872 resultados para learned helplessness


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Understanding farmer behaviour is needed for local agricultural systems to produce food sustainably while facing multiple pressures. We synthesize existing literature to identify three fundamental questions that correspond to three distinct areas of knowledge necessary to understand farmer behaviour: 1) decision-making model; 2) cross-scale and cross-level pressures; and 3) temporal dynamics. We use this framework to compare five interdisciplinary case studies of agricultural systems in distinct geographical contexts across the globe. We find that these three areas of knowledge are important to understanding farmer behaviour, and can be used to guide the interdisciplinary design and interpretation of studies in the future. Most importantly, we find that these three areas need to be addressed simultaneously in order to understand farmer behaviour. We also identify three methodological challenges hindering this understanding: the suitability of theoretical frameworks, the trade-offs among methods and the limited timeframe of typical research projects. We propose that a triangulation research strategy that makes use of mixed methods, or collaborations between researchers across mixed disciplines, can be used to successfully address all three areas simultaneously and show how this has been achieved in the case studies. The framework facilitates interdisciplinary research on farmer behaviour by opening up spaces of structured dialogue on assumptions, research questions and methods employed in investigation.

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There has been much criticism of President Mbeki's policy of constructive engagement towards Mugabe's regime in Zimbabwe. This has grown since 2000 as the crisis has continued to worsen. This article compares Pretoria's current approach with the Reagan administration's constructive engagement towards Pretoria in the 1980s. Washington made a number of significant mistakes in the design and implementation of this policy and each of these is examined. An investigation of Mbeki's actions concludes that he is currently committing many of the same errors. Not only does this damage Mbeki's credibility, it also damages the credibility of a vital diplomatic tool - reducing constructive engagement once again to a diplomatic fig leaf to cover 'business as usual' with a rogue state.

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In the present study, we investigated the role of noradrenergic transmission in unconditioned and conditioned responses to predatory threats. First, we examined the effects of systemically injected beta-blockers on unconditioned and contextual conditioned response to cat odor. The centrally acting beta-blocker (propranolol) was able to impair unconditioned responses, as well as the acquisition of the contextual fear to cat odor; however, the peripherally acting (nadolol) was not effective. Next, we examined the neural substrate underlying the noradrenergic modulation of the defensive response to cat odor and focused on the dorsal premammillary nucleus (PMd), because it represents the hypothalamic site most responsive to predatory threats and, at the same time, presents a dense plexus of noradrenergic fibers. We were able to see that propranolol significantly reduced PMd-Fos expression in response to cat odor and that beta-adrenoceptor blockade in the PMd, before cat odor exposure, reduced defensive responses to the cat odor and to the cat odor-related environment. We have also shown that beta-adrenoceptor blockade in the PMd, before the exposure to cat odor-related context, impaired the contextual conditioned responses. Overall, the present results provide convincing evidence suggesting that central noradrenergic mediation is critical for the expression of unconditioned and contextual conditioned antipredatory responses. We have further shown that the PMd appears to be an important locus to mediate these beta-adrenoceptor effects.

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The solvation of six solvatochromic probes in a large number of solvents (33-68) was examined at 25 degrees C. The probes employed were the following: 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl) phenolate (RB); 4-[(E)2-(1-methylpyridinium-4-yl)ethenyl] phenolate, MePM; 1-methylquinolinium-8-olate, QB; 2-bromo-4-[(E)-2-(1-methylpyridinium-4-yl)ethenyl] phenolate, MePMBr, 2,6-dichloro-4-(2,4,6-triphenyl pyridinium-1-yl) phenolate (WB); and 2,6-dibromo-4-[(E)-2-(1-methylpyridinium-4-yl)ethenyl] phenolate, MePMBr(2), respectively. Of these, MePMBr is a novel compound. They can be grouped in three pairs, each with similar pK(a) in water but with different molecular properties, for example, lipophilicity and dipole moment. These pairs are formed by RB and MePM; QB and MePMBr; WB and MePMBr(2), respectively. Theoretical calculations were carried out in order to calculate their physicochemical properties including bond lengths, dihedral angles, dipole moments, and wavelength of absorption of the intramolecular charge-transfer band in four solvents, water, methanol, acetone, and DMSO, respectively. The data calculated were in excellent agreement with available experimental data, for example, bond length and dihedral angles. This gives credence to the use of the calculated properties in explaining the solvatochromic behaviors observed. The dependence of an empirical solvent polarity scale E(T)(probe) in kcal/mol on the physicochemical properties of the solvent (acidity, basicity, and dipolarity/polarizability) and those of the probes (pK(a), and dipole moment) was analyzed by using known multiparameter solvation equations. For each pair of probes, values of E(T)(probe) (for example, E(T)(MePM) versus E(T)(RB)) were found to be linearly correlated with correlation coefficients, r, between 0.9548 and 0.9860. For the mercyanine series, the values of E(T)(probe) also correlated linearly, with (r) of 0.9772 (MePMBr versus MePM) and 0.9919 (MePMBr(2) versus MePM). The response of each pair of probes (of similar pK(a)) to solvent acidity is the same, provided that solute-solvent hydrogen-bonding is not seriously affected by steric crowding (as in case of RB). We show, for the first time, that the response to solvent dipolarity/polarizability is linearly correlated to the dipole moment of the probes. The successive introduction of bromine atoms in MePM (to give MePMBr, then MePMBr(2)) leads to the following linear decrease: pK(a) in water, length of the phenolate oxygen-carbon bond, length of the central ethylenic bond, susceptibility to solvent acidity, and susceptibility to solvent dipolarity/polarizability. Thus studying the solvation of probes whose molecular structures are varied systematically produces a wealth of information on the effect of solute structure on its solvation. The results of solvation of the present probes were employed in order to test the goodness of fit of two independent sets of solvent solvatochromic parameters.

