Variable thrust ion engine utilizing thermally decomposable solid fuel Patent

Variable thrust ion engine using thermal decomposition of solid cesium compound to produce propulsive vapo

Obstacles to the Revival of Mobile Grazing Systems in Kazakhstan

Livestock mobility was an essential characteristic of Kazakh livestock production systems, allowing animals to take advantage of spatial and temporal variability in climate and vegetation, optimising forage intake over the year. These systems broke down following the end of the Soviet Union. In this paper we examine the extent and determinants of the recovery of mobile livestock husbandry in south-eastern Kazakhstan, using surveys and semi-structured interviews with livestock farmers and rural households (holding livestock but not registered as farms). We find positive relationships between livestock holding size and probability of mobility. Winter pastures are particularly important for large farms, with households and smaller farms more dependent on supplementary fodder. The major formal property right over pasture is the long-term leasehold, allocated by auction and associated with significant transaction costs. Leasehold markets function poorly, so farms use a combination of leasing, subleasing and short-term contracts with local authorities to assemble the pastoral resources they need. Few farmers conduct more than a simplified summer-winter migration, whilst around 30% of farms and 70% of households (which own the bulk of livestock) are entirely sedentary, staying on over-used village pastures all year round. Many of these producers express a desire for improved pasture access. The 2017 Law on Pastures introduced district-level pasture use planning, with promotion of mobility and allocation of remote pastures to those with poor access. But the Law does not include new land tenure mechanisms appropriate for small producers (owning few livestock and without leaseholds) which can be employed to realise this goal. Moreover, most pastures are already leased. We discuss options for grazing system management which may simultaneously increase the economic contribution of pastures, improve their condition and reduce rural inequalities created by disparities in access to resources

Low-frequency ocean bottom pressure variations in the North Pacific in response to time-variable surface winds

One decade of time-variable gravity field observations from the GRACE satellite mission reveals low-frequency ocean bottom pressure (OBP) variability of up to 2.5 hPa centered at the northern flank of the subtropical gyre in the North Pacific. From a 145 year-long simulation with a coupled chemistry climate model, OBP variability is found to be related to the prevailing atmospheric sea-level pressure and surface wind conditions in the larger North Pacific area. The dominating atmospheric pressure patterns obtained from the climate model run allow in combination with ERA-Interim sea-level pressure and surface winds a reconstruction of the OBP variability in the North Pacific from atmospheric model data only, which correlates favorably (r=0.7) with GRACE ocean bottom pressure observations. The regression results indicate that GRACE-based OBP observations are indeed sensitive to changes in the prevailing sea-level pressure and thus surface wind conditions in the North Pacific, thereby opening opportunities to constrain atmospheric models from satellite gravity observations over the oceans

Measurements of total odd nitrogen (NOy) aboard MOZAIC in-service aircraft: instrument design, operation and performance

A small system for the unattended measurement of total odd nitrogen (NOy, i.e., the sum of NO and its atmospheric oxidation products) aboard civil in-service aircraft in the framework of MOZAIC is described. The instrument employs the detection of NO by its chemiluminescence with O-3 in combination with catalytic conversion of the other NOy compounds to NO at 300degreesC on a gold surface in the presence of H-2. The instrument has a sensitivity of 0.4-0.7 cps/ppt and is designed for unattended operation during 1-2 service cycles of the aircraft (400-800 flight hours). The total weight is 50 kg, including calibration system, compressed gases, mounting, and safety measures. The layout and inlet configuration are governed by requirements due to the certification for passenger aircraft. Laboratory tests are described regarding the conversion efficiency for NO2 and HNO3 (both > 98%). Interference by non-NOy species is <1% for CH3CN and NH3, <5 x 10(-5) % for N2O (corresponding to <0.2 ppt fake NOy from ambient N2O) and 100% for HCN. The time response of the instrument is <1 s (90% change) for NO2. The response for HNO3 is nonlinear: 20 s for 67%, 60 s for 80%, and 150 s for 90% response, respectively

Demographic, Clinical, and Behavioral Determinants of 7-Year Weight Change Trajectories in Roux-en-Y Gastric Bypass Patients.

BACKGROUND: Weight change trajectories after weight-loss surgery may vary significantly. OBJECTIVES: This study evaluated the weight trajectories of Roux-en-Y gastric bypass (RYGB) patients and identified the distinct clinical, behavioral, and demographic features of patients by trajectory. SETTING: Data from 2918 RYGB patients from a comprehensive medical center between January 2004 and November 2016 were included. METHODS: This retrospective, observational study used data for RYGB patients up to year 7 postsurgery. Group-based trajectory models were fitted for percentage weight change. Variables evaluated by trajectory included age, sex, diagnoses, medications, smoking, presurgical body mass index, preoperative weight loss, and early postoperative weight loss. RESULTS: Of 3215 possible patients, 2918 (90.8%) were included (mean age = 46.2 ± 11.2 yr, body mass index = 46.9 ± 7.9 kg/m CONCLUSION: Select clinical, demographic, and behavioral factors may increase or decrease the chance for better weight loss after RYGB

