Development and validation of the Symptomatic Transdiagnostic Test (S2T)

INTRODUCTION

The categorical approach in psychiatry has received many criticisms. Modern research tends to develop a transdiagnostic approach. However, transdiagnostic works lack an overall understanding and focus mainly on anxiety and depression. The aim of the present study was to develop an easy to use tool to evaluate multiple dimensions opening the way for further research in the transdiagnostic approach. This will allow researchers to quickly assess the efficacy of psychotherapeutic interventions on multiple psychopathological dimensions.

METHOD

First, we identified the main symptoms of psychopathology in a sample of mental healthcare workers. Second, we developed the Symptomatic Transdiagnostic Test (S2T) to assess the main symptoms of psychopathology. Third, we evaluated its psychometric properties (exploratory and confirmatory factor analysis, internal consistency) in three non-clinical samples and one clinical sample.

RESULTS

The 66-item S2T included eleven factors referring to: i) negative thoughts and mood; ii) psycho-traumatic and maladaptive symptoms; iii) addiction symptoms; iv) disturbed eating behavior; v) disturbed perception and behavior; vi) panic and agoraphobia; vii) emotional lability; viii) dejection; ix) neurodevelopmental manifestations; x) anxiety and xi) psychic hyperactivity. We found a high internal consistency for the general scale (α=0.96) and the subscales. We found a good concurrent validity. As expected, we found higher levels of symptoms within the clinical population as compared to the non-clinical samples, except for addiction symptoms and disrupted eating behavior. We found negative associations between the symptomatic dimensions and psychological skills.

CONCLUSION

The S2T is a relevant tool for clinicians and researchers to assess the psychopathological profile. The main psychopathological symptoms are negatively related to the psychological skills.

Measurement is the foundation of research and theory on children's eating behaviours: Current issues and directions for progress

Eating behaviours affect food intakes and are involved in the aetiology of obesity. There has been impetus to translate findings about children's eating behaviour into intervention and policy programs. However, measurement limitations have hindered our capacity to understand and influence children's eating behaviours. In the present paper we provide an overview of some of the key methodological and measurement issues facing the field of children's eating behaviours and highlight implications for research and health promotion. Drawing on insight from parallel issues that occur in the measurement of early social and emotional development, we examine two overlapping themes in children's (aged 0-∼12 years) eating behaviours (Somaraki et al., 2021) measurement issues related to validity and reliability, and (Steinsbekk & Wichstrøm, 2015) associated methodological challenges, such as contextual influences and the importance of designing studies that use multiple informants and multiple methods. We then suggest insights and strategies aimed at advancing approaches to measurement of children's eating behaviours. To progress our understanding of children's eating behaviours, we conclude that a range of psychometrically sound, fit-for-purpose measurement instruments and procedures are needed for use in multi-trait, multi-method, multi-informant studies in a range of populations and contexts.

Dietary Patterns and Risk of a New Carious Lesion Postpartum: A Cohort Study

Dental caries (cavities), one of the most common infectious diseases, is caused by a number of factors. Oral microbes, dietary practices, sociodemographic factors, and dental hygiene all inform caries risk. Assessing the impact of diet is complicated as individuals eat foods in combinations, and the interactions among the foods may alter caries risk. Our study aimed to prospectively assess the association between dietary patterns and caries risk in the postpartum period, a potentially sensitive period for caries development. We analyzed in-person dental assessments and telephone food frequency questionnaires (FFQs) from 879 Caucasian women participating in the Center for Oral Health Research in Appalachia Cohort 2 (COHRA2) that were collected biannually for up to 6 y. One-week recall of food intake frequency was assessed using a Likert scale. We used principal component analysis to summarize the FFQ data; the top 2 components described 15% and 12% of the variance in FFQ data. The first component was characterized by high consumption of fruits and vegetables, while the second component was heavily influenced by desserts and crackers. We used a modified Poisson model to predict the risk of an increase in the number of decayed, missing, and filled teeth in the postpartum period by 1) dietary patterns and 2) individual foods and beverages at the previous study visit, after controlling for other known risk factors, including history of carious lesions. Eating a dietary pattern high in desserts and crackers was associated with a 20% increase in the number of decayed, missing, and filled teeth in the postpartum period (95% confidence interval, 1.03-1.39). However, this effect was attenuated among those who also consumed a dietary pattern high in fruits and vegetables. Dietary patterns should be considered when devising interventions aimed at preventing dental caries.

Validation of the French ADNM-20 in the assessment of emotional difficulties resulting from COVID-19 quarantine and outbreak

Background

Multiple psychological consequences of the COVID-19 outbreak and quarantine have been described. However, there is a lack of global conceptualization. We argue that the stressful aspects of the situation, the multiple environmental consequences of the outbreak, and the diversity of symptoms observed in such a situation, suggest that Adjustment disorder (AD) is a promising way to conceptualize the psychological consequences of the outbreak and quarantine. The first aim of the study was to validate the French version of the ADNM. The second aim was to set out adjustment difficulties resulting from COVID-19 outbreak and quarantine.

Method

We recruited 1010 (840 women, 170 men) who consented online to participate. They filled out the French ADNM, visual analogic scales, HADS, IES, and the COPE, to evaluate coping strategies.

Results

We confirmed the factor structure of the ADNM and we found good psychometric properties. We found that 61.3% of participants presented an adjustment disorder related to COVID-19 outbreak. We found multiple risk factors and protective factors to AD due to quarantine and outbreak. We also identified the coping strategies negatively and positively associated with AD.

