5,840 research outputs found
The Tax Reform Act of 1986: Its Effect Business And Individuals
The Tax Reform Act of 1986 represents the m::\u3est massive revision in the history of tax law. It provides for major reductions corporations. in the top tax rate for both individuals and The individual top rate for 1988 will be the lowest since 1931. The tax burden on corporations has become stiffer after being relaxed for 20 years. In addition, the Act repeals or limits many of the tax credits and deductions that encourage certain kinds of investment, particularly those that taxpayers use to avoid paying taxes. The new tax code no longer uses steeply progressive tax rates, and therefore, does not significantly redistribute the tax burden between high- and middle-income taxpayers. However, it compensates for this by limiting the tax preferences heavily used by high-income taxpayers. On the lower end of the spectrum, the Act reduces the tax burden on poor families by removing than fran tax rolls. These provisions were made with the goal of simplifying the tax syste.\u27Tl and making it more fair for all taxpayers
Modification of an impulse-factoring orbital transfer technique to account for orbit determination and maneuver execution errors
A method has previously been developed to satisfy terminal rendezvous and intermediate timing constraints for planetary missions involving orbital operations. The method uses impulse factoring in which a two-impulse transfer is divided into three or four impulses which add one or two intermediate orbits. The periods of the intermediate orbits and the number of revolutions in each orbit are varied to satisfy timing constraints. Techniques are developed to retarget the orbital transfer in the presence of orbit-determination and maneuver-execution errors. Sample results indicate that the nominal transfer can be retargeted with little change in either the magnitude (Delta V) or location of the individual impulses. Additonally, the total Delta V required for the retargeted transfer is little different from that required for the nominal transfer. A digital computer program developed to implement the techniques is described
Bullying of the LGBTQ Community
Our group did a literature review and identified that bullying of the Lesbian, Gay, Bisexual, Transgender and Questioning populations occurs worldwide and is becoming a more prominent global issue. Our group researched and identified bullying in the United States of America, South Africa, Uganda, and Russia. We address these specific countries because of the attention that they have recently received in the media in regards to treatment of people who identify as LGBTQ. We examined this topic and, explored the bio-psycho-social effects of LGBTQ bullying and provided different ways that people can address the problem of bullying of the LGBTQ community through venues such as education and advocating for policy change in the previously stated countries. We also provide information regarding different organizations in the secular and Christian community that are addressing bullying of the LGBTQ
A longitudinal study of infants' early speech production and later letter identification
Letter identification is an early metric of reading ability that can be reliability tested before a
child can decode words. We test the hypothesis that early speech production will be associated
with children's later letter identification. We examined longitudinal growth in early
speech production in 9 typically developing children across eight occasions, every 3 months
from 9 months to 30 months. At each occasion, participants and their caregivers engaged in
a speech sample in a research lab. This speech sample was transcribed for a variety of
vocalizations, which were then transformed to calculate consonant-vowel ratio. Consonantvowel
ratio is a measure of phonetic complexity in speech production. At the age of 72
months, children's letter knowledge was measured. A multilevel model including fixed quadratic
age change and a random intercept was estimated using letter identification as a predictor
of the growth in early speech production from 9±30 months, measured by the
outcome of consonant-vowel ratio. Results revealed that the relation between early speech
production and letter identification differed over time. For each additional letter that a child
identified, their consonant-vowel ratio at the age of 9 months increased. As such, these
results confirmed our hypothesis: more robust early speech production is associated with
more accurate letter identification.(R01 DC006463
An automated online instrument to quantify aerosol-bound reactive oxygen species (ROS) for ambient measurement and health-relevant aerosol studies
The adverse health effects associated with ambient aerosol particles have been well documented, but it is still unclear which aerosol properties are most important for their negative health impact. Some studies suggest the oxidative effects of particle-bound reactive oxygen species (ROS) are potential major contributors to the toxicity of particles. Traditional ROS measurement techniques are labour-intensive, give poor temporal resolution and generally have significant delays between aerosol sampling and ROS analysis. However, many oxidising particle components are reactive and thus potentially short-lived. Thus, a technique to quantify particle-bound ROS online would be beneficial to quantify also the short-lived ROS components.
