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Impacts of El Niño-Southern Oscillation on the wheat market: a global dynamic analysis
No full textAlthough the widespread influence of the El Niño-Southern Oscillation (ENSO) occurrences on crop yields of the main agricultural commodities is well known, the global socio-economic consequences of ENSO still remain uncertain. Given the global importance of wheat for global consumption by providing 20% of global calories and nourishment, the monitoring and prediction of ENSO-induced variations in the worldwide wheat market are essential for allowing national governments to manage the associated risks and to ensure the supplies of wheat for consumers, including the underprivileged. To this end, we propose a global dynamic model for the analysis of ENSO impacts on wheat yield anomalies, export prices, exports and stock-to-use ratios. Our framework focuses on seven countries/regions: the six main wheat-exporting countries - the United States, Argentina, Australia, Canada, the EU, and the group of the main Black Sea export countries, i.e. Russia, Ukraine, and Kazakhstan - plus the rest of the world. The study shows that La Niña exerts, on average, a stronger and negative impact on wheat yield anomalies, exports and stock-to-use ratios than El Niño. In contrast, wheat export prices are positively related to La Niña occurrences evidencing, once again, its steady impact in both the short and long run. Our findings emphasize the importance of the two ENSO extreme phases for the worldwide wheat market
Experimental phenomenology on the role of chromatic accentuation in reading tasks
Get PDFAccording to Gestalt psychologists, color is considered a secondary attribute and a less effective tool if compared to shape, luminance and motion. In this work novel and meaningful visual properties given by chromatic variations in the reading process in normal and dyslexic readers have been studied. It was shown that color highlights wholeness, parts-whole organization and phenomenal fragmentation during reading and comprehension tasks in reading texts made of words and non-words modified through several color conditions: monochromatic (the whole text colored with only one color); word (each word colored in different color); half word (half word colored in a color different from the one of the second half); syllable (every syllable in a different color); letter (each letter in a different color). The aleatory variables here considered were: the reading time, the reading errors and the incorrect answers given in a comprehension test. The outcomes demonstrated that these variables are all directly related and strongly affected by the five chromatic conditions. These findings illustrate similar trends in the four groups of readers: children and adults, normal and dyslexic readers. Further possible researches and eventually some clinical applications are also discussed along with some questions related to color vision. They suggest the main purposes of color for living beings which is that to generate wholeness, parts-whole organization and perceptual fragmentation
Autoantibodies against CYP-2C19: a novel serum marker in pediatric de-novo autoimmune hepatitis?
No full textDiagnosis of de-novo autoimmune hepatitis (AIH) after orthotopic liver transplantation (OLT) is challenging especially in absence of hyper--globulinemia. Circulating autoantibodies are not sensitive nor specific in de-novo AIH, but when positive increase the diagnostic probability. We report the discovery of novel liver microsomal (LM) autoantibodies against CYP-2C19 in a 9-year-old boy with “de novo” AIH developed 7 years after OLT. Graft dysfunction presented with hypertransaminasemia (up to 400 IU/L), while serum γ-globulins remained within the normal range for age. Liver histology and response to high dose prednisone (2mg/kg/day) with the addition of azathioprine therapy further supported the diagnosis of de-novo AIH. Autoantibodies investigation by indirect immunofluorescence (IF) on rodent tissues showed a novel staining pattern involving the pericentral liver zone and sparing the renal tissue. Human but not rat liver proteins immunoblottings allowed us to characterize the novel LM antibodies and to identify CYP-2C19 as human antigen. The finding offers insights into the controversial discussion about autoimmunity versus alloreactivity with regard to the pathogenesis of de-novo AIH. Correct information on human versus rat tissue antigens tested by methods other than IF for antibodies detection may have significant implications for the correct diagnosis and management of patients followed up after OLT
Induzione e controllo di dinamiche complesse in sistemi meccanochimici
No full textMechanochemistry studies chemical processes in far-from-equilibrium conditions driven by the transfer of mechanical energy from a milling body to a reactive substrate.
The objective of this Thesis is to explore how such mechanical forcing induces and controls the onset of complex dynamics and self-organized chemical patterns.
To this aim we develop a numerical model able to simulate the kinematics of one or more milling bodies within a mechanochemical reactor. We show that, depending upon the elasticity of the collisions and the mechanical forcing, a milling body can undergo a transition from periodic to chaotic behaviours. By characterizing the set of collisions between the milling body and the reactor walls, we point out a strong spatial heterogeneity of the collision distributions (and, accordingly, of the kinetic energy dissipation) consistent with a multifractal topology.
