Occurrence of Staphylococcus intermedius on the hair and skin of normal dogs.

Aerobic bacterial populations were studied on the distal hair coat and at the skin surface of the shoulder, rump and abdomen of 10 healthy dogs. Coagulase negative staphylococci (CNS) were more frequently isolated from the hair than the skin at the shoulder and rump. There was no difference in the isolation rate of coagulase positive staphylococci (CPS) (Staphylococcus intermedius) between the hair and skin. Total skin counts were greatest on the abdomen whereas CNS counts from the hair were least at this site. There were no differences between CPS counts at the three sites on either hair or skin. The populations on the relatively unfavourable microenvironment of the distal hair may represent contamination rather than colonisation. The low populations of CPS at the skin surface also indicate contamination or transient colonisation rather than true resident status.     

Actinomycin D for Reinduction of Remission in Dogs With Resistant Lymphoma

Twenty-five dogs with malignant lymphoma refractory to chemotherapy were treated with actinomycin D at a median dose of 0.7 mg/m² (range, 0.5 to 0.9 mg/m²) every 3 weeks. The dogs treated had received between 2 and 8 chemotherapeutic agents (median 7), for a median of 266 days before being treated with actinomycin D. For 23 of the 25 dogs, previous chemotherapy included doxorubicin. No dog responded to actinomycin D chemotherapy.     

Verification by polymerase chain reaction of vertical transmission of Theileria sergenti in cows

To evaluate the transplacental transfer of Theileria sergenti infection in cattle, we used DNA probes to detect T. sergenti in 6 pregnant cows and their calves. All the animals were monitored by parasitologic, serologic, and polymerase chain reaction (PCR) assays for a predicted 875-base-pair (bp) DNA product and a 684-bp amplicon detected by nested PCR in the blood and spleens of aborted fetuses. An open reading frame (ORF) starting at nucleotide 170 and terminating at position 1021 was shown to code for a polypeptide of 283 amino acid residues. All 6 dams and 5 calves were positive for T. sergenti in all tests. One calf was positive only with nested PCR. We conclude that transplacental transmission of T. sergenti is a significant problem. The relevance of the data in the programmed introduction of new (especially pregnant) animals into established clean herds needs serious consideration with regard to control of theileriosis and other tickborne diseases.     

Comparison of Three Solvent Systems for Extraction of Chlorophyll a from Fish Pond Phytoplankton Communities

Chloroform-methanol (2:1 v/v), absolute methanol, and 90% acetone were evaluated for their effectiveness as extractants of chlorophyll a from samples of phytoplankton communities collected from catfish ponds. Chloroform-methanol consistently extracted more chlorophyll a than either 90% acetone or methanol. Precision for the methanol extraction was also unacceptably low, with an average coefficient of variation of 17%. Average coefficients of variation for the chloroform-methanol and 90% acetone extraction procedures were 6 and 5%, respectively. Filtered samples should be steeped in chloroform-methanol for at least 4 h to obtain maximum chlorophyll extraction, and the addition of MgCO₃ to the extractant as a buffer is not necessary.     

CLINICAL USE OF 99mTC-MDP SCINTIGRAPHY IN THE EQUINE MANDIBLE AND MAXILLA

^99mTc-methylene diphosphonate (MDP) radionuclide imaging examinations were done in four horses having clinical evidence of skull trauma or infection. Radiographs were made of each horse prior to scintigraphy. Four case histories are presented. In each instance, scintigraphy provided complementary information to that obtainable through radiography, which aided in accurately localizing and characterizing the site and extent of abnormalities, and which proved particularly valuable as an aid for therapeutic planning.     

Transmutation and functional representation of heterogeneous landscapes

Models of local small-scale ecological processes can be used to describe related processes at larger spatial scales if the influences of increased scale and heterogeneity are carefully considered. In this paper we consider the changes in the functional representation of an ecological process that can occur as one moves from a local small-scale model to a model of the aggregate expression of that process for a larger spatial extent. We call these changes spatial transmutation. We specifically examine landscape heterogeneity as a cause of transmutation. Spatial transmutation as a consequence of landscape heterogeneity is a source of error in the prediction of aggregate landscape behavior from smaller scale models. However, we also demonstrate a procedure for taking advantage of spatial transmutation to develop appropriately scaled landscape functions. First a mathematical function describing the process of interest as a local function of local variables is defined. The spatial heterogeneity of the local variables is described by their statistical distribution in the landscape. The aggregate landscape expression of the local process is then predicted by calculating the expected value of the local function, explicitly integrating landscape heterogeneity. Monte Carlo simulation is used to repeat the local-to-landscape extrapolation for a variety of landscape patterns. Finally, the extrapolated landscape results are regressed on landscape variables to define response functions that explain a useful fraction of the total variation in landscape behavior. The response functions are hypotheses about the functional representation of the local process at the larger spatial scale.     

Structure of the sheep epidermis.

The stratum corneum measured on fresh frozen sections was found to be considerably thicker than previously reported. It was uniformly permeated with sebum, which also formed an intact film over the skin surface and it could readily be divided into two zones. The living epidermis was approximately half as thick as the stratum corneum.     

Identification of a major gene (Mex-1) from Coffea canephora conferring resistance to Meloidogyne exigua in Coffea arabica

Among the most damaging root-knot nematode species, Meloidogyne exigua is especially common in Latin America and constitutes a major agronomic constraint in all major coffee-growing ( Coffea arabica ) areas. Growing nematode-resistant coffee represents the most promising option for control of the pest. The present study aimed to determine the mode of inheritance of the M. exigua resistance transferred into C. arabica from a related species, Coffea canephora , and to identify associated molecular markers. Segregation data analysis of F ₂ progeny derived from a cross between the resistant introgression line T5296 and the susceptible accession Et6 showed that the resistance to M. exigua is controlled by a simply inherited major gene (designated the Mex -1 locus). The gall index distribution exhibited by the F ₂ individuals suggested incomplete dominant expression. Fourteen AFLP markers were found associated with the resistance to M. exigua and a localized genetic map of the chromosome segment carrying Mex -1 was constructed. Furthermore, the association of the identified AFLP markers with Mex -1 was confirmed by analysis of a set of genotypes involving 28 introgression Arabica lines either resistant or susceptible to M. exigua in field conditions. These results represent an important starting point to enhance backcross breeding programmes and to perform an early selection of resistant seedlings.