1,499 research outputs found
Religiosity and Sexual Risk Behaviors Among Latina Adolescents: Trends from 1995 to 2008
Purpose: The purpose of this study was to determine trends in the influence of religiosity on sexual activity of Latina adolescents in the United States from 1995 to 2008 and to determine if differences existed between the Mexican American and other Latina groups.
Methods: The sample comprised the subset of unmarried, 15–21-year-old (mean 17 years) Latina female respondents in the 1995 (n=267), 2002 (n=306), and 2006–2008 (n=400) National Survey of Family Growth (NSFG) datasets. Associations between religiosity (importance of religion and service attendance) and history of ever having sex, number of sex partners, and age of sexual debut were investigated.
Results: Less than one half of Latinas in 1995 (44%) and in 2006–2008 (44%) reported that religion was very important to them, whereas in 2002, 50% reported it was important. Only in 1995 did Latinas who viewed religion as very important have a significantly lower level of sexual initiation. In 1995 and in 2006–2008, Latinas who held religion as very important had significantly fewer partners. In all three cohorts, the higher religious importance group had higher virgin survival rates. Across cohorts, approximately one third of respondents reported frequent religious attendance. In all cohorts, frequent attenders were less likely to have had sex, had fewer partners, and had older age at sexual debut. The survival rate as virgins for Mexican origin Latinas was higher in 1995 and 2002 compared to non-Mexican Latinas but was almost the same in 2006–2008.
Conclusions: Religiosity had a protective association with sexual activity among Latina adolescents. The association of importance of religion with sexual activity has diminished from 1995 to 2008, however, whereas the importance of service attendance has remained stable. The influence of religion was more apparent among the Latinas of Mexican origin, but this greater influence also diminished by 2006–2008
Expanding hot flow in the black hole binary SWIFT J1753.5-0127: evidence from optical timing
We describe the evolution of optical and X-ray temporal characteristics
during the outburst decline of the black hole X-ray binary SWIFT J1753.5-0127.
The optical/X-ray cross-correlation function demonstrates a single positive
correlation at the outburst peak, then it has multiple dips and peaks during
the decline stage, which are then replaced by the precognition dip plus peak
structure in the outburst tail. Power spectral densities and phase lags show a
complex evolution, revealing the presence of intrinsically connected optical
and X-ray quasi-periodic oscillations. For the first time, we quantitatively
explain the evolution of these timing properties during the entire outburst
within one model, the essence of which is the expansion of the hot accretion
flow towards the tail of the outburst. The pivoting of the spectrum produced by
synchrotron Comptonization in the hot flow is responsible for the appearance of
the anti-correlation with the X-rays and for the optical quasi-periodic
oscillations. Our model reproduces well the cross-correlation and phase lag
spectrum during the decline stage, which could not be understood with any model
proposed before.Comment: 13 pages, 11 figures, MNRAS submitte
Ulcerative enteritis in quail
Publication authorized January 31, 1941.Digitized 2007 AES.Includes bibliographical references (page 27)
Kinematic and morphological modeling of the bipolar nebula Sa2-237
We present [OIII]500.7nm and Halpha+[NII] images and long-slit, high
resolution echelle spectra in the same spectral regions of Sa2--237, a possible
bipolar planetary nebula. The image shows a bipolar nebula of about 34" extent,
with a narrow waist, and showing strong point symmetry about the central
object, indicating it's likely binary nature. The long slit spectra were taken
over the long axis of the nebula, and show a distinct ``eight'' shaped pattern
in the velocity--space plot, and a maximum projected outflow velocity of
V=106km/s, both typical of expanding bipolar planetary nebulae. By model
fitting the shape and spectrum of the nebula simultaneously, we derive the
inclination of the long axis to be 70 degrees, and the maximum space velocity
of expansion to be 308 km/s. Due to asymmetries in the velocities we adopt a
new value for the system's heliocentric radial velocity of -30km/s. We use the
IRAS and 21cm radio fluxes, the energy distribution, and the projected size of
Sa2-237 to estimate it's distance to be 2.1+-0.37kpc. At this distance Sa2-237
has a luminosity of 340 Lsun, a size of 0.37pc, and -- assuming constant
expansion velocity -- a nebular age of 624 years. The above radial velocity and
distance place Sa2--237 in the disk of the Galaxy at z=255pc, albeit with
somewhat peculiar kinematics.Comment: 10pp, 4 fig
Asynchronous food-web pathways could buffer the response of Serengeti predators to El Niño southern oscillation
Understanding how entire ecosystems maintain stability in the face of climatic and human disturbance is one of the most fundamental challenges in ecology. Theory suggests that a crucial factor determining the degree of ecosystem stability is simply the degree of synchrony with which different species in ecological food webs respond to environmental stochasticity. Ecosystems in which all food-web pathways are affected similarly by external disturbance should amplify variability in top carnivore abundance over time due to population interactions, whereas ecosystems in which a large fraction of pathways are nonresponsive or even inversely responsive to external disturbance will have more constant levels of abundance at upper trophic levels. To test the mechanism underlying this hypothesis, we used over half a century of demographic data for multiple species in the Serengeti (Tanzania) ecosystem to measure the degree of synchrony to variation imposed by an external environmental driver, the El Niño Southern Oscillation (ENSO). ENSO effects were mediated largely via changes in dry-season vs. wet-season rainfall and consequent changes in vegetation availability, propagating via bottom-up effects to higher levels of the Serengeti food web to influence herbivores, predators and parasites. Some species in the Serengeti food web responded to the influence of ENSO in opposite ways, whereas other species were insensitive to variation in ENSO. Although far from conclusive, our results suggest that a diffuse mixture of herbivore responses could help buffer top carnivores, such as Serengeti lions, from variability in climate. Future global climate changes that favor some pathways over others, however, could alter the effectiveness of such processes in the future
Real-Space Observation of Quantum Tunneling by a Carbon Atom: Flipping Reaction of Formaldehyde on Cu(110)
We
present a direct observation of carbon-atom tunneling in the
flipping reaction of formaldehyde between its two mirror-reflected
states on a Cu(110) surface using low-temperature scanning tunneling
microscopy (STM). The flipping reaction was monitored in real time,
and the reaction rate was found to be temperature independent below
10 K. This indicates that this reaction is governed by quantum mechanical
tunneling, albeit involving a substantial motion of the carbon atom
(∼1 Å). In addition, deuteration of the formaldehyde molecule
resulted in a significant kinetic isotope effect (<i>R</i><sub>CH<sub>2</sub>O</sub>/<i>R</i><sub>CD<sub>2</sub>O</sub> ≈ 10). The adsorption structure, reaction pathway, and tunneling
probability were examined by density functional theory calculations,
which corroborate the experimental observations
Humour as social dreaming:Stand-up comedy as therapeutic performance
Stand-up comedy binds dramatic cultural spectacle to ritualised, intimate exposure. Examining ‘case’ examples from live comic performance, this paper describes stand-up as a kind of social dreaming. The article proposes a theoretical frame drawing on Thomas Ogden’s notion of ‘talking as dreaming’ and psychoanalytic accounts connecting humour and melancholia. Locating the stand-up comedian’s propensity for humour in a specialist capacity to hone, display and process traumata, the paper characterises stand-up as a performative oscillation evoking paranoid-schizoid and depressive anxieties. A psychosocial gloss places stand-up as a cultural resource in the service of the popular-as-therapeutic. The paper articulates complementarities between Henri Bergson’s formulations on the function of laughter and an emergent object relations account in order to help to recognise ‘containing’ and ‘cultural-restorative’ aspects of much stand-up, understood as contemporary psychosocial ritual
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