2,060 research outputs found

    PLECOPTERA OR STONEFLIES (INSECTA) OF INDIANA: DIVERSITY AND CONSERVATION STATUS OF SPECIES

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    Stoneflies (Plecoptera) are indicators of water quality and have been lost in dramatic numbers from Midwest states, including Indiana. This study synthesizes over 5,000 specimen level records from museums and recent fieldwork to build a current species list, assess watershed level species richness, and calculate state level conservation assessments using NatureServe’s Conservation Rank Calculator. Results include 1,050 positive occurrence records that yielded 92 species. Among these is one recently described species, a new species not yet described, and three previously described species new to Indiana. We have also found additional locations for rare species and confirmed the presence of a few species thought to be extirpated. United States Geological Survey Hierarchical Unit Code scale 6 (HUC6) drainages with the highest species richness values were the Patoka-White (73 species), Lower Ohio-Salt (60 species), and the Wabash River (57 species). The other seven drainages produced from five to 28 species, being limited by low gradient streams due to lake plain landscapes and by stream nutrient enrichment from agriculture. Eleven species were rated as extirpated or presumed extirpated, leaving 81 extant species. Of these, 17 were rated as critically imperiled (S1), 26 imperiled (S2), 25 vulnerable (S3), while only 13 species were rated as secure (S4 & S5). Watersheds and specific streams were discussed for their ability to support individual species or rich assemblages.Indianapolis Zoo funded via Indiana Department of Natural Resourcesunpublishednot peer reviewedOpe

    The DEEP2 Redshift Survey: Lyman Alpha Emitters in the Spectroscopic Database

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    We present the first results of a search for Lyman-alpha emitters (LAEs) in the DEEP2 spectroscopic database that uses a search technique that is different from but complementary to traditional narrowband imaging surveys. We have visually inspected ~20% of the available DEEP2 spectroscopic data and have found nine high-quality LAEs with clearly asymmetric line profiles and an additional ten objects of lower quality, some of which may also be LAEs. Our survey is most sensitive to LAEs at z=4.4-4.9 and that is indeed where all but one of our high-quality objects are found. We find the number density of our spectroscopically-discovered LAEs to be consistent with those found in narrowband imaging searches. The combined, averaged spectrum of our nine high-quality objects is well fit by a two-component model, with a second, lower-amplitude component redshifted by ~420 km/s with respect to the primary Lyman-alpha line, consistent with large-scale outflows from these objects. We conclude by discussing the advantages and future prospects of blank-sky spectroscopic surveys for high-z LAEs.Comment: Accepted for publication in Ap

    Population Stratification of a Common APOBEC Gene Deletion Polymorphism

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    The APOBEC3 gene family plays a role in innate cellular immunity inhibiting retroviral infection, hepatitis B virus propagation, and the retrotransposition of endogenous elements. We present a detailed sequence and population genetic analysis of a 29.5-kb common human deletion polymorphism that removes the APOBEC3B gene. We developed a PCR-based genotyping assay, characterized 1,277 human diversity samples, and found that the frequency of the deletion allele varies significantly among major continental groups (global F (ST) = 0.2843). The deletion is rare in Africans and Europeans (frequency of 0.9% and 6%), more common in East Asians and Amerindians (36.9% and 57.7%), and almost fixed in Oceanic populations (92.9%). Despite a worldwide frequency of 22.5%, analysis of data from the International HapMap Project reveals that no single existing tag single nucleotide polymorphism may serve as a surrogate for the deletion variant, emphasizing that without careful analysis its phenotypic impact may be overlooked in association studies. Application of haplotype-based tests for selection revealed potential pitfalls in the direct application of existing methods to the analysis of genomic structural variation. These data emphasize the importance of directly genotyping structural variation in association studies and of accurately resolving variant breakpoints before proceeding with more detailed population-genetic analysis

    Stellar Mass--Gas-phase Metallicity Relation at 0.5z0.70.5\leq z\leq0.7: A Power Law with Increasing Scatter toward the Low-mass Regime

