1,083 research outputs found

    Influencia de la infestación por Dacus Oleae sobre el flavor de aceites, extraídos de aceitunas atacadas, por análisis HPLC y HRGC de compuestos volátiles

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    The authors have examined the influence of the Dacus Oleae infestation on the aroma of the oils obtained from olives of Coratina and Nebbio varieties at different levels of attack. The results obtained indicated a worsening of the qualitative level of the oils obtained from increasing percentages of infested olives; these were found to have a great decrease of phenolic substances and higher contents of both volatile alcohols and aldehydes with an unpleasant sensation. Of particular interest was hexanal/total volatile alcohols ratio, in which having been well correlated with the extent of infestation, would permit one to establish in an objective manner, if and how much the olives from which an oil has been extracted have suffered a Dacus attack.Los autores han examinado la influencia de la infestación por Dacus Oleae sobre el aroma de aceites obtenidos de aceitunas de las variedades Coratina y Nebbio en diferentes estados de ataque. Los resultados obtenidos indicaron un empeoramiento de los niveles de calidad de los aceites obtenidos a medida que se incrementaba el porcentaje de aceitunas infestadas; mostrando una gran disminución de las sustancias fenólicas y altos contenidos tanto de alcoholes volátiles como de aldehídos, con una sensación desagradable. De particular interés fue la relación hexanal/alcoholes volátiles totales, la cual ha sido bien correlacionada con la extensión de la infestación, lo que permitiría establecer de una manera objetiva, sí y cuantas de las aceitunas de las cuales se ha extraído, han sufrido ataque por Dacus

    Evaluation of the energy utilization index in sheep milk cooling systems

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    The energy consumption of sheep milk cooling systems (MCSs) was quantified in this study to provide original information filling a literature gap on the impact of sheep milk cooling on the energy and economic balance in dairy farms. Performance and energy monitoring tests were conducted simultaneously on 22 MCSs in Sardinia (Italy). The results determined the cooling time as a function of the performance class and number of milkings. The Energy Utilization Index (EUI) was applied to measure the energy required to cool down the milk and estimate the incidence on its price. The average EUI was 1.76 kWh 100 L−1 for two-milkings and 2.43 kWh 100 L−1 for four-milkings MCSs, whereas the CO2 emissions ranged from 998 to 1378 g CO2 100 L−1 for two- and four-milkings MCSs, respectively. The estimated energy consumption for the storage of refrigerated sheep milk was 0.12 kWh 100 L−1. The malfunctioning MCSs averagely consumed 31% more energy than regular systems. The energy cost for cooling accounted for 0.61% on the current sheep milk price in Italy. Based on the analysis, the reported EUI values can be used as a preliminary indicator of the regular operation of MCSs

    Robots, Trade and Employment in Italian Local Labour Systems

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    Three main shocks have affected advanced economies over the last 25 years, with significant consequences for work, production and economic growth. The first is technological change associated with robotics and the so-called Fourth Industrial Revolution. The second, which is partly related to the first, is the diffusion of ICT and the development of intelligent software applied both to industry and tertiary activities. The third is the strong competitive pressure from low cost and emerging countries, which have changed the geography of world production and trade flows, often within global value chains. Following the seminal papers of Acemoglu and Restrepo (2017) and Dauth, Findeisen, Südekum and Woessner (2017), the aim of this paper is to assess the impact of these three shocks on employment in Italian local labour markets in the period 1991-2011. What is new in our approach is the explicit consideration of the role played by the different typologies of local labour systems and industrial districts. We find that robots do not have any negative effect on employment in local labour markets. On the contrary, robots seem to be associated with a growth in overall employment, mainly due to the tertiary sector. The second result is that there is some evidence of a positive effect of ICT investments on local employment, in particular non-manufacturing employment. The last and most robust result of the econometric analysis is the negative impact of trade with low cost countries on local employment. This result has one almost absolute protagonist: China. All these impacts are not homogeneous across the national territory and partly depend on the characteristics of the local productive systems and industrial districts

    Dynamical properties across a quantum phase transition in the Lipkin-Meshkov-Glick model

