67 research outputs found
Potential changes in larval dispersal and alongshore connectivity on the central Chilean coast due to an altered wind climate
14 pages, 8 figuresClimate change is likely to result in significant alterations in the atmospheric and oceanic circulation, which may, as a result, affect species that depend on an ocean-driven nutrient supply and particularly those that possess a dispersal phase in their life history. In this paper we investigate the potential changes in larval dispersal and connectivity of marine populations on the Chilean coast due to altered wind forcing consistent with a future climate change scenario. Numerical ocean simulations forced by modeled present-day and future winds under the Intergovernmental Panel on Climate Change A2 scenario are used to investigate the potential changes in nearshore circulation. Off-line particle-tracking simulations are then analyzed to determine resulting changes in larval dispersal and connectivity under each scenario as a function of pelagic larval duration and for two different possible larval behaviors: passive and vertical migration. It is found that the projected future winds drive an intensification of the upwelling circulation, which results in a relative annual mean surface cooling of 1°C over much of the domain, an increase in the strength of the poleward undercurrent, and a more energetic mesoscale eddy field. Neutrally buoyant larvae are inferred to have low rates of settlement under present conditions and are more strongly disadvantaged under the simulated future conditions than larvae with vertically migrating behavior. Larvae that posses an ability to sink out of the surface Ekman layer are found to have higher rates of settlement under present conditions and are, in fact, favored slightly in the A2 scenario for pelagic larval durations longer than 2 days. This behavior-dependent response to future conditions may potentially drive a reorganization of coastal communitiesSupport for this study was provided through the Laboratorio Internacional en Cambio Global (LINCGlobal) and CMA through Fondecyt grant 1100646. We thank Rene Garreaud from the Universidad de Chile for providing the output from the PRECIS model simulations and for his useful comments. The authors thankfully acknowledge the computer resources, technical expertise, and assistance provided by the Barcelona Supercomputing Center. S.A.N. acknowledges support by FONDAP-FONDECYT grant 15001–0001 to CASEBPeer Reviewe
Effect of consuming endophyte-infected fescue seed on transcript abundance in the mammary gland of lactating and dry cows, as assessed by RNA sequencing
Ergot alkaloids in endophyte-infected grasses inhibit prolactin secretion and reduce milk production in lactating cows. However, we previously showed that prepartum consumption of infected seed throughout the dry period did not inhibit subsequent milk production and prior exposure to bromocriptine (ergot peptide) actually increased production in the next lactation. To identify changes in the transcriptome and molecular pathways mediating the mammary gland's response to ergot alkaloids in the diet, RNA sequencing (RNA-seq) was performed on mammary tissues obtained from 22 multiparous Holstein cows exposed to 1 of 3 treatments. Starting at 90 ± 4 d prepartum, cows were fed endophyte-free fescue seed (control; CON), endophyte-free fescue seed plus 3×/wk subcutaneous injections of bromocriptine (BROMO; 0.1 mg/kg of BW), or endophyte-infected fescue seed (INF) as 10% of the diet. Cows were dried off 60 ± 2 d prepartum. Mammary biopsies from 4 (BROMO, INF) or 5 (CON) cows/treatment at each of the 3 phases were obtained: 7 d before dry off during the initial lactation (L1), mid-dry period (D), and 10 d postpartum (L2). Although tissue from the same cow was preferentially used at 3 phases (L1, D, L2), tissue from additional cows were used to as necessary to provide RNA of sufficient quality. Individual samples were used to generate individual RNA-seq libraries. Normalized reads of the RNA-seq data were organized into technical and biological replicates before processing with the RSEM software package. Each lactation phase was processed separately and genes that differed between any of 3 treatments were identified. A large proportion of genes differentially expressed in at least 1 treatment (n = 866) were found to be similarly expressed in BROMO and INF treatments, but differentially expressed from CON (n = 575, total for 3 phases). Of genes differentially expressed compared with CON, 104 genes were common to the L1 and L2 phases. Consistent with the production findings, networks most affected by treatments in L1 and L2 included lipid metabolism, small molecule biochemistry, and molecular transport, whereas networks related more to developmental and cellular functions and maintenance were evident during D phase. Similar patterns of expression in BROMO and INF during late and early lactation suggest involvement of similar cell signaling pathways or mechanisms of action for BROMO and INF and the importance of prolactin messaging pathways
Consumption of endophyte-infected fescue seed during the dry period does not decrease milk production in the following lactation.
