121 research outputs found
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What causes the word gap? Financial concerns may systematically suppress child-directed speech
Parents with fewer educational and economic resources (low socioeconomic-status, SES) tend to speak less to their children, with consequences for children’s later life outcomes. Despite this well-established and highly popularized link, surprisingly little research addresses why the SES “word gap” exists. Moreover, existing research focuses on individual-level explanations with little attention to structural constraints with which parents must contend. In two pre-registered studies, we test whether experiencing financial scarcity itself can suppress caregivers’ speech to their children. Study 1 suggests that caregivers who are prompted to reflect on scarcity—particularly those who reflect on financial scarcity—speak to their 3-year-olds less than a control group in a subsequent play session. Study 2 finds that caregivers speak less to their children at the end of the month—when they are more likely to be experiencing financial hardship—than the rest of the month. Thus, above and beyond the individual characteristics of parents, structural constraints may affect how much parents speak to their children
T-duality with H-flux: non-commutativity, T-folds and G x G structure
Various approaches to T-duality with NSNS three-form flux are reconciled.
Non-commutative torus fibrations are shown to be the open-string version of
T-folds. The non-geometric T-dual of a three-torus with uniform flux is
embedded into a generalized complex six-torus, and the non-geometry is probed
by D0-branes regarded as generalized complex submanifolds. The
non-commutativity scale, which is present in these compactifications, is given
by a holomorphic Poisson bivector that also encodes the variation of the
dimension of the world-volume of D-branes under monodromy. This bivector is
shown to exist in SU(3) x SU(3) structure compactifications, which have been
proposed as mirrors to NSNS-flux backgrounds. The two SU(3)-invariant spinors
are generically not parallel, thereby giving rise to a non-trivial Poisson
bivector. Furthermore we show that for non-geometric T-duals, the Poisson
bivector may not be decomposable into the tensor product of vectors.Comment: 25 pages, LaTeX; v2: typos corrected, references adde
Matrix theory origins of non-geometric fluxes
We explore the origins of non-geometric fluxes within the context of M theory
described as a matrix model. Building upon compactifications of Matrix theory
on non-commutative tori and twisted tori, we formulate the conditions which
describe compactifications with non-geometric fluxes. These turn out to be
related to certain deformations of tori with non-commutative and
non-associative structures on their phase space. Quantization of flux appears
as a natural consequence of the framework and leads to the resolution of
non-associativity at the level of the unitary operators. The quantum-mechanical
nature of the model bestows an important role on the phase space. In
particular, the geometric and non-geometric fluxes exchange their properties
when going from position space to momentum space thus providing a duality among
the two. Moreover, the operations which connect solutions with different fluxes
are described and their relation to T-duality is discussed. Finally, we provide
some insights on the effective gauge theories obtained from these matrix
compactifications.Comment: 1+31 pages, reference list update
Gauged Supergravities from Twisted Doubled Tori and Non-Geometric String Backgrounds
We propose a universal geometric formulation of gauged supergravity in terms
of a twisted doubled torus. We focus on string theory (M-theory) reductions
with generalized Scherk-Schwarz twists residing in the O(n,n) (E_{7(7)})
duality group. The set of doubled geometric fluxes, associated with the duality
twists and identified naturally with the embedding tensor of gauged
supergravity, captures all known fluxes, i.e. physical form fluxes, ordinary
geometric fluxes, as well as their non-geometric counterparts. Furthermore, we
propose a prescription for obtaining the effective geometry embedded in the
string theory twisted doubled torus or in the M-theory megatorus and apply it
for several models of geometric and non-geometric flux compactifications.Comment: 36 pages, 1 figure. v2: minor changes; v3: version to appear in NP
The multiple meanings of "wheezing": a questionnaire survey in Portuguese for parents and health professionals
