447 research outputs found
First Direct Detection Limits on sub-GeV Dark Matter from XENON10
The first direct detection limits on dark matter in the MeV to GeV mass range
are presented, using XENON10 data. Such light dark matter can scatter with
electrons, causing ionization of atoms in a detector target material and
leading to single- or few-electron events. We use 15 kg-days of data acquired
in 2006 to set limits on the dark-matter-electron scattering cross section. The
strongest bound is obtained at 100 MeV where sigma_e < 3 x 10^{-38} cm^2 at 90%
CL, while dark matter masses between 20 MeV and 1 GeV are bounded by sigma_e <
10^{-37} cm^2 at 90% CL. This analysis provides a first proof-of-principle that
direct detection experiments can be sensitive to dark matter candidates with
masses well below the GeV scale.Comment: Submitted to PR
An Innovative Model of Agricultural Educationand Training in Guinea: Trending Toward Self-Sustainability
Exploringlocally-designed Agricultural Education and Training (AET) programs provides opportunitiesfor the entire system of AET to improve. Recognizing this potential, researchers conducted a case study of the Centre d’Apprentissage et de Formation Professionnelle Post-Primaire (i.e.,Center for Post Primary Professional Training [CAFPPP]) located in Macenta, Guinea.The case study was completed in conjunction with a comprehensive program review and participant-engaged strategic planning process. Results illuminate CAFPPP facessignificant challenges, including (a) limited funding, (b) insufficient teacher and administrator training,(c) limited curricular scope,and (d)systematic challenges. Additionally, three critical strengthswere identified at CAFPPP,(a)utilization of an effective, practice-based educational model, (b) stakeholder support, and (c) access to fertile agricultural land. Considering bothstrengths and weaknesses, researchers and CAFPPP stakeholders co-created a model to propel CAFPPP toward itsstatedgoal of becomingan “autonomous center of excellence.”The dynamic model envisionsa school leveraging its strengths to systematically address identified weaknessesvia intersecting approaches to funding, teacher and administrator development, and graduate support. Presentation of the model is supplemented with a discussionof, and recommendationsfor, application of themodel at CAFPPP. Furthermore, opportunities for all AET programs to reflect upon, and evaluate, current strategies in light of the proposed model are discusse
Lay perceptions of mental toughness: Understanding conceptual similarities and differences between lay and sporting contexts
Abstract: The predominant focus on sporting populations has limited our conceptual understanding of mental toughness in lay contexts. On the basis of its wider benefits beyond sports, we sought to understand the central and peripheral attributes of mental toughness from a layperson’s perspective. To this end, we employed a prototype analysis which consisted of two studies. In Study 1, a list of attributes of mental toughness was generated. In Study 2, these attributes were ranked for their centrality to mental toughness. Study 1 was an open-format questionnaire, where 138 laypeople generated a final list of 75 attributes of mental toughness. The most frequently mentioned attributes were self-belief, determination, perseverance, resilience and focus, which largely supported important attributes identified by athletes in existing mental toughness literature. Study 2 surveyed 136 laypeople, who identified mental strength, overcomes obstacles, achieves/operates under pressure, determination and resilience/recovery as the most central attributes to mental toughness. Although determination and resilience aligned with existing sporting accounts of mental toughness, the remaining attributes reflect differences in perception of mental toughness between sporting and lay contexts. Examination of peripherally-rated attributes provides insights into mental toughness as an enduring form of suffering. Overall, determination and resilience emerged as frequently mentioned, as well as highly central, and, as such, represent the foundation for a universal (i.e., not context-specific) understanding of mental toughness
Herding cats: observing live coding in the wild
After a momentous decade of live coding activities, this paper seeks to explore the practice with the aim of situating it in the history of contemporary arts and music. The article introduces several key points of investigation in live coding research and discusses some examples of how live coding practitioners engage with these points in their system design and performances. In the light of the extremely diverse manifestations of live coding activities, the problem of defining the practice is discussed, and the question raised whether live coding will actually be necessary as an independent category
The Hot QCD White Paper: Exploring the Phases of QCD at RHIC and the LHC
The past decade has seen huge advances in experimental measurements made in
heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and more
recently at the Large Hadron Collider (LHC). These new data, in combination
with theoretical advances from calculations made in a variety of frameworks,
have led to a broad and deep knowledge of the properties of thermal QCD matter.
