Nutrient supply to anticyclonic meso-scale eddies off western Australia estimated with artificial tracers released in a circulation model

The phytoplankton distribution off western Australia in the period from April to October is unique in that high biomass is generally associated with anticyclonic eddies and not with cyclonic eddies. As the western Australian region is oligotrophic this anomalous feature must be related to differing nutrient supply pathways to the surface mixed layer of cyclonic and anticyclonic eddies. A suite of modelled abiotic tracers suggests that cyclonic eddies are predominantly supplied by diapycnal processes that remain relatively weak until June–July, when they rapidly increase because of deepening surface mixed layers, which start to tap into the nutrient-replete waters below the euphotic zone. To the contrary, we find that anticyclonic eddies are predominantly supplied by injection of shelf waters, which carry elevated levels of inorganic nutrients and biomass. These injections start with the formation of the eddies in April–May, continue well into the austral winter and reach as far as several hundred kilometers offshore. The diapycnal supply of nutrients is suppressed in anticyclonic eddies since the injection of warm, low-salinity shelf waters delays the erosion of the density gradient at the base of the mixed layer. Our results are consistent with the observed seasonal cycles of chlorophyll a and observation of particulate organic matter export out of the surface mixed layer of an anticyclonic eddy in the region

Public injecting and public amenity in an inner-city suburb of Melbourne, Australia

Background: Public drug markets and injecting impose significant burden on individuals and the community. This study aimed to document public injecting and amenity in North Richmond, an inner-city suburb of Melbourne, Australia. Methods: A rapid assessment methodology was employed. Data comprised: secondary data on drug use indicators, structured observations and interviews with key stakeholders. Primary data were collected from May to October 2012. Quantitative data are summarised using descriptive statistics. Basic content analysis was performed on interview transcripts. Results: An average of 1843 needle–syringes (NS) were collected per month from syringe disposal bins and street-sweeps in the period January–December 2012. Discarded NS and other injecting paraphernalia were observed in a variety of locations. Stakeholder interviews indicated substantial concerns over the presence of NS and witnessing injecting and overdose. Discussion: Public injecting is widespread, frequent, and highly visible in North Richmond and has a substantial negative effect on public amenity. The research identified two main priorities: (1) enhance access to harm reduction services and materials; and (2) improve public amenity. Among other responses, the study findings support the introduction of a supervised injecting facility (SIF) as a viable component of a comprehensive harm reduction response to illicit drug use in this area

Food Deprivation, Body Weight Loss and Anxiety-Related Behavior in Rats

In behavioral studies, food deprivation protocols are routinely used to initiate or maintain motivational states that are required in a particular test situation. However, there is limited evidence as to when food deprivation compromises animal welfare. This study investigated the effects of different lengths of food deprivation periods and restricted (fixed-time) feeding on body weight loss as well as anxiety-related and motivated behavior in 5–6 month old male and female Wistar rats. The observed body weight loss was not influenced by sex and ranged between 4% (16 h deprivation) to approximately 9% (fixed-time feeding). Despite significant body weight loss in all groups, the motivation to eat under the aversive test conditions of the modified open field test increased only after 48 h of food deprivation. Long-lasting effects on anxiety as measured in the elevated plus maze test 24 h after refeeding have not been observed, although fixed-time feeding could possibly lead to a lasting anxiogenic effect in female rats. Overall, female rats showed a more anxiolytic profile in both tests when compared to male rats. Despite these sex differences, results suggest that food deprivation is not always paralleled by an increased motivation to feed in a conflict situation. This is an important finding as it highlights the need for tailored pilot experiments to evaluate the impact of food deprivation protocols on animals in regard to the principles of the 3Rs introduced by Russell and Burch. View Full-Tex

Why is adolescent drinking declining? A systematic review and narrative synthesis

Background: Adolescent drinking has declined across many developed countries from the turn of the century. The aim of this review is to explore existing evidence examining possible reasons for this decline. Methods: We conducted systematic searches across five databases: Medline, PsycINFO, CINAHL, Informit Health and Scopus. Studies were included if association between declining alcohol consumption and potential explanatory factors were measured over time. Narrative synthesis was undertaken due to substantial methodological heterogeneity in these studies. Results: 17 studies met the inclusion criteria. Five studies found moderate evidence for changes in parental practices as a potential cause for the decline. Five studies that examined whether alcohol policy changes influenced the decline found weak evidence of association. Three studies explored whether alcohol use has been substituted by illicit substances but no evidence was found. Two studies examined the effect of a weaker economy; both identified increase in adolescent alcohol use during times of economic crisis. One study indicated that changes in exposure to alcohol advertising were positively associated with the decline and another examined the role of immigration of non-drinking populations but found no evidence of association. One study tested participation in organised sports and party lifestyle as a potential cause but did not use robust analytical methods and therefore did not provide strong evidence of association for the decline. Conclusions: The most robust and consistent evidence was identified for shifts in parental practices. Further research is required using robust analytical methods such as ARIMA modelling techniques and utilising cross-national data