RESUMEN
Beekeeping contributes to poverty reduction in many developing countries, and in addition, provides pollination services for sustainable crop production. In Nepal, management practices associated with beekeeping are poorly characterized, and so the potential for this sector to further contribute to livelihood development remains unclear. This study sought to examine and identify factors associated with production efficiency and financial profitability of beekeeping with the aim of enhancing economic gains for Nepali beekeepers. Our study included a sample of 150 respondents from more than twenty commercial beekeeping districts across the Terai and mountainous regions of Nepal. Profitability of beekeeping with the European honeybee (Apis mellifera) Linnaeus, 1758 (Hymenoptera: Apidae) and the Asian honeybee Apis cerana Fabricius, 1793 (Hymenoptera: Apidae) was quantified and disaggregated according to several variables, including hive-derived products produced, marketing strategy employed, number of beehives managed, and postharvest management practices. Our results showed that the different types of management practices adopted (such as number of beehives kept, colony multiplication, supplementary feeding, month of honey harvesting, and marketing approach) significantly influenced the productivity and economic profitability of beekeeping. Our results also revealed that professional supports, such as the availability of subsidies and training, were key factors to enhance productivity. As a whole, this study provides insight into the biological factors and management practices associated with higher economic returns from beekeeping. This work can help guide policymakers and professional support agencies to expand commercial beekeeping for sustainable livelihood development in Nepal and beyond.
Asunto(s)
Apicultura , Miel , Animales , Abejas , Humanos , Nepal , PolinizaciónRESUMEN
Using double-blind, placebo-controlled procedures, the effects of low and high therapeutic dosages of methionyl-human growth hormone (met-hGH) on body composition, muscle protein metabolism and serum lipids were studied in 7 fit adults without growth hormone (GH) deficiency. Dose-dependent changes in body composition were observed that in part appeared to be influenced by a response-recovery effect, as measured by responses factored according to the duration of washout between exposure to the low and high dosages of met-hGH (6 weeks vs. 12 weeks vs. 18 weeks). Increases in fat-free weight were accompanied by an increase in skeletal muscle protein metabolism. Basal levels of cholesterol were inversely related to peak levels of GH in response to exercise stimulation and IGF-I, while GH supplementation lowered levels of total cholesterol and high- and low-density lipoproteins. A dose-dependent effect occurred for total cholesterol, and the percent change in cholesterol was related to the percent change in insulin-like growth factor I (IGF-I). Endogenous levels of GH were attenuated in response to stimulation and IGF-I levels were increased after treatment with GH, but no dose-dependent changes were observed. We conclude that met-hGH alters body composition and muscle protein metabolism, and decreases stored and circulating lipids in fit adults with a pre-existing supranormal body composition. The physiological profile of the person was not as important as the treatment conditions in determining the somatic and physiological response outcomes.
Asunto(s)
Composición Corporal/efectos de los fármacos , Hormona del Crecimiento/análogos & derivados , Lípidos/sangre , Proteínas Musculares/metabolismo , Adulto , Creatinina/orina , Relación Dosis-Respuesta a Droga , Femenino , Hormona del Crecimiento/administración & dosificación , Hormona de Crecimiento Humana , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Lipoproteínas/sangre , Masculino , Metilhistidinas/orina , Aptitud FísicaRESUMEN
The influence of acute treadmill exercise on natural killer (NK) cell tumor cytotoxicity in vitro was studied in elderly women after participation in a program of physical exercise training (PET) (n = 7) or after participation in a paralleling nonexercise control (NEC) condition (n = 7). The two study groups were equated (p greater than 0.05) according to age, percent total body fat, functional status as measured by multi-inventory ranking, and exercise capacity. After the experimental period, the PET subjects had a greater basal level of NK activity than the NEC subjects (PET 38.2 percent specific lysis, %SL, vs. NEC 28.8 %SL; p less than 0.05). Both groups experienced an increase in NK activity after acute treadmill exercise (PET 38.2-57.4 %SL, p less than 0.01; NEC 28.8-37.8 %SL, p less than 0.05), but the increase in the PET subjects was significantly (p less than 0.05) greater than that observed in the NEC subjects. We conclude that natural cellular-mediated tumor cytotoxicity is increased in response to acute exercise and long-term PET in elderly women.