Conclusion

Adjustment disorder is a relevant concept to understand psychological manifestations caused by quarantine and outbreak. The French ANDM has good psychometric properties to evaluate such manifestations. The association between coping strategies and AD symptoms suggest that CBT may be the best intervention to help people suffering from AD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40359-021-00683-7.

Preliminary exploration of the use of the Children's Eating Behaviour Questionnaire (CEBQ) and Feeding Practices and Structure Questionnaire (FPSQ) in Vietnamese mothers

OBJECTIVE

This preliminary pilot study aims to explore the use of the Feeding Practices and Structure Questionnaire (FPSQ) and Children's Eating Behaviour Question (CEBQ) in a sample of Vietnamese mothers.

SUBJECTS/METHODS

Cross-sectional data from the FPSQ and CEBQ were collected from a convenience sample of mothers (n = 102) who attended the Ho Chi Minh City Nutrition Centre in Viet Nam. Mothers had at least one child aged 2-5 years. The reliability of the questionnaire subscales was tested using Cronbach's alpha coefficients. Face validity was assessed using dialogue from a translation-back-translation procedure undertaken by an expert committee, and cognitive interviews conducted in a subsample of mothers (n = 6). Based on these findings, exploratory factor analyses (EFAs) were performed to assess the underlying structures of both questionnaires in this sample.

RESULTS

Cronbach's alpha coefficients for the original questionnaires ranged from 0.23 to 0.92. Limitations in translation and comprehension of items surfaced, warranting modifications of the questionnaires, which were subsequently examined using EFA. EFA of the FPSQ and CEBQ revealed a six-factor structure with 23 items, and a six-factor structure with 27 items, respectively, which were interpretable solutions for this sample. Cronbach's alpha coefficients were >0.70 for all subscales in the revised questionnaires.

CONCLUSIONS

Modified versions of the FPSQ and CEBQ are proposed for use in Viet Nam. However, prior to their use, further reliability and validity testing must be undertaken in larger samples, including assessment of test-retest reliability and construct validity, as well as confirmatory factor analysis to verify the proposed factor structures.

Parental stress, food parenting practices and child snack intake during the COVID-19 pandemic

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented disruptions to the lives of families. This study aimed to investigate the impact of pandemic-associated stress on food parenting practices including interactions surrounding snacks, and child diet.

METHODS

Parents (N = 318) of 2-12-year old children completed a cross-sectional online survey assessing current COVID-19-specific stress, pre-COVID-19 stress, financial stress (e.g. food insecurity), food parenting practices, and child snack intake frequency. Structural Equation Modeling was used to model simultaneous paths of relationships and test direct and indirect effects.

RESULTS

Stress, including financial hardship, was higher compared with before the crisis. The majority of children had regular mealtimes and irregular snack times. Higher COVID-19-specific stress was associated with more non-nutritive use of food and snacks (e.g. emotional and instrumental feeding), but also more structure and positive interactions (e.g. eating with or engaging with child around mealtimes). Higher COVID-19-specific stress was also associated with greater child intake frequency of sweet and savory snacks, with some evidence for mediation by snack parenting practices.

CONCLUSION

Our findings indicate that stress associated with the COVID-19 pandemic may be linked to child snack intake with potential impacts on child obesity risk, and suggest several modifiable points of intervention within the family context.

The Feeding Practices and Structure Questionnaire: development and validation of age appropriate versions for infants and toddlers

Background

In order to measure and understand trajectories of parental feeding practices and their relationship with child eating and weight, it is desirable to perform assessment from infancy and across time, in age-appropriate ways. While many feeding practices questionnaires exist, none is presently available that enables tracking of feeding practices from infancy through childhood. The aim of the study was to develop a version of the Feeding Practices and Structure Questionnaire (FPSQ) for parents with infants and toddlers (< 2 years) to be used in conjunction with the original FPSQ for older children (≥2 years) to measure feeding practices related to non-responsiveness and structure across childhood.

Methods

Constructs and items for the FPSQ for infants and toddlers were derived from the existing and validated FPSQ for older children and supplemented by a review of the literature on infant feeding questionnaires. Following expert review, two versions of the questionnaire were developed, one for milk feeding parents and one for solid feeding parents. Data from two studies were combined (child ages 0–24 months) to test the derived constructs with Confirmatory Factor Analysis for the milk feeding (N = 731) and solid feeding (N = 611) versions.

Results

The milk feeding version consisted of four factors (18 items) and showed acceptable model fit and good internal reliability: ‘feeding on demand vs. feeding routine’ (α = 0.87), ‘using food to calm’ (α = 0.87), ‘persuasive feeding’ (α = 0.71), ‘parent-led feeding’ (α = 0.79). The same four factors showed acceptable model fit for the solid feeding version (21 items), likewise with good internal reliability (α = 0.74, 0.86, 0.85, 0.84 respectively). Two additional factors (13 items) were developed for the solid feeding version that appeared developmentally appropriate only for children aged 12 months or older: ‘family meal environment’ (α = 0.81) and ‘using (non-)food rewards’ (α = 0.92). The majority of factor-factor correlations were in line with those of the original FPSQ.

Conclusions

The FPSQ milk and solid feeding versions are the first measures specifically developed as precursors to the FPSQ to measure parental feeding practices in children < 2 years, particularly practices related to non-responsiveness and structure. Further validation in more diverse samples is required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01079-x.

