bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flight Behaviour and Selective Degeneration of Flight Muscles in the Adult Cricket (Gryllus Bimaculatus)
Authors: Shiga S. , Kogawauchi S. , Yasuyama K. , Yamaguchi T. 
Published: April 2021

ABSTRACTTethered adult crickets (Gryllus bimaculatus De Geer) assume a full flight posture: they point the antennae straight ahead, hold the fore-and midlegs close to the body, stiffen the abdomen for steering and extend the hindlegs directly backwards. Tomioka and Yamaguchi (1980) have reported that about 30% of the animals displaying flight behaviour also flap their hindwings, but the remaining crickets vibrate their wings through a narrow range instead of flapping them. They distinguished the latter type of behaviour from normal flight behaviour and designated it ‘pseudo-flight behaviour’.
Do Fish Sniff? A New Mechanism of Olfactory Sampling in Pleuronectid Flounders
Authors: Nevitt Gabrielle A. 
Published: April 2021

ABSTRACT
Although olfaction is known to be a highly developed sense in a variety of fishes, little information is available about behavioral mechanisms by which fishes sample the olfactory environment. This study was undertaken to assess the role of spontaneous jaw protrusion (‘coughing’) as a potential mechanism for olfactory sampling in pleuronectid flounders.
Investigations were carried out using a combination of physiological, morpho-logical and behavioral techniques. Physiological results show (1) that typical respirations are coupled to measurable olfactory sac pressure fluctuations and (2) that during a coughing event, water is rapidly sucked into the olfactory sac. Morphological results indicate (3) a direct linkage system between the protrusion apparatus and the olfactory or associated accessory sacs, and (4) that coughing is associated with a rapid expansion or stretching of these sacs. Lastly, behavioral studies demonstrate (5) that coughing rates increase significantly over background activity when flounders are presented with attractive food odorants. From these results, I propose that coughing in pleuronectid flounders represents a behavior truly analogous to sniffing in certain air-breathing organisms.
Vertical Flight in the Greater Horseshoe Bat Rhinolophus Ferrumequinum
Authors: Aldridge H. D. J. N. 
Published: April 2021

ABSTRACT
The kinematics, aerodynamics and energetics of vertical flight in Rhinolophus ferrumequinum (Schreber) are described. During the downstroke the resultant force generated by the wings tends to accelerate the animal upwards and forwards. Towards the end of the downstroke the wings generate negative thrust and, consequently, the animal accelerates backwards. When, during the upstroke, the wings are accelerated backwards (the ‘flick’) a significant thrust is generated. Total specific mechanical power is approximately 11.92Wkg-1, of which 84% is required during the downstroke.
Thermoregulation and Energetic Decision-Making by the Honeybees Apis Cerana, Apis Dorsata and Apis Laboriosa
Authors: Underwood Benjamin A. 
Published: April 2021

Summary
Thoracic flight temperatures (Tth) of workers of three species of honeybees (genus Apis) in Nepal were measured at relatively low ambient temperatures (Ta). At Ta = 18–24 °C, A. dorsata workers arriving at feeders to collect concentrated (⩾=40%) sugar syrup maintained higher temperature gradients (Tth — Ta) than workers arriving at feeders with dilute (6–17%) syrup. Temperature gradients were inversely related to Ta, indicating thermoregulation at low Ta. Similarly, temperature gradients varied inversely with Ta in A. cerana and A. laboriosa workers arriving at feeders at Ta = 12–20 °C. Temperature data suggest that honeybees have the ability to regulate heat production in flight and that they may vary their flight efforts according to expected gains and associated costs. Temperature gradients of A. laboriosa workers in flight are apparently about the same as those of A. mellifera workers, whose body mass is only half that of A. laboriosa. The circulatory systems of A. laboriosa workers show no striking differences from those of other species of Apis and are therefore probably equally effective at retaining heat in the thorax. This suggests that the relatively low (in relation to the body size) Tth— Ta maintained by A. laboriosa may be an indication of a relatively low metabolic rate and consequent low heat production. This is supported by an analysis of mass1,/3-specific wing-loading and, in turn, suggests that A. laboriosa may be grouped with A. dorsata and A. florea as a relatively low-powered, open-nesting honeybee, in contrast to the more high-powered cavity-nesters, A. cerana and A. mellifera.
The Swimmeret Rhythm and its Relationships With Postural and Locomotor Activity in the Isolated Nervous System of the Crayfish Procambarus Clarkii
Authors: Barthe Jean-Yves , Bévengut Michelle , Clarac François 
Published: April 2021

