2,406 research outputs found
Dam breach modelling: influence on downstream water levels and a proposal of a physically based module for flood propagation software
Get PDFThe influence exerted by the method used for computing the dam breach hydrograph on the simulated maximum water levels throughout the downstream valley is essential for selecting a specific computing module to be implemented in the numerical codes used by practitioners. This module should be able to balance the need for a reasonable physical description of the phenomenon and, at the same time, limit as much as possible the maximum number of parameters. In order to feed a debate on this field, in this paper the performances of some parametric models used for the dam breach module implemented in the popular HEC-RAS software, and a simplified but physically based model have been analysed. The performances of the dam breach models have been assessed with reference to the historical event of the Big Bay dam, using both one-dimensional and two-dimensional (1-D and 2-D) flood propagation modelling. The results show that the physically based model considered here, without any operations of ad hoc calibration, has provided the best results in predicting computation of that event. Therefore, it may be proposed as a valid alternative to parametric models, which need the estimation of some parameters that can add further uncertainties in studies like these
Hepatocellular Carcinoma in a non-Cirrhotic Liver of a HCV-Positive Woman with Sustained Viral Response
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Modulation of en-route charges to redistribute traffic in the European airspace
Get PDFPeak-load pricing (PLP), a two-tariffs charging scheme commonly used in public transport and utilities, is tested on the European Air Traffic Management (ATM) system as a means for reducing capacity-demand imbalances. In particular, a centralised approach to PLP (CPLP) where a Central Planner (CP) sets en-route charges on the network is presented. CPLP consists of two phases: in the first, congested airspace sectors and their peak and off-peak hours are identified; in the second, CP assesses and sets en-route charges in order to reduce overall shift on the network. Such charges should guarantee that Air Navigation Service Providers (ANSPs) are able to recover their operational costs while inducing the Airspace Users (AUs) to route their flights in a way that respects airspace capacity. The interaction between CP and AUs is modelled as a Stackelberg game and formulated by means of bilevel linear programming. Two heuristic approaches, based on Coordinate-wise Descent and Genetic Algorithms are implemented to solve the CPLP model on a data set obtained from historical data for an entire day of traffic on European airspace. Results show that significant improvements in traffic distribution in terms of shift and sector load can be achieved through this simple en-route charges modulation scheme
Ionic liquid-templated preparation of mesoporous silica embedded with nanocrystalline sulfated zirconia
Get PDFA series of mesoporous silicas impregnated with nanocrystalline sulphated zirconia was prepared by a sol-gel process using an ionic liquid-templated route. The physicochemical properties of the mesoporous sulphated zirconia materials were studied using characterisation techniques such as inductively coupled optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray microanalysis, elemental analysis and X-ray photoelectron spectroscopy. Analysis of the new silicas indicates isomorphous substitution of silicon with zirconium and reveals the presence of extremely small (< 10 nm) polydispersed zirconia nanoparticles in the materials with zirconium loadings from 27.77 to 41.4 wt.%
Evolution of the Anisakis risk management in the European and Italian context
Get PDFDue to the social and legislative implications, the presence of Anisakis spp. larvae in fishery products has become a concern for both the consumers and the official Control Authorities. The issuance of a large number of provisions, aimed at better managing fish products intended to be consumed raw or almost raw and the associated risks, resulted in a very complicate legal framework. In this work, we analyzed the evolution of the normative through an overview on the local and international legislations, focusing on issues that are of practical interest for Food Business Operators (FBOs) in the fishery chain. In addition, we performed a survey across the Department of Prevention of the Italian Local Health Authorities (LHA) and the main fish markets in Italy to collect the operating procedures and the monitoring plans. Overall, we found many differences, due to the absence of a national reference standard for the management of the Anisakis risk. From this examination, it turns clear that only a participation of all the involved institutions, a strategy of synergistic interventions, as well as a correct training of FBOs, can result in an effective risk management and a proper risk communication, which should overcome states of confusion and unnecessary negative impacts on the economy
Circulating tumour cells in colorectal cancer
Get PDFAbstract Background The detection of circulating tumour cells (CTC) in blood sample in patients with early or advanced colorectal cancer has a potential prognostic value. Methods The challenge of CTC detection is related to the requirement of high sensitivity combined with high specificity method. CTCs detection can be distinguished between indirect and direct methods. The former ones are based on the recognition of tissue-, organ- or tumour-specific markers by immuno-histochemistry (indirect immuno-mediated methods) or (real-time) RT-PCR (indirect molecular methods), whilst the latter are related to CTCs selection based on the physical properties of density and sizes. Ongoing and future isolation by size of epithelial tumour cells (ISET) developments concerning automated image analysis on the filter and transmission of high definition images through the web for 'on line' cytopathological consultations are aimed to speed up the work of cytopathologists on CTC/ circulating tumour microemboli (CTM) detection. Conclusions CTC detection in colorectal cancer (CRC) correlates with pathological stage and clinical outcome in particular in those patients with advanced disease. CRC CTC level before and after CT are an independent prognostic factor for progression-free and overall survival. The positive prognostic value of complete clearance CTC after surgery may be useful to select patients for adjuvant chemotherapy
Evaluation of RAS mutational status through BEAMing assay to monitor disease progression of metastatic colorectal cancer: a case report
Get PDFAssessment of a Sampling Plan Based on Visual Inspection for the Detection of Anisakid Larvae in Fresh Anchovies (Engraulis encrasicolus). A First Step Towards Official Validation?
