127 research outputs found

    Harmonic oscillatory orientation relative to the wind in nocturnal roosting flights of the swift Apus apus.

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    Swifts regularly spend the night flying at high altitude. From previous studies based on tracking radar observations, we know that they stay airborne during the night and prefer to orient themselves into the wind direction with an increased angular concentration with increasing wind speed. In this study, we investigated the orientation relative to the wind of individual swifts by frequency (discrete Fourier transform) and autocorrelation analysis based on time series (10s intervals) of the angle between the swifts' heading and the wind direction for radar trackings of long duration (9-60 min). The swifts often showed a significant harmonic oscillation of their heading direction relative to the wind, with a frequency mostly in the range 1-17 mHz, corresponding to cycle periods of 1-16 min. The swifts also sometimes performed circling flights at low wind speeds. Wind speed ranged from 1.3 to 14.8 m s(-1), and we expected to find different patterns of orientation at different wind speeds, assuming that the swifts adapt their orientation to avoid substantial displacement during their nocturnal flights. However, oscillatory orientation was found at all wind speeds with variable frequencies/periods that did not show any consistent relationship with wind speed. It remains to be shown whether cyclic heading changes are a regular feature of bird orientation

    Mikrososiologisia merkintöjä Viron mafiasta

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    Umebors åsikter rörande grönområden

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    Grönområden kan bidra med en mängd nyttor till en stad som till exempel att reglera lokalklimatet, säkerställa vattenresurser och så vidare. Grönområden gynnar också människors hälsa både genom att verka mentalt återhämtande och underlätta och inspirera till fysisk aktivitet. Analysen av vad åsikterna kring grönområden i Umeå stad var utgick ifrån en enkätundersökning på nätet som dels publicerades på Umeå kommuns hemsida och dessutom skickades ut med e-post till de föreningar som fanns registrerade hos kommunen samt de verksamma på SLU i Umeå. Datainsamlingen avbröts när antalet svarande uppgått till 1000 stycken. Svaren kom från ett brett urval av befolkningen, och personer med olika åldrar, kön, uppväxtmiljöer med mera fanns representerade. Människor från de olika svarandekategorierna skiljde sig generellt inte ifrån varandra vad gäller preferenser för grönområden. Resultaten visade tydligt att det var mycket viktigt med tillgängliga grönområden samt att de flesta inte var beredda att ta sig längre än 100 - 300 meter för att besöka något av dessa områden i så hög utsträckning som de hade lust. Det var i samma utsträckning viktigt för de svarande att ha utsikt mot grönområden från arbetsplatser och bostäder. Områdena skulle också tillhandahålla en variationsrik miljö. Villigheten var också stor för att ta omvägar för att gå igenom något grönområde på väg i något annat ärende. Promenader och avkoppling var de aktiviteter som grönområden helst skulle möjliggöra, och upptrampade stigar var det föredragna underlaget att ta sig fram på i grönområden. En viktig sak var att de svarande ville kunna känna avskildhet när de besökte något grönområde. De miljöer som uppskattades mest att besöka var de som innehöll stora grova lövträd, skog och små vattendrag. Detsamma gäller för de miljöer som var intressantast att titta på. Blandskogen var den överlägset mest populära skogstypen. Arbetet mynnade också ut i ett antal tillämpningsförslag till Umeå kommun utifrån de åsikter som kommit fram i enkätundersökningen. Dessa förslag kan tjäna som ett underlag och bidra till kommunens grönplaneringsarbete. Fokus har lagts på områden inom den av kommunen tänkta femkilometersstaden som sträcker sig från centrum och universitetsområdet. Säkerställandet av en god kvalitet på grönstrukturen inom femkilometerstaden blir viktigt då det finns stora intressen för exploateringar för bostäder och verksamheter.Green spaces can provide a multitude of benefits to a city such as regulating local climate, securing water resources and so on. Green areas also benefit human health both by promoting mental recovery, and facilitate and inspire physical activity. The analysis of the views of green areas in Umeå town was drawn from a survey online that was partly published on Umeå Municipality's website and also sent out by e-mail to the associations that were registered by the municipality and people at SLU in Umeå. The data collection was stopped when the number of respondents reached a 1,000. The answers came from a broad range of the population, and people of different ages, gender, childhood environments, and more were represented. People from the different respondent categories did generally not differ from each other in terms of preference for greenery. The results clearly showed the importance to have available green space and that most were not prepared to travel further than 100 - 300 meters to visit any of these areas as often as they wanted. Equally important for the defendants was a view of greenery from their workplaces and homes. These areas should also provide a variety of environments. Willingness was also great to take detours through a green space when out on other business. The activities that green areas should allow were walking and relaxation, and moving on trodden paths was the preferred way to get around in green spaces. An important thing was that respondents wanted to feel solitude while visiting a green space. The most popular environments to visit were those that contained large deciduous trees, forests and small streams. The same goes for the environments that were interesting to watch. Mixed forests were by far the most popular wood type. The work also resulted in a number of implementing proposals for Umeå municipality based on the opinions that have emerged in the survey. These suggestions may support and contribute to the local green planning. The focus was on areas of the municipality proposed “five kilometres town” that extends from downtown and campus. Ensuring the quality of the green structure within the “five kilometres town” become important when there are major interests for exploitation for homes and businesses

