Parous women perform less moderate to vigorous physical activity than their nulliparous peers: a population-based study in Denmark

OBJECTIVES

The World Health Organization (WHO) highlights parous women as a key population for monitoring trends of physical activity (PA). We aimed to estimate the proportion of Danish women non-adhering to WHO PA guidelines in parous women compared with nulliparous women and to describe leisure-time PA intensity in each of these groups.

STUDY DESIGN

Cross-sectional study.

METHODS

This population-based study builds on a sample of 27,668 women aged 16-40 years from the Danish National Health Survey 2021. These data were linked with childbirth data from the Danish National Birth Registry. The primary outcome was self-reported weekly hours of moderate to vigorous leisure-time PA (MVPA) dichotomized into: (i) adhering to WHO guidelines for MVPA or (ii) not adhering to WHO guidelines for MVPA. Binomial regression analysis was used to calculate prevalence proportions (PP) and prevalence proportion ratios (PPR).

RESULTS

Of the 27,668 women, a total of 20,022 were included; 9338 (46.6%) parous women and 10,684 (53.4%) nulliparous women. The PP of women non-adhering to WHO PA guidelines was 63.8% (95% CI 62.9-64.8) for parous and 51.3% (95% CI 50.4-52.3) for nulliparous women, corresponding to a PPR of 1.24 (95% CI 1.21; 1.27).

CONCLUSIONS

The proportion of parous women who did not adhere to WHO PA guidelines for MVPA was 24% higher than that of nulliparous women. This highlights parous women as a subgroup of the adult population at increased risk of non-adherence to WHO PA guidelines. These findings call for future research to inform new strategies aiming to promote PA in parous women.

Validation of the virtual measurement of the Essential Frailty Toolset

Funding Acknowledgements

Type of funding sources: None.

Background

The Essential Frailty Toolset (EFT) is a valid measurement of frailty in people with heart valve disease. COVID-19 has prompted the transition to virtual health consultations and necessitates the validation of the virtual assessment of frailty.

Methods

We conducted a prospective observational cohort study to compare the measurement of EFT in person and virtual format within a maximum 2-week window of repeated measurement. The weighted Kappa tests was used to measure the agreement of EFT scores between assessments; we explored the effect of the sequence of measurement using the Cochran-Mantel-Haenszel statistic to test the general association between the timing of measurement and differences of EFT score.

Results

We recruited a sample of 49 patients, with a mean age of 81 ± 7 years, including 29 men (59.2%); the primary valvular heart diseases were aortic stenosis (n=40, 81.6%), mitral regurgitation (n=2, 4.1%) and tricuspid regurgitation (n=7, 14.3%). The virtual measurement of frailty was conducted using a standardised protocol. The platform for virtual connection selected by patients was FaceTime (n=20, 40.8%) and Zoom (n=29, 59.2%); the median (IQR) number of days between the in-person and the virtual assessment was 5 (3,10). The weighted Kappa estimate was 0.69 (95% CI 0.55, 0.82), illustrating a strong agreement between the separate scores obtained. The test for the general association was non-significant (p=0.82), indicating a lack of evidence for detecting an association between EFT scores and chronological order of assessment.

Conclusion

The EFT can be reliably measured virtual in older patients with valvular heart disease to inform clinical care.

Urolithiasis in pregnancy: Advances in imaging modalities and evaluation of current trends in endourological approaches

OBJECTIVE

Given the challenges involved in diagnosis and treatment of pregnant women with urolithiasis, we aim to review the imaging modalities and current endourological management of these patients.

MATERIALS AND METHODS

We performed a review of the available literature on urolithiasis in pregnancy. This included evaluation, diagnostic imaging, and therapeutic options. The databases we searched from included Google Scholar and PubMed. A total of 346 abstracts were screened. After our inclusion/exclusion criteria were met, we were left with 42 sources: 18 retrospective studies, 10 reviews/meta-analyses, 8 sets of guidelines, 5 randomized control trials, and 1 prospective cohort.

