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  • 1
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    German Medical Science GMS Publishing House; Düsseldorf
    In:  48. Kongress für Allgemeinmedizin und Familienmedizin; 20140918-20140920; Hamburg; DOC14degam067 /20140911/
    Publication Date: 2014-09-12
    Keywords: Allgemeinmedizin ; Anwendbarkeit ; Leitlinien ; ddc: 610
    Language: German
    Type: conferenceObject
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  • 2
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    German Medical Science GMS Publishing House; Düsseldorf
    In:  HEC 2016: Health - Exploring Complexity; Joint Conference of GMDS, DGEpi, IEA-EEF, EFMI; 20160828-20160902; München; DOCAbstr. 663 /20160808/
    Publication Date: 2016-08-11
    Keywords: Environmental epidemiology ; Health geography ; Paediatric epidemiology ; ddc: 610
    Language: German
    Type: conferenceObject
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  • 3
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    German Medical Science; Düsseldorf, Köln
    In:  50. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie (gmds), 12. Jahrestagung der Deutschen Arbeitsgemeinschaft für Epidemiologie; 20050912-20050915; Freiburg im Breisgau; DOC05gmds122 /20050908/
    Publication Date: 2005-09-09
    Keywords: ddc: 610
    Language: German
    Type: conferenceObject
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  • 4
    ISSN: 0014-5793
    Keywords: Bacteriorhodopsin ; Membrane model ; Phospholipid-coated bead
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 158 (1989), S. 729-737 
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary From measurements of gas exchange of single tethered bees flying in a closed-circuit miniature respiration wind tunnel atRQ=1.0, a relative metabolic power (relative metabolic rate) ofP mrel=0.515±0.1W g−1 was calculated based on a body mass of 80 mg for an ‘empty’ bee. This did not vary significantly over the temperature range 25.3°C≤T a≤34.0°C, but was significantly lower atT a=20°C. Over the range 22°C≤T a≤26°CP mrel was 0.379±0.07 W g−1. Relative metabolic powerP m rel was calculated from round-about or wind tunnel post-flight thorax cooling rates (exponentially rising from 1 to 5.5°C min−1 per °C temperature difference at wind velocities from 0 to 4.3 m s−1) and from differences between thorax surface temperature and ambient temperature (exponentially decreasing from 6 to 1°C over the same range of wind velocities). A value ofP mrel=0.195±0.09W g−1 was found, independent of wind velocity. From measurements of exhaustion flights of defined fed bees executing prolonged flights (30.6±4.7 min) in front of an open-jet wind tunnel, a relative metabolic power of 0.309±0.05 W g−1 was calculated, which did not vary significantly over the temperature range 25°C≤T a≤35°C, but was significantly lower atT a=20°C. Our data from 3 experimentally different determinations ofP mrel are compared to data from a number of literature sources. A critical discussion suggests probable values of approximately 0.3 W g−1 for tethered flights (round-abouts, wind-tunnels), 0.4 W g−1 for medium speed free-foraging flights, and 0.5 W g−1 for hovering flight. Probable mechanical flight power for a muscle efficiency of 0.2 in medium speed free-foraging flight is approximately 70 mW g−1 body mass (equivalent to 5.6 mW for an ‘empty’ 80 mg bee) and 230 mW g−1 flight muscle mass. This is in the upper range of theoretical calculations, but not excessively high.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 158 (1989), S. 711-718 
