A Carleman estimate and an energy method for a first-order symmetric hyperbolic system

For a symmetric hyperbolic system of the first order, we prove a Carleman estimate under some positivity condition concerning the coefficient matrices. Next, applying the Carleman estimate, we prove an observability L2-estimate for initial values by boundary data

Inverse coefficient problems for a transport equation by local Carleman estimate

We consider the transport equation ∂tu(x,t)+(H(x) - ∇u(x,t))+p(x)u(x,t)=0 in Ω ×(0,t) where Ω ⊂ ℝn is a bounded domain, and discuss two inverse problems which consist of determining a vector-valued function p(x) or a real-valued function Ω by initial values and data on a subboundary of Ω. Our results are conditional stability of Hölder type in a subdomain D provided that the outward normal component of H(x) is positive on ∂D∩∂Ω. The proofs are based on a Carleman estimate where the weight function depends on H

Raltegravir, tenofovir, and emtricitabine in an HIV-Infected patient with HCV chronic hepatitis, NNRTI intolerance and protease inhibitors-induced severe liver toxicity

<p>Abstract</p> <p>Background</p> <p>in HIV-infected patients with HCV-related chronic hepatitis, liver impairment and drug toxicity may substantially reduce the number of possible therapeutic options.</p> <p>Case Description</p> <p>we here describe the case of an HCV-HIV coinfected woman who had repeated severe episodes of drug-related liver toxicity with indinavir, saquinavir, fosamprenavir, and darunavir, with minimal further therapeutic options left in this class. Previous treatment-limiting side effects with efavirenz and nevirapine also precluded use of non-nucleoside reverse transcriptase inhibitors. Introduction of an integrase-inhibitor regimen based on raltegravir, tenofovir, and emtricitabine allowed a prompt achievement of undetectable viral load and a substantial rise of CD4 count to high levels, with no subsequent episodes of hepatic toxicity, and no other side effects.</p> <p>Conclusions</p> <p>given the relatively common prevalence of HCV-related chronic hepatitis among people with HIV, raltegravir might represent an important alternative option for a substantial number of patients who cannot be treated with protease inhibitors or NNRTI because of drug-related hepatic toxicity.</p

Load Management with Predictions of Solar Energy Production for Cloud Data Centers

Power supply of big infrastructures is today a tremendous operational cost for providers and the expected growth of Internet traffic and services will lead to a further expansion of the computing and networking infrastructures and this, in its turn, raises also concerns in terms of sustainability. In this context, renewable energy generators can help to both reduce costs and alleviate the concerns of sustainability of big infrastructures. In this paper, we consider the case of Data Centers (DCs) composed of a few sites located in different geographical positions and powered with solar energy. Due to the intermittent nature of solar energy, different time zones and price of electricity in different locations, load management strategies are fundamental. We consider predictions of the solar energy production performed through Artificial Neural Networks and we assess the impact of predictions on load management decisions and, ultimately, on the DC performance

Geological field investigation for the assessment of the low-grade geothermal resources from volcanic terrains of the Island of Salina (Aeolian Islands, Italy)

Abstract The subsoil as a "thermal reservoir" is a modern concept that is leading to continuous developments of innovative methods of energy production. If volcanic areas have been so far considered suitable for exploitation of medium-to-high enthalpy resources, it is also true that an incredible potential confined to low grade resources is available. The geological background of Sicily makes the island as one of the most suitable contexts of southern Italy where geothermal resources could have great potential to increase their whole usage. Several active volcanic zones or areas at high hydrothermalism offer advantageous exploitation from low to high enthalpy geothermal resources. Here we present a case study from Santa Marina Salina (Aeolian Island Arc) with a detailed field survey providing information on lithostratigraphic features and on hydrogeological conditions of the area. The study is aimed at testing the thermal conductivity distribution at various depths by means of a theoretical model. Such an approach allowed the definition of the most suitable areas and their low-grade geothermal potential through different thematic maps for thermal conductivity in the shallow subsurface (0-150 m). Collected data become crucial for correct sizing of low-enthalpy geothermal installations, leading to optimization of the final planned technical solutions efficiency

Health related quality of life outcomes in HIV-Infected patients starting different combination regimens in a randomised multinational trial: the INITIO-QoL Substudy

