1,445 research outputs found
Allometry of thermal variables in mammals: consequences of body size and phylogeny
No full textA large number of analyses have examined how basal metabolic rate (BMR) is affected by body mass in mammals. By contrast, the critical ambient temperatures that define the thermo-neutral zone (TNZ), in which BMR is measured, have received much less attention. We provide the first phylogenetic analyses on scaling of lower and upper critical temperatures and the breadth of the TNZ in 204 mammal species from diverse orders. The phylogenetic signal of thermal variables was strong for all variables analysed. Most allometric relationships between thermal variables and body mass were significant and regressions using phylogenetic analyses fitted the data better than conventional regressions. Allometric exponents for all mammals were 0.19 for the lower critical temperature (expressed as body temperature - lower critical temperature), −0.027 for the upper critical temperature, and 0.17 for the breadth of TNZ. The small exponents for the breadth of the TNZ compared to the large exponents for BMR suggest that BMR per se affects the influence of body mass on TNZ only marginally. However, the breadth of the TNZ is also related to the apparent thermal conductance and it is therefore possible that BMR at different body masses is a function of both the heat exchange in the TNZ and that encountered below and above the TNZ to permit effective homeothermic thermoregulation
Developmental phenotypic plasticity in a marsupial
No full textClimate change is likely to substantially affect the distribution ranges of species. However, little is known about how different mammalian taxa respond morphologically and physiologically to a rapid change of climate. Our objective was to provide the first quantitative data on the effect of continuous cold exposure during development on morphological and functional variables of a marsupial. Fat-tailed dunnarts ('Sminthopsis crassicaudata', Dasyuridae) were reared at an ambient temperature (Ta) of 16°C [cold-reared (CR)] or 22°C [warm-reared (WR)] until they reached adult age (>200 days). Body and head length of CR animals were significantly longer than in WR animals (mean ± s.e.m.; body: CR 80.8±6mm, WR 76.4±5mm; head: CR 29.4±3mm, WR 27.5±2mm), but other body attributes were not significantly different. Use of torpor was more frequent, torpor bout duration was longer and average daily metabolic rate and percentage of savings when using torpor were significantly higher (P200 days). Body and head length of CR animals were significantly longer than in WR animals (mean ± s.e.m.; body: CR 80.8±6mm, WR 76.4±5mm; head: CR 29.4±3mm, WR 27.5±2mm), but other body attributes were not significantly different. Use of torpor was more frequent, torpor bout duration was longer and average daily metabolic rate and percentage of savings when using torpor were significantly higher (
Carl Friedrich Geiser and Ferdinand Rudio : the men behind the first International Congress of Mathematicians
No full textThe first International Congress of Mathematicians (ICM) was held in Zurich in 1897, setting the standards for all future ICMs. Whilst giving an overview of the congress itself, this thesis focuses on the Swiss organisers, who were predominantly university professors and secondary school teachers. As this thesis aims to offer some insight into their lives, it includes their biographies, highlighting their individual contributions to the congress. Furthermore, it explains why Zurich was chosen as the first host city and how the committee proceeded with the congress organisation.
Two of the main organisers were the Swiss geometers Carl Friedrich Geiser (1843-1934) and Ferdinand Rudio (1856-1929). In addition to the congress, they also made valuable contributions to mathematical education, and in Rudio’s case, the history of mathematics. Therefore, this thesis focuses primarily on these two mathematicians.
As for Geiser, the relationship to his great-uncle Jakob Steiner is explained in more detail. Furthermore, his contributions to the administration of the Swiss Federal Institute of Technology are summarised. Due to the overarching theme of mathematical education and collaborations in this thesis, Geiser’s schoolbook "Einleitung in die synthetische Geometrie" is considered in more detail and Geiser’s methods are highlighted.