ABSTRACT
An in vitro preparation was developed consisting of the five thoracic and six abdominal ganglia of the crayfish nerve cord, isolated from anterior nervous structures and from peripheral sensory inputs.
The central activities of the thoracic leg, swimmeret and abdominal positioning motor systems and their relationships were studied. When motor outputs were tonic in the thoracic leg nerves (90% of the preparations), continuous rhythmic activity occurred and persisted for several hours in the swimmeret nerves. Interruptions of the swimmeret rhythm were associated with rhythmic motor outputs in the leg nerves (10% of the preparations). Motor activity in the abdominal positioning system was mainly tonic.
Swimmeret rhythm reversibly disappeared during application of a sucrose block between the thoracic and abdominal parts of the nerve cord. Electrical stimulation of the connectives posterior to the block induced bouts of rhythmic swimmeret activity.
Comparisons of the swimmeret rhythm (period) and the metachronal wave (duration, phase) showed that sectioning of the connectives between the thoracic and abdominal ganglia modified the period but did not affect the properties of the metachronal wave.
We conclude that the presence of descending inputs from thoracic ganglia is necessary for persistent swimmeret activity.
Activation by N-Ethylmaleimide of a Cl− -Dependent K+ Flux in Isolated Trout Hepatocytes
Authors: Bianchini Laurence , Fossat Barthélémy , Porthé-nibelle Jacqueline , Lahlou Brahim 
Published: April 2021

ABSTRACT
Isolated trout hepatocytes when swollen in hypotonic medium undergo a regulatory volume decrease (RVD), which occurs via KCl loss. The system shows characteristics similar to those of the transporter described in red cells. This led us to investigate, in trout hepatocytes, the effect of another signal known to activate this flux in red cells, i.e. treatment with the sulphhydryl-group reagent N-ethylmaleimide (NEM). NEM treatment resulted in a striking increase in ouabain-resistant K+ uptake measured by an isotope pulse uptake technique. The time course of the response to NEM was similar to that obtained with a hypotonic shock, indicating that the effect of NEM was immediate and transient. The NEM-stimulated K+ influx demonstrated the same anion sensitivity as the volume-induced K+ influx, i.e. a specific requirement for Br− or Cl−. Efflux experiments showed that NEM treatment produced a stimulation of both K+ and Cl− effluxes leading to a substantial net loss (10 %) of cellular KC1, as confirmed by analysis of ionic contents. This KCl loss is consistent with the rapid cell shrinkage observed after addition of NEM. The Cl−-dependent K+ influx was found to be indepen-dent of external Na+ ; in addition, NEM had no effect on Na+ content, indicating that Na+ is not implicated in this process. The effect of loop diuretics was tested on the NEM-stimulated K+ influx. As observed for the volume-induced K+ flux, a high concentration of furosemide (10−3moll−1) is required for full inhibition of this flux; no effect was obtained with bumetanide (10−4moll−1). Consequently, NEM appears to activate a KCl cotransport similar to the one induced in hypotonically swollen cells. Finally, the combination of the two treatments, NEM and hypotonic shock, was found to increase the K+ fluxes even further, suggesting additivity of the two stimuli by mutual positive interaction.
A New in Vitro Assay for Carbon Dioxide Excretion by Trout Red Blood Cells: Effects of Catecholamines
Authors: Wood Chris M. , Perry Steve F. 
Published: April 2021

