Occupational risk of exposure to methicillin-resistant Staphylococcus aureus (MRSA) and the quality of infection hygiene in nursing homes

• Staff members were not colonised with MRSA. • But staff were exposed to MRSA from air, sedimented dust and surfaces. • MRSA was found in the rooms of MRSA-colonised residents but not in common areas. • Staff worry about MRSA and spreading it to other residents, family, and acquaintances. • The use of protective eyewear and facemasks could be improved. Methicillin-resistant Staphylococcus aureus (MRSA) is an increasing health concern across the globe and is often prevalent at long-term care facilities, such as nursing homes. However, we know little of whether nursing home staff is exposed to MRSA via air and surfaces. We investigated whether staff members at nursing homes are colonised with and exposed to culturable MRSA, and assessed staff members’ self-reported knowledge of MRSA and compliance with infection hygiene guidelines. Five nursing homes with MRSA positive residents were visited in Copenhagen, Denmark. Personal bioaerosol exposure samples and environmental samples from surfaces, sedimented dust and bioaerosols were examined for MRSA and methicillin-susceptible S. aureus (MSSA) to determine occupational exposure. Swabs were taken from staffs’ nose, throat, and hands to determine whether they were colonised with MRSA. An online questionnaire about MRSA and infection control was distributed. No staff members were colonised with MRSA, but MRSA was detected in the rooms of the colonised residents in two out of the five nursing homes. MRSA was observed in air (n = 4 out of 42, ranging from 2.9–7.9 CFU/m³), sedimented dust (n = 1 out of 58, 1.1 × 10³ CFU/m²/d), and on surfaces (n = 9 out of 113, 0.04–70.8 CFU/m²). The questionnaire revealed that half of the staff members worry about spreading MRSA to others. Identified aspects for improvement were improved availability and use of protective equipment, not transferring cleaning supplies (e.g., vacuum cleaners) between residents’ rooms and to reduce worry of MRSA, e.g., through education.     

The effect of seasonality on oxidative metabolism in the sea urchin Loxechinus albus

The objective of the present study was to investigate seasonal variations in the oxidative metabolism of the sea urchin Loxechinus albus gonads. The reported spawning period for this species is from September to November. Lipid radical content showed non-significant changes upon the seasons. Ascorbyl radical content and the content of α-tocopherol were lower in samples collected in spring and summer as compared to the values in winter-collected animals. Ascorbate content decreased in samples collected in fall as compared to those collected in winter. For the lipophilic compartment, the lipid radical content/α-tocopherol content ratio is an indicator of oxidative stress. This index increased significantly in tissues during spawning as compared to the values in samples collected during winter. The ascorbyl content/ascorbate content ratio is an indicator of oxidative stress for the hydrophilic milieu. A significant decrease by 66% was determined in tissues from gonads of animals collected in summer as compared to values in animals collected in winter. The data reported here suggest a different profile of response against oxidative stress at the lipophilic and hydrophilic milieus in L. albus gonads.     

Influence of emergence success on the annual reproductive output of leatherback turtles

Reproductive output of leatherback turtles (Dermochelys coriacea) is affected by the stochastic nature of emergence success. Average emergence success of nests at Playa Grande, Costa Rica was 0.38 ± 0.27. Incubation temperature affected development of leatherback turtle eggs and emergence of hatchlings from the nest. We found that high temperatures reduced hatching success and emergence rate and increased embryonic mortality both early and late during incubation at Playa Grande. There was a temporal effect on emergence success that resulted in more hatchlings being produced at the beginning of the season, because of higher emergence success, than toward the end. Likewise, production of hatchlings varied from year to year. The average annual reproductive output was 252 ± 141 hatchlings per female. The 2005–2006 nesting season had the highest emergence success and produced the greatest number of hatchlings per female compared to the 2004–2005 (+120%) and 2006–2007 (+41%) seasons. However, average clutch size (62 ± 10) and clutch frequency (9.45 ± 1.63), were not different among years. Turtles that had nested a high number of years exhibited greater clutch frequency and arrived earlier to nest than turtles that had nested in fewer numbers of years. Nesting when environmental conditions favor high developmental success and emergence rate may constitute an advantageous reproductive strategy.     

