975 resultados para Second Nature
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The poet -- Experience -- Character -- Manners -- Gifts --Nature -- Politics -- Nominalist and realist -- New England reformers.
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pt. I. Acts of a public and general nature.--pt. II. Acts of a private and local nature.--[pt. III] Resolutions.
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A large number of macrocyclic miniproteins with diverse biological activities have been isolated from the Rubiaceae, Violaceae, and Cucurbitaceae plant families in recent years. Here we report the three-dimensional structure determined using H-1 NMR spectroscopy and demonstrate potent insecticidal activity for one of these peptides, kalata B2. This peptide is one of the major components of an extract from the leaves of the plant Oldenlandia affinis. The structure consists of a distorted triple-stranded beta-sheet and a cystine knot arrangement of the disulfide bonds and is similar to those described for other members of the cyclotide family. The unique cyclic and knotted nature of these molecules makes them a fascinating example of topologically complex proteins. Examination of the sequences reveals that they can be separated into two subfamilies, one of which contains a larger number of positively charged residues and has a bracelet-like circularization of the backbone. The second subfamily contains a backbone twist due to a cis-peptidyl-proline bond and may conceptually be regarded as a molecular Mobius strip. Kalata B2 is the second putative member of the Mobius cyclotide family to be structurally characterized and has a cis-peptidyl-proline bond, thus validating the suggested name for this subfamily of cyclotides. The observation that kalata B2 inhibits the growth and development of Helicoverpa armigera larvae suggests a role for the cyclotides in plant defense. A comparison of the sequences and structures of kalata B1 and B2 provides insight into the biological activity of these peptides.
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The modern grid system or the smart grid is likely to be populated with multiple distributed energy sources, e.g. wind power, PV power, Plug-in Electric Vehicle (PEV). It will also include a variety of linear and nonlinear loads. The intermittent nature of renewable energies like PV, wind turbine and increased penetration of Electric Vehicle (EV) makes the stable operation of utility grid system challenging. In order to ensure a stable operation of the utility grid system and to support smart grid functionalities such as, fault ride-through, frequency response, reactive power support, and mitigation of power quality issues, an energy storage system (ESS) could play an important role. A fast acting bidirectional energy storage system which can rapidly provide and absorb power and/or VARs for a sufficient time is a potentially valuable tool to support this functionality. Battery energy storage systems (BESS) are one of a range suitable energy storage system because it can provide and absorb power for sufficient time as well as able to respond reasonably fast. Conventional BESS already exist on the grid system are made up primarily of new batteries. The cost of these batteries can be high which makes most BESS an expensive solution. In order to assist moving towards a low carbon economy and to reduce battery cost this work aims to research the opportunities for the re-use of batteries after their primary use in low and ultra-low carbon vehicles (EV/HEV) on the electricity grid system. This research aims to develop a new generation of second life battery energy storage systems (SLBESS) which could interface to the low/medium voltage network to provide necessary grid support in a reliable and in cost-effective manner. The reliability/performance of these batteries is not clear, but is almost certainly worse than a new battery. Manufacturers indicate that a mixture of gradual degradation and sudden failure are both possible and failure mechanisms are likely to be related to how hard the batteries were driven inside the vehicle. There are several figures from a number of sources including the DECC (Department of Energy and Climate Control) and Arup and Cenex reports indicate anything from 70,000 to 2.6 million electric and hybrid vehicles on the road by 2020. Once the vehicle battery has degraded to around 70-80% of its capacity it is considered to be at the end of its first life application. This leaves capacity available for a second life at a much cheaper cost than a new BESS Assuming a battery capability of around 5-18kWhr (MHEV 5kWh - BEV 18kWh battery) and approximate 10 year life span, this equates to a projection of battery storage capability available for second life of >1GWhrs by 2025. Moreover, each vehicle manufacturer has different specifications for battery chemistry, number and arrangement of battery cells, capacity, voltage, size etc. To enable research and investment in this area and to maximize the remaining life of these batteries, one of the design challenges is to combine these hybrid batteries into a grid-tie converter where their different performance characteristics, and parameter variation can be catered for and a hot swapping mechanism is available so that as a battery ends it second life, it can be replaced without affecting the overall system operation. This integration of either single types of batteries with vastly different performance capability or a hybrid battery system to a grid-tie 3 energy storage system is different to currently existing work on battery energy storage systems (BESS) which deals with a single type of battery with common characteristics. This thesis addresses and solves the power electronic design challenges in integrating second life hybrid batteries into a grid-tie energy storage unit for the first time. This study details a suitable multi-modular power electronic converter and its various switching strategies which can integrate widely different batteries to a grid-tie inverter irrespective of their characteristics, voltage levels and reliability. The proposed converter provides a high efficiency, enhanced control flexibility and has the capability to operate in different operational modes from the input to output. Designing an appropriate control system for this kind of hybrid battery storage system is also important because of the variation of battery types, differences in characteristics and different levels of degradations. This thesis proposes a generalised distributed power sharing strategy based on weighting function aims to optimally use a set of hybrid batteries according to their relative characteristics while providing the necessary grid support by distributing the power between the batteries. The strategy is adaptive in nature and varies as the individual battery characteristics change in real time as a result of degradation