643 research outputs found
Does the Poor’s Consumption of Calories Respond to Changes in Income? Evidence from Pakistan
This paper examines the relationship between income and calorie consumption for households in developing countries. Recent papers have questioned the strength of this relationship on the basis of several measurement problems that tend to overstate the responsiveness of calories consumption to income. The paper uses a household data set from Pakistan and estimates calories income elasticities for rural and urban households. The estimation takes into account the concerns raised by Behrman and Deolalikar (1987) and Bouis and Haddad (1992) about quality effects and unobservable variables. The paper finds that the elasticity is significantly different from zero. Furthermore, the relationship appears to be different according to households’ incomes. Poor households’ responsiveness of calories intake to changes in income is greater than that of the entire sample. These results are consistent with the conventional wisdom that existed before the recent criticisms.
EDUCATION AND SMOKING: WERE VIETNAM WAR DRAFT AVOIDERS ALSO MORE LIKELY TO AVOID SMOKING?
We use the Vietnam War draft avoidance behavior documented by Card and Lemieux (2001) as a quasi-natural experiment to infer causation from education to smoking and find strong evidence that education, whether measured in years of completed schooling or in educational attainment categories, reduces the probability of smoking at the time of the interview, more particularly the probability of smoking regularly. However, while we find that more education substantially increases the probability of never smoking, there is little evidence that it helps people stop smoking, although the estimates are fairly imprecise. Potential mechanisms linking education and smoking are also explored.
Education and Smoking: Were Vietnam War Draft Avoiders Also More Likely to Avoid Smoking?
We use the Vietnam War draft avoidance behavior documented by Card and Lemieux (2002) as a quasi-natural experiment to infer causation from education to smoking and find strong evidence that education, whether it be measured in years of completed schooling or in educational attainment categories, reduces the probability of smoking at the time of the interview, more particularly the probability of smoking regularly. Interestingly, however, while we find that more education substantially increases the probability of never smoking, our other main finding is suggestive that increased education has a limited impact on smoking cessation behavior. On the one hand there is little evidence that it helps to increase the probability of not smoking regularly at the time of the interview, conditional on having smoked regularly at any time. However, among former regular smokers, those with more education have significantly shorter smoking careers.
LONG TERM EFFECTS OF CIVIL CONFLICT ON WOMEN'S HEALTH OUTCOMES IN PERU
We investigate the long term effects of Peru's internal conflict on women's outcomes. According to Peru's Truth and Reconciliation Commission (CVR), the conflict was responsible for over 69,000 deaths and disappearances from 1980-2000 and between 500,000 to 1 million internally displaced persons. This conflict affected households' ability to generate income because of the death or disappearance of income earners and loss of productive assets. Using data from Peru's Demographic and Health Surveys and district-level conflict data published by the CVR, we find long-term effects of the conflict on some indicators of women's health, particularly on height and anemia.
In vitro-in vivo, cross-life stage and inter-species extrapolation of the biotransformation and uptake of benzo[a]pyrene in two fish species using toxicokinetic models
Toxicokinetic (TK) models are in silico tools that are used to assess the uptake, biotransformation, and elimination of environmental contaminants. Such models can be used in ecological risk assessment (ERA) and in research to evaluate chemical bioaccumulation. This information is especially useful for fish, which are an important taxonomic group used in ERA. Presently, the TK models developed for fish are accurate for neutral organic chemicals; however, the models do not commonly consider chemicals that are actively biotransformed. Furthermore, most TK models for aquatic organisms focus strictly on the adult life stage, while few are explicitly developed for early-life stages (ELS). Thus, the overall objective of this thesis was to develop life-stage specific TK models for the rapidly biotransformed model chemical, benzo[a]pyrene (B[a]P), in two physiologically distinct species of fishes, i.e., the fathead minnow (Pimephales promelas) and the white sturgeon (Acipenser transmontanus).
The first study (Chapter 2) focused on integrating biotransformation of B[a]P into life stage-specific TK models for a standard laboratory fish model, the fathead minnow. Whole-body embryos, and adult liver and gall bladder (bile) were collected from fish aqueously exposed to B[a]P. The respective tissues were analyzed for the activity of phase I and phase II enzymes to assess biotransformation capacity, and B[a]P metabolites were measured to act as a model validation data set. The biotransformation rate of B[a]P was determined using measurements of in vitro intrinsic clearance and implemented into a multi-compartment adult model using in vitro-in vivo extrapolation. For the embryo-larval stage, whole-body biotransformation was allometrically scaled from the calculations of adult biotransformation and directly implemented into a one-compartment embryo-larval TK model. No difference in phase I or II activity was observed with exposure to increasing concentrations to aqueous B[a]P; however, a significant increase in B[a]P metabolites was observed in both life stages. Both models showed good predictive power with model predictions within one order of magnitude of measured values.