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Envejecimiento/inmunología , Citotoxicidad Inmunológica/inmunología , Ejercicio Físico/fisiología , Células Asesinas Naturales/inmunología , Actividades Cotidianas , Anciano , Composición Corporal , Pruebas Inmunológicas de Citotoxicidad , Prueba de Esfuerzo , Femenino , Humanos , Educación y Entrenamiento Físico , Distribución AleatoriaRESUMEN
The effects of biosynthetic methionyl-human growth hormone (met-hGH) on body composition and endogenous secretion of growth hormone (GH) and insulin-like growth factor I (IGF-I) were studied in eight well-trained exercising adults between 22 and 33 yr of age. By the use of double-blind procedures, met-hGH (2.67 mg/0.5 ml diluent, 3 days/wk) and bacteriostatic water (placebo, 0.5 ml, 3 days/wk) were administered in a repeated-measures design that counterbalanced treatment order. Duration of each treatment was 6 wk. Subjects trained with progressive resistance exercise throughout and were maintained on a high-protein diet monitored by extensive compositional analyses of daily dietary intake records. Hydrodensitometry revealed that met-hGH significantly decreased percent body fat (%fat) and increased fat-free weight (FFW) and FFW/fat weight (FW), whereas the placebo treatment did not change any of these measures. Changes in FFW/FW correlated with the relative dose of met-hGH but did not correlate with either the peak GH response to L-dopa/arginine stimulation or IGF-I levels obtained after treatment with placebo. There were no differences between treatments in the dietary intakes of total kilocalories, protein, carbohydrates, and fat. Mean IGF-I levels were elevated after treatment with met-hGH compared with postplacebo levels. After treatment with met-hGH, five of seven subjects had a suppressed GH response to stimulation from either L-dopa/arginine or submaximal exercise. We conclude that supraphysiological doses of met-hGH will alter body composition in exercising adults in a relative dose-dependent manner and that such treatment may suppress endogenous release of GH in some individuals.
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Tejido Adiposo/efectos de los fármacos , Composición Corporal/efectos de los fármacos , Hormona del Crecimiento/farmacología , Aptitud Física , Adulto , Peso Corporal/efectos de los fármacos , Método Doble Ciego , Ejercicio Físico , Femenino , Hormona del Crecimiento/metabolismo , Humanos , Factor I del Crecimiento Similar a la Insulina/sangre , Masculino , Proteínas Recombinantes/farmacologíaRESUMEN
Nuclei from butyrate-treated or control HeLa cells were separated into micrococcal nuclease sensitive and resistant chromatin. Those regions most sensitive to the nuclease, amounting to some 10% of the chromatin, consisted mainly of mononucleosomes with equimolar amounts of the inner histones H2A, H2B, H3, and H4, very little H1, and equimolar amounts of the two small high-mobility group (HMG) proteins, HMG-14 and -17. Both in butyrate-treated and in control cells, these nuclease sensitive monomers were some 5--7-fold enriched in DNA sequences which are transcribed into cytoplasmic polyadenylated RNA, while resistant monomers are depleted in the same sequences. Electrophoretic analyses of the transcriptionally active mononucleosomes revealed heterogeneity. Several subcomponents were resolved when monomers of butyrate-treated or control cells were electrophoresed at low ionic strength. Active monomer subcomponents differ in their molar content of HMG-14 and -17, in their content of H1 and A24, and in the length of their DNA. Some minor differences between nucleosomes of butyrate-treated and control cells were observed.
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Butiratos/farmacología , Nucleosomas/análisis , Transcripción Genética , Centrifugación por Gradiente de Densidad , Cromatina/aislamiento & purificación , ADN/metabolismo , Células HeLa/metabolismo , Histonas/análisis , Humanos , Nucleasa Microcócica/metabolismo , Nucleoproteínas/análisisRESUMEN
Transposon Tn10 was used to mutagenize the fadR gene in Escherichia coli. Mutants bearing fadR:Tn10 insertion mutations were found to (i) utilize the noninducing fatty acid decanoate as sole carbon source, (ii) beta-oxidize fatty acids at constitutive rates, and (iii) contain constitutive levels of the five key beta-oxidative enzymes. These characteristics were identical to those observed in spontaneous fadR mutants. The constitutive phenotype presented by the fadR:Tn10 mutants was shown to be genetically linked to the associated transposon-encoded drug resistance. These results suggest that the fadR gene product exerts negative control over the fatty acid degradative regulon. The fadR gene of E. coli has been mapped through the use of transposon-mediated fadR insertion mutations. The fadR locus is at 25.5 min on the revised map and cotransduces with purB, hemA, and trp. Three-factor conjugational and transductional crosses indicate that the order of loci in this region of the chromosome is purB-fadR-hemA-trp. Spontaneous fadR mutants were found to map at the same location. Strains that exhibit alterations in the control of the fad regulon in response to changes in temperature were also isolated and characterized. These fadR(Ts) mutants were constitutive for the fad enzymes at elevated temperatures and inducible for these activities at low temperatures. The fadR(Ts) mutations also map at the fadR locus. These results strongly suggest that the fadR gene product is a repressor protein.
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Escherichia coli/genética , Ácidos Grasos/metabolismo , Genes Reguladores , Proteínas Represoras/genética , Factores de Transcripción/genética , Mapeo Cromosómico , Cromosomas Bacterianos , Elementos Transponibles de ADN , Inducción Enzimática , Escherichia coli/metabolismo , Mutación , TemperaturaRESUMEN
Experiments were performed to assess the role of the fadL gene in Escherichia coli. These studies have revealed that this organism requires a functional fadL gene in order to (i) transport optimally the fatty acids C10 to C18:1 into the cell, (ii) optimally grow on and oxidize C10 to C18:1 fatty acids, and (iii) incorporate efficiently C12 to C18:1 fatty acids into its membrane phospholipids. A defect in the fadL gene does not prevent E. coli from optimally utilizing fatty acids with chain lengths less than 10 carbon atoms. These results suggest that the fadL gene governs a transport component(s) which is required for the optimal transport of fatty acids with chain lengths greater than 9 carbon atoms.