Increasingly quantitative descriptions of the quark-gluon plasma (QGP) created
in these collisions have established that the QGP is a strongly coupled liquid
with the lowest value of specific viscosity ever measured. However, much
remains to be learned about the precise nature of the initial state from which
this liquid forms, how its properties vary across its phase diagram and how, at
a microscopic level, the collective properties of this liquid emerge from the
interactions among the individual quarks and gluons that must be visible if the
liquid is probed with sufficiently high resolution. This white paper, prepared
by the Hot QCD Writing Group as part of the U.S. Long Range Plan for Nuclear
Physics, reviews the recent progress in the field of hot QCD and outlines the
scientific opportunities in the next decade for resolving the outstanding
issues in the field.Comment: 110 pages, 33 figures, 429 references. Prepared as part of the U.S.
Long-Range Plan for Nuclear Physic
Dark sectors 2016 Workshop: community report
This report, based on the Dark Sectors workshop at SLAC in April 2016,
summarizes the scientific importance of searches for dark sector dark matter
and forces at masses beneath the weak-scale, the status of this broad
international field, the important milestones motivating future exploration,
and promising experimental opportunities to reach these milestones over the
next 5-10 years
US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report
This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in
Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference
Live Coding, Live Notation, Live Performance
This paper/demonstration explores relationships between code, notation including representation, visualisation and performance. Performative aspects of live coding activities are increasingly being investigated as the live coding movement continues to grow and develop. Although live instrumental performance is sometimes included as an accompaniment to live coding, it is often not a fully integrated part of the performance, relying on improvisation and/or basic indicative forms of notation with varying levels of sophistication and universality. Technologies are developing which enable the use of fully explicit music notations as well as more graphic ones, allowing more fully integrated systems of code in and as performance which can also include notations of arbitrary complexity. This itself allows the full skills of instrumental musicians to be utilised and synchronised in the process.
This presentation/demonstration presents work and performances already undertaken with these technologies, including technologies for body sensing and data acquisition in the translation of the movements of dancers and musicians into synchronously performable notation, integrated by live and prepared coding. The author together with clarinetist Ian Mitchell present a short live performance utilising these techniques, discuss methods for the dissemination and interpretation of live generated notations and investigate how they take advantage of instrumental musicians’ training-related neuroplasticity skills
Mercury toxicity in livers of northern pike (Esox lucius) from Isle Royale, USA
Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 147 (2008): 331-338, doi:10.1016/j.cbpc.2007.12.003.Many laboratory studies have documented that mercury can be toxic to fish, but it is
largely unknown if mercury is toxic to fish in their natural environments. The objective of our
study was to investigate the toxic effects of mercury on northern pike (Esox lucius) at Isle
Royale, Michigan. In 124 northern pike from eight inland lakes, concentrations of total mercury
in skin-on fillets ranged from 0.069 to 0.622 µg/g wet wt. Concentrations of total mercury in
livers increased exponentially compared with concentrations in fillets, to a maximum of 3.1 µg/g
wet wt. Methylmercury constituted a majority of the mercury in livers with total mercury
concentrations <0.5 µg/g wet wt, but declined to 28-51% of the mercury in livers with total
mercury concentrations >0.5 µg/g wet wt. Liver color (absorbance at 400 nm) varied among
northern pike and was positively related to liver total mercury concentration. The pigment
causing variation in liver color was identified as lipofuscin, which results from lipid peroxidation
of membranous organelles. An analysis of covariance revealed lipofuscin accumulation was
primarily associated with mercury exposure, and this association obscured any normal
accumulation from aging. We also documented decreased lipid reserves in livers and poor
condition factors of northern pike with high liver total mercury concentrations. Our results
suggest (i) northern pike at Isle Royale are experiencing toxicity at concentrations of total
mercury common for northern pike and other piscivorous fish elsewhere in North America and
(ii) liver color may be useful for indicating mercury exposure and effects in northern pike at Isle
Royale and possibly other aquatic ecosystems and other fish species.Financial support was provided by the U.S. Environmental Protection Agency STAR Graduate Fellowship Program to P.E.D
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