The second study (Chapter 3) focused on developing life-stage specific TK models for white sturgeon. Similar to chapter 2, whole-body embryos were sampled from white sturgeon larvae aqueously exposed to B[a]P for assessment of phase I and II activity, and for measurements of whole-body B[a]P metabolites. In contrast to chapter 2, however, whole-body biotransformation of B[a]P could not be scaled from the calculated value of sub-adult B[a]P biotransformation, and therefore, was internally calibrated. The calibrated value of whole-body biotransformation was implemented into a one-compartment embryo-larval TK model and used to make predictions of the internal concentrations of B[a]P metabolites. Due to logistical and ethical reasons (white sturgeon are an endangered species in Canada), an aqueous B[a]P exposure with the adult life stage could not be conducted. Instead, an experimental data set of four chemicals was compiled from previously conducted sub-adult sturgeon bioaccumulation studies found in the scientific literature to be used as a model validation data set. A multi-compartment TK model was parameterized using direct measurements of wet mass, tissue volume, tissue lipid fraction, tissue water content and cardiac output, and literature values of oxygen consumption, from sub-adult white sturgeon, and used to make predictions of the internal concentrations of organic contaminants in the sub-adult life stage. The model results showed that both models could accurately predict the bioaccumulation of organic contaminants within one order of magnitude.
In chapter 4, the life-stage and species specific models were used to characterize the differences in the uptake and biotransformation of B[a]P between life-stages and species. In the fathead minnow, the results of the life-stage analysis showed that the embryo-larval life-stage accumulated a greater abundance of parent B[a]P and B[a]P metabolites; however, the accumulation was slower than what was observed in the adults. The results of the life-stage analysis in white sturgeon showed a similar uptake of parent B[a]P between life stages, but a larger abundance of B[a]P metabolites was predicted in the sub-adult life stage. In both species, the results suggest that the embryo-larval stage might have a lesser capacity to generate the enzymes required for biotransformation B[a]P. The comparative species analysis showed that in both the embryo-larval and sub-adult/adult life stages, white sturgeon showed substantially slower biotransformation of B[a]P. Accordingly, in both life stages, a lesser abundance of metabolites was predicted/measured in the white sturgeon. It was concluded that the embryo-larval life stage of white sturgeon would be comparatively more susceptible to the effects of aryl hydrocarbon receptor binding, as a result of the slower rates of biotransformation, while the sub-adult/adult life stage of the fathead minnow would be comparatively more susceptible to the genotoxic effects associated with B[a]P exposure, as a result of the faster rates of biotransformation.
Overall, the models developed in this thesis contribute to the increasing scope of applications in which TK models can be used in ERA and research by providing a basis in which cross-life stage and interspecies extrapolation can be conducted for the bioaccumulation of actively biotransformed chemicals
Does the Poor’s Consumption of Calories Respond to Changes in Income? Evidence from Pakistan
This paper examines the relationship between income and
calorie consumption for households in developing countries. Recent
papers have questioned the strength of this relationship on the basis of
several measurement problems that tend to overstate the responsiveness
of calories consumption to income. The paper uses a household data set
from Pakistan and estimates calories income elasticities for rural and
urban households. The estimation takes into account the concerns raised
by Behrman and Deolalikar (1987) and Bouis and Haddad (1992) about
quality effects and unobservable variables. The paper finds that the
elasticity is significantly different from zero. Furthermore, the
relationship appears to be different according to households’ incomes.
Poor households’ responsiveness of calories intake to changes in income
is greater than that of the entire sample. These results are consistent
with the conventional wisdom that existed before the recent
criticisms
HEALTH, AGING AND SOCIO-ECONOMIC CONDITIONS IN MEXICO
We investigate the long-term effect of childhood and adult socio-economic conditions on the health of the elderly in Mexico. We utilize a panel of individuals aged 50 and above from the Mexican Health and Aging Survey to examine whether the transition from good health in 2001 to good health in 2003 is affected by the conisions under which the individual lived at the age of 10, accounting for education and income. We find that socio-economic conditions affect the health of the elderly in Mexico. Individuals with higher levels of income and from higher childhood socio-economic backgrounds are more likely to remain in good health, conditional on their health in 2001. Our paper contributes to the literature of the long-term effects of socio-economic status by considering the case of the elderly in a developing country.
Alien Registration- Picard, Wilda (Biddeford, York County)
https://digitalmaine.com/alien_docs/5496/thumbnail.jp
Alien Registration- Picard, Wilda (Biddeford, York County)
https://digitalmaine.com/alien_docs/5496/thumbnail.jp
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