1,707 research outputs found
Linguaggio politico e scrittura storica nel basso medioevo. Alcune riflessioni metodologiche
Starting from the political dimension that isrelated to every form of writing of history – meant as anoriented reconstruction of the past connected to the politicaland ideological context of reference – this paper proposessome general considerations about the political languageused in the writing of history. Special attention willbe given to particular themes, like the presence of semanticchanges, the continuing existence of schemes, concepts,words, periods, and the persistence of forms andmethods of definition that, in different chronological divisions,can contextualize different realities, in spite of theterminological analogies. The city historiography andchronicle studies between the 13th and the 15th centurieslend themselves to such an analysis, because they registerand picture the effective changing of the social, politicand economic structures of the urban realities whose historythey narrate, in a political context characterized byfluidity, hybridity, interchangeability of forms of government.This is a political context, then, that is very fruitfulfrom the point of view of political practice
Monitoraggio della viscoelasticità di un modello di coltura cellulare 3D per lo studio della fibrosi epatica
Lo sviluppo di fibrosi epatica si associa caratteristicamente a un eccesso di produzione e reticolazione della matrice extracellulare del tessuto, che causa un progressivo aumento del modulo elastico e della viscosità dell’organo – che a loro volta determinano ipertensione portale e insufficienza funzionale.
Modelli avanzati che riproducano in vitro il microambiente epatico sono cruciali per lo studio della patogenesi del fenomeno e per la valutazione di adeguate terapie future.
Un esempio chiaro di questa strategia viene presentato in un recente lavoro di ricerca, nel quale Cacopardo et al. propongono una strategia basata sull’utilizzo di tipi differenti di idrogel, con proprietà elastiche e viscosità variabili, per studiare la meccano-dinamica in un ambiente di coltura tridimensionale.
Idrogel di carichi di cellule sono dunque stati differenzialmente reticolati mediante transglutaminasi microbica, utilizzando un metodo citocompatibile originale che consenta l’esposizione delle cellule a un ambiente con proprietà meccaniche che variano nel tempo. Per la coltura dei costrutti 3D è stato inoltre utilizzato un bioreattore che si è dimostrato utile anche per monitorare nel tempo le proprietà meccaniche dei costrutti cellulari.
I risultati hanno mostrato che una maggiore “solidità” della matrice è coerente con l’aumento dello stress cellulare.
Il metodo proposto si è dimostrato quindi in grado di imitare efficacemente il microambiente meccanico associato alla fibrosi epatica e in evoluzione nel tempo e, di conseguenza, potrebbe fornire nuove informazioni sui processi fisiopatologici correlati e suggerire più efficaci strategie terapeutiche
Blood Gas, Acid-Base and Electrolyte Analysis in Healthy Dromedary Camel Calves up to 21 Days of Life
: The importance of prompt evaluation and care of the newborn is essential for reducing neonatal mortality, which represents a major cause of loss in camelids. This study investigated the blood gases, acid-base and electrolyte profiles in healthy dromedary calves during the first 3 weeks of life, assessing possible associations with age. Twenty-one dromedary camel calves aged 1 to 21 days were sampled, and venous whole blood analyzed through a VETSTAT® analyzer. The following parameters were measured: sodium (Na+), potassium (K+), chloride (Cl-), hydrogen ion concentration (pH), partial pressure carbon dioxide (pCO2), partial pressure oxygen (pO2), total hemoglobin concentration (tHb), hemoglobin oxygen saturation (sO2), total carbon dioxide (tCO2), bicarbonate (HCO3-), base excess (BE) and anion gap (AG). Calves were divided in two groups; younger calves (1-10 d), and older calves (11-21 d). Statistical analysis showed an effect of age, with lower K+ (p < 0.001) and higher Na+ and Cl- (p < 0.05) mean concentrations in the younger calves compared to the older ones, and higher pCO2 and lower sO2 mean concentrations in the older group. These preliminary results firstly described the blood gas, acid-base and electrolyte profiles in the healthy dromedary calf during the first 3 weeks of age, suggesting an effect of age on some parameters
Ensemble using different Planetary Boundary Layer schemes in WRF model for wind speed and direction prediction over Apulia region
Abstract. The Weather Research and Forecasting mesoscale model (WRF) was used to simulate hourly 10 m wind speed and direction over the city of Taranto, Apulia region (south-eastern Italy). This area is characterized by a large industrial complex including the largest European steel plant and is subject to a Regional Air Quality Recovery Plan. This plan constrains industries in the area to reduce by 10 % the mean daily emissions by diffuse and point sources during specific meteorological conditions named wind days. According to the Recovery Plan, the Regional Environmental Agency ARPA-PUGLIA is responsible for forecasting these specific meteorological conditions with 72 h in advance and possibly issue the early warning. In particular, an accurate wind simulation is required. Unfortunately, numerical weather prediction models suffer from errors, especially for what concerns near-surface fields. These errors depend primarily on uncertainties in the initial and boundary conditions provided by global models and secondly on the model formulation, in particular the physical parametrizations used to represent processes such as turbulence, radiation exchange, cumulus and microphysics. In our work, we tried to compensate for the latter limitation by using different Planetary Boundary Layer (PBL) parameterization schemes. Five combinations of PBL and Surface Layer (SL) schemes were considered. Simulations are implemented in a real-time configuration since our intention is to analyze the same configuration implemented by ARPA-PUGLIA for operational runs; the validation is focused over a time range extending from 49 to 72 h with hourly time resolution. The assessment of the performance was computed by comparing the WRF model output with ground data measured at a weather monitoring station in Taranto, near the steel plant. After the analysis of the simulations performed with different PBL schemes, both simple (e.g. average) and more complex post-processing methods (e.g. weighted average, linear and nonlinear regression, and artificial neural network) are adopted to improve the performances with respect to the output of each single setup. The neural network approach comes out as the most promising method
