175 research outputs found
The Dynamic Assessment and Referral System for Substance Abuse (DARSSA): development, functionality, and end-user satisfaction
The Dynamic Assessment and Referral System for Substance Abuse (DARSSA) conducts a computerized substance abuse assessment; prints personalized summary reports that include tailored substance abuse treatment referral lists; and, for individuals who provide authorization, automatically faxes their contact information to a best match substance abuse treatment provider (dynamic referral). After piloting the program and resolving problems that were noted, we enrolled a sample of 85 medical patients. The DARSSA identified 48 (56%) participants who were risky substance users, many of whom had not been identified during their routine medical assessment. Mean satisfaction scores for all domains ranged between Good to Excellent across patients, nurses, doctors, and substance abuse treatment providers. The median completion time was 13min. Of the 48 risky substance using participants, 20 (42%) chose to receive a dynamic referral. The DARSSA provides a user-friendly, desirable service for patients and providers. It has the potential to improve identification of substance abuse in medical settings and to provide referrals that would not routinely be provided. Future studies are planned to establish its efficacy at promoting treatment initiation and abstinence
D-brane potentials in the warped resolved conifold and natural inflation
In this paper we obtain a model of Natural Inflation from string theory with
a Planckian decay constant. We investigate D-brane dynamics in the background
of the warped resolved conifold (WRC) throat approximation of Type IIB string
compactifications on Calabi-Yau manifolds. When we glue the throat to a compact
bulk Calabi-Yau, we generate a D-brane potential which is a solution to the
Laplace equation on the resolved conifold. We can exactly solve this equation,
including dependence on the angular coordinates. The solutions are valid down
to the tip of the resolved conifold, which is not the case for the more
commonly used deformed conifold. This allows us to exploit the effect of the
warping, which is strongest at the tip. We inflate near the tip using an
angular coordinate of a D5-brane in the WRC which has a discrete shift
symmetry, and feels a cosine potential, giving us a model of Natural Inflation,
from which it is possible to get a Planckian decay constant whilst maintaining
control over the backreaction. This is because the decay constant for a wrapped
brane contains powers of the warp factor, and so can be made large, while the
wrapping parameter can be kept small enough so that backreaction is under
control.Comment: 41 pages, 3 appendices, 1 figure, PDFLaTex; various clarifications
added along with a new appendix on b-axions and wrapped D5 branes;version
matches the one published in JHE
Smoking, Cardiac Symptoms, and an Emergency Care Visit: A Mixed Methods Exploration of Cognitive and Emotional Reactions
Emergency departments and hospitals are being urged to implement onsite interventions to promote smoking cessation, yet little is known about the theoretical underpinnings of behavior change after a healthcare visit. This observational pilot study evaluated three factors that may predict smoking cessation after an acute health emergency: perceived illness severity, event-related emotions, and causal attribution. Fifty smokers who presented to a hospital because of suspected cardiac symptoms were interviewed, either in the emergency department (ED) or, for those who were admitted, on the cardiac inpatient units. Their data were analyzed using both qualitative and quantitative methodologies to capture the individual, first-hand experience and to evaluate trends over the illness chronology. Reported perceptions of the event during semistructured interview varied widely and related to the individual's intentions regarding smoking cessation. No significant differences were found between those interviewed in the ED versus the inpatient unit. Although the typical profile was characterized by a peak in perceived illness severity and negative emotions at the time the patient presented in the ED, considerable pattern variation occurred. Our results suggest that future studies of eventrelated perceptions and emotional reactions should consider using multi-item and multidimensional assessment methods rated serially over the event chronology
Power and the durability of poverty: a critical exploration of the links between culture, marginality and chronic poverty
LibrettOS: A Dynamically Adaptable Multiserver-Library OS
We present LibrettOS, an OS design that fuses two paradigms to simultaneously
address issues of isolation, performance, compatibility, failure
recoverability, and run-time upgrades. LibrettOS acts as a microkernel OS that
runs servers in an isolated manner. LibrettOS can also act as a library OS
when, for better performance, selected applications are granted exclusive
access to virtual hardware resources such as storage and networking.
Furthermore, applications can switch between the two OS modes with no
interruption at run-time. LibrettOS has a uniquely distinguishing advantage in
that, the two paradigms seamlessly coexist in the same OS, enabling users to
simultaneously exploit their respective strengths (i.e., greater isolation,
high performance). Systems code, such as device drivers, network stacks, and
file systems remain identical in the two modes, enabling dynamic mode switching
and reducing development and maintenance costs.
To illustrate these design principles, we implemented a prototype of
LibrettOS using rump kernels, allowing us to reuse existent, hardened NetBSD
device drivers and a large ecosystem of POSIX/BSD-compatible applications. We
use hardware (VM) virtualization to strongly isolate different rump kernel
instances from each other. Because the original rumprun unikernel targeted a
much simpler model for uniprocessor systems, we redesigned it to support
multicore systems. Unlike kernel-bypass libraries such as DPDK, applications
need not be modified to benefit from direct hardware access. LibrettOS also
supports indirect access through a network server that we have developed.
Applications remain uninterrupted even when network components fail or need to
be upgraded. Finally, to efficiently use hardware resources, applications can
dynamically switch between the indirect and direct modes based on their I/O
load at run-time.
