Skeletal muscle mitochondrial and lipid droplet content assessed with standardized grid sizes for stereology.

Skeletal muscle mitochondrial (Mito) and lipid droplet (Lipid) content are often measured in human translational studies. Stereological point counting allows computing Mito and Lipid volume density (Vd) from micrographs taken with transmission electron microscopes. Former studies are not specific as to the size of individual squares that make up the grids, making reproducibility difficult, particularly when different magnifications are used. Our objective was to determine which size grid would be best at predicting fractional volume efficiently without sacrificing reliability and to test a novel method to reduce sampling bias. Methods: ten subjects underwent vastus lateralis biopsies. Samples were fixed, embedded, and cut longitudinally in ultrathin sections of 60 nm. Twenty micrographs from the intramyofibrillar region were taken per subject at Ã-33,000 magnification. Different grid sizes were superimposed on each micrograph: 1,000 Ã- 1,000 nm, 500 Ã- 500 nm, and 250 Ã- 250 nm. Results: mean Mito and Lipid Vd were not statistically different across grids. Variability was greater when going from 1,000 Ã- 1,000 to 500 Ã- 500 nm grid than from 500 Ã- 500 to 250 Ã- 250 nm grid. Discussion: this study is the first to attempt to standardize grid size while keeping with the conventional stereology principles. This is all in hopes of producing replicable assessments that can be obtained universally across different studies looking at human skeletal muscle mitochondrial and lipid droplet content.

Whole-rat protein content estimation: applicability of the Nx6.25 factor

The amino acid composition of the protein from three strains of rat (Wistar, Zucker lean and Zucker obese), subjected to reference and high-fat diets has been used to determine the mean empirical formula, molecular weight and N content of whole-rat protein. The combined whole protein of the rat was uniform for the six experimental groups, containing an estimate of 17.3% N and a mean aminoacyl residue molecular weight of 103.7. This suggests that the appropriate protein factor for the calculation of rat protein from its N content should be 5.77 instead of the classical 6.25. In addition, an estimate of the size of the non-protein N mass in the whole rat gave a figure in the range of 5.5 % of all N. The combination of the two calculations gives a protein factor of 5.5 for the conversion of total N into rat protein.

Measurement of total estrone content in foods. Application to dairy products.

Estrone is a powerful growth-inducing hormone that is present in milk, mainly in the form of fatty acid esters, at concentrations that promote growth in experimental animals. We present here a method useful for the measurement of this natural hormone in foods and applied it to several common dairy products. Samples were frozen, finely powdered, and lyophilized then extracted with trichloromethane/methanol; the dry extract was saponified with potassium hydroxide. The free estrone evolved was extracted with ethyl acetate and was used for the estimation of total estrone content through radioimmunoassay. Application of the method to dairy products showed high relative levels of total estrone (essentially acyl-estrone) in milk, in the range of 1 ¿M, which were halved in skimmed milk. Free estrone levels were much lower, in the nanomolar range. A large proportion of estrone esters was present in all other dairy products, fairly correlated with their fat content. The amount of estrone carried by milk is well within the range, where its intake may exert a physiological response in the sucklings for which it is provided. These growth-inducing and energy expenditure-lowering effects may affect humans ingesting significant amounts of dairy products.

Different effects of hyperlipidic diets in human lactation and adulthood: growth versus the development of obesity

After birth, the body shifts from glucose as primary energy substrate to milk-derived fats, with sugars from lactose taking a secondary place. At weaning, glucose recovers its primogeniture and dietary fat role decreases. In spite of human temporary adaptation to a high-fat (and sugars and protein) diet during lactation, the ability to thrive on this type of diet is lost irreversibly after weaning. We could not revert too the lactating period metabolic setting because of different proportions of brain/muscle metabolism in the total energy budget, lower thermogenesis needs and capabilities, and absence of significant growth in adults. A key reason for change was the limited availability of foods with high energy content at weaning and during the whole adult life of our ancestors, which physiological adaptations remain practically unchanged in our present-day bodies. Humans have evolved to survive with relatively poor diets interspersed by bouts of scarcity and abundance. Today diets in many societies are largely made up from choice foods, responding to our deeply ingrained desire for fats, protein, sugars, salt etc. Consequently our diets are not well adjusted to our physiological needs/adaptations but mainly to our tastes (another adaptation to periodic scarcity), and thus are rich in energy roughly comparable to milk. However, most adult humans cannot process the food ingested in excess because our cortical-derived craving overrides the mechanisms controlling appetite. This is produced not because we lack the biochemical mechanisms to use this energy, but because we are unprepared for excess, and wholly adapted to survive scarcity. The thrifty mechanisms compound the effects of excess nutrients and damage the control of energy metabolism, developing a pathologic state. As a consequence, an overflow of energy is generated and the disease of plenty develops.

