198 research outputs found
Criteria for the Evaluation of Italian Scientific Institutes for Research, Hospitalization and Healthcare (IRCCS): Comparison with European Standards and Certification Models
The definition of the title 'Istituto di Ricovero e Cura a Carattere Scientifico' (IRCCS) and how this title is given by the Italian Ministry of Health is presented. Specifically, the first assessment of a commission concerning the essential information for the accreditation process is introduced. Moreover, the two years review process that aims to collect last updated information of the IRCCS, to identify level of excellence and critical aspects, is also explained. The present Italian forms and international manuals like Joint Commission, OECI and HCERES were schematized using UML diagrams. The current IRCCS accreditation forms are presented with the suggested updates organized in some levels of structuring. We compared the Italian forms with the manuals required to obtain international certifications (Joint Commission and OECI) and we analyzed the criteria for the evaluation of research units in France (the HCERES standards). Although it is a preliminary study, the use of UML diagrams allows to schematize a new accreditation model, in line with European guidelines and the most important international certifications
Diversidad de orbículas en poaceae
87-96Anthers of ten species of Poaceae from the province of Buenos Aires (Argentina) were investigated with scanning and transmission electron microscopes. The orbicules can be defined as corpuscles of variable size that show the same electron-density, reaction to the dyes, autofluorescence and resistance to acetolysis as pollen exine does. The orbicules are randomly dispersed on the inner anther locule and they are often attached to a tapetal membrane. In this study, four different types and four subtypes of orbicules were identified. We conclude that the different orbicules types described in this work are representative of the studied tribes, and we suggest that the orbicules morphology may be a useful character in systematic studies
Chemical inhibition of xylem cellular activity impedes the removal of drought-induced embolisms in poplar stems – new insights from micro-CT analysis
SiO2nanoparticles modulate the electrical activity of neuroendocrine cells without exerting genomic effects
Engineered silica nanoparticles (NPs) have attracted increasing interest in several applications, and particularly in the field of nanomedicine, thanks to the high biocompatibility of this material. For their optimal and controlled use, the understanding of the mechanisms elicited by their interaction with the biological target is a prerequisite, especially when dealing with cells particularly vulnerable to environmental stimuli like neurons. Here we have combined different electrophysiological approaches (both at the single cell and at the population level) with a genomic screening in order to analyze, in GT1-7 neuroendocrine cells, the impact of SiO2NPs (50\u2009\ub1\u20093\u2009nm in diameter) on electrical activity and gene expression, providing a detailed analysis of the impact of a nanoparticle on neuronal excitability. We find that 20\u2009\ub5g\u2009mL-1NPs induce depolarization of the membrane potential, with a modulation of the firing of action potentials. Recordings of electrical activity with multielectrode arrays provide further evidence that the NPs evoke a temporary increase in firing frequency, without affecting the functional behavior on a time scale of hours. Finally, NPs incubation up to 24\u2009hours does not induce any change in gene expression
Augmentation of abscisic acid (ABA) levels by drought does not induce short-term stomatal sensitivity to CO2 in two divergent conifer species
The stomata of conifers display very little short-term response to changes in atmospheric CO2 concentration (Ca), whereas the stomatal responses of angiosperms to Ca increase in response to water stress. This behaviour of angiosperm stomata appears to be dependent on foliar levels of abscisic acid (ABAf). Here two alternative explanations for the stomatal insensitivity of conifers to Ca are tested: that conifers have either low ABAf or a higher or absent threshold for ABA-induced sensitivity. The responsiveness of stomatal conductance (gs) to a sequence of transitions in Ca (386, 100, and 600 μmol mol−1) was recorded over a range of ABAf in an angiosperm and two divergent conifer species. The different ABA levels were induced by a mild drought cycle. Although the angiosperm and conifer species showed similar proportional increases in ABAf following drought, conifer stomata remained insensitive to changes in Ca whereas angiosperm stomata showed enhanced sensitivity with increasing ABAf. The conifers, however, had much higher ABAf prior to drought than the angiosperm species, suggesting that non-sensitivity to Ca in these conifers was due to an absent or inactive response/signalling pathway rather than insufficient ABAf
The mycorrhizal root-shoot axis elicits Coffea arabica growth under low phosphate conditions
Coffee is one of the most traded commodities world-wide. As with 70% of land plants, coffee is associated with arbuscular mycorrhizal (AM) fungi, but the molecular bases of this interaction are unknown. We studied the mycorrhizal phenotype of two commercially important Coffea arabica cultivars (‘Typica National’ and ‘Catimor Amarillo’), upon Funnelliformis mosseae colonisation grown under phosphorus limitation, using an integrated functional approach based on multi-omics, physiology and biochemistry. The two cultivars revealed a strong biomass increase upon mycorrhization, even at low level of fungal colonisation, improving photosynthetic efficiency and plant nutrition. The more important iconic markers of AM symbiosis were activated: We detected two gene copies of AM-inducible phosphate (Pt4), ammonium (AM2) and nitrate (NPF4.5) transporters, which were identified as belonging to the C. arabica parental species (C. canephora and C. eugenioides) with both copies being upregulated. Transcriptomics data were confirmed by ions and metabolomics analyses, which highlighted an increased amount of glucose, fructose and flavonoid glycosides. In conclusion, both coffee cultivars revealed a high responsiveness to the AM fungus along their root-shoot axis, showing a clear-cut re-organisation of the major metabolic pathways, which involve nutrient acquisition, carbon fixation, and primary and secondary metabolism