We introduce a new portable instrument to allow online, continuous measurement of particle-bound ROS using a chemical assay of 27-dichlorofluorescein (DCFH) with horseradish peroxidase (HRP), via fluorescence spectroscopy. All components of the new instrument are attached to a containing shell, resulting in a compact system capable of automated continuous field deployment over many hours or days.
From laboratory measurements, the instrument was found to have a detection limit of ~4 nmol [HO] equivalents per cubic metre (m) air, a dynamic range up to at least ~2000 nmol [HO] equivalents per m air and a time resolution of †12 min. The instrument allows for ~16 h automated measurement if unattended and shows a fast response to changes in concentrations of laboratory-generated oxidised organic aerosol. The instrument was deployed at an urban site in London, and particulate ROS levels of up to 24 nmol [HO] equivalents per m air were detected with PM concentrations up to 28 ”g m.
The new and portable Online Particle-bound ROS Instrument (OPROSI) allows fast-response quantification; this is important due to the potentially short-lived nature of particle-bound ROS as well as fast-changing atmospheric conditions, especially in urban environments. The instrument design allows for automated operation and extended field operation with twice-daily presence of an operator. As well as having sensitivity suitable for ambient level measurement, the instrument is also suitable at concentrations such as those required for laboratory and chamber toxicological studies.The authors would like to thank ERC (the European Research Council, grant no. 279405) for their funding of this study. Infrastructure at Marylebone Road was supported by NERC (the Natural Environment Research Council, Clearflo grant no. NE/H003231/1) and Defra (Department of Environment Food and Rural Affairs, contract AQ0643 Automatic London Network (2010-14) RMP 5442)
Semiautomated text analytics for qualitative data synthesis
Approaches to synthesizing qualitative data have, to date, largely focused on
integrating the findings from published reports. However, developments in text
mining software offer the potential for efficient analysis of large pooled primary
qualitative datasets. This case study aimed to (a) provide a stepâbyâstep guide to
using one software application, Leximancer, and (b) interrogate opportunities
and limitations of the software for qualitative data synthesis. We applied
Leximancer v4.5 to a pool of five qualitative, UKâbased studies on transportation
such as walking, cycling, and driving, and displayed the findings of the
automated content analysis as intertopic distance maps. Leximancer enabled
us to âzoom outâ to familiarize ourselves with, and gain a broad perspective
of, the pooled data. It indicated which studies clustered around dominant topics
such as âpeople.â The software also enabled us to âzoom inâ to narrow the
perspective to specific subgroups and lines of enquiry. For example, âpeopleâ
featured in men's and women's narratives but were talked about differently,
with men mentioning âkidsâ and âold,â whereas women mentioned âthingsâ
and âstuff.â The approach provided us with a fresh lens for the initial inductive
step in the analysis process and could guide further exploration. The limitations
of using Leximancer were the substantial data preparation time involved and the
contextual knowledge required from the researcher to turn lines of inquiry into
meaningful insights. In summary, Leximancer is a useful tool for contributing
to qualitative data synthesis, facilitating comprehensive and transparent data
coding but can only inform, not replace, researcherâled interpretive work
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The organizational social context of mental health services and clinician attitudes toward evidence-based practice: a United States national study.
UnlabelledABSTBACKGROUND: Evidence-based practices have not been routinely adopted in community mental health organizations despite the support of scientific evidence and in some cases even legislative or regulatory action. We examined the association of clinician attitudes toward evidence-based practice with organizational culture, climate, and other characteristics in a nationally representative sample of mental health organizations in the United States.MethodsIn-person, group-administered surveys were conducted with a sample of 1,112 mental health service providers in a nationwide sample of 100 mental health service institutions in 26 states in the United States. The study examines these associations with a two-level Hierarchical Linear Modeling (HLM) analysis of responses to the Evidence-Based Practice Attitude Scale (EBPAS) at the individual clinician level as a function of the Organizational Social Context (OSC) measure at the organizational level, controlling for other organization and clinician characteristics.ResultsWe found that more proficient organizational cultures and more engaged and less stressful organizational climates were associated with positive clinician attitudes toward adopting evidence-based practice.ConclusionsThe findings suggest that organizational intervention strategies for improving the organizational social context of mental health services may contribute to the success of evidence-based practice dissemination and implementation efforts by influencing clinician attitudes
Are buffers around home representative of physical activity spaces among adults?
