8,133 research outputs found
The hidden world of artificial cavities in the northern Campania Plain: architectural variability and cataloging challenge
In Campania (southern Italy), sinkholes phenomena induced by the widespread presence of anthropogenic cavities in the Neapolitan and Caserta provinces are frequent and well-known. Nevertheless in many urban centers of this area, cavities have been reported in specific geological investigations although their real extent is almost unknown. In these towns the underground mining activities were performed to extract volcanic tuffs for buildings. The urban development have sealed every signal of the presence of cavities, which thus represent a geological hazard and contribute to subsoil instability of many places.
The need to carry out a survey of underground quarrings in urban centers has two reasons:
a) The anthropic hypogea represent an absolute documentary value, still unduly neglected and little used for the purposes of a correct and sustainable management of the territory, natural resources and historical and artistic heritage. The enhancement and sustainable reuse of hypogea contributes to enhancing the cultural and tourist promotion of a territory.
b) In a correct urban management, the knowledge of the city subsoil is a priority, as the presence of cavities may easily trigger the collapse of the shallow or deeper soils.
The difficulty of drawing up a univocal cataloging system lies in the definition of database framework that includes all the possible architectural, geological and geotechnical elements of the cavities. In fact, the type of extraction is not the same throughout the territory even over short distances as it was strongly conditioned by the lithological characteristics of the volcanoclastic material in the subsoil, as well as by the purpose of extraction.
The construction of a cavity system initially involved an excavation carried out as a âbottleâ or a âbellâ from the ground level up to the tuff unit, developing at depth according to its thickness. During excavation, access points were realized through the poorly lithified or loose deposits, with a square or pseudo-circular cross-section; sometimes they were supported by containment walls made of tuff bricks resting on the lower tuff bank. A single vertical excavation is sometimes added at certain distance, so as to determine in depth the coalescence of several chambers, also through the construction of narrow tunnels or wide passages, long connecting tunnels, multiple level chambers. Access shafts were often realized with a system of stairs with one or more ramps, with steps directly carved into the tuff.
This contribution will show the main cavity typologies recognized across an area north of Naples, although the study is still far from exhaustive. Data were managed into a GIS environment such as to provide a first proposal of a geological underground database framework
Evaluation of Tranche in Securitization and Long-range Ising Model
This econophysics work studies the long-range Ising model of a finite system
with spins and the exchange interaction and the external
field as a modely for homogeneous credit portfolio of assets with default
probability and default correlation . Based on the discussion
on the phase diagram, we develop a perturbative calculation method for
the model and obtain explicit expressions for and the
normalization factor in terms of the model parameters and . The
effect of the default correlation on the probabilities
for defaults and on the cumulative distribution
function are discussed. The latter means the average loss rate
of the``tranche'' (layered structure) of the securities (e.g. CDO), which are
synthesized from a pool of many assets. We show that the expected loss rate of
the subordinated tranche decreases with and that of the senior
tranche increases linearly, which are important in their pricing and ratings.Comment: 21 pages, 9 figure
Metastatic melanoma: An unusual presentation
In this report we describe a case of a malignant cutaneous melanoma metastasizing to the pleural surface and peritoneal cavity 5 years after surgical resection of the primary lesion. Malignant cutaneous melanoma is a very aggressive cancer able to metastasize anywhere in the body. Pleural secondary lesions represent a rare event described only in a small number of patients and the association with peritoneal localizations may suggest an uncommon pattern of spread that we discuss. Free full text available at www.tumorionline.it
Complete response to capecitabine in a frail, elderly patient with metastatic colorectal cancer: A case report
The clinical management of frail, elderly patients affected by colorectal cancer (CRC) remains a subject of debate. The present study reports the case of an elderly man with metastatic CRC (mCRC) who was successfully treated with capecitabine. The patient survived for 29 months, thus highlighting its potential activity in terms of obtaining a complete response and high efficacy. A 77-year-old man presented with adenocarcinoma of the rectum with multiple and synchronous liver metastases, in addition to several comorbidities. The patient received singleâagent capecitabine chemotherapy (825 mg/mq twice a day) on days 1-14 of a 21-day cycle. Following 12 cycles of well-tolerated therapy, a computed tomography scan revealed a complete response with no evidence of liver metastases. An overall survival of 29 months was documented, and the patient eventually succumbed to a diabetes-related complication. In compromised patients with mCRC, reduced-dose capecitabine is an excellent therapeutic option due to its positive safety profile, activity and efficacy
Correlation between ion composition of oligomineral water and calcium oxalate crystal formation
The ion content of drinking water might be associated with urinary stone formation, representing a keystone of conservative nephrolithiasis management. However, the effects of specific ions on calcium oxalate crystal formation and their mechanism of action are still highly controversial. We report an investigation of the effects of oligomineral waters with similar total salt amount but different ion composition on calcium oxalate (CaOx) precipitation in vitro, combining gravimetric and microscopic assays. The results suggest that the âcollectiveâ physicochemical properties of the aqueous medium, deriving from the ion combination rather than from a single ionic species, are of importance. Particularly, the ability of ions to strengthen/weaken the aqueous medium structure determines an increase/decrease in the interfacial energy, modulating the formation and growth of CaOx crystals
