Exploratory modelling of the impacts of sea-level rise on the Sundarbans mangrove forest, West Bengal, India.

In this paper we conduct exploratory simulations of the possible evolution of the Indian Sundarbans mangroves to 2100 under a range of future sea-level rise (SLR) scenarios, considering the effects of both inundation and shoreline erosion. The Sea Level Affecting Marshes Model (SLAMM) is used to simulate habitat transitions due to inundation and these outputs are combined with an empirical model of SLR-driven shoreline erosion. A set of plausible climate-induced SLR scenarios are considered, together with delta subsidence and constrained vertical sediment accretion. Significant mangrove decline is found in all cases: the greater the rise in sea level the greater the losses. By the end of the century, the Indian Sundarbans mangroves could lose between 42 % and 80 % of their current area if current management is continued. Managed realignment could offset these losses but at the expense of productive land and the migration of the human population.

Removal From Play After Concussion and Recovery Time.

OBJECTIVE: Despite increases in education and awareness, many athletes continue to play with signs and symptoms of a sport-related concussion (SRC). The impact that continuing to play has on recovery is unknown. This study compared recovery time and related outcomes between athletes who were immediately removed from play and athletes who continued to play with an SRC. METHODS: A prospective, repeated measures design was used to compare neurocognitive performance, symptoms, and recovery time between 35 athletes (mean ± SD age, 15.61 ± 1.65 years) immediately removed after an SRC (REMOVED group) compared with 34 athletes (mean ± SD age, 15.35 ± 1.73 years) who continued to play (PLAYED group) with SRC. Neurocognitive and symptom data were obtained at baseline and at 1 to 7 days and 8 to 30 days after an SRC. RESULTS: The PLAYED group took longer to recover than the REMOVED group (44.4 ± 36.0 vs 22.0 ± 18.7 days; P = .003) and were 8.80 times more likely to demonstrate protracted recovery (≥21 days) (P < .001). Removal from play status was associated with the greatest risk of protracted recovery (adjusted odds ratio, 14.27; P = .001) compared with other predictors (eg, sex). The PLAYED group exhibited significantly worse neurocognitive and greater symptoms than the REMOVED group. CONCLUSIONS: SRC recovery time may be reduced if athletes are removed from participation. Immediate removal from play is the first step in mitigating prolonged SRC recovery, and these data support current consensus statements and management guidelines.

Diel Surface Temperature Range Scales with Lake Size.

Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer diel ranges in their near-surface temperatures of between 4 and 7°C. Large diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored.

Single-dose bright light and/or caffeine effect on nocturnal performance.

BACKGROUND: The impact of the separate and combined effects of a 1-h exposure to bright light (approximately 3000 lx) and a 200-mg dose of caffeine on nocturnal performance was studied during a simulated shift-work schedule beginning 1730 in the evening and ending 1000 the next morning. HYPOTHESIS: Light and caffeine exposure were expected to improve nocturnal fatigue degradation. METHODS: There were 11 subjects tested under 4 treatment conditions: 1) 1 h Dim Light-Placebo; 2) 1 h Bright Light-Placebo; 3) 1 h Dim Light-Caffeine; 4) 1 h Bright Light-Caffeine. Exposure to the light occurred between 0130 and 0230 hours. Caffeine or placebo was administered at 0140 hours. RESULTS: Choice Reaction Time (RT) recorded during the four post-treatment sessions were shorter for the Bright Light-Caffeine, Bright Light-Placebo, and Dim Light-Caffeine conditions than for the Dim Light-Placebo condition. During the sessions beginning 0430 and 0830 hours, the shortest RT was recorded for the Bright Light-Caffeine treatment. The largest number of trials without false alarms per session for the working memory task (letter cancellation) was found for the Bright Light-Caffeine condition. Exposure for 1 h to 3000 lx reduced melatonin concentration between 42-47% from 0230 to 0410 hours. A 200-mg dose of caffeine also reduced melatonin levels, although to a lesser degree than 1 h exposure to 3000 lx. CONCLUSION: Although 1 h exposure to bright light at 0130 hours combined with a 200-mg dose of caffeine maintains performance throughout the remainder of the night/early morning, a 1-h exposure to bright light without the caffeine may actually degrade performance.