A Locally Corrected Multiblob Method with Hydrodynamically Matched Grids for the Stokes Mobility Problem

Inexpensive numerical methods are key to enable simulations of systems of a large number of particles of different shapes in Stokes flow. Several approximate methods have been introduced for this purpose. We study the accuracy of the multiblob method for solving the Stokes mobility problem in free space, where the 3D geometry of a particle surface is discretised with spherical blobs and the pair-wise interaction between blobs is described by the RPY-tensor. The paper aims to investigate and improve on the magnitude of the error in the solution velocities of the Stokes mobility problem using a combination of two different techniques: an optimally chosen grid of blobs and a pair-correction inspired by Stokesian dynamics. Optimisation strategies to determine a grid with a certain number of blobs are presented with the aim of matching the hydrodynamic response of a single accurately described ideal particle, alone in the fluid. Small errors in this self-interaction are essential as they determine the basic error level in a system of well-separated particles. With a good match, reasonable accuracy can be obtained even with coarse blob-resolutions of the particle surfaces. The error in the self-interaction is however sensitive to the exact choice of grid parameters and simply hand-picking a suitable blob geometry can lead to errors several orders of magnitude larger in size. The pair-correction is local and cheap to apply, and reduces on the error for more closely interacting particles. Two different types of geometries are considered: spheres and axisymmetric rods with smooth caps. The error in solutions to mobility problems is quantified for particles of varying inter-particle distances for systems containing a few particles, comparing to an accurate solution based on a second kind BIE-formulation where the quadrature error is controlled by employing quadrature by expansion (QBX).Comment: 49 pages, 37 figure

Serum fatty acid profile does not reflect seafood intake in adolescents with atopic eczema.

AIM: Long-chain polyunsaturated fatty acids (LCPUFAs) are immunomodulatory, but their role in allergy development is controversial. We investigated whether proportions of LCPUFAs in serum phospholipids were related to allergic diagnosis, seafood intake and LCPUFA proportions in cord blood.</br></br> METHODS: Serum was obtained from 148 birth cohort children at 13 years of age. Forty had atopic eczema, 53 had respiratory allergy, and 55 were nonallergic. Proportions of LCPUFAs were determined in serum phospholipids; cord blood from 128 of the individuals was previously analysed. Seafood intake was estimated using questionnaires.</br></br> RESULTS: Allergic and nonallergic individuals did not differ significantly regarding individual LCPUFAs. However, arachidonic acid over docosahexaenoic acid (DHA) ratio was higher in allergic, compared with nonallergic, adolescents. In nonallergic individuals, LCPUFA proportions in cord serum and adolescent serum correlated weakly. In individuals with atopic eczema and respiratory allergy, these correlations were weak or absent. A moderate correlation between seafood intake and serum DHA was seen in nonallergic individuals and those with respiratory allergy, but not in those with atopic eczema.</br></br> CONCLUSION: Serum LCPUFA pattern was similar in allergic and nonallergic adolescents. Fatty acid metabolism may be altered in atopic eczema subjects, suggested by poor correlations between fatty acid intake and serum levels

Psychometric properties of the Swedish Diabetes Empowerment Scale

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73436/1/j.1471-6712.2007.00463.x.pd

Proportions of polyunsaturated fatty acids in umbilical cord blood at birth are related to atopic eczema development in the first year of life

Atopic eczema, the most common atopic disease in infants, may pave the way for sensitization and allergy later in childhood. Fatty acids have immune-regulating properties and may regulate skin permeability. Here we examine whether the proportions of fatty acids among the infant and maternal plasma phospholipids at birth were associated with maternal dietary intake during pregnancy and development of atopic eczema during the first year of age in the Nutritional impact on Immunological maturation during Childhood in relation to the Environment (NICE) birth cohort. Dietary data were collected with a semi-quantitative food frequency questionnaire, fatty acids were measured with GC-MS and atopic eczema was diagnosed by a pediatric allergologist at 12 months of age. We found that higher proportions of n-6 PUFAs (including arachidonic acid) but lower proportions of n-3 PUFAs (including DPA) in the infant’s phospholipids at birth were associated with an increased risk of atopic eczema at 12 months of age. The n-6 and n-3 PUFAs were related to maternal intake of meat and fish, respectively. Our results suggest that prenatal exposure to unsaturated fatty acids is associated with eczema development in the infant. Maternal diet during pregnancy may partly explain the fatty acid profiles in utero

Increased telomere attrition following renal transplantation: impact of anti-metabolite therapy

Background: The uremic milieu exposes chronic kidney disease (CKD) patients to premature ageing processes. The impact of renal replacement therapy (dialysis and renal transplantation [RTx]) or immunosuppressive treatment regimens on ageing biomarkers has scarcely been studied. Methods: In this study telomere length in whole blood cells was measured in 49 dialysis patients and 47 RTx patients close to therapy initiation and again after 12 months. Forty-three non-CKD patients were included as controls. Results: Non-CKD patients had significantly (P &#60;= 0.01) longer telomeres than CKD patients. Telomere attrition after 12 months was significantly greater in RTx patients compared to dialysis patients (P = 0.008). RTx patients receiving mycophenolate mofetil (MMF) had a greater (P = 0.007) degree of telomere attrition compared to those treated with azathioprine. After 12 months, folate was significantly higher in RTx patients than in dialysis patients (P &#60; 0.0001), whereas the opposite was true for homocysteine (P &#60; 0.0001). The azathioprine group had lower levels of folate after 12 months than the MMF group (P = 0.003). Conclusions: The associations between immunosuppressive therapy, telomere attrition, and changes in folate indicate a link between methyl donor potential, immunosuppressive drugs, and biological ageing. The hypothesis that the increased telomere attrition, observed in the MMF group after RTx, is driven by the immunosuppressive treatment, deserves further attention

