355 research outputs found

    A multi-disciplinary approach combining geological, geomorphological and geophysical data for mapping the susceptibility to sinkholes

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    The Salento region of southern Italy has a great number of active sinkholes, related to both natural and anthropogenic cavities. The presence of sinkholes is at the origin of several problems to the built-up environment, due to the increasing population growth and development pressures. In such a context, the detection of cavities, and therefore the assessment of the sinkhole hazard presents numerous difficulties. Multidisciplinary – approach, comprising geological, geomorphological and geophysical analyses, is therefore necessary to obtain comprehensive knowledge of the complex phenomena in karstic areas. Geophysical methods can also be of great help to identify and map the areas at higher risk of collapse. In this case it is important to identify the features related to the underground voids, likely evolving to sinkholes, by contrasts in physical properties such as density, electrical resistivity, and so on, with the surrounding sediments. At the same time, identification of the presence of sinkholes by geophysical methods has to adapt to the different geological conditions, so that there is not the possibility to use the same techniques everywhere. At this aim, the present paper illustrates the advantages of integrating geological and geomorphological surveys with surface geophysical techniques such as seismic, geoelectrical and ground penetrating radar methods for the identification of sinkhole-prone areas. The present work illustrates the results concerning a sinkhole system at Nociglia (inland Salento, southeastern Italy) where the shallow phreatic speleogenesis operates close to the water table level with formation of karst conduits and proto-caves whose evolution occurs through successive roof collapse, formation of wide caverns and sinkhole development at the surface. All of this creates serious problems to the nearby infrastructures, including a province road that has often been threatened by the sinkhole development. Geological and geomorphological analyses provided the basic data necessary to constitute a framework to understand the mechanism of sinkholes formation and at the same time to guide the choice of the most suitable geophysical techniques, and the interpretation of the measurements as well. The different geophysical methods are eventually discussed in order to point out their ability to locate the main karst conduits and caves

    A new revolutionary practice: operaisti and the 'refusal of work' in 1970's Italy

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    The social protest that engulfed Italy in the 1970s found a theoretical analysis in the work of the operaisti. Through a series of concepts, they outlined a new revolutionary practice that aimed to return to a more authentic reading of Marxism. This article focuses on the notion of ‘refusal of work’ and the ancillary concept of ‘appropriation’ and examines how these theoretical tools emerged out of radical protest in factories and were put forward by the operaisti as a central plank of a revolutionary strategy for the working clas

    Prime osservazioni su specie perenni ed annue autoriseminanti in vista della organizzazione di catene di foraggiamento in ambienti mediterranei

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    Nel corso del periodo 1987-89 sono state valutate le potenzialità produttive e la distribuzione della produzione di 32 tra ecotipi e varietà di graminacee e leguminose foraggere annue e perenni provenienti prevalentemente dall'Italia centrale. La prova è stata condotta contemporaneamente in tre ambienti appartenenti a diverse zone bioclimatiche dell'area mediterranea (Perugia, Grosseto e Sassari) utilizzando uno schema sperimentale a blocchi randomizzati con quattro ripetizioni. I rilievi effettuati hanno riguardato il ricopri mento specifico e la produzione di sostanza secca determinata con criteri differenti: mensilmente per le leguminose annue; al 50% della fioritura e quindi mensilmente per le leguminose perenni; all'inizio della spigatura e quindi mensilmente per le graminacee. Per le specie annuali oltre alla sostanza secca è stata determinata la produzione di seme. L'obiettivo è stato quello di caratterizzare materiali che possano essere impiegati scalarmente per dilatare il periodo di utilizzazione diretta al pascolo. Dai risultati è stato possibile individuare, a seconda delle località, alcune popolazione di Medicago polymorpha L., Trifolium subterraneum L. e Lotus sp. pl. che hanno permesso di anticipare il periodo di utilizzazione primaverile e prolungare quello autunnale. Su questa base sono stati ipotizzati esempi di catene di foraggiamento semplificate (a tre anelli). Per quanto concerne le specie annue autoriseminanti, esse sembrano poter svolgere un importante ruolo nella regolazione della distribuzione stagionale della produzione foraggera nelle due località caratterizzate da un clima più tipicamente mediterraneo (Grosseto e Sassari) mentre la produzione di seme è risultata più che soddisfacente per assicurare l'autorisemina in tutte e tre le località. During the period 1987-1989, the yield and the distribution of forage production of 32 ecotypes and varieties of annual and perennial forage Iegumes and grasses were evaluated. The origin of plant materials was CentraI Italy. The trial was carried out in three environments characterized by different Mediterranean subclimates (Perugia, Grosseto and Sassari). The experimental design was a randomized complete block with four replicates. Specific ground cover was assessed in fall 1987, 1988 and 1989. Dry matter yield was assessed: monthly for annual legumes; at 50% of flowering and then monthly for perennial legumes; at early heading and then monthly for grasses. Seed yield of annual species was also recorded. Aim of the trial was to characterize plant materials that could be utilized subsequently in order to extend the period of direct utilization of herbage by grazing animals. It was possible depending on localities, to identify some populations of Medicago polymorpha L., Trifolium subterraneum L. and Lotus sp. pl.. that allowed to bring forward the spring utilization and to extend the autumn utilization. On the basis of the resu1ts obtained, it was possible to set up some simplified forage chains. Annual self reseeding species seemed to be more important to improve seasonal distribution of herbages in the typical Mediterranean locations (Sassari and Grosseto). Seed production was more than appreciable in order to allow self reseeding at the three locations

