763 research outputs found

    Computational Mesoscale Modeling and Homogenization of Liquid-Phase Sintering of Particle Agglomerates

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    Liquid phase sintering of particle agglomerates is simulated as the viscous deformation due to particle-particle contact, whereby the single driving force is the surface tension on the particle/pore interface. Particles are modeled as purely viscous fluids (with no elasticity). Computational homogenization is adopted for the RVE with Dirichlet boundary conditions. A surface motion algorithm was developed that requires complete remeshing of the FE-mesh based on a maximum deformation criterion. Since the particles are intrinsically incompressible, the macroscopic compressibility is determined from shrinking porosity in the substructure. The numerical examples include free sintering of an RVE and a fully coupled FE2-simulation of a specimen with inhomogeneous initial distribution of porosity

    Combining Spatiotemporal Corridor Design for Reindeer Migration with Harvest Scheduling in Northern Sweden

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    Reindeer husbandry and commercial forestry seek to co-exist in the forests of Northern Sweden. As interwoven as the two industries are, conflicts have arisen. Forest practices have reduced the distribution of lichen, the main winter diet for reindeer. Forest practices have also increased forest density, compromising the animals’ ability to pass through forested areas on their migration routes. In an attempt to reduce impacts on reindeer husbandry, we present a spatially explicit harvest scheduling model that includes reindeer corridors with user-defined spatial characteristics. We illustrate the model in a case study and explore the relationship between timber revenues and the selection and maintenance of reindeer corridors. The corridors are not only to include sufficient lichen habitat, but they are also supposed to ensure access for reindeer by connecting lichen areas with linkages that allow unobstructed travel. Since harvest scheduling occurs over a planning horizon, the spatial configuration of corridors can change from one time period to the next in order to accommodate harvesting activities. Our results suggest that maintaining reindeer corridors in harvest scheduling can be done at minimal cost. Also, we conclude that including corridor constraints in the harvest scheduling model is critical to guarantee connectivity of reindeer pastures

    The sarcopenia and physical frailty in older people : multi-component treatment strategies (SPRINTT) project: description and feasibility of a nutrition intervention in community-dwelling older Europeans

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    Background The "Sarcopenia and Physical Frailty in Older People: Multicomponent Treatment Strategies" (SPRINTT) project sponsored a multi-center randomized controlled trial (RCT) with the objective to determine the effect of physical activity and nutrition intervention for prevention of mobility disability in community-dwelling frail older Europeans. We describe here the design and feasibility of the SPRINTT nutrition intervention, including techniques used by nutrition interventionists to identify those at risk of malnutrition and to carry out the nutrition intervention. Methods SPRINTT RCT recruited older adults (>= 70 years) from 11 European countries. Eligible participants (n = 1517) had functional limitations measured with Short Physical Performance Battery (SPPB score 3-9) and low muscle mass as determined by DXA scans, but were able to walk 400 m without assistance within 15 min. Participants were followed up for up to 3 years. The nutrition intervention was carried out mainly by individual nutrition counseling. Nutrition goals included achieving a daily protein intake of 1.0-1.2 g/kg body weight, energy intake of 25-30 kcal/kg of body weight/day, and serum vitamin D concentration >= 75 mmol/L. Survey on the method strategies and feasibility of the nutrition intervention was sent to all nutrition interventionists of the 16 SPRINTT study sites. Results Nutrition interventionists from all study sites responded to the survey. All responders found that the SPRINTT nutrition intervention was feasible for the target population, and it was well received by the majority. The identification of participants at nutritional risk was accomplished by combining information from interviews, questionnaires, clinical and laboratory data. Although the nutrition intervention was mainly carried out using individual nutritional counselling, other assisting methods were used as appropriate. Conclusion The SPRINTT nutrition intervention was feasible and able to adapt flexibly to varying needs of this heterogeneous population. The procedures adopted to identify older adults at risk of malnutrition and to design the appropriate intervention may serve as a model to deliver nutrition intervention for community-dwelling older people with mobility limitations. Aim To describe the methods and feasibility of the nutritional intervention carried out within the SPRINTT Randomized cotrolled trial. We also illustrate how nutrition interventionists identified participants at risk of malnutrition and the lessons learnt from the nutrition intervention. Findings SPRINTT nutrition intervention was well-received by the majority of the participants. It was mainly carried out using tailored nutrition counselling, but also other means of delivering the intervention were successfully used. Compared with a standard nutrition prescription, an individualized protocol to diagnose malnutrition and follow-up by tailored nutrition counselling helped achieve nutritional targets more effectively in spite of diversity of population in nutritional habits and in some cases reluctance to accept changes. Message The SPRINTT nutrition intervention was feasible and allowed flexibility to the varying needs and cultural differences of this heterogeneous population of frail, older Europeans. It may serve as a model to educate and improve nutrition among community-dwelling older people at risk of mobility limitations.Peer reviewe

