X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • The Company of Biologists  (28)
  • Biodiversity Research  (28)
  • 1
    Online Resource
    Online Resource
    Terrestrial locomotion imposes high metabolic requirements on bats
    The Company of Biologists ; 2012
    In:  Journal of Experimental Biology
    Details
    In: Journal of Experimental Biology, The Company of Biologists
    Abstract: The evolution of powered flight involved major morphological changes in Chiroptera. Nevertheless, all bats are also capable of crawling on the ground and some are even skilled sprinters. We asked if a highly derived morphology adapted for flapping flight imposes high metabolic requirements on bats when moving on the ground. We measured the metabolic rate during terrestrial locomotion in mastiff bats, Molossus currentium; a species that is both, a fast-flying aerial-hawking bat and an agile crawler on the ground. Metabolic rates of bats averaged 8.0 ± 4.0 ml CO2 min-1 during a one minute period of sprinting at 1.3 ± 0.6 km h-1. With rising average speed, mean metabolic rates increased, reaching peak values that were similar to those of flying conspecifics. Metabolic rates of M. currentium were higher than those of similar-sized rodents under steady-state conditions that sprinted at similar velocities. When M. currentium sprinted at peak velocities its aerobic metabolic rate was 3-5 times higher than those of rodent species running continuously in steady-state condition. Costs of transport (J kg-1 m-1) were more than ten times higher for running than for flying bats. We conclude that at the same speed bats experience higher metabolic rates during short sprints than quadruped mammals during steady-state terrestrial locomotion, yet running bats achieve higher maximal mass-specific aerobic metabolic rates than non-volant mammals such as rodents.
    Type of Medium: Online Resource
    ISSN: 1477-9145 , 0022-0949
    URL: Article
    DOI: 10.1242/jeb.076224
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2012
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
  • 2
    Online Resource
    Online Resource
    Nathusius' bats optimize long-distance migration by flying at maximum range speed
    The Company of Biologists ; 2019
    In:  Journal of Experimental Biology Vol. 222, No. 4 ( 2019-02-15)
    Details
    In: Journal of Experimental Biology, The Company of Biologists, Vol. 222, No. 4 ( 2019-02-15)
    Abstract: Aerial migration is the fastest, yet most energetically demanding way of seasonal movement between habitats. However, for many taxa, and bats in particular, we lack a clear understanding of the energy requirements for migration. Here, we examined the energetic cost and flight speed of the long-distance migratory Nathusius’ bat (Pipistrellus nathusii). We measured flight metabolism in relation to airspeed in a wind tunnel, inferred the optimal traveling speed over long distances, i.e. maximum range speed, and compared this value with flight speed measured in wild conspecifics. Body mass and wing morphologies were similar in captive and wild bats, indicating that the body condition of captive bats was similar to that of migratory bats. Nine out of the 12 captive bats exhibited a U-shaped relationship between flight metabolic power and airspeed when flying in the wind tunnel. The flight metabolic rate across all airspeeds averaged 0.98±0.28 W, which corresponds well to established allometric relationships between flight metabolic rate and body mass for bats. During summer migration, P. nathusii traveled at an average speed of 6.9±0.7 m s−1, which was significantly higher than the minimum power speed (5.8±1.0 m s−1), yet within the range of expected maximum range speed inferred from wind tunnel experiments. This suggests that P. nathusii may migrate at an energetically optimal speed and that aerial refueling does not substantially lower migratory speed in P. nathusii.
