109,222 research outputs found
The Full Wealth of Conviction and Cognition: Psychology\'s Modernist Critique of Fundamentalism in Postmodern Perspective
The author draws parallels between psychology and religious modernism as exemplified in the writings of such figures as Harry Emerson Fosdick. Miller suggests that psychological research arguing that fundamentalists are \"cognitivcly challenged\" is more reflective of psychology\'s unacknowledged modernist assumptions than descriptive of fundamentalists. A post-modernist recognition of psychology\'s bias should help redirect efforts toward understanding fundamentalists\' pressing desire to preserve a particular orderly culture
Sequence-Based Mapping and Genome Editing Reveal Mutations in Stickleback Hps5 Cause Oculocutaneous Albinism and the casper Phenotype.
Here, we present and characterize the spontaneous X-linked recessive mutation casper, which causes oculocutaneous albinism in threespine sticklebacks (Gasterosteus aculeatus). In humans, Hermansky-Pudlak syndrome results in pigmentation defects due to disrupted formation of the melanin-containing lysosomal-related organelle (LRO), the melanosome. casper mutants display not only reduced pigmentation of melanosomes in melanophores, but also reductions in the iridescent silver color from iridophores, while the yellow pigmentation from xanthophores appears unaffected. We mapped casper using high-throughput sequencing of genomic DNA from bulked casper mutants to a region of the stickleback X chromosome (chromosome 19) near the stickleback ortholog of Hermansky-Pudlak syndrome 5 (Hps5). casper mutants have an insertion of a single nucleotide in the sixth exon of Hps5, predicted to generate an early frameshift. Genome editing using CRISPR/Cas9 induced lesions in Hps5 and phenocopied the casper mutation. Injecting single or paired Hps5 guide RNAs revealed higher incidences of genomic deletions from paired guide RNAs compared to single gRNAs. Stickleback Hps5 provides a genetic system where a hemizygous locus in XY males and a diploid locus in XX females can be used to generate an easily scored visible phenotype, facilitating quantitative studies of different genome editing approaches. Lastly, we show the ability to better visualize patterns of fluorescent transgenic reporters in Hps5 mutant fish. Thus, Hps5 mutations present an opportunity to study pigmented LROs in the emerging stickleback model system, as well as a tool to aid in assaying genome editing and visualizing enhancer activity in transgenic fish
On the problems of measuring transient temperature in cryogenic fluids
Cryogenic sensor errors in measuring transient temperature in cryogenic fluid
The academic value of internships: benefits across disciplines and student backgrounds
While student benefits from internship experience have been frequently documented in research, the emphasis has been on internship effects on employment and career indicators. This work is concerned with effects on academic outcomes and focuses on the robustness of such effects across academic disciplines as well as for different achievement levels of students, student gender, and ethnicity. We present findings from a longitudinal sample (n > 15,000) that covers an extensive range of subjects and disciplines for large Undergraduate cohorts. Main effects and interactions for student background characteristics were investigated showing stable academic benefits for advantaged and disadvantaged students. Further, using ordinal logistic multi-level modelling, we explored the impact on the probability of attaining a higher degree classification for different student scenarios, thus illustrating the practical significance of these internship effects. Effects are less likely to stem from maturation or self-selection. Findings are therefore discussed against a background of motivational approaches suitable to integrate both direct and indirect paths from internship experience to academic outcomes to career indicators
Experimental constraints on the polarizabilities of the 6s^2 1S0 and 6s6p 3P0 states of Yb
We utilize accurate experimental data available in the literature to yield
bounds on the polarizabilities of the ground and first excited states of atomic
Yb. For the 6s^2 1S0 ground state, we find the polarizability alpha to be
constrained to 134.4<alpha<144.2 in atomic units, while for the 6s6p 3P0
excited state we find 280.1<alpha<289.9. The uncertainty in each of these
values is 1.0. These constraints provide a valuable check for ab initio and
semi-empirical methods used to compute polarizabilities and other related
properties in Yb.Comment: 7 pages, 1 figur
A probabilistic model checking approach to analysing reliability, availability, and maintainability of a single satellite system
Satellites now form a core component for space
based systems such as GPS and GLONAS which provide
location and timing information for a variety of uses. Such
satellites are designed to operate in-orbit and have lifetimes of
10 years or more. Reliability, availability and maintainability
(RAM) analysis of these systems has been indispensable in
the design phase of satellites in order to achieve minimum
failures or to increase mean time between failures (MTBF)
and thus to plan maintainability strategies, optimise reliability
and maximise availability. In this paper, we present formal
modelling of a single satellite and logical specification of
its reliability, availability and maintainability properties. The
probabilistic model checker PRISM has been used to perform
automated quantitative analyses of these properties