    Relationship Between Anticholinergic Burden and Health-Related Quality of Life Among Residents in Long-Term Care

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    Objectives Anticholinergic burden defined by the Anticholinergic Risk Scale (ARS) has been associated with cognitive and functional decline. Associations with health-related quality of life (HRQoL) have been scarcely studied. The aim of this study was to examine the association between anticholinergic burden and HRQoL among older people living in long-term care. Further, we investigated whether there is an interaction between ARS score and HRQoL in certain underlying conditions. Design and participants Cross-sectional study in 2017. Participants were older people residing in long-term care facilities (N=2474) in Helsinki. Measurements Data on anticholinergic burden was assessed by ARS score, nutritional status by Mini Nutritional Assessment, and HRQoL by the 15D instrument. Results Of the participants, 54% regularly used ARS-defined drugs, and 22% had ARS scores >= 2. Higher ARS scores were associated with better cognition, functioning, nutritional status and higher HRQoL. When viewing participants separately according to a diagnosis of dementia, nutritional status or level of dependency, HRQoL was lower among those having dementia, worse nutritional status, or being dependent on another person's help (adjusted for age, sex, comorbidities). Significant differences within the groups according to ARS score were no longer observed. However, interactions between ARS score and dementia and dependency emerged. Conclusion In primary analysis there was an association between ARS score and HRQoL. However, this relationship disappeared after stratification by dementia, nutritional status and dependency. The reasons behind the interaction concerning dementia or dependency remain unclear and warrant further studies.Peer reviewe

    Preferential attentional engagement drives attentional bias to snakes in Japanese macaques (Macaca fuscata) and humans (Homo sapiens)

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    © 2018, The Author(s). In humans, attentional biases have been shown to negative (dangerous animals, physical threat) and positive (high caloric food, alcohol) stimuli. However, it is not clear whether these attentional biases reflect on stimulus driven, bottom up, or goal driven, top down, attentional processes. Here we show that, like humans, Japanese macaques show an attentional bias to snakes in a dot probe task (Experiment 1). Moreover, this attentional bias reflects on bottom up driven, preferential engagement of attention by snake images (Experiment 2a), a finding that was replicated in a study that used the same methodology in humans (Experiment 2b). These results are consistent with the notion that attentional bias to snakes reflects on an evolutionarily old, stimulus driven threat detection mechanism which is found in both species

    Symptom burden in community-dwelling older people : temporal trends in the Helsinki Aging Study

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    Background Changes in older people's symptoms across recent decades have not been investigated. Aims We analyzed temporal trends in symptom burden by comparing data from independent, cross-sectional cohorts retrieved in 1989, 1999, 2009, and 2019. Furthermore, we compared the association between symptom burden and psychological wellbeing (PWB) in older men and women. Methods The Helsinki Aging Study recruited a random sample of people aged 75, 80, and 85 in 1989, and random samples aged 75, 80, 85, 90, and 95 in 1999, 2009, and 2019 (four study waves). Altogether, 6263 community-dwelling people answered the questions concerning symptoms in the questionnaire surveys. The symptoms inquired in all study waves were dizziness, back pain, joint pain, chest pain, shortness of breath, and loss of appetite. Symptom burden was calculated according to the number of symptoms and their frequency (score range: 0-6). PWB and the Charlson comorbidity index were calculated. Results Symptom burden decreased in both men and women aged 75 and 80 from 1989 to 2019. Changes in cohorts aged 85 + were nonsignificant. There was a significant difference in symptom burden between men and women in all ages with men having fewer symptoms. PWB decreased with increasing symptom burden. Men had greater PWB than women up to severe levels of symptom burden. Conclusions Symptom burden decreased from 1989 to 2019 in cohorts aged 75-80, whereas changes remained nonsignificant in cohorts aged 85 +. To our knowledge, this is the first study to examine temporal trends in symptom burden.Peer reviewe