Fria eller fälla : att besluta om träd i offentliga miljöer

Träd i offentliga miljöer, till exempel på kyrkogårdar, i parker, alléer och städer har ofta höga värden. Det finns många olika lagstiftningar som reglerar vad man får och inte får göra med träden. Åtgärder som utförs på träd väcker ofta känslor hos allmänheten. I detta Movium Fakta sammanfattas en nyligen publicerad vägledning, som presenterar en modell i tio steg för hur besluts- och samrådsprocesser kan utformas när det gäller åtgärder på värdefulla träd

Skandia-grisen & ICA-Stig

Syftet med uppsatsen är att analysera hur företag kan använda humor i reklam för att återfå konsumenternas positiva attityd. Vilken betydelse en produkts engageringsgrad har för att återfå konsumenters positiva attityd i relation till humoristisk reklam. Detta behandlas utifrån fallföretagen Skandia och ICA. Bidra till förståelse samt belysa sambandet mellan humoristisk reklam, konsumenters attityd samt hög- och lågengagemangsprodukter. Uppsatsen utgår ifrån ett deduktivt angreppssätt och bygger på två fallföretag. Vi använder oss av både kvantitativ och kvalitativ metod i form av en enkätundersökning samt semistrukturerade intervjuer. Det teoretiska ramverket för uppsatsen består av reklam, humor, varumärke, attityd, FCB-modellen samt Reed och Ewings kommunikationsmodell. Vårt empiriska material utgörs av sekundärdata om fallföretagen Skandia och ICA, enkätundersökning samt intervjuer med personer inom reklambranschen. Vårt resultat blev följande: Om en produkt är hög- eller lågengagerande är individuellt. Företag bör ha i åtanke vilken typ av produkt reklaminslaget ska representera då olika produkter endast är lämpliga med viss typ av humor. Tiden är en viktig faktor för att återfå konsumenters positiva attityd efter en skandal samt även produktkategorin avgör hur lätt det är att återfå den positiva attityden

Exposure to a Farm Environment During Pregnancy Increases the Proportion of Arachidonic Acid in the Cord Sera of Offspring

Growing up in a farm environment is protective against allergy development. Various explanations have been put forward to explain this association. Fatty acids are regulators of immune function and the composition of fatty acids in the circulation system may affect immune development. Here, we investigate whether the fatty acid composition of cord serum differs for infants born to Farm (n = 26) or non-Farm mothers (n =29) in the FARMFLORA birth-cohort. For comparison, the levels of fatty acids in the maternal diet, serum and breast milk around 1 month post-partum were recorded. The fatty acids in the cord sera from infants born to Farm mothers had higher proportions of arachidonic acid (20:4 n-6) and adrenic acid (22:4 n-6) than those from infants born to non-Farm mothers. No differences were found for either arachidonic acid or adrenic acid in the diet, samples of the serum, or breast milk from Farm and non-Farm mothers obtained around 1 month post-partum. The arachidonic and adrenic acid levels in the cord blood were unrelated to allergy outcome for the infants. The results suggest that a farm environment may be associated with the fatty acid composition to which the fetus is exposed during pregnancy

Diet in 1-year-old farm and control children

BACKGROUND: A farming environment confers strong protection against allergy development. We have previously shown that farming mothers consume more full-fat dairy than control mothers, who instead consume more low-fat dairy, margarine, and oils; margarine and oil intake was associated with increased risk of allergy development in their children. OBJECTIVES: The aims of this study were to investigate the differences in diet between children in farming and control families at 1 year of age, to investigate the relation between the diets of the mothers and their children, and to relate the children's diet to allergy development. DESIGN: The diet of 1-year-old children from dairy farming families (n=28) and from control families in the same rural area (n=37) was assessed by 24-h dietary recalls, followed by 24-h food diaries. Allergy was diagnosed by pediatricians at 3 years of age using strict predefined criteria. RESULTS: Farm children had a higher intake of farm milk, whole cream, cholesterol, saturated fat, and fat in total and tended to eat more butter, while controls consumed more carbohydrates and poultry and tended to eat more margarine. Farm children also had higher intakes of homemade porridge/gruel, oily fish, and iodine. The intake of butter and whole milk in children and mothers correlated significantly in farm families but not in controls. A weak negative association was found between seafood intake and allergy development, while allergy was positively associated with the intake of pork as well as zinc in the control group; these intakes also correlated with each other. CONCLUSIONS: Consistent with mothers in farming families, the children consumed more full-fat dairy and saturated fat than did controls, but this could not be linked to the low risk of allergy in the farming group. Seafood intake might protect against allergy development, in accordance with earlier findings