Experience and social factors influence movement and habitat selection in scimitar-horned oryx (Oryx dammah) reintroduced into Chad.

Reintroduced animals-especially those raised in captivity-are faced with the unique challenge of navigating a wholly unfamiliar environment, and often make erratic or extensive movements after release. Naïveté to the reintroduction landscape can be costly, e.g., through increased energy expenditure, greater exposure to predation, and reduced opportunities to forage. Integration with an extant population may provide opportunities for social information transfer. However, in the absence of interactions with residents, it is unclear how individual and social learning may affect an animal's ability to track resources in an unfamiliar landscape. We use integrated step selection functions (iSSFs) to address these knowledge gaps, by evaluating the extent to which environmental factors, individual experience (time since release), and social information-sharing (group size) influence movement decisions by scimitar-horned oryx (Oryx dammah) reintroduced into their native range for the first time in ca. 30 years. We found that both experience and social factors influenced the habitat selection and movement behavior of reintroduced oryx. Of four candidate iSSFs, the model that included environmental, experience, and group size variables performed best in both dry and wet periods. Statistically significant interaction terms between environmental variables and experience were generally larger than similar terms for group size, indicating that experience may affect habitat selection by reintroduced oryx more strongly than social factors. These findings may inform the management of recovering wildlife populations, update widely-held expectations about how released ungulates acclimate to novel landscapes, and demonstrate the utility of long-term monitoring of reintroduced populations.

Observations on the prevalence of trypanosomosis in small ruminants, equines and cattle, in relation to tsetse challenge, in The Gambia.

The prevalence of trypanosome infections in Djallonké sheep and West African Dwarf goats at different sites in The Gambia showed a significant, positive correlation with contemporary assessments of tsetse challenge. A similar correlation was observed in village N'Dama cattle which showed comparable prevalence values in the same areas. Trypanosome prevalences also tended to be higher in horses and donkeys in areas with high tsetse challenge compared with sites with relatively few flies. A ranking of the numbers of tsetse blood-meals from cattle, small ruminants and equines (1:0.06: > 0.03) corresponded with the estimated biomass of these livestock groups (1:0.09:0.05). Observations on the grazing ranges of livestock showed that, while cattle foraged widely into tsetse-infested habitat, sheep, goats and donkeys remained closer to the villages. This difference indicated that, under the management system practised in The Gambia, small ruminants and equines were probably exposed to a lower level of tsetse attack than cattle.

Tsetse-trypanosomiasis challenge to village N'Dama cattle in The Gambia: field assessments of spatial and temporal patterns of tsetse-cattle contact and the risk of trypanosomiasis infection.

The severity of the trypanosomiasis problem in a particular location is traditionally assessed in terms of a challenge index-the product of some measure of tsetse abundance and infection-rate-which is assumed to be proportional to the force of infection. However, this index masks variation in the force of infection between herds and among individuals within herds. It is also not comparable between sites since the relative abundance of tsetse to hosts may vary. We have studied spatial distribution of herds of cattle in relation to tsetse in The Gambia and calculated an index of challenge based on the ratio of vectors to hosts over the livestock ranging area. This index is strongly correlated with estimates of the force of infection calculated from the incidence of infection in susceptible zebu; and it provides information on heterogeneity in exposure of different herds to tsetse.

Cattle-tsetse contact in relation to the daily activity patterns of Glossina morsitans submorsitans in The Gambia.

