1,145 research outputs found
Application of Fuzzy Cognitive Mapping in Livelihood Vulnerability Analysis
Feedback mechanisms are important in the analysis of vulnerability and resilience of social-ecological systems, as well as in the analysis of livelihoods, but how to evaluate systems with direct feedbacks has been a great challenge. We applied fuzzy cognitive mapping, a tool that allows analysis of both direct and indirect feedbacks and can be used to explore the vulnerabilities of livelihoods to identified hazards. We studied characteristics and drivers of rural livelihoods in the Great Limpopo Transfrontier Conservation Area in southern Africa to assess the vulnerability of inhabitants to the different hazards they face. The process involved four steps: (1) surveys and interviews to identify the major livelihood types; (2) description of specific livelihood types in a system format using fuzzy cognitive maps (FCMs), a semi-quantitative tool that models systems based on people’s knowledge; (3) linking variables and drivers in FCMs by attaching weights; and (4) defining and applying scenarios to visualize the effects of drought and changing park boundaries on cash and household food security. FCMs successfully gave information concerning the nature (increase or decrease) and magnitude by which a livelihood system changed under different scenarios. However, they did not explain the recovery path in relation to time and pattern (e.g., how long it takes for cattle to return to desired numbers after a drought). Using FCMs revealed that issues of policy, such as changing situations at borders, can strongly aggravate effects of climate change such as drought. FCMs revealed hidden knowledge and gave insights that improved the understanding of the complexity of livelihood systems in a way that is better appreciated by stakeholders
A cross-sectional study to determine the seroprevalence of bluetongue virus serotype 8 in sheep and goats in 2006 and 2007 in the Netherlands
Background: In August 2006 a major epidemic of bluetongue virus serotype 8 (BTV8) started off in North-West Europe. In the course of 2007 it became evident that BTV8 had survived the winter in North-West Europe, re-emerged and spread exponentially. Recently, the European Union decided to start vaccination against BTV8. In order to improve the understanding of the epidemiological situation, it was necessary to execute a cross-sectional serological study at the end of the BT vector season. Cattle were the target species for cross-sectional serological studies in Europe at the end of 2006 and 2007. However, there was no information on the BTV8- seroprevalence in sheep and goats. Results: On the basis of our cross-sectional study, the estimated seroprevalence of BTV8-exposed locations in the Netherlands in 2006 was 0% for goats (95% confidence interval: 0 ¿ 5.6%) and 7.0% for sheep (95% confidence interval: 3.5 ¿ 12.9%). The estimated seroprevalence of BTV-8 exposed locations in 2007 was 47% for goats (95% confidence interval: 36 ¿ 58%) and 70% for sheep (95% confidence interval: 63 ¿ 76%). There was a wide range in within-location seroprevalence in locations with goats and sheep (1 ¿ 100%). A gradient in seroprevalence was seen, with the highest level of seroprevalence in the southern Netherlands, the area where the epidemic started in 2006, and a decreasing seroprevalence when going in a northern direction. Conclusion: There is a much higher estimated seroprevalence of locations with goats exposed to BTV8 than can be inferred from the rather low number of reported clinical outbreaks in goats. This is probably due to the fact that clinical signs in infected goats are far less obvious than in sheep. The wide range in within-location seroprevalence observed means that the proportion of animals protected in 2008 by a natural infection in 2006 and/or 2007 can differ highly between flocks. This should be taken into account when vaccinating animals
Capturing aerosol droplet nucleation and condensation bursts using PISO and TVD schemes
A mathematical model for single-species aerosol production and transport is formulated, and solved using an adapted PISO algorithm. The model is applied to a laminar flow diffusion chamber, using a finite volume method on a collocated grid. In tran- sient simulations, a sharp scalar front (e.g., vapor mass fraction), is shown to introduce unphysical oscillation in the solution, when applying a second order linear interpolation in the convective terms. At increased grid resolution, these oscillations are strongly at- tenuated. When applying a TVD scheme (here the MUSCL scheme), a time-accurate monotonicity-preserving solution is obtained. The numerical dissipation introduced by the MUSCL scheme implies increased spatial resolution to restore high accuracy levels. We develop a one-dimensional grid refinement algorithm, which relates the grid density in one direction to the magnitude of the scalar gradient. In combination with the MUSCL scheme, this gives accurate results, with a significant reduction in computational effort, in comparison with a uniform fine grid