RESULTS

We begin our review with the literature available on the safety and efficacy of imaging modalities in the surgical planning for urolithiasis in pregnant patients. This includes renal ultrasound, abdominal x-ray, computed tomography scan, and magnetic resonance imaging. While computed tomography may result in an added radiation exposure, with possible safety concerns, magnetic resonance imaging seems to be safer, however a less sensitive test. We next describe safety, efficacy, and outcomes of various surgical interventions for urolithiasis in pregnant patients. This encompasses ureteral stenting, percutaneous nephrostomy, ureteroscopy, extracorporeal shock wave lithotripsy, and percutaneous nephrolithotomy. Ureteroscopy is a safer approach, but percutaneous nephrolithotomy offers higher stone-free rates. Using an evidence-based approach, we propose an algorithm for management of the pregnant women with renal colic.

CONCLUSION

Management of the pregnant women with suspected urolithiasis is a unique challenge for healthcare providers. A multi-disciplinary approach should be taken to optimize outcomes through an evidence-based approach.

Evaluation of environmental conditions as a decontamination approach for SARS‐CoV ‐2 when applied to common library, archive, and museum related materials

Aims

The purpose of this study was to evaluate the effects of ambient or altered environmental conditions on the inactivation of SARS‐CoV‐2 applied to materials common in libraries, archives and museums.

Methods and Results

Porous and non‐porous materials (e.g. paper, plastic protective book cover) were inoculated with approximately 1 × 10⁵ TCID₅₀ SARS CoV‐2 (USA‐WA1/2020), dried, placed within test chamber in either a stacked or unstacked configuration, and exposed to environmental conditions ranging from 4 to 29°C at 40 ± 10% relative humidity. The amount of infectious SARS‐CoV‐2 was then assessed at various timepoints from 0 to 10 days. Ambient conditions resulted in varying inactivation rates per material type. Virus inactivation rate decreased when materials were stacked or at colder temperatures. Virus inactivation rate increased when materials were unstacked or at warmer temperatures.

Conclusions

SARS‐CoV‐2 at ambient conditions resulted in the inactivation of virus below limit of quantitation (LOQ) for all materials by Day 8. Warmer temperatures, for a subset of materials, increased SARS‐CoV‐2 inactivation, and all were <LOQ by Day 3.

Significance and Impact of the Study

These results provide information for the library, archives and museum community regarding the inactivation of SARS‐CoV‐2, showing that inactivation is possible using prescribed environmental conditions and is a potential method of decontamination for items not compatible with common liquid disinfectants.

Introduction to automatic forage stations and measurement of forage intake rate in an active open barn for horses

Interest in the use of open barns on Swedish horse farms is increasing as an alternative to keeping horses in box stalls and as a 2007 law requires phasing out of tie stalls. To provide adequate forage to satisfy welfare requirements for nutrition, gut health and behavioural needs, the use of automated feeding is also increasing. Studies on forage intake rate report wide variation but provide little information on how to introduce horses to an automatic forage station and on how forage intake rate varies in individual horses fed using an automatic forage station. This study documented the process of training 22 horses to use a transponder-controlled automatic forage feeding station and measured forage intake rates. Observations on the learning period of horses for transponder-controlled automatic forage stations showed that after 4 days, 48% of the horses had reached the goal of 90% intake. After 8 days, learning was completed in 71% of horses and at 16 days in 95% of horses. Measurements of forage intake rate revealed significant differences between individual horses. Overall mean intake rate ± SD, based on 314 observations, was 22.4 ± 6.7 min/kg forage DM. Evaluation of the number of intake measurements required to set a representative average ration in the automatic station for an individual horse showed that the variation levelled off at four samples. In conclusion, horses quickly learned how to use an automatic forage station, with two-thirds of horses achieving this within 7 days. To ensure the correct ration in a timed transponder-controlled automatic forage station, each horse's forage intake rate must be measured at least four times to obtain a representative average.

