The need for nonuniform risk acceptability across climate change scenarios.

Climate change risk assessment studies focus on identifying and analyzing different risks considering several climate change scenarios and on evaluating the cost-effectiveness of different adaptation measures. However, risk acceptability is often not reflected on in the context of climate change risk studies. Noting that the different climate change scenarios depict drastically contrasting images of the future in terms of population growth, economic development, and changes to life expectancy, this article uses risk acceptance criteria that are based on socioeconomic considerations to highlight the need for nonuniform risk acceptability across climate change scenarios. For this purpose, the optimum implied cost of averting a fatality derived based on the life quality index concept and the value of a quality-adjusted life year derived based on the time principle of acceptable life risk are assessed in three different climate change scenarios for Sweden. Additionally, an illustrative example that assesses the acceptable probability of failure of a steel rod under axial tension in the different climate change scenarios is presented. It is shown that risk acceptance criteria can vary considerably across the different climate change scenarios (e.g., more than 190% variation in the acceptable probability of failure for Sweden in the considered example). This article demonstrates that the ability of societies to afford risk-reducing measures may vary considerably across the different climate change scenarios. Hence, it can be concluded that (1) in the context of climate change risk assessments, risk acceptance criteria need to be developed to account for the different climate change scenarios, and (2) these criteria may vary considerably across the different climate change scenarios. Finally, relevant challenges and research needs are also provided.

Vertebral Fractures Assessed by Dual-Energy X-Ray Absorptiometry and All-Cause Mortality: The Tromsø Study, 2007-2020.

Vertebral fractures have been associated with increased mortality, but findings are inconclusive, and many vertebral fractures avoid clinical attention. We investigated this association in a general population of 2,476 older adults aged ≥55 years from Tromsø, Norway, who were followed over 2007-2020, using dual-energy x-ray absorptiometry (DXA) at baseline to evaluate vertebral fractures (mild, moderate, or severe). We used multiple Cox regression models to estimate hazard ratios (HRs) for all-cause mortality, adjusted for age, sex, body mass index, education, smoking, alcohol intake, cardiovascular disease, and respiratory disease. Mean follow-up in the cohort was 11.2 (standard deviation, 2.7) years; 341 participants (13.8%) had ≥1 vertebral fracture at baseline, and 636 participants (25.7%) died between baseline and follow-up. Full-adjustment models showed a nonsignificant association between vertebral fracture status (yes/no) and mortality. Participants with ≥3 vertebral fractures (HR = 2.43, 95% confidence interval: 1.57, 3.78) or ≥1 severe vertebral fracture (HR = 1.65, 95% confidence interval: 1.26, 2.15) had increased mortality compared with those with no vertebral fractures. Dual-energy x-ray absorptiometry-based screening could be a potent and feasible tool in detecting vertebral fractures that are often clinically silent yet independently associated with premature death. Our data indicated that detailed vertebral assessment could be warranted for a more accurate survival estimation.

Comparing associations of handgrip strength and chair stand performance with all-cause mortality-implications for defining probable sarcopenia: the Tromsø Study 2015-2020.

BACKGROUND: Widely adopted criteria suggest using either low handgrip strength or poor chair stand performance to identify probable sarcopenia. However, there are limited direct comparisons of these measures in relation to important clinical endpoints. We aimed to compare associations between these two measures of probable sarcopenia and all-cause mortality. METHODS: Analyses included 7838 community-dwelling participants (55% women) aged 40-84 years from the seventh survey of the Tromsø Study (2015-2016), with handgrip strength assessed using a Jamar + Digital Dynamometer and a five-repetition chair stand test (5-CST) also undertaken. We generated sex-specific T-scores and categorised these as "not low", "low", and "very low" handgrip strength or 5-CST performance. Cox Proportional Hazard regression models were used to investigate associations between these two categorised performance scores and time to death (up to November 2020 ascertained from the Norwegian Cause of Death registry), adjusted for potential confounders including lifestyle factors and specific diseases. RESULTS: A total of 233 deaths occurred (median follow-up 4.7 years) with 1- and 5-year mortality rates at 3.1 (95% confidence interval [CI] 2.1, 4.6) and 6.3 (95% CI 5.5, 7.2) per 1000 person-years, respectively. There was poor agreement between the handgrip strength and 5-CST categories for men (Cohen's kappa [κ] = 0.19) or women (κ = 0.20). Fully adjusted models including handgrip strength and 5-CST performance mutually adjusted for each other, showed higher mortality rates among participants with low (hazard ratio [HR] 1.22, 95% CI 0.87, 1.71) and very low (HR 1.68, 95% CI 1.02, 2.75) handgrip strength compared with the not low category. Similar associations, although stronger, were seen for low (HR 1.88, 95% CI 1.38, 2.56) and very low (HR 2.64, 95% CI 1.73, 4.03) 5-CST performance compared with the not low category. CONCLUSIONS: We found poor agreement between T-score categories for handgrip strength and 5-CST performance and independent associations with mortality. Our findings suggest that these tests identify different people at risk when case-finding probable sarcopenia. As discussions on an international consensus for sarcopenia definitions proceed, testing both handgrip strength and chair stand performance should be recommended rather than viewing these as interchangeable assessments.