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    It is of high interest, in the context of Adiabatic Quantum Computation, to better understand the complex dynamics of a quantum system subject to a time-dependent Hamiltonian, when driven across a quantum phase transition. We present here such a study in the Lipkin-Meshkov-Glick (LMG) model with one variable parameter. We first display numerical results on the dynamical evolution across the LMG quantum phase transition, which clearly shows a pronounced effect of the spectral avoided level crossings. We then derive a phenomenological (classical) transition model, which already shows some closeness to the numerical results. Finally, we show how a simplified quantum transition model can be built which strongly improve the classical approach, and shed light on the physical processes involved in the whole LMG quantum evolution. From our results, we argue that the commonly used description in term of Landau-Zener transitions is not appropriate for our model.Comment: 7 pages, 5 figures; corrected reference

    Time-Dependent Analysis of Precast Segmental Bridges

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    Prestressed segmentally constructed balanced cantilever bridges are often subjected to larger deflections than those predicted by calculations, especially for long-term effects. In this paper, the case of modular balanced cantilever bridges, which are prestressed segmental bridges obtained through a repetition of the same double cantilever, is investigated. The considered bridges are two typical cases of modular balanced cantilever both subjected to large deformations during their lifetime. In this case, due to the unusual employed static scheme, creep deflections indefinitely evolve over time particularly at the end of the cantilevers and in correspondence with the central joint. These remarkable deflections cause discomfort for vehicular traffic and in certain cases can lead to the bridge collapse. Important extraordinary maintenance interventions were necessary to restore the viability of the bridges and to replace the viaduct design configuration. To this aim, the static schemes of the structures were varied, introducing new constraints, new tendons, and carbon fiber reinforcements. In the present work, time analysis was performed to compare the time-dependent behavior of the bridge according to two different creep models, the CEB-FIP Model Code 2010 and the RILEM Model B3, with the real-time-dependent behavior of the bridge observed during its lifetime. The two different employed models exhibit different behaviors in terms of displacements and bending moments acting on the bridge. Interesting considerations are made on their reliability in simulating the long-term creep effects that evolve indefinitely over time. Moreover, retrofitting techniques have been proposed and modeled to predict their effectiveness in reducing time-dependent deflections

    Italian Deprivation Index and Dental Caries in 12-Year-Old Children: A Multilevel Bayesian Analysis

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    Evidence from the literature has shown that people with a lower socioeconomic status enjoy less good health than people with a higher socioeconomic status. The Italian deprivation index (DI) was used with the aim to evaluate the association between the DMFT index and risk factors for dental caries, including city population and DI. The study included 4,305 12-year-old children living in 38 cities classified by demographic size as small, midsize and large. Zero-inflated negative binomial multilevel regression models were used to assess risk factors for DMFT and to address excess of zero DMFT and overdispersion through a Bayesian approach. The difference in the average level of DMFT among children living in cities with different DI quintile was not statistically significant (p = 0.578). The DI and ln(population), included as city-level fixed effects in the two-level variance components model, were not statistically significant. Consuming sweet drinks on average increased the mean DMFT of a susceptible child, while having a highly educated mother reduced it. Un-observed heterogeneity among cities was detected for the probability to be non-susceptible to caries (city-level variance = 0.26 with 95% credibility interval 0.09–0.57), while no territorial effect was found for the mean DMFT of the susceptible children. Our results suggest that the DI and city population did not play a role in explaining between-city variability. Interventions against social deprivation can be influential on the perception of oral health in Italian 12-year-old children to the extent that they can also affect individual level factors

    JNK1 ablation improves pancreatic β-cell mass and function in db/db diabetic mice without affecting insulin sensitivity and adipose tissue inflammation