0539 Are Short Sleepers Uncoupled Sleepers?

Introduction

While short sleep durations (&lt;7h/night) are associated with increased diabetes risk, there is limited evidence that increasing the habitual sleep duration of short sleepers is either feasible, or will reliably improve metabolic health outcomes. Furthermore, in the absence of insomnia disorder, it remains unclear whether habitual short sleep mainly reflects a genetic predisposition or a lifestyle choice. In a randomized controlled study we delivered a sleep extension protocol based on CBTi principles to overweight ‘short sleepers’ at increased risk of Type II diabetes.

Methods

18 male short sleepers (Mage=41.4; MBMI=29.57; baseline mean TST=5.8 h/ night) with no complaints of insomnia were randomized to the sleep extension intervention or control condition (printed sleep hygiene advice). The 6-week intervention commenced with personalized sleep re-scheduling negotiated in a 60-minute 1-to-1 session, and supported by elements of sleep hygiene, stimulus control, relaxation and cognitive strategies. Outcomes included sleep duration (actigraphy), fasting insulin, Mean Amplitude of Glycemic Excursions (MAGE) from continuous glucose monitoring, and blood pressure. Data were analyzed in linear fixed effects models including time, group and baselines values.

Results

Adherence to the 6-week protocol was high. Relative to controls (n=8), intervention participants (n = 10) showed a significant increase in TST (95%CI 46.91min, 101.64min, p&lt;0.001; MDiff = 79.4min, p&lt;0.001) and significant reductions in fasting insulin (95%CI -32.08 pmol/L, -.97.0 pmol/L; p=0.04; MDiff = -10.2 pmol/L, p=0.06); MAGE (95%CI -0.77, -0.08, p=0.02; MDiff -0.35, p=0.05) and diastolic (95%CI -22, -5, p=0.004; MDiff=-12, p=0.004); and systolic blood pressure (95%CI -20, -2, p=0.03; MDiff=-10, p=0.006).

Conclusion

CBTi-based sleep extension protocols offer feasible and effective lifestyle interventions in the management of metabolic health in overweight short sleepers who fit published categorization of non-complaining poor sleepers with an undeveloped insomnia identity whose subjective sleep experience and objective sleep characteristics are ‘uncoupled’.

Support

School of Sport, Exercise and Health Sciences, Loughborough University

The effect on consent rates for deceased organ donation in Wales after the introduction of an opt-out system

Organ transplantation saves and transforms lives. Failure to secure consent for organ retrieval is widely regarded as the single most important obstacle to transplantation. A soft opt‐out system of consent for deceased organ donation was introduced into Wales in December 2015, whilst England maintained the existing opt‐in system. Cumulative data on consent rates in Wales were compared with those in England, using a two‐sided sequential procedure that was powered to detect an absolute difference in consent rates between England and Wales of 10%. Supplementary risk‐adjusted logistic regression analysis examined whether any difference in consent rates between the two nations could be attributed to variations in factors known to influence UK consent rates. Between 1 January 2016 and 31 December 2018, 8192 families of eligible donors in England and 474 in Wales were approached regarding organ donation, with overall consent rates of 65% and 68%, respectively. There was a steady upward trend in the proportion of families consenting to donation after brain death in Wales as compared with England and after 33 months, this reached statistical significance. No evidence of any change in the donation after circulatory death consent rate was observed. Risk‐adjusted logistic regression analysis revealed that by the end of the study period the probability of consent to organ donation in Wales was higher than in England (OR [95%CI] 2.1 [1.26–3.41]). The introduction of a soft opt‐out system of consent in Wales significantly increased organ donation consent though the impact was not immediate.

