Characteristic Angles in the Wetting of an Angular Region: Deposit Growth

As was shown in an earlier paper [1], solids dispersed in a drying drop migrate to the (pinned) contact line. This migration is caused by outward flows driven by the loss of the solvent due to evaporation and by geometrical constraint that the drop maintains an equilibrium surface shape with a fixed boundary. Here, in continuation of our earlier paper [2], we theoretically investigate the evaporation rate, the flow field and the rate of growth of the deposit patterns in a drop over an angular sector on a plane substrate. Asymptotic power laws near the vertex (as distance to the vertex goes to zero) are obtained. A hydrodynamic model of fluid flow near the singularity of the vertex is developed and the velocity field is obtained. The rate of the deposit growth near the contact line is found in two time regimes. The deposited mass falls off as a weak power Gamma of distance close to the vertex and as a stronger power Beta of distance further from the vertex. The power Gamma depends only slightly on the opening angle Alpha and stays between roughly -1/3 and 0. The power Beta varies from -1 to 0 as the opening angle increases from 0 to 180 degrees. At a given distance from the vertex, the deposited mass grows faster and faster with time, with the greatest increase in the growth rate occurring at the early stages of the drying process.Comment: v1: 36 pages, 21 figures, LaTeX; submitted to Physical Review E; v2: minor additions to Abstract and Introductio

Deviation from Optimum Fallow Periods for Dry Rice Fields in Sarawak: The Effects on Rice Production

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。A predictable decline in rice yields is realized when dry rice fields are farmed after shorter than optimum fallow periods in specified contexts. Where fields are only sporadically and not consistently farmed in fallow periods that are less than optimum, no predictable decline in yields will occur

Cracks in rubber under tension exceed the shear wave speed

The shear wave speed is an upper limit for the speed of cracks loaded in tension in linear elastic solids. We have discovered that in a non-linear material, cracks in tension (Mode I) exceed this sound speed, and travel in an intersonic range between shear and longitudinal wave speeds. The experiments are conducted in highly stretched sheets of rubber; intersonic cracks can be produced simply by popping a balloon.Comment: 4 pages, 5 eps figure

The Inverse Shapley Value Problem

For $f$ a weighted voting scheme used by $n$ voters to choose between two candidates, the $n$ \emph{Shapley-Shubik Indices} (or {\em Shapley values}) of $f$ provide a measure of how much control each voter can exert over the overall outcome of the vote. Shapley-Shubik indices were introduced by Lloyd Shapley and Martin Shubik in 1954 \cite{SS54} and are widely studied in social choice theory as a measure of the "influence" of voters. The \emph{Inverse Shapley Value Problem} is the problem of designing a weighted voting scheme which (approximately) achieves a desired input vector of values for the Shapley-Shubik indices. Despite much interest in this problem no provably correct and efficient algorithm was known prior to our work. We give the first efficient algorithm with provable performance guarantees for the Inverse Shapley Value Problem. For any constant \eps > 0 our algorithm runs in fixed poly$(n)$ time (the degree of the polynomial is independent of \eps) and has the following performance guarantee: given as input a vector of desired Shapley values, if any "reasonable" weighted voting scheme (roughly, one in which the threshold is not too skewed) approximately matches the desired vector of values to within some small error, then our algorithm explicitly outputs a weighted voting scheme that achieves this vector of Shapley values to within error \eps. If there is a "reasonable" voting scheme in which all voting weights are integers at most \poly(n) that approximately achieves the desired Shapley values, then our algorithm runs in time \poly(n) and outputs a weighted voting scheme that achieves the target vector of Shapley values to within error $\eps=n^{-1/8}.

Is combinatorial chemistry on the right track for drug discovery?

