265 research outputs found

    A scaled fundamental equation for the thermodynamic properties of carbon dioxide in the critical region

    Get PDF
    A scaled fundamental equation is presented for the thermodynamic properties of carbon dioxide in the critical region. The equation is constructed by combining earlier experimental pressure data of Michels and co‐workers with new specific heat data obtained by one of the authors and represents the thermodynamic properties of carbon dioxide in the critical region at temperatures from 301.15 to 323 K and at densities from 290 to 595 kg/m3

    Limaria hians (Mollusca : Limacea): a neglected reef-forming keystone species

    Get PDF
    1. A key component of physical habitat along braided river systems is the exposed riverine sediment within the active zone. The relatively unmanaged, gravel-bed Fiume Tagliamento, Italy, provides the focus for exploring two ecologically important properties of exposed riverine sediments: their within-patch and between-patch variability in calibre. 2. To characterize between-patch variation in exposed riverine sediments, replicate (within-patch) samples were obtained from three geomorphologically distinct locations along 130 km of the river: bar heads along the margin of the low-flow channel, the heads of major bars across the exposed surface of the active zone, and floodplain surfaces. A photographic technique enabled rapid and consistent field sampling of the coarse sediments at bar heads along the low-flow channel margin and on major bars across the dry bed. 3. A downstream decrease in particle size and an increase in within-patch heterogeneity in sediment size were observed within bar head sediments along the margin of the low-flow channel. Comparisons between major bar and low-flow channel samples revealed greatest within-patch variability in individual sediment size indices (D50, A- and B-axes of the larger particles) at headwater sites, greatest between-patch variability in the three measured indices in the central reaches, and lowest between-patch variability at downstream sites. However, there was a distinct increase in the overall heterogeneity in particle size, which was sustained across all patches, in a downstream direction. 4. There was a clear downstream decrease in the size of floodplain sediments in the headwaters, but thereafter there was no distinct downstream trend in any of the calculated particle size indices. 5. The geomorphological controls on the observed patterns and the potential ecological significance of the patterns, particularly for plant establishment, are discussed in relation to the relative relief of the active zone, and the highly variable hydrological and climatic regime along the river

    Effects of n-butanol and filipin on membrane permeability of developing wheat endosperm with different sterol phenotypes.

    Get PDF
    Sterols are considered structural components of higher plant membranes on the basis of their presence in membrane-containing subcellular fractions [1—3], their effect on plant membrane permeability when added exogenously [4,5] and the sensitivity of plant cells to the polyene antibiotic filipin [6—8], which action is known to depend on the presence of sterols in the membrane (see [8]). Our recent finding of a gene that controls the free sterol level of developing wheat endosperm [9—11 ] allows to investígate whether endogenous sterol modifies membrane permeability in the same way as that added externally. We report here on the effect of «-butanol and filipin on the leakage properties of developing wheat endosperms with different genetically determined free sterol levéis

    Kidney injury molecule-1 is an early biomarker of cadmium nephrotoxicity

    Get PDF
    Cadmium (Cd) exposure results in injury to the proximal tubule characterized by polyuria and proteinuria. Kidney injury molecule-1 (Kim-1) is a transmembrane glycoprotein not normally detected in the mature kidney, but is upregulated and shed into the urine following nephrotoxic injury. In this study, we determine if Kim-1 might be a useful early biomarker of Cd nephrotoxicity. Male Sprague–Dawley rats were given daily injections of Cd for up to 12 weeks. Weekly urine samples were analyzed for Kim-1, protein, creatinine, metallothionein, and Clara cell protein CC-16. Significant levels of Kim-1 were detected in the urine by 6 weeks and continued to increase throughout the treatment period. This appearance of Kim-1 occurred 4–5 weeks before the onset of proteinuria, and 1–3 weeks before the appearance of metallothionein and CC-16. Higher doses of Cd gave rise to higher Kim-1 excretion. Reverse transcriptase-polymerase chain reaction (RT-PCR) expression analysis showed that Kim-1 transcript levels were increased after 6 weeks at the low dose of Cd. Immunohistochemical analysis showed that Kim-1 was present in proximal tubule cells of the Cd-treated rats. Our results suggest that Kim-1 may be a useful biomarker of early stages of Cd-induced proximal tubule injury

    Cost-effectiveness findings from the Agewell pilot study of behaviour change to promote health and wellbeing in later life

    Get PDF
    Background: Participation in cognitive and physical activities may help to maintain health and wellbeing in older people. The Agewell study explored the feasibility of increasing cognitive and physical activity in older people through a goal-setting approach. This paper describes the findings of the cost-effectiveness analysis.Method: Individuals over the age of 50 and attending an Agewell centre in North Wales were randomised to one of three conditions: control (IC), goal-setting (GS), or goal-setting with mentoring (GM). We undertook a cost-effectiveness analysis comparing GS vs. IC, GM vs. IC and GM vs. GS. The primary outcome measure for this analysis was the QALY, calculated using the EQ-5D. Participants’ health and social care contacts were recorded and costed using national unit costs.Results: Seventy participants were followed-up at 12 months. Intervention set up and delivery costs were £252 per participant in the GS arm and £269 per participant in the GM arm. Mean health and social care costs over 12 months were £1,240 (s.d. £3,496) per participant in the IC arm, £1,259 (s.d. £3,826) per participant in the GS arm and £1,164 (s.d. £2,312) per participant in the GM arm. At a willingness to pay threshold of £20,000 per QALY there was a 65% probability that GS was cost-effective compared to IC (ICER of £1,070). However, there was only a 41% probability that GM was cost-effective compared to IC (ICER of £2,830) at a threshold of £20,000 per QALY.Conclusion: Setting up and running the community based intervention was feasible. Due to the small sample size it is not possible to draw a firm conclusion about cost-effectiveness; however, our preliminary results suggest that goalsetting is likely to be cost-effective compared to the control condition of no goal-setting, the addition of mentoring was effective but not cost-effective