Social integration of migrant physicians in inpatient rehabilitation

Purpose

In Germany, numerous inpatient rehabilitation facilities employ migrant physicians. Yet the remote location of many such institutions makes it difficult for migrant physicians to establish social relationships and networks near their place of employment. This lack of social resources has implications for employee retention, quality of life, and quality of care. In this light, our study examines the following questions: what social relationships do migrant doctors have access to? What challenges and opportunities do these relationships represent? Our aim is to provide concrete recommendations for stakeholders to improve the social integration of migrant physicians.

Methodology

Semi-structured interviews with 58 migrant physicians and their colleagues. Braun & Clarke thematic analysis.

Results

Migrant physicians' social relationships fall into four broad categories: friends and acquaintances in general, family, community of origin, and working team. Migrant physicians in our sample face difficulties in each of these four categories.

Implications

Establishing social relationships in rural and semi-urban areas is more difficult for migrants in general, and migrant physicians in particular. We propose a number of recommendations to overcome these challenges on several levels: individual, work team, institution, regional, and trans-regional.

Key messages

The integration of migrant physicians in inpatient rehabilitation facilities is challenging. Specific measures can help the retention of migrant physicians.

0723 Associations Between Opioids, Non-Opioids and Central Sleep Apnea: A Case-Control Study

Introduction

Opioids are known to contribute to central sleep apnea (CSA), as they depress responsiveness to carbon dioxide and hypoxia. However, the role of non-opioid medications (antihistamines, myorelaxants, neuroleptics, antidepressants, and hypnotics) in CSA remains unclear. Given the hypothesized impact of non-opioids on the central nervous system, we examined associations between opioid and non-opioid medications and CSA.

Methods

Among all adults who underwent polysomnography testing at the University of Michigan’s Sleep Center between 2013-2018 (n=10,479), we identified 105 cases of CSA. Of these patients, we randomly selected 300 controls. Demographic and health characteristics, use of medications were obtained from medical charts. We classified study participants into three categories based on medication use: non-opioids only, opioids alone or in combination with non-opioids, and none. CSA was defined as a binary outcome using polysomnographic criteria as per the International Classification of Sleep Disorders-Third Edition. We used logistic regression to examine associations between medication use and CSA.

Results

Among participants, male:female ratio was 1:1 with a mean age of 49 (±14.3 SD) years. Opioid use alone was rare (4%), but more common in combination with non-opioids (17%), while the exclusive use of non-opioids was found among 38%.

In adjusted analyses for age and sex, those who used non-opioid alone were less likely to have a CSA diagnosis (OR=0.88, (95% CI 0.5-1.6); however, the use of opioids (alone or in combination with non-opioids) was associated with a 4-fold higher odds of CSA.

Conclusion

These data suggest that non-opioids have a protective influence on CSA. Conversely, opioids, alone, or in combination with non-opioids, were associated with increased CSA risk, that may be attributed to opioids alone, or to opioids and non-opioids interactions. However, as opioids were mostly co-prescribed with non-opioids, the sole effect of opioids from the synergistic effect with non-opioids are difficult to disentangle.

Support

Dr. Gavidia was supported by a T32 Post-Doctoral Fellowship in Neuroscience NIH/NINDS T32 NS 007222

An oceanic perspective on Greenland's recent freshwater discharge since 1850

Instrumental data evidence an accelerating freshwater release from Arctic sea ice export and the Greenland Ice Sheet over the past three decades causing cooling and freshening in the subpolar North Atlantic region. However, evaluating the observed acceleration on a historical oceanic and climatic perspective remains challenging given the short available instrumental time series. Here we provide a marine perspective on the freshwater releases to the ocean since 1850 as reflected in the northern limb of the Subpolar Gyre. Our reconstructions suggest that the recent acceleration tracks back to the 1940s/50s and is unprecedented since 1850. The melting, initiated by the 1920s natural rise in solar irradiance, accelerated in response to a combined effect of natural and anthropogenic forcing factors. We find that Greenland’s freshwater discharge has contributed to a nutrient-driven fertilization of the upper ocean and consequently increased the marine primary productivity since the 1940s/50s.

Changes in dietary intake, plasma carotenoids and erythrocyte membrane fatty acids in breast cancer survivors after a lifestyle intervention: results from a single-arm trial

BACKGROUND

The influence of nutrition on breast cancer prognosis is still inconclusive and therefore dietary interventions incorporating dietary biomarkers are needed to confirm compliance with dietary goals and clarify biological mechanisms. The present study assessed whether a lifestyle intervention in breast cancer survivors could affect dietary biomarkers of fruit and vegetables and fatty acids.

METHODS

In this phase II single-arm trial, 37 overweight/obese early stage breast cancer patients completed a 12-week diet and exercise intervention. The intervention involved 1-h weekly diet sessions delivered by a dietician and 75-min bi-weekly physical activity sessions of moderate-to-high intensity led by trained monitors. Before and after the intervention, three 24-h dietary recalls were carried out to calculate nutrient intakes and, in addition, blood samples were taken to measure plasma carotenoids, vitamin E and retinol concentrations and erythrocyte membrane fatty acid (EFA) composition. Wilcoxon signed rank tests were used to assess changes in dietary and biomarkers measurements over the intervention period.

RESULTS

After the intervention, there was a significant increase in the intake of dietary carotenoids (+15.1% compared to baseline) but not plasma carotenoids levels (+6.3%). Regarding the EFA levels, we observed a significant decrease in percentage of saturated fatty acids (-1.4%) and n-6 polyunsaturated fatty acids (-2.9%) and an increase in monounsaturated fatty acids (1.7%) and total and long-chain n-3 polyunsaturated fatty acids (by 13.1% and 13.7%, respectively). A favourable decrease in the ratio of long-chain n-6 to n-3 polyunsaturated fatty acids (-9.1%) was also observed.

