785 research outputs found

    A principal stratification approach to assess the differences in prognosis between cancers caused by hormone replacement therapy and by other factors

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    Several recent studies have reported that women who have used hormone replacement therapy (HRT), and developed breast cancer, tend to have a better prognosis than women with breast cancer who have not used HRT. One possible explanation is that tumors caused by HRT are more benign than tumors caused by other factors. Although it is relevant to quantify differences in prognostic factors across subtypes of breast cancer, it is not obvious how to do this correctly. This is because the tumors which occur among women who are treated with HRT are a mixture of HRT-induced and other tumors. We propose a framework based on principal stratification to distinguish women with HRT-induced tumors from women with tumors caused by other factors. To estimate the difference in prognosis for these two groups, we propose two estimation methods, which can be used under both cohort and case-control sampling schemes

    Materials preparation and longevity in hyperthermal atomic oxygen

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    Flight hardware fabrication, the design and fabrication of an atom beam source, construction of a surface science laboratory, and progress in research on processes and mechanisms of interaction of hyperthermal atoms at solid surfaces are discussed

    Striving to be prepared for the painful: Management strategies following a family member's diagnosis of advanced cancer

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    Background: Cancer has consequences not only for the sick person but also for those who have a close relationship with that person. Greater knowledge about how family members manage the situation in the period immediately following the diagnosis means greater opportunity to provide the best possible support for the family. The purpose of this study was to explore management strategies that family members use when the patient is in the early stage of treatment for advanced cancer. Methods: Twenty family members of cancer patients were included in the study shortly after the diagnosis. The patients had been diagnosed 8-14 weeks earlier with advanced lung cancer or gastrointestinal cancer. The data were collected in interviews with family members and subjected to qualitative latent content analysis. Through the identification of similarities and dissimilarities in the units of meaning, abstraction into codes and sub-themes became possible. The sub-themes were then brought together in one overarching theme. Results: The overall function of management strategies is expressed in the theme Striving to be prepared for the painful. The family members prepare themselves mentally for the anticipated tragedy. Family relationships become increasingly important, and family members want to spend all their time together. They try to banish thoughts of the impending death and want to live as normal a life as possible. It becomes important to family members to live in the present and save their energy for the time when they will need it the most. How participants handle their worries, anxiety and sadness can be categorized into seven sub-themes or management strategies: Making things easier in everyday life, Banishing thoughts about the approaching loss, Living in the present, Adjusting to the sick person’s situation, Distracting oneself by being with others, Shielding the family from grief, and Attempting to maintain hope. Conclusions: The findings revealed that the family members have their own resources for handling the early stage of the cancer trajectory in an acceptable way. There is a need for longitudinal studies to generate knowledge for designing evidence-based intervention programmes that can prevent future ill-health in these vulnerable family members

    Measurement of Untruncated Nuclear Spin Interactions via Zero- to Ultra-Low-Field Nuclear Magnetic Resonance

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    Zero- to ultra-low-field nuclear magnetic resonance (ZULF NMR) provides a new regime for the measurement of nuclear spin-spin interactions free from effects of large magnetic fields, such as truncation of terms that do not commute with the Zeeman Hamiltonian. One such interaction, the magnetic dipole-dipole coupling, is a valuable source of spatial information in NMR, though many terms are unobservable in high-field NMR, and the coupling averages to zero under isotropic molecular tumbling. Under partial alignment, this information is retained in the form of so-called residual dipolar couplings. We report zero- to ultra-low-field NMR measurements of residual dipolar couplings in acetonitrile-2-13^{13}C aligned in stretched polyvinyl acetate gels. This represents the first investigation of dipolar couplings as a perturbation on the indirect spin-spin JJ-coupling in the absence of an applied magnetic field. As a consequence of working at zero magnetic field, we observe terms of the dipole-dipole coupling Hamiltonian that are invisible in conventional high-field NMR. This technique expands the capabilities of zero- to ultra-low-field NMR and has potential applications in precision measurement of subtle physical interactions, chemical analysis, and characterization of local mesoscale structure in materials.Comment: 6 pages, 3 figure

    Automation of a Wireless Cotton Module Tracking System for Cotton Fiber Quality Mapping

