1,115 research outputs found
Short- and long-term effects of rote rehearsal on ESL learners’ processing of L2 collocations
Worldwide there is thought to be around 750 million people who speak English as a foreign language (Crystal, 2003, p. 69). For these speakers the difference between make a picture and take a picture may seem arbitrary. However, use of the former is likely to influence how their second language (L2) performance is perceived (Boers, Eyckmans, Kappel, Stengers, & Demecheleer, 2006). Consequently, L2 speakers' use of collocations (“fixed, identifiable, non-idiomatic phrases and constructions”; Benson, Benson, & Ilson, 1997, p. xv) and other formulaic sequences is an important aspect of L2 competence (Wray, 2002).
Several factors appear to influence the acquisition and use of L2 collocations. One of them is L1–L2 collocational congruency. Research has demonstrated that word-for-word translation equivalents (congruent collocations) are processed more efficiently than incongruent collocations (Wolter & Gyllstad, 2011; Yamashita & Jiang, 2010). Moreover, research has demonstrated that collocational frequency, and the frequency of formulaic sequences more generally, influences processing, with more frequent combinations being processed more quickly (Siyanova-Chanturia, Conklin, & van Heuven, 2011; Wolter & Gyllstad, 2013).
Researchers have also explored the role of different L2 input conditions on the processing of collocations. Sonbul and Schmitt (2013) compared the effects of three treatments (enriched, enhanced, and decontextualized input) on the collocational competence of learners of English as a second language (ESL). For explicit knowledge, they observed an improvement in both receptive and productive tests for all treatment conditions, but for implicit knowledge no gains were found. Peters (2012) examined L2-German learners' acquisition of words and formulaic sequences as dependent on an instructional method (directing learners' attention through instructions) and input enhancement (bolding and underlining). In a form recall test, input enhancement led to gains in learners' knowledge, whereas the instructional method did not seem to affect their results.
The present study brings together a number of questions that have been prominent in the literature by examining the short- and long-term effects of two different input conditions on ESL learners' processing of L2 collocations, as well as exploring the influence of frequency and collocational congruency
Invasive Group A Streptococcal Infection in High School Football Players, New York City, 2003
After being notified that 2 high school football teammates were hospitalized with confirmed or suspected invasive group A streptococcal infections, we conducted an investigation of possible spread among other team members. This investigation highlights a need for guidelines on management of streptococcal and other infectious disease outbreaks in team sport settings
Features and Prognosis of Severe Malaria Caused by Plasmodium falciparum, Plasmodium vivax and Mixed Plasmodium Species in Papua New Guinean Children
BACKGROUND: Mortality from severe pediatric falciparum malaria appears low in Oceania but Plasmodium vivax is increasingly recognized as a cause of complications and death. The features and prognosis of mixed Plasmodium species infections are poorly characterized. Detailed prospective studies that include accurate malaria diagnosis and detection of co-morbidities are lacking. METHODS AND FINDINGS: We followed 340 Papua New Guinean (PNG) children with PCR-confirmed severe malaria (77.1% P. falciparum, 7.9% P. vivax, 14.7% P. falciparum/vivax) hospitalized over a 3-year period. Bacterial cultures were performed to identify co-incident sepsis. Clinical management was under national guidelines. Of 262 children with severe falciparum malaria, 30.9%, 24.8% and 23.2% had impaired consciousness, severe anemia, and metabolic acidosis/hyperlactatemia, respectively. Two (0.8%) presented with hypoglycemia, seven (2.7%) were discharged with neurologic impairment, and one child died (0.4%). The 27 severe vivax malaria cases presented with similar phenotypic features to the falciparum malaria cases but respiratory distress was five times more common (P=0.001); one child died (3.7%). The 50 children with P. falciparum/vivax infections shared phenotypic features of mono-species infections, but were more likely to present in deep coma and had the highest mortality (8.0%; P=0.003 vs falciparum malaria). Overall, bacterial cultures were positive in only two non-fatal cases. 83.6% of the children had alpha-thalassemia trait and seven with coma/impaired consciousness had South Asian ovalocytosis (SAO). CONCLUSIONS: The low mortality from severe falciparum malaria in PNG children may reflect protective genetic factors other than alpha-thalassemia trait/SAO, good nutrition, and/or infrequent co-incident sepsis. Severe vivax malaria had similar features but severe P. falciparum/vivax infections were associated with the most severe phenotype and worst prognosis
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Simple measures of climate, soil properties and plant traits predict national scale grassland soil carbon stocks
1. Soil carbon (C) storage is a key ecosystem service. Soil C stocks play a vital role in soil fertility and climate regulation, but the factors that control these stocks at regional and national scales are unknown, particularly when their composition and stability are considered. As a result, their mapping relies on either unreliable proxy measures or laborious direct measurements.
