1,205 research outputs found
Untangling the Mechanics and Topology in the Frictional Response of Long Overhand Elastic Knots
Article / Letter to editorLeids Instituut Onderzoek Natuurkund
Allelic diversity of HMW and LMW glutenin subunits and Ï-gliadins in Canadian hard red spring bread wheat (Triticum aestivum L.) developed over 150 years
Non-Peer ReviewedWheat (Triticum aestivum L.) is a major cereal crop that is grown around the world. Wheat based products are an important component of human diet as source of calories and proteins. The wheat grain storage proteins are made up of glutenin and gliadin subunits that form gluten in the dough, when wheat flour is mixed with water. The viscoelastic properties of wheat dough lend itself to make diverse food products consumed around the world. During the past few years, wheat gluten has been blamed for increased incidence of some chronic diseases such as obesity and associated cardiovascular ailments and type-2 diabetes. The main objective of this study was to study the diversity in wheat glutenins and gliadins, the two proteins that make up gluten, during 150 years of wheat improvement in Canada. A set of 37 hard red spring wheat cultivars were grown during 2013 and 2014, in a randomized complete block design with four replicates at the Kernen farm, University of Saskatchewan. Cultivars were selected based on the year of release from 1860 to 2007 and subdivided into historical and modern wheats. Historical cultivars included 11 entries released in Canada from 1860 until 1935 and the modern group included 26 cultivars released after 1935 and up to 2007. Gluten protein composition was determined by SDS-PAGE. Most of the genotypes in both groups had the combination Glu-A1b (2*), Glu-B1c (7+9) and Glu-D1d (5+10) for the high molecular weight glutenins (HMW-GS). Another allele that remained stable was the low molecular weight glutenin (LMW-GS) Glu-A3e present in 91% (historical) to 58% (modern) of the cultivars. Most variation was observed in the frequency of appearance of the most common subunits in the LMW-GS Glu-B3 and Glu-D3. For instance, in the historical group, the most common alleles were the Glu-B3bâ (55%) and the Glu-D3a (37%) or Glu-D3b (36%) whereas in modern cultivars Glu-B3h (58%) and the Glu-D3c (58%) were most frequent. Regarding Ï-gliadins encoded by the Gli-B1, a relative high proportion of the historical genotypes carried the Gli-B1b subunit whereas in modern cultivars the Gli-B1d (58%) was common. No major alterations in the gluten subunits were observed between the Canadian historical and modern hard red spring wheat cultivars developed over the last century and half. However, subtle differences were found in the HMW-GS and the LMW-GS Glu-A3, and the frequency of appearance in the Glu-D3 and Glu-B3 (LMW-GS) and the Gli-B1 (Ï-gliadins). The impact of the alterations on the incidence of Celiac disease is currently being studied
Influence of Education, Family Composition and Family Atmosphere at the Alcohol Consumption of Young Adolescents
Alcoholgebruik op jonge leeftijd is zeer verontrustend. In dit onderzoek werd nagegaan of opleidingsniveau, gezinssamenstelling en gezinsklimaat samenhangen met het alcoholgebruik van jonge adolescenten en tevens of gezinsklimaat een modererende invloed heeft op de verbanden tussen opleidingsniveau/gezinssamenstelling en alcoholgebruik
Observation of Andreev Reflection Enhanced Shot Noise
We have experimentally investigated the quasiparticle shot noise in
NbN/MgO/NbN superconductor - insulator - superconductor tunnel junctions. The
observed shot noise is significantly larger than theoretically expected. We
attribute this to the occurrence of multiple Andreev reflection processes in
pinholes present in the MgO barrier. This mechanism causes the current to flow
in large charge quanta (Andreev clusters), with a voltage dependent average
value of m = 1+ 2 Delta/eV times the electron charge. Because of this charge
enhancement effect, the shot noise is increased by the factor m.Comment: 4 pages, 5 figures include
Teaching Critical Reflection in Occupational Therapy: A Quantitative Pre/Post Evaluation of Student Learning
This study was designed to answer the question, âDoes student recognition of the assumptions underlying occupational therapy practice increase after participation in guided exercises of critical reflection?â The project is grounded in critical occupational therapy (as first named by Whiteford and Townsend) to promote students to reflect actively on dominant disciplinary ideologies and self-reflect on how oneâs social positionality impacts understandings of occupational participation. The concept of non-sanctioned occupations was drawn on as a means to facilitate changes in student recognition. A one group, quantitative pre/post design with six open-ended responses was undertaken with masterâs-level students (N = 53) at two private universities. A learning module involving an interactive 90-min lecture with a pre-assigned reading and associated reflection guide was used to facilitate questioning of disciplinary ideologies. Even when introduced in small amounts, the use of critical occupational therapy in education shows benefits. Wilcoxon signed rank tests indicated the learning model increased student recognition of underlying personal assumptions. Thematic qualitative analysis confirmed these results and described patterns of change between pre/post surveys. This study demonstrates the potential for occupational therapy curricula to embed methods that instill critical self-reflection in emerging practitioners, with the promise of transforming clinical assessment and practice
IF impedance and mixer gain of NbN hot electron bolometers
The intermediate frequency (IF) characteristics, the frequency dependent IF impedance, and the mixer conversion gain of a small area hot electron bolometer (HEB) have been measured and modeled. The device used is a twin slot antenna coupled NbN HEB mixer with a bridge area of 1Ă0.15 ”m^2, and a critical temperature of 8.3 K. In the experiment the local oscillator frequency was 1.300 THz, and the (IF) 0.05â10 GHz. We find that the measured data can be described in a self-consistent manner with a thin film model presented by Nebosis et al. [Proceedings of the Seventh International Symposium on Space Terahertz Technology, Charlottesville, VA, 1996 (unpublished), pp. 601â613], that is based on the two temperature electron-phonon heat balance equations of Perrin-Vanneste [J. Phys. (Paris) 48, 1311 (1987)]. From these results the thermal time constant, governing the gain bandwidth of HEB mixers, is observed to be a function of the electron-phonon scattering time, phonon escape time, and the electron temperature. From the developed theory the maximum predicted gain bandwidth for a NbN HEB is found to be 5.5â6 GHz. In contrast, the gain bandwidth of the device under discussion was measured to be ~2.3 GHz which, consistent with the outlined theory, is attributed to a somewhat low critical temperature and nonoptimal film thickness (6 nm)
RAMESES publication standards: realist syntheses
PMCID: PMC3558331This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
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