CONCLUSIONS

After a short-term diet and exercise intervention in overweight/obese breast cancer survivors, we observed significant changes in dietary nutrients and fatty acid biomarkers, suggesting positive dietary changes that could be relevant for breast cancer prognosis.

Sea ice variability in the southern Norwegian Sea during glacial Dansgaard-Oeschger climate cycles

The last glacial period was marked by pronounced millennial-scale variability in ocean circulation and global climate. Shifts in sea ice cover within the Nordic Seas are believed to have amplified the glacial climate variability in northern high latitudes and contributed to abrupt, high-amplitude temperature changes over Greenland. We present unprecedented empirical evidence that resolves the nature, timing, and role of sea ice fluctuations for abrupt ocean and climate change 32 to 40 thousand years ago, using biomarker sea ice reconstructions from the southern Norwegian Sea. Our results document that initial sea ice reductions at the core site preceded the major reinvigoration of convective deep-water formation in the Nordic Seas and abrupt Greenland warming; sea ice expansions preceded the buildup of a deep oceanic heat reservoir. Our findings suggest that the sea ice variability shaped regime shifts between surface stratification and deep convection in the Nordic Seas during abrupt climate changes.

Dynamic Greenland ice sheet driven by pCO2 variations across the Pliocene Pleistocene transition

It is generally considered that the perennial glaciation of Greenland lasting several orbital cycles began around 2.7 Ma along with the intensification of Northern Hemisphere glaciation (NHG). Both data and model studies have demonstrated that a decline in atmospheric pCO₂ was instrumental in establishing a perennial Greenland ice sheet (GrIS), yet models have generally used simplistic pCO₂ constraints rather than data-inferred pCO₂ evolution. Here, using a method designed for the long-term coupling of climate and cryosphere models and pCO₂ scenarios from different studies, we highlight the pivotal role of pCO₂ on the GrIS expansion across the Plio-Pleistocene Transition (PPT, 3.0–2.5 Ma), in particular in the range between 280 and 320 ppm. Good qualitative agreement is obtained between various IRD reconstructions and some of the possible evolutions of the GrIS simulated by our model. Our results underline the dynamism of the GrIS waxing and waning under pCO₂ levels similar to or lower than today, which supports recent evidence of a dynamic GrIS during the Plio-Pleistocene.

Previous work has argued for a CO₂ control on the development of the Plio-Pleistocene Transition (PPT, 3.0–2.5 Ma) Greenland Ice Sheet (GrIS). Here based on transient ice sheet experiments, the authors demonstrate the pivotal role of modern-like CO₂ on the onset and dynamism of the PPT GrIS.

High-Resolution Benthic Mg/Ca Temperature Record of the Intermediate Water in the Denmark Strait Across D-O Stadial-Interstadial Cycles

Dansgaard-Oeschger (D-O) climate instabilities that took place during Marine Isotope Stage 3 are connected to changes in ocean circulation patterns and sea ice cover. Here we explore in detail the configuration of the water column of the Denmark Strait during D-O events 8-5. How the ocean currents and water masses within the Denmark Strait region responded and were connected to the North Atlantic are discussed. We investigate sediment core GS15-198-36CC, from the northern side of the Greenland-Iceland Ridge, at 30-year temporal resolution. Stable carbon and oxygen isotope reconstructions based on benthic foraminifera, together with a high-resolution benthic foraminiferal record of Mg/Ca paleothermometry, is presented. The site was bathed by warm intermediate waters during stadials and cool but gradually warming intermediate water during interstadials. We suggest that stadial conditions in the Denmark Strait are characterized by a well-stratified water column with a warm intermediate water mass that lies beneath a cold fresh body of water where sea ice and brine rejection work in consort to uphold the halocline conditions. Interstadial periods are not a pure replicate of modern times, but rather have two modes of operation, one similar to today, and the other incorporating a brief period of warm intermediate water and increased ventilation.

Rehabilitation-specific challenges and advantages in the integration of migrant physicians in Germany: a multiperspective qualitative interview study in rehabilitative settings

OBJECTIVES

In Germany, rehabilitative healthcare institutions increasingly rely on migrant physicians to meet their staffing needs. Yet until now, research on the integration of migrant physicians has focussed entirely on the acute care setting. This study is the first to address the specific advantages and challenges to integration in the field of rehabilitative medicine where a high number of migrant physicians work. From the experiences of migrant physicians and their colleagues, we provide actionable suggestions to counteract potential sources of conflict and thereby improve the integration of migrant physicians in the German workforce.

STUDY DESIGN

We conducted a qualitative interview study.

METHODS

We conducted 23 interviews with a total of 26 participants occupying a variety of roles in two different rehabilitation centres (maximum variation sampling). Interviews were recorded, transcribed verbatim and parsed through thematic analysis.

RESULTS

Our research revealed advantages and challenges to integration in three distinct areas: rehabilitative care institutions, competencies of migrant professionals and interpersonal relations. The first set of issues hinges on the work processes within rehabilitative hospitals, professional prospects there and the location of the institutions themselves. Second, migrant physicians may encounter difficulties because of limited linguistic skills and country-specific knowledge. And finally, aspects of their interactions with care teams and patients may constitute barriers to integration.

CONCLUSIONS

Some of the factors influencing the integration of migrant physicians are the same in both rehabilitative and acute medicine, but the rehabilitative setting presents distinct advantages and challenges that are worthy of study in their own right. We outline several measures which could help overcome challenges to the integration of migrant physicians, including those associated with professional relationships. Further research is needed to develop concrete support programmes.

