2,933 research outputs found
Joint Optimal Pricing and Electrical Efficiency Enforcement for Rational Agents in Micro Grids
In electrical distribution grids, the constantly increasing number of power
generation devices based on renewables demands a transition from a centralized
to a distributed generation paradigm. In fact, power injection from Distributed
Energy Resources (DERs) can be selectively controlled to achieve other
objectives beyond supporting loads, such as the minimization of the power
losses along the distribution lines and the subsequent increase of the grid
hosting capacity. However, these technical achievements are only possible if
alongside electrical optimization schemes, a suitable market model is set up to
promote cooperation from the end users. In contrast with the existing
literature, where energy trading and electrical optimization of the grid are
often treated separately or the trading strategy is tailored to a specific
electrical optimization objective, in this work we consider their joint
optimization. Specifically, we present a multi-objective optimization problem
accounting for energy trading, where: 1) DERs try to maximize their profit,
resulting from selling their surplus energy, 2) the loads try to minimize their
expense, and 3) the main power supplier aims at maximizing the electrical grid
efficiency through a suitable discount policy. This optimization problem is
proved to be non convex, and an equivalent convex formulation is derived.
Centralized solutions are discussed first, and are subsequently distributed.
Numerical results to demonstrate the effectiveness of the so obtained optimal
policies are then presented
Host factors and early treatments to restrict paediatric HIV infection and early disease progression
open6noA body of evidence indicates that a threshold level of the virus is required to establish systemic and persistent HIV infection in the host and that this level depends on virus-host interactions. Mother-to-child transmission (MTCT) of HIV is the main source of paediatric HIV infection and occurs when the host's immune system is still developing. Thus, innate resistance and immunity, rather than adaptive immune response, may be the main drivers in restricting the establishment of HIV reservoirs and the long-lived persistence of HIV infection in infants. Genetic variations in HIV co-receptors and their ligands, as well as in Toll-like receptors and defensins, key elements of innate immunity, have been demonstrated to influence the risk of perinatal HIV infection and disease progression in HIV-infected infants. Early treatments with combined antiretroviral therapy (cART) restrict paediatric infection by reducing the level of the transmitted/infecting virus to below the threshold required for the onset of immune response to the virus and also significantly reduce HIV reservoirs. However, despite long periods with no signs and symptoms of HIV infection, all early cART-treated children who later discontinued cART had a rebound of HIV, except for one case in whom a period of viral remission occurred. Which parameters predict viral remission or viral rebound after cART discontinuation? Could early cART prevent rather than just reduce the establishment of viral reservoirs? And, if so, how? Answers to these questions are also important in order to optimise the use of early cART in infants at high risk of HIV infection.openGianesin, Ketty; Petrara, Raffaella; Freguja, Riccardo; Zanchetta, Marisa; Giaquinto, Carlo; DE ROSSI, AnitaGianesin, Ketty; Petrara, Raffaella; Freguja, Riccardo; Zanchetta, Marisa; Giaquinto, Carlo; DE ROSSI, Anit
Circadian pathway genetic variation and cancer risk: Evidence from genome-wide association studies
Background: Dysfunction of the circadian clock and single polymorphisms of some circadian genes have been linked to cancer susceptibility, although data are scarce and findings inconsistent. We aimed to investigate the association between circadian pathway genetic variation and risk of developing common cancers based on the findings of genome-wide association studies (GWASs).
Methods: Single nucleotide polymorphisms (SNPs) of 17 circadian genes reported by three GWAS meta-analyses dedicated to breast (Discovery, Biology, and Risk of Inherited Variants in Breast Cancer (DRIVE) Consortium; cases, n = 15,748; controls, n = 18,084), prostate (Elucidating Loci Involved in Prostate Cancer Susceptibility (ELLIPSE) Consortium; cases, n = 14,160; controls, n = 12,724) and lung carcinoma (Transdisciplinary Research In Cancer of the Lung (TRICL) Consortium; cases, n = 12,160; controls, n = 16,838) in patients of European ancestry were utilized to perform pathway analysis by means of the adaptive rank truncated product (ARTP) method. Data were also available for the following subgroups: estrogen receptor negative breast cancer, aggressive prostate cancer, squamous lung carcinoma and lung adenocarcinoma.