<p>Abstract</p> <p>Background</p> <p>Most epidemiological studies on pediatric asthma rely on the report of "wheezing" in questionnaires. Our aim was to investigate the understanding of this term by parents and health professionals.</p> <p>Methods</p> <p>A cross-sectional survey was carried out in hospital and community settings within the south of Portugal. Parents or caregivers self-completed a written questionnaire with information on social characteristics and respiratory history. Multiple choice questions assessed their understanding of "wheezing". Health professionals (physicians, nurses and physiotherapists) were given an adapted version. We used bivariate analysis and multivariate models to study associations between definitions of "wheezing" and participants' characteristics.</p> <p>Results</p> <p>Questionnaires from 425 parents and 299 health professionals were included. The term "wheezing" was not recognized by 34% of parents, more frequently those who were younger (OR 0.4 per 10-year increment, 95% CI 0.3-0.7), had lower education (OR 3.3, 95% CI 1.5-7.4), and whose children had no history of respiratory disease (OR 4.6, 95% CI 2.5-8.7) (all ORs adjusted). 31% of parents familiar with "wheezing" either did not identify it as a sound, or did not locate it to the chest, while tactile (40%) and visual (34%) cues to identify "wheezing" were frequently used. Nurses reported using visual stimuli and overall assessments more often than physicians (p < 0.01). The geographical location was independently associated with how parents recognized and described "wheezing".</p> <p>Conclusions</p> <p>Different meanings for "wheezing" are recognized in Portuguese language and may be influenced by education, respiratory history and regional terminology. These findings are likely applicable to other non-English languages, and suggest the need for more accurate questionnaires and additional objective measurement instruments to study the epidemiology of wheezing disorders.</p
Has management accounting research been critical?
This paper examines the contributions Management Accounting Research (MAR) has (and has not) made to social and critical analyses of management accounting in the twenty-five years since its launch. It commences with a personalised account of the first named author’s experiences of behavioural, social and critical accounting in the twenty-five years before MAR appeared. This covers events in the UK, especially the Management Control Workshop, Management Accounting Research conferences at Aston, the Inter-disciplinary Perspectives on Accounting Conferences; key departments and professors; and elsewhere the formation of pan-European networks, and reflections on a years’ visit to the USA.
Papers published by MAR are analysed according to year of publication, country of author and research site, research method, research subject (type of organization or subject studied), data analysis method, topic, and theory. This revealed, after initial domination by UK academics, increasing Continental European influence; increasing use of qualitative methods over a wide range of topics, especially new costing methods, control system design, change and implementation, public sector transformation, and more recently risk management and creativity. Theoretical approaches have been diverse, often multi-disciplinary, and have employed surprisingly few economic theories relative to behavioural and social theories. The research spans mainly large public and private sector organisations especially in Europe. Seven themes perceived as of interest to a social and critical theory analysis are evaluated, namely: the search for ‘Relevance Lost’ and new costing; management control, the environment and the search for ‘fits’; reconstituting the public sector; change and institutional theory; post-structural, constructivist and critical contributions; social and environmental accounting; and the changing geography of time and space between European and American research. The paper concludes by assessing the contributions of MAR against the aspirations of groups identified in the opening personal historiography, which have been largely met. MAR has made substantial contributions to social and critical accounting (broadly defined) but not in critical areas endeavouring to give greater voice and influence to marginalised sectors of society worldwide. Third Sector organisations, politics, civil society involvement, development and developing countries, labour, the public interest, political economy, and until recently social and environmental accounting have been neglected
A ten-dimensional action for non-geometric fluxes
The NSNS Lagrangian of ten-dimensional supergravity is rewritten via a change
of field variables inspired by Generalized Complex Geometry. We obtain a new
metric and dilaton, together with an antisymmetric bivector field which leads
to a ten-dimensional version of the non-geometric Q-flux. Given the involved
global aspects of non-geometric situations, we prescribe to use this new
Lagrangian, whose associated action is well-defined in some examples
investigated here. This allows us to perform a standard dimensional reduction
and to recover the usual contribution of the Q-flux to the four-dimensional
scalar potential. An extension of this work to include the R-flux is discussed.
