4,706 research outputs found
Who Will Be Uninsured After Health Insurance Reform?
Projects state-by-state compositions of the uninsured after reforms take effect including those eligible for Medicaid or exchanges but not enrolled, those exempt from the individual mandate due to a lack of affordable options, and undocumented immigrants
Ultrafast switching of photonic entanglement
To deploy and operate a quantum network which utilizes existing
telecommunications infrastructure, it is necessary to be able to route
entangled photons at high speeds, with minimal loss and signal-band noise,
and---most importantly---without disturbing the photons' quantum state. Here we
present a switch which fulfills these requirements and characterize its
performance at the single photon level; it exhibits a 200-ps switching window,
a 120:1 contrast ratio, 1.5 dB loss, and induces no measurable degradation in
the switched photons' entangled-state fidelity (< 0.002). Furthermore, because
this type of switch couples the temporal and spatial degrees of freedom, it
provides an important new tool with which to encode multiple-qubit states in a
single photon. As a proof-of-principle demonstration of this capability, we
demultiplex a single quantum channel from a dual-channel,
time-division-multiplexed entangled photon stream, effectively performing a
controlled-bit-flip on a two-qubit subspace of a five-qubit, two-photon state
All-optical switching of photonic entanglement
Future quantum optical networks will require the ability to route entangled
photons at high speeds, with minimal loss and added in-band noise, and---most
importantly---without disturbing the photons' quantum state. Here we present an
all-optical switch which fulfills these requirements and characterize its
performance at the single photon level. It exhibits a 200-ps switching window,
120:1 contrast, 1.5-dB loss, and induces no measurable degradation in the
switched photons' entangled-state fidelity (< 0.002). As a proof-of-principle
demonstration of its capability, we use the switch to demultiplex a single
quantum channel from a dual-channel, time-division-multiplexed entangled photon
stream. Furthermore, because this type of switch couples the temporal and
spatial degrees of freedom, it provides an important new tool with which to
encode multiple-qubit quantum states on a single photon
Phylogeography of Rift Valley Fever Virus in Africa and the Arabian Peninsula
Rift Valley Fever is an acute zoonotic viral disease caused by Rift Valley Fever virus (RVFV) that affects ruminants and humans in Sub-Saharan Africa and the Arabian Peninsula. We used phylogenetic analyses to understand the demographic history of RVFV populations, using sequence data from the three minigenomic segments of the virus. We used phylogeographic approaches to infer RVFV historical movement patterns across its geographic range, and to reconstruct transitions among host species. Results revealed broad circulation of the virus in East Africa, with many lineages originating in Kenya. Arrival of RVFV in Madagascar resulted from three major waves of virus introduction: the first from Zimbabwe, and the second and third from Kenya. The two major outbreaks in Egypt since 1977 possibly resulted from a long-distance introduction from Zimbabwe during the 1970s, and a single introduction took RVFV from Kenya to Saudi Arabia. Movement of the virus between Kenya and Sudan, and CAR and Zimbabwe, was in both directions. Viral populations in West Africa appear to have resulted from a single introduction from Central African Republic. The overall picture of RVFV history is thus one of considerable mobility, and dynamic evolution and biogeography, emphasizing its invasive potential, potentially more broadly than its current distributional limits
Suicide Screening in Primary Care: Use of an Electronic Screener to Assess Suicidality and Improve Provider Follow-Up for Adolescents
Purpose
The purpose of this study was to assess the feasibility of using an existing computer decision support system to screen adolescent patients for suicidality and provide follow-up guidance to clinicians in a primary care setting. Predictors of patient endorsement of suicidality and provider documentation of follow-up were examined.
Methods
A prospective cohort study was conducted to examine the implementation of a CDSS that screened adolescent patients for suicidality and provided follow-up recommendations to providers. The intervention was implemented for patients aged 12â20 years in two primary care clinics in Indianapolis, Indiana.
