intensive and critical care nursing, ii) to develop a basic measurement scale for competence assessment in intensive and critical care nursing for graduating nursing students, and iii) to describe and evaluate graduating nursing students’ basic competence in intensive and critical care nursing by seeking the reference basis of self-evaluated basic competence in intensive and critical care nursing from ICU nurses. However, the main focus of this study was on the outcomes of nursing education in this nursing speciality. The study was carried out in different phases: basic exploration of competence (phase 1 and 2), instrumentation of competence (phase 3) and evaluation of competence (phase 4). Phase 1 (n=130) evaluated graduating nursing students’ basic biological and physiological knowledge and skills for working in intensive and critical care with Basic Knowledge Assessment Tool version 5 (BKAT-5, Toth 2012). Phase 2 focused on defining competence in intensive and critical care nursing with the help of literature review (n=45 empirical studies) as well as competence requirements in intensive and critical care nursing with the help of experts (n=45 experts) in a Delphi study. In phase 3 the scale Intensive and Critical Care Nursing Competence Scale (ICCN-CS) was developed and tested twice (pilot test 1: n=18 students and n=12 nurses; pilot test 2: n=56 students and n=54 nurses). Finally, in phase 4, graduating nursing students’ competence was evaluated with ICCN-CS and BKAT version 7 (Toth 2012). In order to develop a valid assessment scale of competence for graduating nursing students and to evaluate and establish the competence of graduating nursing students, empirical data were retrieved at the same time from both graduating nursing students (n=139) and ICU nurses (n=431). Competence can be divided into clinical and general professional competence. It can be defined as a specific knowledge base, skill base, attitude and value base and experience base of nursing and the personal base of an intensive and critical care nurse. Personal base was excluded in this self-evaluation based scale. The ICCN-CS-1 consists of 144 items (6 sum variables). Finally, it became evident that the experience base of competence is not a suitable sum variable in holistic intensive and critical care competence scale for graduating nursing students because of their minor experience in this special nursing area. ICCN-CS-1 is a reliable and tolerably valid scale for use among graduating nursing students and ICU nurses Among students, basic competence of intensive and critical care nursing was self-rated as good by 69%, as excellent by 25% and as moderate by 6%. However, graduating nursing students’ basic biological and physiological knowledge and skills for working in intensive and critical care were poor. The students rated their clinical and professional competence as good, and their knowledge base and skill base as moderate. They gave slightly higher ratings for their knowledge base than skill base. Differences in basic competence emerged between graduating nursing students and ICU nurses. The students’ self-ratings of both their basic competence and clinical and professional competence were significantly lower than the nurses’ ratings. The students’ self-ratings of their knowledge and skill base were also statistically significantly lower than nurses’ ratings. However, both groups reported the same attitude and value base, which was excellent. The strongest factor explaining students’ conception of their competence was their experience of autonomy in nursing. Conclusions: Competence in intensive and critical care nursing is a multidimensional concept. Basic competence in intensive and critical care nursing can be measured with self-evaluation based scale but alongside should be used an objective evaluation method. Graduating nursing students’ basic competence in intensive and critical care nursing is good but their knowledge and skill base are moderate. Especially the biological and physiological knowledge base is poor. Therefore in future in intensive and critical care nursing education should be focused on both strengthening students’ biological and physiological knowledge base and on strengthening their overall skill base. Practical implications are presented for nursing education, practice and administration. In future, research should focus on education methods and contents, mentoring of clinical practice and orientation programmes as well as further development of the scale.

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Vad händer i tidvattenzonen? Var går gränsen mellan land och hav, vad händer i tidvattenzonen och vem ansvarar för detta? I västra Indiska oceanen (VIO) kan avståndet mellan den lägsta nivån för lågvattnet och den högsta nivån för högvattnet vara flera kilometer och nivåskillnaderna upp till 6 meter och detta skapar ett stort och föränderligt område. Syftet med min avhandling är att öka förståelsen för tidvattenzonen i tropiska och subtropiska västra Indiska oceanen. Sammanfattningsvis visar mina studier att det finns ett mycket stort värde i den komplexa tidvattenzonen, men också att det här området hotas från både land och hav, genom t.ex. överexploatering, erosion och föroreningar. Uttnyttjandet av tidvattenzonen är stort och min avhandling har visat att aktiviteter såsom fiske i form av plocking av musslor och andra ryggradslösa djur och hamnaktiviteter påverkar den biologiska mångfalden negativt, vilket leder till försämrad levnadsstandard för resursutnyttjande människor i regionen. För att förbättra situationen krävs det mer forskning, miljöövervakning och bättre förvaltning av tidvattenzonen. Experter i regionen har rangordnat förslag på förvaltningsstrategier som skulle kunna testas för att förbättra miljön och skapa ett mer hållbart nyttjande. Avhandlingen visar även att det är möjligt att använda fjärranalysteknik såsom satellitbildsanalys för att kvantifiera mängden sjögräsvegetation (i form av biomassa), vilket kan ha stor betydelse för att förbättra storskalig miljöövervakning av kustnära naturtyper (habitat). I avhandlingsarbetet har jag använt mig av ett multidisciplinärt tillvägagångssätt och använt metoder såsom ekologisk och biologisk provtagning, intervjuer, observationer, diskussionsgrupper, frågeformulär och fjärranalys. Resultaten presenterade i denna avhandling ger en ökad kunskap om tidvattenzonen i utvecklingsländerna inom VIO-regionen som kan användas för att initiera och fortsätta att utveckla hållbara förvaltningsstrategier av biologiska resurser.

