bluuebunny/crossref_metadata_2025 huggingface dataset:
The psychological features of patellofemoral pain: a systematic review
Authors: Maclachlan Liam R. , Collins Natalie J. , Matthews Mark L.G. , Hodges Paul W. , Vicenzino Bill
Published: March 2017

Background

Patellofemoral pain (PFP) is prevalent in adolescence and adulthood and often persists. In contrast to other persistent musculoskeletal conditions, for which non-physical, psychological features are implicated, PFP remains largely conceptualised in mechanical terms.

Aims

To (1) identify whether the psychological characteristics of individuals with PFP differs from asymptomatic controls and (2) evaluate the correlations between psychological characteristics and PFP severity.

Study design

Systematic review

Methods

A systematic review of the literature was conducted according to PRISMA guidelines. The Epidemiological Appraisal Instrument was used to evaluate quality. Studies measuring psychological constructs with patient-reported measures were included. Standardised mean differences were calculated and supported by narrative synthesis.

Results

Twenty-five studies were eligible. Quality results ranged from 28.3% to 61.7%. Psychological constructs were reported under four groupings: mental health, cognitive factors, behavioural factors and other factors. There is limited evidence of mental health and cognitive differences in some individuals with PFP. Features demonstrating linear correlations with pain and physical function included anxiety/depression, catastrophising, praying and hoping and pain-related fear.

Conclusions

Anxiety, depression, catastrophising and fear of movement may be elevated in individuals with PFP and correlate with pain and reduced physical function. These results derive from a limited number of studies. Future research should aim to evaluate if and how psychological factors contribute to PFP.

Clinical relevance

Patients are likely to benefit from clinician vigilance to the presence of psychological factors.
Exploring similarities and differences in hospital adverse event rates between Norway and Sweden using Global Trigger Tool
Authors: Deilkås Ellen Tveter , Risberg Madeleine Borgstedt , Haugen Marion , Lindstrøm Jonas Christoffer , Nylén Urban , Rutberg Hans , Michael Soop
Published: March 2017

Objectives

In this paper, we explore similarities and differences in hospital adverse event (AE) rates between Norway and Sweden by reviewing medical records with the Global Trigger Tool (GTT).

Design

All acute care hospitals in both countries performed medical record reviews, except one in Norway. Records were randomly selected from all eligible admissions in 2013. Eligible admissions were patients 18 years of age or older, undergoing care with an in-hospital stay of at least 24 hours, excluding psychiatric and care and rehabilitation. Reviews were done according to GTT methodology.

Setting

Similar contexts for healthcare and similar socioeconomic and demographic characteristics have inspired the Nordic countries to exchange experiences from measuring and monitoring quality and patient safety in healthcare. The co-operation has promoted the use of GTT to monitor national and local rates of AEs in hospital care.

Participants

10 986 medical records were reviewed in Norway and 19 141 medical records in Sweden.

Results

No significant difference between overall AE rates was found between the two countries. The rate was 13.0% (95% CI 11.7% to 14.3%) in Norway and 14.4% (95% CI 12.6% to 16.3%) in Sweden. There were significantly higher AE rates of surgical complications in Norwegian hospitals compared with Swedish hospitals. Swedish hospitals had significantly higher rates of pressure ulcers, falls and ‘other’ AEs. Among more severe AEs, Norwegian hospitals had significantly higher rates of surgical complications than Swedish hospitals. Swedish hospitals had significantly higher rates of postpartum AEs.

Conclusions

The level of patient safety in acute care hospitals, as assessed by GTT, was essentially the same in both countries. The differences between the countries in the rates of several types of AEs provide new incentives for Norwegian and Swedish governing bodies to address patient safety issues.
Investigating skin-to-skin care patterns with extremely preterm infants in the NICU and their effect on early cognitive and communication performance: a retrospective cohort study
Authors: Gonya Jenn , Ray William C , Rumpf R Wolfgang , Brock Guy
Published: March 2017

Objectives

The primary objective of the study was to investigate how patterns of skin-to-skin care might impact infant early cognitive and communication performance.

Design

This was a retrospective cohort study.

Setting

This study took place in a level-IV all-referral neonatal intensive care unit in the Midwest USA specialising in the care of extremely preterm infants.

Participants

Data were collected from the electronic medical records of all extremely preterm infants (gestational age <27 weeks) admitted to the unit during 2010–2011 and who completed 6-month and 12-month developmental assessments in the follow-up clinic (n=97).

Outcome measures

Outcome measures included the cognitive and communication subscales of the Bayley Scales of Infant Development, Third Edition (Bayley-III); and skin-to-skin patterns including: total hours of maternal and paternal participation throughout hospitalisation, total duration in weeks and frequency (hours per week).

Analysis

Extracted data were analysed through a multistep process of logistic regressions, t-tests, χ2tests and Fisher's exact tests followed with exploratory network analysis using novel visual analytic software.

Results

Infants who received above the sample median in total hours, weekly frequency and total hours from mothersandfathers of skin-to-skin care were more likely to score ≥80 on the cognitive and communication scales of the Bayley-III. However, the results were not statistically significant (p>0.05). Mothers provided the majority of skin-to-skin care with a sharp decline at 30 weeks corrected age, regardless of when extremely preterm infants were admitted. Additional exploratory network analysis suggests that medical and skin-to-skin factors play a parallel, non-synergistic role in contributing to early cognitive and communication performance as assessed through the Bayley-III.

