461 research outputs found
Avoiding deontic explosion by contextually restricting aggregation
In this paper, we present an adaptive logic for deontic conflicts, called P2.1(r), that is based on Goble's logic SDLaPe-a bimodal extension of Goble's logic P that invalidates aggregation for all prima facie obligations. The logic P2.1(r) has several advantages with respect to SDLaPe. For consistent sets of obligations it yields the same results as Standard Deontic Logic and for inconsistent sets of obligations, it validates aggregation "as much as possible". It thus leads to a richer consequence set than SDLaPe. The logic P2.1(r) avoids Goble's criticisms against other non-adjunctive systems of deontic logic. Moreover, it can handle all the 'toy examples' from the literature as well as more complex ones
Regression modeling weather and biolsolids effects on dryland wheat yields in Eastern Colorado, 2001-2012
In the western Great Plains, climate dictates dryland wheat (Triticum aestivum, L) productivity. Producers use inorganic N fertilizers to improve crop yields in this region, while municipalities recycle sewage biosolids in the area. Will biosolids (from the Littleton/Englewood, CO Wastewater Treatment Plant) applications to western Great Plains dryland agroecosystems interact with weather to affect wheat production? To this end, we regressed crop yields on weather variables from 2000 through 2011 at a site about 40 km (approximately 25 miles) east of Byers, CO (Byers). We used SAS (Proc Reg) to develop several multiple regression models to predict crop yields. Our model of choice included four weather parameters for Byers wheat production. Regression variables included September and May precipitation and October and May monthly mean temperatures. Biosolids or nitrogen fertilizer application did not appear in our chosen model. We validated the wheat models using weather data and yields from the Colorado State University (CSU) Crops Testing Program from Akron, Burlington, Lamar, and Yuma, CO. According to t-tests comparing mean observed and predicted yields, the Byers model predicted yields from 2000-2011 at these locations with a +5.3% mean absolute error. A positive result of these analyses is that biosolids produced the same crop yields as commercial N fertilizer from 2001 through 2011
Regression modeling weather and biolsolids effects on dryland wheat yields in Eastern Colorado, 2001-2012
In the western Great Plains, climate dictates dryland wheat (Triticum aestivum, L) productivity. Producers use inorganic N fertilizers to improve crop yields in this region, while municipalities recycle sewage biosolids in the area. Will biosolids (from the Littleton/Englewood, CO Wastewater Treatment Plant) applications to western Great Plains dryland agroecosystems interact with weather to affect wheat production? To this end, we regressed crop yields on weather variables from 2000 through 2011 at a site about 40 km (approximately 25 miles) east of Byers, CO (Byers). We used SAS (Proc Reg) to develop several multiple regression models to predict crop yields. Our model of choice included four weather parameters for Byers wheat production. Regression variables included September and May precipitation and October and May monthly mean temperatures. Biosolids or nitrogen fertilizer application did not appear in our chosen model. We validated the wheat models using weather data and yields from the Colorado State University (CSU) Crops Testing Program from Akron, Burlington, Lamar, and Yuma, CO. According to t-tests comparing mean observed and predicted yields, the Byers model predicted yields from 2000-2011 at these locations with a +5.3% mean absolute error. A positive result of these analyses is that biosolids produced the same crop yields as commercial N fertilizer from 2001 through 2011
Cosmological Implications of Neutrinos
The lectures describe several cosmological effects produced by neutrinos.
Upper and lower cosmological limits on neutrino mass are derived. The role that
neutrinos may play in formation of large scale structure of the universe is
described and neutrino mass limits are presented. Effects of neutrinos on
cosmological background radiation and on big bang nucleosynthesis are
discussed. Limits on the number of neutrino flavors and mass/mixing are given.Comment: 41 page, 7 figures; lectures presented at ITEP Winter School,
February, 2002; to be published in the Proceeding
Erythrocyte Inosine triphosphatase activity: A potential biomarker for adverse events during combination antiretroviral therapy for HIV
The purine analogues tenofovir and abacavir are precursors of potential substrates for the enzyme Inosine 5â-triphosphate pyrophosphohydrolase (ITPase). Here, we investigated the association of ITPase activity and ITPA genotype with the occurrence of adverse events (AEs) during combination antiretroviral therapy (cART) for human immunodeficiency virus (HIV) infection. In 393 adult HIV-seropositive patients, AEs were defined as events that led to stop of cART regimen. ITPase activity 4 mmol IMP/mmol Hb/hour was considered as normal. ITPA genotype was determined by testing two ITPA polymorphisms: c.94C>A (p. Pro32Thr, rs1127354) and c.124+21A>C (rs7270101). Logistic regression analysis determined odds ratios for developing AEs. In tenofovir-containing regimens decreased ITPase activity was associated with less AEs (p = 0.01) and longer regimen duration (p = 0.001). In contrast, in abacavir-containing regimens decreased ITPase activity was associated with more AEs (crude p = 0.02) and increased switching of medication due to AEs (p = 0.03). ITPA genotype wt/wt was significantly associated with an increase in the occurrence of AEs in tenofovir-containing regimens. Decreased ITPase activity seems to be protective against occurrence of AEs in tenofovir-containing cART, while it is associated with an increase in AEs in abacavir-containing regimens