Results: We found a highly significant statistical association between circadian pathway genetic variation and the risk of breast (pathway P value = 1.9 x 10(-6); top gene RORA, gene P value = 0.0003), prostate (pathway P value= 4.1x10(-6); top gene ARNTL, gene P value = 0.0002) and lung cancer (pathway P value = 6.9 x 10(-7); top gene RORA, gene P value= 2.0 x 10(-6)), as well as all their subgroups. Out of 17 genes investigated, 15 were found to be significantly associated with the risk of cancer: four genes were shared by all three malignancies (ARNTL, CLOCK, RORA and RORB), two by breast and lung cancer (CRY1 and CRY2) and three by prostate and lung cancer (NPAS2, NR1D1 and PER3), whereas four genes were specific for lung cancer (ARNTL2, CSNK1E, NR1D2 and PER2) and two for breast cancer (PER1, RORC).
Conclusions: Our findings, based on the largest series ever utilized for ARTP-based gene and pathway analysis, support the hypothesis that circadian pathway genetic variation is involved in cancer predisposition
Associations of clock genes polymorphisms with soft tissue sarcoma susceptibility and prognosis
BACKGROUND:
Dysfunction of the circadian clock and polymorphisms of some circadian genes have been linked to cancer development and progression. We investigated the relationship between circadian genes germline variation and susceptibility or prognosis of patients with soft tissue sarcoma.
PATIENTS AND METHODS:
We considered the 14 single nucleotide polymorphisms (SNPs) of 6 core circadian genes that have a minor allele frequency >\u20095% and that are known to be associated with cancer risk or prognosis. Genotyping was performed by q-PCR. Peripheral blood and clinic-pathological data were available for 162 patients with liposarcoma or leiomyosarcoma and 610 healthy donors. Associations between the selected clock genes polymorphisms and sarcoma susceptibility or prognosis were tested assuming 3 models of inheritance: additive, recessive and dominant. Subgroup analysis based on sarcoma histotype was performed under the additive genetic model. Multivariate logistic regression and multivariate Cox proportional hazard regression analyses were utilized to assess the association between SNPs with patient susceptibility and survival, respectively. Pathway variation analysis was conducted employing the Adaptive Rank Truncated Product method.
RESULTS:
Six out of the 14 analyzed SNPs were statistically significantly associated with susceptibility or prognosis of soft tissue sarcoma (P <\u20090.05). The present analysis suggested that carriers of the minor allele of the CLOCK polymorphism rs1801260 (C) or of PER2 rs934945 (T) had a reduced predisposition to sarcoma (26% and 35% respectively with the additive model) and liposarcoma (33% and 41% respectively). The minor allele (A) of NPAS2 rs895520 was associated with an increased predisposition to sarcoma of 33% and leiomyosarcoma of 44%. RORA rs339972 C allele was associated with a decreased predisposition to develop sarcoma assuming an additive model (29%) and leiomyosarcoma (36%). PER1 rs3027178 was associated with a reduced predisposition only in liposarcoma subgroup (32%). rs7602358 located upstream PER2 was significantly associated with liposarcoma survival (HR: 1.98; 95% CI 1.02-3.85; P\u2009=\u20090.04). Germline genetic variation in the circadian pathway was associated with the risk of developing soft tissue sarcoma (P\u2009=\u20090.035).
