201 research outputs found
Increasing Student Voice and Empowerment Through Technology: The Perceptions of Communication Apprehensive Latter-day Saint (LDS) Seminary Students
Many students appear to be disinterested and unengaged in traditional classroom settings. Numerous educational theorists suggest that students need current technology and communication in order to get students more involved in classroom discussion. This study examined a group of Latter-day Saint (LDS) students who were not involved vocally in the classroom (communication apprehensive), yet were highly involved in peer-to-peer communication via technology outside of the classroom. Issues of power are critically examined utilizing LDS and Freirean lenses of student voice, democracy, and empowerment. These issues are consistent with the LDS Church Educational System’s efforts to help students to explain, share, and testify of gospel truths. Student surveys concerning the use of technology and communication were instrumental in selecting a purposeful sample of five students for further study. These students, ranging from grades ninth to twelfth, were interviewed regarding their perceptions of the potential of educational technology implementation in LDS seminary classrooms in an effort to engage the communication apprehensive students. The data derived from this multiple case study design were analyzed using constructed grounded theory. Several key findings emerged through the analysis. The participants felt that some form of communicative technology could be empowering and advantageous to apprehensive students. However, the technological tool selected should be innovative and independent of currently existent resources. The participants also noted that some degree of communication apprehension still exists when using communicative technology. Ultimately, it is people who empower and give voice to the apprehensive student, not technological mediums alone
Analyze This! A Cosmological Constraint Package for CMBEASY
We introduce a Markov Chain Monte Carlo simulation and data analysis package
that extends the CMBEASY software. We have taken special care in implementing
an adaptive step algorithm for the Markov Chain Monte Carlo in order to improve
convergence. Data analysis routines are provided which allow to test models of
the Universe against measurements of the cosmic microwave background,
supernovae Ia and large scale structure. We present constraints on cosmological
parameters derived from these measurements for a CDM cosmology and
discuss the impact of the different observational data sets on the parameters.
The package is publicly available as part of the CMBEASY software at
www.cmbeasy.org.Comment: Published version, JCAP style, 16 pages, 7 figures. The software is
available at http://www.cmbeasy.or
CosmoSIS: Modular cosmological parameter estimation
Cosmological parameter estimation is entering a new era. Large collaborations
need to coordinate high-stakes analyses using multiple methods; furthermore
such analyses have grown in complexity due to sophisticated models of cosmology
and systematic uncertainties. In this paper we argue that modularity is the key
to addressing these challenges: calculations should be broken up into
interchangeable modular units with inputs and outputs clearly defined. We
present a new framework for cosmological parameter estimation, CosmoSIS,
designed to connect together, share, and advance development of inference tools
across the community. We describe the modules already available in CosmoSIS,
including CAMB, Planck, cosmic shear calculations, and a suite of samplers. We
illustrate it using demonstration code that you can run out-of-the-box with the
installer available at http://bitbucket.org/joezuntz/cosmosisComment: Finally got around to updating to refereed version. 31 pages, 8
figure
CMBfit: Rapid WMAP likelihood calculations with normal parameters
We present a method for ultra-fast confrontation of the WMAP cosmic microwave
background observations with theoretical models, implemented as a publicly
available software package called CMBfit, useful for anyone wishing to measure
cosmological parameters by combining WMAP with other observations. The method
takes advantage of the underlying physics by transforming into a set of
parameters where the WMAP likelihood surface is accurately fit by the
exponential of a quartic or sextic polynomial. Building on previous physics
based approximations by Hu et.al., Kosowsky et.al. and Chu et.al., it combines
their speed with precision cosmology grade accuracy. A Fortran code for
computing the WMAP likelihood for a given set of parameters is provided,
pre-calibrated against CMBfast, accurate to Delta lnL ~ 0.05 over the entire
2sigma region of the parameter space for 6 parameter ``vanilla'' Lambda CDM
models. We also provide 7-parameter fits including spatial curvature,
gravitational waves and a running spectral index.Comment: 14 pages, 8 figures, References added, accepted for publication in
Phys.Rev.D., a Fortran code can be downloaded from
http://space.mit.edu/home/tegmark/cmbfit
Spurious long memory, uncommon breaks and the implied–realized volatility puzzle
One of the puzzles in international finance is the frequent finding that implied volatility is a biased predictor of realized volatility. However, given asset price volatility is often characterized as possessing long memory, the recent literature has shown that allowing for long-range dependence removes this bias. Of course, the appearance of long memory can be generated by the presence of structural breaks. This paper discusses the effect of structural breaks on the implied-realized volatility relation. Simulations show that if significant structural breaks are omitted, testing can spuriously show the typical patterns of fractional cointegration found in the literature. Next, empirical results show that foreign exchange implied and realized volatility contains structural breaks. The breaks in the implied series never closely anticipate or co-occur with those of the realized series, suggesting that the market has no ability to forecast structural change. When breaks are accounted for in the bi-variate framework, the point estimate of the slope parameter falls and the null of unbiasedness can be rejected. Allowing for structural breaks suggests that the implied-realized volatility puzzle might not be solved after all
Antenatal steroids in preterm labour for the prevention of neonatal deaths due to complications of preterm birth
Background In high-income countries, administration of antenatal steroids is standard care for women with anticipated preterm labour. However, although >1 million deaths due to preterm birth occur annually, antenatal steroids are not routine practice in low-income countries where most of these deaths occur
GTP avoidance in Tetrahymena thermophila requires tyrosine kinase activity, intracellular calcium, NOS, and guanylyl cyclase
