7,382 research outputs found
Didática e formação de docentes: saberes necessários à prática
info:eu-repo/semantics/publishedVersio
A Monte Carlo study of the three-dimensional XY universality class:Universal amplitude ratios
We simulate lattice models in the three-dimensional XY universality class in
the low and the high temperature phase. This allows us to compute a number of
universal amplitude ratios with unprecedented precision: R_{\Upsilon}=0.411(2),
R_B=2.83(1), R_{\xi}^+=0.3562(10) and R_{\xi}^-=0.850(5). These results can be
compared with those obtained from other theoretical methods, such as field
theoretic methods or the high temperature series expansion and also with
experimental results for the lambda-transition of He. In addition to the XY
model, we study the three-dimensional two-component model on the
simple cubic lattice. The parameter of the model is chosen such that
leading corrections to scaling are small.Comment: 28 pages 5 figure
Using object-based geomorphometry for hydro-geomorphological analysis in a Mediterranean research catchment
Abstract. The aim of the paper is to apply an object-based geomorphometric procedure to define the runoff contribution areas and support a hydro-geomorphological analysis of a 3 km2 Mediterranean research catchment (southern Italy). Daily and sub-hourly discharge and electrical conductivity data were collected and recorded during a 3-year monitoring activity. Hydro-chemograph analyses carried out on these data revealed a strong seasonal hydrological response in the catchment that differed from the stormflow events that occur in the wet periods and in dry periods. This analysis enabled us to define the hydro-chemograph signatures related to increasing flood magnitude, which progressively involves various runoff components (baseflow, subsurface flow and surficial flow) and an increasing contributing area to discharge. Field surveys and water table/discharge measurements carried out during a selected storm event enabled us to identify and map specific runoff source areas with homogeneous geomorphological units previously defined as hydro-geomorphotypes (spring points, diffuse seepage along the main channel, seepage along the riparian corridors, diffuse outflow from hillslope taluses and concentrate sapping from colluvial hollows). Following the procedures previously proposed and used by authors for object-based geomorphological mapping, a hydro-geomorphologically oriented segmentation and classification was performed with the eCognition (Trimble, Inc.) package. The best agreement with the expert-based geomorphological mapping was obtained with weighted plan curvature at different-sized windows. By combining the hydro-chemical analysis and object-based hydro-geomorphotype map, the variability of the contribution areas was graphically modeled for the selected event, which occurred during the wet season, by using the log values of flow accumulation that better fit the contribution areas. The results allow us to identify the runoff component on hydro-chemographs for each time step and calculate a specific discharge contribution from each hydro-geomorphotype. This kind of approach could be useful when applied to similar, rainfall-dominated, forested and no-karst catchments in the Mediterranean eco-region
A transição do Ensino Secundário para o Ensino Superior: factores contributivos para uma boa adaptação e relação com o sucesso académico universitário
O elevado crescimento da frequência do Ensino Superior, cerca de 30% nos últimos 30
anos, (Lencastre, L. et al., 2000) e as altas taxas de insucesso a nível universitário(40.6%) têm despertado a atenção quer de investigadores sociais quer da sociedade em geral. No nosso entender, é fundamental tentar perceber se esse insucesso se situa logo no primeiro ano e se está relacionado com a adaptação ao mais alto nível de ensino, no sentido de se desenvolverem estratégias de promoção duma boa adaptação e, consequentemente, do sucesso académico. É neste sentido, que nos propomos, neste estudo, tentar analisar os possíveis factores que contribuem para uma adaptação bem sucedida à Universidade, bem como os possíveis factores de risco. Esta análise centra-se necessariamente no conhecimento e caracterização da população alvo (alunos do 1º ano da Universidade da Madeira no presente ano lectivo) assim como das implicações da transição entre níveis de ensino e da consequente adaptação ao ambiente Universitário
Суб'єктність як модальний оператор особистості (Subjectivity as of the individual modal operator)
У статті досліджено концепт «суб’єктність» як специфічний «модальний оператор» особистості (необхідність, можливість, дійсність), який визначає спрямованість суб’єктної активності індивіда. Проаналізовано поняття «суб’єктність» у філософії Аристотеля, Канта, Фіхте, Шеллінга, Гегеля. Розглянуто діалектику змісту і форми суб’єктності; проаналізовано потенціал концепції суб’єктної активності індивіда у визначенні сутності поняття «суб’єктність».
