Modelling the effects of UV radiation on the survival of Antarctic krill (Euphausia superba Dana) in the face of limited data

Antarctic krill, Euphausia superba, is a keystone species of the Antarctic ecosystem. A fishery for krill may compete with land-based predators (penguins and seals), particularly during the breeding season. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is moving towards management in small scale units. The management models specify predation and fishing mortality as space and time dependent but do not yet include non-predation natural mortality. Krill are known to be highly susceptible to ultraviolet radiation (UV) but there are limited empirical data. We develop a model for krill mortality caused by UV and parameterize and assess it by comparison with experimental data. The analysis allows us to identify key parameters that should be measured in future experiments and also leads to suggestions about modification of experimental procedure. We illustrate the method for krill found in the Livingston Island area and show that (a) it is possible to estimate the component of natural mortality due to UV-induced damage and (b) that cohorts born in 1979, 1984, or 1997 have different survival in the first 5 years of life, associated with differential UV exposure. In particular, those born in 1997 may have experienced as much as 10% lower survival than those born in 1979. The method developed here allows a potentially important source of krill mortality to be incorporated into the management models and suggests key experiments and field work in the future.     

The social context of childcare practices and child malnutrition in Niger's recent food crisis

In 2004–05, Niger suffered a food crisis during which global attention focused on high levels of acute malnutrition among children. In response, decentralised emergency nutrition programmes were introduced into much of southern Niger. Child malnutrition, however, is a chronic problem and its links with food production and household food security are complex. This qualitative, anthropological study investigates pathways by which children are rendered vulnerable in the context of a nutritional 'emergency'. It focuses on household-level decisions that determine resource allocation and childcare practices in order to explain why practices apparently detrimental to children's health persist. Risk aversion, the need to maintain self-identity and status, and constrained decision making result in a failure to invest extra necessary resources ingrowth-faltering children. Understanding and responding to the social context of child malnutrition will help humanitarian workers to integrate their efforts more effectively with longer-term development programmes aimed at improving livelihood security.     

Microbial transformation of synthetic estrogen 17α-ethinylestradiol

Natural estrogens such as estrone, 17β-estradiol, estriol, and the particularly recalcitrant synthetic estrogen 17α-ethinylestradiol used as oral contraceptive, accumulate in the environment and may give rise to health problems. The processes participating in their removal from soil, wastewater, water-sediments, groundwater-aquifer material, and wastewater or sewage treatment plant effluents may involve the action of bacterial and microbial consortia, and in some cases fungi and algae. This review discusses the different efficiencies of bacterial degradation of 17α-ethinylestradiol under aerobic and anaerobic conditions, the role of sulfate-, nitrate-, and iron-reducing conditions in anaerobic degradation, and the role of sorption. The participation of autotrophic ammonia oxidizing bacteria and heterotrophic bacteria in cometabolic degradation of estrogens, the estrogen-degrading action of ligninolytic fungi and their extracellular enzymes (lignin peroxidase, manganese-dependent peroxidase, versatile peroxidase, laccase), and of algae are discussed in detail.     

Pancreatic and sacral agenesis in association with maternal diabetes mellitus: Case report

Sacral agenesis was diagnosed sonographically in the fetus of a diabetic mother and pancreatic agenesis was found additionally at autopsy.     

Connectivity of Streams and Wetlands to Downstream Waters: An Integrated Systems Framework

Interest in connectivity has increased in the aquatic sciences, partly because of its relevance to the Clean Water Act. This paper has two objectives: (1) provide a framework to understand hydrological, chemical, and biological connectivity, focusing on how headwater streams and wetlands connect to and contribute to rivers; and (2) briefly review methods to quantify hydrological and chemical connectivity. Streams and wetlands affect river structure and function by altering material and biological fluxes to the river; this depends on two factors: (1) functions within streams and wetlands that affect material fluxes; and (2) connectivity (or isolation) from streams and wetlands to rivers that allows (or prevents) material transport between systems. Connectivity can be described in terms of frequency, magnitude, duration, timing, and rate of change. It results from physical characteristics of a system, e.g., climate, soils, geology, topography, and the spatial distribution of aquatic components. Biological connectivity is also affected by traits and behavior of the biota. Connectivity can be altered by human impacts, often in complex ways. Because of variability in these factors, connectivity is not constant but varies over time and space. Connectivity can be quantified with field‐based methods, modeling, and remote sensing. Further studies using these methods are needed to classify and quantify connectivity of aquatic ecosystems and to understand how impacts affect connectivity.     

Scaling up site disputes: strategies to redefine ‘local’ in the fight against fracking

Plans to replace an aging diesel backup energy plant with liquid natural gas (LNG) generators in Whitehorse, Yukon, resulted in a public outcry, involving community meetings, massive petitions, and demonstrations. Are these civil society protests just a case of a local siting dispute – a response to an unwanted industrial site in an urban neighborhood? Here, it is argued that siting debates are not the driver of these campaigns, but instead are harnessed by activists to advance a broader environmental movement. By linking the LNG project to more distant extraction, involving hydraulic fracturing (‘fracking’), movement leaders portray the entire territory as part of the ‘local’ for Whitehorse residents. Movement leaders rely upon two key mechanisms: claiming insider status, and identifying visible symbols. This case reveals the strategic use by environmental movements of local concerns to recruit support for broader campaigns, and the value of local, place-based activism for broader environmental movements.     

Regulation of spirocyst discharge in the model sea anemone, Nematostella vectensis

Test probes were touched to tentacles to investigate whether discharge of spirocysts likely is regulated by hair bundle mechanoreceptors. Significantly more spirocysts discharge onto test probes in the presence of vibrations at 11–15 Hz as compared to 0 Hz. Adding N-acetylneuraminic acid, NANA, shifts maximal discharge of spirocysts upwards to 36–40 Hz, and possibly to 21–25 Hz. In contrast, NANA shifts maximal discharge of basitrichous isorhiza nematocysts downwards to 1–20 Hz. Thus, discharge of cnidae (‘stinging capsules’) is differentially regulated according to the type of cnida. Furthermore, it appears that chemodetection of N-acetylated sugars is not a prerequisite to capturing prey because, in seawater alone, maximal discharge of cnidae occurs at frequencies overlapping movements of calmly swimming prey. Nevertheless, chemodetection of N-acetylated sugars broadens the range of frequencies stimulating maximal discharge of cnidae and, therefore, likely enhances prey capture.     

Differing rates of extra-group paternity between two populations of the Australian magpie (Gymnorhina tibicen)

Extra-pair paternity (EPP) is a common feature of the mating systems of many birds. The rate of EPP may vary between species, races and populations. A comparison of extra-group paternity (EGP) rates was made between two races of a group-living passerine, the Australian magpie (Gymnorhina tibicen), to determine if similar mating systems were being employed. The two populations had similar social structure, but differed in group size and dispersal. It was predicted that dispersal differences would have a profound effect on the rate of EGP between the populations, as the population with the lower rate of dispersal and higher chance of breeding with a close relative would engage in EGPs more frequently. Eight microsatellite loci were used to determine parentage in the white-backed Australian magpie (G. t. tyrannica). The rate of EGP was found to be 44%. Dispersal rates were estimated from observational data. Over half of the juvenile magpie cohort from the previous breeding season left the territorial group. These results contrast sharply with the results found by other researchers in a population of western Australian magpies (G. t. dorsalis). In this population, 82% EGP is recorded and dispersal of juveniles is close to nil. The results indicate that dispersal rate is a potentially important predictor of rates of extra-group fertilisations between populations of this species, and suggest that females maximise their reproductive output by avoiding breeding with close kin.Communicated by M. Soler