Ergot alkaloids in endophyte-infected grasses inhibit prolactin (PRL) secretion and may reduce milk production of cows consuming these grasses. We investigated the effects of consuming endophyte-infected fescue seed during late lactation and the dry period on mammary growth, differentiation, and milk production. Twenty-four multiparous Holstein cows were randomly assigned to 3 treatment groups. Starting at 90±4 d prepartum, cows were fed endophyte-free fescue seed (control; CON), endophyte-free fescue seed plus 3×/wk subcutaneous injections of bromocriptine (0.1mg/kg of body weight, positive control; BROMO), or endophyte-infected fescue seed (INF) as 10% of the diet on an as fed basis. Although milk yield of groups did not differ before treatment, at dry off (-60 d prepartum) INF and BROMO cows produced less milk than CON. Throughout the treatment period, basal concentrations of PRL and the prepartum increase in plasma PRL were reduced in INF and BROMO cows compared with CON cows. Three weeks after the end of treatment, circulating concentrations of PRL were equivalent across groups. In the subsequent lactation milk yield was not decreased; in fact, BROMO cows exhibited a 9% increase in milk yield relative to CON. Evaluation of mammary tissue during the dry period and the subsequent lactation, by quantitative histology and immunohistochemical analysis of proliferation markers and putative mammary stem or progenitor cell markers, indicated that feeding endophyte-infected fescue seed did not significantly affect mammary growth and development. Feeding endophyte-infected grasses during the dry period may permit effective utilization of feed resources without compromising milk production in the next lactation
Perceived and Actual Breast Cancer Risk
Perceived risk can influence health behaviors. Studies using various populations and breast cancer risk bias assessment methods have identified both risk over- and underestimation. Among 1803 women in primary care settings, 47 percent were at average epidemiologic risk (Gail-calculated relative risk ±50 percent of age-adjusted population average) and 55 percent perceived themselves to be at average risk (compared to same-age others) but there were mismatches or ‘biases’: 31 percent underestimated personal risk; 26 percent overestimated. Multiple logistic regression revealed that smokers were more likely to overestimate risk. Overestimation decreased with more education. Mammography use did not independently predict perception bias but, among never-screened women aged over 40 years, those contemplating mammograms were most likely to overestimate risk; precontemplators were most likely to underestimate. Implications for research and intervention are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66881/2/10.1177_135910539800300203.pd
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Spectroscopic probes of the structure of hydrous uranium oxide precursors to UO sub 2 ceramic fuel
Fourier Transform infrared spectroscopy, x-ray powder diffraction and thermal analysis show that one example of ammonium diuranate'' observed as an intermediate in the U(VI) sol-gel process is a layered hydrous uranium oxide with a proposed structural formula of (NH){sub 4}{sub 2}((UO{sub 2}){sub 8}O{sub 4}(OH){sub 10}){center dot}8H{sub 2}O, an ammonium ion intercalate. Examples of polyamine intercalation compounds hydrous uranium oxide are also given
Reef fishes captured by recreational spearfishing on reefs of Bahia State, northeast Brazil
Forage Yield and Nutritive Value of Turf Bermudagrasses Managed to Simulate a Horse Pasture Management Scheme in the U.S. Upper Transition Zone
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Comprehensive strategy for corrective actions at the Savannah River Site General Separations Area
The Savannah River Site (SRS), operated by the Westinghouse Savannah River Company for the United States Department of Energy, contains a number of waste disposal units that are currently in various stages of corrective action investigations, closures, and postclosure corrective actions. Many of these sites are located within a 40-square-kilometer area called the General Separations Area (GSA). The SRS has proposed to the regulatory agencies, the United States Environmental Protection Agency (EPA) and the South Carolina Department of Health and Environmental Control (SCDHEC), that groundwater investigations and corrective actions in this area be conducted under a comprehensive plan. The proposed plan would address the continuous nature of the hydrogeologic regime below the GSA and the potential for multiple sources of contamination. This paper describes the proposed approach
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A ground water flow model for the A/M Area of the SRS
In 1984 and 1985, a quasi three-dimensional groundwater flow model was developed for the A/M Area (Savannah River Laboratory Complex) of the Savannah River Site to assist in the design of a groundwater recovery well network to remediate groundwater contaminated with chlorinated hydrocarbon solvents. In 1986, the existing groundwater flow model was used to evaluate the effectiveness of groundwater remediation systems. Since the original model was developed, additional monitoring wells have been installed, the understanding of the hydrogeologic system has improved and the horizontal and vertical extent of the contamination in the groundwater systems has been better defined. The objective of this study is to update and improve the existing A/M Area groundwater flow model by incorporating recent hydrologic information. The new model is calibrated to 1989--1990 groundwater levels and surface water flows. The model area is approximately 31 square miles and encompasses a manufacturing and processing area designated the A/M Area, a previous waste effluent disposal basin and overflow to a natural depression (Lost Lake), and several surface water features. The simulations are run on 80386-based personal computer using the public-domain groundwater flow code MODFLOW. This calibrated coarse-grid model is a base model. Specific areas of interest can be further discritized to provide more detailed and accurate water level elevations for use in particle tracking and capture analysis. The particle tracking and capture analysis are used to evaluate the groundwater contamination capture and removal capacity of proposed recovery wells
Prolonged Grief, Autobiographical Memory, and Its Interaction With Value Orientations in China and Switzerland
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