1,946 research outputs found
Estimating The Costs And Cost-effectiveness Of Promoting Mammography Screening Among US-based Latinas
Purpose: We characterize the costs and cost-effectiveness of a community health worker (CHW)-based intervention to promote screening mammography among US-based non-adherent Latinas.
Methods: The parent study was a randomized controlled trial for 536 Latinas aged 42-74 years old who had sought care within a safety net health center in Western Washington. Participants were block-randomized within clinic to the control arm (usual care) or intervention arm (CHW-led motivational interviewing intervention). We used the perspective of the organization implementing promotional activities to characterize costs and cost-effectiveness. Cost data were categorized as program set-up and maintenance (initial training, booster/annual training) program implementation (administrative activities, intervention delivery); and, overhead/miscellaneous expenses. Cost-effectiveness was calculated as the incremental cost of screening for each additional woman screened between the intervention and control arms.
Results: The respective costs per participant for standard care and the intervention arm were 300.99. There were no study arm differences in 1-year QALYs among women who completed a 12-month follow-up survey (intervention= 0.8827, standard care = 0.8841). Most costs pertained to program implementation and administrative activities specifically. The incremental cost per additional woman screened was $2,595.32.
Conclusions: Our findings are within the ranges of costs and cost-effectiveness for other CHW programs to promote screening mammography among underserved populations. Our strong study design and focus on non-adherent women provides important strengths to this body of work, especially give implementation and dissemination science efforts regarding CHW-based health promotion for health disparity populations
The Importance of Slow-roll Corrections During Multi-field Inflation
We re-examine the importance of slow-roll corrections during the evolution of
cosmological perturbations in models of multi-field inflation. We find that in
many instances the presence of light degrees of freedom leads to situations in
which next to leading order slow-roll corrections become significant. Examples
where we expect such corrections to be crucial include models in which modes
exit the Hubble radius while the inflationary trajectory undergoes an abrupt
turn in field space, or during a phase transition. We illustrate this with two
examples -- hybrid inflation and double quadratic inflation. Utilizing both
analytic estimates and full numerical results, we find that corrections can be
as large as 20%. Our results have implications for many existing models in the
literature, as these corrections must be included to obtain accurate
observational predictions -- particularly given the level of accuracy expected
from CMB experiments such as PlanckComment: v1: 21 pages, 3 figures, 1 appendix. v2: clarifications to
{\S}{\S}2.1, 3.1 and 4, {\S}5.3 added, references added, results unchanged.
Matches published version in JCA
Assessment of the physiological impact of endocrine disrupting chemicals on salmonid fish from selected sites in Scotland and Northern Ireland
1. Recent research in the UK and elsewhere has demonstrated that industrial and domestic effluents may contain compounds of both natural and synthetic origin which are steroid estrogens, or mimic the activity of steroid estrogens. Although present in solution at very low concentrations the sensitivity of the endocrine system of animals to interference is such that these contaminants represent a potentially disruptive threat.
2. A survey of gonadal structure in roach populations in English rivers revealed that a high proportion (25% â 60%) of male fish within the sampled populations displayed evidence of abnormal gonadal development in the form of ovarian tissue within the testes. These effects were most pronounced at sites where discharged effluents represented a high proportion of total flow in the river. The functional significance of these observations has yet to be established.
3. Concerns have been raised regarding the possible susceptibility of valuable salmon and trout populations to endocrine disruptive processes. This report describes the results of a fieldbased investigation of indicators of estrogen exposure in salmonid fish exposed to potentially estrogenic effluent discharges at sites in Scotland and Northern Ireland.
4. This study addressed the possibility that native salmonid populations are being exposed to estrogenic contaminants via both domestic and industrial discharges and that this exposure may result in inappropriate and possibly detrimental physiological effects in exposed fish.
5. This objective was addressed by the sampling of brown trout and Atlantic salmon from sites receiving a STW discharge and from pristine sites. Blood levels of the estrogen-inducible yolk precursor vitellogenin were measured to assess whether there was evidence that the
targeted populations were exposed to acute estrogen exposure. In addition, gonadal material sampled from each fish was examined microscopically for evidence of abnormal reproductive development, the presence of which would be indicative of early or possibly chronic exposure to estrogens.
