985 resultados para Historical sense
Resumo:
Before the spread of extensive settled cultivation, the Indian subcontinent would have been inhabited by territorial hunter–gatherers and shifting cultivators with cultural traditions of prudent resource use. The disruption of closed material cycles by export of agricultural produce to centres of non-agricultural population would have weakened these traditions. Indeed, the fire-based sacrificial ritual and extensive agricultural settlements might have catalysed the destruction of forests and wildlife and the suppression of tribal peoples during the agricultural colonization of the Gangetic plains. Buddhism, Jainism and later the Hindu sects may have been responses to the need for a reassertion of ecological prudence once the more fertile lands were brought under cultivation. British rule radically changed the focus of the country's resource use pattern from production of a variety of biological resources for local consumption to the production of a few commodities largely for export. The resulting ecological squeeze was accompanied by disastrous famines and epidemics between the 1860s and the 1920s. The counterflows to tracts of intensive agriculture have reduced such disasters since independence. However, these are quite inadequate to balance the state-subsidized outflows of resources from rural hinterlands. These imbalances have triggered serious environmental degradation and tremendous overcrowding of the niche of agricultural labour and marginal cultivator all over the country.
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In order to further develop the logic of service, value creation, value co-creation and value have to be formally and rigorously defined, so that the nature, content and locus of value and the roles of service providers and customers in value creation can be unambiguously assessed. In the present article, following the underpinning logic of value-in-use, it is demonstrated that in order to achieve this, value creation is best defined as the customer’s creation of value-in-use. The analysis shows that the firm’s and customer’s processes and activities can be divided into a provider sphere, closed for the customer, and a customer sphere, closed for the firm. Value creation occurs in the customer sphere, whereas firms in the provider sphere facilitate value creation by producing resources and processes which represent potential value or expected value-in use for their customers. By getting access to the closed customer sphere, firms can create a joint value sphere and engage in customers’ value creation as co-creators of value with them. This approach establishes a theoretically sound foundation for understanding value creation in service logic, and enables meaningful managerial implications, for example as to what is required for co-creation of value, and also further theoretical elaborations.
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The similar to 2500 km-long Himalaya plate boundary experienced three great earthquakes during the past century, but none of them generated any surface rupture. The segments between the 1905-1934 and the 1897-1950 sources, known as the central and Assam seismic gaps respectively, have long been considered holding potential for future great earthquakes. This paper addresses two issues concerning earthquakes along the Himalaya plate boundary. One, the absence of surface rupture associated with the great earthquakes, vis-a-vis the purported large slip observed from paleoseismological investigations and two, the current understanding of the status of the seismic gaps in the Central Himalaya and Assam, in view of the paleoseismological and historical data being gathered. We suggest that the ruptures of earthquakes nucleating on the basal detachment are likely to be restricted by the crustal ramps and thus generate no surface ruptures, whereas those originating on the faults within the wedges promote upward propagation of rupture and displacement, as observed during the 2005 Kashmir earthquake, that showed a peak offset of 7 m. The occasional reactivation of these thrust systems within the duplex zone may also be responsible for the observed temporal and spatial clustering of earthquakes in the Himalaya. Observations presented in this paper suggest that the last major earthquake in the Central Himalaya occurred during AD 1119-1292, rather than in 1505, as suggested in some previous studies and thus the gap in the plate boundary events is real. As for the Northwestern Himalaya, seismically generated sedimentary features identified in the 1950 source region are generally younger than AD 1400 and evidence for older events is sketchy. The 1897 Shillong earthquake is not a decollement event and its predecessor is probably similar to 1000 years old. Compared to the Central Himalaya, the Assam Gap is a corridor of low seismicity between two tectonically independent seismogenic source zones that cannot be considered as a seismic gap in the conventional sense. (C) 2011 Elsevier B.V. All rights reserved.
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Plants produce volatile organic compounds (VOCs) in a variety of contexts that include response to abiotic and biotic stresses, attraction of pollinators and parasitoids, and repulsion of herbivores. Some of these VOCs may also exhibit diel variation in emission. In Ficus racemosa, we examined variation in VOCs released by fig syconia throughout syconium development and between day and night. Syconia are globular enclosed inflorescences that serve as developing nurseries for pollinating and parasitic fig wasps. Syconia are attacked by gallers early in their development, serviced by pollinators in mid phase, and are attractive to parasitoids in response to the development of gallers at later stages. VOC bouquets of the different development phases of the syconium were distinctive, as were their day and night VOC profiles. VOCs such as alpha-muurolene were characteristic of the pollen-receptive diurnal phase, and may serve to attract the diurnally-active pollinating wasps. Diel patterns of release of volatiles could not be correlated with their predicted volatility as determined by Henry's law constants at ambient temperatures. Therefore, factors other than Henry's law constant such as stomatal conductance or VOC synthesis must explain diel variation in VOC emission. A novel use of weighted gene co-expression network analysis (WGCNA) on the volatilome resulted in seven distinct modules of co-emitted VOCs that could be interpreted on the basis of syconium ecology. Some modules were characterized by the response of fig syconia to early galling by parasitic wasps and consisted largely of green leaf volatiles (GLVs). Other modules, that could be characterized by a combination of syconia response to oviposition and tissue feeding by larvae of herbivorous galler pollinators as well as of parasitized wasps, consisted largely of putative herbivore-induced plant volatiles (HIPVs). We demonstrated the usefulness of WGCNA analysis of the volatilome in making sense of the scents produced by the syconia at different stages and diel phases of their development.
