973 resultados para So(4) Gauge Field
Resumo:
Using the so-called ac field technique, we investigate experimentally the influence of optical beam coupling on the generation of subharmonic gratings in a photorefractive sillenite crystal. By the use of two different recording configurations, we are able to distinguish between effects caused by material nonlinearities and effects caused by optical beam coupling.
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Using the so-called ac field technique, we investigate experimentally the influence of optical beam coupling on the generation of subharmonic gratings in a photorefractive sillenite crystal. By the use of two different recording configurations, we are able to distinguish between effects caused by material nonlinearities and effects caused by optical beam coupling.
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Archival research was conducted on the inception of preemployment psychological testing, as part of the background screening process, to select police officers for a local police department. Various issues and incidents were analyzed to help explain why this police department progressed from an abbreviated version of a psychological battery, to a much more sophisticated and comprehensive set of instruments. While doubts about psychological exams do exist, research has shown that many are valid and reliable in predicting job performance of police candidates. During a three year period, a police department hired 162 candidates (133 males and 29 females) who received "acceptable" psychological ratings and 71 candidates (58 males and 13 females) who received "marginal" psychological ratings. A document analysis consisted of variables that have been identified as job performance indicators which police psychological testing tries to predict, and "screen in" or "screen out" appropriate applicants. The areas of focus comprised the 6-month police academy, the 4-month Field Training Officer (FTO) Program, the remaining probationary period, and yearly performance up to five years of employment. Specific job performance variables were the final academy grade average, supervisors' evaluation ratings, reprimands, commendations, awards, citizen complaints, time losses, sick time usage, reassignments, promotions, and separations. A causal-comparative research design was used to determine if there were significant statistical differences in these job performance variables between police officers with "acceptable" psychological ratings and police officers with "marginal" psychological ratings. The results of multivariate analyses of variance, t-tests, and chi-square procedures as applicable, showed no significant differences between the two groups on any of the job performance variables.
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The main inputs to the hippocampus arise from the entorhinal cortex (EC) and form a loop involving the dentate gyrus, CA3 and CA1 hippocampal subfields and then back to EC. Since the discovery that the hippocampus is involved in memory formation in the 50's, this region and its circuitry have been extensively studied. Beyond memory, the hippocampus has also been found to play an important role in spatial navigation. In rats and mice, place cells show a close relation between firing rate and the animal position in a restricted area of the environment, the so-called place field. The firing of place cells peaks at the center of the place field and decreases when the animal moves away from it, suggesting the existence of a rate code for space. Nevertheless, many have described the emergence of hippocampal network oscillations of multiple frequencies depending on behavioral state, which are believed to be important for temporal coding. In particular, theta oscillations (5-12 Hz) exhibit a spatio-temporal relation with place cells known as phase precession, in which place cells consistently change the theta phase of spiking as the animal traverses the place field. Moreover, current theories state that CA1, the main output stream of the hippocampus, would interplay inputs from EC and CA3 through network oscillations of different frequencies, namely high gamma (60-100 Hz; HG) and low gamma (30-50 Hz; LG), respectively, which tend to be nested in different phases of the theta cycle. In the present dissertation we use a freely available online dataset to make extensive computational analyses aimed at reproducing classical and recent results about the activity of place cells in the hippocampus of freely moving rats. In particular, we revisit the debate of whether phase precession is due to changes in firing frequency or space alone, and conclude that the phenomenon cannot be explained by either factor independently but by their joint influence. We also perform novel analyses investigating further characteristics of place cells in relation to network oscillations. We show that the strength of theta modulation of spikes only marginally affects the spatial information content of place cells, while the mean spiking theta phase has no influence on spatial information. Further analyses reveal that place cells are also modulated by theta when they fire outside the place field. Moreover, we find that the firing of place cells within the theta cycle is modulated by HG and LG amplitude in both CA1 and EC, matching cross-frequency coupling results found at the local field potential level. Additionally, the phase-amplitude coupling in CA1 associated with spikes inside the place field is characterized by amplitude modulation in the 40-80 Hz range. We conclude that place cell firing is embedded in large network states reflected in local field potential oscillations and suggest that their activity might be seen as a dynamic state rather than a fixed property of the cell.
