4,072 research outputs found
Advances in survival analysis: applications and extensions of the "standard" competing risks model
Political Institutions and the Dynamics of Investment
We present a theoretical model of the provision of a durable public good over an infinite horizon. In each period, there is a societal endowment of which each of n districts owns a share. This endowment can either be invested in the public good or consumed. We characterize the planner's optimal solution and time path of investment and consumption. We then consider alternative political mechanisms for deciding on the time path, and analyze the Markov perfect equilibrium of these mechanisms. One class of these mechanisms involves a legislature where representatives of each district bargain with each other to decide how to divide the current period's societal endowment between investment in the public good and transfers to each district. The second class of mechanisms involves the districts making independent decisions for how to divide their own share of the endowment between consumption and investment. We conduct an experiment to assess the performance of these mechanisms, and compare the observed allocations to the Markov perfect equilibrium
Relationship between mild to moderate renal dysfunction and obstructive sleep apnea: Data from the European sleep apnea database
The relationship between severity of obstructive sleep apnea (OSA) and kidney function was investigated in the European Sleep Apnea Database (ESADA), where clinical, sleep, and biochemical data of patients studied for suspected OSA in 24 sleep centres of 17 European countries are stored. After excluding patients with missing data or extremely high/low creatinine values, data from 8112 subjects (2328 female) with creatinine values ranging between 0.5 and 2.0 mg% were analyzed. Estimated glomerular filtration rate (eGFR) was obtained with the Modified Diet in Renal Disease (MDRD) equation. Patients were subdivided into two groups: group 1 (n = 3709) studied by full polysomnography; group 2 (n = 4403) studied by nocturnal cardiorespiratory monitoring. Altogether, 8.5% subjects had an eGFR<60 ml/min/1.73m2. At univariate analysis, eGFR correlated to age, comorbidities and severity of OSA in both groups. At logistic regression analysis, risk factors for eGFR<60 were in group 1: diabetes, female gender, age, body mass index, and lowest nocturnal SaO2 (r2=0.086); in group 2: hypertension, female gender, age, and lowest nocturnal SaO2 (r2=0.087). In conclusion, as expected, comorbidities, female gender and advanced age are significant risk factors for low eGFR in subjects with OSA. While traditional severity measures of OSA (apnea/hypopnea index, oxygen desaturation index) did not contribute to low eGFR, more severe nocturnal hypoxia captured by lowest nocturnal SaO2 appeared as a significant predictor in this large patient cohort. The ESADA study is supported by ResMed and Philips Respironics
Earthquake‐induced landslide scenarios for seismic microzonation. Application to the Accumoli area (Rieti, Italy)
Scenarios of earthquake-induced landslides are necessary for seismic microzonation (SM) studies since they must be integrated with the mapping of instability areas. The PARSIFAL (Probabilistic Approach to pRovide Scenarios of earthquake‐Induced slope FAiLures) approach provides extensive analyses, over tens to thousands of square kilometers, and is designed as a fully comprehensive methodology to output expected scenarios which depend on seismic input and saturation conditions. This allows to attribute a rating, in terms of severity level, to the landslide-prone slope areas in view of future engineering studies and designs. PARSIFAL takes into account first-time rock- and earth-slides as well as re-activations of existing landslides performing slope stability analyses of different failure mechanisms. The results consist of mapping earthquake-induced landslide scenarios in terms of exceedance probability of critical threshold values of co-seismic displacements (P[D≥Dc|a(t),ay]). PARSIFAL was applied in the framework of level 3 SM studies over the municipality area of Accumoli (Rieti, Italy), strongly struck by the 2016 seismic sequence of Central Apennines. The use of the PARSIFAL was tested for the first time to screen the Susceptibility Zones (ZSFR) from the Attention Zones (ZAFR) in the category of the unstable areas, according to the guidelines by Italian Civil Protection. The results obtained were in a GIS-based mapping representing the possibility for a landslide to be induced by an earthquake (with a return period of 475 years) in three different saturation scenarios (i.e. dry, average, full). Only 41% of the landslide-prone areas in the Municipality of Accumoli are existing events, while the remaining 59% is characterized by first-time earth- or rock-slides. In dry conditions, unstable conditions or P[D≥Dc|a(t),ay]>0 were for 54% of existing landslides, 17% of first-time rock-slides and 1% of first-time earth- slides. In full saturation conditions, the findings are much more severe since unstable conditions or P[D≥Dc|a(t),ay]>0 were found for 58% of the existing landslides and for more than 80% of first-time rock- and earth-slides. Moreover, comparison of the total area of the ZAFR versus ZSFR, resulted in PARSIFAL screening reducing of 22% of the mapped ZAFR
Asthma in the elderly: A different disease?
