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In this paper we discuss the development of a parallel software for the numerical simulation of Participating Life Insurance Policies in distributed environments. The main computational kernels in the mathematical models for the solution of the problem are multidimensional integrals and stochastic differential equations. The former is solved by means of Monte Carlo method combined with the Antithetic Variates variance reduction technique, while differential equations are approximated via a fully implicit, positivity-preserving, Euler method. The parallelization strategy we adopted relies on the parallelization of Monte Carlo algorithm. We implemented and tested the software on a PC Linux cluster. [ABSTRACT FROM AUTHOR]

We present a parallel algorithm for distributed memory multiprocessors, which is based on generalized marching (GM), one of the fastest methods in the class of fast Poisson solvers. The GM algorithm is not suited for any but very coarse-grain parallel processing. The main difficulty with parallelization is that the number of independent processes and the amount of work in each process change exponentially and in inverse proportion of each other. To improve parallelism, the matrices involved in GM are diagonalized performing multiple FFTs. In this way, independent processes extending across all the algorithm are obtained. The parallel GM has been tested on an Ncube/10 and a Symuit S2010, running the Express communication system. A performance evaluation has been carried out using a scaled efficiency model and some classical parameters. [ABSTRACT FROM AUTHOR]

Echolocation enables people with impaired or no vision to comprehend the surrounding spatial information through the reflected sound. However, this technique often requires substantial training, and the accuracy of echolocation is subject to various conditions. Furthermore, the individuals who practice this sensing method must simultaneously generate the sound and process the received audio information. This paper proposes and evaluates a proof-of-concept light detection and ranging (LIDAR) assist spatial sensing (LASS) system, which intends to overcome these restrictions by obtaining the spatial information of the user's surroundings through a LIDAR sensor and translating the spatial information into the stereo sound of various pitches. The stereo sound of relative pitch represents the information regarding objects' angular orientation and horizontal distance, respectively, thus granting visually impaired users an enhanced spatial perception of his or her surrounding areas and potential obstacles. This paper is divided into two phases: Phase I is to engineer the hardware and software of the LASS system and Phase II focuses on the system efficacy study. The study, approved by the Penn State Institutional Review Board, included 18 student volunteers, who were recruited through the Penn State Department of Psychology Subject Pool. This paper demonstrates that the blindfolded individuals equipped with the LASS system are able to quantitatively identify the surrounding obstacles, differentiate their relative distance, and distinguish the angular location of multiple objects with minimal training.

The internal carotid artery agenesis is a rare malformation disorder. We report the case of a 12-year-old boy suffering migraine, who had presented an episode featuring amaurosis fugax, spontaneously regressed. CT angiography images show hypoplasia of the left common carotid artery with loss of opacification of the left internal carotid artery consistent to agenesis. Moreover CT scans through the skull base demonstrate absence of left petrous carotid canal and an hypertrophic left middle cerebral artery originating from an aberrant artery arising from the right cavernous carotid. All diagnostic examinations confirmed the presence of the internal carotid artery agenesis, as Lie's type IV. We started an annual follow up that over the next 7 years did not reveal any change in magnetic resonance angiography images.

Osteopontin is a proinflammatory molecule, modulating TH1 and TH17 responses. Several reports suggest its involvement in multiple sclerosis (MS) pathogenesis. We previously reported that OPN gene variations at the 3' end are a predisposing factor for MS development and evolution. In this paper, we extended our analysis to a gene variation at the 5' end on the -156G > GG single nucleotide polymorphism (SNP) and replicated our previous findings at the 3' end on the +1239A > C SNP. We found that only +1239A > C SNP displayed a statistically significant association with MS development, but both +1239A > C and -156G > GG had an influence on MS progression, since patients homozygous for both +1239A and -156GG alleles displayed slower progression of disability and slower switch to secondary progression than those carrying +1239C and/or -156G and those homozygous for +1239A only. Moreover, patients homozygous for +1239A also displayed a significantly lower relapse rate than those carrying +1239C, which is in line with the established role of OPN in MS relapses.

Study Objectives: To verify the existence of a symptomatic form of restless legs syndrome (RLS) secondary to multiple sclerosis (MS) and to identify possible associated risk factors., Design: Prospective, multicenter, case-control epidemiologic survey., Settings: Twenty sleep centers certified by the Italian Association of Sleep Medicine., Patients: Eight hundred and sixty-one patients affected by MS and 649 control subjects., Interventions: N/A., Measures and Results: Data regarding demographic and clinical factors, presence and severity of RLS, the results of hematologic tests, and visual analysis of cerebrospinal magnetic resonance imaging studies were collected. The prevalence of RLS was 19% in MS and 4.2% in control subjects, with a risk to be affected by RLS of 5.4 (95%confidence interval: 3.56-8.26) times greater for patients with MS than for control subjects. In patients with MS, the following risk factors for RLS were significant: older age; longer MS duration; the primary progressive MS form; higher global, pyramidal, and sensory disability; and the presence of leg jerks before sleep onset. Patients with MS and RLS more often had sleep complaints and a higher intake of hypnotic medications than patients with MS without RLS. RLS associated with MS was more severe than that of control subjects., Conclusions: RLS is significantly associated with MS, especially in patients with severe pyramidal and sensory disability. These results strengthen the idea that the inflammatory damage correlated with MS may induce a secondary form of RLS. As it does in idiopathic cases, RLS has a significant impact on sleep quality in patients with MS; therefore, it should be always searched for, particularly in the presence of insomnia unresponsive to treatment with common hypnotic drugs.