The daily flight activity patterns of one of the main vectors of animal trypanosomiasis in West Africa, Glossina morsitans submorsitans, were assessed using four different methods. Results from all the methods showed that there was some flight activity nearly every hour in all seasons but they differed in the level of contact between grazing cattle herds and G.m.submorsitans. In the late dry season, trap data indicated that there was negligible activity from midday to late afternoon, whereas observations of tsetse contact with cattle herds or hand-net collections on herd followings showed no fall in attack rates, on the cattle by G.m.submorsitans. Differences between trap and animal-baited collection data may be attributable to the type of G.m.submorsitans sampled by each method. Male G.m.submorsitans captured by traps were more fat depleted than those caught on ox-baited flyrounds or by hand-net collections on herd followings. All methods showed that male G.m.submorsitans were most fat depleted in the late dry season and least in the early dry season. It was concluded that the traps were mainly sampling the spontaneous flights of G.m.submorsitans. Hunger and endogenous rhythms increase the likelihood of spontaneous flights towards dusk, particularly in conditions such as those at midday in the very hot, late dry season. However, the presence of cattle herds in infested habitats probably activated nearby G.m.submorsitans and the continual movement through the grazing areas ensured contact with tsetse throughout grazing.(ABSTRACT TRUNCATED AT 250 WORDS)

Nailfold capillary circulation in osteoarthritis.

Nailfold capillaries in 28 patients with OA affecting the distal interphalangeal joints were compared to 23 age- and sex-matched controls without OA. Patients with OA showed a significantly lower density of capillaries in their nailfolds and significantly more capillary morphological abnormalities including haemorrhage, 'drop out', dilatation and irregularity. There was a trend for OA patients to have warmer fingers with reduced finger to brachial blood pressure ratios. There were significant correlations between nailfold capillary numbers and average joint tenderness and between capillary morphological changes and joint swelling. These results reveal a relationship between interphalangeal joint OA and nailfold capillary abnormalities and density. As changes in microcirculation may be pertinent to the pathogenesis of OA, further studies which could explore possible causal relationships are warranted.

Cattle migration and stocking densities in relation to tsetse-trypanosomiasis challenge in The Gambia.

The local migration of village N'Dama cattle between two study sites, Niamina East and Bansang, 40 km apart in the inland region of The Gambia, West Africa, is described. The consequences of seasonal variations in local stocking densities on the epidemiology of African animal trypanosomiasis are reported. Tsetse abundance at each study site was monitored throughout the study period from trap catches, and cattle censuses at each site were carried out on a monthly basis. Detailed ecological, productivity and health data, including dietary intake and trypanosomiasis prevalence, were collected from selected study herds resident at the two sites and from a third group of (four) herds that migrated annually between the two areas to spend the late dry season period in Niamina East. It was shown that the migration strategy allowed migrants to maintain a high level of green grazing in the diet throughout the year. Cattle were moved to the area of highest tsetse density in the region to obtain this grazing, but it appeared that individual risk of trypanosome infection was diminished by a dilution effect created by locally high livestock densities. Trypanosomiasis prevalences in resident cattle at Niamina East were best correlated with the tsetse catch/trap/day 2 months previously, once this index of tsetse abundance had been corrected to allow for changes in relative stocking density.

The presence of Sjögren's syndrome is a major determinant of the pattern of interstitial lung disease in scleroderma and other connective tissue diseases.

A number of patients with scleroderma, Sjögren's syndrome and other connective tissue diseases (CTD) were assessed to ascertain the prevalence of respiratory abnormalities as defined by bronchoalveolar lavage (BAL), standard respiratory function studies and gallium scan of the lung, and the relationship of these abnormalities to the presence or absence of dyspnea. These results suggest that respiratory symptoms are very common in CTD and in scleroderma, particularly if Sjögren's syndrome is also present. Our findings also suggest the presence of 2 patterns of interstitial lung involvement in scleroderma. In scleroderma alone this appears to be characterized by the presence of increased neutrophil proportions in the BAL, decreased DLCO, and no increase in gallium uptake within the lung. Where scleroderma is associated with Sjögren's syndrome, there is an increase in the proportion of lymphocytes in the BAL and respiratory symptoms are very prominent, the latter associated with an increase in gallium uptake within the lung. This suggests that Sjögren's is a major determinant of the pattern of interstitial lung disease seen in CTD.