Interior Models of Uranus and Neptune

'Empirical' models (pressure vs. density) of Uranus and Neptune interiors constrained by the gravitational coefficients J_2, J_4, the planetary radii and masses, and Voyager solid-body rotation periods are presented. The empirical pressure-density profiles are then interpreted in terms of physical equations of state of hydrogen, helium, ice (H_2O), and rock (SiO_2) to test the physical plausibility of the models. The compositions of Uranus and Neptune are found to be similar with somewhat different distributions of the high-Z material. The big difference between the two planets is that Neptune requires a non-solar envelope while Uranus is best matched with a solar composition envelope. Our analysis suggests that the heavier elements in both Uranus' and Neptune's interior might increase gradually towards the planetary centers. Indeed it is possible to fit the gravitational moments without sharp compositional transitions.Comment: 16 pages, accepted for publication in Ap

Biology and population dynamics of cowcod (Sebastes levis) in the southern California Bight

Cowcod (Sebastes levis) is a large (100-cm-FL), long-lived (maximum observed age 55 yr) demersal rockfish taken in multispecies commercial and recreational fisheries off southern and central California. It lives at 20–500 m depth: adults (>44 cm TL) inhabit rocky areas at 90–300 m and juveniles inhabit fine sand and clay at 40–100 m. Both sexes have similar growth and maturity. Both sexes recruit to the fishery before reaching full maturity. Based on age and growth data, the natural mortality rate is about M =0.055/yr, but the estimate is uncertain. Biomass, recruitment, and mortality during 1951–98 were estimated in a delay-difference model with catch data and abundance indices. The same model gave less precise estimates for 1916–50 based on catch data and assumptions about virgin biomass and recruitment such as used in stock reduction analysis. Abundance indices, based on rare event data, included a habitat-area–weighted index of recreational catch per unit of fishing effort (CPUE index values were 0.003–0.07 fish per angler hour), a standardized index of proportion of positive tows in CalCOFI ichthyoplankton survey data (binomial errors, 0–13% positive tows/yr), and proportion of positive tows for juveniles in bottom trawl surveys (binomial errors, 0–30% positive tows/yr). Cowcod are overfished in the southern California Bight; biomass during the 1998 season was about 7% of the virgin level and recent catches have been near 20 metric tons (t)/yr. Projections based on recent recruitment levels indicate that biomass will decline at catch levels > 5 t/yr. Trend data indicate that recruitment will be poor in the near future. Recreational fishing effort in deep water has increased and has become more effective for catching cowcod. Areas with relatively high catch rates for cowcod are fewer and are farther offshore. Cowcod die after capture and cannot be released alive. Two areas recently closed to bottom fishing will help rebuild the cowcod stock

Translational Retinal Research and Therapies.

The following review summarizes the state of the art in representative aspects of gene therapy/translational medicine and evolves from a symposium held at the School of Veterinary Medicine, University of Pennsylvania on November 16, 2017 honoring Dr. Gustavo Aguirre, recipient of ARVO's 2017 Proctor Medal. Focusing on the retina, speakers highlighted current work on moving therapies for inherited retinal degenerative diseases from the laboratory bench to the clinic

Comparative Ovarian and Pituitary Hormone Secretion in Pregnant Meishan and Yorkshire Gilts

Chinese Meishan and Yorkshire were used to investigate mechanisms regulating the production and secretion of relaxin, progesterone, prolactin (PRL), and growth hormone (GH) during late pregnancy and lactation. Uterine surgical removal (hysterectomy) of nongravid gilts during the estrous cycle (day 8) extends luteal function to 150 days which is beyond the duration of normal pregnancy. Hysterectomy provides a useful model to examine shifts in hormone secretion at the time of expected parturition in gravid pigs. Blood samples were collected via an indwelling jugular cannula twice daily (0800 and 2000 hours) from days 90 to 120 and every 20 minutes within a 3-hour period on days 112 to 116. Relaxin and progesterone are hormones of ovarian origin, and PRL and GH are hormones secreted by the pituitary gland. Parturition occurred earlier (day 114) in Yorkshire than Meishan (day 115) gilts. The prepartum peak relaxin release occurred about 16 hours earlier in both breeds, thereafter relaxin dropped to basal levels during lactation. After hysterectomy, relaxin plasma levels were consistently greater in Meishan compared with Yorkshire gilts from days 110-118. A programmed peak relaxin release occurred one day earlier in Yorkshire compared with Meishan gilts. Following the relaxin peak, corpora lutea persisted in both breeds, but Meishan gilts continued to secrete consistently greater amounts of relaxin than Yorkshire gilts. Progesterone plasma levels remained higher longer in late pregnant Meishan compared with Yorkshire gilts. After hysterectomy, progesterone plasma levels were consistently higher in Meishan compared with Yorkshire gilts from days 101 to 118. Prolactin circulating concentration increased during late pregnancy and early lactation, but at a higher level in Yorkshire compared with Meishan gilts. Growth hormone blood levels increased only during late pregnancy and early lactation in both Meishan and Yorkshire gilts. These results indicate significant differences in the timing, and in some cases, magnitude of hormone secretion profiles in pregnant and hysterectomized Yorkshire and Meishan gilts

