530 research outputs found
Seasonal changes in berry fluorescence induced by different levels of uv-radiation
Plant stress is usually diagnosed via physiological measurements on leaves such as water potential,
photosynthetic rate or chlorophyll fluorescence. Since stress in the case of grapevines is of concern with respect
to the quality of the fruit, we attempted to use one of the above mentioned techniques, chlorophyll fluorescence,
directly on the fruit itself in order to investigate stress responses in vivo. Berry fluorescence was measured in an
experiment with different levels of UV-B and UV-A radiation in the field in 2000 in Geisenheim with the variety
Riesling. UV radiation has been shown to affect chlorophyll and was thus likely to show differences in
fluorescence signals. Berry fluorescence was measured periodically between veraison and harvest on darkadapted
berries (20min). For each berry, a light response curve was recorded followed by a recovery phase in the
dark. The maximum quantum yield of PSII (qY) was determined after a saturation pulse at each light intensity.
The qY decreased exponentially with increasing light intensity. The response level of the quantum yield of PSII
decreased during ripening indicating a loss in chlorophyll and/or PSII capacity for all treatments. Effects of the
different levels of UV-radiation on the light curve were only detected at the end of the ripening period, with
higher quantum yield values recorded for the treatments protected against UV-A and UV-A+UV-B. Similar
results were obtained after recovery in the dark. Changes in fluorescence signals were accompanied by a visual
change in berry colour indicating changes in skin pigmentation, which may also have some effect on fruit
qualityinfo:eu-repo/semantics/publishedVersio
Validation of an empirical model for grapevine leaf area estimation with data from simplified pruning systems
The performance of a mathematical model developed for non-destructive estimation of primary leaf area
per shoot of Tempranillo grapevines, was tested using independent datasets from two vineyards with simplified
pruning techniques. The first dataset was collected in Portugal on Cabernet Sauvignon grapevines subjected to
mechanical hedge pruning and the second one in Germany on minimal pruned Riesling grapevines. For both
datasets the model presented a very good fit between observed and estimated values with the error increasing with
the increase in leaf area per shoot. The mean absolute percent error for all systems was lower or equal to 10% with
lower absolute values (7.7%) for the Riesling dataset. Both linear regression between observed (dependent variable)
and estimated (independent variable) leaf area had high and significant R2 with an intercept not significantly
different from zero. Fitted lines were not significantly different from 1 for Cabernet Sauvignon, but slightly yet
significantly different from 1 for Riesling fitted line (1.03), indicating that the model underestimated the leaf area
per shoot. The good results obtained with this validation test show that the model can be used to accurately predict
primary leaf area per shoot independent of variety, training system and climatic conditionsinfo:eu-repo/semantics/publishedVersio
Four new coordination polymers involving transition metals with 1,2,4,5-benzenetetracarboxylate and pyridyl-donor ligand di(4-pyridyl) sulfide
AbstractFour new coordination polymers namely {[Mn2(BT)(DPS)2(H2O)6]·10H2O}n (MnBTDPS), {[Co2(BT)(DPS)2(H2O)6]·10H2O}n (CoBTDPS), {[Cu2(BT)(DPS)(H2O)4]·5H2O}n (CuBTDPS) and {[Zn2(BT)(DPS)2]·6H2O}n (ZnBTDPS), where BT=1,2,4,5-benzenetetracarboxylate and DPS=di(4-pyridyl) sulfide, were synthesized and characterized by thermal analysis, vibrational spectroscopy (Raman and infrared) and single crystal X-ray diffraction analysis. In all compounds, the DPS ligands are coordinated to metal sites in a bridging mode and the carboxylate moiety of BT ligands adopts a monodentate coordination mode, as indicated by the Raman spectra data through the Δν (νasym(COO)−ν sym(COO)) value. According to X-ray diffraction analysis, MnBTDPS and CoBTDPS are isostructural and in these cases, the metal centers exhibit a distorted octahedral geometry. In CuBTBPP, the Cu2+ centers geometries are best described as square-pyramids, according to the trigonality index τ=0.14 for Cu1 and τ=0.10 for Cu2. On the other hand, in ZnBTDPS, the Zn2+ sites adopt a tetrahedral geometry. Finally, the four compounds formed two-dimensional sheets that are connected to each other through hydrogen bonding giving rise to three-dimensional supramolecular arrays
Influence de différents niveaux de rayonnement UV sur la physiologie, le taux de pigments et la composition des baies, cépage Riesling
Changes in the stratospheric ozone concentration causes UV-radiation to increase. The response to UV-B radiation on the organ and cellular level is mainly an increase in the formation of UV-absorbing compounds meant to decrease UV-radiation penetration into the tissue. Some key enzymes involved in flavonoid biosynthesis and the phenyl-propanoid pathway have been shown to be up-regulated by UV-radiation, as are levels of key antioxidants glutathione and ascorbate, whereas carotenoid pigment formation and the incorporation of nitrogen into amino acids can be inhibited. Since components such as flavonoids, amino acids and carotenoids are important constituents of grapes with a marked effect on flavour development, some influence of altered UV-radiation can be expected. We investigated these possible effects under field conditions by selectively attenuating various portions of the light spectrum in the UV-part with polyester and di- and tri-acetate films and exposing the entire canopy or parts thereof to these conditions during berry development. We evaluated skin pigment composition using a non-destructive spectro-photometric technique. There was a strong UV-induced shift towards the formation of red and brown pigment components without affecting sugar levels. Chlorophyll degradation in the berry skin proceeded faster in the high UV-radiation treatments and this could be assessed for non-destructively by measuring berry fluorescence. Amino acid concentration was reduced under high levels of UV-B radiation and both the total bound glycosidic secondary metabolites and phenolics were increased. There were some effects noticeable on fermentation velocity and the retention of free and bound aromatic components in the wineinfo:eu-repo/semantics/publishedVersio
Kullback-Leibler and Renormalized Entropy: Applications to EEGs of Epilepsy Patients
Recently, renormalized entropy was proposed as a novel measure of relative
entropy (P. Saparin et al., Chaos, Solitons & Fractals 4, 1907 (1994)) and
applied to several physiological time sequences, including EEGs of patients
with epilepsy. We show here that this measure is just a modified
Kullback-Leibler (K-L) relative entropy, and it gives similar numerical results
to the standard K-L entropy. The latter better distinguishes frequency contents
of e.g. seizure and background EEGs than renormalized entropy. We thus propose
that renormalized entropy might not be as useful as claimed by its proponents.