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    We present the stellar mass (MM_{*})--gas-phase metallicity relation (MZR) and its scatter at intermediate redshifts (0.5z0.70.5\leq z\leq0.7) for 1381 field galaxies collected from deep spectroscopic surveys. The star formation rate (SFR) and color at a given MM_{*} of this magnitude-limited (R24R\lesssim24 AB) sample are representative of normal star-forming galaxies. For masses below 109M10^9 M_\odot, our sample of 237 galaxies is \sim10 times larger than those in previous studies beyond the local universe. This huge gain in sample size enables superior constraints on the MZR and its scatter in the low-mass regime. We find a power-law MZR at 108M<M<1011M10^{8} M_\odot < M_{*} < 10^{11} M_\odot: 12+log(O/H)=(5.83±0.19)+(0.30±0.02)log(M/M){12+log(O/H) = (5.83\pm0.19) + (0.30\pm0.02)log(M_{*}/M_\odot)}. Our MZR shows good agreement with others measured at similar redshifts in the literature in the intermediate and massive regimes, but is shallower than the extrapolation of the MZRs of others to masses below 109M10^{9} M_\odot. The SFR dependence of the MZR in our sample is weaker than that found for local galaxies (known as the Fundamental Metallicity Relation). Compared to a variety of theoretical models, the slope of our MZR for low-mass galaxies agrees well with predictions incorporating supernova energy-driven winds. Being robust against currently uncertain metallicity calibrations, the scatter of the MZR serves as a powerful diagnostic of the stochastic history of gas accretion, gas recycling, and star formation of low-mass galaxies. Our major result is that the scatter of our MZR increases as MM_{*} decreases. Our result implies that either the scatter of the baryonic accretion rate or the scatter of the MM_{*}--MhaloM_{halo} relation increases as MM_{*} decreases. Moreover, our measures of scatter at z=0.7z=0.7 appears consistent with that found for local galaxies.Comment: 18 pages, 10 figures. Accepted by ApJ. Typos correcte

    The DEEP2 Redshift Survey: Lyα Emitters in the Spectroscopic Database

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    We present the first results of a search for Lyα emitters (LAEs) in the DEEP2 spectroscopic database that uses a search technique that is different from but complementary to traditional narrowband imaging surveys. We have visually inspected ~20% of the available DEEP2 spectroscopic data and have found nine high-quality LAEs with clearly asymmetric line profiles and an additional 10 objects of lower quality, some of which may also be LAEs. Our survey is most sensitive to LAEs at z = 4.4–4.9 and that is indeed where all but one of our high-quality objects are found. We find the number density of our spectroscopically discovered LAEs to be consistent with those found in narrowband imaging searches. The combined, averaged spectrum of our nine high-quality objects is well fit by a two-component model, with a second, lower amplitude component redshifted by ~420 km s^(−1) with respect to the primary Lyα line, consistent with large-scale outflows from these objects. We conclude by discussing the advantages and future prospects of blank-sky spectroscopic surveys for high-z LAEs

    Investigation of False Positive Results with an Oral Fluid Rapid HIV-1/2 Antibody Test

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    BACKGROUND: In March 2004, the OraQuick® rapid HIV antibody test became the first rapid HIV test approved by the US Food and Drug Administration for use on oral fluid specimens. Test results are available in 20 minutes, and the oral fluid test is non-invasive. From August 2004–June 2005, we investigated a sudden increase in false-positive results occurring in a performance study of OraQuick® oral-fluid rapid HIV tests in Minnesota. METHODOLOGY/PRINCIPAL FINDINGS: In a field investigation, we reviewed performance study data on oral-fluid and whole-blood OraQuick® rapid HIV test device lots and expiration dates and assessed test performance and interpretation with oral-fluid and whole-blood specimens by operators who reported false-positive results. We used multivariate logistic regression to evaluate client demographic and risk characteristics associated with false-positive results. Next, we conducted an incidence study of false-positive OraQuick rapid HIV tests in nine US cities and tested both oral-fluid and finger-stick whole-blood specimens from clients; reactive tests were confirmed with Western blot. Sixteen (4.1%) false-positive oral-fluid results occurred in the performance study from April 15, 2004 through August 31, 2004 with unexpired devices from six test lots among 388 HIV-uninfected clients (specificity, 95.9%; 95% CI: 93.4–97.6). Three test operators who had reported false-positive results performed and interpreted the test according to package-insert instructions. In multivariate analysis, only older age was significantly associated with false-positive results (adjusted odds ratio = 4.5, 95% CI: 1.2–25.7). In the incidence study, all valid oral-fluid and whole-blood results from 2,268 clients were concordant and no false-positive results occurred (100% specificity). CONCLUSIONS/SIGNIFICANCE: The field investigation did not identify a cause for the increase in false-positive oral-fluid results, and the incidence study detected no false-positive results. The findings suggest this was an isolated cluster; the test's overall performance was as specified by the manufacturer

