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Abstract Plant biomass is a fundamental ecosystem attribute that is sensitive to rapid climatic changes occurring in the Arctic. Nevertheless, measuring plant biomass in the Arctic is logistically challenging and resource intensive. Lack of accessible field data hinders efforts to understand the amount, composition, distribution, and changes in plant biomass in these northern ecosystems. Here, we present The Arctic plant aboveground biomass synthesis dataset, which includes field measurements of lichen, bryophyte, herb, shrub, and/or tree aboveground biomass (g m−2) on 2,327 sample plots from 636 field sites in seven countries. We created the synthesis dataset by assembling and harmonizing 32 individual datasets. Aboveground biomass was primarily quantified by harvesting sample plots during mid- to late-summer, though tree and often tall shrub biomass were quantified using surveys and allometric models. Each biomass measurement is associated with metadata including sample date, location, method, data source, and other information. This unique dataset can be leveraged to monitor, map, and model plant biomass across the rapidly warming Arctic.

Abstract Background Pain is a common, debilitating, and feared symptom, including among cancer survivors. However, large-scale population-based evidence on pain and its impact in cancer survivors is limited. We quantified the prevalence of pain in community-dwelling people with and without cancer, and its relation to physical functioning, psychological distress, and quality of life (QoL). Methods Questionnaire data from participants in the 45 and Up Study (Wave 2, n = 122,398, 2012–2015, mean age = 60.8 years), an Australian population-based cohort study, were linked to cancer registration data to ascertain prior cancer diagnoses. Modified Poisson regression estimated age- and sex-adjusted prevalence ratios (PRs) for bodily pain and pain sufficient to interfere with daily activities (high-impact pain) in people with versus without cancer, for 13 cancer types, overall and according to clinical, personal, and health characteristics. The relation of high-impact pain to physical and mental health outcomes was quantified in people with and without cancer. Results Overall, 34.9% (5,436/15,570) of cancer survivors and 31.3% (32,471/103,604) of participants without cancer reported bodily pain (PR = 1.07 [95% CI = 1.05–1.10]), and 15.9% (2,468/15,550) versus 13.1% (13,573/103,623), respectively, reported high-impact pain (PR = 1.13 [1.09–1.18]). Pain was greater with more recent cancer diagnosis, more advanced disease, and recent cancer treatment. High-impact pain varied by cancer type; compared to cancer-free participants, PRs were: 2.23 (1.71–2.90) for multiple myeloma; 1.87 (1.53–2.29) for lung cancer; 1.06 (0.98–1.16) for breast cancer; 1.05 (0.94–1.17) for colorectal cancer; 1.04 (0.96–1.13) for prostate cancer; and 1.02 (0.92–1.12) for melanoma. Regardless of cancer diagnosis, high-impact pain was strongly related to impaired physical functioning, psychological distress, and reduced QoL. Conclusions Pain is common, interfering with daily life in around one-in-eight older community-dwelling participants. Pain was elevated overall in cancer survivors, particularly for certain cancer types, around diagnosis and treatment, and with advanced disease. However, pain was comparable to population levels for many common cancers, including breast, prostate and colorectal cancer, and melanoma.

Abstract Climate change is leading to species redistributions. In the tundra biome, shrubs are generally expanding, but not all tundra shrub species will benefit from warming. Winner and loser species, and the characteristics that may determine success or failure, have not yet been fully identified. Here, we investigate whether past abundance changes, current range sizes and projected range shifts derived from species distribution models are related to plant trait values and intraspecific trait variation. We combined 17,921 trait records with observed past and modelled future distributions from 62 tundra shrub species across three continents. We found that species with greater variation in seed mass and specific leaf area had larger projected range shifts, and projected winner species had greater seed mass values. However, trait values and variation were not consistently related to current and projected ranges, nor to past abundance change. Overall, our findings indicate that abundance change and range shifts will not lead to directional modifications in shrub trait composition, since winner and loser species share relatively similar trait spaces.