    Type of Medium: Online Resource
    ISSN: 1477-9145 , 0022-0949
    URL: Article
    DOI: 10.1242/jeb.176396
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2019
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
  • 3
    Online Resource
    Online Resource
    Low turnover rates of carbon isotopes in tissues of two nectar-feeding bat species
    The Company of Biologists ; 2003
    In:  Journal of Experimental Biology Vol. 206, No. 8 ( 2003-04-15), p. 1419-1427
    Details
    In: Journal of Experimental Biology, The Company of Biologists, Vol. 206, No. 8 ( 2003-04-15), p. 1419-1427
    Abstract: Stable isotopes of carbon are commonly used to characterize dietary preferences in animals. Because turnover rates of carbon isotopes are related to metabolic rate, we wanted to determine the rates at which carbon isotopes are exchanged in tissues of two species of nectar-feeding bats(Leptonycteris curasoae and Glossophaga soricina), both of which have relatively high mass-specific metabolic rates. To test the hypothesis that isotope turnover is higher in nectar-feeding bats, because of their high mass-specific metabolic rates, than in other eutherian mammals, we conducted diet-switching experiments and chose three target tissues (hair,wing membrane and blood) to evaluate the isotopic turnover rates. We made the following predictions: (1) isotopic composition should change towards higherδ 13C-values due to the turnover of carbon isotopes of C3 origin with those of C4/CAM origin; (2) the turnover rates of carbon isotopes would differ between the three types of tissues in the following order of decreasing turnover rates: blood & gt;wing membrane & gt;hair; and (3) turnover rates of nectar-feeding bats should exceed those reported for other small mammals because of the high mass-specific metabolic rate of nectar-feeding bats. Compared to the initial diet, target tissues were enriched in heavy carbon isotopes by 2.8‰ in L. curasoae and by 2.6‰ in G. soricina. After changing the diet from C3 to C4/CAM origin we found an increase in abundance of 13C in blood and wing membrane in all experimental subjects. The estimated half life of carbon isotope turnover ranged from 100 to 134 days and did not differ significantly between blood and wing membrane,nor did it differ between the two species. The low turnover rate in wing membrane may reflect its specific composition and the relatively low temperature of this tissue, and long-lived erythrocytes in bat blood may be responsible for the low turnover rate of carbon isotopes in blood. The turnover rate of stable carbon isotopes in hair was low in L. curasoae and undetectable in G. soricina, which may be explained by the seasonal growth of the hair in these two species. Because both species are small (10 and 25 g, respectively) and nectar-feeding bats have higher mass-specific metabolic rates than bats in temperate regions or similar sized terrestrial mammals, our findings of low turnover rates were unexpected.
    Type of Medium: Online Resource
    ISSN: 1477-9145 , 0022-0949
    URL: Article
    DOI: 10.1242/jeb.00274
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2003
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
  • 4
    Online Resource
    Online Resource
    An insect trap as habitat: cohesion-failure mechanism prevents adhesion of Pameridea roridulae bugs to the sticky surface of the plant Roridula gorgonias
    The Company of Biologists ; 2008
    In:  Journal of Experimental Biology Vol. 211, No. 16 ( 2008-08-15), p. 2647-2657
    Details
    In: Journal of Experimental Biology, The Company of Biologists, Vol. 211, No. 16 ( 2008-08-15), p. 2647-2657
    Abstract: The glandular trichomes of the plant Roridula gorgonias release an extremely adhesive, visco-elastic, resinous secretion that traps a variety of insects, including those having a considerable body size. However, the specialized mutualistic mirid bug Pameridea roridulae lives and walks on this sticky plant surface without being trapped. We have sought to reveal the mechanism underlying the apparent non-sticky nature of the cuticle of this bug. In this study, we have visualized intact plant and insect surfaces using cryo-scanning electron microscopy and measured the adhesive properties of the plant secretion on different surfaces. We present a combination of structural and experimental results that suggest that a thick and cohesively weak film of an outermost, epicuticular greasy secretion acts as a `sloughing-off' layer,preventing the formation of contacts between the sticky plant secretion and the solid insect cuticle. In a comparative study of fresh cuticle fractures of flies representing a typical prey of R. gorgonias, a thin,fragmentary layer of epicuticular grease was revealed. These results indicate that, when trapping prey, the plant adhesive might form proper contact with solid islands of the insect cuticle that are free of epicuticular grease.
