38 research outputs found

    History of the Department of Romance Languages at The Ohio State University

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    Prepared for the Centennial of The Ohio State University

    Toxic metal enrichment and boating intensity: sediment records of antifoulant copper in shallow lakes of eastern England

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    Tributyltin (TBT), an aqueous biocide derived from antifouling paint pollution, is known to have impacted coastal marine ecosystems, and has been reported in the sediment of the Norfolk and Suffolk Broads, a network of rivers and shallow lakes in eastern England. In the marine environment, the 1987 TBT ban has resulted in expanded use of alternative biocides, raising the question of whether these products too have impacted the Broads ecosystem and freshwaters in general. Here we examine the lake sediment record in the Norfolk and Suffolk Broads for contamination by copper (Cu) (as an active biocide agent) and zinc (Zn) (as a component of booster biocides), to assess their occurrence and potential for causing environmental harm in freshwater ecosystems. We find that, after the introduction of leisure boating, there is a statistically significant difference in Cu enrichment between heavily and lightly boated sites, while no such difference exists prior to this time. At the heavily boated sites the onset of Cu enrichment coincides with a period of rapid increase in leisure boating. Such enrichment is maintained to the present day, with some evidence of continued increase. We conclude that Cu-based antifouling has measurably contaminated lakes exposed to boating, at concentrations high enough to cause ecological harm. Similar findings can be expected at other boated freshwater ecosystems elsewhere in the world

    Alternative splicing: the pledge, the turn, and the prestige

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    Rapid and highly variable warming of lake surface waters around the globe

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    In this first worldwide synthesis of in situ and satellite-derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade-1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors - from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade-1) to ice-free lakes experiencing increases in air temperature and solar radiation (0.53°C decade-1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes

    The impact of women's social position on fertility in developing countries

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    This paper examines ideas about possible ways in which the extent of women's autonomy, women's economic dependency, and other aspects of their position vis-à-vis men influence fertility in Third World populations. Women's position or “status” seems likely to be related to the supply of children because of its links with age at marriage. Women's position may also affect the demand for children and the costs of fertility regulation, though some connections suggested in the literature are implausible. The paper ends with suggestions for future research.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45660/1/11206_2005_Article_BF01124382.pd

    An evaluation of iron bioavailability and speciation in western Lake Superior with the use of combined physical, chemical, and biological assessment

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    An iron-dependent cyanobacterial bioreporter (Synechococcus strain KAS101) was used in unison with size-fractionated iron content (>0.45, <0.45, <0.02 ”m), and chemical characterization of iron complexation (C18 resin column) to elucidate the bioavailable forms of iron present in Lake Superior during periods of inverse thermal stratification (May) and strong thermal stratification (September) of the water column. The results provide evidence of organic complexation of iron in Lake Superior waters. Iron in most sampled water was complexed by organic compounds that behaved like fulvic acids, whereas some samples showed evidence for the presence of siderophore-like compounds. The presence of dissolved organic matter suppressed the cellular luminescence of the bioreporter, indicating an increased iron bioavailability. This effect could result either from the presence of siderophores forming iron complexes that are bioavailable to the bioreporter, or from more indirect effects because of the presence of other organic compounds, such as fulvic acids or polysaccharides. Model ligand additions, iron bioaccumulation, and photo-oxidation of dissolved organic matter were used to assess the bioavailability of organically complexed iron to the bioreporter. A significant fraction of the iron (40–100%) was bioavailable to the bioreporter. Iron bioavailability was high enough for the bioreporter not to be iron limited in the water collected from Lake Superior. This measure of bioavailability to picocyanobacteria is relevant because picoplankton accounted for the majority of chlorophyll a in Lake Superior during this study

    Behavioral Health Risks in Perinatally HIV-Exposed Youth: Co-Occurrence of Sexual and Drug Use Behavior, Mental Health Problems, and Nonadherence to Antiretroviral Treatment

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    In a sample of perinatally HIV-infected (PHIV+) and perinatally HIV-exposed, uninfected (PHEU) adolescents, we examined the co-occurrence of behavioral health risks including mental health problems, onset of sexual and drug use behaviors, and (in PHIV+ youth) nonadherence to antiretroviral therapy (ART). Participants, recruited from 2007 to 2010, included 349 youth, ages 10–16 years, enrolled in a cohort study examining the impact of HIV infection and ART. Measures of the above behavioral health risks were administered to participants and primary caregivers. Nearly half the participants met study criteria for at least one behavioral health risk, most frequently, mental health problems (28%), with the onset of sexual activity and substance use each reported by an average of 16%. Among the sexually active, 65% of PHIV+ and 50% of PHEU youth reported unprotected sex. For PHIV +youth, 34% reported recent ART nonadherence, of whom 45% had detectable HIV RNA levels. Between 16% (PHIV+) and 11% (PHEU) of youth reported at least two behavioral health risks. Older age, but not HIV status, was associated with having two or more behavioral health risks versus none. Among PHIV+ youth, living with a birth mother (versus other caregivers) and detectable viral load were associated with co-occurrence of behavioral health risks. In conclusion, this study suggests that for both PHIV+ and PHEU youth, there are multiple behavioral health risks, particularly mental health problems, which should be targeted by service systems that can integrate prevention and treatment efforts

    Pesticide Residues

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    METHODOLOGY for residue analysis has advanced rapidly during the current review period, from November 1962 through October 1964. Notable progress has been made in the development and refinement of methods of analysis by which any or all of a large number of pesticide residue chemicals can be detected and measured in one general operation. This is of particular significance because great interest has developed-outside the scientific community as well as within - in the possible presence of pesticide chemicals in all parts of our environment, including man himself. Only by the use of improved methodology will it be possible to accomplish the task of detecting, identifying, and measuring the many possible residual pesticide chemicals. It is only after the presence or absence of these chemicals in any part of our environment has been proved unequivocally that the medical man, the lawyer, the lawmaker, the administrators in government and in industry, and other interested groups can assess the significance of such residues. There are 300 to 400 chemicals registered for use on food products alone, and a few hundred more are registered for other uses whereby they may become part of our environment. The chemist cannot know which of the hundreds of possible pesticide chemical residues to look for in samples of air, water, soil, plants, human and animal tissues, prepared foods, etc. There is an urgent need for general procedures that can identify and measure a large number of chemicals at one time. They must be highly sensitive and accurate, since it is essential that all monitoring of our environment be at a level considerably below any tolerance or otherwise critical level, so that trends can be more readily recognized and assessed for significance. Upward or downward trends in any portion of our environment will be recognizable only when the methodology becomes sufficiently sensitive and accurate so that analyses in the fraction-of-a-part-per-million or even part-per-billion range become routinely dependable (Fischbach, H. Pub. 1082, National Research Council, p. 55, Nov. 29,1962)
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