Curvature Effects and Flow Uniformity Optimization of a Blood Microchannel

An important field of study in microfluidics is in the realm of blood rheology in microdevices. Many types of geometries have been developed for different lab-on-chip applications for sampling and analysis. The majority of experimental and numerical studies have revolved around straight blood vessel geometries, but in recent years there have been more complex profiles analyzed, such as microbifurcations. Some devices are developed to study blood flow similar to the microvascular network, such as diverging and converging bifurcations to study arterioles, which form a closed network. Cell adhesion studies of microchannels are also common, where symmetric bifurcation and confluence has been examined. Since sharp turns as well as bifurcation and confluence are common, the hemodynamics should be examined for many different shapes and the effects of channel geometry to the adhesion phenomena should be looked at. Different devices have different goals, such as isolating circulating tumor cells from blood, separating leukocytes from blood and isolating circulating tumor cells from peripheral blood. Studies have been targeted in breast cancer, cervical cancer and smooth muscle cell applications. Some studies provide result as to the role that the hemodynamic forces have on the recruitment of the metastatic cancer cells to endothelial cells, but the effects of device geometry on adhesion isn’t typically discussed formally. It has been shown that more complex geometries exhibit more non-uniform cell adhesion, adding to the confusion in the results and that an improvement in the velocity uniformity has been shown to improve the uniformity of the cell adhesion in sharp turn devices

Materials Design using Correlated Oxides: Optical Properties of Vanadium Dioxide

Materials with strong electronic Coulomb interactions play an increasing role in modern materials applications. "Thermochromic" systems, which exhibit thermally induced changes in their optical response, provide a particularly interesting case. The optical switching associated with the metal-insulator transition of vanadium dioxide (VO2), for example, has been proposed for use in "intelligent" windows, which selectively filter radiative heat in hot weather conditions. In this work, we develop the theoretical tools for describing such a behavior. Using a novel scheme for the calculation of the optical conductivity of correlated materials, we obtain quantitative agreement with experiments for both phases of VO2. On the example of an optimized energy-saving window setup, we further demonstrate that theoretical materials design has now come into reach, even for the particularly challenging class of correlated electron systems.Comment: 4+x pages, 2 figure

Fractal Dimensions in Perceptual Color Space: A Comparison Study Using Jackson Pollock's Art

The fractal dimensions of color-specific paint patterns in various Jackson Pollock paintings are calculated using a filtering process which models perceptual response to color differences (\Lab color space). The advantage of the \Lab space filtering method over traditional RGB spaces is that the former is a perceptually-uniform (metric) space, leading to a more consistent definition of ``perceptually different'' colors. It is determined that the RGB filtering method underestimates the perceived fractal dimension of lighter colored patterns but not of darker ones, if the same selection criteria is applied to each. Implications of the findings to Fechner's 'Principle of the Aesthetic Middle' and Berlyne's work on perception of complexity are discussed.Comment: 21 pp LaTeX; two postscript figure

The Effects of the Jump-In Whole-School Intervention on the Weight Development of Children in Amsterdam, the Netherlands

BACKGROUNDThis study assessed the effects of the “Jump-in” whole-school intervention in Amsterdam, the Netherlands, on children's weight development by comparing children exposed to the intervention and controls from 3 other large Dutch cities. Jump-in is a comprehensive intervention that aims to stimulate healthy nutrition and physical activity in children at primary schools in Amsterdam. In addition, the relationship between the intervention's implementation degree and its effectiveness was studied.METHODSDemographic and anthropometric data, collected by youth health care professionals via routine health checks at T0 (2014) and T1 (2019), were used to analyze possible intervention effects by comparing the weight development of children exposed to the Jump-in intervention versus unexposed controls. Implementation logs from health promotion professionals were used to determine intervention effects per implementation degree. Multilevel regression analyses were used for all analyses.RESULTSIn total, 4299 children were included mean age ± 5.5 years (T0), 10.6 years (T1), and ≈50% boys/girls at both times. Receiving the fully implemented intervention resulted in a decline in standardized body-mass index (zBMI) compared to the controls (−0.23, confidence interval [CI] −0.33, −0.13). It also led to higher odds to move into a healthier weight category over time (odds ratio [OR] 1.36, CI 1.06, 1.74), yet no statistically significant shift towards a healthy weight was found.CONCLUSIONSRelative to the controls, children exposed to the intervention showed positive zBMI developments, with stronger effects when the implementation degree was higher. Despite positive results, creating more impact might require the further integration of school-based programs into whole-systems approaches that include other energy-balance behaviors

Processo agroindustrial: obtenção de embutido fermentado tipo salame de caprino.

bitstream/CNPAT/7861/1/ct_74.pd

Influence of Annealing on the Optical and Scintillation Properties of CaWO4_4 Single Crystals

We investigate the influence of oxygen annealing on the room temperature optical and scintillation properties of CaWO$_4$ single crystals that are being produced for direct Dark Matter search experiments. The applied annealing procedure reduces the absorption coefficient at the peak position of the scintillation spectrum ($\sim430$ nm) by a factor of $\sim6$ and leads to an even larger reduction of the scattering coefficient. Furthermore, the annealing has no significant influence on the \emph{intrinsic} light yield. An additional absorption occurring at $\sim400$ nm suggests the formation of O$^-$ hole centers. Light-yield measurements at room temperature where one crystal surface was mechanically roughened showed an increase of the \emph{measured} light yield by $\sim40$ and an improvement of the energy resolution at 59.5 keV by $\sim12$ for the annealed crystal. We ascribe this result to the reduction of the absorption coefficient while the surface roughening is needed to compensate for the also observed reduction of the scattering coefficient after annealing

What Do Secondary Schools Need to Create Healthier Canteens? The Development of an Implementation Plan

Introduction: The Netherlands Nutrition Centre developed guidelines to improve the availability and accessibility of healthier food products in Dutch canteens. This paper describes the development of an implementation plan to facilitate implementation of Guidelines for Healthier Canteens in Dutch secondary schools.Materials and Methods: In cooperation with stakeholders (i.e., school/caterer managers/employees, school canteen advisors, researchers) and based on theory, we developed an implementation plan in three steps. First, we identified factors that impede/facilitate stakeholders to create a healthier school canteen during 14 interviews. Second, 25 experts discussed and prioritized these identified factors in an expert meeting. Third, we translated these factors into tools to be included in the implementation plan, by making use of behavior change taxonomies and evidence-based implementation strategies.Results: The plan aims to support stakeholders in implementing healthier school canteens and consists of five tools: (1) tailored advice based on an online questionnaire to assess schools' and stakeholders' context and the Canteen Scan (i.e., an online tool to assess the availability and accessibility of food/drink products); (2) communication materials with information and examples; (3) online community for support by sharing experiences/questions; (4) digital newsletter as reminder/support; (5) fact sheet with students' needs/wishes to tailor the canteen.Discussion: This study illustrates how collaboration between science, policy and practice resulted in a tailored implementation plan aimed to support schools to adhere to school canteen policy. This development serves as a good example for researchers, health promotion policymakers, and practitioners how to create an implementation plan that fits the needs of stakeholders