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A study of the history and philosophy of the contribution of India towards the exploration of space since antiquity provides interesting insights. The contributions are described during the three periods namely: (1) the ten millenniums from 10,000 BC with a twilight period up to 900 AD; (2) the ten centuries from 900 AD to 1900 AD; and (3) the ten decades from 1900 AD to 2000 AD; called mythological, medieval, and modern respectively. Some important events during the above periods provide a reference view of the progress. The Vedas during the mythological period and the Siddhantas during the medieval periods, which are based on astronomical observations, indicate that the Indian contribution preceded other cultures. But most Western historians ignore this fact time and again in spite of many proofs provided to the contrary. This chapter also shows that Indians had the proper scientific attitude of developing any physical theory through the triplet of mind, model, and measurements. It is this same triplet that forms the basis of the present day well known Kalman filter technique. Up to about 1500 BC the Indian contribution was leading but during foreign invasion and occupation it lagged and has been improving only after independence.
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1. Resilience-based approaches are increasingly being called upon to inform ecosystem management, particularly in arid and semi-arid regions. This requires management frameworks that can assess ecosystem dynamics, both within and between alternative states, at relevant time scales. 2. We analysed long-term vegetation records from two representative sites in the North American sagebrush-steppe ecosystem, spanning nine decades, to determine if empirical patterns were consistent with resilience theory, and to determine if cheatgrass Bromus tectorum invasion led to thresholds as currently envisioned by expert-based state-and-transition models (STM). These data span the entire history of cheatgrass invasion at these sites and provide a unique opportunity to assess the impacts of biotic invasion on ecosystem resilience. 3. We used univariate and multivariate statistical tools to identify unique plant communities and document the magnitude, frequency and directionality of community transitions through time. Community transitions were characterized by 37-47% dissimilarity in species composition, they were not evenly distributed through time, their frequency was not correlated with precipitation, and they could not be readily attributed to fire or grazing. Instead, at both sites, the majority of community transitions occurred within an 8-10year period of increasing cheatgrass density, became infrequent after cheatgrass density peaked, and thereafter transition frequency declined. 4. Greater cheatgrass density, replacement of native species and indication of asymmetry in community transitions suggest that thresholds may have been exceeded in response to cheatgrass invasion at one site (more arid), but not at the other site (less arid). Asymmetry in the direction of community transitions also identified communities that were at-risk' of cheatgrass invasion, as well as potential restoration pathways for recovery of pre-invasion states. 5. Synthesis and applications. These results illustrate the complexities associated with threshold identification, and indicate that criteria describing the frequency, magnitude, directionality and temporal scale of community transitions may provide greater insight into resilience theory and its application for ecosystem management. These criteria are likely to vary across biogeographic regions that are susceptible to cheatgrass invasion, and necessitate more in-depth assessments of thresholds and alternative states, than currently available.
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Global efforts in macromolecular crystallography started in the thirties of the last century. However, definitive results began to emerge only in the late fifties and the early sixties. India has a long tradition in crystallography. The country had a head start in theoretical and computational structural biology, thanks to the efforts of G.N. Ramachandran and his colleagues in the fifties and the sixties. However, macromolecular crystallography got off the ground in India only in the eighties, particularly after the Bangalore group received adequate support from the Department of Science and Technology under their Thrust Area Programme. The Bangalore centre was also identified as a national nucleus for the development of the area in the country. Since then work in the area has spread widely and is being carried out by several groups, mainly led by scientists trained at Bangalore or their descendents, in about thirty institutions in India. In addition to the Department of Science and Technology, the effort is now supported by other agencies like the Department of Biotechnology and the Council of Scientific and Industrial Research. The problems addressed by macromolecular crystallographers in India encompass almost all aspects of modern biology. Indian efforts in macromolecular crystallography have also become an important component of the international efforts in the area.