Long-term survival after successful out-of-hospital resuscitation
Between 1983 and 1989, 962 patients in Rotterdam were resuscitated outside hospital, of whom 240 (25%) could be discharged alive. A follow-up study was performed to determine prognosis in these patients. Of the 240 survivors of out-of-hospital resuscitation 80% survived after 1 year and 61% after 5 years. During the first year, 9% suffered from myocardial (re)infarction and 13% underwent coronary bypass surgery or angioplasty. Within the first 3 years after resuscitation 60% of the patients were readmitted to hospital. Permanent or temporary neurological deficits were observed in 30 patients (14%). Patients with a primary arrhythmia without myocardial infarction had a worse prognosis than patients with a cardiac arrest in the context of an infarct. Survival was better in patients in whom resuscitation was initiated by physicians or ambulance-nurses, than in patients resuscitated by lay-people. Multivariate analysis revealed that this difference could be explained by a larger proportion of patients with a primary arrhythmia in the latter group. Since long-term prognosis after out-of-hospital resuscitation is satisfactory, programmes for resuscitation courses should be stimulated. Such programmes should aim predominantly at relatives of patients with known heart disease, police officers and children
Fatigue in primary Sjogren's syndrome
OBJECTIVE: To assess fatigue in relation to depression, blood pressure,
and plasma catecholamines in patients with primary Sjogren's syndrome
(SS), in comparison with healthy controls and patients with rheumatoid
arthritis. METHODS: For the assessment of fatigue the Multidimensional
Fatigue Inventory (MFI) was used, a 20 item questionnaire, covering the
following dimensions: general fatigue, physical fatigue, mental fatigue,
reduced motivation, and reduced activity. Furthermore, the Zung depression
scale was used to quantify aspects of depression. Forty nine female
primary SS patients, 44 female patients with rheumatoid arthritis (RA),
and 32 healthy women filled in both questionnaires. In addition, supine
values of blood pressure and plasma catecholamines were measured in the
patients with primary SS. RESULTS: Primary SS patients were more fatigued
compared with the healthy controls on all the five dimensions of the MFI.
When the analyses were repeated using depression as a covariate, group
differences disappeared for the dimensions of reduced motivation and
mental fatigue. In the primary SS patients, significant positive
correlations between depression and the dimensions of reduced motivation
and mental fatigue were found. Comparing patients with primary SS with
those with RA, using depression as covariate, no statistically significant
differences were found between these groups. No relation between fatigue
and blood pressure was found, but a negative correlation was observed
between the general fatigue subscale of the MFI and plasma noradrenaline.
CONCLUSION: Patients with primary SS report more fatigue than healthy
controls on all the dimensions of the MFI and when controlling for
depression significant differences remain on the dimensions of general
fatigue, physical fatigue, and reduced activity. The negative correlations
between levels of noradrenaline and general fatigue in patients with
primary SS may imply the involvement of the autonomic nervous system in
chronic fatigue
The effects of the introduction of a project-based curriculum in the mechnaical engineering course at the University of Twente
Comparative interactomics analysis of different ALS-associated proteins identifies converging molecular pathways
Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease with no effective treatment available. An increasing number of genetic causes of ALS are being identified, but how these genetic defects lead to motor neuron degeneration and to which extent they affect common cellular pathways remains incompletely understood. To address these questions, we performed an interactomic analysis to identify binding partners of wild-type (WT) and ALS-associated mutant versions of ATXN2, C9orf72, FUS, OPTN, TDP-43 and UBQLN2 in neuronal cells. This analysis identified several known but also many novel binding partners of these proteins. Interactomes of WT and mutant ALS proteins were very similar except for OPTN and UBQLN2, in which mutations caused loss or gain of protein interactions. Several of the identified interactomes showed a high degree of overlap: shared binding partners of ATXN2, FUS and TDP-43 had roles in RNA metabolism; OPTN- and UBQLN2-interacting proteins were related to protein degradation and protein transport, and C9orf72 interactors function in mitochondria. To conf
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