Parasitological and immunological progress control during and after chemotherapy of canine leishmaniasis]

Promastigote Leishmania-organisms were diagnostically cultivated in vitro from popliteal lymph node aspirates obtained from 32 of in total 36 dogs returning from endemic areas. Isoenzyme analysis (glucosephosphate-isomerase (GPI), phosphoglucomutase (PGM) and glutamate-oxaloacetate-transaminase (GOT) resulted in the identification of Leishmania infantum (syn. Leishmania (L.) infantum) for all 18 isolates investigated. Parasites were still able to be cultivated in vitro in 79% of 28 biopsies (from 15 dogs) even following chemotherapy by Glucantime, independent of the time of sampling and the course of disease after treatment. Dogs with a progressive form of disease (despite chemotherapy) showed only a minor or no reduction (between 0 and 4.8%) of the relative antibody concentration (determined by ELISA), whereas regressive forms of disease (without recurrences observed in the period of 10 to 37 months after therapy) demonstrated a marked reduction of the relative antibody concentration (between 6.7 and 16.2%) within the first 5 to 8 months; thereafter the decrease diminished and changed to a persistent low relative antibody concentration.     

Long‐term Effects of Pyrethrin and Cyfluthrin,a Type II Synthetic Pyrethroid,Insecticide Applications on Bull Reproductive Parameters

The objectives of this study were to determine effects of cyfluthrin and pyrethrin spray products, used in combination with cyfluthrin topical and ear tag applications, on bull reproductive parameters over 18 weeks. Angus or Angus x Simmental bulls were randomly assigned to one of three treatment groups: (i) no exposure to pyrethrins/cyfluthrin (CONT; n = 10), (ii) cyfluthrin ear tag and topical applications (ET; n = 10), or (iii) cyfluthrin ear tag, topical, premise spray and pyrethrin fog spray applications (ET+S; n = 8). Bull body weight was measured every 3 week, and body condition score and scrotal circumference were recorded on weeks 0, 9 and 18. Semen and serum were collected every 3 weeks for sperm evaluation and testosterone measurement, respectively. There was a treatment × week interaction (p < 0.01) for sperm with primary defects; bulls in CONT group had a greater (p = 0.01) percentage of sperm with primary defects than bulls treated with insecticides at week 18. Overall and progressive sperm motility, normal sperm morphology, secondary sperm defects and serum testosterone concentrations changed (p < 0.01) over time in all bulls; however, treatment did not affect (p ≥ 0.13) any of these parameters. There were also no treatment effects (p ≥ 0.08) on bull body weight, body condition score or scrotal circumference. The use of pyrethrin‐ and cyfluthrin‐based insecticides, regardless of application, did not negatively affect reproductive parameters in beef bulls when administered over 18 weeks.     

Effect of Ozone Treatment on Cultures of Nannochloropsis oculata, Isochrysis galbana, and Chaetoceros gracilis

This research evaluated ozone treatment of three unicellular algal species commonly used in the culture of marine larvae. Isochrvsis galbana and Nannochloropsis oculata were found to be resistant to total residual oxidants (TRO); whereas, Chaetoceros gracilis was relatively sensitive to TRO. Isochrvsis galbana remained in log-phase growth after treatment with 0.05 mg/L to 0.50 mg/L TRO, and N. oculata exhibited strong growth after being exposed to TRO levels up to 0.67 mg/L. Only TRO levels of 0.92 mg/L and 0.90 tng/L reduced cell counts of N. oculata and I. galbana , respectively. Furthermore, algal cultures having higher concentrations at the time of ozone treatment may respond more favorably to the treatment. Initially, C. gracilis was reduced in cell count at TRO levels above 0.06 mg/L, but log-phase growth was resumed 2 d after exposure to TRO levels as high as 0.31 mg/L. It is concluded that I. galbana and N. oculata can be successfully treated with ozone in the mass production stages without hampering the timely production of concentrated cultures. Although C. gracilis was found to be relatively sensitive, ozone treatment of starter cultures can be performed routinely with this species. We have demonstrated that ozone treatment of algal cultures is a feasible technique, but studies need to be conducted on ozone treatment of other species of unicellular algae and on ozone treatment of varying concentrations of algae in order to enhance the applications of this technique. Also, in order to determine the extent of disinfection of algal cultures, bacterial and viral composition of the cultures should be evaluated in future studies.     

Economic considerations in agroforestry projects

Economic benefits that can accrue to the small farmer from incorporating trees in his farm system, and the economic constraints and costs he may face in doing so, are reviewed. Various economic considerations other than cash outlays and incomings, such as impact of risk, need to be taken into account. Issues are discussed that can arise in identifying, designing and implementing projects intended to help farmers to capture the economic potentials of agroforestry and to avoid or remove related economic impediments. Correct understanding of the factors which will affect the success of project interventions, valuation of the costs and benefits of trees as perceived by the farmer rather than by outsiders, distributional and equity issues, and identification of operational measures to ensure tangible short-term economic benefits are highlighted. The need for giving priority to research into the economic impacts of agroforestry practices on small farmer situations is stressed.