(The article defines the concept of «subjectity» as a specific «modal operator» of personality (necessity, possibility, reality) which directs individual objective activities. We analyzed the concept of «subjectity» in the philosophy of Aristotle, Kant, Fichte, Schelling, Hegel. We found the difference of the terms «subject» and «subjectity». The term «subject» is mainly focused on the epistemological aspect when it comes to the adequacy or inadequacy of reflection of objective existence. Subjectity is understood as a quality of subject.The purpose of this study is: to identify the dialectics of subjectity’s content and form; to analyze the potential of the concept of individual subjective activity in the determining of the concept of «subjectity» nature.Aristotle stated that subjectity can be hidden, it can exist only as a possibility, or being actualized. The concept of subjectity indicates activity of a thinking individual in the cognition of reality and it’s transformation. Kant, Fichte, Schelling and Hegel studied the principle of the representation of subject and object relationship in the cognition as a necessary condition of the productive activity of consciousness. They defined consciousness as the basis of personality. Kant formulated the categorical imperative as the highest level of subjectiity. Fichte proposed the position about the autonomy of «Me». Self-consciousness arises as a reflection of motivation, «Me» acquires subjectity. Self- consciousness is the basis of subjectity. Schelling defined that «Me» is characterized not only by self- consciousness, but by the tendency to the objectification of itself. «Identical» is the basis of the world. It appears in nature and human consciousness, in history and art. Absolute identity has two forms: subjective consciousness and object nature. Hegel develops
the concept of absolute principle: human cognition is self-consciousness of the absolute principle of reality. The highest level of consciousness is subjectivity itself; true independence, containing the opposites and overcomes them itself.The meaning of «subjectity» reveals itself as the way of self-determination (choice and decision-making, harmonization of reality); as the form of self – fulfillment (interactivity, productivity); as the need to be responsible (reflexive) in disposing of freedom in the limited space and time
Phenotypic effects of expanded ataxin-1 polyglutamines with interruptions in vitro
Spinocerebellar ataxia type 1 is a neurodegenerative disease caused by expansion of an uninterrupted glutamine repeat in ataxin-1 protein. Protein aggregation and immunoreactivity to 1C2 monoclonal antibody are two distinct pathognomonic features of expanded ataxin-1, as well as of other polyglutamine disorders. Rare cases of non-affected elderly subjects carrying expanded ataxin-1 alleles were found in random population. However, in these alleles the glutamine stretch was interrupted by histidines. Due to lack of phenotype, these alleles should be considered "normal". Most importantly, occurrence of these unusual alleles provides a unique opportunity to investigate which molecular properties of expanded ataxin-1 are not coupled to polyglutamine pathogenesis. Towards this goal, we compared in vitro the immunoreactivity to 1C2 antibody and the ability to form aggregates of interrupted and uninterrupted alleles. Immunoblotting showed that expanded-interrupted ataxin-1 had an affinity to 1C2 resembling that of normal ataxin-1. On the contrary, filter assay showed that aggregation rate of expanded-interrupted ataxin-1 resembles that of expanded-uninterrupted ataxin-1. These observations indicate that affinity for 1C2 does not directly correlate with self-aggregation of ataxin-1. Moreover, self-aggregation is not directly affected by histidine interruptions. In conclusion, these results support the hypothesis that mechanisms underlying neuronal degeneration are triggered by protein misfolding rather than by protein aggregation
A review on effects of biological soil crusts on hydrological processes
Biological soil crusts (BSCs) are complex consortia of microorganisms able to modify soil physical, chemical, and hydrological characteristics and influence soil erosion resistance. Given their importance, this paper analyses the current knowledge about BSCs reporting the findings of 163 papers about different BSC aspects published from 1990 to 2023. At first, a review of the BSC main detection methods (visual inspection, remote sensing, and morphological characterization) is presented as they represent valuable tools in BSC identification and mapping, revealing some issues related to the adopted classification criteria and the BSC microbial composition. Then, the literature results about their influence on soil characteristics, hydrology, and erosion processes are reported. Although their positive effects on soil characteristics (e.g., stability and fertility) and resistance to soil erosion are widely recognized, conflicting results are reported on their influence on soil hydrology. The analysis of the available literature allowed for providing indications about the choice of which microorganisms are the most suitable to form BSCs, following the required objectives (soil physic-chemical improvements, soil hydrology, erosion processes resistance, cost, and time to produce their effects). In particular, the results showed that i) the BSC effects on the soil physic-chemical characteristics improve along their successional series; ii) bacteria and cyanobacteria can be considered the most valuable BSC in limiting and degraded conditions (sediment concentration in the runoff reduced by 87% in comparison to bare soils, cost of 350 USD ha−1, and a recovery time of 5–10 years); iii) the intrinsic heterogeneity of BSCs does not allow for explaining the divergence of the literature results on soil hydrology; and iv) mosses are the best BSC anti-erosive type as they produce the most similar effects as compared to vegetation. Finally, the main steps required to obtain microbial inoculums, the effects of their application to induce BSC formation, and future prospects of research are reported
