85 research outputs found
Review of Cloud Computing Opportunities
This paper will begin by defining some of the challenges that we face on the MACSUR project in termsĀ of evaluating model uncertainty and carrying out model integration. I will briefly review what cloudĀ technologies are available, followed with some suggestions about how those cloud technologies canĀ be used in order to contribute to meeting the challenges set out in the first part of the paper.'Month 12' deliverable for WP1 is a review of the opportunities for using cloud computing to developĀ the potential for model inter-comparison and interlinking in MACSUR. A challenging aspect ofĀ compiling this review is that before an 'opportunity' for any kind of model linking/comparison can beĀ identified, a lot of information about the specifics of extant models and workflows must be gatheredĀ from each of the three themes (TradeM, CropM, and LiveM).This deliverable must, however, be more than just saying āthese are the computing tools that we canĀ use to ...ā. There are a number of different challenges at different levels; a hierarchy of challenges, ifĀ you like. For example, in order to get models ātalkingā to one another, adequate protocols for theĀ transference of data and scaleability will need to be established, and then things like uncertaintyĀ analysis for these integrated models will need to be addressed. Further issues exist relating to humanĀ behaviour and logistics (e.g. MACSUR is a large project with many members from all over Europe,Ā with substantial distances between many of itās members).The term āCloudā is very ambiguous, and Cloud Computing covers a huge range of services, and aĀ number of innovative tools exist which can make international collaborative research more effective.Ā Two examples (already implemented on the MACSUR website) are: a discussion forum (where projectĀ members can create topics, make or reply to posts, and upload documents) and a complete surveyingĀ platform (to provide an un-restricted and fully featured survey platform for MACSUR members'Ā information gathering needs.
Bimodality in Damped Lyman alpha Systems
We report evidence for a bimodality in damped Ly systems (DLAs). Using [C II]
158 mu cooling rates, lc, we find a distribution with peaks at lc=10^-27.4 and
10^-26.6 ergs s^-1 H^-1 separated by a trough at lc^crit ~= lc < 10^-27.0 ergs
s^-1 H^-1. We divide the sample into low cool DLAs with lc < lc^crit and high
cool DLAs with lc > lc^crit and find the Kolmogorv-Smirnov probabilities that
velocity width, metallicity, dust-to-gas ratio, and Si II equivalent width in
the two subsamples are drawn from the same parent population are small. All
these quantities are significantly larger in the high cool population, while
the H I column densities are indistinguishable in the two populations. We find
that heating by X-ray and FUV background radiation is insufficient to balance
the cooling rates of either population. Rather, the DLA gas is heated by local
radiation fields. The rare appearance of faint, extended objects in the Hubble
Ultra Deep Field rules out in situ star formation as the dominant
star-formation mode for the high cool population, but is compatible with in
situ star formation as the dominant mode for the low cool population. Star
formation in the high cool DLAs likely arises in Lyman Break galaxies. We
investigate whether these properties of DLAs are analogous to the bimodal
properties of nearby galaxies. Using Si II equivalent width as a mass
indicator, we construct bivariate distributions of metallicity, lc, and areal
SFR versus the mass indicators. Tentative evidence is found for correlations
and parallel sequences, which suggest similarities between DLAs and nearby
galaxies. We suggest that the transition-mass model provides a plausible
scenario for the bimodality we have found. As a result, the bimodality in
current galaxies may have originated in DLAs.Comment: Accepted for publication in the Astrophysical Journal 18 pages 14
figure
Overview of case studies
MACSUR comprises 18 regional case studies for analysing the effects of climate change on agriculture with integrated inter-disciplinary models. Three case studies in Finland, Austria, and Italy have been selected as pilot studies because of their advancement in integration and representation of European farming systems and regions
The UCSD Radio-Selected Quasar Survey for Damped Lyman alpha System
As large optical quasar surveys for damped Lya become a reality and the study
of star forming gas in the early Universe achieves statistical robustness, it
is now vital to identify and quantify the sources of systematic error. Because
the nature of optically-selected quasar surveys makes them vulnerable to dust
obscuration, we have undertaken a radio-selected quasar survey for damped Lya
systems to address this bias. We present the definition and results of this
survey. We then combine our sample with the CORALS dataset to investigate the
HI column density distribution function f(N) of damped Lya systems toward
radio-selected quasars. We find that f(N) is well fit by a power-law f(N) = k_1
N^alpha_1, with log k_1 = 22.90 and alpha_1 = -2.18. This power-law is in
excellent agreement with that of optically-selected samples at low N(HI), an
important yet expected result given that obscuration should have negligible
effect at these gas columns. However, because of the relatively small size of
the radio-selected sample, 26 damped Lya systems in 119 quasars, f(N) is not
well constrained at large N(HI) and the first moment of the HI distribution
function, Omega_g, is, strictly speaking, a lower limit. The power-law is steep
enough, however, that extrapolating it to higher column densities implies only
a modest, logarithmic increase in Omega_g. The radio-selected value of Omega_g
= 1.15 x 10^-3, agrees well with the results of optically-selected surveys.