Conclusions

This study suggests an association between early and frequent skin-to-skin care with extremely preterm infants and early cognitive and communication performance.
Effectiveness of chronic care models for the management of type 2 diabetes mellitus in Europe: a systematic review and meta-analysis
Authors: Bongaerts Brenda W C , Müssig Karsten , Wens Johan , Lang Caroline , Schwarz Peter , Roden Michael , Rathmann Wolfgang
Published: March 2017

Objectives

We evaluated the effectiveness of European chronic care programmes for type 2 diabetes mellitus (characterised by integrative care and a multicomponent framework for enhancing healthcare delivery), compared with usual diabetes care.

Design

Systematic review and meta-analysis.

Data sources

MEDLINE, Embase, CENTRAL and CINAHL from January 2000 to July 2015.

Eligibility criteria

Randomised controlled trials focussing on (1) adults with type 2 diabetes, (2) multifaceted diabetes care interventions specifically designed for type 2 diabetes and delivered in primary or secondary care, targeting patient, physician and healthcare organisation and (3) usual diabetes care as the control intervention.

Data extraction

Study characteristics, characteristics of the intervention, data on baseline demographics and changes in patient outcomes.

Data analysis

Weighted mean differences in change in HbA1c and total cholesterol levels between intervention and control patients (95% CI) were estimated using a random-effects model.

Results

Eight cluster randomised controlled trials were identified for inclusion (9529 patients). One year of multifaceted care improved HbA1c levels in patients with screen-detected and newly diagnosed diabetes, but not in patients with prevalent diabetes, compared to usual diabetes care. Across all seven included trials, the weighted mean difference in HbA1c change was −0.07% (95% CI −0.10 to −0.04) (−0.8 mmol/mol (95% CI −1.1 to −0.4)); I2=21%. The findings for total cholesterol, LDL-cholesterol and blood pressure were similar to HbA1c, albeit statistical heterogeneity between studies was considerably larger. Compared to usual care, multifaceted care did not significantly change quality of life of the diabetes patient. Finally, measured for screen-detected diabetes only, the risk of macrovascular and mircovascular complications at follow-up was not significantly different between intervention and control patients.

Conclusions

Effects of European multifaceted diabetes care patient outcomes are only small. Improvements are somewhat larger for screen-detected and newly diagnosed diabetes patients than for patients with prevalent diabetes.
‘right@home’: a randomised controlled trial of sustained nurse home visiting from pregnancy to child age 2 years, versus usual care, to improve parent care, parent responsivity and the home learning environment at 2 years
Authors: Goldfeld Sharon , Price Anna , Bryson Hannah , Bruce Tracey , Mensah Fiona , Orsini Francesca , Gold Lisa , Hiscock Harriet , Smith Charlene , Bishop Lara , Jackson Dianne , Kemp Lynn
Published: March 2017

Introduction

By the time children start school, inequities in learning, development and health outcomes are already evident. Sustained nurse home visiting (SNHV) offers a potential platform for families experiencing adversity, who often have limited access to services. While SNHV programmes have been growing in popularity in Australia and internationally, it is not known whether they can improve children's learning and development when offered via the Australian service system. The right@home trial aims to investigate the effectiveness of an SNHV programme, offered to women from pregnancy to child age 2 years, in improving parent care of and responsivity to the child, and the home learning environment.

Methods and analysis

Pregnant Australian women (n=722) are identified after completing a screening survey of 10 factors known to predict children's learning and development (eg, young pregnancy, poor mental or physical health, lack of support). Consenting women—surveyed while attending clinics at 10 hospitals in Victoria and Tasmania—are enrolled if they report having 2 or more risk factors. The intervention comprises 25 home visits from pregnancy to 2 years, focusing on parent care of the child, responsivity to the child and providing a good quality home learning environment. The standard, universal, Australian child and family health service provides the comparator (control). Primary outcome measures include a combination of parent-reported and objective assessments of children's sleep, safety, nutrition, parenting styles and the home learning environment, including the Home Observation of the Environment Inventory and items adapted from the Longitudinal Study of Australian Children.

Ethics and dissemination

This study is approved by the Royal Children's Hospital Human Research Ethics Committees (HREC 32296) and site-specific HRECs. The investigators and sponsor will communicate the trial results to stakeholders, participants, healthcare professionals, the public and other relevant groups via presentations and publications.

Trial registration number

ISRCTN89962120, pre-results.
Patient-reported outcomes and associations with pleural effusion in outpatients with heart failure: an observational cohort study
Authors: Gundersen Guri H , Norekvål Tone M , Graven Torbjørn , Haug Hilde H , Skjetne Kyrre , Kleinau Jens O , Gustad Lise T , Dalen Håvard
Published: March 2017

Objectives

We aimed to study whether patient-reported outcomes, measured by quality of life (QoL) and functional class, are sensitive to pleural effusion (PLE) in patients with heart failure (HF), and to study changes in QoL and functional class during follow-up of PLE.

Methods

A cohort of 62 patients from an outpatient HF clinic was included. The amount of PLE was quantified using a pocket-sized ultrasound imaging device. Self-reports of QoL and functional class were collected using the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and the New York Heart Association (NYHA) functional classification.