Critical to the effective implementation of high throughput methods of synthesis is the necessity for a significant supporting level of automation. There are a number of critical issues associated with the successful introduction, and supporting role, of automation of small molecule chemical synthesis. Clearly there are needs for automation to increase drug candidate synthesis throughput. Automation of repetitive and laborious tasks associated with the synthesis process can release skilled chemists to apply their talents to the more challenging investigational aspects of developing new synthetic protocols. This provides continuity in the compound supply pipeline and ensures an optimal use of the automated platform for compound production. The very high fidelity of performing repetitive processes that can be managed through automation also removes some of the limitations and errors associated with more fallible human operators. This can include very difficult tasks associated with tracking data, and general information and inventory management. Taken collectively, these attributes associated with automation can lead to greater efficiencies, throughputs and improved allocation of human resources with concomitant reductions in costs associated with current day and future drug discovery. In our library development/synthesis paradigm, we feel that automation support must be invoked early in the process and that this automation support must continue throughout the project

Annie Marion Maclean, Feminist Pragmatist and Methodologist

Annie Marion Maclean was a major Chicago sociologist and methodologist. She was profoundly influenced by the gendered division of labor in sociology during her era. Maclean combined her work with the men and women of the early Chicago school of sociology and the women of Hull-House, an early social settlement. As a feminist pragmatist, Maclean was both a theorist and practitioner who used qualitative and quantitative methods. She set precedents in the Chicago school of ethnography, participant observation, and critical methodology. Maclean, however, was not the “mother” of ethnography. Harriet Martineau holds a far stronger claim to be a founding contributor to the origin and development of ethnographic methodologies in the social sciences

The Functional and Identity Indispensability Scale (FIIS)

This research further elaborated the concept of indispensability by developing and testing a new measure, the Functional and Identity Indispensability Scale (FIIS), to assess two dimensions on which groups can claim indispensability: functional indispensability and identity indispensability. In Study 1 we developed and validated the FIIS with a sample of 452 American college students. Results showed the expected two-factor structure and supported the prediction that identity and functional are two distinct, but related, forms of indispensability. FIIS showed a consistent structure across majority and minority members and the reliability of the two subscales was good. In Study 2, a sample of 154 White-American citizens evaluated the perceived indispensability (FIIS) of three minority groups: African-Americans, Hispanic-Americans, and Asian-Americans. Results showed the scale’s sensitivity. Participants attributed greater identity (vs. functional) indispensability to African-Americans, whereas the pattern was reversed for Asian-Americans. No differences were found for Hispanic-Americans. Criterion validity was supported by (a) positive associations with competence and warmth, (b) negative associations with negative emotions and with social distance towards all minority group targets. The psychometric properties of the FIIS suggest its potential to be valuable addition to the existing literature on common identities and intergroup relations.info:eu-repo/semantics/acceptedVersio

Development and preliminary validation of a tool measuring concordance and belief about performing pressure-relieving activities for pressure ulcer prevention in spinal cord injury

Objective: To develop and examine the reliability, and validity of a questionnaire measuring concordance for performing pressure-relief for pressure ulcer (PrU) prevention in people with Spinal Cord Injury (SCI). Methods: Phase I included item development, content and face validity testing. In phase II, the questionnaire was evaluated for preliminary acceptability, reliability and validity among 48 wheelchair users with SCI. Results: Thirty-seven items were initially explored. Item and factor analysis resulted in a final 26-item questionnaire with four factors reflecting concordance, perceived benefits, perceived negative consequences, and personal practical barriers to performing pressure-relief activities. The internal consistency reliability for four domains were very good (Cronbach's α = .75-.89). Pearson correlation coefficient on a test-retest of the same subjects yielded significant correlations in concordance (r = .91, p = .005), perceived benefit (r = .71, p < .04), perceived negative consequences (r = .98, p < .0001), personal barriers (r = .93, p= .002). Participants with higher levels of concordance reported a greater amount of pressure-relieving performed. Individuals viewing PrU as a threatening illness were associated with higher scores of concordance and tended to report a greater amount of pressure-relieving performance which provides evidence of criterion related validity. Conclusion: The new questionnaire demonstrated good preliminary reliability and validity in people with SCI. Further evaluation is necessary to confirm these findings using larger samples with follow-up data for predictive validity. Such a questionnaire could be used by clinicians to identify high risk of patients and to design individualised education programme for PrU prevention