The air speed of migrating birds and its relationship to the wind

Summary This paper deals with the flight speeds of migrating birds observed by radar over a Swiss Alpine pass. The distributions of air speeds for different classes of birds and the influence of the wind on air speeds were investigated. Our findings differ greatly from observations of bird migration over the North Atlantic Ocean and the North American continent. Our data reveal: (1) that the air speeds of the bulk of migrating birds were in the range of 8–18 m/s and that the amount of slow flyers (air speed below 5 m/s) was less than 5%; (2) that there was an obvious influence of the wind on air speeds and, moreover, the data showed a distinctly variable compensatory behavior among different bird classes; (3) that the wind component in the direction of the bird's heading was a better predictor for air speed than the wind direction. Although we do not speculate about possibilities and mechanisms of wind detection, a simple argument shows how birds could estimate wind directions if they do use the moving surface as a reference system.     

Time-varying models for extreme values

We propose a new approach for modeling extreme values that are measured in time and space. First we assume that the observations follow a Generalized Extreme Value (GEV) distribution for which the location, scale or shape parameters define the space–time structure. The temporal component is defined through a Dynamic Linear Model (DLM) or state space representation that allows to estimate the trend or seasonality of the data in time. The spatial element is imposed through the evolution matrix of the DLM where we adopt a process convolution form. We show how to produce temporal and spatial estimates of our model via customized Markov Chain Monte Carlo (MCMC) simulation. We illustrate our methodology with extreme values of ozone levels produced daily in the metropolitan area of Mexico City and with rainfall extremes measured at the Caribbean coast of Venezuela.     

Prenatal diagnosis of X-linked retinitis pigmentosa (RP) in five pregnancies at risk

Five pregnancies at risk for X-linked retinitis pigmentosa (RP) have been monitored by first-trimester prenatal diagnosis using DNA markers flanking the RP2 and RP3 loci. Three affected and two unaffected fetuses, including a female carrying a wild-type genotype, were predicted on the basis of marker segregation and estimation of the recombination fraction.     

Bioaccumulation of selected organochlorines in bats and tits: Influence of chemistry and biology

We analyzed six organochlorine compounds (HCB, lindane, p,p’-DDE, PCB # 138, #153, and # 180) from populations of the European great tit (Parus major) and from five species of bats (Pipistrellus pipistrellus, Nyctalus noctula, Plecotus auritus, Plecotus austriacus, Myotis myotis). A weak positive correlation between K_ow (n-octanol /water partition coefficient) and bioaccumulation (measured as residue values) was found within each species. However, the ratio of the concentrations in bats compared to titmice increased significantly with increasing K_ow. We argue that this is explained by the intensive juvenile feeding through long-term lactation and thus by the more intensive transfer of strongly lipophilic xenobiotics from mother to juvenile in mammals compared to birds. Further, there were clear variations between bat species with ranges of up to 11 times the lowest value for a single compound. These differences are related to different feeding habits of the adults and to different species-specific life history traits, such as age at maturity and number of offspring.     

Analysis of six relevant toxaphene congeners in biological samples using ion trap MS/MS

Farmed and wild Scottish Atlantic salmon were obtained from retail suppliers, producers, and Stirling University in Scotland during January, 1999, for determination of 17 2,3,7,8-C1-substituted PCDDs and PCDFs, and seven nonortho- and mono-ortho-PCBs. The study confirms previous reports of relatively high concentrations of PCDDs, PCDFs and, especially, PCBs in farmed Scottish salmon. The results indicate that high consumption of salmon, particularly by children under 5 years, could lead to intakes above the tolerable daily intake (TDI) and tolerable weekly intake (TWI) for these chemicals, especially the PCBs, when combined with mean or high level intakes from the typical UK diet. These results suggest further investigation of farmed salmon and salmon feed, including feed fortified with fish oil and feed fortified with selected vegetable oils, is warranted.     

Testing the extended biotic index in Slovakia: consistency, advantages, and limitations versus the saprobic assessment method of water quality.

The European Union Water Framework Directive requires the achievement of environmental objectives for the ecological quality of water bodies. A comparable implementation of the Directive throughout member countries of the European Union is necessary to verify equal protection of surface waters. The Directive specifies that member states determine ecological quality by means of biological indices. To improve comparability of water quality assessment, this research carried out an intercalibration trial between the Slovak Saprobic Index and the Italian protocol of the Extended Biotic Index, as part of a cooperative program between Italy and the Slovak Republic. When assessing streams with no or low pollution, statistics showed similar results for both methods. In contrast, the comparison of indices was not accurate in the case of severely affected waters. Reliable conversion formulas are feasible to transform the Italian Extended Biotic Index into the Slovak Saprobic Index, and not vice versa.     

Rutabaga roots, a rich source of oviposition stimulants for the cabbage root fly

Summary. Two recently identified compounds ("CIFs"), present on the leaf surface of Brassica oleracea (cabbage), are the strongest oviposition stimulants known for the cabbage root fly, Delia radicum. Cabbage leaves contain these compounds in extremely low concentrations, and the amount of CIFs obtained from purifying leaf extracts was so small that it limited further research. We were able to purify far more of these two compounds from the roots of Brassica napus var. napobrassica (rutabaga). Apart from being a richer source of CIFs, rutabaga roots are considerably easier to collect and process than leaves. In addition, we isolated and identified a new CIF compound from the roots that is also very active in stimulating oviposition in the cabbage root fly. Received 26 May 2000; accepted 26 July 2000     

Parental awareness and perception for correct use of child restraint systems and airbags in Brazil

Objective: The objective of this study was to obtain information about the current knowledge and habits of parents who transport children in cars in Brazil.

Methods: A cross-sectional survey was conducted using specifically designed self-report questionnaires to parents of children attending a private pediatric office in a town in southwest Brazil. Data were collected regarding children's age, gender, height, and weight and possession of an automobile child restraint system (CRS), its type, frequency and adequacy of use, and reasons for not possessing or not using the devices. Parents were asked whether their cars were equipped with airbags and about the use of the restraints in seats with airbags.

Results: We interviewed parents of 293 children transported in cars who met the criteria for use of a CRS. Children were younger than 1 year in 15.3% of the cases, between 1 and 4 years in 38.6%, and older than 4 in 46.1%. Cars were equipped with CRS in 78.5% of the cases, but in only 58% of the cases was the device proper for child's age and adequately installed in the seat. Among owners of the devices, 84.3% reported that they always used it. Reasons for infrequency were forgetting the device at home or in another car (6.4%), the child disliking the device (3.2%), or the false impression that the child was grown enough not to use it (3.2%)l 87.1% did not justify why they did not always use the CRS. Considering type of CRS, correct installation of the seat, and frequency of use, only 44.4% of children under 1 year, 69.9% of those 1 to 4 years, and 52.6% over age 4 were protected. Only 28.6% of the parents knew that children should never be positioned in a seat with active airbags.

Conclusion: Considering appropriateness for age, correctness of installation (in the back seat in the correct orientation), and frequency of use, only 50.85% (149/293) of the children were reported as always protected with a CRS. Children between 1 and 4 years were more likely to always use a CRS in this Brazilian survey. We were also able to identify an important gap in the knowledge about airbags among parents. Further efforts are needed to correct those distortions.