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131.
This paper investigates the effect of the introduction of an irrigation technique on the technical efficiency of olive production in a sample of olive-growing farms in Tunisia, estimating the Cobb-Douglas form of stochastic frontier production function. Results indicate that estimated technical efficiency scores vary, ranging from a minimum of 3.0% to a maximum of 91.2% with a mean value of 61.2%. This suggests that olive-growing farms in Tunisia can increase their production on average by 38.8% through more efficient use of technology and inputs. The introduction of irrigation increased productivity, however, the estimated technical efficiency of irrigated olive farms varies across farms and they are less efficient than non-irrigated farms. This finding suggests that the introduction of irrigation to non-irrigated farms has the potential to increase production levels, however, the current production of the irrigated farms is far from the "best practice frontier" that realizes maximum possible output. Accumulation of experience and knowledge by farm owners and selection of olive cultivar significantly contribute to improving technical efficiency.  相似文献   
132.
Balanites aegyptiaca Del. kernels were chemically,physically and morphologically characterized. Crude oil (49.0%) andcrude protein (32.4%) were the two major constituents of the kernels.Phytic acid content was relatively high compared to other legumes. Incontrast, antitryptic activities of the kernel flours were very low.Sapogenin contents of the full fat, defatted and testa flours were 1.5, 2.7and 3.0%, respectively. The hardness of the kernel was found to be about10.4 × 105 N/m2, which was somewhat high. The morphologicalstructure of the kernel using a scanning electron microscope revealedthat the protein matrix was embedded in a lake of oil droplets. Oilrecovery, as a function of pressing time, pressure, temperature and particlesize was investigated. With increasing temperature up to 70 °C at 400 bar, for 120 min, an oil recovery of 79.4% wasobtained. Using an expeller at 115 °C, about 85% of thekernel oil was recovered. The reduction of particle size had a negativeeffect on oil recovery under the same conditions. The fatty acidcomposition was not affected by the pressing temperature up to 115 °C. The total amount of the unsaturated fatty acids was found tobe up to 74.8% (50 °C) and 75.1% (115 °C)of the total fatty acids content.  相似文献   
133.
Leather finishing processes using toxic organic solvent based produce volatile organic compounds (VOC), chronic exposure to this chemicals effect on workers' health causing many diseases especially lung cancer. So, polyurethane waterbased was synthesized for application in leather finishing instead of organic solvent based because it’s economic and safety for industry and workers. Preparation of water-based polyurethane (PU) depends on the reaction of polyethylene glycol (PEG, 300) with isophorone diisocyanate (IPDI) and the reaction of IPDI-1,4-butanediol (BDO) together with dimethylolpropionic acid (DMPA), was synthesized by poly-addition polymerization reaction. PU was then modified with different amounts of silicon dioxide nanoparticles (1-5 % SiO2), used as a binder in leather finishing. Leather coated was characterized physically, chemically and thermally by FTIR, GPC, DLS, TEM, SEM and TGA. The results revel that, water vapor permeability (WVP) of leather coated with PU modified with SiO2 showed improvement due to the existence of SiO2 particles which increases the interspaces of the polyurethane coating. SEM showed that when the amount of SiO2 nanoparticles increases, there is uniform nanoparticles accumulated can be observed. EDX prove the presence of Si and O2 elements and the formation of SiO2 nanoparticles. Mechanical properties discussed that tensile strength; tear strength and elongation at break % increase with increase SiO2 concentration until 3 % SiO2 nanoparticles. TGA showed an improvement of thermal stability of coated leather modified with SiO2. Therefore, this study succeeded in preparation of safe, ecofriendly of water-based polyurethane binders which modified with SiO2 for using in leather finishing.  相似文献   
134.
Brown seaweeds produce useful bioactive substances with high cosmetic and pharmacological values due to the presence of antioxidant derivatives, mainly phlorotannins (PHT), which are of particular interest. A central composite rotatable design (CCRD) with three variables (extraction time, dry material-to-solvent ratio and ethanol concentration) and two responses was performed to optimize the microwave-assisted extraction (MAE) of phlorotannins from Cystoseira sedoides using response surface methodology (RSM). Results showed that the independent variables significantly affected both phlorotannin content and the scavenging capacity. The optimum operating conditions were extraction time, 101.74 sec; dry material-to-solvent ratio, 1:10 g/mL; and ethanol extraction, 50%. Under these conditions, the predicted values of PHT content and radical scavenging activity-IC50 were close to the observed values and were 383.887 µg PGE/g Dm and 18.353 µg/mL, respectively. Characterization of the phlorotannin-rich fraction was conducted by high-performance liquid chromatography and Fourier transform infrared spectroscopy. The evaluation of the anticancer activity against MCF-7 breast cancer cell line showed a potent activity to trigger apoptotic death in more than a half of the MCF-7 cells, with an estimated IC50 value of 78 μg/mL. In addition, this fraction induced a notable growth regression effect on 3D spheroids model in a concentration-dependent manner, with a growth rate of about 1.17, at 200 µg/mL.