CLOSING THE LEAK: KEEPING LATE-DECIDING STUDENTS IN THE PIPELINE TO BIOMEDICAL RESEARCH CAREERS

With the increased competitiveness of undergraduate, graduate, and professional programs, the continuously accelerating rate of technological innovation and development of new global means of communication, and the evolving face of the local, national, and global job markets, choosing a long-term career has become a challenge for many. More and more students opt to take a gap period in their education, pre- or post-college, for soul searching to determine their future path or for improving their skills and competitiveness for successfully applying to academic institutions. Even though such gap years can lead to more mature and determined students, they often derail the educational path of the individual by leading to loss of interest or to new commitments which hinder going back to school. Engaging students in academic and skills training programs that keep them within the academic environment and provide them with exposure to the benefits of higher education has been shown to increase their persistence, leading to an increased rate of attaining higher-level degrees. A number of United States (US) federal funding agencies, including the National Institutes of Health (NIH), have programs such as the Bridges to Baccalaureate Program (support for easing a student's transition from a 2-year junior or community college to a 4-year baccalaureate-granting institution) and Post-baccalaureate Research Education Program (PREP, support for recent college graduates from underrepresented groups or disadvantaged backgrounds to strengthen their research skills and academic competitiveness for pursuing a doctorate degree in the Biomedical Sciences). At Xavier University of Louisiana (Xavier), we have developed a post-baccalaureate technician program under Project Pathways (the NIH National Institute of General Medical Sciences (NIGMS) Division of Training, Workforce Development, and Diversity (TWD)-funded Building Infrastructure Leading to Diversity (BUILD) Program), that provides research experience and training in soft skills to recent Xavier graduates to increase their preparation and competitiveness for graduate programs. The BUILD Technicians also receive both mentee and mentor training and serve as near-peer mentors to undergraduate students in their labs, increasing their scientific identity and preparing them for their future role as graduate teaching assistants. Here, we report the lessons learned from this program and how its differences from other post-baccalaureate programs, including those under the NIH PREP umbrella, have led to improved outcomes for Xavier graduates gaining admission to graduate programs in the Biomedical Sciences.

Venous thromboembolism in IBD: Increased risk for women in CD?

Although coagulation disturbances have been described in inflammatory bowel disease (IBD), it remains unclear how common venous thromboembolism (VTE) is in IBD, and what factors influence VTE frequency. We evaluated VTE in Crohn's disease (CD) and ulcerative colitis (UC) at LSUHSC-S, a southern US medical center with an approximately equal White: African-American (AA) (1.12:1) patient base. This retrospective study evaluated VTE as a co-morbidity in IBD as a function of age, gender and race based on ICD-10 coding (2011-2015.) Results. Of 276 IBD diagnostic records, 213 were for CD (77.17%) and 63 for UC (22.8%). 52% of the CD patients were white, 42% were AA, and 6% were other. 42% of CD patients were male, with 58% were female. 6.1% (13 patients) of the 213 CD patients had a VTE. Of these 13 CD patients, 9 had active disease and 4 were in remission. 9 of 13 were female and 4 were male, with 5 white patients and 4 A A patients. 63 patients were diagnosed with UC, 3.38-fold fewer cases than CD. 25 UC patients were white, 25 were AA and 13 were in other ethnic groups. Of 63 UC cases, 2 UC patients had a VTE, both with active disease. At our institution, VTE appears to be 3x more frequently associated with CD than UC and was more common in white female patients. The recognition of VTE risk in CD, particularly in women, may be an important observation which may guide therapy and limit potentially life-threatening consequences.

Dietetics students' experiences of dietetics workforce preparation and preparedness: a systematic review and qualitative synthesis

BACKGROUND

Dietetics students are a widely researched group. As emerging dietitians, they can provide valuable insights to inform how dietetics education programmes may be enhanced to meet contemporary healthcare needs. This review aimed to systematically synthesise dietetics students' experiences of dietetics workforce preparation.

METHODS

MEDLINE, CINAHL, Embase, PsycINFO, ERIC, Informit and ProQuest Dissertations and Theses Global were searched to identify research published until June 2017. Studies investigating dietetics students' experiences of dietetics workforce preparation, and employing qualitative data collection and analysis methods were included. Data analysis was guided by thematic synthesis, where themes were constructed through an iterative and inductive process. Study quality was appraised using the RATS Qualitative Research Review Guidelines.