Screening for Tamoxifen Ocular Toxicity: A Prospective Study

Specific ocular complications, namely retinopathy, keratopathy and optic neuritis, have been described in women being treated with tamoxifen for metastatic breast cancer or taking this drug as an adjuvant postoperative therapy. We examined 61 patients who had been using tamoxifen for at least one year, in order to detect the incidence of ocular complications. Two patients had retinopathy after having taken high cumulative doses of tamoxifen. Another had corneal deposits and a fourth had optic neuritis. It thus appears that systematic screening of all symptom-free patients using this drug for metastatic breast cancer is superfluous. However, an ophthalmological assessment every two years or earlier in case of visual complaints for patients taking tamoxifen as an adjuvant therapy remains useful, because the oncological therapy can be adjusted if serious ocular complications arise.

[Mental health in Bonaire - an inspiration for the Dutch New Mental Health Movement]

In 2010 the bes-islands in the Caribbean became a special municipality of the Netherlands. Healthcare was upgraded to match Dutch standards over a short period of time. With a population of 15,518 inhabitants in 2010 (19,408 in 2016), Bonaire received its own fact-team (flexible assertive community treatment). It subsequently became a unique experiment for the Dutch New Mental Health Movement.<br/> AIM: To describe the development of a modern mental health care system in a limited geographic area.<br/> METHOD: Site visitation, interviews and analysis of historical data sources.<br/> RESULTS: The local mental health team takes integral responsibility for all the mh care needs in Bonaire. There is no intricate diagnostic referral system. Consultation access lines are short. The team was able to dramatically reduce the need for hospitalization. Collaboration with the somatic hospital and general practitioners runs smoothly and the facilities offer complementary care. Societal integration is insured due to mental health professionals living interspersed in the neighborhood, the low threshold allowing them to respond to signals efficiently. There is a natural development of the following three domains of care: reduction of symptoms, societal participation and personal remission.<br/> CONCLUSION: Integrated mental health services in a geographically small area, as presented by the Dutch New Mental Health Movement, enables the possibility of recovery oriented care.

Climate induced human demographic and cultural change in northern Europe during the mid-Holocene

The transition from hunter-gatherer-fisher groups to agrarian societies is arguably the most significant change in human prehistory. In the European plain there is evidence for fully developed agrarian societies by 7,500 cal. yr BP, yet a well-established agrarian society does not appear in the north until 6,000 cal. yr BP for unknown reasons. Here we show a sudden increase in summer temperature at 6,000 cal. yr BP in northern Europe using a well-dated, high resolution record of sea surface temperature (SST) from the Baltic Sea. This temperature rise resulted in hypoxic conditions across the entire Baltic sea as revealed by multiple sedimentary records and supported by marine ecosystem modeling. Comparison with summed probability distributions of radiocarbon dates from archaeological sites indicate that this temperature rise coincided with both the introduction of farming, and a dramatic population increase. The evidence supports the hypothesis that the boundary of farming rapidly extended north at 6,000 cal. yr BP because terrestrial conditions in a previously marginal region improved.

Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1

The reconstruction of the signal from hadrons and jets emerging from the proton-proton collisions at the Large Hadron Collider (LHC) and entering the ATLAS calorimeters is based on a three-dimensional topological clustering of individual calorimeter cell signals. The cluster formation follows cell signal-significance patterns generated by electromagnetic and hadronic showers. In this, the clustering algorithm implicitly performs a topological noise suppression by removing cells with insignificant signals which are not in close proximity to cells with significant signals. The resulting topological cell clusters have shape and location information, which is exploited to apply a local energy calibration and corrections depending on the nature of the cluster. Topological cell clustering is established as a well-performing calorimeter signal definition for jet and missing transverse momentum reconstruction in ATLAS.

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton-proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton-proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of [Formula: see text] TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about [Formula: see text] is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than [Formula: see text] and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing.

Performance of algorithms that reconstruct missing transverse momentum in [Formula: see text]= 8 TeV proton-proton collisions in the ATLAS detector

The reconstruction and calibration algorithms used to calculate missing transverse momentum ([Formula: see text] ) with the ATLAS detector exploit energy deposits in the calorimeter and tracks reconstructed in the inner detector as well as the muon spectrometer. Various strategies are used to suppress effects arising from additional proton-proton interactions, called pileup, concurrent with the hard-scatter processes. Tracking information is used to distinguish contributions from the pileup interactions using their vertex separation along the beam axis. The performance of the [Formula: see text] reconstruction algorithms, especially with respect to the amount of pileup, is evaluated using data collected in proton-proton collisions at a centre-of-mass energy of 8 [Formula: see text] during 2012, and results are shown for a data sample corresponding to an integrated luminosity of [Formula: see text]. The simulation and modelling of [Formula: see text]  in events containing a Z boson decaying to two charged leptons (electrons or muons) or a W boson decaying to a charged lepton and a neutrino are compared to data. The acceptance for different event topologies, with and without high transverse momentum neutrinos, is shown for a range of threshold criteria for [Formula: see text] , and estimates of the systematic uncertainties in the [Formula: see text]  measurements are presented.