Get PDFThe presence of anisakid larvae in fish is a public
health issue, and effective risk management procedures are
needed to avoid that heavily infected products reach the market.
Currently, an official sampling plan for fresh fish defining
sample size, inspection methods, and criteria to accept or reject
the merchandise is lacking at the European and Italian
level. In this study, we compared the visual inspection proposed
by the sampling plan of the Lombardy Region (Italy) to
the UV press method and to an optimized digestion procedure
with the aim to assess its ability in detecting visible parasites.
Thirty-one batches of Engraulis encrasicolus, each composed
of ∼30 specimens, were collected and subsequently analyzed
with the three techniques. The mean abundance (MA) was
calculated after each procedure and compared on the basis of
a threshold value. The results showed that the visual inspection
performed similarly to the digestion method, with a sensitivity
of 93 %, a specificity of 100 %, and an accuracy of
97 %. Overall, the comparison showed that, in the proposed
sampling plan, the visual inspection is effective in rejecting
unmarketable anchovies and in preventing the commercialization
of unsafe products. This method is simple, less demanding
than digestion in terms of time and equipment, and thus suitable as a standardized procedure to be routinely applied by
food business operators. The hazard characterization, performed
by sequencing the mtDNA cox2 gene, has identified
the visible larvae as Anisakis pegreffii in 98 % of the cases,
highlighting the zoonotic potential of the parasites found and
the need for preventive measure
Synthesis of novel cognition enhancer with pyrazolo[5,1-c][1,2,4]benzotriazine core acting at gamma-aminobutyric acid type A (GABAA) receptor.
Get PDFMemory dysfunction associated with aging, neurodegenerative and psychiatric disorders represents an increasing medical need. Advances in research exploring the biological mechanisms underlying learning and memory have opened new potential approaches for development of memory-enhancing therapies addressed to selective neuronal targets. In this work, we synthesized some derivatives with a pyrazolo[5,1-c][1,2,4]benzotriazine core to identify ligands on GABA A receptors subtype (benzodiazepine site on GABAA- receptor) endowed with the potential of enhancing cognition activity without the side effects usually associated with non-selective GABAA modulators. In fact, there is much evidence that GABAA-R (γ-aminobutyric acid, type A receptor) subtype ligands have relevance in learning and memory. In vitro and in vivo tests have been performed. Pharmacological data indicate that compounds 7, 13, 14 and 22 act as dual functional modulators of GABA A-Rs (promnemonic and anxiolytic agents) while only compounds 3 and 10 stand out as selectively displaying good antiamnesic and procognitive activity (1 and 3 mg/kg, respectively). © 2013 Elsevier Ltd. All rights reserved
On the design of smart parking networks in the smart cities: an optimal sensor placement model
Get PDFSmart parking is a typical IoT application that can benefit from advances in
sensor, actuator and RFID technologies to provide many services to its users and parking
owners of a smart city. This paper considers a smart parking infrastructure where sensors
are laid down on the parking spots to detect car presence and RFID readers are embedded
into parking gates to identify cars and help in the billing of the smart parking. Both types
of devices are endowed with wired and wireless communication capabilities for reporting
to a gateway where the situation recognition is performed. The sensor devices are tasked
to play one of the three roles: (1) slave sensor nodes located on the parking spot to detect
car presence/absence; (2) master nodes located at one of the edges of a parking lot to detect
presence and collect the sensor readings from the slave nodes; and (3) repeater sensor nodes,
also called ''anchor'' nodes, located strategically at specific locations in the parking lot to
increase the coverage and connectivity of the wireless sensor network. While slave and
master nodes are placed based on geographic constraints, the optimal placement of the
relay/anchor sensor nodes in smart parking is an important parameter upon which the cost
and e ciency of the parking system depends. We formulate the optimal placement of sensors
in smart parking as an integer linear programming multi-objective problem optimizing the
sensor network engineering e ciency in terms of coverage and lifetime maximization, as
well as its economic gain in terms of the number of sensors deployed for a specific coverage
and lifetime. We propose an exact solution to the node placement problem using single-step
and two-step solutions implemented in the Mosel language based on the Xpress-MPsuite of
libraries. Experimental results reveal the relative e ciency of the single-step compared to
the two-step model on di erent performance parameters. These results are consolidated by
simulation results, which reveal that our solution outperforms a random placement in terms
of both energy consumption, delay and throughput achieved by a smart parking network
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