Bedtime negative affect, sleep quality and subjective health in rural China.

BACKGROUND: The overall level of negative affect (NeA) has been linked to impaired health. However, whether the diurnal timing of NeA matters and whether the NeA-health relationship is mediated by sleep quality remain unclear. METHODS: Using a longitudinal dataset (2006, 2009 and 2014 waves) consisting of 1959 participants, we examined the within-person impact of both bedtime NeA and non-bedtime NeA measured by Day Reconstruction Method (DRM) on subjective health measured by Visual Analogue Scale (VAS), and the mediating effect of sleep quality on the NeA-health relationships by fixed effect models. RESULTS: Bedtime NeA predicted poorer health, while non-bedtime NeA was unrelated to health. The deleterious impact of bedtime NeA reduced and became non-significant after sleep quality was controlled for. Bedtime NeA also significantly predicted impaired sleep quality. CONCLUSIONS: Bedtime NeA is a stronger predictor of poorer health than non-bedtime NeA, and the deleterious influence of bedtime NeA on health seems to operate through poor sleep quality. Therefore, interventions to reduce bedtime NeA could potentially improve subsequent sleep quality, thereby protecting people to some extent from impaired health status.

Within-lake habitat heterogeneity mediates community response to warming trends.

Climate change is rapidly altering many aquatic systems, and life history traits and physiological diversity create differences in organism responses. In addition, habitat diversity may be expressed on small spatial scales, and it is therefore necessary to account for variation among both species and locations when evaluating climate impacts on biological communities. Here, we investigated the effects of temperature and spatial heterogeneity on long-term community composition in a large boreal lake. We used a five-decade time series of water temperature and relative abundance of fish species captured in the littoral zone throughout the summer at 10 discrete locations around the lake. We applied a spatial dynamic factor analysis (SDFA) model to this time series, which estimates the sensitivity of each species to changing water temperature while accounting for spatiotemporal variation. This analysis described the trend in community composition at each sampling location in the lake, given their different trends in temperature over time. The SDFA indicated different magnitude and direction of species responses to temperature; some species increased while others decreased in abundance. The model also identified five unique trends in species abundance across sites and time, indicating residual dynamics in abundance after accounting for temperature effects. Thus, different regions in the lake have experienced different trajectories in community change associated with different rates of temperature change. These results highlight the importance of considering habitat heterogeneity in explaining and predicting future species abundances, and our model provides a means of visualizing spatially-explicit temporal variation in species' dynamics.

Associations between ambient air pollution and blood markers of inflammation and coagulation/fibrinolysis in susceptible populations.

The pathophysiological pathways linking particulate air pollution to cardiovascular disease are still not fully understood. We examined the association between ambient air pollutants and blood markers of inflammation and coagulation/fibrinolysis in three potentially susceptible populations. Three panels of non-smoking individuals were examined between 3/2007 and 12/2008: 1) with type 2 diabetes mellitus (T2D, n=83), 2) with impaired glucose tolerance (IGT, n=104), and 3) with a potential genetic predisposition which could affect detoxifying and inflammatory pathways (n=87) defined by the null polymorphism for glutathione S-transferase M1 (GSTM1) in combination with a certain single nucleotide polymorphism on the C-reactive protein (CRP) or the fibrinogen gene. Study participants had blood drawn up to seven times every four to six weeks. In total, 1765 blood samples were analysed for CRP, interleukin (IL)-6, soluble CD40 ligand (sCD40L), fibrinogen, myeloperoxidase (MPO), and plasminogen activator inhibitor-1 (PAI-1). Hourly mean values of particulate air pollutants, particle number concentrations in different size ranges and gaseous pollutants were collected at fixed monitoring sites and individual 24hour averages calculated. Associations between air pollutants and blood markers were analysed for each panel separately and taking the T2D panel and the IGT panel together, using additive mixed models adjusted for long-term time trend and meteorology. For the panel with potential genetic susceptibility, CRP and MPO increased for most lags, especially with the 5-day average exposure (% change of geometric mean and 95% confidence interval: 22.9% [12.0;34.7] for CRP and 5.0% [0.3;9.9] for MPO per interquartile range of PM2.5). Small positive associations were seen for fibrinogen while sCD40L, PAI-1 and IL-6 mostly decreased in association with air pollution concentrations. Except for positive associations for fibrinogen we did not see significant results with the two other panels. Participants with potential genetic susceptibility showed a clear association between inflammatory blood biomarkers and ambient air pollutants. Our results support the hypothesis that air pollution increases systemic inflammation especially in susceptible populations which may aggravate atherosclerotic diseases and induce multi-organ damage.

Biotic control of stream fluxes: spawning salmon drive nutrient and matter export.

Organisms can control movements of nutrients and matter by physically modifying habitat. We examined how an ecosystem engineer, sockeye salmon (Oncorhynchus nerka), influences seasonal fluxes of sediments, nitrogen (N), and phosphorus (P) in streams of southwestern Alaska. The purpose of this study was to investigate whether salmon act as net importers or net exporters of matter and nutrients from streams and how these roles change as a function of salmon population density. We measured discharge and concentrations of suspended sediments and total N and P every 7-14 days for up to four summers in 10 streams spanning a gradient in salmon densities. We statistically allocated whole-season fluxes to salmon activities, such as excretion and bioturbation, and to export by hydrologic discharge. In addition, we used counts of spawning salmon to estimate nutrient and matter imports by salmon to streams. Large seasonal pulses of suspended sediments, P, and N were associated with salmon spawning activities, often increasing export an order of magnitude higher than during pre-salmon levels. Years and streams with more salmon had significantly higher levels of export of sediments and nutrients. In addition, years with higher precipitation had higher background export of P and N. Salmon exported an average of the equivalent of 189%, 60%, and 55% of total matter, P, and N that salmon imported in their bodies. The relative magnitude of export varied; salmon exported more than their bodies imported in 80%, 20%, and 16% across all streams and years for sediments, P, and N, respectively. A bioassay experiment indicated that the P exported by salmon is directly available for use by primary producers in the downstream lake. These results demonstrate that salmon not only move nutrients upstream on large spatial scales via their migration from the ocean and subsequent death, but also redistribute matter and nutrients on finer spatial scales through their spawning activities.

You need not make the journey alone: overcoming impediments to providing palliative care in a public urban teaching hospital.

The majority of dying patients continue to receive care in acute, tertiary settings. This has generated the development of hospital-based palliative care (HBPC). The Symptom Management and Palliative Care Program (SMPCP) at LAC+USC Medical Center provides HBPC. The SMPCP operates as an interdisciplinary consultative service, assessing inpatients, and documenting recommendations for primary physicians. Over a 28-month period the SMPCP provided clinical recommendations, education, and research for patients, family members, and hospital staff Demographic, clinical, psychosocial, financial, and outcome information was collected on 265 patients. The SMPCP documented the attainment of defined quality end-points, including pain control within 24 hours, a Do Not Resuscitate (DNR) discussion with patient and family within 72 hours, and control of nausea and vomiting within 24 hours. Team members also documented impediments to implementing recommendations and the success of interventions to overcome impediments. Results indicated that the SMPCP achieved a high rate of quality end-point attainment when impediments were not present. The most significant impediments resulted from behaviors by primary physicians. The SMPCP's ability to overcome barrier behaviors improved the rate of end-point attainment, confirming the importance of palliative care at the end of life.