9,507 research outputs found
Bicycling to school during the transition from childhood into adolescence : a six-year longitudinal study
Little is known about bicycling to school as children age. At baseline (2002) self-report data from 1070 children were gathered (51.9% boys; mean age: 10 years). The measurements were repeated in 2003 (n = 1039), 2004 (n = 907), 2005 (n = 549) and 2008 (n = 515). The rates of children bicycling to school significantly varied across time points from 46% at the age of ten, 69% at the age of 11, 83% at the age of 12, 70% at the age of 13 toward 78% at the age of 16. Starting from the age of 11, the average duration of time spent bicycling to school significantly increased over time. According to multilevel regression analyses 13.6% of the variance in rates of bicycling to school was situated at the school level. 39.6% at the pupil level and 46.7% at the measurement level. The differences in rates and durations across time points were independent from gender, BMI, SES and having siblings. Pupils engaging in bicycling to school at younger ages had a higher change of engaging in bicycling to school at 16 years old (ORs: 2.69-7.61; ICC bicycling rates: 0.46, ICC bicycling durations: 0.82). This finding emphasizes the need for promoting bicycling to school at young age
Modeling Biased Technical Change. Implications for Climate Policy
Climate-economy models aiming at quantifying the costs and effects of climate change impacts and policies have become important tools for climate policy decision-making. Although there are several important dimensions along which models differ, this paper focuses on a key component of climate change economics and policy, namely technical change. This paper tackles the issues of whether technical change is biased towards the energy sectors, the importance of the elasticity of substitution between factors in determining this bias and how mitigation policy is likely to affect it. The analysis is performed using the World Induced Technical Change model, WITCH. Three different versions of the model are proposed. The starting set-up includes endogenous technical change only in the energy sector. A second version introduces endogenous technical change in both the energy and non-energy sectors. A third version of the model embodies different sources of technical change, namely R&D and human capital. Although different formulations of endogenous technical change have only a minor influence on climate policy costs, the macroeconomic effects on knowledge and human capital formation can vary greatly.Technical Change, Climate Policy, Stabilization Cost
Health promotion interventions in social economy companies in Flanders (Belgium)
BACKGROUND: Disadvantaged groups are often not reached by mainstream health promotion interventions. Implementing health promotion (HP) interventions in social economy companies, can be an opportunity to reach those people. The implementation of these interventions in social economy companies was studied. Factors that could be related to the implementation of HP and being supportive towards implementation in the future, were investigated.
METHODS: An online, quantitative survey was sent to all 148 sheltered and social workshops in Flanders. In the questionnaire, the status of HP interventions and characteristics of the workshop were explored. Personal factors (such as attitudes towards HP, behavioural control, social norms and moral responsibility) were asked to the person responsible for implementation of HP interventions. Univariate and multivariate logistic regressions were performed.
RESULTS: Respondents of 88 workshops completed the questionnaire. Almost 60 % of the workshops implemented environmental or policy interventions. Having a positive attitude towards HP, being more morally responsible, and having the subjective norm that employees are positive towards health promotion at work, were related to being more supportive towards the implementation of HP in the univariate analyses. Only attitude stayed significantly related to being more supportive towards the implementation of HP in the multivariate analyses.
CONCLUSIONS: Sheltered and social workshops are open to HP interventions, but more can be done to optimize the implementation. To persuade persons responsible for the implementation of HP to invest more in HP, changing attitudes concerning the benefits of health promotion for the employee and the company, is an important strategy
Hepatocyte-derived IL-10 plays a crucial role in attenuating pathogenicity during the chronic phase of T. congolense infection
Bovine African Trypanosomosis is an infectious parasitic disease affecting livestock productivity and thereby impairing the economic development of Sub-Saharan Africa. The most important trypanosome species implicated is T. congolense, causing anemia as most important pathological feature. Using murine models, it was shown that due to the parasite's efficient immune evasion mechanisms, including (i) antigenic variation of the variable surface glycoprotein (VSG) coat, (ii) induction of polyclonal B cell activation, (iii) loss of B cell memory and (iv) T cell mediated immunosuppression, disease prevention through vaccination has so far been impossible. In trypanotolerant models a strong, early pro-inflammatory immune response involving IFN-gamma, TNF and NO, combined with a strong humoral anti-VSG response, ensures early parasitemia control. This potent protective inflammatory response is counterbalanced by the production of the anti-inflammatory cytokine IL-10, which in turn prevents early death of the host from uncontrolled hyper-inflammation-mediated immunopathologies. Though at this stage different hematopoietic cells, such as NK cells, T cells and B cells as well as myeloid cells (i.e. alternatively activated myeloid cells (M2) or Ly6c(-) monocytes), were found to produce IL-10, the contribution of non-hematopoietic cells as potential IL-10 source during experimental T. congolense infection has not been addressed. Here, we report for the first time that during the chronic stage of T. congolense infection non-hematopoietic cells constitute an important source of IL-10. Our data shows that hepatocyte-derived IL-10 is mandatory for host survival and is crucial for the control of trypanosomosis-induced inflammation and associated immunopathologies such as anemia, hepatosplenomegaly and excessive tissue injury.
