406 research outputs found

    Larval food limitation in a speyeria butterfly (Nymphalidae): How many butterflies can be supported?

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    For herbivorous insects the importance of larval food plants is obvious, yet the role of host abundance and density in conservation are relatively understudied. Populations of Speyeria butterflies across North America have declined and Speyeria adiaste is an imperiled species endemic to the southern California Coast Ranges. In this paper, we study the link between the food plant Viola purpurea quercetorum and abundance of its herbivore Speyeria adiaste clemencei to better understand the butterfly’s decline and aid in restoration of this and other Speyeria species. To assess the degree to which the larval food plant limits adult abundance of S. a. clemencei in 2013, we compared adult population counts to population size predicted from a Monte Carlo simulation using data for number of V. pur. quercetorum plants, number of leaves per plant, and leaf area per plant, with lab estimates of leaf area consumed to reach pupal stage on the non-native host V. papilionacea. Results indicated an average estimate of 765 pupae (median = 478), with 77% of the distribution being \u3c1000 pupae. However, this was heavily dependent on plant distribution, and accounting for the number of transect segments with sufficient host to support a pupa predicted 371 pupae. The adult population empirical estimate was 227 individuals (95% CI is 146 to 392), which lies near the first quartile of the simulated distribution. These results indicate that the amount of host available to larvae was more closely linked to adult abundance than the amount of host present, especially when considering assumptions of the analyses. The data also indicate that robust populations require host density well in excess of what is eaten by larvae, in combination with appropriate spacing, to mitigate factors such as competition, starvation from leaving host patches, or unrelated to food plant, such as mortality from drought, predators, parasites, or disease

    Effects of calcium channel blockers on coronary vasoconstriction induced by endothelin-1 in closed chest pigs

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    AbstractThe purpose of this study was to determine the effects of endothelin-1 on the coronary vascular bed of closed chest pigs. Endothelin-1 (3 to 30 pmol/kg body weight) was selectively administered into the left anterior descending coronary artery. Coronary blood flow and epicardial vessel diameter were measured by quantitative arteriography. Arterial pressure increased after a 30 pmol/kg dose and heart rate was not changed.Coronary blood flow and vessel diameter of the left anterior descending artery significantly decreased by 74% and 32%, respectively (p < 0.01 versus control) after the 30 pmol/kg dose, whereas these variables modestly decreased in the left circumflex artery. Endothelin-1 in doses of 10 to 30 pmol/kg produced electrocardiographic ST segment elevation associated with decreased oxygen saturation of coronary sinus venous blood. Endothelin-induced coronary vasoconstriction was significantly inhibited after treatment with intravenous diltiazem (0.2 mg/kg, n = 6) or nifedipine (0.1 mg/kg, n = 5), but not after vehicle administration (n = 4).This study demonstrates that intracoronary administration of endothelin-1 causes significant myocardial ischemia through coronary vasoconstriction, which is inhibited by a calcium channel blocker. The data suggest that calcium influx into the smooth muscle cells appears to be involved at least in part in the mechanism of endothelin-induced coronary vasoconstriction in vivo

    Specifying Disclosure Protection Rules for Reporting Results from Restricted-use Data

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    https://deepblue.lib.umich.edu/bitstream/2027.42/154770/1/Specifiying-Disclosure-Rules.pdfDescription of Specifiying-Disclosure-Rules.pdf : Poste

    Validation and preliminary data from a health-related quality of life questionnaire for owners of dogs with cardiac disease

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    BACKGROUND: Cardiac disease in dogs impacts the quality of life (QoL) of their owners, but owners\u27 QoL has not been comprehensively assessed in this population. OBJECTIVES: To develop, validate, and provide preliminary data from a health-related QoL (hrQoL) questionnaire for owners of dogs with cardiac disease. SUBJECTS: A total of 141 owners of dogs with cardiac disease were studied. METHODS: An owner hrQoL (O-hrQoL) questionnaire containing 20 items related to areas of a person\u27s life that could be impacted by caring for a dog with cardiac disease was developed and administered to owners of dogs with cardiac disease. The highest possible total score was 100, with higher scores indicating a worse hrQoL. Readability, internal consistency, face and construct validity, and item-total correlations were assessed. RESULTS: Median O-hrQoL score was 35 (range, 0-87). The questionnaire had good internal consistency (Cronbach\u27s alpha = 0.933), construct validity (Spearman\u27s r = 0.38-0.53; Kendall\u27s tau = 0.30-0.43; P \u3c .001), and item-total correlation (Spearman\u27s r = 0.44-0.79; Kendall\u27s tau = 0.34-0.66; all P \u3c .001). Fifty percent of owners indicated a negative effect of dogs\u27 cardiac disease on their own QoL, but all owners responded that caring for their dogs either had strengthened (n = 76; 53.9%) or had no effect on their relationship with their dog (n = 65; 46.1%). CONCLUSIONS AND CLINICAL IMPORTANCE: The O-hrQoL questionnaire had good validity, and results suggest that owners\u27 QoL is significantly impacted by caring for dogs with cardiac disease. Additional research on effective approaches to minimizing the negative effects of a dog\u27s cardiac disease on the owner is warranted

