18,069 research outputs found
Dental Professionals in Non-Dental Settings
This report focuses on nine oral health innovations seeking to increase access to preventive oral health care in nondental settings. Two additional reports in this series describe the remaining programs that provide care in dental settings and care to young children. The nine innovations described here integrate service delivery and workforce models in order to reduce or eliminate socioeconomic, geographic, and cultural barriers to care. Although the programs are diverse in their approaches as well as in the specific characteristics of the communities they serve, a common factor among them is the implementation of multiple strategies to increase the number of children from low-income families who access preventive care, and also to engage families and communities in investing in and prioritizing oral health. For low-income children and their families, the barriers that must be addressed to increase access to preventive oral health care are numerous. For example, even children covered by public insurance programs face a shortage of dentists that accept Medicaid and who specialize in pediatric dentistry. The effects of poverty intersect with other barriers such as living in remote geographic areas and having a community-wide history of poor access to dental care in populations such as recent immigrants. Overcoming these barriers requires creative strategies that address transportation barriers, establish welcoming environments for oral health care, and are linguistically and culturally relevant. Each of these nine programs is based on such strategies, including:-Expanding the dental workforce through training new types of providers or adding new providers to the workforce toincrease reach and community presence;-Implementing new strategies to increase the cost-effectiveness of care so that more oral health care services are available and accessible;-Providing training and technical assistance that increase opportunities for and competence in delivering oral health education and care to children;-Offering oral health care services in existing, familiar community venues such as schools, Head Start programs and senior centers;-Developing creative service delivery models that address transportation and cultural barriers as well as the fear and stigma associated with dental care that may arise in communities with historically poor access.The findings from the EAs of these programs are synthesized to highlight diverse and innovative strategies for overcoming barriers to access. These strategies have potential for rigorous evaluation and could emerge as best practices. If proven effective, these innovative program elements could then be disseminated and replicated to increase access for populations in need of preventive oral health care
Perturbative QCD Fragmentation Functions for Production of P-wave Mesons with Charm and Beauty
We calculate the leading order QCD fragmentation functions for the production
of -wave charmed beauty mesons. Long-distance effects are factored into two
nonperturbative parameters: the derivative of the radial wavefunction at the
origin and a second parameter related to the probability for a
heavy quark pair that is produced in a color-octet -wave state to form a
color-singlet -wave bound state. The four states and those states
which lie below the flavor threshold eventually all decay into the
ground state through hadronic cascades or by emitting photons. The total
fragmentation probabilities for production of the ground state from
the cascades of the and states are about and
respectively. Thus the direct production of the -wave
states via fragmentation may account for a significant fraction of the
inclusive production rate of the at large transverse momentum in high
energy colliders. Our analytic results for the -wave fragmentation functions
disagree with those obtained earlier in the literature.Comment: 31 pages, Latex file, 1 figure (postscript file appended at the end
Amplitudes and Spinor-Helicity in Six Dimensions
The spinor-helicity formalism has become an invaluable tool for understanding
the S-matrix of massless particles in four dimensions. In this paper we
construct a spinor-helicity formalism in six dimensions, and apply it to derive
compact expressions for the three, four and five point tree amplitudes of
Yang-Mills theory. Using the KLT relations, it is a straightforward process to
obtain amplitudes in linearized gravity from these Yang-Mills amplitudes; we
demonstrate this by writing down the gravitational three and four point
amplitudes. Because there is no conserved helicity in six dimensions, these
amplitudes describe the scattering of all possible polarization states (as well
as Kaluza-Klein excitations) in four dimensions upon dimensional reduction. We
also briefly discuss a convenient formulation of the BCFW recursion relations
in higher dimensions.Comment: 26 pages, 2 figures. Minor improvements of the discussio
Performance Analysis of Using the Next generation Australian SBAS with Precise Point Positioning Capability for Intelligent Transport Systems
© 2019 IEEE. In 2018, a next-generation Satellite-Based Augmentation System (SBAS) test-bed was launched in Australia/New-Zealand in preparation for building an operational system. This new generation SBAS includes Ll legacy SBAS, new dual-frequency multi-constellation (DFMC) SBAS, and orbit and clock corrections for precise point positioning (PPP) using GPS and Galileo. In this paper, the next generation SBAS and its models are first presented, and the benefits of using its new components are discussed. Test results for lane identification applications in Intelligent Transport Systems (ITS) are presented and analyzed. Kinematic tests were performed in different ITS environments. These are characterized by different levels of sky-visibility and multipath, including clear sky, suburban, low-density urban, and high-density urban environments. Performance analysis show that results vary widely depending on the operational conditions but all SBAS solutions have better positioning accuracy compared with the standalone solutions that are currently used in transport applications. The DFMC SBAS slightly outperformed the Ll SBAS, with accuracy at sub-meter, and it has advantages during periods of fluctuations of the ionosphere with an extended coverage area. As expected, the SBAS-based PPP solutions have shown to give the best positioning precision and accuracy among all tested solution types, with sub-decimeter level accuracy, provided that enough convergence time is available. The paper concluded by giving remarks on the use of this new technology for ITS
Explicit Zeta Functions for Bosonic and Fermionic Fields on a Noncommutative Toroidal Spacetime
Explicit formulas for the zeta functions corresponding to
bosonic () and to fermionic () quantum fields living on a
noncommutative, partially toroidal spacetime are derived. Formulas for the most
general case of the zeta function associated to a quadratic+linear+constant
form (in {\bf Z}) are obtained. They provide the analytical continuation of the
zeta functions in question to the whole complex plane, in terms of series
of Bessel functions (of fast, exponential convergence), thus being extended
Chowla-Selberg formulas. As well known, this is the most convenient expression
that can be found for the analytical continuation of a zeta function, in
particular, the residua of the poles and their finite parts are explicitly
given there. An important novelty is the fact that simple poles show up at
, as well as in other places (simple or double, depending on the number of
compactified, noncompactified, and noncommutative dimensions of the spacetime),
where they had never appeared before. This poses a challenge to the
zeta-function regularization procedure.Comment: 15 pages, no figures, LaTeX fil
A Naturally Large Four-Point Function in Single Field Inflation
Non-Gaussianities of the primordial density perturbations have emerged as a
very powerful possible signal to test the dynamics that drove the period of
inflation. While in general the most sensitive observable is the three-point
function in this paper we show that there are technically natural inflationary
models where the leading source of non-Gaussianity is the four-point function.
