28 research outputs found
A Calorimetric Search on Double Beta Decay of 130Te
We report on the final results of a series of experiments on double decay of
130Te carried out with an array of twenty cryogenic detectors. The set-up is
made with crystals of TeO2 with a total mass of 6.8 kg, the largest operating
one for a cryogenic experiment. Four crystals are made with isotopically
enriched materials: two in 128Te and two others in 130Te. The remaining ones
are made with natural tellurium, which contains 31.7 % and 33.8 % 128Te and
130Te, respectively. The array was run under a heavy shield in the Gran Sasso
Underground Laboratory at a depth of about 3500 m.w.e. By recording the pulses
of each detector in anticoincidence with the others a lower limit of 2.1E23
years has been obtained at the 90 % C.L. on the lifetime for neutrinoless
double beta decay of 130Te. In terms of effective neutrino mass this is the
most restrictive limit in direct experiments, after those obtained with Ge
diodes. Limits on other lepton violating decays of 130Te and on the
neutrinoless double beta decay of 128Te to the ground state of 128Xe are also
reported and discussed. An indication is presented for the two neutrino double
beta decay of 130Te. Some consequences of the present results in the
interpretation of geochemical experiments are discussed.Comment: 14 pages, 3 figures, 2 tables; more analysis details. Accepted for
publication on Physics Letters
Carbon-sensitive pedotransfer functions for plant available water
Currently accepted pedotransfer functions show negligible effect of management-induced changes to soil organic carbon (SOC) on plant available water holding capacity (θAWHC), while some studies show the ability to substantially increase θAWHC through management. The Soil Health Institute\u27s North America Project to Evaluate Soil Health Measurements measured water content at field capacity using intact soil cores across 124 long-term research sites that contained increases in SOC as a result of management treatments such as reduced tillage and cover cropping. Pedotransfer functions were created for volumetric water content at field capacity (θFC) and permanent wilting point (θPWP). New pedotransfer functions had predictions of θAWHC that were similarly accurate compared with Saxton and Rawls when tested on samples from the National Soil Characterization database. Further, the new pedotransfer functions showed substantial effects of soil calcareousness and SOC on θAWHC. For an increase in SOC of 10 g kg–1 (1%) in noncalcareous soils, an average increase in θAWHC of 3.0 mm 100 mm–1 soil (0.03 m3 m–3) on average across all soil texture classes was found. This SOC related increase in θAWHC is about double previous estimates. Calcareous soils had an increase in θAWHC of 1.2 mm 100 mm–1 soil associated with a 10 g kg–1 increase in SOC, across all soil texture classes. New equations can aid in quantifying benefits of soil management practices that increase SOC and can be used to model the effect of changes in management on drought resilience
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Linking soil microbial community structure to potential carbon mineralization: A continental scale assessment of reduced tillage
Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical disturbance, and soil pH influenced microbial sensitivity to physical disturbance. Furthermore, 28% of amplicon sequence variants (ASVs), which were important in modeling Cmin, were enriched under soils managed with minimal physical disturbance. Sequences identified as enriched under minimal disturbance and important for modeling Cmin, were linked to organisms which could produce extracellular polymeric substances and contained metabolic strategies suited for tolerating environmental stressors. Understanding how physical disturbance shapes microbial communities across climates and inherent soil properties and drives changes in Cmin provides the context necessary to evaluate management impacts on standardized measures of soil microbial activity
Constraints on exotic lepton doublets with minimal coupling to the standard model
We investigate the consequences of introducing a set of exotic doublet
leptons which couple to the standard model leptons in a minimal way. Through
these additional gauge invariant and renormalizable coupling terms, new sources
of tree-level flavor changing currents are induced via mixing. In this work, we
derive constraints on the parameters that govern the couplings to the exotic
doublets by invoking the current low-energy experimental data on processes such
as leptonic Z decays, , , and - conversion in atomic nuclei. Moreover, we have analyzed
the role these doublets play on the lepton anomalous magnetic moments, and
found that their contribution is negligible.Comment: 18 pages, 1 figure, 2 tables (REVTeX4.1); v2: added discussions in
Sec.II, III & IX and new ref. To appear in JHEP. arXiv admin note: text
overlap with arXiv:1011.473
AD51B in Familial Breast Cancer
Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk
Race and Nation in White-Power Music
This dissertation examines the themes of race and nation in the 30-year-old genre of white-power music. Specifically, it explores how white-power musicians construct `in' and `out' groups of `friend' and `foe.' It does so by analyzing how white-power songs employ anti-Semitic conspiracy theory, an anti-media rhetoric that ignores white-power music's place in the world of media and communications, anti-government conspiracies that blame a supposed Jewish takeover for all of the social problems in contemporary western societies, `natural' and `historical' discourse about the character of whiteness itself, and shifting white-power claims to physical territory and nationhood. Ultimately, the aim of this dissertation is to argue that white-power musicians' ideas about race and nation continue to attract fans and followers from across the western world not because they are `fringe' or `extremist' philosophies, but rather because they reflect white-supremacist currents in mainstream thought that stem from a 400-year history of western colonialism and racial exploitation