    Effect of type of diet on blood and plasma taurine concentrations, cardiac biomarkers, and echocardiograms in 4 dog breeds

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    BACKGROUND: Associations of diet with dilated cardiomyopathy are under investigation. OBJECTIVES: That cardiac assessment would show abnormalities in healthy dogs eating grain-free (GF) diets or diets with Food and Drug Administration (FDA)-listed ingredients of concern (peas, lentils, or potatoes) as top 10 ingredients (FDA-PLP), but not in dogs eating grain-inclusive (GI) diets or diets without FDA-listed ingredients of concern (PLP) in the top 10 ingredients (NoFDA-PLP). ANIMALS: One hundred eighty-eight healthy Doberman Pinschers, Golden Retrievers, Miniature Schnauzers, and Whippets. METHODS: This study was an observational cross-sectional study. Echocardiograms, cardiac biomarkers, and blood and plasma taurine concentrations were compared between dogs eating GF (n = 26) and GI (n = 162) diets, and between FDA-PLP (n = 39) and NoFDA-PLP (n = 149) diets, controlling for age and breed. Demographic characteristics, murmurs, genetic status, and ventricular premature complexes (VPCs) during examination were compared between dogs eating different diet types. RESULTS: No differences in echocardiographic variables, N-terminal pro-B-type natriuretic peptide or whole blood taurine were noted between dogs eating different diet types. Dogs eating GF diets had higher median high-sensitivity cardiac troponin I (hs-cTnI) (GF 0.076 ng/mL [Interquartile range (IQR), 0.028-0.156] vs. GI 0.048 [IQR, 0.0026-0.080]; P \u3c .001) and higher median plasma taurine (GF 125 nmol/mL [IQR, 101-148] vs GI 104 [IQR, 86-123]; P = .02) than dogs eating GI diets. Dogs eating FDA-PLP diets had higher median hs-cTnI (0.059 ng/mL [IQR, 0.028-0.122]) than dogs eating NoFDA-PLP diets (0.048 [IQR, 0.025-0.085]; P = .006). A greater proportion of dogs eating FDA-PLP diets (10%) had VPCs than dogs eating NoFDA-PLP diets (2%; P = .04). CONCLUSIONS AND CLINICAL IMPORTANCE: Higher hs-cTnI in healthy dogs eating GF and FDA-PLP diets might indicate low-level cardiomyocyte injury

    Relationships of Race and Socioeconomic Status to Postpartum Depressive Symptoms in Rural African American and Non-Hispanic White Women

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    This study examines the potential racial disparity in postpartum depression (PPD) symptoms among a cohort of non-Hispanic white and African American women after taking into consideration the influence of socioeconomic status (SES). Participants (N = 299) were recruited from maternity clinics serving rural counties, with over-sampling of low SES and African Americans. The Edinburgh Postnatal Depression Scale (EPDS) was administered 1 and 6 months postpartum, and subjective SES scale at 6 months postpartum. Demographic information was collected during enrollment and 1 month postpartum, with updates at 6 months postpartum. Separate logistic regressions were conducted for 1 and 6 month time points for minor-major PPD (EPDS ≥ 10) and major PPD (EPDS > 12); with marital status, poverty, education, subjective SES, and race predictors entered in block sequence. After including all other predictors, race was not a significant predictor of minor-major or major PPD at 1 or 6 months postpartum. Subjective SES was the most consistent predictor of PPD, being significantly associated with minor-major PPD and major PPD at 6 months postpartum, with higher subjective SES indicating lower odds of PPD, even after accounting for all other predictors. This study shows that significant racial disparities were not observed for minor-major or major PPD criteria at 1 or 6 months postpartum. The most consistent and significant predictor of PPD was subjective SES. Implications of these findings for future research, as well as PPD screening and intervention are discussed
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