623 research outputs found

    Nitrogen and Sulfur Fertilization Effects on Camelina Sativa in West Central Kansas

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    Camelina sativa is early maturing and possesses characteristics that make it a good fit as a rotation crop in dryland wheat cropping systems. Nitrogen (N) and sulfur (S) play very important roles in oilseed production, including camelina. This study was undertaken in 2013 and 2014 to determine N and S rates necessary for optimum camelina production in West Central Kansas. The experiment was set up as randomized complete blocks with four replications in a split-plot arrangement. Treatments were two S rates (0 and 18 lb/a) as the main plots, and N rates (0, 20, 40, and 80 lb/a) were the subplots. The results showed that plant stand, plant height, harvest index, biomass yield, and protein and oil content were unaffected by N and S application. Similarly, S application had no effect on seed yield. However, N rate had a significant (P \u3c 0.05) effect on seed yield. Yield differences were realized for 2013 (~450 lb/a) and 2014 (~900 lb/a)

    Seeding Date Effects on Camelina Seed Yield and Quality Traits

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    Identifying crops that are adapted to dryland environments of the central and northern Great Plains (GP) has been a major challenge. An alternative crop with potential for dryland crop production in the GP is camelina (Camelina sativa L. Crantz). Time of planting is an important management consideration that can affect camelina production. Early planting allows camelina to mature before the onset of hot summer temperatures in the central GP that can affect seed yield. A study was carried out in the spring of 2013 and 2014 to evaluate planting date effects on spring camelina varieties grown under dryland conditions in western Kansas. In this study, three spring varieties (Blaine Creek, Pronghorn, and Shoshone) were planted at three seeding dates (early, mid, and late). Parameters collected included plant height, harvest index, seed yield, and oil and protein content. Our findings indicate that seeding date affected time of flowering and physiological maturity (P \u3c 0.05) but had no effect on oil content. Year × camelina variety interaction had a significant effect on seed yield. Similarly, protein content differed among the varieties (Blaine Creek \u3e Pronghorn \u3e Shoshone). Blaine Creek consistently produced the highest yield in both years and had a protein content of 30%

    "We are not the only ones to blame': District Assemblies' perspectives on the state of planning in Ghana

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    Planning has failed to exert effective influence on the growth of human settlements in Ghana. As a result, the growth of cities has been chaotic. The district assemblies, which are the designated planning authorities, are commonly blamed for this failure, yet little attention has been given to district assemblies perspectives of what factors lead to failures in planning. This paper attempts to fill this gap. Drawing on fieldwork in Ghana, it argues that, from the perspective of district assemblies, five major challenges inhibit planning, namely: an inflexible land ownership system, an unresponsive legislative framework, undue political interference, an acute human resource shortage, and the lack of a sustainable funding strategy. The paper concludes with proposals for reforming the planning system in Ghan

    Vessel-Fibre Ratio, Specific Gravity And Durability Of Four Ghanaian Hardwoods

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    Several factors affect wood durability but the influence of anatomy is scarcely studied. Vessels and fibres sampled across and along stems of Milicia excelsa (Welw.) C. C. Berg) (odum), En-tandrophragma cylindricum (Sprague) Sprague (sapele), Terminalia ivorensis A. Chev. (emire) and Antiaris toxicaria Lesch. (kyenkyen) were studied to understand the relationship between their vessel-fibre (V-F) ratios, specific gravities (SGs) and durabilities. Vessels, fibres and their proportions were examined from macerates and T.S. of prepared slides. While the timbers ex-hibit major hardwood cell-types (e.g. vessels, fibres and parenchyma), intra-stem variability ex-ists with more vessels and greater V-F ratios at the crowns and in sapwoods than at the butts and in heartwoods, unlike for fibres. Inter-specific variation also shows A. toxicaria has the greatest vessel content then T. ivorensis, E. cylindricum and M. excelsa, a contrary pattern for fibre con-tents. V-F ratio ranks as: A. toxicaria > E. cylindricum > T. ivorensis > M. excelsa, while SGs are higher in E. cylindricum (667) and M. excelsa (635) than in T. ivorensis (507) and A. toxi-caria (505), which hardly differ from published data. Except for E. cylindricum, butts have the greatest SGs. Correlations between their V-F ratios and SGs are R2 = 34%, 84%, 32% and 1% respectively. Timbers with greatest vessels and V-F ratios but least fibres and SGs have weak relationship and very low durabilities, as in A. toxicaria (R2 = 1%). However, M. excelsa, which has the strongest V-F ratio and SG relationship (R2 = 84%), is very durable.Keywords: Cell type, durability class, macerates, paratracheal parenchyma, vessel- fibre rati

