341 research outputs found
Keeping Tabs on Financial Innovation: Product Identifiers in Consumer Financial Regulation
The financial crisis of 2008 gave rise to renewed discussion about whether financial innovations should undergo higher scrutiny for potential harm and, if so, what type? In this Article, the authors propose a new system for monitoring financial innovations through a system of registration, data collection and analysis using unique product identifiers. Creating product identifiers would increase monitoring abilities substantially at relatively low cost by facilitating the linkage of separate databases. The assignment of unique product identifiers would also minimize errors in the identification and classification of different financial products. These identifiers would be available to both the government and the public to harness outside analysis by independent researchers in order to improve the monitoring of financial risk
The Cepheid distance to the Local Group Galaxy NGC 6822
Recent estimates of the Cepheid distance modulus of NGC 6822 differ by 0.18
mag. To investigate this we present new multi-epoch JHKs photometry of
classical Cepheids in the central region of NGC 6822 and show that there is a
zero-point difference from earlier work. These data together with optical and
mid-infrared observations from the literature are used to derive estimates of
the distance modulus of NGC 6822. A best value of 23.40 mag is adopted, based
on an LMC distance modulus of 18.50 mag. The standard error of this quantity is
~0.05 mag. We show that to derive consistent moduli from Cepheid observations
at different wavelengths, it is necessary that the fiducial LMC
period-luminosity relations at these wavelengths should refer to the same
subsample of stars. Such a set is provided. A distance modulus based on RR
Lyrae variables agrees with the Cepheid result.Comment: accepted for publication in MNRA
Coastal development and precipitation drive pathogen flow from land to sea: evidence from a Toxoplasma gondii and felid host system
Rapidly developing coastal regions face consequences of land use and climate change including flooding and increased sediment, nutrient, and chemical runoff, but these forces may also enhance pathogen runoff, which threatens human, animal, and ecosystem health. Using the zoonotic parasite Toxoplasma gondii in California, USA as a model for coastal pathogen pollution, we examine the spatial distribution of parasite runoff and the impacts of precipitation and development on projected pathogen delivery to the ocean. Oocysts, the extremely hardy free-living environmental stage of T. gondii shed in faeces of domestic and wild felids, are carried to the ocean by freshwater runoff. Linking spatial pathogen loading and transport models, we show that watersheds with the highest levels of oocyst runoff align closely with regions of increased sentinel marine mammal T. gondii infection. These watersheds are characterized by higher levels of coastal development and larger domestic cat populations. Increases in coastal development and precipitation independently raised oocyst delivery to the ocean (average increases of 44% and 79%, respectively), but dramatically increased parasite runoff when combined (175% average increase). Anthropogenic changes in landscapes and climate can accelerate runoff of diverse pathogens from terrestrial to aquatic environments, influencing transmission to people, domestic animals, and wildlife
A mixed methods multiple case study of implementation as usual in children’s social service organizations: study protocol
Background
Improving quality in children’s mental health and social service settings will require implementation strategies capable of moving effective treatments and other innovations (e.g., assessment tools) into routine care. It is likely that efforts to identify, develop, and refine implementation strategies will be more successful if they are informed by relevant stakeholders and are responsive to the strengths and limitations of the contexts and implementation processes identified in usual care settings. This study will describe: the types of implementation strategies used; how organizational leaders make decisions about what to implement and how to approach the implementation process; organizational stakeholders’ perceptions of different implementation strategies; and the potential influence of organizational culture and climate on implementation strategy selection, implementation decision-making, and stakeholders’ perceptions of implementation strategies. Methods/design
This study is a mixed methods multiple case study of seven children’s social service organizations in one Midwestern city in the United States that compose the control group of a larger randomized controlled trial. Qualitative data will include semi-structured interviews with organizational leaders (e.g., CEOs/directors, clinical directors, program managers) and a review of documents (e.g., implementation and quality improvement plans, program manuals, etc.) that will shed light on implementation decision-making and specific implementation strategies that are used to implement new programs and practices. Additionally, focus groups with clinicians will explore their perceptions of a range of implementation strategies. This qualitative work will inform the development of a Web-based survey that will assess the perceived effectiveness, relative importance, acceptability, feasibility, and appropriateness of implementation strategies from the perspective of both clinicians and organizational leaders. Finally, the Organizational Social Context measure will be used to assess organizational culture and climate. Qualitative, quantitative, and mixed methods data will be analyzed and interpreted at the case level as well as across cases in order to highlight meaningful similarities, differences, and site-specific experiences. Discussion
This study is designed to inform efforts to develop more effective implementation strategies by fully describing the implementation experiences of a sample of community-based organizations that provide mental health services to youth in one Midwestern city
Toxoplasma gondii, source to sea: higher contribution of domestic felids to terrestrial parasite loading despite lower infection prevalence
Abstract: Environmental transmission of Toxoplasma gondii, a global zoonotic parasite, adversely impacts human and animal health. Toxoplasma is a significant cause of mortality in threatened Southern sea otters, which serve as sentinels for disease threats to people and animals in coastal environments. As wild and domestic felids are the only recognized hosts capable of shedding Toxoplasma oocysts into the environment, otter infection suggests land-to-sea pathogen transmission. To assess relative contributions to terrestrial parasite loading, we evaluated infection and shedding among managed and unmanaged feral domestic cats, mountain lions, and bobcats in coastal California, USA. Infection prevalence differed among sympatric felids, with a significantly lower prevalence for managed feral cats (17%) than mountain lions, bobcats, or unmanaged feral cats subsisting on wild prey (73-81%). A geographic hotspot of infection in felids was identified near Monterey Bay, bordering a high-risk site for otter infection. Increased odds of oocyst shedding were detected in bobcats and unmanaged feral cats. Due to their large populations, pet and feral domestic cats likely contribute more oocysts to lands bordering the sea otter range than native wild felids. Continued coastal development may influence felid numbers and distribution, increase terrestrial pathogens in freshwater runoff, and alter disease dynamics at the human-animal-environment interface
Brain activation modulated by sentence comprehension.
