bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Identification of Motor and Unpaired Median Neurones Innervating the Locust Oviduct
Authors: Kalogianni E. , Pflüger H.-J. 
Published: April 2021

ABSTRACT
The different classes of neurones supplying the locust oviduct were individually identified by intracellular recording and staining. We could thus show that different regions of the oviduct are innervated by different sets of neurones. Three motor neurones (oviductal neurones 1–3, OVN1-3) supply the oviduct via nerve N2B of the seventh abdominal ganglion. Whereas all three motor neurones innervate the junctional area of the lateral and the common oviduct (OVNI, 2 and 3), the lateral oviduct is innervated by only one motor neurone (OVN2) and the common oviduct by two motor neurones (OVNI and 2). The cell bodies of all three motor neurones lie ventrally, near the origin of the sternal root, and their neuropilar branches are confined to the seventh abdominal ganglion. The neuropilar branches of OVNI and 2 extend mainly in the ipsilateral half of the ganglion; those of OVN3 reside exclusively in the contralateral half.
The oviductal motor neurones, produce a phasic motor pattern, the oviductal rhythm, which causes neurogenic contractions of the junctional area and the common oviduct. These contractions serve to retain eggs in the lateral oviduct.
The oviduct is also supplied by a large number (16–20) of median neurones with bilateral axons. All of these appear to innervate the lateral oviduct, but only two project to the junctional area and the common oviduct. The cell bodies of the median neurones are situated in the seventh abdominal ganglion and are arranged in two groups: a posterior group made up of 10–12 cells and an anterior group with 6–8 cells. Their primary neurites run towards the centre of the ganglion in the dorsal plane, where they bifurcate, sending a secondary neurite through each oviductal nerve. Their neuropilar branches are confined to the seventh abdominal ganglion, but some also possess thin axon collaterals projecting to the terminal abdominal ganglion. The anterior and posterior median neurones show considerable differences in their branching pattern within the ganglion. The posterior cells are all likely to be neurones of the well-known DUM cell group, but the anterior median cells probably represent a different class of neurone. Posterior median neurones support overshooting soma action potentials of 60–80 mV amplitude, with a characteristic undershoot of 6–15 mV. Orthodromic stimulation of these neurones results in a reduction of the amplitude and frequency of the oviductal contractions, suggesting that they have a modulatory role.
Cardiac Output and Blood flow Distributiont During Swimming and Voluntary Diving of the Tufted Duck (Aythya Fuligula)
Authors: Bevan R. M. , Butler P. J. 
Published: April 2021

ABSTRACT
Cardiac output and blood flow distribution were continuously measured in the tufted duck when diving voluntarily. Blood flows through pulmonary, ischiadic, carotid and brachiocephalic arteries were recorded using miniature pulsed Doppler flow probes. By measuring these flows, cardiac output and blood flow to the leg muscles and to the flight muscles could be calculated.
Heart rate and were well correlated, making the former a very good indicator of any changes in the latter. Blood flow to the leg muscles increased substantially during both swimming and diving to five times the resting rate. Cardiac output, though, was lower during the later portions of a dive than it was during swimming. A consequence of this lower was that the proportion of supplying the leg muscles was much greater during diving than it was whilst the duck was swimming. This indicates that more extensive peripheral vasoconstriction was occurring during diving. The blood flow to the wing muscles during diving was found to be significantly lower than that at rest but there was no net change in blood flow through the brachiocephalic arteries as the blood flow to the head increased.
Peripheral vasoconstriction must, therefore, have been occurring in other parts of the body during diving, possibly within the vascular beds supplying the gastrointestinal tract, the skin and the respiratory muscles. This study supports the prediction that voluntary diving in tufted ducks is a compromise between the physiological response to involuntary submergence and that to exercise in air, but with the bias towards the latter.
Scaling of Muscle Fibres and Locomotion
Authors: Rome Lawrence C. 
Published: April 2021