    Strategies of product innovation and diferentiation do lead to higher wages: An empirical investigation in the Brazilian industry

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    Presented at the GLOBELICS 6th International Conference 2008 22-24 September, Mexico City, Mexico

    Bone-forming perivascular cells: Cellular heterogeneity and use for tissue repair

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    : Mesenchymal progenitor cells are broadly distributed across perivascular niches-an observation conserved between species. One common histologic zone with a high frequency of mesenchymal progenitor cells within mammalian tissues is the tunica adventitia, the outer layer of blood vessel walls populated by cells with a fibroblastic morphology. The diversity and functions of (re)generative cells present in this outermost perivascular niche are under intense investigation; we have reviewed herein our current knowledge of adventitial cell potential with a somewhat narrow focus on bone formation. Antigens of interest to functionally segregate adventicytes are discussed, including CD10, CD107a, aldehyde dehydrogenase isoforms, and CD140a, among others. Purified adventicytes (such as CD10+ , CD107alow , and CD140a+ cells) have stronger osteogenic potential and promote bone formation in vivo. Recent bone tissue engineering applications of adventitial cells are also presented. A better understanding of perivascular progenitor cell subsets may represent a beneficial advance for future efforts in tissue repair and bioengineering

    Assessing safety culture in NICU: psychometric properties of the Italian version of Safety Attitude Questionnaire and result implications

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    Neonatal intensive care units (NICUs) are a high-risk setting. The Safety Attitude Questionnaire (SAQ) is a widely used tool to measure safety culture. The aims of the study are to verify the psychometric properties of the Italian version of SAQ, to evaluate safety culture in the NICUs and to identify improvement interventions

    X-ray irradiated cultures of mouse cortical neural stem/progenitor cells recover cell viability and proliferation with dose-dependent kinetics

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    Exposure of the developing or adult brain to ionizing radiation (IR) can cause cognitive impairment and/ or brain cancer, by targeting neural stem/progenitor cells (NSPCs). IR effects on NSPCs include transient cell cycle arrest, permanent cell cycle exit/differentiation, or cell death, depending on the experimental conditions. In vivo studies suggest that brain age influences NSPC response to IR, but whether this is due to intrinsic NSPC changes or to niche environment modifications remains unclear. Here, we describe the dose-dependent, time-dependent effects of X-ray IR in NSPC cultures derived from the mouse foetal cerebral cortex. We show that, although cortical NSPCs are resistant to low/moderate IR doses, high level IR exposure causes cell death, accumulation of DNA double-strand breaks, activation of p53- related molecular pathways and cell cycle alterations. Irradiated NSPC cultures transiently upregulate differentiation markers, but recover control levels of proliferation, viability and gene expression in the second week post-irradiation. These results are consistent with previously described in vivo effects of IR in the developing mouse cortex, and distinct from those observed in adult NSPC niches or in vitro adult NSPC cultures, suggesting that intrinsic differences in NSPCs of different origins might determine, at least in part, their response to IR