    Type of Medium: Online Resource
    ISSN: 1477-9145 , 0022-0949
    URL: Article
    DOI: 10.1242/jeb.019273
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2008
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
  • 5
    Online Resource
    Online Resource
    A dominant-negative form of the E3 ubiquitin ligase Cullin-1 disrupts the correct allocation of cell fate in the neural crest lineage
    The Company of Biologists ; 2006
    In:  Development Vol. 133, No. 3 ( 2006-02-01), p. 559-568
    Details
    In: Development, The Company of Biologists, Vol. 133, No. 3 ( 2006-02-01), p. 559-568
    Abstract: Selective protein degradation is an efficient and rapid way of terminating protein activity. Defects in protein degradation are associated with a number of human diseases, including potentially DiGeorge syndrome, which is characterised by abnormal development of the neural crest lineage during embryogenesis. We describe the identification of Xenopus Cullin-1, an E3 ubiquitin ligase, and show that blocking the function of endogenous Cullin-1 leads to pleiotropic defects in development. Notably, there is an increased allocation of cells to a neural crest fate and within this lineage, an increase in melanocytes at the expense of cranial ganglia neurons. Most of the observed effects can be attributed to stabilisation ofβ-catenin, a known target of Cullin-1-mediated degradation from other systems. Indeed, we show that blocking the function of Cullin-1leads to a decrease in ubiquitinated β-catenin and an increase in totalβ-catenin. Our results show that Cullin-1-mediated protein degradation plays an essential role in the correct allocation of neural crest fates during embryogenesis.
    Type of Medium: Online Resource
    ISSN: 1477-9129 , 0950-1991
    URL: Article
    DOI: 10.1242/dev.02201
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2006
    detail.hit.zdb_id: 2007916-3
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
  • 6
    Online Resource
    Online Resource
    Oxidation of linoleic and palmitic acid in pre-hibernating and hibernating common noctule bats revealed by 13C breath testing
    The Company of Biologists ; 2017
    In:  Journal of Experimental Biology
    Details
    In: Journal of Experimental Biology, The Company of Biologists
    Abstract: Mammals fuel hibernation by oxidizing saturated and unsaturated fatty acids from triacylglycerols in adipocytes, yet the relative importance of these two categories as an oxidative fuel may change during hibernation. We studied the selective use of fatty acids as an oxidative fuel in noctule bats (Nyctalus noctula). Pre-hibernating noctule bats that were fed 13C-enriched linoleic acid (LA) showed 12 times higher tracer oxidation rates compared to conspecifics fed 13C-enriched palmitic acid (PA). After this experiment, we supplemented the diet of bats with the same fatty acids on 5 subsequent days to enrich their fat depots with the respective tracer. We then compared the excess 13C enrichment (APE) in breath of bats for torpor and arousal events during early and late hibernation. We observed higher APE values in breath of bats fed 13C-enriched LA than in bats fed 13C-enriched PA for both states, torpor and arousal, and also for both periods. Thus, hibernating bats oxidized selectively endogenous LA instead of PA, most likely because of faster transportation rates of PUFA compared with SFA. We did not observe changes in APE values in the breath of torpid animals between early and late hibernation. Skin temperature of torpid animals increased by 0.7°C between early and late hibernation in bats fed PA, whereas it decreased by -0.8°C in bats fed LA, highlighting that endogenous LA may fulfil two functions when available in excess: serving as an oxidative fuel and supporting cell membrane functionality.
