DE-PASS best evidence statement (BESt): determinants of adolescents' device-based physical activity and sedentary behaviour in settings: a systematic review and meta-analysis.

BACKGROUND: Although physical activity (PA) is associated with significant health benefits, only a small percentage of adolescents meet recommended PA levels. This systematic review with meta-analysis explored the modifiable determinants of adolescents' device-based PA and/or sedentary behaviour (SB), evaluated in previous interventions and examined the associations between PA/SB and these determinants in settings. METHODS: A search was conducted on five electronic databases, including papers published from January 2010 to July 2023. Randomized Controlled Trials (RCTs) or Controlled Trials (CTs) measuring adolescents' device-based PA/SB and their modifiable determinants at least at two time points: pre- and post-intervention were considered eligible. PA/SB and determinants were the main outcomes. Modifiable determinants were classified after data extraction adopting the social-ecological perspective. Robust Bayesian meta-analyses (RoBMA) were performed per each study setting. Outcomes identified in only one study were presented narratively. The risk of bias for each study and the certainty of the evidence for each meta-analysis were evaluated. The publication bias was also checked. PROSPERO ID: CRD42021282874. RESULTS: Fourteen RCTs (eight in school, three in school and family, and one in the family setting) and one CT (in the school setting) were included. Fifty-four modifiable determinants were identified and were combined into 33 broader determinants (21 individual-psychological, four individual-behavioural, seven interpersonal, and one institutional). RoBMAs revealed none or negligible pooled intervention effects on PA/SB or determinants in all settings. The certainty of the evidence of the impact of interventions on outcomes ranged from very low to low. Narratively, intervention effects in favour of the experimental group were detected in school setting for the determinants: knowledge of the environment for practicing PA, d = 1.84, 95%CI (1.48, 2.20), behaviour change techniques, d = 0.90, 95%CI (0.09, 1.70), choice provided, d = 0.70, 95%CI (0.36, 1.03), but no corresponding effects on PA or SB were found. CONCLUSIONS: Weak to minimal evidence regarding the associations between the identified modifiable determinants and adolescents' device-based PA/SB in settings were found, probably due to intervention ineffectiveness. Well-designed and well-implemented multicomponent interventions should further explore the variety of modifiable determinants of adolescents' PA/SB, including policy and environmental variables.

Exploring correlates of physical activity behaviour in UK children and their inter-relationships using a multidisciplinary approach: A concept mapping study.

It is still unknown which correlates of physical activity behaviour (PAB) may be effective and how they may influence PAB in UK children. The objective of the current study was to generate a conceptual analysis of the correlates of PAB in UK children (5-12 years) using the input of researchers in the field of physical activity (PA experts; PAE) and other fields (non-PA experts; non-PAE). A concept mapping approach was used to identify potential (new) correlates of PAB in children, assess their importance based on rating of potential modifiability and effect, and generate a concept map depicting the associations between them. In the first (brainstorming) stage (n = 32 experts) yielded 93 correlates, including 14 new correlates not identified in previous reviews. In the second (rating and sorting) stage (n = 26 experts), 32 correlates were rated as important and a four-cluster concept map was generated including themes related to Society/community, Home/social setting, Personal/social setting and Psychological/emotional correlates. Two additional concept maps were generated for PAE and non-PAE. From expert opinion, we identified new correlates of PAB that warrant further research and we highlight the need to consider the interaction between intrapersonal and external correlates when designing interventions to promote PA in UK children.

A new composite measure of colonoscopy: the Performance Indicator of Colonic Intubation (PICI).

