1,016 research outputs found
Social protection programs and employment: The case of Mexico’s “Seguro Popular” program
Mexico created Seguro Popular in 2002 with the goal of providing free or subsidized health insurance coverage to 47 million uninsured people by the year 2013. Only individuals lacking the social security protections granted to all formal sector workers and their families are eligible. Hence, one unintended consequence of the program could be an increase in the size of the informal sector. The introduction of the Seguro Popular program was conducted in stages, across municipalities and time. We exploit this variation and implement a differences-in-differences approach in order to identify the causal effect of the program in formal employment outcomes. We analyze the effect of Seguro Popular using 33 large and relatively rich cities from labor force surveys conducted from 2001 to 2004. In order to measure the effect for poorer municipalities, we also use the individual-level Oportunidades dataset that covers 136 municipalities from 2002 to 2004. We find little evidence of any correlation between Seguro Popular and the decision of workers to be employed in the formal or informal sector. One possible explanation of our findings is the low enrollment of the Seguro Popular program during the period we study. We provide suggestive evidence from the 33 cities that the result holds for the 2005 to 2006 period as well. We conclude that the recent increase in informal employment in Mexico is due to other causes.Mexico, informality, employment
Avian community structure and diversity in relation to coastal development in the Sian Ka’an Biosphere Reserve and Riviera Maya, Quintana Roo, Mexico
Habitat loss and fragmentation caused by tourist development along the eastern coast of the Yucatan Peninsula of Mexico represents a big threat to the survival of Nearctic-Neotropical migratory songbirds. This habitat plays a crucial role for successful migration for many migratory birds. However, the effects of habitat loss and fragmentation on these birds have not been well documented in the region. From September- December, 2006-2008, we mist-netted and conducted transect surveys to assess the variation in the avian community among three different levels of development (high, medium and low). The study area included two small reserves (10-20 ha) in the hotel zone associated with the Riviera Maya (high development), two sites with limited development within the Sian Ka’an Biosphere Reserve associated with small fishing camps (medium development), and two undeveloped sites located on a private ranch within Sian Ka’an (low development). I assessed species richness and abundance of four avian groups: the entire community, year-round residents, winter residents, and transients. Species richness and abundance decreased significantly with the greatest levels of disturbance. The high development level had the least species richness and abundance, whereas the medium development level had the greatest richness for all bird classes. However, my results suggest that small reserves in the hotel zone can be important compliments to the large, undisturbed reserves (Sian Ka’an) for both resident and migrant birds. Forty-six percent of all birds species captured in mist nets were Nearctic-Neotropical migrants; thus this group composed a significant component of the avian community. The dominance in the year-round resident community by the endemic Black Catbird (Dumetella glabrirostris) at medium and low development sites showed that coastal dune vegetation is also important in maintaining populations of endemic species, which are sensitive to levels of disturbance. The use of two different survey methods (mist-netting and transect surveys) produced complimentary descriptions of community composition. Because many year-round resident species and migrants depend on this scarce and discontinuous coastal habitat, and because of the intense development pressure on this coastal zone, better conservation strategies are needed to successfully sustain the avian community of this region
Effect of energy density and virginiamycin supplementation in diets on growth performance and digestive function of finishing steers.
ObjectiveThis study was determined the influence of virginiamycin supplementation on growth-performance and characteristics of digestion of cattle with decreasing dietary net energy value of the diet for maintenance (NEm) from 2.22 to 2.10 Mcal/kg.MethodsEighty crossbred beef steers (298.2±6.3 kg) were used in a 152-d performance evaluation consisting of a 28-d adaptation period followed by a 124-d growing-finishing period. During the 124-d period steers were fed either a lesser energy dense (LED, 2.10 Mcal/kg NEm) or higher energy dense (HED, 2.22 Mcal/kg NEm) diet. Diets were fed with or without 28 mg/kg (dry matter [DM] basis) virginiamycin in a 2×2 factorial arrangement. Four Holstein steers (170.4±5.6 kg) with cannulas in the rumen (3.8 cm internal diameter) and proximal duodenum were used in 4×4 Latin square experiment to study treatment effects on characteristics of digestion.ResultsNeither diet energy density nor virginiamycin affected average daily gain (p>0.10). As expected, dry matter intake and gain efficiency were greater (p<0.01) for LED- than for HED-fed steers. Virginiamycin did not affect estimated net energy value of the LED diet. Virginiamycin increased estimated NE of the HED diet. During daylight hours when the temperature humidity index averaged 81.3±2.7, virginiamycin decreased (p<0.05) ruminal temperature. Virginiamycin did not influence (p>0.10) ruminal or total tract digestion. Ruminal (p = 0.02) and total tract digestion (p<0.01) of organic matter, and digestible energy (p<0.01) were greater for HED vs LED. Ruminal microbial efficiency was lower (p<0.01) for HED vs LED diets.ConclusionThe positive effect of virginiamycin on growth performance of cattle is due to increased efficiency of energy utilization, as effects of virginiamycin on characteristics of digestion were not appreciable. Under conditions of high ambient temperature virginiamycin may reduce body temperature
An Architecture for Emotional and Context-Aware Associative Learning for Robot Companions
This work proposes a theoretical architectural model based on the brain's fear learning system with the purpose of generating artificial fear conditioning at both stimuli and context abstraction levels in robot companions. The proposed architecture is inspired by the different brain regions involved in fear learning, here divided into four modules that work in an integrated and parallel manner: the sensory system, the amygdala system, the hippocampal system and the working memory. Each of these modules is based on a different approach and performs a different task in the process of learning and memorizing environmental cues to predict the occurrence of unpleasant situations. The main contribution of the model proposed here is the integration of fear learning and context awareness in order to fuse emotional and contextual artificial memories. The purpose is to provide robots with more believable social responses, leading to more natural interactions between humans and robots
The chemistry and bioactive properties behind microalgae-enriched gluten-free breads
This work aims to: (i) assess volatiles composition of microalgae-enriched gluten-free breads (prepared
with Tetraselmis chuii, Chlorella vulgaris and Microchloropsis gaditana); (ii) report the bioaccessibility of
protein and minerals after a static in vitro digestion model; (iii) understand how it affects the bioactive
properties of gluten-free breads in regard to antioxidant capacity and the α-amylase inhibitory potential.