A selection of Rudio’s contributions to the history of mathematics is studied as well. His book "Archimedes, Huygens, Lambert, Legendre" is analysed and compared to E W Hobson’s treatise "Squaring the Circle". Furthermore, Rudio’s papers relating to the commentary of Simplicius on quadratures by Antiphon and Hippocrates are considered, focusing on Rudio’s translation of the commentary and on "Die Möndchen des Hippokrates". The thesis concludes with an analysis of Rudio’s popular lectures "Leonhard Euler" and "Über den Antheil der mathematischen Wissenschaften an der Kultur der Renaissance", which are prime examples of his approach to the history of mathematics
Heterothermy in pouched mammals – a review
No full textHibernation and daily torpor (i.e. temporal heterothermy) have been reported in many marsupial species of diverse families and are known to occur in ~15% of all marsupials, which is a greater proportion than the percentage of heterothermic placentals. Therefore, we aimed to gather data on heterothermy, including minimal body temperature, torpor metabolic rate and torpor bout duration for marsupials, and relate these physiological variables to phylogeny and other physiological traits. Data from published studies on 41 marsupial species were available for the present analysis. Heterothermic marsupials ranged from small species such as planigales weighing 7 g to larger species such as quolls weighing up to 1000 g. We used the marsupial phylogeny to estimate various heterothermic traits where the current dataset was incomplete. The torpor metabolic rate in relation to basal metabolic rate (%) ranged from 5.2 to 62.8% in daily heterotherms and from 2.1 to 5.2% in marsupial hibernators, and was significantly correlated with the minimum body temperature in daily heterotherms (R² = 0.77, P 0.05). The mean torpor bout duration ranged from 2 to 15 h in daily heterotherms and from 85 to 342 h in hibernators, and decreased significantly with increasing minimum body temperature in daily heterotherms (R² = 0.31,
Thermobiology, energetics and activity patterns of the Eastern tube-nosed bat (<i>Nyctimene robinsoni</i>) in the Australian tropics: effect of temperature and lunar cycle
No full textSUMMARY
Currently, there are no data on the thermal biology of free-ranging pteropodid bats (Chiroptera). Therefore, our aim was to investigate physiological and behavioural strategies employed by the fruit bat Nyctimene robinsoni (body mass ∼50 g) in winter in tropical Northern Queensland in relation to ambient temperature (Ta) and the lunar cycle. Daily body temperature (Tb) fluctuations in free-ranging bats were measured via radio-telemetry and metabolic rate was measured in captivity via open-flow respirometry (Ta, 15–30°C). Free-ranging bats showed a significant 24 h circadian cycle in Tb, with the lowest Tb at the end of the rest phase just after sunset and the highest Tb at the end of the activity phase just before sunrise. Average daily core Tb ranged from 34.7±0.6 to 37.3±0.8°C (mean ± s.d.) over an average daily Ta range of 17.1±1.1 to 23.5±1.8°C. Tb never fell below 30°C but Tb was significantly reduced during the full moon period compared with that during the new moon period. Tb was correlated with Ta during the second half of the rest phase (P&lt;0.001) but not during the active phase. Resting metabolic rate of bats was significantly affected by Ta (P&lt;0.001, R2=0.856). Our results show that tube-nosed bats exhibit reduced Tb on moonlit nights when they reduce foraging activity, but during our study torpor was not expressed. The energy constraints experienced here by tube-nosed bats with relatively moderate Ta fluctuations, short commuting distances between roosting and feeding locations, and high availability of food were probably not substantial enough to require use of torpor.</jats:p
Union City - Fritz Reuter Altenheim
No full textThe Fritz Reuter Altenheim, a retirement community named for the German author, Fritz Reuter.
It was established in 1897 and has always been a retirement home with a skilled nursing wing.
This facility provides 3 levels of care: Total Independent Apartments, Residential care and Skilled Nursing Care.Original file name IMG_1937 (2).jp
Fritz Bley Collection 1911-1913
No full textTwelve letters from the author and journalist Fritz Bley to his publisher, Georg Mueller in Munich; 1911-1913.digitizedFritz Bley (1853-1931) published the journal ‘Zeitfragen’
Jean Fritz, 15th Annual ODU Literary Festival
No full textJean Fritz has written over twenty historical biographies for young readers, including Stonewall, Where Do You Think You\u27re Going, Christopher Columbus?, The Double Life of Pocahontas, China Homecoming, And Then What Happened, Paul Revere?, and Why Don\u27t You Get a Horse, Sam Adams?, all of which were named ALA Notable Children\u27s Books. She is also the author of a memoir, Homesick: My Own Story, which won the 1983 American Book Award for Children\u27s Fiction. Jean Fritz has also been presented with the Laura Ingalls Wilder Award by the American Library Association for her substantial and lasting contribution to children\u27s literature
Fritz von Unruh Collection. 1951-1954
No full textThis collection contains a eulogy for Alwin Kronacher (German-born American dramaturgical consultant, actor and director) (1951); two theatrical programs for Fritz von Unruh plays (1952-1953); and a biographical sheet (1954).Author, 1885-1970The original German language inventory is available in the folderProcessed for digitizationdigitize
Activity patterns and torpor in two free-ranging carnivorous marsupials in arid Australia in relation to precipitation, reproduction, and ground cover
No full textIt is generally assumed that in unpredictable environments, the use of daily torpor and its interaction with daily activity are largely dependent on environmental thermal conditions and resource availability. Using temperature telemetry, we compared the thermal biology and activity patterns of 2 species of mulgaras ('Dasycercus blythi' and 'D. cristicauda') at 3 sites of different habitat types in central Australia. The work compared a dry period with a wet period (resource pulse). The most obvious functional difference among populations was observed in the timing of the onset of activity, which began significantly earlier in dense unburned spinifex (on average 17.7min before sunset) than in burned spinifex (4.6min after sunset) or on gibber plains (21.8min after sunset). However, although the seasonal expression of torpor differed significantly between males and females, torpor use as well as seasonal timing was similar among sites and periods despite differences in rainfall and habitat. It appears that predominantly reproductive activity governed torpor depth and duration in all measured populations and both species. Our data suggest that while the timing of activity is modulated by the amount of vegetation cover and thus protection from diurnal predators, torpor expression and winter reproduction in mulgaras are functionally linked and surprisingly more or less independent of apparent resource availability. Consequently, in mulgaras, daily torpor does not seem to be employed in response to immediate energy shortage but more likely to allow reallocation of energy and nutrients towards reproduction
- …