BACKGROUND AND STUDY AIM: Cecal intubation rate (CIR) is an established performance indicator of colonoscopy. In some patients, cecal intubation with acceptable tolerance is only achieved with additional sedation. This study proposes a composite Performance Indicator of Colonic Intubation (PICI), which combines CIR, comfort, and sedation. METHODS : Data from 20 085 colonoscopies reported in the 2011 UK national audit were analyzed. PICI was defined as the percentage of procedures achieving cecal intubation with median dose (2 mg) of midazolam or less, and nurse-assessed comfort score of 1 - 3/5. Multivariate logistic regression analysis evaluated possible associations between PICI and patient, unit, colonoscopist, and diagnostic factors. RESULTS : PICI was achieved in 54.1 % of procedures. PICI identified factors affecting performance more frequently than single measures such as CIR and polyp detection, or CIR + comfort alone. Older age, male sex, adequate bowel preparation, and a positive fecal occult blood test as indication were associated with a higher PICI. Unit accreditation, the presence of magnetic imagers in the unit, greater annual volume, fewer years' experience, and higher training/trainer status were associated with higher PICI rates. Procedures in which PICI was achieved were associated with significantly higher polyp detection rates than when PICI was not achieved. CONCLUSIONS : PICI provides a simpler picture of performance of colonoscopic intubation than separate measures of CIR, comfort, and sedation. It is associated with more factors that are amenable to change that might improve performance and with higher likelihood of polyp detection. It is proposed that PICI becomes the key performance indicator for intubation of the colon in colonoscopy quality improvement initiatives.

Long-term perspective on wildfires in the western USA.

Understanding the causes and consequences of wildfires in forests of the western United States requires integrated information about fire, climate changes, and human activity on multiple temporal scales. We use sedimentary charcoal accumulation rates to construct long-term variations in fire during the past 3,000 y in the American West and compare this record to independent fire-history data from historical records and fire scars. There has been a slight decline in burning over the past 3,000 y, with the lowest levels attained during the 20th century and during the Little Ice Age (LIA, ca. 1400-1700 CE [Common Era]). Prominent peaks in forest fires occurred during the Medieval Climate Anomaly (ca. 950-1250 CE) and during the 1800s. Analysis of climate reconstructions beginning from 500 CE and population data show that temperature and drought predict changes in biomass burning up to the late 1800s CE. Since the late 1800s , human activities and the ecological effects of recent high fire activity caused a large, abrupt decline in burning similar to the LIA fire decline. Consequently, there is now a forest "fire deficit" in the western United States attributable to the combined effects of human activities, ecological, and climate changes. Large fires in the late 20th and 21st century fires have begun to address the fire deficit, but it is continuing to grow.

Climate refugia: joint inference from fossil records, species distribution models and phylogeography.

Climate refugia, locations where taxa survive periods of regionally adverse climate, are thought to be critical for maintaining biodiversity through the glacial-interglacial climate changes of the Quaternary. A critical research need is to better integrate and reconcile the three major lines of evidence used to infer the existence of past refugia - fossil records, species distribution models and phylogeographic surveys - in order to characterize the complex spatiotemporal trajectories of species and populations in and out of refugia. Here we review the complementary strengths, limitations and new advances for these three approaches. We provide case studies to illustrate their combined application, and point the way towards new opportunities for synthesizing these disparate lines of evidence. Case studies with European beech, Qinghai spruce and Douglas-fir illustrate how the combination of these three approaches successfully resolves complex species histories not attainable from any one approach. Promising new statistical techniques can capitalize on the strengths of each method and provide a robust quantitative reconstruction of species history. Studying past refugia can help identify contemporary refugia and clarify their conservation significance, in particular by elucidating the fine-scale processes and the particular geographic locations that buffer species against rapidly changing climate.

The national colonoscopy audit: a nationwide assessment of the quality and safety of colonoscopy in the UK.

OBJECTIVE: To perform a comprehensive audit of all colonoscopy undertaken in the UK over a 2-week period. DESIGN: Multi-centre survey. All adult (≥16 years of age) colonoscopies that took place in participating National Health Service hospitals between 28 February 2011 and 11 March 2011 were included. RESULTS: Data on 20,085 colonoscopies and 2681 colonoscopists were collected from 302 units. A validation exercise indicated that data were collected on over 94% of all procedures performed nationally. The unadjusted caecal intubation rate (CIR) was 92.3%. When adjusted for impassable strictures and poor bowel preparation the CIR was 95.8%. The polyp detection rate was 32.1%. The polyp detection rate for larger polyps (≥10 mm diameter) was 11.7%. 92.3% of resected polyps were retrieved. 90.2% of procedures achieved acceptable levels of patient comfort. A total of eight perforations and 52 significant haemorrhages were reported. Eight patients underwent surgery as a consequence of a complication. CONCLUSIONS: This is the first national audit of colonoscopy that has successfully captured the majority of adult colonoscopies performed across an entire nation during a defined time period. The data confirm that there has been a significant improvement in the performance of colonoscopy in the UK since the last study reported seven years ago (CIR 76.9%) and that performance is above the required national standards.