Snow is an important driver of ecosystem processes in cold biomes. Snow accumulation determines ground temperature, light conditions, and moisture availability during winter. It also affects the growing season’s start and end, and plant access to moisture and nutrients. Here, we review the current knowledge of the snow cover’s role for vegetation, plant-animal interactions, permafrost conditions, microbial processes, and biogeochemical cycling. We also compare studies of natural snow gradients with snow experimental manipulation studies to assess time scale difference of these approaches. The number of tundra snow studies has increased considerably in recent years, yet we still lack a comprehensive overview of how altered snow conditions will affect these ecosystems. Specifically, we found a mismatch in the timing of snowmelt when comparing studies of natural snow gradients with snow manipulations. We found that snowmelt timing achieved by snow addition and snow removal manipulations (average 7.9 days advance and 5.5 days delay, respectively) were substantially lower than the temporal variation over natural spatial gradients within a given year (mean range 56 days) or among years (mean range 32 days). Differences between snow study approaches need to be accounted for when projecting snow dynamics and their impact on ecosystems in future climates.

Australia introduced COVID-19 infection prevention and control measures in early 2020. To help prepare health services, the Australian Government Department of Health commissioned a modelled evaluation of the impact of disruptions to population breast, bowel, and cervical cancer screening programmes on cancer outcomes and cancer services. We used the Policy1 modelling platforms to predict outcomes for potential disruptions to cancer screening participation, covering periods of 3, 6, 9, and 12 mo. We estimated missed screens, clinical outcomes (cancer incidence, tumour staging), and various diagnostic service impacts. We found that a 12-mo screening disruption would reduce breast cancer diagnoses (9.3% population-level reduction over 2020–2021) and colorectal cancer (up to 12.1% reduction over 2020–21), and increase cervical cancer diagnoses (up to 3.6% over 2020–2022), with upstaging expected for these cancer types (2, 1.4, and 6.8% for breast, cervical, and colorectal cancers, respectively). Findings for 6–12-mo disruption scenarios illustrate that maintaining screening participation is critical to preventing an increase in the burden of cancer at a population level. We provide programme-specific insights into which outcomes are expected to change, when changes are likely to become apparent, and likely downstream impacts. This evaluation provided evidence to guide decision-making for screening programmes and emphasises the ongoing benefits of maintaining screening in the face of potential future disruptions.

Australia’s National Bowel Cancer Screening Program (NBCSP) has the potential to prevent almost 84 000 bowel cancer deaths if 60% program participation rates could be reached and maintained over the next two decades. Immunochemical faecal occult blood test (iFOBT) is used as an initial screening tool. Participants who test positive are referred for colonoscopy for diagnostic assessment. Concerns about colonoscopy capacity and lengthy wait times between positive iFOBT and colonoscopy have hampered efforts to promote the program. However, a separate research paper published in this issue of PHRP shows that only an estimated 10–14% of Medicare-funded colonoscopies (almost 75% of all colonoscopies) in Australia are generated by the NBCSP. Inappropriate use of colonoscopy as a primary screening tool and failure to prioritise NBCSP participants may be the main reasons for long colonoscopy wait times associated with the program. Promoting clinical practice guidelines, and the Direct Access Colonoscopy initiative for priority patients, are key to reducing colonoscopy wait times and proactive promotion of the NBCSP.

Objectives and importance of study: Colorectal cancer (CRC) is Australia’s fourth most commonly diagnosed cancer. CRC screening is an effective intervention to reduce this burden. The National Bowel Cancer Screening Program (NBCSP) provides 2-yearly immunochemical faecal occult blood tests (iFOBTs) to Australians aged 50–74 years; a diagnostic colonoscopy is conducted after a positive iFOBT. Clinical guidelines inform colonoscopy usage, and appropriate use of these guidelines is vital to investigate gastrointestinal symptoms, detect bowel abnormalities and CRC, and remove precancerous polyps. Colonoscopy services are under strain, with limited formal strategies to prioritise patients. There are concerns among practitioners and patient advocates that the NBCSP generates additional colonoscopy requests and increases wait times, worsening patient outcomes and prolonging distress. In this research study, we estimate and project colonoscopy use in Australia from 2001 to 2030 and determine the impact of the NBCSP by examining model-estimated NBCSP colonoscopy demand. Methods: Colonoscopy use in Australia was compiled using Medicare Benefits Schedule (MBS) claims for colonoscopies from 2001 to 2019. From these data, projections were made from 2020 to 2030. Policy1-Bowel, a microsimulation model, was used to estimate NBCSP-related colonoscopy demand from screening follow-up and colonoscopic surveillance from 2006 to 2030. Results: MBS-funded colonoscopy use increased from 284 676 in 2001 to 663 213 in 2019. Annual use is projected to be more than 780 000 by 2030. Of these, 10–14% are projected to be generated by the NBCSP. Per-capita MBS-funded colonoscopy utilisation increased 0.2% annually over 2015–2019, a slowing of growth compared to previous trends. Conclusion: The NBCSP accounts for a modest fraction of colonoscopy use in Australia, and a better understanding of colonoscopy use not associated with the NBCSP is needed. Promoting adherence to guideline-recommended iFOBT and colonoscopy use could ease pressure on services and improve outcomes.