Branched-gallium phosphide nanowires seeded by palladium nanoparticles.

Palladium nanoparticles were produced by a chemical reagent-free and versatile method called spark ablation with control over particle size and density. These nanoparticles were used as catalytic seed particles for gallium phosphide nanowire growth by metalorganic vapour-phase epitaxy. Controlled growth of GaP nanowires using significantly small Pd nanoparticles between 10 and 40 nm diameter was achieved by varying several growth parameters. Low V/III ratios below 2.0 promote higher Ga incorporation into the Pd nanoparticles. Moderate growth temperatures under 600 °C avoid kinking and undesirable GaP surface growth. In addition, a second batch of palladium nanoparticles of concentration up to 1000 particlesµm-2was deposited onto the GaP nanowires. Subsequently, three-dimensional nanostructures evolved, with branches growing along the surface of the GaP nanowires. The GaP nanowires revealed a zinc blende structure with multiple twinning and a PdGa phase at the tip of the nanowires and branches.

Device-measured physical activity, sedentary time, and risk of all-cause mortality: an individual participant data analysis of four prospective cohort studies.

OBJECTIVES: To examine whether moderate-to-vigorous physical activity (MVPA) modifies the association between sedentary time and mortality and vice versa, and estimate the joint associations of MVPA and sedentary time on mortality risk. METHODS: This study involved individual participant data analysis of four prospective cohort studies (Norway, Sweden, USA, baseline: 2003-2016, 11 989 participants ≥50 years, 50.5% women) with hip-accelerometry-measured physical activity and sedentary time. Associations were examined using restricted cubic splines and fractional polynomials in Cox regressions adjusted for sex, education, body mass index, smoking, alcohol, study cohort, cardiovascular disease, cancer, and/or diabetes, accelerometry wear time and age. RESULTS: 6.7% (n=805) died during follow-up (median 5.2 years, IQR 4.2 years). More than 12 daily sedentary hours (reference 8 hours) was associated with mortality risk only among those accumulating <22 min of MVPA per day (HR 1.38, 95% CI 1.10 to 1.74). Higher MVPA levels were associated with lower mortality risk irrespective of sedentary time, for example, HR for 10 versus 0 daily min of MVPA was 0.85 (95% CI 0.74 to 0.96) in those accumulating <10.5 daily sedentary hours and 0.65 (95% CI 0.53 to 0.79) in those accumulating ≥10.5 daily sedentary hours. Joint association analyses confirmed that higher MVPA was superior to lower sedentary time in lowering mortality risk, for example, 10 versus 0 daily min of MVPA was associated with 28-55% lower mortality risk across the sedentary time spectrum (lowest risk, 10 daily sedentary hours: HR 0.45, 95% CI 0.31 to 0.65). CONCLUSIONS: Sedentary time was associated with higher mortality risk but only in individuals accumulating less than 22 min of MVPA per day. Higher MVPA levels were associated with lower mortality risk irrespective of the amount of sedentary time.

Assembling your nanowire: an overview of composition tuning in ternary III-V nanowires.

