Electron-Ion Structure Factors and the General Accuracy of Linear Response

We show that electron-ion structure factors in fluid metallic systems can be well understood from an application of linear response in the electron system, combined with hard-sphere like correlation for the ionic component. In particular, we predict that electron-ion structure factors fall into two general classes, one for high ($Z>3$) and one for low ($Z\leq2$) valence metals, and make suggestions for experiments to test these ideas. In addition, we show how the general success of electronic linear response for most metallic systems stems in part from an intrinsic interference between atomic and electronic length scales which weakens the nonlinear response. The main exception to this is metallic hydrogen.Comment: to appear in J. Non-Crystalline Solids, part of LAM-10 conference proceedings. RevTex, 12 pages, 2 figure

Occupational and food allergy: focus on allergen extracts

The aim of this thesis is, first, the diagnostic work-up of occupational and food allergies in the absence of well-validated commercially available standardised extracts for Skin Prick Test. Second, to investigate cross-reactivity in occupational and food allergic patients. Third, the treatment of, employees with an occupational allergy in order to enable the continuation of work. The number of work-related symptoms among greenhouse workers is increasing and the prevalence of food allergies is rising. The sequence of diagnostic procedures is the history first, followed by skin tests and RAST tests, and challenge tests as final instruments. Unfortunately, commercial standardised extracts to diagnose the more uncommon allergies caused by relatively unknown allergens are generally not available. Therefore, we made new in house manufactured extracts, for the diagnosis of occupational and food allergies e.g. several flower pollen, A. cucumeris, latex, fruits (peach, kiwi, banana, avocado), and hazelnut

A key-formula to compute the gravitational potential of inhomogeneous discs in cylindrical coordinates

We have established the exact expression for the gravitational potential of a homogeneous polar cell - an elementary pattern used in hydrodynamical simulations of gravitating discs. This formula, which is a closed-form, works for any opening angle and radial extension of the cell. It is valid at any point in space, i.e. in the plane of the distribution (inside and outside) as well as off-plane, thereby generalizing the results reported by Durand (1953) for the circular disc. The three components of the gravitational acceleration are given. The mathematical demonstration proceeds from the "incomplete version of Durand's formula" for the potential (based on complete elliptic integrals). We determine first the potential due to the circular sector (i.e. a pie-slice sheet), and then deduce that of the polar cell (from convenient radial scaling and subtraction). As a by-product, we generate an integral theorem stating that "the angular average of the potential of any circular sector along its tangent circle is 2/PI times the value at the corner". A few examples are presented. For numerical resolutions and cell shapes commonly used in disc simulations, we quantify the importance of curvature effects by performing a direct comparison between the potential of the polar cell and that of the Cartesian (i.e. rectangular) cell having the same mass. Edge values are found to deviate roughly like 2E-3 x N/256 in relative (N is the number of grid points in the radial direction), while the agreement is typically four orders of magnitude better for values at the cell's center. We also produce a reliable approximation for the potential, valid in the cell's plane, inside and close to the cell. Its remarkable accuracy, about 5E-4 x N/256 in relative, is sufficient to estimate the cell's self-acceleration.Comment: Accepted for publication in Celestial Mechanics and Dynamical Astronom

The Implementation of Families First in the Netherlands: A One Year Follow-up [IF: 0.725]

Contains fulltext : 63625.pdf (publisher's version ) (Closed access)This study examined whether the American family preservation program Families First was successfully implemented in the Netherlands. Data were collected on 250 children of 177 families who received Families First. At the start of treatment 78% of the children appeared to have serious behavioral problems, 67% of the parents experienced a high level of parental stress, and 63% of the children went through a substantial number of life events during the year preceding the treatment. On average the treatments had the intended duration (about 4 weeks), intensity (about 10 hours a week) and availability (during working hours as well as in evenings and in weekends), and family workers did adhere to important guidelines of treatment delivery. One year after treatment 76% of the children were still living at home. Moreover, children's behavioral problems, parental stress and the number of life events turned out to be significantly decreased. It was concluded that Families First had reached its intended target group, delivered the treatment as intended, and achieved its intended outcomes, suggesting a successful implementation in the Netherlands

Invited review: Milk lactose—Current status and future challenges in dairy cattle

peer-reviewedLactose is the main carbohydrate in mammals' milk, and it is responsible for the osmotic equilibrium between blood and alveolar lumen in the mammary gland. It is the major bovine milk solid, and its synthesis and concentration in milk are affected mainly by udder health and the cow's energy balance and metabolism. Because this milk compound is related to several biological and physiological factors, information on milk lactose in the literature varies from chemical properties to heritability and genetic associations with health traits that may be exploited for breeding purposes. Moreover, lactose contributes to the energy value of milk and is an important ingredient for the food and pharmaceutical industries. Despite this, lactose has seldom been included in milk payment systems, and it has never been used as an indicator trait in selection indices. The interest in lactose has increased in recent years, and a summary of existing information about lactose in the dairy sector would be beneficial for the scientific community and the dairy industry. The present review collects and summarizes knowledge about lactose by covering and linking several aspects of this trait in bovine milk. Finally, perspectives on the use of milk lactose in dairy cattle, especially for selection purposes, are outlined