36,975 research outputs found
Evolution and characterization of the quarry waste in relation to slope stability: preliminary evaluation in the Carrara marble basin (Italy)
No full textThe Carrara marble quarries (Apuan Alps, north-western Tuscany) are among the most famous in the world and nowadays are also a tourist resource. In time, the intense quarrying formed wide and thick dumps of waste block and pebble material (locally named ravaneti), representing a typical landscape of the Apuan area. Nowadays, a great amount of quarry dumps lies on steep slopes and invades many valley bottoms, where usually there is only underground water flow, without any superficial flow. During rainstorms, the water level may quickly rise to a significant runoff. This often causes floods, landslides and debris flows, as recently occurred on September 23, 2003. In such a context, this research aimed at determining the triggering conditions of the instability phenomena involving quarry waste. In particular, three quarry dumps were selected in the Torano basin (upstream of Carrara). At first, the spatial and morphological evolution of the dumps was studied, trying to understand also the different grain size of the material accumulated in time; then, a detailed geomorphologic analysis was performed, individuating several areas with different characteristics (quarry activity, instability phenomena, debris flow prone areas, land use, etc). Finally, many grain size analyses were carried out in the three quarry dumps. The wide heterogeneity of the grain size needed two methodologies: the coarse fraction (blocks and pebbles) was analysed by means of image analysis, while the finer material (gravel, sand, silt and clay) was analysed in laboratory. The research is clearly in progress, nevertheless represents a first important step to individuate the triggering factors of debris flow phenomena in quarry dumps. In fact, the hazard estimation of the quarry areas is extremely important: for protecting quarrymen and quarrying activity, for the safety of the densely populated areas downstream and for protecting and appreciating the tourist appeal
Quarry waste and slope instability: preliminary assessment of some controlling factors in the Carrara marble basin (Italy)
No full textThe intense quarrying activities in the Carrara marble district (Apuan Alps, Italy) has led to the formation of widespread and thick quarry waste accumulations, which lie on steep slopes and invade many valley bottoms. In this area, rainstorms often cause floods, landslides, debris flows and deaths (e.g. on September 23, 2003). This research is aimed at determining the triggering conditions of the instability involving quarry waste. Firstly, the 23 September 2003 event was analysed in order to characterize its pluviometric features and effects. Then, three quarry dumps were selected upstream of Carrara and their evolution was studied. Subsequently, geomorphologic surveying distinguished areas with different characteristics (quarry activity, landslide areas, debris flow prone areas, land use, etc.). Furthermore, several grain size analyses were performed. Finally, in order to evaluate the hydrological behaviour of the quarry waste, the discharge of a spring at the toe of a quarry dump was examined and compared with the trend of a rainfall event. The research is still in progress, but these results may represent a first important step to identifying the main triggering factors of debris flows in quarry dumps
Frataxin deficiency increases cyclooxygenase 2 and prostaglandins in cell and animal models of Friedreich's ataxia
No full text© The Author 2014. Published by Oxford University Press
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.An inherited deficiency of the mitochondrial protein frataxin causes Friedreich's ataxia (FRDA); the mechanism by which this deficiency triggers neuro- and cardio-degeneration is unclear. Microarrays of neural tissue of animal models of the disease showed decreases in antioxidant genes, and increases in inflammatory genes. Cyclooxygenase (COX)-derived oxylipins are important mediators of inflammation. We measured oxylipin levels using tandem mass spectrometry and ELISAs in multiple cell and animal models of FRDA. Mass spectrometry revealed increases in concentrations of prostaglandins, thromboxane B2, 15-HETE and 11-HETE in cerebellar samples of knockin knockout mice. One possible explanation for the elevated oxylipins is that frataxin deficiency results in increased COX activity. While constitutive COX1 was unchanged, inducible COX2 expression was elevated over 1.35-fold (P < 0.05) in two