Results

At baseline, 26 (42%) patients had PLE of which 19 (31%) patients had moderate to severe amounts of PLE. Patients with no to mild PLE had a lower MLHFQ score (mean 42, SD 21) compared with patients with a moderate to severe amount of PLE (mean 55, SD 24), p=0.03. For 28 patients (45%) with follow-up data, we observed a linear improvement of the MLHFQ-score (3.2, 95% CI 1.2 to 5.1) with each centimetre reduction of PLE. Correspondingly, patient-reported NYHA-class followed the same pattern as the MLHFQ-score.

Conclusions

Our study indicates that patient-reported outcome measures as MLHFQ may be sensitive tools to identify patients with HF at highest risk of symptomatic PLE and that treatment targeting reduction of PLE during follow-up is essential to improvement of QoL and functional capacity of outpatients with HF.

Trial registration number

NCT01794715; Results
My Home is My Marae: Kaupapa Māori evaluation of an approach to injury prevention
Authors: Hayward Brooke , Lyndon Mataroria , Villa Luis , Madell Dominic , Elliot-Hohepa Andrea , Le Comte Lyndsay
Published: March 2017

Objective

The objective of this study was to evaluate the New Zealand Accident Compensation Corporation's (ACC) ‘My Home is My Marae’ approach to injury prevention for whānau (families).

Setting

Over an 18 month period from November 2013 to June 2014, 14 ‘My Home is My Marae’ trials were conducted across the South Auckland and Far North regions of New Zealand. ACC engaged with local Māori providers of healthcare, education and social services to deliver the home safety intervention.

Participants

Participants of this evaluation were a purposive sample of 14 staff from six provider organisations in South Auckland and the Far North regions of New Zealand.

Methods

Kaupapa Māori theory-based evaluation and appreciative inquiry methodologies underpinned the evaluation. Interview participants led discussions about strengths and weaknesses of the approach, and partnerships with ACC and other organisations. The evaluation was also supported by pre-existing information available in project documentation, and quantitative data collected by Māori providers.

Results

Five key critical success factors of ‘My Home is My Marae’ were found from interviews: mana tangata (reputation, respect and credibility); manākitanga (showing care for people); kānohi-ki-te-kānohi (face-to-face approach); capacity building for kaimahi, whānau and providers and ‘low or no cost’ solutions to hazards in the home. Data collected for the Far North area showed that 76% of the hazards identified could be resolved through ‘low or no cost’ solutions. Unfortunately, similar data were not available for South Auckland.

Conclusions

Injury prevention or health promotion approaches that seek to engage with whānau and/or Māori communities would benefit from applying critical success factors of ‘My Home is My Marae’.
Cross-sectional survey on defensive practices and defensive behaviours among Israeli psychiatrists
Authors: Reuveni I , Pelov I , Reuveni H , Bonne O , Canetti L
Published: March 2017

Objective

Psychiatry is a low-risk specialisation; however, there is a steady increase in malpractice claims against psychiatrists. Defensive psychiatry (DP) refers to any action undertaken by a psychiatrist to avoid malpractice liability that is not for the sole benefit of the patient's mental health and well-being. The objectives of this study were to assess the scope of DP practised by psychiatrists and to understand whether awareness of DP correlated with defensive behaviours.

Methods

A questionnaire was administered to 213 Israeli psychiatry residents and certified psychiatrists during May and June 2015 regarding demographic data and experience with malpractice claims, medicolegal literature and litigation. Four clinical scenarios represented defensive behaviours and reactions (feelings and actions) to malpractice claims.

Results

Forty-four (20.6%) certified psychiatrists and four (1.9%) residents were directly involved in malpractice claims, while 132 (62.1%) participants admitted to practising DP. Residents acknowledged the practice of DP more than did senior psychiatrists (p=0.038).

Awareness of DP correlated with unnecessary hospitalisation of suicidal patients, increased unnecessary follow-up visits and prescribing smaller drug dosages than required for pregnant women and elderly patients.

Conclusions

This study provides evidence that DP is well established in the routine clinical daily practice of psychiatrists. Further studies are needed to reveal whether DP effectively protects psychiatrists from malpractice suits or, rather, if it impedes providing quality psychiatric care and represents an economic burden that leads to more harm for the patient.
Design and reliability of a specific instrument to evaluate patient safety for patients with acute myocardial infarction treated in a predefined care track: a retrospective patient record review study in a single tertiary hospital in the Netherlands
Authors: Eindhoven Daniëlle C , Borleffs C Jan Willem , Dietz Marlieke F , Schalij Martin J , Brouwers Corline , de Bruijne Martine C
Published: March 2017

Objective

Numerous studies have shown that a substantial number of patients suffer from adverse events (AEs) as a result of hospital care. However, specific data on AEs in acute cardiac care are scarce. The current manuscript describes the development and validation of a specific instrument to evaluate patient safety of a predefined care track for patients with acute myocardial infarction (AMI).

Design

Retrospective patient record review study.

Setting and participants

A total of 879 hospital admissions treated in a tertiary care centre for an AMI (age 64±12 years, 71% male).

Main outcome measure

In the first phase, the medical records of patients with AMI warranting coronary angiography or coronary intervention were analysed for process deviations. In the second phase, the medical records of these patients were checked for any harm that had occurred which was caused by the healthcare provider or the healthcare organisation (AE) and whether the harm that occurred was preventable.

