2,778 research outputs found
Does microfinance have an impact? Three quantitative approaches in rural areas of Bangladesh and Andhra Pradesh, India
Microfinance has attracted, since its inception at the end of the seventies, the attention
of many people and institutions, both at academic and donor levels. However, evidence
is mixed so far and no definitive conclusion has yet emerged with respect to the positive
effects of microfinance, in part because of the great differences among the different
microfinance schemes but also because of methodological issues. This work aims to add
some further evidence to the impact debate, with three studies in two different rural
areas from Bangladesh and India.
The first study is based on the second round of a survey in Bangladesh undertaken by
the World Bank. A Propensity Score Matching approach was chosen to study the impact
of borrowing on household income and expenditures per capita. In this case positive
impact can only be seen in extraordinary expenditures, in particular in house extensions
and investments in houses and land, but not in current expenditures or food
expenditures.
The second and third studies analyse a dataset collected in five districts of Andhra
Pradesh, India. The former tries to answer the question of whether borrowing from Self-
Help groups (SHGs) has any effect on income and income per capita at household level.
Pooled ordinary least squares and difference in differences approaches are used to that
end. A significant impact is found in this study on income and income per capita.
In the last empirical work the main interest is focused on the distributional impact, on
the understanding that anti-poverty measures should be focused on households at the
bottom tail of income and income per capita distributions. Its analysis is based on
quantile regression, with cross sectional and panel data approaches. Distributional
impact shows, however, that the poorest might not be benefitting from these
interventions as much as better-off or not-so-poor household
Scalable Inference of Gene Regulatory Networks with the Spark Distributed Computing Platform Cristo
Inference of Gene Regulatory Networks (GRNs) remains an important open challenge in computational biology. The goal of bio-model inference is to, based on time-series of gene expression data, obtain the sparse topological structure and the parameters that quantitatively understand and reproduce the dynamics of biological system. Nevertheless, the inference of a GRN is a complex optimization problem that involve processing S-System models, which include large amount of gene expression data from hundreds (even thousands) of genes in multiple time-series (essays). This complexity, along with the amount of data managed, make the inference of GRNs to be a computationally expensive task. Therefore, the genera- tion of parallel algorithmic proposals that operate efficiently on distributed processing platforms is a must in current reconstruction of GRNs. In this paper, a parallel multi-objective approach is proposed for the optimal inference of GRNs, since min- imizing the Mean Squared Error using S-System model and Topology Regularization value. A flexible and robust multi-objective cellular evolutionary algorithm is adapted to deploy parallel tasks, in form of Spark jobs. The proposed approach has been developed using the framework jMetal, so in order to perform parallel computation, we use Spark on a cluster of distributed nodes to evaluate candidate solutions modeling the interactions of genes in biological networks.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Modelling for implantation of the systems preventive management in the singular sectors
7º/th International Conference on Industrial Engineering and Industrial Management.
