321 research outputs found

    Electromagnetic detection and real-time DMLC adaptation to target rotation during radiotherapy.

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    PURPOSE: Intrafraction rotation of more than 45° and 25° has been observed for lung and prostate tumors, respectively. Such rotation is not routinely adapted to during current radiotherapy, which may compromise tumor dose coverage. The aim of the study was to investigate the geometric and dosimetric performance of an electromagnetically guided real-time dynamic multileaf collimator (DMLC) tracking system to adapt to intrafractional tumor rotation. MATERIALS/METHODS: Target rotation was provided by changing the treatment couch angle. The target rotation was measured by a research Calypso system integrated with a real-time DMLC tracking system employed on a Varian linac. The geometric beam-target rotational alignment difference was measured using electronic portal images. The dosimetric accuracy was quantified using a two-dimensional ion chamber array. For each beam, the following five delivery modes were tested: 1) nonrotated target (reference); 2) fixed rotated target with tracking; 3) fixed rotated target without tracking; 4) actively rotating target with tracking; and 5) actively rotating target without tracking. Dosimetric performance of the latter four modes was measured and compared to the reference dose distribution using a 3 mm/3% γ-test. RESULTS: Geometrically, the beam-target rotational alignment difference was 0.3° ± 0.6° for fixed rotation and 0.3° ± 1.3° for active rotation. Dosimetrically, the average failure rate for the γ-test for a fixed rotated target was 11% with tracking and 36% without tracking. The average failure rate for an actively rotating target was 9% with tracking and 35% without tracking. CONCLUSIONS: For the first time, real-time target rotation has been accurately detected and adapted to during radiation delivery via DMLC tracking. The beam-target rotational alignment difference was mostly within 1°. Dose distributions to fixed and actively rotating targets with DMLC tracking were significantly superior to those without tracking

    Segmenting consumers of meat and dairy products from five European countries: Implications for promoting sustainable food choices

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    Accelerating the transition of agri-food systems towards higher sustainability requires greater understanding of consumers’ decision-making related to sustainable food choices, together with competing drivers which may result in unsustainable food choice demand. Meat and dairy production systems negatively contribute to greenhouse gas targets, unless sustainable production methods are applied, and these are understood by consumers and used in food choices. The psychological factors determining consumers’ attitudes towards sustainably produced meat and dairy products were assessed. Data were collected through an online survey across five European countries (Czechia, Spain, Sweden, Switzerland, and the United Kingdom) (n = 2,490) in November 2021. The results showed consumers perceived food sustainability to be less important than sensory and healthiness attributes. UK consumers showed the strongest intentions to increase consumption of sustainably produced meat and dairy products. In contrast, Swiss consumers demonstrated the weakest intentions. A twostage cluster analysis based on consumers’ perceived attribute importance identified four distinct segments: low food involvement (19.6%), high food involvement (31.9%), price-sensitive (23.2%), and health- and sustainability-involved (25.3%) consumer segments. Respondents in low food involvement and price-sensitive consumer segments tended to be younger and have lower environmental preservation attitudes and were more prevalent in Switzerland and Czechia. Those in high food involvement and health- and sustainability-involved consumer segments perceived higher importance of food sustainability and were more prevalent in Spain and Sweden. These respondents expressed greater intentions to increase consumption of sustainably produced meat and dairy products, at the same time being more likely to recognise the utility of sustainability labelling information. Animal welfare information was perceived to be most important for respondents in all the segments with the exception of those in the price-sensitive consumer segment. Building on the results, recommendations for promoting consumer sustainable food choices are propose

    European Permanent Grasslands: A Systematic Review of Economic Drivers of Change, Including a Detailed Analysis of the Czech Republic, Spain, Sweden, and UK

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    \ua9 2024 by the authors. Permanent grasslands (PG) feature in the European rural landscape and represent a major agricultural production resource. They support multiple non-provisioning ecosystem services (ES), including climate regulation, flood control, biodiversity, and pollination. PG are at risk of loss or degradation due to agricultural land use and land management changes. The objective of this systematic review is to identify the main economic influences shaping management and maintenance of PG, and the risks and opportunities for delivery of a range of ES. A total of 51 papers were included. Relevant policy interventions and economic drivers are identified in relation to how they shape the management of EU grasslands over time and across farming systems, countries, or biogeographic zones. A high reliance on public payments from the EU Common Agricultural Policy (CAP), with uneven impact on mitigating PG losses and associated ES provisions, was identified, which needs to be considered in relation to ongoing CAP reform. There is a gap in the literature regarding economic tipping points for change. Future research needs to identify and map ES provisions by PG along with trade-offs and synergies, and link this to policy. There are substantive challenges to maintaining Europe’s PG area and management, which must be addressed through EU-wide instruments