Abbreviations: CCRD: Central composite rotatable design; Dm: Dry material; DMBA: 2,4-dimethoxy benzaldehyde; DMSO: Dimethyl sulfoxide; DPPH: 1,1-diphenyl-2-picrylhydrazyl; EDTA: Ethylene diamine tetraacetic acid; FBS: Fetal bovine serum; FT-IR: Fourier transform infrared; HPLC: High-performance liquid chromatography; IC50: Half-maximal inhibitory concentration; MAE: Microwave-assisted extraction; Min: minutes; PBS: Phosphate buffered saline; PGE: Phloroglucinol equivalent; PHT: Phlorotannins; PHT-SED: phlorotannins derived from Cystoseira sedoides; PI: Propidium iodide; RSA: Radical scavenging activity; RSM: Response surface methodology; Sec: seconds  相似文献   
135.
The demand for animal protein especially fish is growing rapidly perhaps due to rapid expansion of population, increased incomes, and changes in eating habits and life styles of consumers. Capture fisheries are currently overexploited and their yield has become stagnant over the last decades and, in some cases, has even declined. Nevertheless, aquaculture has the potential to meet these challenges if well practiced. The study therefore, aims to estimate Technical Efficiency of tank culture systems using Data Envelopment Analysis (DEA). Additionally, it also investigates the determinants of technical inefficiency by employing a regression model. The estimated technical efficiency was 0.89, which means that the fish farmers can reach full technical efficiency through reducing their input usage by another 11%. Results indicate that farmer’s experience, educational level, extension training, job status, and water management have positive and statistically significant impacts on technical efficiency. Therefore, increase in any of these factors will have a direct impact on technical efficiency.  相似文献   
136.
This paper provides a conceptual framework to explain why disparities may exist in food safety code compliance by food stores in different neighborhoods. Explanations include market dynamics, community characteristics, retailer attributes, inspector characteristics, and enforcement approaches, and interactions among the factors. A preliminary and limited empirical test of some of these relationships in Detroit, Michigan shows a higher rate of food safety violations by stores in poorer neighborhoods and in neighborhoods with higher concentrations of African-American residents. Stores inspected by female inspectors also scored higher numbers of critical violations, suggesting a need for greater examination of the social relations associated with enforcement interactions in food safety studies.
Kameshwari PothukuchiEmail:

Kameshwari Pothukuchi   PhD, is Associate Professor of Urban Planning at Wayne State University. She conducts research on issues related to urban food security, including grocery stores, community gardens, and community and regional food planning. A policy guide on community and regional food planning, co-authored by her, was recently adopted by the American Planning Association (). Rayman Mohamed   PhD, is Assistant Professor of Urban Planning at Wayne State University. He conducts research on land use and environmental planning. His recent articles examine decision making by developers, the economics of conservation subdivisions, and the relationship between sprawl and the costs of infrastructure. David A. Gebben   is a graduate student of agricultural economics and a research assistant in the Global Urban Studies Program at Michigan State University.  相似文献   
137.
The structure of BPSL1549, a protein of unknown function from Burkholderia pseudomallei, reveals a similarity to Escherichia coli cytotoxic necrotizing factor 1. We found that BPSL1549 acted as a potent cytotoxin against eukaryotic cells and was lethal when administered to mice. Expression levels of bpsl1549 correlate with conditions expected to promote or suppress pathogenicity. BPSL1549 promotes deamidation of glutamine-339 of the translation initiation factor eIF4A, abolishing its helicase activity and inhibiting translation. We propose to name BPSL1549 Burkholderia lethal factor 1.  相似文献   
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In the present study, we investigated the effect of grape seed and skin supplement (GSSS), on lactating dairy ewes’ production. Ten dairy pregnant ewes from northern Tunisia were allocated to two groups: control diet (C) and supplemented with 20 % (w/w) GSSS. The experiment lasted for 8 weeks and took place after 2 months of lambing. During the experiment, daily milk yield and milk composition were determined. Supplementation of the diet with GSSS increased milk production (P?<?0.001), calcium (P?<?0.01), free iron (P?<?0.01) and urea content (P?<?0.001) but had no effect on milk fat nor protein. From these data, it is concluded that the inclusion of GSSS in sheep diets increased significantly ewes’ milk yield.  相似文献   
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