Uncovering the roles of automatic attitudes and controlled processes in the regulation of physical activity behavior in children.

Despite substantial research efforts to increase engagement in physical activity (PA), children are not sufficiently active. Dual-process theories suggest that PA behavior regulation occurs through both controlled (i.e., reflective, conscious) and automatic (i.e., non-reflective, less conscious) processes. Automatic processes depend on affective valuations and attitudes towards PA and have been shown to predict PA behavior. However, their role in PA behavior regulation in children remains unclear. Therefore, the current study investigated the unique association of automatic attitudes towards PA on self-reported seven-day PA recall, after accounting for the effects of known controlled precursors of PA (i.e., explicit attitudes, PA self-efficacy, and PA intentions). In a cross-sectional design, 69 children (age = 10.8 ± 0.6 years) completed the Single-Category Implicit Association Task (SC-IAT) and self-reported measures of PA and controlled precursors of PA. In a hierarchical regression analysis, controlled processes accounted for 28.3 % of the variance in PA behavior. Although the bivariate association between automatic attitudes and PA was not significant, the association between them became significant but negative in the fully adjusted model (b = -1.70; p = 0.025). The fully adjusted model accounted for 35.0 % of the variance in PA. In summary, the findings indicated that both controlled and automatic processes predicted PA in children, although the association with automatic attitudes was not in the expected direction in the adjusted model. Future studies are warranted to further understand the role of automatic processes in the regulation of PA behavior in children.

DE-PASS Best Evidence Statement (BESt): modifiable determinants of physical activity and sedentary behaviour in children and adolescents aged 5-19 years-a protocol for systematic review and meta-analysis.

INTRODUCTION: Physical activity among children and adolescents remains insufficient, despite the substantial efforts made by researchers and policymakers. Identifying and furthering our understanding of potential modifiable determinants of physical activity behaviour (PAB) and sedentary behaviour (SB) is crucial for the development of interventions that promote a shift from SB to PAB. The current protocol details the process through which a series of systematic literature reviews and meta-analyses (MAs) will be conducted to produce a best-evidence statement (BESt) and inform policymakers. The overall aim is to identify modifiable determinants that are associated with changes in PAB and SB in children and adolescents (aged 5-19 years) and to quantify their effect on, or association with, PAB/SB. METHODS AND ANALYSIS: A search will be performed in MEDLINE, SportDiscus, Web of Science, PsychINFO and Cochrane Central Register of Controlled Trials. Randomised controlled trials (RCTs) and controlled trials (CTs) that investigate the effect of interventions on PAB/SB and longitudinal studies that investigate the associations between modifiable determinants and PAB/SB at multiple time points will be sought. Risk of bias assessments will be performed using adapted versions of Cochrane's RoB V.2.0 and ROBINS-I tools for RCTs and CTs, respectively, and an adapted version of the National Institute of Health's tool for longitudinal studies. Data will be synthesised narratively and, where possible, MAs will be performed using frequentist and Bayesian statistics. Modifiable determinants will be discussed considering the settings in which they were investigated and the PAB/SB measurement methods used. ETHICS AND DISSEMINATION: No ethical approval is needed as no primary data will be collected. The findings will be disseminated in peer-reviewed publications and academic conferences where possible. The BESt will also be shared with policy makers within the DE-PASS consortium in the first instance. SYSTEMATIC REVIEW REGISTRATION: CRD42021282874.

A rapid upward shift of a forest ecotone during 40 years of warming in the Green Mountains of Vermont.