Injection drug use and patterns of highly active antiretroviral therapy use: an analysis of ALIVE, WIHS, and MACS cohorts

<p>Abstract</p> <p>Background</p> <p>Sustained use of antiretroviral therapy has been consistently shown to be one of the primary predictors of long-term effectiveness. Switching and discontinuation reflect patient and provider decisions that may limit future treatment options. In this study, we utilize data reported at semi-annual study visits from three prospective cohort studies, the AIDS Link to IntraVenous Exposure (ALIVE), the Women's Interagency HIV Study (WIHS), and the Multicenter AIDS Cohort Study (MACS), to investigate determinants of HAART modification with a particular focus on reported injection drug use (IDU).</p> <p>Methods</p> <p>Longitudinal data collected between 1996 and 2004 contributed from 2,266 participants (37% with a reported history of IDU) who reported initiating their first HAART regimen during follow-up were utilized. Separate proportional-hazards models were used to identify factors measured prior to HAART-initiation associated with the time to first HAART discontinuation and first switch of components of HAART among continuous HAART users.</p> <p>Results</p> <p>The use of PI- vs. NNRTI-based regimens among HAART users with and without any history of IDU was similar over follow-up. The median time to a first report of discontinuation of HAART was 1.1 years for individuals with a history of IDU but 2.5 years for those without a history of IDU and multivariate analyses confirmed overall that individuals with a history of IDU were at greater risk for HAART discontinuation (adj RH = 1.24, 95% CI: 1.03–1.48). However, when restricting to data contributed after 1999, there was no longer any significant increased risk (adj RH = 1.05, 95% CI: 0.81–1.36). After adjusting for pre-HAART health status and prior ARV exposure, individuals who were ethnic/racial minorities, reported an annual income < $10,000/year, and were not employed were at significantly greater risk for HAART discontinuation. The median time to a first change in HAART regimen was approximately 1.5 years after first HAART report and was not elevated among those with a history of IDU (adj RH = 1.09, 95% CI: 0.89–1.34).</p> <p>Conclusion</p> <p>Our analyses demonstrate that injection drug use by itself does not appear to be an independent risk factor for HAART switching or discontinuation in more recent years. However, as continued HAART use is of paramount importance for long-term control of HIV infection, efforts to improve maintenance to therapy among disadvantaged and minority populations remain greatly needed.</p

Development and Testing of Insulated Drillpipe

The Geothermal Research Department at Sandia National Laboratories, in collaboration with Drill Cool Systems, Inc., has worked to develop and test insulated drillpipe (IDP). IDP will allow much cooler drilling fluid to reach the bottom of the hole, making possible the use of downhole motors, electronics, and steering tools that are now unusable in high-temperature formations. Other advantages of cooler fluid include reduced degradation of drilling fluid, longer bit life, and reduced corrosion rates. The paper describes the theoretical background, laboratory testing, and field testing of IDP. Structural and thermal laboratory testing procedures and results are described. Results are given for a field test in a geothermal well, in which circulating temperatures in IDP are compared with those in conventional drillpipe (CDP) at different flow rates. A brief description of the software used to model wellbore temperature and to calculate sensitivity to IDP design differences is included, along with a comparison of calculated and measured wellbore temperatures in the field test. Analysis of mixed (IDP and CDP) drill strings and discussion of where IDP should be placed in a mixed string are presented

Bedrock Geology of Rockwood Quadrangle, Randolph and Jackson Counties, Illinois and Perry County, Missouri

Relief shown by contours and spot heights"Illinois geology based on field work by R. Jacobson and J. McLeod, 2004-2005.""Digital cartography by M. Jones, Illinois State Geological Survey."Includes text and 1 location map with index to adjoining quadranglesIncludes text, 1 colored stratigraphic column, and 1 diagramIncludes bibliographical references (data sheet