Results
The sample included 2,134 adolescent patients (51% female; 60% black; mean ageâ=â14.6 years [standard deviationâ=â2.1]). Just over 6% of patients screened positive for suicidality. A positive endorsement of suicidality was more common among patients who were female, depressed, and seen by an adolescentâmedicine board-certified provider as opposed to general pediatric provider. Providers documented follow-up action for 83% of patients who screened positive for suicidality. Documentation of follow-up action was correlated with clinic site and Hispanic race. The majority of patients who endorsed suicidality (71%) were deemed not actively suicidal after assessment by their provider.
Conclusions
Incorporating adolescent suicide screening and provider follow-up guidance into an existing computer decision support system in primary care is feasible and well utilized by providers. Female gender and depressive symptoms are consistently associated with suicidality among adolescents, although not all suicidal adolescents are depressed. Universal use of a multi-item suicide screener that assesses recency might more effectively identify suicidal adolescents
Concurrent bariatric operations and association with perioperative outcomes: Registry based cohort study
Coevolutionary dynamics shape the structure of bacteriaâphage infection networks
Coevolutionâreciprocal evolutionary change among interacting species driven by natural selectionâis thought to be an important force in shaping biodiversity. This ongoing process takes place within tangled networks of species interactions. In microbial communities, evolutionary change between hosts and parasites occurs at the same time scale as ecological change. Yet, we still lack experimental evidence of the role of coevolution in driving changes in the structure of such species interaction networks. Filling this gap is important because network structure influences community persistence through indirect effects. Here, we quantified experimentally to what extent coevolutionary dynamics lead to contrasting patterns in the architecture of bacteriaâphage infection networks. Specifically, we look at the tendency of these networks to be organized in a nested pattern by which the more specialist phages tend to infect only a proper subset of those bacteria infected by the most generalist phages. We found that interactions between coevolving bacteria and phages become less nested over time under fluctuating dynamics, and more nested under arms race dynamics. Moreover, when coevolution results in high average infectivity, phages and bacteria differ more from each other over time under arms race dynamics than under fluctuating dynamics. The tradeoff between the fitness benefits of evolving resistance/infectivity traits and the costs of maintaining them might explain these differences in network structure. Our study shows that the interaction pattern between bacteria and phages at the community level depends on the way coevolution unfolds.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149309/1/evo13731_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149309/2/evo13731.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149309/3/evo13731-sup-0001-TableS1.pd
Bifidobacterium breve UCC2003 Exopolysaccharide Modulates the Early Life Microbiota by Acting as a Potential Dietary Substrate
Background: Bifidobacterium represents an important early life microbiota member. Specific bifidobacterial components, exopolysaccharides (EPS), positively modulate host responses, with purified EPS also suggested to impact microbeâmicrobe interactions by acting as a nutrient substrate. Thus, we determined the longitudinal effects of bifidobacterial EPS on microbial communities and metabolite profiles using an infant model colon system. Methods: Differential gene expression and growth characteristics were determined for each strain; Bifidobacterium breve UCC2003 and corresponding isogenic EPS-deletion mutant (B. breve UCC2003del). Model colon vessels were inoculated with B. breve and microbiome dynamics monitored using 16S rRNA sequencing and metabolomics (NMR). Results: Transcriptomics of EPS mutant vs. B. breve UCC2003 highlighted discrete differential gene expression (e.g., eps biosynthetic cluster), though overall growth dynamics between strains were unaffected. The EPS-positive vessel had significant shifts in microbiome and metabolite profiles until study end (405 h); with increases of Tyzzerella and Faecalibacterium, and short-chain fatty acids, with further correlations between taxa and metabolites which were not observed within the EPS-negative vessel. Conclusions: These data indicate that B. breve UCC2003 EPS is potentially metabolized by infant microbiota members, leading to differential microbial metabolism and altered metabolite by-products. Overall, these findings may allow development of EPS-specific strategies to promote infant health
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