Activities of amino acid metabolizing enzymes in the stomach and small intestitine of developing rats

The activities of aspartate and alanine transaminase, serine dehydratase, arginase, glutamate dehydrogenase, adenylate deaminase and glutamine synthetase were determined in the stomach and small intestine of developing rats. Despite the common embryonic origin of the intestine and stomach, their enzymes showed quite different activity levels and patterns of development, depending on their roles. Most enzyme activities were low during late intrauterine life and after birth, attaining adult levels with the change of diet at weaning. No arginase activity was found in the stomach and no changes were detected in adenylate deaminase in the stomach or intestine throughout the period studied. Alanine transaminase, serine dehydratase and, to some extent, glutamine synthetase levels, significantly higher in late intrauterine life, decreased after birth, suggesting that the foetal stomach has a transient ability to handle amino acids.

Regional and cellular patterns of reelin mRNA expression in the forebrain of the developing and adult mouse

The reelin gene encodes an extracellular protein that is crucial for neuronal migration in laminated brain regions. To gain insights into the functions of Reelin, we performed high-resolution in situ hybridization analyses to determine the pattern of reelin expression in the developing forebrain of the mouse. We also performed double-labeling studies with several markers, including calcium-binding proteins, GAD65/67, and neuropeptides, to characterize the neuronal subsets that express reelin transcripts. reelinexpression was detected at embryonic day 10 and later in the forebrain, with a distribution that is consistent with the prosomeric model of forebrain regionalization. In the diencephalon, expression was restricted to transverse and longitudinal domains that delineated boundaries between neuromeres. During embryogenesis,reelin was detected in the cerebral cortex in Cajal-Retzius cells but not in the GABAergic neurons of layer I. At prenatal stages, reelin was also expressed in the olfactory bulb, and striatum and in restricted nuclei in the ventral telencephalon, hypothalamus, thalamus, and pretectum. At postnatal stages, reelin transcripts gradually disappeared from Cajal-Retzius cells, at the same time as they appeared in subsets of GABAergic neurons distributed throughout neocortical and hippocampal layers. In other telencephalic and diencephalic regions,reelin expression decreased steadily during the postnatal period. In the adult, there was prominent expression in the olfactory bulb and cerebral cortex, where it was restricted to subsets of GABAergic interneurons that co-expressed calbindin, calretinin, neuropeptide Y, and somatostatin. This complex pattern of cellular and regional expression is consistent with Reelin having multiple roles in brain development and adult brain function.

FY12 Recycled Content Plastic Bag and Soy Inks report

This report summarizes the purchasing activity for soy based inks and recycled content trash bags for the Iowa DOT.

Aprenentatge per a la comprensió en entorns virtuals als centres de secundària: La Xarxa School plus

[cat] Aquest projecte és una continuació del programa de recerca iniciat amb el projecte de R+D "School+ more than a platform to build the school of tomorrow" (IST-2000-25162) parcialment finançat per la Unió Europea a través de la convocatòria L'Escola del Demà, del Programa de Tecnologies de la Societat de la Informació del 5è Programa Marc. Aquesta iniciativa va ser seguida i aprofundida amb el projecte "Aprenentatge per a la comprensió en entorns virtuals als centres de secundària: la Xarxa School+", parcialment finançat pel DURSI a través de la convocatòria ARIE 2004. En aquest sentit, s'inscriu sota el mateix paraigües epistemològic (sociocultural) i metodològic (construccionista) dels projectes anteriors, i es basa en la utilització de diferents tipus d'evidències,en aquest cas però prestant especial atenció a la qüestió de l'avaluació de l'aprenentatge per a la comprensió i la dotació de sentit. En aquest context adquireix especial rellevància la idea del portafoli -o e-portafoli, webfoli, portafoli electrònic o digital- com a estratègia avaluadora de la comprensió i afavoridora de formes més complexes d'aprenentatge. En aquest informe, i d¿acord amb allò manifestat al projecte de recerca, es donen respostes a les següents qüestions: (a) quines són les possibilitats i les limitacions del portafoli electrònic com a sistema per avaluar processos d'aprenentatge de caràcter complex, orientats a la comprensió i la dotació de sentit; (b) com tenen lloc els processos d'innovació i millora a l'ensenyament secundari quan es fan servir entorns virtuals d'informació i comunicació, i es persegueix el desenvolupament d'un model pedagògic i curricular de caràcter interdisciplinari;(c) quins processos pedagògics, organitzatius, cognitius i emocionals estan implicats en les situacions d'aprenentatge orientades a la comprensió i la dotació de sentit, i no en la memorització i repetició de continguts; (d) com es desenvolupen experiències de col·laboració entre professors, estudiants i centres de secundària.

Postanoxic functional recovery of the developing heart is slightly altered by endogenous or exogenous nitric oxide.

