Cardiopulmonary Exercise Testing Provides Prognostic Information in Advanced Cystic Fibrosis Lung Disease

Rationale: Cardiopulmonary exercise testing (CPET) provides prognostic information in cystic fibrosis (CF); however, its prognostic value for patients with advanced CF lung disease is unknown. Objectives: To determine the prognostic value of CPET on the risk of death or lung transplant (LTX) within 2 years. Methods: We retrospectively collected data from 20 CF centers in Asia, Australia, Europe, and North America on patients with a forced expiratory volume in 1 second (FEV1) ⩽ 40% predicted who performed a cycle ergometer CPET between January 2008 and December 2017. Time to death/LTX was analyzed using mixed Cox proportional hazards regression. Conditional inference trees were modeled to identify subgroups with increased risk of death/LTX. Results: In total, 174 patients (FEV1, 30.9% ± 5.8% predicted) were included. Forty-four patients (25.5%) died or underwent LTX. Cox regression analysis adjusted for age, sex, and FEV1 revealed percentage predicted peak oxygen uptake ([Formula: see text]o2peak) and peak work rate (Wpeak) as significant predictors of death/LTX: adjusted hazard ratios per each additional 10% predicted were 0.60 (95% confidence interval, 0.43-0.90; P = 0.008) and 0.60 (0.48-0.82; P < 0.001). Tree-structured regression models, including a set of 11 prognostic factors for survival, identified Wpeak to be most strongly associated with 2-year risk of death/LTX. Probability of death/LTX was 45.2% for those with a Wpeak ⩽ 49.2% predicted versus 10.9% for those with a Wpeak > 49.2% predicted (P < 0.001). Conclusions: CPET provides prognostic information in advanced CF lung disease, and Wpeak appears to be a promising marker for LTX referral and candidate selection.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Positive airway pressure therapy adherence and outcomes in obstructive sleep apnea: An exploratory longitudinal retrospective randomized chart review

Background

Positive airway pressure (PAP) therapy is prescribed to patients with obstructive sleep apnea (OSA). A commonly used definition for PAP therapy adherence is based upon the minimum requirements to receive Medicare coverage in the US, defined as PAP usage of four or more hours per night on 70 percent of nights for at least 30 consecutive days. However, little evidence exists to support this definition for PAP therapy adherence. Therefore, the present study sought to determine the efficacy of the present definition of PAP therapy adherence on longitudinal outcomes in patients with OSA, using objectively measured PAP device usage time.

Methods

An exploratory longitudinal, retrospective, randomized chart review was done to assess clinical outcomes between patients with OSA who were defined as PAP therapy adherent (n=50) and non-adherent (n=50) during an eight-year observation period.

Results

No significant differences were shown between groups for mortality, hospitalizations, or development of co-morbidities during the observation period. However, logistic regression showed significantly higher odds of adherence in male patients compared to female patients (OR=8.519; 95%CI=1.301-55.756; p=0.025) and significantly lower odds of adherence in patients with higher normal (OR=0.039; 95%CI=0.005-0.392; p=0.003), mild excessive (OR=0.039; 95%CI=0.003-0.517; p=0.014), and severe excessive (OR=0.088; 95%CI=0.012-0.635; p=0.016) daytime sleepiness compared to patients with lower normal daytime sleepiness. An increasing number of hospitalizations also corresponded with a significant decrease in odds of being adherent (OR=0.741; 95%CI=0.551-0.995; p=0.046).

Conclusion

The present study supports a steadily growing body of literature calling for more consideration and evidence to support a definition of PAP therapy adherence that is clinically meaningful.

The bacterial replication origin BUS promotes nucleobase capture

Genome duplication is essential for the proliferation of cellular life and this process is generally initiated by dedicated replication proteins at chromosome origins. In bacteria, DNA replication is initiated by the ubiquitous DnaA protein, which assembles into an oligomeric complex at the chromosome origin (oriC) that engages both double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) to promote DNA duplex opening. However, the mechanism of DnaA specifically opening a replication origin was unknown. Here we show that Bacillus subtilis DnaAATP assembles into a continuous oligomer at the site of DNA melting, extending from a dsDNA anchor to engage a single DNA strand. Within this complex, two nucleobases of each ssDNA binding motif (DnaA-trio) are captured within a dinucleotide binding pocket created by adjacent DnaA proteins. These results provide a molecular basis for DnaA specifically engaging the conserved sequence elements within the bacterial chromosome origin basal unwinding system (BUS).

Authoritarianism, perceptions of security threats, and the COVID-19 pandemic: A new perspective

This article offers a new perspective on when and why individual-level authoritarian perceptions of security threats change. We reexamine claims that authoritarian members of the public responded to the COVID-19 pandemic in a counterintuitive fashion. The response was counterintuitive in that, rather than a desire for a stronger government with the ability to impose measures to address the pandemic and its consequences, authoritarian individuals rejected a stronger government response and embraced individual autonomy. The article draws on perceptions of security threats-issues that directly or indirectly harm personal or collective safety and welfare-from surveys in two different contexts in England: 2012, when perceptions of the threat from infectious disease was low relative to most other security threats, and 2020, when perceptions of the personal and collective threat of COVID-19 superseded all other security threats. We argue that the authoritarian response was not counterintuitive once we account for the type of threat it represented.

Cell division angle regulates the tissue mechanics and tunes the amount of cerebellar folding

Modeling has proposed that the amount of neural tissue folding is set by the level of differential-expansion between tissue layers and that the wavelength is set by the thickness of the outer layer. Here we used inbred mouse strains with distinct amounts of cerebellar folding to investigate these predictions. We identified a critical period where the folding amount diverges between the strains. In this period, regional changes in the level of differential-expansion between the external granule layer (EGL) and underlying core correlate with the folding amount in each strain. Additionally, the thickness of the EGL is regionally adjusted during the critical period alongside corresponding changes in wavelength. While the number of SHH-expressing Purkinje cells predicts the folding amount, the proliferation rate in the EGL is the same between the strains. However, regional changes in the cell division angle within the EGL predicts both the tangential-expansion and thickness of the EGL. Cell division angle is likely a tunable mechanism whereby both the level of differential-expansion and thickness of the EGL are regionally tuned to set the amount and wavelength of folding.

