Effect of habitat fragmentation on levels and patterns of genetic diversity in natural populations of the peat moss Polytrichum commune

Peat bogs represent unique ecosystems that are under particular threat from fragmentation due to peat harvesting, with only 38% of the original peatland in Europe remaining intact and unaffected by peat cutting, drainage and silviculture. In this study, we have used microsatellite markers to determine levels and patterns of genetic diversity in both cut and uncut natural populations of the peat moss Polytrichum commune. Overall diversity levels suggest that there is more genetic variation present than had previously been assumed for bryophytes. Despite this, diversity values from completely cut bogs were found to be lower than those from uncut peatlands (average 0.729 versus 0.880). In addition, the genetic diversity was more highly structured in the cut populations, further suggesting that genetic drift is already affecting genetic diversity in peat bogs subjected to fragmentation.

Comparative non-shivering thermogenesis in adjacent populations of the common spiny mouse (Acomys cahirinus) from opposite slopes: the effects of increasing salinity

We compared non-shivering thermogenesis between two adjacent populations of the common spiny mouse Acomys cahirinus from different habitats, in relation to increasing salinity. Individuals were captured from the north- and south-facing slopes of the same valley, that represent

Expression of the common heat-shock protein receptor CD91 is increased on monocytes of exposed yet HIV-1-seronegative subjects.

The significantly higher surface expression of the surface heat-shock protein receptor CD91 on monocytes of human immunodeficiency virus type-1 (HIV-1)-infected, long-term nonprogressors suggests that HIV-1 antigen uptake and cross-presentation mediated by CD91 may contribute to host anti-HIV-1 defenses and play a role in protection against HIV-1 infection. To investigate this further, we performed phenotypic analysis to compare CD91 surface expression on CD14+ monocytes derived from a cohort of HIV-1-exposed seronegative (ESN) subjects, their seropositive (SP) partners, and healthy HIV-1-unexposed seronegative (USN) subjects. The median fluorescent intensity (MFI) of CD91 on CD14+ monocytes was significantly higher in ESN compared with SP (P=0.028) or USN (P=0.007), as well as in SP compared with USN subjects (P=0.018). CD91 MFI was not normalized in SP subjects on highly active antiretroviral therapy (HAART) despite sustainable, undetectable plasma viraemia. Data in three SP subjects experiencing viral rebounds following interruption of HAART showed low CD91 MFI comparable with levels in USN subjects. There was a significant positive correlation between CD91 MFI and CD8+ T cell counts in HAART-naïve SP subjects (r=0.7, P=0.015). Increased surface expression of CD91 on CD14+ monocytes is associated with the apparent HIV-1 resistance that is observed in ESN subjects.

Distribution of the common lizard (Zootoca vivipara) and landscape favourability for the species in Northern Ireland

The common lizard (Zootoca vivipara) is Ireland’s only native reptile, forming a key part of the island’s biodiversity. However, there is a general paucity of distributional and abundance data for the species. In this study, we collated incidental records for common lizard sightings to define the distribution of the species in Northern Ireland. Maximum entropy modelling was employed to describe species-habitat associations. The resulting predicted landscape favourability was used to evaluate the current status of the species based on the distribution of its maximum potential range in relation to the degree of fragmentation of remaining suitable habitat. In common with previous studies in the Republic of Ireland, sightings were highly clustered indicating under-recording, observer bias, and fragmentation of suitable habitat. A total of 98 records were collated from 1905 to 2009. The species was recorded in 63 (ca. 34%) of 186 × 10 km Northern Irish grid squares. Lizard occurrence was strongly and positively associated with landscapes dominated by heathland, bog and coastal habitats. The single best approximating model correctly classified the presence of lizards in 84.2% of cases. Upland heath, lowland raised bog and sand dune systems are all subject to Habitat Action Plans in Northern Ireland and are threatened by conversion to agriculture, afforestation, invasive species encroachment and infrastructural development. Consequently, remaining common lizard populations are likely to be small, isolated and highly fragmented. Establishment of an ecological network to preserve connectivity of remaining heath and bog will not only benefit remaining common lizard populations but biodiversity in general.

Evidence of natural occurrence of the banned antibiotic chloramphenicol in herbs and grass

Chloramphenicol (CAP), a broad-spectrum antibiotic, was detected in several herb and grass samples from different geographic origins. Due to its suspected carcino-genicity and linkages with the development of aplastic anemia in humans, CAP is banned for use in food-producing animals in the European Union (EU) and many other countries. However, products of animal origin originating from Asian countries entering the European market are still found noncompliant (containing CAP) on a regular basis, even when there is no history of chloramphenicol use in these countries. A possible explanation for the continued detection of these residues is the natural occurrence of CAP in plant material which is used as animal feed, with the consequent transfer of the substance to the animal tissues. Approximately 110 samples were analyzed using liquid chromatography coupled with mass spectrometric detection. In 26 samples, the presence of CAP was confirmed using the criteria for banned substances defined by the EU. Among other plant materials, samples of the Artemisia family retrieved from Mongolia and from Utah, USA, and a therapeutic herb mixture obtained from local stores in the Netherlands proved to contain CAP at levels ranging from 0.1 to 450 mu g/kg. These findings may have a major impact in relation to international trade and safety to the consumer. The results of this study demonstrate that noncompliant findings in animal-derived food products may in part be due to the natural occurrence of chloramphenicol in plant material. This has implications for the application of current EU, USA, and other legislation and the interpretation of analytical results with respect to the consideration of CAP as a xenobiotic veterinary drug residue and the regulatory actions taken upon its detection in food.