While our results indicate that dust obscuration is likely not a major issue
for surveys of damped Lya systems, we estimate that a radio-selected sample of
approximately 100 damped Lya systems will be required to obtain the precision
necessary to absolutely confirm an absence of dust bias.Comment: 12 pages, 9 Figures. Accepted to ApJ April 11, 200
General outline for a two-year extension of MACSUR: Cross-cutting activities
FACCE MACSUR has indicated a possible extension of funding by two years until May 2017 (phase 2). For phase 2, hub and theme coordinators suggest the following main activities, that will be discussed during the remainder of the meeting and in the coming months: Evolution, upscaling, and transfer of knowledge gained in regional case studies; Assessment of additional scenarios of socio-economic and climate trends; Further development of an interdisciplinary scientific community; Extending scaling methods for crop models to the European and global scale; Intensification of feed quality and animal health modelling with climate change; Economic models from farm to global level capable of reflecting climate change
An 84 microGauss Magnetic Field in a Galaxy at Redshift z=0.692
The magnetic field pervading our Galaxy is a crucial constituent of the
interstellar medium: it mediates the dynamics of interstellar clouds, the
energy density of cosmic rays, and the formation of stars. The field associated
with ionized interstellar gas has been determined through observations of
pulsars in our Galaxy. Radio-frequency measurements of pulse dispersion and the
rotation of the plane of linear polarization, i.e., Faraday rotation, yield an
average value B ~ 3 microGauss. The possible detection of Faraday rotation of
linearly polarized photons emitted by high-redshift quasars suggests similar
magnetic fields are present in foreground galaxies with redshifts z > 1. As
Faraday rotation alone, however, determines neither the magnitude nor the
redshift of the magnetic field, the strength of galactic magnetic fields at
redshifts z > 0 remains uncertain. Here we report a measurement of a magnetic
field of B ~ 84 microGauss in a galaxy at z =0.692, using the same
Zeeman-splitting technique that revealed an average value of B = 6 microGauss
in the neutral interstellar gas of our Galaxy. This is unexpected, as the
leading theory of magnetic field generation, the mean-field dynamo model,
predicts large-scale magnetic fields to be weaker in the past rather than
stronger
MACSUR ā Summary of research results, phase 1: 2012-2015
MACSUR ā Modelling European Agriculture with Climate Change for Food Security ā is a Ā knowledge hub that was formally created in June 2012 as a European scientific network. Ā The strategic aim of the knowledge hub is to create a coordinated and globally visible Ā network of European researchers and research groups, with intra- and interdisciplinary Ā interaction and shared expertise creating synergies for the development of scientific Ā resources (data, models, methods) to model the impacts of climate change on agriculture Ā and related issues. This objective encompasses a wide range of political and sociological Ā aspects, as well as the technical development of modelling capacity through impact Ā assessments at different scales and assessing uncertainties in model outcomes. We achieve Ā this through model intercomparisons and model improvements, harmonization and Ā exchange of data sets, training in the selection and use of models, assessment of benefits Ā of ensemble modelling, and cross-disciplinary linkages of models and tools. The project Ā engages with a diverse range of stakeholder groups and to support the development of Ā resources for capacity building of individuals and countries. Commensurate with this broad Ā challenge, a network of currently 300 scientists (measured by the number of individuals on Ā the central e-mail list) from 18 countries evolved from the original set of research groups Ā selected by FACCE. Ā In the spirit of creating and maintaining a network for intra- and interdisciplinary Ā knowledge exchange, network activities focused on meetings of researchers for sharing Ā expertise and, depending on group resources (both financial and