The paper also contains a brief review on non-geometry.Comment: 47 pages; v2: minor modifications, references added, version to be
published in JHE
Comprehensive annotation of the Parastagonospora nodorum reference genome using next-generation genomics, transcriptomics and proteogenomics
Parastagonospora nodorum, the causal agent of Septoria nodorum blotch (SNB), is an economically important pathogen of wheat (Triticum spp.), and a model for the study of necrotrophic pathology and genome evolution. The reference P. nodorum strain SN15 was the first Dothideomycete with a published genome sequence, and has been used as the basis for comparison within and between species. Here we present an updated reference genome assembly with corrections of SNP and indel errors in the underlying genome assembly from deep resequencing data as well as extensive manual annotation of gene models using transcriptomic and proteomic sources of evidence (https://github.com/robsyme/Parastagonospora_nodorum_SN15). The updated assembly and annotation includes 8,366 genes with modified protein sequence and 866 new genes. This study shows the benefits of using a wide variety of experimental methods allied to expert curation to generate a reliable set of gene models
The genome of the emerging barley pathogen Ramularia collo-cygni
Background
Ramularia collo-cygni is a newly important, foliar fungal pathogen of barley that causes the disease Ramularia leaf spot. The fungus exhibits a prolonged endophytic growth stage before switching life habit to become an aggressive, necrotrophic pathogen that causes significant losses to green leaf area and hence grain yield and quality.
Results
The R. collo-cygni genome was sequenced using a combination of Illumina and Roche 454 technologies. The draft assembly of 30.3 Mb contained 11,617 predicted gene models. Our phylogenomic analysis confirmed the classification of this ascomycete fungus within the family Mycosphaerellaceae, order Capnodiales of the class Dothideomycetes. A predicted secretome comprising 1053 proteins included redox-related enzymes and carbohydrate-modifying enzymes and proteases. The relative paucity of plant cell wall degrading enzyme genes may be associated with the stealth pathogenesis characteristic of plant pathogens from the Mycosphaerellaceae. A large number of genes associated with secondary metabolite production, including homologs of toxin biosynthesis genes found in other Dothideomycete plant pathogens, were identified.
Conclusions
The genome sequence of R. collo-cygni provides a framework for understanding the genetic basis of pathogenesis in this important emerging pathogen. The reduced complement of carbohydrate-degrading enzyme genes is likely to reflect a strategy to avoid detection by host defences during its prolonged asymptomatic growth. Of particular interest will be the analysis of R. collo-cygni gene expression during interactions with the host barley, to understand what triggers this fungus to switch from being a benign endophyte to an aggressive necrotroph
The role of ETG modes in JET-ILW pedestals with varying levels of power and fuelling
We present the results of GENE gyrokinetic calculations based on a series of JET-ITER-like-wall (ILW) type I ELMy H-mode discharges operating with similar experimental inputs but at different levels of power and gas fuelling. We show that turbulence due to electron-temperature-gradient (ETGs) modes produces a significant amount of heat flux in four JET-ILW discharges, and, when combined with neoclassical simulations, is able to reproduce the experimental heat flux for the two low gas pulses. The simulations plausibly reproduce the high-gas heat fluxes as well, although power balance analysis is complicated by short ELM cycles. By independently varying the normalised temperature gradients (omega(T)(e)) and normalised density gradients (omega(ne )) around their experimental values, we demonstrate that it is the ratio of these two quantities eta(e) = omega(Te)/omega(ne) that determines the location of the peak in the ETG growth rate and heat flux spectra. The heat flux increases rapidly as eta(e) increases above the experimental point, suggesting that ETGs limit the temperature gradient in these pulses. When quantities are normalised using the minor radius, only increases in omega(Te) produce appreciable increases in the ETG growth rates, as well as the largest increases in turbulent heat flux which follow scalings similar to that of critical balance theory. However, when the heat flux is normalised to the electron gyro-Bohm heat flux using the temperature gradient scale length L-Te, it follows a linear trend in correspondence with previous work by different authors
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