    Consumers across five European countries prioritise animal welfare above environmental sustainability when buying meat and dairy products

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    Food production systems, especially meat and dairy supply chains, contribute to greenhouse gas emissions. An important question emerges as to whether consumers care about environmental sustainability when buying food products, as this can determine their consumption practices. Further, if sustainability labels are available, identifying information that is relevant to consumers is important. This research therefore aimed to identify the attributes that are most important for consumers when buying meat or dairy products and the perceived helpfulness of sustainability labels for meat and dairy products and important label properties. An online survey was conducted in five European countries (i.e. Czechia, Spain, Sweden, Switzerland, and the UK). Consumers valued similar attributes when buying meat and dairy products across all countries. Freshness, quality/taste and animal welfare emerged as the most important attributes, while environmental attributes such as food miles, carbon footprint, and organic production were the least important. Sustainability labels for meat and dairy products were perceived as helpful. Regression analysis identified similar patterns within all five countries regarding the predictors of the perceived helpfulness of sustainability labels. Attitudes towards sustainable food consumption, environmental attitudes, and food production and policies emerged as significant positive predictors in most models. Most importantly, information regarding animal welfare, food safety, and health and nutrition was perceived as being more important than environmental sustainability. This suggests that food choice decisions are unlikely to be made based on the environmental sustainability of a food product’s production alone

    Detection of emphysema progression in alpha 1-antitrypsin deficiency using CT densitometry; Methodological advances

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    <p>Abstract</p> <p>Background</p> <p>Computer tomography (CT) densitometry is a potential tool for detecting the progression of emphysema but the optimum methodology is uncertain. The level of inspiration affects reproducibility but the ability to adjust for this variable is facilitated by whole lung scanning methods. However, emphysema is frequently localised to sub-regions of the lung and targeted densitometric sampling may be more informative than whole lung assessment.</p> <p>Methods</p> <p>Emphysema progression over a 2-year interval was assessed in 71 patients (alpha 1-antitrypsin deficiency with PiZ phenotype) with CT densitometry, using the 15<sup>th </sup>percentile point (Perc15) and voxel index (VI) -950 Hounsfield Units (HU) and -910 HU (VI -950 and -910) on whole lung, limited single slices, and apical, central and basal thirds. The relationship between whole lung densitometric progression (ΔCT) and change in CT-derived lung volume (ΔCT<sub>Vol</sub>) was characterised, and adjustment for lung volume using statistical modelling was evaluated.</p> <p>Results</p> <p>CT densitometric progression was statistically significant for all methods. ΔCT correlated with ΔCT<sub>Vol </sub>and linear regression indicated that nearly one half of lung density loss was secondary to apparent hyperinflation. The most accurate measure was obtained using a random coefficient model to adjust for lung volume and the greatest progression was detected by targeted sampling of the middle third of the lung.</p> <p>Conclusion</p> <p>Progressive hyperinflation may contribute significantly to loss of lung density, but volume effects and absolute tissue loss can be identified by statistical modelling. Targeted sampling of the middle lung region using Perc15 appears to be the most robust measure of emphysema progression.</p

    Effectiveness, cost-effectiveness and cost-benefit of a single annual professional intervention for the prevention of childhood dental caries in a remote rural Indigenous community

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    Background The aim of the study is to reduce the high prevalence of tooth decay in children in a remote, rural Indigenous community in Australia, by application of a single annual dental preventive intervention. The study seeks to (1) assess the effectiveness of an annual oral health preventive intervention in slowing the incidence of dental caries in children in this community, (2) identify the mediating role of known risk factors for dental caries and (3) assess the cost-effectiveness and cost-benefit of the intervention. Methods/design The intervention is novel in that most dental preventive interventions require regular re-application, which is not possible in resource constrained communities. While tooth decay is preventable, self-care and healthy habits are lacking in these communities, placing more emphasis on health services to deliver an effective dental preventive intervention. Importantly, the study will assess cost-benefit and cost-effectiveness for broader implementation across similar communities in Australia and internationally. Discussion There is an urgent need to reduce the burden of dental decay in these communities, by implementing effective, cost-effective, feasible and sustainable dental prevention programs. Expected outcomes of this study include improved oral and general health of children within the community; an understanding of the costs associated with the intervention provided, and its comparison with the costs of allowing new lesions to develop, with associated treatment costs. Findings should be generalisable to similar communities around the world. The research is registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), registration number ACTRN12615000693527; date of registration: 3rd July 2015

