258 research outputs found

    The Diffusion of Microfinance

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    We examine how participation in a microfinance program diffuses through social networks. We collected detailed demographic and social network data in 43 villages in South India before microfinance was introduced in those villages and then tracked eventual participation. We exploit exogenous variation in the importance (in a network sense) of the people who were first informed about the program, "the injection points". Microfinance participation is higher when the injection points have higher eigenvector centrality. We estimate structural models of diffusion that allow us to (i) determine the relative roles of basic information transmission versus other forms of peer influence, and (ii) distinguish information passing by participants and non-participants. We find that participants are significantly more likely to pass information on to friends and acquaintances than informed non-participants, but that information passing by non-participants is still substantial and significant, accounting for roughly a third of informedness and participation. We also find that, conditioned on being informed, an individual's decision is not significantly affected by the participation of her acquaintances.

    Faktor snage nanostrukturiranog bizmut telurida određen oblicima

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    Bismuth telluride is a thermoelectric material with high figure of merit, used for cooling applications at room temperature. To investigate the effect of morphology and grain size on transport parameters, nanostructured bismuth telluride has been synthesized under different reaction conditions and characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. From the measurement of electrical conductivity and thermoelectric power, power factor for different samples has been obtained. The results show that the transport parameters are critically influenced by the morphology and dimension of the samples that in turn depend on the condition of synthesis. The experimentally observed variation of electrical conductivity with the change of dimensionality of the samples from 2D to 0D, which is in line with the theoretical prediction made by other workers, is discussed. There is a variation of the power factor of the samples prepared under different conditions of synthesis.Bizmut telurid je termoelektrična tvar s visokom učinkovitošću koja se rabi za hlađenje na sobnim temperaturama. Radi istraživanja učinka oblika i veličine zrna na transportne parametre, sintetizirali smo nanostrukturirani bizmut telurid u različitim uvjetima i ispitivali rentgenskom difrakcijom, te propusnom i pretražnom elektronskom mikroskopijom. Mjerenjem električne vodljivosti i termoelektrične snage niza uzoraka odredili smo faktore snage. Ishodi analize pokazuju da transportni parametri jako ovise o obliku i veličini uzoraka, koji pak ovise o uvjetima njihove sinteze. Raspravljamo o opaženim promjenama električne vodljivosti ovisnim o dimenzionalnosti uzoraka od 2D do 0D i nalazimo sklad s teorijskim predviđanjima drugih autora. Nalazimo promjene faktora snage uzoraka pripremljenih uz različite uvjete sinteze

    Faktor snage nanostrukturiranog bizmut telurida određen oblicima

    Get PDF
    Bismuth telluride is a thermoelectric material with high figure of merit, used for cooling applications at room temperature. To investigate the effect of morphology and grain size on transport parameters, nanostructured bismuth telluride has been synthesized under different reaction conditions and characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. From the measurement of electrical conductivity and thermoelectric power, power factor for different samples has been obtained. The results show that the transport parameters are critically influenced by the morphology and dimension of the samples that in turn depend on the condition of synthesis. The experimentally observed variation of electrical conductivity with the change of dimensionality of the samples from 2D to 0D, which is in line with the theoretical prediction made by other workers, is discussed. There is a variation of the power factor of the samples prepared under different conditions of synthesis.Bizmut telurid je termoelektrična tvar s visokom učinkovitošću koja se rabi za hlađenje na sobnim temperaturama. Radi istraživanja učinka oblika i veličine zrna na transportne parametre, sintetizirali smo nanostrukturirani bizmut telurid u različitim uvjetima i ispitivali rentgenskom difrakcijom, te propusnom i pretražnom elektronskom mikroskopijom. Mjerenjem električne vodljivosti i termoelektrične snage niza uzoraka odredili smo faktore snage. Ishodi analize pokazuju da transportni parametri jako ovise o obliku i veličini uzoraka, koji pak ovise o uvjetima njihove sinteze. Raspravljamo o opaženim promjenama električne vodljivosti ovisnim o dimenzionalnosti uzoraka od 2D do 0D i nalazimo sklad s teorijskim predviđanjima drugih autora. Nalazimo promjene faktora snage uzoraka pripremljenih uz različite uvjete sinteze