2. Using data from an extensive national survey of English grasslands we show that surface soil (0-7cm) C stocks in size fractions of varying stability can be predicted at both regional and national scales from plant traits and simple measures of soil and climatic conditions.
3. Soil C stocks in the largest pool, of intermediate particle size (50-250 µm), were best explained by mean annual temperature (MAT), soil pH and soil moisture content. The second largest C pool, highly stable physically and biochemically protected particles (0.45-50 µm), was explained by soil pH and the community abundance weighted mean (CWM) leaf nitrogen (N) content, with the highest soil C stocks under N rich vegetation. The C stock in the small active fraction (250-4000 µm) was explained by a wide range of variables: MAT, mean annual precipitation, mean growing season length, soil pH and CWM specific leaf area; stocks were higher under vegetation with thick and/or dense leaves.
4. Testing the models describing these fractions against data from an independent English region indicated moderately strong correlation between predicted and actual values and no systematic bias, with the exception of the active fraction, for which predictions were inaccurate.
5. Synthesis and Applications: Validation indicates that readily available climate, soils and plant survey data can be effective in making local- to landscape-scale (1-100,000 km2) soil C stock predictions. Such predictions are a crucial component of effective management strategies to protect C stocks and enhance soil C sequestration
A grammar-based distance metric enables fast and accurate clustering of large sets of 16S sequences
Background: We propose a sequence clustering algorithm and compare the partition quality and execution time of the proposed algorithm with those of a popular existing algorithm. The proposed clustering algorithm uses a grammar-based distance metric to determine partitioning for a set of biological sequences. The algorithm performs clustering in which new sequences are compared with cluster-representative sequences to determine membership. If comparison fails to identify a suitable cluster, a new cluster is created.
Results: The performance of the proposed algorithm is validated via comparison to the popular DNA/RNA sequence clustering approach, CD-HIT-EST, and to the recently developed algorithm, UCLUST, using two different sets of 16S rDNA sequences from 2,255 genera. The proposed algorithm maintains a comparable CPU execution time with that of CD-HIT-EST which is much slower than UCLUST, and has successfully generated clusters with higher statistical accuracy than both CD-HIT-EST and UCLUST. The validation results are especially striking for large datasets.
Conclusions: We introduce a fast and accurate clustering algorithm that relies on a grammar-based sequence distance. Its statistical clustering quality is validated by clustering large datasets containing 16S rDNA sequences
Genotyping of Streptococcus agalactiae (group B streptococci) isolated from vaginal and rectal swabs of women at 35-37 weeks of pregnancy
<p>Abstract</p> <p>Background</p> <p>Group B streptococci (GBS), or <it>Streptococcus agalactiae</it>, are the leading bacterial cause of meningitis and bacterial sepsis in newborns. Here we compared different culture media for GBS detection and we compared the occurrence of different genotypes and serotypes of GBS isolates from the vagina and rectum.</p> <p>Methods</p> <p><it>Streptococcus agalactiae </it>was cultured separately from both rectum and vagina, for a total of 150 pregnant women, i) directly onto Columbia CNA agar, or indirectly onto ii) Granada agar resp. iii) Columbia CNA agar, after overnight incubation in Lim broth.</p> <p>Results</p> <p>Thirty six women (24%) were colonized by GBS. Of these, 19 harbored GBS in both rectum and vagina, 9 only in the vagina and 8 exclusively in the rectum. The combination of Lim broth and subculture on Granada agar was the only culture method that detected all GBS positive women. Using RAPD-analysis, a total of 66 genotypes could be established among the 118 isolates from 32 women for which fingerprinting was carried out. Up to 4 different genotypes in total (rectal + vaginal) were found for 4 women, one woman carried 3 different genotypes vaginally and 14 women carried two 2 different genotypes vaginally. Only two subjects were found to carry strains with the same genotype, although the serotype of both of these strains was different.</p> <p>Eighteen of the 19 subjects with GBS at both sites had at least one vaginal and one rectal isolate with the same genotype.</p> <p>We report the presence of two to four different genotypes in 22 (61%) of the 36 GBS positive women and the presence of identical genotypes in both sites for all women but one.</p> <p>Conclusion</p> <p>The combination of Lim broth and subculture on Granada medium provide high sensitivity for GBS detection from vaginal and rectal swabs from pregnant women. We established a higher genotypic diversity per individual than other studies, with up to four different genotypes among a maximum of 6 isolates per individual picked. Still, 18 of the 19 women with GBS from both rectum and vagina had at least one isolate from each sampling site with the same genotype.</p
Causal Loop Analysis of coastal geomorphological systems
As geomorphologists embrace ever more sophisticated theoretical frameworks that shift from simple notions of evolution towards single steady equilibria to recognise the possibility of multiple response pathways and outcomes, morphodynamic modellers are facing the problem of how to keep track of an ever-greater number of system feedbacks. Within coastal geomorphology, capturing these feedbacks is critically important, especially as the focus of activity shifts from reductionist models founded on sediment transport fundamentals to more synthesist ones intended to resolve emergent behaviours at decadal to centennial scales. This paper addresses the challenge of mapping the feedback structure of processes controlling geomorphic system behaviour with reference to illustrative applications of Causal Loop Analysis at two study cases: (1) the erosion–accretion behaviour of graded (mixed) sediment beds, and (2) the local alongshore sediment fluxes of sand-rich shorelines. These case study examples are chosen on account of their central role in the quantitative modelling of geomorphological futures and as they illustrate different types of causation. Causal loop diagrams, a form of directed graph, are used to distil the feedback structure to reveal, in advance of more quantitative modelling, multi-response pathways and multiple outcomes. In the case of graded sediment bed, up to three different outcomes (no response, and two disequilibrium states) can be derived from a simple qualitative stability analysis. For the sand-rich local shoreline behaviour case, two fundamentally different responses of the shoreline (diffusive and anti-diffusive), triggered by small changes of the shoreline cross-shore position, can be inferred purely through analysis of the causal pathways. Explicit depiction of feedback-structure diagrams is beneficial when developing numerical models to explore coastal morphological futures. By explicitly mapping the feedbacks included and neglected within a model, the modeller can readily assess if critical feedback loops are included
Evolving Responsibility or Revolving Bias? The Role of the Media in the anti-sugar debate in the UK Press.