The health-related quality of life (HRQoL) outcomes in HIV-infected, treatment-naive patients starting different HAART regimens in a 3-year, randomized, multinational trial were compared. HRQoL was measured in a subgroup of patients enrolled in the INITIO study (153/911), using a modified version of the MOS-HIV questionnaire. The regimens compared in the INITIO trial were composed by two NRTIs (didanosine + stavudine) plus either an NNRTI (efavirenz) or a PI (nelfinavir), or both (efavirenz + nelfinavir). Primary HRQoL outcomes were Physical and Mental Health Summary scores (PHS and MHS, respectively). During follow-up, an increase of PHS score was observed in all treatment arms. The MHS score remained substantially unchanged with the four-drug combination and showed with both NNRTI- and PI-based three-drug regimens a marked trend toward improvement, which became statistically significant when a multiple imputation method was used to adjust for missing data. Overall, starting all the combination regimens compared in the INITIO study was associated with a maintained or slightly improved HRQOL status, consistently with the positive immunological and virological changes observed in the main study. The observed differences in the MHS indicate a possible HRQoL benefit associated to the use of three-drug, two-class regimens and no additional benefit for the use of four-drug, three-class regimens, confirming that three-drug, two-class regimens that include two NRTIs plus either an NNRTI or a PI should be preferred as initial treatment of HIV infection

Learning about Actions and Events in Shared NeMuS

The categorization process of information from pure data or learned in unsuper- vised artificial neural networks is still manual, especially in the labeling phase. Such a process is fundamental to knowledge representation [6], especially for symbol-based systems like logic, natural language processing and textual infor- mation retrieval. Unfortunately, applying categorization theory in large volumes of data does not lead to good results mainly because there is no generic and systematic way of categorizing such data processed by artificial neural networks and joining investigated conceptual structures. Connectionist approaches are capable of extracting information from arti- ficial neural networks, but categorizing them as symbolic knowledge have been little explored. The obstacle lies on the difficulty to find logical justification from response patterns of these networks [2]. This gets worse when considering induc- tive learning from dynamic data which is very important to Cognitive Sciences that considers categorization as a mental operation of classifying objects, actions and events [1]. We shall address the discoveries of our on-going investigation on the problem of inductively learning (IL) from dynamic data by applying a novel framework for neural-symbolic representation and reasoning called share Neural Multi-Space (NeMuS) used in the Amao system[4]. Instead of woking like traditional ap- proaches for ILP, e.g. [5], Amao uses a shared NeMuS of a give background knowledge (BK) and uses inverse unification as the generalization mechanism of a set of logically connected expressions from the Herbrand Base (HB) of BK that defines positive examples

Dynamics of SARS-CoV-2 exposure in Malawian infants between February 2020 and May 2021

Background: Very limited information is available on SARS-CoV-2 seroprevalence in infants in sub-Saharan countries. Objective: In this study, we aimed to determine the rate and the temporal evolution of SARS CoV-2 seropositivity in breastfed Malawian infants. Study design: Blood samples (n = 250) from 158 infants, born to HIV-negative women and women living with HIV, collected from February 2020 to May 2021, were first tested using an Anti-IgG/A/M SARS CoV 2 ELISA assay against trimeric spike protein, and then, if positive, confirmed using a second ELISA assay detecting IgG against Receptor Binding Domain. Results: The confirmed prevalence of anti-SARS CoV-2 antibodies was 31.0% (95% CI: 23.7%-38.3%) with no significant difference between HIV-exposed and HIV-unexposed infants (29.3% and 37.1% respectively, P = 0.410). The presence of anti-SARS-CoV-2 IgG was not associated with maternal socioeconomic or demographic indices. Conclusions: Our data underline the wide spread of the SARS-CoV-2 infection in the pediatric population in sub-Saharan Africa. Design of more specific serological tests for African samples and improvements in serosurveillance programs are needed for more rigorous monitoring of the dynamics of SARS-CoV-2 infection in Africa

Lipid profile during pregnancy in HIV-infected women

Purpose: We investigated the evolution of serum lipid levels in HIV-infected pregnant women and the potential effect of antiretroviral treatment during pregnancy using data from a national surveillance study. Method: Fasting lipid measurements collected during routine care in pregnancy were used, analyzing longitudinal changes and differences in lipid values at each trimester by protease inhibitors (Pls) and stavudine use. Multivariate analyses were used to control for simultaneous factors potentially leading to hyperlipidemia. Study population included 248 women. Results: Lipid values increased progressively and significantly during pregnancy: mean increases between the first and third trimesters were 141.6 mg/dL for triglycerides (p <.001), 60.8 mg/dL for total cholesterol (p <.001), 13.7 mg/dL for HDL cholesterol (p <.001), and 17.8 mg/dL for LDL cholesterol (p =.001). At all trimesters, women on PIs had significantly higher triglyceride values compared to women not on Pis. The effect of Pls on cholesterol levels was less consistent. Stavudine showed a dyslipidemic effect at first trimester only. Multivariate analyses confirmed these observations and suggested a potential role of other cofactors in the development of hyperlipidemia during pregnancy. Conclusion: The changes observed point to the need to further explore the causes and the clinical correlates of hyperlipidemia during pregnancy in women with HIV