Parametric forcing approach to rough-wall turbulent channel flow

The effects of rough surfaces on turbulent channel flow are modelled by an extra force term in the Navier–Stokes equations. This force term contains two parameters, related to the density and the height of the roughness elements, and a shape function, which regulates the influence of the force term with respect to the distance from the channel wall. This permits a more flexible specification of a rough surface than a single parameter such as the equivalent sand grain roughness. The effects of the roughness force term on turbulent channel flow have been investigated for a large number of parameter combinations and several shape functions by direct numerical simulations. It is possible to cover the full spectrum of rough flows ranging from hydraulically smooth through transitionally rough to fully rough cases. By using different parameter combinations and shape functions, it is possible to match the effects of different types of rough surfaces. Mean flow and standard turbulence statistics have been used to compare the results to recent experimental and numerical studies and a good qualitative agreement has been found. Outer scaling is preserved for the streamwise velocity for both the mean profile as well as its mean square fluctuations in all but extremely rough cases. The structure of the turbulent flow shows a trend towards more isotropic turbulent states within the roughness layer. In extremely rough cases, spanwise structures emerge near the wall and the turbulent state resembles a mixing layer. A direct comparison with the study of Ashrafian, Andersson & Manhart (Intl J. Heat Fluid Flow, vol. 25, 2004, pp. 373–383) shows a good quantitative agreement of the mean flow and Reynolds stresses everywhere except in the immediate vicinity of the rough wall. The proposed roughness force term may be of benefit as a wall model for direct and large-eddy numerical simulations in cases where the exact details of the flow over a rough wall can be neglecte

Land Conservation and Energy Infrastructure: Threats and Opportunities

2009 Berkley Conference Summar

Proximity to Pollution Sources and Risk of Amphibian Limb Malformation

The cause of limb deformities in wild amphibian populations remains unclear, even though the apparent increase in prevalence of this condition may have implications for human health. Few studies have simultaneously assessed the effect of multiple exposures on the risk of limb deformities. In a cross-sectional survey of 5,264 hylid and ranid metamorphs in 42 Vermont wetlands, we assessed independent risk factors for nontraumatic limb malformation. The rate of nontraumatic limb malformation varied by location from 0 to 10.2%. Analysis of a subsample did not demonstrate any evidence of infection with the parasite Ribeiroia. We used geographic information system (GIS) land-use/land-cover data to validate field observations of land use in the proximity of study wetlands. In a multiple logistic regression model that included land use as well as developmental stage, genus, and water-quality measures, proximity to agricultural land use was associated with an increased risk of limb malformation (odds ratio = 2.26; 95% confidence interval, 1.42–3.58; p < 0.001). The overall discriminant power of the statistical model was high (C = 0.79). These findings from one of the largest systematic surveys to date provide support for the role of chemical toxicants in the development of amphibian limb malformation and demonstrate the value of an epidemiologic approach to this problem

Evidence behind the use of molecular tests in melanocytic lesions and practice patterns of these tests by dermatopathologists

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146490/1/cup13327_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146490/2/cup13327-sup-0001-AppendixS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146490/3/cup13327.pd

A Decision Tree for Donor Human Milk: An Example Tool to Protect, Promote, and Support Breastfeeding

Despite decades of breastfeeding promotion, exclusive breastfeeding rates for the first 6 months of life remain low: around 40% globally. Infants that are admitted to a neonatal ward are even less likely to be exclusively breastfed. Lactogenesis is frequently delayed in mothers that deliver early, with the added burden of separation of the unstable newborn and mother. For such vulnerable infants, donor human milk is recommended by the World Health Organization, UNICEF, and professional organizations as the next best alternative when mother's own milk is unavailable and can serve as a bridge to full feeding with mother's own milk. Hospital support of optimal breastfeeding practices is essential with thoughtful integration of donor human milk policies for those infants that need it most. We propose a decision tree for neonatal wards that are considering the use of donor human milk to ensure donor human milk is used to replace formula, not to replace mothers' own milk. By first evaluating barriers to full feeding with mother's own milk, healthcare workers are encouraged to systematically consider the appropriateness of donor human milk. This tool also seeks to prevent overuse of donor human milk, which has the potential to undermine successful lactation development. In settings where donor human milk supplies are limited, prioritization of infants by medical status is also needed. Readily available and easy-to-use tools are needed to support healthcare staff and mothers in order to improve lactation development and neonatal nutrition

