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.

Operationalising coastal resilience to flood and erosion hazard: A demonstration for England

Resilience is widely seen as an important attribute of coastal systems and, as a concept, is increasingly prominent in policy documents. However, there are conflicting ideas on what constitutes resilience and its operationalisation as an overarching principle of coastal management remains limited. In this paper, we show how resilience to coastal flood and erosion hazard could be measured and applied within policy processes, using England as a case study. We define resilience pragmatically, integrating what is presently a disparate set of policy objectives for coastal areas. Our definition uses the concepts of resistance, recovery and adaptation, to consider how the economic, social and environmental dimensions of coastal systems respond to change. We develop a set of composite indicators for each dimension, grounded empirically with reference to national geospatial datasets. A prototype Coastal Resilience Model (CRM) has been developed, which combines the dimensions and generates a quantitative resilience index. We apply it to England's coastal hazard zone, capturing a range of different stakeholder perspectives using relative indicator weightings. The illustrative results demonstrate the practicality of formalising and quantifying resilience. To re-focus national policy around the stated desire of enhancing resilience to coastal flooding and erosion would require firm commitment from government to monitor progress towards resilience, requiring extension of the present risk-based approach, and a consensus methodology in which multiple (and sometimes conflicting) stakeholder values are explicitly considered. Such a transition may also challenge existing governance arrangements at national and local levels, requiring incentives for coastal managers to engage with and apply this new approach, more departmental integration and inter-agency cooperation. The proposed Coastal Resilience Model, with the tools to support planning and measure progress, has the potential to help enable this transition.

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.

Glutathione transferases and glutathione-binding proteins of termites: purification and characterisation

Termites have an important role in the cycling of carbon and trace elements in the biosphere through their degradation of wood, grasses and humus. Glutathione transferases (GSTs) are detoxication enzymes found in all organisms; GSTs are known to protect insects from the toxic effects of plant chemicals and pesticides. The activities and characteristics of termite GSTs were investigated in three Australian termite families. Multiple GST isozymes were purified from whole body preparations of the three termite species by affinity chromatography and subsequent chromatofocusing. Termite GSTs exhibited a broad range of activities toward model substrates but were most active with 1-chloro-2,4-dinitrobenzene. The pI values of termite GSTs ranged between 7.4 and 5.8, while the apparent molecular weights of subunits ranged between 25.9 and 27.7 kDa. The N-terminal sequence of a glutathione-binding protein that was purified from Mastotermes darwiniensis was similar to the N-terminal sequence of a streptococcal protein of unknown function previously implicated in glomerulonephritis in humans.

Social effects of diazepam use: a longitudinal field study

A longitudinal panel study examined the effects of actual use of diazepam (Valium) on subjective reports of life quality, affect, performance, stress, social support, control, coping and other variables related to mental health. Standardized interviews were conducted with 675 persons from the Detroit Metropolitan Area. Based on prescription records, diazepam users and nonusers were selected to represent a variety of sociodemographic characteristics rather than to be a completely random sample. Significant others in work and in personal life were also interviewed. Four interviews took place, one approximately every 6 weeks. Testing for social effects was conducted by within- and across-person analyses of 367 respondents who reported taking the medication at some time during the study and by comparisons with 308 respondents who did not report taking Valium. Users of Valium tended to take less Valium than prescribed. They also reported consuming less alcohol when using Valium than at other times and less than non-Valium users. Although there was a modest, positive cross-sectional relation between Valium use and distress, numerous multivariate analyses controlling for levels of stress and health indicated no notable effects of Valium use on any of the social or psychological indicators, including anxiety. Several interpretations of the results are examined including the possibility that the effects of Valium use were short-lived rather than long-term and that Valium may have been taken in anticipation of anxiety rather than after its occurrence.

Nitrogen fixation by bacteria from the hindgut of termites

Anaerobically grown bacteria isolated from the hindgut contents of the termites Coptotermes lacteus (Froggatt), Mastotermes darwiniensis Froggatt and Nasutitermes exitiosus (Hill) were nitrogenase-positive as assayed by acetylene reduction. Nitrogen fixation, confirmed with 15N2, was highest in the isolate from M. darwiniensis. All isolates were identified as Citrobacter freundii (Braak) Werkman & Gillen.