A study of Polygyra inflecta (Say)

http://deepblue.lib.umich.edu/bitstream/2027.42/56715/1/OP276.pd

Microscopic theory of solvent mediated long range forces: influence of wetting

We show that a general density functional approach for calculating the force between two big particles immersed in a solvent of smaller ones can describe systems that exhibit fluid-fluid phase separation: the theory captures effects of strong adsorption (wetting) and of critical fluctuations in the solvent. We illustrate the approach for the Gaussian core model, a simple model of a polymer mixture in solution and find extremely attractive, long ranged solvent mediated potentials between the big particles for state points lying close to the binodal, on the side where the solvent is poor in the species which is favoured by the big particles.Comment: 7 pages, 3 figures, submitted to Europhysics Letter

User benefits and funding strategies

The justification, economic and technological benefits of NASA Space Programs (aside from pure scientific objectives), in improving the quality of life in the United States is discussed and outlined. Specifically, a three-step, systematic method is described for selecting relevant and highly beneficial payloads and instruments for the Interim Upper Stage (IUS) that will be used with the space shuttle until the space tug becomes available. Viable Government and private industry cost-sharing strategies which would maximize the number of IUS payloads, and the benefits obtainable under a limited NASA budget were also determined. Charts are shown which list the payload instruments, and their relevance in contributing to such areas as earth resources management, agriculture, weather forecasting, and many others

Generation of defects and disorder from deeply quenching a liquid to form a solid

We show how deeply quenching a liquid to temperatures where it is linearly unstable and the crystal is the equilibrium phase often produces crystalline structures with defects and disorder. As the solid phase advances into the liquid phase, the modulations in the density distribution created behind the advancing solidification front do not necessarily have a wavelength that is the same as the equilibrium crystal lattice spacing. This is because in a deep enough quench the front propagation is governed by linear processes, but the crystal lattice spacing is determined by nonlinear terms. The wavelength mismatch can result in significant disorder behind the front that may or may not persist in the latter stage dynamics. We support these observations by presenting results from dynamical density functional theory calculations for simple one- and two-component two-dimensional systems of soft core particles.Comment: 25 pages, 11 figure

Collective shuttling of attracting particles in asymmetric narrow channels

The rectification of a single file of attracting particles subjected to a low frequency ac drive is proposed as a working mechanism for particle shuttling in an asymmetric narrow channel. Increasing the particle attraction results in the file condensing, as signalled by the dramatic enhancement of the net particle current. Magnitude and direction of the current become extremely sensitive to the actual size of the condensate, which can then be made to shuttle between two docking stations, transporting particles in one direction, with an efficiency much larger than conventional diffusive models predict

Dynamic density functional study of a driven colloidal particle in polymer solutions

The Dynamic Density Functional (DDF) theory and standard Brownian dynamics simulations (BDS) are used to study the drifting effects of a colloidal particle in a polymer solution, both for ideal and interacting polymers. The structure of the stationary density distributions and the total induced current are analyzed for different drifting rates. We find good agreement with the BDS, which gives support to the assumptions of the DDF theory. The qualitative aspect of the density distribution are discussed and compared to recent results for driven colloids in one-dimensional channels and to analytical expansions for the ideal solution limit

Examining How Neighborhood Socioeconomic Status, Geographic Accessibility, and Informational Accessibility Influence the Uptake of a Free Population-Level Physical Activity Intervention for Children