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The research aimed to analyze the role of nurses in the Family Health Strategy (FHS) in the control of Dengue and Chikungunya fever in the cities of Parnamirim and Santa Cruz. It is exploratory and descriptive nature of research, with a qualitative approach, which was developed with nurses of the Family Health Strategy in the municipalities of Parnamirim and Santa Cruz. All research process followed the ethical standards laid out research in Resolution No. 466/2012 of the National Health Council about research involving human beings. Data collection was performed using a semi-structured questionnaire with open and closed questions, organized into three parts: the profile of respondents, knowledge of the disease (transmission, prevention, control) and description of practices. The actions performed by nurses are punctual performed when there is growing disease of the number of cases in order to try to reduce the number of cases. The principal methodology used for them is to talk and guidelines resulting from campaigns and home visits, using leaflets and social networks. Regarding knowledge of nurses in the city of Santa Cruz on Dengue Fever and Chikungunya, is clearly some gaps. Nursing professionals know recognize a suspected case of dengue, but get confused when trying to explain to the Chikungunya fever, exhibiting the same symptoms of dengue. Although everybody had participated in a training on Chikungunya Fever and Dengue, a very limited knowledge of nurses regarding the clinical management. It is suggested that further studies are developed on the ground a few nurses have accepted to participate in the study, so that we can identify strategies, interventions, activities and nursing actions that are consistent with the reality of working in favor of coping Aedes epidemics aegypti that have positive impact on reducing the infestation rates and may be suitable and applied in other regions.
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The research aimed to analyze the role of nurses in the Family Health Strategy (FHS) in the control of Dengue and Chikungunya fever in the cities of Parnamirim and Santa Cruz. It is exploratory and descriptive nature of research, with a qualitative approach, which was developed with nurses of the Family Health Strategy in the municipalities of Parnamirim and Santa Cruz. All research process followed the ethical standards laid out research in Resolution No. 466/2012 of the National Health Council about research involving human beings. Data collection was performed using a semi-structured questionnaire with open and closed questions, organized into three parts: the profile of respondents, knowledge of the disease (transmission, prevention, control) and description of practices. The actions performed by nurses are punctual performed when there is growing disease of the number of cases in order to try to reduce the number of cases. The principal methodology used for them is to talk and guidelines resulting from campaigns and home visits, using leaflets and social networks. Regarding knowledge of nurses in the city of Santa Cruz on Dengue Fever and Chikungunya, is clearly some gaps. Nursing professionals know recognize a suspected case of dengue, but get confused when trying to explain to the Chikungunya fever, exhibiting the same symptoms of dengue. Although everybody had participated in a training on Chikungunya Fever and Dengue, a very limited knowledge of nurses regarding the clinical management. It is suggested that further studies are developed on the ground a few nurses have accepted to participate in the study, so that we can identify strategies, interventions, activities and nursing actions that are consistent with the reality of working in favor of coping Aedes epidemics aegypti that have positive impact on reducing the infestation rates and may be suitable and applied in other regions.
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The capacity of dry protonated calcium alginate beads to sorb metals from an industrial effluent was studied and compared with a commercial ion-exchange resin (Lewatit TP 207). Both sorbents decreased zinc, nickel, iron and calcium concentrations in the effluent, and released sodium during treatment. Alginate beads removed lower amounts of heavy metals than the resin, but exhibited faster uptake kinetics. Zinc desorption from the sorbents was achieved in 30 minutes using 0.1 M HCl or 0.1 M H(2)SO(4). Desorption ratios with these acids varied between 90 and 100% for alginate, and 98 to 100% for the ion-exchange resin. Reusability tests with HCl showed that alginate beads can stand acid desorption and recover binding capacity. Overall, the comparison of dry protonated alginate beads with the resin supports the potential of the biosorbent for the treatment of industrial effluents.