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In round-about experiments (rate of success 40%) 80% of the bees began flying after thorax surface temperature had increased toT ts=34.1±1.8°C (warming). The starting temperature difference ΔT ts(=T ts−T a)=6.7±3.06 °C at an ambient temperature of 18.0°C≤T a≤29.6°C (‘normal starts’). The latter decreased to 2.80±0.83°C after 2–5 min and remained constant during 85% of the flight time (42.5±29.2 min) (Fig. 1A). 20% of the bees began flying at ΔT ts=1.6±0.3°C and continued to warm up during the first third of their flight (‘emergency starts’) (Fig. 1 B). During slowT a changes ΔT ts remained constant. Immediately after a flight stop, temperature increased by 6.2–18.7% during the following 30–60 s (‘out effect’) (Fig. 1C). Dangling the legs resulted in a pronounced temperature loss ofT ts≤1°C (Fig. 1 D). ΔT ts was negatively correlated withT a at the start (ΔT ts (°C)=88.32e−0.0926 Ta(°C); Fig. 2A), but not correlated toT a during the flight at 20.5°C≤T a≤26.7°C andv=0.72 ms−1 (Fig. 2B). Individual variation was high (Fig. 2C). Flight duration was not correlated toT a (Fig. 2D). During wind tunnel flights (rate of success 16–38%) ΔT ts reached a steady value after 2–5 min, remained steady during two thirds of the flight, and was not dependent onT a (Fig. 3C). The mean value of ΔT ts was 2.16±0.30°C at 19°C≤T a≤34°C andv=1.8 ms−1. Heating constants in still air before short walks, longer walks (t≥4 min) and round-about flights were 2.28±0.86 min−1, 3.55±1.33 min−1 and 3.64±0.73 min−1, respectively, but only 1.04±0.26 min−1 under wind tunnel conditions (resting, but exposed to a wind speed of 1.8 m s−1). Cooling constants after flight stop averaged 0.87±0.24 min−1 in still air, 2.8±0.2 min−1 in animals rotated at 0.72 m s−1, and 1.32±0.22 min−1 in animals exposed to a wind speed of 1.8 m s−1. No statistical difference in heating and cooling constants were found in the temperature range 18°C≤T a≤34°C. A significant positive correlation was found between ΔT ts and $$\dot V_{O_2 }$$ in resting bees exposed to a wind speed of 1.8 m s−1 (Fig. 4A-C).
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 158 (1989), S. 739-749 
    ISSN: 1432-136X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using manometric and gas analytical methods oxygen consumption $$\dot V_{O_2 }$$ , carbon dioxide production $$\dot V_{CO_2 }$$ , respiratory quotientRQ, (Fig. 1A-C) and thorax surface temperature difference ΔT ts (Fig. 3) were determined in single bees. The animals were either sitting in respiratory chambers or were suspended by the scutum, in which case they were resting, ‘walking’ (turning a small polystyrene ball) or flying in a closed miniature wind tunnel. During resting (sitting in Warburg vessels) at an ambient temperatureT a=10°C,RQ was 1.01±0.2 (n=905) with variations due to method (Fig. 1D, E).RQ values during walking were determined in single cases. In no case were they significantly different from 1.00. After the first 10 min of flight meanRQ was 1.00±0.04. It was significantly smaller than 1.00 (RQ=0.97) only during the last 5% of long-time flights (mean flight duration 58.8±28.8 min). With the exception of near-exhaustion conditions no signs of fuels other than carbohydrates were found. Metabolic rateP m was 19.71±21.38 mW g−1 during ‘resting’ at 20°C≤T a≤30°C indicating that many resting bees actively thermoregulate at higherT a. After excluding bees which were actively thermoregulating, by an approximationP m was 5.65±2.44 mW g−1 at 20°C≤T a≤30°C. ‘True resting metabolic rate’ for sitting bees atT a=10°C was 1.31±0.53 mW g−1 (Fig. 2A, B). A significant negative correlation was found between relative (specific) oxygen consumption $$\dot V_{O_2 }$$ rel and body massM b at 85 mg≤M b≤150 mg. At 0°C≤T ts≤16.5°C a significant (α-0.01) positive correlation was found between $$\dot V_{O_2 }$$ and ΔT ts in single resting bees: $$\dot V_{O_2 }$$ ΔT Ts+0.099, or betweenP m and ΔT ts:P m=1.343 ΔT ts+0.581 (Fig. 3D) $$\dot V_{O_2 }$$ in ml h−1,P m in mW,T in °C). During walking (duration 13.15±5.71 min,n=13) at 12.5°C≤T a≤21°C a stable ΔT ts of 11.41±3.37°C, corresponding to 167 mW g−1, was reached for 80 to 90% of the walking time (Fig. 4B). During wind tunnel flights of tethered animals the minimal metabolic power measured in exhaustion experiments was 240 mW g−1. Calculation of factors of increase inP m is of limited value in poikilotherms, in which true resting conditions are not exactly defined.
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