Human ICOS is a T cell costimulatory molecule supporting IL10 secretion. A pilot study investigating variations of the ICOS gene 3'UTR detected 8 polymorphisms forming three haplotypes (A, B, C). Haplotype-A and -C displayed the highest difference. Activated T cells from healthy AA homozygotes expressed significantly less ICOS and secreted more IL10 than AC heterozygotes, whereas AB heterozygotes displayed intermediate levels. Analysis of 441 multiple sclerosis patients and 793 controls showed that frequency of AA homozygosity was significantly lower in MS patients with relapsing-remitting onset (N=416) than in controls (OR=0.70). Moreover, AA patients with relapsing-remitting onset had lower relapse rate and multiple sclerosis severity score than non-AA patients.

Vigabatrin is considered the drug of choice for infantile spasms and simple and complex partial epilepsy in childhood. Its mechanism of action relies on the irreversible inhibition of gamma-aminobutyric acid (GABA) transaminase. Since June 1997 several articles have been published reporting visual field constriction in adult patients on vigabatrin therapy. Recently, 7 pediatric patients, 1 on vigabatrin monotherapy and 6 on add-on therapy with visual field constriction have been described. We have observed 30 pediatric patients with epilepsy (14 boys and 16 girls), ages ranging from 4 to 20 years (mean: 11 years and 2 months) treated with vigabatrin for infantile spasms, simple and complex partial epilepsy, who had never complained of ophthalmologic disturbances. Twenty-one patients underwent complete routine ophthalmologic examination (fundus oculi, visual acuity, intraocular pressure, and visual field tests); 9 children (<6 years old) underwent only fundus examination, because collaboration was lacking. We report on 4 children showing constriction of visual field, prevailing in nasal hemifield. In 1 child, visual abnormalities were stable even 10 months after vigabatrin discontinuation, while in another a greater improvement was observed 5 months after discontinuation. The possible mechanisms have been discussed and the cone dysfunction, connected with GABA augmentation in the outer retina, has been outlined. We suggest a possible protocol to control visual abnormalities in epileptic children.

Background and Objective: Anecdotal reports in patients with acute and chronic iron overload have recently indicated that the efficacy and safety of an alternative chelation program including intravenous and/or continuous delivery of deferoxamine (DFO) may be in contrast with the risk of developing lung injury. Production of oxygen radicals has been postulated to be an important mechanism by which polymorphonuclear leukocytes (PMNs) could cause tissue injury in patients undergoing this alternative treatment method., Methods: PMNs obtained from healthy donors were incubated at 37 degrees C for 30 min with DFO (across the drug concentration 0.125 to 10 mg/mL). Superoxide (O2) production was measured by superoxide inhibitable cytochrome c reduction as well as by an NBT densitometric kinetic test. In the same run the effect of lipid peroxidation was demonstrated by means of a malonyl-dialdehyde (MDA) assay., Results: Preincubation of PMNs with any study concentration of DFO significantly enhanced O2 release as well as MDA production upon PMA stimulation. Maximal intracellular and extracellular O2-release as well as MDA production occurred at certain drug concentrations., Interpretation and Conclusions: Our in vitro findings suggest that O2-release may be an additional detrimental contribution to tissue injury in some patients who develop pulmonary toxic effects while on intravenous and/or continuous DFO administration.

Background: Human recombinant granulocyte colony-stimulating factor (rhG-CSF), widely used to combat chemotherapy-induced neutropenia, stimulates both in vivo and in vitro intra- and extra-cellular O2- production in human polymorphonuclear cells (PMNs)., Patients and Methods: Twelve patients with solid tumors or acute lymphoblastic leukemia were treated during induced aplasia with rhG-CSF (5 micrograms/kg/day). Intra- and extracellular O2- production by PMNs isolated from these patients after 5 days of rhG-CSF therapy was assessed following both fMLP and PMA stimulation., Results: All patients showed a rise in PMN count; administration of rhG-CSF enhanced intra- and extracellular O2- release after fMLP but not after PMA stimulation., Conclusions: rhG-CSF potentiates in vivo O2- production by PMNs stimulated with receptor-mediated agonists via G-protein (e.g. fMLP), but not by those stimulated with agonists that bypass receptors via protein kinase C (e.g. PMA).