Response of foundation macrophytes to near‐natural simulated marine heatwaves

Marine heatwaves have been observed worldwide and are expected to increase in both frequency and intensity due to climate change. Such events may cause ecosystem reconfigurations arising from species range contraction or redistribution, with ecological, economic and social implications. Macrophytes such as the brown seaweed Fucus vesiculosus and the seagrass Zostera marina are foundation species in many coastal ecosystems of the temperate northern hemisphere. Hence, their response to extreme events can potentially determine the fate of associated ecosystems. Macrophyte functioning is intimately linked to the maintenance of photosynthesis, growth and reproduction, and resistance against pathogens, epibionts and grazers. We investigated morphological, physiological, pathological and chemical defence responses of western Baltic Sea F. vesiculosus and Z. marina populations to simulated near‐natural marine heatwaves. Along with (a) the control, which constituted no heatwave but natural stochastic temperature variability (0HW), two treatments were applied: (b) two late‐spring heatwaves (June, July) followed by a summer heatwave (August; 3HW) and (c) a summer heatwave only (1HW). The 3HW treatment was applied to test whether preconditioning events can modulate the potential sensitivity to the summer heatwave. Despite the variety of responses measured in both species, only Z. marina growth was impaired by the accumulative heat stress imposed by the 3HW treatment. Photosynthetic rate, however, remained high after the last heatwave indicating potential for recovery. Only epibacterial abundance was significantly affected in F. vesiculosus. Hence both macrophytes, and in particular F. vesiculosus, seem to be fairly tolerant to short‐term marine heatwaves at least at the intensities applied in this experiment (up to 5°C above mean temperature over a period of 9 days). This may partly be due to the fact that F. vesiculosus grows in a highly variable environment, and may have a high phenotypic plasticity.     

Streptomonospora litoralis sp. nov., a halophilic thiopeptides producer isolated from sand collected at Cuxhaven beach

Antonie van Leeuwenhoek - Strain M2T was isolated from the beach of Cuxhaven, Wadden Sea, Germany, in course of a program to attain new producers of bioactive natural products. Strain M2T produces...     

Myeloperoxidase-mediated LDL oxidation and endothelial cell toxicity of oxidized LDL: attenuation by (−)-epicatechin

Recent data suggest an inverse epidemiological association between intake of flavanol-rich cocoa products and cardiac mortality. Potential beneficial effect of cocoa may be attributed to flavanol-mediated improvement of endothelial function, as well as to enhancement of bioavailability and bioactivity of nitric oxide in vivo. ( ? )-Epicatechin is one bioactive flavanol found in cocoa. This review deals with protective actions of ( ? )-epicatechin on two key processes in atherogenesis, oxidation of LDL and damage to endothelial cell by oxidized LDL (oxLDL), with emphasis on data from this laboratory. ( ? )-Epicatechin not only abrogates or attenuates LDL oxidation but also counteracts deleterious actions of oxLDL on vascular endothelial cells. These protective actions are only partially shared by other vasoprotective agents such as vitamins C and E or aspirin. Thus, ( ? )-epicatechin appears to be a pleiotropic protectant for both LDL and endothelial cells.     

Evaluating the effectiveness of conservation site networks under climate change: accounting for uncertainty

We forecasted potential impacts of climate change on the ability of a network of key sites for bird conservation (Important Bird Areas; IBAs) to provide suitable climate for 370 bird species of current conservation concern in two Asian biodiversity hotspots: the Eastern Himalaya and Lower Mekong. Comparable studies have largely not accounted for uncertainty, which may lead to inappropriate conclusions. We quantified the contribution of four sources of variation (choice of general circulation models, emission scenarios and species distribution modelling methods and variation in species distribution data) to uncertainty in forecasts and tested if our projections were robust to these uncertainties. Declines in the availability of suitable climate within the IBA network by 2100 were forecast as ‘extremely likely’ for 45% of species, whereas increases were projected for only 2%. Thus, we predict almost 24 times as many ‘losers’ as ‘winners’. However, for no species was suitable climate ‘extremely likely’ to be completely lost from the network. Considerable turnover (median = 43%, 95% CI = 35–69%) in species compositions of most IBAs were projected by 2100. Climatic conditions in 47% of IBAs were projected as ‘extremely likely’ to become suitable for fewer priority species. However, no IBA was forecast to become suitable for more species. Variation among General Circulation Models and Species Distribution Models contributed most to uncertainty among forecasts. This uncertainty precluded firm conclusions for 53% of species and IBAs because 95% confidence intervals included projections of no change. Considering this uncertainty, however, allows robust recommendations concerning the remaining species and IBAs. Overall, while the IBA network will continue to sustain bird conservation, climate change will modify which species each site will be suitable for. Thus, adaptive management of the network, including modified site conservation strategies and facilitating species' movement among sites, is critical to ensure effective future conservation.     

Novel Systems for Dynamically Assessing Insulin Action in Live Cells Reveals Heterogeneity in the Insulin Response

Regulated GLUT4 trafficking is a key action of insulin. Quantitative stepwise analysis of this process provides a powerful tool for pinpointing regulatory nodes that contribute to insulin regulation and insulin resistance. We describe a novel GLUT4 construct and workflow for the streamlined dissection of GLUT4 trafficking; from simple high throughput screens to high resolution analyses of individual vesicles. We reveal single cell heterogeneity in insulin action highlighting the utility of this approach – each cell displayed a unique and highly reproducible insulin response, implying that each cell is hard‐wired to produce a specific output in response to a given stimulus. These data highlight that the response of a cell population to insulin is underpinned by extensive heterogeneity at the single cell level. This heterogeneity is pre‐programmed within each cell and is not the result of intracellular stochastic events.     

Burden of Giardia duodenalis Infection and Its Adverse Effects on Growth of Schoolchildren in Rural Malaysia

Background

Giardia duodenalis infection and malnutrition are still considered as public health problems in many developing countries especially among children in rural communities. This study was carried out among Aboriginal (Orang Asli) primary schoolchildren in rural peninsular Malaysia to investigate the burden and the effects of Giardia infection on growth (weight and height) of the children.

Methods/Findings

Weight and height of 374 children aged 7–12 years were assessed before and after treatment of Giardia infection. The children were screened for Giardia parasite using trichrome staining technique. Demographic and socioeconomic data were collected via face-to-face interviews using a pre-tested questionnaire. Overall, 22.2% (83/374) of the children were found to be infected with Giardia. Nutritional status of children was assessed and the results showed that the mean weight and height were 23.9 kg (95% CI = 23.3, 24.5) and 126.6 cm (95% CI = 125.6, 127.5), respectively. Overall, the prevalence of severe underweight, stunting and wasting were 28.3%, 23.8% and 21.0%, respectively. Multiple linear regression analyses showed sex, Giardia infection and household monthly income as the significant determinants of weight while sex and level of mother''s education were the significant determinants of height. Weight and height were assessed at 3 and 6 months after treatment of Giardia infection. It was found that Giardia infection has a significant association with the weight of children but not with height.

Conclusions/Significance

This study reveals high prevalence of Giardia infection and malnutrition among Aboriginal children in rural Malaysia and clearly highlights an urgent need to identify integrated measures to control these health problems in the rural communities. Essentially, proper attention should be given to the control of Giardia infection in Aboriginal communities as this constitutes one of the strategies to improve the nutritional status of Aboriginal children.