Prioriteitstelling onderzoeksvragen weidevogels

In september 2008 heeft het secretariaat van de Kenniskring aan Alterra verzocht om samen met een aantal leden van de kenniskring een beknopt overzicht te maken van de huidige kennis op het gebied van het Weidevogelonderzoek. Specifiek gewenste acties waren: het opstellen van een overzicht van de bestaande kennis, het organiseren van een bijeenkomst met deskundigen op het gebied van ecologisch weidevogelonderzoek en het opstellen van een notitie met onderzoeksonderwerpen en prioriteiten

Op naar kerngebieden voor weidevogels in Nederland : werkdocument met randvoorwaarden en handreiking

Een methode is uitgewerkt om kerngebieden te identificeren voor weidevogels. Als gidssoort is de grutto gebruikt, implicaties voor de andere weidevogelsoorten zijn aangeduid. Als zoekgebied voor kerngebieden zijn aangeduid gebieden die voldoen aan minumumdichtheden (15 dan wel 30 bp/100 ha). Aan de hand van trendgegevens is geanalyseerd welke factoren bepalend zijn voor de aantalsontwikkeling. De resultaten hiervan zijn als randvoorwaarden gehanteerd voor de nadere invulling van de kerngebieden. Met een metapopulatiemodel is verkend aan welke ruimtelijke voorwaarden kerngebieden moeten voldoen: o.a. omvang en onderlinge afstanden, in relatie tot de ruimtelijke kwaliteit. Scenarioberekeningen zijn uitgevoerd naar verschillende ruimtelijke invullingen. Er is een handreiking opgesteld als voorbeeld hoe kerngebieden in de praktijk geidentificeerd en uitgewerkt zouden kunnen worden

A new in vitro assay for quantitation of chemotherapy-induced mucositis.

Patients receiving high-dose chemotherapy (HD-CT) are at risk of severe mucositis. Most prevention studies evaluate the degree of mucositis on clinical, and therefore subjective, measurements. The aim of this study was to develop an objective in vitro assay of chemotherapy-induced mucositis. Twelve patients with locally advanced breast carcinoma received HD-CT followed by peripheral stem cell reinfusion. Before and twice weekly after HD-CT, the mucosa was evaluated by an oral washing, a buccal smear and the World Health Organization (WHO) toxicity grading; furthermore, blood leucocyte levels were determined. For the oral washings, the percentage of viable epithelial cells was determined by trypan blue dye exclusion and leucocytes were counted by fluorescence microscopy after incubation with acridine orange. Maturity of buccal cells was assessed by staining buccal smears for morphology according to Papanicolaou (Whitacker D and Williams V, 1994). Eight healthy volunteers served as controls. The mean percentage (+/- s.e.m.) of viable oral epithelial cells was stable in controls (44 +/- 2%). In patients, they increased after HD-CT, which was significant after day 7 compared with pretreatment (P < or = 0.05). In addition, a shift from mature to immature epithelial cells in buccal smears was observed. Oral leucocyte levels were closely correlated with the blood leucocyte counts. The WHO score followed the results of these other evaluations with some delay. The viability of buccal cells obtained by oral washings increases after HD-CT. This is possibly because of desquamation of the upper oral mucosa layer, with a shift from mature to more immature cells. These data can be quantitated, and this assay may therefore be useful in studies aimed at prevention of mucositis

Computed Tomography-Based Body Composition Is Not Consistently Associated with Outcome in Older Patients with Colorectal Cancer

Background: Current literature is inconsistent in the associations between computed tomography (CT)-based body composition measures and adverse outcomes in older patients with colorectal cancer (CRC). Moreover, the associations with consecutive treatment modalities have not been studied. This study compared the associations of CT-based body composition measures with surgery- and chemotherapy-related complications and survival in older patients with CRC. Materials and Methods: A retrospective single-center cohort study was conducted in patients with CRC aged ≥65 years who underwent elective surgery between 2010 and 2014. Gender-specific standardized scores of preoperative CT-based skeletal muscle (SM), muscle density, intermuscular adipose tissue (IMAT), visceral adipose tissue (VAT), subcutaneous adipose tissue, IMAT percentage, SM/VAT, and body mass index (BMI) were tested for their associations with severe postoperative complications, prolonged length of stay (LOS), readmission, and dose-limiting toxicity using logistic regression and 1-year and long-term survival (range 3.7–6.6 years) using Cox regression. Bonferroni correction was applied to account for multiple testing. Results: The study population consisted of 378 patients with CRC with a median age of 73.4 (interquartile range 69.5–78.4) years. Severe postoperative complications occurred in 13.0%, and 39.4% of patients died during follow-up. Dose-limiting toxicity occurred in 77.4% of patients receiving chemotherapy (n = 53). SM, muscle density, VAT, SM/VAT, and BMI were associated with surgery-related complications, and muscle density, IMAT, IMAT percentage, and SM/VAT were associated with long-term survival. After Bonferroni correction, no CT-based body composition measure was significantly associated with adverse outcomes. Higher BMI was associated with prolonged LOS. Conclusion: The associations between CT-based body composition measures and adverse outcomes of consecutive treatment modalities in older patients with CRC were not consistent or statistically significant. Implications for Practice: Computed tomography (CT)-based body composition, including muscle mass, muscle density, and intermuscular, visceral, and subcutaneous adipose tissue, showed inconsistent and nonsignificant associations with surgery-related complications, dose-limiting toxicity, and overall survival in older adults with colorectal cancer. This study underscores the need to verify whether CT-based body composition measures are worth implementing in clinical practice

