739 research outputs found

    Conventional Tillage versus No-till: Characteristics of Producers and Farms

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    A survey of Oklahoma farmers was conducted to determine characteristics of farms across three tillage categories: conventional tillage exclusively; no-till exclusively; other (combination of systems). The seven percent that use no-till exclusively crop more acres, rent more acres, and use more crop rotations than farms that use conventional tillage exclusively.no-till, conventional tillage, survey, farm machinery, farm size, wheat, perceptions, Crop Production/Industries, Farm Management, Q10, Q12,

    The poverty impacts of improved cowpea varieties in Nigeria: a counterfactual analysis

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    Open Access Article; Published online: 12 June 2019Adoption of improved agricultural technologies has long been recognized as critical for reducing poverty through increased productivity, incomes, and asset accumulation. Using a nationally representative survey data from a sample of over 1500 households in Nigeria, this paper evaluates the impacts of adoption of improved cowpea varieties on income and asset poverty reduction using an endogenous switching regression model. The results showed that adoption of improved cowpea varieties increased per capita household income and asset ownership by 17 and 24 percentage points, respectively. The results based on the observed and counterfactual income and asset distributions further showed that adoption reduced both income poverty and asset poverty by 5 percentage points. The paper concludes with a discussion of the policy options for increasing adoption and impacts of improved cowpea varieties in Nigeria

    Yield stress and shear-banding in granular suspensions

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    We study the emergence of a yield stress in dense suspensions of non-Brownian particles, by combining local velocity and concentration measurements using Magnetic Resonance Imaging with macroscopic rheometric experiments. We show that the competition between gravity and viscous stresses is at the origin of the development of a yield stress in these systems at relatively low volume fractions. Moreover, it is accompanied by a shear banding phenomenon that is the signature of this competition. However, if the system is carefully density matched, no yield stress is encountered until a volume fraction of 62.7 0.3%

    Gestational diabetes and endothelial function: impact of gestational insulin resistance on reactive hyperhemia index

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    Our aim was to characterize endothelial function in gestational diabetes by evaluating the reactive hyperemia index (RHI, LnRHI). A prospective, descriptive and comparative study was conducted on a population of pregnant women aged over 20 and under 36, located in the gestational age group 24-38th week of amenorrhea. They were divided into two groups. Group 1 (G1): group of pregnancies without diabetes, consists of pregnant women with no risk factor for gestational diabetes and with normal fasting blood glucose. Group 2 (G2): group of pregnancies with diabetes, includes pregnancies whose oral glucose tolerance tests (OGTT) came back positive. Anthropo-physiological parameters (age, weight, height, blood pressure (PA) and biochemical parameters (glycemia, insulinemia, HOMA-IR, cholesterol, triglycerides) were measured. RHI and LnRHI were determined at Endopat 2000. The two groups were matched for age, weight, heart rate (HR) and blood pressure (BP). Levels of glucose (G1:0.76±0.11; G2:1.11±0.11; p˂0.0001), insulin (G1:7.67±4.35; G2:22.9±3.75; p˂0.0001), HOMA-IR (G1:1.51±0.97; G2:6.29±1.23; p˂0.0001), total cholesterol (G1:1±0.81; G2:2.49±0.74; p=0.002), HDL cholesterol (G1:0.45±0.23; G2: 0.8±0.19; p=0.004, LDL cholesterol (G1:0.42±0.54; G2:1.39±0.6; p=0.004), triglycerides (G1:0.65±0.49; G2:1.48±0.27; p=0.0018), were significantly higher in the diabetic group. Both RHI and LnRHI were negatively correlated with HOMA-IR (respectively, r=-0.8931, p<0.0001; r=-0.8938; p<0.0001). HOMA-IR index was independently associated with levels of RHI and LnRHI (respectively r²=0.797; p<0.0001); (r²=0.804; p<0.0001)). Thus, gestational insulin resistance would be associated with a change in endothelial function such as a decrease in endothelium-dependent vasodilatation reflecting endothelial dysfunction, hence an increase in cardiovascular risk

    Soils and Nutrients Losses and Gains during Rainy Season in the Fadama of Semi-Arid Sokoto, Nigeria

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    A study was conducted to quantify the amount of soil and plant nutrients losses and gains during rainy season in the fadama land in the Sokoto semi-arid ecosystem, Nigeria. Field measurements revealed that about 33.3 tonne ha-1 of soil was moved from the adjacent uplands by run-off and wind and subsequently deposited in the fadama, while 22 ton ha-1 was removed from the fadama land during the period of the study (May-September). Over the same period, plant nutrients losses (in kg ha-1) with the eroded soil amounted to 30.8 organic matter, 0.3 K, 9.0 Na and 0.07 available P. Nutrient gains (in kg ha-1) amounted to 2.2 Total N and 4.4 Mg. Soil deposition was found to be greater than soil removal because of the gusty winds that accompany early and late rains.The major problem of erosion in the fadama lands is the deposition of sandy materials moved from the upland which are by far less fertile. The continuous deposition of these materials could render the fertile fadama infertile. Soil removal is not a very serious threat to the fadama as soil deposition because the land is often flat and covered with vegetation in almost all part of the year with little cover in the dry season and early part of the rainy season.Key words: Nutrient losses, Erosion, Fadama, Semi-arid Sokoto and Rainy seaso
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