313 research outputs found

    VOC Air Pollution in Urban Areas – A Microscale Model experimentally validated

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    Previous theoretical and experimental studies (S. T. A.- Università di Pisa (DIMNP), 1998; Agostini E., M. Corezzi, I. Ciucci, M. Mazzini 2003; Agostini E., I. Ciucci, M. Mazzini, S. Strinati, 2003) even if partial, evidenced the problem of atmospheric pollution by Volatile Organic Compounds (VOC) in Livorno (Tuscany). This pollution is caused mainly by the presence of an important refinery, other industries and traffic. Other relevant VOC emission sources are linked to port activities and to numerous small companies using paints and solvents. Figure 1 shows the map of Livorno, situated on the Tyrrhenian sea. This is a simple site from the orography point of view, except for the southern zone where a promontory and a chain of hills impose a more complex pattern of air fluxes. The industrial zone is localized in the north of the map and the harbour activities along the coast (west area). It’s difficult to define a specific zone for the companies using solvents and paints, even though a grater concentration is present around the axis Viale Carducci – Piazza Repubblica – Via Grande. The map outlines also the air pollution measurement stations managed by ARPAT (points) and the meteorological stations (crosses). The simulation of the emission scenario, was done by using ISC3 (U. S. Environmental Protection Agency) code for treating diffuse sources and CALINE4 (California Department of Transportation) for those related to traffic on main roads. The research work focuses the attention on the results of model validation by experimental data obtained along the roads of the studied area. The possibility to extend the application of this model to sites with similar orography and town-planning characteristics is also discussed in the aim of obtaining information about the level of atmospheric pollution on sites where there aren’t measurement stations

    Histochemical characterisation and gene expression analysis of skeletal muscles from maremmana and aubrac steers reared on grazing and feedlot systems

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    This study aimed to characterise the fibre composition of Triceps brachii (TB) and Semimem-branosus (SM) muscles from 20 Maremmana (MA) and 20 Aubrac (AU) steers, and the effect of grazing activity in comparison with feedlot system. The histochemical method was performed with the m-ATPase method with an acid pre-incubation, thus allowing to distinguish type I, IIA, and IIB fibres. Additionally, on total RNA extracted from SM muscle, the expressions of atp1a1, mt-atp6, and capn1 genes were evaluated, in order to find potential associations with muscle fibre histochemical characteristics. In SM muscle, the MA steers had the greater frequency of oxidative fibres (type I and IIA) and the higher atp1a1 expression, in comparison to AU steers. Conversely, AU steers had a greater frequency of type IIB fibres, and the higher capn1 expression. A similar histochemical pattern was observed in TB muscle. The grazing activity was probably insufficient to determine differences both for fibre proportion and size, and gene expressions, except for mt-atp6 expression that was surprisingly highest in feedlot MA in comparison to other steers. These findings further the knowledge of muscle properties belonging to these breeds, and the effect of voluntary physical activity since few studies were available in this regard

    Spark Plasma Sintering of LiFePO4: AC Field Suppressing Lithium Migration

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    Our work proposes a comparison between Spark Plasma Sintering of LiFePO(4) carried out using an Alternating Current (AC) and Direct Current (DC). It quantifies the Li-ion migration using DC, and it validates such hypothesis using impedance spectroscopy, X-ray photoelectron spectroscopy and inductively coupled plasma optical emission spectroscopy. The use of an AC field seems effective to inhibit undesired Li-ion migration and achieve high ionic conductivity as high as 4.5 × 10(−3) S/cm, which exceeds by one order of magnitude samples processed under a DC field. These results anticipate the possibility of fabricating a high-performance all-solid-state Li-ion battery by preventing undesired Li loss during SPS processing

    Are large carnivores the real issue? Solutions for improving conflict management through stakeholder participation