RESULTS

From the 3301 records identified, five studies met the inclusion criteria and the views of 120 dietetics students from two countries over a 9-year period were synthesised. The overarching theme of 'navigating through the ups and downs' was underpinned by four main themes: enduring hurdles; reconciling expectations; transforming self; and making and breaking connections. Quality appraisal results rated selection bias as being inadequate/inappropriate across all studies.

CONCLUSIONS

Dietetics students undertake a transformational journey through dietetics education. They are inspired by seeing what is possible through meaningful encounters with practitioners in diverse settings. However, they are challenged by competitive environments and perceived ideals that are embedded in the profession. Strategies that focus on exposing dietetics students to inspirational practitioners, increasing and celebrating diversity in academic/placement settings, and incentivising collaboration across dietetics education, could act as catalysts to enhance the experience of future dietetics students and the nutrition-related health of those they will serve.

BUILDING INFRASTRUCTURE LEADING TO DIVERSITY PROGRAM AT XAVIER UNIVERSITY OF LOUISIANA, PROJECT PATHWAYS

Xavier University of Louisiana (XULA) is the only historically Black and Catholic institution of higher education in the United States. XULA's mission focuses on "the promotion of a more just and humane society" by educating students in a diverse learning environment. Even though Xavier's reputation in the sciences attracts many of the best and brightest students in the nation, the University also continues to provide an excellent educational opportunity to many students who, due to socioeconomic disparities, lack the appropriate preparation for college. The ultimate goal of Project Pathways, the National Institutes of Health (NIH)-funded BUILD (Building Infrastructure Leading to Diversity) Program at Xavier, is to increase the number of students who enter graduate programs in biomedical disciplines, successfully earn terminal degrees, and enter the biomedical research workforce. Xavier's plan to meet this challenge is based on a holistic approach, providing an integrated and coordinated student support and research skills training network. This coordinated effort cuts across academic departments in biomedical disciplines, academic support offices that include the Student Academic Success Office (SASO), the Office of Career Services (OCS), and the Center for Undergraduate Research and Graduate Opportunity (CURGO), as well as the Center for the Advancement of Teaching and Faculty Development (CAT+FD) for faculty support and mentor training. This work seeks to counter the regular practice at higher education institutions that have yet to address the importance of integrated programming across academic programs, student support programs, and research programs. This lack of coordinated and integrated programming often leads to duplication of efforts and ineffective use of resources. Xavier's BUILD program intentionally provides mechanisms and safeguards to ensure that coordination and integration occur at all levels. The overall hypothesis of Project Pathways is that when in a systematic way underrepresented minorities are provided with: early awareness and deepening exposure to biomedical careers;supportive relationships for students as they move through the pathway;suitable infrastructure; andmeaningful student engagement in biomedical research experiences and adequate research resources, a higher number will succeed in first entering, and later successfully completing graduate programs, leading to increased diversity in the biomedical research workforce. Preliminary assessment results are very encouraging; these results show higher course pass rates and better student preparation overall. The Project Pathways' initiatives can be replicated at other institutions with similar goals.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Whole-exome sequencing of the BDR cohort: evidence to support the role of the PILRA gene in Alzheimer's disease

AIM

Late-onset Alzheimer's disease (LOAD) accounts for 95% of all Alzheimer's cases and is genetically complex in nature. Overlapping clinical and neuropathological features between AD, FTD and Parkinson's disease highlight the potential role of genetic pleiotropy across diseases. Recent genome-wide association studies (GWASs) have uncovered 20 new loci for AD risk; however, these exhibit small effect sizes. Using NGS, here we perform association analyses using exome-wide and candidate-gene-driven approaches.

METHODS

Whole-exome sequencing was performed on 132 AD cases and 53 control samples. Exome-wide single-variant association and gene burden tests were performed for 76 640 nonsingleton variants. Samples were also screened for known causative mutations in familial genes in AD and other dementias. Single-variant association and burden analysis was also carried out on variants in known AD and other neurological dementia genes.

