984 resultados para R. Johnson
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Several recent studies have examined the connection between religion and medical service utilization. This relationship is complicated because religiosity may be associated with beliefs that either promote or hinder medical helpseeking. The current study uses structural equation modeling to examine the relationship between religion and fertility-related helpseeking using a probability sample of 2183 infertile women in the United States. We found that, although religiosity is not directly associated with helpseeking for infertility, it is indirectly associated through mediating variables that operate in opposing directions. More specifically, religiosity is associated with greater belief in the importance of motherhood, which in turn is associated with increased likelihood of helpseeking. Religiosity is also associated with greater ethical concerns about infertility treatment, which are associated with decreased likelihood of helpseeking. Additionally, the relationships are not linear throughout the helpseeking process. Thus, the influence of religiosity on infertility helpseeking is indirect and complex. These findings support the growing consensus that religiously-based behaviors and beliefs are associated with levels of health service utilization.
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Background: School-based sex education is effective in reducing risky sexual behavior among adolescents that may lead to unintended pregnancies and sexually transmitted infections. However, most sex education policies in the US do not support evidence-based programs. Understanding parental attitudes around sex education is crucial to overcoming perceived barriers to implementing school-based sex education. Little research has been published on the opinions of parents in Texas, which accounts for 12% of the nation’s teen births. Purpose: The purpose of this study was to examine whether Texas parents favor teaching sex education in schools, in what grades they think sex education should be taught, what content they think should be taught, and who they think should make decisions regarding sex education. Methods: We commissioned a telephone survey of parents of children 18 years or younger in Harris County, Texas. Survey questions assessed demographic characteristics and opinions about sex education. We used chi-square tests to examine differences across sociodemographic characteristics. Results: 1,201 parents completed the survey. The majority of parents (80%) responded that sex education should begin in middle school or earlier, and two-thirds said that it should include information about condoms and contraception. Hispanic parents showed the highest support for teaching sex education and providing medically accurate information on condoms and contraception in middle school or earlier. Conclusion: Parents in Harris County overwhelmingly support sex education that includes medically accurate information about condoms and contraception beginning before high school. These data provide evidence to change sex education policies to better reflect parental opinions.
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Studies of interstitial waters obtained from DSDP Leg 64 drill sites in the Gulf of California have revealed information both on early diagenetic processes in the sediments resulting from the breakdown of organic matter and on hydrothermal interactions between sediments and hot doleritic sill intrusions into the sediments. In all the sites drilled sulfate reduction occurred as a result of rapid sediment accumulation rates and of relatively high organic carbon contents; in most sites methane production occurred after sulfate depletion. Associated with this methane production are high values of alkalinity and high concentrations of dissolved ammonia, which causes ion exchange processes with the solid phases leading to intermediate maxima in Mg++, K+, Rb+, and Sr++(?). Though this phenomenon is common in Leg 64 drill sites, these concentration reversals had been noticed previously only in Site 262 (Timor Trough) and Site 440 (Japan Trench). Penetrating, hot dolerite sills have led to substantial hydrothermal alteration in sediments at sites drilled in the Guaymas Basin. Site 477 is an active hydrothermal system in which the pore-water chemistry typically shows depletions in sulfate and magnesium and large increases in lithium, potassium, rubidium, calcium, strontium, and chloride. Strontium isotope data also indicate large contributions of volcanic matter and basalt to the pore-water strontium concentrations. At Sites 478 and 481 dolerite sill intrusions have cooled to ambient temperatures but interstitial water concentrations of Li+, Rb+, Sr++ , and Cl- show the gradual decay of a hydrothermal signal that must have been similar to the interstitial water chemistry at Site 477 at the time of sill intrusion. Studies of oxygen isotopes of the interstitial waters at Site 481 indicate positive values of d18O (SMOW) as a result of high-temperature alteration reactions occurring in the sills and the surrounding sediments. A minimum in dissolved chloride at about 100-125 meters sub-bottom at Sites 478, 481, and particularly Site 479 records a possible paleosalinity signal, associated with an event that substantially lowered salinities in the inner parts of the Gulf of California during Quaternary time.
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Altered basalt dikes from Hole 504B were partially melted at 1150°C and 1180°C to determine the composition of the first melts as oceanic Layer 2C is assimilated by a magma chamber. The partial melts are chemically similar to actinolite, the most abundant secondary mineral, but the melts are not simply melted actinolite. High TiO2, P2O5, and K2O abundances of the melts indicate that minor secondary minerals that are enriched in these elements also contribute to the melt. The incorporation of partial melts into a ridge-crest magma chamber may explain the local variability that is sometimes found in ocean ridge basalts that are not readily explained fractional crystallization or partial melting.