Objective: Over the 15 years since the 45 and Up Study (the Study) was established, researchers have harnessed its capacity for enabling rigorous, comprehensive investigation of cancer causes, care, and outcomes. For the first time in Australia, the entire cancer-control continuum could be investigated by linking questionnaire data with cancer registry notifications, hospital records, outpatient medical services and prescription medications at scale. Here, we use lung cancer as a case study to demonstrate the Study’s potential to improve cancer control. Method: Narrative description. Results: Between 2006–2013, approximately 1200 participants in the Study cohort who had no prior history of cancer were diagnosed with lung cancer, allowing the generation of novel, policy- and practice-relevant evidence for tobacco control, screening, and systems of care. The Study produced evidence on the continuing impact of smoking, including that ‘light smoking’ (1–5 cigarettes/day) is associated with nine times the risk of lung cancer compared to never-smoking; and that 54% of lung cancers could be avoided long-term if all Australians who smoked were to quit. The Study was used to validate a lung cancer screening risk prediction tool, correctly identifying 70% of the participants with a history of smoking who developed lung cancer within a 6-year period as ‘high-risk’. Potential inequities in lung cancer care were identified using the Study cohort, including suboptimal levels of radiotherapy utilisation, below benchmark levels of systemic therapy for patients with metastatic disease, and high numbers of emergency department presentations prior to diagnosis. Participants with lung cancer reported poorer quality of life than those with almost any other cancer type, and about 50% reported severe physical functioning limitations. The Study also provided the infrastructure for the first comprehensive report on lung cancer health system costs. Lessons learnt: As a statewide, population-based cohort, the Study provides reliable estimates of cancer risk, health services utilisation, and person-centred outcomes that can inform policy and practice decision making; and has provided the backbone for localising policy-relevant insights from international experience. We have found that the direct involvement of clinicians and policy makers in research design, and engagement with community networks, can yield tractable, policy-relevant, and ultimately impactful scientific insights.

Summary: Background: Overweight and obesity is a growing public health issue as it contributes to the future burden of obesity-related diseases, including cancer, especially in high-income countries. In Australia, 4.3% of all cancers diagnosed in 2013 were attributable to overweight and obesity. Our aim was to examine Australian age-specific incidence trends over the last 35 years for obesity-related cancers based on expert review (colorectal, liver, gallbladder, pancreas, breast in postmenopausal women, uterine, ovary, kidney, thyroid, and multiple myeloma) individually and pooled. Methods: Australian incidence data for 10 obesity-related cancers among people aged 25–84 years, diagnosed from 1983 to 2017, were obtained from the Australian Cancer Database. We used age–period–cohort modelling and joinpoint analysis to assess trends, estimating incidence rate ratios (IRR) by birth-cohort for each individual cancer and pooled, and the annual percentage change. The analyses were also conducted for non-obesity-related cancers over the same period. Findings: The total number of cancers where some proportion is obesity-related, diagnosed from 1983-2017, was 1,005,933. This grouping was 34.7% of cancers diagnosed. The IRR of obesity-related cancers increased from 0.77 (95% CI 0.73, 0.81) for the 1903 birth-cohort to 2.95 (95% CI 2.58, 3.38) for the recent 1988 cohort relative to the 1943 cohort. The IRRs of non-obesity related cancers were stable with non-significant decreases in younger cohorts. These trends were broadly similar across sex and age groups. Interpretation: The incidence of obesity-related cancers in Australia has increased by birth-cohort across all age-groups, which should be monitored. Obesity, a public health epidemic, needs to be addressed through increased awareness, policy support and evidence-based interventions. Funding: This research received no specific funding.

