178 research outputs found
Appalachian Goodbyes
This is a collection of poetry and nonfiction using the Japanese poetic form of haibun (a back and forth between haiku and prose, both sections attempting to clarify and further each other while approaching the subject in entirely different manners) as a form of memoir instead. This collection is about my home that has not always felt like home and what it means to love and hate an Appalachian identity. It is also about my relationships, both with Appalachia and the world outside it and with the people who call it home and the people I have met when I have left it. It is about hurt and pain and loss and grief and confusion and frustration and love and happiness and family, but it is mostly about learning how to leave and remain and come back all at the same time
AIDS AND THE COLLEGE STUDENT: KNOWLEDGE, BELIEFS, AND INFORMATION SEEKING
A questionnaire on knowledge, beliefs, and information-seeking
behavior about Acquired Immune Deficiency Syndrome (AIDS) was
administered to a total of 1,300 university students, and 1,001 were
completed and returned. The aim of the study was to investigate the
relationship between college students' knowledge and beliefs about
AIDS and their information-seeking behavior about AIDS. Students were
found to be knowledgeable about the disease, but the majority (50.5%)
were not worried about contracting AIDS. The findings revealed that
students who are more knowledgeable about AIDS seek more information
than those less knowledgeable about AIDS. It was also found that
students who feel more highly susceptible to AIDS are more likely to
seek information about the disease. The primary sources of student
information on AIDS were television, newspapers, magazines, and radio;
however, doctors and health-care professionals were considered the
most trust-worthy sources of AIDS information. The data suggest that
medically supported information on AIDS should be provided to college
students by health educators via the popular media sources
Laser Heterodyne Radiometer for Sensitive Detection of CO2 and CH4
We propose to develop an inexpensive, miniaturized, passive laser heterodyne radiometer (LHR) using commercially available telecommunications laser components to measure two significant carbon cycle gases in the atmospheric column: carbon dioxide (CO2) and methane (CH4). This instrument would operate in tandem with the passive aerosol sensor currently used in AERONET (an established network of more than 450 ground aerosol monitoring instruments worldwide). Because aerosols induce a radiative effect that influences terrestrial carbon exchange, simultaneous detection of aerosols with these key carbon cycle gases offers a uniquely comprehensive measurement approach that supports the Decadal Survey. Laser heterodyne radiometry is a technique for detecting weak signals that was adapted from radio receiver technology. In a radio receiver, a weak input signal from a radio antenna is mixed with a stronger local oscillator signal. The mixed signal (beat note, or intermediate frequency) has a frequency equal to the difference between the input signal and the local oscillator. The intermediate frequency is amplified and sent to a detector that extracts the audio from the signal. In a laser heterodyne radiometer, the weak input signal is light that has undergone absorption by a trace gas. The local oscillator is a laser at a near-by frequency - in this case a low-cost distributed feedback (DFB) telecommunications laser. These two light waves are superimposed in either a beamsplitter or in a fiber coupler (as is the case in this design). The signals are mixed in the detector, and the RF beat frequency is extracted. Changes in concentration of the trace gas are realized through analyzing changes in the beat frequency amplitude. A schematic of the progression of the LHR development project is shown in the figure below. At the center (within the dashed line), light from the local oscillator is superimposed upon light that has undergone absorption by a trace gas, in a single mode fiber coupler. Superimposed light is mixed in a fast photoreceiver, and the beat signal is analyzed for changes in absorption. The left portion of the figure depicts a progression of light sources that pass through the trace gas, increasing in complexity in the downward direction. On the right side of the figure, RF signal processing progresses from a commercially available spectrum analyzer to a RF receiver, and finally to an RF filter bank to deconvolute portions of the beat frequency more heavily weighted for different altitudes
Design of an endoscope lens shielding device for use in laparoscopic procedures
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Each author submitted a separate title page and abstract. Cataloged from PDF version of thesis.Includes bibliographical references (p. 23 [i.e. p. 33]).Laparoscopic surgical tools and techniques have revolutionized many gynecological and abdominal procedures, leading to dramatic reductions in recovery time and scarring for the patient. While techniques and instruments for performing laparoscopic surgery have improved over the years, loss of vision through the endoscopic lens caused by fog, liquid, and solid debris common to laparoscopic procedures remains a significant problem. In this paper, the prototype of a shielding mechanism that maintains visibility through the laparoscope by removing debris from the distal end of the lens is presented. This device provides an inexpensive, disposable, and convenient alternative to the current practice of removing, cleaning, and re-inserting the laparoscope during surgical procedures. This device is shown in multiple trials to repeatedly remove debris from the distal tip of the lens, thereby restoring vision for the surgeon without requiring removal or reinsertion of the endoscope.by Emily Faith Houston and Jarred Lee Schantz and Evan Michael Lampe.S.B
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Longitudinal predictors of early language in infants with Down syndrome: a preliminary study
Purpose: Children with Down syndrome (DS) typically have marked delays in language development relative to their general cognitive development, with particular difficulties in expressive compared to receptive language. Although early social communication skills, including gestures and joint attention, have been shown to be related to later language outcomes in DS, knowledge is limited as to whether these factors exclusively predict outcomes, or whether other factors (e.g. perceptual and non-verbal skills) are involved. This study addressed this question. Method: Longitudinal data for a group of infants with DS (n=14) and a group of typically-developing (TD) infants (n=35) were collected on measures that have been shown to predict language in TD infants and/or those with developmental delays. These included: non-verbal mental ability, speech segmentation skills, and early social communication skills (initiating and responding to joint attention, initiating behavioural requests). Results: Linear regression analyses showed that speech segmentation and initiating joint attention were the strongest predictors of later language in the TD group, whereas non-verbal mental ability and responding to joint attention were the strongest predictors of later language for infants with DS. Conclusions: Speech segmentation ability may not determine language outcomes in DS, and language acquisition may be more constrained by social communication and general cognitive skills
