3,631 research outputs found
A Reanalysis of the Carbon Abundance in the Translucent Cloud toward HD 24534
We have reanalyzed the Goddard High Resolution Spectrograph data set
presented by Snow et al. which contains the interstellar intersystem C II]
2325A line through the translucent cloud toward HD 24534 (X Persei). In
contrast to the results of Snow et al., we clearly detect the C II] feature at
the 3-sigma confidence level and measure a C^+ column density of 2.7 +/- 0.8 x
10^17 cm^-2. Accounting for the C I column density along the line of sight, we
find 10^6 C/H = 106 +/- 38 in the interstellar gas toward this star. This
gas-phase carbon-to-hydrogen ratio suggests that slightly more carbon depletion
may be occurring in translucent as compared to diffuse clouds. The average
diffuse-cloud C/H, however, is within the 1-sigma uncertainty of the
measurement toward HD 24534. We therefore cannot rule out the possibility that
the two cloud types have comparable gas-phase C/H, and therefore comparable
depletions of carbon.Comment: 9 pages, 3 figures, to appear in the Astrophysical Journal Letter
Automatic identification of the number of food items in a meal using clustering techniques based on the monitoring of swallowing and chewing
The number of distinct foods consumed in a meal is of significant clinical concern in the study of obesity and other eating disorders. This paper proposes the use of information contained in chewing and swallowing sequences for meal segmentation by food types. Data collected from experiments of 17 volunteers were analyzed using two different clustering techniques. First, an unsupervised clustering technique, Affinity Propagation (AP), was used to automatically identify the number of segments within a meal. Second, performance of the unsupervised AP method was compared to a supervised learning approach based on Agglomerative Hierarchical Clustering (AHC). While the AP method was able to obtain 90% accuracy in predicting the number of food items, the AHC achieved an accuracy \u3e95%. Experimental results suggest that the proposed models of automatic meal segmentation may be utilized as part of an integral application for objective Monitoring of Ingestive Behavior in free living conditions
Environmental Evaluation Report onn Various Completed Channel Improvement Projects in Eastern Arkansas
The objective of this report is to evaluate the beneficial and adverse effects that certain channel improvement projects have had on the natural or man-made environments of selected areas in eastern Arkansas. This evaluation will be used as a baseline for determining the immediate and long-term effects that a project may have on the existing environment of the Village Creek Basin
Stressing the Hormone: Biological and Psychosocial Factors associated with Chronic Stress
Chronic stress has been associated with a constellation of deleterious psychological and physical health outcomes. We collected cortisol from hair (CORT) to assess chronic stress retrospectively for 3 monthsâ time (3cms). Over two studies from the UMass Boston campus and the local community, we recruited in t1: 134 adults (ages 18-67; M = 29.49, SD = 12.48) and t2: 145 adults (ages18-30, M = 22.56, SD = 3.54) to participate on two studies assessing objective biological stress (via hair cortisol), subjective perceived stress (via self-reports), psychosocial factors, and health indicators. In follow-up Study 2, we also included indices of perceived discrimination, cardiovascular parameters, and affective vigilance.
Results: t1: CORT levels were positively associated with Total perceived stress and one health indicator: systolic blood pressure. An SES by Race interaction predicted both higher CORT and perceived stress, although higher SES did not always confer the expected benefit of higher SES: minorities in high SES had the greatest CORT, systolic blood pressure, and lowest self-rated health.
