Where's the beef?: Incorporating cattle into sustainable agroforestry systems in the Amazon Basin

Low external input agroforestry systems hold great promise as alternative, sustainable production systems for small-to-medium farmers in the Amazon Basin. The design of such systems is considered essential to stabilize agricultural production and avoid the cycle of continuing destruction of primary forest [Anderson A (1990) In: Anderson A (ed) Alternatives to Deforestation: Steps toward Sustainable Use of the Amazon Rain Forest pp 3–23. Columbia University Press, New York]. In order to be successful, these systems must be compatible with local ecological conditions and adoptable by farmers. Currently, many small-to-medium producers in the Amazon Basin use a slash and burn agricultural strategy that combines annual cropping with cattle grazing in mixed farming systems. While cattle play an important role in household economic survival, grazing-induced land degradation threatens the long-term viability of these farms [Loker W (1993) Human Organization 52(1)14–24]. This paper presents a model of a low external input agroforestry system that incorporates farmer preferences and practices but uses well-adapted grass-legume pastures, rotational grazing and the management of natural forest regeneration to enhance productivity in an ecologically sound manner. This system provides farmers with the benefits of both annual crops and cattle raising, avoids the land degradation that characterizes current practices and effectively incorporates trees into the production system.     

Crystal structure of Cd,Zn metallothionein

The anomalous scattering data from five Cd in the native protein were used to determine the crystal structure of cadmium, zinc (Cd,Zn) metallothionein isoform II from rat liver. The structure of a 4-Cd cluster was solved by direct methods. A 2.3 A resolution electron density map was calculated by iterative single-wavelength anomalous scattering. The structure is folded into two domains. The amino terminal domain (beta) of residues 1 to 29 enfolds a three-metal cluster of one Cd and two Zn atoms coordinated by six terminal cysteine thiolate ligands and three bridging cysteine thiolates. The carboxyl terminal domain (alpha) of residues 30 to 61 enfolds a 4-Cd cluster coordinated by six terminal and five bridging cysteine thiolates. All seven metal sites have tetrahedral coordination geometry. The domains are roughly spherical, and the diameter is 15 to 20 A; there is limited contact between domains. The folding of alpha and beta is topologically similar but with opposite chirality. Redundant, short cysteine-containing sequences have similar roles in cluster formation in both alpha and beta.     

Control of seed-borne Sclerotinia sclerotiorum by fungicidal treatment of sunflower seed

Treatment of sunflower seeds with benomyl, vinclozolin, iprodione or procymidone virtually eliminated seed-borne Sclerotinia sclerotiorum. Applications of fungicides increased the number of surviving seedlings when seeds were sown in vermiculite or in steam-sterilized soil. With the exception of benomyl, fungicides were significantly more effective when applied in acetone solutions than when 100 g a.i./100 kg of seed was applied as conventional dry dressings. There was no difference in effectiveness between the two application methods when the dry dressings were applied at 200 g a.i/100 kg of seed. The acetone infusion method had no deleterious effects on germination of disease-free seed nor on seedling vigour. For a comparable level of control, less fungicide was needed in the infusion treatment than in the dust treatment. If fungicidal treatment of sunflower seeds is used routinely then the introduction of S. sclerotiorum into uninfested land could be controlled.     

Prevalence and risk factors for anti-Toxoplasma gondii antibodies in goats of the Seridó Oriental microregion, Rio Grande do Norte state, Northeast region of Brazil

The prevalence and risk factors for anti-Toxoplasma gondii antibodies were investigated in goats of the Seridó Oriental microregion, Rio Grande do Norte state, Northeast region of Brazil. Three hundred and sixty-six blood samples from goats collected by jugular venopuncture were used. For the serologic diagnosis of Toxoplasma gondii infection, the indirect fluorescent-antibody test (IFAT) with cut-off value 1:64 was carried out. The prevalence of anti-T. gondii antibodies was 30.6% [95% CI=25.9-35.6%] with titers ranging from 1:64 to 1:16,384. The multivariate logistic regression analysis showed that the risk factors associated to anti-T. gondii antibodies were presence of cats in the herd, extensive/semi-intensive management systems and lack of mineral supplementation.     

Apparent clinical resolution of pinnal actinic keratoses and squamous cell carcinoma in a cat using topical imiquimod 5% cream

Imiquimod is a topical immune response modifier and stimulator used in humans to treat a number of cutaneous neoplasms. This case report describes a cat with actinic keratoses and squamous cell carcinoma of the pinnae. The pinnal lesions were treated with topical 5% imiquimod three times per week. Treatment was discontinued after 82 days of therapy. Twelve weeks of topical imiquimod application resulted in clinical resolution of the pinnal lesions. Although no post-treatment biopsies were performed, there was no relapse of the pinnal lesions in 5 months of clinical follow-up. Expected side effects were limited to erythema, crusting, alopecia, and mild discomfort at the sites of application during the first 3 weeks of application. These results suggest that topical imiquimod, although unproven, might be a therapeutic option or adjunct to therapy for cats with actinic keratoses and squamous cell carcinoma, especially those cats for whom surgery and radiation therapy are not an option.