ABSTRACT
A new in vitro assay was developed and critically characterized to measure the rate of CO2excretion by trout red blood cells (RBCs) from HCO3- in their natural plasma under normal in vivo conditions of acid-base status. The assay is based on the addition of [14C]bicarbonate to the whole blood and collection of the resultant 14CO2in the overlying gas phase. The assay simulates the exposure of blood passing through the gills, and measured CO2excretion rates are representative of those occurring in vivo. Rates are linear over the 3 min time course of the assay, related to haematocrit in a non-linear fashion, elevated by the addition of carbonic anhydrase, reduced by blockade with acetazolamide, and sensitive to variations of equilibration . Large variations in plasma [HCO3-] have only a small effect on CO2excretion rates when the blood is chronically equilibrated at these levels. Acute elevations in [HCO3-], however, create a non-equilibrium situation, resulting in large increases in CO2excretion. When the blood is acidified, to duplicate typical post-exercise metabolic acidosis, adrenaline causes a marked inhibition of RBC CO2excretion. The response is transient, reaching a peak 5–8 min after addition of adrenaline and disappearing by 30–60 min. The magnitude of the adrenergic inhibition is correlated with the magnitude of the RBC pHi regulatory response, expressed as the RBC transmembrane pH difference (pHe—pHi). These results support the ‘CO2retention theory’ explaining observed increases in blood vivo after exhaustive exercise and catecholamine infusions in fish.
Temporal Analysis of Snail Feeding Rhythms: A Three-Phase Relaxation Oscillator
Authors: Elliott C. J. H. , Andrew T. 
Published: April 2021

ABSTRACT
Rhythmic fictive feeding was recorded from the motoneurones of the buccal ganglia of Lymnaea stagnalis. The times of the action potentials were recorded by microcomputer and the lengths of the three phases (N1, N2 and N3) making up each feeding cycle were determined. During spontaneous rhythmic fictive feeding in Lymnaea stagnalis the cycle period varied randomly. Most of the variation in cycle period arose from alterations in the duration of the N3 (swallowing) phase of the rhythm; the N1 (protraction) and N2 (rasp) phases were fixed in length. The firing rates of feeding motoneurones active in the N1 and N3 phases increased with feeding rate: this was not true of those active in the N2 phase. In rhythms produced by stimulating the SO modulatory interneurone, both the N1 and N3 phases varied in duration. The N2 duration remained constant. The temporal analysis is accounted for by the neuronal model based on the synaptic interactions recorded by Elliott and Benjamin (1985a,b; J. Neurophysiol. 54, 1396-1421).
A Comparative Study of Host Recognition and the Sense of Taste inLeptinotarsa
Authors: Sperling J. L. Haley , Mitchell B. K. 
Published: April 2021

ABSTRACTThree species of Leptinotarsa beetles (L. decemlineata, L. texana and L. haldemani) with different host plant specificity were studied using behavioural and sensory physiological measures in an attempt to determine whether responses from chemosensory cells in the galeal sensilla of adult beetles vary with host plant preference in an understandable manner. Saps from leaves of Solarium tuberosum, S. elaeagnifolium, S. dulcamara and Lycopersicon esculentum were used as sensory stimuli. Behavioural observations were made on newly emerged adults and approach time, exploration time and number of bites in the first minute of the first meal were recorded. Number of bites in the first minute of the first meal differed across the four plant species for the three beetle species. For L. decemlineata and L. texana, sensory responses from cells in the galeal sensilla showed differences across plant species that could be related to host preference. It is suggested that at least two general types of sensory coding may be involved in host recognition by beetles in this genus. First, a ‘coarse-grained’ code based on degree of variability of input may operate to help the insect distinguish non-solanaceous plants from solanaceous ones. Second, a ‘fine-grained’ code may help distinguish host from non-host within the family Solanaceae or perhaps within the genus Solanum. This fine-grained code may have elements of both the labelled line and across-fibre pattern codes discussed in the literature.
Partitioning of Acid-Base Regulation Between Renal and Extrarenal Sites in the Adult, Terrestrial Stage of the Salamander Ambystoma Tigrinum During Respiratory Acidosis
Authors: Stiffler Daniel F. 
Published: April 2021

