219 research outputs found
Per poter dare qualità alla ragione: una fntasia di colori ed una sinfonia di suoni.
Dare qualità alla ragione è una risposta laica alla ansia ed alle angosce della modernità che ha rinunciato a vane promesse religiose (riprese talvolta desacralizzandole, con nuovi, ma sempre vuoti, vestiti ideologici) e maggiormente della post-modernità che non crede più neppure ad indefiniti ed inesistenti fini teleologici. Lo strutturalismo (mutuato da ricerche antropologiche) si presenta come un linguaggio aspro, ma sincero, per rappresentare la complessità della realtà, nella parzialità di ogni rappresentazione. Pressoché in parallelo, si presenta il contributo sociologico e politico, della Scuola di Francoforte neomarxista, a partire dalla critica marxiana al fallace marxismo ortodosso sovietico ed alla vacua società dei consumi occidentale. Sempre in parallelo, il falsificazionismo rappresenta un punto di arrivo di una ricerca filosofica che, dalla filosofia della scienza, si estende alla critica delle dottrine politiche, per sostenere idee di libertà e giustizia. Allora dare qualità alla ragione non è un problema banale, di fronte ai moltissimi fallimenti della storia, passata e recente. Per questo, è necessario concepire, mettere in atto e sostenere, sempre in modo critico e molto responsabile, soluzioni parziali, per tempi limitati e spazi ristretti, sapendo che solo lo incontro, il dialogo e la accoglienza, con altre soluzioni parziali, permetteranno di costruire una rete mirabile di piccole intese, per quanto precarie, fragili e provvisorie. La identità soft tra vero, bene e bello, dove i primi due sono di incerta natura e definizione, mentre il terzo si rifà semplicemente alla educazione civica ed un galateo minimo, senza richiamare falsi assoluti, porta a ricercare la ricchezza e la gioia di una fantasia di colori ed una sinfonia di suoni. Pertanto clemenza, verso gli altri, e temperanza, con se stessi, sono le piccole doti richieste
Emotional Intelligence and risk taking in investment decision-making
Previous work on investment decision-making suggested that emotions prevent investors from taking risks and from investing in a rational way, whereas other work found that there is great variability in people’s ability to manage and use emotional feedbacks. We hypothesized that people with high trait emotional intelligence should be more willing, than people with low trait emotional intelligence, to accept risks when making an investment. Data supported a model in which trait emotional intelligence predicted willingness to invest both when the expected value is positive and when it is negative. The effect of trait emotional intelligence was significant even controlling for other variables, like attitude toward economic risk and money attitude. We believe that these results help improving the understanding of how emotions influence investors’ behavior and show that their role is not always detrimental but depends on the interplay between individual differences and situational factors
Scanning Electron Microscope Cytochemistry of Blood Cells
The backscattered electron imaging (BEI) mode of scanning electron microscopy (SEM) has been applied to study various histo-cytochemical reactions in biological specimens since the early seventies. Due to numerous, recent technical improvements the BEI mode of SEM now belongs to the routine of many SEM laboratories.
For cytochemistry, BEI has been mainly used to: visualize intracellular structures and organelles; recognize the different cell types in heterogeneous populations or tissues; study the correlations between enzymatic activities and cell surface features.
We have evaluated the most relevant results obtained in the study of blood cells and the possible future applications of these techniques
Audio vs. Video: Does Viewing Support Learning? A Comparision of an Audio-Visual with an Auditory Virtual Lecture
Häufig wird behauptet, dass audiovisuelle Informationen gegenüber auditiven lernwirksamer sind. Dies wird meist mit der kognitiv-anregenden Funktion begründet, die der audiovisuellen Darstellung zugeschrieben wird. Bisherige empirische Arbeiten konnten das auch tendenziell bestätigen; allerdings beziehen sich diese Befunde überwiegend auf das video- oder fernsehgestützte Lernen, bei dem den Lernenden keine zusätzlichen textbasierten Informationen zur Verfügung stehen. Für den Bereich der virtuellen Vorlesung wurde noch nicht untersucht, ob sich eine audiovisuelle Präsentation des Vortragenden gegenüber einer rein auditiven Präsentation positiv auf den Lernerfolg auswirkt. In einer empirischen Studie mit 61 Versuchspersonen wurde daher Lernenden ein Ausschnitt aus einer Online-Vorlesung in zwei Variationen präsentiert. Während die eine Gruppe eine Lerneinheit bearbeitete, in der sie neben textbasierten Informationen eine Videosequenz (Aufnahme des Dozenten) präsentiert bekam, bearbeitete die zweite Gruppe die gleiche Lerneinheit; hier war jedoch nur die Stimme des Dozenten hörbar. In einem direkt anschließenden Wissens- und späteren Behaltenstest zeigten sich keine signifikanten Leistungsunterschiede zwischen den beiden Gruppen. Jedoch berichtete die Mehrheit der Versuchspersonen, dass sie die Videovariante für affektiv-unterstützender hält als die Tonvariante. (ZPID
MHD simulations of plasma dynamics in pinch discharges in capillary plasmas
Magnetohydrodynamic simulation results related to the
capillary discharge dynamics are presented. The main physical
process that should be taken into account is the ablation
of the capillary wall material evaporated by the heat flux
from the capillary plasma. The possible applications of
the capillary discharges related to the physics of the
X-ray lasers and the use of the capillary plasma to provide
a guiding for ultrashort high-intensity laser pulses over
a distance greater than the defocusing length are discussed
The nasal delivery of nanoencapsulated statins – An approach for brain delivery