Residential buffers are frequently used to assess built environment characteristics relevant to physical activity (PA), yet little is known about how well they represent the spatial areas in which individuals undertake PA. We used System for Observing Play and Recreation in Communities data for 217 adults from five US states who wore an accelerometer and a GPS for three weeks to create newly defined PA-specific activity spaces. These PA spaces were based on PA occurring in bouts of â„10min and were defined as 1) the single minimum convex polygon (MCP) containing all of a participant's PA bout minutes and 2) the combination of many MCPs constructed using each PA bout independently. Participants spent a large proportion of their PA bout time outside of 0.5, 1, and 5 mile residential buffers, and these residential buffers were a poor approximation of the spatial areas in which PA bouts occurred. The newly proposed GPS-based PA spaces can be used in future studies in place of the more general concept of activity space to better approximate built environments experienced during PA
Where Are Adults Active? An Examination of Physical Activity Locations Using GPS in Five US Cities
Increasing physical activity (PA) at the population level requires appropriately targeting intervention development. Identifying the locations in which participants with various sociodemographic, body weight, and geographic characteristics tend to engage in varying intensities of PA as well as locations these populations underutilize for PA may facilitate this process. A visual location-coding protocol was developed and implemented in Google Fusion Tables and Maps using data from participants (N = 223, age 18â85) in five states. Participants concurrently wore ActiGraph GT1M accelerometers and Qstarz BT-Q1000X GPS units for 3 weeks to identify locations of moderate-to-vigorous (MVPA) or vigorous (VPA) bouts. Cochran-Mantel-Haenzel general association tests examined usage differences by participant characteristics (sex, age, race/ethnicity, education, body mass index (BMI), and recruitment city). Homes and roads encompassed >40% of bout-based PA minutes regardless of PA intensity. Fitness facilities and schools were important for VPA (19 and 12% of bout minutes). Parks were used for 13% of MVPA bout minutes but only 4% of VPA bout minutes. Hispanics, those without a college degree, and overweight/obese participants frequently completed MVPA bouts at home. Older adults often used roads for MVPA bouts. Hispanics, those with â€high school education, and healthy/overweight participants frequently had MVPA bouts in parks. Applying a new location-coding protocol in a diverse population showed that adult PA locations varied by PA intensity, sociodemographic characteristics, BMI, and geographic location. Although homes, roads, and parks remain important locations for demographically targeted PA interventions, observed usage patterns by participant characteristics may facilitate development of more appropriately targeted interventions
Efficiency of scalar-parameterized mechanisms
We consider the problem of allocating a fixed amount of an infinitely divisible resource among multiple
competing, fully rational users. We study the efficiency guarantees that are possible when we restrict to
mechanisms that satisfy certain scalability constraints motivated by large scale communication networks;
in particular, we restrict attention to mechanisms where users are restricted to one-dimensional strategy
spaces. We first study the efficiency guarantees possible when the mechanism is not allowed to price differen-
tiate. We study the worst-case efficiency loss (ratio of the utility associated with a Nash equilibrium to the
maximum possible utility), and show that the proportional allocation mechanism of Kelly (1997) minimizes
the efficiency loss when users are price anticipating. We then turn our attention to mechanisms where price
differentiation is permitted; using an adaptation of the Vickrey-Clarke-Groves class of mechanisms, we con-
struct a class of mechanisms with one-dimensional strategy spaces where Nash equilibria are fully efficient.
These mechanisms are shown to be fully efficient even in general convex environments, under reasonable
assumptions. Our results highlight a fundamental insight in mechanism design: when the pricing flexibility
available to the mechanism designer is limited, restricting the strategic flexibility of bidders may actually
improve the efficiency guarantee.National Science FoundationArmy Research OfficeDARPA - Next Generation Internet InitiativeNational Science Foundation Graduate Research Fellowshi
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