for example. A suitable bidirectional distributed control strategy or a module independent control technique has been developed corresponding to each mode of operation of the proposed modular converter. Stability is an important consideration in control of all power converters and as such this thesis investigates the control stability of the multi-modular converter in detailed. Many controllers use PI/PID based techniques with fixed control parameters. However, this is not found to be suitable from a stability point-of-view. Issues of control stability using this controller type under one of the operating modes has led to the development of an alternative adaptive and nonlinear Lyapunov based control for the modular power converter. Finally, a detailed simulation and experimental validation of the proposed power converter operation, power sharing strategy, proposed control structures and control stability issue have been undertaken using a grid connected laboratory based multi-modular hybrid battery energy storage system prototype. The experimental validation has demonstrated the feasibility of this new energy storage system operation for use in future grid applications.
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The goal of this project was to explore activism, attitudes, and imagery connecting Black churchgoers in Miami, Florida and the natural environment. The research approach was qualitative, began as exploratory research, and used the techniques of snowball sampling, participant observation, and semi-structured interviews. Three case studies representing various socio-economic levels, denominations, participant education levels, and environmental facets were chosen for in-depth ethnographic research. There are three major findings in the research. First, there is a link between the preservation of Black history and the preservation of the environment among Black churchgoers, who feel strong connections to a sense of place, rural life, and the past. However their work is strongly directed to bring about benefits for people and the environment in the present and the future. Second, public access to public lands is a basic and important right espoused by these Black churchgoing activists. Third, the vocabulary used by Black churchgoing activists regarding the natural environment differs from today's “mainstream” environmentalists. The concept of “beauty” is pivotal to Black appreciation of and activism toward the environment and is reminiscent of the early environmental protection movement in the United States and conservationists such as John Muir. These findings concerning how Black spirituality relates to the environment adds to the sparse literature on the subject, and provides for potential linkages between Blacks and “mainstream” environmental groups to benefit both parties. An understanding of the connections between Black spirituality and perceptions of the environment should facilitate the development of better programs to improve and protect the environment. Environmental projects may also address the social and economic needs of Black communities, churches, and congregations, as well as the ecosystem. ^
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We organized an international campaign to observe the blazar 0716+714 in the optical band. The observations took place from February 24, 2009 to February 26, 2009. The global campaign was carried out by observers from more that sixteen countries and resulted in an extended light curve nearly seventy-eight hours long. The analysis and the modeling of this light curve form the main work of this dissertation project. In the first part of this work, we present the time series and noise analyses of the data. The time series analysis utilizes discrete Fourier transform and wavelet analysis routines to search for periods in the light curve. We then present results of the noise analysis which is based on the idea that each microvariability curve is the realization of the same underlying stochastic noise processes in the blazar jet. ^ Neither reoccuring periods nor random noise can successfully explain the observed optical fluctuations. Hence in the second part, we propose and develop a new model to account for the microvariability we see in blazar 0716+714. We propose that the microvariability is due to the emission from turbulent regions in the jet that are energized by the passage of relativistic shocks. Emission from each turbulent cell forms a pulse of emission, and when convolved with other pulses, yields the observed light curve. We use the model to obtain estimates of the physical parameters of the emission regions in the jet.^
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Immigrants from Jamaica represent the largest number of migrants to the United States from the English speaking Caribbean. Research indicates that of all Caribbean immigrants they are most likely to retain the ethnic identity of their home country for the longest period of time. This dissertation explored the nature of ethnic identity and sought to determine its impact upon the additional variables of self-esteem and academic factors. A secondary analysis was carried out using data collected in the Spring of 1992 by Portes and Rumbaut on the children of immigrants attending the eighth and ninth grades in local schools in San Diego and southern Florida. A sample of 151 second-generation Jamaican immigrants was selected from the data set. ^ Six hypotheses yielded mixed results. Both parents who have a Jamaican ethnic identity present in the household are the best predictor Jamaican youth who retain a Jamaican ethnic identity. It was expected that ethnic identity would be a predictor of positive academic factors. The study showed that ethnic identity was not associated with one of the academic factors which were examined: help given with homework. ^ Neither family economic status nor parents' level of education played a significant role in the retention of Jamaican identity. Other findings were that there was no mean difference in the self-esteem scores of respondents who had similar ethnic identities to their parents and those who did not. There was also no difference found in the academic factors of either group. The study also showed that there was a small correlation between parent-child conflict and self-esteem. Specifically, the study found that the higher the conflict between youth and their parents, the lower the self-esteem of the youth. Finally it found that time lived in the U.S. was the best predictor of a higher GPA and it was also related to lower self-esteem. ^ Surprisingly, the study found that the relationship between ethnic identity and SES was the opposite of what was expected in that it found that SES was higher when there was no Jamaican identity. ^
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Extracts from a treatise in which Locke sets out his labour theory of property.