© 2016 Clementino et al. Purpose: Along with their cholesterol-lowering effect, statins have shown a wide range of pleiotropic effects potentially beneficial to neurodegenerative diseases. However, such effects are extremely elusive via the conventional oral administration. The purpose of the present study was to prepare and characterize the physicochemical properties and the in vivo biodistribution of simvastatin-loaded lecithin/chitosan nanoparticles (SVT-LCNs) suitable for nasal administration in view of an improved delivery of the statins to the brain. Materials and methods: Chitosan, lecithin, and different oil excipients were used to prepare nanocapsules loaded with simvastatin. Particle size distribution, surface charge, structure, simvastatin loading and release, and interaction with mucus of nanoparticles were determined. The nanoparticle nasal toxicity was evaluated in vitro using RPMI 2651 nasal cell lines. Finally, in vivo biodistribution was assessed by gamma scintigraphy via Tc99m labeling of the particles. Results: Among the different types of nanoparticles produced, the SVT-LCN_MaiLab showed the most ideal physicochemical characteristics, with small diameter (200 nm), positive surface charge (+48 mV) and high encapsulation efficiency (EE; 98%). Size distribution was further confirmed by nanoparticle tracking analysis and electron microscopy. The particles showed a relatively fast release of simvastatin in vitro (35.6%±4.2% in 6 hours) in simulated nasal fluid. Blank nanoparticles did not show cytotoxicity, evidencing that the formulation is safe for nasal administration, while cytotoxicity of simvastatin-loaded nanoparticles (IC50) was found to be three times lower than the drug solution (9.92 vs 3.50 μM). In rats, a significantly higher radioactivity was evidenced in the brain after nasal delivery of simvastatin-loaded nanoparticles in comparison to the administration of a similar dose of simvastatin suspension. Conclusion: The SVT-LCNs developed presented some of the most desirable characteristics for mucosal delivery, that is, small particle size, positive surface charge, long-term stability, high EE, and mucoadhesion. In addition, they displayed two exciting features: First was their biodegradability by enzymes present in the mucus layer, such as lysozyme. This indicates a new Trojan-horse strategy which may enhance drug release in the proximity of the nasal mucosa. Second was their ability to enhance the nose-to-brain transport as evidenced by preliminary gamma scintigraphy studies
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A multi-model evaluation of aerosols over South Asia: common problems and possible causes
Atmospheric pollution over South Asia attracts special attention due to its effects on regional climate, water cycle and human health. These effects are potentially growing owing to rising trends of anthropogenic aerosol emissions. In this study, the spatio-temporal aerosol distributions over South Asia from seven global aerosol models are evaluated against aerosol retrievals from NASA satellite sensors and ground-based measurements for the period of 2000–2007. Overall, substantial underestimations of aerosol loading over South Asia are found systematically in most model simulations. Averaged over the entire South Asia, the annual mean aerosol optical depth (AOD) is underestimated by a range 15 to 44% across models compared to MISR (Multi-angle Imaging SpectroRadiometer), which is the lowest bound among various satellite AOD retrievals (from MISR, SeaWiFS (Sea-Viewing Wide Field-of-View Sensor), MODIS (Moderate Resolution Imaging Spectroradiometer) Aqua and Terra). In particular during the post-monsoon and wintertime periods (i.e., October–January), when agricultural waste burning and anthropogenic emissions dominate, models fail to capture AOD and aerosol absorption optical depth (AAOD) over the Indo–Gangetic Plain (IGP) compared to ground-based Aerosol Robotic Network (AERONET) sunphotometer measurements. The underestimations of aerosol loading in models generally occur in the lower troposphere (below 2 km) based on the comparisons of aerosol extinction profiles calculated by the models with those from Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) data. Furthermore, surface concentrations of all aerosol components (sulfate, nitrate, organic aerosol (OA) and black carbon (BC)) from the models are found much lower than in situ measurements in winter. Several possible causes for these common problems of underestimating aerosols in models during the post-monsoon and wintertime periods are identified: the aerosol hygroscopic growth and formation of secondary inorganic aerosol are suppressed in the models because relative humidity (RH) is biased far too low in the boundary layer and thus foggy conditions are poorly represented in current models, the nitrate aerosol is either missing or inadequately accounted for, and emissions from agricultural waste burning and biofuel usage are too low in the emission inventories. These common problems and possible causes found in multiple models point out directions for future model improvements in this important region
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The AeroCom evaluation and intercomparison of organic aerosol in global models
This paper evaluates the current status of global modeling of the organic aerosol (OA) in the troposphere and analyzes the differences between models as well as between models and observations. Thirty-one global chemistry transport models (CTMs) and general circulation models (GCMs) have participated in this intercomparison, in the framework of AeroCom phase II. The simulation of OA varies greatly between models in terms of the magnitude of primary emissions, secondary OA (SOA) formation, the number of OA species used (2 to 62), the complexity of OA parameterizations (gas-particle partitioning, chemical aging, multiphase chemistry, aerosol microphysics), and the OA physical, chemical and optical properties. The diversity of the global OA simulation results has increased since earlier AeroCom experiments, mainly due to the increasing complexity of the SOA parameterization in models, and the implementation of new, highly uncertain, OA sources. Diversity of over one order of magnitude exists in the modeled vertical distribution of OA concentrations that deserves a dedicated future study. Furthermore, although the OA / OC ratio depends on OA sources and atmospheric processing, and is important for model evaluation against OA and OC observations, it is resolved only by a few global models.