Author summary
Bovine African Trypanosomosis is a parasitic disease of veterinary importance that adversely affects the public health and economic development of sub-Saharan Africa. The most important trypanosome species implicated is T. congolense, causing anemia as most important pathological feature and major cause of death. Using murine models, it was shown that the disease is characterized by a well-timed and balanced production of pro-inflammatory cytokine promoting factors followed by an anti-inflammatory response, involving IL-10. The latter is required to attenuate infection-associated pathogenicity and to prevent early host death from uncontrolled hyper-inflammation mediated immunopathologies. However, the cellular source of IL-10 in vivo and the window within which these cells exert their function during the course of African trypanosomiasis remain poorly understood, which hampers the design of effective therapeutic strategies. Using a T. congolense infection mouse model, relevant for bovine trypanosomosis, we demonstrate that during the chronic stage of infection hepatocyte-derived IL-10, but not myeloid cell-derived IL-10, regulates the main infection-associated immunopathologies and ultimately mediates host survival. Hence, strategies that tilt the balance of hepatocyte cytokine production in favor of IL-10 could majorly impact the wellbeing and survival of T. congolense-infected animals. Given the unmet medical need for this parasite infection, our findings offer promise for improved treatment protocols in the field
The British Academy Brian Barry Prize Essay: mandatory citizenship for immigrants
Long-term immigrants often have the option but not the obligation to acquire citizenship in their state of residence. Contrary to the received wisdom, this article defends the idea of mandatory citizenship for immigrants. It suggests that the current asymmetry in the distribution of political obligations between native-born citizens and immigrants is unfair. It also argues that mandatory citizenship is required by the principle that those who persistently affect others should share a democratic setting. Finally, it claims that mandatory citizenship is more compatible with the ideal of democratic equality and more conducive to a stable society
A systematic review to identify the use of stated preference research in the field of older adult care
In the design of long-term care systems, preferences can serve as an essential indication to better tailor services to the needs, wishes and expectations of its consumers. The aim of this systematic review was to summarize and synthesize available evidence on long-term care preferences that have been elicited by quantitative stated-preference methods. The databases PubMed and Web of Science were searched for the period 2000 to 2020 with an extensive set of search terms. Two independent researchers judged the eligibility of studies. The final number of included studies was 66, conducted in 19 different countries. Studies were systematized according to their content focus as well as the survey method used. Irrespective of the heterogeneity of studies with respect to research focus, study population, sample size and study design, some consistent findings emerged. When presented with a set of long-term care options, the majority of study participants preferred to âage in placeâ and make use of informal or home-based care. With increasing severity of physical and cognitive impairments, preferences shifted toward the exclusive use of formal care. Next to the severity of care needs, the influence on preferences of a range of other independent variables such as income, family status and education were tested; however, none showed consistent effects across all studies. The inclusion of choice-based elicitation techniques provides an impression of how studies operationalized long-term care and measured preferences. Future research should investigate how preferences might change over time and generations as well as peopleâs willingness and realistic capabilities of providing care
Approximating Invertible Maps by Recovery Channels: Optimality and an Application to Non-Markovian Dynamics
We investigate the problem of reversing quantum dynamics, specifically via
optimal Petz recovery maps. We focus on typical decoherence channels, such as
dephasing, depolarizing and amplitude damping. We illustrate how well a
physically implementable recovery map simulates an inverse evolution. We extend
this idea to explore the use of recovery maps as an approximation of inverse
maps, and apply it in the context of non-Markovian dynamics. We show how this
