171 research outputs found
Individuality in northern lapwing migration and its link to timing of breeding
We tracked eight adult northern lapwings Vanellus vanellus (six females and two males) from a Dutch breeding colony by light-level geolocation year-round, three of them for multiple years. We show that birds breeding virtually next to each other may choose widely separated wintering grounds, stretching from nearby the colony west towards the UK and Ireland, and southwest through France into Iberia and Morocco. However, individual lapwings appeared relatively faithful to a chosen wintering area, and timing of outward and homeward migration can be highly consistent between years. Movements of migratory individuals were usually direct and fast, with some birds covering distances of approximately 2000 km within 2 to 4 days of travel. The two males wintered closest and returned earliest to the breeding colony. The female lapwings returned well before the onset of breeding, spending a pre-laying period of 19 to 54 days in the wider breeding area. Despite the potential for high migration speeds, the duration that birds were absent from the breeding area increased with distance to wintering areas, a pattern which was mainly driven by an earlier outward migration of birds heading for more distant wintering grounds. Moreover, females that overwintered closer to colony bred earlier. A large variation in migration strategies found even within a single breeding colony has likely supported the speciesâ responsiveness to recent climate change as evidenced by a shortened migration distance and an advanced timing of reproduction in Dutch lapwings since the middle of the 20th century.
Migration strategies may vary between species, populations, individuals and between years within an individual. Individuals from a particular breeding population may migrate to the same wintering area or they may spread out over much of the non-breeding range. These connections between breeding and non-breeding areas of a migratory species are called âmigratory connectivityâ, and the strength of migratory connectivity has implications for the species ecology, evolution and conservation (Webster et al. 2002). Furthermore, the choice of a certain wintering area and migratory strategy may affect annual schedules including timing of events at breeding area (Marra et al. 1998), which demonstrates the importance to follow individuals throughout the annual cycle. Knowledge of variation in migratory routines within and between individuals of a population is also important to understanding and predicting the ability of species responses to environmental change, including climate change (Conklin et al. 2013).
We employed GLS (Global Location Sensing, also called âlight-level geolocationâ or just âgeolocationâ) technique based on the analysis of diurnal changes in light levels to track annual movements of northern lapwings (Vanellus vanellus; here synonymously termed âlapwing(s)â). Archival tags (âgeolocatorsâ) record light intensities to determine dusk and dawn times from which geographical positions (two fixes daily) are calculated; day (night) length determines the latitude and time of local midday (midnight) the longitude (Hill ).
Lapwings have been intensively ringed in many European countries for many years. Imboden (1974) undertook an extensive analysis (nicely summarized in Alerstam ) of ring recoveries collected during 1900 to 1969 from birds ringed as unfledged young and recovered within their first year of life or later. Albeit relying mainly on dead recoveries of hunted individuals, this analysis enabled the reconstruction of average seasonal movement patterns at population(s) level. It also revealed a large overlap in non-breeding locations used by lapwings originating from widely separated breeding colonies. Here, we present results from a first-time tracking study on this species by charting the year-round whereabouts of adult lapwings from a Dutch breeding colony. Some individuals were tracked for multiple years thereby providing first insights into individual consistency of migratory timing and choice of non-breeding locations. Finally, we investigate if spatial variation in non-breeding location relates to temporal variation of events at breeding area
Comparison of the skin sensitization potential of 3 red and 2 black tattoo inks using interleukin-18 as a biomarker in a reconstructed human skin model
Comparison of the skin sensitization potential of 3 red and 2 black tattoo inks using interleukin-18 as a biomarker in a reconstructed human skin model
Uncertainty Quantification and Certification Prediction of Low-Boom Supersonic Aircraft Configurations