Social responsibility of the media theory has been around for decades, and this theory is closely related to a report published by the Hutchins Commission in 1947, A Free and Responsible Press. Using social responsibility theory as a theoretical framework and recommendations from A Free and Responsible Press report, we analysed the coverage about the anti-sugar debate and the supermarket industry in the British press in a period between 2010 and 2015. Using content analysis as a method, we analysed press releases and surveys published by Action on Sugar as a main anti-sugar advocate in the UK and then we traced these public relations (PR) materials in the press coverage. We also analysed media bias focusing on the nature of quoting sources and whether media give a voice to everyone, both the anti-sugar activists and the relevant industry figures who claim that sugar is not the only reason for the current obesity problem. Results show that the media do not give a voice to the industry but only to the anti-sugar NGO. Nevertheless, the media remove sources from the industry from their coverage even when Action on Sugar mentions the industry in their documents
Land-use simplification weakens the association between terrestrial producer and consumer diversity in Europe
Land-use change is one of the primary drivers of species loss, yet little is known about its effect on other components of biodiversity that may be at risk, such as local associations between trophic levels. Here, we ask whether, and to what extent, landscape simplification, measured as the percentage of arable land in the landscape, disrupts the functional and phylogenetic association between plants and primary consumers. Across seven European regions, we inferred the potential associations (functional and phylogenetic) between host plants and butterflies in 561 semi-natural grasslands. Local plant diversity showed a strong bottom-up effect on butterfly diversity in the most complex landscapes, but this effect disappeared in simple landscapes. The functional associations between plant and butterflies are, therefore, the results of processes that act not only locally but are also dependent on the surrounding landscape context. Similarly, landscape simplification reduced the phylogenetic congruence among host plants and butterflies indicating that closely related butterfly species are more generalist in the potential resource lineages used. These processes occurred without any detectable change in species richness of plants or butterflies along the gradient of arable land. The structural properties of ecosystems are experiencing substantial erosion, with potentially pervasive effects on ecosystem functions and future evolutionary trajectories. Loss of interacting species might trigger cascading extinction events and reduce the stability of trophic interactions, as well as influence the longer-term resilience of ecosystem functions. This underscores a growing realization that species richness is a crude and insensitive metric and that both functional and phylogenetic associations, measured across multiple trophic levels, are likely to provide far deeper insights into the resilience of ecosystems, and the functions they provide
Measurement of the mass and lifetime of the baryon
A proton-proton collision data sample, corresponding to an integrated
luminosity of 3 fb collected by LHCb at and 8 TeV, is used
to reconstruct , decays. Using the , decay mode for calibration, the lifetime ratio and absolute
lifetime of the baryon are measured to be \begin{align*}
\frac{\tau_{\Omega_b^-}}{\tau_{\Xi_b^-}} &= 1.11\pm0.16\pm0.03, \\
\tau_{\Omega_b^-} &= 1.78\pm0.26\pm0.05\pm0.06~{\rm ps}, \end{align*} where the
uncertainties are statistical, systematic and from the calibration mode (for
only). A measurement is also made of the mass difference,
, and the corresponding mass, which
yields \begin{align*} m_{\Omega_b^-}-m_{\Xi_b^-} &= 247.4\pm3.2\pm0.5~{\rm
MeV}/c^2, \\ m_{\Omega_b^-} &= 6045.1\pm3.2\pm 0.5\pm0.6~{\rm MeV}/c^2.
\end{align*} These results are consistent with previous measurements.Comment: 11 pages, 5 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-008.htm
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