Pensions and Intertemporal Choice: Evidence from the U.S. Military

SSRN-id2383874We study a choice made by over 20,000 U.S. military personnel annually between the High-3 and Redux retirement plans. Compared to High-3, Redux offers a $30,000 current lump sum payment in exchange for lower future annuity payments. Despite break-even discount rates between 10chose Redux. The likelihood of choosing Redux is decreasing with the break-even discount rate and is related to individual demographics. The implied personal discount rates from this choice are around 9.2Offering this choice has already saved the government over$2 billion in future retirement payments

Computational modeling of low-density lipoprotein accumulation at the carotid artery bifurcation after stenting

Restenosis typically occurs in regions of low and oscillating wall shear stress, which also favor the accumulation of atherogenic macromolecules such as low-density lipoprotein (LDL). This study aims to evaluate LDL transport and accumulation at the carotid artery bifurcation following carotid artery stenting (CAS) by means of computational simulation. The computational model consists of coupled blood flow and LDL transport, with the latter being modeled as a dilute substance dissolved in the blood and transported by the flow through a convection-diffusion transport equation. The endothelial layer was assumed to be permeable to LDL, and the hydraulic conductivity of LDL was shear-dependent. Anatomically realistic geometric models of the carotid bifurcation were built based on pre- and post-stent computed tomography (CT) scans. The influence of stent design was investigated by virtually deploying two different types of stents (open- and closed-cell stents) into the same carotid bifurcation model. Predicted LDL concentrations were compared between the post-stent carotid models and the relatively normal contralateral model reconstructed from patient-specific CT images. Our results show elevated LDL concentration in the distal section of the stent in all post-stent models, where LDL concentration is 20 times higher than that in the contralateral carotid. Compared with the open-cell stents, the closed-cell stents have larger areas exposed to high LDL concentration, suggesting an increased risk of stent restenosis. This computational approach is readily applicable to multiple patient studies and, once fully validated against follow-up data, it can help elucidate the role of stent strut design in the development of in-stent restenosis after CAS

Antioxidant and anti-cholinesterase activity of Globularia meridionalis extracts and isolated constituents.

The antioxidant and anti-cholinesterase properties of Globularia meridional (Podp.) O. Schwarz (Globulariaceae) were investigated. G. meridionalis aerial parts and roots were extracted with methanol, and the total extract successively partitioned with n-hexane. The methanol fraction of the roots showed the highest antioxidant activity with IC50 values of 8.0 and 2.1 μg/mL in the DPPH and β-carotene bleaching tests, respectively. From this fraction, three flavonoids, namely pectolinarigenin 7- O-β-glucoside, apigenin 7- O-β-glucoside and luteolin, and two phenylethanoids, namely acteoside and isoacteoside, were isolated. Potential anti-cholinesterase effects were assessed through the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibition assay. The n-hexane fraction of the roots exhibited the highest activity against both AChE and BChE with IC50 values of 65.5 and 70.4 μg/mL, respectively

Studies on the potential antioxidant properties of Senecio stabianus Lacaita (Asteraceae) and its inhibitory activity against carbohydrate-hydrolysing enzymes

This study showed for the first time the antioxidant and hypoglycaemic properties of the methanol, n-hexane and ethyl acetate extracts from Senecio stabianus Lacaita, a plant that belongs to the Asteraceae family. The antioxidant activities were carried out using two different in vitro assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and 2,2\u2032-azinobis(3- ethylbenzthiazoline-6-sulphonate) (ABTS) test. The ethyl acetate extract showed the highest activity with inhibitory concentration 50% (IC 50) values of 35.5 and 32.7 \u3bcg mL -1 on DPPH test and ABTS test, respectively. This activity may be related to a good total phenol and flavonoid content. All extracts were also tested for their potential inhibitory activity of \u3b1-amylase and \u3b1-glucosidase digestive enzymes. The n-hexane extract exhibited the highest \u3b1-amylase inhibition with an IC 50 value of 0.21 mg mL -1. Through bioassay-guided fractionation processes seven fractions (A-G) were obtained and tested. Based on the phytochemical analysis, the activity of n-hexane extract may be related to the presence of monoterpenes and sesquiterpenes

Stable water isotope as foundamental tool in karst aquifer studies: some results from isotopic applications in the Apuan Alps carbonatic complexes (NW Tuscany)

The management and protection of water resources in karst environment require detailed knowledge of the aquifer system which can be obtained through a multidisciplinary approach, including not only hydrogeological/structural assessment, but also the use of tools not commonly used in hydrogeology, as the isotope ratios. In the present work some examples of isotopic applications on karst aquifers are discussed in relation to hydrogeological studies carried out in the Carrione Stream, Frigido River, and Versilia River catchments (Apuan Alps, Tuscany). In particular, during such studies the isotopic ratios 18O / 16O and 2H / 1H of the water molecule, mainly, and 13C / 12C of inorganic carbon in solution were used. The isotopic data, and their comparison with the hydrogeological and structural-geological ones, were useful: to obtain information about the hydrodynamic conditions in the aquifer; to define the recharge area of main springs; and to identify different circulation systems drained by closing springs which have similar chemistry. The obtained results confirm that in karst systems, where it is often difficult to carry out conventional hydrogeological surveys, the isotopic instruments have a fundamental role in the study of water circulation