ABSTRACT
To reconcile the scaling of the mechanics and energetics of locomotion to recent data on the scaling of the mechanics of muscle fibres, I have extended the theory of Taylor and colleagues that the energetic cost of locomotion is determined by the cost of generating force by the fibres. By assuming (1) that the cost of generating force in a fibre is proportional to Vmax (maximum velocity of shortening) and (2) that, at physiologically equivalent speeds, animals of different body sizes recruit the same fibre types, this extension quantitatively predicts the scaling of the energetics of locomotion, as well as other observations, from the scaling of Vmax of the muscle fibres. First, the energetic cost of locomotion at physiologically equivalent speeds scales with Mb−0 16, where Mb is body mass, as does Vmax of a given fibre type. However, the energetic cost at absolute speeds (cost of transport) scales with Mb−0.30, because small animals must compress their recruitment order into a narrower speed range and, hence, recruit faster muscle fibre types at a given running speed. Thus, it costs more for small animals to move 1kg of their body mass 1 km not only because a given muscle fibre type from a small animal costs more to generate force than from a large one, but also because small animals recruit faster fibre types at a given absolute running speed.
In addition, this analysis provides evidence that Vmax scales similarly to 1/tc (where tc is foot contact time) and muscle shortening velocity (V), in agreement with recent models. Finally, this extension predicts that, at physiologically equivalent speeds, the weight-specific energetic cost per step is independent of body size, as has been found empirically.
Intracellular Recordings From Intact Locusts Flying Under Closed-Loop Visual Conditions
Authors: Hensler Klaus 
Published: April 2021

ABSTRACT
The flight path of locusts is under permanent visual and mechanoreceptive control (the latter evaluates changes in wind direction). Involuntary course deviations are compensated immediately by a neuronal feedback system or ‘autopilot’, which induces corrective steering movements of the wings, abdomen and legs and which are generally accompanied by compensatory head movements (Taylor, 1981; Hensler and Robert, 1990). During apparently straight flight the flight path is not perfectly straight, but instead the insect oscillates slightly along a mean course (Robert, 1988; Hensler and Robert, 1990).
Pollutant-Induced Depression of the Transmembrane Sodium Gradient in Muscles of Mussels
Authors: Børseth Jan Fredrik , Aunaas Tore , Einarson Sigrun , Nordtug Trond , Olsen Anders Johny , Zachariassen Karl Erik 
Published: April 2021

ABSTRACT
This study deals with the effects of chemical pollutants on the transmembrane potential difference for sodium in smooth muscle cells of Mytilus edulis. A method for indirect determination of extracellular space, intracellular ion concentrations and has been developed and is applied in the investigations. The determination is based on concentration data from haemolymph and muscle tissue samples. The precision of the method used was tested by direct measurements of the apparent intracellular concentration of sodium and the membrane potential. On the basis of these tests, the method was evaluated as reasonably good.
The method was used to study the sensitivity of the transmembrane in Mytilus edulis to 96 h exposures to various sublethal concentrations of formaldehyde, methanol and mercury. Both formaldehyde and mercury induced a depression of . The observed depressions could be ascribed to a change in both the electrogenic and the chemical components of . A depression of was associated with subsequent clinical injury and death. Methanol did not cause death or any changes in . Because of the observed correlation between depression of and clinical injury, is suggested to have a potential as an indicator of toxicity.
Flow Visualization Experiments on Tethered Flying Green Lacewings Chrysopa Dasyptera
Authors: Grodnitsky Dmitry L. , Morozov Pahvel P. 
Published: April 2021

ABSTRACT
Experiments on dust visualization of the flow around tethered flying green lacewings showed that, contrary to expectations based on the Weis-Fogh clap-and-fling mechanism, a leading edge separation bubble does not exist near either fore-or hindwings. At the beginning of the stroke cycle each wing operates as an independent generator of vorticity. The vortex bubbles of all the four wings then unite, producing a single U-shaped bubble. A hypothetical spatial structure for the vortex wake is derived from a series of registrated sections of the wake illuminated with a flat light beam. Some problems of wing functional morphology and insect flight aerodynamics are also discussed.
Energy Allocation and Yield and Cost of Growth in Young Esox Lucius and CoregonuS Lavaretus (Teleostei): Influence of Species, Prey Type and Body Size
Authors: Wieser Wolfgang , Laich Andreas , Medgyesy Nikolaus 
Published: April 2021