Search for lepton-flavour-violating decays of the Higgs and Z bosons with the ATLAS detector

Direct searches for lepton flavour violation in decays of the Higgs and Z bosons with the ATLAS detector at the LHC are presented. The following three decays are considered: [Formula: see text], [Formula: see text], and [Formula: see text]. The searches are based on the data sample of proton-proton collisions collected by the ATLAS detector corresponding to an integrated luminosity of 20.3 [Formula: see text] at a centre-of-mass energy of [Formula: see text] TeV. No significant excess is observed, and upper limits on the lepton-flavour-violating branching ratios are set at the 95[Formula: see text] confidence level: Br[Formula: see text], Br[Formula: see text], and Br[Formula: see text].

Measurement of the [Formula: see text] and [Formula: see text] production cross sections in multilepton final states using 3.2 fb[Formula: see text] of [Formula: see text] collisions at [Formula: see text] = 13 TeV with the ATLAS detector

A measurement of the [Formula: see text] and [Formula: see text] production cross sections in final states with either two same-charge muons, or three or four leptons (electrons or muons) is presented. The analysis uses a data sample of proton-proton collisions at [Formula: see text] TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015, corresponding to a total integrated luminosity of 3.2 fb[Formula: see text]. The inclusive cross sections are extracted using likelihood fits to signal and control regions, resulting in [Formula: see text] pb and [Formula: see text] pb, in agreement with the Standard Model predictions.

A measurement of the calorimeter response to single hadrons and determination of the jet energy scale uncertainty using LHC Run-1 pp-collision data with the ATLAS detector

A measurement of the calorimeter response to isolated charged hadrons in the ATLAS detector at the LHC is presented. This measurement is performed with 3.2 nb[Formula: see text] of proton-proton collision data at [Formula: see text] [Formula: see text] from 2010 and 0.1 nb[Formula: see text] of data at [Formula: see text] [Formula: see text] from 2012. A number of aspects of the calorimeter response to isolated hadrons are explored. After accounting for energy deposited by neutral particles, there is a 5% discrepancy in the modelling, using various sets of Geant4 hadronic physics models, of the calorimeter response to isolated charged hadrons in the central calorimeter region. The description of the response to anti-protons at low momenta is found to be improved with respect to previous analyses. The electromagnetic and hadronic calorimeters are also examined separately, and the detector simulation is found to describe the response in the hadronic calorimeter well. The jet energy scale uncertainty and correlations in scale between jets of different momenta and pseudorapidity are derived based on these studies. The uncertainty is 2-5% for jets with transverse momenta above 2 [Formula: see text], where this method provides the jet energy scale uncertainty for ATLAS.

[A soccer player with an unstable knee]

A 19-year-old soccer player presented with instability of his left knee after a rotation trauma. Congenital absence of the anterior cruciate ligament was suspected because of leg length discrepancy and specific MRI findings. He regained stability after an anterior cruciate reconstruction.

Measurement of the [Formula: see text] dijet cross section in pp collisions at [Formula: see text] TeV with the ATLAS detector

The dijet production cross section for jets containing a b-hadron (b-jets) has been measured in proton-proton collisions with a centre-of-mass energy of [Formula: see text] TeV, using the ATLAS detector at the LHC. The data used correspond to an integrated luminosity of [Formula: see text]. The cross section is measured for events with two identified b-jets with a transverse momentum [Formula: see text] GeV and a minimum separation in the [Formula: see text]-[Formula: see text] plane of [Formula: see text]. At least one of the jets in the event is required to have [Formula: see text] GeV. The cross section is measured differentially as a function of dijet invariant mass, dijet transverse momentum, boost of the dijet system, and the rapidity difference, azimuthal angle and angular distance between the b-jets. The results are compared to different predictions of leading order and next-to-leading order perturbative quantum chromodynamics matrix elements supplemented with models for parton-showers and hadronization.

Measurement of the photon identification efficiencies with the ATLAS detector using LHC Run-1 data

The algorithms used by the ATLAS Collaboration to reconstruct and identify prompt photons are described. Measurements of the photon identification efficiencies are reported, using 4.9 fb[Formula: see text] of pp collision data collected at the LHC at [Formula: see text] [Formula: see text] and 20.3 fb[Formula: see text] at [Formula: see text] [Formula: see text]. The efficiencies are measured separately for converted and unconverted photons, in four different pseudorapidity regions, for transverse momenta between 10 [Formula: see text] and 1.5 [Formula: see text]. The results from the combination of three data-driven techniques are compared to the predictions from a simulation of the detector response, after correcting the electromagnetic shower momenta in the simulation for the average differences observed with respect to data. Data-to-simulation efficiency ratios used as correction factors in physics measurements are determined to account for the small residual efficiency differences. These factors are measured with uncertainties between 0.5% and 10% in 7 [Formula: see text] data and between 0.5% and 5.6% in 8 [Formula: see text] data, depending on the photon transverse momentum and pseudorapidity.

Test of CP invariance in vector-boson fusion production of the Higgs boson using the Optimal Observable method in the ditau decay channel with the ATLAS detector

A test of CP invariance in Higgs boson production via vector-boson fusion using the method of the Optimal Observable is presented. The analysis exploits the decay mode of the Higgs boson into a pair of [Formula: see text] leptons and is based on 20.3 [Formula: see text] of proton-proton collision data at [Formula: see text] = 8 [Formula: see text] collected by the ATLAS experiment at the LHC. Contributions from CP-violating interactions between the Higgs boson and electroweak gauge bosons are described in an effective field theory framework, in which the strength of CP violation is governed by a single parameter [Formula: see text]. The mean values and distributions of CP-odd observables agree with the expectation in the Standard Model and show no sign of CP violation. The CP-mixing parameter [Formula: see text] is constrained to the interval [Formula: see text] at 68% confidence level, consistent with the Standard Model expectation of [Formula: see text].