Detecting latitudinal range shifts of forest trees in response to recent climate change is difficult because of slow demographic rates and limited dispersal but may be facilitated by spatially compressed climatic zones along elevation gradients in montane environments. We resurveyed forest plots established in 1964 along elevation transects in the Green Mountains (Vermont) to examine whether a shift had occurred in the location of the northern hardwood-boreal forest ecotone (NBE) from 1964 to 2004. We found a 19% increase in dominance of northern hardwoods from 70% in 1964 to 89% in 2004 in the lower half of the NBE. This shift was driven by a decrease (up to 76%) in boreal and increase (up to 16%) in northern hardwood basal area within the lower portions of the ecotone. We used aerial photographs and satellite imagery to estimate a 91- to 119-m upslope shift in the upper limits of the NBE from 1962 to 2005. The upward shift is consistent with regional climatic change during the same period; interpolating climate data to the NBE showed a 1.1 degrees C increase in annual temperature, which would predict a 208-m upslope movement of the ecotone, along with a 34% increase in precipitation. The rapid upward movement of the NBE indicates little inertia to climatically induced range shifts in montane forests; the upslope shift may have been accelerated by high turnover in canopy trees that provided opportunities for ingrowth of lower elevation species. Our results indicate that high-elevation forests may be jeopardized by climate change sooner than anticipated.

Mechanical-Ventilation Supply and Options for the COVID-19 Pandemic. Leveraging All Available Resources for a Limited Resource in a Crisis.

The novel coronavirus disease (COVID-19) has exposed critical supply shortages both in the United States and worldwide, including those in intensive care unit (ICU) and hospital bed supply, hospital staff, and mechanical ventilators. Many of those who are critically ill have required days to weeks of supportive invasive mechanical ventilation (IMV) as part of their treatment. Previous estimates set the U.S. availability of mechanical ventilators at approximately 62,000 full-featured ventilators, with 98,000 non-full-featured devices (including noninvasive devices). Given the limited availability of this resource both in the United States and in low- and middle-income countries, we provide a framework to approach the shortage of IMV resources. Here we discuss evidence and possibilities to reduce overall IMV needs, discuss strategies to maximize the availability of IMV devices designed for invasive ventilation, discuss the underlying methods in the literature to create and fashion new sources of potential ventilation that are available to hospitals and front-line providers, and discuss the staffing needs necessary to support IMV efforts. The pandemic has already pushed cities like New York and Boston well beyond previous ICU capacity in its first wave. As hot spots continue to develop around the country and the globe, it is evident that issues may arise ahead regarding the efficient and equitable use of resources. This unique challenge may continue to stretch resources and require care beyond previously set capacities and boundaries. The approaches presented here provide a review of the known evidence and strategies for those at the front line who are facing this challenge.

A new hypothesis for the origin of Amazonian Dark Earths.

Amazonian Dark Earths (ADEs) are unusually fertile soils characterised by elevated concentrations of microscopic charcoal particles, which confer their distinctive colouration. Frequent occurrences of pre-Columbian artefacts at ADE sites led to their ubiquitous classification as Anthrosols (soils of anthropic origin). However, it remains unclear how indigenous peoples created areas of high fertility in one of the most nutrient-impoverished environments on Earth. Here, we report new data from a well-studied ADE site in the Brazilian Amazon, which compel us to reconsider its anthropic origin. The amounts of phosphorus and calcium-two of the least abundant macronutrients in the region-are orders of magnitude higher in ADE profiles than in the surrounding soil. The elevated levels of phosphorus and calcium, which are often interpreted as evidence of human activity at other sites, correlate spatially with trace elements that indicate exogenous mineral sources rather than in situ deposition. Stable isotope ratios of neodymium, strontium, and radiocarbon activity of microcharcoal particles also indicate exogenous inputs from alluvial deposition of carbon and mineral elements to ADE profiles,  beginning several thousands of years before the earliest evidence of soil management for plant cultivation in the region. Our data suggest that indigenous peoples harnessed natural processes of landscape formation, which led to the unique properties of ADEs, but were not responsible for their genesis. If corroborated elsewhere, this hypothesis would transform our understanding of human influence in Amazonia, opening new frontiers for the sustainable use of tropical landscapes going forward.

