Culture of Piscirickettsia salmonis on enriched blood agar.

Piscirickettsia salmonis is the etiologic agent of piscirickettsiosis, an economically significant disease of fish. Isolation of P. salmonis by culturing on fish cell lines has been the standard technique since the initial isolation of the organism. The ability to grow P. salmonis on artificial media would relieve facilities of the cost of maintaining cell lines, permit isolation at fish culture sites with fewer contamination problems, and allow easier transport of isolates to diagnostic facilities for confirmation assays. This report describes the successful culture of P. salmonis on enriched blood agar.     

Antibiotic susceptibility of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolated from subclinical bovine mastitis cases and in vitro efficacy of bacteriophage

Staphylococcus aureus is an opportunistic pathogen that may cause severe infections in livestock, and represents the major cause of mastitis in dairy cows. Currently, instead of using antibiotics, new strategies are sought to reduce this clinical health problem. The aim of this study was to determine the efficacy of phage therapy to kill S. aureus strains obtained from farms located at the State of Guanajuato, México. Thirty-six S. aureus strains from cow milk with subclinical mastitis were isolated and identified, and the susceptibility to antibiotics and four phages also isolated in this work was tested. It was found that more of 90% of S. aureus isolates were not susceptible to six or more antibiotics, and 100% were resistant to penicillin, dicloxacillin, cefotaxime, ampicillin and cephalothin, and 81 and 77%, to tetracycline and cefuroxime, respectively. Fortunately, 100% of S. aureus isolates were susceptible to phages used in this work, which was detected as clear zones using specific phage. It was shown for the first time, that phages used in this study are active against pathogenic S. aureus and might be incorporated into the therapy as an important tool for the control of staphylococcal bovine mastitis, specially to antibiotic-resistant S. aureus strains isolated in farm located at the state of Guanajuato, México; and its use might be extended to other regions inside or outside the country.     

Thrombocytosis and central nervous system involvement in a case of canine acute megakaryoblastic leukemia

This case report presents a 14‐month‐old female Poodle mix with acute megakaryoblastic leukemia based on a marked thrombocytosis, abnormal platelet morphology, circulating dwarf megakaryocytes, and blast cells in the blood. Bone marrow abnormalities included dysmegakaryopoiesis dygranulopoiesis, and an increased number of blast cells was observed in the blood. Extensive leukemic involvement was also found in the liver, spleen, lymph nodes, lungs, kidneys, and brain. The cytopathologic features of the abnormal circulating cells were highly suggestive of being megakaryocytic in origin, which was supported by negative myeloperoxidase staining and positive von Willebrand factor staining on immunocytochemistry (ICC). The neoplastic cells were also CD61 positive and had variable von Willebrand factor expression on ICC. Although there were only 25% blast cells in the bone marrow, which theoretically supported myelodysplastic syndrome, the hypothesis that this case represented acute myeloid leukemia of megakaryoblastic origin was confirmed by the continuous increase in circulating blast cell numbers during follow‐up visits and the extensive leukemic involvement of parenchymal organs.     

Toward a model for local stakeholder participation in landscape-level wildlife conservation

The conservation community is increasingly taking a landscape-level approach to wildlife conservation. This approach faces obstacles, including how to ensure transboundary wildlife conservation goals that can be realized through local management actions, and how and when to engage local stakeholders in landscape conservation planning processes. Currently, local stakeholder participation is not institutionalized within these processes. This paper examines the potential role of local stakeholders in landscape conservation. In this paper, we present a preliminary model of cross-level coordination that could facilitate development and implementation of conservation across social–ecological landscapes, highlighting the possible contributions of local stakeholders. The feasibility of this model is contingent on addressing a range of challenges associated with local stakeholder participation in extra-local conservation decisions. Ultimately, we present suggestions for future research examining the potential for a locally inclusive, participatory approach to wildlife conservation across complex landscapes.     

Proteolytic activity in some Patagonian plants from Argentina

Six Patagonian plants were screened for proteolytic activity: Colliguaja integerrima, Euphorbia collina, E. peplus and Stillingia patagonica (Euphorbiaceae), Philibertia gilliesii (Asclepiadaceae) and Grindelia chiloensis (Asteraceae). P. gilliesii extracts showed the highest specific activity, followed by S. patagonica and E. collina. Proteolytic activity was unnoticeable in the other three species studied. Inhibition assays revealed that P. gilliesii and S. patagonica extracts contain cysteine-type peptidases and that in E. collina serine-type peptidases are present.     

Tree planting by small producers in the tropics: A comparative study of Brazil and Panama

Forest regrowth is a notable phenomenon across the tropical forest latitudes. Such reforestation takes place in the wake of land abandonment, occurs cyclically in a rotational agricultural system, and may result from the deliberate planting of trees by farmers. Although less extensive than successional forest regeneration, tree planting by small farmers can have potentially important environmental impacts at both the site and global scale. This paper examines tree-planting efforts by small farmers in the tropical frontier regions of Panama and Brazil in order to gauge the magnitude of reforestation activities, and to identify factors that influence these efforts. This paper discusses the environmental regulations, forestry law, and tenure institutions in both countries, and performs a comparative analysis of reforestation efforts with information derived from household surveys (n = 356) and in-depth tree planting interviews (n = 35). Results from logistic regression are also presented. Our results show that tree planting occurs more frequently in Panama, which we attribute to greater external support in the provisioning of extension and materials and strong market incentives. We suggest that the proximity of the study sites to Panama City facilitates external support and market drivers. Finally, our results suggest that land tenure security is an influential determinant of reforestation activities in both countries.This revised version was published online in November 2005 with corrections to the Cover Date.