3,146 research outputs found
Evaluation of the Financial Impact of Flood Management on Residential Losses
The purpose of this paper is to examine the impacts that the National Flood Insurance Program (NFIP) has had on the costs of flooding and on their distribution among payers. This study thus probes the NFIP's financial impact, the centerpiece question about program effectiveness. For the analysis, this paper models the institutional and economic framework of flood relief compensation into the HAZUS-flood model, and calculates the NFIP impact on the distribution of payers for flood losses in special flood hazard areas.Risk and Uncertainty,
IDENTIFICATION OF ECONOMIES OF SCOPE IN A STOCHASTIC PRODUCTION ENVIRONMENT
This paper extends the definition of economies of scope to multioutput firms that face an uncertain production environment. Identification of economies of scope in this environment, however, requires separability assumptions on the technology. These identification restrictions are demonstrated in the paper, and for each identification restriction the definition of economies of scope is generalized to the case of uncertain production and risk aversion.Production Risk, Multioutput, Production, Identification, Risk and Uncertainty,
Hacia la constitucionalización del precedente judicial en Colombia, ¿un esfuerzo por controlar a las fuentes del derecho?
El activismo judicial y la creación derivada del derecho han situado al precedentecomo fuente de derecho, algunas veces, fuente principal para la práctica jurídica. En realidad, se argumenta, el constituyente derivado parecería llegar tarde a lainstitucionalización del precedente como fuente principal de derecho. El juez colombiano no ha sido neófito en la creación de normas jurídicas por medio de la cosa juzgada implícita. Por ello, se explorará cuál ha sido el recorrido, en lapráctica colombiana, de la reforma constitucional dirigida a regular los efectos relativos de la producción jurisprudencial
Heterogeneous effects of risk-taking on bank efficiency : a stochastic frontier model with random coefficients
We estimate a stochastic frontier model with random inefficiency parameters, which allows us not only to identify the role of bank risk-taking on driving cost and profit inefficiency, but also to recognize heterogeneous effects of risk exposure on banks with different characteristics. We account for an integral group of risk exposure covariates including credit, liquidity, capital and market risk, as well as bank-specific characteristics of size and affiliation. The model is estimated for the Colombian banking sector during the period 2002-2012. Results suggest that risk-taking drives inefficiency and its omission leads to over (under) estimate cost (profit) efficiency. Risk-taking is also found to have different effects on efficiency of banks with different size and affiliation, and those involved in mergers and acquisitions. In particular, greater exposures to credit and market risk are found to be key profit efficiency drivers.Likewise, lower liquidity risk and capital risk lead to higher efficiency in both costs and profits. Large, foreign and merged banks benefit more when assuming credit risk, while small, domestic and non-merged banks institutions take advantage of assuming higher market riskJorge E. Galán acknowledges financial support
from the Spanish Ministry of Education and Science, research project ECO2012-340
Harvesting Thermal Fluctuations: Activation Process Induced by a Nonlinear Chain in Thermal Equilibrium
We present a model in which the immediate environment of a bistable system is
a molecular chain which in turn is connected to a thermal environment of the
Langevin form. The molecular chain consists of masses connected by harmonic or
by anharmonic springs. The distribution, intensity, and mobility of thermal
fluctuations in these chains is strongly dependent on the nature of the springs
and leads to different transition dynamics for the activated process. Thus, all
else (temperature, damping, coupling parameters between the chain and the
bistable system) being the same, the hard chain may provide an environment
described as diffusion-limited and more effective in the activation process,
while the soft chain may provide an environment described as energy-limited and
less effective. The importance of a detailed understanding of the thermal
environment toward the understanding of the activation process itself is thus
highlighted
Parasitoids of Polistes myersi Bequaert, 1934 (Vespidae, Polistinae)
Information about parasitoids of neotropical vespids is scarce. Parasitoids collected from 43 colonies of Polistes myersi Bequaert, 1934 and one ofPolistes erythrocephalus Latreille, 1813 are reported from an Andean region of Colombia. Colony parasitism rates in P. myersi ranged from 35 % to 57 %, being higher in colonies with more cells; however, the number of parasitized colonies did not differ when considering the mean number of adult wasps (8.2 vs. 8.1 respectively). Parasitoidism ranged from one up to four species per colony. P. myersi parasitoids were: Seminotalaeviceps (Cresson, 1879) (Trigonalidae); Signiphora polistomyiella Richards, 1935 (Signiphoridae); Elasmuspolistis Burks, 1971 (Eulophidae, Elasminae); and a new species of Xenos(Strepsiptera, Xenidae). The latter three are first records for Colombia. P. myersi and P. erythrocephalus are the first host reports for the trigonalid S.laeviceps. We also report an unknown Tachinid fly species of the tribe Blondeliini attacking P. myersi
Manejo de la vía aérea en pacientes llevados a cirugía bariátrica en el Hospital Universitario de San Ignacio, Bogotá, Colombia