Results: t2: Perceived stress measures and new measures of discrimination were negatively associated with well-being and health. Higher racial/ethnic pride was associated with better health, but also increased daily discrimination and waist-to-hip ratio. The SES by Race interaction was again associated with Total perceived stress and minorities in higher SES reported greatest Total stress. Minorities also showed the greatest vigilance. Specifically, African-Americans had the longest latencies for social devaluation words during a modified Stroop, the greatest city stress, and the greatest pride/identity for heritage group
Distributing the burdens of climate change
Global climate change raises many questions for environmental political theorists. This article focuses on the question of identifying the agents that should bear the financial burden of preventing dangerous climate change. Identifying in a fair way the agents that should take the lead in climate mitigation and adaptation, as well as the precise burdens that these parties must bear, will be a key aspect of the next generation of global climate policies. After a critical review of a number of rival approaches to burden sharing, the paper argues that only a principled and philosophically robust reconciliation of three approaches to burden sharing (âcontribution to problemâ, âability to payâ and âbeneficiary paysâ) can generate a satisfactory mix of theoretical coherence and practical application
Objective and Subjective Stress Differences: Foreign-Born and U.S. Native Adults in Boston Communities
This study compares two high-risk populations: foreign- and US-born adults residing in the same Boston neighborhoods noted for high violence, low income, and greater morbidity and mortality for several chronic diseases (Health of Boston, 2010). The aims of the study are to improve community engagement and to identify stress-related differences between foreign and US-born adults and the interrelations between physiological and subjective stress indices in these populations. This presentation is part of the mini-symposium titled: How Community-Academic Partnership Initiatives Can Contribute to Translational Research
Yttrium-90 microsphere induced gastrointestinal tract ulceration
© 2008 South et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Hubble Space Telescope Observations of UV Oscillations in WZ Sagittae During the Decline from Outburst
We present a time series analysis of Hubble Space Telescope observations of
WZ Sge obtained in 2001 September, October, November and December as WZ Sge
declined from its 2001 July superoutburst. Previous analysis of these data
showed the temperature of the white dwarf decreased from ~29,000 K to ~18,000
K. In this study we binned the spectra over wavelength to yield ultraviolet
light curves at each epoch that were then analyzed for the presence of the
well-known 27.87 s and 28.96 s oscillations. We detect the 29 s periodicity at
all four epochs, but the 28 s periodicity is absent. The origin of these
oscillations has been debated since their discovery in the 1970s and competing
hypotheses are based on either white dwarf non-radial g-mode pulsations or
magnetically-channelled accretion onto a rotating white dwarf. By analogy with
the ZZ Ceti stars, we argue that the non-radial g-mode pulsation model demands
a strong dependence of pulse period on the white dwarf's temperature. However,
these observations show the 29 s oscillation is independent of the white
dwarf's temperature. Thus we reject the white dwarf non-radial g-mode pulsation
hypothesis as the sole origin of the oscillations. It remains unclear if
magnetically-funnelled accretion onto a rapidly rotating white dwarf (or belt
on the white dwarf) is responsible for producing the oscillations. We also
report the detection of a QPO with period ~18 s in the September light curve.
The amplitudes of the 29 s oscillation and the QPO vary erratically on short
timescales and are not correlated with the mean system brightness nor with each
other.Comment: 20 pages, 3 figures, 1 table; accepted for publication in Ap
Far Ultraviolet Observations of the Dwarf Nova VW Hyi in Quiescence
We present a 904-1183 A spectrum of the dwarf nova VW Hydri taken with the
Far Ultraviolet Spectroscopic Explorer during quiescence, eleven days after a
normal outburst, when the underlying white dwarf accreter is clearly exposed in
the far ultraviolet. However, model fitting show that a uniform temperature
white dwarf does not reproduce the overall spectrum, especially at the shortest
wavelengths. A better approximation to the spectrum is obtained with a model
consisting of a white dwarf and a rapidly rotating ``accretion belt''. The
white dwarf component accounts for 83% of the total flux, has a temperature of
23,000K, a v sin i = 400 km/s, and a low carbon abundance. The best-fit
accretion belt component accounts for 17% of the total flux, has a temperature
of about 48,000-50,000K, and a rotation rate Vrot sin i around 3,000-4,000
km/s. The requirement of two components in the modeling of the spectrum of VW
Hyi in quiescence helps to resolve some of the differences in interpretation of
ultraviolet spectra of VW Hyi in quiescence. However, the physical existence of
a second component (and its exact nature) in VW Hyi itself is still relatively
uncertain, given the lack of better models for spectra of the inner disk in a
quiescent dwarf nova.Comment: 6 figures, 10 printed page in the journal, to appear in APJ, 1 Sept.
2004 issue, vol. 61
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