    Nitrogen Uptake in Soils under Different Water Table Depths

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    A mathematical model was used to examine the interactions of NH4+ transport to rice roots, as well as to calculate root length densities required to relate N uptake to concentrations of NH4 + in solution around the rooting medium for three water treatments: water table 30 cm below the surface, 15 cm below the surface and a flooded system. Measured uptake was greatest for the plants under the 30 cm treatment, followed by the 15 cm treatment, then the flooded treatment. Solution concentrations were highest under the flooded treatment followed by the 30 cm treatment, then the 15 cm treatment. Calculated root length densities were greatest for the plants under the 30 cm water table treatment, followed by those under the 15 cm treatment, then the flooded treatment. Measured root length densities were similarly greatest for the plants under the 30 cm water table treatment, followed by those under the 15 cm water table depth treatment, then the flooded treatment. However, differences between measured and calculated root length densities became significant for all treatments after 30 days of treatment imposition. Transport rates varied with treatments but uptake rates did not reflect these differences in transport rates, thus, transport through the growth medium did not limit uptake of nitrogen by the plants

    Molecular and behavioral mechanisms mediating paclitaxel-induced changes in affect-like behavior in mice

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    The antineoplastic paclitaxel is associated with negative affective outcomes, such as depression, anxiety, and decreased quality of life during treatment and convalescence. With the Baby Boomer population approaching peak cancer age, it is dire that the mechanisms behind paclitaxel-induced changes in mood are uncovered. Cancer-free male and female C57BL/6J mice were treated with one set of four injections of vehicle or paclitaxel (32mg/kg cumulative), or two sets of four injections of vehicle or paclitaxel (64mg/kg cumulative), and periodically assessed for depression-like behaviors. Paclitaxel caused significant, time-dependent deficits in sucrose preference and operant responding for palatable food. Because there is growing evidence to support the role of kappa opioid receptors (KORs) in stress-mediated depression and reward dysfunction, we investigated KOR signaling as a putative mechanism of paclitaxel-induced depression-like behaviors. The selective KOR antagonist norbinaltorphimine (norBNI) reversed paclitaxel-induced attenuation of sucrose preference. At the molecular level, paclitaxel time-dependently induced an increase in the expression of Prodynorphin mRNA, the precursor for endogenous KOR agonists, in the nucleus accumbens (NAc). Using the [35S]GTPγS assay, we discovered that a history of paclitaxel time-dependently attenuated activation of dopamine D2 receptors (D2R) and KORs in the NAc but not caudate putamen. These data suggest that paclitaxel-induced changes in affect-like behavior may be due to time- and region-dependent dysregulation of KOR and D2R signaling. These observations help to establish the roles of KOR and D2R systems in paclitaxel-induced disruption of behavioral reward, thus revealing potential neurochemical targets for therapeutic intervention in cancer survivors with treatment-resistant depression.https://scholarscompass.vcu.edu/gradposters/1038/thumbnail.jp

    Field measurements and statistical analysis of perforated grating surfaces for grating fresh cassava into mash in Ghana

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    Processing of cassava into mash requires grating of fresh cassava tubers through the abrasive action of the grating surfaces of cassava graters that grind against the cassava and transforms it into mash. Over the years, improved cassava graters have been designed and made available on the market. In spite of improvements in design, there are no standards for the manufacture of grating surfaces and this affects interchangeability of the product. Mechanised grating of fresh cassava into mash contributes to reduce postharvest losses of cassava, increase its shelf life and improve food security. However, majority of the cassava grating surfaces are poorly made with substandard measurements that affect the desired particle size of mash for gari, a staple food for millions of people in West Africa. This study assessed cassava grating surfaces focusing on the abrasive elements (tooth diameter and inter-tooth spacing). Qualitative data were gathered from local metal fabricators and female gari processors in separate focus group discussions. The purpose was to gather the narratives underlying the issues being studied so as to complement and enrich the quantitative data. 112 tooth diameters and 112 inter-tooth spacing of perforated cassava grating surfaces were randomly measured in 16 different study areas in 3 regions of Ghana, namely Western, Central and Ashanti. Results from the qualitative data showed that grating of cassava was done repeatedly (about 2-3 times) before reaching the desired particle size of mash for gari. Most customers desire grating surfaces that ensure effective contact between the cassava and the metal grating surface to reduce grating time. Results from the field measurements showed high variation in existing tooth diameters (min=1.80, max=4.50 mm) and inter-tooth spacings (min=3.50, max=12.00 mm) that resulted in non-uniform particle size of cassava mash. Using statistical analysis, tooth diameters (min=3.18, max=3.42mm) and inter-tooth spacings (min=7.12, max=7.78mm) were determined at 95% confidence interval. For practical purposes, tooth diameter of 3 mm and inter-tooth spacing of 8 mm are recommended. The availability of such data will contribute significantly to standardise perforated cassava grating surfaces to achieve product interchangeability and desired quality of grated mash for gari. This will contribute to improve the manufacture of cassava graters and sustainable gari processing business in Ghana and Africa.Keywords: Fresh cassava, cassava grating surface, gari, food quality, Ghan