    Type of Medium: Online Resource
    ISSN: 1477-9145 , 0022-0949
    URL: Article
    DOI: 10.1242/jeb.168096
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2017
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
  • 7
    Online Resource
    Online Resource
    Electrolyte Transport Through a Cation-Selective ion Channel in Large Intestinal Enterocytes of Xenopus Laevis
    The Company of Biologists ; 1991
    In:  Journal of Experimental Biology Vol. 155, No. 1 ( 1991-01-01), p. 275-290
    Details
    In: Journal of Experimental Biology, The Company of Biologists, Vol. 155, No. 1 ( 1991-01-01), p. 275-290
    Abstract: Electrogenic ion transport through the colon epithelium of the African clawed toad (Xenopus laevis) was investigated with electrophysiological methods in vitro. Interest was focused on a previously described phenomenon, that removal of Ca2+ from the mucosal Ringer’s solution increases electrogenic sodium absorption. Our results clearly show that Ca2+ removal reveals an apical ion channel that is not a specific Na+ channel, but a non-selective cation channel with an ‘apparent’ ion selectivity of the order K+ & gt;Na+=Rb+ & gt;Cs+ & gt;Li+. This Ca2+-sensitive current increased linearly with the mucosal pH, and could be inhibited by other divalent cations (Mg2+, Ba2+) and the organic ion channel blockers quinidine and verapamil. The mucosal Ca2+ concentration that induced a half-maximal inhibition of the Ca2+-sensitive current was about 1 μmoll−1 and was independent of the mucosal pH. Owing to the high Ca2+ sensitivity, a regulation of the channel conductivity by extracellular Ca2+ is ruled out. It is concluded that this channel, which is almost identical to similar channels found in amphibian skin and bladder, acts as a pathway for cation absorbing or secreting processes. Possibly the binding of extracellular Ca2+ is related to selectivity changes of the Ca2+-sensitive ion channel.
    Type of Medium: Online Resource
    ISSN: 0022-0949 , 1477-9145
    URL: Article
    DOI: 10.1242/jeb.155.1.275
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 1991
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
  • 8
    Online Resource
    Online Resource
    Stable carbon isotopes in exhaled breath as tracers for dietary information in birds and mammals
    The Company of Biologists ; 2008
    In:  Journal of Experimental Biology Vol. 211, No. 14 ( 2008-07-15), p. 2233-2238
    Details
    In: Journal of Experimental Biology, The Company of Biologists, Vol. 211, No. 14 ( 2008-07-15), p. 2233-2238
    Abstract: The stable carbon isotope ratio of exhaled CO2(δ13Cbreath) reflects the isotopic signature of the combusted substrate and is, therefore, suitable for the non-invasive collection of dietary information from free-ranging animals. However,δ 13Cbreath is sensitive to changes in ingested food items and the mixed combustion of exogenous and endogenous substrates. Therefore, experiments under controlled conditions are pivotal for the correct interpretation of δ13Cbreath of free-ranging animals. We measured δ13Cbreath in fasted and recently fed insectivorous Myotis myotis (Chiroptera) to assess the residence time of carbon isotopes in the pool of metabolized substrate, and whether δ13Cbreath in satiated individuals levels off at values similar to the dietary isotope signature(δ13Cdiet) in insect-feeding mammals. Meanδ 13Cbreath of fasted individuals was depleted by–5.8‰ (N=6) in relation toδ 13Cdiet. After feeding on insects, bats exchanged 50% of carbon atoms in the pool of metabolized substrates within 21.6±10.5 min, which was slower than bats ingesting simple carbohydrates. After 2 h, δ13Cbreath of satiated bats levelled off at –2.6‰ belowδ 13Cdiet, suggesting that bats combusted both exogenous and endogenous substrate at this time. A literature survey revealed that small birds and mammals metabolize complex macronutrients at slower rates than simple macronutrients. On average, δ13Cbreathof fasting birds and mammals was depleted in 13C by–3.2±2.0‰ in relation toδ 13Cdiet. δ13Cbreathof satiated animals differed by –0.6±2.3‰ fromδ 13Cdiet when endogenous substrates were not in isotopic equilibrium with exogenous substrates and by +0.5±1.8‰(N=6 species) after endogenous substrates were in isotopic equilibrium with exogenous substrates.