ABSTRACT
Energy partitioning was studied in the larvae and early juveniles of two species of freshwater fish with different life styles, Coregonus lavaretus and Esox lucius, by measuring simultaneously the rates of feeding, oxygen consumption and growth in long-term experiments. Comparison between the two species is based on measurements at 15°C, but a group of C. lavaretus was also monitored at 10°C.
The intensity of routine oxygen consumption was mass-independent in the smallest larvae, but above about 10 mg wet body mass (m) it scaled with an allometry of m−0.103 in C. lavaretus and m−0.154 in E. lucius. Routine, minimum and maximum rates of metabolism were higher in C. lavaretus than in E. lucius, whereas the mass-specific rate induced by feeding showed a quite different and more complex relationship to species.
The mass-specific rate of growth scaled with m−0.133 (r=0.54) in C. lavaretus but with m−0 24 (r=0.90) in E. lucius.
Comparison of five experimental groups, differing from each other with respect to species, type of prey (Artemia nauplii or Rutilus rutilus larvae), experimental temperature and body size, suggested a general pattern of energy partitioning, with 62±3.7% of metabolizable food energy being allocated to growth, and 38±3.7% to metabolic expenditures.
The relationship between metabolic rate and growth rate, expressed as the ‘yield ratio’, mg dry body mass μmol−1O2, the inverse of the net cost of growth, proved to be nearly invariant in all experimental groups, namely 0.043 mg μmol−1. However, two experiments with the smallest pike larvae led to higher growth rates per metabolic expenditure, suggesting that in E. lucius oxygen consumption may reach an aerobic maximum for growth at a routine rate of about 200–220 μmol O2g−1 dry bodymassh−1.
Gross costs of growth include mass-dependent maintenance expenditures. Expressed in mass-independent units, E. lucius was more efficient in converting food energy into growth than was C. lavaretus’, its superiority in this respect ranged from 7 to 17% depending on body mass and diet.
The results are discussed with regard to the question of whether in small poikilothermie metazoans the allocation of metabolic energy follows the rules of addition or compensation. Furthermore, growth performance of the fish larvae is compared with that of microorganisms on the basis of the ‘yield ATP’ concept.
Multisegmental Analyses of Acoustic Startle in the Flying Cricket (Teleogryllus Oceanicus): Kinematics and Electromyography
Authors: Miles Carol I. , May Michael L. , Holbrook Eric H. , Hoy Ronald R. 
Published: April 2021

ABSTRACT
Tethered, flying Australian field crickets (Teleogryllus oceanicus) stimulated with ultrasound respond with a rapid, short-latency turn from the sound source. We analyzed the kinematics of two behavioral components of this acoustic startle response and recorded electromyograms from the muscles involved in producing them. The two behavior patterns studied were the swing of the metathoracic leg, which has been shown to elicit a short-latency turn, and a lateral swing of the antennae, for which a direct role in steering has not been demonstrated.
The kinematic data showed that when a pulse of ultrasound was presented to one side of the animal (1) the contralateral metathoracic leg abducted and elevated, while the ipsilateral leg remained in place, (2) both antennae swung laterally, but the contralateral antenna moved farther than the ipsilateral antenna, (3) increases in stimulus intensity elicited larger movements of the leg and contralateral antenna, while the ipsilateral antenna showed little sensitivity to stimulus intensity, and (4) for the leg, the latency to the onset of the swing decreased and the duration of the movement increased with increasing stimulus intensity.
Electromyograms were recorded from the leg abductor M126 and two antennal muscles: the medial scapo-pedicellar muscle M6 and the lateral scapo-pedicellar muscle M7. M7 moves the antenna laterally, M6 moves it medially. Upon stimulation with ultrasound (1) both M126 and M7 showed increasing spike activity with increasing intensity of the ultrasound stimulus, (2) M126 showed a decrease in latency to the first spike and an increase in the duration of spike activity with increasing stimulus intensity, (3) latencies for M6 and M7 were not correlated with stimulus intensity, but M7 had significantly shorter latencies than M6 and the contralateral M7 had significantly shorter latencies than the ipsilateral M7, and (4) the ipsilateral M126 spiked in response to ultrasound in 6 of the 10 animals tested. In these cases, however, latency to the first spike was substantially longer, and the spike frequency was lower than for the muscle’s response to contralateral stimuli. We attempt to correlate these electromyogram data with the kinematic data and relate them to the relevance of the two behavior patterns to the execution of an escape response.
Directional Sensitivity and Mechanical Coupling Dynamics of Campaniform Sensilla During Chord-Wise Deformations of the Fly Wing
Authors: Dickinson Michael H. 
Published: April 2021