Search for the Higgs boson produced in association with a W boson and decaying to four b-quarks via two spin-zero particles in pp collisions at 13 TeV with the ATLAS detector

This paper presents a dedicated search for exotic decays of the Higgs boson to a pair of new spin-zero particles, [Formula: see text], where the particle a decays to b-quarks and has a mass in the range of 20-60 GeV. The search is performed in events where the Higgs boson is produced in association with a [Formula: see text] boson, giving rise to a signature of a lepton (electron or muon), missing transverse momentum, and multiple jets from b-quark decays. The analysis is based on the full dataset of pp collisions at [Formula: see text] recorded in 2015 by the ATLAS detector at the CERN Large Hadron Collider, corresponding to an integrated luminosity of 3.2 [Formula: see text]. No significant excess of events above the Standard Model prediction is observed, and a [Formula: see text] confidence-level upper limit is derived for the product of the production cross section for [Formula: see text] times the branching ratio for the decay [Formula: see text]. The upper limit ranges from 6.2 pb for an a-boson mass [Formula: see text] to 1.5 pb for [Formula: see text].

Measurement of the Inelastic Proton-Proton Cross Section at sqrt[s]=13 TeV with the ATLAS Detector at the LHC

This Letter presents a measurement of the inelastic proton-proton cross section using 60  μb^{-1} of pp collisions at a center-of-mass energy sqrt[s] of 13 TeV with the ATLAS detector at the LHC. Inelastic interactions are selected using rings of plastic scintillators in the forward region (2.07<|η|<3.86) of the detector. A cross section of 68.1±1.4  mb is measured in the fiducial region ξ=M_{X}^{2}/s>10^{-6}, where M_{X} is the larger invariant mass of the two hadronic systems separated by the largest rapidity gap in the event. In this ξ range the scintillators are highly efficient. For diffractive events this corresponds to cases where at least one proton dissociates to a system with M_{X}>13  GeV. The measured cross section is compared with a range of theoretical predictions. When extrapolated to the full phase space, a cross section of 78.1±2.9  mb is measured, consistent with the inelastic cross section increasing with center-of-mass energy.

Performance of pile-up mitigation techniques for jets in [Formula: see text] collisions at [Formula: see text] TeV using the ATLAS detector

The large rate of multiple simultaneous proton-proton interactions, or pile-up, generated by the Large Hadron Collider in Run 1 required the development of many new techniques to mitigate the adverse effects of these conditions. This paper describes the methods employed in the ATLAS experiment to correct for the impact of pile-up on jet energy and jet shapes, and for the presence of spurious additional jets, with a primary focus on the large 20.3 [Formula: see text] data sample collected at a centre-of-mass energy of [Formula: see text]. The energy correction techniques that incorporate sophisticated estimates of the average pile-up energy density and tracking information are presented. Jet-to-vertex association techniques are discussed and projections of performance for the future are considered. Lastly, the extension of these techniques to mitigate the effect of pile-up on jet shapes using subtraction and grooming procedures is presented.

Search for gluinos in events with an isolated lepton, jets and missing transverse momentum at [Formula: see text] = 13 Te V with the ATLAS detector

The results of a search for gluinos in final states with an isolated electron or muon, multiple jets and large missing transverse momentum using proton-proton collision data at a centre-of-mass energy of [Formula: see text] are presented. The dataset used was recorded in 2015 by the ATLAS experiment at the Large Hadron Collider and corresponds to an integrated luminosity of 3.2 fb[Formula: see text]. Six signal selections are defined that best exploit the signal characteristics. The data agree with the Standard Model background expectation in all six signal selections, and the largest deviation is a 2.1 standard deviation excess. The results are interpreted in a simplified model where pair-produced gluinos decay via the lightest chargino to the lightest neutralino. In this model, gluinos are excluded up to masses of approximately 1.6 Te V depending on the mass spectrum of the simplified model, thus surpassing the limits of previous searches.

Search for bottom squark pair production in proton-proton collisions at [Formula: see text] TeV with the ATLAS detector

The result of a search for pair production of the supersymmetric partner of the Standard Model bottom quark ([Formula: see text]) is reported. The search uses 3.2 fb[Formula: see text]  of pp collisions at [Formula: see text] TeV collected by the ATLAS experiment at the Large Hadron Collider in 2015. Bottom squarks are searched for in events containing large missing transverse momentum and exactly two jets identified as originating from b-quarks. No excess above the expected Standard Model background yield is observed. Exclusion limits at 95 % confidence level on the mass of the bottom squark are derived in phenomenological supersymmetric R-parity-conserving models in which the [Formula: see text] is the lightest squark and is assumed to decay exclusively via [Formula: see text], where [Formula: see text] is the lightest neutralino. The limits significantly extend previous results; bottom squark masses up to 800 (840) GeV are excluded for the [Formula: see text] mass below 360 (100) GeV whilst differences in mass above 100 GeV between the [Formula: see text] and the [Formula: see text] are excluded up to a [Formula: see text] mass of 500 GeV.

The performance of the jet trigger for the ATLAS detector during 2011 data taking

The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton-proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon-nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction.

Study of the rare decays of [Formula: see text] and [Formula: see text] into muon pairs from data collected during the LHC Run 1 with the ATLAS detector

A study of the decays [Formula: see text] and [Formula: see text] has been performed using data corresponding to an integrated luminosity of 25 fb[Formula: see text] of 7 and 8 TeV proton-proton collisions collected with the ATLAS detector during the LHC Run 1. For the [Formula: see text] dimuon decay, an upper limit on the branching fraction is set at [Formula: see text] at 95 % confidence level. For [Formula: see text], the branching fraction [Formula: see text] is measured. The results are consistent with the Standard Model expectation with a p value of 4.8 %, corresponding to 2.0 standard deviations.

