Testosterone concentrations and male genital organ morphology in Greenland sledge dogs (Canis familiaris) dietary exposed to organohalogen contaminants

This study investigated whether low-level, long-term in utero and post-natal exposure to organohalogen pollutants disrupts male reproductive organ morphology and testosterone production in Greenland sledge dogs (Canis familiaris), as a model of Arctic top predators feeding on marine mammals. Six male dogs were followed for 1 year and testosterone concentrations, testes/baculum morphology and baculum bone mineral density (BMD) was determined. Three males were exposed to organohalogenated contaminants (OHCs) in utero through maternal dietary intake of minke whale blubber (Balaenoptera acutorostrata), with a post-weaning ∑OHC intake of 10.4–11.7 µg kg^?1 day^?1 resulting in an adipose tissue range of ∑OHC 4518–5729 ng (g lw)^?1 after 1 year. Three control males were exposed to very low concentrations of OHCs through pork fat. No significant differences were seen in plasma testosterone concentrations, baculum weight, BMD, and testicular length in the six male dogs (control, n = 3 and exposed, n = 3) measured at 3, 5, 7, 9, and 12 months of age. Testicular weights were significantly lower in the exposed group (p = 0.015, n = 2). Although this study had a limited number of animals, it was observed that in utero and the following 12 months of chronic exposure to a complex mixture of contaminants in the form of naturally accumulated OHCs does not affects testosterone levels, but possibly affects testicular weights in sledge dogs.     

Dynamics of fisheries that affect the population growth rate coefficient

Conventional surplus production models indicate that destruction of fish populations by overfishing is difficult, if not impossible, but catastrophic declines in abundance of exploited populations are common. Surplus production models also do not predict large continuing fluctuations in yield, but large fluctuations in yield are common. Conventional surplus production models assume that fisheries do not impact the population's capacity to increase, but changes in age structure or a decrease in age-specific fecundity resulting from fishing can decrease the coefficient of increase. A surplus production model is developed in which fishing reduces the capacity of a population to increase; the model is applied to describe the fluctuations observed in yield of lake herring (Coregonus artedii) from the upper Great Lakes. The fisheries of the Great Lakes were decimated by the combined effects of heavy fishing and a changing environment. For some species, yield increased to high levels and then the fisheries collapsed; for other species, yield and effort fluctuated greatly.     

AN OPTIMIZATION MODEL FOR EFFICIENT MANAGEMENT OF URBAN WATER RESOURCES1

ABSTRACT: A mathematical programming model is proposed to determine economically efficient urban water resource allocation and pricing policy by maximizing the sum of the consumer and producer surplus. The optimization of this nonlinear problem is accomplished by the use of linear programming algorithm. The feasibility of using recycled water for municipal purposes is examined in a planning context. The impact of higher water quality discharge standards on pricing and allocation of water is analyzed and the attractiveness of water reuse option is demonstrated.     

Long-term dispersion and availability of metals from submarine mine tailing disposal in a fjord in Arctic Norway

Mining of Cu took place in Kvalsund in the Arctic part of Norway in the 1970s, and mine tailings were discharged to the inner part of the fjord, Repparfjorden. Metal speciation analysis was used to assess the historical dispersion of metals as well as their potential bioavailability from the area of the mine tailing disposal. It was revealed that the dispersion of Ba, Cr, Ni, Pb and Zn from the mine tailings has been limited. Dispersion of Cu to the outer fjord has, however, occurred; the amounts released and dispersed from the mine tailing disposal area quantified to be 2.5–10 t, less than 5% of Cu in the original mine tailings. An estimated 80–390 t of Cu still remains in the disposal area from the surface to a depth of 16 cm. Metal partitioning showed that 56–95% of the Cu is bound in the potential bioavailable fractions (exchangeable, reducible and oxidisable) of the sediments, totalling approximately 70–340 t, with potential for continuous release to the pore water and re-precipitation in over- and underlying sediments. Surface sediments in the deposit area were affected by elevated Cu concentrations just above the probable effect level according to the Norwegian sediment quality criteria, with 50–80% Cu bound in the exchangeable, reducible and oxidisable fractions, potentially available for release to the water column and/or for uptake in benthic organisms.     