CONCLUSIONS:
Genetic variation of circadian genes appears to play a role in the determinism of patient susceptibility and prognosis. These findings prompt further studies to fully dissect the molecular mechanisms
Planning and management of actions on transportation system to address extraordinary events in post-emergency situations. A multidisciplinary approach
The main aim of the work is the design and implementation of an integrated procedure for the identification of optimum action plans (satisfying expenditure constraints) on a road transportation system to minimize the impact produced on it by extraordinary events, in particular earthquakes. The attention is focused particularly on post-emergency situations related to effects on transportation networks caused by extraordinary events; the effects are considered with reference to bridges. Addressing the transition from physical effects to functional effects (relating to mobility) on the single infrastructure element calls for a commitment which has appeared challenging in view of the strongly innovative content involved. The analysis process consists in different steps. At the first step an effort must be made in order to acquire knowledge about the characteristics of the set of infrastructures (bridges) and about a set of possible seismic scenarios. By using fragility curves of bridges, the damage state of the network links (in which bridges are included) can be obtained. By making a series of hypotheses on how a bridge damage state can influence links’ functionality, a set of “damaged” (lower capacity) road network models has been carried out. At the next step of the process, interaction between transportation supply and demand, by way of static or dynamic traffic assignment models, allows to measure the performance of the system, or rather, its overall response to extraordinary events using suitable performance indexes. Then, the network risk curve (probability of the seismic action vs. transportation system performance indexes) is derived. At the end of the process a cost-effective retrofit strategy has been identified. The procedure has been applied to a test network at regional scale in the north-east of Italy
Basal cell carcinoma: 10-year experience with electrochemotherapy
BACKGROUND: Electrochemotherapy (ECT), by combining manageable cytotoxic agents with short electric pulses, represents an effective palliative skin-directed therapy. The accumulated evidence indicates that ECT stands out as a safe and well-tolerated alternative treatment for patients with multiple or large basal cell carcinoma (BCC), who are not suitable for conventional treatments. However, long-term data and shared indications are lacking.
METHODS: In this observational study, we retrospectively analyzed 84 prospectively collected patients with multiple, recurrent or locally advanced BCC who were not candidate for standard therapies and received bleomycin-based ECT according to the European Standard Operative Procedures of ECT, from 2006 to 2016.
RESULTS: Disease extent was local, locally advanced and metastatic in 40 (48%), 41 (49%) and 3 (3%), respectively. Forty-four (52%) individuals had multiple BCCs. Grade 3 skin toxicity after ECT was observed in 6% of cases. Clearance rate was 50% (95% CI 39-61%). Primary presentation (p = 0.004), tumor size <3 cm (p < 0.001), well-defined borders (p = 0.021), absence of tumor ulceration (p = 0.001), non-aggressive BCC histology (p = 0.046) and age 6469 years were associated with higher complete response rate. In patients with local BCC, the clearance rate was 72.5 and 85% after one or two ECT cycles, respectively. In the laBCC group, 32 patients (78%) achieved an objective response. Five-year recurrence rate for local and laBCC was 20 and 38%, respectively (p 64 0.001).
CONCLUSIONS: One or two ECT cycles with bleomycin may be a valuable palliative treatment in well-selected patients with multiple BCCs and favorable tumor features. Validation of predictive factors will be imperative to match patients with optimal ECT treatment modalities. Management of laBCC with ECT warrants further investigation. Trial registration ISRCTN14633165 Registered 24 March 2017 (retrospectively registered)
GNSS-based dam monitoring: The application of a statistical approach for time series analysis to a case study
Dams are one of the most important engineering works of the current human society, and it is crucial to monitor and obtain analytical data to log their conditions, predict their behavior and, eventually, receive early warnings for planning interventions and maintenance activities. In this context, GNSS-based point displacement monitoring is nowadays a consolidated technique that is able to provide daily millimeter level accuracy, even with less sophisticated and less expensive single-frequency equipment. If properly designed, daily records of such monitoring systems produce time series that, when long enough, allow for an accurate reconstruction of the geometrical deformation of the structure, thus guiding semi-automatic early warning systems. This paper focuses on the procedure for the GNSS time series processing with a statistical approach. In particular, real-world times series collected from a dam monitoring test case are processed as an example of data filtering. A