4,323 research outputs found
HCU400: An Annotated Dataset for Exploring Aural Phenomenology Through Causal Uncertainty
The way we perceive a sound depends on many aspects-- its ecological
frequency, acoustic features, typicality, and most notably, its identified
source. In this paper, we present the HCU400: a dataset of 402 sounds ranging
from easily identifiable everyday sounds to intentionally obscured artificial
ones. It aims to lower the barrier for the study of aural phenomenology as the
largest available audio dataset to include an analysis of causal attribution.
Each sample has been annotated with crowd-sourced descriptions, as well as
familiarity, imageability, arousal, and valence ratings. We extend existing
calculations of causal uncertainty, automating and generalizing them with word
embeddings. Upon analysis we find that individuals will provide less polarized
emotion ratings as a sound's source becomes increasingly ambiguous; individual
ratings of familiarity and imageability, on the other hand, diverge as
uncertainty increases despite a clear negative trend on average
Fast optical preparation, control, and readout of a single quantum dot spin
We propose and demonstrate the sequential initialization, optical control, and readout of a single spin trapped in a semiconductor quantum dot. Hole spin preparation is achieved through ionization of a resonantly excited electron-hole pair. Optical control is observed as a coherent Rabi rotation between the hole and charged-exciton states, which is conditional on the initial hole spin state. The spin-selective creation of the charged exciton provides a photocurrent readout of the hole spin state. © 2008 The American Physical Society
An Adolescent Nutrition Learning Model to Facilitate Behavior Change in Overweight Teens
Understanding the process by which adolescents learn about nutrition is necessary for developing tailored education that leads to sustainable behavior change. Teens aged 15–17 participating in an obesity prevention program were interviewed. From the data, three themes emerged and informed development of an adolescent nutrition learning model. The themes were (a) valuable nutrition information provided by a reputable source, (b) hands-on learning as a learning preference, and (c) the linking of concepts learned to behavior change. The adolescent nutrition learning model that resulted encapsulates obese adolescents\u27 process for learning about nutrition to bring about behavior change and can be integrated into nutrition education programs and interventions
Football (Soccer) as a probable cause of long-term neurological impairment and neurodegeneration: a narrative review of the debate
Football (soccer) is the most widely played sport across the globe. Due to some recent high-profile cases and epidemiological studies suggesting football can lead to neurodegeneration, scientific and public interest has been piqued. This has resulted in research into whether an association between football participation and neurodegeneration or neurological impairment is present. It has been theorised that a combination of repeated sub-concussive and concussive injuries, due to ball-heading and head collisions, may lead to neurodegeneration. However, evidence remains conflicting. Due to the popularity of the sport, and the serious conditions it has been linked to, it is important to determine whether repeated head impacts during football participation can play a causative role in neurodegenerative disease. To answer this question, a review of the current literature was carried out. Epidemiological evidence showed a higher incidence of amyotrophic lateral sclerosis amongst amateur and professional footballers and that footballers in positions that involve less contact and heading, e.g., goalkeepers lead significantly longer lives. Additionally, imaging studies reach a similar conclusion, reporting changes in brain structure, blood flow, and inflammatory markers in footballers when compared to controls. However, studies looking at an association between heading frequency and cognition show a lack of consensus on whether a higher heading exposure results in reduced cognition. Similarly, in neuropathological studies, signs of chronic traumatic encephalopathy (CTE) have been found in some former players, with contrasting studies suggesting low levels of CTE-type pathology are found in the general population, regardless of exposure to head trauma. The majority of studies suggest a link between football and neurodegenerative disease. However, the high prevalence of retrospective cohort and cross-sectional studies, often plagued by recall bias, undermine the conclusions drawn. Therefore, until larger prospective cohort studies are conducted, concrete conclusions cannot be made. However, caution can be exercised to limit head impacts
FUSE and HST/STIS far-ultraviolet observations of AM Herculis in an extended low state
We have obtained FUSE and HST/STIS time-resolved spectroscopy of the polar AM
Herculis during a deep low state. The spectra are entirely dominated by the
emission of the white dwarf. Both the far-ultraviolet (FUV) flux as well as the
spectral shape vary substantially over the orbital period, with maximum flux
occurring at the same phase as during the high state. The variations are due to
the presence of a hot spot on the white dwarf, which we model quantitatively.
The white dwarf parameters can be determined from a spectral fit to the faint
phase data, when the hot spot is self-eclipsed. Adopting the distance of
79+8-6pc determined by Thorstensen, we find an effective temperature of
19800+-700K and a mass of Mwd=0.78+0.12-0.17Msun. The hot spot has a lower
temperature than during the high state, ~34000-40000K, but covers a similar
area, ~10% of the white dwarf surface. Low state FUSE and STIS spectra taken
during four different epochs in 2002/3 show no variation of the FUV flux level
or spectral shape, implying that the white dwarf temperature and the hot spot
temperature, size, and location do not depend on the amount of time the system
has spent in the low state. Possible explanations are ongoing accretion at a
low level, or deep heating, both alternatives have some weaknesses that we
discuss. No photospheric metal absorption lines are detected in the FUSE and
STIS spectra, suggesting that the average metal abundances in the white dwarf
atmosphere are lower than 1e-3 times their solar values.Comment: ApJ in press, 12 pages, 11 figure
Performance of LED-Based Fluorescence Microscopy to Diagnose Tuberculosis in a Peripheral Health Centre in Nairobi.
Sputum microscopy is the only tuberculosis (TB) diagnostic available at peripheral levels of care in resource limited countries. Its sensitivity is low, particularly in high HIV prevalence settings. Fluorescence microscopy (FM) can improve performance of microscopy and with the new light emitting diode (LED) technologies could be appropriate for peripheral settings. The study aimed to compare the performance of LED-FM versus Ziehl-Neelsen (ZN) microscopy and to assess feasibility of LED-FM at a low level of care in a high HIV prevalence country
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