RESULTS

Tentative single-variant and burden associations were seen in several genes with kinase and protease activity. Exome-wide burden analysis also revealed significant burden of variants in PILRA (P = 3.4 × 10^-5 ), which has previously been linked to AD via GWAS, hit ZCWPW1. Screening for causative mutations in familial AD and other dementia genes revealed no pathogenic variants. Variants identified in ABCA7, SLC24A4, CD33 and LRRK2 were nominally associated with disease (P < 0.05) but did not withstand correction for multiple testing. APOE (P = 0.02) and CLU (P = 0.04) variants showed significant burden on AD.

CONCLUSIONS

In addition, polygenic risk scores (PRS) were able to distinguish between cases and controls with 83.8% accuracy using 3268 variants, sex, age at death and APOE ε4 and ε2 status as predictors.

Cannabis use and adherence to antipsychotic medication: a systematic review and meta-analysis

BACKGROUND

Substance use may increase the risk of non-adherence to antipsychotics, resulting in negative outcomes in patients with psychosis.

METHOD

We aimed to quantitatively summarize evidence regarding the effect of cannabis use, the most commonly used illicit drug amongst those with psychosis, on adherence to antipsychotic medication. Studies were identified through a systematic database search. Adopting random-effects models, pooled odds ratios (OR) for risk of non-adherence to antipsychotic medications were calculated comparing: cannabis-users at baseline v. non-users at baseline; non users v. continued cannabis users at follow-up; non-users v. former users at follow-up; former users v. current users.

RESULTS

Fifteen observational studies (n = 3678) were included. Increased risk of non-adherence was observed for cannabis users compared to non-users (OR 2.46, n = 3055). At follow-up, increased risk of non-adherence was observed for current users compared to non-users (OR 5.79, n = 175) and former users (OR 5.5, n = 192), while there was no difference between former users and non-users (OR 1.12, n = 187).

CONCLUSIONS

Cannabis use increases the risk of non-adherence and quitting cannabis use may help adherence to antipsychotics. Thus, cannabis use may represent a potential target for intervention to improve medication adherence in those with psychosis.

Application of sensitive, high-resolution imaging at a commercial lab-based X-ray micro-CT system using propagation-based phase retrieval

Several dedicated commercial lab-based micro-computed tomography (μCT) systems exist, which provide high-resolution images of samples, with the capability to also deliver in-line phase contrast. X-ray phase contrast is particularly beneficial when visualizing very small features and weakly absorbing samples. The raw measured projections will include both phase and absorption effects. Extending our previous work that addressed the optimization of experimental conditions at the commercial ZEISS Xradia 500 Versa system, single-distance phase-contrast imaging is demonstrated on complex biological and material samples. From data captured at this system, we demonstrate extraction of the phase signal or the correction of the mixed image for the phase shift, and show how this procedure increases the contrast and removes artefacts. These high-quality images, measured without the use of a synchrotron X-ray source, demonstrate that highly sensitive, micrometre-resolution imaging of 3D volumes is widely accessible using commercially advanced laboratory devices.

Forty years of temporal analysis of products

A detailed understanding of reaction mechanisms and kinetics is required in order to develop and optimize catalysts and catalytic processes. Temporal analysis of products (TAP) is an instrument capable of providing such understanding.

A preliminary spatial assessment of risk: Marine birds and chronic oil pollution on Canada's Pacific coast

Chronic oil pollution poses substantial risks to marine birds and other marine wildlife worldwide. On Canada's Pacific coast, the negative ecological consequences to marine birds and marine ecosystems in general remain poorly understood. Using information relating to oil spill probability of occurrence, areas of overall importance to marine birds, and the at-sea distribution and density of 12 marine bird species and seven bird groups, including multiple Species at Risk, we undertook a spatial assessment of risk. Our results identify two main areas important to marine birds potentially at higher risk of exposure to oil. For individual bird species or species groups, those predicted to have elevated bird densities near the mainland and the northeast coast of Vancouver Island were identified as being at higher potential risk of exposure. Our results, however, should be considered preliminary. As with other anthropogenic stressors, in order to better understand and subsequently mitigate the consequences of chronic oil pollution on marine birds, improved information relating to marine birds and the occurrence of oil spills on Canada's Pacific coast is needed.