The ability to grow defect-free nanowires in lattice-mismatched material systems and to design their properties has made them ideal candidates for applications in fields as diverse as nanophotonics, nanoelectronics and medicine. After studying nanostructures consisting of elemental and binary compound semiconductors, scientists turned their attention to more complex systems-ternary nanowires. Composition control is key in these nanostructures since it enables bandgap engineering. The use of different combinations of compounds and different growth methods has resulted in numerous investigations. The aim of this review is to present a survey of the material systems studied to date, and to give a brief overview of the issues tackled and the progress achieved in nanowire composition tuning. We focus on ternary III x III1-x V nanowires (AlGaAs, AlGaP, AlInP, InGaAs, GaInP and InGaSb) and IIIV x V1-x nanowires (InAsP, InAsSb, InPSb, GaAsP, GaAsSb and GaSbP).

Improved quality of InSb-on-insulator microstructures by flash annealing into melt.

Monolithic integration of III-V semiconductors with Silicon technology has instigated a wide range of new possibilities in the semiconductor industry, such as combination of digital circuits with optical sensing and high-frequency communication. A promising CMOS compatible integration process is rapid melt growth (RMG) that can yield high quality single crystalline material at low cost. This paper represents the study on ultra-thin InSb-on-insulator microstructures integrated on a Si platform by a RMG-like process. We utilize flash lamp annealing (FLA) to melt and recrystallize the InSb material for an ultra-short duration (milliseconds), to reduce the thermal budget necessary for integration with Si technology. We compare the result from FLA to regular rapid thermal annealing (seconds). Recrystallized InSb was characterized using electron back scatter diffraction which indicate a transition from nanocrystalline structure to a crystal structure with grain sizes exceeding 1 µm after the process. We further see a 100× improvement in electrical resistivity by FLA annealed sample when compared to the as-deposited InSb with an average Hall mobility of 3100 cm2 V-1 s-1 making this a promising step towards realizing monolithic mid-infrared detectors and quantum devices based on InSb.

Aerotaxy: gas-phase epitaxy of quasi 1D nanostructures.

Cost- and resource-efficient growth is necessary for many applications of semiconductor nanowires. We here present the design, operational details and theory behind Aerotaxy, a scalable alternative technology for producing quality crystalline nanowires at a remarkably high growth rate and throughput. Using size-controlled Au seed particles and organometallic precursors, Aerotaxy can produce nanowires with perfect crystallinity and controllable dimensions, and the method is suitable to meet industrial production requirements. In this report, we explain why Aerotaxy is an efficient method for fabricating semiconductor nanowires and explain the technical aspects of our custom-built Aerotaxy system. Investigations using SEM (scanning electron microscope), TEM (transmission electron microscope) and other characterization methods are used to support the claim that Aerotaxy is indeed a scalable method capable of producing nanowires with reproducible properties. We have investigated both binary and ternary III-V semiconductor material systems like GaAs and GaAsP. In addition, common aspects of Aerotaxy nanowires deduced from experimental observations are used to validate the Aerotaxy growth model, based on a computational flow dynamics (CFD) approach. We compare the experimental results with the model behaviour to better understand Aerotaxy growth.

A multiple risk factor program is associated with decreased risk of cardiovascular disease in 70-year-olds: A cohort study from Sweden.

