Study of perturbed periodic systems of differential equations - The Stroboscopic method

Stroboscopic method for solving perturbed periodic systems of differential equation

Elevated cerebral spinal fluid biomarkers in children with mucopolysaccharidosis I-H.

Mucopolysaccharidosis (MPS) type-IH is a lysosomal storage disease that results from mutations in the IDUA gene causing the accumulation of glycosaminoglycans (GAGs). Historically, children with the severe phenotype, MPS-IH (Hurler syndrome) develop progressive neurodegeneration with death in the first decade due to cardio-pulmonary complications. New data suggest that inflammation may play a role in MPS pathophysiology. To date there is almost no information on the pathophysiologic changes within the cerebral spinal fluid (CSF) of these patients. We evaluated the CSF of 25 consecutive patients with MPS-IH. While CSF glucose and total protein were within the normal range, we found a significantly mean elevated CSF opening pressure at 24 cm H2O (range 14-37 cm H2O). We observed a 3-fold elevation in CSF heparan sulfate and a 3-8 fold increase in MPS-IH specific non-reducing ends, I0S0 and I0S6. Cytokine analyses in CSF of children with MPS-IH showed significantly elevated inflammatory markers including: MCP-1 SDF-1a, IL-Ra, MIP-1b, IL-8, and VEGF in comparison to unaffected children. This is the largest report of CSF characteristics in children with MPS-IH. Identification of key biomarkers may provide further insight into the inflammatory-mediated mechanisms related to MPS diseases and perhaps lead to improved targeted therapies

Anti-motility and reductions in the concentrations of gut electrolytes: Mechanisms for the anti-spasmodic use of the seeds of avocado (Persea americana Mill) in folk medicine

The seeds of avocado (Persea americana Mill) are used in traditional medicine to treat, allay or prevent some spasm-related disorders, for instance, diarrhoea. The chloroform and methanol fractions of the chloroform-methanol extract of the seeds of P. americana were investigated for their qualitative and quantitative phytochemical constituents as well as effects on gastro-intestinal motility (transit) and castor oil-induced intestinal fluid sodium ion (Na+) and potassium ion (K+) concentrations in Wistar rats. The qualitative and quantitative phytochemical studies of the chloroform and methanol fractions showed the presence and amounts of alkaloids (2.92 ± 0.14 g/100 g and 2.81 ± 0.08 g/100 g respectively), flavonoids (3.43 ± 0.19 g/100 g and 3.11 ± 0.16 g/100 g, respectively), tannins (2.64 ± 0.13 g/100 g and 2.85 ± 0.14 g/100 g, respectively), steroids (1.51 ± 0.07 g/100 g and 1.27 ± 0.04 g/100 g, respectively), saponins (2.35 ± 0.08 % and 2.47 ± 0.09%, respectively), terpenoids, proteins and carbohydrates in both fractions. Fats and oil were present only in the chloroform fraction. At the two doses (100 and 200 mg/kg body weight), the chloroform and methanol fractions produced significant (p<0.05) and dose-related decreases in the gastro-intestinal motility and concentration of the intestinal fluid potassium ions but only the chloroform fraction at the dose of 200 mg/kg body weight significantly (p<0.05) decreased the concentration of the intestinal fluid sodium ions. Results of the fractions were comparable with those of the standard anti-diarrhoeal drug, hyoscine butylbromide (3 mg/kg body weight). The results indicate that the chloroform-methanol extract of the seeds of P. americana contains compounds with anti-spasmodic effect.Keywords: Persea americana, spasm-related, castor oil, gastro-intestinal motility and electrolytesAfrican Journal of Biotechnology Vol. 12(37), pp. 5610-561