Midday measurements of leaf water potential and stomatal conductance are highly correlated with daily water use of Thompson Seedless grapevines
A study was conducted to determine the relationship between midday measurements of vine water status and daily water use of grapevines measured with a weighing lysimeter. Water applications to the vines were terminated on August 24th for 9 days and again on September 14th for 22 days. Daily water use of the vines in the lysimeter (ETLYS) was approximately 40 L vine−1 (5.3 mm) prior to turning the pump off, and it decreased to 22.3 L vine−1 by September 2nd. Pre-dawn leaf water potential (ΨPD) and midday Ψl on August 24th were −0.075 and −0.76 MPa, respectively, with midday Ψl decreasing to −1.28 MPa on September 2nd. Leaf g s decreased from ~500 to ~200 mmol m−2 s−1 during the two dry-down periods. Midday measurements of g s and Ψl were significantly correlated with one another (r = 0.96) and both with ETLYS/ETo (r = ~0.9). The decreases in Ψl, g s, and ETLYS/ETo in this study were also a linear function of the decrease in volumetric soil water content. The results indicate that even modest water stress can greatly reduce grapevine water use and that short-term measures of vine water status taken at midday are a reflection of daily grapevine water us
A multiscale hybrid model for pro-angiogenic calcium signals in a vascular endothelial cell
Cytosolic calcium machinery is one of the principal signaling mechanisms by which endothelial cells (ECs) respond to external stimuli during several biological processes, including vascular progression in both physiological and pathological conditions. Low concentrations of angiogenic factors (such as VEGF) activate in fact complex pathways involving, among others, second messengers arachidonic acid (AA) and nitric oxide (NO), which in turn control the activity of plasma membrane calcium channels. The subsequent increase in the intracellular level of the ion regulates fundamental biophysical properties of ECs (such as elasticity, intrinsic motility, and chemical strength), enhancing their migratory capacity. Previously, a number of continuous models have represented cytosolic calcium dynamics, while EC migration in angiogenesis has been separately approached with discrete, lattice-based techniques. These two components are here integrated and interfaced to provide a multiscale and hybrid Cellular Potts Model (CPM), where the phenomenology of a motile EC is realistically mediated by its calcium-dependent subcellular events. The model, based on a realistic 3-D cell morphology with a nuclear and a cytosolic region, is set with known biochemical and electrophysiological data. In particular, the resulting simulations are able to reproduce and describe the polarization process, typical of stimulated vascular cells, in various experimental conditions.Moreover, by analyzing the mutual interactions between multilevel biochemical and biomechanical aspects, our study investigates ways to inhibit cell migration: such strategies have in fact the potential to result in pharmacological interventions useful to disrupt malignant vascular progressio
Lattice permutations and Poisson-Dirichlet distribution of cycle lengths
We study random spatial permutations on Z^3 where each jump x -> \pi(x) is
penalized by a factor exp(-T ||x-\pi(x)||^2). The system is known to exhibit a
phase transition for low enough T where macroscopic cycles appear. We observe
that the lengths of such cycles are distributed according to Poisson-Dirichlet.
This can be explained heuristically using a stochastic
coagulation-fragmentation process for long cycles, which is supported by
numerical data.Comment: 18 pages, 14 figure
"Plantar pro gasto": a importância do autoconsumo entre famílias de agricultores do Rio Grande do Sul.
O artigo discute a valoração e importância da produção para o autoconsumo na reprodução social das unidades familiares e caracteriza os alimentos autoconsumidos. Vale-se da pesquisa "Agricultura Familiar, Desenvolvimento Local e Pluriatividade" (UFRGS/UFPel/ CNPq-2003) que propiciou a formação de um banco de dados com informações sobre a dinâmica da agricultura familiar em quatro regiões distintas da geografia gaúcha, suas fontes e tipos de renda, entre estas o autoconsumo. Trazer este debate significa retomar um tema pouco discutido até então, e que, embora marginalizado ou considerado sem importância, desenvolve importante papel como renda não monetária, fortalece a segurança alimentar e adentra esferas da sociabilidade e identidade social. Além da introdução, apresenta-se o papel do autoconsumo na agricultura familiar, o cálculo da produção para o autoconsumo, discussão dos objetivos e resultados, e considerações finais. Os resultados demonstram que a produção para o autoconsumo é uma estratégia recorrente pelas unidades familiares e se diferencia de acordo com a dinâmica da agricultura familiar. Diferença esta expressa em valores relativos (%) e no número de estabelecimentos pertencentes a estratos diferenciados de autoconsumo, e pouco nos tipos de alimentos produzidos para este fim, observando-se uma homogeneidade dos hábitos alimentares
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