891 resultados para Soviet and Post-Soviet Studies


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21 cm cosmology opens an observational window to previously unexplored cosmological epochs such as the Epoch of Reionization (EoR), the Cosmic Dawn and the Dark Ages using powerful radio interferometers such as the planned Square Kilometer Array (SKA). Among all the other applications which can potentially improve the understanding of standard cosmology, we study the promising opportunity given by measuring the weak gravitational lensing sourced by 21 cm radiation. We performed this study in two different cosmological epochs, at a typical EoR redshift and successively at a post-EoR redshift. We will show how the lensing signal can be reconstructed using a three dimensional optimal quadratic lensing estimator in Fourier space, using single frequency band or combining multiple frequency band measurements. To this purpose, we implemented a simulation pipeline capable of dealing with issues that can not be treated analytically. Considering the current SKA plans, we studied the performance of the quadratic estimator at typical EoR redshifts, for different survey strategies and comparing two thermal noise models for the SKA-Low array. The simulation we performed takes into account the beam of the telescope and the discreteness of visibility measurements. We found that an SKA-Low interferometer should obtain high-fidelity images of the underlying mass distribution in its phase 1 only if several bands are stacked together, covering a redshift range that goes from z=7 to z=11.5. The SKA-Low phase 2, modeled in order to improve the sensitivity of the instrument by almost an order of magnitude, should be capable of providing images with good quality even when the signal is detected within a single frequency band. Considering also the serious effect that foregrounds could have on this detections, we discussed the limits of these results and also the possibility provided by these models of measuring an accurate lensing power spectrum.

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We report a case of a 78-year-old female with a proximal femur fracture caused by an accidental fall who died suddenly 1h after orthopaedic prosthesis insertion. Post-mortem computed tomography (CT) scan and histological examination of samples obtained with post-mortem percutaneous needle biopsies of both lungs were performed. Analysis of the medical history and the clinical scenario immediately before death, imaging data, and biopsy histology established the cause of death without proceeding to traditional autopsy. It was determined to be acute right ventricular failure caused by massive pulmonary fat embolism. Although further research in post-mortem imaging and post-mortem tissue sampling by needle biopsies is necessary, we conclude that the use of CT techniques and percutaneous biopsy, as additional tools, can offer a viable alternative to traditional autopsy in selected cases and may increase the number of minimally invasive forensic examinations performed in the future.

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This article offers an analysis of a struggle for control of a women’s development project in Nepal. The story of this struggle is worth telling, for it is rife with the gender politics and neo-colonial context that underscore much of what goes on in contemporary Nepal. In particular, my analysis helps to unravel some of the powerful discourses, threads of interest, and yet unintended effects inevitable under a regime of development aid. The analysis demonstrates that the employment of already available discursive figures of the imperialist feminist and the patriarchal third world man are central to the rhetorical strategies taken in the conflict. I argue that the trans-discursive or “borderland” nature of development in general and women’s development in particular result in different constructions of “development” goals, means and actors based not only on divergent cultural categories but on historically specific cultural politics. I argue further that the apolitical discourse of development serves to cloak its inherently political project of social and economic transformation, making conflicts such as the one that occurred in this case not only likely to occur but also likely to be misunderstood.

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In this article, I examine the values and meanings that adhere to objects made by Maithil women at a development project in Janakpur, Nepal – objects collectors have called ‘Janakpur Art’. I seek to explain how and why changes in pictorial content in Janakpur Art – shifts that took place over a period of five or six years in the 1990s – occurred, and what such a change might indicate about the link between Maithil women’s lives, development, and tourism. As I will demonstrate, part of the appeal for consumers of Janakpur Art has been that it is produced at a ‘women’s development project’ seeking to empower its participants. And yet, the project’s very successes threaten to displace the producers (and what they produce) from their perceived qualities/identities as ‘traditional’ and ‘primitive,’ thereby bringing into question the authenticity of the ‘art’ they produce. The conundrum begs this question: can developing women produce primitive art?