6. A total of 209 fish were examined from four sites in Scotland [R. Teviot, Slitrig Water (tributary of the R. Teviot), Wilson Burn and Ale Water (pristine sites)]. Fish sampled from the R. Teviot were removed downstream of the Hawick STW discharge. In all the fish which
were sampled blood vitellogenin levels were low, displaying no evidence of environmental
estrogen-induced elevation. The gonadal structure of all the sampled fish was normal, with no evidence of ovarian tissue in male testes and no evidence of unusual ovarian development in female fish.
7. A total of 64 fish were examined from three sites in Northern Ireland (Minnowburn, Collin River and Ravernet River; all tributaries of the R. Lagan). As was the case for the Scottish sites, no evidence of gonadal abnormalities was obtained in fish from any site.
8. In addition to the field sampling, the estrogenicity of the effluents discharged at each site were evaluated by bioassay. In Northern Ireland, rainbow trout were held in cages submerged in the vicinity of the New Holland Sewage Treatment Works (STW) effluent discharge (R. Lagan). An aquarium-based exposure of rainbow trout to Hawick STW (R. Teviot) final effluent, at concentrations up to 100%, was employed. Analysis of blood vitellogenin levels after a period of or 11 â 14 days exposure in aquaria revealed that the Hawick STW effluent was not estrogenic. However, fish exposed to New Holland STW final effluent in situ for 3 weeks displayed elevated blood vitellogenin levels, relative to fish caged at control sites, indicating that the effluent contained estrogenic components.
9. Water samples collected from both study sites were analysed for total alkylphenols and alkylphenol ethoxylates (APEs; ubiquitous environmental contaminants and known estrogen mimics found in high concentrations in English rivers with a high incidence of intersexuality). Samples from the Hawick sites contained very low levels of APEs (< 3 :g l-1). Similar levels were found in samples from the sites in Northern Ireland with the exception of effluent samples taken downstream of the Barbour Campbell Linen Mill which contained 12 :g l-1 total APEs. Steroids were not quantified in these samples.
10. The microscopic examination of gonad structure, and analysis of blood vitellogenin levels, indicated that there was no evidence of exposure to estrogenic contaminants in the salmonid fish populations of the R. Teviot or R. Lagan.
11. A number of factors probably contribute to this result. Salmonid fish exhibit a life-history very different to that of cyprinid fish such as roach in which effluent-related intersexuality has been reported. Trout and salmon normally spawn in clean gravel beds in the upper reaches of a river system and newly-hatched and early juvenile salmonid fish remain in these relatively pristine stretches of river. They are therefore not usually exposed to point-source effluent discharges during critical early developmental stages when the reproductive system is particularly sensitive to external influences. In addition, both salmon and migratory brown trout (sea trout) are anadromous fish, spending a significant proportion of their lives at sea. These factors contrast with the potential for life-long exposure to contaminants displayed by non-migratory cyprinid fish which spawn in the main body of the river. Additionally, salmonid fish are less tolerant of poor water quality than cyprinid fish and even the nonmigratory brown trout are therefore not normally present in rivers subject to high effluent input. Most rivers which support populations of salmonid fish do not pass through heavily populated or industrialised areas. There is therefore less likelihood that these fish populations
will encounter high concentrations of endocrine disrupting chemicals (EDCs).
12. Overall, these data do not provide absolute reassurance that salmonid fish are unaffected
by estrogens and estrogen mimics present in effluent discharges but they do indicate that if a
problem does exist it may be localised and on a smaller scale than has been reported for cyprinid fish.
13. Consideration should be given to a more widespread survey of gonad structure in salmonid fish populations in order to confirm these preliminary conclusions. It should also be considered whether reproductive performance of salmonid fish might be influenced by
exposure to EDCs via mechanisms which do not involve alterations in gonadal structure (e.g. alterations in fecundity, gamete quality, behavioural changes). In addition, the possibility that aspects of the salmonid life-history other than reproductive development may be affected by EDCs should be examined.
