674 research outputs found
Notes on Phelps County ores
In conclusion, summing up the evidence both field and theoretic, there are very good reasons for believing that the deposits which have been worked and are not being worked are not the only deposits of magnitude in the county but by intelligent prospecting along lines already suggested other large and valuable deposits will be found. From the manner of the ores concentration it is not to be expected that every deposit will have a surface outcrop neither is it probable that every depression will be found to contain an ore deposit but when these phenomena occur, together with other evidences of mineralization, the condition at least warrents sic the expense of prospecting by pits or otherwise --page 17
Supervoid Origin of the Cold Spot in the Cosmic Microwave Background
We use a WISE-2MASS-Pan-STARRS1 galaxy catalog to search for a supervoid in
the direction of the Cosmic Microwave Background Cold Spot. We obtain
photometric redshifts using our multicolor data set to create a tomographic map
of the galaxy distribution. The radial density profile centred on the Cold Spot
shows a large low density region, extending over 10's of degrees. Motivated by
previous Cosmic Microwave Background results, we test for underdensities within
two angular radii, , and . Our data, combined with an
earlier measurement by Granett et al 2010, are consistent with a large supervoid with centered at . Such a supervoid, constituting a
fluctuation in the model, is a plausible cause
for the Cold Spot.Comment: 4 pages, 2 figures, Proceedings of IAU 306 Symposium: Statistical
Challenges in 21st Century Cosmolog
Salmon for Terrestrial Protected areas
Although managers safeguard protected areas for migratory species, little consideration has been given to how migratory species might benefit parks. Additionally, whereas land‐sea connections are considered in management of protected areas, most effort has focused on reducing negative “downstream” processes. Here, we offer a proposal to promote positive “upstream” processes by safeguarding the seasonal pulse of marine nutrients imported into freshwater and riparian ecosystems by spawning migrations of Pacific salmon. Currently, high rates of fishing limit this important contribution to species and processes that terrestrial parks were designed to protect. Accordingly, we propose limiting exploitation in areas and periods through which salmon runs bound for terrestrial protected areas can migrate. Best suited for less commercially valuable but relatively abundant and widespread pink and chum salmon (O. gorbuscha and keta), our proposal thus considers ecosystem and societal needs for salmon. We conclude by outlining strategies to overcome socio‐economic barriers to implementation
Plasma biomarkers and genetics in the diagnosis and prediction of Alzheimer's disease
Plasma biomarkers for Alzheimer's disease-related pathologies have undergone rapid developments during the past few years, and there are now well-validated blood tests for amyloid and tau pathology, as well as neurodegeneration and astrocytic activation. To define Alzheimer's disease with biomarkers rather than clinical assessment, we assessed prediction of research-diagnosed disease status using these biomarkers and tested genetic variants associated with the biomarkers that may reflect more accurately the risk of biochemically defined Alzheimer's disease instead of the risk of dementia. In a cohort of Alzheimer's disease cases (N=1439, mean age 68 years [SD=8.2]) and screened controls (N=508, mean age 82 years [SD=6.8]), we measured plasma concentrations of the 40 and 42 amino acid-long amyloid β fragments (Aβ40 and Aβ42, respectively), tau phosphorylated at amino acid 181 (P-tau181), neurofilament light (NfL), and glial fibrillary acidic protein (GFAP) using state-of-the-art Single molecule array (Simoa) technology. We tested the relationships between the biomarkers and Alzheimer's disease genetic risk, age at onset, and disease duration. We also conducted a genome-wide association study for association of disease risk genes with these biomarkers. The prediction accuracy of Alzheimer's disease clinical diagnosis by the combination of all biomarkers, APOE and polygenic risk score reached AUC=0.81, with the most significant contributors being ε4, Aβ40 or Aβ42, GFAP and NfL. All biomarkers were significantly associated with age in cases and controls (p<4.3x10-5). Concentrations of the Aβ-related biomarkers in plasma were significantly lower in cases compared with controls, whereas other biomarker levels were significantly higher in cases. In the case-control genome-wide analyses, APOE-ε4 was associated with all biomarkers (p=0.011- 4.78x10-8), except NfL. No novel genome-wide significant SNPs were found in the case-control design; however, in a case-only analysis, we found two independent genome-wide significant associations between the Aβ42/Aβ40 ratio and WWOX and COPG2 genes. Disease prediction modelling by the combination of all biomarkers indicates that the variance attributed to P-tau181 is mostly captured by APOE-ε4, whereas Aβ40, Aβ42, GFAP and NfL biomarkers explain additional variation over and above APOE. We identified novel plausible genome wide-significant genes associated with Aβ42/Aβ40 ratio in a sample which is fifty times smaller than current genome-wide association studies in Alzheimer's disease
The Cold Spot in the Cosmic Microwave Background: the Shadow of a Supervoid
Standard inflationary hot big bang cosmology predicts small
fluctuations in the Cosmic Microwave Background (CMB) with
isotropic Gaussian statistics. All measurements support the
standard theory, except for a few anomalies discovered in the
Wilkinson Microwave Anisotropy Probe maps and confirmed recently
by the Planck satellite. The Cold Spot is one of the most
significant of such anomalies, and the leading explanation of it
posits a large void that imprints this extremely cold area via
the linear Integrated Sachs-Wolfe (ISW) effect due to the decay
of gravitational potentials over cosmic time, or via the Rees-
Sciama (RS) effect due to late-time non-linear evolution.
Despite several observational campaigns targeting the Cold Spot
region, to date no suitably large void was found at higher
redshifts z>0.3. Here we report the detection of an R=(192±15)h
−1Mpc size supervoid of depth δ=−0.13±0.03, and centred at
redshift z=0.22. This supervoid, possibly the largest ever
found, is large enough to significantly affect the CMB via the
non-linear RS effect, as shown in our Lemaitre-Tolman-Bondi
framework. This discovery presents the first plausible
explanation for any of the physical CMB anomalies, and raises
the possibility that local large-scale structure could be
responsible for other anomalies as well
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