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    The ability to map the profit made across a cotton field would enable producers to see in detail where money is being made or lost on their farms. This ability, which requires sitespecific knowledge of yield, fiber quality, and input costs would further enable them to implement precise field management practices to ensure that they receive the highest return possible on each portion of a field and do not waste materials and other inputs throughout the field. Investigators at Texas A&M previously developed a wireless-GPS system that tracks where a module of cotton comes from within a field. This system is a necessary component in mapping fiber quality, which is a major determiner of price and thus profit. Three drawbacks to the previous wireless-GPS system are that (1) a person must manually trigger the system to send wireless communications when a field machine dumps its load of cotton, (2) multiple field machines of the same type (e.g., two cotton pickers) cannot be used simultaneously on the same system within the same field, and (3) no software is available to automatically produce fiber-quality maps after the data are downloaded from the gin. The first two drawbacks, the need for an automatic communication-triggering system and the needed capability for multiple field machines of the same type are the problems addressed in this work. To solve the first problem, a sensing and control system was added to a harvester to automatically indicate when the machine is dumping a basket load of cotton so that wireless messages can be automatically sent from the harvester to subsequent field machines without human intervention. This automated communication-triggering system was incorporated into the existing wireless- GPS system, rigorously field tested, and ultimately proven to operate as designed. Linking data collected with this system together with classing information will enable producers to create fiber-quality maps, and linking fiber-quality maps with yield and input-cost maps will enable them to create profit maps. Additionally, a radio-frequency identification (RFID) system was integrated with the wireless-GPS system to allow for multiple field machines of the same type. The RFID system was also rigorously field tested and proven to operate as designed. Finally, the entire system was field tested as a whole and operated according to design. Thus, the wireless-GPS module tracking system now operates without human intervention and works with multiple field machines of each type, two additional capabilities required for practical use in large farming operations

    Adherence to dietary recommendations for Swedish adults across categories of greenhouse gas emissions from food

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    Objective To explore associations between diet-related greenhouse gas emissions (GHGE), nutrient intakes and adherence to the Nordic Nutrition Recommendations among Swedish adults. Design Diet was assessed by 4d food records in the Swedish National Dietary Survey. GHGE was estimated by linking all foods to carbon dioxide equivalents, using data from life cycle assessment studies. Participants were categorized into quartiles of energy-adjusted GHGE and differences between GHGE groups regarding nutrient intakes and adherence to nutrient recommendations were explored. Setting Sweden. Subjects Women (n 840) and men (n 627) aged 18-80 years. Results Differences in nutrient intakes and adherence to nutrient recommendations between GHGE groups were generally small. The dietary intake of participants with the lowest emissions was more in line with recommendations regarding protein, carbohydrates, dietary fibre and vitamin D, but further from recommendations regarding added sugar, compared with the highest GHGE group. The overall adherence to recommendations was found to be better among participants with lower emissions compared with higher emissions. Among women, 27 % in the lowest GHGE group adhered to at least twenty-three recommendations compared with only 12 % in the highest emission group. For men, the corresponding figures were 17 and 10 %, respectively. Conclusions The study compared nutrient intakes as well as adherence to dietary recommendations for diets with different levels of GHGE from a national dietary survey. We found that participants with low-emission diets, despite higher intake of added sugar, adhered to a larger number of dietary recommendations than those with high emissions

    Achieving Social and Ecological Outcomes in Collaborative Environmental Governance: Good Examples from Swedish Moose Management

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    Collaborative governance approaches have been suggested as strategies to handle wicked environmental problems. Evaluations have found promising examples of effective natural resource governance, but also highlighted the importance of social-ecological context and institutional design. The aim of this study was to identify factors that contribute to the achievement of social and ecological sustainability within Swedish moose (Alces alces) management. In 2012, a multi-level collaborative governance regime was implemented to decrease conflicts among stakeholders. We carried out semi-structured interviews with six 'good examples' (i.e., Moose Management Groups that showed positive social and ecological outcomes). We found that 'good examples' collectively identified existing knowledge gaps and management challenges and used their discretionary power to develop procedural arrangements that are adapted to the social-ecological context, their theory of change, and attributes of local actors. This contributed to the creation of bridging social capital and principled engagement across governance levels. Thus, our results indicate the existence of higher-order social learning as well as a positive feedback from within-level collaboration dynamics to between-level collaboration. Furthermore, our study illustrates the importance of institutional flexibility to utilize the existing knowledge across stakeholder groups and to allow for adaptations based on the social learning process

    Expectations about voluntary efforts in collaborative governance and the fit with perceived prerequisites of intrinsic motivation in Sweden’s ecosystem-based moose management system

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    Collaborative governance regimes may be vulnerable because of dependency on stakeholders??? voluntary engagement and efforts. This study focuses on the Swedish moose management system, a multi-level collaborative governance regime inspired by the ecosystem approach. Self-determination theory is used to explore perceived prerequisites of basic needs for intrinsic motivation across sub-groups of stakeholder representatives who are engaged across different social-ecological contexts. Questionnaire data collected among representatives at two governance levels, moose management groups (n = 624) and moose management units (n = 979), were subjected to two-step cluster analysis. The analyses revealed two sub-groups of representatives, characterized by differences in species composition and land ownership structure: managers of multi-ungulate areas and managers of large-carnivore areas. In several respects, these groups significantly differed in how they perceived the prerequisites. This included prerequisites of perceived competence with regard to their need for knowledge of topics and usefulness of monitoring methods, perceived autonomy operationalized as possibilities to perform their tasks with sufficient time, resources, and support from their organizations, and perceived relatedness to different groups of actors. Further efforts should be made to understand the conditions required for representatives to energize and direct their behavior. The institutional system must better fit the needs of stakeholder representatives across various local contexts, otherwise the space for local voluntary engagement might be hampered
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