258 research outputs found

    Composition Of ω-3 And ω-6 Fatty Acids In Freeze-dried Chicken Embryo Eggs With Different Days Of Development

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    Fatty acids ω-3 and ω-6 composition and specially DHA were determined in freeze-dried chicken embryo eggs with pre-determined incubation periods. Fertile and embryo eggs presented palmitic (23.18 ± 0.54%), stearic (7.70 ± 0.28%), palmitoleic (3.00 ± 0.19%), oleic (36.28 ± 0.58%), linoleic (22.18 ± 0.34%), linolenic (1.08 ± 0.04%), arachidonic (2.04 ± 0.03%), docosahexaenoic (0.91 ± 0.03%), total ω-3 acids (2.26 ± 0.10%) and total ω-6 acids (24.62 ± 0.33%). There were no significant differences in total contents of ω-3 fatty acids (p=0.1226) between freeze-dried chicken embryo eggs with different incubation periods (3, 5, 7, 9, and 11 days) and fertile freeze-dried chicken eggs (day 0). However, there were significant differences in total medium contents of ω-6 fatty acids (P=0.001). There was also a strong statistical evidence that quadratic model was related with expected values of DHA content (p= 0.0013).472219224Abril, R., Barclay, B., Fatty acid analysis of poultry eggs as methyl esters (1999) Método OT-GCPE, Rev. 3.1, , OmegaTech. Bolder, Co. 24/03/99(1996) Official Methods and Recommended Practices of de American Oil Chemists' Society. 4th Ed., , American Oil Chemists' Society, Champaign IIBragagnolo, N., Turatti, J.M., Evaluation of "light" eggs in Brazil (1999) Associazione Italiana di Avicoltura Scientifica, Instituto di Zootecnia, 2, pp. 177-181. , Paper presented at VIII European Symposium on the Quality of Eggs and Eggs Products, Bologna, ItáliaBeig, D., Garcia, F.C.M., (1986) O Embrião de Galinha, , Campo Grande : UFMS/ Imprensa UniversitáriaCherian, G., Sim, J.S., Net transfer and incorporation of yolk n-3 fatty acids into developing chick embryos (1993) Poultry Science, 72, pp. 98-105Cherian, G., Gopalakrishnan, N., Akiba, Y., Sim, J.S., Effect of maternal dietary n-3 fatty acids on the accretion of long-chain polyunsaturated fatty acids in the tissues of developing chick embryo (1997) Biology of Neonate, 72, pp. 165-174Connor, W.E., Importance of n-3 fatty acids in health and disease (2000) American Journal of Clinical Nutritional, 71 (SUPPL.), pp. 171S-175SFarkas, K., Noble, R.C., Speake, B.K., Development changes in the levels of molecular species of triacylglicerol that contain docosahexaenoic acid in adipose tissue of chick embryo (1996) Comparative Biochemistry and Physiology B-Biochemistry and Molecular Biology, 115, pp. 1-6Ferrier, L.K., Gaston, L.J., Leeson, S., Squires, J., Weaver, B.J., Holub, B.J., α-linolenic acid - and docosahexaenoic acid - enriched eggs from hens fed flaxseed: Influence on blood lipids and platelet phospholipid fatty acids in human (1995) The American Journal of Clinical Nutrition, 62, pp. 81-86Lin, D.S., Connor, W.E., Anderson, G.J., The incorporation of n-3 and n-6 essential fatty acids into chicken embryo from eggs yolks having vastly different fatty acid compositions (1991) Pediatric Research, 29, pp. 601-605Maldjian, A., Falkas, K., Noble, R.C., Cocchi, M., Speake, B.K., The transfer of docosahexaenoic acid from the yolk to the tissues of chicken embryo (1995) Biochimica et Biophysica Acta, 1258, pp. 81-99Nettleton, J.A., (1995) Omega-3 Fatty Acids and Health, , Chapman and Hall, New YorkNoble, R.C., Cocchi, M., Lipid metabolism and the neonatal chicken (1990) Prog. Lipid Res., 29, pp. 107-140Park, Y.K., Koo, M.H., Carvalho, P.O., Recentes Progresses dos Alimentos Funcionais (1997) Bol. SBCTA, 31Salatin, J., Pastured poultry profits (1993) Polyface Swoope, , VirginiaSpeake, B.K., Murray, A.M.B., Noble, R.C., Transport and transformations of yolk lipids during development of avian embryo (1998) Prog. Lipid Res., 37, pp. 1-32Stadelman, W.J., Pratt, D.E., Factors influencing composition the hen's egg (1989) World's Poultry Science Journal, 45, pp. 247-261Thapon, J.L., Bourgeois, C.M., L'oeuf et les ovoproduits (1994) Lavoisier -Technique et Documentation, , ParisVieira, S., Hoffmann, R., Estatísitica experimental (1989) Atlas, , São Paul

    Force and Motion Generation of Molecular Motors: A Generic Description

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    We review the properties of biological motor proteins which move along linear filaments that are polar and periodic. The physics of the operation of such motors can be described by simple stochastic models which are coupled to a chemical reaction. We analyze the essential features of force and motion generation and discuss the general properties of single motors in the framework of two-state models. Systems which contain large numbers of motors such as muscles and flagella motivate the study of many interacting motors within the framework of simple models. In this case, collective effects can lead to new types of behaviors such as dynamic instabilities of the steady states and oscillatory motion.Comment: 29 pages, 9 figure