Results

Of all 879 patients included in the analysis, 40% (n=354) had 1 or more process deviation. Of these 354 patients, 116 (33%) had an AE. Patients with AE experienced more process deviations compared with patients without AE (2±1.7 vs 1.5±0.9 process deviations per patient, p=0.005). Inter-rater reliability in assessing a causal relation of healthcare with the origin of an AE showed a κ of 0.67 (95% CI 0.51 to 0.83).

Conclusions

This study shows that it is possible to develop a reliable method, which can objectively assess process deviations and the occurrence of AEs in a specified population. This method could be a starting point for developing an electronic tracking system for continuous monitoring in strictly predefined care tracks.
Recruitment and retention of participants in randomised controlled trials: a review of trials funded and published by the United Kingdom Health Technology Assessment Programme
Authors: Walters Stephen J , Bonacho dos Anjos Henriques-Cadby Inês , Bortolami Oscar , Flight Laura , Hind Daniel , Jacques Richard M , Knox Christopher , Nadin Ben , Rothwell Joanne , Surtees Michael , Julious Steven A
Published: March 2017

Background

Substantial amounts of public funds are invested in health research worldwide. Publicly funded randomised controlled trials (RCTs) often recruit participants at a slower than anticipated rate. Many trials fail to reach their planned sample size within the envisaged trial timescale and trial funding envelope.

Objectives

To review the consent, recruitment and retention rates for single and multicentre randomised control trials funded and published by the UK's National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme.

Data sources and study selection

HTA reports of individually randomised single or multicentre RCTs published from the start of 2004 to the end of April 2016 were reviewed.

Data extraction

Information was extracted, relating to the trial characteristics, sample size, recruitment and retention by two independent reviewers.

Main outcome measures

Target sample size and whether it was achieved; recruitment rates (number of participants recruited per centre per month) and retention rates (randomised participants retained and assessed with valid primary outcome data).

Results

This review identified 151 individually RCTs from 787 NIHR HTA reports. The final recruitment target sample size was achieved in 56% (85/151) of the RCTs and more than 80% of the final target sample size was achieved for 79% of the RCTs (119/151). The median recruitment rate (participants per centre per month) was found to be 0.92 (IQR 0.43–2.79) and the median retention rate (proportion of participants with valid primary outcome data at follow-up) was estimated at 89% (IQR 79–97%).

Conclusions

There is considerable variation in the consent, recruitment and retention rates in publicly funded RCTs. Investigators should bear this in mind at the planning stage of their study and not be overly optimistic about their recruitment projections.
Partitioning of reactive yellow 86 between aqueous and micellar media studied by differential absorption spectroscopy
Authors: ul Haq Naveed , Usman Muhammad , Hussain Ajaz , Farooqi Zahoor Hussain , Saeed Muhammad , Hanif Sadia , Irfan Muhammad , Siddiq Mohammad , Rana Usman Ali
Published: March 2017

The present study describes the partitioning of a reactive dye, reactive yellow 86, between aqueous and micellar media of a cationic surfactant (cetyltrimethyl ammonium bromide, CTAB), as well as an anionic surfactant (sodium dodecyl sulphate, SDS). In a systematic investigation, we have recorded the UV–vis absorption spectra of the dye as a function of surfactant’s concentration above and below the critical micelle concentration (CMC). Absorption spectra display a red shift in the case of CTAB and a hypochromic shift upon using SDS. The partition coefficient (Kx) was calculated using differential absorption data, and the value of free energy of partition (ΔGp) was calculated using this Kx value. The results revealed that the dye is solubilized in CTAB micelles to a greater extent than in SDS micelles.
Classification and analysis of VMS data in vertical line fisheries: incorporating uncertainty into spatial distributions
Authors: Ducharme-Barth Nicholas D. , Ahrens Robert N.M.
Published: March 2017

Commercial fishing fleets play a critical role in the population dynamics of exploited stocks. Understanding the spatial distribution of fleets allows managers to anticipate how fishing pressure on exploited stocks changes in response to fishing regulations or to large-scale perturbations. By anticipating how fishing pressure changes, managers can develop proactive responses to better protect stocks that are vulnerable to overfishing. Modern fisheries monitoring techniques, including vessel monitoring systems (VMS), have advanced this endeavor. This paper presents a framework for using VMS data to develop spatial distributions of catch, fishing effort, and catch per unit of effort (CPUE) as well as associated estimates of uncertainty in a vertical line fishery. VMS data are classified as fishing using a random forest (RF) model. Uncertainty is calculated using a two-step approach to account for uncertainty arising from the RF modeling process and the classification accuracy of the model. This framework is applied to investigate changes in the Gulf of Mexico reef fish fishery during a period of 6 years, including the 2010 Deepwater Horizon oil spill.
Exploring the effect of sampling, protogyny, and larval advection on stock estimates subject to no-take closures in a spatially complex coral reef line fishery on the Great Barrier Reef, Australia
Authors: Little L. Richard , Punt André E. , Tuck Geoffrey N. , Mapstone Bruce D.
Published: March 2017