Locke's writings on the labour theory of property provided eighteenth century proponents of the concept of copyright at common law (that is, copyright as a natural authorial property right) with a philosophical basis upon which to develop their arguments. The commentary explores the significance of a series of correspondence between John Locke and Edward Clarke, then MP for Taunton, concerning the lapse of the Licensing Act 1662 (uk_1662), and in the run up to the passing of the Statute of Anne 1710 (uk_1710). The commentary argues that, regardless of how Locke's writings on property were subsequently co-opted in the mid-eighteenth century debates as to the nature of copyright, it is doubtful whether Locke himself considered that copyright existed at common law.
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Context: The stellar population of the 30 Doradus star-forming region in the Large Magellanic Cloud contains a subset of apparently single, rapidly rotating O-type stars. The physical processes leading to the formation of this cohort are currently uncertain.
Aims: One member of this group, the late O-type star VFTS 399, is found to be unexpectedly X-ray bright for its bolometric luminosity-in this study we aim to determine its physical nature and the cause of this behaviour.
Methods: To accomplish this we performed a time-resolved analysis of optical, infrared and X-ray observations.
Results: We found VFTS 399 to be an aperiodic photometric variable with an apparent near-IR excess. Its optical spectrum demonstrates complex emission profiles in the lower Balmer series and select He i lines-taken together these suggest an OeBe classification. The highly variable X-ray luminosity is too great to be produced by a single star, while the hard, non-thermal nature suggests the presence of an accreting relativistic companion. Finally, the detection of periodic modulation of the X-ray lightcurve is most naturally explained under the assumption that the accretor is a neutron star.
Conclusions: VFTS 399 appears to be the first high-mass X-ray binary identified within 30 Dor, sharing many observational characteristics with classical Be X-ray binaries. Comparison of the current properties of VFTS 399 to binary-evolution models suggests a progenitor mass 25 M⊙ for the putative neutron star, which may host a magnetic field comparable in strength to those of magnetars. VFTS 399 is now the second member of the cohort of rapidly rotating "single" O-type stars in 30 Dor to show evidence of binary interaction resulting in spin-up, suggesting that this may be a viable evolutionary pathway for the formation of a subset of this stellar population.
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Daniel Bromley argues against Oran Young’s FIT model as a basis for environmental governance, on the grounds that humans cannot manage nature and that attempts to do so are based on a scientistic, modernist conceit. At issue is the role of natural and social scientists in adjudicating questions about what we ought to do to close governance gaps and address unsustainable behaviors. If Bromley is right, then the lessons of the American pragmatist tradition recommend against attempts to “fit” social institutions to the natural world. The first objective of this paper is to argue that Bromley’s view is not in keeping with the pragmatism of C. S. Peirce and John Dewey, which actually places a high value on natural and social scientific modes of inquiry in the service of social ends. I argue that Young’s proposal is in fact a development of the pragmatist idea that social institutions must be fit in the sense of fitness, i.e., resilient and able to navigate uncertainty. Social institutions must also evolve to accommodate the emerging values of the agents who operate within them. The second objective of this paper is to examine the role of social science expertise in the design of social policies. Governance institutions typically rely on the testimony of natural scientists, at least in part, to understand the natural systems they operate within. However, natural systems are also social systems, so it seems pertinent to ask whether there is a role for social systems experts to play in helping to design environmental governance institutions. I argue that social scientists can make a unique contribution as experts on social institutions, and as such, are necessary to bring about a transformation of the unsustainable institutions that are preventing us from achieving stated sustainable development goals.
