Assessment of Endocrine Disruption in Fish and Estrogenic Potency of Waters in Georgia

Proceedings of the 2011 Georgia Water Resources Conference, April 11, 12, and 13, 2011, Athens, Georgia.Recent reports of intersex fish (males with oocytes in their testicular tissue) in water bodies around the world have stimulated widespread concern about the effects that chemicals are having in the environment. Intersex fish have decreased sperm production, decreased sperm motility and decreased fertilization success compared to histologically ‘normal’ male fish. Estrogens and estrogen-like chemicals in the environment are known to induce intersex and other forms of endocrine disruption in fish. To date, a systematic evaluation of the severity and extent of intersex fish has not been completed in Georgia. Therefore, our objectives are (1) assess intersex condition in black bass collected from rivers and lakes across Georgia, and (2) determine spatial and temporal trends in estrogenic potency (a measure of the estrogens and estrogen-like substances) of surface waters. Study sites include the Oconee River and its major tributaries, the Ocmulgee River, the Savannah River and the Broad River as a reference (no major wastewater effluent discharges). Fish and water samples were collected upstream and downstream of municipal wastewater effluent discharges in each river (except Broad River). Fish were also sampled from lakes across Georgia with no major wastewater inputs to determine a natural ‘background’ rate of intersex in fish from relatively unpolluted water bodies. Gonads from all fish were examined histologically the intersex condition and incidence rates were compared among sites. We hypothesize that incidence of intersex fish will be associated with estrogens in surface waters. Potency of estrogens in surface waters will be determined by use of an in vitro yeast-based reporter gene assay. This study will provide the first investigation of intersex fish in many of Georgia’s rivers and lakes and will be the first to investigate the estrogenic potency of surface waters across the state.Sponsored by: Georgia Environmental Protection Division U.S. Geological Survey, Georgia Water Science Center U.S. Department of Agriculture, Natural Resources Conservation Service Georgia Institute of Technology, Georgia Water Resources Institute The University of Georgia, Water Resources FacultyThis book was published by Warnell School of Forestry and Natural Resources, The University of Georgia, Athens, Georgia 30602-2152. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-307) or the other conference sponsors

On the relationship of magnetocrystalline anisotropy and stoichiometry in epitaxial L1(0) CoPt (001) and FePt (001) thin films

Two series of epitaxial CoPt and FePt films, with nominal thicknesses of 42 or 50 nm, were prepared by sputtering onto single-crystal MgO(001) substrates in order to investigate the chemical ordering and the resultant magnetic properties as a function of alloy composition. In the first series, the film composition was kept constant, while the substrate temperature was increased from 144 to 704 degrees C. In the second series the substrate temperature was kept constant at 704 degrees C for CoPt and 620 degrees C for FePt, while the alloy stoichiometry was varied in the nominal range of 40-60-at. % Co(Fe). Film compositions and thicknesses were measured via Rutherford backscattering spectrometry. The lattice and long-range order parameter for the L1(0) phase were obtained for both sets of films using x-ray diffraction. The room-temperature magnetocrystalline anisotropy constants were determined for a subset of the films using torque magnetometry. The order parameter was found to increase with increasing temperature, with ordering occurring more readily in FePt when compared with CoPt. A perpendicular anisotropy developed in CoPt for substrate temperatures above 534 degrees C and in FePt above 321 degrees C. The structure and width of the magnetic domains in CoPt and FePt, as seen by magnetic force microscopy, also demonstrated an increase in magnetic anisotropy with increasing temperature. For the films deposited at the highest temperatures (704 degrees C for CoPt and 620 degrees C for FePt), the order parameter reached a maximum near the equiatomic composition, whereas the magnetocrystalline anisotropy increased as the concentration of Co or Fe was increased from below to slightly above the equiatomic composition. It is concluded that nonstoichiometric L1(0) CoPt and FePt, with a slight excess of Co or Fe, are preferable for applications requiring the highest anisotropies

Structural, electronic, and magnetic investigation of magnetic ordering in MBE-grown CrxSb2-xTe3 thin films