ABSTRACT
Adult Ambystoma tigrinum were cannulated non-occlusively in the truncus arteriosus and subjected to 24 h of hypercapnia in 3% CO2. Adults showed the typical compensatory pattern, shared by larvae and many other amphibians, of partial compensation (44%) for the induced respiratory acidosis. Adults whose urinary bladders were ligated to allow the urine to bypass the bladder compensated as well as shams, indicating that the urinary bladder of this species is not necessary for compensation. Radioisotopic measurements of net and unidirectional fluxes of Na+ or Cl- in whole animals showed no effects of hypercapnia. Partitioning of acid-base responses showed that 75–80 % of the regulation takes place across the skin. The rest is accomplished by the kidneys. This did not change during hypercapnia and there was no evidence of renal involvement in the compensation. Total ammonia (NH3+NH4+) comprised only about one-sixth of the total cutaneous acid excretion. The charge associated with the cutaneous excretion of H+ equivalents was balanced by both Na+ uptake and Cl- loss. In contrast to larvae, whose cutaneous electrical potential difference (PD) increases during hypercapnia, adults decrease their PD. This could mean that acidosis stimulates an electrogenic H+ secretion and/or that cutaneous Na+ and Cl-permeabilities change. Both possibilities are consistent with the data.
Function of a Muscle Whose Apodeme Travels through a Joint Moved by Other Muscles: Why the Retractor Unguis Muscle in Stick Insects is Tripartite and Has No Antagonist
Authors: Radnikow G. , Bässler U. 
Published: April 2021

ABSTRACT
The course of the common apodeme of the tripartite retractor unguis muscle is described for the stick insects Carausius morosus and Acrophylla wulfingii. This apodeme travels through the femoro-tibial joint well outside the axis of rotation of the joint, but movements of the femoro-tibial joint do not affect the position of the tarsal claws, which are moved by the retractor unguis muscle. The independence of tarsal position upon tibial position is not produced by a neural compensation mechanism but by a sophisticated morphological arrangement combined with specialized physiological properties. These mechanisms consist of two parts. (1) Moderate claw flexions are mainly produced by the smaller tibial parts of the muscle and their influence on claw position is not affected by tibial position, because they lie distal to the femoro-tibial joint. (2) The retractor unguis muscle works against strong elastic structures and the claw assumes the position where the elastic force is counterbalanced by the muscle force. The maximum muscle force of the strong femoral part of the muscle is nearly independent of muscle length. Therefore, the force it transfers to the elastic structures is also nearly independent of tibial position.
Dynamic Properties of Orientation to a Visually Fixated Target by Walking Colorado Beetles
Authors: Lönnendonker Ulrich 
Published: April 2021

ABSTRACT
The dynamic components of the fixation behaviour of walking Colorado beetles were examined. The beetles walked on top of a locomotion compensator under closed-loop conditions. The fixation target was a yellow disk with small black stripes (‘Colorado dummy’). The paths of beetles walking towards the stationary dummy were characterized by oscillations, and were investigated by applying a fast Fourier transform to the turning-velocity time course. The power density peaks near 0.3 Hz with varying amplitude. Films of the fixation reaction revealed that this frequency was much slower than the stepping-pattern frequency of the beetles. During orientation to other stimuli (wind or gravity), the oscillations were not present, showing that they were not an artefact of the motor output. However, they were present in other forms of visual orientation, such as the optomotor response and during positive phototaxis.
A frequency-response curve (Bode diagram) under closed-loop conditions was obtained for the fixation reaction by changing the dummy position sinusoidally and measuring the phase and amplitude of the tracking response. A simple model of this behaviour, including a low-pass filter and an integrator, describes the reaction. Hence, the reaction can be understood as the simple resonance behaviour of an underdamped closed-position loop. The question of whether this can explain zigzagging paths in other species is discussed.
Sensory Coding for Feeding Deterrence in the Grasshopper Schistocerca Americana
Authors: Chapman R. F. , Ascoli-Christensen A. , White P. R. 
Published: April 2021

