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

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

A study of simulated weld heat affected zone structures and properties of HY-80 low alloy stee

Single and double cycle simulation techniques have been employed to investigate the structure and properties of the heat affected zone in HY-80 steel due to a single submerged arc weld run and to the deposition of a tempering bead on a pre-existing edge bead heat affected zone. The thermal cycles used for simulation had peak temperatures of 1275°C, 930°C, 7650C and 6500C and corresponded to those experienced in the parent material during the submerged arc welding of 1.5 in. thick plate using a nominal heat input of 54kJ. in and a preheat temperature of 120°C. Double cycling utilized specific combinations of these thermal cycles. Half the total number of simulated specimens received post cycle heat treatment at 650°C. Charpy V-notch impact transition curves and tensile and hardness data have been obtained for each condition studied and structural examination has employed the carbon extraction replica technique in the electron microscope. The results indicate that the properties of the weld heat affected zone in HY-80 steel are superior to those obtained for QT-35 steel but inferior to those of the HY-80 parent material. The tempering bead technique has been shown to have, at best, only a limited tempering effect on the grain coarsened region of an edge bead heat affected zone and can also cause an increase in the susceptibility of this region to brittle fracture. Post weld heat treatment at 6500C is recommended, wherever possible, for HY-80 weldments. The calculation of weld heat affected zone thermal cycles, which correlate well with the practical situation, has been made possible by the development of a series of computer programs. These programs include functions to account for the release of latent heat from the solidifying weld pool and the variation of thermal conductivity with temperature

Ion cyclotron waves in the Earth’s magnetotail during CASSINI’s Earth swing-by

The properties of low frequency magnetotail waves observed during CASSINI’s Earth swing-by are examined. A maximum in the distribution of the waves about half the proton cyclotron frequency and a peak at linear polarisation are found and their implications are analysed in detail. Data on the fluid plasma velocity for the observation interval are not available and thus no unique conclusions about Doppler shift influence on the properties of the waves can be made. This determines the need to analyse different hypotheses in order to understand the origin of the waves. The plausibility of competing interpretations, such as off-resonance proton cyclotron waves and bi-ion cyclotron waves at the gyrofrequency of a heavy ion component of the magneto-tail plasma in the form of He ++ ions of solar wind origin is questioned.Key words. Space plasma physics (waves and instabilities) – Magnetospheric physics (plasma waves and instabilities; magnetotail