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    Social conflicts around large carnivores are increasing in Europe, often associated to the species expansion into human-modified and agricultural landscapes. Large carnivores can be seen as an added value by some but as a source of difficulties by others, depending on different val-ues, attitudes, livelihoods, and everyday activities. Therefore, the effective involvement of the different interest groups is important to identify and shape tailored solutions that can potentially be implemented, complementing top-down approaches that might, on their own, result in lack of implementation and buy-in. To improve dialogue in conflictual situations, as part of a European project promoted by the European Parliament, we assessed the practical implementation of participatory processes in three sample areas in Europe where wolves and bears have recently been increasingly impacting human activities. Our results demonstrate that collaboration among different and generally contrasting groups is possible. Even in situations where large-carnivore impacts were seen as unsatisfactorily managed for many years, people were still willing and eager to be involved in alternative discussion processes hoping this would lead to concrete solutions. An important and common highlight among the three study areas was that all the management interventions agreed upon shared the general scope of improving the conditions of the groups most impacted by large carnivores. The process showed the importance of building trust and supporting dialogue for knowledge co-production and mitigation of conflicts between stakeholders and that controversial environmental issues have the potential to trigger a meaningful dialogue about broader societal issues. The direct involvement and support of competent authorities, as well as the upscaling of this process at larger administrative and social scales, remain important challenges

    The influence of road networks on brown bear spatial distribution and habitat suitability in a human-modified landscape

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    Roads are human infrastructure that heavily affect wildlife, often with marked impacts on carnivores, including brown bears Ursus arctos. Here, we assessed the potential impact of road networks on the distribution of brown bears in the small, isolated and endangered Cantabrian population of north-western Spain. To ascertain whether local road networks affect brown bear spatial distribution, we first assessed potential influences on the distance of bear locations to roads using candidate models which included topographic variables, landcover types, bear age and reproductive status, traffic volume and road visibility. Then, we built two sets of habitat suitability models, both with and without roads, to discern the possible loss of habitat suitability caused by roads. The mean distance of bear locations to the nearest road was 968 804 m and the closest road was a low traffic road in 72.5% of cases. Candidate models showed little influence of our variables on bear distance to the nearest road, with the exception of elevation. Habitat suitability models revealed that road networks in our study area seem to have almost no effect on brown bear habitat suitability, except for females with yearlings during the denning season. However, this result may also be a consequence of the fact that only a small proportion (16.5%) of the cells classified as suitable bear habitats were crossed by roads, that is, most of the roads are primarily located in unsuitable bear habitats in the Cantabrian Mountains. Compared to previous studies conducted in other populations, mainly North American ones, our findings might suggest a different response of Eurasian brown bears to roads due to a longer bear-human coexistence in Europe versus North America. However, the indirect approach used in our study does not exclude other detrimental effects, for example, road mortality, increased stress and movement pattern disruption, only detectable by more direct approaches such as telemetry

    A modal theorem-preserving translation of a class of three-valued logics of incomplete information

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    International audienceThere are several three-valued logical systems that form a scattered landscape, even if all reasonable connectives in three-valued logics can be derived from a few of them. Most papers on this subject neglect the issue of the relevance of such logics in relation with the intended meaning of the third truth-value. Here, we focus on the case where the third truth-value means unknown, as suggested by Kleene. Under such an understanding, we show that any truth-qualified formula in a large range of three-valued logics can be translated into KD as a modal formula of depth 1, with modalities in front of literals only, while preserving all tautologies and inference rules of the original three-valued logic. This simple information logic is a two-tiered classical propositional logic with simple semantics in terms of epistemic states understood as subsets of classical interpretations. We study in particular the translations of Kleene, Gödel, ᴌukasiewicz and Nelson logics. We show that Priest’s logic of paradox, closely connected to Kleene’s, can also be translated into our modal setting, simply by exchanging the modalities possible and necessary. Our work enables the precise expressive power of three-valued logics to be laid bare for the purpose of uncertainty management

    Frequency Dependent Dynamical Electromechanical Response of Mixed Ionic-Electronic Conductors

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    Frequency dependent dynamic electromechanical response of the mixed ionic-electronic conductor film to a periodic electric bias is analyzed for different electronic and ionic boundary conditions. Dynamic effects of mobile ions concentration (stoichiometry contribution), charge state of acceptors (donors), electron concentration (electron-phonon coupling via the deformation potential) and flexoelectric effect contribution are discussed. A variety of possible nonlinear dynamic electromechanical response of MIEC films including quasi-elliptic curves, asymmetric hysteresis-like loops with pronounced memory window and butterfly-like curves are calculated. The electromechanical response of ionic semiconductor is predicted to be a powerful descriptor of local valence states, band structure and electron-phonon correlations that can be readily measured in the nanoscale volumes and in the presence of strong electronic conductivity.Comment: 36 pages, 10 figures, accepted to J. Appl. Phy

    Vocalization deficits in mice over-expressing alpha-synuclein, a model of pre-manifest Parkinson’s disease.