Simulation is used to evaluate the ability of a two-region, age-structured assessment model to provide accurate and precise estimates of stock status (i.e., the ratio of female spawning biomass to unfished female spawning biomass) for coral trout (Plectropomus leopardus) on the Great Barrier Reef (GBR), Australia. The model used to generate the simulated data used by the assessment model is a spatially complex age- and sex-structured population dynamics model that captures the protogynous nature of coral trout. Stock status is underestimated (negatively biased), with the extent of negative bias related to mis-specification of the breeding strategy of the target fish stock, the impact of the amount of larval connectivity among reefs, the number of reefs closed to fishing, as well as exploitation rates. The estimates of stock status were less negatively biased when fishery-independent index and age- and length-composition data were available from closed areas. The results will inform the development of management strategies for coral trout in the GBR and highlight the importance of basing evaluations of estimation and management performance on operating models that capture ecologically important processes such as metapopulation dynamics and protogynous life history.
Effects of wood decay by Heterobasidion annosum on the vulnerability of Norway spruce stands to wind damage: a mechanistic modelling approach
Authors: Honkaniemi Juha , Lehtonen Mika , Väisänen Hannu , Peltola Heli
Published: March 2017

The increase of wood decay due to the fungal pathogen Heterobasidion annosum is expected to increase the vulnerability of tree stands to wind damage due to the decrease in tree anchorage (by wood decay in roots) and stem strength (by wood decay in stem wood). In this work, we developed a framework to simulate the effects of wood decay by Heterobasidion annosum on the vulnerability of Norway spruce (Picea abies (L.) Karst.) stands to wind damage in terms of uprooting and stem breakage. We also demonstrated the model performance by using tree- and stand-level sensitivity analyses. The increase in the amount of wood decay decreased the predicted wind speeds needed for both uprooting and stem breakage of trees and increased the predicted amount of wind damage. The probability of uprooting was higher than stem breakage for infected trees, which was opposite to the findings for the healthy trees. Because of some simplifications in the modelling due to the lack of proper experimental data (e.g., effects of wood decay on strength of roots and stem in Norway spruce), our model may overestimate the risk of wind damage caused by wood decay. Therefore, further model validation is still needed based on experimental research.
Upper-crustal orogenic lid and mid-crustal core complexes: signature of a collapsed orogenic plateau in the hinterland of the Grenville Province 1This article is one of a series of papers published in CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology.
Authors: Rivers Toby
Published: March 2017

This paper provides a re-interpretation of the crustal architecture of the Ottawan hinterland of the Grenville Province in light of published empirical and numerical models of orogenic collapse. It is now seen as a series of high-grade, mid-crustal core complexes from tens to hundreds of kilometres across that are juxtaposed against segments of the lower grade upper and uppermost crust including the orogenic lid. Juxtaposition of such contrasting crustal levels, which exhibit decoupled tectonic styles corresponding to the orogenic infrastructure and suprastructure, respectively, is interpreted as a signature of the foundering of an orogenic plateau into a mid-crustal channel. Ottawan metamorphism progressed from granulite-facies in the mid crust at ∼1090–1050 Ma, through amphibolite-facies in the upper crust at ∼1050–1020 Ma, to heating to ≤500 °C in the uppermost crust at ∼1020–980 Ma. This temporal progression is interpreted to reflect conductive heat transfer during collapse, as hot mid-crustal core complexes were exhumed against successively higher crustal levels. Exhumation was facilitated by substantial thinning and lengthening of the mid crust by simple- and pure-shear mechanisms. This was accompanied by wholesale boudinage of the brittle uppermost crust. Moreover, it may have resulted in excision of part of the ductile upper crust, which appears under-represented. Collapse was accompanied by diverse magmatic and hydrothermal products, their range of structural states implying that high-strain Ottawan deformation in the mid crust took place beneath an orogenic lid that was not penetratively deformed. Preliminary analysis indicates the Grenvillian inliers exhibit a comparable range of crustal levels to the Grenville Province, suggesting the orogenic plateau may have extended ∼5000 km along strike from Labrador to Texas.
The Dog Bay – Liberty Line and its significance for Silurian tectonics of the northern Appalachian orogen1This article is one of a series of papers published in this CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology.2Geological Survey of Canada Contribution 20100257.
Authors: Reusch Douglas N. , van Staal Cees R.
Published: March 2017

The Dog Bay Line, a Silurian suture key to deciphering Appalachian accretionary history, was first recognized in Newfoundland. It marks where the Ordovician Tetagouch–Exploits ensimatic back-arc basin (TEB), which had opened within the leading peri-Gondwanan Gander terrane, finally closed. Here, we extrapolate this suture into New England, placing it between the Liberty–Orrington–Miramichi inliers (LOM) and the Merrimack–Fredericton trough (MFT). Southeastward, marine strata of the MFT overlie the TEB passive margin, exposed in the Ganderian St. Croix block, and display southeast-vergent structures transected by Acadian cleavage. They structurally underlie southeast-vergent thrusts at the base of the LOM. Northwestward, the LOM, Central Maine – Matapedia trough (CMMT), and Lower Silurian igneous rocks record elements of the upper plate trench–arc system, respectively, a subduction complex, forearc basin, and arc. The CMMT forearc received detritus both from the northwesterly arc region, and also from the Early Silurian-exhumed subduction complex. Minimal contrast in Silurian turbidites near the line may be due to sediment bypassing the subduction complex, and (or) a common provenance when the complex emerged above sea level. Salinic unconformities in the upper plate (arc–trench) reflect episodes of shortening, within an overall extensional setting that resulted in thinned, weakened lithosphere, and also final uplift accompanying latest Silurian slab breakoff. Silurian strata of the Coastal Volcanic Belt document a separate arc system built on Ganderia’s trailing edge, where northwest-directed subduction of a narrow seaway led to latest Silurian collision with buoyant, strong lithosphere of Avalonia’s passive margin, and the onset of Acadian typically dextral-oblique, northwest-vergent deformation.
Ordovician A-type plutons in the Antigonish Highlands, Nova Scotia1This article is one of a series of papers published in CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology.
Authors: Escarraga E.A. , Barr S.M. , Murphy J.B. , Hamilton M.A.
Published: March 2017