Asthma is a chronic airway disease that affects all ages, but does this definition also include the elderly? Traditionally, asthma has been considered a disease of younger age, but epidemiological studies and clinical experience support the concept that asthma is as prevalent in older age as it is in the young. With the ever-increasing elderly population worldwide, the detection and proper management of the disease in old age may have a great impact from the public health perspective. Whether asthma in the elderly maintains the same characteristics as in young populations is an interesting matter. The diagnostic process in older individuals with suspected asthma follows the same steps, namely a detailed history supported by clinical examination and laboratory investigations; however, it should be recognised that elderly patients may partially lose reversibility of airway obstruction. The correct interpretation of spirometric curves in the elderly should take into account the physiological changes in the respiratory system. Several factors contribute to delaying the diagnosis of asthma in the elderly, including the age-related impairment in perception of breathlessness. The management of asthma in advanced age is complicated by the comorbidities and polypharmacotherapy, which advocate for a comprehensive approach with a multidimensional assessment. It should be emphasised that older age frequently represents an exclusion criterion for eligibility in clinical trials, and current asthma medications have rarely been tested in elderly asthmatics. Ageing is associated with pharmacokinetic changes of the medications. As a consequence, absorption, distribution, metabolism and excretion of antiasthmatic medications can be variably affected. Similarly, drug-to-drug interactions may reduce the effectiveness of inhaled medications and increase the risk of side-effects. For this reason, we propose the term “geriatric asthma” be preferred to the more generic “asthma in the elderly”
Increase in IL-6 levels among major depressive disorder patients after a 6-week treatment with duloxetine 60 mg/day: a preliminary observation
Immune modifications, including changes in interleukin (IL)-6 levels, have often been observed in major depressive disorder (MDD) during treatment with selective serotonin reuptake inhibitors (SSRIs) or the serotonin norepinephrine reuptake inhibitor (SNRI) venlafaxine. Nevertheless, no equivalent observation for the SNRI duloxetine has been made to date
Integrated energy planning to meet 2050 European targets:A Southern Italian region case study
Anti-inflammatory effects of pre-seasonal Th1-adjuvant vaccine to Parietaria judaica in asthmatics
4D printing for modular construction components – Applications and main developments
Since the end of the 20th century, a rapid expansion has characterised digital fabrication techniques in different areas of human activity. In particular, in the construction sector, their use has enabled the production of unprecedented modular components that can be customised according to specific application requirements. This includes the use of additive manufacturing techniques employing 4D printing for the production of responsive modular elements. However, despite being able to contribute to mitigating the effects of climate change, they are still scarcely used. This essay intends to analyse the main peculiarities of 4D printing techniques for the production of modular elements for architecture, highlighting their main limitations and potentialities that influence their use.
Article info
Received: 18/09/2023; Revised: 15/10/2023; Accepted: 29/10/202
Computational Modeling of Magnesium Hydroxide Precipitation and Kinetics Parameters Identification
Magnesium is a critical raw material and its recovery as Mg(OH)2 from saltwork brines can be realized via precipitation. The effective design, optimization, and scale-up of such a process require the development of a computational model accounting for the effect of fluid dynamics, homogeneous and heterogeneous nucleation, molecular growth, and aggregation. The unknown kinetics parameters are inferred and validated in this work by using experimental data produced with a T2mm-mixer and a T3mm-mixer, guaranteeing fast and efficient mixing. The flow field in the T-mixers is fully characterized by using the k-ε turbulence model implemented in the computational fluid dynamics (CFD) code OpenFOAM. The model is based on a simplified plug flow reactor model, instructed by detailed CFD simulations. It incorporates Bromley's activity coefficient correction and a micro-mixing model for the calculation of the supersaturation ratio. The population balance equation is solved by exploiting the quadrature method of moments, and mass balances are used for updating the reactive ions concentrations, accounting for the precipitated solid. To avoid unphysical results, global constrained optimization is used for kinetics parameters identification, exploiting experimentally measured particle size distribution (PSD). The inferred kinetics set is validated by comparing PSDs at different operative conditions both in the T2mm-mixer and the T3mm-mixer. The developed computational model, including the kinetics parameters estimated for the first time in this work, will be used for the design of a prototype for the industrial precipitation of Mg(OH)2 from saltwork brines in an industrial environment
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