Impact of an outdoor loose parts play intervention on Nova Scotian preschoolers' physical literacy: a mixed-methods randomized controlled trial

BACKGROUND

Physical activity participation among preschoolers in childcare settings are low, and interventions to increase physical activity levels have produced mixed results. The Physical Literacy in the Early Years (PLEY) project implemented a six-month childcare-based outdoor loose parts play intervention in childcare centres in Nova Scotia, Canada. The purpose of this study was to examine the impact of the PLEY project on the development of domains of physical literacy (physical activity, physical competence, confidence and motivation, knowledge and understanding) in preschoolers attending childcare centres using mixed-methods.

METHODS

Preschoolers (3-5 years) were recruited from 19 childcare centres in Nova Scotia and centres were randomized (parallel design) to the outdoor loose parts play intervention group (n = 11) or control (n = 8) group for 6 months. Participants, early childhood educators, and assessors were not blinded to group assignment. Quantitative and qualitative measures were used to comprehensively assess the impact of the PLEY project on all domains of physical literacy. At 3- and 6-months, early childhood educators participated in focus groups to assess how the intervention supported the development of 4 physical literacy domains: physical activity, physical competence, confidence and motivation, and knowledge and understanding. Physical activity and physical competence were also assessed with accelerometry and the Test of Gross Motor Development-3, respectively.

RESULTS

Two hundred and nine preschoolers participated in the study (intervention group: n = 115; control group: n = 94). Accelerometer data showed that while baseline physical activity was similar between groups, children in the intervention group had higher physical activity at 3- (F(1,187) = 8.30, p = 0.004) and 6-months (F(1,187) = 9.90, p = 0.002) post-intervention. There was no intervention effect on physical competence scores. Thematic analysis of focus group data revealed that outdoor loose parts play contributed to development in all 4 physical literacy domains, including increased movement repertoires, social development, and enjoyment of physical activity. No adverse events or side effects of the intervention were reported.

CONCLUSIONS

Participation in the PLEY project was associated with increased development of various domains of physical literacy and perceived physical literacy among preschoolers, and outdoor loose parts play may be encouraged as an effective strategy to increase physical literacy in early learning settings.

TRIAL REGISTRATION

Biomed Central (ISRCTN14058106), 20/10/2017.

Survey of exercise testing and training in cystic fibrosis clinics in the UK: a decade of progress

OBJECTIVES

Regular exercise testing is recommended for people with cystic fibrosis (pwCF), as is the provision and regular review of exercise training programmes. A previous survey on exercise testing and training for pwCF in the UK was conducted over a decade ago. With the landscape of CF changing considerably during this time, this survey aimed to evaluate UK-based exercise testing and training practices for pwCF a decade on.

DESIGN

Cross-sectional, online survey.

PARTICIPANTS

A survey was distributed electronically to UK CF clinics and completed by the individual primarily responsible for exercise services. Descriptive statistics and qualitative analyses were undertaken.

RESULTS

In total, 31 CF centres participated, representing ~50% of UK specialist clinics. Of these, 94% reported using exercise testing, 48% of which primarily use cardiopulmonary exercise testing. Exercise testing mostly occurs at annual review (93%) and is most often conducted by physiotherapists (62%). A wide variation in protocols, exercise modalities, normative reference values and cut-offs for exercise-induced desaturation are currently used. All centres reportedly discuss exercise training with pwCF; 94% at every clinic appointment. However, only 52% of centres reportedly use exercise testing to inform individualised exercise training. Physiotherapists typically lead discussions around exercise training (74%).

CONCLUSIONS

These data demonstrate that the majority of respondent centres in the UK now offer some exercise testing and training advice for pwCF, representing a marked improvement over the past decade. However, continued efforts are now needed to standardise exercise practices, particularly regarding field testing practices and the translation of test results into personalised training programmes for pwCF.

The DNA replication initiation protein DnaD recognises a specific strand of the Bacillus subtilis chromosome origin

Genome replication is a fundamental biological activity shared by all organisms. Chromosomal replication proceeds bidirectionally from origins, requiring the loading of two helicases, one for each replisome. However, the molecular mechanisms underpinning helicase loading at bacterial chromosome origins (oriC) are unclear. Here we investigated the essential DNA replication initiation protein DnaD in the model organism Bacillus subtilis. A set of DnaD residues required for ssDNA binding was identified, and photo-crosslinking revealed that this ssDNA binding region interacts preferentially with one strand of oriC. Biochemical and genetic data support the model that DnaD recognizes a new single-stranded DNA (ssDNA) motif located in oriC, the DnaD Recognition Element (DRE). Considered with single particle cryo-electron microscopy (cryo-EM) imaging of DnaD, we propose that the location of the DRE within oriC orchestrates strand-specific recruitment of helicase during DNA replication initiation. These findings significantly advance our mechanistic understanding of bidirectional replication from a bacterial chromosome origin.

4-dimensional local radial basis function interpolation of large, uniformly spaced datasets

BACKGROUND AND OBJECTIVE

Large, uniformly spaced, complex and time varying datasets derived from high resolution medical image velocimetry can provide a wealth of information regarding small-scale transient physiological flow phenomena and pulsation of anatomical boundaries. However, there remains a need for interpolation techniques to effectively reconstruct a fully 4-dimensional functional relationship from this data. This paper presents a preliminary evaluation of a 4-dimensional local radial basis function (RBF) algorithm as a means of addressing this problem for laminar flows.

METHODS

A 4D interpolation algorithm is proposed based on a Local Hermitian Interpolation (LHI) using a combination of multi-quadric RBF with a partition of unity scheme. The domain is divided into uniform sub-systems with size restricted to immediately neighbouring points. The validity of the algorithm is first established on a known 4D analytical dataset and a CFD based laminar flow phantom. Application is then demonstrated through characterisation of a large 4D laminar flow dataset obtained from magnetic resonance imaging (MRI) measurements of cerebrospinal fluid velocities in the brain.

RESULTS

Performance of the algorithm is compared to that of a quad-linear interpolation, demonstrating favourable improvement in accuracy. The technique is shown to be robust, computationally efficient and capable of refined interpolation in Euclidean space and time. Application to MR velocimetry data is shown to produce promising results for the 4D reconstruction of the transient flow field and movement of the fluid boundaries at spatial and temporal locations intermediate to the original data.