Therefore, nutritional composition and bioactive properties of gluten-free breads before and after in vitro
digestion model were examined. Identification of compounds responsible for the overall aroma of microalgae
using GC–MS was done. There was a considerable decrease in protein and minerals available after in
vitro digestion, as well as in the antioxidant potential. The overall aroma of microalgae-enriched breads
was mainly due to the presence of alcohols, representing the major class of volatiles present in breads
(3% to 59%), being lower for T. chuii-enriched bread. Terpenes also existed in considerable amounts
especially in M. gaditana (24%) where γ-terpinene was the most abundant. Alkanoic acids were the most
abundant lipophilic bioactive compounds (25%–68%), and 9,12-octadecadienoic acid was the major identified
compound (13%–51%). Phytic acid is also present in all microalgae-enriched breads and may contribute
to the decrease in the bioaccessibility of nutrients.info:eu-repo/semantics/publishedVersio
Grape seed carbons for studying the influence of texture on supercapacitor behaviour in aqueous electrolytes
Microporous carbon materials having a negligible contribution of mesopores have been synthesised by cyclic oxidation/desorption of grape seeds char using air, ozone and HNO3 as oxidant agents. By adequate selection of the operating conditions (oxidation procedure and number of cycles), it is possible to tune the volume and pore size distribution (PSD) of carbon materials and therefore determine the influence of carbon textural properties on the electrochemical behaviour of carbon-carbon symmetric supercapacitors operating in different aqueous electrolytes. The results confirm that although energy density can be improved using neutral electrolytes because of their higher stability potential window compared to acidic or basic electrolytes, it is important to adapt the textural properties of the carbon materials to improve the ions' diffusion inside the porosity for assuring the charging of the double layer at high current densities to reach high power densitiesThe authors greatly appreciate the financial support from the Spanish Ministerio de Ciencia e Innovación (CTQ2009-09983
Multicolor flickering studies of X1822-371
We report on the analysis of high-speed multicolor photometry of the
eclipsing X-ray binary X1822-371. We used new eclipse timings to derive a
revised optical ephemeris. A quadratic fit to the eclipse timings is not
statistically significant but suggests that the orbital period is increasing on
a timescale of P/|Pdot|= (4.2 +/- 1.4) 10^6 yr. We find no systematic delay or
advance of the optical timings with respect to the X-ray timings. Average UBVRI
light curves show the deep eclipse of the disc by the secondary star
superimposed on the broader and shallower occultation of the inner disc regions
by the outer disc (dip), and an orbital hump centred at phase +0.25 which is
mostly seen in the U and B bands. The starting phase of the dip occurs earlier
for shorter wavelengths, while the egress occurs at the same phase in all
bands. This suggests that the thickening of the outer, occulting disc rim is
gradual with azimuth at ingress but decreases sharply at egress. We fit
synthetic photometry to the extracted colors of the inner and outer disc
regions to estimate their effective temperatures. We find Teff= (9+/-5) 10^7 K
and Teff= (6+/-2) 10^4 K, respectively, for the inner and outer disc regions.
The orbital dependency of the flickering activity is derived from the mean
scatter of the individual light curves with respect to the average UBVRI light
curves. The flickering curves show a broad eclipse at the dipping phases, the
depth of which decreases with increasing wavelength. The blue, eclipsed
flickering component is associated with the inner disc regions and can be
fitted by a blackbody spectrum of Teff= (2.1+/-0.8) 10^8 K, whereas the
uneclipsed flickering component probably arises from the outermost disc regions
and is well described by a blackbody of Teff= (9.6+/-0.7) 10^3 K.Comment: 8 pages, 5 postscript figures, coded with MNRAS latex file. To appear
in Monthly Notices of the Royal Astronomical Societ
A Situation-Aware Fear Learning (SAFEL) Model for Robots
This work proposes a novel Situation-Aware FEar Learning (SAFEL) model for robots. SAFEL combines concepts of situation-aware expert systems with well-known neuroscientific findings on the brain fear-learning mechanism to allow companion robots to predict undesirable or threatening situations based on past experiences. One of the main objectives is to allow robots to learn complex temporal patterns of sensed environmental stimuli and create a representation of these patterns. This memory can be later associated with a negative or positive “emotion”, analogous to fear and confidence. Experiments with a real robot demonstrated SAFEL’s success in generating contextual fear conditioning behaviour with predictive capabilities based on situational information
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