[full abstract is in the paper]Comment: 16th ACM SIGPLAN/SIGOPS International Conference on Virtual Execution
Environments (VEE '20), March 17, 2020, Lausanne, Switzerlan
Cooperative signaling between Wnt1 and integrin-linked kinase induces accelerated breast tumor development
Bacterial Leaf Symbiosis in Angiosperms: Host Specificity without Co-Speciation
Bacterial leaf symbiosis is a unique and intimate interaction between bacteria and flowering plants, in which endosymbionts are organized in specialized leaf structures. Previously, bacterial leaf symbiosis has been described as a cyclic and obligate interaction in which the endosymbionts are vertically transmitted between plant generations and lack autonomous growth. Theoretically this allows for co-speciation between leaf nodulated plants and their endosymbionts. We sequenced the nodulated Burkholderia endosymbionts of 54 plant species from known leaf nodulated angiosperm genera, i.e. Ardisia, Pavetta, Psychotria and Sericanthe. Phylogenetic reconstruction of bacterial leaf symbionts and closely related free-living bacteria indicates the occurrence of multiple horizontal transfers of bacteria from the environment to leaf nodulated plant species. This rejects the hypothesis of a long co-speciation process between the bacterial endosymbionts and their host plants. Our results indicate a recent evolutionary process towards a stable and host specific interaction confirming the proposed maternal transmission mode of the endosymbionts through the seeds. Divergence estimates provide evidence for a relatively recent origin of bacterial leaf symbiosis, dating back to the Miocene (5–23 Mya). This geological epoch was characterized by cool and arid conditions, which may have triggered the origin of bacterial leaf symbiosis
Testing Atmospheric Oxidation in an Alabama Forest
The chemical species emitted by forests create complex atmospheric oxidation chemistry and influence global atmospheric oxidation capacity and climate. The Southern Oxidant and Aerosol Study (SOAS) provided an opportunity to test the oxidation chemistry in a forest where isoprene is the dominant biogenic volatile organic compound. Hydroxyl (OH) and hydroperoxyl (HO_2) radicals were two of the hundreds of atmospheric chemical species measured, as was OH reactivity (the inverse of the OH lifetime). OH was measured by laser-induced fluorescence (LIF) and by taking the difference in signals without and with an OH scavenger that was added just outside the instrument’s pinhole inlet. To test whether the chemistry at SOAS can be simulated by current model mechanisms, OH and HO_2 were evaluated with a box model using two chemical mechanisms: Master Chemical Mechanism, version 3.2 (MCMv3.2), augmented with explicit isoprene chemistry and MCMv3.3.1. Measured and modeled OH peak at about 10^6 cm^(−3) and agree well within combined uncertainties. Measured and modeled HO_2 peak at about 27 pptv and also agree well within combined uncertainties. Median OH reactivity cycled between about 11 s^(−1) at dawn and about 26 s^(−1) during midafternoon. A good test of the oxidation chemistry is the balance between OH production and loss rates using measurements; this balance was observed to within uncertainties. These SOAS results provide strong evidence that the current isoprene mechanisms are consistent with measured OH and HO_2 and, thus, capture significant aspects of the atmospheric oxidation chemistry in this isoprene-rich forest
Genome sequence of the tsetse fly (Glossina morsitans):Vector of African trypanosomiasis
Tsetse flies are the sole vectors of human African trypanosomiasis throughout sub-Saharan Africa.
Both sexes of adult tsetse feed exclusively on blood and contribute to disease transmission. Notable
differences between tsetse and other disease vectors include obligate microbial symbioses, viviparous
reproduction, and lactation. Here, we describe the sequence and annotation of the 366-megabase
Glossina morsitans morsitans genome. Analysis of the genome and the 12,308 predicted
protein-encoding genes led to multiple discoveries, including chromosomal integrations of bacterial
(Wolbachia) genome sequences, a family of lactation-specific proteins, reduced complement of
host pathogen recognition proteins, and reduced olfaction/chemosensory associated genes. These
genome data provide a foundation for research into trypanosomiasis prevention and yield important
insights with broad implications for multiple aspects of tsetse biology.IS
The neutron and its role in cosmology and particle physics
Experiments with cold and ultracold neutrons have reached a level of
precision such that problems far beyond the scale of the present Standard Model
of particle physics become accessible to experimental investigation. Due to the
close links between particle physics and cosmology, these studies also permit a
deep look into the very first instances of our universe. First addressed in
this article, both in theory and experiment, is the problem of baryogenesis ...
The question how baryogenesis could have happened is open to experimental
tests, and it turns out that this problem can be curbed by the very stringent
limits on an electric dipole moment of the neutron, a quantity that also has
deep implications for particle physics. Then we discuss the recent spectacular
observation of neutron quantization in the earth's gravitational field and of
resonance transitions between such gravitational energy states. These
measurements, together with new evaluations of neutron scattering data, set new
constraints on deviations from Newton's gravitational law at the picometer
scale. Such deviations are predicted in modern theories with extra-dimensions
that propose unification of the Planck scale with the scale of the Standard
Model ... Another main topic is the weak-interaction parameters in various
fields of physics and astrophysics that must all be derived from measured
neutron decay data. Up to now, about 10 different neutron decay observables
have been measured, much more than needed in the electroweak Standard Model.
This allows various precise tests for new physics beyond the Standard Model,
competing with or surpassing similar tests at high-energy. The review ends with
a discussion of neutron and nuclear data required in the synthesis of the
elements during the "first three minutes" and later on in stellar
nucleosynthesis.Comment: 91 pages, 30 figures, accepted by Reviews of Modern Physic
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