Recent climate warming in the Arctic is enhancing microbial decomposition of soil organic matter, which may result in globally significant greenhouse gas releases to the atmosphere. To better predict future impacts, bacterial and fungal community structures in both the bulk soil and the rhizosphere of Arctic birch, Betula glandulosa, were determined in control, greenhouse summer warming, and annual factorial nitrogen (N) and phosphate (P) addition treatments twelve years after their establishment. DNA sequence analyses at multiple taxonomic levels consistently indicated substantial bulk soil and rhizosphere microbial community differences among the fertilization treatments but no significant greenhouse effects. These results suggest that climate warming will likely increase the activity rates of soil microbial decomposers but without substantially altering the structure of either the bacterial or fungal communities. Differential abundance testing revealed changes in ectomycorrhizal fungal species of the genus Thelephora in both bulk soil and rhizosphere, with increases in their relative abundance in P and N + P amended plots compared with warming and controls. Because birch is the principal low Arctic ectomycorrhizal host, our results suggest that these fungi may promote this shrub’s competitiveness where tundra soil nutrient availability is enhanced by warming or other means, ultimately contributing to arctic vegetation “greening.”

Abstract Background Improved survival means that cancer is increasingly becoming a chronic disease. Understanding and improving functional outcomes are critical to optimising survivorship. We quantified physical and mental health-related outcomes in people with versus without cancer, according to cancer type. Methods Questionnaire data from an Australian population-based cohort study (45 and Up Study (n = 267,153)) were linked to cancer registration data to ascertain cancer diagnoses up to enrolment. Modified Poisson regression estimated age- and sex-adjusted prevalence ratios (PRs) for adverse person-centred outcomes—severe physical functional limitations (disability), moderate/high psychological distress and fair/poor quality of life (QoL)—in participants with versus without cancer, for 13 cancer types. Results Compared to participants without cancer (n = 244,000), cancer survivors (n = 22,505) had greater disability (20.6% versus 12.6%, respectively, PR = 1.28, 95%CI = (1.25–1.32)), psychological (22.2% versus 23.5%, 1.05 (1.02–1.08)) and poor/fair QoL (15.2% versus 10.2%; 1.28 (1.24–1.32)). The outcomes varied by cancer type, being worse for multiple myeloma (PRs versus participants without cancer for disability 3.10, 2.56–3.77; distress 1.53, 1.20–1.96; poor/fair QoL 2.40, 1.87–3.07), lung cancer (disability 2.81, 2.50–3.15; distress 1.67, 1.46–1.92; poor/fair QoL 2.53, 2.21–2.91) and non-Hodgkin’s lymphoma (disability 1.56, 1.37–1.78; distress 1.20, 1.05–1.36; poor/fair QoL 1.66, 1.44–1.92) and closer to those in people without cancer for breast cancer (disability 1.23, 1.16–1.32; distress 0.95, 0.90–1.01; poor/fair QoL 1.15, 1.05–1.25), prostate cancer (disability 1.11, 1.04–1.19; distress 1.09, 1.02–1.15; poor/fair QoL 1.15, 1.08–1.23) and melanoma (disability 1.02, 0.94–1.10; distress 0.96, 0.89–1.03; poor/fair QoL 0.92, 0.83–1.01). Outcomes were worse with recent diagnosis and treatment and advanced stage. Physical disability in cancer survivors was greater in all population subgroups examined and was a major contributor to adverse distress and QoL outcomes. Conclusions Physical disability, distress and reduced QoL are common after cancer and vary according to cancer type suggesting priority areas for research, and care and support.

Climate change in arctic tundra is projected to affect air temperature, snow depth, soil fertility, and caribou herbivory, which may alter plant community composition by shifting niche space to favor particular species’ life history strategies. We report responses of a Canadian mesic birch hummock tundra plant community to a range of manipulative experiments (greenhouse warming, fertilization, snow fence, and caribou exclosure treatments). Aboveground biomass of each plant species was measured in the same permanent 1 m2 areas using the point frame method in 2005, 2011, and 2017. Although the greenhouse treatment had few effects on individual species, total vascular plant community biomass was enhanced between 2011 and 2017. Furthermore, species’ biomass across all control plots was stable from 2005 to 2011 but increased significantly from 2011 to 2017, with air temperatures also warmer over that same period. Species responded to high-level nitrogen and high-level nitrogen and phosphorus combined additions, with deciduous shrubs and graminoids increasing and evergreen shrubs decreasing. The snow fences and caribou exclosures had little effect on species biomass. Although vegetation greening trends have been reported in arctic environments that are primarily influenced by maritime climate, our study is one of the first to provide plot-based evidence of recent plant biomass increases in the low Arctic’s continental interior.

