5,465 research outputs found
Hippie Communes of the West Coast: A Study of Gender Roles and the Evolution of the Counterculture\u27s Definition of Freedom
Following the deterioration of conditions in the Haight-Ashbury in 1968, hippies moved to communes throughout the west coast, specifically in the nearby Santa Cruz Mountains above San Francisco in California. Beginning as a utopian vision, many of the traditions and problems that commune residents sought to escape manifested again in communal life, including the division of races, repression of women, and intolerance of homosexuals. Additionally, they could not escape the financial realities of the world they lived in, and communes were plagued with health issues and unscrupulous individuals. Eventually, women of the communes, forced to provide income for their families when their men drifted away, engaged in successful entrepreneurial ventures such as natural food co-ops -- the beginnings of the natural food craze which still exists today
MIRACAL: A mission radiation calculation program for analysis of lunar and interplanetary missions
A computational procedure and data base are developed for manned space exploration missions for which estimates are made for the energetic particle fluences encountered and the resulting dose equivalent incurred. The data base includes the following options: statistical or continuum model for ordinary solar proton events, selection of up to six large proton flare spectra, and galactic cosmic ray fluxes for elemental nuclei of charge numbers 1 through 92. The program requires an input trajectory definition information and specifications of optional parameters, which include desired spectral data and nominal shield thickness. The procedure may be implemented as an independent program or as a subroutine in trajectory codes. This code should be most useful in mission optimization and selection studies for which radiation exposure is of special importance
3D Biomimetic Platform
An apparatus and method that utilizes a radiation source and a simulated microgravity to provide combined stressors. The response of cells/bacteria/viruses and/or other living matter to the combined stressors can be evaluated to predict the effects of extended space missions. The apparatus and method can also be utilized to study diseases and to develop new treatments and vaccinations
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Featural and configural face processing in adults and infants: A behavioral and electrophysiological investigation
We sought to elucidate the behavioral and electrophysiological correlates of face processing, in adults and infants, by manipulating either the featural or configural information within the face. Two different experiments are reported. In these experiments, event-related potentials (ERPs) were recorded from the scalp while adult, 8-month-old, and 4-month-old participants completed configural-change and featural-change face tasks. The infants also completed a behavioral visual paired-comparison task with featural and configural face changes. ERP results reveal hemispheric differences in processing featural but not configural changes for the N170 in adults. Furthermore, featural and configural changes are processed differently within the right and left hemispheres. The right hemisphere N170 is significantly greater for configural compared to featural changes. The left hemisphere N170, however, exhibits the opposite effect. Infant data suggest that similar to adults, 8-month-old, but not 4-month-old participants, exhibit similar hemispheric differences between featural and configural changes for the P400 component. Behavioral results suggest increased sensitivity to both featural and configural face changes in 8-month-olds compared to 4-month-olds
Precisely computing bound orbits of spinning bodies around black holes I: General framework and results for nearly equatorial orbits
Very large mass ratio binary black hole systems are of interest both as a
clean limit of the two-body problem in general relativity, as well as for their
importance as sources of low-frequency gravitational waves. At lowest order,
the smaller body moves along a geodesic of the larger black hole's spacetime.
Post-geodesic effects include the gravitational self force, which incorporates
the backreaction of gravitational-wave emission, and the spin-curvature force,
which arises from coupling of the small body's spin to the black hole's
spacetime curvature. In this paper, we describe a method for precisely
computing bound orbits of spinning bodies about black holes. Our analysis
builds off of pioneering work by Witzany which demonstrated how to describe the
motion of a spinning body to linear order in the small body's spin. Exploiting
the fact that in the large mass-ratio limit spinning-body orbits are close to
geodesics and using closed-form results due to van de Meent describing
precession of the small body's spin along black hole orbits, we develop a
frequency-domain formulation of the motion which can be solved very precisely.