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Restriction endonucleases interact with DNA at specific sites leading to cleavage of DNA. Bacterial DNA is protected from restriction endonuclease cleavage by modifying the DNA using a DNA methyltransferase. Based on their molecular structure, sequence recognition, cleavage position and cofactor requirements, restriction-modification (R-M) systems are classified into four groups. Type III R-M enzymes need to interact with two separate unmethylated DNA sequences in inversely repeated head-to-head orientations for efficient cleavage to occur at a defined location (25-27 bp downstream of one of the recognition sites). Like the Type I R-M enzymes, Type III R-M enzymes possess a sequence-specific ATPase activity for DNA cleavage. ATP hydrolysis is required for the long-distance communication between the sites before cleavage. Different models, based on 1D diffusion and/or 3D-DNA looping, exist to explain how the long-distance interaction between the two recognition sites takes place. Type III R-M systems are found in most sequenced bacteria. Genome sequencing of many pathogenic bacteria also shows the presence of a number of phase-variable Type III R-M systems, which play a role in virulence. A growing number of these enzymes are being subjected to biochemical and genetic studies, which, when combined with ongoing structural analyses, promise to provide details for mechanisms of DNA recognition and catalysis.
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G-Quadruplexes occupy important regulatory regions in the genome. DNA G-quadruplexes in the promoter regions and RNA quadruplexes in the UTRs (untranslated regions) have been individually studied and variously implicated at different regulatory levels of gene expression. However, the formation of G-quadruplexes in the sense and antisense strands and their corresponding roles in gene regulation have not been studied in much detail. In the present study, we have elucidated the effect of strand asymmetry in this context. Using biophysical methods, we have demonstrated the formation of stable G-quadruplex structure in vitro using CD and UV melting. Additionally, ITC was employed to demonstrate that a previously reported selective G-quadruplex ligand was able to bind and stabilize the G-quadruplex in the present sequence. Further, we have shown using reporter constructs that although the DNA G-quadruplex in either strand can reduce translation efficiency, transcriptional regulation differs when G-quadruplex is present in the sense or antisense strand. We demonstrate that the G-quadruplex motif in the antisense strand substantially inhibits transcription, while when in the sense strand, it does not affect transcription, although it does ultimately reduce translation. Further, it is also shown that the G-quadruplex stabilizing ligand can enhance this asymmetric transcription regulation as a result of the increased stabilization of the G-quadruplex.
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Over the past several decades, Flux-Transport Dynamo (FTD) models have emerged as a popular paradigm for explaining the cyclic nature of solar magnetic activity. Their defining characteristic is the key role played by the mean meridional circulation in transporting magnetic flux and thereby regulating the cycle period. Most FTD models also incorporate the so-called Babcock-Leighton (BL) mechanism in which the mean poloidal field is produced by the emergence and subsequent dispersal of bipolar active regions. This feature is well grounded in solar observations and provides a means for assimilating observed surface flows and fields into the models in order to forecast future solar activity, to identify model biases, and to clarify the underlying physical processes. Furthermore, interpreting historical sunspot records within the context of FTD models can potentially provide insight into why cycle features such as amplitude and duration vary and what causes extreme events such as Grand Minima. Though they are generally robust in a modeling sense and make good contact with observed cycle features, FTD models rely on input physics that is only partially constrained by observation and that neglects the subtleties of convective transport, convective field generation, and nonlinear feedbacks. Here we review the formulation and application of FTD models and assess our current understanding of the input physics based largely on complementary 3D MHD simulations of solar convection, dynamo action, and flux emergence.
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The nonstructural protein NSs, encoded by the S RNA of groundnut bud necrosis virus (GBNV) (genus Tospovirus, family Bunyaviridae) has earlier been shown to possess nucleic-acid-stimulated NTPase and 50 a phosphatase activity. ATP hydrolysis is an essential function of a true helicase. Therefore, NSs was tested for DNA helicase activity. The results demonstrated that GBNV NSs possesses bidirectional DNA helicase activity. An alanine mutation in the Walker A motif (K189A rNSs) decreased DNA helicase activity substantially, whereas a mutation in the Walker B motif resulted in a marginal decrease in this activity. The parallel loss of the helicase and ATPase activity in the K189A mutant confirms that NSs acts as a non-canonical DNA helicase. Furthermore, both the wild-type and K189A NSs could function as RNA silencing suppressors, demonstrating that the suppressor activity of NSs is independent of its helicase or ATPase activity. This is the first report of a true helicase from a negative-sense RNA virus.