Previously unrecognized A-type granitoid and gabbroic rocks cover an area of ∼100 km2 in the central Antigonish Highlands in Avalonian northern mainland Nova Scotia. The granitoid rocks in this suite occur, together with minor gabbro, in separate mappable bodies named the Brora Lake, Haggarts Lake, West Barneys River, McGraths Mountain, and Leadbetter Road plutons and are the focus of this study. They are mainly alkali feldspar granite and quartz syenite with varied texture and modal mineralogy. Close spatial association, gradational contact relations, and magma-mingling relationships suggest that all of these rocks, including the gabbro, are coeval. Hence a U–Pb (zircon) age of 469.4 +/– 0.5 Ma obtained for a quartz syenite sample from the Brora Lake pluton is interpreted to indicate a Middle Ordovician age for all of these granitoid and gabbroic rocks. Most granitic and quartz syenitic samples have hypersolvus texture, characterized by strongly perthitic alkali feldspar, and some also contain interstitial granophyre, both features indicative of shallow emplacement. Mafic minerals include iron-rich calcic and calcic–sodic amphibole, hedenbergite, and in some samples fayalite. Most of the rocks have high concentrations of K, Na, P, Ti, and Fe and are alkalic, with agpaitic indices as high as 0.98. Discrimination diagrams indicate that they are A-type granitoid rocks formed in a within-plate extensional setting. Age correlatives of these A-type granitoid and gabbroic rocks are not yet known elsewhere in Avalonia. The available data suggest that this ca. 470 Ma magmatism occurred while Avalonia was a separate microcontinent in the Rheic Ocean.
Ophiolite obduction in the Quebec Appalachians, Canada — 40Ar/39Ar age constraints and evidence for syn-tectonic erosion and sedimentation1Geological Survey of Canada Contribution 20100430.2GEOTOP (Centre de recherche en géochimie et géodynamique) Contribution 2011-0002.3This article is one of a series of papers published in this CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology.
Authors: De Souza Stéphane , Tremblay Alain , Ruffet Gilles , Pinet Nicolas
Published: March 2017

Detailed field work conducted in the Dunnage zone of the Quebec Appalachians, is herein combined with 40Ar/39Ar dating on a series of ophiolitic massifs, crosscutting granites, and associated metamorphic rocks occurring along the Baie Verte–Brompton line, the Taconian suture between Laurentia and Lower Paleozoic peri-Laurentian oceanic terranes. Studied massifs are the Lac-Brompton ophiolite and the Rivière-des-Plante Ultramafic Complex in southern Quebec, and the Nadeau Ophiolitic Mélange in the Gaspé Peninsula. Our work suggests that these massifs form remnants of eroded ophiolitic nappes, which are unconformably overlain by the Saint-Daniel and Rivière-Port-Daniel mélanges, and correlate with the Thetford-Mines and Mont-Albert ophiolitic complexes. Our 40Ar/39Ar data and compiled regional age constraints indicate that ophiolite obduction was diachronous along the strike of the orogen. The timing of obduction and mélange formation varies according to the irregular geometry of the Early Paleozoic Laurentian margin, with earlier collision occurring along, or at the margins of promontories. Obduction was initiated with the formation of infraophiolitic metamorphic soles between ca. 479 and 472 Ma in southern Quebec and the Nadeau Ophiolitic Mélange, and possibly as late as ca. 470–466 Ma for the Mont-Albert Complex. These sole rocks were later exhumed and translated onto the Laurentian margin with the overlying ophiolites between 475 and 460–457 Ma. The uplifting and erosion of the orogenic wedge during the waning stages of obduction, has resulted in the sedimentation of olistostromal mélanges and onlapping flysch units above the ophiolitic nappes, as well as foredeep flysch successions during the latest Arenig(?) to earliest Caradoc.
Tectono-stratigraphic setting of the Moreton’s Harbour Group and its implications for the evolution of the Laurentian margin: Notre Dame Bay, Newfoundland1This article is one of a series of papers published in this CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology.
Authors: Cutts J.A. , Zagorevski A. , McNicoll V. , Carr S.D.
Published: March 2017