Do stronger school smoking policies make a difference? Analysis of the health behaviour in school-aged children survey

Background: Associations of the strength of school smoking policies with cigarette, e-cigarette and cannabis use in Wales were examined. Methods: Nationally representative cross-sectional survey of pupils aged 11–16 years (N=7376) in Wales. Senior management team members from 67 schools completed questionnaires about school smoking policies, substance use education and tobacco cessation initiatives. Multi-level, logistic regression analyses investigated self-reported cigarette, e-cigarette and cannabis use, for all students and those aged 15–16 years. Results: Prevalence of current smoking, e-cigarette use and cannabis use in the past month were 5.3%, 11.5% and 2.9%, respectively. Of schools that provided details about smoking policies (66/67), 39.4% were strong (written policy applied to everyone in all locations), 43.9% were moderate (written policy not applied to everyone in all locations) and 16.7% had no written policy. There was no evidence of an association of school smoking policies with pupils’ tobacco or e-cigarette use. However, students from schools with a moderate policy [OR = 0.47; 95% (confidence interval) CI: 0.26–0.84] were less likely to have used cannabis in the past month compared to schools with no written policy. This trend was stronger for students aged 15–16 years (moderate policy: OR = 0.42; 95% CI: 0.22–0.80; strong policy: OR = 0.45; 95% CI: 0.23–0.87). Conclusions: School smoking policies may exert less influence on young people’s smoking behaviours than they did during times of higher adolescent smoking prevalence. Longitudinal studies are needed to examine the potential influence of school smoking policies on cannabis use and mechanisms explaining this association.

EM modelling of arbitrary shaped anisotropic dielectric objects using an efficient 3D leapfrog scheme on unstructured meshes

The standard Yee algorithm is widely used in computational electromagnetics because of its simplicity and divergence free nature. A generalization of the classical Yee scheme to 3D unstructured meshes is adopted, based on the use of a Delaunay primal mesh and its high quality Voronoi dual. This allows the problem of accuracy losses, which are normally associated with the use of the standard Yee scheme and a staircased representation of curved material interfaces, to be circumvented. The 3D dual mesh leapfrog-scheme which is presented has the ability to model both electric and magnetic anisotropic lossy materials. This approach enables the modelling of problems, of current practical interest, involving structured composites and metamaterials.

Percutaneous endoscopic gastrostomy versus nasogastric feeding in older individuals with non-stroke dysphagia: a systematic review

OBJECTIVE

The objective of this systematic review was to evaluate existing studies on the effectiveness of percutaneous endoscopic gastrostomy (PEG) feeding compared to nasogastric (NG) feeding for patients with non-stroke related dysphagia.

METHODS

We searched Ovid MEDLINE, EMBASE, the Cochrane Library, Web of Science and PubMed databases through to December 2013 using the terms "percutaneous endoscopic gastrostomy", "gastrostomy", "PEG", "nasogastric", "nasogastric tube", "nasogastric feeding" and "intubation". We included randomized controlled trials (RCTs) and non-RCTs which compared PEG with NG feeding in individuals with non-stroke dysphagia.

RESULTS

9 studies involving 847 participants were included in the final analysis, including two randomized trials. Pooled analysis indicated no significant difference in the risk of pneumonia [relative risk (RR) = 1.18, 95% confidence interval (CI) = 0.87-1.60] and overall complications [relative risk (RR) = 0.80, 95% confidence interval (CI) = 0.63-1.02] between PEG and NG feeding. A meta-analysis was not possible for mortality and nutritional outcomes, but three studies suggested improved mortality outcomes with PEG feeding while two out of three studies reported PEG feeding to be better from a nutritional perspective.