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This research study investigates the role and impact of psychoanalytically-informed short-term parent work with long-term foster carers of looked-after children, in support of the foster placement. The study reflects on the data gathered from four child assessments and five foster families seen by a psychoanalytic child psychotherapist for four sessions each. It draws on psychoanalytic ideas from a range of theoretical traditions, exploring such concepts as trauma, defences, compulsion to repeat, psychological-mindedness, ‘container/contained’ (Bion) and ‘holding environment’ (Winnicott). One distinctive contribution of this research is what it adds to our already existing understanding of the defences (or responses) aroused in the carer when faced with the intense and distressing affect associated with the child’s early trauma; and the impact of this legacy of trauma on the child, on the carer and on the wider Social Services system. Applying Grounded Theory and psychoanalytically-informed clinical case study methodology to the research material, the study breaks down the data analysis into seven stages of coding, from the initial reading of the data to the eventual development of two key hypotheses. One of the predominant themes that emerged from the analysis was the carer’s capacity to remain focused on the child’s emotional needs and how this in turn was linked to the direction of the therapist’s focus. The successive analyses of the data culminated in the hypothesis that the more the therapist focused on the carer and the carer’s emotional states in the course of the parent work, the more the carer was enabled to focus on the child’s emotional needs. As the system of categories emerged according to the themes exemplified in the sessions, a particular focus of analysis became the concept of psychologicalmindedness, considered under several sub-categories: displaying insightful comments; awareness of the child’s bodily states; awareness of the child’s affect; the carer’s ability to recognize the child’s defences; and the carer’s ability to make links between the child’s current difficulties and the child’s past experiences. Through this analysis it became apparent that degree of psychological-mindedness was closely linked to the individual carer’s capacity to metabolize the child’s distressed and distressing communication. This in turn led to a deeper exploration of the situations that were particularly challenging for the carers: i.e., instances when the child was compelled to repeat past traumatic emotional states and as a result was communicating intense distress. This exploration eventually generated the second hypothesis: that in reaction to the child’s distress, the response of each carer could be plotted somewhere along a spectrum, from either distancing themselves from the child’s emotional state to seeking excessive closeness with the child (merging). The next stage of the analysis developed four new categories of carer responses to the distressed child: identification and distancing from the child; identification and merging with the child; the category that describes the carer’s psychologicalmindedness as being ‘impaired’; and ‘good enough’ caring. This then led to an exploration of the carer’s own defences at these most challenging times. This research demonstrates clearly that even within the short space of four sessions of weekly psychoanalytic parent work, it is possible to achieve significant improvement in a carer’s capacity to bear the child’s compulsion to repeat early traumas, and to help the carers become more emotionally available to provide the child with effective psychological parenting at such difficult and challenging times. Key words: looked-after children; long-term foster carers; psychoanalytic short-term parent work; trauma; compulsion to repeat; psychological-mindedness; empathy; defences; psychoanalytically-informed clinical case study research methodology; Grounded Theory research methodology.
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Les travaux sur la nutrition en vitamines B des ruminants montrent des résultats très variés sur les quantités de ces nutriments disponibles pour l’animal selon la nature de la ration. Ces divergences sont dues à des changements des populations microbiennes dans le rumen, causées par les facteurs physico-chimiques de la ration. Une amélioration de la compréhension des effets de la nature de la diète sur la synthèse et l’utilisation des vitamines B dans le rumen pourrait aider à identifier les conditions sous lesquelles une supplémentation en ces vitamines serait bénéfique pour la vache. Le but de ce travail de thèse est donc d’améliorer la compréhension des effets de l’espèce fourragère, de la maturité et de la longueur des particules de fourrage sur les apports en vitamines B chez la vache laitière. Pour évaluer chacune de ces variables, les concentrations de thiamine, riboflavine, niacine, vitamine B6, folates et vitamine B12 ont été mesurées dans les échantillons d’aliments et de digesta duodénal recueillis lors de trois projets réalisés à l’Université du Michigan par l’équipe du Dr. M. Allen. Dans la première étude, l’effet de l’espèce fourragère des ensilages a été évalué au cours de deux expériences similaires durant lesquelles les vaches recevaient une diète à base d’ensilage de luzerne ou de dactyle. Les diètes à base de luzerne ont été associées à une augmentation de la dégradation de la thiamine et de la vitamine B6 dans le rumen par rapport aux diètes à base