255 research outputs found

    Toward integrated conservation of North America's crop wild relatives

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    North America harbors a rich native flora of crop wild relatives—the progenitors and closely related species of domesticated plants—as well as a range of culturally significant wild utilized plants. Despite their current and potential future value, they are rarely prioritized for conservation efforts; thus many species are threatened in their natural habitats, and most are underrepresented in plant genebanks and botanical gardens. Further coordination of efforts among land management, botanical, and agricultural science organizations will improve conservation and general public awareness with regard to these species. We present examples of productive collaborations focused on wild cranberries (Vaccinium macrocarpon and Vaccinium oxycoccos) and chile peppers (Capsicum annuum var. glabriusculum). We then discuss five shared priorities for further action: (1) understand and document North America's crop wild relatives and wild utilized plants, (2) protect threatened species in their natural habitats, (3) collect and conserve ex situ the diversity of prioritized species, (4) make this diversity accessible and attractive for plant breeding, research, and education, and (5) raise public awareness of their value and the threats to their persistence

    The Host Galaxy and Central Engine of the Dwarf AGN POX 52

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    We present new multi-wavelength observations of the dwarf Seyfert 1 galaxy POX 52 in order to investigate the properties of the host galaxy and the active nucleus, and to examine the mass of its black hole, previously estimated to be ~ 10^5 M_sun. Hubble Space Telescope ACS/HRC images show that the host galaxy has a dwarf elliptical morphology (M_I = -18.4 mag, Sersic index n = 4.3) with no detected disk component or spiral structure, confirming previous results from ground-based imaging. X-ray observations from both Chandra and XMM show strong (factor of 2) variability over timescales as short as 500 s, as well as a dramatic decrease in the absorbing column density over a 9 month period. We attribute this change to a partial covering absorber, with a 94% covering fraction and N_H = 58^{+8.4}_{-9.2} * 10^21 cm^-2, that moved out of the line of sight in between the XMM and Chandra observations. Combining these data with observations from the VLA, Spitzer, and archival data from 2MASS and GALEX, we examine the spectral energy distribution (SED) of the active nucleus. Its shape is broadly similar to typical radio-quiet quasar SEDs, despite the very low bolometric luminosity of L_bol = 1.3 * 10^43 ergs/s. Finally, we compare black hole mass estimators including methods based on X-ray variability, and optical scaling relations using the broad H-beta line width and AGN continuum luminosity, finding a range of black hole mass from all methods to be M_bh = (2.2-4.2) * 10^5 M_sun, with an Eddington ratio of L_bol/L_edd = 0.2-0.5.Comment: 19 pages, 16 figures, accepted for publication in Ap

    The Lick AGN Monitoring Project: Alternate Routes to a Broad-line Region Radius

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    It is now possible to estimate black hole masses across cosmic time, using broad emission lines in active galaxies. This technique informs our views of how galaxies and their central black holes coevolve. Unfortunately, there are many outstanding uncertainties associated with these "virial" mass estimates. One of these comes from using the accretion luminosity to infer a size for the broad-line region. Incorporating the new sample of low-luminosity active galaxies from our recent monitoring campaign at Lick Observatory, we recalibrate the radius-luminosity relation with tracers of the accretion luminosity other than the optical continuum. We find that the radius of the broad-line region scales as the square root of the X-ray and Hbeta luminosities, in agreement with recent optical studies. On the other hand, the scaling appears to be marginally steeper with narrow-line luminosities. This is consistent with a previously observed decrease in the ratio of narrow-line to X-ray luminosity with increasing total luminosity. The radius of the broad-line region correlates most tightly with Hbeta luminosity, while the X-ray and narrow-line relations both have comparable scatter of a factor of two. These correlations provide useful alternative virial BH masses in objects with no detectable optical/UV continuum emission, such as high-redshift galaxies with broad emission lines, radio-loud objects, or local active galaxies with galaxy-dominated continua.Comment: 8 pages, 1 figure, accepted for publication in Ap

    Concordance of Self-Report and Measured Height and Weight of College Students

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    Objective: This study examined associations between college students\u27 self-report and measured height and weight. Methods: Participants (N = 1,686) were 77% white, 62% female, aged 18–24 years (mean ± SD, 19.1 ± 1.1 years), and enrolled at 8 US universities. Body mass index (BMI) was calculated for self-report (via online survey); trained researchers measured height and weight and categorized them as normal (18.5 to \u3c 25), overweight (25 to \u3c 30), obese (30 to \u3c 35), and morbidly obese (≥ 35). Results: Concordance of self-report vs objectively measured BMI groups using chi-square revealed that 93% were accurate, 4% were underestimated, and 2.7% were overestimated. Pearson correlations and adjusted linear regression revealed significant associations between self-report and measured BMI (r = .97; P \u3c .001) and BMI adjusted for age, gender, and race/ethnicity (R2 = .94). Concordance was also high between BMI categories (kappa = 0.77; P \u3c .001). Conclusions and Implications: Findings provide support for the utility of self-report height and weight for survey research in college students