    Type of Medium: Online Resource
    ISSN: 1477-9145 , 0022-0949
    URL: Article
    DOI: 10.1242/jeb.018523
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2008
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
  • 9
    Online Resource
    Online Resource
    Inflammatory challenge increases measures of oxidative stress in a free-ranging, long-lived mammal
    The Company of Biologists ; 2013
    In:  Journal of Experimental Biology
    Details
    In: Journal of Experimental Biology, The Company of Biologists
    Abstract: Oxidative stress - the imbalance between reactive oxygen species (ROS) and neutralising antioxidants - has been under debate as the main cause of ageing in aerobial organisms. The level of ROS should increase during infections as part of the activation of an immune response, leading to oxidative damage on proteins, lipids and DNA. Yet, it is unknown how long-lived organisms, especially mammals, cope with oxidative stress. Bats are known to carry a variety of zoonotic pathogens and at the same time are despite their high mass-specific basal metabolic rate unusually long-lived, which may be partly caused by low oxidative damage of organs. Here, we ask if an immune challenge causes oxidative stress in free-ranging bats, measuring two oxidative stress markers. We injected 20 short-tailed fruit bats (Carollia perspicillata) with bacterial derived lipopolysaccharides (LPS) and 20 individuals with phosphate-buffered saline solution (PBS) as a control. Individuals injected with LPS showed an immune reaction by increased white blood cell count after 24h, whereas there was no significant change in leukocyte counts in control animals. The biological antioxidant potential (BAP) remained the same in both groups, but reactive oxygen metabolites (ROM) increased after treatment with LPS, indicating a significant increase in oxidative stress in animals when mounting an immune reaction toward the inflammatory challenge. Control individuals did not show a change in oxidative stress markers. We conclude that in a long-lived mammal, even high concentrations of antioxidants do not immediately neutralise free radicals produced during a cellular immune response. Thus, fighting an infection may lead to oxidative stress in bats.
    Type of Medium: Online Resource
    ISSN: 1477-9145 , 0022-0949
    URL: Article
    DOI: 10.1242/jeb.090837
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2013
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
  • 10
    Online Resource
    Online Resource
    Deep learning is widely applicable to phenotyping embryonic development and disease
    The Company of Biologists ; 2021
    In:  Development Vol. 148, No. 21 ( 2021-11-01)
    Details
    In: Development, The Company of Biologists, Vol. 148, No. 21 ( 2021-11-01)
    Abstract: Genome editing simplifies the generation of new animal models for congenital disorders. However, the detailed and unbiased phenotypic assessment of altered embryonic development remains a challenge. Here, we explore how deep learning (U-Net) can automate segmentation tasks in various imaging modalities, and we quantify phenotypes of altered renal, neural and craniofacial development in Xenopus embryos in comparison with normal variability. We demonstrate the utility of this approach in embryos with polycystic kidneys (pkd1 and pkd2) and craniofacial dysmorphia (six1). We highlight how in toto light-sheet microscopy facilitates accurate reconstruction of brain and craniofacial structures within X. tropicalis embryos upon dyrk1a and six1 loss of function or treatment with retinoic acid inhibitors. These tools increase the sensitivity and throughput of evaluating developmental malformations caused by chemical or genetic disruption. Furthermore, we provide a library of pre-trained networks and detailed instructions for applying deep learning to the reader's own datasets. We demonstrate the versatility, precision and scalability of deep neural network phenotyping on embryonic disease models. By combining light-sheet microscopy and deep learning, we provide a framework for higher-throughput characterization of embryonic model organisms. This article has an associated ‘The people behind the papers’ interview.
    Type of Medium: Online Resource
    ISSN: 0950-1991 , 1477-9129
    URL: Article
    DOI: 10.1242/dev.199664
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2021
    detail.hit.zdb_id: 2007916-3
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Online Resource
    Open Access Request
    Availability (electronic / print)
Nothing or not found what you are looking for? Please check your search query or use the Interlibrary Loan Search.
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages