90 research outputs found

    Expression of Cadherin Superfamily Genes during Ferret Brain Development

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    Cadherins are a superfamily of Ca2+-dependent cell adhesion molecules with more than 100 members (Redies et al., 2005). They are multifunctional transmembrane glycoproteins found in several kinds of cell-cell contact, including adherens junctions. They regulate a wide variety of crucial developmental mechanisms, including cell proliferation, cell differentiation, cell-cell recognition, neurite outgrowth, synaptogenesis and angiogenesis. In this study, I cloned eighteen novel members of the classic cadherin and delta-protocadherin subgroups and investigated their expression patterns by in situ hybridization from the brain of ferret, an animal model suitable for visual cortical and cerebrovascular research. I also showed seven members of the cadherin superfamily and an intracellular binding partner of delta-protocadherins, protein phosphatase 1alpha as novel markers for developing blood vessels in the ferret brain. Some of the cadherin molecules are restricted to specific brain regions or a subset of blood vessels. The expression levels show a peak during perinatal vascular development. My results suggest that multiple cadherins, which are also involved in neurogenesis, are regulators of angiogenesis in developing vertebrate brain, supporting the idea of a common mechanism behind "neuroangiogenesis"

    Effects of varying condensed distillers solubles, drying, and cooling temperatures on glass transition temperature of distillers dried grains

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    Distillers dried grains with solubles (DDGS), a coproduct of ethanol fuel production, is used as an animal feed and often must be transported long distances. DDGS flowability problems often create nuisance in storage and transportation. Materials above the glass transition temperature (Tg) can exist in a “rubbery state,”’ which is often responsible for particle agglomeration and caking. This study investigated the effects of varying condensed distillers solubles (CDS) (10, 15, and 20%, wb), drying (100, 200, and 300°C), and cooling temperature (–12 and 35°C) levels on the Tg of DDGS. Tg ranged from 34 to 58°C and 41 to 59°C for cooling temperatures of –12°C and 35°C, respectively. Tg data were used to develop an overall regression model, which yielded a predictive model with R² of 0.74 and SEM of 3.16. Using this model, optimum drying and cooling temperatures were determined. These conditions may be used to reduce flow problems

    Effect of Processing Conditions on Nutrient Disappearance of Cold-pressed and Hexane-extracted Camelina and Carinata Meals in vitro

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    Camelina and carinata are oilseed crops that have recently gained increasing attention as biofuel sources. The meals remaining after oil extraction contain relatively high concentration of protein and, because of this, there is interest in using them in livestock diets. However, the nutritional qualities of these meals are not well defined and may vary with processing conditions. In our experiment, we evaluated meals from cold-pressed and solvent-extracted camelina and carinata meals manufactured using 6 different processing conditions. Estimates of total in vitro OM and CP disappearance of each meal were determined according to a modified 2-phase procedure of Tilley and Terry (1963). We detected no differences in CP disappearance of camelina meal manufactured under cold-pressed extraction. In contrast, we noted differences in OM disappearance of camelina and carinata meals which had undergone different cold-press processing conditions. Differences were also observed in OM and CP disappearance of oilseed meals under varied hexane extraction conditions. Our data suggests that hexane extraction produced, on average, meals with greater OM disappearance than cold-pressing, but there were interactions by oilseed type. Hexane extraction performed under a temperature of 80°C for 90 min resulted in camelina meals with the greatest CP disappearance, whereas a temperature of 120°C for 65 min resulted in meals with the lowest CP disappearance

    Effects of Amylose-To-Amylopectin Ratios on Binding Capacity of DDGS/Soy-Based Aquafeed Blends

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    Demands for seafood products are steadily increasing. Alternative protein sources are required to compensate for enormous amounts of fishmeal that is needed for global seafood production. Starch is a food polymer that can be added to fish feed formulations to enhance binding and expanding capabilities of extrudates. Floatability, a key factor for most aqua feeds, can be optimized by the addition of certain starch sources. Six ingredient blends with a similar protein content (~32.5%) containing two starch sources, Hylon VII (containing 70% amylose, 30% amylopectin) or Waxy I (containing 0% amylose, 100% amylopectin), 20% distillers dried grain with solubles (DDGS), and 15, 25, and 35% moisture content were used along with appropriate amounts of soybean meal, menhaden fishmeal, whey, vitamin and mineral mix to investigate nutritionally-balanced feeds for Nile tilapia (Oreochromis niloticus L.). The blends were processed using a laboratory single-screw extruder with varying temperature settings (90-90-90°C, 100-120-120°C, and 100-120-140°C), screw speeds (100, 120, and 140 rpm), and length/diameter ratio (3.4, 6.6, 9.2) of the die. Extensive analyses of expansion ratio (ER), unit density (UD), sinking velocity (SV), and pellet durability indices (PDI), water absorption (WAI) and water solubility indices (WSI) were conducted to evaluate the effects of the two starch sources on extrudate binding and floating capacity. By varying process conditions, significant differences (P\u3e0.05) among the blends were detected for all extrudate physical properties. Significantly higher values for ER, UD, and PDI were achieved by using the Waxy I starch source, while values for SV and WAI decreased. For WSI no significant differences were detected. Increasing the moisture content from 15-35% resulted in a significant increase in ER, WAI, and PDI and a significant decrease in UD. WSI showed no clear pattern in changes. The impact of different amylopectin to amylose ratio, temperature and moisture content on extrudate stability, cohesion and physical properties was demonstrated in this study. All formulations yielded viable extrudates while the blends with the amylopectin as the sole source of starch resulted in higher quality extrudates