ABSTRACT
The complex morphology of an insect campaniform sensillum is responsible for transforming strains of the integument into a displacement of the campaniform dome and subsequently a deformation of the dendritic membrane. In this paper, the first step in this coupling process was investigated in identified campaniform sensilla on the wing of the blowfly by stimulating the sensilla with chord-wise deflections of the wing blade. Campaniform sensilla neurones were sensitive to both dorsal and ventral deflections of the wing, and thus exhibited no strong directional sensitivity to the chord-wise components of wing deformation. These results are consistent with a simplified mechanical model in which the wing veins act as cylinders that undergo bending and torsion during chord-wise wing deformation.
By comparing the responses of campaniform neurones to chord-wise deflections of the wing with those evoked by direct punctate stimulation of the dome, it is possible to estimate the dynamic properties of the coupling process that links wing deformation to dome deformation. In the identified campaniform neurone examined, wing-dome coupling attenuates high frequencies and transforms the chord-wise deflections of the wing into dome deformation similar in degree of excitation to that caused by direct punctate indentions that are two or more orders of magnitude smaller in size.
Studies on Adaptation to Salinity in Gammarus Spp
Authors: Beadle L. C. , Cragg J. B. 
Published: April 2021

ABSTRACT
Four species of Gammarus were studied: the fresh-water G. pulex, the brackish water G. duebeni, and two normally marine species G. locusta and obtusatus, the former of which has also been recorded from brackish water. The relation between osmotic pressure and chloride of the blood and of the external medium, after sudden transfer to salinities which could be withstood for at least 24 hr., is shown in Fig. 1. The changes in blood osmotic pressure are due to salt and not to water movements. The marine species G. obtusatus and locusta maintain a very hypertonic blood in dilute sea water and can withstand 50% (270 mM.) and 25 % (135 mM.) sea water respectively. The brackish water G. duebeni has a tolerance range from pure sea water to water containing a trace of salt, but is not as well adapted to fresh water as G. pulex. For a wide salinity tolerance range two mechanisms are necessary, (a) for regulating the blood concentration within certain limits, and (6) for maintaining a low intracellular concentration of certain ions (e.g. Cl) in spite of changes in blood concentration. Defection of the latter mechanism can alone account for the inability of G. pulex to withstand direct transfer to more than about 40 % sea water (115 mM.). On the basis of this work and that of others on other animals the following hypothesis is suggested. Adaptation to fresh water has proceeded by two main stages : (a) Probably by active ion absorption, a high blood concentration is maintained (as in Eriocheir sinensis and Telphusa fluviatile) and is associated with a large blood/tissue Cl gradient. Such animals can still be transferred suddenly to a high concentration of sea water, (b) Evolution of the renal salt-reabsorption mechanism, and. lowering of both blood concentration and blood/tissue Cl gradient to levels more easily maintained (as in G. pulex and most fresh-water animals). The consequent loss of power to maintain a large blood/tissue Cl gradient entails inability to withstand transfer to more than low concentrations of sea water, unless, as in certain species, a special mechanism is evolved for preventing the blood concentration from rising.
The Effects of Castration by Parasites and X-Rays on the Secondary Sex Characters of Prawns (Leander Spp.)
Authors: Callan H. G. 
Published: April 2021

ABSTRACT
Contrary to the assertion of Giard that Leander males when parasitized by Bopyrus undergo sex reversal, Leander xiphias and L. squilla show no modifications of the secondary sex characters, while the testes, although reduced in size, never produce oocytes. This is probably true also of L. serratus. The power of a parasite to induce sex reversal is probably limited by the degree of sex separation of the host species. The species which show sex reversal (“castration parasitaire”) are thus considered to possess a less complete sexseparating mechanism than those, such as Leander, which are not reversed by parasites. Breeding females of Leander develop an incubatory chamber under the abdomen, involving many structural changes. These “breeding characters” are not formed by parasitized females, nor by females castrated by X-rays. It is possible that there is a female sex hormone in Crustacea, but the evidence is not yet conclusive.
Local and General Factors in the Development of “Pattern” in Rhodnius Prolixus (Hemiptera)
Authors: Wigglesworth V. B. 
Published: April 2021