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The presentation was offered as part of the CUNY Library Assessment Conference, Reinventing Libraries: Reinventing Assessment, held at the City University of New York in June 2014.

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BACKGROUND: In northern Vietnam the Neonatal health - Knowledge Into Practice (NeoKIP, Current Controlled Trials ISRCTN44599712) trial has evaluated facilitation as a knowledge translation intervention to improve neonatal survival. The results demonstrated that intervention sites, each having an assigned group including local stakeholders supported by a facilitator, lowered the neonatal mortality rate by 50% during the last intervention year compared with control sites. This process evaluation was conducted to identify and describe mechanisms of the NeoKIP intervention based on experiences of facilitators and intervention group members. METHODS: Four focus group discussions (FGDs) were conducted with all facilitators at different occasions and 12 FGDs with 6 intervention groups at 2 occasions. Fifteen FGDs were audio recorded, transcribed verbatim, translated into English, and analysed using thematic analysis. RESULTS: Four themes and 17 sub-themes emerged from the 3 FGDs with facilitators, and 5 themes and 18 sub-themes were identified from the 12 FGDs with the intervention groups mirroring the process of, and the barriers to, the intervention. Facilitators and intervention group members concurred that having groups representing various organisations was beneficial. Facilitators were considered important in assembling the groups. The facilitators functioned best if coming from the same geographical area as the groups and if they were able to come to terms with the chair of the groups. However, the facilitators' lack of health knowledge was regarded as a deficit for assisting the groups' assignments. FGD participants experienced the NeoKIP intervention to have impact on the knowledge and behaviour of both intervention group members and the general public, however, they found that the intervention was a slow and time-consuming process. Perceived facilitation barriers were lack of money, inadequate support, and the function of the intervention groups. CONCLUSIONS: This qualitative process evaluation contributes to explain the improved neonatal survival and why this occurred after a latent period in the NeoKIP project. The used knowledge translation intervention, where facilitators supported multi-stakeholder coalitions with the mandate to impact upon attitudes and behaviour in the communes, has low costs and potential for being scaled-up within existing healthcare systems.

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Em um esforço continuo de sobrevivência, corporações buscam meios para expandir seus negócios, seja dentro de seus mercados atuantes, ou na exploração de novos mercados. Para alcançar esse objetivo, inovações são realizadas pelos funcionários que, por meio de suas iniciativas, praticam o empreendedorismo coorporativo. São diversas formas em que o empreendedorismo corporativo se manifesta, dentre elas por meio de aquisições. Ao comprar uma outra empresa, a empresa compradora tem como motivação a busca de alguns atributos que complementem seus objetivos iniciais. Após a compra, o processo de integração entre as duas empresas é, por muitas vezes, complicado e penoso. O objetivo desse estudo é o de identificar quais são essas motivações de compra, os problemas enfrentados durante a integração entre as duas empresas, e quais são as lições aprendidas por grandes/médias corporações quando adquirem Start-ups. Muitos estudos atualmente tratam de temas relacionados à aquisição de empresas, porém, quando se trata de Start-ups, pouca literatura é encontrada. Os resultados dessa pesquisa são fruto de entrevistas com os gestores e empreendedores que participaram do processo de aquisição da SAMURAI pela Momentum e da Save-me pela Buscapé – empresas brasileiras. Os resultados são seis sugestões que devem ser consideradas por grandes/medias corporações antes e durante o processo de aquisição de uma strat-up: (i) A base de clientes da empresa comprada deve ser cuidadosamente considerada; (ii) um contato muito próximo entre os gestores das duas empresas é crucial antes da realização da aquisição; (iii) a contratação de uma empresa de consultoria em aquisições pode ser primordial durante o processo de integração; (iv) o empreendedor tem um papel de central importância para o future da nova empresa formada após a aquisição; (v) a forma como a integração entre as duas empresas ocorrerá após a compra deve ser cuidadosamente escolhida e (iv) a criação de uma corporate venture deve ser levada em consideração.

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Sleep helps the consolidation of declarative memories in the laboratory, but the pro-mnemonic effect of daytime naps in schools is yet to be fully characterized. While a few studies indicate that sleep can indeed benefit school learning, it remains unclear how best to use it. Here we set out to evaluate the influence of daytime naps on the duration of declarative memories learned in school by students of 10–15 years old. A total of 584 students from 6th grade were investigated. Students within a regular classroom were exposed to a 15-min lecture on new declarative contents, absent from the standard curriculum for this age group. The students were then randomly sorted into nap and non-nap groups. Students in the nap group were conducted to a quiet room with mats, received sleep masks and were invited to sleep. At the same time, students in the non-nap group attended regular school classes given by their usual teacher (Experiment I), or English classes given by another experimenter (Experiment II). These 2 versions of the study differed in a number of ways. In Experiment I (n = 371), students were pre-tested on lecture-related contents before the lecture, were invited to nap for up to 2 h, and after 1, 2, or 5 days received surprise tests with similar content but different wording and question order. In Experiment II (n = 213), students were invited to nap for up to 50 min (duration of a regular class); surprise tests were applied immediately after the lecture, and repeated after 5, 30, or 110 days. Experiment I showed a significant ∼10% gain in test scores for both nap and non-nap groups 1 day after learning, in comparison with pre-test scores. This gain was sustained in the nap group after 2 and 5 days, but in the non-nap group it decayed completely after 5 days. In Experiment II, the nap group showed significantly higher scores than the non-nap group at all times tested, thus precluding specific conclusions. The results suggest that sleep can be used to enhance the duration of memory contents learned in school.

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Includes bibliography