Slope threshold for overland flow resistance on sandy soils
Recent research on rill flows recognised that an 18% slope can be used to distinguish between ‘gentle’ and ‘steep’ slope cases for the detected differences in hydraulic (flow depth and velocity) and sediment transport variables (flow transport capacity, actual sediment load). The effects of slope on flow velocity, friction factor and transport capacity and their interactions affect process-based erosion modelling. The main aim of this paper is to investigate, for the first time, how slope affects the overland flow resistance on sandy soils, which are characterised by loose particles readily available to be transported and deposited. Using literature measurements carried out in sandy soils for both gentle and steep slopes, a theoretical overland flow resistance equation, based on the integration of the power velocity distribution, is tested. The relationship between the velocity profile parameter Γ, the channel slope, the Reynolds and Froude number is calibrated using measurements characterized by a wide range of hydraulic conditions and distinguishing between gentle (5.2%–13.2%) and steep (17.4%–42.3%) slope conditions. The analysis demonstrated that: (1) the parameter Γ can be accurately estimated by Equation (15) in which the exponents are independent of slope condition; (2) the coefficient a of Equation (15) is equal to 0.8750 and 0.8984 for the gentle and steep slope condition, respectively; (3) the estimations of the Darcy–Weisbach friction factor f (Equation 19) are accurate and characterised by errors less than or equal to ±5% for 97.2% of cases; and (4) in the range of steep slopes, the flow resistance law calibrated for the gentle slope condition (Equation (19) with a = 0.8750) systematically overestimates the f value. In conclusion, this study allowed the recognition, for an unlimited soil detachment condition and an overland flow, of how the energy dissipation processes and the estimate of the friction factor are affected by slope. Highlights: A theoretical overland flow resistance law is tested by data obtained on sandy soils. Differences between gentle and steep slope conditions are investigated. The Darcy–Weisbach friction factor estimate by the flow resistance law is accurate. The law calibrated for gentle slopes overestimates f in the range of steep slopes
Femicide Fatal Risk Factors: A Last Decade Comparison between Italian Victims of Femicide by Age Groups
Femicide is a wide-spread lethal form of violence against women. Despite its diffusion, to date, very few studies analyzed possible victims' age differences in regard to fatal risk factors for femicide. To this aim, we carried out archive research on Italian femicide cases in the last decade, by comparing prior types of violence suffered and motives for femicide, which are considered crucial fatal risk factors for femicide, across adolescent/young (15-24 years), adults (25-64 years) and older women (65-93 years). From 2010 to 2019 we found 1207 female victims. Characteristics of victims, perpetrators, and their relationship were consistent with those found by international studies and underlined that the majority of femicides were perpetrated by an intimate partner. The results regarding fatal risk factors comparisons across age groups showed the existence of significant differences regarding both types of violence suffered prior to femicide and motives for femicide. The results are discussed in terms of policy implication and intervention
HEMODIALYSIS-RELATED LYMPHOMONONUCLEAR RELEASE OF INTERLEUKIN 12 IN PATIENTS WITH END-STAGE RENAL DISEASE.
Abstract: Interleukin-12 (IL-12) is a cytokine produced by peripheral blood mononuclear cells (PBMC) that causes interferon-gamma (IFN-gamma) production and enhancement of cell-mediated cytotoxicity. To clarify the role of hemodialysis biocompatibility on IL-12 production and uremic immunodeficiency, we have studied the IL-12 and IFN-gamma release by PBMC harvested from 12 patients dialyzed with cuprophan membrane (CU), eight patients dialyzed with polymethylmethacrylate membrane (PMMA), and eight nondialyzed uremic patients (UR). Ten healthy subjects constituted the control group (CON). PBMC were cultured for 48 h with and without nonspecific mitogen stimulation. In unstimulated conditions, CU showed an IL-12 PBMC production higher than CON, UR, and PMMA (46.67 +/- 30.13 versus 2.56 +/- 1.38, 6.16 +/- 7.09, and 4.62 +/- 4.76 pg/ml, respectively; P < 0.01). IL-12 production was correlated with C3a concentration measured at the outlet of hemodialyzer after 15 min of dialysis (r = 0.69, P < 0.01). IL-12 release in CU remained unchanged under mitogen stimulation (44.34 +/- 23.86 pg/ml) and was lower than in CON, UR, and PMMA (66.0 +/- 12.41, 68.37 +/- 25.78, and 67.75 +/- 22.61 pg/ml, respectively; P < 0.05). IFN-gamma production was similar, in unstimulated conditions, in all groups. Under stimulation, IFN-gamma release was lower in CU (13.42 +/- 12.04 IU/ml) than in CON, UR, and PMMA (51.84 +/- 30.74, 32.16 +/- 13.86, and 32.16 +/- 13.86 IU/ml, respectively; P < 0.01). These results demonstrate that hemodialysis with CU induces monocyte activation with an enhanced release of IL-12. On the contrary, stimulated PBMC production of both IL-12 and IFN-gamma is lower in these patients than in CON, UR, and PMMA. The altered release of these cytokines could play a role in cell-mediated immunodeficiency of the uremic patients dialyzed with CU
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