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    The cJun N-terminal Kinases (JNK) emerged as a major link between obesity and insulin resistance, but their role in the loss of pancreatic β-cell mass and function driving the progression from insulin resistance to type-2 diabetes and in the complications of diabetes was not investigated to the same extent. Furthermore, it was shown that pan-JNK inhibition exacerbates kidney damage in the db/db model of obesity-driven diabetes. Here we investigate the role of JNK1 in the db/db model of obesity-driven type-2 diabetes. Mice with systemic ablation of JNK1 (JNK1−/−) were backcrossed for more than 10 generations in db/+ C57BL/KS mice to generate db/db-JNK1−/− mice and db/db control mice. To define the role of JNK1 in the loss of β-cell mass and function occurring during obesity-driven diabetes we performed comprehensive metabolic phenotyping, evaluated steatosis and metabolic inflammation, performed morphometric and cellular composition analysis of pancreatic islets, and evaluated kidney function in db/db-JNK1−/− mice and db/db controls. db/db-JNK1−/− mice and db/db control mice developed insulin resistance, fatty liver, and metabolic inflammation to a similar extent. However, db/db-JNK1−/− mice displayed better glucose tolerance and improved insulin levels during glucose tolerance test, higher pancreatic insulin content, and larger pancreatic islets with more β-cells than db/db mice. Finally, albuminuria, kidney histopathology, kidney inflammation and oxidative stress in db/db-JNK1−/− mice and in db/db mice were similar. Our data indicate that selective JNK1 ablation improves glucose tolerance in db/db mice by reducing the loss of functional β-cells occurring in the db/db mouse model of obesity-driven diabetes, without significantly affecting metabolic inflammation, steatosis, and insulin sensitivity. Furthermore, we have found that, differently from what previously reported for pan-JNK inhibitors, selective JNK1 ablation does not exacerbate kidney dysfunction in db/db mice. We conclude that selective JNK1 inactivation may have a superior therapeutic index than pan-JNK inhibition in obesity-driven diabetes

    Agricultural sustainability estimation of the European photovoltaic greenhouses

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    The integration of the photovoltaic (PV) energy in the greenhouse farm has raised concerns on the agricultural sustainability of this specific agrosystem in terms of crop planning and management, due to the shading cast by the PV panels on the canopy. The PV greenhouse (PVG) can be classified on the basis of the PV cover ratio (PVR), that is the ratio of the projected area of PV panels to the ground and the total greenhouse area. In this paper, we estimated the yield of 14 greenhouse horticultural and floricultural crops inside four commercial PVG types spread in southern Europe, with PVR ranging from 25 to 100%. The aim of the work is to identify the PVG types suitable for the cultivation of the considered species, based on the best trade-off between PV shading and crop production. The daily light integral (DLI) was used to compare the light scenarios inside the PVGs to the crop light requirements, and estimate the potential yield. The structures with a PVR of 25% were compatible with the cultivation of all considered species, including the high light demanding ones (tomato, cucumber, sweet pepper), with an estimated negligible or limited yield reduction (below 25%). The medium light species (such as asparagus) with an optimal DLI lower than 17 mol m−2 d−1 and low light crops can be cultivated inside PVGs with a PVR up to 60%. Only low light demanding floricultural species with an optimal DLI lower than 10 mol m−2 d−1, such as poinsettia, kalanchoe and dracaena, were compatible inside PVGs with a PVR up to 100%. Innovative cropping systems should be considered to overcome the penalizing light scenarios of the PVGs with high PVR, also implementing LED supplementary lighting. This paper contributes to identify the sustainable PVG types for the chosen species and the alternative crop managements in terms of transplantation period and precision agriculture techniques, aimed at increasing the crop productivity and adaptability inside the PVG agrosystems

    Computational reconstruction of pacemaking and intrinsic electroresponsiveness in cerebellar Golgi cells.

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    The Golgi cells have been recently shown to beat regularly in vitro (Forti et al., 2006. J. Physiol. 574, 711-729). Four main currents were shown to be involved, namely a persistent sodium current (I(Na-p)), an h current (I(h)), an SK-type calcium-dependent potassium current (I(K-AHP)), and a slow M-like potassium current (I(K-slow)). These ionic currents could take part, together with others, also to different aspects of neuronal excitability like responses to depolarizing and hyperpolarizing current injection. However, the ionic mechanisms and their interactions remained largely hypothetical. In this work, we have investigated the mechanisms of Golgi cell excitability by developing a computational model. The model predicts that pacemaking is sustained by subthreshold oscillations tightly coupled to spikes. I(Na-p) and I(K-slow) emerged as the critical determinants of oscillations. I(h) also played a role by setting the oscillatory mechanism into the appropriate membrane potential range. I(K-AHP), though taking part to the oscillation, appeared primarily involved in regulating the ISI following spikes. The combination with other currents, in particular a resurgent sodium current (I(Na-r)) and an A-current (I(K-A)), allowed a precise regulation of response frequency and delay. These results provide a coherent reconstruction of the ionic mechanisms determining Golgi cell intrinsic electroresponsiveness and suggests important implications for cerebellar signal processing, which will be fully developed in a companion paper (Solinas et al., 2008. Front. Neurosci. 2:4)
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