Effect Of Position Of An Outlier On The Influence Curve Of The Measures Of Preferred Direction For Circular Data

Circular or angular data occur in many fields of applied statistics. A common problem of interest in circular data is estimating a preferred direction and its corresponding distribution. It is complicated by the wrap-around effect on the circle, which exists because there is no natural minimum or maximum. The usual statistics employed for linear data are inappropriate for directional data, as they do not account for its circular nature. The robustness of the three common choices for summarizing the preferred direction (the sample circular mean, sample circular median and a circular analog of the Hodges-Lehmann estimator) are evaluated via their influence functions

A More Efficient Way Of Obtaining A Unique Median Estimate For Circular Data

The procedure for computing the sample circular median occasionally leads to a non-unique estimate of the population circular median, since there can sometimes be two or more diameters that divide data equally and have the same circular mean deviation. A modification in the computation of the sample median is suggested, which not only eliminates this non-uniqueness problem, but is computationally easier and faster to work with than the existing alternative

Homogenization of nonlinear stochastic partial differential equations in a general ergodic environment

In this paper, we show that the concept of sigma-convergence associated to stochastic processes can tackle the homogenization of stochastic partial differential equations. In this regard, the homogenization problem for a stochastic nonlinear partial differential equation is studied. Using some deep compactness results such as the Prokhorov and Skorokhod theorems, we prove that the sequence of solutions of this problem converges in probability towards the solution of an equation of the same type. To proceed with, we use a suitable version of sigma-convergence method, the sigma-convergence for stochastic processes, which takes into account both the deterministic and random behaviours of the solutions of the problem. We apply the homogenization result to some concrete physical situations such as the periodicity, the almost periodicity, the weak almost periodicity, and others.Comment: To appear in: Stochastic Analysis and Application

Determination of the efficacy of ultrasound combined with essential oils on the decontamination of Salmonella inoculated lettuce leaves

Salmonella is one of main pathogenic bacteria present in fresh produce. Ultrasound has been reported to be effective at inactivating food-borne pathogens. Moreover, ultrasound can be combined with essential oils to enhance its efficacy. This study evaluates the reduction and inactivation of Salmonella enterica Abony inoculated on lettuce leaves by the application of continuous and pulsed ultrasound as well as ultrasound combined with the essential oil of oregano and thyme. The physicochemical properties of these essential oil nanoemulsions are characterised while the structural damage of treated leaves is determined by the electrolyte leakage. Ultrasound combined with essential oils enhanced the microbial reduction on lettuce leaves and inactivation on the treated water, resulting on significant differences at concentrations higher than 0.018% (v/v) compared to control. Particle size, zeta potential and pH varied between 35 and 133 nm, −26 to −36 mV and 5.67 to 5.38, respectively. Electrolyte leakage was similar for both the control and the treated samples, increasing when essential oils were applied.peer-reviewe

Supplémentation en farine fortifiée « Misola » chez les personnes vivant avec le VIH sous traitement ARV au Mali.

Position du problème: Tester l’apport d’une supplémentation en farine fortifiée chez les personnes vivant avec le VIH sous traitement antirétroviral au Mali. Méthodes : Nous avons réalisé une étude prospective longitudinale chez 52 patients infectés par le VIH en ambulatoire sous traitement antirétroviral. A l'introduction de la farine ‘Misola', les paramètres de suivi à 3 mois ont été : (poids/taille), le taux de CD4 et la numération formule sanguine. Résultats : La majorité de nos patients était des femmes (69%). L'âge moyen était de 38 ans avec des extrêmes de 20 à 58 ans. La normalisation de l'indice de masse corporel de J15 à J60 était de 100%. L'augmentation de la reprise pondérale était significative (p=0,0001). Les paramètres biologiques étudiés étaient également augmentés à J60. Conclusion : La supplémentation en farine Misola semble être un facteur de gain pondéral rapide chez les PVIH sous ARV. Nous recommandons une étude randomisée sur un grand échantillon pour confirmer ces résultat

Peripheral nervous system manifestations in a Sandhoff disease mouse model: nerve conduction, myelin structure, lipid analysis