    Tipping points and farmer decision-making in European permanent grassland (PG) agricultural systems

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    Permanent grasslands (PG) provide multifunctional ecosystem services (ES) in Europe and globally, which are threatened by both increased farming intensity and land use change in marginal areas. Farm management decisions can represent critical thresholds, or behavioural “tipping points”, in the agricultural system. Decisions are influenced by a combination of agronomic, policy and social factors. Transformation of PG systems can be facilitated through positive tipping points and relevant policy implementation to ensure sustainable PG systems. The aim of this research was to understand the drivers of decisions regarding land use changes and management towards critical positive and negative tipping points across five biogeographic zones in Europe. Interview methodology assessed farmers’ preferences and priorities regarding the adoption of sustainable PG systems. Participants were selected from five case study countries, each representing a different biogeographic zone in Europe (Continental/Pannonian: Czech Republic, Boreal: Sweden, Mediterranean: Spain, Alpine: Switzerland, and Atlantic: UK). The sample also covered three farming intensity types within these biogeographic zones: high input/intensive conventional farms (≥1.0 LU /ha); low input/extensive conventional farms (&lt;1.0 LU/ha); and certified organic farms. In total, 373 farm interviews were obtained from the case study countries between October 2020 and October 2021. The analysis focuses on drivers of change and considers tipping points across these countries, considering case studies of land use changes (specifically land abandonment) and land management practices (specifically changes in stocking rates). The most common reasons for PG management changes towards either intensification or extensification were economic. Farmers require policy support to increase provision of non-market ES, while rebalancing subsidies can deliver environmental ES at scale through abandonment (e.g., through the creation of specific habitats that support some threatened species). Agri-environment schemes (AES)and subsidies could be more flexible to allow farmers to better adapt grassland management to local production conditions and unpredictable circumstances such as droughts, floods, or market shocks. To maintain PG that delivers more goods and services, financial compensation for ES delivery was perceived to be the most significant support mechanism needed, while easier access to ES provision expertise through extension or consultancy services is considered important factor

    A Minimal Threshold of c-di-GMP Is Essential for Fruiting Body Formation and Sporulation in Myxococcus xanthus

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    Generally, the second messenger bis-(3’-5’)-cyclic dimeric GMP (c-di-GMP) regulates the switch between motile and sessile lifestyles in bacteria. Here, we show that c-di-GMP is an essential regulator of multicellular development in the social bacterium Myxococcus xanthus. In response to starvation, M. xanthus initiates a developmental program that culminates in formation of spore-filled fruiting bodies. We show that c-di-GMP accumulates at elevated levels during development and that this increase is essential for completion of development whereas excess c-di-GMP does not interfere with development. MXAN3735 (renamed DmxB) is identified as a diguanylate cyclase that only functions during development and is responsible for this increased c-di-GMP accumulation. DmxB synthesis is induced in response to starvation, thereby restricting DmxB activity to development. DmxB is essential for development and functions downstream of the Dif chemosensory system to stimulate exopolysaccharide accumulation by inducing transcription of a subset of the genes encoding proteins involved in exopolysaccharide synthesis. The developmental defects in the dmxB mutant are non-cell autonomous and rescued by co-development with a strain proficient in exopolysaccharide synthesis, suggesting reduced exopolysaccharide accumulation as the causative defect in this mutant. The NtrC-like transcriptional regulator EpsI/Nla24, which is required for exopolysaccharide accumulation, is identified as a c-diGMP receptor, and thus a putative target for DmxB generated c-di-GMP. Because DmxB can be—at least partially—functionally replaced by a heterologous diguanylate cyclase, these results altogether suggest a model in which a minimum threshold level of c-di-GMP is essential for the successful completion of multicellular development in M. xanthus
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