4,324 research outputs found

    MICROFINANCE MARKET NICHES AND CLIENT PROFILES IN BOLIVIA

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    This paper presents and interprets descriptive statistics generated from data obtained in a survey of clients of five microfinance organizations believed to be among the best in Bolivia. These lenders represent different combinations of organizational design, lending technology, and market area of operations. Two are regulated financial intermediaries and three are NGOs. Two operate in rural areas (PRODEM and Sartawi) and three operate in urban areas (BancoSol, FIE, and Caja Los Andes). Two offer individual loans and three grant loans through joint liability groups. The paper discusses household-enterprise profiles of a sample of 622 clients and identifies terms and conditions of loan contracts with these organizations to evaluate the depth and quality of their outreach. The interpretation seeks to establish connections between key characteristics of the clients and features of the lending technologies that lead to the matching of classes of borrowers with particular organizations and that influence the choice of market niches. Data on loan sizes suggest the existence of different but broadly overlapping market niches associated with three tiers of clients. The sharpest distinction is between urban and rural clients. The matching between clients and organizations also reflects a weak but positive correlation between levels of poverty and loan sizes. According to an index of basic needs fulfillment of their clients, these organizations can be ranked as: FIE and Caja Los Andes (first tier), BancoSol (second tier), and PRODEM and Sartawi (third tier). The same ranking is obtained when clients are ordered according to loan size, the ratio of loan size to the value of sales, and the value of monthly sales. The three tiers of clients are associated with different socio-economic features of their household-enterprises: sex, education, household size, access to electricity, water supplies, and sewage facilities, employment-generating capacity of the enterprise, informality and separation of household and enterprise, occupations and the like. The development of lending technologies that do not rely on standard financial statements and collateralizable assets is a formidable innovation that explains the outreach and sustainability of these organizations. Differences in the guarantees required for loans dominate distinctions in lending technology. Trade-offs between loan size, interest rates, and guarantee requirements attract different subsets of the clientele. Joint liability seems to be appropriate for very poor people, but group borrowers eventually outgrow this relationship. Caja Los Andes and FIE have shown that it is possible to supply individual loans to poor people and be profitable. Most clients are satisfied with the services received. The lowest satisfaction concerns loan sizes and loan-size rationing may be widespread. At least in urban areas, increasing competition will force these organizations to improve their services and adjust loan sizes. All of these organizations are expanding the frontier of microfinance by developing lending technologies for a much poorer clientele than is reached by collateral-based lenders. This is a formidable achievement.Financial Economics,

    Bridging Proprietary Modelling and Open-Source Model Management Tools : The Case of PTC Integrity Modeller and Epsilon

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    While the majority of research on Model-Based Software Engineering revolves around open-source modelling frameworks such as EMF, the use of commercial and closed-source modelling tools such as RSA, Rhapsody, MagicDraw and PTC Integrity Modeller appears to be the norm in industry at present. This technical gap can prohibit industrial users from reaping the benefits of state-of-the-art research-based tools in their practice. In this paper, we discuss an attempt to bridge a proprietary UML modelling tool (PTC Integrity Modeller), which is used for model-based development of safety-critical systems at Rolls-Royce, with an open-source family of languages for automated model management (Epsilon). We present the architecture of our solution, the challenges we encountered in developing it, and a performance comparison against the tool's built-in scripting interface

    Automatic generation of UML profile graphical editors for Papyrus

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    UML profiles offer an intuitive way for developers to build domain-specific modelling languages by reusing and extending UML concepts. Eclipse Papyrus is a powerful open-source UML modelling tool which supports UML profiling. However, with power comes complexity, implementing non-trivial UML profiles and their supporting editors in Papyrus typically requires the developers to handcraft and maintain a number of interconnected models through a loosely guided, labour-intensive and error-prone process. We demonstrate how metamodel annotations and model transformation techniques can help manage the complexity of Papyrus in the creation of UML profiles and their supporting editors. We present Jorvik, an open-source tool that implements the proposed approach. We illustrate its functionality with examples, and we evaluate our approach by comparing it against manual UML profile specification and editor implementation using a non-trivial enterprise modelling language (Archimate) as a case study. We also perform a user study in which developers are asked to produce identical editors using both Papyrus and Jorvik demonstrating the substantial productivity and maintainability benefits that Jorvik delivers

