2,784 research outputs found
A method for finding new sets of axioms for classes of semigroups
We introduce a general technique for finding sets of axioms for a given class of semigroups. To illustrate the technique, we provide new sets of defining axioms for groups of exponent n, bands, and semilattices
Scavenger 0.1: A Theorem Prover Based on Conflict Resolution
This paper introduces Scavenger, the first theorem prover for pure
first-order logic without equality based on the new conflict resolution
calculus. Conflict resolution has a restricted resolution inference rule that
resembles (a first-order generalization of) unit propagation as well as a rule
for assuming decision literals and a rule for deriving new clauses by (a
first-order generalization of) conflict-driven clause learning.Comment: Published at CADE 201
Validation of the SCID-hu Thy/Liv mouse model with four classes of licensed antiretrovirals.
BackgroundThe SCID-hu Thy/Liv mouse model of HIV-1 infection is a useful platform for the preclinical evaluation of antiviral efficacy in vivo. We performed this study to validate the model with representatives of all four classes of licensed antiretrovirals.Methodology/principal findingsEndpoint analyses for quantification of Thy/Liv implant viral load included ELISA for cell-associated p24, branched DNA assay for HIV-1 RNA, and detection of infected thymocytes by intracellular staining for Gag-p24. Antiviral protection from HIV-1-mediated thymocyte depletion was assessed by multicolor flow cytometric analysis of thymocyte subpopulations based on surface expression of CD3, CD4, and CD8. These mice can be productively infected with molecular clones of HIV-1 (e.g., the X4 clone NL4-3) as well as with primary R5 and R5X4 isolates. To determine whether results in this model are concordant with those found in humans, we performed direct comparisons of two drugs in the same class, each of which has known potency and dosing levels in humans. Here we show that second-generation antiretrovirals were, as expected, more potent than their first-generation predecessors: emtricitabine was more potent than lamivudine, efavirenz was more potent than nevirapine, and atazanavir was more potent than indinavir. After interspecies pharmacodynamic scaling, the dose ranges found to inhibit viral replication in the SCID-hu Thy/Liv mouse were similar to those used in humans. Moreover, HIV-1 replication in these mice was genetically stable; treatment of the mice with lamivudine did not result in the M184V substitution in reverse transcriptase, and the multidrug-resistant NY index case HIV-1 retained its drug-resistance substitutions.ConclusionGiven the fidelity of such comparisons, we conclude that this highly reproducible mouse model is likely to predict clinical antiviral efficacy in humans
Energy Conversion Research
Contains research objectives and reports on three research projects.U. S. Air Force (Research and Technology Division) under Contract AF33(615)-1083 with the Air Force Aero Propulsion Laboratory, Wright-Patterson Air Force Base, Ohi
Sampling a Littoral Fish Assemblage: Comparison of Small-Mesh Fyke Netting and Boat Electrofishing
We compared small-mesh (4-mm) fyke netting and boat electrofishing for sampling a littoral fish assemblage in Muskegon Lake, Michigan. We hypothesized that fyke netting selects for small-bodied fishes and electrofishing selects for large-bodied fishes. Three sites were sampled during May (2004 and 2005), July (2005 only), and September (2004 and 2005). We found that the species composition of captured fish differed considerably between fyke netting and electrofishing based on nonmetric multidimensional scaling (NMDS). Species strongly associated with fyke netting (based on NMDS and relative abundance) included the brook silverside Labidesthes sicculus, banded killifish Fundulus diaphanus, round goby Neogobius melanostomus, mimic shiner Notropis volucellus, and bluntnose minnow Pimephales notatus, whereas species associated with electrofishing included the Chinook salmon Oncorhynchus tshawytscha, catostomids (Moxostoma spp. and Catostomus spp.), freshwater drum Aplodinotus grunniens, walleye Sander vitreus, gizzard shad Dorosoma cepedianum, and common carp Cyprinus carpio. The total length of fish captured by electrofishing was 12.8 cm (95% confidence interval ¼ 5.5– 17.2 cm) greater than that of fish captured by fyke netting. Size selectivity of the gears contributed to differences in species composition of the fish captured, supporting our initial hypothesis. Thus, small-mesh fyke nets and boat electrofishers provided complementary information on a littoral fish assemblage. Our results support use of multiple gear types in monitoring and research surveys of fish assemblages.