The primary objective of this work was to develop and demonstrate a process for accurate and efficient uncertainty quantification and certification prediction of low-boom, supersonic, transport aircraft. High-fidelity computational fluid dynamics models of multiple low-boom configurations were investigated including the Lockheed Martin SEEB-ALR body of revolution, the NASA 69 Delta Wing, and the Lockheed Martin 1021-01 configuration. A nonintrusive polynomial chaos surrogate modeling approach was used for reduced computational cost of propagating mixed, inherent (aleatory) and model-form (epistemic) uncertainty from both the computation fluid dynamics model and the near-field to ground level propagation model. A methodology has also been introduced to quantify the plausibility of a design to pass a certification under uncertainty. Results of this study include the analysis of each of the three configurations of interest under inviscid and fully turbulent flow assumptions. A comparison of the uncertainty outputs and sensitivity analyses between the configurations is also given. The results of this study illustrate the flexibility and robustness of the developed framework as a tool for uncertainty quantification and certification prediction of low-boom, supersonic aircraft
Challenges in predicting the change in the cumulative exposure of new tobacco and related products based on emissions and toxicity doseâresponse data
Funding: This work was funded by the Netherlands Food and Consumer Product Safety Authority (NVWA), Utrecht, the Netherlands. Project number 9.7.1Many novel tobacco products have been developed in recent years. Although many may emit lower levels of several toxicants, their risk in the long term remains unclear. We previously published a method for the exposure assessment of mixtures that can be used to compare the changes in cumulative exposure to carcinogens among tobacco products. While further developing this method by including more carcinogens or to explore its application to non-cancer endpoints, we encountered a lack of data that are required for better-substantiated conclusions regarding differences in exposure between products. In this special communication, we argue the case for more data on adverse health effects, as well as more data on the composition of the emissions from tobacco products. Such information can be used to identify significant changes in relevance to health using the cumulative exposure method with different products and to substantiate regulatory decisions.Publisher PDFPeer reviewe
Statins Impair Antitumor Effects of Rituximab by Inducing Conformational Changes of CD20
Jakub Golab and colleagues found that statins significantly decrease rituximab-mediated complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity against B cell lymphoma cells
Surface free energy of polyurethane coatings with improved hydrophobicity
The polarity of polyurethane coats was studied on the basis of the goniometric method for determination of wetting angle values, on the basis of calculated surface free energy (SFE) values by the van OssâGood and OwensâWendt methods, and on the basis of polarity measurements with the use of the 1H NMR spectra. Test polyurethanes were synthesised in the reaction of methylene diphenyl 4,4âČ-diisocyanate (MDI) or 3-izocyanatomethyl â3,5,5- trimethylcyclohexyl isocyanate (IPDI) and polyoxyethylene glycols or polyesters poly(Δ-caprolactone) diols and poly(ethyleneadipate) diol with different molecular weights, and some diols as chain extenders, in dioxane. The type of raw material was found to significantly affect the phase structure of the obtained polyurethane elastomers and to control physical interactions within those structures, thus influencing the SFE values. Fundamental reduction in the SFE value of a coating below 28 mJ/m2 was achieved by the use of 2,2,3,3-tetrafluoro-1,4-butanediol as the urethane prepolymer chain extender
MAGIC observations of MWC 656, the only known Be/BH system
Context: MWC 656 has recently been established as the first observationally
detected high-mass X-ray binary system containing a Be star and a black hole
(BH). The system has been associated with a gamma-ray flaring event detected by
the AGILE satellite in July 2010. Aims: Our aim is to evaluate if the MWC 656
gamma-ray emission extends to very high energy (VHE > 100 GeV) gamma rays.
Methods. We have observed MWC 656 with the MAGIC telescopes for 23 hours
during two observation periods: between May and June 2012 and June 2013. During
the last period, observations were performed contemporaneously with X-ray
(XMM-Newton) and optical (STELLA) instruments. Results: We have not detected
the MWC 656 binary system at TeV energies with the MAGIC Telescopes in either
of the two campaigns carried out. Upper limits (ULs) to the integral flux above
300 GeV have been set, as well as differential ULs at a level of 5% of
the Crab Nebula flux. The results obtained from the MAGIC observations do not
support persistent emission of very high energy gamma rays from this system at
a level of 2.4% the Crab flux.Comment: Accepted for publication in A&A. 5 pages, 2 figures, 2 table
Feasibility, tailoring and properties of polyurethane/bioactive glass composite scaffolds for tissue engineering
- âŠ