This work arises from research funded by the John Fell Oxford University Press Research Fund. LJC-M and LBD acknowledge financial support from EPSRC. LBD acknowledges financial support from the Science and Technology Facilities Council (UK) and AS from the Cambridge Commonwealth Trust.We report the structural, electronic, and magnetic study of Cr-doped Sb2Te3 thin films grown by a two-step deposition process using molecular-beam epitaxy (MBE). The samples were investigated using a variety of complementary techniques, namely, x-ray diffraction (XRD), atomic force microscopy, SQUID magnetometry, magneto-transport, and polarized neutron reflectometry (PNR). It is found that the samples retain good crystalline order up to a doping level of x = 0.42 (in CrxSb2-xTe3), above which degradation of the crystal structure is observed by XRD. Fits to the recorded XRD spectra indicate a general reduction in the c-axis lattice parameter as a function of doping, consistent with substitutional doping with an ion of smaller ionic radius. The samples show soft ferromagnetic behavior with the easy axis of magnetization being out-of-plane. The saturation magnetization is dependent on the doping level, and reaches from ~2 μBto almost 3 μB per Cr ion. The transition temperature (Tc) depends strongly on the Cr concentration and is found to increase with doping concentration. For the highest achievable doping level for phase-pure films of x = 0.42 ,a Tc of 125 K was determined. Electric transport measurements find surface-dominated transport below ∼10 K. The magnetic properties extracted from anomalous Hall effect data are in excellent agreement with the magnetometry data. PNR studies indicate a uniform magnetization profile throughout the film, with no indication of enhanced magnetic order towards the sample surface.Publisher PDFPeer reviewe

Knowledge of Chlamydia trachomatis among men and women approached to participate in community-based screening, Scotland, UK

Background: Poor awareness and knowledge of Chlamydia trachomatis could be a barrier to uptake of screening. This study aimed to determine the level of awareness and knowledge of chlamydia among young people who were being approached in a variety of community settings and offered opportunistic screening.Methods: Men and women aged 16-24 years were approached in education, health and fitness, and workplace settings and invited to complete a self-administered questionnaire then provide a urine sample for chlamydia testing. Follow-up semi-structured interviews with 24 respondents were carried out after test results were received.Results: 363 questionnaires were completed (43.5% from men). Whilst awareness of chlamydia was high, knowledge decreased as questions became increasingly focussed so that around half of respondents were unaware of the asymptomatic nature of chlamydia infections. Men's knowledge of symptoms was consistently lower than women's, with most men failing to identify unusual discharge as a symptom in men (men 58.3%, female 45.8%, p = 0.019); fewer men knew unusual discharge was a symptom among women (men 65.3% female 21.4%, p < 0.001). The asymptomatic nature of the infection resonated with respondents and was the commonest piece of information they picked up from their participation in the study.Conclusions: Despite scientific gains in understanding chlamydia infection, public understanding remains limited. Greater efforts are required to translate scientific evidence to the public. An improvement in knowledge may maximise gains from interventions to improve detection

The wired city [1973]

This paper was originally published in Telecommunication Journal of Australia, Volume 23, No 3, 1973. It was presented as the opening paper at the UNESCO Seminar on the 'Communication Revolution' held in Melbourne on 20-24 August, 1973.The Australian Post Office has just commenced a complex operation to plan the course of telecommunications in Australia beyond the year 2000 A.D. This article indicates the national significance of the undertaking and the complexities of the issues involved. The potential facilities which may be offered to subscribers are outlined, some of which call for a network of markedly different capabilities to the existing telephone networks. There are conceptual attractions in providing all facilities in a single wideband distribution network but there are also offsetting difficulties which must be examined. Even if a single distribution network is adopted there may well be several switching networks.Facilities of the type envisaged will have far reaching impacts on major facets of society such as town planning, transport patterns, education, structure of the economy and behaviour patterns.The telecommunications planner is entering new and little-charted fields which will call for close relationships with other professional disciplines and extensive consultation with relevant groups in society