ABSTRACT
Most studies on morphogenesis have been made upon composite structures, such as eyes or appendages, whose form is controlled by the co-operation of a great number of cells. In insects, however, the tiny fragment of cuticle laid down by a single cell may possess morphological characters controlled by the activities of that cell alone. The cuticle of insects provides, therefore, an unusually simple medium for the study of morphogenesis and the nature of those processes which “determine” the activity of a given cell.
The Determination of Characters at Metamorphosis in Rhodnius Prolixus (Hemiptera)
Authors: Wigglesworth V. B. 
Published: April 2021

ABSTRACT
Two factors have been recognized as regulating moulting and metamorphosis in Rhodnius prolixus: a “moulting hormone” and a so-called “inhibitory hormone” (Wigglesworth, 1934, 1936).
A Change in the Chromatophore Pattern of Crustacea at Sexual Maturity
Authors: Knowles F. G. W. , Callan H. G. 
Published: April 2021

ABSTRACT
White chromatophores appear on the egg-bearing segments of female prawns and shrimps at sexual maturity. Such chromatophores do not appear in the females whose gonads have been destroyed by X-rays or by parasites. It is probable that this appearance of white chromatophores at sexual maturity is correlated with the metabolic changes occurring at yolk deposition in the ovaries.
The Protoplasmic Viscosity of Paramecium
Authors: Brown R. H. J. 
Published: April 2021

ABSTRACT
Since Heilbrunn’s work in 1926 most workers have agreed that the viscosity of protoplasm is low; all the recent observations, with one exception, have given figures which are not markedly different from each other. The exception, the work of Fetter (1926) on Paramecium, gives a viscosity value which is much higher than that found in other material. The present paper constitutes a re-examination of the viscosity values given by Fetter.
The Toxicity of the Double Chlorides of Mercury and Sodium
Authors: Jones J. R. Erichsen 
Published: April 2021

ABSTRACT
Mercuric chloride, one of the most toxic of inorganic substances, does not ionize in aqueous solution, but in the presence of sodium chloride forms the double chlorides NaHgCl3 and Na2HgCl4 which ionize readily. It has been variously claimed that the ionization of mercuric chloride, thus effected, is accompanied by an increase of toxicity, by a decrease of toxicity, or that the toxicity of the solution remains unaltered. In an investigation of the toxicity of mixed solutions of HgCl2 and NaCl to the minnow, Phoxinus phoxinus (L.), it is found that the addition, to HgCl2 solutions, of sufficient NaCl to convert the whole of the HgCl2 into the double chloride Na2HgCl4, and even ten times this quantity of NaCl effects no marked change in the toxicity of the solution. On the addition of a considerable excess of NaCl a marked prolongation of the survival time occurs, the maximum antagonistic effect being evident when the solution is approximately isotonic. Almost exactly the same result is obtained if the NaCl is replaced by quantities of glucose sufficient to effect equal changes in the osmotic pressure of the solutions, and thus the antagonistic action of the sodium chloride appears to be due to the physical, rather than the chemical, changes its addition brings about in the nature of the toxic solution.
Physiological Effects of a Hypotonic Environment
Authors: Wells G. P. , Ledingham Isabel C. , Gregory Mary 
Published: April 2021

ABSTRACT
If polychaete rhythmic muscles are suspended in sea water, which is then suddenly replaced by dilute sea water, they typically respond to the change by showing, first excitation, then inhibition, then accommodation to the new fluid (Wells & Ledingham, 1940a). Shock effects, followed by accommodation, have also been shown to follow sudden salinity change in marine amoebae (Pantin, 1924) and in the hearts of Limulus, Carcinus and a tortoise (Carlson, 1905; Girault, 1935). The experiments here described were undertaken primarily in order to find out whether similar phenomena occur in cilia. The action of hypotonic fluids on the lamellibranch gill has been described by Fredericq (1922) and by Tomita (1934), but neither author paid any attention to the behaviour of the cilia immediately after salinity change.