    Microfinance Market Niches and Client Profiles in Bolivia

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    This paper presents and interprets descriptive statistics generated from data obtained in a survey of clients of five microfinance organizations believed to be among the best in Bolivia. These lenders represent different combinations of organizational design, lending technology, and market area of operations. Two are regulated financial intermediaries and three are NGOs. Two operate in rural areas (PRODEM and Sartawi) and three operate in urban areas (BancoSol, FIE, and Caja Los Andes). Two offer individual loans and three grant loans through joint liability groups. The paper discusses household-enterprise profiles of a sample of 622 clients and identifies terms and conditions of loan contracts with these organizations to evaluate the depth and quality of their outreach. The interpretation seeks to establish connections between key characteristics of the clients and features of the lending technologies that lead to the matching of classes of borrowers with particular organizations and that influence the choice of market niches. Data on loan sizes suggest the existence of different but broadly overlapping market niches associated with three tiers of clients. The sharpest distinction is between urban and rural clients. The matching between clients and organizations also reflects a weak but positive correlation between levels of poverty and loan sizes. According to an index of basic needs fulfillment of their clients, these organizations can be ranked as: FIE and Caja Los Andes (first tier), BancoSol (second tier), and PRODEM and Sartawi (third tier). The same ranking is obtained when clients are ordered according to loan size, the ratio of loan size to the value of sales, and the value of monthly sales. The three tiers of clients are associated with different socio-economic features of their household-enterprises: sex, education, household size, access to electricity, water supplies, and sewage facilities, employment-generating capacity of the enterprise, informality and separation of household and enterprise, occupations and the like. The development of lending technologies that do not rely on standard financial statements and collateralizable assets is a formidable innovation that explains the outreach and sustainability of these organizations. Differences in the guarantees required for loans dominate distinctions in lending technology. Trade-offs between loan size, interest rates, and guarantee requirements attract different subsets of the clientele. Joint liability seems to be appropriate for very poor people, but group borrowers eventually outgrow this relationship. Caja Los Andes and FIE have shown that it is possible to supply individual loans to poor people and be profitable. Most clients are satisfied with the services received. The lowest satisfaction concerns loan sizes and loan-size rationing may be widespread. At least in urban areas, increasing competition will force these organizations to improve their services and adjust loan sizes. All of these organizations are expanding the frontier of microfinance by developing lending technologies for a much poorer clientele than is reached by collateral-based lenders. This is a formidable achievement

    Prediction of Nephropathy in Type 2 Diabetes: An Analysis of the ACCORD Trial Applying Machine Learning Techniques

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    Applying data mining and machine learning (ML) techniques to clinical data might identify predictive biomarkers for diabetic nephropathy (DN), a common complication of type 2 diabetes mellitus (T2DM). A retrospective analysis of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial was intended to identify such factors using ML. The longitudinal data were stratified by time after patient enrollment to differentiate early and late predictors. Our results showed that Random Forest and Simple Logistic Regression methods exhibited the best performance among the evaluated algorithms. Baseline values for glomerular filtration rate (GFR), urinary creatinine, urinary albumin, potassium, cholesterol, low-density lipoprotein, and urinary albumin to creatinine ratio were identified as DN predictors. Early predictors were the baseline values of GFR, systolic blood pressure, as well as fasting plasma glucose (FPG) and potassium at month 4. Changes per year in GFR, FPG, and triglycerides were recognized as predictors of late development. In conclusion, ML-based methods successfully identified predictive factors for DN among patients with T2DM

    High Hepatitis E Seroprevalence Among Displaced Persons in South Sudan.

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    AbstractLarge protracted outbreaks of hepatitis E virus (HEV) have been documented in displaced populations in Africa over the past decade though data are limited outside these exceptional settings. Serological studies can provide insights useful for improving surveillance and disease control. We conducted an age-stratified serological survey using samples previously collected for another research study from 206 residents of an internally displaced person camp in Juba, South Sudan. We tested serum for anti-HEV antibodies (IgM and IgG) and estimated the prevalence of recent and historical exposure to the virus. Using data on individuals' serostatus, camp arrival date, and state of origin, we used catalytic transmission models to estimate the relative risk of HEV infection in the camp compared with that in the participants' home states. The age-adjusted seroprevalence of anti-HEV IgG was 71% (95% confidence interval = 63-78), and 4% had evidence of recent exposure (IgM). We estimated HEV exposure rates to be more than 2-fold (hazard ratio = 2.3, 95% credible interval = 0.3-5.8) higher in the camp than in the participants' home states, although this difference was not statistically significant. HEV transmission may be higher than previously appreciated, even in the absence of reported cases. Improved surveillance in similar settings is needed to understand the burden of disease and minimize epidemic impact through early detection and response