14. For example, smoltification (pre-migratory sea water adaptation) is a critically important
aspect of the salmonid life history. Smoltification is closely regulated by the endocrine system and may be susceptible to interference by chemicals which mimic or interfere with the activity of hormones other than estrogens.
15. It should also be considered whether sources of contamination other than effluent discharges (e.g. agricultural run-off) may expose salmonid fish to endocrine-disrupting chemicals
Separate and overlapping brain areas encode subjective value during delay and effort discounting
AbstractMaking decisions about rewards that involve delay or effort requires the integration of value and cost information. The brain areas recruited in this integration have been well characterized for delay discounting. However only a few studies have investigated how effort costs are integrated into value signals to eventually determine choice. In contrast to previous studies that have evaluated fMRI signals related to physical effort, we used a task that focused on cognitive effort. Participants discounted the value of delayed and effortful rewards. The value of cognitively effortful rewards was represented in the anterior portion of the inferior frontal gyrus and dorsolateral prefrontal cortex. Additionally, the value of the chosen option was encoded in the anterior cingulate cortex, caudate, and cerebellum. While most brain regions showed no significant dissociation between effort discounting and delay discounting, the ACC was significantly more activated in effort compared to delay discounting tasks. Finally, overlapping regions within the right orbitofrontal cortex and lateral temporal and parietal cortices encoded the value of the chosen option during both delay and effort discounting tasks. These results indicate that encoding of rewards discounted by cognitive effort and delay involves partially dissociable brain areas, but a common representation of chosen value is present in the orbitofrontal, temporal and parietal cortices
Investigating knitwear product development in small and medium enterprises: A report of practices related to environmental sustainability
There is rising interest into the inner workings of the fashion supply chain due to increasing concern surrounding environmental impact, social responsibility, and economic growth. Studies designed to understand the fashion industry often presume the knitwear sector to follow the linear product development process of the woven garment sector. However, knitwear practitioners are profoundly aware of many complex distinctions, one example being the ability to seamlessly create three dimensional garments with minimal finishing. In spite of these differences, there is little known research which specifically identifies the current knitwear design and manufacture system, or how often such seamless production methods are utilised. To bridge the gap in knowledge, a quantitative questionnaire was designed for a holistic overview of the key product development processes within knitwear small and medium enterprises (SMEs). The questionnaire had three focuses, design, manufacture, and retail, reflecting the sectors dynamism. 31 companies of varying sizes completed the survey, of these, 26 designed knitwear, 25 manufactured it, and 21 companies retailed directly to consumers. Results showed that the sampled SMEs have a keen interest in developing sustainable products, albeit at surface level, with most choosing to reduce impact through their material and fibre choices, with less importance placed on manufacturing processes. Other revelations included the low uptake of 3D garment simulation software, designed to reduce the need for multiple prototypes and the reliance on cut and sew processes. This study revealed several areas where environmental impact can be reduced and aims to inform future studies within the knitwear industry focused on material use, product life-cycle analysis, waste reduction and digital technology adoption
Stochastic volatility and leverage effect
We prove that a wide class of correlated stochastic volatility models exactly
measure an empirical fact in which past returns are anticorrelated with future
volatilities: the so-called ``leverage effect''. This quantitative measure
allows us to fully estimate all parameters involved and it will entail a deeper
study on correlated stochastic volatility models with practical applications on
option pricing and risk management.Comment: 4 pages, 2 figure
Exact soliton solutions of coupled nonlinear Schr\"odinger equations: Shape changing collisions, logic gates and partially coherent solitons
The novel dynamical features underlying soliton interactions in coupled
nonlinear Schr{\"o}dinger equations, which model multimode wave propagation
under varied physical situations in nonlinear optics, are studied. In this
paper, by explicitly constructing multisoliton solutions (upto four-soliton
solutions) for two coupled and arbitrary -coupled nonlinear Schr{\"o}dinger
equations using the Hirota bilinearization method, we bring out clearly the