    Glycemic Control and Effects of Canagliflozin in Reducing Albuminuria and eGFR:A Post Hoc Analysis of the CREDENCE Trial

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    BACKGROUND: In the Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) trial, the sodium-glucose cotransporter-2 (SGLT2) inhibitor canagliflozin improved kidney and cardiovascular outcomes and reduced the rate of estimated glomerular filtration decline (eGFR slope) in patients with type 2 diabetes and CKD. In other clinical trials of patients with CKD or heart failure, the protective effects of SGLT2 inhibitors on eGFR slope were greater in participants with versus participants without type 2 diabetes. This post hoc analysis of the CREDENCE trial assessed whether the effects of canagliflozin on eGFR slope varied according to patient subgroups by baseline glycated hemoglobin A1c (HbA1c).METHODS: CREDENCE ( ClinicalTrials.gov [ NCT02065791 ]) was a randomized controlled trial in adults with type 2 diabetes with an HbA1c of 6.5%-12.0%, an eGFR of 30-90 ml/min per 1.73 m 2 , and a urinary albumin-to-creatinine ratio of 300-5000 mg/g. Participants were randomly assigned to canagliflozin 100 mg once daily or placebo. We studied the effect of canagliflozin on eGFR slope using linear mixed-effects models.RESULTS: The annual difference in total eGFR slope was 1.52 ml/min per 1.73 m 2 (95% confidence interval [CI], 1.11 to 1.93) slower in participants randomized to canagliflozin compared with placebo. The rate of eGFR decline was faster in those with poorer baseline glycemic control. The mean difference in total eGFR slope between canagliflozin and placebo was greater in participants with poorer baseline glycemic control (difference in eGFR slope of 0.39, 1.36, 2.60, 1.63 ml/min per 1.73 m 2 for HbA1c subgroups 6.5%-7.0%, 7.0%-8.0%, 8.0%-10.0%, 10.0%-12.0%, respectively; Pinteraction = 0.010). The mean difference in change from baseline in urinary albumin-to-creatinine ratio between participants randomized to canagliflozin and placebo was smaller in patients with baseline HbA1c 6.5%-7.0% (-17% [95% CI, -28 to -5]) compared with those with an HbA1c of 7.0%-12% (-32% [95% CI, -40 to -28]; Pinteraction = 0.03).CONCLUSIONS: The effect of canagliflozin on eGFR slope in patients with type 2 diabetes and CKD was more pronounced in patients with higher baseline HbA1c, partly because of the more rapid decline in kidney function in these individuals.CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Evaluation of the Effects of Canagliflozin on Renal and Cardiovascular Outcomes in Participants With Diabetic Nephropathy (CREDENCE), NCT02065791.</p

    The Lick AGN Monitoring Project: Reverberation Mapping of Optical Hydrogen and Helium Recombination Lines

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    We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z < 0.05) Seyfert 1 galaxies with expected masses in the range ~10^6-10^7M_sun and also the well-studied nearby active galactic nucleus (AGN) NGC 5548. Nine of the objects in the sample (including NGC 5548) showed optical variability of sufficient strength during the monitoring campaign to allow for a time lag to be measured between the continuum fluctuations and the response to these fluctuations in the broad Hbeta emission, which we have previously reported. We present here the light curves for the Halpha, Hgamma, HeII 4686, and HeI 5876 emission lines and the time lags for the emission-line responses relative to changes in the continuum flux. Combining each emission-line time lag with the measured width of the line in the variable part of the spectrum, we determine a virial mass of the central supermassive black hole from several independent emission lines. We find that the masses are generally consistent within the uncertainties. The time-lag response as a function of velocity across the Balmer line profiles is examined for six of the AGNs. Finally we compare several trends seen in the dataset against the predictions from photoionization calculations as presented by Korista & Goad. We confirm several of their predictions, including an increase in responsivity and a decrease in the mean time lag as the excitation and ionization level for the species increases. Further confirmation of photoionization predictions for broad-line gas behavior will require additional monitoring programs for these AGNs while they are in different luminosity states. [abridged]Comment: 37 pages, 18 figures and 15 tables, accepted for publication in the Astrophysical Journa

    Early Change in Albuminuria with Canagliflozin Predicts Kidney and Cardiovascular Outcomes:A Post Hoc Analysis from the CREDENCE Trial