The comprehension of visually presented sentences produces brain activation that increases with the linguistic complexity of the sentence. The volume of neural tissue activated (number of voxels) during sentence comprehension was measured with echoplanar functional magnetic resonance imaging. The modulation of the volume of activation by sentence complexity was observed in a network of four areas: the classical left-hemisphere language areas (the left laterosuperior temporal cortex, or Wernicke's area, and the left inferior frontal gyrus, or Broca's area) and their homologous righthemisphere areas, although the right areas had much smaller volumes of activation than did the left areas. These findings generally indicate that the amount of neural activity that a given cognitive process engenders is dependent on the computational demand that the task imposes. This study examines what it means to be "thinking harder" in the course of sentence comprehension, in terms of functional magnetic resonance imaging (fMRI)-measured brain activation. One of the challenges of brain science is to relate the dynamics of higher level cognition to the equally dynamic activity of brain-level events. A possible meeting ground between these two levels is the modLulation in the amount of neuronal activity (at the brain level) in a given task, measured as a function of the amount of computational demand that the task places on cognitive resources (1). In particular, we examined whether sentences that were more computationally demanding also engender more brain activation (2, 3). At the cognitive level, sentence comprehension requires combining information from a sequence of words and phrases, computing their syntactic and thematic relations, and using world knowledge to construct a representation of the sentence meaning. These processes require the consumption of computational resources to perform the comprehension operations and also to maintain the representations of the component word meanings, propositions, and relational structures in an activated state during the processing (1). At the brain level, sentence comprehension entails activation in a network of cortical areas, most prominent of which are the left laterosuperior temporal cortex (Wernicke's area) (4) and the left inferio
Dust mass-loss rates from AGB stars in the Fornax and Sagittarius dwarf Spheroidal galaxies
To study the effect of metallicity on the mass-loss rate of asymptotic giant
branch (AGB) stars, we have conducted mid-infrared photometric measurements of
such stars in the Sagittarius (Sgr dSph) and Fornax dwarf spheroidal galaxies
with the 10-m camera VISIR at the VLT. We derive mass-loss rates for 29
AGB stars in Sgr dSph and 2 in Fornax. The dust mass-loss rates are estimated
from the and colours. Radiative transfer models are used to
check the consistency of the method. Published IRAS and Spitzer data confirm
that the same tight correlation between colour and dust mass-loss
rates is observed for AGB stars from galaxies with different metallicities,
i.e. the Galaxy, the LMC and the SMC.
The derived dust mass-loss rates are in the range 5 to
3 Myr for the observed AGB stars in Sgr dSph
and around 5 Myr for those in Fornax; while
values obtained with the two different methods are of the same order of
magnitude. The mass-loss rates for these stars are higher than the nuclear
burning rates, so they will terminate their AGB phase by the depletion of their
stellar mantles before their core can grow significantly. Some observed stars
have lower mass-loss rates than the minimum value predicted by theoretical
models.Comment: 12 pages, 9 figures, accepted for publication in MNRA
AGB Variables and the Mira Period-Luminosity Relation
Published data for large amplitude asymptotic giant branch variables in the
Large Magellanic Cloud are re-analysed to establish the constants for an
infrared (K) period-luminosity relation of the form: Mk=rho[log P-2.38] +
delta. A slope of rho=-3.51+/-0.20 and a zero point of delta=-7.15+/-0.06 are
found for oxygen-rich Miras (if a distance modulus of 18.39+/-0.05 is used for
the LMC). Assuming this slope is applicable to Galactic Miras we discuss the
zero-point for these stars using the revised Hipparcos parallaxes together with
published VLBI parallaxes for OH Masers and Miras in Globular Clusters. These
result in a mean zero-point of delta=-7.25+/-0.07 for O-rich Galactic Miras.
The zero-point for Miras in the Galactic Bulge is not significantly different
from this value.
Carbon-rich stars are also discussed and provide results that are consistent
with the above numbers, but with higher uncertainties. Within the uncertainties
there is no evidence for a significant difference between the period-luminosity
relation zero-points for systems with different metallicity.Comment: 15 pages, 3 figures, accepted for MNRA
Discovery of the first symbiotic star in NGC6822
We report the discovery of the first symbiotic star (V=21.6, K_S=15.8 mag) in
the Local Group dwarf irregular galaxy NGC6822. This star was identified during
a spectral survey of Ha emission-line objects using the Southern African Large
Telescope (SALT) during its performance-verification phase. The observed strong
emission lines of HI and HeII suggest a high electron density and T* < 130 000
K for the hot companion. The infrared colours allow us to classify this object
as an S-type symbiotic star, comprising a red giant losing mass to a compact
companion. The red giant is an AGB carbon star, and a semi-regular variable,
pulsating in the first overtone with a period of 142 days. Its bolometric
magnitude is M_bol=-4.4 mag.
We review what is known about the luminosities of extragalactic symbiotic
stars, showing that most, possibly all, contain AGB stars. We suggest that a
much larger fraction of Galactic symbiotic stars may contain AGB stars than was
previously realised.Comment: 6 pages, 4 figures, accepted to MNRA
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