Design of an innovative beam monitor for particle therapy for the simultaneous measurement of beam fluence and energy
Reproducibility and Accuracy of the Radiofrequency Echographic Multi-Spectrometry for Femoral Mineral Density Estimation and Discriminative Power of the Femoral Fragility Score in Patients with Primary and Disuse-Related Osteoporosis
We aimed to investigate the reproducibility and accuracy of Radiofrequency Echographic Multi-Spectrometry (REMS) for femoral BMD estimation and the reproducibility and discriminative power of the REMS-derived femoral fragility score. 175 patients with primary and disuse-related osteoporosis were recruited: one femoral Dual-energy X-ray Absorptiometry (DXA) scan and two femoral REMS scans were acquired. No significant test—retest differences were observed for all REMS-derived variables. The diagnostic concordance between DXA and REMS was 63% (Cohen’s kappa = 0.31) in patients with primary osteoporosis and 13% (Cohen’s kappa: −0.04) in patients with disuse-related osteoporosis. No significant difference was observed between REMS and DXA for either femoral neck BMD (mean difference between REMS and DXA: −0.015 g/cm(2)) or total femur BMD (mean difference: −0.004 g/cm(2)) in patients with primary osteoporosis. Significant differences between the two techniques were observed in patients with disuse-related osteoporosis (femoral neck BMD difference: 0.136 g/cm(2); total femur BMD difference: 0.236 g/cm(2)). Statistically significant differences in the fragility score were obtained between the fractured and non-fractured patients for both populations. In conclusion, REMS showed excellent test-retest reproducibility, but the diagnostic concordance between DXA and REMS was between minimal and poor. Further studies are required to improve the REMS—derived estimation of femoral BMD
Spike S1 domain interactome in non-pulmonary systems: A role beyond the receptor recognition
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 2019 (COVID-19), which, since 2019 in China, has rapidly become a worldwide pandemic. The aggressiveness and global spread were enhanced by the many SARS-CoV-2 variants that have been isolated up to now. These mutations affect mostly the viral glycoprotein Spike (S), the capsid protein mainly involved in the early stages of viral entry processes, through the recognition of specific receptors on the host cell surface. In particular, the subunit S1 of the Spike glycoprotein contains the Receptor Binding Domain (RBD) and it is responsible for the interaction with the angiotensin-converting enzyme 2 (ACE2). Although ACE2 is the primary Spike host receptor currently studied, it has been demonstrated that SARS-CoV-2 is also able to infect cells expressing low levels of ACE2, indicating that the virus may have alternative receptors on the host cells. The identification of the alternative receptors can better elucidate the pathogenicity and the tropism of SARS-CoV-2. Therefore, we investigated the Spike S1 interactomes, starting from host membrane proteins of non-pulmonary cell lines, such as human kidney (HK-2), normal colon (NCM460D), and colorectal adenocarcinoma (Caco-2). We employed an affinity purification-mass spectrometry (AP-MS) to pull down, from the membrane protein extracts of all cell lines, the protein partners of the recombinant form of the Spike S1 domain. The purified interactors were identified by a shotgun proteomics approach. The lists of S1 potential interacting proteins were then clusterized according to cellular localization, biological processes, and pathways, highlighting new possible S1 intracellular functions, crucial not only for the entrance mechanisms but also for viral replication and propagation processes
Models for the lithium abundances of multiple populations in globular clusters and the possible role of the Big Bang lithium
Globular cluster stars show chemical abundance patterns typical of hot-CNO
processing. Lithium is easily destroyed by proton capture in stellar
environments, so its abundance may be crucial to discriminate among different
models proposed to account for multiple populations. In order to reproduce the
observed O-Na anticorrelation and other patterns typical of multiple
populations, the formation of second generation stars must occur from the
nuclearly processed stellar ejecta, responsible of the chemical anomalies,
diluted with pristine gas having the composition of first generation stars. The
lithium abundance in the unprocessed gas -which is very likely to be equal to
the lithium abundance emerging from the Big Bang- affects the lithium chemical
patterns among the cluster stars. This paper focuses on a scenario in which
processed gas is provided by asymptotic giant branch (AGB) stars. We examine
the predictions of this scenario for the lithium abundances of multiple
populations. We study the role of the non-negligible lithium abundance in the
ejecta of massive AGB (A(Li)~2), and, at the same time, we explore how our
models can constrain the extremely large ---and very model dependent--- lithium
yields predicted by recent super--AGB models. We show that the super--AGB
yields may be tested by examining the lithium abundances in a large set of blue
main sequence stars in wCen and/or NGC2808. In addition, we examine the
different model results obtained by assuming for the pristine gas either the
Big Bang abundance predicted by the standard models (A(Li)=2.6-2.7), or the
abundance detected at the surface of population II stars (A(Li)=2.2-2.3). Once
a chemical model is well constrained, the O--Li distribution could perhaps be
used to shed light on the primordial lithium abundance
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