The aim of our study was to quantify sex-specific patterns of smoking prevalence and initiation in 10-year birth cohorts from 1910 to 1989 in Australia. We combined individual data of 385,810 participants from 33 cross-sectional surveys conducted between 1962 and 2018. We found that age-specific smoking prevalence varied considerably between men and women within birth cohorts born before 1960. The largest difference was observed in the earliest cohort (1910-1919), with up to 37.7% point greater proportion of current smokers in men than in women. In subsequent cohorts, the proportion decreased among men, but increased among women, until there was no more than 7.4% point difference in the 1960-69 birth cohort. In the 1970-79 and 1980-89 cohorts, smoking among men marginally increased, but the proportion was at most ~11.0% points higher than women. Our analysis of initiation indicated that many women born before the 1930s who smoked commenced smoking after age 25 years (e.g., ~27% born in 1910-19); compared to at most 8% of men in any birth cohort. The earliest birth cohort (1910-1919) had the greatest difference in age at initiation between sexes; 26.6 years in women versus 19.0 in men. In later cohorts, male and female smokers initiated increasingly earlier, converging in the 1960-69 cohort (17.6 and 17.8 years, respectively). While 22.9% of men and 8.4% of women initiated smoking aged < = 15 in the 1910-1919 cohort, in the latest cohort (1980-89) the reverse was true (21.4% and 28.8% for men and women, respectively). Marked differences in smoking prevalence and age at initiation existed between birth cohorts of Australian men and women born before 1960; after this, sex-specific trends in prevalence and initiation were similar. Understanding these patterns may inform the evaluation of tobacco control policies and the targeting of potential interventions for exposed populations such as lung cancer screening.

The coronavirus disease 2019 (COVID-19) pandemic has caused major disruptions to many aspects of life in Australia and globally. This includes actual and potential future impacts on Australia’s three national screening programs for breast, bowel and cervical cancer. These programs aim to improve cancer outcomes through an organised approach to the early detection of cancer and precancer in asymptomatic populations. The design of each program varies according to biological differences in the three cancers, the available screening technology, the target population, and variations in their administration of Australia’s federal, state and territory jurisdictions. The observed and potential impacts of COVID-19 on these programs, and on related activities such as the current national enquiry into lung cancer screening feasibility, therefore vary significantly. This article focuses on observed short-term impacts, adaptations and the longer-term outlook for cancer screening in relation to COVID-19. It summarises potential responses to minimise the harms of disruptions caused by COVID-19, and highlights research and policy opportunities in the pandemic response and recovery which could inform and accelerate optimisation of cancer screening in the long term.

The late 1990s marked a turning point for tobacco control in Australia. In March 1996, the Liberal-National Coalition won government after 13 years of Labor rule. Prime Minister John Howard had campaigned on cutting expenditure, and had long been a proponent of small government and the private sector. Yet within 2 years of taking office, the Howard Government funded Australia’s first big budget National Tobacco Campaign and commenced a review of the Tobacco Advertising Prohibition Act 1992 to phase out industry sponsorship of international sporting events. The Honourable Dr Michael Wooldridge, Minister for Health from 1996 to his retirement from politics in 2001, reflects on how these reforms to tobacco control were achieved and how the public health community can best engage with policy makers to advocate for reform. He stresses the importance of public health not being defined by ideology, and that politicians must be scientifically well informed and supported in doing what is in the nation’s best interest for public health. He assesses the current state of play and argues more investment in tobacco control is needed today, suggesting it remains the “best buy” in health.

Smoking prevalence in Australia has decreased by 75% over the past 40 years. A major reduction in disease burden attributed to smoking has occurred in parallel, adjusted for the time lag between tobacco harms and disease occurrence. Yet, paradoxically, governments have seldom invested in tobacco control measures that require a financial outlay, such as social marketing, at required levels for optimal outcomes. The percentage of disease burden caused by smoking in Australia (9.3%) remains higher than that of any other preventable risk factor and the social costs are estimated at $136.9 billion annually. Tobacco control is rightly seen as an Australian public health success story. However, with up to two in three of Australia’s 2.5 million current smokers at risk of dying prematurely from a smoking-related disease, much more needs to be done. In this paper, we explore a brief history of tobacco control in relation to policy reform and recent evidence, and outline the case for re-energising tobacco control at a time when public health has gained new political and social currency.