XVII Congreso de Ingeniería de Organización. Valladolid, July 10-12, 2013El objetivo fundamental de este estudio ha sido el desarrollo de un sistema distri-buido de Gestión de la Prevención de Riesgos Laborales de aplicación general a sectores empresariales de actividad singular. El estudio propone, las herramientas necesarias para la modelización de los sistemas tendentes a la implantación espe-cífica de las herramientas de gestión preventiva aplicables en los sectores singula-res. Conscientes de la existencia de modelos específicos centrados en el estricto cumplimiento de la legislación vigente, éstos pueden adolecer de la suficiente efi-cacia que proporcionen los resultados adecuados de acorde con la problemática que realmente se plantean en materia preventiva en los sectores singulares. Al mismo tiempo, se pretende desarrollar una metodología científica que permita la identificación y correcta clasificación empresarial de los sectores singulares con el fin de dar un tratamiento preventivo eficaz de los riesgos intrínsecos a las activi-dades que en ellos se desarrollan, teniendo en cuenta la legislación específica que les afecta en materia preventiva y de seguridad industrial, y en base a una correcta identificación de los peligros y evaluación de los riesgos que permita con posterioridad ejercer las acciones preventivas pertinentes tendentes a la gestión eficaz de dichos riesgos, con el fin de eliminarlos y/o reducirlos a niveles aceptables”.Departamento de Ingeniería Civil, de Materiales y Fabricación / Cátedra de Gestión del Transporte
Activation energy in particle suspensions
Assuming that the molar activation energy in a fluid is interpreted as a measure of the potential energy barrier required for the molecular movement [1], the viscosity of a fluid depends on the actual size of the molecules, and the presence of solid particles in a suspension increases the dissipation of energy when the system flows, therefore it is expected that the viscosity of the suspension is higher than that of the pure solvent at a given temperature. The dependence of the viscosity of some silica/glycol suspensions with the temperature can be fitted using an empirical function analogous to the Arrhenius equation, lnη=E/RT-lnC, where η is the viscosity, C is a system-dependent constant, E is the molar activation energy for the viscous flow, T is the absolute temperature and R is the gas universal constant. When the temperature of the suspension decreases two effects are observed. First, larger aggregates of particles are formed due to the reduction of the thermal agitation and, second, the number of links among the molecules of the liquid phase increases. These two effects give place to a higher increase in the viscosity with the temperature compared to the pure solvent. Assuming that a higher viscosity value is due to a smaller free volume available for the molecular movement, and taking into account that the free suspension volume is limited only to the liquid fraction [2], it should be expected that the viscosity of the suspension is less sensitive to temperature than that of the pure solvent.
In this work the dependence on the temperature of the viscosity values of the silica/glycol suspensions is compared to that of the liquid media. The results have shown a lower activation energy when the solid volume fraction increases, which has been explained with a scheme that assumes that the particle links are less sensitive to thermal energy absorption than the joining bonds among the solvent molecules. Our conclusion is that, for a given mechanical energy applied to the system, the thermal energy absorbed by the system is mainly used in the rupture of bonds between the solvent molecules. This study can be useful to understand the mechanisms that govern the differences in the activation energy values found between samples of foods, in which many factors are connected with sample composition [3].
[1] Briscoe B, Luckham P, Zhu S. Rheological properties of poly (ethylene oxide) aqueous solutions. J Appl Polym Sci 70 (1998) 419-429.
[2] Shenoy AV. Rheology of filled polymer systems. Kluwer Acad Pub, 1999, The Netherlands.
[3] Alvarez MD, Canet W. Time-independent and time-dependent rheological characterization of vegetable-based infant purees. J Food Eng 114 (2013) 449-464.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech
Acid-Sensing Ion Channels Activated by Evoked Released Protons Modulate Synaptic Transmission at the Mouse Calyx of Held Synapse
Acid-sensing ion channels (ASICs) regulate synaptic activities and play important roles in neurodegenerative diseases. We found that these channels can be activated in neurons of the medial nucleus of the trapezoid body (MNTB) of the auditory system in the CNS. A drop in extracellular pH induces transient inward ASIC currents (IASICs) in postsynaptic MNTB neurons from wild-type mice. The inhibition of IASICs by psalmotoxin-1 (PcTx1) and the absence of these currents in knock-out mice for ASIC-1a subunit (ASIC1a−/−) suggest that homomeric ASIC-1as are mediating these currents in MNTB neurons. Furthermore, we detect ASIC1a-dependent currents during synaptic transmission, suggesting an acidification of the synaptic cleft due to the corelease of neurotransmitter and H+ from synaptic vesicles. These currents are capable of eliciting action potentials in the absence of glutamatergic