BACKGROUND: In individuals below 65 years of age, primary prevention programs have not been successful in reducing the risk of cardiovascular disease (CVD) and death. However, no large study to our knowledge has previously evaluated the effects of prevention programs in individuals aged 65 years or older. The present cohort study evaluated the risk of CVD in a primary prevention program for community-dwelling 70-year-olds. METHOD AND FINDINGS: In 2012-2017, we included 3,613 community-dwelling 70-year-olds living in Umeå, in the north of Sweden, in a health survey and multidimensional prevention program (the Healthy Ageing Initiative [HAI]). Classic risk factors for CVD were evaluated, such as blood pressure, lipid levels, obesity, and physical inactivity. In the current analysis, each HAI participant was propensity-score-matched to 4 controls (n = 14,452) from the general Swedish population using national databases. The matching variables included age, sex, diagnoses, medication use, and socioeconomic factors. The primary outcome was the composite of myocardial infarction, angina pectoris, and stroke. The 18,065 participants and controls were followed for a mean of 2.5 (range 0-6) years. The primary outcome occurred in 128 (3.5%) HAI participants and 636 (4.4%) controls (hazard ratio [HR] 0.80, 95% CI 0.66-0.97, p = 0.026). In HAI participants, high baseline levels of blood pressure and lipids were associated with subsequent initiation of antihypertensive and lipid-lowering therapy, respectively, as well as with decreases in blood pressure and lipids during follow-up. In an intention-to-treat approach, the risk of the primary outcome was lower when comparing all 70-year-olds in Umeå, regardless of participation in HAI, to 70-year-olds in the rest of Sweden for the first 6 years of the HAI project (HR 0.87, 95% CI 0.77-0.97, p = 0.014). In contrast, the risk was similar in the 6-year period before the project started (HR 1.04, 95% CI 0.93-1.17, p = 0.03 for interaction). Limitations of the study include the observational design and that changes in blood pressure and lipid levels likely were influenced by regression towards the mean. CONCLUSIONS: In this study, a primary prevention program was associated with a lower risk of CVD in community-dwelling 70-year-olds. With the limitation of this being an observational study, the associations may partly be explained by improved control of classic risk factors for CVD with the program.

Dislocation-Free and Atomically Flat GaN Hexagonal Microprisms for Device Applications.

III-nitrides are considered the material of choice for light-emitting diodes (LEDs) and lasers in the visible to ultraviolet spectral range. The development is hampered by lattice and thermal mismatch between the nitride layers and the growth substrate leading to high dislocation densities. In order to overcome the issue, efforts have gone into selected area growth of nanowires (NWs), using their small footprint in the substrate to grow virtually dislocation-free material. Their geometry is defined by six tall side-facets and a pointed tip which limits the design of optoelectronic devices. Growth of dislocation-free and atomically smooth 3D hexagonal GaN micro-prisms with a flat, micrometer-sized top-surface is presented. These self-forming structures are suitable for optical devices such as low-loss optical cavities for high-efficiency LEDs. The structures are made by annealing GaN NWs with a thick radial shell, reforming them into hexagonal flat-top prisms with six equivalents either m- or s-facets depending on the initial heights of the top pyramid and m-facets of the NWs. This shape is kinetically controlled and the reformation can be explained with a phenomenological model based on Wulff construction that have been developed. It is expected that the results will inspire further research into micron-sized III-nitride-based devices.

Embedded sacrificial AlAs segments in GaAs nanowires for substrate reuse.

We report on the use of a sacrificial AlAs segment to enable substrate reuse for nanowire synthesis. A silicon nitride template was deposited on a p-type GaAs substrate. Then a pattern was transferred to the substrate by nanoimprint lithography and reactive ion etching. Thermal evaporation was used to define Au seed particles. Metalorganic vapour phase epitaxy was used to grow AlAs-GaAs NWs in the vapour-liquid-solid growth mode. The yield of synthesised nanowires, compared to the number expected from the patterned template, was more than 80%. After growth, the nanowires were embedded in a polymer and mechanically removed from the parent substrate. The parent substrate was then immersed in an HCl:H2O (1:1) mixture to dissolve the remaining stub of the sacrificial AlAs segment. The pattern fidelity was preserved after peeling off the nanowires and cleaning, and the semiconductor surface was flat and ready for reuse. Au seed particles were then deposited on the substrate by use of pulse electrodeposition, which was selective to the openings in the growth template, and then nanowires were regrown. The yield of regrowth was less optimal compared to the first growth but the pattern was preserved. Our results show a promising approach to reduce the final cost of III-V nanowire based solar cells.

Differences in sarcopenia prevalence between upper-body and lower-body based EWGSOP2 muscle strength criteria: the Tromsø study 2015-2016.

