(De)constructing Paradigmaticity in Syntax: An Information-Theoretic Approach

The notions of paradigmatic and syntagmatic relations are central to linguistics. Traditionally, two linguistic forms are paradigmatically related if they fall in the same grammatical slot and can substitute for each other, and syntagmatically related if they occur next to each other. For example, in mainstream American English, modals may and can have a paradigmatic relationship since they share a syntactic position, but the modal may and perfect auxiliary have have a syntagmatic relationship as they co-occur in distinct syntactic positions, e.g. They may have eaten. Paradigmatically related forms may form a closed set, or paradigm. Paradigms are well-studied in morphology, e.g., English adjective inflections -er (comparative), -est (superlative), and -∅ (no suffix, positive) form a clear paradigm, but they are often less clear-cut in syntax (cf. Lehmann 2015). This study proposes a new approach for examining this issue which re-casts the conventionally categorical contrast between paradigmatic and syntagmatic relationships as a gradient information-theoretic notion, pointwise mutual information. The more strongly negative the PMI between two forms appearing in the same constructional environment, the more paradigmatic the relationship, and if PMI ≥ 0, it is not paradigmatic at all. Paradigmaticity between forms in this approach is thus the degree of mutual exclusivity between them. This proposal is motivated by cases in syntax where some forms belonging to similar functional domains may co-occur only occasionally, and thus appear marginally paradigmatic. Examples include the negative and affirmative potential modality markers 唔 m4 and 得 dak1 in Cantonese resultatives, and the focus marker も mo and case marker を o in Japanese. The PMI measure can describe both relations as strongly but not categorically paradigmatic. This study then extends this gradient measure to evaluate the degree to which paradigmatically related forms constitute a paradigm. This is done by taking the distribution of PMIs between any pair of members in the paradigm, then taking a summary statistic like the mean, median or maximum. This complements notions of gradient paradigmaticity from previous work (e.g. Lehmann 2015, Diewald & Smirnova 2010), which focus on factors like semantic dependence, by extending the notion to formal co-occurrence probability. Before the analysis, one must first identify a set of k forms from similar semantic domains that occur in the same constructional context, e.g. Japanese postnominal particles. Each instance of the construction examined containing the forms under investigation is then extracted from a corpus and modelled as a k-dimensional Bernoulli random vector, which is 0 when a form is absent and 1 when present (ignoring ordering information). To estimate PMI, the forms’ (co-)occurrence probabilities can be estimated in multiple ways. With the maximum likelihood estimator (MLE), the probability of (co-)occurrence is just the empirical proportion of times in which form(s) (co-)occur in the corpus. Yet since zero empirical co-occurrence probabilities are common in this type of situation, MLEs can be undefined, making it hard to compare across undefined values (which can be due to small n or truly high paradigmaticity), and usual Wald tests and confidence intervals based on asymptotic normality fail. An alternative is additive smoothing, from which one can get Dirichlet-based posterior intervals. Rather than smoothing word counts directly, I treat the Bernoulli random vectors as categorical random variables with 2^k categories (one for each combination of forms), so smoothing can be applied to each of these co-occurrence categories. With a sizeable form inventory, most co-occurrences will be extremely infrequent, so smoothing would be excessive using standard hyperparameter choices like alpha =1. I thus cap the maximum number of forms appearing at the maximum attested number M, and use the reciprocal of the number of resulting categories to concentrate density near zero. The study describes two applications to Japanese, revealing some patterns not statable in categorical approaches. The study adds to existing computational research (Salle & Villavicencio 2019) suggesting negative PMI encodes syntactic information, and adds a quantitative, formal dimension to paradigmaticity, a notion mostly explored in qualitative, semantic ways (Lehmann 2015, Diewald & Smirnova 2010)

Text Segmentation Similarity Revisited: A Flexible Distance-based Approach for Multiple Boundary Types

Segmentation of texts into discourse and prosodic units is a ubiquitous problem in corpus linguistics and psycholinguistics, yet best practices for its evaluation – whether evaluating consistency between human segmenters or humanlikeness of machine segmenters – remain understudied. Building on segmentation edit distance (Fournier & Inkpen 2012, Fournier 2013), this paper introduces a new measure for evaluating similarity between two segmentations of the same text with multiple, mutually exclusive boundary types, accounting for varying identifiability and confusability between these types. We implement a dynamic programming algorithm for calculation specifically geared towards this type of segmentation problem, apply it to a case study of intonation unit segmentation measuring inter-annotator agreement, and make suggestions for interpreting results

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Comprehensive molecular characterization of the hippo signaling pathway in cancer

Hippo signaling has been recognized as a key tumor suppressor pathway. Here, we perform a comprehensive molecular characterization of 19 Hippo core genes in 9,125 tumor samples across 33 cancer types using multidimensional “omic” data from The Cancer Genome Atlas. We identify somatic drivers among Hippo genes and the related microRNA (miRNA) regulators, and using functional genomic approaches, we experimentally characterize YAP and TAZ mutation effects and miR-590 and miR-200a regulation for TAZ. Hippo pathway activity is best characterized by a YAP/TAZ transcriptional target signature of 22 genes, which shows robust prognostic power across cancer types. Our elastic-net integrated modeling further reveals cancer-type-specific pathway regulators and associated cancer drivers. Our results highlight the importance of Hippo signaling in squamous cell cancers, characterized by frequent amplification of YAP/TAZ, high expression heterogeneity, and significant prognostic patterns. This study represents a systems-biology approach to characterizing key cancer signaling pathways in the post-genomic era