CONCLUSION

This study has demonstrated feasibility of an accurate, stable and efficient 4-dimensional local RBF interpolation method for large, transient laminar flow velocimetry datasets. The proposed approach does not suffer from ill-conditioning or high computational cost due to domain decomposition into local stencils where the RBF is only ever applied to a limited number of points. This work offers a potential tool to assist medical diagnoses and drug delivery through better understanding of physiological flow fields such as cerebrospinal fluid. Further work will evaluate the technique on a wider range of flow fields and against CFD simulation.

SirA inhibits the essential DnaA:DnaD interaction to block helicase recruitment during Bacillus subtilis sporulation

Bidirectional DNA replication from a chromosome origin requires the asymmetric loading of two helicases, one for each replisome. Our understanding of the molecular mechanisms underpinning helicase loading at bacterial chromosome origins is incomplete. Here we report both positive and negative mechanisms for directing helicase recruitment in the model organism Bacillus subtilis. Systematic characterization of the essential initiation protein DnaD revealed distinct protein interfaces required for homo-oligomerization, interaction with the master initiator protein DnaA, and interaction with the helicase co-loader protein DnaB. Informed by these properties of DnaD, we went on to find that the developmentally expressed repressor of DNA replication initiation, SirA, blocks the interaction between DnaD and DnaA, thereby restricting helicase recruitment from the origin during sporulation to inhibit further initiation events. These results advance our understanding of the mechanisms underpinning DNA replication initiation in B. subtilis, as well as guiding the search for essential cellular activities to target for antimicrobial drug design.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Neuroimaging Correlates of Post-Traumatic Stress Disorder in Traumatic Brain Injury: A Systematic Review of the Literature

Introduction

Neuroimaging has been a highly utilized technique for studying traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) independently of one another, however, neuroimaging has increasingly been identified as a useful tool in better understanding TBI-related psychiatric conditions, such as PTSD.

Objectives

To complete a systematic review of the literature examining neuroimaging findings in TBI-related PTSD and to highlight the current literature’s limitations in order to strengthen future research.

Methods

A PRISMA compliant literature search was conducted in PubMed (MEDLINE), PsychINFO, EMBASE, and Scopus databases prior to May of 2019. The initial database query yielded 4388 unique articles, which were narrowed down based on specified inclusion criteria (e.g., clear TBI definition, clinician-diagnosed PTSD, statistically analyzed relationship between neuroimaging and PTSD, quantified time interval between TBI and neuroimaging).

Results

A final cohort of 10 articles met inclusion criteria, comprising the findings of 482 participants with TBI. Key neuroanatomical findings among the included articles suggest that PTSD is associated with significant changes in whole-brain networks of resting state connectivity and disruptions in bilateral frontal and temporal white matter tracts, fronto-limbic pathways, the internal capsule, and the uncinate fasciculus (Figure 1). Figure 1a:

POS0516 PLASMA CALPROTECTIN WAS ASSESSED IN MULTIPLE BIOLOGICAL TREATMENT STRATEGIES FOR EARLY RHEUMATOID ARTHRITIS

Background

Plasma calprotectin is a sensitive inflammatory marker in patients with rheumatoid arthritis (RA) and reflects activation of granulocytes and macrophages. Plasma calprotectin has not previously been studied in a head-to-head trial of multiple biological mechanisms of action versus active conventional therapy (ACT) with methotrexate and prednisolone.

Objectives

To assess the effect of treatment on plasma calprotectin levels in patients with early RA by determining the 24-week change in the four arms of the NORD-STAR Study, a large multicenter randomized head-to-head clinical trial of ACT versus tumor necrosis factor inhibition, T-cell co-stimulation inhibition, and interleukin-6 inhibition (1).

Methods

Calprotectin was analyzed in plasma samples at baseline, week 4 and week 24 from 400 treatment naïve patients with early RA in the NORD-STAR Study. Samples were analyzed using a calprotectin ELISA alkaline phosphatase (ALP) kit from CalproLab (Oslo, Norway) in a Dynex DS2 processing system (normal levels <910 µg/L). Patients were assessed by clinical (CRP, 28 SJC/TJC, physician global) and patients’ reported assessments. Crude and adjusted linear regression analyses were performed in R 4.0.3 with calprotectin levels at week 24 as the outcome. The four arms were represented by three dummy variables. The adjustment variables were age, sex, anti-CCP status and country. Both analyses were adjusted for baseline calprotectin levels.

Results

At baseline, the mean time since diagnosis was 15.7 days (SD) (22.9), mean age 53.7 (15.0) years, ACPA positive 81%, and female 66%. Mean calprotectin levels were 1931 (1495) µg/L at baseline, 866 (951) µg/L at week 4, and 629 (661) µg/L at week 24. At baseline, normal calprotectin levels (<910 µg/L) were observed in 27% of all patients (ACT 22%, certolizumab-pegol and methotrexate 30%, abatacept and methotrexate 25%, tocilizumab and methotrexate 31%). At week 24, normal calprotectin levels were observed in 82% of all patients (ACT 68%, certolizumab-pegol and methotrexate 91%, abatacept and methotrexate 80%, tocilizumab and methotrexate 90%).

Observed calprotectin levels at week 24 were significantly lower in patients treated with certolizumab-pegol and methotrexate -336µg/L (97) (p< 0.006) or tocilizumab and methotrexate -284 (99) (p < 0.004), versus ACT when adjusted for age, sex, anti-CCP status, baseline calprotectin level, and country; however, a significant difference was not observed in patients treated with abatacept and methotrexate -110 (96) (p = 0.25). The Figure 1 shows the average percentage change in calprotectin levels from baseline to week 24 for all treatment groups.

Figure 1.

Average percentage change in calprotectin levels from baseline to week 24. ACT: active conventional therapy, CZP+MTX: certolizumab-pegol and methotrexate, ABA+MTX: abatacept and methotrexate, TCZ+MTX: tocilizumab and methotrexate.

Conclusion

Calprotectin, a sensitive biomarker of inflammation, normalized in the majority of patients. The decline differed between treatment groups and was largest in patients treated with a TNF inhibitor and methotrexate, suggesting that calprotectin reflects the activity of specific inflammatory pathways rather than overall inflammation. The findings of this study should be further explored.

