Converting energy from fusion into useful forms

If fusion power reactors are to be feasible, it will still be necessary to convert the energy of the nuclear reaction into usable form. The heat produced will be removed from the reactor core by a primary coolant, which might be water, helium, molten lithium-lead, molten lithium-containing salt, or CO2. The heat could then be transferred to a conventional Rankine cycle or Brayton (gas turbine) cycle. Alternatively it could be used for thermochemical processes such as producing hydrogen or other transport fuels. Fusion presents new problems because of the high energy neutrons released. These affect the selection of materials and the operating temperature, ultimately determining the choice of coolant and working cycle. The limited temperature ranges allowed by present day irradiated structural materials, combined with the large internal power demand of the plant, will limit the overall thermal efficiency. The operating conditions of the fusion power source, the materials, coolant, and energy conversion system will all need to be closely integrated.Comment: 22 pages, 4 figures, Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy December 11, 201

The Outcome of the ArtFrame Project, a Domain-Specific BIBFRAME Exploration

The presentation consists of three parts. Jason Kovari’s presentation examines the larger context of the various domain-specific explorations of BIBFRAME extension development, with particular focus on the overlap between art works and rare materials held in libraries. Melanie Wacker and Amber Billey then discuss the specifics of the ARTFRAME project including its initial goals, timeline, community outreach, outcome, as well as tools used and lessons learned throughout the project. Finally, Marie-Chantal L’Ecuyer-Coelho explores the contributions of ARLIS/NA's CAC as a community partner to the ARTFRAME project, highlighting its role in the process of delineating the requirements of art descriptive metadata, and developing an ontology extension suited to the specific characteristics of art objects

Cloud Vertical Distribution across Warm and Cold Fronts in CloudSat–CALIPSO Data and a General Circulation Model

Cloud vertical distributions across extratropical warm and cold fronts are obtained using two consecutive winters of CloudSat–Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) observations and National Centers for Environmental Prediction reanalysis atmospheric state parameters over the Northern and Southern Hemisphere oceans (30°–70°N/S) between November 2006 and September 2008.These distributions generally resemble those from the original model introduced by the Bergen School in the 1920s, with the following exceptions: 1) substantial low cloudiness, which is present behind and ahead of the warm and cold fronts; 2) ubiquitous high cloudiness, some of it very thin, throughout the warm-frontal region; and 3) upright convective cloudiness near and behind some warm fronts. One winter of GISS general circulation model simulations of Northern and Southern Hemisphere warm and cold fronts at 2° x 2.5° x 32 levels resolution gives similar cloud distributions but with much lower cloud fraction, a shallower depth of cloudiness, and a shorter extent of tilted warm-frontal cloud cover on the cold air side of the surface frontal position. A close examination of the relationship between the cloudiness and relative humidity fields indicates that water vapor is not lifted enough in modeled midlatitude cyclones and this is related to weak vertical velocities in the model. The model also produces too little cloudiness for a given value of vertical velocity or relative humidity. For global climate models run at scales coarser than tens of kilometers, the authors suggest that the current underestimate of modeled cloud cover in the storm track regions, and in particular the 50°–60°S band of the Southern Oceans, could be reduced with the implementation of a slantwise convection parameterization

Incidence and risk factors for chronic elevation of alanine aminotransferase levels in HIV-infected persons without hepatitis b or c virus co-infection