    Modeling Distillers Dried Grains with Solubles (DDGS) Mass Flow Rate as Affected by Drying and Storage Conditions

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    Ethanol production in 2015 was over 15 million gallons in the United States, and it is projected to increase in the next few years to meet market demands. With the continued growth in the ethanol industry, there has been enormous expansion in distillers grains production. Because the local market for distillers dried grains with solubles (DDGS) is often saturated, it is essential to transport DDGS long distances, across the United States and to international markets. Caking and agglomeration of DDGS particles in hoppers and other storage structures are typical during transportation. The current study deals with DDGS prepared by combining condensed distillers solubles (CDS) with distillers wet grains and then drying at varying temperatures. DDGS was stored in conical hoppers under varying ambient temperature, consolidation pressure, and time conditions. We investigated the effects of CDS (10, 15, and 20% wb), drying temperature (100, 200, and 300°C), drying time (20, 40, and 60 min), cooling temperature (0, 25, and 50°C), consolidation pressure (0, 1.72, and 3.43 kPa), and consolidation time (0, 3, and 6 days) levels on various flow parameters. To examine these factors, Taguchi’s experimental design with an L18 orthogonal array was implemented. Response surface modeling yielded mass flow rate = f(Hausner ratio, angle of repose) with R2 = 0.99, and it predicted moisture content for good, fair, and poor flow. Results showed that drying temperature, drying time, and cooling type were the main factors in predicting mass flow rate. The Johansson model for predicted mass flow rate was calibrated with experimental data, and a new parameter, compressibility factor, with a value of 0.96 g2/(min cm3), was determined to quantify the divergence of compressible and cohesive materials (such as DDGS) for free-flowing bulk solids. Thus, the predicted models may be beneficial for quantitative understanding of DDGS flow

    Effects of CDS and drying temperature on the flowability behavior of DDGS

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    Due to increasing demand for alternative fuels and theneed to reduce dependence on fossil fuels, the growth of bioethanol production has been rising. One of the problems facing this industry is transportation of the coproduct dried distillers grains with solubles (DDGS) over long distances, because caking and agglomeration between particles can lead to bulk flow problems. In this study, DDGS was prepared by combining condensed distillers solubles (CDS) and distillers wet grains (DWG) and then oven drying to achieve 8% (db) moisture content. The effects of drying temperature (100, 200, and 300°C) and CDS (10, 15, and 20%wb ) level on the resulting flowability behavior of the DDGS particles were investigated. Statistical analyses indicated significant differences (α = 0.05, 95% confidence level) due to drying temperature and CDS main effects and significant interaction effects between CDS level and drying temperature for many of the flow parameters. Surface regression analysis of the ratio of total flow index/Jenike flow function as a function of CDS and drying temperature resulted in an R 2 value of 0.94. Partial least squares (PLS) regression yielded an R 2 of 0.90 for the Jenike flow function index as a function of all flow and physical properties using only two multivariate components. Understanding the effects of varying drying temperatures and CDS levels can help guide efforts to overcome DDGS flowability problems

    Cross-Sectional Staining and Surface Properties of DDGS Particles and Their Influence on Flowability

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    With the U.S. fuel ethanol industry projected to grow during the next several years, supplies of distillers dried grains with solubles (DDGS) are anticipated to continue to grow as well. DDGS is used primarily as livestock feed. Much of the DDGS must be shipped, often over large distances, outside the Corn Belt (which is where most of the corn-based ethanol plants are currently located). Stickiness and caking among particles is a common issue for DDGS, and it often leads to flowability problems. To address this, the objective of this study was to understand the cross-sectional and surface natures of DDGS particles from five ethanol plants, and how they interact with DDGS properties. This study examined the distribution patterns of chemical components within cross-sections, within section edges (i.e., surface layers), and on surfaces using standard staining techniques; chemical composition was determined using standard protocols; and physical and flowability properties were also determined. Crude protein in the samples was 28.33–30.65% db, crude fat was 9.40–10.98% db, and neutral detergent fiber (NDF) was 31.84–39.90% db. Moisture contents were 4.61–8.08% db, and geometric mean diameters were 0.37–0.52 mm. Cross-sectional staining showed protein levels of 19.57–40.39%, and carbohydrate levels of 22.17–43.06%, depending on the particle size examined and the production plant from which the DDGS was sampled. Staining of DDGS particles indicated a higher amount of surface layer protein compared with carbohydrate thickness in DDGS particles that had a lower flow function index (which indicated potential flow issues). Additionally, surface fat staining suggested that higher surface fat also occurred in samples with worse flow problems. This study represents another step toward understanding why DDGS particles stick together during storage and transport, and will hopefully help to improve DDGS material handling strategies
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