    Stalinin kultin juurilla

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    Magnetic compass orientation in European robins is dependent on both wavelength and intensity of light

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    Magnetic compass orientation in birds has been shown to be light dependent. Results from behavioural studies indicate that magnetoreception capabilities are disrupted under light of peak wavelengths longer than 565 nm, and shifts in orientation have been observed at higher light intensities (43-44x1015 quanta s-1 m-2). To investigate further the function of the avian magnetic compass with respect to wavelength and intensity of light, we carried out orientation cage experiments with juvenile European robins, caught during their first autumn migration, exposed to light of 560.5 nm (green), 567.5 nm (green-yellow) and 617 nm (red) wavelengths at three different intensities (1 mW m-2, 5 mW m-2 and 10 mW m-2). We used monochromatic light of a narrow wavelength range (half bandwidth of 9-11 nm, compared with half bandwidths ranging between 30 nm and 70 nm used in other studies) and were thereby able to examine the magnetoreception mechanism in the expected transition zone between oriented and disoriented behaviour around 565 nm in more detail. We show (1) that European robins show seasonally appropriate migratory directions under 560.5 nm light, (2) that they are completely disoriented under 567.5 nm light under a broad range of intensities, (3) that they are able to orient under 617 nm light of lower intensities, although into a direction shifted relative to the expected migratory one, and (4) that magnetoreception is intensity dependent, leading to disorientation under higher intensities. Our results support the hypothesis that birds possess a light-dependent magnetoreception system based on magnetically sensitive, antagonistically interacting spectral mechanisms, with at least one high-sensitive short-wavelength mechanism and one low-sensitive long-wavelength mechanism

    Are flight paths of nocturnal songbird migrants influenced by local coastlines at a peninsula?

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    By recording nocturnally migrating passerines with tracking radar we have investigated how coastlines affect the migrants’ flight paths. Birds could use coastlines as an orientation aid or as a reference cue to compensate for wind drift while migrating. However, on the small scale of Falsterbo Peninsula in southern Sweden, we found very little effect of coastlines on migrants flight paths, irrespective of altitude. We tracked 2 930 migrants in three autumn and two spring seasons, at altitudes from 60 up to 3 000 meters. We compared tracks of migrants flying in three different areas, which correspond to the three main coastlines, and can demonstrate that the orientation of the tracks did not differ in a way consistent with the coastlines between the areas in autumn, and showed only a slight effect in spring. This is in accordance with earlier infrared device monitoring in Falsterbo, but contrary to earlier visual observations. It supports the view of nocturnally migrating passerines as mainly broad-front migrants. Even though the coastlines on the scale of the peninsula affected the flight paths very little, it is possible that the coastline has an effect on a larger regional scale, by migrants avoiding long sea crossings and thereby being funneled towards the peninsula, but this remains to be investigated

    Flight Speeds among Bird Species: Allometric and Phylogenetic Effects

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    Flight speed is expected to increase with mass and wing loading among flying animals and aircraft for fundamental aerodynamic reasons. Assuming geometrical and dynamical similarity, cruising flight speed is predicted to vary as (body mass)1/6 and (wing loading)1/2 among bird species. To test these scaling rules and the general importance of mass and wing loading for bird flight speeds, we used tracking radar to measure flapping flight speeds of individuals or flocks of migrating birds visually identified to species as well as their altitude and winds at the altitudes where the birds were flying. Equivalent airspeeds (airspeeds corrected to sea level air density, Ue) of 138 species, ranging 0.01–10 kg in mass, were analysed in relation to biometry and phylogeny. Scaling exponents in relation to mass and wing loading were significantly smaller than predicted (about 0.12 and 0.32, respectively, with similar results for analyses based on species and independent phylogenetic contrasts). These low scaling exponents may be the result of evolutionary restrictions on bird flight-speed range, counteracting too slow flight speeds among species with low wing loading and too fast speeds among species with high wing loading. This compression of speed range is partly attained through geometric differences, with aspect ratio showing a positive relationship with body mass and wing loading, but additional factors are required to fully explain the small scaling exponent of Ue in relation to wing loading. Furthermore, mass and wing loading accounted for only a limited proportion of the variation in Ue. Phylogeny was a powerful factor, in combination with wing loading, to account for the variation in Ue. These results demonstrate that functional flight adaptations and constraints associated with different evolutionary lineages have an important influence on cruising flapping flight speed that goes beyond the general aerodynamic scaling effects of mass and wing loading

