Fekete Potentials and Polynomials for Continua

AbstractFor planar continua, upper and lower bounds are given for the growth of the associated Fekete potentials, polynomials and energies. The main result is that for continua K of capacity 1 whose outer boundary is an analytic Jordan curve, the family of Fekete polynomials is bounded on K. Our work makes use of precise results of Pommerenke on the growth of the discriminant and on the distribution of the Fekete points. We also use potential theory, including the exterior Green function with pole at infinity. The Lipschitz character of this function determines the separation of the Fekete points

Modeling of tribo-electrification of a pneumatically conveyed powder in a squared duct using DEM-CFD

Dry separation technology is a sustainable alternative to conventional wet separation technology for production of food ingredients. This paper is concerned with the exploration of a new driving force for dry separation, i.e. triboelectrification. To investigate the possibilities of this driving force, we modified our in-house DEM-CFD code to model a learning system where powder is tribo-electrically charged by conveying it pneumatically through a squared tube. The charged particles will electrostatically interact with both other charged particles, as well as their induced charges on the conducting walls. We show that the amount of acquired charge depends on the electrostatic interaction between particles and walls and show the corresponding spatial distribution of the particles. They depend both highly on the (mean) charge of the particles. We observed a critical charge per particle after which particles charged rapidly to their saturation charge. This critical charge is delicate and lower than expected from first order derivations

Practical and validated tool to assess falls risk in the primary care setting:A systematic review

Objective: Although several falls risk assessment tools are available, it is unclear which have been validated and which would be most suitable for primary care practices. This systematic review aims to identify the most suitable falls risk assessment tool for the primary care setting (ie, requires limited time, no expensive equipment and no additional space) and that has good predictive performance in the assessment of falls risk among older people living independently. Design: A systematic review based on prospective studies. Methods: An extensive search was conducted in the following databases: PubMed, Embase, CINAHL, Cochrane and PsycINFO. Tools were excluded if they required expensive and/or advanced software that is not usually available in primary care units and if they had not been validated in at least three different studies. Of 2492 articles published between January 2000 and July 2020, 27 were included. Results: Six falls risk assessment tools were identified: Timed Up and Go (TUG) test, Gait Speed test, Berg Balance Scale, Performance Oriented Mobility Assessment, Functional Reach test and falls history. Most articles reported area under the curve (AUC) values ranging from 0.5 to 0.7 for these tools. Sensitivity and specificity varied substantially across studies (eg, TUG, sensitivity:10%–83.3%, specificity:28.4%–96.6%). Conclusions: Given that none of the falls risk assessment tools had sufficient predictive performance (AUC <0.7), other ways of assessing high falls risk among independently living older people in primary care should be investigated. For now, the most suitable way to assess falls risk in the primary care setting appears to involve asking patients about their falls history. Compared with the other five tools, the falls history requires the least amount of time, no expensive equipment, no training and no spatial adjustments. The clinical judgement of healthcare professionals continues to be most important, as it enables the identification of high falls risk even for patients with no falls history. Trial registraion number: The Netherlands Trial Register, NL7917; Pre-results

Early life supply of competitive exclusion products reduces colonization of Extended Spectrum Beta-Lactamase producing Escherichia coli in broilers

Broilers are an important reservoir of ESBL/pAmpC-producing bacteria. In previous studies a single supply of a competitive exclusion (CE) product before challenge with a high dose of ESBL/pAmpC-producing E. coli led to reduced colonization, excretion and transmission, but could not prevent colonization. The hypothesized mechanism is competition; therefore in this study the effect of a prolonged supply of CE products on colonization, excretion and transmission of ESBL-producing E. coli after challenge with a low dose at day 0 or day 5 was investigated. Day-old broilers (Ross 308) (n=220) were housed in isolators. Two CE products, containing unselected fermented intestinal bacteria (CEP) or a selection of pre- and probiotics (SYN), were supplied in drinking water from day 0 to 14. At day 0 or day 5 broilers were challenged with 0.5 mL with 101 or 102 cfu/mL E. coli encoding the beta–lactamase gene blaCTX-M-1 on an IncI plasmid (CTX-M-1-E. coli). Presence and concentration of CTX-M-1-E. coli was determined using cloacal swabs (day 0-14, 16, 19, 21) and cecal content (day 21). Cox proportional hazard model and a mixed linear regression model were used to determine the effect of the intervention on colonization and excretion (log10 cfu/g). When challenged at day of hatch, no effect of CEP was observed. When challenged at day 5, both CEP and SYN led to a prevention of colonization with CTX-M-1-E. coli in some isolators. In the remaining isolators, we observed reduced time until colonization (HR between 3.71 ×10-3 and 3.11), excretion (up to -1.60 log10 cfu/g) and cecal content (up to -2.80 log10 cfu/g) and a 1.5 to 3-fold reduction in transmission rate. Colonization after a low dose challenge with ESBL-producing E. coli can be prevented by CE products. However, if at least one bird is colonized it spreads through the whole flock. Prolonged supply of CE products provided shortly after hatch, may be applicable as an intervention to reduce prevalence of ESBL/pAmpC-producing bacteria in the broiler production chain