ResumenIntroducciónLa obesidad ha aumentado en los últimos años y aún más los obesos mórbidos, en quienes se han reconocido comorbilidades que dificultan el manejo perioperatorio anestésico, incluido el manejo de la vía aérea. En la valoración preanestésica existen parámetros del examen físico y de la historia clínica que son predictores de intubaciones difíciles o fallidas, y es en estos casos cuando el fibroscopio retromolar de Bonfils ha sido una herramienta útil.ObjetivoObservar los predictores de vía aérea difícil a partir del examen físico, la incidencia de intubación difícil y las herramientas utilizadas para el manejo de la vía aérea en pacientes obesos.Material y métodosEstudio observacional descriptivo de 352 pacientes obesos llevados a cirugía bariátrica en el Hospital Universitario de San Ignacio, Bogotá, en quienes se evaluó índice de masa corporal, apertura oral, Mallampati, distancia tiromentoniana, circunferencia del cuello y uso de laringoscopio o fibroscopio retromolar de Bonfils y su dificultad en la utilización.ConclusionesLa intubación con fibroscopio retromolar de Bonfils es exitosa en el 100% de los casos observados en pacientes obesos y la dificultad de la intubación con dicho dispositivo no se correlaciona con los parámetros evaluados.AbstractIntroductionObesity has increased in the past few years, more so for the morbidly obese; in whom comorbilities that complicate the perioperative anaesthetic and airway management have been identified. The pre-anaesthetic assessment of the patient includes parameters of physical examination and medical history that predict difficulties when intubating or failure to do so. In such cases, the Bonfils retromolar fibroscope has proven to be a useful tool.GoalTo observe and identify predicting evidence of a difficult airway through physical examination; to revise the incidence of difficult intubation and the use of tools for airway management of obese patients.Material and methodsThis is a descriptive observational study carried out on 352 obese patients who underwent bariatric surgery at Hospital Universitario San Ignacio, Bogotá. On these patients we assessed the following parameters: body mass index (BMI), oral opening, mallampati score, distance between thyroid and chin, neck circumference, use of laryngoscope or Bonfils retromolar fibroscope and the difficulties encountered for both.ConclusionsIntubation with the Bonfils retromolar fibroscope proves successfull in 100% of observed cases of obese patients, and intubation difficulty does not correlate with the parameters considered in our assessment
Fine particulate matter pollution and risk of community-acquired sepsis
While air pollution has been associated with health complications, its effect on sepsis risk is unknown. We examined the association between fine particulate matter (PM2.5) air pollution and risk of sepsis hospitalization. We analyzed data from the 30,239 community-dwelling adults in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort linked with satellite-derived measures of PM2.5 data. We defined sepsis as a hospital admission for a serious infection with ≥2 systemic inflammatory response (SIRS) criteria. We performed incidence density sampling to match sepsis cases with 4 controls by age (±5 years), sex, and race. For each matched group we calculated mean daily PM2.5 exposures for short-term (30-day) and long-term (one-year) periods preceding the sepsis event. We used conditional logistic regression to evaluate the association between PM2.5 exposure and sepsis, adjusting for education, income, region, temperature, urbanicity, tobacco and alcohol use, and medical conditions. We matched 1386 sepsis cases with 5544 non-sepsis controls. Mean 30-day PM2.5 exposure levels (Cases 12.44 vs. Controls 12.34 µg/m3; p = 0.28) and mean one-year PM2.5 exposure levels (Cases 12.53 vs. Controls 12.50 µg/m3; p = 0.66) were similar between cases and controls. In adjusted models, there were no associations between 30-day PM2.5 exposure levels and sepsis (4th vs. 1st quartiles OR: 1.06, 95% CI: 0.85–1.32). Similarly, there were no associations between one-year PM2.5 exposure levels and sepsis risk (4th vs. 1st quartiles OR: 0.96, 95% CI: 0.78–1.18). In the REGARDS cohort, PM2.5 air pollution exposure was not associated with risk of sepsis
Morphological characterization of ponds and tidal courses in coastal wetlands using Google Earth imagery
Ponds and tidal courses are significant landforms that frequently arise in marshes and tidal flats environments. An understanding of their development and permanence is relevant to determine future dynamic processes that alter tidal flats and salt marshes environments, such as changes in the sea level, increase in the wave activity, and some other variations associated to the climate change. Direct access for monitoring in these regions is complex, extremely expensive and not always feasible. Remote sensing imagery represents a monitoring alternative, but requires the research of specific image processing procedures to extract the information concerning to these environmental studies. In this work, we developed a methodology for assessing the relevant morphological parameters of ponds and tidal courses using Google Earth imagery. An automatic classifier identifies these landforms as such (accuracy over 86%), producing a shape descriptors dataset. Then, ponds and tidal courses in tidal flats are morphologically characterized, and their behavior is compared to the surrounding environment. Subsequent analysis found significant differences in morphological characteristics that arise independently of the marsh environmental conditions. The evidence suggests that the evolution processes of the depressions in salt flat environments are clearly different in comparison with salt marshes environments. In salt marshes, the permanence and evolution of the depressions is related to the age of marshes, whereas in tidal flats the dynamic processes and sediment input have influence on depressions evolution.Fil: Revollo Sarmiento, Gisela Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Revollo Sarmiento, Natalia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; ArgentinaFil: Delrieux, Claudio Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras; ArgentinaFil: Perillo, Gerardo Miguel E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Geología; Argentin
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