5,873 research outputs found
Psychiatric Challenge of Witnesses
Although insane\u27 persons were incompetent as witnesses at early common law, the modern view is that the effect of mental illness upon competency is a preliminary question for the court in the absence of contrary statutory direction. An insane person is generally said to be a competent witness if he can understand the sanctions imposed to elicit the truth and can correctly recount the occurrence which is the subject of his testimony. Some courts exclude evidence of insanity offered for purposes of impeachment but most courts admit such evidence, treating medical and lay testimony with equal respect because of the refusal of the earlier cases to consider insanity as exclusively within the province of experts
Conservation of structure and mechanism in primary and secondary transporters exemplified by SiaP, a sialic acid binding virulence factor from Haemophilus influenzae
Extracytoplasmic solute receptors (ESRs) are important components of solute uptake systems in bacteria, having been studied extensively as parts of ATP binding cassette transporters. Herein we report the first crystal structure of an ESR protein from a functionally characterized electrochemical ion gradient-dependent secondary transporter. This protein, SiaP, forms part of a tripartite ATP-independent periplasmic transporter specific for sialic acid in Haemophilus influenzae. Surprisingly, the structure reveals an overall topology similar to ATP binding cassette ESR proteins, which is not apparent from the sequence, demonstrating that primary and secondary transporters can share a common structural component. The structure of SiaP in the presence of the sialic acid analogue 2,3-didehydro-2-deoxyN-acetylneuraminic acid reveals the ligand bound in a deep cavity with its carboxylate group forming a salt bridge with a highly conserved Arg residue. Sialic acid binding, which obeys simple bimolecular association kinetics as determined by stopped-flow fluorescence spectroscopy, is accompanied by domain closure about a hinge region and the kinking of an alpha-helix hinge component. The structure provides insight into the evolution, mechanism, and substrate specificity of ESR-dependent secondary transporters that are widespread in prokaryotes
On parametrised cold dense matter equation of state inference
Constraining the equation of state of cold dense matter in compact stars is a
major science goal for observing programmes being conducted using X-ray, radio,
and gravitational wave telescopes. We discuss Bayesian hierarchical inference
of parametrised dense matter equations of state. In particular we generalise
and examine two inference paradigms from the literature: (i) direct posterior
equation of state parameter estimation, conditioned on observations of a set of
rotating compact stars; and (ii) indirect parameter estimation, via
transformation of an intermediary joint posterior distribution of exterior
spacetime parameters (such as gravitational masses and coordinate equatorial
radii). We conclude that the former paradigm is not only tractable for
large-scale analyses, but is principled and flexible from a Bayesian
perspective whilst the latter paradigm is not. The thematic problem of Bayesian
prior definition emerges as the crux of the difference between these paradigms.
The second paradigm should in general only be considered as an ill-defined
approach to the problem of utilising archival posterior constraints on exterior
spacetime parameters; we advocate for an alternative approach whereby such
information is repurposed as an approximative likelihood function. We also
discuss why conditioning on a piecewise-polytropic equation of state model -
currently standard in the field of dense matter study - can easily violate
conditions required for transformation of a probability density distribution
between spaces of exterior (spacetime) and interior (source matter) parameters.Comment: Accepted for publication in MNRAS, 43 pages, 7 figure
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Root density distribution and biomass allocation of co-occurring woody plants on contrasting soils in a subtropical savanna parkland
Background and aims: Root niche partitioning among trees/shrubs and grasses facilitates their coexistence in savannas, but little is known regarding root distribution patterns of co-occurring woody plants, and how they might differ on contrasting soils. Methods: We quantified root distributions of co-occurring shrubs to 2m on argillic and non-argillic soils. Results: Root biomass in the two shrub communities was 3- to 5- fold greater than that in the grassland community. Prosopis glandulosa, the dominant overstory species was deep-rooted, while the dominant understory shrub, Zanthoxylum fagara, was shallow-rooted (47% vs. 25% of root density at depths >0.4m). Shrubs on argillic soils had less aboveground and greater belowground mass than those on non-argillic soils. Root biomass and density on argillic soils was elevated at shallow (0.4m. Root density decreased exponentially with increasing distance from woody patch perimeters. Conclusions: Belowground biomass (carbon) pools increased markedly with grassland-to-shrubland state change. The presence/absence of a restrictive barrier had substantial effects on root distributions and above- vs. belowground biomass allocation. Differences in root distribution patterns of co-occurring woody species would facilitate their co-existence.NSF [BSR-9109240]; NASA [NAGW-2662]; NSF Doctoral Dissertation Improvement Grant [DEB/DDIG-1600790]; USDA/NIFA Hatch Project [1003961]; Sid Kyle Graduate Merit Assistantship from the Department of Ecosystem Science and Management; Tom Slick Graduate Research Fellowship from the College of Agriculture and Life Sciences, Texas AM University; Office of Graduate and Professional Studies at Texas AM University12 month embargo; first online: 11 March 2019This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Preferential Myosin Heavy Chain Isoform B Expression May Contribute to the Faster Velocity of Contraction in Veins versus Arteries