Moody's Correlated Binomial Default Distributions for Inhomogeneous Portfolios
This paper generalizes Moody's correlated binomial default distribution for
homogeneous (exchangeable) credit portfolio, which is introduced by Witt, to
the case of inhomogeneous portfolios. As inhomogeneous portfolios, we consider
two cases. In the first case, we treat a portfolio whose assets have uniform
default correlation and non-uniform default probabilities. We obtain the
default probability distribution and study the effect of the inhomogeneity on
it. The second case corresponds to a portfolio with inhomogeneous default
correlation. Assets are categorized in several different sectors and the
inter-sector and intra-sector correlations are not the same. We construct the
joint default probabilities and obtain the default probability distribution. We
show that as the number of assets in each sector decreases, inter-sector
correlation becomes more important than intra-sector correlation. We study the
maximum values of the inter-sector default correlation. Our generalization
method can be applied to any correlated binomial default distribution model
which has explicit relations to the conditional default probabilities or
conditional default correlations, e.g. Credit Risk, implied default
distributions. We also compare some popular CDO pricing models from the
viewpoint of the range of the implied tranche correlation.Comment: 29 pages, 17 figures and 1 tabl
Gas Analysis and Monitoring Systems for the RPC Detector of CMS at LHC
The Resistive Plate Chambers (RPC) detector of the CMS experiment at the LHC
proton collider (CERN, Switzerland) will employ an online gas analysis and
monitoring system of the freon-based gas mixture used. We give an overview of
the CMS RPC gas system, describe the project parameters and first results on
gas-chromatograph analysis. Finally, we report on preliminary results for a set
of monitor RPC.Comment: 9 pages, 8 figures. Presented by Stefano Bianco (Laboratori Nazionali
di Frascati dell'INFN) at the IEEE NSS, San Diego (USA), October 200
NAB-paclitaxel and gemcitabine in metastatic pancreatic ductal adenocarcinoma (PDAC): From clinical trials to clinical practice
Background: Pancreatic adenocarcinoma is an aggressive disease with poor prognosis. In a randomized phase III trial, combination of Nab-paclitaxel (Nab-P) plus gemcitabine showed superior activity and efficacy in first-line treatment compared with gemcitabine alone. Methods: Nab-P is not dispensed in Italy; however, we obtained this drug from our Ethics Committee for compassionate use. The aim of this study was to evaluate the efficacy and safety profile of this Nab-P and gemcitabine combination in a cohort of patients treated outside clinical trials. From January 2012 to May 2014, we included 41 patients with advanced pancreatic adenocarcinoma receiving combination of 125 mg/m2 Nab-P and 1 g/m2 gemcitabine on days 1, 8 and 15 of a 28-day cycle, as first-line treatment. Median age of patients was 67 (range 41-77) years, and 11 patients were aged â„70 years. Results: Eastern Co-operative Oncology Group performance status was 0 or 1 in 32 patients (78 %) and 2 in nine patients (22 %). Primary tumor was located in the pancreatic head or body/tail in 24 (58.5 %) and 17 (41.5 %) patients, respectively, and nine patients had received biliary stent implantation before starting chemotherapy. Median carbohydrate antigen 19-9 level was 469 U/l (range 17.4-61546 U/l) and 29 patients (70.7 %) had referred pain at the time of diagnosis. Patients received a median six cycles (range 1-14) of treatment. Overall response rate was 36.6 %; median progression-free survival was 6.7 months [(95 % confidence interval (CI) 5.966-8.034), and median overall survival was 10 months (95 % CI 7.864-12.136). Treatment was well tolerated. No grade 4 toxicity was reported. Grade 3 toxicity included neutropenia in 10 patients (24.3 %), thrombocytopenia in five (12 %), anemia in three (7.3 %), diarrhea in four (9.7 %), nausea and vomiting in two (4.9 %), and fatigue in six (14.6 %). Finally, pain control was achieved in 24 of 29 patients (82.3 %) with a performance status improvement of 10 % according to the Karnofsky scale. Conclusions: Our results confirm that combination of gemcitabine plus Nab-P is effective both in terms of overall response rate, progression-free survival and overall survival, with a good safety profile
High rate, fast timing Glass RPC for the high {\eta} CMS muon detectors
The HL-LHC phase is designed to increase by an order of magnitude the amount
of data to be collected by the LHC experiments. To achieve this goal in a
reasonable time scale the instantaneous luminosity would also increase by an
order of magnitude up to . The region of the forward
muon spectrometer () is not equipped with RPC stations. The
increase of the expected particles rate up to (including a
safety factor 3) motivates the installation of RPC chambers to guarantee
redundancy with the CSC chambers already present. The actual RPC technology of
CMS cannot sustain the expected background level. The new technology that will
be chosen should have a high rate capability and provides a good spatial and
timing resolution. A new generation of Glass-RPC (GRPC) using low-resistivity
(LR) glass is proposed to equip at least the two most far away of the four high
muon stations of CMS. First the design of small size prototypes and
studies of their performance in high-rate particles flux is presented. Then the
proposed designs for large size chambers and their fast-timing electronic
readout are examined and preliminary results are provided.Comment: 14 pages, 11 figures, Conference proceeding for the 2016 Resistive
Plate Chambers and Related Detector
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