Understanding why patients die after gastrostomy tube insertion: a retrospective analysis of mortality.

OBJECTIVES: To understand the causes of mortality of inpatients receiving a percutaneous endoscopic gastrostomy (PEG) tube compared with a survival curve predicted from a model proposed by Levine et al (2007). DESIGN: A retrospective study of patients receiving a PEG over an 18-month period. SETTING: Royal United Hospital Bath, a district general hospital in the southwest of England. PATIENTS: Fifty-five cases, with 44 found eligible for inclusion. INTERVENTIONS: A Levine score was calculated for this cohort. A survival curve after PEG was produced and compared with the Kaplan-Meier curve predicted by the Levine model. MAIN OUTCOME MEASURES: Mortality over a period of 1 year. RESULTS: The mortality at 1, 3, 6, and 12 months was 16%, 20%, 25%, and 28%, respectively. This matched the predicted death rate from the Levine model closely (Pearson's rank correlation coefficient = 0.96). CONCLUSIONS: The authors found that the mortality of patients receiving a PEG followed that predicted for a similar cohort of patients without PEGs in the Levine model. This suggests that the deaths observed were due to underlying comorbidities, can provide a baseline for mortality targets for PEG services, and is useful patient information regarding the risks and benefits of the procedure. The findings demonstrate that PEG does no harm and supports the accepted opinion that nutrition support is associated with a better outcome. Furthermore, they show that most deaths occur within the first month of placement and would support arguments for delaying placement until outcome from the underlying condition is more predictable.

Weak climatic control of stand-scale fire history during the late holocene.

Forest fire occurrence is affected by multiple controls that operate at local to regional scales. At the spatial scale of forest stands, regional climatic controls may be obscured by local controls (e.g., stochastic ignitions, topography, and fuel loads), but the long-term role of such local controls is poorly understood. We report here stand-scale (<100 ha) fire histories of the past 5000 years based on the analysis of sediment charcoal at two lakes 11 km apart in southeastern British Columbia. The two lakes are today located in similar subalpine forests, and they likely have experienced the same late-Holocene climatic changes because of their close proximity. We evaluated two independent properties of fire history: (1) fire-interval distribution, a measure of the overall incidence of fire, and (2) fire synchroneity, a measure of the co-occurrence of fire (here, assessed at centennial to millennial time scales due to the resolution of sediment records). Fire-interval distributions differed between the sites prior to, but not after, 2500 yr before present. When the entire 5000-yr period is considered, no statistical synchrony between fire-episode dates existed between the two sites at any temporal scale, but for the last 2500 yr marginal levels of synchrony occurred at centennial scales. Each individual fire record exhibited little coherency with regional climate changes. In contrast, variations in the composite record (average of both sites) matched variations in climate evidenced by late-Holocene glacial advances. This was probably due to the increased sample size and spatial extent represented by the composite record (up to 200 ha) plus increased regional climatic variability over the last several millennia, which may have partially overridden local, non-climatic controls. We conclude that (1) over past millennia, neighboring stands with similar modern conditions may have experienced different fire intervals and asynchronous patterns in fire episodes, likely because local controls outweighed the synchronizing effect of climate; (2) the influence of climate on fire occurrence is more strongly expressed when climatic variability is relatively great; and (3) multiple records from a region are essential if climate-fire relations are to be reliably described.

Seven hundred years of human-driven and climate-influenced fire activity in a British Columbia coastal temperate rainforest.

While wildland fire is globally most common at the savannah-grassland ecotone, there is little evidence of fire in coastal temperate rainforests. We reconstructed fire activity with a ca 700-year fire history derived from fire scars and stand establishment from 30 sites in a very wet (up to 4000 mm annual precipitation) temperate rainforest in coastal British Columbia, Canada. Drought and warmer temperatures in the year prior were positively associated with fire events though there was little coherence of climate indices on the years of fires. At the decadal scale, fires were more likely to occur after positive El Niño-Southern Oscillation and Pacific Decadal Oscillation phases and exhibited 30-year periods of synchrony with the negative phase of the Arctic Oscillation. Fire frequency was significantly inversely correlated with the distance from former Indigenous habitation sites and fires ceased following cultural disorganization caused by disease and other European impacts in the late nineteenth century. Indigenous people were likely to have been the primary ignition source in this and many coastal temperate rainforest settings. These data are directly relevant to contemporary forest management and discredit the myth of coastal temperate rainforests as pristine landscapes.

