2,667 research outputs found
Remote programmable position controller final report, may 1963 - feb. 1964
Remote programmable position controller for guidance signal processor and tape mode
Design of Drip Irrigation Lines
This report presents a simple way of estimating friction drop along the lateral line, pressure distribution along the drip line, and variation of emitter discharge along the lateral. Design charts are presented for determining pressure and length of the lateral lines and submains of a drip irrigation system
Correlation Between Plaque and Gingivitis
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141522/1/jper0424.pd
Increasing the Net Charge and Decreasing the Hydrophobicity of Bovine Carbonic Anhydrase Decreases the Rate of Denaturation with Sodium Dodecyl Sulfate
AbstractThis study compares the rate of denaturation with sodium dodecyl sulfate (SDS) of the individual rungs of protein charge ladders generated by acylation of the lysine ΔâNH3+ groups of bovine carbonic anhydrase II (BCA). Each acylation decreases the number of positively charged groups, increases the net negative charge, and increases the hydrophobic surface area of BCA. This study reports the kinetics of denaturation in solutions containing SDS of the protein charge ladders generated with acetic and hexanoic anhydrides; plotting these rates of denaturation as a function of the number of modifications yields a U-shaped curve. The proteins with an intermediate number of modifications are the most stable to denaturation by SDS. There are four competing interactionsâtwo resulting from the change in electrostatics and two resulting from the change in exposed hydrophobic surface areaâthat determine how a modification affects the stability of a rung of a charge ladder of BCA to denaturation with SDS. A model based on assumptions about how these interactions affect the folded and transition states has been developed and fits the experimental results. Modeling indicates that for each additional acylation, the magnitude of the change in the activation energy of denaturation (ÎÎGâĄ) due to changes in the electrostatics is much larger than the change in ÎÎG⥠due to changes in the hydrophobicity, but the intermolecular and intramolecular electrostatic effects are opposite in sign. At the high numbers of acylations, hydrophobic interactions cause the hexanoyl-modified BCA to denature nearly three orders of magnitude more rapidly than the acetyl-modified BCA
Optical properties of nanocrystal films: blue shifted transitions as signature of strong coupling
We present a theoretical study at the atomistic level of the optical properties of semiconductor nanocrystal films. We investigate the dependence of the absorption coefficient on size, inter-dot separation, surface stoichiometry and morphology, temperature, position of the Fermi level and light polarization. Our results show that, counter-intuitively, huge blue shifts are expected in some intra-band transitions for strongly coupled arrays, in contrast with the predicted and observed red shift of the band gap absorption in such systems. Furthermore, we find that the energies of such transitions can be tuned within a range of several hundreds of meV, just by engineering the inter-dot separation in the film through the choice of appropriately sized capping ligands. Finally we discuss the application of this effect to nanocrystal-based intermediate-band solar cells
Fracture hospitalizations between years 2000 and 2007 in Switzerland: a trend analysis
Summary: In Switzerland, the total number and incidence of hospitalizations for major osteoporotic fractures increased between years 2000 and 2007, while hospitalizations due to hip fracture decreased. The cost impact of shorter hospital stays was offset by the increasing cost per day of hospitalization. Introduction: The aim of the study was to establish the trends and epidemiological characteristics of hospitalizations for major osteoporotic fractures (MOF) between years 2000 and 2007 in Switzerland. Methods: Sex- and age-specific trends in the number and crude and age-standardized incidences of hospitalized MOF (hip, clinical spine, distal radius, and proximal humerus) in women and men aged â„45years were analyzed, together with the number of hospital days and cost of hospitalization, based on data from the Swiss Federal Statistical Office hospital database and population statistics. Results: Between 2000 and 2007, the absolute number of hospitalizations for MOF increased by 15.9% in women and 20.0% in men, mainly due to an increased number of non-hip fractures (+37.7% in women and +39.7% in men). Hospitalizations for hip fractures were comparatively stable (â1.8% in women and +3.3% in men). In a rapidly aging population, in which the number of individuals aged â„45years grew by 11.1% (women) and 14.6% (men) over the study period, the crude and age-standardized incidences of hospitalizations decreased for hip fractures and increased for non-hip MOF, both in women and men. The length of hospital stay decreased for all MOF in women and men, the cost impact of which was offset by an increase in the daily costs of hospitalization. Conclusions: Between years 2000 and 2007, hospitalizations for MOF continued to increase in Switzerland, driven by an increasing number and incidence of hospitalizations for non-hip fractures, although the incidence of hip fractures has decline
Twitter and non-elites. Interpreting power dynamics in the life story of the (#)BRCA Twitter stream
In May 2013 and March 2015, actress Angelina Jolie wrote in the New York Times about her choice to undergo preventive surgery. In her two op-eds she explained that - as a carrier of the BRCA1 gene mutation - preventive surgery was the best way to lower her heightened risk of developing breast and ovarian cancer. By applying a digital methods approach to BRCA-related tweets from 2013 and 2015, before, during and after the exposure of Jolieâs story, this study maps and interprets Twitter discursive dynamics at two time points of the BRCA Twitter stream. Findings show an evolution in curation and framing dynamics occurring between 2013 and 2015, with individual patient advocates replacing advocacy organisations as top curators of BRCA content and coming to prominence as providers of specialist illness narratives. These results suggest that between 2013 and 2015, Twitter went from functioning primarily as an organisation-centred news reporting mechanism, to working as a crowdsourced specialist awareness system. This paper advances a twofold contribution. First, it points at Twitterâs fluid functionality for an issue public and suggests that by looking at the life story â rather than at a single time point â of an issue-based Twitter stream we can track the evolution of power roles underlying discursive practices and better interpret the emergence of non-elite actors in the public arena. Second, the study provides evidence of the rise of activist cultures that rely on fluid, non-elite, collective and individual social media engagement
How new technology is addressed by researchers in educational studies: approaches from high-performing universities in China and the UK
There is a crisis of expectation in relation to educational technology. This is sometimes interpreted as a failure of academic researchers to disseminate their work to educational practitioners. However, another interpretation dwells on the lack of vision characterising such research. Because teachers often encounter research most intensely during their own pre-service and in-service education, we review academic research here through a snapshot of output from 10 leading university Education departments sampled in the UK and China. Empirical papers with a central interest in new technology were scarce, representing around 10% of the sample. Research was strongly situated in 'classroom' contexts although, as critics have suggested, with limited attention to the wider ecology of those places and with teachers being the focal interest as much as students. An 'outcomes' research orientation was less common than an interest in process. Although this was approached with different methodologies in China and the UK. Discussion addresses the challenge of effective and authoritative dissemination and constraints arising from the political economy of research itself
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