STIRAP transport of Bose-Einstein condensate in triple-well trap

The irreversible transport of multi-component Bose-Einstein condensate (BEC) is investigated within the Stimulated Adiabatic Raman Passage (STIRAP) scheme. A general formalism for a single BEC in M-well trap is derived and analogy between multi-photon and tunneling processes is demonstrated. STIRAP transport of BEC in a cyclic triple-well trap is explored for various values of detuning and interaction between BEC atoms. It is shown that STIRAP provides a complete population transfer at zero detuning and interaction and persists at their modest values. The detuning is found not to be obligatory. The possibility of non-adiabatic transport with intuitive order of couplings is demonstrated. Evolution of the condensate phases and generation of dynamical and geometric phases are inspected. It is shown that STIRAP allows to generate the unconventional geometrical phase which is now of a keen interest in quantum computing.Comment: 9 pages, 6 figures. To be published in Laser Physics (v. 19, n.4, 2009

Per- and polyfluoroalkyl substances (PFAS) exposure and thyroid cancer risk

BACKGROUND: Although per- and polyfluoroalkyl substances (PFAS) exposure is a potential contributor to the increasing thyroid cancer trend, limited studies have investigated the association between PFAS exposure and thyroid cancer in human populations. We therefore investigated associations between plasma PFAS levels and thyroid cancer diagnosis using a nested case-control study of patients with thyroid cancer with plasma samples collected at/before cancer diagnosis. METHODS: 88 patients with thyroid cancer using diagnosis codes and 88 healthy (non-cancer) controls pair-matched on sex, age (±5 years), race/ethnicity, body mass index, smoking status, and year of sample collection were identified in the BioMe population (a medical record-linked biobank at the Icahn School of Medicine at Mount Sinai in New York); 74 patients had papillary thyroid cancer. Eight plasma PFAS were measured using untargeted analysis with liquid chromatography-high resolution mass spectrometry and suspect screening. Associations between individual PFAS levels and thyroid cancer were evaluated using unconditional logistic regression models to estimate adjusted odds ratios (OR adj) and 95% confidence intervals (CI). FINDINGS: There was a 56% increased rate of thyroid cancer diagnosis per doubling of linear perfluorooctanesulfonic acid (n-PFOS) intensity (OR adj, 1.56, 95% CI: 1.17-2.15, P = 0.004); results were similar when including patients with papillary thyroid cancer only (OR adj, 1.56, 95% CI: 1.13-2.21, P = 0.009). This positive association remained in subset analysis investigating exposure timing including 31 thyroid cancer cases diagnosed ≥1 year after plasma sample collection (OR adj, 2.67, 95% CI: 1.59-4.88, P < 0.001). INTERPRETATION: This study reports associations between exposure to PFAS and increased rate of (papillary) thyroid cancer. Thyroid cancer risk from PFAS exposure is a global concern given the prevalence of PFAS exposure. Individual PFAS studied here are a small proportion of the total number of PFAS supporting additional large-scale prospective studies investigating thyroid cancer risk associated with exposure to PFAS chemicals. FUNDING: National Institutes of Health grants and The Andrea and Charles Bronfman Philanthropies

Selection of an optimal neural network architecture for computerâ aided detection of microcalcificationsâ Comparison of automated optimization techniques

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134870/1/mp5036.pd

Risk factors for severe outcomes in Extended-Spectrum Beta-Lactamase (ESBL) Bacteremia: a single-center study

Expanded-spectrum beta-lactamase (ESBL) bacteremia often leads to severe outcomes like mortality and treatment failure. This study aimed to identify risk factors in patients with ESBL bacteremia. A retrospective cohort analysis was conducted among patients aged 13 years and above who were admitted to Hospital Canselor Tuanku Muhriz (HCTM) due to ESBL bacteremia between the period of January 2015 and August 2019. Patients with polymicrobial bacteremia were excluded. The all-cause in HCTM mortality rate was 30.2%, while the infection-related mortality rate was 22.5%. The risk factors of all-cause in-hospital mortality include hypertension, diabetes mellitus, skin and soft tissue infections (SSTIs), urinary catheterisation and mechanical ventilation. The independent risk factor associated with mortality was mechanical ventilation (AOR 3.12; CI 1.06- 9.18; p = 0.04). No association found between appropriate empirical antibiotic treatment with mortality (p = 0.74), treatment success (p = 0.71) or length of hospital stay (p = 0.84). However, appropriate definitive treatment was associated with a lower mortality rate (p<0.01) and higher treatment success (p<0.01). Mechanical ventilation was the only independent risk factor significantly associated with mortality, while appropriate definitive treatment was associated with a lower mortality rate and higher treatment success