Nitric oxide synthase (NOS) is strongly and transiently expressed in the developing heart but its function is not well documented. This work examined the role, either protective or detrimental, that endogenous and exogenous NO could play in the functioning of the embryonic heart submitted to hypoxia and reoxygenation. Spontaneously beating hearts isolated from 4-day-old chick embryos were either homogenized to determine basal inducible NOS (iNOS) expression and activity or submitted to 30 min anoxia followed by 100 min reoxygenation. The chrono-, dromo- and inotropic responses to anoxia/reoxygenation were determined in the presence of NOS substrate (L-arginine 10 mM), NOS inhibitor L-NIO (1-5 mM), or NO donor (DETA NONOate 10-100 microM). Myocardial iNOS was detectable by immunoblotting and its activity was specifically decreased by 53% in the presence of 5 mM L-NIO. L-Arginine, L-NIO and DETA NONOate at 10 microM had no significant effect on the investigated functional parameters during anoxia/reoxygenation. However, irrespective of anoxia/reoxygenation, DETA NONOate at 100 microM decreased ventricular shortening velocity by about 70%, and reduced atrio-ventricular propagation by 23%. None of the used drugs affected atrial activity and hearts of all experimental groups fully recovered at the end of reoxygenation. These findings indicate that (1) by contrast with adult heart, endogenously released NO plays a minor role in the early response of the embryonic heart to reoxygenation, (2) exogenous NO has to be provided at high concentration to delay postanoxic functional recovery, and (3) sinoatrial pacemaker cells are the less responsive to NO.

Phosphorus content of ditch sediments as indicator of critical source areas

Selostus : Kilpailukykyinen menetelmä pistemäisten fosforikuormitusalueiden paikantamiseen

Technology and research in a global Networked University Digital Library (NUDL)

Digital Libraries (DLs) are extremely complex information systems that support the creation, management, distribution, and preservation of complex information resources, while allowing effective and efficient interaction among the several societies that benefit from DL content and services. In this paper, we focus on our experience facing challenges of building, maintaining, and developing the Networked University Digital Library (www.nudl.org), an extension of the Networked Digital Library of Theses and Dissertations (www.ndltd.org). NUDL is a worldwide initiative that addresses making the intellectual property produced in universities more accessible, stimulating international collaboration across all disciplines. We detail technological aspects of our solutions and research activities carried out to provide powerful and enriched services for the communities served by this initiative.

Metabolic syndrome according to different definitions in a rapidly developing country of the African region

Rapport de synthèseLe syndrome métabolique représente un ensemble de facteurs de risque métaboliques souvent présents simultanément et il est associé à un risque accru de développer des maladies cardiovasculaires. La prevalence du syndrome métabolique est à la hausse au niveau mondial comme cela a souvent été documenté, en particulier dans les pays développés. Pourtant, les données concernant le syndrome métabolique dans les pays de la région sub-saharienne restent rares.Au cours des dernières années, plusieurs définitions du syndrome métabolique ont été formulées, dont celle du 'National Cholesterol Education Program Adult Treatment Panel III', celle de 1 Organisation Mondiale de la Santé et celle du 'International Diabetes Federation'. Parmi les controverses au sujet du syndrome métabolique persiste la question de l'utilité de rechercher la présence du syndrome métabolique chez les patients diabétiques, étant donné que la présence d'un diabète en soit suffit pour identifier un individu à haut risque de faire un événement cardiovasculaire.L'objectif de ce travail de thèse a été de déterminer la prévalence du syndrome métabolique selon les trois définitions majeures mentionnées ci-dessus, grâce à une étude de population transversale, réalisée aux Seychelles en 2004 dans un échantillon représentatif de la population âgée de 24-65 ans (n=1255, taux de participation de 80.3%). L'intérêt d'examiner cette question dans ce pays était d'obtenir des informations dans un pays en transition épidémiologique.Les résultats de ce travail montrent que la prévalence du syndrome métabolique aux Seychelles est élevée, quelque soit la définition utilisée. Selon la définition utilisée, cette prévalence était d'environ 25% chez les hommes et variant entre 25 et 35% chez les femmes.Cependant, malgré des prévalences semblables selon ces trois définitions, la concordance entre ces définitions n'était pas bonne, impliquant que ces différentes définitions classifient, à un certain degré, des individus différents comme étant porteurs du syndrome métabolique.En outre, la plupart (environ 80%) des individus diabétiques avaient un syndrome métabolique. Après exclusion des individus diabétiques, la prévalence du syndrome métabolique dans la population est réduite d'environ un tiers, à environ 20-25%.Ces résultats montrent que, d'une part, le fardeau de maladie dû au syndrome métabolique aux Seychelles, un pays en voie de développement, est considérable. Cette observation peut potentiellement s'appliquer à d'autres pays à un stade de développement semblable. Cela renforce le besoin de mettre en oeuvre des stratégies de santé publique afin de cibler les causes de ces désordres métaboliques, tels que le surpoids et la sédentarité. D'un point de vue du diagnostic, les trois définitions du syndrome métabolique semblent classifier un nombre semblable de personnes atteints du syndrome métabolique dans cette population. Par contre, la relativement mauvaise concordance entre ces définitions - certaines personnes identifiés comme porteurs du syndrome métabolique selon une définition ne le sont pas selon une autre - confirme la nécessité de clarifier la signification de ces différentes définitions et/ou éventuellement de développer une définition unifiée et fiable du syndrome métabolique.

Equilibrium moisture content of flax/linseed and fibre hemp straw fractions

Selostus: Pellavan ja kuituhampun korren jakeiden tasapainokosteus