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    Background The association between early changes in albuminuria and kidney and cardiovascular events is primarily based on trials of renin-angiotensin system blockade. It is unclear whether this association occurs with sodium-glucose cotransporter 2 inhibition. Methods TheCanagliflozin and Renal Events inDiabeteswith EstablishedNephropathy Clinical Evaluation (CREDENCE) trial enrolled 4401 patients with type 2 diabetes and CKD (urinary albumin-creatinine ratio [UACR].300 mg/g). This post hoc analysis assessed canagliflozin's effect on albuminuria and how early change in albuminuria (baseline to week 26) is associated with the primary kidney outcome (ESKD, doubling of serum creatinine, or kidney death), major adverse cardiovascular events, and hospitalization for heart failure or cardiovascular death. Results Complete data for early change in albuminuria and other covariates were available for 3836 (87.2%) participants in the CREDENCE trial. Compared with placebo, canagliflozin lowered UACR by 31% (95% confidence interval [95% CI], 27% to 36%) at week 26, and significantly increased the likelihood of achieving a 30% reduction in UACR ( odds ratio, 2.69; 95% CI, 2.35 to 3.07). Each 30% decrease in UACR over the first 26 weeks was independently associated with a lower hazard for the primary kidney outcome (hazard ratio [HR], 0.71; 95% CI, 0.67 to 0.76; P,0.001), major adverse cardiovascular events (HR, 0.92; 95% CI, 0.88 to 0.96; P,0.001), and hospitalization for heart failure or cardiovascular death (HR, 0.86; 95% CI, 0.81 to 0.90; P,0.001). Residual albuminuria levels at week 26 remained a strong independent risk factor for kidney and cardiovascular events, overall and in each treatment arm. Conclusions In people with type 2 diabetes and CKD, use of canagliflozin results in early, sustained reductions in albuminuria, which were independently associated with long-term kidney and cardiovascular outcomes

    The Lick AGN Monitoring Project: Broad-Line Region Radii and Black Hole Masses from Reverberation Mapping of Hbeta

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    We have recently completed a 64-night spectroscopic monitoring campaign at the Lick Observatory 3-m Shane telescope with the aim of measuring the masses of the black holes in 12 nearby (z < 0.05) Seyfert 1 galaxies with expected masses in the range ~10^6-10^7 M_sun and also the well-studied nearby active galactic nucleus (AGN) NGC 5548. Nine of the objects in the sample (including NGC 5548) showed optical variability of sufficient strength during the monitoring campaign to allow for a time lag to be measured between the continuum fluctuations and the response to these fluctuations in the broad Hbeta emission. We present here the light curves for the objects in this sample and the subsequent Hbeta time lags for the nine objects where these measurements were possible. The Hbeta lag time is directly related to the size of the broad-line region, and by combining the lag time with the measured width of the Hbeta emission line in the variable part of the spectrum, we determine the virial mass of the central supermassive black hole in these nine AGNs. The absolute calibration of the black hole masses is based on the normalization derived by Onken et al. We also examine the time lag response as a function of velocity across the Hbeta line profile for six of the AGNs. The analysis of four leads to ambiguous results with relatively flat time lags as a function of velocity. However, SBS 1116+583A exhibits a symmetric time lag response around the line center reminiscent of simple models for circularly orbiting broad-line region (BLR) clouds, and Arp 151 shows an asymmetric profile that is most easily explained by a simple gravitational infall model. Further investigation will be necessary to fully understand the constraints placed on physical models of the BLR by the velocity-resolved response in these objects.Comment: 24 pages, 16 figures and 13 tables, submitted to Ap

    Genetic Studies of a Cluster of Acute Lymphoblastic Leukemia Cases in Churchill County, Nevada

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    OBJECTIVE: In a study to identify exposures associated with 15 cases of childhood leukemia, we found levels of tungsten, arsenic, and dichlorodiphenyldichloroethylene in participants to be higher than mean values reported in the National Report on Human Exposure to Environmental Chemicals. Because case and comparison families had similar levels of these contaminants, we conducted genetic studies to identify gene polymorphisms that might have made case children more susceptible than comparison children to effects of the exposures. DESIGN: We compared case with comparison children to determine whether differences existed in the frequency of polymorphic genes, including genes that code for enzymes in the folate and purine pathways. We also included discovery of polymorphic forms of genes that code for enzymes that are inhibited by tungsten: xanthine dehydrogenase, sulfite oxidase (SUOX gene), and aldehyde oxidase. PARTICIPANTS: Eleven case children were age- and sex-matched with 42 community comparison children for genetic analyses. Twenty parents of case children also contributed to the analyses. RESULTS: One bilalleleic gene locus in SUOX was significantly associated with either case or comparison status, depending on which alleles the child carried (without adjusting for multiple comparisons). CONCLUSIONS: Although genetic studies did not provide evidence that a common agent or genetic susceptibility factor caused the leukemias, the association between a SUOX gene locus and disease status in the presence of high tungsten and arsenic levels warrants further investigation. RELEVANCE: Although analyses of community clusters of cancer have rarely identified causes, these findings have generated hypotheses to be tested in subsequent studies
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