BACKGROUND: The European Working Group on Sarcopenia in Older People (EWGSOP2) recommends grip strength and chair stand tests to be used as primary defining measures. It is unclear how either test affects prevalence estimates. METHODS: This cross-sectional study involved 3498 community-dwelling participants (40-84 years) from the 7th Tromsø Study survey (2015-2016). We used grip strength, five-repetition chair stands, four-meter Walk Speed Test, Timed-Up-and-Go (TUG) and Dual-Energy X-ray Absorptiometry measurements. Data were analyzed using multiple linear regression models and ROC-curves. RESULTS: Probable and confirmed sarcopenia prevalence was 1.3 and 4.4% based on grip strength and chair stands, respectively. There was very low agreement between grip strength and chair stand cut-offs (κ = 0.07), with only 4.3% of participants defined as having probable sarcopenia overlapping in the two criteria. Participants with grip strength-based sarcopenia had lower mean height, weight, waist circumference, and appendicular lean mass relative to body height (ALMheight2) than non-sarcopenic participants (all p < 0.001), after adjusting for multiple covariates. Conversely, participants with chair stand-based sarcopenia had similar height, higher weight, waist circumference and body fat% compared to non-sarcopenic participants (all p < 0.05). Area-under-curves (AUCs) for TUG-time were significantly larger when using chair stand instead of grip strength cut-offs (0.86, 95% CI 0.84-0.89 vs. 0.75, 95% CI 0.69-0.83). CONCLUSIONS: Using chair stands instead of grip strength more than doubled probable sarcopenia prevalence across all ages. The two measures defined individuals of contradictory anthropometrics, body composition, and dissimilar physical function to have probable sarcopenia. Researchers should further evaluate the consequences of using different strength measures in the EWGSOP2 definition to classify sarcopenia.

Simulation of GaAs Nanowire Growth and Crystal Structure.

Growing GaAs nanowires with well-defined crystal structures is a challenging task, but may be required for the fabrication of future devices. In terms of crystal phase selection, the connection between theory and experiment is limited, leaving experimentalists with a trial and error approach to achieve the desired crystal structures. In this work, we present a modeling approach designed to provide the missing connection, combining classical nucleation theory, stochastic simulation, and mass transport through the seed particle. The main input parameters for the model are the flows of the growth species and the temperature of the process, giving the simulations the same flexibility as experimental growth. The output of the model can also be directly compared to experimental observables, such as crystal structure of each bilayer throughout the length of the nanowire and the composition of the seed particle. The model thus enables for observed experimental trends to be directly explored theoretically. Here, we use the model to simulate nanowire growth with varying As flows, and our results match experimental trends with a good agreement. By analyzing the data from our simulation, we find theoretical explanations for these experimental results, providing new insights into how the crystal structure is affected by the experimental parameters available for growth.

Associations of Sarcopenia and Its Components with Bone Structure and Incident Falls in Swedish Older Adults.

The aim of this study was to compare bone structure parameters and likelihood of falls across European Working Group on Sarcopenia in Older People (EWGSOP2) sarcopenia categories. 3334 Swedish 70-year olds had appendicular lean mass (normalized to height; ALMHt), lumbar spine and total hip areal BMD (aBMD) estimated by dual-energy X-ray absorptiometry. Volumetric BMD (vBMD) and structure at the distal and proximal tibia and radius were estimated by peripheral quantitative computed tomography. Hand grip strength and timed up-and-go were assessed, and sarcopenia was defined according to EWGSOP2 criteria. Incident falls were self-reported 6 and 12 months after baseline. Only 0.8% and 1.0% of participants had probable and confirmed sarcopenia, respectively. Almost one-third of participants with confirmed sarcopenia reported incident falls, compared with 20% for probable sarcopenia and 14% without sarcopenia (P = 0.025). Participants with confirmed sarcopenia had poorer bone parameters (all P < 0.05) except endosteal circumference at the proximal radius and tibia, while those with probable sarcopenia had lower cortical area at the proximal radius (B = - 5.9; 95% CI - 11.7, - 0.1 mm2) and periosteal and endosteal circumferences at the proximal tibia (- 3.3; - 6.4, - 0.3 and - 3.8; - 7.5, - 0.1 mm2, respectively), compared with those without sarcopenia. Compared with probable sarcopenia, confirmed sarcopenic participants had significantly lower lumbar spine and total hip aBMD, distal radius and tibia total vBMD, and proximal radius and tibia cortical vBMD, area and thickness (all P < 0.05). Swedish 70-year olds with confirmed sarcopenia demonstrate poorer BMD and bone architecture than those with probable and no sarcopenia, and have increased likelihood of incident falls.