References

[1]Hetland ML, et. al., Active conventional treatment and three different biological treatments in early rheumatoid arthritis: phase IV investigator initiated, randomised, observer blinded clinical trial. BMJ. 2020 Dec 2;371:m4328. doi: 10.1136/bmj.m4328. PMID: 33268527; PMCID: PMC7708829.

Acknowledgements

I would like to acknowledge the NORD-STAR Study group.

Disclosure of Interests

David Stevens: None declared, Marte Heiberg: None declared, Amirhossein Kazemi: None declared, Ronald van Vollenhoven: None declared, Jon Lampa: None declared, Anna Rudin: None declared, Kristina Lend: None declared, Merete Lund Hetland: None declared, Mikkel Østergaard: None declared, Michael Nurmohamed: None declared, Kim Hørslev-Petersen: None declared, Dan Nordström Consultant of: Abbvie, BMS, Lilly, MSD, Novartis, Pfizer, Roche and UCB, Björn Gudbjornsson: None declared, Till Uhlig: None declared, Espen A Haavardsholm: None declared, Hilde Berner Hammer Speakers bureau: AbbVie, Novartis, and Lilly.

Environmental Correlates of Physical Activity, Sedentary Behavior, and Self-Rated Health in Chronic Obstructive Pulmonary Disease

PURPOSE

Physical activity (PA) predicts important health outcomes in chronic obstructive pulmonary disease (COPD). In the general population, environmental factors have the potential to influence PA; however, data are limited in this clinical population. Therefore, we sought to investigate associations between the environment and PA, sedentary behavior, and self-rated health in COPD.

METHODS

Sociodemographic, PA, sedentary behavior, and self-rated health data were collected from a prospective cohort of 418 individuals with COPD (65% female; 58 ± 8 yr), while environmental data were drawn from a national environmental data repository and individually matched to participant postal code. Environmental variables included social and material deprivation, urban form index, surrounding greenness, and air quality (concentrations of air pollution for fine particles, nitrogen dioxide, ozone, and sulphur dioxide). Logistic and multivariate linear regression models were used to investigate the strongest environmental predictors.

RESULTS

The models showed a statistically significant negative correlation between PA level and ozone pollution (P = .023; adjusted OR = 0.85: 95% CI, 0.74-0.98). Urban form index was also significantly associated with sedentary behavior (β = 0.113; t value = 1.71; P = .011). Self-rated health was significantly positively correlated with PA level (P = .006; adjusted OR = 2.22: 95% CI, 1.25-3.94), and significantly inversely correlated with sedentary behavior (β = -0.159; t value =-2.42; P = .016).

CONCLUSION

These new data may identify barriers to PA and assist clinicians in the prescription of exercise for individuals living with COPD.

Parents and Children Should Be More Active Together to Address Physical Inactivity and Sedentary Behaviours

Increasing rates of physical inactivity and sedentary behaviours among children and the youth are important determinants of chronic disease. Supporting children's participation in organised physical activities like sports has been promoted as a public health strategy to increase physical activity. Evidence shows that successful interventions are family-focused, although research on how parental eating and physical activity behaviours influence children's behaviours is deficient. In this commentary, we argue that interventions for countering physical inactivity and sedentary behaviours should include greater focus on home and social environments, specifically the influence and involvement of parents, siblings, and friends in supporting these health behaviours. We conclude that the design of interventions to prevent chronic diseases in children should also consider more carefully the conditions in which the behaviours of children and their parents occur. This means encouraging parents and children to be active together to address physical inactivity and sedentary behaviours, while being mindful of unintended consequences of focusing on one behaviour over another.

Diagnosing COVID-19; towards a feasible COVID-19 rule-out protocol

Introduction: We present the results of the COVID-19 rule-out protocol at Ghent University Hospital, a step-wise testing approach which included repeat NFS SARS-CoV-2 rRT-PCR, respiratory multiplex RT-PCR, low-dose chest CT and bronchoscopy with BAL to confirm or rule-out SARS-CoV-2 infection in patients admitted with symptoms suggestive of COVID-19.

Results: Between 19 March 2020 and 30 April 2020, 455 non-critically ill patients with symptoms suspect for COVID-19 were admitted. The initial NFS for SARS-CoV-2 rRT-PCR yielded 66.9%, the second NFS 25.4% and bronchoscopy with BAL 5.9% of total COVID-19 diagnoses. In the BAL fluid, other respiratory pathogens were detected in 65% (13/20) of the COVID-19 negative patients and only in 1/7 COVID-19 positive patients. Retrospective antibody testing at the time around BAL sampling showed a positive IgA or IgG in 42.9 % of the COVID-19 positive and 10.5% of the COVID-19 negative group. Follow-up serology showed 100% COVID-19 positivity in the COVID-19 positive group and 100% IgG negativity in the COVID-19 negative group.

Conclusion: In our experience, bronchoscopy with BAL can have an added value to rule-in or rule-out COVID-19 in patients with clinical and radiographical high-likelihood of COVID-19 and repeated negative NFS testing. Furthermore, culture and respiratory multiplex PCR on BAL fluid can aid to identify alternative microbial etiological agents in this group. Retrospective analysis of antibody development in this selected group of patients suggests that the implementation of serological assays in the routine testing protocol will decrease the need for invasive procedures like bronchoscopy.

The impact of COVID‐19 upon the delivery of exercise services within cystic fibrosis clinics in the United Kingdom

Objectives

The COVID‐19 pandemic has resulted in unprecedent changes to clinical practice, and as the impact upon delivery of exercise services for people with cystic fibrosis (CF) in the United Kingdom was unknown, this was characterised via a national survey.

Methods

An electronic survey was distributed to healthcare professionals involved in the exercise management of CF via established professional networks.

Results

In total, 31 CF centres participated. Findings included significant reductions in exercise testing and widespread adaptation to deliver exercise training using telehealth methods. Promisingly, 71% stated that they would continue using virtual methods of engaging patients in future practice.

Conclusion

These findings highlight adaptation to the COVID‐19 pandemic and the need to develop sustainable and standardised telehealth services to manage patients moving forwards.