<p>Abstract</p> <p>Background</p> <p>Sandhoff disease is an inherited lysosomal storage disease caused by a mutation in the gene for the β-subunit (<it>Hexb </it>gene) of β-hexosaminidase A (αβ) and B (ββ). The β-subunit together with the GM2 activator protein catabolize ganglioside GM2. This enzyme deficiency results in GM2 accumulation primarily in the central nervous system. To investigate how abnormal GM2 catabolism affects the peripheral nervous system in a mouse model of Sandhoff disease (<it>Hexb-/-</it>), we examined the electrophysiology of dissected sciatic nerves, structure of central and peripheral myelin, and lipid composition of the peripheral nervous system.</p> <p>Results</p> <p>We detected no significant difference in signal impulse conduction velocity or any consistent change in the frequency-dependent conduction slowing and failure between freshly dissected sciatic nerves from the <it>Hexb</it>+/- and <it>Hexb</it>-/- mice. The low-angle x-ray diffraction patterns from freshly dissected sciatic and optic nerves of <it>Hexb</it>+/- and <it>Hexb</it>-/- mice showed normal myelin periods; however, <it>Hexb</it>-/- mice displayed a ~10% decrease in the relative amount of compact optic nerve myelin, which is consistent with the previously established reduction in myelin-enriched lipids (cerebrosides and sulfatides) in brains of <it>Hexb-/- </it>mice. Finally, analysis of lipid composition revealed that GM2 content was present in the sciatic nerve of the <it>Hexb</it>-/- mice (undetectable in <it>Hexb</it>+/-).</p> <p>Conclusion</p> <p>Our findings demonstrate the absence of significant functional, structural, or compositional abnormalities in the peripheral nervous system of the murine model for Sandhoff disease, but do show the potential value of integrating multiple techniques to evaluate myelin structure and function in nervous system disorders.</p

Austerity and the lives of people with learning disabilities. A thematic synthesis of current literature

The Financial Crisis of 2008 resulted in many western economies implementing cuts in health and social care. This systematic review provides a holistic picture of the impact of austerity policy on the lives of people with learning disabilities (LD) and the collateral effects on the people who support them. Our review suggests that in the current climate of economic austerity, available funding to support people with LD is no longer aligned to their care needs. Cuts in disability services have adversely affected the well-being both of people with LD and their informal carers. Individuals with LD have lost social support and are experiencing increased social isolation. Heightened demands on family carers’ time have negatively influenced their wider roles, including parental functioning, and labour market participation. Our review provides the foundations for further discourse and research on the effects of austerity on people with LD and their family carers

Intracranial V. cholerae Sialidase Protects against Excitotoxic Neurodegeneration

Converging evidence shows that GD3 ganglioside is a critical effector in a number of apoptotic pathways, and GM1 ganglioside has neuroprotective and noötropic properties. Targeted deletion of GD3 synthase (GD3S) eliminates GD3 and increases GM1 levels. Primary neurons from GD3S−/− mice are resistant to neurotoxicity induced by amyloid-β or hyperhomocysteinemia, and when GD3S is eliminated in the APP/PSEN1 double-transgenic model of Alzheimer's disease the plaque-associated oxidative stress and inflammatory response are absent. To date, no small-molecule inhibitor of GD3S exists. In the present study we used sialidase from Vibrio cholerae (VCS) to produce a brain ganglioside profile that approximates that of GD3S deletion. VCS hydrolyzes GD1a and complex b-series gangliosides to GM1, and the apoptogenic GD3 is degraded. VCS was infused by osmotic minipump into the dorsal third ventricle in mice over a 4-week period. Sensorimotor behaviors, anxiety, and cognition were unaffected in VCS-treated mice. To determine whether VCS was neuroprotective in vivo, we injected kainic acid on the 25th day of infusion to induce status epilepticus. Kainic acid induced a robust lesion of the CA3 hippocampal subfield in aCSF-treated controls. In contrast, all hippocampal regions in VCS-treated mice were largely intact. VCS did not protect against seizures. These results demonstrate that strategic degradation of complex gangliosides and GD3 can be used to achieve neuroprotection without adversely affecting behavior

Prostaglandin E2 Reverses Aberrant Production of an Inflammatory Chemokine by Microglia from Sandhoff Disease Model Mice through the cAMP-PKA Pathway

Background: Sandhoff disease (SD) is a neurodegenerative lysosomal b-hexosaminidase (Hex) deficiency involving excessive accumulation of undegraded substrates, including terminal GlcNAc-oligosaccharides and GM2 ganglioside. Microglia-mediated neuroinflammation contributes to the pathogenesis and progression of SD. Our previous study demonstrated that MIP-1a, a putative pathogenic factor for SD, is up-regulated in microglial cells derived from SD model mice (SD-Mg) through activation of Akt and JNK. Methodology/Principal Findings: In this study, we first demonstrated that prostaglandin E2 (PGE2), which is one of the lipid mediators derived from arachidonic acid and is known to suppress activation of microglia, reduced the aberrant MIP-1a production by SD-Mg to the same level as by WT-Mg. PGE2 also attenuated the activation of Akt and JNK. The inhibition of MIP-1a production and the activation of Akt and JNK occurred through the EP2 and 4/cAMP/PKA signaling pathway in the murine microglia derived from SD model mice. Conclusions/Significance: We propose that PGE2 plays a role as a negative regulator of MIP-1a production in th