1,347 research outputs found
A universe in a global monopole
We investigate brane physics in a universe with an extra dimensional global
monopole and negative bulk cosmological constant. The graviton zero mode is
naturally divergent; we thus invoke a physical cut-off to induce four
dimensional gravity on a brane at the monopole core. Independently, the massive
Kaluza-Klein modes have naturally compactified extra dimensions, inducing a
discrete spectrum. This spectrum remains consistent with four dimensional
gravity on the brane, even for small mass gap. Extra dimensional matter fields
also induce four dimensional matter fields on the brane, with the same
Kaluza-Klein spectrum of excited states. We choose parameters to solve the
hierarchy problem; that is, to induce the observed hierarchy between particle
and Planck scales in the effective four dimensional universe.Comment: 22 pages, 2 eps figures, revte
Joint Statement on Pediatric Education at Schools of Pharmacy
Providing health care for children is a unique specialty, and pediatric patients represent approximately 25% of the population. Education of pharmacy students on patients across the lifespan is required by current Accreditation Council for Pharmacy Education standards and outcomes; thus, it is essential that pharmacy students gain a proficiency in caring for children. A collaborative panel of pediatric faculty members from schools and colleges of pharmacy was established to review the current literature regarding pediatric education in Doctor of Pharmacy curricula and establish updated recommendations for the provision of pediatric pharmacy education. This statement outlines five recommendations supporting inclusion of pediatric content and skills in Doctor of Pharmacy curricula
Triplet-sensitization by lead halide perovskite thin films for near-infrared-to-visible upconversion
Lead halide-based perovskite thin films have attracted great attention due to
the explosive increase in perovskite solar cell efficiencies. The same
optoelectronic properties that make perovskites ideal absorber materials in
solar cells are also beneficial in other light-harvesting applications and make
them prime candidates as triplet sensitizers in upconversion via
triplet-triplet annihilation in rubrene. In this contribution, we take
advantage of long carrier lifetimes and carrier diffusion lengths in perovskite
thin films, their high absorption cross sections throughout the visible
spectrum, as well as the strong spin-orbit coupling owing to the abundance of
heavy atoms to sensitize the upconverter rubrene. Employing bulk perovskite
thin films as the absorber layer and spin-mixer in inorganic/organic
heterojunction upconversion devices allows us to forego the additional
tunneling barrier owing from the passivating ligands required for colloidal
sensitizers. Our bilayer device exhibits an upconversion efficiency in excess
of 3% under 785 nm illumination
Developing and validating Parkinson's disease subtypes and their motor and cognitive progression
Peer reviewedPublisher PD
Breast Mass Characterization Using 3âDimensional Automated Ultrasound as an Adjunct to Digital Breast Tomosynthesis
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135628/1/jum201332193.pd
Evaluation of Clustering and Genotype Distribution for Replication in Genome Wide Association Studies: The Age-Related Eye Disease Study
Genome-wide association studies (GWASs) assess correlation between traits and DNA sequence variation using large numbers of genetic variants such as single nucleotide polymorphisms (SNPs) distributed across the genome. A GWAS produces many trait-SNP associations with low p-values, but few are replicated in subsequent studies. We sought to determine if characteristics of the genomic loci associated with a trait could be used to identify initial associations with a higher chance of replication in a second cohort. Data from the age-related eye disease study (AREDS) of 100,000 SNPs on 395 subjects with and 198 without age-related macular degeneration (AMD) were employed. Loci highly associated with AMD were characterized based on the distribution of genotypes, level of significance, and clustering of adjacent SNPs also associated with AMD suggesting linkage disequilibrium or multiple effects. Forty nine loci were highly associated with AMD, including 3 loci (CFH, C2/BF, LOC387715/HTRA1) already known to contain important genetic risks for AMD. One additional locus (C3) reported during the course of this study was identified and replicated in an additional study group. Tag-SNPs and haplotypes for each locus were evaluated for association with AMD in additional cohorts to account for population differences between discovery and replication subjects, but no additional clearly significant associations were identified. Relying on a significant genotype tests using a log-additive model would have excluded 57% of the non-replicated and none of the replicated loci, while use of other SNP features and clustering might have missed true associations
Current ecotoxicity testing needs among selected U.S. federal agencies
U.S. regulatory and research agencies use ecotoxicity test data to assess the hazards associated with substances that may be released into the environment, including but not limited to industrial chemicals, pharmaceuticals, pesticides, food additives, and color additives. These data are used to conduct hazard assessments and evaluate potential risks to aquatic life (e.g., invertebrates, fish), birds, wildlife species, or the environment. To identify opportunities for regulatory uses of non-animal replacements for ecotoxicity tests, the needs and uses for data from tests utilizing animals must first be clarified. Accordingly, the objective of this review was to identify the ecotoxicity test data relied upon by U.S. federal agencies. The standards, test guidelines, guidance documents, and/or endpoints that are used to address each of the agenciesâ regulatory and research needs regarding ecotoxicity testing are described in the context of their application to decision-making. Testing and information use, needs, and/or requirements relevant to the regulatory or programmatic mandates of the agencies taking part in the Interagency Coordinating Committee on the Validation of Alternative Methods Ecotoxicology Workgroup are captured. This information will be useful for coordinating efforts to develop and implement alternative test methods to reduce, refine, or replace animal use in chemical safety evaluations
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