    Human Young Children as well as Adults Demonstrate ‘Superior’ Rapid Snake Detection When Typical Striking Posture Is Displayed by the Snake

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    Humans as well as some nonhuman primates have an evolved predisposition to associate snakes with fear by detecting their presence as fear-relevant stimuli more rapidly than fear-irrelevant ones. In the present experiment, a total of 74 of 3- to 4-year-old children and adults were asked to find a single target black-and-white photo of a snake among an array of eight black-and-white photos of flowers as distracters. As target stimuli, we prepared two groups of snake photos, one in which a typical striking posture was displayed by a snake and the other in which a resting snake was shown. When reaction time to find the snake photo was compared between these two types of the stimuli, its mean value was found to be significantly smaller for the photos of snakes displaying striking posture than for the photos of resting snakes in both the adults and children. These findings suggest the possibility that the human perceptual bias for snakes per se could be differentiated according to the difference of the degree to which their presence acts as a fear-relevant stimulus

    Legislative strengthening meets party support in international assistance: a closer relationship?

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    Recent reports recommend that international efforts to help strengthen legislatures in emerging democracies should work more closely with support for building stronger political parties and competitive party systems. This article locates the recommendations within international assistance more generally and reviews the arguments. It explores problems that must be addressed if the recommendations are to be implemented effectively. The article argues that an alternative, issue-based approach to strengthening legislatures and closer links with civil society could gain more traction. However, that is directed more centrally at promoting good governance for the purpose of furthering development than at democratisation goals sought by party aid and legislative strengtheners in the democracy assistance industry

    Deltagardriven forskning – VĂ€xtodlingsgruppen, resultat och utvĂ€rdering av arbetet under 1998 till 2001

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    DÄ arbetet i vÀxtodlingsgruppen pÄbörjades var förvÀntningarna pÄ deltagardriven forskning att den sammanlagda erfarenheten hos lantbrukare, forskare och rÄdgivare skulle bidra till utförandet av relevanta gÄrdsförsök. Lantbrukarna önskade dessutom strÀva efter att öka och vidarebefordra den kunskap som fanns i gruppen, samt att fÄ etablerade forskare att undersöka omrÄden som praktikerna upplever som viktiga och svÄra. Redan i initialskedet slog vÀxtodlingsgruppen fast att arbeta för att gemensamt identifiera problem och anvÀnda relevanta forskningsmetoder pÄ gÄrdsnivÄ. Syftet var att genom olika odlingsÄtgÀrder kunna förbÀttra förutsÀttningarna för ekologisk vÀxtodling. Ett mÄl var att finna effektiva metoder för optimal vÀxtnÀringstillförsel i ekologisk produktion pÄ lerjordar i MÀlardalen. För nÀrvarande saknas bra underlag för hur kvÀveleveransen varierar under sÀsongen framförallt till strÄsÀd. Detta pÄverkar i sin tur bÄde skördeutfall, proteinhalt, miljöbelastning och ekonomi. Ett annat mÄl var att kunna reglera ogrÀsförekomsten, frÀmst kvickrot och tistel, pÄ ett effektivt sÀtt i vÀxtföljden. Motivationen för lantbrukarna har under projektets gÄng varit att frÀmja det ekologiska lantbruket som helhet. Detta har möjliggjorts genom erfarenhetsutbyte pÄ grupptrÀffar kombinerat med gÄrdsbesök dÀr lantbrukarnas intressen och frÄgestÀllningar har varit drivande. VÀxtodlingsgruppen har pÄ sÄ vis initialt bidragit till ett lokalt utvecklingsarbete och en uppbyggnad av ökat kunnande inom ekologiskt vÀxtodling
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