2,359 research outputs found
Detection of Single Ion Spectra by Coulomb Crystal Heating
The coupled motion of ions in a radiofrequency trap has been used to connect
the frequency- dependent laser-induced heating of a sympathetically cooled
spectroscopy ion with changes in the fluorescence of a laser-cooled control
ion. This technique, sympathetic heating spectroscopy, is demonstrated using
two isotopes of calcium. In the experiment, a few scattered photons from the
spectroscopy ion are transformed into a large deviation from the steady-state
fluorescence of the control ion. This allows us to detect an optical transition
where the number of scattered photons is below our fluorescence detection
limit. Possible applications of the technique to molecular ion spectroscopy are
briefly discussed.Comment: 7 Pages,10 Figure
Pioneering Tree Improvement in Oklahoma
The pioneering tree improvement work in Oklahoma started in 1965 when Clayton Posey moved from Auburn University to Oklahoma State University. Clayton was hired by Glen Durrell (Department Head) to fill a teaching/research position in the Department of Forestry. As a native Oklahoman, Clayton recognized the need to start some long-term studies with the economically important timber species in the state. Fortunately he had access to McIntire-Stennis funds which he used to initiate studies with loblolly pine (Pinus taeda) shortleaf pine (Pinus echinata) and eastern cottonwood (Populus deltoides). Tree selection started in 1966 and concurrently the Kiamichi Field Station was transferred to the Forestry Department from Horticulture. In typical Oklahoma fashion a strong spirit of cooperation emerged with Dierks Lumber Company (soon to be acquired by Weyerhaeuser), Herron Lumber Company, Oklahoma Forestry Division, and the Tiak District of the Ouachita National Forest all assisting with the program. The cooperative spirit was formalized in 1980 when the Oklahoma Forestry Division officially joined the Western Gulf Forest Tree Improvement Program.Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003
Effect of a Patient-Centered Phone Call by a Clinical Officer at Time of HIV Testing on Linkage to Care in Rural Kenya.
In a randomized controlled trial, we tested whether a structured, patient-centered phone call from a clinical officer after HIV testing improved linkage to/re-engagement in HIV care. Among 130 HIV-positive persons, those randomized to the phone call were significantly more likely to link to care by 7 and 30 days (P = .04)
Resource Requirements for Fault-Tolerant Quantum Simulation: The Transverse Ising Model Ground State
We estimate the resource requirements, the total number of physical qubits
and computational time, required to compute the ground state energy of a 1-D
quantum Transverse Ising Model (TIM) of N spin-1/2 particles, as a function of
the system size and the numerical precision. This estimate is based on
analyzing the impact of fault-tolerant quantum error correction in the context
of the Quantum Logic Array (QLA) architecture. Our results show that due to the
exponential scaling of the computational time with the desired precision of the
energy, significant amount of error correciton is required to implement the TIM
problem. Comparison of our results to the resource requirements for a
fault-tolerant implementation of Shor's quantum factoring algorithm reveals
that the required logical qubit reliability is similar for both the TIM problem
and the factoring problem.Comment: 19 pages, 8 figure
Factors predictive of successful retention in care among HIV-infected men in a universal test-and-treat setting in Uganda and Kenya: A mixed methods analysis.
BackgroundPrevious research indicates clinical outcomes among HIV-infected men in sub-Saharan Africa are sub-optimal. The SEARCH test and treat trial (NCT01864603) intervention included antiretroviral care delivery designed to address known barriers to HIV-care among men by decreasing clinic visit frequency and providing flexible, patient-centered care with retention support. We sought to understand facilitators and barriers to retention in care in this universal treatment setting through quantitative and qualitative data analysis.MethodsWe used a convergent mixed methods study design to evaluate retention in HIV care among adults (age > = 15) during the first year of the SEARCH (NCT01864603) test and treat trial. Cox proportional hazards regression was used to evaluate predictors of retention in care. Longitudinal qualitative data from n = 190 in-depth interviews with HIV-positive individuals and health care providers were analyzed to identify facilitators and barriers to HIV care engagement.ResultsThere were 1,863 men and 3,820 women who linked to care following baseline testing. Retention in care was 89.7% (95% CI 87.0-91.8%) among men and 89.0% (86.8-90.9%) among women at one year. In both men and women older age was associated with higher rates of retention in care at one year. Additionally, among men higher CD4+ at ART initiation and decreased time between testing and ART initiation was associated with higher rates of retention. Maintaining physical health, a patient-centered treatment environment, supportive partnerships, few negative consequences to disclosure, and the ability to seek care in facilities outside of their community of residence were found to promote retention in care.ConclusionsFeatures of the ART delivery system in the SEARCH intervention and social and structural advantages emerged as facilitators to retention in HIV care among men. Messaging around the health benefits of early ART start, decreasing logistical barriers to HIV care, support of flexible treatment environments, and accelerated linkage to care, are important to men's success in ART treatment programs. Men already benefit from increased social support following disclosure of their HIV-status. Future efforts to shift gender norms towards greater equity are a potential strategy to support high levels of engagement in care for both men and women
Gaps in the Child Tuberculosis Care Cascade in 32 Rural Communities in Uganda and Kenya.
Background:Reducing tuberculosis (TB) deaths among children requires a better understanding of the gaps in the care cascade from TB diagnosis to treatment completion. We sought to assess the child TB care cascade in 32 rural communities in Uganda and Kenya using programmatic data. Methods:This is a retrospective cohort study of 160,851 children (ages <15 years) living in 12 rural communities in Kenya and 22 in Uganda. We reviewed national TB registries from health centers in and adjacent to the 32 communities, and we included all child TB cases recorded from January 1, 2013 to June 30, 2016. To calculate the first step of the child TB care cascade, the number of children with active TB, we divided the number of reported child TB diagnoses by the 2015 World Health Organization (WHO) child TB case detection ratio for Africa of 27%. The remaining components of the Child TB Care Cascade were ascertained directly from the TB registries and included: diagnosed with TB, started on TB treatment, and completed TB treatment. Results:In two and a half years, a total of 42 TB cases were reported among children living in 32 rural communities in Uganda and Kenya. 40% of the children were co-infected with HIV. Using the WHO child TB case detection ratio, we calculated that 155 children in this cohort had TB during the study period. Of those 155 children, 42 were diagnosed and linked to TB care, 42 were started on treatment, and 31 completed treatment. Among the 42 children who started TB treatment, reasons for treatment non-completion were loss to follow up (7%), death (5%), and un-recorded reasons (5%). Overall, 20% (31/155) of children completed the child TB care cascade. Conclusion:In 32 rural communities in Uganda and Kenya, we estimate that 80% of children with TB fell off the care cascade. Reducing morbidity and mortality from child TB requires strengthening of the child TB care cascade from diagnosis through treatment completion
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