strategy attenuates non-Markovian effects, such as the backflow of information.Comment: 7 pages, 8 figure
OBSERVATIONS OF BIRDS FEEDING ON THE FRUIT OF A SUCCESSIONAL TREE, TOPOBEA MULTIFLORA, IN SOUTHWESTERN COSTA RICA
Abstract â We observed several individuals of a tropical fruiting tree, Topobea multiflora (Melastomataceae), to determine the diversity and prevalence of bird species that use this plant as a food source. Conducted on the south Pacific slope of Costa Rica, these observations are of interest because T. multiflora, though it grows in early successional habitat, attracts many bird species typically associated with mature forest. Most of these species are potential candidates for dispersing the small seeds of mature forest species as they leave the forest to feed on the fruit of T. multiflora. In this study, we recorded 477 observations of 24 species belonging to seven families feeding on T. multiflora fruit during ten count periods of observation. The family Thraupidae (tanagers) had both the highest proportion of feeding observations (65.8%) and the greatest diversity of all visiting taxa (13 species). The five species with the highest overall prevalence (prevalence >5%) were Silverâthroated Tanager (Tangara icterocephala), Cherrieâs Tanager (Ramphocelus costaricensis), Thickâbilled Euphonia (Euphonia laniirostris), Common Bushâtanager (Chlorospingus ophthalmicus), and Bayâheaded Tanager (Tangara gyrola). Our results suggest that several species of Neotropical frugivores, because of their relationship to T. multiflora, may be considered indicator species of ongoing forest regeneration in southwestern Costa Rica. Resumen â Observaciones de especies de aves alimentĂĄndose de frutos de Topobea multiflora en el sudoeste de Costa Rica Observamos varios ejemplares de ĂĄrboles con frutos de la especie Topobea multiflora (Melastomataceae) para determinar la diversidad y prevalencia de las especies de aves que se alimentan de esta planta. Estas observaciones, realizadas en la pendiente sudâPacifica de Costa Rica, son de interĂ©s ya que T. multiflora, si bien crece en hĂĄbitats con disturbio o en regeneraciĂłn, atrae muchas especies generalmente asociadas a bosques maduros. La mayorĂa de estas especies son candidatos potenciales para la dispersiĂłn de semillas de especies de plantas de bosques maduros cuando se alejan del bosque para alimentarse de los frutos de T. multiflora. En este estudio, registramos 477 observaciones de alimentaciĂłn de frutos de T. multiflora, correspondientes a 24 especies pertenecientes a siete familias. La familia Thraupidae (tangaras) presento la mayor abundancia (341 observaciones) y la mayor riqueza de especies (13 especies). Las cinco especies con mayor prevalencia (> 5%) fueron: Tangara goliplateada (Tangara icterocephala), Tangara costarricense (Ramphocelus costaricensis), Eufonia piquigruesa (Euphonia laniirostris), Clorospingo comĂșn (Chlorospingus ophthalmicus) y Tangara cabecibaya (Tangara gyrola). Nuestros resultados sugieren que varias especies de aves frugĂvoras Neotropicales, debido a que frecuentan plantas de T. multiflora, podrĂan ser consideradas especies indicadoras de procesos de regeneraciĂłn de bosques.
Hemozoin is a key factor in the induction of malaria-associated immunosuppression
Infection-associated immunoincompetence during malaria might result from macrophage dysfunction. In the present study, we investigated the role of macrophages as target for immunosuppression during infection, using the murine Plasmodium c. chabaudi model. Special attention has been paid to the analysis of processing/presentation of protein antigens and presentation of peptides, using cocultures of peritoneal exudate cells (PECs) from infected mice and antigen-specific T-cell hybridomas. The results obtained indicate a defective processing of protein antigens that becomes maximal at acute parasitemias. In addition, macrophages from acutely infected mice suppress the interleukin-2 production by the antigen-activated T-cell hybridomas. This effect was independent of prostaglandin and nitric oxide production by the macrophage. The possible role of parasite components in the impaired accessory cell function of PECs was investigated and hemozoin, the end-product of the hemoglobin catabolism by intraerythrocytic malaria parasites, was found to induce similar infection-associated deficiencies in vitro. Moreover, hemozoin, was shown to mimic the immunosuppressive effects induced in PECs during in-vivo infections with P. chabaudi. In conclusion, we propose that hemozoin is a key factor in the malaria-associated immunosuppression, affecting both the antigen processing and immunomodulatory functions of macrophages
- âŠ