170 research outputs found
Electromagnetic Form Factors in the hypercentral CQM
We report on the recent results of the hypercentral Constituent Quark Model
(hCQM). The model contains a spin independent three-quark interaction which is
inspired by Lattice QCD calculations and reproduces the average energy values
of the SU(6) multiplets. The splittings are obtained with a SU(6)-breaking
interaction, which can include also an isospin dependent term. Concerning
Constituent Quark models, we have shown for the first time that the decreasing
of the ratio of the elastic form factors of the proton is due to relativistic
effects using relativistic corrections to the e.m. current and boosts. Now the
elastic nucleon form factors have been recalculated, using a relativistic
version of the hCQM and a relativistic quark current showing a very detailed
reproduction of all the four form factor existing data over the complete range
of 0-4 . Futhermore, the model has been used for predictions concerning
the electromagnetic transverse and longitudinal transition form factors giving
a good description of the medium behaviour. We show that the
discrepancies in the reproduction of the helicity amplitudes at low are
due to pion loops. We have calculated the helicity amplitudes for all the 3 and
4 star resonances opening the possibility of application to the evaluation of
cross sections.Comment: 5 pages, 7 figures, Invited talk at the ICTP 4th International
Conference on Perspectives in Hadronic Physics, Trieste, Italy, 12-16 May
2003. Accepted by Eur. Phys. J.
Impact of Leaf Removal, Applied Before and After Flowering, on Anthocyanin, Tannin, and Methoxypyrazine Concentrations in âMerlotâ (Vitis viniferaL.) Grapes and Wines
7siThe development and accumulation of secondary metabolites in grapes determine wine color, taste, and aroma. This study aimed to investigate the effect of leaf removal before flowering, a practice recently introduced to reduce cluster compactness and Botrytis rot, on anthocyanin, tannin, and methoxypyrazine concentrations in Merlot' grapes and wines. Leaf removal before flowering was compared with leaf removal after flowering and an untreated control. No effects on tannin and anthocyanin concentrations in grapes were observed. Both treatments reduced levels of 3-isobutyl-2-methoxypyrazine (IBMP) in the grapes and the derived wines, although the after-flowering treatment did so to a greater degree in the fruit specifically. Leaf removal before flowering can be used to reduce cluster compactness, Botrytis rot, and grape and wine IBMP concentration and to improve wine color intensity but at the expense of cluster weight and vine yield. Leaf removal after flowering accomplishes essentially the same results without loss of yield. © 2016 American Chemical Society.reservedmixedSivilotti, Paolo; Herrera, Jose Carlos; Lisjak, Klemen; BaĆĄa Äesnik, Helena; Sabbatini, Paolo; Peterlunger, Enrico; Castellarin, Simone DiegoSivilotti, Paolo; Herrera, Jose Carlos; Lisjak, Klemen; BaĆĄa Äesnik, Helena; Sabbatini, Paolo; Peterlunger, Enrico; Castellarin, Simone Dieg
FOXO Regulates Organ-Specific Phenotypic Plasticity In Drosophila
Phenotypic plasticity, the ability for a single genotype to generate different phenotypes in response to environmental conditions, is biologically ubiquitous, and yet almost nothing is known of the developmental mechanisms that regulate the extent of a plastic response. In particular, it is unclear why some traits or individuals are highly sensitive to an environmental variable while other traits or individuals are less so. Here we elucidate the developmental mechanisms that regulate the expression of a particularly important form of phenotypic plasticity: the effect of developmental nutrition on organ size. In all animals, developmental nutrition is signaled to growing organs via the insulin-signaling pathway. Drosophila organs differ in their size response to developmental nutrition and this reflects differences in organ-specific insulin-sensitivity. We show that this variation in insulin-sensitivity is regulated at the level of the forkhead transcription factor FOXO, a negative growth regulator that is activated when nutrition and insulin signaling are low. Individual organs appear to attenuate growth suppression in response to low nutrition through an organ-specific reduction in FOXO expression, thereby reducing their nutritional plasticity. We show that FOXO expression