BACKGROUND: Chronic liver disease in human immunodeficiency virus (HIV)-infected patients is mostly caused by hepatitis virus co-infection. Other reasons for chronic alanine aminotransferase (ALT) elevation are more difficult to diagnose. METHODS: We studied the incidence of and risk factors for chronic elevation of ALT levels (greater than the upper limit of normal at 2 consecutive semi-annual visits) in participants of the Swiss HIV Cohort Study without hepatitis B virus (HBV) or hepatitis C virus (HCV) infection who were seen during the period 2002-2008. Poisson regression analysis was used. RESULTS: A total of 2365 participants were followed up for 9972 person-years (median age, 38 years; male sex, 66%; median CD4+ cell count, 426/microL; receipt of antiretroviral therapy [ART], 56%). A total of 385 participants (16%) developed chronic elevated ALT levels, with an incidence of 3.9 cases per 100 person-years (95% confidence interval [CI], 3.5-4.3 cases per 100 person-years). In multivariable analysis, chronic elevated ALT levels were associated with HIV RNA level >100,000 copies/mL (incidence rate ratio [IRR], 2.23; 95% CI, 1.45-3.43), increased body mass index (BMI, defined as weight in kilograms divided by the square of height in meters) (BMI of 25-29.9 was associated with an IRR of 1.56 [95% CI, 1.24-1.96]; a BMI 30 was associated with an IRR of 1.70 [95% CI, 1.16-2.51]), severe alcohol use (1.83 [1.19-2.80]), exposure to stavudine (IRR per year exposure, 1.12 [95% CI, 1.07-1.17]) and zidovudine (IRR per years of exposure, 1.04 [95% CI, 1.00-1.08]). Associations with cumulative exposure to combination ART, nucleoside reverse-transcriptase inhibitors, and unboosted protease inhibitors did not remain statistically significant after adjustment for exposure to stavudine. Black ethnicity was inversely correlated (IRR, 0.52 [95% CI, 0.33-0.82]). Treatment outcome and mortality did not differ between groups with and groups without elevated ALT levels. CONCLUSIONS: Among patients without hepatitis virus co-infection, the incidence of chronic elevated ALT levels was 3.9 cases per 100 person-years, which was associated with high HIV RNA levels, increased BMI, severe alcohol use, and prolonged stavudine and zidovudine exposure. Long-term follow-up is needed to assess whether chronic elevation of ALT levels will result in increased morbidity or mortality

Sediment Starvation Destroys New York City Marshes' Resistance to Sea Level Rise

New York City (NYC) is representative of many vulnerable coastal urban populations, infrastructures, and economies threatened by global sea level rise. The steady loss of marshes in NYC's Jamaica Bay is typical of many urban estuaries worldwide. Essential to the restoration and preservation of these key wetlands is an understanding of their sedimentation. Here we present a reconstruction of the history of mineral and organic sediment fluxes in Jamaica Bay marshes over three centuries, using a combination of density measurements and a detailed accretion model. Accretion rate is calculated using historical land use and pollution markers, through a wide variety of sediment core analyses including geochemical, isotopic, and paleobotanical analyses. We find that, since 1800 CE, urban development dramatically reduced the input of marsh stabilizing mineral sediment. However, as mineral flux decreased, organic matter flux increased. While this organic accumulation increase allowed vertical accumulation to outpace sea level, reduced mineral content causes structural weakness and edge failure. Marsh integrity now requires mineral sediment addition to both marshes and subsurface channels and borrow pits, a solution applicable to drowning estuaries worldwide. Integration of marsh mineral/organic accretion history with modeling provides parameters for marsh preservation at specific locales with sea level rise

Comparison of the antiremodeling effects of losartan and mirabegron in a rat model of uremic cardiomyopathy

Uremic cardiomyopathy is characterized by diastolic dysfunction (DD), left ventricular hypertrophy (LVH), and fibrosis. Angiotensin-II plays a major role in the development of uremic cardiomyopathy via nitro-oxidative and inflammatory mechanisms. In heart failure, the beta-3 adrenergic receptor (beta 3-AR) is up-regulated and coupled to endothelial nitric oxide synthase (eNOS)-mediated pathways, exerting antiremodeling effects. We aimed to compare the antiremodeling effects of the angiotensin-II receptor blocker losartan and the beta 3-AR agonist mirabegron in uremic cardiomyopathy. Chronic kidney disease (CKD) was induced by 5/6th nephrectomy in male Wistar rats. Five weeks later, rats were randomized into four groups: (1) sham-operated, (2) CKD, (3) losartan-treated (10 mg/kg/day) CKD, and (4) mirabegron-treated (10 mg/kg/day) CKD groups. At week 13, echocardiographic, histologic, laboratory, qRT-PCR, and Western blot measurements proved the development of uremic cardiomyopathy with DD, LVH, fibrosis, inflammation, and reduced eNOS levels, which were significantly ameliorated by losartan. However, mirabegron showed a tendency to decrease DD and fibrosis; but eNOS expression remained reduced. In uremic cardiomyopathy, beta 3-AR, sarcoplasmic reticulum ATPase (SERCA), and phospholamban levels did not change irrespective of treatments. Mirabegron reduced the angiotensin-II receptor 1 expression in uremic cardiomyopathy that might explain its mild antiremodeling effects despite the unchanged expression of the beta 3-AR.Peer reviewe

Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age