In passing we also make some critical remarks about the implementation of these
methods.Comment: 15 pages, 4 Postscript figures. Submitted to Phys. Rev. E, 199
Analysis of molecular changes induced by mineral trioxide aggregate on sPLA2
The aim of this study was to analyze the effects of MTA on the structure and enzymatic activity of sPLA2 in order to provide subsidies for improvement in the formulation of the product. MTA powder was incubated for 60 min in the presence of sPLA2 and was analyzed by chromatography, electrospray mass (ESI-MS) and small-angle X-ray scattering (SAXS). It was find that the elution profile, retention time, and fragmentation of sPLA2 were altered after treatment with MTA. Calcium was the MTA component that most amplified the inflammatory signal. Significant interactions were found between MTA and sPLA2, which could aid in our understanding of the mechanisms of action of MTA during the inflammatory process and it may facilitate the structural modification of MTA, thereby improving its biological safety and consequently the rate of the treatment success305453458The authors wish to thank the National Laboratory of Synchrotron Light (LNLS - Brazil) for the use of their facility and equipment and to Brazilian division of the IADR (SBPqO), which partially supported this study through PRONAC award. The authors also thanks to Prof. Marcos Toyama for its support on the chromatography graph
Application-Layer Connector Synthesis
International audienceThe heterogeneity characterizing the systems populating the Ubiquitous Computing environment prevents their seamless interoperability. Heterogeneous protocols may be willing to cooperate in order to reach some common goal even though they meet dynamically and do not have a priori knowledge of each other. Despite numerous e orts have been done in the literature, the automated and run-time interoperability is still an open challenge for such environment. We consider interoperability as the ability for two Networked Systems (NSs) to communicate and correctly coordinate to achieve their goal(s). In this chapter we report the main outcomes of our past and recent research on automatically achieving protocol interoperability via connector synthesis. We consider application-layer connectors by referring to two conceptually distinct notions of connector: coordinator and mediator. The former is used when the NSs to be connected are already able to communicate but they need to be speci cally coordinated in order to reach their goal(s). The latter goes a step forward representing a solution for both achieving correct coordination and enabling communication between highly heterogeneous NSs. In the past, most of the works in the literature described e orts to the automatic synthesis of coordinators while, in recent years the focus moved also to the automatic synthesis of mediators. Within the Connect project, by considering our past experience on automatic coordinator synthesis as a baseline, we propose a formal theory of mediators and a related method for automatically eliciting a way for the protocols to interoperate. The solution we propose is the automated synthesis of emerging mediating connectors (i.e., mediators for short)
The metabolic syndrome and risk of sudden cardiac death: The atherosclerosis risk in communities study
Background--Prior studies have demonstrated a link between the metabolic syndrome and increased risk of cardiovascular mortality. Whether the metabolic syndrome is associated with sudden cardiac death is uncertain. Methods and Results--We characterized the relationship between sudden cardiac death and metabolic syndrome status among participants of the ARIC (Atherosclerosis Risk in Communities) Study (1987-2012) free of prevalent coronary heart disease or heart failure. Among 13 168 participants, 357 (2.7%) sudden cardiac deaths occurred during a median follow-up of 23.6 years. Participants with the metabolic syndrome (n=4444) had a higher cumulative incidence of sudden cardiac death than those without it (n=8724) (4.1% versus 2.3%, P < 0.001). After adjustment for participant demographics and clinical factors other than components of the metabolic syndrome, the metabolic syndrome was independently associated with sudden cardiac death (hazard ratio, 1.70, 95% confidence interval, 1.37-2.12, P < 0.001). This relationship was not modified by sex (interaction P=0.10) or race (interaction P=0.62) and was mediated by the metabolic syndrome criteria components. The risk of sudden cardiac death varied according to the number of metabolic syndrome components (hazard ratio 1.31 per additional component of the metabolic syndrome, 95% confidence interval, 1.19-1.44, P < 0.001). Of the 5 components, elevated blood pressure, impaired fasting glucose, and low high-density lipoprotein were independently associated with sudden cardiac death. Conclusions--We observed that the metabolic syndrome was associated with a significantly increased risk of sudden cardiac death irrespective of sex or race. The risk of sudden cardiac death was proportional to the number of metabolic syndrome components
Fisiologia digestiva de suínos alimentados com rações contendo diferentes fontes de fósforo
Revealing the spatio-phenotypic patterning of cells in healthy and tumor tissues with mLSR-3D and STAPL-3D
Stem cells & developmental biolog
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