We finally propose a new mechanochemical mechanism for promoting collective behaviours in an ensemble of coupled chemical oscillators, in which the chemical information is transferred non-locally through a milling body and the chemical oscillators are placed at the reactor walls. Our analysis reveals the crucial role played by the spatio-temporal dynamics of the signal carrier in the global chemical coupling. A switch from synchronized to desynchronized scenarios can thus be controlled by tuning the mechanical properties of the device
Los Mosaicos funerarios de Túnez, España e Italia: siglos III-VII
Get PDFLa tesis se ocupa de los mosaicos funerarios de los siglos III-VII d.C. en Túnez, España e Italia.
Introducción en italiano
El capitulo I comprende:
- Estado de la cuestión - Objetivos
- Metodología
- Limites geográficos
- Limites cronológicos - Estructura del corpus
El capitulo II comprende:
- El mosaico funerario - Definición
- Tipología
- Disposición
- Lugares de hallagzo
El capitulo III comprende el repertorio de los mosaicos funerarios de Byzacena
El capitulo IV comprende el repertorio de los mosaicos funerarios de Zeugitana
El capitulo V comprende el repertorio de los mosaicos funerarios de España
El capitulo VI comprende el repertorio de los mosaicos funerarios de Italia (en italiano)
Los capítulos III, IV, V y VI están compartidos en dos partes: la primera con las fichas de cada mosaico y la segunda con el comentario con un estudio sobre epigrafía, onomastica, iconografía y busqueda de los talleres musivos.
El capitulo VII se incentra sobre la origen, el desarrollo y la decadencia del mosaico funerario.
El capitulo VIII presenta un estudio sobre los clientes de los mosaicos funerarios.
El capitulo IX quiere estudiar el fenomeno del mosaico funerario dentro del Mediterraneo Occidental (en italiano)
Finalmente las conclusiones en italiano
Externalities in ruminant farms in Sardinia: Landscape and Water Footprint
No full textThis thesis focuses on the sustainability of livestock production in Sardinia, considering some externalities, Landscape, Ecosystem services and Water Footprint. The use of environmental resources as farm externalities, under the Common Agricultural Policies (CAP) framework, was reviewed. Two specific indexes were developed (Livestock Index and Grazing Impact Index), and georeferenced maps were made to determine the environmental impact of stocking rate and identify overgrazed areas. Livestock is important to utilize and valorize large areas in Sardinia, especially those at risk of abandonment, thus livestock agroforestry was studied as a mean to improve the ecosystem services of Sardinian farms, by quantifying the surface utilized and evaluating sustainability based on the livestock and grazing impact indexes. Results showed that livestock agroforestry is an important environmental resource for animal production in Mediterranean areas, but it would be fundamental to reduce stocking rates to avoid the potential harmful effects of overgrazing on landscape productivity and value. A new approach to calculate the water footprint of meat and milk, the Net Water Footprint (WFPnet), was developed and compared with the Water Footprint (WFP) in different production scenarios. For meat production, WFPnet values were equal to 5% and 54% of those obtained with the WFP calculation, whereas for milk production the WFPnet were equal to 4% and 63% of those calculated with the WFP method
Effects of seismic sequences on structures with hysteretic or damped dissipative behaviour
No full textRepeated seismic events strongly affect the building capacity in earthquake-prone regions, as its resilience, intended as the capacity of a system to quickly revert to a fully operational state after a damage due to a significant event, depends on the ability to withstand cumulated damage. This paper investigates the effects of repeated seismic sequences on structures characterized by different hysteretic behaviour. To this aim, non-linear single-degree-of-freedom (SDOF) systems were subjected to ten recorded seismic sequences taken from literature. The elasto-plastic and pivot hysteresis rules were analysed first, considering both hardening and softening behaviour. From each analysis, the inelastic spectrum of the seismic sequence was computed for different ductility levels, and the ductility demand was calculated and compared with the values for an only seismic event. It was shown that the effect of seismic sequences is quite significant, and a reduction of the behaviour factor from 15% for bilinear with hardening and pivot hysteretic rules to 35% for elasto-plastic systems with high ductility should be adopted in design to increase the seismic resilience. The use of linear and non-linear viscous dampers was also analysed in SDOF systems subjected to seismic sequences, demonstrating the effectiveness of this mitigation measure. Nonlinear viscous dampers with an initial friction force were found to dramatically reduce the acceleration and displacement demand, although it cannot avoid residual displacements at the end of the seismic events, and can be recommended for structures with short vibration periods. Nonlinear and linear dampers have the advantage of allowing full recentring of the structure at the end of the seismic events, thus significantly improving resilience
Partnership in teacher education: a theoretical and practical analysis