Introduction With almost 50% of cases preventable and the Australian National Bowel Cancer Screening Program in place, colorectal cancer (CRC) is a prime candidate for investment to reduce the cancer burden. The challenge is determining effective ways to reduce morbidity and mortality and their implementation through policy and practice. Pathways-Bowel is a multistage programme that aims to identify best-value investment in CRC control by integrating expert and end-user engagement; relevant evidence; modelled interventions to guide future investment; and policy-driven implementation of interventions using evidence-based methods.Methods and analysis Pathways-Bowel is an iterative work programme incorporating a calibrated and validated CRC natural history model for Australia (Policy1-Bowel) and assessing the health and cost outcomes and resource use of targeted interventions. Experts help identify and prioritise modelled evaluations of changing trends and interventions and critically assess results to advise on their real-world applicability. Where appropriate the results are used to support public policy change and make the case for optimal investment in specific CRC control interventions. Fourteen high-priority evaluations have been modelled or planned, including evaluations of CRC outcomes from the changing prevalence of modifiable exposures, including smoking and body fatness; potential benefits of daily aspirin intake as chemoprevention; increasing CRC incidence in people aged

Global warming has pronounced effects on tundra vegetation, and rising mean temperatures increase plant growth potential across the Arctic biome. Herbivores may counteract the warming impacts by reducing plant growth, but the strength of this effect may depend on prevailing regional climatic conditions. To study how ungulates interact with temperature to influence growth of tundra shrubs across the Arctic tundra biome, we assembled dendroecological data from 20 sites, comprising 1153 individual shrubs and 223 63 annual growth rings. Evidence for ungulates suppressing shrub radial growth was only observed at intermediate summer temperatures (6.5 °C–9 °C), and even at these temperatures the effect was not strong. Multiple factors, including forage preferences and landscape use by the ungulates, and favourable climatic conditions enabling effective compensatory growth of shrubs, may weaken the effects of ungulates on shrubs, possibly explaining the weakness of observed ungulate effects. Earlier local studies have shown that ungulates may counteract the impacts of warming on tundra shrub growth, but we demonstrate that ungulates’ potential to suppress shrub radial growth is not always evident, and may be limited to certain climatic conditions.

The potential benefits of meditation exercises to promote more focused student attention and engagement have only rarely been quantitatively investigated at the college/university level. Here, I report student perceptions on the impacts of regular short mind-calming exercises at the beginning of every class in second, third, and fourth-year biology undergraduate courses, using voluntary anonymous surveys that were completed by at least two-thirds of each class (total enrollments 326, 68, and 15 respectively).In the third year course, 93% of respondents indicated that the exercise was “enjoyable and relaxing”, 73% indicated that it was “a valuable use of lecture time because I feel it enhances deep learning”, 75% found it a useful perspective “to achieving balance/calm in my life”, and 76% rejected the suggestion that although “the exercises are useful, they are not course-related material and therefore are inappropriate within class time”. Responses to several other distinct survey statements were also strongly positive, and furthermore, very similar favourable results as above were obtained in the other two courses. Overall, although it is unclear whether these very short exercises actually enhanced learning, many studentsperceivedthat it did. Finally, my teaching performance in university-based student assessments of the third-year course was significantly elevated in the year with mind-calming exercises compared to each of the previous nine iterations in which I had been an instructor. Together, these quantitative results suggest that the regular use of such exercises has multiple direct and indirect benefits that may contribute to more effective undergraduate learning and teaching. Les bénéfices potentiels d’exercices de méditation pour promouvoir une meilleure attention et une meilleure participation des étudiants ont rarement été étudiés de façon quantitative au niveau collégial ou universitaire. Dans cet article, je rapporte les perceptions des étudiants sur les effets de courts exercices pour apaiser le mental au début de chaque classe dans des cours de biologie de deuxième, de troisième et de quatrième années, en utilisant des questionnaires anonymes remplis bénévolement par au moins deux-tiers des étudiants dans chaque classe (effectifs totaux de 326, 68 et 15 respectivement).Dans le cours de troisième année, 93 % des répondants ont indiqué que l’exercice était « plaisant et relaxant », 73 % ont indiqué qu’il était « une bonne utilisation du temps de classe parce que selon moi, l’apprentissage profond est amélioré », 75 % ont trouvé que c’était une perspective utile « pour atteindre l’équilibre et le calme dans ma vie », et 76 % ont rejeté la suggestion selon laquelle, bien que « les exercices soient utiles, ils ne font pas partie de la matière du cours et par conséquent ils ne sont pas appropriés dans le cadre de la classe ». Les réponses à plusieurs autres déclarations distinctes du questionnaire étaient également fortement positives et, de plus, des résultats favorables semblables à ceux rapportés ci-dessus ont été obtenus dans les deux autres cours. Dans l’ensemble, bien qu’il ne soit pas clair si ces très courts exercices renforcentréellement l’apprentissage, de nombreux étudiantsont eu l’impression que c’était le cas. Pour finir, les évaluations de mon enseignement par les étudiants du cours de troisième année dans les questionnaires préparés par l’université étaient considérablement meilleures au cours de l’année où nous avons pratiqué des exercices pour apaiser le mental par rapport à chacune des neuf évaluations précédentes dans les cours que j’avais enseignés. Pris dans leur ensemble, ces résultats quantitatifs suggèrent que l’utilisation régulière de tels exercices présente de nombreux bénéfices directs et indirects qui peuvent contribuer à un enseignement et à un apprentissage meilleurs au niveau du premier cycle.