Candidate target genes for loss of heterozygosity on human chromosome 17q21

Loss of heterozygosity (LOH) on chromosome 17q21 has been detected in 30% of primary human breast tumours. The smallest common region deleted occurred in an interval between the D17S746 and D17S846 polymorphic sequences tagged sites that are located on two recombinant PI-bacteriophage clones of chromosome 17q21: 122F4 and 50H1, respectively. To identify the target gene for LOH, we defined a map of this chromosomal region. We found the following genes: JUP, FK506BP10, SC65, Gastrin (GAS) and HAP1. Of the genes that have been identified in this study, only JUP is located between D17S746 and D17S846. This was of interest since earlier studies have shown that JUP expression is altered in breast, lung and thyroid tumours as well as cell lines having LOH in chromosome 17q21. However, no mutations were detected in JUP using single-strand conformation polymorphism analysis of primary breast tumour DNAs having LOH at 17q21. We could find no evidence that the transcription promoter for JUP is methylated in tumour DNAs having LOH at 17q21. We suspect that the target gene for LOH in primary human breast tumours on chromosome 17q21 is either JUP and results in a haploinsufficiency for expression or may be an unidentified gene located in the interval between D17S846 and JUP. © 2004 Cancer Research UK

Simulation of rough wall turbulent channel flow using a parametric forcing approach

The effects of rough walls on turbulent channel flow are simulated by adding a simple forcing term to the Navier-Stokes equations. An extensive parameter study is used to explore the effects of this term on turbulent channel flow. By varying the roughness height parameter and the roughness factor contained in the forcing term it is possible to simulate roughnesses of various strengths ranging from transitionally rough to very rough cases. A good qualitative agreement is found with the results of recent experimental and numerical studies of rough-wall turbulent channel flow for the mean flow statistics. The streamwise velocity shows a very good preservation of the outer layer similarity for both its mean and its fluctuations. The flow structure shows a weakening of the streamwise streaks above the roughness sublayer. Within the roughness sublayer the turbulent structure changes to a more isotropic state, while close to the wall a mixing layer-like turbulent state emerges in extremely rough cases. The roughness force term is a possible candidate for a wall model in large eddy and direct numerical simulations where the small-scale structure of the flow over a rough surface can be neglected

Analysis of media coverage on breastfeeding policy in Washington State

Thesis (Master's)--University of Washington, 2016-06Background: Framing of messages about breastfeeding policy in the media can foster or hinder interpretations of policy’s potential benefits and may ultimately influence important policy decisions in institutions and legislative bodies. Objectives: To evaluate how breastfeeding policies were framed in print and web-based newspapers in Washington State; to identify sources of frames; to examine the balance of media coverage in support or against breastfeeding policy adoption. Methods: Print and web-based newspaper articles published from January 2000 through June 2014 specifically discussing breastfeeding policy were analyzed and coded (n= 131). A sub-sample (n= 46) was double coded. Inter-coder agreement was acceptable (Krippendorff α coefficient 0.83). Results: The number of articles about breastfeeding policy grew overall between 2000 and 2014 and peaked during periods of specific policy development. Seventy-four articles had a neutral tone, 49 supported breastfeeding policy and four were in opposition. Nine distinct supporting frames were identified and six distinct opposing frames. The most frequent supporting frames were health benefits of breastfeeding and challenges of breastfeeding in public. The most common opposing frame was indecency of breastfeeding in public. Many framed messages did not reference a source of information. Conclusions: There is limited but growing media coverage of breastfeeding policies. For the most part, coverage is supportive of the need for policies. Breastfeeding advocates can apply information about using message framing to craft effective policy development strategies

A Comparative Analysis of Accessibility of Food Services in Oakland and Berkeley

Residential proximity to food service areas is relevant to health studies. Using cartographic representation and analysis, this paper shows travel times from residences to restaurants and grocery stores, demonstrating convenience and access within certain geographic areas. Travel within two California cities, Oakland and Berkeley, is examined and discussed. A relationship between race and median income on the census tract level and locations of fast food and grocery stores is defined. The study\u27s findings illustrate that compared with higher income and White populations, lower income and non-White populations have a relatively longer travel time to grocery stores and a relatively shorter travel time to fast food restaurants. Therefore, within the selected geographic areas, lower income and non-White populations experience greater access to unhealthy food choices and relatively limited availability of healthy food