2,264 research outputs found

    VIC ... High Yielding, Strong Gluten Durum

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    'Vic' (CI 17789) is a durum wheat cultivar (variety) developed by the North Dakota Agricultural Experiment Station, North Dakota State University, in cooperation with Agricultural Research, Science and Education Administration, the U. S. Department of Agriculture. Vic combines high grain yield and strong gluten characteristics. Gluten strength gives superior cooked firmness to various pasta products made from durum semolina. The improved yielding ability and strong gluten of Vic should make it a potential replacement for all presently grown normal height cultivars. Vic was developed in only six years from the final cross by utilizing early generation (F 3) yield and quality testing and three years of winter nurseries

    Interacting Turing-Hopf Instabilities Drive Symmetry-Breaking Transitions in a Mean-Field Model of the Cortex: A Mechanism for the Slow Oscillation

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    Electrical recordings of brain activity during the transition from wake to anesthetic coma show temporal and spectral alterations that are correlated with gross changes in the underlying brain state. Entry into anesthetic unconsciousness is signposted by the emergence of large, slow oscillations of electrical activity (≲1  Hz) similar to the slow waves observed in natural sleep. Here we present a two-dimensional mean-field model of the cortex in which slow spatiotemporal oscillations arise spontaneously through a Turing (spatial) symmetry-breaking bifurcation that is modulated by a Hopf (temporal) instability. In our model, populations of neurons are densely interlinked by chemical synapses, and by interneuronal gap junctions represented as an inhibitory diffusive coupling. To demonstrate cortical behavior over a wide range of distinct brain states, we explore model dynamics in the vicinity of a general-anesthetic-induced transition from “wake” to “coma.” In this region, the system is poised at a codimension-2 point where competing Turing and Hopf instabilities coexist. We model anesthesia as a moderate reduction in inhibitory diffusion, paired with an increase in inhibitory postsynaptic response, producing a coma state that is characterized by emergent low-frequency oscillations whose dynamics is chaotic in time and space. The effect of long-range axonal white-matter connectivity is probed with the inclusion of a single idealized point-to-point connection. We find that the additional excitation from the long-range connection can provoke seizurelike bursts of cortical activity when inhibitory diffusion is weak, but has little impact on an active cortex. Our proposed dynamic mechanism for the origin of anesthetic slow waves complements—and contrasts with—conventional explanations that require cyclic modulation of ion-channel conductances. We postulate that a similar bifurcation mechanism might underpin the slow waves of natural sleep and comment on the possible consequences of chaotic dynamics for memory processing and learning

    Perfect design or practical study? A workshop on navigating the challenges of community based prevention research

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    Subject: There is a shared interest among public health researchers in tackling methodological issues surrounding community based research, and on moving beyond a focus on individual level change. As part of a project on community empowerment funded by the People’s Health Trust, we have conducted a feasibility study on quantitative and economic evaluation of complex community-based interventions. To understand different quantitative methods that can be used to evaluate community empowerment interventions, we have undertaken a methodological literature review that identified the following sets of challenges: Defining population of interest – interventions taking place at a community level are not specifically targeted at a well-defined group of individuals. Therefore it is challenging to even find those who are affected by an intervention. Diverse and un-prescribed effects – the effect of community empowerment interventions are likely broad, suggesting we need to measure multiple outcomes in order to detect change. This increases the likelihood of detecting spurious change and can require a lot of resource. Furthermore, in many cases these outcomes are not pre-defined by a programme (i.e. communities choose their own foci)

    Sense of competence, autonomy and relatedness during primary-secondary transition: children express their own experiences

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    This paper contributes a greater understanding of the importance of a sense of competence, autonomy and relatedness to children experiencing the primarysecondary schooling transition, drawing on the perspectives of the young people themselves. We address how the perspectives of transitioning children can further substantiate and illuminate Ryan and Deci’s Self Determination Theory (SDT; Ryan and Deci, 2019). SDT claims that satisfaction of a person’s needs for competence (attainment and confidence), autonomy (self-direction and capacity to critique) and relatedness (feeling affectively bonded to others) allows them to achieve ‘positiveexperience and wellness outcomes’ (p.219). We draw on data from two research projects, one a survey study of 288 transitioning children; and one a life-history study of 23 transitioning children. Our findings illustrated the potential benefits of policymakers giving priority to a wider range of conceptions of competence beyond attainment in mathematics/English, in order to support transitioning children’s sense of competence including their self-confidence. Findings also highlighted the need to nurture children’s capacity to recognise and direct their own schooling trajectories more autonomously, directing their energies into engagement with learning and relationships rather than into riling against controls or seeking to avoid humiliation and punishment. Most positively, our data manifested children’s high levels of relatedness to both peers and teachers as they transitioned to new secondary schools. And above all, our data emphasised and exemplified the need for relatedness to accompany children’s strong sense of competence and autonomy during transition

    The AUSTRAL VLBI Observing Program

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    The AUSTRAL observing program was started in 2011, performing geodetic and astrometric very long baseline interferometry (VLBI) sessions using the new Australian AuScope VLBI antennas at Hobart, Katherine, and Yarragadee, with contribution from the Warkworth (New Zealand) 12 m and Hartebeesthoek (South Africa) 15 m antennas to make a southern hemisphere array of telescopes with similar design and capability. Designed in the style of the next-generation VLBI system, these small and fast antennas allow for a new way of observing, comprising higher data rates and more observations than the standard observing sessions coordinated by the International VLBI Service for Geodesy and Astrometry (IVS). In this contribution, the continuous development of the AUSTRAL sessions is described, leading to an improvement of the results in terms of baseline length repeatabilities by a factor of two since the start of this program. The focus is on the scheduling strategy and increased number of observations, aspects of automated operation, and data logistics, as well as results of the 151 AUSTRAL sessions performed so far. The high number of the AUSTRAL sessions makes them an important contributor to VLBI end-products, such as the terrestrial and celestial reference frames and Earth orientation parameters. We compare AUSTRAL results with other IVS sessions and discuss their suitability for the determination of baselines, station coordinates, source coordinates, and Earth orientation parameters

    The TANAMI Program

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    TANAMI (Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry) is a monitoring program to study the parsec-scale structures and dynamics of relativistic jets in active galactic nuclei (AGN) of the Southern Hemisphere with the Long Baseline Array and associated telescopes. Extragalactic jets south of -30 degrees declination are observed at 8.4 GHz and 22 GHz every two months at milliarcsecond resolution. The initial TANAMI sample is a hybrid radio and gamma-ray selected sample since the combination of VLBI and gamma-ray observations is crucial to understand the broadband emission characteristics of AGN.Comment: Confernce Proceedings for "X-ray Astronomy 2009" (Bologna), 3 pages, 3 figures, needs cls-fil
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