Smooth muscle myosin heavy chains occur in 2 isoforms, SMA (slow) and SMB (fast). We hypothesized that the SMB isoform is predominant in the faster-contracting rat vena cava compared to thoracic aorta. We compared the time to half maximal contraction in response to a maximal concentration of endothelin-1 (ET-1; 100 nM), potassium chloride (KCl; 100 mM) and norepinephrine (NE; 10 µM). The time to half maximal contraction was shorter in the vena cava compared to aorta (aorta: ET-1 = 235.8 ± 13.8 s, KCl = 140.0 ± 33.3 s, NE = 19.8 ± 2.7 s; vena cava: ET-1 = 121.8 ± 15.6 s, KCl = 49.5 ± 6.7 s, NE = 9.0 ± 3.3 s). Reverse-transcription polymerase chain reaction supported the greater expression of SMB in the vena cava compared to aorta. SMB was expressed to a greater extent than SMA in the vessel wall of the vena cava. Western analysis determined that expression of SMB, relative to total smooth muscle myosin heavy chains, was 12.5 ± 4.9-fold higher in the vena cava compared to aorta, while SMA was 4.9 ± 1.2-fold higher in the aorta than vena cava. Thus, the SMB isoform is the predominant form expressed in rat veins, providing one possible mechanism for the faster response of veins to vasoconstrictors
Investigation into the changing colonisation of skin bacteria during isotretinoin treatment for acne vulgaris
Poster presentatio
X-PSI Parameter Recovery for Temperature Map Configurations Inspired by PSR J0030+0451
In the last few years, the NICER collaboration has provided mass and radius
inferences, via pulse profile modeling, for two pulsars: PSR J0030+0451 and PSR
J0740+6620. Given the importance of these results for constraining the equation
of state of dense nuclear matter, it is crucial to validate them and test their
robustness. We therefore explore the reliability of these results and their
sensitivity to analysis settings and random processes, including noise,
focusing on the specific case of PSR J0030+0451. We use X-PSI, one of the two
main analysis pipelines currently employed by the NICER collaboration for mass
and radius inferences. With synthetic data that mimic the PSR J0030+0451 NICER
data set, we evaluate the recovery performances of X-PSI under conditions never
tested before, including complex modeling of the thermally emitting neutron
star surface. For the test cases explored, our results suggest that X-PSI is
capable of recovering the true mass and radius within reasonable credible
intervals. This work also reveals the main vulnerabilities of the analysis: a
significant dependence on noise and the presence of multi-modal structure in
the posterior surface. Noise particularly impacts our sensitivity to the
analysis settings and widths of the posterior distributions. The multi-modal
structure in the posterior suggests that biases could be present if the
analysis is unable to exhaustively explore the parameter space. Convergence
testing, to ensure an adequate coverage of the parameter space and a suitable
representation of the posterior distribution, is one possible solution to these
challenges.Comment: 27 pages, 13 figure
Animated PowerPoint Presentations For Teaching Operations And Supply Chain Management: Perceived Value And Electronic Exchange Of Files
This paper presents the innovation of sharing animated PowerPoint presentations used in teaching operations and supply chain management techniques and concepts through an international electronic exchange. The plan for the exchange is presented and discussed. The potential benefits to faculty and students of using PowerPoint animations in operations and supply chain management classes are discussed. Evidence of these benefits is also provided. Readers are provided with information about how to join the exchange
Cosmic Dust Catalog
Since May 1981, the National Aeronautics and Space Administration (NASA) has used aircraft to collect cosmic dust (CD) particles from Earth's stratosphere. Specially designed dust collectors are prepared for flight and processed after flight in an ultraclean (Class-100) laboratory constructed for this purpose at the Lyndon B. Johnson Space Center (JSC) in Houston, Texas. Particles are individually retrieved from the collectors, examined and cataloged, and then made available to the scientific community for research. Cosmic dust thereby joins lunar samples and meteorites as an additional source of extraterrestrial materials for scientific study. This catalog summarizes preliminary observations on 468 particles retrieved from collection surfaces L2021 and L2036. These surfaces were flat plate Large Area Collectors (with a 300 cm2 surface area each) which was coated with silicone oil (dimethyl siloxane) and then flown aboard a NASA ER-2 aircraft during a series of flights that were made during January and February of 1994 (L2021) and June 7 through July 5 of 1994 (L2036). Collector L2021 was flown across the entire southern margin of the US (California to Florida), and collector L2036 was flown from California to Wallops Island, VA and on to New England. These collectors were installed in a specially constructed wing pylon which ensured that the necessary level of cleanliness was maintained between periods of active sampling. During successive periods of high altitude (20 km) cruise, the collectors were exposed in the stratosphere by barometric controls and then retracted into sealed storage container-s prior to descent. In this manner, a total of 35.8 hours of stratospheric exposure was accumulated for collector L2021, and 26 hours for collector L2036
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