currents. A significant characteristic of these homomeric ASIC-1as is their permeability to Ca2+. Activation of ASIC-1a in MNTB neurons by exogenous H+ induces an increase in intracellular Ca2+. Furthermore, the activation of postsynaptic ASIC-1as during high-frequency stimulation (HFS) of the presynaptic nerve terminal leads to a PcTx1-sensitive increase in intracellular Ca2+ in MNTB neurons, which is independent of glutamate receptors and is absent in neurons from ASIC1a−/− mice. During HFS, the lack of functional ASICs in synaptic transmission results in an enhanced short-term depression of glutamatergic EPSCs. These results strongly support the hypothesis of protons as neurotransmitters and demonstrate that presynaptic released protons modulate synaptic transmission by activating ASIC-1as at the calyx of Held–MNTB synapse.Fil: González Inchauspe, Carlota María Fabiola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Urbano Suarez, Francisco Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Di Guilmi, Mariano Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Uchitel, Osvaldo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin
The Role of the university in eco-entrepreneurship: evidence from the eurobarometer survey on attitudes of European entrepreneurs towards eco-innovation
There is an increasing social and political awareness of the importance of sustainable innovations. Strategic partnerships between policy makers, businesses, researchers and citizens are key to developing, implementing and applying eco-innovation, essential for the transition to a competitive green economy. Within this innovation ecosystem, universities can play a central role in creating viable alternative models that are driven by environmental sustainability. Based on evidence from the first survey on Eco-innovation in Europe- ‘The Eurobarometer 315 Survey on Attitudes of European Entrepreneurs towards Eco-Innovation’, the present paper examines the impact of university collaboration on eco-innovating small firms. It also considers how technology push, demand side factors and the regulatory framework, drive eco-innovation in European SMEs. This paper has several implications for managers, as well as for policy makers. For managers, it should be stressed that collaboration with universities is essential to drive all types of eco-innovations. Our findings also suggest that national government should foster cooperation with universities following EU example (eg. European Innovation Partnership in EcoAP), as national policies based on subsidies and fiscal incentives appear to be ineffective
EFFECTS OF LOUVERS SHADING DEVICES ON VISUAL COMFORT AND ENERGY DEMAND OF AN OFFICE BUILDING. A CASE OF STUDY
This paper evaluates the building energy demand and visual comfort of a real case
with a glazed façade office building placed in Málaga (Mediterranean city in the south of
Spain). South oriented facades receive such a high solar gain that cooling demand cannot
be handled by the current HVAC system. As an environmental friendly solution, a shading
control strategy based on vertical and horizontal louvers is proposed.
The study consists of a comparison between the actual and the refurbished building
with shading devices. Daylighting simulation is done with Daysim (Daysim, 2016). A
group of offices with south, east and north oriented facades is chosen for the study. Horizontal
louvers in the south façade and vertical louvers in the east facade are modelled
and simulated. The simulation changes the angle of the louver: 0º (perpendicular to the
glazing), -30º, 30º, -60º, 60º. Visual comfort parameters analyzed are: illuminance, daylight
autonomy (DA) and useful daylight index (UDI). With respect to the thermal comfort,
not only louvers orientation try to provide solar protection for glazed areas in cooling
period but also maximize solar gains in heating period. However, an excessive daylight
could affect discomfort glare. Shading control strategy must provide the equilibrium
between both aspects. Thermal demand is calculated with Trnsys (TRNSYS, 2016).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Video-based assistance system for training in minimally invasive surgery
In this paper, the development of an assisting system for laparoscopic surgical training is presented. With this system, we expect to facilitate the training process at the first stages of training in laparoscopic surgery and to contribute to an objective evaluation of surgical skills. To achieve this, we propose the insertion of multimedia contents and outlines of work adapted to the level of experience of trainees and the detection of the movements of the laparoscopic instrument into the monitored image. A module to track the instrument is implemented focusing on the tip of the laparoscopic tool. This tracking method does not need the presence of artificial marks or special colours to distinguish the instruments. Similarly, the system has another method based on visual tracking to localize support multimedia content in a stable position of the field of vision. Therefore, this position of the support content is adapted to the movements of the camera or the working area. Experimental results are presented to show the feasibility of the proposed system for assisting in laparoscopic surgical training
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