bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dietary maintenance of bioluminescence in a deep-sea mysid
Authors: Frank Tamara M. , Widder Edith A. , Latz Michael I. , Case James F. 
Published: April 2021

ABSTRACT
Dietary acquisition of the specific constituents of bioluminescent systems, frequently suggested for various midwater organisms (Haneda, Johnson & Shimomura, 1966; Shimomura, Inoue, Johnson & Haneda, 1980; McCapra & Hart, 1980), has been demonstrated experimentally only in the batrachoidid fish, Porichthys notatus. The luciferins and luciferases of Porichthys and the ostracod Vargula (= Cypridina) hilgendorfii cross-react, suggesting structural similarity (Cormier, Crane & Nakano, 1967; Tsuji, Haneda, Lynch & Sugiyama, 1971). Normally, non-luminescent Porichthys from Puget Sound luminesce after injection of V. hilgendorfii luciferin or feeding with dried V. hilgendorfii (Tsuji, Barnes & Case, 1972; Barnes, Case & Tsuji, 1973) or V. tsujii (Warner & Case, 1980). Specific dietary maintenance of bioluminescence has also been suggested for bioluminescent crustaceans. Shimomura et al. (1980) found large amounts of luciferin in the digestive tracts of various shrimps, and suggested that their luminescence had dietary origins.
The Contribution of the Alkaline Pericardial Fluid of Freshwater Turtles to Acid Buffering During Prolonged Anoxia
Authors: Jackson Donald C. , Heisler Norbert 
Published: April 2021

ABSTRACT
The role of buffering of the high pericardial fluid [HCO3−] of the turtle, Chrysemy spicta bellii Gray, was evaluated during prolonged anoxia at 3 and 10°C. At 3°C, pericardial fluid samples were collected from groups of animals after 0, 1, 2, 4 and 8 weeks of anoxia, and the ionic composition of these samples was compared to plasma values from the same animals. At 10 °C, pericardial and plasma samples were taken from normoxic turtles and from turtles after 11 days of anoxia. The samples were analysed for total CO2, [Cl−] and [lactate-]. At 3°C, the fall in pericardial [HCO3−] and the rise in [lactate−] lagged behind the same changes in the plasma, until after about 8 weeks of anoxia the composition of pericardial fluid became identical with that of plasma. At 10 °C, pericardial [HCO3−] fell significantly after 11 days of anoxia but was still above plasma [HCO3−], while [lactate-] was essentially the same in both fluids. We conclude that the pericardial fluid does participate in the buffering of lactic acid during prolonged anoxia. However, its involvement is delayed, possibly until the energy supply for the active carrier-mediated transfer processes responsible for the high [HCO3−] gradient breaks down as a consequence of the prolonged anoxia. Analysis of the overall buffering in the body reveals that the contribution of the pericardial fluid is minor.
The Influence of Starvation on the Thermal Death-Point on Insects
Authors: Mellanby Kenneth 
Published: April 2021

ABSTRACT
Previous work (Mellanby, 1932) has shown that insects may be killed at temperatures above the normal by various factors. There is no definite “thermal death-point” above which they are killed instantly, and below which they survive in a normal manner. Various factors contribute to the death of insects, and in different circumstances different factors are limiting. If the temperature is above 40° C. the heat is sufficient to kill many species. The actual lethal temperature depends on the length of the exposure, and may also be influenced by atmospheric humidity. Below 40° C., in moist air, the heat is usually the limiting factor, but in dry air insects which cannot conserve the water in their bodies die from desiccation.
Further experiments have shown that starvation is a factor which may influence the thermal death-point. Experiments made with the human body-louse, Pediculus humanus corporis de G., and with the mosquito, Culex fatigans, illustrate this point, and are here described.
Diffraction Patterns Produced by Bacteria
Authors: Ponder Eric 
Published: April 2021

ABSTRACT
By treating the diffraction patterns produced by cultures of bacilli as the result of diffraction through a grating, Pijper has been led to the conclusion that the bacilli are oriented at right angles to the surface of the culture medium. It is shown in this paper that his results are better accounted for by supposing the organisms to be lying at random, under which circumstances only those patterns resulting from the diffraction of light by their breadths are perceptible to the eye.
The Liberation and Utilisation of Oxygen By the Population of Rock-Pools
Authors: Stephenson T. A. , Zoond A. , Eyre Joyce 
Published: April 2021

ABSTRACT
A. P. Orr (1933), in the course of a study of the physical and chemical conditions prevailing in the sea near coral reefs, and in shallow pools on their surface, found that the oxygen content of the water in pools containing coral may rise to a very high figure (sometimes as high as a supersaturation of 278 per cent.) by the end of the period of low water during the daytime, falling to a low figure (e.g. 18 per cent, saturation) by the end of low water at night. Respiration by plants and animals uses up oxygen in both light and darkness; photosynthesis produces an excess of oxygen during daylight. The photosynthesis is due not only to free-living algae, but also (and in some places predominantly) to the symbiotic algae known as zooxanthellae which abound in the tissues of nearly all reef-corals. The effect can be detected in open water over coral, but is naturally much less marked there than in pools. C. M. Yonge, M. J. Yonge and A. G. Nicholls (1932) and S. M. Marshall (1932) studied the oxygen production of corals and their larvae experimentally. Oxygen determinations on coral reefs, and experiments on corals, have also been made by other authors—for references see Yonge, Yonge and Nicholls (1932) and Verwey (1931).
Regression of Anterior Pituitary Reactions II and III In the Mouse Ovary
Authors: Kennedy Walter P. 
Published: April 2021