is necessary to maintain organ-specific differences in nutritional-plasticity and insulin-sensitivity, while organ-autonomous changes in FOXO expression are sufficient to autonomously alter an organ's nutritional-plasticity and insulin-sensitivity. These data identify a gene (FOXO) that modulates a plastic response through variation in its expression. FOXO is recognized as a key player in the response of size, immunity, and longevity to changes in developmental nutrition, stress, and oxygen levels. FOXO may therefore act as a more general regulator of plasticity. These data indicate that the extent of phenotypic plasticity may be modified by changes in the expression of genes involved in signaling environmental information to developmental processes
Trace elements in hemodialysis patients: a systematic review and meta-analysis
<p>Abstract</p> <p>Background</p> <p>Hemodialysis patients are at risk for deficiency of essential trace elements and excess of toxic trace elements, both of which can affect health. We conducted a systematic review to summarize existing literature on trace element status in hemodialysis patients.</p> <p>Methods</p> <p>All studies which reported relevant data for chronic hemodialysis patients and a healthy control population were eligible, regardless of language or publication status. We included studies which measured at least one of the following elements in whole blood, serum, or plasma: antimony, arsenic, boron, cadmium, chromium, cobalt, copper, fluorine, iodine, lead, manganese, mercury, molybdenum, nickel, selenium, tellurium, thallium, vanadium, and zinc. We calculated differences between hemodialysis patients and controls using the differences in mean trace element level, divided by the pooled standard deviation.</p> <p>Results</p> <p>We identified 128 eligible studies. Available data suggested that levels of cadmium, chromium, copper, lead, and vanadium were higher and that levels of selenium, zinc and manganese were lower in hemodialysis patients, compared with controls. Pooled standard mean differences exceeded 0.8 standard deviation units (a large difference) higher than controls for cadmium, chromium, vanadium, and lower than controls for selenium, zinc, and manganese. No studies reported data on antimony, iodine, tellurium, and thallium concentrations.</p> <p>Conclusion</p> <p>Average blood levels of biologically important trace elements were substantially different in hemodialysis patients, compared with healthy controls. Since both deficiency and excess of trace elements are potentially harmful yet amenable to therapy, the hypothesis that trace element status influences the risk of adverse clinical outcomes is worthy of investigation.</p
ConcentraçÔes de cloreto de cĂĄlcio e tempos de armazenamento nos teores de açĂșcares redutores de uvas cv red globe (Vitis vinifera L)
Desempenho vitivinĂcola da Cabernet Sauvignon sobre diferentes porta-enxertos em regiĂŁo de altitude de Santa Catarina
Diversification de l'économie rurale et qualité de vie
AutresThe priorities of the axis 3 of the FEADER (" diversification of the rural economy and the quality of life in rural areas ") should be differentiated according to the nature of the rural spaces (periurban, intermediate, remote). So, the actions of development of the services to the population they should be favored in the periurban areas whereas the actions of training could be targeted at the remote areas. Furthermore, the level of delegation of the measures was argued from some elements of public economics (while being aware of the important role of the politic and social factors).Les prioritĂ©s de l`axe 3 du FEADER (« diversification de l`Ă©conomie rurale et qualitĂ© de vie en milieu rural » ) devraient ĂȘtre diffĂ©renciĂ©es en fonction de la nature des espaces ruraux (pĂ©riurbain, rural intermĂ©diaire, rural isolĂ©). Ainsi, les actions de dĂ©veloppement des services Ă la population devraient-ils ĂȘtre favorisĂ©s dans le pĂ©riurbain tandis que les actions de formation pourraient ĂȘtre ciblĂ©es sur le rural isolĂ©. De plus, le niveau de dĂ©lĂ©gation des mesures a Ă©tĂ© argumentĂ© Ă partir de quelques Ă©lĂ©ments d`Ă©conomie publique (tout en Ă©tant conscient du rĂŽle important des facteurs d`ordre socio-politique)
Effects of pH, sulphur dioxide, alcohol content, temperature and storage time on colour composition of a young Portuguese red table wine
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