No full textThe aim of this study is to discuss theoretical and practical issues of the partnership in teacher education. A brief background of the debate in the last years is presented, questions about the partnership concept are introduced, the experience of the Brazilian university performing the inter-institutional work is analyzed and an overview is given of how the issue has been addressed in Québec. The current study seeks to note controversies and possible achievements of teachers in their struggles for the greater social approbation of the teaching profession. The research process benefited from documentary analysis, on-site observations and interviews; the last ones carried out in Brazil. The concept of partnership shows ambiguity. On the one hand, it is a strong ally for the implementation of official educational reforms, which puts it in scene between universities and schools. On the other hand, as a collaborative practice between the researchers and the school teachers, it helps to create new theoretical and practical basis for the initial and extended formation of the teaching professionals, in which academic knowledge and experience are articulated. In the case here analyzed, in the Brazilian scenario, the partnership helps to introduce innovations through institutional arrangements with other rationality, by which teachers are valued as collaborators in the processes of teacher training. Thus, we can affirm that the partnership is a relatively recent practice in the field of education, which involves tensions between official interests; and objectives of both collaborative work and collective struggles for the appreciation of the teaching profession of researchers at universities and teachers at schools
Identification of a HERV-K env surface peptide highly recognized in Rheumatoid Arthritis (RA) patients: a cross-sectional case–control study
No full textEndogenous retroviruses (HERV) are believed to be pathogenic in several autoimmune diseases. Among them, HERV-K viruses have been reported recently to be involved in the pathogenesis of rheumatoid arthritis (RA). In this study we have explored the role of humoral immune response against HERV-K as a potential pathogenetic mechanism in RA. Four different peptides from the extracellular portion of the env protein of HERV-K (env-su19–37, env-su109–126, env-su164–186, env-su209–226) were selected by bioinformatic analysis on the basis of their putative immunogenicity. Indirect enzyme-linked immunosorbent assay (ELISA) was then carried out to quantify antibodies against those peptides on blood samples of 70 consecutive RA patients and 71 healthy controls (HC). Differences between the two groups were analysed using the Mann–Whitney test. Potential correlations between RA laboratory, clinical descriptors and immunoglobulin (Ig)G levels were explored by bivariate regression analysis. Serum autoantibodies against one of four tested peptides of HERV-K (env-su19–37) were significantly higher in RA than in HC (19 versus 3%, P = 0·0025). Subgroup analysis showed no association between anti-HERV-K peptide humoral response and clinical, serological and clinimetric RA disease descriptors. Serum from RA patients in our series reacted significantly against HERV-K env-su19–37 peptide in comparison to the general population suggesting a role for the HERV-K- related, secondary antigenic-driven immune response in the pathogenesis of RA. Further studies are needed to confirm these results and to explore the role of this HERV-K surface peptide as a potential therapeutic target
Strategie di sorveglianza attiva e networking per il controllo delle infezioni da Listeria monocytogenes
Get PDFAim: the aim of this project was to activate an hospital and community surveillance system of listeriosis through epidemiological prospective and retrospective longitudinal study to describe prevalence of invasive infection and phenotypically and genotipically characteristics of the strains circulating in Northern Sardinia isolated from humans, foods and environment samples.
Methods: L.monocytogenes strains isolated from 2013 to 2016 in food and environment samples and patients were analyzed for presence of virulence genes. The strains were characterized genotypically (PCR, PFGE, MLST) to define the spread of the pathogen and the relationships clonality between the strains of human and food origin. Furthermore, it was characterized the immune profile of patients with invasive disease vs health controls, through antigen specific stimulation of PBMC and cytofluorimetric analysis in blood samples.
Results: Samples were positive for all 7 virulence-associated genes analyzed. 51,3%, 35,1% and 13,5% were identified serotype 4b, 1/2a and 1/2b, respectively. The PFGE showed the presence of 5 pulsetype, gruped in two major clusters (A,B,C-D,E) with 31,91% similarity index (Dice). This genetic variability was confirmed by MLST which identified 5 different STs (ST 1, ST 5, ST 8, ST 101, ST 121).
Cytofluorimetric analysis showed the percentage of CD8 and CD4 T-cells significantly less in patient compared to a health control (19 ± 4 vs 4 ± 0.02, p> 0.0001); although, the CD8 cells of patient produced levels of cytokines (TNFα, IL-2) higher than health control.
Conclusion: the results show that the active surveillance programs could be a crucial tool for assessing the incidence of listeriosis and describe the molecular characteristics of L.monocytogenes isolated. Also, the data obtained are an important tool for study how the immune profile can promote the development of invasive disease. The results obtained and the research protocols used are disclosed through a website