The Moreton’s Harbour Group lies along the Red Indian Line, the fundamental Iapetus suture that separates rocks of peri-Laurentian affinity with rocks of peri-Gondwanan affinity in the Newfoundland Appalachians. Characterization of age and environment of formation of the Moreton’s Harbour Group is an important constraint on evolution of the Laurentian margin during Ordovician closure of Iapetus Ocean and associated marginal basins. The Moreton’s Harbour Group comprises a fault-bounded ophiolitic sequence of layered gabbro, sheeted diabase, pillow basalt, and felsic intrusive rocks. It is offset by high-angle shear zones that were contemporaneous with a 477.4 ± 0.4 Ma syn-tectonic and syn-magmatic suite of trondhjemite and tonalite. Trace element data from the felsic suite indicate formation in a supra-subduction zone setting, although isotopic data from the felsic intrusive rocks (εNd (–5.02) to (–10.53), Tdm 1200–1800 Ma) indicate a significant amount of contamination from Mesoproterozoic or older continental crust. The age and tectonic setting of the Moreton’s Harbour Group suggest that it is the northernmost extent of the ca. 480 Ma Annieopsquotch Ophiolite Belt. We present a model in which the Moreton’s Harbour Group formed in response to propagation of the Annieopsquotch Ophiolite Belt spreading centre into the Dashwoods microcontinent. This ridge propagation model supports the formation of the Annieopsquotch Ophiolite Belt immediately outboard of Dashwoods and explains its rapid accretion to the composite Laurentian margin.
The Salinic Orogeny in northern New Brunswick: geochronological constraints and implications for Silurian stratigraphic nomenclature1This article is one of a series of papers published in this CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology.
Authors: Wilson Reginald A. , Kamo Sandra L.
Published: March 2017

The Salinic Orogeny is defined to encompass tectonic interactions that affect all elements of Ganderia involved in the closure of the Tetagouche–Exploits back-arc basin between the Late Ordovician and Early Devonian. Hence, the D1 and D2 deformations in the Miramichi Highlands and Elmtree Inlier of northern New Brunswick are Salinic events, and onlap of Lower Silurian rocks onto exhumed parts of the Brunswick Subduction Complex represents the earliest (Salinic A) of three Silurian unconformities in the region. Upper Ordovician to Lower Silurian rocks of the Matapédia successor basin contain widespread evidence of Middle Silurian tectonism (e.g., disconformities, angular unconformities, and fold interference patterns) created by Devonian overprinting of Silurian folds lacking axial planar cleavage (Salinic B). Recent U–Pb radioisotopic dating of chemically abraded zircon from rhyolite just above the Salinic B unconformity has yielded an age of 422.3 ± 0.3 Ma; combined with late Early Silurian fossil ages just below the unconformity, this indicates a ca. 5 million year Middle Silurian hiatus. Finally, Upper Silurian (Ludfordian) rocks are locally disconformably overlain by polymictic conglomerates that form the base of the Devonian section (Salinic C). All Silurian rocks in northeastern New Brunswick have historically been included in the Chaleurs Group; however, unconformities and local stratigraphic variations (especially compared with the type locality) support the introduction of new higher rank names in New Brunswick. Hence, the Quinn Point Group is introduced to incorporate Lower Silurian rocks, the Petit Rocher Group to include Upper Silurian sedimentary rocks in the Nigadoo River Syncline, and the Dickie Cove Group for Upper Silurian volcanic rocks in the Charlo – Jacquet River area. Upper Silurian rocks west of Campbellton that are contiguous with the Chaleurs Group in Quebec, will remain part of the Chaleurs Group.
Effects of packet retransmission with finite packet lifetime on traffic capacity in scale-free networks
Authors: Jiang Zhong-Yuan , Ma Jian-Feng
Published: March 2017

Existing routing strategies such as the global dynamic routing [X. Ling, M. B. Hu, R. Jiang and Q. S. Wu, Phys. Rev. E 81, 016113 (2010)] can achieve very high traffic capacity at the cost of extremely long packet traveling delay. In many real complex networks, especially for real-time applications such as the instant communication software, extremely long packet traveling time is unacceptable. In this work, we propose to assign a finite Time-to-Live (TTL) parameter for each packet. To guarantee every packet to arrive at its destination within its TTL, we assume that a packet is retransmitted by its source once its TTL expires. We employ source routing mechanisms in the traffic model to avoid the routing-flaps induced by the global dynamic routing. We compose extensive simulations to verify our proposed mechanisms. With small TTL, the effects of packet retransmission on network traffic capacity are obvious, and the phase transition from flow free state to congested state occurs. For the purpose of reducing the computation frequency of the routing table, we employ a computing cycle [Formula: see text] within which the routing table is recomputed once. The simulation results show that the traffic capacity decreases with increasing [Formula: see text]. Our work provides a good insight into the understanding of effects of packet retransmission with finite packet lifetime on traffic capacity in scale-free networks.
Mining High Utility Sequential Patterns with Negative Item Values
Authors: Xu Tiantian , Dong Xiangjun , Xu Jianliang , Dong Xue
Published: March 2017