Phosphorus Immobilization in Poultry Litter and Litter-amended soils with Aluminum, Calcium and Iron amendments
Arkansas produces approximately one billion broilers each year. Phosphorous (P) runoff from fields receiving poultry litter is believed to be one of the primary factors affecting water quality in Northwest Arkansas. Poultry litter contains approximately 20 g P kg-1, of which about 2 g P kg-1 is water soluble. Soils that have received repeated heavy applications of litter may have water soluble P contents of as high as 10 mg P Kg-1 soil. The objective of this study was to determine if soluble P levels could be reduced in poultry litter and litter-amended soils with Al,Ca, and/or Fe amendments. Poultry litter was amended with alum, sodium aluminate, quick lime, slaked lime, calcitic limestone, dolomitic limestone, gypsum, ferrous chloride, ferric chloride, ferrous sulfate and ferric sulfate, and incubated in the dark at 25°C for one week. Three soils which had been excessively fertilized with poultry litter were amended with alum, ferrous sulfate, calcitic limestone, gypsum and slaked lime and incubated for 4 weeks at 25 °C. In the litter studies, the Ca treatments were tested with and without CaF2 additions in an attempt to precipitate fluorapatite. At the end of the incubation period, the litter and soils were extracted with deionized water and soluble reactive P (SRP) was determined. SRP levels in the poultry litter were reduced from over 2,000 mg P kg-1 litter to less than 1 mg P kg-1 litter with the addition of alum, quick lime, slaked lime, ferrous chloride, ferric chloride, ferrous sulfate and ferric sulfate under favorable pH conditions. S.RP levels in the soils were reduced from approximately 5 mg P Kg-1 soil to less than 0.05 mg P Kg-1 soil with the addition of alum and ferrous sulfate under favorable pH conditions. Gypsum and sodium aluminate reduced SRP levels in litter by 50 to 60 percent while calcitic and dolomitic limestone were even less effective. In soils, the Ca amendments were less effective than the Al and Fe amendments, although slaked lime was effective at high pH. The results of these studies suggest that treating litter and excessively fertilized soils with some of these compounds, particularly alum, could significantly reduce the amount of SRP in runoff from littered pastures. Therefore, chemical additions to reduce SRP in litter and soil may be a best management practice in situations where eutrophication of adjacent water bodies due to P runoff has been identified. Preliminary calculations indicate that this .p ractice may be economically feasible. However, more research is needed to determine any beneficial and/or detrimental aspects of this practice
Grain opacity and the bulk composition of extrasolar planets. I. Results from scaling the ISM opacity
The opacity due to grains in the envelope of a protoplanet regulates the
accretion rate of gas during formation, thus the final bulk composition of
planets with primordial H/He is a function of it. Observationally, for
exoplanets with known mass and radius it is possible to estimate the bulk
composition via internal structure models. We first determine the reduction
factor of the ISM grain opacity f_opa that leads to gas accretion rates
consistent with grain evolution models. We then compare the bulk composition of
synthetic low-mass and giant planets at different f_opa with observations. For
f_opa=1 (full ISM opacity) the synthetic low-mass planets have too small radii,
i.e., too low envelope masses compared to observations. At f_opa=0.003, the
value calibrated with the grain evolution models, synthetic and actual planets
occupy similar mass-radius loci. The mean enrichment of giant planets relative
to the host star as a function of planet mass M can be approximated as
Z_p/Z_star = beta*(M/M_Jup)^alpha. We find alpha=-0.7 independent of f_opa in
synthetic populations in agreement with the observational result (-0.71+-0.10).
The absolute enrichment level decreases from beta=8.5 at f_opa=1 to 3.5 at
f_opa=0. At f_opa=0.003 one finds beta=7.2 which is similar to the
observational result (6.3+-1.0). We thus find observational hints that the
opacity in protoplanetary atmospheres is much smaller than in the ISM even if
the specific value of the grain opacity cannot be constrained here. The result
for the enrichment of giant planets helps to distinguish core accretion and
gravitational instability. In the simplest picture of core accretion where
first a critical core forms and afterwards only gas is added, alpha=-1. If a
core accretes all planetesimals inside the feeding zone, alpha=-2/3. The
observational result lies between these values, pointing to core accretion as
the formation mechanism.Comment: 21 pages, 15 figures. Accepted for A&
The Hilbert Action in Regge Calculus
The Hilbert action is derived for a simplicial geometry. I recover the usual
Regge calculus action by way of a decomposition of the simplicial geometry into
4-dimensional cells defined by the simplicial (Delaunay) lattice as well as its
dual (Voronoi) lattice. Within the simplicial geometry, the Riemann scalar
curvature, the proper 4-volume, and hence, the Regge action is shown to be
exact, in the sense that the definition of the action does not require one to
introduce an averaging procedure, or a sequence of continuum metrics which were
common in all previous derivations. It appears that the unity of these two dual
lattice geometries is a salient feature of Regge calculus.Comment: 6 pages, Plain TeX, no figure
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