We examine a range of orbits with this formulation, focusing in this paper on
orbits which are eccentric and nearly equatorial (i.e., the orbit's motion is
out of the equatorial plane), but for which the small body's
spin is arbitrarily oriented. We discuss generic orbits with general small-body
spin orientation in a companion paper. We characterize the behavior of these
orbits and show how the small body's spin shifts the frequencies and
which affect orbital motion. These frequency shifts change
accumulated phases which are direct gravitational-wave observables,
illustrating the importance of precisely characterizing these quantities for
gravitational-wave observations. (Abridged)Comment: 38 pages, 5 figures, submitted to Physical Review D; corrected typo
in Equation (C6
Precisely computing bound orbits of spinning bodies around black holes II: Generic orbits
In this paper, we continue our study of the motion of spinning test bodies
orbiting Kerr black holes. Non-spinning test bodies follow geodesics of the
spacetime in which they move. A test body's spin couples to the curvature of
that spacetime, introducing a "spin-curvature force" which pushes the body's
worldline away from a geodesic trajectory. The spin-curvature force is an
important example of a post-geodesic effect which must be modeled carefully in
order to accurately characterize the motion of bodies orbiting black holes. One
motivation for this work is to understand how to include such effects in models
of gravitational waves produced from the inspiral of stellar mass bodies into
massive black holes. In this paper's predecessor, we describe a technique for
computing bound orbits of spinning bodies around black holes with a
frequency-domain description which can be solved very precisely. In that paper,
we present an overview of our methods, as well as present results for orbits
which are eccentric and nearly equatorial (i.e., the orbit's motion is no more
than out of the equatorial plane). In this paper, we apply
this formulation to the fully generic case -- orbits which are inclined and
eccentric, with the small body's spin arbitrarily oriented. We compute the
trajectories which such orbits follow, and compute how the small body's spin
affects important quantities such as the observable orbital frequencies
, and .Comment: 24 pages, 8 figures, submitted to Physical Review D; typos in
supplementary Mathematica notebook correcte
Review of Indigenous Oral Health
Indigenous Australians1 have poorer oral health than other Australians [1, 2]. Indigenous people suffer from more caries, periodontal diseases, and tooth loss than non-Indigenous people [3]. Tooth decay among the Indigenous population more commonly goes untreated, leading to more extractions. This discrepancy is attributed in part to the fact that access to culturally appropriate and timely dental care is often not available to Indigenous people, especially in rural and remote areas. Other information on oral health such as culturally appropriate resources about maintaining healthy teeth and mouths, and nutritional guidance on how much sugar is contained in certain foods and drinks, is also less available for the Indigenous Australian population. If Indigenous oral health is to be ameliorated, access to dental care must be improved, and an integrated holistic approach to oral health, which includes preventative measures, needs to be established
Impossibility to eliminate observer effect in the assessment of adherence in clinical trials.
PURPOSE: To utilize the Travoprost Dosing Aid (DA) in the assessment of patient medication adherence, while also determining whether or not altering the functionality of the DA in three randomized subject groups can reduce observer effect.
METHODS: Forty-five subjects were randomized into three groups: two with monitored DAs and one without monitoring. One group of subjects was given a DA that both monitored drop usage and had visual and audible alarms, while the other monitored group included subjects given a DA that had no alarms but continued to monitor drop usage. The third group was given a DA that had no alarm reminders or dose usage monitoring. Subjects were informed that some monitors would not be functional, in an attempt to reduce observer effect, or the effect of being monitored on subject behavior and adherence. A six-item questionnaire was also utilized to assess how the subjects felt about their adherence and DA use.
RESULTS: The overall adherence rates were found to be 78% in the fully functional group (95% confidence interval: 70-88) and 76% in the no alarms group (95% confidence interval: 65-89). No association was seen between questionnaire response and medication adherence. The patients in the DA group without alarms had a significantly higher odds ratio of medication adherence if they reported on the questionnaire that using the DA did affect how much they used their drops.
CONCLUSION: Though the use of DA was expected to reveal different rates of adherence depending on the functionality of the DA between groups, patients with a nonfunctioning DA did not have a significant difference in medication adherence compared to those given a fully functional DA. This supports that an observer effect was not reduced despite these interventions, and that the subjects adhered to taking their medications as if they had a functioning DA and were being monitored
Sea ice biogeochemistry and material transport across the frozen interface
Author Posting. © Oceanography Society, 2011. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 24 no. 3 (2011): 202–218, doi:10.5670/oceanog.2011.72.The porous nature of sea ice not only provides a habitat for ice algae but also opens a pathway for exchanges of organic matter, nutrients, and gases with the seawater below and the atmosphere above. These constituents permeate the ice cover through air-ice gas exchange, brine drainage, seawater entrainment into the ice, and air-sea gas exchange within leads and polynyas. The central goal in sea ice biogeochemistry since the 1980s has been to discover the physical, biological, and chemical rates and pathways by which sea ice affects the distribution and storage of biogenic gases (namely CO2, O2, and dimethyl sulfide) between the ocean and the atmosphere. Historically, sea ice held the fascination of scientists for its role in the ocean heat budget, and the resulting view of sea ice as a barrier to heat and mass transport became its canonical representation. However, the recognition that sea ice contains a vibrant community of ice-tolerant organisms and strategic reserves of carbon has brought forward a more nuanced view of the "barrier" as an active participant in polar biogeochemical cycles. In this context, the organisms and their habitat of brine and salt crystals drive material fluxes into and out of the ice, regulated by liquid and gas permeability. Today, scientists who study sea ice are acutely focused on determining the flux pathways of inorganic carbon, particulate organics, climate-active gases, excess carbonate alkalinity, and ultimately, the role of all of these constituents in the climate system. Thomas and Dieckmann (2010) recently reviewed sea ice biogeochemistry, and so we do not attempt a comprehensive review here. Instead, our goal is to provide a historical perspective, along with some recent discoveries and observations to highlight the most outstanding questions and possibly useful avenues for future research
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