High utility sequential patterns (HUSP) refer to those sequential patterns with high utility (such as profit), which play a crucial role in many real-life applications. Relevant studies of HUSP only consider positive values of sequence utility. In some applications, however, a sequence consists of items with negative values (NIV). For example, a supermarket sells a cartridge with negative profit in a package with a printer at higher positive return. Although a few methods have been proposed to mine high utility itemsets (HUI) with NIV, they are not suitable for mining HUSP with NIV because an item may occur more than once in a sequence and its utility may have multiple values. In this paper, we propose a novel method High Utility Sequential Patterns with Negative Item Values (HUSP-NIV) to efficiently mine HUSP with NIV from sequential utility-based databases. HUSP-NIV works as follows: (1) using the lexicographic quantitative sequence tree (LQS-tree) to extract the complete set of high utility sequences and using I-Concatenation and S-Concatenation mechanisms to generate newly concatenated sequences; (2) using three pruning methods to reduce the search space in the LQS-tree; (3) traversing LQS-tree and outputting all the high utility sequential patterns. To the best of our knowledge, HUSP-NIV is the first method to mine HUSP with NIV, which is shown efficient on both synthetic and real datasets.
Detecting Hidden Chaotic Regions and Complex Dynamics in the Self-Exciting Homopolar Disc Dynamo
Authors: Wei Zhouchao , Moroz Irene , Sprott Julien Clinton , Wang Zhen , Zhang Wei
Published: March 2017

In 1979, Moffatt pointed out that the conventional treatment of the simplest self-exciting homopolar disc dynamo has inconsistencies because of the neglect of induced azimuthal eddy currents, which can be resolved by introducing a segmented disc dynamo. Here we return to the simple dynamo system proposed by Moffatt, and demonstrate previously unknown hidden chaotic attractors. Then we study multistability and coexistence of three types of attractors in the autonomous dynamo system in three dimensions: equilibrium points, limit cycles and hidden chaotic attractors. In addition, the existence of two homoclinic orbits is proved rigorously by the generalized Melnikov method. Finally, by using Poincaré compactification of polynomial vector fields in three dimensions, the dynamics near infinity of singularities is obtained.
Subsumed Homoclinic Connections and Infinitely Many Coexisting Attractors in Piecewise-Linear Maps
Authors: Simpson David J. W. , Tuffley Christopher P.
Published: March 2017

We establish an equivalence between infinitely many asymptotically stable periodic solutions and subsumed homoclinic connections for [Formula: see text]-dimensional piecewise-linear continuous maps. These features arise as a codimension-three phenomenon. The periodic solutions are single-round: they each involve one excursion away from a central saddle-type periodic solution. The homoclinic connection is subsumed in the sense that one branch of the unstable manifold of the saddle solution is contained entirely within its stable manifold. The results are proved by using exact expressions for the periodic solutions and components of the stable and unstable manifolds which are available because the maps are piecewise-linear. We also describe a practical approach for finding this phenomenon in the parameter space of a map and illustrate the results with the three-dimensional border-collision normal form.
Study on Chaotic Behavior of the Restricted Four-Body Problem with an Equilateral Triangle Configuration
Authors: Cheng Xuhua , She Zhikun
Published: March 2017

In this paper, the chaotic behavior of a planar restricted four-body problem with an equilateral triangle configuration is analytically studied. Firstly, according to the perturbation method of Melnikov, the planar restricted four-body problem is regarded as a perturbation of the two-body model. Then, we show that the Melnikov integral function has a simple zero, arriving at the existence of transversal homoclinic orbits. Afterwards, since the standard Smale–Birkhoff homoclinic theorem cannot be directly applied to the case of a degenerate saddle, we alternatively construct an invertible map [Formula: see text] and check that [Formula: see text] is a Smale horseshoe map, showing that our restricted four-body problem possesses chaotic behavior of the Smale horseshoe type.
Bosonic vertex representations of the toroidal superalgebras in type D(m,n)
Authors: Jing Naihuan , Xu Chongbin
Published: March 2017

In this paper, vertex representations of the 2-toroidal Lie superalgebras of type [Formula: see text] are constructed using both bosonic fields and vertex operators based on their loop algebraic presentation.
Structure of the unitary subgroup of the group algebra 𝔽2n(QD)16
Authors: Raza Zahid , Ahmad Maqsood
Published: March 2017

In this paper, we established the structure of unitary unit subgroup [Formula: see text] of the group algebra [Formula: see text], where [Formula: see text] is the Quasi-dihedral [D. S. Dummit and R. Foote, Abstract Algebra, 3rd edn. (Wiley, 2004), pp. 71–72] (Semi-Dihedral [B. Huppert, Endliche Gruppen (Springer, 1967), pp. 90–93]) group of order 16 and [Formula: see text] is any finite field of characteristic 2 with [Formula: see text] elements.
On λ-extensions of commutative rings
Authors: Kumar Rahul , Gaur Atul
Published: March 2017

Let [Formula: see text] be commutative rings with identity such that [Formula: see text]. We recall that [Formula: see text] is called a [Formula: see text]-extension of rings if the set of all subrings of [Formula: see text] containing [Formula: see text] (the “intermediate rings”) is linearly ordered under inclusion. In this paper, a characterization of integrally closed [Formula: see text]-extension of rings is given. For example, we show that if [Formula: see text] is a local ring, then [Formula: see text] is an integrally closed [Formula: see text]-extension of rings if and only if there exists [Formula: see text] such that [Formula: see text] and [Formula: see text] is a valuation domain. Let [Formula: see text] be a subring of [Formula: see text] such that [Formula: see text] is invariant under action by [Formula: see text], where [Formula: see text] is a subgroup of the automorphism group of [Formula: see text]. If [Formula: see text] is a [Formula: see text]-extension of rings, then [Formula: see text] is a [Formula: see text]-extension of rings under some conditions.