Impact of an outdoor loose parts intervention on Nova Scotia preschoolers' fundamental movement skills: a multi-methods randomized controlled trial

Development of fundamental movement skills in early childhood supports lifelong health. The potential for outdoor play with loose parts to enhance fundamental movement skills has not been investigated. A multi-methods randomized controlled design was used to determine the efficacy of integrating outdoor loose parts play into Nova Scotia childcare centers (19 sites: 11 interventions, 8 control). Movement skills (n = 209, age 3–5 years) were assessed over a 6-month period to investigate changes in fundamental movement skills over time and between groups. Qualitative data was also collected on the educators' perceptions of outdoor loose parts play. Quantitative data (fundamental movement skills) revealed a non-intervention effect, however, educators spoke of outdoor loose parts play providing opportunities to combine/ repeat movements and take risks; supporting physical, cognitive and socio-emotional (holistic) development; and increasing awareness of children's physical development and how to support it. Our findings demonstrate value in outdoor loose parts play for the development of fundamental movement skills in childcare settings.

Adoption and continued use of mobile contact tracing technology: multilevel explanations from a three-wave panel survey and linked data

OBJECTIVE

To identify the key individual-level (demographics, attitudes, mobility) and contextual (COVID-19 case numbers, tiers of mobility restrictions, urban districts) determinants of adopting the NHS COVID-19 contact tracing app and continued use overtime.

DESIGN AND SETTING

A three-wave panel survey conducted in England in July 2020 (background survey), November 2020 (first measure of app adoption) and March 2021 (continued use of app and new adopters) linked with official data.

PARTICIPANTS

N=2500 adults living in England, representative of England's population in terms of regional distribution, age and gender (2011 census).

PRIMARY OUTCOME

Repeated measures of self-reported app usage.

ANALYTICAL APPROACH

Multilevel logistic regression linking a range of individual level (from survey) and contextual (from linked data) determinants to app usage.

RESULTS

We observe initial app uptake at 41%, 95% CI (0.39% to 0.43%), and a 12% drop-out rate by March 2021, 95% CI (0.10% to 0.14%). We also found that 7% of nonusers as of wave 2 became new adopters by wave 3, 95% CI (0.05% to 0.08%). Initial uptake (or failure to use) of the app associated with social norms, privacy concerns and misinformation about third-party data access, with those living in postal districts with restrictions on mobility less likely to use the app. Perceived lack of transparent evidence of effectiveness was associated with drop-out of use. In addition, those who trusted the government were more likely to adopt in wave 3 as new adopters.

CONCLUSIONS

Successful uptake of the contact tracing app should be evaluated within the wider context of the UK Government's response to the crisis. Trust in government is key to adoption of the app in wave 3 while continued use is linked to perceptions of transparent evidence. Providing clear information to address privacy concerns could increase uptake, however, the disparities in continued use among ethnic minority participants needs further investigation.

Is Persistent Motor or Vocal Tic Disorder a Milder Form of Tourette Syndrome?

Background

Persistent motor or vocal tic disorder (PMVT) has been hypothesized to be a forme fruste of Tourette syndrome (TS). Although the primary diagnostic criterion for PMVT (presence of motor or vocal tics, but not both) is clear, less is known about its clinical presentation.

Objective

The goals of this study were to compare the prevalence and number of comorbid psychiatric disorders, tic severity, age at tic onset, and family history for TS and PMVT.

Methods

We analyzed data from two independent cohorts using generalized linear equations and confirmed our findings using meta‐analyses, incorporating data from previously published literature.

Results

Rates of obsessive–compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD) were lower in PMVT than in TS in all analyses. Other psychiatric comorbidities occurred with similar frequencies in PMVT and TS in both cohorts, although meta‐analyses suggested lower rates of most psychiatric disorders in PMVT compared with TS. ADHD and OCD increased the odds of comorbid mood, anxiety, substance use, and disruptive behaviors, and accounted for observed differences between PMVT and TS. Age of tic onset was approximately 2 years later, and tic severity was lower in PMVT than in TS. First‐degree relatives had elevated rates of TS, PMVT, OCD, and ADHD compared with population prevalences, with rates of TS equal to or greater than PMVT rates.

Conclusions

Our findings support the hypothesis that PMVT and TS occur along a clinical spectrum in which TS is a more severe and PMVT a less severe manifestation of a continuous neurodevelopmental tic spectrum disorder. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Physical activity, sedentary time and sleep in cystic fibrosis youth: A bidirectional relationship?

PURPOSE

Physical activity (PA) and sleep are highly important for those with cystic fibrosis (CF), yet, despite this and suggestions of a bidirectional relationship between these factors in healthy children, their relationship is yet to be investigated.

METHODS

PA, sedentary time (SED), and sleep were objectively derived over seven days in 58 youth (11.9 ± 2.7 years; 29 CF). Generalized linear latent and mixed models with a random intercept and slope at child-level were adjusted for age, sex, wear-time, type of day, group and mean PA/SED and sleep.

RESULTS

Every additional 10 min sedentary was associated with 5.6 and 5.0 min less sleep and 10.6 and 12.0 min less wake after sleep onset (WASO) that night, in CF and healthy children, respectively. PA, regardless of intensity, was not associated with total sleep time but every additional 10 min of light PA (LPA) was associated with 3.0 min less WASO in healthy participants. Ten mins more sleep was associated with 3.1 and 1.7 min less SED in CF and healthy children, respectively. In CF, greater sleep time led to less LPA (3.6 min) the following day, whereas, in healthy children, poor sleep quality (greater WASO) was associated with more LPA (1.4 min) and moderate-to-vigorous PA (5.2 min) the following day.

CONCLUSION

A bidirectional relationship between SED and subsequent total sleep time was evident, irrespective of group, whereas the relationship between sleep and PA was group dependent. These findings have important implications regarding the reciprocal effects of promoting PA or sleep quantity or quality.

Contact electrification between identical polymers as the basis for triboelectric/flexoelectric materials

Polymer contact electrification offers the possibility to harvest mechanical energy using lightweight, flexible and low-cost materials, but the mechanism itself is still unresolved. Several recent studies confirm heterolytic covalent bond breaking as the mechanism for surface charge formation. Here it is shown that the reason for the formation of surface charge by contacting two identical polymers results from the fluctuation in the surface irregularities, and that contacted materials with a greater porosity or surface roughness differential result in a greater generation of surface charge. Porosity and surface roughness create uneven surface length percentage changes in the lateral direction during deformation, which changes the charge density across the surface during relaxation. Multilayered membranes exhibit flexoelectric properties upon pressing and releasing by generating charge without separating individual membrane layers. This new insight deepens the understanding of polymer contact electrification and highlights better ways to prepare triboelectric or flexoelectric nanogenerator devices.