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Resumen: Este trabajo analiza la acción colectiva sindical postnacional en el MERCOSUR en un período histórico signado por profundas mutaciones políticas, económicas, y productivas sociales (1991-2012) a partir de los relatos y representaciones de sus protagonistas. El trabajo cualitativo intentará explicar la configuración del sindicalismo internacional en la globalización, y describir las estrategias del movimiento obrero mercosureño. La metodología cualitativa ilustra un trabajo de campo a partir de entrevistas en profundidad a 34 sindicalistas del Mercosur, y entrevistas adicionales a tres representantes de la Confederación Sindical de las Américas, dos empresarios del Mercosur, un especialista académico en la dimensión sociolaboral de la integración regional y un representante de la OIT en la región. La metodología de análisis e interpretación de dichas entrevistas ha sido la teoría fundamentada, entendida como la técnica más idónea de aprehender los procesos sociales a través de las voces de los líderes obreros, comprender su realidad, sus representaciones y sistema de valores, sus ideas y su acción colectiva. La literatura de los movimientos sociales en la globalización capitalista ha puesto el énfasis en la emergencia de nuevos colectivos cuyos reclamos se concentran en el reconocimiento (Fraser y Honneth, 2006) de sus identidades que el modelo fordista de producción pareció invisibilizar y soslayar ante la primacía de las prácticas económicas y demandas distributivas. Esta tesis conjuga una perspectiva dualista y demuestra que las estrategias de reconocimiento y las reivindicaciones de redistribución de tipo clasista se resignificaron en el escenario postnacional a través de la Coordinadora de Centrales Sindicales del Cono Sur –CCSCS- (subregional) y, con un desarrollo menor: los Sindicatos Globales (FSI, GUFs) en la acción sectorial [1991-2012]. Para arribar al núcleo configurativo de sus representaciones y su sistema de valores, la investigación transitó por los sentidos y significados del trabajo, las mutaciones productivas y de las condiciones del trabajo, las teorías del fin del trabajo, la precarización y la representación de los trabajadores más frágiles: mujeres, jóvenes y migrantes. En un segundo orden se interpeló sobre la gobernanza mundial, los organismos internacionales, el régimen normativo internacional, la civilización capitalista, para luego abordar el estudio específico del Mercosur y la acción obrera en dicho proceso. El núcleo determinó que para los representantes obreros la acción colectiva sindical debe ser postnacional y su objetivo es limitar la globalización capitalista neoliberal. La CCSCS conformó desde sus inicios un movimiento capaz de elevarse al rango supranacional para representar la voz de los trabajadores del MERCOSUR. La pluralidad configuró su mayor virtud durante sus primeros 20 años, reconociendo una experiencia de aprendizaje de tolerancia y respeto, que ellos definen como la unidad en la diversidad. Esta entidad constituye un patrimonio único como paradigma del sindicalismo postnacional. Los sindicatos del Cono Sur adoptaron diversas modalidades de acción colectiva: a) reactiva (con repertorios de insubordinación, de lucha y resistencia al modelo neoliberal), b) proactiva (con repertorios de incidencia normativa en el MERCOSUR) y c) participativa (con repertorios de producción propositiva de incidencia en la dimensión social del MERCOSUR). Su acción colectiva reactiva, normativa y propositiva fue eficaz a mediano plazo para participar e incidir en el MERCOSUR, crear una dimensión social del bloque y dotar de derechos normativos a los ciudadanos de la región. Su acción tuvo un sentido político de gran poder instituyente, con capacidad movilización y alta exposición pública. Sin embargo, en la segunda década su lógica de construcción quedó subordinada a los procesos nacionales y a los partidos gobernantes, dejó de ser performativa y de creación política, dirimiéndose en la esfera social junto a otros movimientos sociales emergentes, y provocó un ciclo de desmovilización. Simultáneamente, emergió con fuerza otra modalidad de sindicalismo postnacional con la fusión y refundación de los Sindicatos Globales. Su acción sectorial contribuye a restaurar las demandas de distribución que habían quedado soslayadas, pero esta tesis manifiesta que los protagonistas afirman que sus marcos de acción colectiva deberán ser conjuntos para ser exitosa. El sindicalismo postnacional en el MERCOSUR se define a sí mismos como agente de desarrollo, protagonista del modelo socioproductivo, pero también como vehículo partícipe de la democracia y de una matriz sustentable de desarrollo
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Resumen: El propósito de este artículo es reflexionar críticamente desde una perspectiva intercultural acerca de la vigencia y el sentido de los géneros musicales tradicionales en la actualidad en la provincia de La Rioja. Centramos el estudio en los géneros más antiguos: la ‘baguala’ y la ‘vidalita andina’, en la localidad de San Blas de los Sauces. Para ello, analizamos los cambios y permanencias en las estructuras de ambas y el desarrollo de la dimensión discursiva, tomando como referencia principal la tesis doctoral de Isabel Aretz (1978). Los géneros son abordados como fenómenos estéticos situados en un contexto histórico y social. En dicho marco, se analizan sus modos de producción y recepción a partir de observaciones de corte etnográfico, así como de entrevistas a músicos, vidaleros, vecinos, funcionarios del Estado y referentes culturales.