various features underlying the fascinating shape changing (intensity
redistribution) collisions of solitons, including changes in amplitudes, phases
and relative separation distances, and the very many possibilities of energy
redistributions among the modes of solitons. However in this multisoliton
collision process the pair-wise collision nature is shown to be preserved in
spite of the changes in the amplitudes and phases of the solitons. Detailed
asymptotic analysis also shows that when solitons undergo multiple collisions,
there exists the exciting possibility of shape restoration of atleast one
soliton during interactions of more than two solitons represented by three and
higher order soliton solutions. From application point of view, we have shown
from the asymptotic expressions how the amplitude (intensity) redistribution
can be written as a generalized linear fractional transformation for the
-component case. Also we indicate how the multisolitons can be reinterpreted
as various logic gates for suitable choices of the soliton parameters, leading
to possible multistate logic. In addition, we point out that the various
recently studied partially coherent solitons are just special cases of the
bright soliton solutions exhibiting shape changing collisions, thereby
explaining their variable profile and shape variation in collision process.Comment: 50 Pages, 13 .jpg figures. To appear in PR
Planck \u27s Dusty GEMS: VII. Atomic carbon and molecular gas in dusty starburst galaxies at z = 2 to 4
The bright 3 P 1 - 3 P 0 ([CI] 1-0) and 3 P 2 - 3 P 1 ([CI] 2-1) lines of atomic carbon are becoming more and more widely employed as tracers of the cold neutral gas in high-redshift galaxies. Here we present observations of these lines in the 11 galaxies of the set of Planck\u27s Dusty GEMS, the brightest gravitationally lensed galaxies on the extragalactic submillimeter sky probed by the Planck satellite. We have [CI] 1-0 and [CI] 2-1 measurements for seven and eight of these galaxies, respectively, including four galaxies where both lines have been measured. We use our observations to constrain the gas excitation mechanism, excitation temperatures, optical depths, atomic carbon and molecular gas masses, and carbon abundances. Ratios of L CI /L FIR are similar to those found in the local universe, and suggest that the total cooling budget through atomic carbon has not significantly changed in the last 12 Gyr. Both lines are optically thin and trace 1 - 6
7 10 7 M of atomic carbon. Carbon abundances, X CI , are between 2.5 and 4
7 10 -5 , for an ultra-luminous infrared galaxy (ULIRG) CO-to-H 2 conversion factor of α CO = 0.8 M / [K km s -1 pc 2 ]. Ratios of molecular gas masses derived from [CI] 1-0 and CO agree within the measurement uncertainties for five galaxies, and agree to better than a factor of two for another two with [CI] 1-0 measurements, after carefully taking CO excitation into account. This does not support the idea that intense, high-redshift starburst galaxies host large quantities of "CO-dark" gas. These results support the common assumptions underlying most molecular gas mass estimates made for massive, dusty, high-redshift starburst galaxies, although the good agreement between the masses obtained with both tracers cannot be taken as independent confirmation of either α CO or X CI
Corporate financing decisions: UK survey evidence
Despite theoretical developments in recent years, our understanding of corporate capital structure remains incomplete. Prior empirical research has been dominated by archival regression studies which are limited in their ability to fully reflect the diversity found in practice. The present paper reports on a comprehensive survey of corporate financing decision-making in UK listed companies. A key finding is that firms are heterogeneous in their capital structure policies. About half of the firms seek to maintain a target debt level, consistent with trade-off theory, but 60 per cent claim to follow a financing hierarchy, consistent with pecking order theory. These two theories are not viewed by respondents as either mutually exclusive or exhaustive. Many of the theoretical determinants of debt levels are widely accepted by respondents, in particular the importance of interest tax shield, financial distress, agency costs and also, at least implicitly, information asymmetry. Results also indicate that cross-country institutional differences have a significant impact on financial decisions
Perturbation-induced radiation by the Ablowitz-Ladik soliton
An efficient formalism is elaborated to analytically describe dynamics of the
Ablowitz-Ladik soliton in the presence of perturbations. This formalism is
based on using the Riemann-Hilbert problem and provides the means of
calculating evolution of the discrete soliton parameters, as well as shape
distortion and perturbation-induced radiation effects. As an example, soliton
characteristics are calculated for linear damping and quintic perturbations.Comment: 13 pages, 4 figures, Phys. Rev. E (in press
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