remove–restore technique based on a collocation approach is applied here. Basically, it consists of an initial deterministic modeling by polynomials and periodical components through least squares adjustment and Fourier transform, respectively, followed by a stochastic modeling based on empirical covariance estimation and a collocation approach. Filtered time series are interpreted by autoregressive models based on environmental factors such as air or water temperature and reservoir water level. Spatial analysis is finally performed by computing correlations between displacements of the monitored points, as well as by visualizing the overall structure deformation in time. Results positively validate the proposed data processing workflow, providing useful hints for the implementation of automatic early warning systems in the framework of structural monitoring based on continuous displacement measurements
Stochastic Multi-Objective Evacuation Model Under Managed and Unmanaged policies
Abstract Natural and man-created disasters, such as hurricanes, earthquakes, tsunamis, accidents and terrorist attacks, require evacuation and assistance routes. Evacuation routes are mostly based on the capacities of the road network. However, in extreme cases, such as earthquakes, road network infrastructure may adversely be affected, and may not supply their required capacities. If for various situations, the potential damage for critical roads can be identified in advance, it is possible to develop an evacuation model, that can be used in various situations. This paper focuses on the development of a model for the design of an optimal evacuation network which simultaneously minimizes retrofit costs of critical links (bridges, tunnels, etc.) and evacuation time. The model considers infrastructures' vulnerability (as a stochastic function which is dependent on the event location and magnitude), road network, transportation demand and evacuation areas. Furthermore, the model evaluates the benefits of managed evacuation (system optimum) when compared to unmanaged evacuation (user equilibrium). The paper presents a mathematic model for the presented problem. However, since an optimal solution cannot be found within a reasonable timeframe, a heuristic model is presented as well. This heuristic model is based on evolutionary algorithms, which also provides a mechanism for solving the problem as a multi-objective stochastic problem. Using a real-world data, the algorithm is evaluated and compared to the unmanaged evacuation conditions. The results clearly demonstrate the advantages of managed evacuation, as the average travel time can be reduced by 5% to 30%
Análisis multi-temporal de los cambios de uso de la tierra de las zonas urbanas y periurbanas en ciudades medievales del centro de Italia
Debido a la urbanización irresponsable ocurrida en las últimas décadas, algunas ciudades de origen medieval han visto perder su identidad arquitectónica y social. Con el fin de poner de relieve estas modificaciones, se estudiaron los cambios de uso del suelo en las zonas urbanas y periurbanas de 2 pequeñas ciudades medievales del centro de Italia (provincia de Viterbo, región de Lazio), a través de la realización de una investigación multi-temporal de la restitución fotogramétrica de los vuelos históricos (1934-2010). Los resultados mostraron que en el interior de las murallas de la ciudad un número variable de espacios verdes intersticiales y pequeños patios siguen existiendo en el año 2010 y en las áreas suburbanas perviven actividades agrícolas residuales, principalmente el cultivo de frutas y verduras, probablemente para el mercado local y/o el consumo doméstico. La planificación urbana debería tener en cuenta estos elementos, a fin de mejorar los vínculos funcionales entre las áreas urbanas y agrícolas, como las compensaciones pertinentes para mantener la agricultura urbana y de una economía de subsistencia. El mantenimiento de estos hábitats importantes puede ayudar a preservar las peculiaridades históricas de las ciudades medievales y mejorar la calidad de vida de los habitantes de las ciudades.Due to the reckless urbanization occurred in recent years, some towns of medieval origin risk to loose their architectural and social identity. In order to highlight the modifications occurred in the last 80 years, we studied the land use changes in the urban and peri-urban zones of two small medieval towns of central Italy (Viterbo province, Lazio region), performing a multi-temporal investigation by means of the photogrammetric restitution of historical flights (1934-2010). Results showed that inside the city walls a variable number of green spaces and small backyards remain in 2010 and in the suburban areas residual agricultural activities, mainly the cultivation of fruit and vegetables, probably for local market and/or home consumption. Urban planning should take into account these elements, in order to enhance the functional links among urban and agricultural areas, as relevant trade-offs for maintaining urban gardening and for a subsistence economy. The maintenance of these important habitats can help to preserve the historical peculiarities of medieval towns and to improve the quality of life of urban residents
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