Copyright by the American Fisheries Society 2007, Originally published in the North American Journal of Fisheries Management 27: 825-831, 2007
Increased usage of special educational services by children born to mothers with systemic lupus erythematosus and antiphospholipid antibodies
Introduction: Surveys of long-term health and
developmental outcomes of children born to mothers
with systemic lupus erythematosus (SLE) have
suggested an increase in learning disabilities among
these children. We performed this observational study
to investigate the relationship between maternal
autoantibodies and antiphospholipid antibody
syndrome (APS) in maternal lupus patients and
neurocognitive development among their offspring.
Methods: SLE mothers with at least one live birth
postlupus diagnosis were enrolled. Data on maternal
medical/obstetric history and children’s perinatal/
medical history were collected by structured interview
and medical record reviews. The primary outcome was
requirement for special educational (SE) services,
a proxy for developmental delays. Multiple logistic
regression modelling was used to examine
associations between APS and autoantibodies with SE
usage, accounting for SLE disease severity and
potential confounders.
Results: Data on 38 mothers and 60 offspring were
analysed: SE service usage was reported for 15 of 60
(25%) offspring. Maternal APS history was
significantly associated with increased use of SE
services among offspring, including after adjustment
for lupus anticoagulant (LA) positivity and potential
confounders (OR 5.5–9.4 for delays age ≥2; p<0.05).
The presence of LA, but not other antiphospholipid
antibodies, was also associated with increased SE
services usage.
Conclusions: Maternal APS and LA were
independently associated with increased usage of
special educational services among offspring of
women with SLE.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108201/1/Lupus Sci Med-2014-Marder-.pdf5
The worrying mind in control: an investigation of adaptive working memory training and cognitive bias modification in worry-prone individuals
Worry refers to the experience of uncontrollable negative thoughts. Cognitive models suggest that the combination of negative information processing biases along with diminished attentional control contribute to worry. In the current study we investigate whether promoting a) adaptive interpretation bias and b) efficient deployment of attentional control would influence the tendency to worry. Worry-prone individuals (n = 60) received either active cognitive bias modification for interpretation bias (CBM-I) combined with sham working memory training (WMT), adaptive WMT combined with sham CBM-I, or sham WMT combined with sham CBM-I. Neither of the active training conditions reduced worry during a breathing focus task relative to the control condition. However, when considering inter-individual differences in training-related improvements, we observed a relation between increases in positive interpretation bias and a decrease in negative intrusions. Moreover, increases in working memory performance were related to a reduction in reactivity of negative intrusions to a worry period. Our findings show that facilitating a more benign interpretation bias and improving working memory capacity can have beneficial effects in terms of worry, but also highlight that transfer related gains from existing training procedures can be dependent upon improvement levels on the training task
History-sensitive versus future-sensitive approaches to security in distributed systems
We consider the use of aspect-oriented techniques as a flexible way to deal
with security policies in distributed systems. Recent work suggests to use
aspects for analysing the future behaviour of programs and to make access
control decisions based on this; this gives the flavour of dealing with
information flow rather than mere access control. We show in this paper that it
is beneficial to augment this approach with history-based components as is the
traditional approach in reference monitor-based approaches to mandatory access
control. Our developments are performed in an aspect-oriented coordination
language aiming to describe the Bell-LaPadula policy as elegantly as possible.
Furthermore, the resulting language has the capability of combining both
history- and future-sensitive policies, providing even more flexibility and
power.Comment: In Proceedings ICE 2010, arXiv:1010.530
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