79 research outputs found
Using R-based VOStat as a low resolution spectrum analysis tool
We describe here an online software suite VOStat written mainly for the Virtual Observatory, a novel structure in which astronomers share terabyte scale data. Written mostly in the public-domain statistical computing language and environment R, it can do a variety of statistical analysis on multidimensional, multi-epoch data with errors.
Included are techniques which allow astronomers to start with multi-color data in the form of low-resolution spectra and select special kinds of sources in a variety of ways including color outliers. Here we describe the tool and demonstrate it with an example from Palomar-QUEST, a synoptic sky survey
Grand Unification as a Bridge Between String Theory and Phenomenology
In the first part of the talk, I explain what empirical evidence points to
the need for having an effective grand unification-like symmetry possessing the
symmetry SU(4)-color in 4D. If one assumes the premises of a future predictive
theory including gravity--be it string/M theory or a reincarnation--this
evidence then suggests that such a theory should lead to an effective grand
unification-like symmetry as above in 4D, near the string-GUT-scale, rather
than the standard model symmetry. Advantages of an effective supersymmetric
G(224) = SU(2) SU(2) SU(4) or SO(10) symmetry in 4D
in explaining (i) observed neutrino oscillations, (ii) baryogenesis via
leptogenesis, and (iii) certain fermion mass-relations are noted. And certain
distinguishing tests of a SUSY G(224) or SO(10)-framework involving CP and
flavor violations (as in , , edm's of the
neutron and the electron) as well as proton decay are briefly mentioned.
Recalling some of the successes we have had in our understanding of nature so
far, and the current difficulties of string/M theory as regards the large
multiplicity of string vacua, some comments are made on the traditional goal of
understanding {\em vis a vis} the recently evolved view of landscape and
anthropism.Comment: A chart showing some insights gained in the world of the very small
and that of the very large is included. A few relevant references are added.
Some clarification is made in the last section as regards the question of
understanding versus landscape and anthropis
Effectiveness of early intervention programs for parents of preterm infants: a meta-review of systematic reviews
Background: Various intervention programs exist for parents of preterm babies and some systematic reviews (SRs) have synthesised the evidence of their effectiveness. These reviews are, however, limited to specific interventions, components, or outcomes, and a comprehensive evidence base is lacking. The aim of this meta-review was to appraise and meta-synthesise the evidence from existing SRs to provide a comprehensive evidence base on the effectiveness of interventions for parents of preterm infants on parental and infant outcomes.
Methods: We conducted a comprehensive search of the following databases to identify relevant SRs: Cochrane library, Web of science, EMBASE, CINAHL, British Nursing Index, PsycINFO, Medline, ScienceDirect, Scopus, IBSS, DOAJ, ERIC, EPPI-Centre, PROSPERO, WHO Library. Additional searches were conducted using authors’ institutional libraries, Google Scholar, and the reference lists of identified reviews. Identified articles were screened in two stages against an inclusion criteria with titles and abstracts screened first followed by full-text screening. Selected SRs were appraised using the AMSTAR tool. Extracted data using a predesigned tool were synthesised narratively examining the direction of impact on outcomes.
Results: We found 11 SRs eligible for inclusion that synthesised a total of 343 quantitative primary studies. The average quality of the SRs was ‘medium’. Thirty four interventions were reported across the SRs with considerable heterogeneity in the structural framework and the targeted outcomes that included maternal-infant dyadic, maternal/parental, and infant outcomes. Among all interventions, Kangaroo Care (KC) showed the most frequent positive impact across outcomes (n = 19) followed by Mother Infant Transaction Program (MITP) (n = 14). Other interventions with most consistent positive impact on infant outcomes were Modified-Mother Infant Transaction Program (M-MITP) (n = 6), Infant Health and Development Program (IHDP) (n = 5) and Creating Opportunities for Parent Empowerment (COPE) (n = 5). Overall, interventions with both home and facility based components showed the most frequent positive impact across outcomes.
Conclusions: Neonatal care policy and planning for preterm babies should consider the implementation of
interventions with most positive impact on outcomes. The heterogeneity in interventions and outcomes calls for the development and implementation of an integrated program for parents of preterm infants with a clearly defined global set of parental and infant outcomes
Lepton Flavor Violation in Supersymmetric SO(10) Grand Unified Models
The study for lepton flavor violation combined with the neutrino oscillation
may provide more information about the lepton flavor structure of the grand
unified theory. In this paper, we study two lepton flavor violation processes,
and , in the context of supersymmetric SO(10)
grand unified models. We find the two processes are both of phenomenological
interest. In particular the latter may be important in some supersymmetric
parameter space where the former is suppressed. Thus, Z-dacay may offer another
chance for looking for lepton flavor violation.Comment: 26 pages, 10 figure
Media coverage of climate change: an international comparison
We present an international comparison of broadsheet newspaper coverage of climate change. We employ two complementary theoretical lenses, multiple streams theory and institutional theory, to explore why climate change has become headline news in some countries but has received comparatively little coverage in others. The study utilises a worldwide sample across 41 different countries for the year 2008, covering 113 leading national broadsheet newspapers. A cross-sectional regression model is used to identify whether and how a range of contextual factors impact coverage of climate change. To a certain extent, a country’s direct exposure to climate change and the measures that have been taken to combat global warming influence the position of climate change on the media agenda. Crucially, however, we identify a number of contextual factors that impact climate change-related media coverage in different national contexts. In particular, we find a significantly positive relationship between regulatory quality and levels of media coverage. At the same time, unemployment trends are significantly negatively related to media attention to climate change. Gross domestic product per capita does not help to explain levels of climate change-related media coverage. In other words, climate change appears to have moved beyond simply being a ‘rich country issue’
Leptogenesis and Neutrino Oscillations Within A Predictive G(224)/SO(10)-Framework
A framework based on an effective symmetry that is either G(224)= SU(2)_L x
SU(2)_R xSU(4)^c or SO(10) has been proposed (a few years ago) that
successfully describes the masses and mixings of all fermions including
neutrinos, with seven predictions, in good accord with the data. Baryogenesis
via leptogenesis is considered within this framework by allowing for natural
phases (~ 1/20-1/2) in the entries of the Dirac and Majorana mass-matrices. It
is shown that the framework leads quite naturally, for both thermal as well as
non-thermal leptogenesis, to the desired magnitude for the baryon asymmetry.
This result is obtained in full accord with the observed features of the
atmospheric and solar neutrino oscillations, as well as with those of the quark
and charged lepton masses and mixings, and the gravitino-constraint. Hereby one
obtains a unified description of fermion masses, neutrino oscillations and
baryogenesis (via leptogenesis) within a single predictive framework.Comment: Efficiency factor updated, some clarifications and new references
added. 19 page
VOStat: A Distributed Statistical Toolkit for the Virtual Observatory
The nature of astronomical data is changing: data volumes are following Moore's law with a doubling every 18 months and data sets consisting of a billion data vectors in a 100-dimensional parameter space are becoming commonplace. Sophisticated statistical techniques are crucial to fully and efficiently exploit these and maximize the scientific return. A long-standing limitation, however, on the range and capability of such analyses has been the paucity of non-proprietary software.
VOStat is the result of a cross-disciplinary collaboration between astronomers and statisticians to meet these challenges; it is a prototype knowledge-based statistical toolkit implemented within the VO paradigm for the entire astronomical community. VOStat consists of an easily extensible distributed web-based framework transparently accessed via a single science endpoint.
An exploratory science application is presented to demonstrate some of the functionality currently offered by VOStat
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