Quantum Computing and Hidden Variables I: Mapping Unitary to Stochastic Matrices

This paper initiates the study of hidden variables from the discrete, abstract perspective of quantum computing. For us, a hidden-variable theory is simply a way to convert a unitary matrix that maps one quantum state to another, into a stochastic matrix that maps the initial probability distribution to the final one in some fixed basis. We list seven axioms that we might want such a theory to satisfy, and then investigate which of the axioms can be satisfied simultaneously. Toward this end, we construct a new hidden-variable theory that is both robust to small perturbations and indifferent to the identity operation, by exploiting an unexpected connection between unitary matrices and network flows. We also analyze previous hidden-variable theories of Dieks and Schrodinger in terms of our axioms. In a companion paper, we will show that actually sampling the history of a hidden variable under reasonable axioms is at least as hard as solving the Graph Isomorphism problem; and indeed is probably intractable even for quantum computers.Comment: 19 pages, 1 figure. Together with a companion paper to appear, subsumes the earlier paper "Quantum Computing and Dynamical Quantum Models" (quant-ph/0205059

A New Swiss Federal Act on Gambling: From Missed Opportunities towards a Public Health Approach?

In January 2019, a new Swiss Federal Act on Gambling (Loi federal de jeux d'argent: LJAr) entered into force following a vote by the Swiss electorate. Intended to modernize and harmonize previous law and open the market for online casinos; the new regulations have highlighted the need for a comprehensive monitoring system. The present article outlines work undertaken by experts within the field to identify and elaborate the first steps towards developing such a monitoring system. This work includes the mapping of institutional actors and draft conceptualization of an impact model, including structural (i.e., prevention and intervention-based components), process (means), and outcomes (effect) indicators. Initial estimations of effective access to indicators and their perceived priority for data gathering are also described. Subsequent steps necessary for implementation of this public health approach for gambling are considered including grey areas for future action

Fasting plasma glucose and risk factor assessment: Comparing sensitivity and specificity in identifying gestational diabetes in urban black African women

Background. Identifying women with gestational diabetes mellitus (GDM) allows interventions to improve perinatal outcomes. A fasting plasma glucose (FPG) level ≥5.1 mmol/L is 100% specific for a diagnosis of GDM. The International Association of Diabetes and Pregnancy Study Groups acknowledges that FPG <4.5 mmol/L is associated with a low probability of GDM.Objectives. The validity of selective screening based on the presence of risk factors was compared with the universal application of FPG ≥4.5 mmol/L to identify women with GDM. FPG ≥4.5 mmol/L or the presence of one or more risk factors was assumed to indicate an intermediate to high risk of GDM and therefore the need for an oral glucose tolerance test (OGTT).Methods. Consecutive black South African (SA) women were recruited to a 2-hour 75 g OGTT at 24 - 28 weeks’ gestation in an urban community health clinic. Of 969 women recruited, 666 underwent an OGTT, and of these 589 were eligible for analysis. The glucose oxidase laboratory method was used to measure plasma glucose concentrations. The World Health Organization GDM diagnostic criteria were applied. All participants underwent a risk factor assessment. The χ2 test was used to determine associations between risk factors and a positive diagnosis of GDM. The sensitivity and specificity of a positive diagnosis of GDM were calculated for FPG ≥4.5 mmol/L, FPG ≥5.1 mmol/L, and the presence of one or more risk factors.Results. The prevalence of overt diabetes mellitus and GDM was 0.5% and 7.0%, respectively. Risk factor-based selective screening indicated that 204/589 (34.6%) of participants needed an OGTT, but 18/41 (43.9%) of positive GDM diagnoses were missed. Universal screening using the FPG threshold of ≥4.5 mmol/L indicated that 152/589 (25.8%) of participants needed an OGTT, and 1/41 (2.4%) of positive diagnoses were missed. An FPG of ≥5.1 mmol/L identified 36/41 (87.8%) of GDM-positive participants. The sensitivity and specificity of the presence of one or more risk factors were 56% and 67%, respectively. The sensitivity and specificity of FPG ≥4.5 mmol/L were 98% and 80%, respectively.Conclusions. Universal screening using FPG ≥4.5 mmol/L had greater sensitivity and specificity in identifying GDM-affected women and required fewer women to undergo a resource-intensive diagnostic OGTT than risk factor-based selective screening. A universal screening strategy using FPG ≥4.5 mmol/L may be more efficient and cost-effective than risk factor-based selective screening for GDM in black SA women.