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After the Congress, a six-day field trip, will be held through three southwestern provinces of Angola (Huíla, Namibe and Cunene), every day starting and ending in the city of Lubango, for overnight stay in Lubango, with the purpose to observe some of the main sites of geological interest in this zone of Angola. The itinerary of this field trip presents the geologic history of Southwestern Angola and its evolution in the scope of the Congo Craton, through a trip that begins in the first excursion days by the oldest geologic formations and phenomena until the recent geologic formations and phenomena on the last excursion days. On the first and second excursion days, September 5th and September 6th, the field trip will go along the Kunene Anorthosite Complex of Angola (KAC), to observe some petrographic features of the KAC that are important to understand the emplacement of this huge igneous massif of the early Kibarean age. These days of the field trip allow the observation of Earthen Construction, because this region of Cunene is privileged to appreciate a kind of Eco-construction, made of raw earth and in wattle and daub, built with ancient techniques, which constitute a real GeoHeritage. On September 7th, in the morning, the destination will be Tundavala, to visit Tundavala Gap, a huge escarpment of more than 1,000 m high cutted in Neo-Archean and Paleo-Proterozoic igneous rocks, the Ruins of Tundavala (quartzite blocks with sedimentary structures) and Tundavala Waterfalls on a quartzitic scarp. After lunch, the field trip continues towards Humpata plateau to observe the panoramic view over Lubango city from the Statue of Cristo Rei, then the outcrops of dolomitic limestones with stromatolites and dolerites and finally the Leba passage, a huge escarpment and one of the most spectacular parts of the Serra da Chela, traversed by a mountain road built in the early 70s of the last century, that can be observed from the belvedere of the Serra da Chela. On September 8th, the destination is the carbonatite complexes of Tchivira and Bonga, belonging to the Mesozoic alkaline massifs of ultrabasic rocks, a rift valley system that occurs during the Early Cretaceous. In this forth excursion day, due to the huge dimensions of these two carbonatite structures it will be visited, only, the Complex of Bonga, namely the outcrops of the northern part of the structure and secondary deposits on the boundary on the southern part of the of the Complex. The last two excursion days, September 9th and September 10th, are to observe the Cretaceous Basin of Namibe. On September 9th, the northern part of Namibe Basin will be visited to observe the volcanic basic rocks of Namibe as well as the interesting paleontological site of Bentiaba. On September 10th, the destination is the southern and more recent part of Namibe Basin, where on the Namib Desert, the exotic plant Welwitschia mirabilis can be observed, as well as Arco, an oasis in the desert. This last excursion day, ends up at the dunes of Tombwa near the mouth of Curoca river and the beautiful bay of Tombwa, where can be observed heavy minerals in their beach sands.
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Recently, media 'scandals' have pervaded a number of Australian body contact sports, in particular rugby league, rugby union and Australian rules football. Utilising the theoretical framework of masculinities, this research interviews footballers to gauge their perceptions of this media attention and how it compares to their own perspectives regarding off-field violence. Drawing inspiration from James Messerschmidt's (2000) 'Nine Lives' study and R.W. Connell's (1995) theoretical masculinities framework, in-depth, semi-structured interviews—known as life histories—were conducted with 12 footballers. Twelve life histories were completed with four men from each of the three major Australian football codes, namely Australian rules football, rugby union and rugby league. The research explores linkages between masculinity, body contact sport and engagement (or lack thereof) in violence 'off field'.
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We theoretically study the influence of Coulomb potential for photoionization of hydrogen atoms in an intense laser field with elliptical polarization. The total ionization rates, photoelectron energy spectra, and photoelectron angular distributions are calculated with the Coulomb-Volkov wave functions in the velocity gauge and compared with those calculated in the length gauge as well as those calculated with the Volkov wave functions. By comparing the results obtained by the Coulomb-Volkov and Volkov wave functions, we find that for linear polarization the influence of Coulomb potential is obvious for low-energy photoelectrons, and as the photoelectron energy and/or the laser intensity increase, its influence becomes smaller. This trend, however, is not so clear for the case of elliptical polarization. We also find that the twofold symmetry in the photoelectron angular distributions for elliptical polarization is caused by the cooperation of Coulomb potential and interference of multiple transition channels. About the gauge issue, we show that the difference in the photoelectron angular distributions obtained by the velocity and length gauges becomes rather obvious for elliptical polarization, while the difference is generally smaller for linear polarization.
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The quadrupolar hyperfine interactions of in-diffused (111)In -> (111)Cd probes in polycrystalline isostructural Zr(4)Al(3) and Hf(4)Al(3) samples containing small admixtures of the phases (Zr/Hf)(3)Al(2) were investigated. A strong preference of (111)In solutes for the contaminant (Zr/Hf)(3)Al(2) minority phases was observed. Detailed calculations of the electric field gradient (EFG) at the Cd nucleus using the full-potential augmented plane wave + local orbital formalism allowed us to assign the observed EFG fractions to the various lattice sites in the (Zr/Hf)(3)Al(2) compounds and to understand the preferential site occupation of the minority phases by the (111)In atoms. The effects of the size of the supercell and relaxation around the oversized In and Cd probe atoms were investigated in detail.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)