Relation of circulating concentrations of chemokine receptor CCR5 ligands to C-peptide, proinsulin and HbA1c and disease progression in type 1 diabetes
Th1 related chemokines CCL3 and CCL5 and Th2 related CCL4 as ligands of the receptor CCR5 contribute to disease development in animal models of type 1 diabetes. In humans, no data are available addressing the role of these chemokines regarding disease progression and remission. We investigated longitudinally circulating concentrations of CCR5 ligands of 256 newly diagnosed patients with type 1 diabetes. CCR5 ligands were differentially associated with beta-cell function and clinical remission. CCL5 was decreased in remitters and positively associated with HbA1c suggestive of a Th1 associated progression of the disease. Likewise, CCL3 was negatively related to C-peptide and positively associated with the beta-cell stress marker proinsulin but increased in remitters. CCL4 associated with decreased beta-cell stress shown by negative association with proinsulin. Blockage of chemokines or antagonism of CCR5 by therapeutic agents such as maraviroc may provide a new therapeutic target to ameliorate disease progression in type 1 diabetes
Breakup reaction models for two- and three-cluster projectiles
Breakup reactions are one of the main tools for the study of exotic nuclei,
and in particular of their continuum. In order to get valuable information from
measurements, a precise reaction model coupled to a fair description of the
projectile is needed. We assume that the projectile initially possesses a
cluster structure, which is revealed by the dissociation process. This
structure is described by a few-body Hamiltonian involving effective forces
between the clusters. Within this assumption, we review various reaction
models. In semiclassical models, the projectile-target relative motion is
described by a classical trajectory and the reaction properties are deduced by
solving a time-dependent Schroedinger equation. We then describe the principle
and variants of the eikonal approximation: the dynamical eikonal approximation,
the standard eikonal approximation, and a corrected version avoiding Coulomb
divergence. Finally, we present the continuum-discretized coupled-channel
method (CDCC), in which the Schroedinger equation is solved with the projectile
continuum approximated by square-integrable states. These models are first
illustrated by applications to two-cluster projectiles for studies of nuclei
far from stability and of reactions useful in astrophysics. Recent extensions
to three-cluster projectiles, like two-neutron halo nuclei, are then presented
and discussed. We end this review with some views of the future in
breakup-reaction theory.Comment: Will constitute a chapter of "Clusters in Nuclei - Vol.2." to be
published as a volume of "Lecture Notes in Physics" (Springer
Light propagation in statistically homogeneous and isotropic universes with general matter content
We derive the relationship of the redshift and the angular diameter distance
to the average expansion rate for universes which are statistically homogeneous
and isotropic and where the distribution evolves slowly, but which have
otherwise arbitrary geometry and matter content. The relevant average expansion
rate is selected by the observable redshift and the assumed symmetry properties
of the spacetime. We show why light deflection and shear remain small. We write
down the evolution equations for the average expansion rate and discuss the
validity of the dust approximation.Comment: 42 pages, no figures. v2: Corrected one detail about the angular
diameter distance and two typos. No change in result
Oscillation effects on neutrino decoupling in the early universe
In the early universe, neutrinos decouple from equilibrium with the
electromagnetic plasma at a temperature which is only slightly higher than the
temperature where electrons and positrons annihilate. Therefore neutrinos to
some extent share in the entropy transfer from e^+e^- to other species, and
their final temperature is slightly higher than the canonical value T_nu =
(4/11)^{1/3} T_gamma. We study neutrino decoupling in the early universe with
effects of neutrino oscillations included, and find that the change in neutrino
energy density from e^+ e^- annihilations can be about 2-3% higher if
oscillation are included. The primordial helium abundance can be changed by as
much as 1.5 x 10^-4 by neutrino oscillations.Comment: minor changes, matches version to appear in PR
Measurement of and charged current inclusive cross sections and their ratio with the T2K off-axis near detector
We report a measurement of cross section and the first measurements of the cross section
and their ratio
at (anti-)neutrino energies below 1.5
GeV. We determine the single momentum bin cross section measurements, averaged
over the T2K -flux, for the detector target material (mainly
Carbon, Oxygen, Hydrogen and Copper) with phase space restricted laboratory
frame kinematics of 500 MeV/c. The
results are and $\sigma(\nu)=\left( 2.41\
\pm0.022{\rm{(stat.)}}\pm0.231{\rm (syst.)}\ \right)\times10^{-39}^{2}R\left(\frac{\sigma(\bar{\nu})}{\sigma(\nu)}\right)=
0.373\pm0.012{\rm (stat.)}\pm0.015{\rm (syst.)}$.Comment: 18 pages, 8 figure
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