Geographic variation in jungle cat (Felis chaus Schreber, 1777) (Mammalia,Carnivora, Felidae) body size: is competition responsible?

There is a striking difference in body size of jungle cats ( Felis chaus ) in the west and the east of their distribution, with Israeli cats being 43% heavier than Indian cats. We tested the hypothesis that increasing competition from other small felids towards the east is responsible for the difference in body size. We measured jungle cat skulls for eight cranial and dental variables and related these to independent variables such as species richness (local and regional), latitude, longitude, temperature, and precipitation. Data from a narrow band between latitudes 24.0°N and 33.9°N, where Bergmann's rule was largely not observed, showed that the western population (≤ 50.0°E longitude) of jungle cats is larger than the eastern (> 60.0°E longitude) population with the size difference being most evident in the upper carnassials (P⁴L). Species richness at the regional level showed a significant negative relation to P⁴L. An even spacing in condylobasal length for a small-cat guild from India through null model analysis indicated the occurrence of character displacement. The results support the hypothesis that competition is responsible for geographical variation in jungle cat body size in the region where Bergmann's rule does not apply. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 163–172.     

Post-harvest age-induced seed dormancy of Acer ginnala and its alleviation by growth regulator and low temperature treatments

One-month-old fruits of Acer ginnala with winged pericarp attached gave 44% germination and this was not increased by cold treatment at 4°C for 0, 10, 20, or 30 days, gibberellic acid treatment at 0, 1, 10, 100 or 1000 mg litre^-1, or ethephon treatment at 0, 2, 20, 200 or 2000 mg litre^-1. After 6 months of storage at 20–25 °C, germination of untreated fruits fell to 5% but could be restored to that of 1-month-old fruits by incubation at 4 °C for 30 days. After 9 months storage, no germination occurred in untreated fruits. Cold treatment (30 days at 4 °C partially restored germination (26%). Treatment with either gibberellic acid (1000 mg litre^-1) and 30 days at 4 °C (40%) or ethephon (100 mg litre^-] and 30 days at 4 °C improved germination (69%). The combination of all three treatments, i.e. 100 mg litre^-1 gibberellic acid, 100 mg litre^-1 ethephon and 30 days at 4 °C, optimised germination (86%). Thus, dormancy of A. ginnala developed during storage but could be reversed by a combination of treatment with low temperature and growth regulators. The highest germination (86%) was achieved after low temperature and growth regulator treatment of stored fruit.     

Taxonomy of wild pigs (Sus) of the Philippines

Native wild pigs of the Philippines are now in grave danger of extinction. Study of available material indicates that three species are present: Sundaland Sus barbatus on Palawan, and two endemic species, Sus philippensis (with three subspecies, one of them here described as new) on Luzon, Mindanao, Basilan, Leyte, Samar, Catanduanes and Mindoro, and Sus cebifroms on Negros, debit and Panay. Specimens from Jolo. Masbale and Bohol presently remain unallocated to species, and may reflect the occurrence of hybridization.     

A MINIATURIZED ENRICHMENT SEROLOGY METHOD FOR RAPID DETECTION of SALMONELLA FROM POULTRY MEAT and REARING FARMS ENVIRONMENT

A miniaturization of the enrichment serology method for the detection of Salmonella was improved in order to make the technique more reliable, cheaper, and faster. the miniaturized method ("Micromethod") was compared to the Sperber and Deibel's method ("Macromethod") and with a classical isolation method; 1062 samples including 700 rearing farms environment samples, 247 poultry meat samples, and 115 nonfat dry milk samples were analyzed. Specificity of both enrichment serology methods was about 92–99.4%. Sensitivity of Micromethod was better than that of the Macromethod for the environmental samples (86.8 and 74.1%, respectively) and the poultry meat samples (87.5 and 77.5%, respectively) but was the same for the nonfat dry milk samples (82.5%). the costs of both methods were respectively 0.43 US $ for the Macromethod and 0.20 US $ for the Micromethod. This "Micromethod" could be proposed for the screening of Salmonella positive batches in the food industries.     

DIFFERENTIATION OF A PRIMARY CHEMICALLY INDUCED RAT NEPHROBLASTOMA IN ORGAN CULTURE

The differentiation in organ culture of a rat nephroblastoma is compared with differentiation of normal rat metanephric tissue under the same conditions. The nephroblastoma arose in a 19 week old female Fischer F344 rat given a single intraperitoneal injection of 4.0 μmole methyl(methoxymethy1)nitrosamine (DMN-OMe)/g body weight at one day of age. The tumor consisted almost entirely of spindle cells although a few well-differentiated tubules were scattered throughout the tumor mass. No primitive tubules were seen, but focal aggregates of tumor cells suggestive of nascent epithelial differentiation were frequent. Fragments of the nephroblastoma were cultured on gelfoam sponge in Williams Medium E supplemented with hydrocortisone, insulin, and fetal bovine serum. Within one day extensive tubulogenesis was observed. High mitotic activity resulted in a steady increase in the size of cultured explants over a period of 6 days. By day six, differentiating tubules filled the explant tissue. Cultured fragments were nearly indistinguishable histologically from normal F344 rat fetal kidney explanted to organ culture on day 15 of gestation and grown in vitro for the same period.     

Environmental change and the phenology of European aphids

Aphids, because of their short generation time and low developmental threshold temperatures, are an insect group expected to respond particularly strongly to environmental changes. Forty years of standardized, daily data on the abundance of flying aphids have been brought together from countries throughout Europe, through the EU Thematic Network 'EXAMINE'. Relationships between phenology, represented by date of first appearance in a year in a suction trap, of 29 aphid species and environmental data have been quantified using the residual maximum likelihood (REML) methodology. These relationships have been used with climate change scenario data to suggest plausible changes in aphid phenology. In general, the date of first record of aphid species in suction traps is expected to advance, the rate of advance varying with location and species, but averaging 8 days over the next 50 years. Strong relationships between aphid phenology and environmental variables have been found for many species, but they are notably weaker in species living all year on trees. Canonical variate analysis and principal coordinate analysis were used to determine ordinations of the 29 species on the basis of the presence/absence of explanatory variables in the REML models. There was strong discrimination between species with different life cycle strategies and between species feeding on herbs and trees, suggesting the possible value of trait-based groupings in predicting responses to environmental changes.