Structural Investigation of the Odessa Meteorite Crater Using High Resolution Geophysics in a Complex Environment

From its discovery in 1921, the Odessa Meteorite Crater has interested researchers and mining companies who had initially hoped to locate a buried mass of meteoric iron. To find the impactor, a major geologic study of the crater was conducted in 1941. Even though the impactor has not been found, the thorough geologic constraints make the crater an excellent location to test the application of near-surface geophysical methods to complex environments. Recently, researchers have focused on determining the age of the crater, the environmental effects of the impact, and the size, incident angle, and direction of the impactor responsible for the crater. However, the heavily eroded and anthropogenically modified state of the exposed crater presents several challenges to impactor attribute estimation. The exposed rim is irregular in shape such that the original size and shape of the crater is indeterminate, only ~3 m of the estimated 30 m of original crater depth remain unfilled by post impact sediment, and previous geologic studies have left the remains of several large trenches transecting the crater rim. To more accurately determine the original size of the crater, ERT and GPR geophysical methods were used to image the exposed and unexposed rim strata. However, the geologic complexity of the crater and the presence of anthropogenic or “cultural” noise posed problems to both ERT and GPR data acquisition and processing. Geophysical results point to a main crater of ~120 m in diameter and ~35 m depth. Additionally, the eastern non-circular portion of the expose crater rim is hypothesized to have form from the simultaneous impact of a small meteorite broken from the main meteorite during atmospheric entry. Further ERT study is recommended to investigate the secondary crater further

A Happy Abundance : Tales, Memoirs and More Past and Present in Wayne, Maine

https://digitalmaine.com/wayne_books/1002/thumbnail.jp

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo

Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

A monograph of the pheasants

v.1 (1918

MBL Agreement of Association

Document establishing the Marine Biological Laboratory as a Massachusetts corporationPurpose "to establish and maintain a laboratory or station for scientific study and investigation, and a school for instruction in biology and natural history"Correspondenc

For a Sociological Reconstruction: W.E.B. Du Bois, Stuart Hall and Segregated Sociology

Racism and intellectual segregation limit and divide the sociological tradition. The white sociological mainstream historically ignored the contribution of black sociologists and today it confers the discussion of racism to a specialist sub-field. Black sociologists by contrast have long been attentive to white sociology. Through a detailed discussion of the writings of W.E.B Du Bois and Stuart Hall and their respective dialogues with figures like Max Weber and C Wright Mills, an argument is made for a profound reconstruction of sociology at both the level of analysis and of form that changes the way sociology tells about racism and society as a whole

A Happy Abundance : Tales, Memoirs and More Past and Present in Wayne, Maine

https://digitalmaine.com/wayne_books/1002/thumbnail.jp