55 research outputs found
using HYP-smeared staggered fermions in unquenched QCD
We present results for kaon mixing parameter calculated using
HYP-smeared improved staggered fermions on the MILC asqtad lattices. We use
three lattice spacings (, and fm), ten different
valence quark masses (), and several light sea-quark
masses in order to control the continuum and chiral extrapolations. We derive
the next-to-leading order staggered chiral perturbation theory (SChPT) results
necessary to fit our data, and use these results to do extrapolations based
both on SU(2) and SU(3) SChPT. The SU(2) fitting is particularly
straightforward because parameters related to taste-breaking and matching
errors appear only at next-to-next-to-leading order. We match to the continuum
renormalization scheme (NDR) using one-loop perturbation theory. Our final
result is from the SU(2) analysis, with the SU(3) result providing a (less
accurate) cross check. We find and ,
where the first error is statistical and the second systematic. The error is
dominated by the truncation error in the matching factor. Our results are
consistent with those obtained using valence domain-wall fermions on lattices
generated with asqtad or domain-wall sea quarks.Comment: 37 pages, 31 figures, most updated versio
Quantum Algorithm Implementations for Beginners
As quantum computers become available to the general public, the need has
arisen to train a cohort of quantum programmers, many of whom have been
developing classical computer programs for most of their careers. While
currently available quantum computers have less than 100 qubits, quantum
computing hardware is widely expected to grow in terms of qubit count, quality,
and connectivity. This review aims to explain the principles of quantum
programming, which are quite different from classical programming, with
straightforward algebra that makes understanding of the underlying fascinating
quantum mechanical principles optional. We give an introduction to quantum
computing algorithms and their implementation on real quantum hardware. We
survey 20 different quantum algorithms, attempting to describe each in a
succinct and self-contained fashion. We show how these algorithms can be
implemented on IBM's quantum computer, and in each case, we discuss the results
of the implementation with respect to differences between the simulator and the
actual hardware runs. This article introduces computer scientists, physicists,
and engineers to quantum algorithms and provides a blueprint for their
implementations
Genome-wide association analyses of physical activity and sedentary behavior provide insights into underlying mechanisms and roles in disease prevention
Although physical activity and sedentary behavior are moderately heritable, little is known about the mechanisms that influence these traits. Combining data for up to 703,901 individuals from 51 studies in a multi-ancestry meta-analysis of genome-wide association studies yields 99 loci that associate with self-reported moderate-to-vigorous intensity physical activity during leisure time (MVPA), leisure screen time (LST) and/or sedentary behavior at work. Loci associated with LST are enriched for genes whose expression in skeletal muscle is altered by resistance training. A missense variant in ACTN3 makes the alpha-actinin-3 filaments more flexible, resulting in lower maximal force in isolated type IIA muscle fibers, and possibly protection from exercise-induced muscle damage. Finally, Mendelian randomization analyses show that beneficial effects of lower LST and higher MVPA on several risk factors and diseases are mediated or confounded by body mass index (BMI). Our results provide insights into physical activity mechanisms and its role in disease prevention. Multi-ancestry meta-analyses of genome-wide association studies for self-reported physical activity during leisure time, leisure screen time, sedentary commuting and sedentary behavior at work identify 99 loci associated with at least one of these traits
The isimodeni style: traditional beadwork, Zulu trinket or, South African sartorial tradition on Durban’s Golden Mile?
Beadwork is a well-documented aspect of the socio-political culture of isiZulu-speaking groupings in Southern Africa. Whilst scholarship on beadwork deals largely with the denotative and connotative value it offers wearers, this article’s contribution relates both to its commodification and apolitical value by confronting a general assumption that a beadwork style known as isimodeni (modern beadwork), produced as a trinket for tourists along Durban’s racially stratified Golden Mile since the 1960s, is an authentic representation of a Zulu material culture. The paper probes how traditional beadwork and rickshaw rides (with both highly decorated carts and pullers) were earmarked by tourism officials of the time as commodities that could serve a demand for colourful exoticism and accessible “Zulu” culture. Methodologically, the article draws on the visual analysis of beaded artefacts and photographs, in addition to ethnographic data derived from unstructured interviews with beadworkers on the Durban beachfront, to examine how a beadwork tradition transformed into a “Zulu” tourism commodity, and then transmuted into a nationalised form of ethnic identity and sartorial tradition
Genome-wide association analyses of physical activity and sedentary behavior provide insights into underlying mechanisms and roles in disease prevention
Although physical activity and sedentary behavior are moderately heritable, little is known about the mechanisms that influence these traits. Combining data for up to 703,901 individuals from 51 studies in a multi-ancestry meta-analysis of genome-wide association studies yields 99 loci that associate with self-reported moderate-to-vigorous intensity physical activity during leisure time (MVPA), leisure screen time (LST) and/or sedentary behavior at work. Loci associated with LST are enriched for genes whose expression in skeletal muscle is altered by resistance training. A missense variant in ACTN3 makes the alpha-actinin-3 filaments more flexible, resulting in lower maximal force in isolated type IIA muscle fibers, and possibly protection from exercise-induced muscle damage. Finally, Mendelian randomization analyses show that beneficial effects of lower LST and higher MVPA on several risk factors and diseases are mediated or confounded by body mass index (BMI). Our results provide insights into physical activity mechanisms and its role in disease prevention.publishedVersionPeer reviewe
Norepinephrine potentiates and serotonin depresses visual cortical responses by transforming eligibility traces
Reinforcement allows organisms to learn which stimuli predict subsequent biological relevance. Hebbian mechanisms of synaptic plasticity are insufficient to account for reinforced learning because neuromodulators signaling biological relevance are delayed with respect to the neural activity associated with the stimulus. A theoretical solution is the concept of eligibility traces (eTraces), silent synaptic processes elicited by activity which upon arrival of a neuromodulator are converted into a lasting change in synaptic strength. Previously we demonstrated in visual cortical slices the Hebbian induction of eTraces and their conversion into LTP and LTD by the retroactive action of norepinephrine and serotonin Here we show in vivo in mouse V1 that the induction of eTraces and their conversion to LTP/D by norepinephrine and serotonin respectively potentiates and depresses visual responses. We also show that the integrity of this process is crucial for ocular dominance plasticity, a canonical model of experience-dependent plasticity
Considering planned change anew: stretching large group interventions strategically, emotionally and meaningfully
Large Group Interventions, methods for involving “the whole system” in a change process, are important contemporary planned organizational change approaches. They are well known to practitioners but unfamiliar to many organizational researchers, despite the fact that these interventions address crucial issues about which many organizational researchers are concerned. On the other hand, these interventions do not appear to be informed by contemporary developments in organizational theorizing. This disconnect on both sides is problematic. We describe such interventions and their importance; illustrate them with extended descriptions of particular Future Search and Whole‐Scale™ change interventions; summarize research on strategy, emotion, and sensemaking that may inform them; and suggest questions about the interventions that may stimulate research and reflection on practice. We also discuss conditions that may foster effective engagement between Large Group Interventions practitioners and organizational researchers. Our approach represents a way to conduct a review that combines scholarly literature and skilled practice and to initiate a dialog between them
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