OP0018 A MULTICENTER RANDOMIZED STUDY IN EARLY RHEUMATOID ARTHRITIS TO COMPARE ACTIVE CONVENTIONAL THERAPY VERSUS THREE BIOLOGICAL TREATMENTS: 24 WEEK EFFICACY RESULTS OF THE NORD-STAR TRIAL

Background:

The optimal first-line treatment of patients (pts) with early rheumatoid arthritis (RA) is yet to be established.

Objectives:

The primary aim was to assess and compare the proportion of pts who achieved remission with active conventional therapy (ACT) and with three different biologic therapies after 24 wks. Secondary aims were to assess and compare other efficacy measures.

Methods:

The investigator-initiated NORD-STAR trial (NCT01491815) was conducted in the Nordic countries and Netherlands. In this multicenter, randomized, open-label, blinded-assessor study pts with treatment-naïve, early RA with DAS28>3.2, and positive RF or ACPA, or CRP >10mg/L were randomized 1:1:1:1. Methotrexate (25 mg/week after one month) was combined with: 1) (ACT): oral prednisolone (tapered quickly);or: sulphasalazine, hydroxychloroquine and mandatory intra-articular (IA) glucocorticoid (GC) injections in swollen joints <wk 20; 2) certolizumab 200 mg EOW SC (CZP); 3) abatacept 125 mg/wk SC (ABA); tocilizumab 162 mg/wk SC (TCZ). IA GC was allowed in all arms <wk 20. Primary outcome was clinical disease activity index remission (CDAI≤2.8) at wk 24. Secondary outcomes included CDAI remission over time and other remission criteria. Dichotomous outcomes were analyzed by adjusted logistic regression with non-responder imputation (NRI). Non-inferiority analyses had a pre-specified margin of 15%.

Results:

812 pts were randomized. Age was 54.3±14.7 yrs (mean±SD), 31.2% were male, DAS28 5.0±1.1, 74.9% were RF and 81.9% ACPA positive. Fig 1 shows the adjusted CDAI remission rates over time with 95% CI. Table shows crude remission and response rates and absolute differences in adjusted remission and response rates (superiority analysis). Differences in remission and response rates with CZP and TCZ, but not with ABA, remained within the pre-defined non-inferiority margin versus ACT, Fig 2.

Figure 1.

CDAI remission over time (adj. estimates with 95% CI)

Figure 2.

Non-inferiority analysis of protocol population. Estimated differences in CDAI remission rates between Arm 1 (active conventional therapy) and Arms 2, 3, and 4 (biologic arms) as reference with 95% confidence intervals, adjusted for gender, ACPA status, country, age, body-mass index and baseline DAS28-CRP. ABA, abatacept; CZP, certolizumab-pegol; MTX, methotrexate; TCZ, tocilizumab.

Conclusion:

High remission rates were found across all four treatment arms at 24 wks. Higher CDAI remission rate was observed for ABA versus ACT (+9%) and for CZP (+4%), but not for TCZ (-1%). With the predefined 15% margin, ACT was non-inferior to CZP and TCZ, but not to ABA. This underscores the efficacy of active conventional therapy based on MTX combined with glucocorticoids and may guide future treatment strategies for early RA.

Table.

Primary and key secondary outcomes at 24 weeks (ITT)

Active conventional therapy (ACT)Certolizumab+MTXAbatacept+MTXTocilizumab+MTXNo of pts (ITT)200203204188§Crude remission and response ratesCDAI remission42.0%47.8%52.5%41.0%ACR/EULAR Boolean remission34.0%38.4%37.3%31.4%DAS28 remission63.5%68.5%69.6%63.3%SDAI remission41.5%49.8%51.5%42.6%EULAR good response71.5%76.9%79.9%71.3%Difference (95% CI) in rates with Arm 1 as reference (adjusted)CDAI remissionRef4% (-5 to 13%)9% (0.1 to 19%)-1% (-10 to 9%)ACR/EULAR Boolean remissionRef4% (-6 to 13%)5% (-5 to 14%)-4% (-13 to 6%)DAS28 remissionRef3% (-6 to 11%)5% (-4 to 13%)-1% (-10 to 8%)SDAI remissionRef6% (-3 to 18%)9% (-0.3 to 18%)1% (-8 to 11%)EULAR good responseRef4% (-4 to 14%)8% (-2 to 18%)0.4% (-10 to 11%)

§17 patients allocated to Tocilizumab did not receive it due to its unavailability and were excluded from ITT.

Acknowledgments:

Manufacturers provided CZP and ABA.

Disclosure of Interests:

Merete L. Hetland Grant/research support from: BMS, MSD, AbbVie, Roche, Novartis, Biogen and Pfizer, Consultant of: Eli Lilly, Speakers bureau: Orion Pharma, Biogen, Pfizer, CellTrion, Merck and Samsung Bioepis, Espen A Haavardsholm Grant/research support from: AbbVie, UCB Pharma, Pfizer Inc, MSD Norway, Roche Norway, Consultant of: Pfizer, AbbVie, Janssen-Cilag, Gilead, UCB Pharma, Celgene, Lilly, Paid instructor for: UCB Pharma, Speakers bureau: Pfizer, AbbVie, UCB Pharma, Celgene, Lilly, Roche, MSD, Anna Rudin Consultant of: Astra/Zeneca, Dan Nordström Consultant of: Abbvie, Celgene, Lilly, Novartis, Pfizer, Roche and UCB., Speakers bureau: Abbvie, Celgene, Lilly, Novartis, Pfizer, Roche and UCB., Michael Nurmohamed Grant/research support from: Not related to this research, Consultant of: Not related to this research, Speakers bureau: Not related to this research, Björn Gudbjornsson Speakers bureau: Novartis and Amgen, Jon Lampa Speakers bureau: Pfizer, Janssen, Novartis, Kim Hørslev-Petersen: None declared, Till Uhlig Consultant of: Lilly, Pfizer, Speakers bureau: Grünenthal, Novartis, Gerdur Gröndal: None declared, Mikkel Ǿstergaard Grant/research support from: AbbVie, Bristol-Myers Squibb, Celgene, Merck, and Novartis, Consultant of: AbbVie, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo Nordisk, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, Speakers bureau: AbbVie, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo Nordisk, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi, and UCB, Marte Heiberg: None declared, Jos Twisk: None declared, Simon Krabbe: None declared, Kristina Lend: None declared, Inge Olsen: None declared, Joakim Lindqvist: None declared, Anna-Karin H Ekwall Consultant of: AbbVie, Pfizer, Kathrine L. Grøn Grant/research support from: BMS, Meliha C Kapetanovic: None declared, Francesca Faustini: None declared, Riitta Tuompo: None declared, Tove Lorenzen: None declared, Giovanni Cagnotto: None declared, Eva Baecklund: None declared, Oliver Hendricks Grant/research support from: Pfizer, MSD, Daisy Vedder: None declared, Tuulikki Sokka-Isler: None declared, Tomas Husmark: None declared, Maud-Kristine A Ljosa: None declared, Eli Brodin: None declared, Torkell Ellingsen: None declared, Annika Soderbergh: None declared, Milad Rizk Speakers bureau: AbbVie, Åsa Reckner: None declared, Per Larsson: None declared, Line Uhrenholt Speakers bureau: Abbvie, Eli Lilly and Novartis (not related to the submitted work), Søren Andreas Just: None declared, David Stevens: None declared, Trine Bay Laurberg Consultant of: UCB Pharma (Advisory Board), Gunnstein Bakland Consultant of: Novartis, UCB, Ronald van Vollenhoven Grant/research support from: BMS, GSK, Lilly, UCB, Pfizer, Roche, Consultant of: AbbVie, AstraZeneca, Biogen, Biotest, Celgene, Gilead, Janssen, Pfizer, Servier, UCB, Speakers bureau: AbbVie, Pfizer, UCB

Review of metastatic colorectal cancer treatment pathways and early clinical experience of trifluridine/tipiracil in the UK named patient programme

Background

The standard first- and second- line chemotherapy backbone regimens for metastatic colorectal cancer (mCRC) are 5-fluorouracil (5-FU)/capecitabine-based with addition of irinotecan or oxaliplatin. Until recently, evidence for optimal sequencing post second-line was sparse. Trifluridine/tipiracil (indicated for mCRC and gastric cancer after standard chemotherapies) was made available to UK patients via a named patient programme (NPP) before receiving marketing authorisation in Europe in 2016, allowing characterisation of UK treatment pathways, and evaluation of trifluridine/tipiracil in a UK non-trial population.

Methods

Data collected routinely for the NPP were analysed to describe the patient demographics, clinical characteristics and treatment pathways. Patients eligible for the programme were adults (≥18 years) with histologically or cytologically confirmed mCRC who had previously received chemotherapy treatment(s).

Results

Of the 250 eligible patients enrolled in the NPP, 194 patients received ≥1 dose of trifluridine/tipiracil and 56 patients did not receive trifluridine/tipiracil. The following results are reported first for patients who received trifluridine/tipiracil and second for those who did not receive trifluridine/tipiracil: median (IQR) age was 63.0 (54.0–69.0) and 62.0 (54.8–69.0) years; Eastern Cooperative Oncology Group performance status score was 0 for 28 and 14%, 1 for 65 and 70%, 2 for 7 and 16%. In terms of previous systemic treatments 47 and 43% had 2 prior lines of therapy. FOLFOX-, FOLFIRI- and CAPOX-based therapies were the most common first-line regimens in patients receiving trifluridine/tipiracil (37, 35 and 21%, respectively), and in patients not receiving trifluridine/tipiracil (41, 30 and 20%, respectively). Second-line treatment regimens in patients receiving and not receiving trifluridine/tipiracil were most commonly FOLFIRI-based (48 and 41%, respectively) and FOLFOX-based (19 and 21%, respectively). Patients received a median of 2 cycles of trifluridine/tipiracil with a median treatment duration of 1.8 (95% CI: 1.8–2.4) months. In patients who discontinued treatment due to disease progression, the median progression-free duration was 2.8 (95% CI: 2.4–2.9) months.

Conclusions

The results highlight the number of treatment pathways used to treat mCRC in routine UK clinical practice prior to the marketing authorisation and National Institute for Health and Care Excellence approval of trifluridine/tipiracil and highlight the lack of clinical guidelines for mCRC.

Identification of a basal system for unwinding a bacterial chromosome origin

Genome duplication is essential for cell proliferation, and DNA synthesis is generally initiated by dedicated replication proteins at specific loci termed origins. In bacteria, the master initiator DnaA binds the chromosome origin (oriC) and unwinds the DNA duplex to permit helicase loading. However, despite decades of research it remained unclear how the information encoded within oriC guides DnaA-dependent strand separation. To address this fundamental question, we took a systematic genetic approach in vivo and identified the core set of essential sequence elements within the Bacillus subtilis chromosome origin unwinding region. Using this information, we then show in vitro that the minimal replication origin sequence elements are necessary and sufficient to promote the mechanical functions of DNA duplex unwinding by DnaA. Because the basal DNA unwinding system characterized here appears to be conserved throughout the bacterial domain, this discovery provides a framework for understanding oriC architecture, activity, regulation and diversity.

DNA replication initiation in Bacillus subtilis: structural and functional characterization of the essential DnaA-DnaD interaction

The homotetrameric DnaD protein is essential in low G+C content gram positive bacteria and is involved in replication initiation at oriC and re-start of collapsed replication forks. It interacts with the ubiquitously conserved bacterial master replication initiation protein DnaA at the oriC but structural and functional details of this interaction are lacking, thus contributing to our incomplete understanding of the molecular details that underpin replication initiation in bacteria. DnaD comprises N-terminal (DDBH1) and C-terminal (DDBH2) domains, with contradicting bacterial two-hybrid and yeast two-hybrid studies suggesting that either the former or the latter interact with DnaA, respectively. Using Nuclear Magnetic Resonance (NMR) we showed that both DDBH1 and DDBH2 interact with the N-terminal domain I of DnaA and studied the DDBH2 interaction in structural detail. We revealed two families of conformations for the DDBH2-DnaA domain I complex and showed that the DnaA-interaction patch of DnaD is distinct from the DNA-interaction patch, suggesting that DnaD can bind simultaneously DNA and DnaA. Using sensitive single-molecule FRET techniques we revealed that DnaD remodels DnaA-DNA filaments consistent with stretching and/or untwisting. Furthermore, the DNA binding activity of DnaD is redundant for this filament remodelling. This in turn suggests that DnaA and DnaD are working collaboratively in the oriC to locally melt the DNA duplex during replication initiation.

