DEMAND SYSTEM CHOICE BASED ON TESTING THE ENGEL CURVE SPECIFICATION

It is common to use a demand systems approach in estimating the key parameters from household consumption data. In conducting these studies the researcher is faced with selecting a functional form. In turn, each functional form implies a particular shape for the Engel curves. This analysis highlights the importance of testing the shape of Engel curves, especially if the researcher is interested in elasticity estimates well away from the sample mean. Using consumption data for selected households in Italy it is shown that many popular functional forms are rejected by the data.Demand and Price Analysis,

Guía para la construcción de matrices insumo-producto y de contabilidad social en Colombia

Las matrices insumo-producto y de contabilidad social constituyen fuentes de información importante para el entendimiento de las relaciones productivas y económicas de un país en un determinado momento del tiempo. En Colombia, la construcción de estos instrumentos tiene una larga experiencia aunque poca ha sido su documentación. Este artículo pretende exponer de manera clara y concisa el procedimiento necesario para su construcción.Input-output and social accounting matrices depict the most significant production and economic relations within a country. Although there is a long experience in building this kind of instruments, none of the studies done in the country exposes the procedure on how replicate them. This article presents a standard methodology to build these matrices for the Colombian case

Trochanteric osteotomy in primary and revision total hip arthroplasty: risk factors for non-union

Background: Trochanteric osteotomies (TO) facilitate exposure and "true hip reconstruction” in complex primary and revision total hip arthroplasty (THA). However, non-union represents a clinically relevant complication. The purpose of the present study was to identify risk factors for trochanteric non-union. Methods: All cases of THA approached by TO during the past 10years were analyzed with respect to potential risk factors for non-union. Results: In 298 cases complete data were available for analysis. Trochanteric union occurred in 80.5%, fibrous union in 5.4% and non-union 14.1%. Risk factor analysis revealed a four times higher risk for non-union in anterior trochanteric slide osteotomies compared to extended trochanteric osteotomies and a three times higher risk in cemented versus non-cemented stems. Multiple logistic regression analysis revealed patient's age and use of cement to be independent risk factors for non-union. Conclusions: Femoral cementation and increasing age negatively influence the union of trochanteric osteotomie

The South on the South: Interview with Raewyn Connell

In the first of a series of conversations about the Global South, Social Transformations: Journal of the Global South editors Lisandro E. Claudio and Karl Cheng Chua (STJGS) speak to Raewyn Connell (RC) about the generating conversations about the Global South in the Global South

Hierarchical Generative Adversarial Imitation Learning with Mid-level Input Generation for Autonomous Driving on Urban Environments

Deriving robust control policies for realistic urban navigation scenarios is not a trivial task. In an end-to-end approach, these policies must map high-dimensional images from the vehicle's cameras to low-level actions such as steering and throttle. While pure Reinforcement Learning (RL) approaches are based exclusively on rewards,Generative Adversarial Imitation Learning (GAIL) agents learn from expert demonstrations while interacting with the environment, which favors GAIL on tasks for which a reward signal is difficult to derive. In this work, the hGAIL architecture was proposed to solve the autonomous navigation of a vehicle in an end-to-end approach, mapping sensory perceptions directly to low-level actions, while simultaneously learning mid-level input representations of the agent's environment. The proposed hGAIL consists of an hierarchical Adversarial Imitation Learning architecture composed of two main modules: the GAN (Generative Adversarial Nets) which generates the Bird's-Eye View (BEV) representation mainly from the images of three frontal cameras of the vehicle, and the GAIL which learns to control the vehicle based mainly on the BEV predictions from the GAN as input.Our experiments have shown that GAIL exclusively from cameras (without BEV) fails to even learn the task, while hGAIL, after training, was able to autonomously navigate successfully in all intersections of the city

Construcción de una Matriz de Contabilidad Social para el análisis de políticas de seguridad social en salud

La introducción del nuevo sistema de seguridad social en 1993 trajo cambios en las relaciones existentes entre las instituciones colombianas. En el sector salud, el nuevo sistema conllevó a la creación de agentes intermediarios, quienes han desarrollado un papel de importancia en la determinación de los flujos económicos del sector y sus participantes. Hasta el momento, pocas investigaciones han establecido estas interacciones, lo que motivó a este estudio. En este documento se propone una primera aproximación a la construcción de estas relaciones en una síntesis de la economía colombiana, esto es, una matriz de contabilidad social.Matriz de Contabilidad Social, Sistema de Seguridad social en Salud

Pro/con clinical debate: Is high-volume hemofiltration beneficial in the treatment of septic shock?

Although there have been exciting advances in the management of sepsis and septic shock, mortality still remains high. Recent data suggest that high-volume hemofiltration (HVHF) may play a role in these patients. In contrast to the usual rate of hemofiltration, HVHF is felt to be better able to remove the inflammatory mediators associated with sepsis and septic shock. Such an approach is currently incapable of selectively removing specific mediators. This may be a problem when one considers that several mediators may in fact be beneficial. When determining whether HVHF should be instituted in a patient with septic shock, one need remember that its role is far from clear and its usefulness remains the subject of much debate. Although early data is encouraging, it is clear that additional data is required before HVHF becomes standard management. The authors of this pro/con debate, which is based on a clinical scenario, first describe their own position and then respond to their opponent's position

Total hip replacement in patients with history of illicit injecting drug use

Background: A history of illicit injecting drug use makes indication of total hip arthroplasty (THA) in patients with end stage hip osteoarthritis difficult, as the risk of infection with colonized strains is multiplied if the patient continues to inject or inhale illicit drugs. Methods: A retrospective survivorship analysis of a consecutive series of 27 THA in patients with a history of illicit drug use was performed. Follow-up evaluation consisted of (1) a WOMAC score, (2) a standardized interview including queries on drug habits and eventual additional medico-surgical treatments of the affected hip, (3) a clinical examination in order to complete a Harris Hip Score, (4) radiological examination and (5) blood tests (blood sedimentation rates and C-reactive protein). Defined endpoints were death, implant revised or awaiting revision for deep infection or any other reason and lost to follow-up or follow-up after at least 2years. Results: Overall, 5- and 10-year implant survival rates with failure for any reason were 61% (CI: 41;81) and 52.3% (CI: 29;76) and for septic reasons 70.6% (CI: 52;89) and 60.5% (CI: 36;85), respectively. Even if at the time of THA all patients and respective health care professionals confirmed abstinence of illicit injecting drug use, five patients reported occasional use. Declared abstinence of less than 1year before THA was associated with higher recurrence rates (p=0.001) and both with higher septic failure rates (p=0.023, p=0.061). Positive serology for human deficiency virus did not increase implant failure rates. Conclusion: We use this unacceptable high failure rate as evidence when counseling patients and their health care professionals about the appropriate treatment of osteoarthritis in patients with a history of illicit drug use. Furthermore, we support the request of hair analysis for drugs documenting abstinence of at least 1year before indicating TH