Frost for the trees: Did climate increase erosion in unglaciated landscapes during the late Pleistocene?

Understanding climatic influences on the rates and mechanisms of landscape erosion is an unresolved problem in Earth science that is important for quantifying soil formation rates, sediment and solute fluxes to oceans, and atmospheric CO2 regulation by silicate weathering. Glaciated landscapes record the erosional legacy of glacial intervals through moraine deposits and U-shaped valleys, whereas more widespread unglaciated hillslopes and rivers lack obvious climate signatures, hampering mechanistic theory for how climate sets fluxes and form. Today, periglacial processes in high-elevation settings promote vigorous bedrock-to-regolith conversion and regolith transport, but the extent to which frost processes shaped vast swaths of low- to moderate-elevation terrain during past climate regimes is not well established. By combining a mechanistic frost weathering model with a regional Last Glacial Maximum (LGM) climate reconstruction derived from a paleo-Earth System Model, paleovegetation data, and a paleoerosion archive, we propose that frost-driven sediment production was pervasive during the LGM in our unglaciated Pacific Northwest study site, coincident with a 2.5 times increase in erosion relative to modern rates. Our findings provide a novel framework to quantify how climate modulates sediment production over glacial-interglacial cycles in mid-latitude unglaciated terrain.

Effects of training with heliox and noninvasive positive pressure ventilation on exercise ability in patients with severe COPD.

STUDY OBJECTIVES: We sought to determine whether breathing heliox or using nasal noninvasive positive pressure ventilation (NIPPV) would produce immediate improvements in exercise capability in patients with COPD, and whether training for 6 weeks with one of these modalities would result in greater exercise improvement than with training unassisted. SETTING: US military medical center. METHODS: Thirty-nine patients with severe COPD (mean FEV1 of 33.5% predicted) underwent three incremental treadmill tests to exhaustion unassisted, breathing heliox, or breathing with NIPPV. They were then randomized to undergo 6 weeks of twice-weekly rehabilitation with unassisted exercise training (UT group), training while breathing heliox (HT group), or training while breathing with NIPPV (NT group). The three exercise tests were then repeated. RESULTS: Heliox treatment did not produce any immediate benefit in exercise time or maximum workload in the 39 patients initially tested, the 32 patients who completed the protocol, or the HT group. Furthermore, no training advantage was evident in the HT group (n = 10) compared to the UT group (n = 11). NIPPV did not produce an immediate benefit in the initial tests, but produced a small increase in exercise time in the 32 patients completing the protocol in the final tests. This effect was primarily because of the NT group, who exercised significantly longer (mean +/- SD, 16.8 +/- 4.9 min vs 14.2 +/- 5.6 min, p = 0.0045) and to a higher workload (4.46 +/- 1.55 metabolic equivalents [METs] vs 4.09 +/- 1.75 METs, respectively; p = 0.038) when tested using the ventilator. Compared to the UT group, the NT group started out with a lower exercise time (7.9 +/- 3.5 min vs 12.3 +/- 5.2 min, p = 0.031) in preliminary testing, but the statistical difference was eliminated in the final tests (14.2 +/- 5.6 min vs 16.0 +/- 5.8 min, respectively; p = 0.451). The NT group actually slightly exceeded the UT group when they used the ventilator in final testing, although this was not statistically significant (16.8 +/- 4.9 min vs 16.0 +/- 5.8 min, respectively). CONCLUSION: Heliox treatment does not appear to offer an immediate or training advantage with exercise in patients with COPD. For patients who have undergone regular exercise conditioning with NIPPV, use of the ventilator produces an immediate improvement in both exercise time and maximum workload attained, and it may confer a training advantage.