The Influence of Chironomus plumosus Larvae on Nutrient Fluxes and Phosphorus Fractions in Aluminum Treated Lake Sediment

One of the methods to diminish the internal phosphorus (P) loading is inactivation of P by aluminum (Al). After addition of Al to lake water an Al(OH)₃ floc is formed, which settles to the bottom and initially form a lid on the sediment surface. The effects of Chironomus plumosus larvae on sediment nutrient fluxes and P binding-sites in the sediment after addition of Al were tested. C. plumosus larvae were added to sediment cores in which sediment–water fluxes of nutrients were measured four times. After one month, the sediment was sectioned with depth and P fractions were measured by sequential chemical extraction. The chironomids created burrows through the Al layer which caused a significantly increased efflux of P from the Al treated sediment, because the P had only limited contact to the added Al. The chironomids also affected the P fractions in the sediment by their bioturbating activity. Thus, they caused increased Al concentrations in the upper part of the Al treated sediment. This created an enhanced contact between Al and P in the upper 7 cm of the sediment and, as a result, an increased binding of P to Al and a lowered porewater P. The DIP efflux is therefore expected to be lowered after the initial phase. Al had no effects on the nitrogen fluxes, but the chironomids enhanced the release, and decreased the release or increased the uptake by the sediments.     

Prenatal diagnosis of medium-chain acyl-CoA dehydrogenase (MCAD) deficiency in a family with a previous fatal case of sudden unexpected death in childhood

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a potentially fatal inherited disease with a carrier frequency of approximately 1:100 in most Caucasian populations. The disease is implicated in sudden unexpected death in childhood. A prevalent disease-causing point mutation (A985G) in the MCAD gene has been characterized, thus rendering diagnosis easy in the majority of cases. Since the clinical spectrum of MCAD deficiency ranges from death in the first days of life to an asymptomatic life, there are probably other genetic factors—in addition to MCAD mutations—involved in the expression of the disease. Thus, families who have experienced the death of a child from MCAD deficiency might have an increased risk of a seriously affected subsequent child. In such a family we have therefore performed a prenatal diagnosis on a chorionic villus sample by a highly specific and sensitive polymerase chain reaction (PCR) assay for the G985 mutation. The analysis was positive and resulted in abortion. We verified the diagnosis by direct analysis on blood spots and other tissue material from the aborted fetus and from family members.     

Leveraging foodways for health and justice

ABSTRACT

The global industrial food system is increasingly recognised as a source of poor health that deepens social and economic inequity. Health advocates, policy makers, and food activists strive to improve nutrition and food access across racial and ethnic divides; however, given established approaches, they may miss fundamental pathways for improving health and justice comprehensively. While food access and nutrition are often identified as primary concerns for marginalised communities and the reason for food insecurity and food-related illness, critical food justice scholars use a more expansive lens to suggest a democratised food system is needed, and that solutions based solely in access to healthy food can undermine more systemic approaches. Our research extends this analysis, highlighting the importance of endemic food culture (foodways) as a tool for retaining identity, building community, and maintaining health among refugee populations in one community in Salt Lake City, Utah. Further, this work suggests that community engagement and expertise is essential in leveraging foodways such that marginalised communities can effectively resist cheap, unhealthy, and placeless calories.     

Methyl jasmonate improves radical generation in macrophyte phytoremediation

Phytoremediation is the use of plants to decontaminate and improve waters and soils. Pleustonic macrophytes are plant models for research in waters. In a phytoremediation study, the elicitation of Pistia stratiotes with methyl jasmonate or salicylic acid suggests that oxytetracycline modification rate coefficients could be increased more than threefold. Here we present the elicitation of Pistia stratiotes apical primary root tips. We detected reactive oxygen species generation by X-band electron paramagnetic resonance spectroscopy, using the spin trap α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN). Elicitation using 0.8 mM methyl jasmonate during 1 h increased the relative spin-trapped radical concentration by +12 %. Further, results indicate acute plant toxicity above 0.24 mM salicylic acid.     

A minimum data set of water quality parameters to assess and compare treatment efficiency of stormwater facilities

Urban stormwater runoff is often of poor quality, impacting aquatic ecosystems and limiting the use of stormwater runoff for recreational purposes. Several stormwater treatment facilities (STFs) are in operation or at the pilot testing stage, but their efficiencies are neither well documented nor easily compared due to the complex contaminant profile of stormwater and the highly variable runoff hydrograph. On the basis of a review of available data sets on urban stormwater quality and environmental contaminant behavior, we suggest a few carefully selected contaminant parameters (the minimum data set) to be obligatory when assessing and comparing the efficiency of STFs. Consistent use of the minimum data set in all future monitoring schemes for STFs will ensure broad-spectrum testing at low costs and strengthen comparability among facilities. The proposed minimum data set includes: (i) fine fraction of suspended solids (<63 μm), (ii) total concentrations of zinc and copper, (iii) total concentrations of phenanthrene, fluoranthene, and benzo(b,k)fluoranthene, and (iv) total concentrations of phosphorus and nitrogen. Indicator pathogens and other specific contaminants (i.e., chromium, pesticides, phenols) may be added if recreational or certain catchment-scale objectives are to be met. Issues that need further investigation have been identified during the iterative process of developing the minimum data set.