Charged-particle distributions at low transverse momentum in [Formula: see text] TeV pp interactions measured with the ATLAS detector at the LHC

Measurements of distributions of charged particles produced in proton-proton collisions with a centre-of-mass energy of 13 TeV are presented. The data were recorded by the ATLAS detector at the LHC and correspond to an integrated luminosity of 151 [Formula: see text]. The particles are required to have a transverse momentum greater than 100 MeV and an absolute pseudorapidity less than 2.5. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the dependence of the mean transverse momentum on multiplicity are measured in events containing at least two charged particles satisfying the above kinematic criteria. The results are corrected for detector effects and compared to the predictions from several Monte Carlo event generators.

Search for Higgs and Z Boson Decays to ϕγ with the ATLAS Detector

A search for the decays of the Higgs and Z bosons to a ϕ meson and a photon is performed with a pp collision data sample corresponding to an integrated luminosity of 2.7  fb^{-1} collected at sqrt[s]=13  TeV with the ATLAS detector at the LHC. No significant excess of events is observed above the background, and 95% confidence level upper limits on the branching fractions of the Higgs and Z boson decays to ϕγ of 1.4×10^{-3} and 8.3×10^{-6}, respectively, are obtained.

Search for single production of vector-like quarks decaying into Wb in pp collisions at [Formula: see text] TeV with the ATLAS detector

A search for singly produced vector-like Q quarks, where Q can be either a T quark with charge [Formula: see text] or a Y quark with charge [Formula: see text], is performed in proton-proton collisions recorded with the ATLAS detector at the LHC. The dataset corresponds to an integrated luminosity of 20.3 fb[Formula: see text] and was produced with a centre-of-mass energy of [Formula: see text] TeV. This analysis targets [Formula: see text] decays where the W boson decays leptonically. A veto on massive large-radius jets is used to reject the dominant [Formula: see text] background. The reconstructed Q-candidate mass, ranging from 0.4 to 1.2 TeV, is used in the search to discriminate signal from background processes. No significant deviation from the Standard Model expectation is observed, and limits are set on the [Formula: see text] cross-section times branching ratio. The results are also interpreted as limits on the QWb coupling and the mixing with the Standard Model sector for a singlet T quark or a Y quark from a doublet. T quarks with masses below 0.95 TeV are excluded at 95 % confidence level, assuming a unit coupling and a BR[Formula: see text], whereas the expected limit is 1.10 TeV.

Charged-particle distributions in pp interactions at [Formula: see text] measured with the ATLAS detector

This paper presents measurements of distributions of charged particles which are produced in proton-proton collisions at a centre-of-mass energy of [Formula: see text] and recorded by the ATLAS detector at the LHC. A special dataset recorded in 2012 with a small number of interactions per beam crossing (below 0.004) and corresponding to an integrated luminosity of 160 [Formula: see text] was used. A minimum-bias trigger was utilised to select a data sample of more than 9 million collision events. The multiplicity, pseudorapidity, and transverse momentum distributions of charged particles are shown in different regions of kinematics and charged-particle multiplicity, including measurements of final states at high multiplicity. The results are corrected for detector effects and are compared to the predictions of various Monte Carlo event generator models which simulate the full hadronic final state.

Search for squarks and gluinos in final states with jets and missing transverse momentum at [Formula: see text] =13 [Formula: see text]with the ATLAS detector

A search for squarks and gluinos in final states containing hadronic jets, missing transverse momentum but no electrons or muons is presented. The data were recorded in 2015 by the ATLAS experiment in [Formula: see text] proton-proton collisions at the Large Hadron Collider. No excess above the Standard Model background expectation was observed in 3.2 [Formula: see text] of analyzed data. Results are interpreted within simplified models that assume R-parity is conserved and the neutralino is the lightest supersymmetric particle. An exclusion limit at the 95 % confidence level on the mass of the gluino is set at 1.51 [Formula: see text] for a simplified model incorporating only a gluino octet and the lightest neutralino, assuming the lightest neutralino is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.03 [Formula: see text] are excluded for a massless lightest neutralino. These limits substantially extend the region of supersymmetric parameter space excluded by previous measurements with the ATLAS detector.

Measurement of event-shape observables in [Formula: see text] events in pp collisions at [Formula: see text] [Formula: see text] with the ATLAS detector at the LHC

Event-shape observables measured using charged particles in inclusive Z-boson events are presented, using the electron and muon decay modes of the Z bosons. The measurements are based on an integrated luminosity of [Formula: see text] of proton-proton collisions recorded by the ATLAS detector at the LHC at a centre-of-mass energy [Formula: see text] [Formula: see text]. Charged-particle distributions, excluding the lepton-antilepton pair from the Z-boson decay, are measured in different ranges of transverse momentum of the Z boson. Distributions include multiplicity, scalar sum of transverse momenta, beam thrust, transverse thrust, spherocity, and [Formula: see text]-parameter, which are in particular sensitive to properties of the underlying event at small values of the Z-boson transverse momentum. The measured observables are compared with predictions from Pythia 8, Sherpa, and Herwig 7. Typically, all three Monte Carlo generators provide predictions that are in better agreement with the data at high Z-boson transverse momenta than at low Z-boson transverse momenta, and for the observables that are less sensitive to the number of charged particles in the event.