    Detection and Classification of Human Body Odor Using an Electronic Nose

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    An electronic nose (E-nose) has been designed and equipped with software that can detect and classify human armpit body odor. An array of metal oxide sensors was used for detecting volatile organic compounds. The measurement circuit employs a voltage divider resistor to measure the sensitivity of each sensor. This E-nose was controlled by in-house developed software through a portable USB data acquisition card with a principle component analysis (PCA) algorithm implemented for pattern recognition and classification. Because gas sensor sensitivity in the detection of armpit odor samples is affected by humidity, we propose a new method and algorithms combining hardware/software for the correction of the humidity noise. After the humidity correction, the E-nose showed the capability of detecting human body odor and distinguishing the body odors from two persons in a relative manner. The E-nose is still able to recognize people, even after application of deodorant. In conclusion, this is the first report of the application of an E-nose for armpit odor recognition

    Produzione di seme di leguminose foraggere annuali in tre ambienti italiani

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    The seed production of 18 natural populations and varieties of annual forage legumes mainly collected in CentraI Italy have been evaluated in three Italian sites with contrasting climate and soil types. AlI species belonged to the genus Medicago and Trifolium. The experiments were carried out in Perugia, Grosseto and Sassari that belong to different bioclimatic zones of the Mediterranean area. The folIowing measurements were taken: seedlings establishment, monthly covering rate, seed yield and its components, percentage of hard seeds. The medics seed yields were not uniform between years particular1y in Perugia where the highest average yield was reached (800 kg ha-1) while the lowest one was recorded in Sassari (300 kg ha-1). A subclover seed yield of about 1600 kg ha-1 was recorded in Perugia in the first year. The persian clover was the highest yielding among the clovers with small seed size (1000-1600 kg ha-1). The seed yield components showed that the seed yield and the number of legumes per square meter were not always correlated. Seed hardiness increased going from humid to semiarid environments. The results show a good potential for annual legume seed yield in the Mediterranean environment. This is important either for the persistency by self reseeding of species to be included permanently in pasturelands and also for the seed production at a commercial level. Moreover, results point out that by exploring Italian genetic resources it is possible to find interesting genotypes to be inc1uded in a wide range of agricultural environments. In tre ambienti italiani con caratteristiche pedo-climatiche differenti sono state valutate le potenzialità produttive di seme di 18 popolazioni e varietà di leguminose foraggere annuali, appartenenti ai generi Medicago e Trifolium, provenienti in prevalenza dal Centro-Italia. La prova è stata condotta-contemporaneamente in tre località corrispondenti ad altrettante zone bioclimatiche dell'area mediterranea (Perugia, Grosseto e Sassari). I rilievi effettuati hanno riguardato l'insediamento, il ricoprimento specifico mensile, la produzione di seme e le sue componenti e la percentuale di semi duri. Le produzioni di seme delle mediche sono risultate oscillanti negli anni, avendo raggiunto al primo e al terzo anno valori più elevati che al secondo, in particolar modo a Perugia dove sono state ottenute le produzioni medie più elevate (800 kg ha-1) mentre le più basse sono state registrate a Sassari (300 kg ha-1). La produzione di seme di trifoglio sotterraneo ha raggiunto valori considerevoli a Perugia al primo anno (circa 1600 kg ha-1). Per quanto riguarda i trifogli a seme minuto, il trifoglio persiano ha manifestato un elevato potenziale produttivo al primo anno nei tre ambienti di prova (1000-1600 kg ha-1). Riguardo le componenti della produzione i risultati ottenuti hanno mostrato che non sempre esiste uno stretto legame fra produzione di seme e numero di infruttescenze per unità di superficie. La durezza dei semi è risultata via via crescente dall'ambiente umido a quello semi-arido e mediamente inferiore nel trifoglio sotterraneo rispetto alle mediche ed ai trifogli a seme minuto. I risultati ottenuti hanno evidenziato in generale buone potenzialità per la produzione di seme di leguminose annuali in ambiente mediterraneo. Questo aspetto riveste un'importanza duplice: per la persistenza per autorisemina di specie da inserire permanentemente nella flora dei pascoli, e per la produzione di seme su scala commerciale. Inoltre, i risultati indicano che dall'esplorazione delle risorse genetiche italiane è possibile individuare genotipi particolarmente interessanti per l'inserimento in un'ampia gamma di realtà agricole e ambientali
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