Guanosine 5'-triphosphate (GTP) is a chemorepellent in Tetrahymena thermophila that has been shown to stimulate cell division as well as ciliary reversal. Previous studies have proposed that GTP avoidance is linked to a receptor-mediated, calcium-based depolarization. However, the intracellular mechanisms involved in GTP avoidance have not been previously documented. In this study, we examine the hypothesis that GTP signals through a tyrosine kinase pathway in T. thermophila. Using behavioral assays, enzyme immunosorbent assays, Western blotting, and immunofluorescence, we present data that implicate a tyrosine kinase, phospholipase C, intracellular calcium, nitric oxide synthase (NOS) and guanylyl cyclase in GTP signaling. The tyrosine kinase inhibitor genistein eliminates GTP avoidance in Tetrahymena in behavioral assays. Similarly, pharmacological inhibitors of phospholipase C, NOS, and guanylyl cyclase all eliminated Tetrahymena avoidance to GTP. Immunofluorescence data shows evidence of tyrosine kinase activity in the cilia, suggesting that this enzyme activity could be directly involved in ciliary reversal
Reduction of Cosmological Data for the Detection of Time-varying Dark Energy Density
We present a method for reducing cosmological data to constraints on the
amplitudes of modes of the dark energy density as a function of redshift. The
modes are chosen so that (1) one of them has constant density and (2) the
others are non-zero only if there is time-variation in the dark energy density
and (3) the amplitude errors for the time-varying modes are uncorrelated with
each other. We apply our method to various combinations of three-year WMAP
data, baryon acoustic oscillation data, the 'Gold' supernova data set, and the
Supernova Legacy Survey data set. We find no significant evidence for a
time-varying dark energy density or for non-zero mean curvature. Although by
some measure the limits on four of the time-varying mode amplitudes are quite
tight, they are consistent with the expectation that the dark energy density
does not vary on timescales shorter than a Hubble time. Since we do not expect
detectable time variation in these modes, our results should be viewed as a
systematic error test which the data have passed. We discuss a procedure to
identify modes with maximal signal-to-noise ratio.Comment: 13 pages, 12 figures; Version accepted for publication by JCAP;
Updated with three-year WMAP data; added discussion on systematic error
detectio
Selecting effective incentive structures in health care: A decision framework to support health care purchasers in finding the right incentives to drive performance
<p>Abstract</p> <p>Background</p> <p>The Ontario health care system is devolving planning and funding authority to community based organizations and moving from steering through rules and regulations to steering on performance. As part of this transformation, the Ontario Ministry of Health and Long-Term Care (MOHLTC) are interested in using incentives as a strategy to ensure alignment – that is, health service providers' goals are in accord with the goals of the health system. The objective of the study was to develop a decision framework to assist policymakers in choosing and designing effective incentive systems.</p> <p>Methods</p> <p>The first part of the study was an extensive review of the literature to identify incentives models that are used in the various health care systems and their effectiveness. The second part was the development of policy principles to ensure that the used incentive models are congruent with the values of the Ontario health care system. The principles were developed by reviewing the Ontario policy documents and through discussions with policymakers. The validation of the principles and the suggested incentive models for use in Ontario took place at two meetings. The first meeting was with experts from the research and policy community, the second with senior policymakers from the MOHLTC. Based on the outcome of those two meetings, the researchers built a decision framework for incentives. The framework was send to the participants of both meetings and four additional experts for validation.</p> <p>Results</p> <p>We identified several models that have proven, with a varying degree of evidence, to be effective in changing or enabling a health provider's performance. Overall, the literature suggests that there is no single best approach to create incentives yet and the ability of financial and non-financial incentives to achieve results depends on a number of contextual elements. After assessing the initial set of incentive models on their congruence with the four policy principles we defined nine incentive models to be appropriate for use in Ontario and potentially other health care systems that want to introduce incentives to improve performance. Subsequently, the models were incorporated in the resulting decision framework.</p> <p>Conclusion</p> <p>The design of an incentive must reflect the values and goals of the health care system, be well matched to the performance objectives and reflect a range of contextual factors that can influence the effectiveness of even well-designed incentives. As a consequence, a single policy recommendation around incentives is inappropriate. The decision framework provides health care policymakers and purchasers with a tool to support the selection of an incentive model that is the most appropriate to improve the targeted performance.</p
Proteolytic activation of the essential parasitophorous vacuole cysteine protease SERA6 accompanies malaria parasite egress from its host erythrocyte.
The malaria parasite replicates within an intraerythrocytic parasitophorous vacuole (PV). The PV and host cell membranes eventually rupture, releasing merozoites in a process called egress. Certain inhibitors of serine and cysteine proteases block egress, indicating a crucial role for proteases. The Plasmodium falciparum genome encodes nine serine-repeat antigens (SERAs), each of which contains a central domain homologous to the papain-like (clan CA, family C1) protease family. SERA5 and SERA6 are indispensable in blood-stage parasites, but the function of neither is known. Here we show that SERA6 localizes to the PV where it is precisely cleaved just prior to egress by an essential serine protease called PfSUB1. Mutations that replace the predicted catalytic Cys of SERA6, or that block SERA6 processing by PfSUB1, could not be stably introduced into the parasite genomic sera6 locus, indicating that SERA6 is an essential enzyme and that processing is important for its function. We demonstrate that cleavage of SERA6 by PfSUB1 converts it to an active cysteine protease. Our observations reveal a proteolytic activation step in the malarial PV that may be required for release of the parasite from its host erythrocyte
- …