Ecological impact and cost-effectiveness of wildlife crossings in a highly fragmented landscape:A multi-method approach

Context: Road infrastructure construction is integral to economic development, but negatively affects biodiversity. To mitigate the negative impacts of infrastructure, various types of wildlife crossings are realized worldwide, but little is known about their effectiveness, and cost-effectiveness. Objective: The paper contributes to the methodological and empirical discussion on the effectiveness of wildlife crossings for enhancing the quality of surrounding nature and its cost-effectiveness by analyzing a large-scale wildlife-crossings program in the Netherlands. Method: A multi-criteria cost–benefit analysis is applied, comprised of monetary and non-monetary measures, and a mixed-method approach is used to determine ecological effects. Ecological effects are expressed in the standardized weighted hectare measurement of threat-weighted ecological quality area (1 T-EQA = 1 ha of 100% ecological quality, averagely threatened). Cost-effectiveness is calculated comparing the monetary costs of intervention with ecological benefits (Euro costs/T-EQA), for different types of wildlife crossings and for two other nature policies. Results: The Dutch habitat defragmentation program has induced an increase in nature value of 1734 T-EQA at a cost of Euro 283 million. Ecological gains per hierarchically ordered groups of measures differ strongly: The most effective are ecoducts (wildlife crossing bridges) followed by shared-use viaducts and large fauna tunnels. Ecoducts generated the largest gain in nature value, but were also the most costly measures. In terms of cost-effectiveness, both large fauna tunnels and shared-use viaducts for traffic and animals outperformed ecoducts. Conclusions: Ecoducts deliver ecologically, but their cost-effectiveness appears modest. Purchasing agricultural land for restoration of nature appears more cost-effective than building wildlife crossings. Yet, reducing environmental pressures or their effects on existing nature areas is likely to be most cost-effective.</p

Geolocators lead to better measures of timing and renesting in black-tailed godwits and reveal the bias of traditional observational methods

Long-term population studies can identify changes in population dynamics over time. However, to realize meaningful conclusions, these studies rely on accurate measurements of individual traits and population characteristics. Here, we evaluate the accuracy of the observational methods used to measure reproductive traits in individually marked black-tailed godwits (Limosa limosa limosa). By comparing estimates from traditional methods with data obtained from light-level geolocators, we provide an accurate estimate of the likelihood of renesting in godwits and the repeatability of the lay dates of first clutches. From 2012 to 2018, we used periods of shading recorded on the light-level geolocators carried by 68 individual godwits to document their nesting behaviour. We then compared these estimates to those simultaneously obtained by our long-term observational study. We found that among recaptured geolocator-carrying godwits, all birds renested after a failed first clutch, regardless of the date of nest loss or the number of days already spent incubating. We also found that 43% of these godwits laid a second replacement clutch after a failed first replacement, and that 21% of these godwits renested after a hatched first clutch. However, the observational study correctly identified only 3% of the replacement clutches produced by geolocator-carrying individuals and designated as first clutches a number of nests that were actually replacement clutches. Additionally, on the basis of the observational study, the repeatability of lay date was 0.24 (95% CI 0.17-0.31), whereas it was 0.54 (95% CI 0.28-0.75) using geolocator-carrying individuals. We use examples from our own and other godwit studies to illustrate how the biases in our observational study discovered here may have affected the outcome of demographic estimates, individual-level comparisons, and the design, implementation and evaluation of conservation practices. These examples emphasize the importance of improving and validating field methodologies and show how the addition of new tools can be transformational

The economic and ecological effects of water management choices in the upper Niger river: Development of decision support methods

One million people in the Inner Niger Delta make a living from arable farming, fisheries and livestock. Upstream dams (one built for electricity generation and one for irrigation) affect this downstream multifunctional use of water. Additionally, the Inner Niger Delta, which is one of the largest Ramsar sites in the world, is a hotspot of biodiversity and accommodates two of the largest known breeding colonies of large wading birds in Africa and in addition, is a vital part of the eco-regional network, supporting up to 3 to 4 million staging waterbirds, residents and migrants from all over Europe and western Asia. The hydrological and related ecological conditions in the Inner Delta largely determine the population size of these waterbird species. The major aim of the three-year study was to develop a decision-support system for river management in the Upper Niger, in which ecological and socio-economical impacts and benefits of dams and irrigation systems can be analysed in relation to different water management scenarios. The study involves various components: hydrology, arable farming, livestock, fisheries, ecology and socio-economics. An economic analysis has been conducted to determine the role of dams in the economy of the Inner Niger Delta and the Upper Niger region. By innovatively combining the above information on hydrology, ecology, fisheries, and agriculture, the study shows that building new dams is not an efficient way to increase economic growth and reduce poverty in the region. In fact, such efforts are counter-effective. Instead, development efforts should be aimed at improving the efficiency of the existing infrastructure, as well as of current economic activities in the Inner Niger Delta itself. This approach will also provide greater certainty for the essential eco-regional network functioning of the Inner Delta. © 2006 Taylor & Francis

Dutch guideline on total hip prosthesis

Contains fulltext : 97840.pdf (publisher's version ) (Open Access