    Activity and migratory flights of individual free-flying songbirds throughout the annual cycle:method and first case study

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    We describe a method and device ( 66 (max. 73) nocturnal migratory flights (29 flights in autumn and > 37, max. 44, in spring) adding up to a total of > 434 (max. 495) flight hours. Migratory flights lasted on average 6.6 h with maximum 15.9 h. These flights were aggregated into eight travel episodes (periods of 4-11 nights when flights took place on the majority of nights). Daytime resting levels were much higher during the winter period compared to breeding and final part of spring migration. Daytime resting showed peaks during days between successive nocturnal flights across Sahara, continental Africa and the Arabian Peninsula, indicating that the bird was mostly sleeping between these long migratory flights. Annual activity and flight data for free-living songbirds will open up many new research possibilities. Main topics that can be addressed are e.g. migratory flight performance (total flight investment, numbers and characteristics of flights), timing of stationary periods, activity patterns (resting/sleep, activity level) in different phases of the annual cycle and variability in the annual activity patterns between and within individuals

    How does lean work in emergency care? A case study of a lean-inspired intervention at the Astrid Lindgren Children's hospital, Stockholm, Sweden

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    <p>Abstract</p> <p>Background</p> <p>There is growing interest in applying lean thinking in healthcare, yet, there is still limited knowledge of how and why lean interventions succeed (or fail). To address this gap, this in-depth case study examines a lean-inspired intervention in a Swedish pediatric Accident and Emergency department.</p> <p>Methods</p> <p>We used a mixed methods explanatory single case study design. Hospital performance data were analyzed using analysis of variance (ANOVA) and statistical process control techniques to assess changes in performance one year before and two years after the intervention. We collected qualitative data through non-participant observations, semi-structured interviews, and internal documents to describe the process and content of the lean intervention. We then analyzed empirical findings using four theoretical lean principles (Spear and Bowen 1999) to understand how and why the intervention worked in its local context as well as to identify its strengths and weaknesses.</p> <p>Results</p> <p>Improvements in waiting and lead times (19-24%) were achieved and sustained in the two years following lean-inspired changes to employee roles, staffing and scheduling, communication and coordination, expertise, workspace layout, and problem solving. These changes resulted in improvement because they: (a) standardized work and reduced ambiguity, (b) connected people who were dependent on one another, (c) enhanced seamless, uninterrupted flow through the process, and (d) empowered staff to investigate problems and to develop countermeasures using a "scientific method". Contextual factors that may explain why not even greater improvement was achieved included: a mismatch between job tasks, licensing constraints, and competence; a perception of being monitored, and discomfort with inter-professional collaboration.</p> <p>Conclusions</p> <p>Drawing on Spear and Bowen's theoretical propositions, this study explains how a package of lean-like changes translated into better care process management. It adds new knowledge regarding how lean principles can be beneficially applied in healthcare and identifies changes to professional roles as a potential challenge when introducing lean thinking there. This knowledge may enable health care organizations and managers in other settings to configure their own lean program and to better understand the reasons behind lean's success (or failure).</p

    Adaptive strategies in nocturnally migrating insects and songbirds: contrasting responses to wind.

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    1. Animals that use flight as their mode of transportation must cope with the fact that their migration and orientation performance is strongly affected by the flow of the medium they are moving in, i.e. by the winds. Different strategies can be used to mitigate the negative effects and benefit from the positive effects of a moving flow. The strategies an animal can use will be constrained by the relationship between the speed of the flow and the speed of the animal’s own propulsion in relation to the surrounding air. 2. Here we analyse entomological and ornithological radar data from north-western Europe to investigate how two different nocturnal migrant taxa, the noctuid moth Autographa gamma and songbirds, deal with wind by analysing variation in resulting flight directions in relation to the wind-dependent angle between the animal’s heading and track direction. 3. Our results, from fixed locations along the migratory journey, reveal different global strategies used by moths and songbirds during their migratory journeys. As expected, nocturnally migrating moths experienced a greater degree of wind drift than nocturnally migrating songbirds, but both groups were more affected by wind in autumn than in spring. 4. The songbirds’ strategies involve elements of both drift and compensation, providing some benefits from wind in combination with destination and time control. In contrast, moths expose themselves to a significantly higher degree of drift in order to obtain strong wind assistance, surpassing the songbirds in mean ground speed, at the cost of a comparatively lower spatiotemporal migratory precision. 5. Moths and songbirds show contrasting but adaptive responses to migrating through a moving flow, which are fine-tuned to the respective flight capabilities of each group in relation to the wind currents they travel within
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