Background: No assessment of the National Bowel Screening Program (NBCSP) in Australia, which considers all downstream benefits, costs, and harms, has been done. We aimed to use a comprehensive natural history model and the most recent information about cancer treatment costs to estimate long-term benefits, costs, and harms of the NBCSP (2 yearly immunochemical faecal occult blood testing screening at age 50–74 years) and evaluate the incremental effect of improved screening participation under different scenarios. Methods: In this modelling study, a microsimulation model, Policy1-Bowel, which simulates the development of colorectal cancer via both the conventional adenoma-carcinoma and serrated pathways was used to simulate the NBCSP in 2006–40, taking into account the gradual rollout of NBCSP in 2006–20. The base-case scenario assumed 40% screening participation (currently observed behaviour) and two alternative scenarios assuming 50% and 60% participation by 2020 were modelled. Aggregate year-by-year screening, diagnosis, treatment and surveillance-related costs, resource utilisation (number of screening tests and colonoscopies), and health outcomes (incident colorectal cancer cases and colorectal cancer deaths) were estimated, as was the cost-effectiveness of the NBCSP. Findings: With current levels of participation (40%), the NBCSP is expected to prevent 92 200 cancer cases and 59 000 deaths over the period 2015–40; an additional 24 300 and 37 300 cases and 16 800 and 24 800 deaths would be prevented if participation was increased to 50% and 60%, respectively. In 2020, an estimated 101 000 programme-related colonoscopies will be done, associated with about 270 adverse events; an additional 32 500 and 49 800 colonoscopies and 88 and 134 adverse events would occur if participation was increased to 50% and 60%, respectively. The overall number needed to screen (NNS) is 647–788 per death prevented, with 52–59 colonoscopies per death prevented. The programme is cost-effective due to the cancer treatment costs averted (cost-effectiveness ratio compared with no screening at current participation, AUS$3014 [95% uncertainty interval 1807–5583] per life-year saved) in the cost-effectiveness analysis. In the budget impact analysis, reduced annual expenditure on colorectal cancer control is expected by 2030, with expenditure reduced by a cumulative AUS$1·7 billion, AUS$2·0 billion, and AUS$2·1 billion (2015 prices) between 2030 and 2040, at participation rates of 40%, 50%, and 60%, respectively. Interpretation: The NBCSP has potential to save 83 800 lives over the period 2015–40 if coverage rates can be increased to 60%. By contrast, the associated harms, although an important consideration, are at a smaller magnitude at the population level. The programme is highly cost-effective and within a decade of full roll-out, there will be reduced annual health systems expenditure on colorectal cancer control due to the impact of screening. Funding: Australia Postgraduate Award PhD Scholarship, Translational Cancer Research Network Top-up scholarship (supported by Cancer Institute NSW) and Cancer Council NSW.