Friedreich's mouse models and Friedreich's lymphocytes. Consistent with higher COX2 expression, its activity was also increased by 58% over controls. COX2 expression is driven by multiple transcription factors, including activator protein 1 and cAMP response element-binding protein, both of which were elevated over 1.52-fold in cerebella. Taken together, the results support the hypothesis that reduced expression of frataxin leads to elevation of COX2-mediated oxylipin synthesis stimulated by increases in transcription factors that respond to increased reactive oxygen species. These findings support a neuroinflammatory mechanism in FRDA, which has both pathomechanistic and therapeutic implications.The study was supported by NIH grants NS077777, EY012245 and AG025532 to G.A.C., and USDA-ARS Intramural Projects 5306-51530-019-00D and 1 U24 DK097154-01 to J.W.N. Funding to pay the Open Access publication charges for this article was provided by the NIH
Approccio multidisciplinare per la valutazione della pericolosità di frana: indagini geologico-tecniche, idrogeologiche, geochimiche e isotopiche per la determinazione degli apporti idrici sotterranei nella frana di Cassana in Val di Magra (Massa-Carrara, Italia)
No full textCassana is placed in the Magra River Valley (Tuscany, Italy). A large and slow complex landslide involves the ancient village and causes severe damage and high risk. Many investigations were performed, aiming at gathering data and information and developing methodologies, in order to realize countermeasures and mitigate the risk. Geological and geomorphological investigations, subsurface exploration (core drillings, seismic refraction survey), geotechnical analysis, deformation and piezometer monitoring were carried out. Moreover, chemical and isotopic analyses on the underground waters were performed, aiming at identifying their intake areas and underground ways in the landslide bodies close to the village. The geochemical and isotopic investigations gave a meaningful contribution in reconstructing a geometric, kinematic and hydrogeological model of the Cassana landslide. This allowed the elaboration of a hypothetical outline of the underground water circulation and the individuation of some intake areas and preferential ways of the underground waters, greatly influencing the landslide and village instability. In conclusion, the geochemical and isotopic approach to the slope instability represents a possible and innovatory application of the chemical-isotopic technique in investigating the landslide causes
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Prime values of and , quadratic
No full textWe prove an asymptotic formula for primes of the shape with integers and of the shape with prime. Here is a binary quadratic form with integer coefficients, irreducible over and has no local obstructions. This refines the seminal work of Friedlander and Iwaniec on primes of the form and Heath-Brown and Li on primes of the form , as well as earlier work of the author with Lam and Schindler on primes of the form with a positive definite form.45 page
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Pelvic floor dyssynergia and psychiatric disorders. Does the snake bite its tail?
No full textAIM: Psychological and/or psychiatric disorders (PSY) and functional gastrointestinal disorders (FGID) are often linked. Pelvic floor dyssynergia (PFD) is one of the most frequent FGID, but few studies have investigated its possible relationship with PSY. The aim of the present study was to evaluate whether an increased prevalence of PSY, and of what types, exist in patients affected with PFD. METHODS: Thirty-four female patients PFD and 34 age- and gender-matched control subjects were evaluated. The prevalence rates of axis I psychiatric disorders (DSM IV) and of pathological temperaments (Schneider-Akiskal criteria) were determined. RESULTS: PSY were detected in 29 patients (85.3%) and in 11 controls (32.3%), (p=0.000). A family load was present in 7 patients (20.6%) and in 2 controls (5.9%), (NS). Sixteen patients (47.0%) and no control subjects were diagnosed as having axis I psychiatric disorders (p=0.000); anxiety disorders were the most frequently represented condition. A pat..
K. F. C. Rose, The Date and Author of the Satyricon. With an Introduction by J. P. Sullivan
No full textVerdière Raoul. K. F. C. Rose, The Date and Author of the Satyricon. With an Introduction by J. P. Sullivan. In: L'antiquité classique, Tome 42, fasc. 1, 1973. pp. 279-280
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
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