CONCLUSIONS

Firm conclusions could not be derived on whether PEG feeding is beneficial over NG feeding in older persons with non-stroke dysphagia, as previously published literature were unclear or had a high risk of bias. A well-designed and adequately powered RCT, which includes carer strain and quality of life as outcome measures is therefore urgently needed.

Review: The genetics of Alzheimer's disease; putting flesh on the bones

For two decades the search for genes involved in Alzheimer's disease brought little reward; it was not until the advent of genome-wide association studies (GWAS) that genetic associations started to be revealed. Since 2009 increasingly large GWAS have revealed 20 loci, which in itself is a substantial increase in our understanding, but perhaps the more important feature is that these studies have highlighted novel pathways that are potentially involved in the disease process. This commentary assembles our latest knowledge while acknowledging that the casual functional variants, and undoubtedly, other genes are still yet to be discovered. This is the challenge that remains and the promise of next-generation sequencing is anticipated as there are a number of large initiatives which themselves should start to yield information before long.

The origin of the local 1/4-keV X-ray flux in both charge exchange and a hot bubble

The solar neighbourhood is the closest and most easily studied sample of the Galactic interstellar medium, an understanding of which is essential for models of star formation and galaxy evolution. Observations of an unexpectedly intense diffuse flux of easily absorbed 1/4-kiloelectronvolt X-rays, coupled with the discovery that interstellar space within about a hundred parsecs of the Sun is almost completely devoid of cool absorbing gas, led to a picture of a 'local cavity' filled with X-ray-emitting hot gas, dubbed the local hot bubble. This model was recently challenged by suggestions that the emission could instead be readily produced within the Solar System by heavy solar-wind ions exchanging electrons with neutral H and He in interplanetary space, potentially removing the major piece of evidence for the local existence of million-degree gas within the Galactic disk. Here we report observations showing that the total solar-wind charge-exchange contribution is approximately 40 per cent of the 1/4-keV flux in the Galactic plane. The fact that the measured flux is not dominated by charge exchange supports the notion of a million-degree hot bubble extending about a hundred parsecs from the Sun.

The effect of the environment on symptom dimensions in the first episode of psychosis: a multilevel study

BACKGROUND

The extent to which different symptom dimensions vary according to epidemiological factors associated with categorical definitions of first-episode psychosis (FEP) is unknown. We hypothesized that positive psychotic symptoms, including paranoid delusions and depressive symptoms, would be more prominent in more urban environments.

METHOD

We collected clinical and epidemiological data on 469 people with FEP (ICD-10 F10-F33) in two centres of the Aetiology and Ethnicity in Schizophrenia and Other Psychoses (AESOP) study: Southeast London and Nottinghamshire. We used multilevel regression models to examine neighbourhood-level and between-centre differences in five symptom dimensions (reality distortion, negative symptoms, manic symptoms, depressive symptoms and disorganization) underpinning Schedules for Clinical Assessment in Neuropsychiatry (SCAN) Item Group Checklist (IGC) symptoms. Delusions of persecution and reference, along with other individual IGC symptoms, were inspected for area-level variation.

RESULTS

Reality distortion [estimated effect size (EES) 0.15, 95% confidence interval (CI) 0.06-0.24] and depressive symptoms (EES 0.21, 95% CI 0.07-0.34) were elevated in people with FEP living in more urban Southeast London but disorganized symptomatology was lower (EES -0.06, 95% CI -0.10 to -0.02), after controlling for confounders. Delusions of persecution were not associated with increased neighbourhood population density [adjusted odds ratio (aOR) 1.01, 95% CI 0.83-1.23], although an effect was observed for delusions of reference (aOR 1.41, 95% CI 1.12-1.77). Hallucinatory symptoms showed consistent elevation in more densely populated neighbourhoods (aOR 1.32, 95% CI 1.09-1.61).

CONCLUSIONS

In people experiencing FEP, elevated levels of reality distortion and depressive symptoms were observed in more urban, densely populated neighbourhoods. No clear association was observed for paranoid delusions; hallucinations were consistently associated with increased population density. These results suggest that urban environments may affect the syndromal presentation of psychotic disorders.