d’ensilage de dactyle. La deuxième étude visait à évaluer les effets de la maturité des plantes lors de la mise en silo sur les quantités de vitamines B disponibles pour la vache; les deux expériences se différenciaient par l’espèce fourragère étudiée, soit la luzerne ou le dactyle. Une récolte à un stade de maturité plus élevé a augmenté les flux duodénaux de thiamine, de niacine et de folates lorsque les vaches recevaient des diètes à base d’ensilage de luzerne mais n’a diminué que le flux duodénal de riboflavine chez les animaux recevant des diètes à base d’ensilage de dactyle. La troisième étude a comparé les effets de la longueur de coupe (10 vs. 19 mm) d’ensilages de luzerne et de dactyle sur le devenir des vitamines B dans le système digestif de la vache laitière. Cette étude a permis de constater qu’une augmentation du temps de séchage au champ diminuait les concentrations de vitamines B dans les ensilages. Cependant, la taille des particules des ensilages de luzerne et de dactyle n’a pas affecté les quantités des vitamines B arrivant au duodénum des vaches. En général, les résultats de ces études montrent qu’il existe une corrélation négative entre la synthèse de riboflavine, de niacine et de vitamine B6 et leur ingestion, suggérant une possible régulation de la quantité de ces vitamines B par les microorganismes du rumen. De plus, l’ingestion d’amidon et d’azote a été corrélée positivement avec la synthèse de thiamine, de folates et de vitamine B12, et négativement avec la synthèse de niacine. Ces corrélations suggèrent que les microorganismes qui utilisent préférentiellement l’amidon jouent un rôle majeur pour la synthèse ou la dégradation de ces vitamines. De plus, la présence d’une quantité suffisante d’azote semble avoir un impact majeur sur ces processus. La suite de ces travaux devrait viser la modélisation de ces données afin de mieux appréhender la physiologie de la digestion de ces vitamines et permettre la création de modèles mathématiques capables de prédire les quantités de vitamines disponibles pour les vaches. Ces modèles permettront, lorsqu’intégrés aux logiciels de formulation de ration, d’élaborer une diète plus précise, ce qui améliorera la santé du troupeau et la performance laitière et augmentera les profits du producteur.
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In recent years, a “second wave” of positive psychology has been emerging, characterised, above all, by an awareness and appreciation of the dialectical nature of flourishing. This paper offers a philosophical foundation for this second wave, based on Eastern philosophy, and, in particular, Zen aesthetics. Part one introduces Zen, including its key philosophical ideas and practices, as well as two antecedent traditions that helped to form it, namely, Buddhism and Taoism. Part two then elucidates three aesthetic principles that are integral to Zen: mono no aware (pathos of life), wabi-sabi (desolate beauty), and yūgen (profound grace). The paper discusses how these principles could be of value to positive psychology in fostering dialectical understanding and appreciation, thus highlighting future directions for the field.
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Ce rapport est en accord avec de nombreux travaux sur l'enseignement des sciences qui insistent sur l'importance de partir des connaissances de l'enfant. Le projet d'apprentissage des sciences au primaire qui est le plus élaboré et qui part des idées des enfants est néo-zélandais (Harlen, 1988). Dans ce projet, les guides du maître ont été réalisés après une période de recherche sur les problèmes de l'enseignement et de l'apprentissage des sciences dans les classes primaires. Les impératifs mis de l'avant par ce projet étaient de préparer des activités en classe correspondant davantage au questionnement de l'enfant; de permettre à l'enfant de poser ses propres questions et de mener ses propres recherches; enfin, de ne pas laisser l'enfant seul pour tirer des conclusions et de ne pas l'obliger à accepter des conclusions non rattachées à son expérience personnelle. L'enseignement des sciences doit parvenir à éveiller l'élève, à le rendre plus mûr affectivement et intellectuellement en développant son esprit critique. Cet enseignement doit amener un savoir réinvestissable dans la vie quotidienne, car c'est cette absence de culture scientifique, qui aggrave le sentiment d'impuissance, que l'enfant éprouve une fois adulte devant la situation du monde qui l'environne et qui limite ses capacités d'assimilation et d'adaptation (Astolfi et al. 1978). Cet enseignement doit aussi faire naître chez l'élève le désir d'explorer, d'expérimenter et de laisser libre cours à sa créativité personnelle par le développement d'attitudes. Ces considérations générales nous ont conduit à élaborer (figure 1) dans un premier chapitre une problématique où nous tracerons les grandes lignes des problèmes posés par notre sujet de recherche et la méthodologie retenue. L'apprentissage pose des difficultés tant au niveau de l'élève que de l'enseignant et du savoir. Nous tenterons de cerner ces difficultés et de les expliquer dans un second chapitre. Un troisième chapitre nous amènera à développer brièvement deux approches de la créativité et à définir celle que nous choisissons et pourquoi. Une fois les problèmes circonscris par rapport à la réalité existant dans l'apprentissage scolaire, le dernier chapitre traitera de notre modèle théorique d'intervention didactique où la créativité intervient au niveau de l'objet d'apprentissage, de l'élève et de l'enseignant.