970 resultados para Local Productive Arrangement


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The role of chromosomal inversions in adaptation and speciation is controversial. Historically, inversions were thought to contribute to these processes either by directly causing hybrid sterility or by facilitating the maintenance of co-adapted gene complexes. Because inversions suppress recombination when heterozygous, a recently proposed local adaptation mechanism predicts that they will spread if they capture alleles at multiple loci involved in divergent adaptation to contrasting environments. Many empirical studies have found inversion polymorphisms linked to putatively adaptive phenotypes or distributed along environmental clines. However, direct involvement of an inversion in local adaptation and consequent ecological reproductive isolation has not to our knowledge been demonstrated in nature. In this study, we discovered that a chromosomal inversion polymorphism is geographically widespread, and we test the extent to which it contributes to adaptation and reproductive isolation under natural field conditions. Replicated crosses between the prezygotically reproductively isolated annual and perennial ecotypes of the yellow monkeyflower, Mimulus guttatus, revealed that alternative chromosomal inversion arrangements are associated with life-history divergence over thousands of kilometers across North America. The inversion polymorphism affected adaptive flowering time divergence and other morphological traits in all replicated crosses between four pairs of annual and perennial populations. To determine if the inversion contributes to adaptation and reproductive isolation in natural populations, we conducted a novel reciprocal transplant experiment involving outbred lines, where alternative arrangements of the inversion were reciprocally introgressed into the genetic backgrounds of each ecotype. Our results demonstrate for the first time in nature the contribution of an inversion to adaptation, an annual/perennial life-history shift, and multiple reproductive isolating barriers. These results are consistent with the local adaptation mechanism being responsible for the distribution of the two inversion arrangements across the geographic range of M. guttatus and that locally adaptive inversion effects contribute directly to reproductive isolation. Such a mechanism may be partially responsible for the observation that closely related species often differ by multiple chromosomal rearrangements.

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Gemstone Team CARE (Community Assessment of Resident Experiences)

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Ongoing Cryptococcus gattii outbreaks in the Western United States and Canada illustrate the impact of environmental reservoirs and both clonal and recombining propagation in driving emergence and expansion of microbial pathogens. C. gattii comprises four distinct molecular types: VGI, VGII, VGIII, and VGIV, with no evidence of nuclear genetic exchange, indicating these represent distinct species. C. gattii VGII isolates are causing the Pacific Northwest outbreak, whereas VGIII isolates frequently infect HIV/AIDS patients in Southern California. VGI, VGII, and VGIII have been isolated from patients and animals in the Western US, suggesting these molecular types occur in the environment. However, only two environmental isolates of C. gattii have ever been reported from California: CBS7750 (VGII) and WM161 (VGIII). The incongruence of frequent clinical presence and uncommon environmental isolation suggests an unknown C. gattii reservoir in California. Here we report frequent isolation of C. gattii VGIII MATα and MATa isolates and infrequent isolation of VGI MATα from environmental sources in Southern California. VGIII isolates were obtained from soil debris associated with tree species not previously reported as hosts from sites near residences of infected patients. These isolates are fertile under laboratory conditions, produce abundant spores, and are part of both locally and more distantly recombining populations. MLST and whole genome sequence analysis provide compelling evidence that these environmental isolates are the source of human infections. Isolates displayed wide-ranging virulence in macrophage and animal models. When clinical and environmental isolates with indistinguishable MLST profiles were compared, environmental isolates were less virulent. Taken together, our studies reveal an environmental source and risk of C. gattii to HIV/AIDS patients with implications for the >1,000,000 cryptococcal infections occurring annually for which the causative isolate is rarely assigned species status. Thus, the C. gattii global health burden could be more substantial than currently appreciated.

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Understanding animals' spatial perception is a critical step toward discerning their cognitive processes. The spatial sense is multimodal and based on both the external world and mental representations of that world. Navigation in each species depends upon its evolutionary history, physiology, and ecological niche. We carried out foraging experiments on wild vervet monkeys (Chlorocebus pygerythrus) at Lake Nabugabo, Uganda, to determine the types of cues used to detect food and whether associative cues could be used to find hidden food. Our first and second set of experiments differentiated between vervets' use of global spatial cues (including the arrangement of feeding platforms within the surrounding vegetation) and/or local layout cues (the position of platforms relative to one another), relative to the use of goal-object cues on each platform. Our third experiment provided an associative cue to the presence of food with global spatial, local layout, and goal-object cues disguised. Vervets located food above chance levels when goal-object cues and associative cues were present, and visual signals were the predominant goal-object cues that they attended to. With similar sample sizes and methods as previous studies on New World monkeys, vervets were not able to locate food using only global spatial cues and local layout cues, unlike all five species of platyrrhines thus far tested. Relative to these platyrrhines, the spatial location of food may need to stay the same for a longer time period before vervets encode this information, and goal-object cues may be more salient for them in small-scale space.

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Advances in technology, communication, and transportation over the past thirty years have led to tighter linkages and enhanced collaboration across traditional borders between nations, institutions, and cultures. This thesis uses the furniture industry as a lens to examine the impacts of globalization on individual countries and companies as they interact on an international scale. Using global value chain analysis and international trade data, I break down the furniture production process and explore how countries have specialized in particular stages of production to differentiate themselves from competitors and maximize the benefits of global involvement. Through interviews with company representatives and evaluation of branding strategies such as advertisements, webpages, and partnerships, I investigate across four country cases how furniture companies construct strong brands in an effort to stand out as unique to consumers with access to products made around the globe. Branding often serves to highlight distinctiveness and associate companies with national identities, thus revealing that in today’s globalized and interconnected society, local differences and diversity are more significant than ever.

