Running wheel access fails to resolve impaired sustainable health in mice feeding a high fat sucrose diet.

Diet and physical activity are thought to affect sustainable metabolic health and survival. To improve understanding, we studied survival of mice feeding a low-fat (LF) or high-saturated fat/high sugar (HFS) diet, each with or without free running wheel (RW) access. Additionally several endocrine and metabolic health indices were assessed at 6, 12, 18 and 24 months of age. As expected, HFS feeding left-shifted survival curve of mice compared to LF feeding, and this was associated with increased energy intake and increased (visceral/total) adiposity, liver triglycerides, and increased plasma cholesterol, corticosterone, HOMA-IR, and lowered adiponectin levels. Several of these health parameters improved (transiently) by RW access in HFS and LF fed mice (i.e., HOMA-IR, plasma corticosterone), others however deteriorated (transiently) by RW access only in HFS-fed mice (i.e., body adiposity, plasma resistin, and free cholesterol levels). Apart from these multiple and sometimes diverging health effects of RW access, RW access did not affect survival curves. Important to note, voluntary RW activity declined with age, but this effect was most pronounced in the HFS fed mice. These results thus challenge the hypothesis that voluntary wheel running can counteract HFS-induced deterioration of survival and metabolic health.

Assessment of N and P status at the landscape scale using environmental models and measurements.

We assessed the compliance of a Dutch landscape, dominated by dairy farming, with environmental quality standards using a combination of model calculations and measurements. The total ammonia emission of 2.4 kton NH(3) yr(-1) does not exceed the environmental quality standard (2.6 kton NH(3) yr(-1)). Nevertheless, the total N deposition (on average 24.4 kg N ha(-1) yr(-1)) is such that critical N loads are exceeded at 53% of the nature areas. The deposited N mainly results from non-agricultural sources and agricultural sources outside the area (72%). The calculated average NO(3)(-) concentration in the upper groundwater does not exceed the 50 mg l(-1) threshold. Calculated annual average N-total and P-total concentrations in discharge water are relatively high but these cannot be directly compared with thresholds for surface water. The results suggest that compliance monitoring at the landscape scale needs to include source indicators and cannot be based on state indicators alone.

Addressing the Impact of Atmospheric Nitrogen Deposition on Western European Grasslands.

There is a growing evidence base demonstrating that atmospheric nitrogen deposition presents a threat to biodiversity and ecosystem function in acid grasslands in Western Europe. Here, we report the findings of a workshop held for European policy makers to assess the perceived importance of reactive nitrogen deposition for grassland conservation, identify areas for policy development in Europe and assess the potential for managing and mitigating the impacts of nitrogen deposition. The importance of nitrogen as a pollutant is already recognized in European legislation, but there is little emphasis in policy on the evaluation of changes in biodiversity due to nitrogen. We assess the potential value of using typical species, as defined in the European Union Habitats Directive, for determining the impact of nitrogen deposition on acid grasslands. Although some species could potentially be used as indicators of nitrogen deposition, many of the typical species do not respond strongly to nitrogen deposition and are unlikely to be useful for identifying impact on an individual site. We also discuss potential mitigation measures and novel ways in which emissions from agriculture could be reduced.

N deposition as a threat to the World's protected areas under the Convention on Biological Diversity.

This paper combines the world's protected areas (PAs) under the Convention on Biological Diversity (CBD), common classification systems of ecosystem conservation status, and current knowledge on ecosystem responses to nitrogen (N) deposition to determine areas most at risk. The results show that 40% (approx. 11% of total area) of PAs currently receive >10 kg N/ha/yr with projections for 2030 indicating that this situation is not expected to change. Furthermore, 950 PAs are projected to receive >30 kg N/ha/yr by 2030 (approx. twice the 2000 number), of which 62 (approx. 11,300 km(2)) are also Biodiversity Hotspots and G200 ecoregions; with forest and grassland ecosystems in Asia particularly at risk. Many of these sites are known to be sensitive to N deposition effects, both in terms of biodiversity changes and ecosystem services they provide. Urgent assessment of high risk areas identified in this study is recommended to inform the conservation efforts of the CBD.

Reduced nitrogen in ecology and the environment.

Since the beginning of the 19th century humans have increasingly fixed atmospheric nitrogen as ammonia to be used as fertilizer. The fertilizers are necessary to create amino acids and carbohydrates in plants to feed animals and humans. The efficiency with which the fertilizers eventually reach humans is very small: 5-15%, with much of the remainder lost to the environment. The global industrial production of ammonia amounts to 117 Mton NH(3)-Nyear(-1) (for 2004). By comparison, we calculate that anthropogenic emissions of NH(3) to the atmosphere over the lifecycle of industrial NH(3) in agriculture are 45.3 Mton NH(3)-Nyear(-1), about half the industrial production. Once emitted ammonia has a central role in many environmental issues. We expect an increase in fertilizer use through increasing demands for food and biofuels as population increases. Therefore, management of ammonia or abatement is necessary.

Multiple usage of the CD PLUS/UNIX system: performance in practice.

In August 1994, the CD PLUS/Ovid literature retrieval system based on UNIX was activated for the Faculty of Medicine and Health Sciences of Erasmus University in Rotterdam, the Netherlands. There were up to 1,200 potential users. Tests were carried out to determine the extent to which searching for literature was affected by other end users of the system. In the tests, search times and download times were measured in relation to a varying number of continuously active workstations. Results indicated a linear relationship between search times and the number of active workstations. In the "worst case" situation with sixteen active workstations, the time required for record retrieval increased by a factor of sixteen and downloading time by a factor of sixteen over the "best case" of no other active stations. However, because the worst case seldom, if ever, happens in real life, these results are considered acceptable.

Analysis of external and internal interlibrary loan requests: aid in collection management.

The analysis of 60,779 external interlibrary loan requests for copies of periodical articles from the collection of Erasmus University Medical Library in 1988 is described. The study was used for planning the length of backruns to be retained due to space limitations that forced the disposal of older volumes. More than 50% of requests were for the most recent two-year period, and 90% of requests could be filled with a twenty-year run of periodicals. In 1989, 4,157 internal requests were received for periodicals not owned; these were analyzed to determine those most commonly requested. Prior to subscribing, new titles were reviewed as to price, bibliometric indicators, number of requests, length of backfile, and the number of requesting departments. The Library Advisory Board decides on cancellation or purchase of periodicals; the elements considered are described.

Prevalence of syphilis and hepatitis B among homosexual men in two saunas in Amsterdam.

In a pilot study by field-screening in two different sauna baths, a day-sauna and a night-sauna, 318 homosexual men were investigated for syphilis and hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs). Of the 134 visitors to the day-sauna 35.1% were seroreactive for syphilis, four (3%) carried HBsAg, and 95 (70.9%) anti-HBs. Of the 184 visitors to the night-sauna 33.2% were seroreactive for syphilis, 16 (8.7%), carried HBsAg, and 97 (52.7%) anti-HBs. The correlation between seroreactivity for syphilis and the presence of HBsAg amd anti-HBs was statistically significant.