The median global primary OA (POA) source strength is 56 Tg a−1 (range 34–144 Tg a−1) and the median SOA source strength (natural and anthropogenic) is 19 Tg a−1 (range 13–121 Tg a−1). Among the models that take into account the semi-volatile SOA nature, the median source is calculated to be 51 Tg a−1 (range 16–121 Tg a−1), much larger than the median value of the models that calculate SOA in a more simplistic way (19 Tg a−1; range 13–20 Tg a−1, with one model at 37 Tg a−1). The median atmospheric burden of OA is 1.4 Tg (24 models in the range of 0.6–2.0 Tg and 4 between 2.0 and 3.8 Tg), with a median OA lifetime of 5.4 days (range 3.8–9.6 days). In models that reported both OA and sulfate burdens, the median value of the OA/sulfate burden ratio is calculated to be 0.77; 13 models calculate a ratio lower than 1, and 9 models higher than 1. For 26 models that reported OA deposition fluxes, the median wet removal is 70 Tg a−1 (range 28–209 Tg a−1), which is on average 85% of the total OA deposition.
Fine aerosol organic carbon (OC) and OA observations from continuous monitoring networks and individual field campaigns have been used for model evaluation. At urban locations, the model–observation comparison indicates missing knowledge on anthropogenic OA sources, both strength and seasonality. The combined model–measurements analysis suggests the existence of increased OA levels during summer due to biogenic SOA formation over large areas of the USA that can be of the same order of magnitude as the POA, even at urban locations, and contribute to the measured urban seasonal pattern.
Global models are able to simulate the high secondary character of OA observed in the atmosphere as a result of SOA formation and POA aging, although the amount of OA present in the atmosphere remains largely underestimated, with a mean normalized bias (MNB) equal to −0.62 (−0.51) based on the comparison against OC (OA) urban data of all models at the surface, −0.15 (+0.51) when compared with remote measurements, and −0.30 for marine locations with OC data. The mean temporal correlations across all stations are low when compared with OC (OA) measurements: 0.47 (0.52) for urban stations, 0.39 (0.37) for remote stations, and 0.25 for marine stations with OC data. The combination of high (negative) MNB and higher correlation at urban stations when compared with the low MNB and lower correlation at remote sites suggests that knowledge about the processes that govern aerosol processing, transport and removal, on top of their sources, is important at the remote stations. There is no clear change in model skill with increasing model complexity with regard to OC or OA mass concentration. However, the complexity is needed in models in order to distinguish between anthropogenic and natural OA as needed for climate mitigation, and to calculate the impact of OA on climate accurately
A −436C>A Polymorphism in the Human FAS Gene Promoter Associated with Severe Childhood Malaria
Human genetics and immune responses are considered to critically influence the outcome of malaria infections including life-threatening syndromes caused by Plasmodium falciparum. An important role in immune regulation is assigned to the apoptosis-signaling cell surface receptor CD95 (Fas, APO-1), encoded by the gene FAS. Here, a candidate-gene association study including variant discovery at the FAS gene locus was carried out in a case-control group comprising 1,195 pediatric cases of severe falciparum malaria and 769 unaffected controls from a region highly endemic for malaria in Ghana, West Africa. We found the A allele of c.−436C>A (rs9658676) located in the promoter region of FAS to be significantly associated with protection from severe childhood malaria (odds ratio 0.71, 95% confidence interval 0.58–0.88, pempirical = 0.02) and confirmed this finding in a replication group of 1,412 additional severe malaria cases and 2,659 community controls from the same geographic area. The combined analysis resulted in an odds ratio of 0.71 (95% confidence interval 0.62–0.80, p = 1.8×10−7, n = 6035). The association applied to c.−436AA homozygotes (odds ratio 0.47, 95% confidence interval 0.36–0.60) and to a lesser extent to c.−436AC heterozygotes (odds ratio 0.73, 95% confidence interval 0.63–0.84), and also to all phenotypic subgroups studied, including severe malaria anemia, cerebral malaria, and other malaria complications. Quantitative FACS analyses assessing CD95 surface expression of peripheral blood mononuclear cells of naïve donors showed a significantly higher proportion of CD69+CD95+ cells among persons homozygous for the protective A allele compared to AC heterozygotes and CC homozygotes, indicating a functional role of the associated CD95 variant, possibly in supporting lymphocyte apoptosis
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