Using the recently developed Effective Field Theory of Inflation, we are able
to show that it is possible to impose an approximate parity symmetry and an
approximate continuos shift symmetry on the inflaton fluctuations that allow,
when the dispersion relation is of the form , for a unique
quartic operator, while approximately forbidding all the cubic ones. The
resulting shape for the four-point function is unique. In the models where the
dispersion relation is of the form a similar construction
can be carried out and additional shapes are possible.Comment: 13 pages, 1 figure. v2: extended discussion on near-de-Sitter model
The Highest Redshift Relativistic Jets
We describe our efforts to understand large-scale (10's-100's kpc)
relativistic jet systems through observations of the highest-redshift quasars.
Results from a VLA survey search for radio jets in ~30 z>3.4 quasars are
described along with new Chandra observations of 4 selected targets.Comment: 5 pages, 2 figures, to appear in Extragalactic Jets: Theory and
Observation from Radio to Gamma Ray, Eds. T.A. Rector and D.S. De Youn
Hadronic Production of S-wave and P-wave Charmed Beauty Mesons via Heavy Quark Fragmentation
At hadron colliders the dominant production mechanism of mesons
with large transverse momentum is due to parton fragmentation. We compute the
rates and transverse momentum spectra for production of S-wave and P-wave
mesons at the Tevatron via the direct fragmentation of the bottom
antiquark as well as the Altarelli-Parisi induced gluon fragmentation. Since
all the radially and orbitally excited mesons below the
flavor threshold will cascade into the pseudoscalar ground state through
electromagnetic and/or hadronic transitions, they all contribute to the
inclusive production of . The contributions of the excited S-wave and
P-wave states to the inclusive production of are 58 and 23\%,
respectively, and hence significant.Comment: Changes are made in the Discussio
Differences in the potential for dementia prevention between major ethnic groups within one country: A cross sectional analysis of population attributable fraction of potentially modifiable risk factors in New Zealand
Background: Twelve potentially modifiable risk factors (less education, hypertension, obesity, alcohol, traumatic brain injury (TBI), hearing loss, smoking, depression, physical inactivity, social isolation, diabetes, air pollution) account for an estimated 40% of worldwide dementia cases. We aimed to calculate population attributable fractions (PAFs) for dementia for the four largest New Zealand ethnic groups (European, Māori, Asian, and Pacific peoples) to identify whether optimal dementia prevention targets differed by ethnicity.
Methods: We calculated risk factor prevalence for 10 risk factors using the New Zealand Health Survey 2018/19 and published reports for hearing loss and TBI prevalences. We calculated the PAF for each risk factor using calculated prevalence and relative risk estimates from previous meta-analyses. To account for risk factor overlap, we calculated communality of risk factors and a weighted PAF.
Findings: The weighted PAF for dementia was 47•7% overall in New Zealand, 47•6% for Europeans, 51•4% for Māori, 50•8% for Pacific peoples, and 40•8% for Asians. Highest PAFs for Europeans were hearing loss (8%) and social isolation (5•7%), and for Asians hearing loss (7•3%) and physical inactivity (5•5%). For Māori and Pacific peoples, highest PAFs were for obesity (7•3% and 8•9% respectively) and hearing loss (6•5% and 6•6%).
Interpretation: New Zealand has higher dementia prevention potential than worldwide estimates with high prevalences of untreated hearing loss and obesity. The relative contribution of individual risk factors PAFs varies by ethnic group. Public health strategies for dementia prevention need to be tailored to these differences
The Influence of Ethnicity on the Development of Type 2 Diabetes Mellitus in Women with Gestational Diabetes: A Prospective Study and Review of the Literature
As the worldwide prevalence of type 2 diabetes continues to rise at an alarming rate, the search for susceptible populations likely to benefit from preventative measures becomes more important. One such population is women with a previous history of gestational diabetes mellitus (GDM). In this prospective study of 101 women who had GDM in Australia, ethnicity was a major risk factor for the development of diabetes following a diagnosis of GDM. With a mean followup of 5.5 years after GDM, South Asian women had a significantly higher risk of developing abnormal glucose tolerance (AGT) (69%) than women of all other ethnicities (P < 0.05). The prevalence of diabetes and impaired glucose tolerance was also very high amongst other groups: South East and East Asian (11/27, 41%), Middle-Eastern (8/18, 44%), South European backgrounds (5/12, 42%), and Australian-born women 39% (11/28). A review of the literature supports the role of ethnicity in the development of diabetes amongst these women. These findings have implications for South Asian countries and countries such as Australia where there is a population from diverse ethnic backgrounds and where the implementation of targeted measures to stem the growing tide of diabetes is needed
- …