Integration of Critical Infrastructure and Societal Consequence Models: Impact on Swedish Power System Mitigation Decisions.

Critical infrastructures provide society with services essential to its functioning, and extensive disruptions give rise to large societal consequences. Risk and vulnerability analyses of critical infrastructures generally focus narrowly on the infrastructure of interest and describe the consequences as nonsupplied commodities or the cost of unsupplied commodities; they rarely holistically consider the larger impact with respect to higher-order consequences for the society. From a societal perspective, this narrow focus may lead to severe underestimation of the negative effects of infrastructure disruptions. To explore this theory, an integrated modeling approach, combining models of critical infrastructures and economic input-output models, is proposed and applied in a case study. In the case study, a representative model of the Swedish power transmission system and a regionalized economic input-output model are utilized. This enables exploration of how a narrow infrastructure or a more holistic societal consequence perspective affects vulnerability-related mitigation decisions regarding critical infrastructures. Two decision contexts related to prioritization of different vulnerability-reducing measures are considered-identifying critical components and adding system components to increase robustness. It is concluded that higher-order societal consequences due to power supply disruptions can be up to twice as large as first-order consequences, which in turn has a significant effect on the identification of which critical components are to be protected or strengthened and a smaller effect on the ranking of improvement measures in terms of adding system components to increase system redundancy.

Objectively Measured Physical Activity in Older Adults With and Without Diabetes.

In Brief People with known diabetes were found to be 20% less active than people without diabetes as measured by objective accelerometers. A threshold of 6,000 steps per day was associated with the lowest risk of prevalent diabetes. The study also emphasizes the use of objective techniques to measure physical activity in subjects with diabetes.

Increased postural sway during quiet stance as a risk factor for prospective falls in community-dwelling elderly individuals.

Objective: fall-related injuries constitute major health risks in older individuals, and these risks are projected to increase in parallel with increasing human longevity. Impaired postural stability is a potential risk factor related to falls, although the evidence is inconclusive, partly due to the lack of prospective studies. This study aimed to investigate how objective measures of postural sway predict incident falls. Design, setting and participants: this prospectively observational study included 1,877 community-dwelling individuals aged 70 years who participated in the Healthy Ageing Initiative between June 2012 and December 2015. Measurements: postural sway was measured during eyes-open (EO) and eyes-closed (EC) trials using the Wii Balance Board. Functional mobility, muscle strength, objective physical activity and cognitive performance were also measured. Participants reported incident falls 6 and 12 months after the examination. Results: during follow-up, 255 (14%) prospective fallers were identified. Division of centre of pressure (COP) sway lengths into quintiles revealed a nonlinear distribution of falls for EO trial data, but not EC trial data. After adjustment for multiple confounders, fall risk was increased by 75% for participants with COP sway lengths ≥400 mm during the EO trial (odds ratio [OR] 1.75, 95% confidence interval [CI] 1.09-2.79), and approximately doubled for sway lengths ≥920 mm during the EC trial (OR 1.90, 95% CI 1.12-3.22). Conclusion: objective measures of postural sway independently predict incident falls in older community-dwelling men and women. Further studies are needed to evaluate whether postural sway length is of interest for the prediction of incident falls in clinical settings.

Topological performance measures as surrogates for physical flow models for risk and vulnerability analysis for electric power systems.

Critical infrastructure systems must be both robust and resilient in order to ensure the functioning of society. To improve the performance of such systems, we often use risk and vulnerability analysis to find and address system weaknesses. A critical component of such analyses is the ability to accurately determine the negative consequences of various types of failures in the system. Numerous mathematical and simulation models exist that can be used to this end. However, there are relatively few studies comparing the implications of using different modeling approaches in the context of comprehensive risk analysis of critical infrastructures. In this article, we suggest a classification of these models, which span from simple topologically-oriented models to advanced physical-flow-based models. Here, we focus on electric power systems and present a study aimed at understanding the tradeoffs between simplicity and fidelity in models used in the context of risk analysis. Specifically, the purpose of this article is to compare performance estimates achieved with a spectrum of approaches typically used for risk and vulnerability analysis of electric power systems and evaluate if more simplified topological measures can be combined using statistical methods to be used as a surrogate for physical flow models. The results of our work provide guidance as to appropriate models or combinations of models to use when analyzing large-scale critical infrastructure systems, where simulation times quickly become insurmountable when using more advanced models, severely limiting the extent of analyses that can be performed.