Contamination Assessment and Temporal Evolution of Nitrates in the Shallow Aquifer of the Metauro River Plain (Adriatic Sea, Italy) after Remediation Actions

Over the last decades, groundwater resources at global level have suffered a significant deterioration due to nitrate pollution, mainly related to the input of agricultural fertilizers, manure, sewage, and untreated urban and industrial effluents. The most impacted waters are those forming surface and shallow reservoirs, which usually play a key role in supplying waters to civil, agricultural, and industrial activities. The terminal portion of the Metauro River plain, located in central Italy along the Adriatic Sea coastline, hosts a strategic phreatic aquifer that, along with the surface water of the Metauro River, supplies water to the local population (i.e., about 60,000 people). This shallow coastal aquifer experiences a long-lasting story of nitrate contamination since the 1970s when the increase in the use of agricultural fertilizers contributed to very high levels of pollution (NO3- > 100 mg/L). This fact prompted the local authorities to carry out remediation actions that involve a pumping system to inject the NO3--poor waters from the Metauro River course directly into the shallow aquifer. The present work was aimed at defining the contamination of nitrates in this important water resource. The main geochemical characteristics and the temporal evolution of NO3- concentrations (between 2009 and 2020), in the shallow coastal aquifer of the Metauro River plain, were analyzed by means of classical geochemical analyses and multivariate methods accounting for the compositional nature of the data, to assess the efficiency of the in-situ remediation over time

False-negative RT-PCR in SARS-CoV-2 disease: experience from an Italian COVID-19 unit

False-negative cases of COVID19 are being increasingly reported. Laboratory diagnosis through RT-PCR testing alone lacks adequate sensitivity to be recommended as the only valid criterion to confirm COVID-19 diagnosis

ГЕНЕТИЧЕСКОЕ РАЗНООБРАЗИЕ ШТАММОВ MYCOBACTERIUM AVIUM subsp. HOMINISSUIS, ВЫДЕЛЕННЫХ В ИТАЛИИ, НА ОСНОВЕ АНАЛИЗА ЛОКУСОВ VNTR

Abstract. Background. Mycobacterium avium subsp. hominissuis (MAH) is an important pathogen responsible for most of the human-associated nontuberculous mycobacteria infections. Over the past few decades the incidence of MAH infections is increasing in Italy, as in many countries worldwide. The present study is aimed to elucidate the genetic characteristics of MAH strains isolated from human patients using VNTR typing and to show the genetic relatedness among them. Methods. The genetic diversity of 108 human isolates of MAH was determined by VNTR analysis targeting 8 loci, coded 32, 292, X3, 25, 3, 7, 10 and 47. Results. The VNTR analysis revealed 25 distinct VNTR patterns; of these, 13 patterns were unique, while 12 patterns were shared by 2 or more isolates, thus yielding 12 clusters including a total of 95 isolates. The discriminatory power of our VNTR analysis yielded an HGDI of 0.990, indicating that VNTR typing has an excellent discriminatory power. No association of a particular VNTR pattern with a particular clinical feature, such as the disseminated, pulmonary or extrapulmonary type of infection, was observed. Minimum spanning tree analysis showed that 21 VNTR patterns, occurring either as clustered or unique isolates, differed from the nearest one for one allelic variation. Conclusions. The results obtained through the VNTR analysis showed that most MAH strains displayed a close genetic relationship. This high phylogenetic proximity of the VNTR loci over a long time period supports the concept that the MAH genotype is highly homogeneous in our geographical area, suggesting the hypothesis of the presence of possible sources of infection and transmission pathways at the local level

Pedestrian level of service: the impact of social groups on pedestrian flow characteristics

A comprehensive measure of the level of pedestrian comfort can lead to an improved design of public spaces, to the appropriate dimensioning of urban infrastructure (such as airports, stations and commercial centers), and, most importantly, to a design that is more responsive to people and to that very fundamental human activity: walking. The planning and design of the pedestrian environment is based on pedestrian Levels of Service (LOS). These levels currently classify the level of comfort based on space available for movement and speed (and delay, in case of crosswalks). Guidance is provided for different area types and times of day. Although many methods of assessing pedestrian LOS have been developed, all these do not consider spontaneous pedestrian groups. However, social groups, such as friends, couples, colleagues and families, represent an important component of urban crowds. The paper presents first, an overview of the current methods for assessing pedestrian environment LOS. Then the paper presents the application of the HCM method for the evaluation of a selected site LOS. The calculation is based on collected measurements of pedestrian flow. Some critical issues and inconsistencies result. These have been reviewed and read taking into account the presence of groups in pedestrian flows