    Seeding Date Effects on Camelina Seed Yield and Quality Traits

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    An alternative crop with potential for dryland crop production in the Great Plains is camelina (Camelina sativa L. Crantz). Time of planting is an important management consideration that can affect camelina production. A study was carried out in the spring of 2013, 2014, and 2015 to evaluate seeding date effects on spring camelina varieties grown under dryland conditions in western Kansas. Three spring varieties (Blaine Creek, Pronghorn, and Shoshone) were planted at three seeding dates: early (April 3, 2013; March 17, 2014; and March 18, 2015); mid (April 16, 2013; April 1, 2014; and April 1, 2015); and late (April 30, 2013; April 15, 2014; and April 15, 2015). Parameters collected included time of flowering and physiological maturity, stand count at maturity, seed yield, biomass yield, harvest index, oil and protein content. Our findings indicate that seeding date can affect the time of flowering and physiological maturity, stand count, seed yield, biomass yield, harvest index, and protein content, but it did not affect oil content. Harvest index and oil content was significantly different among varieties. In general, mid and late seeding dates produced the highest yield across the three years. There were yield differences among varieties; Blaine Creek produced the highest seed yield and was significantly different from Pronghorn and Shoshone. Seed yield ranged between 340 and 440 lb/a. Average oil and protein content was 26% and 30%, respectively. Based on environmental factors and agronomic characteristics, camelina varieties were more productive when planted between early and mid-April

    Influence of Different Seeding Dates on Fenugreek (Trigonella foenum-graecum L.) Forage Yield and Nutritive Value

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    Fenugreek (Trigonella foenum-graecum L.) is used as medicinal plant in many Asian countries and has been reported to have forage quality similar to alfalfa. Fenugreek is an annual crop and may have the potential to diversify forage production systems in the central High Plains. This study evaluated forage dry matter (DM) production and the nutritive value of three fenugreek cultivars as influenced by planting date at Hays and Garden City, KS, in 2014. Results at Hays showed forage DM yield of fenugreek cultivars was not affected by planting date, but fenugreek cultivars differed significantly (P \u3c 0.05) in forage DM yield. Averaged across planting date, forage DM production was 760 lb/a for ‘Amber,’ 910 lb/a for ‘F96,’ and 672 lb/a for ‘Tristar.’ Forage crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrient (TDN) concentrations, and relative feed value (RFV) did not differ (P \u3e 0.05) among fenugreek cultivars. Planting early, however, did increase CP levels and lower ADF and NDF concentrations. Despite the lower yields observed in 2014, our preliminary results showed that fenugreek can produce forage with nutritive value comparable to alfalfa and that further testing is needed to determine if fenugreek can provide an option for producers who want to diversify their forage production operations, particularly under limited irrigation conditions

    Nitrogen and Sulfur Fertilization Effects on Camelina Sativa in West Central Kansas

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    Camelina sativa is early maturing and possesses characteristics that make it a good fit as a rotation crop in dryland wheat cropping systems. Nitrogen (N) and sulfur (S) play very important roles in oilseed production, including camelina. This study was conducted over 3 years to determine N and S rates necessary for optimum camelina production in west central Kansas. The experiment was set up as randomized complete blocks with four replications in a split-plot arrangement. Treatments were two sulfur rates (0 and 18 lb/a) as the main plots, and four N rates (0, 20, 40, and 80 lb/a) as the sub-plot. Sulfur application did not affect stand count, biomass yield, harvest index, seed yield, oil and protein content. However, stand count, biomass yield, seed yield, and protein content were affected by N application (P \u3c 0.05). Average oil and protein content were 28.1% and 33.9% respectively. The optimum N rate for yield was 20 lb N/a, which produced around 680 lb/a seed yield. Based on soil test levels of 25 lb N/a, N requirement for camelina production is 45 lb N/a
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