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    Communication and swallowing deficits are common in Parkinson’s disease (PD). Evidence indicates that voice and speech dysfunction manifest early, prior to motor deficits typically associated with striatal dopamine loss. Unlike deficits in the extremities, cranial sensorimotor deficits are refractory to standard dopamine-related pharmacological and surgical interventions, thus the mechanisms underlying vocal deficits are unclear. While neurotoxin models have provided some insight, they typically model nigrostriatal dopamine depletion and are therefore limited. Widespread alpha-synuclein (aSyn) pathology is common to familial and sporadic PD, and transgenic mouse models based on aSyn over-expression present a unique opportunity to explore vocalization deficits in relation to extra-striatal, non-dopaminergic pathologies. Specifically, mice over-expressing human wild-type aSyn under a broad neuronal promoter (Thy1-aSyn) present early, progressive motor and non-motor deficits starting at 2–3 months, followed by parkinsonism with dopamine loss at 14 months. We recorded ultrasonic vocalizations from Thy1-aSyn mice and wild-type (WT) controls at 2–3, 6–7 and 9 months. Thy1- aSyn mice demonstrated early, progressive vocalization deficits compared to WT. Duration and intensity of calls were significantly reduced and call profile was altered in the Thy1-aSyn mice, particularly at 2–3 months. Call rate trended towards a more drastic decrease with age in the Thy1-aSyn mice compared to WT. Alpha-synuclein pathology is present in the periaqueductal gray and may underlie the manifestation of vocalization deficits. These results indicate that aSyn over-expression can induce vocalization deficits at an early age in mice and provides a new model for studying the mechanisms underlying cranial sensorimotor deficits and treatment interventions for PD

    The influence of road networks on brown bear spatial distribution and habitat suitability in a human-modified landscape

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    Roads are human infrastructure that heavily affect wildlife, often with marked impacts on carnivores, including brown bears Ursus arctos. Here, we assessed the potential impact of road networks on the distribution of brown bears in the small, isolated and endangered Cantabrian population of north-western Spain. To ascertain whether local road networks affect brown bear spatial distribution, we first assessed potential influences on the distance of bear locations to roads using candidate models which included topographic variables, landcover types, bear age and reproductive status, traffic volume and road visibility. Then, we built two sets of habitat suitability models, both with and without roads, to discern the possible loss of habitat suitability caused by roads. The mean distance of bear locations to the nearest road was 968 ± 804 m and the closest road was a low traffic road in 72.5% of cases. Candidate models showed little influence of our variables on bear distance to the nearest road, with the exception of elevation. Habitat suitability models revealed that road networks in our study area seem to have almost no effect on brown bear habitat suitability, except for females with yearlings during the denning season. However, this result may also be a consequence of the fact that only a small proportion (16.5%) of the cells classified as suitable bear habitats were crossed by roads, that is, most of the roads are primarily located in unsuitable bear habitats in the Cantabrian Mountains. Compared to previous studies conducted in other populations, mainly North American ones, our findings might suggest a different response of Eurasian brown bears to roads due to a longer bear-human coexistence in Europe versus North America. However, the indirect approach used in our study does not exclude other detrimental effects, for example, road mortality, increased stress and movement pattern disruption, only detectable by more direct approaches such as telemetry.During this research, EG-B was financially supported by a FPU grant (FPU15-03429) from the Spanish Ministry of Science, Innovation and Universities. VP, EG-B, AMG and HRV were financially supported by the I + D + I Project PID2020-114181GB-I00 financed by the Spanish Ministry of Science and Innovation, the Agencia Estatal de Investigación (AEI) and the Fondo Europeo de Desarrollo Regional (FEDER, EU). AMG was supported by the Predoctoral Fellowship PRE2018-086102. AZA was financially supported by a Margarita Salas contract financed by the European Union-NextGenerationEU, Ministerio de Universidades y Plan de Recuperación, Transformación y Resiliencia, through the call of the Universidad de Oviedo (Asturias).Peer reviewe
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