personnel), development Ā of collaborative research activities. The outcome of these activities is the enhanced Ā knowledge of the individual researchers within the network, contributions to conference Ā presentations and scholarly papers, input to stakeholders and the general public, organised Ā courses for students, junior and senior scientists. The most visible outcome are the Ā scientific results of the network activities, represented in the contributions of MACSUR Ā members to the impressive number of more than 200 collaborative papers in peer-reviewed Ā publications. Ā Here, we present a selection of overview and cross-disciplinary papers which include Ā contributions from MACSUR members. It highlights the major scientific challenges Ā addressed, and the methodological solutions and insights obtained. Over and above these Ā highlights, major achievements have been reached regarding data collection, data Ā processing, evaluation, model testing, modelling assessments of the effects of agriculture Ā on ecosystem services, policy, and development of scenarios. Details on these Ā achievements in the context of MACSUR can be found in our online publication FACCE Ā MACSUR Reports at http://ojs.macsur.eu
Genotyping, sequencing and analysis of 140,000 adults from Mexico City
The Mexico City Prospective Study is a prospective cohort of more than 150,000 adults recruited two decades ago from the urban districts of CoyoacĆ”n and Iztapalapa in Mexico City1. Here we generated genotype and exome-sequencing data for all individuals and whole-genome sequencing data for 9,950 selected individuals. We describe high levels of relatedness and substantial heterogeneity in ancestry composition across individuals. Most sequenced individuals had admixed Indigenous American, European and African ancestry, with extensive admixture from Indigenous populations in central, southern and southeastern Mexico. Indigenous Mexican segments of the genome had lower levels of coding variation but an excess of homozygous loss-of-function variants compared with segments of African and European origin. We estimated ancestry-specific allele frequencies at 142āmillion genomic variants, with an effective sample size of 91,856 for Indigenous Mexican ancestry at exome variants, all available through a public browser. Using whole-genome sequencing, we developed an imputation reference panel that outperforms existing panels at common variants in individuals with high proportions of central, southern and southeastern Indigenous Mexican ancestry. Our work illustrates the value of genetic studies in diverse populations and provides foundational imputation and allele frequency resources for future genetic studies in Mexico and in the United States, where the Hispanic/Latino population is predominantly of Mexican descent
Association studies of up to 1.2 million individuals yield new insights into the genetic etiology of tobacco and alcohol use
Tobacco and alcohol use are leading causes of mortality that influence risk for many complex diseases and disorders 1 . They are heritable 2,3 and etiologically related 4,5 behaviors that have been resistant to gene discovery efforts 6ā11 . In sample sizes up to 1.2 million individuals, we discovered 566 genetic variants in 406 loci associated with multiple stages of tobacco use (initiation, cessation, and heaviness) as well as alcohol use, with 150 loci evidencing pleiotropic association. Smoking phenotypes were positively genetically correlated with many health conditions, whereas alcohol use was negatively correlated with these conditions, such that increased genetic risk for alcohol use is associated with lower disease risk. We report evidence for the involvement of many systems in tobacco and alcohol use, including genes involved in nicotinic, dopaminergic, and glutamatergic neurotransmission. The results provide a solid starting point to evaluate the effects of these loci in model organisms and more precise substance use measures
Evidence-based Kernels: Fundamental Units of Behavioral Influence
This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behaviorāinfluence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior
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