    Expression of biomarkers modulating prostate cancer angiogenesis: Differential expression of annexin II in prostate carcinomas from India and USA

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    BACKGROUND: Prostate cancer (PCa) incidences vary with genetic, geographical and ethnic dietary background of patients while angiogenesis is modulated through exquisite interplay of tumor-stromal interactions of biological macromolecules. We hypothesized that comprehensive analysis of four biomarkers modulating angiogenesis in PCa progression in two diverse populations might explain the variance in the incidence rates. RESULTS: Immunohistochemical analysis of 42 PCa biopsies reveals that though Anx-II expression is lost in both the Indian and American population with Gleason scores (GS) ranging between 6 and 10, up to 25 % of cells in the entire high grade (GS > 8) PD PCa samples from US show intense focal membrane staining for Anx-II unlike similarly graded specimens from India. Consistent with this observation, the prostate cancer cell lines PC-3, DU-145 and MDA PCa 2A, but not LNCaP-R, LNCAP-UR or MDA PCa 2B cell lines, express Anx-II. Transcriptional reactivation of Anx-II gene with Aza-dC could not entirely account for loss of Anx-II protein in primary PCa. Cyclooxygenase-2 (COX-2) was moderately expressed in most of high grade PIN and some MD PCa and surrounding stroma. COX-2 was not expressed in PD PCa (GS ~7–10), while adjacent smooth muscles cells stained weakly positive. Decorin expression was observed only in high grade PIN but not in any of the prostate cancers, atrophy or BPH while stromal areas of BPH stained intensively for DCN and decreased with advancing stages of PCa. Versican expression was weak in most of the MD PCa, moderate in all of BPH, moderately focal in PD PC, weak and focal in PIN, atrophy and adjacent stroma. CONCLUSIONS: Expression of pro- and anti-angiogenic modulators changes with stage of PCa but correlates with angiogenic status. Focal membrane staining of Anx-II reappears in high grade PCa specimens only from US indicating differential expression of Anx-II. COX-2 stained stronger in American specimens compared to Indian specimens. The sequential expression of DCN and VCN in progressive stages was similar in specimens from India and USA indicating no population-based differences. The mechanistic and regulatory role of Anx-II in PCa progression warrants further investigation

    Economic development, human development, and the pursuit of happiness, April 1, 2, and 3, 2004

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    This repository item contains a single issue of the Pardee Conference Series, a publication series that began publishing in 2006 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future. This was the Center's spring conference, which took place during April 1, 2, and 3, 2004.The conference asks the questions, how can we make sure that the benefits of economic growth flow into health, education, welfare, and other aspects of human development; and what is the relationship between human development and economic development? Speakers and participants discuss the role that culture, legal and political institutions, the UN Developmental Goals, the level of decision-making, and ethics, play in development

    Credit Constraints and the Measurement of Time Preferences

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    Incentivized experiments are commonly used to estimate marginal rates of intertemporal substitution (MRS) in the lab and in the field in order to make inferences about individual time preferences. This paper considers an integrated model of behavior in which individuals are subject to financial shocks and credit constraints, and take those into account when making experimental choices. The model shows that measured MRS depends on the individual’s effective interest rate which is equal to the relative marginal utility of current and future consumption. Experimental responses should therefore be correlated with other variables that describe the subject’s financial situation, like savings and shocks to income and consumption. We test the model using a new a panel data set from Mali and find evidence for such effects. Our results imply that the relationship between experimentally elicited MRS and time preferences is not straightforward. However, measured MRS can be useful in determining the importance of different types of financial shocks to the household
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