Analysis of oxygen uptake efficiency parameters in young people with cystic fibrosis

PURPOSE

This study characterised oxygen uptake efficiency (OUE) in children with mild-to-moderate cystic fibrosis (CF). Specifically, it investigated (1) the utility of OUE parameters as potential submaximal surrogates of peak oxygen uptake ([Formula: see text]), and (2) the relationship between OUE and disease severity.

METHODS

Cardiopulmonary exercise test (CPET) data were collated from 72 children [36 CF, 36 age- and sex-matched controls (CON)], with OUE assessed as its highest 90-s average (plateau; OUEP), the gas exchange threshold (OUE_GET) and respiratory compensation point (OUE_RCP). Pearson's correlation coefficients, independent t tests and factorial ANOVAs assessed differences between groups and the use of OUE measures as surrogates for [Formula: see text].

RESULTS

A significant (p < 0.05) reduction in allometrically scaled [Formula: see text] and all OUE parameters was found in CF. Significant (p < 0.05) correlations between measurements of OUE and allometrically scaled [Formula: see text], were observed in CF (r = 0.49-0.52) and CON (r = 0.46-0.52). Furthermore, measures of OUE were significantly (p < 0.05) correlated with pulmonary function (FEV_1%predicted) in CF (r = 0.38-0.46), but not CON (r = -0.20-0.14). OUEP was able to differentiate between different aerobic fitness tertiles in CON but not CF.

CONCLUSIONS

OUE parameters were reduced in CF, but were not a suitable surrogate for [Formula: see text]. Clinical teams should, where possible, continue to utilise maximal CPET parameters to measure aerobic fitness in children and adolescents with CF. Future research should assess the prognostic utility of OUEP as it does appear sensitive to disease status and severity.

Static hyperinflation is associated with ventilatory limitation and exercise tolerance in adult cystic fibrosis

INTRODUCTION

Lung hyperinflation is a potential mechanism limiting exercise tolerance. However, available data on the impact of static hyperinflation on exercise performance in adult cystic fibrosis are lacking. Furthermore, the relative contribution of both static and dynamic hyperinflation to exercise performance is unknown.

OBJECTIVES

The aim of this study was to determine the impact of static hyperinflation on exercise tolerance and lung dynamics in adult cystic fibrosis.

METHODS

Clinical data of 107 adult patients with cystic fibrosis, including pulmonary function, lung volumes and cardiopulmonary exercise from the Toronto Cystic Fibrosis database, were collected and analyzed. Patients were classified as having static hyperinflation with a residual volume to total lung capacity (RV/TLC) ratio of 30% or greater.

RESULTS

Patients with static hyperinflation demonstrated a significant reduction in exercise performance [peak oxygen uptake (% predicted) 70 ± 17 vs 80 ± 17; P = .006] and were more likely to experience ventilatory limitation when exercising (Fisher's exact test P < .001). Correlation analysis showed significant relationships between measures of static hyperinflation [RV/TLC ratio (%)] and exercise performance [peak oxygen uptake (% predicted); r = -.38, P < .001] and dynamic hyperinflation (r = -.35, P < .001). Multiple linear regression showed that the contribution of static hyperinflation to exercise performance [peak oxygen uptake (% predicted)] was greater than that of airway obstruction (forced expiratory volume in 1 second).

CONCLUSION

Clinicians working with this patient group in a pulmonary rehabilitation or health care setting may wish to consider using measures of static hyperinflation as end points to determine program or treatment efficacy.

The oxygen uptake efficiency slope is not a valid surrogate of aerobic fitness in cystic fibrosis

BACKGROUND

Maximal cardiopulmonary exercise testing is recommended on an annual basis for children with cystic fibrosis (CF), due to clinically useful prognostic information provided by maximal oxygen uptake (V̇O_2max ). However, not all patients are able, or willing, to reach V̇O_2max , and therefore submaximal alternatives are required. This study explored the validity of the oxygen uptake efficiency slope (OUES) as a submaximal measure of V̇O_2max in children and adolescents with CF.

METHODS

Data were collated from 72 cardiopulmonary exercise tests (36 CF, 36 controls), with OUES determined relative to maximal and submaximal parameters of exercise intensity, time, and individual metabolic thresholds. Pearson's correlation coefficients, independent t-tests, and factorial ANOVAs were used to determine validity.

RESULTS

Significant (P < 0.05) correlations with V̇O_2max were observed for most expressions of OUES, but were consistently weaker in CF (r = 0.30-0.47) when compared to CON (r = 0.58-0.89). Mean differences for all OUES parameters between groups were not significant (P > 0.05). When split by V̇O_2max tertiles, minimal significant differences were found between, and within, groups for OUES, indicating poor discrimination of V̇O_2max .

CONCLUSIONS

The OUES is not a valid (sub) maximal measure of V̇O_2max in children and adolescents with mild-to-moderate CF. Clinicians should continue to use maximal markers (ie, V̇O_2max ) of exercise capacity.

Mounting evidence favoring single-family room neonatal intensive care

Controversy regarding the optimal design for neonatal intensive care has existed for more than 20 years. Recent evidence confirms that in comparison with the traditional open-bay design, the single-room facility provides for improved control of excessive noise and light, improved staff and parental satisfaction with care and equal, or possibly reduced, cost of care. Single-room care was not associated with any increase in adverse outcomes. To optimize long term developmental outcomes, single-room care must be augmented with appropriate developmental therapy and programs to actively support parental involvement.

A GIS-Based Irregular Cellular Automata Model of Land-Use Change

This study proposes an alternative cellular automata (CA) model, which relaxes the traditional CA regular square grid and synchronous growth, and is designed for representations of land-use change in rural-urban fringe settings. The model uses high-resolution spatial data in the form of irregularly sized and shaped land parcels, and incorporates synchronous and asynchronous development in order to model more realistically land-use change at the land parcel scale. The model allows urban planners and other stakeholders to evaluate how different subdivision designs will influence development under varying population growth rates and buyer preferences. A model prototype has been developed in a common desktop GIS and applied to a rapidly developing area of a midsized Canadian city.