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Gemstone Team GREEN JUSTICE

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The time reversal of stochastic diffusion processes is revisited with emphasis on the physical meaning of the time-reversed drift and the noise prescription in the case of multiplicative noise. The local kinematics and mechanics of free diffusion are linked to the hydrodynamic description. These properties also provide an interpretation of the Pope-Ching formula for the steady-state probability density function along with a geometric interpretation of the fluctuation-dissipation relation. Finally, the statistics of the local entropy production rate of diffusion are discussed in the light of local diffusion properties, and a stochastic differential equation for entropy production is obtained using the Girsanov theorem for reversed diffusion. The results are illustrated for the Ornstein-Uhlenbeck process.

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Growth cone guidance and synaptic plasticity involve dynamic local changes in proteins at axons and dendrites. The Dual-Leucine zipper Kinase MAPKKK (DLK) has been previously implicated in synaptogenesis and axon outgrowth in C. elegans and other animals. Here we show that in C. elegans DLK-1 regulates not only proper synapse formation and axon morphology but also axon regeneration by influencing mRNA stability. DLK-1 kinase signals via a MAPKAP kinase, MAK-2, to stabilize the mRNA encoding CEBP-1, a bZip protein related to CCAAT/enhancer-binding proteins, via its 3'UTR. Inappropriate upregulation of cebp-1 in adult neurons disrupts synapses and axon morphology. CEBP-1 and the DLK-1 pathway are essential for axon regeneration after laser axotomy in adult neurons, and axotomy induces translation of CEBP-1 in axons. Our findings identify the DLK-1 pathway as a regulator of mRNA stability in synapse formation and maintenance and also in adult axon regeneration.

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Associating genetic variation with quantitative measures of gene regulation offers a way to bridge the gap between genotype and complex phenotypes. In order to identify quantitative trait loci (QTLs) that influence the binding of a transcription factor in humans, we measured binding of the multifunctional transcription and chromatin factor CTCF in 51 HapMap cell lines. We identified thousands of QTLs in which genotype differences were associated with differences in CTCF binding strength, hundreds of them confirmed by directly observable allele-specific binding bias. The majority of QTLs were either within 1 kb of the CTCF binding motif, or in linkage disequilibrium with a variant within 1 kb of the motif. On the X chromosome we observed three classes of binding sites: a minority class bound only to the active copy of the X chromosome, the majority class bound to both the active and inactive X, and a small set of female-specific CTCF sites associated with two non-coding RNA genes. In sum, our data reveal extensive genetic effects on CTCF binding, both direct and indirect, and identify a diversity of patterns of CTCF binding on the X chromosome.

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info:eu-repo/semantics/nonPublished

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La presencia y actuación en territorio de una institución educativa rural para adultos propicio la formulación de un proyecto de apoyo al desarrollo en la Comunidad La Hortensia, distrito Tacuarendi, provincia de Santa Fe. Esta comunidad se sitúa en la cuenca cañera santafesina, economía regional que fue afectada por políticas económicas liberales y cambios estructurales a ellas asociadas de la década de los 90, encontrándose hoy su población en situación de riesgo social, pobreza estructural y marginalidad. La comunidad comprende alrededor de 40 familias, integradas por pequeños productores y obrero del surco. En este trabajo se presenta la trayectoria seguida en la formulación de un Proyecto de Desarrollo Local que pueda dar respuesta a la problemática mencionada así como el proyecto propuesto. Se inicio mediante un diagnostico participativo, generando junto a la comunidad una hipótesis futurible. Se definieron estrategias empleando el Análisis FODA potenciando fortalezas y disminuyendo debilidades. Se observó en el territorio características que definieron la viabilidad del proyecto. El proyecto propone diversos ejes (productivo, cultural /educativo, organizacional). Se promueve conformar grupos productivos, que con asistencia de un equipo técnico realizaran experiencias productivas asociativas. Se propone la recreación de espacios sociales comunitarios. Se complementaran estas actividades con las acciones de la propuesta educativa de la Escuela para jóvenes y adultos Nª205, que promueve la alfabetización de sus alumnos y su formación como emprendedores. Las expectativas de la intervención propuesta se concentran en lograr el Consejo Local de la comunidad, como factor movilizador de los demás aspectos del proyecto. Las acciones en lo productivo y culturas son medios para lograr y concientizar la importancia de generar nueva institucionalidad en la comunidad. Este trabajo final tiene como objetivo analizar la importancia de una herramienta de intervención, el proyecto de desarrollo local, en una comunidad perteneciente a una economía regional en crisis.

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El presente reporte articula el modelo educativo de van Hiele en su aspecto prescriptivo con la enseñanza de uno de los conceptos fundamentales del Análisis Matemático, continuidad local, a través de la implementación y el desarrollo de un Módulo de Aprendizaje que permite procesos de razonamiento en los estudiantes con el fin de promoverlos de un Nivel II a un Nivel III, el módulo es construido en correspondencia con los descriptores de fases para de dar cuenta de las estructuras mentales elaboradas. Posteriormente, en el análisis de cada uno de los tres casos, se describe en categorías en correspondencia los descriptores y donde se hace explícito como razonan los estudiantes en su paso del Nivel II al Nivel III respecto al concepto de continuidad local.