Variability in target delineation for cavernous sinus meningioma and anaplastic astrocytoma in stereotactic radiosurgery with Leksell Gamma Knife Perfexion.

BACKGROUND: Radiosurgery clinical practice relays on empirical observations and the experience of the practitioners involved in determining and delineating the target and therefore variability in target delineation might be expected for all the radiosurgery approaches, independent of the technique and the equipment used for delivering the treatment. The main aim of this study was to quantify the variability of target delineation for two radiosurgery targets expected to be difficult to delineate. The secondary aim was to investigate the dosimetric implications with respect to the plan conformity. The primary aim of the study has therefore a very general character, not being bound to one specific radiosurgery technique. MATERIALS AND METHODS: Twenty radiosurgery centers were asked to delineate one cavernous sinus meningioma and one astrocytoma and to plan the treatments for Leksell Gamma Knife Perfexion. The analysis of the delineated targets was based on the calculated 50 % agreement volume, AV50. The AV50 was compared to each delineated target by the concordance index and discordance index. The differences in location, size, and shape of the delineated targets were also analyzed using the encompassing volume compared to the common volume, i.e., the AV100, of all delineated structures. RESULTS: Target delineation led to major differences between the participating centers and therefore the AV50 was small in comparison to each delineated target volume. For meningioma, the AV50 was 5.90 cm(3), the AV100 was 2.60 cm(3), and the encompassing volume was 13.14 cm(3). For astrocytoma, the AV50 was 2.06 cm(3) while the AV100 was extremely small, only 0.05 cm(3), and the encompassing volume was 43.27 cm(3). These variations translate into corresponding discrepancies in plan conformity. CONCLUSIONS: Significant differences in shape, size, and location between the targets included in this study were identified and therefore the clinical implications of these differences should be further investigated.

Social inequality in prevalence of NCD risk factors: a cross-sectional analysis from the population-based Tromsø Study 2015-2016.

OBJECTIVE: We aimed to examine associations between educational level, serving as an indicator of socioeconomic position, and prevalence of WHO-established leading behavioural and biological risk factors for non-communicable diseases (NCDs), in middle-aged to older women and men. DESIGN: Population-based cross-sectional study. SETTING: All inhabitants of the municipality of Tromsø, Norway, aged ≥40 years, were invited to the seventh survey (2015-2016) of the Tromsø Study; an ongoing population-based cohort study. PARTICIPANTS: Of the 32 591 invited; 65% attended, and a total of 21 069 women (53%) and men aged 40-99 years were included in our study. OUTCOME MEASURES: We assessed associations between educational level and NCD behavioural and biological risk factors: daily smoking, physical inactivity (sedentary in leisure time), insufficient fruit/vegetable intake (<5 units/day), harmful alcohol use (>10 g/day in women, >20 g/day in men), hypertension, obesity, intermediate hyperglycaemia and hypercholesterolaemia. These were expressed as odds ratios (OR) per unit decrease in educational level, with 95% CIs, in women and men. RESULTS: In women (results were not significantly different in men), we observed statistically significant associations between lower educational levels and higher odds of daily smoking (OR 1.69; 95% CI 1.60 to 1.78), physical inactivity (OR 1.38; 95% CI 1.31 to 1.46), insufficient fruit/vegetable intake (OR 1.54, 95% CI 1.43 to 1.66), hypertension (OR 1.25; 95% CI 1.20 to 1.30), obesity (OR 1.23; 95% CI 1.18 to 1.29), intermediate hyperglycaemia (OR 1.12; 95% CI 1.06 to 1.19), and hypercholesterolaemia (OR 1.07; 95% CI 1.03 to 1.12), and lower odds of harmful alcohol use (OR 0.75; 95% CI 0.72 to 0.78). CONCLUSION: We found statistically significant educational gradients in women and men for all WHO-established leading NCD risk factors within a Nordic middle-aged to older general population. The prevalence of all risk factors increased at lower educational levels, except for harmful alcohol use, which increased at higher educational levels.