683 research outputs found

    Lipase-catalyzed Reactions at Interfaces of Two-phase Systems and Microemulsions

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    This work describes the influence of two polar lipids, Sn-1/3 and Sn-2 monopalmitin, on the activity of lipase in biphasic systems and in microemulsions. In previous communications, we have shown that Sn-2 monoglycerides can replace Sn-1,3 regiospecific lipases at the oil-water interface, causing a drastically reduced rate of lipolysis. We here demonstrate that even if the lipase is expelled from the interface, it can catalyze esterification of the Sn-2 monoglyceride with fatty acids in both macroscopic oil-water systems and in microemulsions, leading to formation of di- and triglyceride

    IMPACT OF A MORE INTENSIVE INSECT PEST INFESTATION LEVEL ON COTTON PRODUCTION: TEXAS HIGH PLAINS

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    This study evaluated implications of increased bollworm problems in a 20-county area of the Texas High Plains relative to cotton yields and economic impact. Results did not indicate a serious effect of bollworms upon lint yield when insecticides were used for control. However, estimated annual reduction in farmer profit due to the bollworm for 1979-81 was over $30 million. Yields were estimated to decline about 300,000 bales without insecticide use and about 30,000 bales with insecticide use. This decline suggests potentially serious implications for the comparative economic position of cotton in this region if insecticide resistance were to develop among insect pests.Crop Production/Industries,

    An Investigation of Somali Women’s Beliefs, Practices, and Attitudes about Health, Health Promoting Behaviours and Cancer Prevention

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    This pilot study examined Somali women's perception of health/access to care, examined their knowledge and attitudes about cancer prevention, and discussed strategies to improve service provision and education. Using a multidisciplinary approach, twelve face-to-face interviews were conducted with Somali women ages 18 and older, residing in a mid-western city. Open coding was used to categorize and reflect the interview statements and to identify reoccurring themes. Somali women are concerned about a variety of health issues and cited the role of culture and religion in developing prevention strategies.   Participants emphasized the use of religious leaders, health care advocates, oral traditions, and translators in providing culturally appropriate health care services. Religion and culture play a prominent role in the Somali community and impact beliefs about health and wellness.  Health practitioners need to work closely with individuals and community leaders to tailor services that are culturally appropriate and accessible.     

    Fatigue Crack Closure Analysis Using Digital Image Correlation

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    Fatigue crack closure during crack growth testing is analyzed in order to evaluate the critieria of ASTM Standard E647 for measurement of fatigue crack growth rates. Of specific concern is remote closure, which occurs away from the crack tip and is a product of the load history during crack-driving-force-reduction fatigue crack growth testing. Crack closure behavior is characterized using relative displacements determined from a series of high-magnification digital images acquired as the crack is loaded. Changes in the relative displacements of features on opposite sides of the crack are used to generate crack closure data as a function of crack wake position. For the results presented in this paper, remote closure did not affect fatigue crack growth rate measurements when ASTM Standard E647 was strictly followed and only became a problem when testing parameters (e.g., load shed rate, initial crack driving force, etc.) greatly exceeded the guidelines of the accepted standard

    Cross talk between Wnt/β-catenin and Irf8 in leukemia progression and drug resistance

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    Progression and disease relapse of chronic myeloid leukemia (CML) depends on leukemia-initiating cells (LIC) that resist treatment. Using mouse genetics and a BCR-ABL model of CML, we observed cross talk between Wnt/{beta}-catenin signaling and the interferon-regulatory factor 8 (Irf8). In normal hematopoiesis, activation of {beta}-catenin results in up-regulation of Irf8, which in turn limits oncogenic {beta}-catenin functions. Self-renewal and myeloproliferation become dependent on {beta}-catenin in Irf8-deficient animals that develop a CML-like disease. Combined Irf8 deletion and constitutive {beta}-catenin activation result in progression of CML into fatal blast crisis, elevated leukemic potential of BCR-ABL-induced LICs, and Imatinib resistance. Interestingly, activated {beta}-catenin enhances a preexisting Irf8-deficient gene signature, identifying {beta}-catenin as an amplifier of progression-specific gene regulation in the shift of CML to blast crisis. Collectively, our data uncover Irf8 as a roadblock for {beta}-catenin-driven leukemia and imply both factors as targets in combinatorial therapy

    Preliminary evaluation of the CellFinder literature curation pipeline for gene expression in kidney cells and anatomical parts

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    Biomedical literature curation is the process of automatically and/or manually deriving knowledge from scientific publications and recording it into specialized databases for structured delivery to users. It is a slow, error-prone, complex, costly and, yet, highly important task. Previous experiences have proven that text mining can assist in its many phases, especially, in triage of relevant documents and extraction of named entities and biological events. Here, we present the curation pipeline of the CellFinder database, a repository of cell research, which includes data derived from literature curation and microarrays to identify cell types, cell lines, organs and so forth, and especially patterns in gene expression. The curation pipeline is based on freely available tools in all text mining steps, as well as the manual validation of extracted data. Preliminary results are presented for a data set of 2376 full texts from which >4500 gene expression events in cell or anatomical part have been extracted. Validation of half of this data resulted in a precision of ~50% of the extracted data, which indicates that we are on the right track with our pipeline for the proposed task. However, evaluation of the methods shows that there is still room for improvement in the named-entity recognition and that a larger and more robust corpus is needed to achieve a better performance for event extraction. Database URL: http://www.cellfinder.org

    Influence of Surfactants on Lipase Fat Digestion in a Model Gastro-intestinal System

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    In the present study, we use a model gastro-intestinal system to study the influence of different food-grade surface-active molecules (Sn-2 monopalmitin, β-lactoglobulin, or lysophosphatodylcholine) on lipase activity. The interfacial activity of lipase and surfactants are assessed with the pendant drop technique, a commonly used tensiometry instrument. A mathematical model is adopted which enables quantitative determination of the composition of the water–oil interface as a function of bulk surfactant concentration in the water–oil mixtures. Our results show a decrease in gastric lipolysis when interfacially active molecules are incorporated into a food matrix. However, only the Sn-2 monopalmitin caused a systematic decrease in triglyceride hydrolysis throughout the gastro-intestinal tract. This effect is most likely due to exclusion of both lipase and triglyceride from the water–oil interface together with a probable saturation of the solubilization capacity of bile with monoglycerides. Addition of β-lactoglobulin or lysophopholipids increased the hydrolysis of fat after the gastric phase. These results can be attributed to an increasing interfacial area with lipase and substrate present at the interface. Otherwise, β-lactoglobulin, or lysophopholipids reduced fat hydrolysis in the stomach. From the mathematical modeling of the interface composition, we can conclude that Sn-2 monopalmitin can desorb lipase from the interface, which, together with exclusion of substrate from the interface, explains the gradually decreased triglyceride hydrolysis that occurs during the digestion. Our results provide a biophysics approach on lipolysis that can bring new insights into the problem of fat uptake
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