    Climate change and the kidney

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    The worldwide increase in temperature has resulted in a marked increase in heat waves (heat extremes) that carries a markedly increased risk for morbidity and mortality. The kidney has a unique role not only in protecting the host from heat and dehydration but also is an important site of heat-associated disease. Here we review the potential impact of global warming and heat extremes on kidney diseases. High temperatures can result in increased core temperatures, dehydration, and blood hyperosmolality. Heatstroke (both clinical and subclinical whole-body hyperthermia) may have a major role in causing both acute kidney disease, leading to increased risk of acute kidney injury from rhabdomyolysis, or heat-induced inflammatory injury to the kidney. Recurrent heat and dehydration can result in chronic kidney disease (CKD) in animals and theoretically plays a role in epidemics of CKD developing in hot regions of the world where workers are exposed to extreme heat. Heat stress and dehydration also has a role in kidney stone formation, and poor hydration habits may increase the risk for recurrent urinary tract infections. The resultant social and economic consequences include disability and loss of productivity and employment. Given the rise in world temperatures, there is a major need to better understand how heat stress can induce kidney disease, how best to provide adequate hydration, and ways to reduce the negative effects of chronic heat exposure.Published versio

    Mapping the magnetic field in the Taurus/B211 filamentary cloud with SOFIA HAWC + and comparing with simulation

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    Optical and infrared polarization mapping and recent Planck observations of the filametary cloud L1495 in Taurus show that the large-scale magnetic field is approximately perpendicular to the long axis of the cloud. We use the HAWC + polarimeter on SOFIA to probe the complex magnetic field in the B211 part of the cloud. Our results reveal a dispersion of polarization angles of 36 °, about five times that measured on a larger scale by Planck. Applying the Davis-Chandrasekhar-Fermi (DCF) method with velocity information obtained from Institut de Radioastronomie Millimétrique 30 m C 18 O(1-0) observations, we find two distinct sub-regions with magnetic field strengths differing by more than a factor 3. The quieter sub-region is magnetically critical and sub-Alfvé nic; the field is comparable to the average field measured in molecular clumps based on Zeeman observations. The more chaotic, super-Alfvé nic sub-region shows at least three velocity components, indicating interaction among multiple substructures. Its field is much less than the average Zeeman field in molecular clumps, suggesting that the DCF value of the field there may be an underestimate. Numerical simulation of filamentary cloud formation shows that filamentary substructures can strongly perturb the magnetic field. DCF and true field values in the simulation are compared. Pre-stellar cores are observed in B211 and are seen in our simulation. The appendices give a deri v ation of the standard DCF method that allows for a dispersion in polarization angles that is not small, present an alternate deri v ation of the structure function version of the DCF method, and treat fragmentation of filaments

    Chromosomal copy number variation analysis by next generation sequencing confirms ploidy stability in Trypanosoma brucei subspecies

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    Although aneuploidy usually results in severe abnormalities in multicellular eukaryotes, recent data suggest that it could be beneficial for unicellular eukaryotes, such as yeast and trypanosomatid parasites, providing increased survival under stressful conditions. Among characterized trypanosomatids, Trypanosoma cruzi, Trypanosoma brucei and species from the genus Leishmania stand out due to their importance in public health, infecting around 20 million people worldwide. The presence of aneuploidies in T. cruzi and Leishmania was recently confirmed by analysis based on next generation sequencing (NGS) and fluorescence in situ hybridization, where they have been associated with adaptation during transmission between their insect vectors and mammalian hosts and in promoting drug resistance. Although chromosomal copy number variations (CCNVs) are present in the aforementioned species, PFGE and fluorescence cytophotometry analyses suggest that aneuploidies are absent from T. brucei. A re-evaluation of CCNV in T. b gambiense based on NGS reads confirmed the absence of aneuploidies in this subspecies. However, the presence of aneuploidies in the other two T. brucei subspecies, T. b. brucei and T. b. rhodesiense, has not been evaluated using NGS approaches. In the present work, we tested for aneuploidies in 26 T. brucei isolates, including samples from the three T. brucei subspecies, by both allele frequency and read depth coverage analyses. These analyses showed that none of the T. brucei subspecies presents aneuploidies, which could be related to differences in the mechanisms of DNA replication and recombination in these parasites when compared with Leishmania

    On positivity of Ehrhart polynomials

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    Ehrhart discovered that the function that counts the number of lattice points in dilations of an integral polytope is a polynomial. We call the coefficients of this polynomial Ehrhart coefficients, and say a polytope is Ehrhart positive if all Ehrhart coefficients are positive (which is not true for all integral polytopes). The main purpose of this article is to survey interesting families of polytopes that are known to be Ehrhart positive and discuss the reasons from which their Ehrhart positivity follows. We also include examples of polytopes that have negative Ehrhart coefficients and polytopes that are conjectured to be Ehrhart positive, as well as pose a few relevant questions.Comment: 40 pages, 7 figures. To appear in in Recent Trends in Algebraic Combinatorics, a volume of the Association for Women in Mathematics Series, Springer International Publishin
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