    Health and function of participants in the Long Life Family Study: A comparison with other cohorts

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    Individuals from families recruited for the Long Life Family Study (LLFS) (n= 4559) were examined and compared to individuals from other cohorts to determine whether the recruitment targeting longevity resulted in a cohort of individuals with better health and function. Other cohorts with similar data included the Cardiovascular Health Study, the Framingham Heart Study, and the New England Centenarian Study. Diabetes, chronic pulmonary disease and peripheral artery disease tended to be less common in LLFS probands and offspring compared to similar aged persons in the other cohorts. Pulse pressure and triglycerides were lower, high density lipids were higher, and a perceptual speed task and gait speed were better in LLFS. Age-specific comparisons showed differences that would be consistent with a higher peak, later onset of decline or slower rate of change across age in LLFS participants. These findings suggest several priority phenotypes for inclusion in future genetic analysis to identify loci contributing to exceptional survival

    The DEEP2 Galaxy Redshift Survey: Design, Observations, Data Reduction, and Redshifts

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    We describe the design and data sample from the DEEP2 Galaxy Redshift Survey, the densest and largest precision-redshift survey of galaxies at z ~ 1 completed to date. The survey has conducted a comprehensive census of massive galaxies, their properties, environments, and large-scale structure down to absolute magnitude M_B = -20 at z ~ 1 via ~90 nights of observation on the DEIMOS spectrograph at Keck Observatory. DEEP2 covers an area of 2.8 deg^2 divided into four separate fields, observed to a limiting apparent magnitude of R_AB=24.1. Objects with z < 0.7 are rejected based on BRI photometry in three of the four DEEP2 fields, allowing galaxies with z > 0.7 to be targeted ~2.5 times more efficiently than in a purely magnitude-limited sample. Approximately sixty percent of eligible targets are chosen for spectroscopy, yielding nearly 53,000 spectra and more than 38,000 reliable redshift measurements. Most of the targets which fail to yield secure redshifts are blue objects that lie beyond z ~ 1.45. The DEIMOS 1200-line/mm grating used for the survey delivers high spectral resolution (R~6000), accurate and secure redshifts, and unique internal kinematic information. Extensive ancillary data are available in the DEEP2 fields, particularly in the Extended Groth Strip, which has evolved into one of the richest multiwavelength regions on the sky. DEEP2 surpasses other deep precision-redshift surveys at z ~ 1 in terms of galaxy numbers, redshift accuracy, sample number density, and amount of spectral information. We also provide an overview of the scientific highlights of the DEEP2 survey thus far. This paper is intended as a handbook for users of the DEEP2 Data Release 4, which includes all DEEP2 spectra and redshifts, as well as for the publicly-available DEEP2 DEIMOS data reduction pipelines. [Abridged]Comment: submitted to ApJS; data products available for download at http://deep.berkeley.edu/DR4

    The JWST Resolved Stellar Populations Early Release Science Program I.: NIRCam Flux Calibration

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    We use globular cluster data from the Resolved Stellar Populations Early Release Science (ERS) program to validate the flux calibration for the Near Infrared Camera (NIRCam) on the James Webb Space Telescope (JWST). We find a significant flux offset between the eight short wavelength detectors, ranging from 1-23% (about 0.01-0.2 mag) that affects all NIRCam imaging observations. We deliver improved zeropoints for the ERS filters and show that alternate zeropoints derived by the community also improve the calibration significantly. We also find that the detector offsets appear to be time variable by up to at least 0.1 mag.Comment: Accepted for publication in RNAA
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