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Drawing on ethnographic research and employing a micro-historical approach that recognizes not only the transnational but also the culturally specific manifestations of modernity, this article centers on the efforts of a young woman to negotiate shifting and conflicting discourses about what a good life might consist of for a highly educated and high caste Hindu woman living at the margins of a nonetheless globalized world. Newly imaginable worlds in contemporary Mithila,South Asia, structure feeling and action in particularly gendered and classed ways, even as the capacity of individuals to actualize those worlds and the “modern” selves envisioned within them are constrained by both overt and subtle means. In the context of shifting cultural anchors, new practices of silence, literacy, and even behaviors interpreted as “mental illness” may become tactics in an individual’s negotiation of conflicting self-representations. The confluence of forces at play in contemporary Mithila, moreover, is creating new structures of feeling that may begin to reverse long-standing locally held assumptions about strong solidarities between natal families and daughters, on the one hand, and weak solidarities between affinal families and new daughters-in-law, on the other.

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In this article, we refine a politics of thinking from the margins by exploring a pedagogical model that advances transformative notions of service learning as social justice teaching. Drawing on a recent course we taught involving both incarcerated women and traditional college students, we contend that when communication among differentiated and stratified parties occurs, one possible result is not just a view of the other but also a transformation of the self and other. More specifically, we suggest that an engaged feminist praxis of teaching incarcerated women together with college students helps illuminate the porous nature of fixed markers that purport to reveal our identities (e.g., race and gender), to emplace our bodies (e.g., within institutions, prison gates, and walls), and to specify our locations (e.g., cultural, geographic, socialeconomic). One crucial theoretical insight our work makes clear is that the model of social justice teaching to which we aspired necessitates re-conceptualizing ourselves as students and professors whose subjectivities are necessarily relational and emergent.

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My purpose in this essay is to explore how ideas about women and development are created and circulated at the moment of consumption of wares produced at a women's development project in Nepal. I analyze the project as an example of the ways that women's development is an object of material and discursive consumption. Artifacts produced and sold by Nepali women, and purchased by tourists from the "first world," become part of an international exchange of power, money, and meaning. Based on a survey of consumers and ethnographic observations, I conclude that feminist tourists forge relations with disempowered "Others" through the pleasurable activity of an alienated market transaction. Consumers of crafts produced at a women's development project assume a position of empowerment and enlightenment, ready to help out their "women" counterparts through their support of an enterprise with circular logic: within the industry of development (although not necessarily for feminist tourists themselves), at least one of the central projects of development is the development project itself. At the same time, feminist tourists locate themselves outside the oppressive structures and ideologies affecting their "third-world sisters." This is a relation of sympathy and imagined empathy, with no sense of differential location within systems of oppression. They fail to examine or articulate the global link between their own purchasing power and local living conditions of Maithil women; the connection is effectively built out of the discourse.

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Creatinine levels in blood serum are typically used to assess renal function. Clinical determination of creatinine is often based on the Jaffe reaction, in which creatinine in the serum reacts with sodium picrate, resulting in a spectrophotometrically quantifiable product. Previous work from our lab has introduced an electrophoretically mediated initiation of this reaction, in which nanoliter plugs of individual reagent solutions can be added to the capillary and then mixed and reacted. Following electrophoretic separation of the product from excess reactant(s), the product can be directly determined on column. This work aims to gain a detailed understanding of the in-capillary reagent mixing dynamics, in-line reaction yield, and product degradation during electrophoresis, with an overall goal of improving assay sensitivity. One set of experiments focuses on maximizing product formation through manipulation of various conditions such as pH, voltage applied, and timing of the applied voltage, in addition to manipulations in the identity, concentration, and pH of the background electrolyte. Through this work, it was determined that dramatic changes in local voltage fields within the various reagent zones lead to ineffective reagent overlapping. Use of the software simulation program Simul 5 enabled visualization of the reaction dynamics within the capillary, specifically the wide variance between the electric field intensities within the creatinine and picrate zones. Because of this simulation work, the experimental method was modified to increase the ionic strength of the creatinine reagent zone to lower the local voltage field, thus producing more predictable and effective overlap conditions for the reagents and allowing the formation of more Jaffe product. As second set of experiments focuses on controlling the post-reaction product degradation. In that vein, we have systematically explored the importance of the identity, concentration, and pH of the background electrolyte on the post-reaction degradation rate of the product. Although prior work with borate background electrolytes indicated that product degradation was probably a function of the ionic strength of the background electrolyte, this work with a glycine background electrolyte demonstrates that degradation is in fact not a function of ionic strength of the background electrolyte. As the concentration and pH of the glycine background increased, the rate of degradation of product did not change dramatically, whereas in borate-buffered systems, the rate of Jaffe product degradation increased linearly with background electrolyte concentration above 100.0 mM borate. Similarly, increasing pH of the glycine background electrolyte did not result in a corresponding increase in product degradation, as it had with the borate background electrolyte. Other general trends that were observed include: increasing background electrolyte concentration increases peak efficiency and higher pH favors product formation; thus, it appears that use of a background electrolyte other than borate, such as glycine, the rate of degradation of the Jaffe product can be slowed, increasing the sensitivity of this in-line assay.

