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Hildebrand JG 《Science (New York, N.Y.)》1986,233(4768):1101-1102
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Responding to changes in rural-urban linkages and government policies, bean (Phaseolus vulgaris L.) production systems in Costa Rica are undergoing transitions. Impacts of changes in bean production systems on environmental and economic sustainability were analysed at the field, farm and policy levels. A combination of interviews, agronomic surveys, on-farm experiments, and secondary information was used. Changes in agronomic and economic conditions over time were assessed by conducting agronomic surveys and experiments on farms representing a range of land-use intensities. Trade-offs between productivity and stability were quantified using Modified Stability Analysis. The adoption of land and agrochemical-intensive methods by resource-poor farmers cultivating steep lands resulted in decreased environmented and economic sustainability. Farmers with adequate resources were able to maintain economic viability by transferring land out of beans and into other commodities, particularly cattle. However, this shift in resource use decreased social equity by decreasing farm labour opportunities for smallholders and landless farmers and diminishing land available for tenants. These studies indicate that the impact of technology introduction on farming system sustainability can be assessed effectively by conducting integrated socioeconomic and agronomic analyses across farms representing various land-use practices and intensities. 相似文献
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Rossi A Rigano D Pergola C Formisano C Basile A Bramanti P Senatore F Sautebin L 《Journal of agricultural and food chemistry》2007,55(13):5053-5061
Feijoa sellowiana Berg. fruits and especially the acetonic extract have been shown to possess biological activities, although the responsible compounds have never been identified. The present study was designed to evaluate the anti-inflammatory activity of an acetonic extract from F. sellowiana Berg. fruits on the nitric oxide (NO) pathway, which plays an important role in inflammation. To this aim the J774 cell line, which expresses inducible nitric oxide synthase (iNOS) following stimulation with lipopolysaccharide (LPS), has been utilized, and the effects of this extract and its fractions on NO production, iNOS protein expression, and signal pathways involved in its regulation have been evaluated. This study demonstrates that at least some part of the anti-inflammatory activity of the acetonic extract is due to the suppression of NO production by flavone and stearic acid. The mechanism of this inhibition seems to be related to an action on the expression of the enzyme iNOS through the attenuation of nuclear factor kappaB (NF-kappaB) and/or mitogen-activated protein kinase (MAPK) activation. 相似文献
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María Elena Pahua-Ramos Leticia Garduño-Siciliano Lidia Dorantes-Alvarez German Chamorro-Cevallos Julieta Herrera-Martínez Obed Osorio-Esquivel Alicia Ortiz-Moreno 《Plant foods for human nutrition (Dordrecht, Netherlands)》2014,69(1):18-24
The objective of this study was to evaluate the effect of reduced-calorie avocado paste on lipid serum profile, insulin sensitivity, and hepatic steatosis in rats fed a hypercholesterolemic-high fructose diet. Thirty five male Wistar rats were randomly separated in five groups: Control group (ground commercial diet); hypercholesterolemic diet plus 60 % fructose solution (HHF group); hypercholesterolemic diet plus 60 % fructose solution supplemented with avocado pulp (HHF+A group); hypercholesterolemic diet plus 60 % fructose solution supplemented with reduced-calorie avocado paste (HHF+P group); and hypercholesterolemic diet plus 60 % fructose solution supplemented with a reduced-calorie avocado paste plus fiber (HHF+FP group). The A, P, and FP were supplemented at 2 g/kg/d. The study was carried out for seven weeks. Rats belonging to the HHF group exhibited significantly (P?≤?0.05) higher total cholesterol, triglycerides, and insulin levels in serum as well as lower insulin sensitivity than the control group. Supplementation with reduced-calorie avocado paste showed a significant (P?≤?0.05) decrease in total cholesterol (43.1 %), low-density lipoprotein (45.4 %), and triglycerides (32.8 %) in plasma as well as elevated insulin sensitivity compared to the HHF group. Additionally, the liver enzymes alanine aminotransferase and aspartate aminotransferase decreased significantly in the HHF-P group (39.8 and 35.1 %, respectively). These results are likely due to biocompounds present in the reduced-calorie avocado paste, such as polyphenols, carotenoids, chlorophylls, and dietary fibre, which are capable of reducing oxidative stress. Therefore, reduced-calorie avocado paste attenuates the effects of a hypercholesterolemic-high fructose diet in rats. 相似文献
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S V Hildebrand D Arpin G Cardinet 《Journal of the American Veterinary Medical Association》1990,196(7):1077-1083
Biopsy specimens of the cutaneous omobrachialis muscle were obtained from 10 horses with a problem of myositis from mild exercise. One horse had been evaluated previously and malignant hyperthermia-like contractures developed in its muscle biopsy specimen during the contracture test. In this study, the halothane-caffeine contracture test and histologic and histochemical evaluations were performed on muscle biopsy specimens. In the contracture test, no muscle biopsy specimen developed contracture in the presence of 2 or 4% halothane alone. The mean (+/- SEM) caffeine-specific concentration in the presence of halothane was 5.23 +/- 0.5 mM for 2% halothane, and 4.46 +/- 0.6 mM for 4% halothane. The caffeine-specific concentration values were not significantly different. Contracture response for any muscle specimen did not resemble contracture associated with malignant hyperthermia. The cutaneous omobrachialis muscle was composed of type-II fibers, with type-I fibers seldom seen. For 9 of the 10 horses, overall fiber morphology was normal; 1 horse had necrotic fibers. Of the 10 muscle specimens, 9 had fibers that had positive reaction for alkaline phosphatase activity; 3 muscle specimens contained ringed myofibers. Three horses of this study were administered general anesthesia; 2 were research horses, anesthetized with halothane and succinylcholine, and 1 was a clinical case given halothane anesthesia plus a non-depolarizing muscle relaxant. One research horse developed a malignant hyperthermia-like reaction to anesthesia, with severe rhabdomyolysis evident after anesthesia, and an episode of muscle cramping in its stall 2 days after anesthesia. The other 2 horses had unremarkable postanesthetic periods. 相似文献
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