    Geniculo-Cortical Projection Diversity Revealed within the Mouse Visual Thalamus

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    This is the final version of the article. It was first available from PLOS via http://dx.doi.org/10.1371/journal.pone.0144846All dLGN cell co-ordinates, V1 injection sites, dLGN boundary coordinates, experimental protocols and analysis scripts are available for download from figshare at https://figshare.com/s/36c6d937b1844eec80a1.The mouse dorsal lateral geniculate nucleus (dLGN) is an intermediary between retina and primary visual cortex (V1). Recent investigations are beginning to reveal regional complexity in mouse dLGN. Using local injections of retrograde tracers into V1 of adult and neonatal mice, we examined the developing organisation of geniculate projection columns: the population of dLGN-V1 projection neurons that converge in cortex. Serial sectioning of the dLGN enabled the distribution of labelled projection neurons to be reconstructed and collated within a common standardised space. This enabled us to determine: the organisation of cells within the dLGN-V1 projection columns; their internal organisation (topology); and their order relative to V1 (topography). Here, we report parameters of projection columns that are highly variable in young animals and refined in the adult, exhibiting profiles consistent with shell and core zones of the dLGN. Additionally, such profiles are disrupted in adult animals with reduced correlated spontaneous activity during development. Assessing the variability between groups with partial least squares regression suggests that 4?6 cryptic lamina may exist along the length of the projection column. Our findings further spotlight the diversity of the mouse dLGN?an increasingly important model system for understanding the pre-cortical organisation and processing of visual information. Furthermore, our approach of using standardised spaces and pooling information across many animals will enhance future functional studies of the dLGN.Funding was provided by a Wellcome Trust grant jointly awarded to IDT and SJE (083205, www.wellcome.ac.uk), and by MRC PhD Studentships awarded to MNL and ACH (http://www.mrc.ac.uk/)

    Tomato: a crop species amenable to improvement by cellular and molecular methods

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    Tomato is a crop plant with a relatively small DNA content per haploid genome and a well developed genetics. Plant regeneration from explants and protoplasts is feasable which led to the development of efficient transformation procedures. In view of the current data, the isolation of useful mutants at the cellular level probably will be of limited value in the genetic improvement of tomato. Protoplast fusion may lead to novel combinations of organelle and nuclear DNA (cybrids), whereas this technique also provides a means of introducing genetic information from alien species into tomato. Important developments have come from molecular approaches. Following the construction of an RFLP map, these RFLP markers can be used in tomato to tag quantitative traits bred in from related species. Both RFLP's and transposons are in the process of being used to clone desired genes for which no gene products are known. Cloned genes can be introduced and potentially improve specific properties of tomato especially those controlled by single genes. Recent results suggest that, in principle, phenotypic mutants can be created for cloned and characterized genes and will prove their value in further improving the cultivated tomato.

    The internal structure of poly(methyl methacrylate) latexes in nonpolar solvents

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    Hypothesis: Poly(methyl methacrylate) (PMMA) latexes in nonpolar solvents are an excellent model system to understand phenomena in low dielectric media, and understanding their internal structure is critical to characterizing their performance in both fundamental studies of colloidal interactions and in potential industrial applications. Both the PMMA cores and the poly(12-hydroxystearic acid) (PHSA) shells of the latexes are known to be penetrable by solvent and small molecules, but the relevance of this for the properties of these particles is unknown. Experiments: These particles can be prepared in a broad range of sizes, and two PMMA latexes dispersed in n-dodecane (76 and 685 nm in diameter) were studied using techniques appropriate to their size. Small-angle scattering (using both neutrons and X-rays) was used to study the small latexes, and analytical centrifugation was used to study the large latexes. These studies enabled the calculation of the core densities and the amount of solvent in the stabilizer shells for both latexes. Both have consequences on interpreting measurements using these latexes. Findings: The PHSA shells are highly solvated (∼85% solvent by volume), as expected for effective steric stabilizers. However, the PHSA chains do contribute to the intensity of neutron scattering measurements on concentrated dispersions and cannot be ignored. The PMMA cores have a slightly lower density than PMMA homopolymer, which shows that only a small free volume is required to allow small molecules to penetrate into the cores. Interestingly, the observations are essentially the same, regardless of the size of the particle; these are general features of these polymer latexes. Despite the latexes being used as a model physical system, the internal chemical structure is complex and must be fully considered when characterizing them

    Diving into the vertical dimension of elasmobranch movement ecology

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    Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

    Designing a broad-spectrum integrative approach for cancer prevention and treatment

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    Targeted therapies and the consequent adoption of "personalized" oncology have achieved notablesuccesses in some cancers; however, significant problems remain with this approach. Many targetedtherapies are highly toxic, costs are extremely high, and most patients experience relapse after a fewdisease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistantimmortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are notreliant upon the same mechanisms as those which have been targeted). To address these limitations, aninternational task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspectsof relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a widerange of high-priority targets (74 in total) that could be modified to improve patient outcomes. For thesetargets, corresponding low-toxicity therapeutic approaches were then suggested, many of which werephytochemicals. Proposed actions on each target and all of the approaches were further reviewed forknown effects on other hallmark areas and the tumor microenvironment. Potential contrary or procar-cinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixedevidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of therelationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. Thisnovel approach has potential to be relatively inexpensive, it should help us address stages and types ofcancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for futureresearch is offered
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