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We describe a case of a fatal speed flying accident in which the victim was electrocuted, burned and fell from a great height. Post-mortem imaging revealed acute appearing fractures on CT, without bone marrow oedema on MRI. Based on the known clinical imaging findings of bone marrow oedema in acute fractures, we concluded that the speed flyer died from electrocution rather than the fall and that the fractures occurred post-mortem. Radiological imaging augmented the reconstruction of the peri-mortem events. Further research is needed to assess whether bone marrow oedema in acute fractures is a reliable vital sign.

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W5.43(194), a conserved tryptophan residue among G-protein coupled receptors (GPCRs) and cannabinoid receptors (CB), was examined in the present report for its significance in CB2 receptor ligand binding and adenylyl cyclase (AC) activity. Computer modeling postulates that this site in CB2 may be involved in the affinity of WIN55212-2 and SR144528 through aromatic contacts. In the present study, we reported that a CB2 receptor mutant, W5.43(194)Y, which had a tyrosine (Y) substitution for tryptophan (W), retained the binding affinity for CB agonist CP55940, but reduced binding affinity for CB2 agonist WIN55212-2 and inverse agonist SR144528 by 8-fold and 5-fold, respectively; the CB2 W5.43(194)F and W5.43(194)A mutations significantly affect the binding activities of CP55940, WIN55212-2 and SR144528. Furthermore, we found that agonist-mediated inhibition of the forskolin-induced cAMP production was dramatically diminished in the CB2 mutant W5.43(194)Y, whereas W5.43(194)F and W5.43(194)A mutants resulted in complete elimination of downstream signaling, suggesting that W5.43(194) was essential for the full activation of CB2. These results indicate that both aromatic interaction and hydrogen bonding are involved in ligand binding for the residue W5.43(194), and the mutations of this tryptophan site may affect the conformation of the ligand binding pocket and therefore control the active conformation of the wild type CB2 receptor. W5.43(194)Y/F/A mutations also displayed noticeable enhancement of the constitutive activation probably attributed to the receptor conformational changes resulted from the mutations.

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N,N'-((4-(Dimethylamino)phenyl)methylene)bis(2-phenylacetamide) was discovered by using 3D pharmacophore database searches and was biologically confirmed as a new class of CB(2) inverse agonists. Subsequently, 52 derivatives were designed and synthesized through lead chemistry optimization by modifying the rings A-C and the core structure in further SAR studies. Five compounds were developed and also confirmed as CB(2) inverse agonists with the highest CB(2) binding affinity (CB(2)K(i) of 22-85 nM, EC(50) of 4-28 nM) and best selectivity (CB(1)/CB(2) of 235- to 909-fold). Furthermore, osteoclastogenesis bioassay indicated that PAM compounds showed great inhibition of osteoclast formation. Especially, compound 26 showed 72% inhibition activity even at the low concentration of 0.1 μM. The cytotoxicity assay suggested that the inhibition of PAM compounds on osteoclastogenesis did not result from its cytotoxicity. Therefore, these PAM derivatives could be used as potential leads for the development of a new type of antiosteoporosis agent.