ABSTRACT
The electrophysiological responses of sensilla on the tibia of Schistocerca americana (Drury) to six compounds were examined. All the compounds were shown to cause feeding deterrence at high concentrations. Nicotine hydrogen tartrate, quinine, hordenine (all alkaloids) and salicin (a phenolic glycoside) all stimulated one cell in each sensillum. This was shown by differential adaptation experiments to be the same cell. In some sensilla this cell also responded to linamarin (a cyanogenic glycoside). Earlier work had shown that the activity of this cell was correlated with feeding deterrence. However, canavanine (a nonprotein amino acid) did not stimulate this cell, although it caused feeding deterrence. All the compounds, except salicin, produced a marked depression in the activity of cells responding to sucrose, and at higher concentrations of the compounds this inhibition was almost complete.
The activity of the deterrent cell and inhibition of the activity of sucrosesensitive cells appear to act together to produce the behavioural effects of most chemicals, but canavanine appears to act only by suppressing the activity of other cells and salicin primarily through activity of the deterrent cell. In addition, quinine disrupts the activity of all the cells and in its presence the deterrent cell adapts very slowly so that the message signalling deterrence is sustained.
At low concentrations, salicin, and probably hordenine, increased the duration of feeding. In the case of hordenine this was due to an increase in the firing rate of sucrose-sensitive neurones; with salicin the increase was associated with a high threshold of response and a rapid rate of adaptation of the deterrent cell.
Thus, similar behavioural effects are produced by a variety of sensory phenomena with each compound acting in a slightly different manner from the others.
Energetics and Power Output of Isolated Fish Fast Muscle Fibres Performing Oscillatory Work
Authors: Moon T. W. , Altringham J. D. , Johnston I. A. 
Published: April 2021

ABSTRACT
Fast myotomal muscle fibres were isolated from the cod (Gadus morhua L.) and the energy cost of contraction was measured under conditions simulating swimming. Fibre bundles were subjected to sinusoidal cycles of shortening and lengthening about their in situ fibre length, and stimulated at selected phases in each cycle. The preparations were poisoned with iodoacetic acid and bubbled with nitrogen to block the synthesis of ATP. After an initial rapid decline over the first 10 cycles, force and net work remained steady in some cases for up to 64 oscillatory length cycles, but more commonly declined slowly after about 30 cycles. The total mechanical work performed increased largely in proportion to the number of work cycles. At the end of each experiment fibres were frozen in isopentane cooled in liquid nitrogen and metabolite concentrations determined by high performance liquid chromatography (HPLC) and enzymatic analysis. Concentrations of adenylates did not differ significantly from control values, although a significant increase in IMP concentrations at 64 cycles accounted for the maintenance of relatively high energy charge values. Creatine (C) concentrations increased and creatine phosphate (CP) concentrations decreased, implying a tight coupling of the ATP/ADP reaction to the CP/C reaction. Muscle economy was calculated as the positive work performed during a work cycle divided by the total chemical energy expended. These values (approx. 7mJ μmol−1) were found to be independent of the number of work cycles performed, although a trend to increase was observed. Muscle efficiency values, calculated assuming a Gibb’s force free energy change for CP splitting in vivo of 55 kJ mol−1, were in the range 12 – 23%.
Efficiency Of Energy Conversion During Shortening Of Muscle Fibres From The Dogfish Scyliorhinus Canicula
Authors: Curtin N. A. , Woledge R. C. 
Published: April 2021

ABSTRACT
Force and heat production were measured during isovelocity shortening of tetanized white myotomal muscle fibres from the dogfish at 12 °C. For each fibre preparation a range of velocities was used. Mechanical power was calculated from force x velocity of shortening. The rate of total energy output during shortening was evaluated as the sum of mechanical power and the rate of heat production. The ratio of mechanical power to total energy rate was taken as a measure of efficiency of energy conversion to mechanical power during shortening. Efficiency was maximal and varied little in the range of shortening velocities 0.42–0.89 fibres lengthss−1 (0.11–0.23 Vmax); maximal efficiency was 0.33±0.01 (±S.E.M., N=23 measurements on seven fibre bundles). The efficiency of the white fibres from dogfish was less than that measured in the same way in earlier experiments on frog muscle and tortoise muscle.