A framework for measuring social value in infrastructure and built environment projects: an industry perspective
As the infrastructure and built environment sectors shift from traditional economic valuation towards more holistic approaches, projects are being designed, built and evaluated in new ways. An important emerging technique for the economic evaluation of projects is social value measurement. This paper sets out the foundations for the social value measurement techniques that underpin the methods and frameworks developed in central governments and by multilateral and international organisations and describes how these can be adapted to value the broader societal and environmental effects of infrastructure and built environment projects. The paper provides practical evidence of social value measurement in valuing heritage impacts for Stonehenge World Heritage Site as well as presenting a detailed account of the foundations of cost-benefit analysis as a tool for social value measurement and non-market valuation
Urban Youth’s Perspectives on Flash Mobs
This is the author's final draft. Copyright 2013 Taylor & Francis.Flash mobs are new, emerging, and evolving social phenomena that have recently been associated with youth violence in U.S. cities. The current study explores how youth understand flash mobs through focus groups conducted in Kansas City, Missouri (a site of violent youth flash mobs). Results indicate that youth have varying familiarity with flash mobs and define them in different ways; that youth perceive youth boredom to be the most frequent cause of problems with flash mobs; that youth connect ongoing social disorder with the violence associated with flash mobs; and that while social media are facilitators of flash mobs, flash mobs have their roots in youth activities that have been going on for generations (e.g., hanging out in groups, cruising)
Field Results from Three Campaigns to Validate the Performance of the Miniaturized Laser Heterodyne Radiometer (MiniLHR) for Measuring Carbon Dioxide and Methane in the Atmospheric Column
In a collaboration between NASA GSFC and GWU, a low-cost, surface instrument is being developed that can continuously monitor key carbon cycle gases in the atmospheric column: carbon dioxide (CO2) and methane (CH4). The instrument is based on a miniaturized, laser heterodyne radiometer (LHR) using near infrared (NIR) telecom lasers. Despite relatively weak absorption line strengths in this spectral region, spectrallyresolved atmospheric column absorptions for these two molecules fall in the range of 60-80% and thus sensitive and precise measurements of column concentrations are possible. In the last year, the instrument was deployed for field measurements at Park Falls, Wisconsin; Castle Airport near Atwater, California; and at the NOAA Mauna Loa Observatory in Hawaii. For each subsequent campaign, improvement in the figures of merit for the instrument has been observed. In the latest work the absorbance noise is approaching 0.002 optical density (OD) noise on a 1.8 OD signal. An overview of the measurement campaigns and the data retrieval algorithm for the calculation of column concentrations will be presented. For light transmission through the atmosphere, it is necessary to account for variation of pressure, temperature, composition, and refractive index through the atmosphere that are all functions of latitude, longitude, time of day, altitude, etc. For temperature, pressure, and humidity profiles with altitude we use the Modern-Era Retrospective Analysis for Research and Applications (MERRA) data. Spectral simulation is accomplished by integrating short-path segments along the trajectory using the SpecSyn spectral simulation suite developed at GW. Column concentrations are extracted by minimizing residuals between observed and modeled spectrum using the Nelder-Mead simplex algorithm. We will also present an assessment of uncertainty in the reported concentrations from assumptions made in the meteorological data, LHR instrument and tracker noise, and radio frequency bandwidth and describe additional future goals in instrument development and deployment targe
Teens’ social media use and collective action
This is the author's accepted manuscript, made available with the permission of the publisher.This research examined how social self-efficacy, collective self-esteem, and need to belong can be used to predict teens’ use of social media. The particular focus was on how these social psychological variables together with social media use account for variation in teens’ participation in a flash mob – an exemplar of 21st-century collective action. Empirical data come from a survey of teens in a major Midwestern city in the USA. Teens’ need to belong was positively associated with the amount of time they reported spending on social networking sites, even when controlling for gender, race, and household socio-economic status. Both teens’ social self-efficacy and time spent on YouTube were positively associated with their intention to participate in a flash mob in the future. These and other findings are discussed in the context of the role of social media in youth culture and collective action
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Do infants with Down syndrome show an early receptive language advantage?
Purpose
The study explored longitudinally the course of vocabulary and general language development in a group of infants with Down syndrome (DS) compared to a group of typically-developing (TD) infants matched on non-verbal mental ability (NVMA).
Method
We compared the vocabulary and general language trajectories of the two groups in two ways: a) at three time points during a 12 month period, and b) at 2 time points when the groups had made equal progress in non-verbal mental ability (a period of 6 months for the TD infants, versus 12 months for the infants with DS).
Results
The TD group had overtaken the DS group on all general language and vocabulary measures by the end of the 12-month period. However, expressive communication and expressive vocabulary were developing at the same rate and level in the two groups when examined over a period in which the two groups were matched in gains in non-verbal mental ability. Furthermore, the infants with DS showed a receptive language advantage over the TD group; this group’s auditory comprehension and receptive vocabulary scores were superior to those of the TD group at both time points when non-verbal mental ability was accounted for.
Conclusion
The results shed light on the widely reported discrepancy between expressive and receptive language in individuals with DS. Although infants with DS appear to be developing language skills more slowly than chronological age TD peers, when NVMA is taken into account, infants with DS do not have expressive language delays and they seem to show a receptive language advantage
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