Organophosphate pesticides exposure in pregnant women and maternal and cord blood thyroid hormone concentrations

Background: Animal studies suggest that organophosphate (OP) pesticides exposure affects thyroid function, but evidence in humans remains sparse and inconclusive. Gestational exposure is of particular interest, since thyroid hormone is essential for fetal brain development. OP pesticides are able to cross the placental and blood-brain barrier and may interfere with fetal development processes regulated by thyroid hormone. Objective: To investigate the association of gestational OP pesticides exposure during pregnancy with maternal and cord blood thyroid hormone concentrations. Methods: This study was embedded within Generation R (Rotterdam, the Netherlands), a prospective population-based birth cohort. Mother-child pairs with OP pesticides assessment and maternal (N = 715) or cord blood (N = 482) thyroid hormone measurements were included. OP pesticides exposure was assessed at < 18, 18–25, and > 25 weeks gestation by measuring six urinary dialkylphosphate (DAP) metabolites. Thyroid stimulating hormone (TSH) and free thyroxine (FT4) were measured in maternal and cord blood. Maternal measures also included total thyroxine (TT4) and TPO antibodies (TPOAbs). To study the association of creatinine-adjusted DAP metabolite concentrations with thyroid function and TPO antibodies, multivariable linear regression models including relevant confounders were used. Results: There was no association of DAP metabolites with maternal TSH, FT4, TT4 or TPOAb concentrations during pregnancy. Similarly, there was no association of DAP metabolites with cord blood TSH or FT4. Results did not change when DAP concentrations were analyzed at individual time points or as mean gestational exposure. Conclusion: Gestational OP pesticides exposure, as assessed by repeatedly measured urinary DAP metabolite concentrations in an urban population, was not associated with maternal or cord blood t

Asymptotic behavior of solutions to the σk\sigma_k-Yamabe equation near isolated singularities

$\sigma_k$-Yamabe equations are conformally invariant equations generalizing the classical Yamabe equation. In an earlier work YanYan Li proved that an admissible solution with an isolated singularity at $0\in \mathbb R^n$ to the $\sigma_k$-Yamabe equation is asymptotically radially symmetric. In this work we prove that an admissible solution with an isolated singularity at $0\in \mathbb R^n$ to the $\sigma_k$-Yamabe equation is asymptotic to a radial solution to the same equation on $\mathbb R^n \setminus \{0\}$. These results generalize earlier pioneering work in this direction on the classical Yamabe equation by Caffarelli, Gidas, and Spruck. In extending the work of Caffarelli et al, we formulate and prove a general asymptotic approximation result for solutions to certain ODEs which include the case for scalar curvature and $\sigma_k$ curvature cases. An alternative proof is also provided using analysis of the linearized operators at the radial solutions, along the lines of approach in a work by Korevaar, Mazzeo, Pacard, and Schoen.Comment: 55 page

A construction of constant scalar curvature manifolds with delaunay-type ends

It has been showed by Byde that it is possible to attach a Delaunay-type end to a compact nondegenerate manifold of positive constant scalar curvature, provided it is locally conformally flat in a neighborhood of the attaching point. The resulting manifold is noncompact with the same constant scalar curvature. The main goal of this paper is to generalize this result. We will construct a one-parameter family of solutions to the positive singular Yamabe problem for any compact non-degenerate manifold with Weyl tensor vanishing to sufficiently high order at the singular point. If the dimension is at most 5, no condition on the Weyl tensor is needed. We will use perturbation techniques and gluing methods