Climate change is having profound influences on Arctic tundra plant composition, community dynamics, and ecosystem processes. Stoichiometric homeostasis (H), the degree to which a plant maintains its internal nutrient concentrations independent of nutrient variations in its environment, may be a useful approach to predict the impacts of these influences. In this case study, we used fertilization manipulation data to calculate homeostasis indices based on nitrogen (HN), phosphorus (HP), and nitrogen to phosphorus ratios (HN:P) of aboveground tissues for seven common tundra vascular species belonging to three growth forms. We then analyzed species H relationships with dominance, spatial stability, and responsiveness to various experimental manipulations. Each of the H indices was correlated amongst tissue types within each species and was generally highest in ericoid mycorrhizal host species and lowest in the ectomycorrhizal birch. Species HP and HN:P were consistently positively correlated with aboveground biomass within the controls and across all manipulations. Furthermore, these same species were spatially stable across experimentally warmed field plots. Stoichiometric homeostasis theory has been successful in predicting grassland community dynamics. This first test of its applicability across a variety of Arctic plant growth forms highlights its considerable potential in predicting tundra plant community structure and responses to environmental change.

Climate change is already altering the landscape at high latitudes. Permafrost is thawing, the growing season is starting earlier, and, as a result, certain regions in the Arctic may be subjected to an increased incidence of freeze-thaw events. The potential release of carbon and nutrients from soil microbial cells that have been lysed by freeze-thaw transitions could have significant impacts on the overall carbon balance of arctic ecosystems, and therefore on atmospheric CO2 concentrations. However, the impact of repeated freezing and thawing with the consequent growth and recrystallization of ice on microbial communities is still not well understood. Soil samples from three distinct sites, representing Canadian geographical low arctic, mid-arctic and high arctic soils were collected from Daring Lake, Alexandra Fjord and Cambridge Bay sampling sites, respectively. Laboratory-based experiments subjected the soils to multiple freeze-thaw cycles for 14 days based on field observations (0 °C to −10 °C for 12 h and −10 °C to 0 °C for 12 h) and the impact on the communities was assessed by phospholipid fatty acid (PLFA) methyl ester analysis and 16S ribosomal RNA gene sequencing. Both data sets indicated differences in composition and relative abundance between the three sites, as expected. However, there was also a strong variation within the two high latitude sites in the effects of the freeze-thaw treatment on individual PLFA and 16S-based phylotypes. These site-based heterogeneities suggest that the impact of climate change on soil microbial communities may not be predictable a priori; minor differential susceptibilities to freeze-thaw stress could lead to a “butterfly effect” as described by chaos theory, resulting in subsequent substantive differences in microbial assemblages. This perspectives article suggests that this is an unwelcome finding since it will make future predictions for the impact of on-going climate change on soil microbial communities in arctic regions all but impossible.

As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

Deciduous shrub growth has increased across the Arctic simultaneously with recent climate warming trends. The reduction in albedo associated with shrub-induced ‘greening’ of the tundra is predicted to cause significant positive feedbacks to regional warming. Enhanced soil fertility arising from climate change is expected to be the primary mechanism driving shrub responses, yet our overall understanding of the relative importance of soil nitrogen (N) and phosphorus (P) availability and the significance of other ecological drivers is constrained by experiments with varying treatments, sites, and durations. We investigated dwarf birch apical stem growth responses to a wide range of ecological factors (enhanced summer temperatures, deepened snow, caribou exclusion, factorial high level nitrogen and phosphorus additions, and low level nitrogen additions) after six years of experimental manipulations in birch hummock tundra. As expected, birch apical stem growth was more strongly enhanced by the substantial increases in nutrient supply than by our changes in any of the other ecological factors. The factorial additions revealed that P availability was at least as important as that of N, and our low N additions demonstrated that growth was unresponsive to moderate increases in soil nitrogen alone. Experimental warming increased apical stem growth 2.5-fold—considerably more than in past studies—probably due to the relatively strong effect of our greenhouses on soil temperature. Together, these results have important implications for our understanding of the biogeochemical functioning of mesic tundra ecosystems as well as predicting their vegetation responses to climate change.