Purpose: To evaluate the uptake of ACT-i-Pass (G5AP), a physical activity (PA) intervention that provides free access to PA opportunities, and to understand the extent to which the intervention provides equitable access to children. Design: This study evaluates the differences in uptake (ie, enrollment) by comparing postal codes of registrants with the postal codes of all eligible children. Setting: Children were provided the opportunity to register for the G5AP during the 2014 to 2015 school year in London, Canada. Participants: The population of grade 5 students in London who registered for the G5AP (n = 1484) and did not register (n = 1589). Intervention: The G5AP offered grade 5 students free access to select PA facilities/programs during 2014 to 2015 school year. Measures: Measures included G5AP registration status, method of recruitment, distance between home and the nearest facility, and neighborhood socioeconomic status. Analysis: Getis-Ord Gi* and multilevel logistic regression were used to analyze these data. Results: There were significant differences in the uptake of the G5AP: residing in neighborhoods of high income (odds ratio [OR] = 1.062, P = .029) and high proportion of recent immigrants (OR = 1.036, P = .001) increased the likelihood of G5AP registration. Children who were recruited actively were significantly more likely to register for the G5AP (OR = 2.444, P \u3c .001). Conclusion: To increase the uptake of a PA intervention, children need to be actively recruited. Interactive presentations provide children with increased access to information about both the program and its nuances that cannot be communicated as effectively through passive methods

Evaluation of GIS Technology in Assessing and Modeling Land Management Practices

There is an increasing concern of land owners to protect and maintain healthy and sustainable agroecosystems through the implementation of best management practices (BMP). The objectives of this study were: (1) To develop and evaluate the use of a Geographic Information System (GIS) technology for enhancing field-scale management practices; (2) evaluate the use of 2-dimensional displays of the landscape and (3) define spatial classes of variables from interpretation of geostatistical parameters. Soil samples were collected to a depth of 2 m at 15 cm increments. Existing data from topographic, land use, and soil survey maps of the Winfred Thomas Agricultural Research Station were converted to digital format. Additional soils data which included texture, pH, and organic matter were also generated. The digitized parameters were used to create a multilayered field-scale GIS. Two dimensional (2-D) displays of the parameters were generated using the ARC/INFO software. The spatial distribution of the parameters evaluated in both fields were similar which could be attributed to the similarity in vegetation and surface elevation. The ratio of the nugget to total semivariance, expressed as a percentage, was used to assess the degree of spatial variability. The results indicated that most of the parameters were moderate spatially dependent Biophysical constraint maps were generated from the database layers, and used in multiple combination to visualize results of the BMP. Understanding the spatial relationships of physical and chemical parameters that exists within a field should enable land managers to more effectively implement BMP to ensure a safe and sustainable environment

What influences home delivery among women who live in urban areas? Analysis of 2014 Ghana Demographic and Health Survey data

Background In Ghana, home delivery among women in urban areas is relatively low compared to rural areas. However, the few women who deliver at home in urban areas still face enormous risk of infections and death, just like those in rural areas. The present study investigated the factors associated with home delivery among women who live in urban areas in Ghana. Materials and methods Data for this study was obtained from the 2014 Ghana Demographic and Health Survey. We used data of 1,441 women who gave birth in the 5 years preceding the survey and were dwelling in urban areas. By the use of Stata version 14.2, we conducted both descriptive and multivariable logistic regression analyses. Results We found that 7.9% of women in urban areas in Ghana delivered at home. The study revealed that, compared to women who lived in the Northern region, women who lived in the Brong Ahafo region [AOR = 0.38, CI = 0.17–0.84] were less likely to deliver at home. The likelihood of home delivery was high among women in the poorest wealth quintile [AOR = 2.02, CI = 1.06–3.86], women who professed other religions [AOR = 3.45; CI = 1.53–7.81], and those who had no antenatal care visits [AOR = 7.17; 1.64–31.3]. Conversely, the likelihood of home delivery was lower among women who had attained secondary/higher education [AOR = 0.30; 0.17–0.53], compared to those with no formal education. Conclusion The study identified region of residence, wealth quintile, religion, antenatal care visits, and level of education as factors associated with home delivery among urban residents in Ghana. Therefore, health promotion programs targeted at home delivery need to focus on these factors. We also recommend that a qualitative study should be conducted to investigate the factors responsible for the differences in home delivery in terms of region, as the present study could not do so