    The Puzzle of the Flyby Anomaly

    Full text link
    Close planetary flybys are frequently employed as a technique to place spacecraft on extreme solar system trajectories that would otherwise require much larger booster vehicles or may not even be feasible when relying solely on chemical propulsion. The theoretical description of the flybys, referred to as gravity assists, is well established. However, there seems to be a lack of understanding of the physical processes occurring during these dynamical events. Radio-metric tracking data received from a number of spacecraft that experienced an Earth gravity assist indicate the presence of an unexpected energy change that happened during the flyby and cannot be explained by the standard methods of modern astrodynamics. This puzzling behavior of several spacecraft has become known as the flyby anomaly. We present the summary of the recent anomalous observations and discuss possible ways to resolve this puzzle.Comment: 6 pages, 1 figure. Accepted for publication by Space Science Review

    Systolic blood pressure reduction during the first 24 h in acute heart failure admission: friend or foe?

    Get PDF
    Aims: Changes in systolic blood pressure (SBP) during an admission for acute heart failure (AHF), especially those leading to hypotension, have been suggested to increase the risk for adverse outcomes. Methods and results: We analysed associations of SBP decrease during the first 24 h from randomization with serum creatinine changes at the last time-point available (72 h), using linear regression, and with 30- and 180-day outcomes, using Cox regression, in 1257 patients in the VERITAS study. After multivariable adjustment for baseline SBP, greater SBP decrease at 24 h from randomization was associated with greater creatinine increase at 72 h and greater risk for 30-day all-cause death, worsening heart failure (HF) or HF readmission. The hazard ratio (HR) for each 1 mmHg decrease in SBP at 24 h for 30-day death, worsening HF or HF rehospitalization was 1.01 [95% confidence interval (CI) 1.00–1.02; P = 0.021]. Similarly, the HR for each 1 mmHg decrease in SBP at 24 h for 180-day all-cause mortality was 1.01 (95% CI 1.00–1.03; P = 0.038). The associations between SBP decrease and outcomes did not differ by tezosentan treatment group, although tezosentan treatment was associated with a greater SBP decrease at 24 h. Conclusions: In the current post hoc analysis, SBP decrease during the first 24 h was associated with increased renal impairment and adverse outcomes at 30 and 180 days. Caution, with special attention to blood pressure monitoring, should be exercised when vasodilating agents are given to AHF patients

    Predictors and associations with outcomes of length of hospital stay in patients with acute heart failure: results from VERITAS

    Get PDF
    Background: The length of hospital stay (LOS) is important in patients admitted for acute heart failure (AHF) because it prolongs an unpleasant experience for the patients and adds substantially to health care costs. Methods and Results: We examined the association between LOS and baseline characteristics, 10-day post-discharge HF readmission, and 90-day post-discharge mortality in 1347 patients with AHF enrolled in the VERITAS program. Longer LOS was associated with greater HF severity and disease burden at baseline; however, most of the variability of LOS could not be explained by these factors. LOS was associated with a higher HF risk of both HF readmission (odds ratio for 1-day increase: 1.08; 95% confidence interval [CI] 1.01–1.16; P = .019) and 90-day mortality (hazard ratio for 1-day increase: 1.05; 95% CI 1.02–1.07; P < .001), although these associations are partially explained by concurrent end-organ damage and worsening heart failure during the first days of admission. Conclusions: In patients who have been admitted for AHF, longer length of hospital stay is associated with a higher rate of short-term mortality. Clinical Trial Registration: VERITAS-1 and -2: Clinicaltrials.gov identifiers NCT00525707 and NCT00524433

    Glassy Vortex State in a Two-Dimensional Disordered XY-Model

    Full text link
    The two-dimensional XY-model with random phase-shifts on bonds is studied. The analysis is based on a renormalization group for the replicated system. The model is shown to have an ordered phase with quasi long-range order. This ordered phase consists of a glass-like region at lower temperatures and of a non-glassy region at higher temperatures. The transition from the disordered phase into the ordered phase is not reentrant and is of a new universality class at zero temperature. In contrast to previous approaches the disorder strength is found to be renormalized to larger values. Several correlation functions are calculated for the ordered phase. They allow to identify not only the transition into the glassy phase but also an additional crossover line, where the disconnected vortex correlation changes its behavior on large scales non-analytically. The renormalization group approach yields the glassy features without a breaking of replica symmetry.Comment: latex 12 pages with 3 figures, using epsf.sty and multicol.st

    Using an Observational Framework to investigate adult language input to young children in a naturalistic environment

    Get PDF
    The correlation between the communicative intent of parents, in terms of their expectation of a response and the response patterns of young children aged 23—25 months during parent—child interactions, was investigated. An Observational Framework was used to code these parameters in interactions between 36 children and their mothers. The children were assigned by cluster analysis to `advanced', `typical' and `delayed' language groups and their responses were coded with respect to the degree of correctness or appropriateness within the interaction. Differences in both the parental response expectations and the children's response patterns across the three clusters are discussed
    corecore