904 resultados para Early and Periodic Screening, Diagnosis, and Treatment Program (U.S.)
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Child obesity in the U.S. is a significant public health issue, particularly among children from disadvantaged backgrounds. Thus, the roles of parents’ human and financial capital and racial and ethnic background have become important topics of social science and public health research on child obesity. Less often discussed, however, is the role of family structure, which is an important predictor of child well-being and indicator of family socioeconomic status. The goal of this study, therefore, is to investigate how preschool aged children’s risk of obesity varies across a diverse set of family structures and whether these differences in obesity are moderated by family poverty status and the mothers’ education. Using a large nationally representative sample of children from the Early Childhood Longitudinal Study – Birth Cohort, we find that preschoolers raised by two biological cohabiting parents or a relative caregiver (generally the grandparent) have greater odds of being obese than children raised by married biological parents. Also, poor children in married biological parent households and non-poor children in married step parent households have greater obesity risks, while poor children in father only, unmarried step, and married step parent families actually have lower odds of obesity than children in non-poor intact households. The implications of these findings for policy and future research linking family structure to children’s weight status are discussed.
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High-resolution records of opal, carbonate, and terrigenous fluxes have been obtained from a high-sedimentation rate core (MD84-527: 43°50'S; 51°19'E; 3269 m) by normalization to 230Th. This method estimates paleofluxes to the seafloor on a point-by-point basis and distinguishes changes in sediment accumulation due to variations in vertical rain rates from those due to changes in syndepositional sediment redistribution by bottom currents. We also measured sediment delta15N to evaluate the changes in nitrate utilization in the overlying surface waters associated with paleoflux variations. Our results show that opal accumulation rates on the seafloor during the Holocene and stage 3, based on 14C dating, were respectively tenfold and fivefold higher than the vertical rain rates, At this particular location, changes in opal accumulation on the seafloor appear to be mainly controlled by sediment redistribution by bottom currents rather than variations in opal fluxes from the overlying water column. Correction for syndepositional sediment redistribution and the improved time resolution that can be achieved by normalization to 230Th disclose important variations in opal rain rates. We found relatively high but variable opal paleoflux during stage 3, with two maxima centered at 36 and 30 kyr B.P., low opal paleoflux during stage 2 and deglaciation and a pronounced maximum during the early Holocene, We interpret this record as reflecting variations in opal production rates associated with climate-induced latitudinal migration of the southern ocean frontal system. Sediments deposited during periods of high opal paleoflux also have high authigenic U concentrations, suggesting more reducing conditions in the sediment, and high Pa-231/Th-230 ratios, suggesting increased scavenging from the water column. Sediment delta15N is circa 1.5 per mil higher during isotopic stage 2 and deglaciation. The low opal rain rates recorded during that period appear to have been associated with increased nitrate depletion. This suggests that opal paleofluxes do not simply reflect latitudinal migration of the frontal system but also changes in the structure of the upper water column. Increased stratification during isotopic stage 2 and deglaciation could have been produced by a meltwater lid, leading to lower nitrate supply rates to surface waters.
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Mode of access: Internet.
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"NCJ 168106."
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Shipping list no.: 94-0188-P.
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Shipping list no.: 2005-0086-P.
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Description based on: Fiscal year 2001; title from cover.
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The spatial and temporal distribution of modern diatom assemblages in surface sediments, on the most dominant macrophytes, and in the water column at 96 locations in Florida Bay, Biscayne Bay and adjacent regions were examined in order to develop paleoenvironmental prediction models for this region. Analyses of these distributions revealed distinct temporal and spatial differences in assemblages among the locations. The differences among diatom assemblages living on subaquatic vegetation and sediments, and in the water column were significant. Because concentrations of salts, total phosphorus (WTP), total nitrogen (WTN) and total organic carbon (WTOC) are partly controlled by water management in this region, diatom-based models were produced to assess these variables. Discriminant function analyses showed that diatoms can also be successfully used to reconstruct changes in the abundance of diatom assemblages typical for different habitats and life habits. ^ To interpret paleoenvironmental changes, changes in salinity, WTN, WTP and WTOC were inferred from diatoms preserved in sediment cores collected along environmental gradients in Florida Bay (4 cores) and from nearshore and offshore locations in Biscayne Bay (3 cores). The reconstructions showed that water quality conditions in these estuaries have been fluctuating for thousands of years due to natural processes and sea-level changes, but almost synchronized shifts in diatom assemblages occurred in the mid-1960’s at all coring locations (except Ninemile Bank and Bob Allen Bank in Florida Bay). These alterations correspond to the major construction of numerous water management structures on the mainland. Additionally, all the coring sites (except Card Sound Bank, Biscayne Bay and Trout Cove, Florida Bay) showed decreasing salinity and fluctuations in nutrient levels in the last two decades that correspond to increased rainfall in the 1990’s and increased freshwater discharge to the bays, a result of increased freshwater deliveries to the Everglades by South Florida Water Management District in the 1980’s and 1990’s. Reconstructions of the abundance of diatom assemblages typical for different habitats and life habits revealed multiple sources of diatoms to the coring locations and that epiphytic assemblages in both bays increased in abundance since the early 1990’s. ^
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This study on China’s relations with Brazil and Argentina, as well as its implications for U.S. concerns examines two main questions: Why China’s increasing influence on Brazil and Argentina may be considered a cause for U.S. security concerns? And if this is the case, how do China’s strategic alliances with the two countries has impacted U.S. leadership? In an effort to look at China’s influence from multidimensional angles and beyond China’s visible economic influence in these two countries, this paper argues that China’s interest in the Latin American region, with a focus on brazil and Argentina, responds to a more crafted, pragmatic and tailored vision with long-term strategic and political goals. The results of this study reveal that China – avoiding intra-regional competition through a strategic diversification of sectors – has been able to secure critical resources for its population as well as promote enduring alliances in the region that could represent a plausible cause of concern for U.S. interests. In this regard, China’s avoidance of a direct challenge to traditional partners’ influence has responded to the gaps left by a gradual, but steady lack of U.S. involvement.
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Dissertação de mestrado em Ciências da Comunicação (área de especialização em Publicidade e Relações Públicas)
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