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OBJECTIVE: To determine the prevalence of metabolic syndrome (MS) and its clinical interrelations in polycystic ovary syndrome (PCOS).METHODS: This was a cross-sectional, prospective study with 100 patients with diagnosed PCOS based on the consensus of Rotterdam (2003). We investigated the interrelationships of MS, with intrinsic PCOS data. Dermatological profile was analyzed, in addition to acanthosis nigricans (AN) in the presence of hirsutism and acne. The use of HOMA-IR (homeostatic model assessment of insulin resistance) aimed at the correlation with MS in order to establish the metabolic dysfunction with the state of insulin resistance.RESULTS: The mean and standard deviations corresponding figures for age, body mass index and waist circumference were, respectively, 25.72 (± 4.87), 30.63 (± 9.31) and 92.09 (± 18.73). The prevalence of MS was 36% and significantly correlated with BMI, AN, and in 51% of patients the state of insulin resistance (HOMA-IR). Regarding skin profile, only AN significant correlation with MS.CONCLUSION: We propose the routine inspection of metabolic components related to severe PCOS. These parameters configure the cardiovascular risk and such conduct is of undoubted importance to public health.

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Extant research on consumer co-operation has acknowledged that the corporate purpose of consumer co-operatives deviates significantly from the purpose of investor-owned firms (IOFs – the dominant form in market economies and in theory development in the field of business economics) and also suggested that the management of consumer co-operatives differs from the management of IOFs. Despite this, there is a scarcity of research focusing on the management of consumer co-operatives in general and the ways this different purpose manifests in their management in particular. In other words, research on consumer cooperatives has only started to discover the importance of identifying the premises of these organizations and generating management and organization theories that take them into account. The overall objective of this study is to map out some of the implications that the purpose of consumer co-operation has for the management and governance of consumer co-operatives. To put it more precisely, by combining interview data gathered from Finnish consumer cooperatives (S Group, OP Bank Group and POP Bank) and extant literature, this study aims to generate or elaborate on definitions and outlines of the features that co-operative purpose poses for the strategic management, governance and managerial competence needed for consumer co-operatives. The study consists of two parts. The first part introduces the research topic, methods and publications, as well as discusses the overall outcomes. The second part consists of four publications that address the research questions from different viewpoints. The analyses of this study indicate that due to the purpose of consumer co-operation, the roles of locality and regionality become emphasized in their management. While locality and regionality are potential sources of competitive advantage for consumer co-operatives, geographic boundness sets significant boundary conditions for the strategic management of these organizations. Further, the purpose of consumer co-operation may pose several challenges to governance and set specific competence demands for the managers of these organizations. Associating the observations from various streams of research on management and governance with the purpose of consumer co-operation and examining these issues further, the thesis contributes to elaboration of theory in the field. While the thesis is by no means comprehensive (but instead reflects a co-operative research project in its early stages), it does shed light on some key ideas of management and governance and offers leads to theory and, thereby, will prove useful to elaborators, disseminators and appliers of knowledge on co-operation.

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The melanocortin peptides, including melanocyte-stimulating hormones, α-, β- and γ-MSH, are derived from the precursor peptide proopiomelanocortin and mediate their biological actions via five different melanocortin receptors, named from MC1 to MC5. Melanocortins have been implicated in the central regulation of energy balance and cardiovascular functions, but their local effects, via yet unidentified sites of action, in the vasculature, and their therapeutic potential in major vascular pathologies remain unclear. Therefore, the main aim of this thesis was to characterise the role of melanocortins in circulatory regulation, and to investigate whether targeting of the melanocortin system by pharmacological means could translate into therapeutic benefits in the treatment of cardiovascular diseases such as hypertension. In experiments designed to elucidate the local effects of α-MSH on vascular tone, it was found that α-MSH improved blood vessel relaxation via a nitric oxide (NO)-dependent mechanism without directly contracting or relaxing blood vessels. Furthermore, α-MSH was shown to regulate the expression and function of endothelial NO synthase in cultured human endothelial cells via melanocortin 1 receptors. In keeping with the vascular protective role, pharmacological treatment of mice with α-MSH analogues displayed therapeutic efficacy in conditions associated with vascular dysfunction such as obesity. Furthermore, α-MSH analogues elicited marked diuretic and natriuretic responses, which together with their vascular effects, seemed to provide protection against sodium retention and blood pressure elevation in experimental models of hypertension. In conclusion, the present results identify novel effects for melanocortins in the local control of vascular function, pointing to the potential future use of melanocortin analogues in the treatment of cardiovascular pathologies.