Relaxation oscillations, stability, and cavity feedback in a superradiant Raman laser

We experimentally study the relaxation oscillations and amplitude stability properties of an optical laser operating deep into the bad-cavity regime using a laser-cooled $^{87}$Rb Raman laser. By combining measurements of the laser light field with nondemolition measurements of the atomic populations, we infer the response of the gain medium represented by a collective atomic Bloch vector. The results are qualitatively explained with a simple model. Measurements and theory are extended to include the effect of intermediate repumping states on the closed-loop stability of the oscillator and the role of cavity feedback on stabilizing or enhancing relaxation oscillations. This experimental study of the stability of an optical laser operating deep into the bad-cavity regime will guide future development of superradiant lasers with ultranarrow linewidths.Comment: 9 pages, 6 figure

Kentucky’s Primary Care Workforce: Current Status and Output of New Trainees January 2020 Update

Primary care is the backbone of American healthcare. Primary care (PC) physicians are especially cost-effective in preventing and managing illness and disability, and prolonging years of quality life. They also contribute significantly to the economy of their communities. Primary care shortages across the Commonwealth are severe. Kentucky ranks 43rd in the USA for its number of PC physicians per 100,000 people. The Commonwealth would have to add 246 primary care physicians annually to reach the US median by the end of 2029. Kentucky produces and retains only about 55 new PC physicians per year, recruiting 55 to 60 more from out of state. This total of 110 – 115 new physicians falls short of the 124 PC physicians that must be added annually to avoid worsening our shortage, and far below the 246 PC physicians that Kentucky would need to add each year to reach the US median in the coming decade

Improved Aircraft Acoustic Technology and its Effect on Airport Community Noise Impact

No abstract availabl

Investigating the insecticidal potential of Geomyces (Myxotrichaceae: Helotiales) and Mortierella (Mortierellacea: Mortierellales) isolated from Antarctica

Fungi isolated from environmentally challenging habitats can have adaptations of potential value when developed as insect pest-controls. Fungal isolates collected from Antarctica, Geomyces sp. I, Geomyces sp. II, Mortierella signyensis and M. alpina, were investigated for (i) growth characteristics at 0-35[degree sign]C, (ii) spore production at 10 and 20[degree sign]C, (iii) viability following exposure to freezing temperatures, and (iv) insecticidal activity against waxmoths (Galleria mellonella L.), houseflies (Musca domestica L.), mealworms (Tenebrio molitor L.) and black vine weevils (Otiorhynchus sulcatus Fabricius). All isolates showed growth between 5-20[degree sign]C, with some showing growth outside this range. Geomyces isolates sporulated over a wider range of conditions than the Mortierella isolates. Spore germination at 10[degree sign]C was higher for Geomyces sp. II when this isolate was produced at 10 compared to 20[degree sign]C (greatest difference 74.6 vs 32.7%). All isolates grew, with the exception of M. alpina, following exposure to -20[degree sign]C for 4 weeks. Insecticidal investigations showed M. alpina and M. signyensis caused significant mortality of waxmoth and housefly larvae via injection and soil inoculation, and M. alpina caused significant mortality of housefly larvae via baiting; the Geomyces isolates had little lethal effect

Bivariate causal mixture model quantifies polygenic overlap between complex traits beyond genetic correlation.

Accumulating evidence from genome wide association studies (GWAS) suggests an abundance of shared genetic influences among complex human traits and disorders, such as mental disorders. Here we introduce a statistical tool, MiXeR, which quantifies polygenic overlap irrespective of genetic correlation, using GWAS summary statistics. MiXeR results are presented as a Venn diagram of unique and shared polygenic components across traits. At 90% of SNP-heritability explained for each phenotype, MiXeR estimates that 8.3 K variants causally influence schizophrenia and 6.4 K influence bipolar disorder. Among these variants, 6.2 K are shared between the disorders, which have a high genetic correlation. Further, MiXeR uncovers polygenic overlap between schizophrenia and educational attainment. Despite a genetic correlation close to zero, the phenotypes share 8.3 K causal variants, while 2.5 K additional variants influence only educational attainment. By considering the polygenicity, discoverability and heritability of complex phenotypes, MiXeR analysis may improve our understanding of cross-trait genetic architectures

Kentucky’s Primary Care Workforce Shortages 2016 - 2025 and Recommendations for Increasing the Production of Primary Care Physicians for Kentucky

An excerpt from the executive summary: Kentucky and the nation face severe shortages of primary care (PC) physicians. PC physicians are essential to cost-effective healthcare. Kentucky ranks 40th among the United States in its PC physician workforce per 100,000 people, with 2,696 practicing PC physicians statewide. The purposes of this white paper are to: Present up-to-date data and information about the primary care workforce in Kentucky Describe current trainee pipelines that supply new primary care physicians to Kentucky Recommend strategies and tactics for improving the primary care physician workforc

Well-managed grazing systems: A forgotten hero of conservation

Ecologically sound grazing management is an underused and underappreciated conservation tool in the eastern United States. We contend that significant policy and educational barriers stand in the way of expanding the use of this conservation tool. Well-managed pasture systems combine vigorous perennial vegetation cover, reduced pesticide and fertilizer inputs, and lower costs of production using ecological approaches to generate ecosystem services for society, as well as economic sustainability for the producer. The majority of currently available conservation policy tools were designed to address either rangeland grazing situations in the western United States or conservation cropping in the eastern United States. To promote well-managed pastures in the eastern United States, resource managers and government agencies struggle to adapt programs that are really designed for annual row crop systems. Additional educational and technical assistance resources are needed for promoting well-managed pasture-based farming in the region. This paper summarizes the potential of well-managed pasture systems to provide ecosystem services, provides thoughts for discussion on the barriers to adoption of such systems in the eastern United States, and offers some solutions to move such systems forward through policy and educational efforts. These ideas were first presented at a symposium as part of the 2011 Annual Conference of the Soil and Water Conservation Society in Washington, DC