Reduction of CO2 emission by optimally tracking a pre-defined target

The recent global financial crisis has highlighted the need for balanced and efficient investments in the reduction of the greenhouse effect caused by emissions of CO₂ on a global scale. In a previous paper, the authors proposed a mathematical model describing the dynamic relation of CO₂ emission with investment in reforestation and clean technology. An efficient allocation of resources to reduce the greenhouse effect has also been proposed. Here, this model is used to provide estimates of the investments needed in land reforestation and in the adoption of clean technologies for an optimum emission and abatement of CO₂, for the period of 1996–2014. The required investments are computed to minimize deviations with respect to the emission targets proposed in the Kyoto Protocol for European Countries. The emission target can be achieved by 2014 with investments in reforestation peaking in 2004, and a reduction of the expected GDP of 42%, relative to 2006. Investments in clean technology should increase between 2008 and 2010 with maximum transfer figures around 70 million American dollars. Total (cumulative) costs are, however, relatively high depending on the price of carbon abatement and the rate at which the expected CO₂ concentration in the atmosphere should be reduced. Results highlight the advantages for policy makers to be able to manage investments in climate policy more efficiently, controlling optimum transfers based on a portfolio of actions that tracks a pre-defined CO₂ concentration target.     

Life History and Conservation of Totoaba macdonaldi

We conducted a literature review on the biology, ecology, fishery, and protection of totoaba ( Totoaba macdonaldi ), an endemic, threatened fish of the Gulf of Calfornia, Mexico. Reinterpretation and integration of published and unpublished information enabled us to confirm and estimate specific biological parameters of the totooba, make hypothetical constructs of its life history, and to propose ideas for its preservation. In specific, we found (1) that the mean age of first reproduction of male and female totoaba are 6 and 7 years, respectively; (2) that the intrinsic rate of natural mortality was estimated as 0.268 per year and (3) that in the mid 1980s an estimated 120,300 juveniles died each year in the shrimp fishery by-catch and 6200 adults (26 kg average weight) died due to poaching. The parameters of an individual growth model for juveniles and adults were also estimated. Decreased spring water input from the Colorado River into the Gulf of California may have caused a contraction of the spawning season and a reduction of the carrying capacity of juvenile totoaba. An increase in annual survival during recent years indicates recovery of the stock that might be related to protection of adults. We argue that habitat restoration, which includes the elimination of growth and recruitment over-fishing, is critical to increasing numbers of totoaba, and thereby lifting the fishing ban, and to the delisting of totoaba.     

Support for First Nations' Land Claims amongst Members of the Wilderness Preservation Movement: The Potential for an Environmental Justice Movement in British Columbia

In this paper we examine the relationship between identification with the environmental movement and support for First Nations' land claims in order to determine the potential for an environmental justice movement in British Columbia. The findings are based on survey data collected from members of a wilderness preservation movement organization based on Vancouver Island. The findings demonstrate that the stronger an individual identifies with the environmental movement, the more s/he supports linking First Nations' land claims to conservation campaigns. We conclude by proposing that the wilderness preservation movement could increase its mobilization potential and widen the scope of the movement by including First Nations' issues in their campaigns. It could do this by expanding its frame to include issues of environmental justice, thereby connecting environmental protection and fair access to resources.     

Evaluation of hexavalent chromium removal in a continuous biological filter with the use of central composite design (CCD)

Hexavalent chromium is frequently found in industrial effluents as a result of the industrial applications of this compound and its anti-corrosive features. However, hexavalent chromium is extremely toxic, and its discharge in water is regulated, with a maximum limit of 0.1 mg/L in accordance with legislation established by CONAMA-Brazil (no. 397, April 3, 2008). To achieve lower discharge values, it is necessary to reduce from Cr(VI) to Cr(III), which is less toxic, and an economic alternative involves biological removal of this compound. Residence time distributions (RTDs) were measured to evaluate the behavior of actual biofilter operation conditions in a biofilter flow. The medium residence time distributions used were 8 and 24 h (recommended by the legislation). To optimize this process, a central composite design was used, considering the initial chromium concentration and pH as the independent variables and the removal of hexavalent chromium as the response. The boundary curves and surface response showed optimal behavior at 3.94 mg/L [Cr(0)] and a pH of 6.2. The removal process of hexavalent chromium is mathematically described by the Michaelis-Menten kinetic model. This model appropriately represents the variation of chromium concentration along the bioreactor.