ABSTRACTA number of tests were carried out to find the duration of the changes induced in the mouse ovary by prolan, and whether they were completely evanescent or productive of more or less permanent alterations. The question is of some interest in view of Mandelstamm and Tschaikowsky’s results (1931) in the production of temporary sterility in mice with prolan, and their experiment was repeated in a modified form with a few animals. Katzman has also reported that the B hormone from pregnancy urine produces profound ovarian luteinisation and complete inhibition of oestrus in rats, but that the impairment of the reproductive mechanism is not permanent.
Retardation of Growth in Axolotls Resulting From Parathyroid Extract Administration
Authors: Thompson J. H. , Huxley Julian S. 
Published: April 2021

ABSTRACT
Axolotls have been used in a series of experiments designed to test the growth-retarding properties of the parathyroid glands of mammals, prepared so as to include the anti-growth hormone. Such retardation of growth has been obtained, and is proportional to dosage. This extends the growth-retarding effect of this hormone to the Anamnia, and to forms which presumably have no parathyroid themselves.
A lightening of colour in normally dark pigmented individuals was noted after a considerable period (about eight weeks) of treatment.
Pregnancy During the Anoestrous Season in the Ferret
Authors: Hammond J. , Walton A. 
Published: April 2021

ABSTRACT
It is generally believed that pregnancy in most species requires critical amounts of ovarian secretions for its maintenance. Since these secretions, as judged by the appearance of the uterus and accessory organs, are considerably diminished during the anoestrum (in those species which have a limited breeding season) we have investigated the behaviour of animals which become pregnant at the end of the breeding season so that pregnancy extends into the time normally occupied by anoestrum.
The Water Relations of Snails and Slugs
Authors: Howes N. H. , Wells G. P. 
Published: April 2021

ABSTRACT
The weight of active specimens of Helix pomatia L. undergoes continual fluctuation, the changes from day to day being often of very great magnitude and presenting the appearance of an irregular rhythm. The animals tend to aestivate at the times when their weight is low. The weight fluctuations are not responses to varying environmental conditions. The weight fluctuations are seen in animals given water but no food, and are not seen in those given food but no water. They are therefore due primarily to variations in the water content of the animals. The amplitude of the fluctuations is greater in fed than in fasting animals. Similar fluctuations, but of somewhat smaller amplitude, occur in snails kept in air saturated with water vapour.
On the Chemical Changes Associated with Metamorphosis in A Beetle (Tenebrio Molitor L.)
Authors: Evans A. C. 
Published: April 2021

ABSTRACT
The changes in carbohydrate, fatty acids, unsaponifiable matter and nitrogen distribution are described in detail during the metamorphosis from larva to adult in the common mealworm, Tenebrio molitor L., and compared with those occurring in Lucilia sericata M.
The Effect of Unilateral Castration on the Remaining Testis of the Mouse
Authors: Rowlands I. W. 
Published: April 2021

ABSTRACT
Unilateral castration was performed on a group of ninety-two adult male mice, and on another group of twenty immature males at the age of 14 days. No hypertrophy nor any microscopic changes could be detected in the remaining testes in either the adult or the immature groups.
The Electrical Properties of Isolated Frog’s Skin
Authors: Pumphrey R. J. 
Published: April 2021

ABSTRACT
In two previous papers in this Journal (Francis and Pumphrey, 1933 ; Francis, 1934) the relation between the potential across pieces of isolated frog’s skin and various environmental factors has been described and discussed. In the work there described the potential was measured by means which were virtually electrostatic and no appreciable work was done by the skin. In this paper is described a method by which the potential can be measured during and after the performance of electrical work on or by the skin. Certain features are common to all the electrical phenomena manifested by cells and tissues and it seems likely that in all cases the basic mechanism is the same. It is probable therefore that the results here described will eventually be of service in the interpretation of the electrical behaviour of nerve and other excitable tissues, where on account of the structure of the tissue such experiments are difficult or impossible of performance.
The Location of Circa-Tidal Pacemakers in the Estuarine Amphipod Corophium Volutator Using A Selective Chilling Technique
Authors: Harris Gerard J. , Morgan Elfed 
Published: April 2021

ABSTRACT
The anatomical location of the control centre(s) for the endogenous tidal rhythm of swimming activity shown by Corophium volutator (Pallas) has been investigated using a selective chilling technique. Rephasing occurred on chilling the whole animal to −3 °C or on chilling either the supra- or sub-oesophageal ganglion alone, whereas cold pulses applied to the telson or mid-body regions were without effect. Ablating the eyes had no effect on the endogenous rhythm. The results are interpreted in terms of two autonomous control centres.
Stick Insect Locomotion on a Wheel: Patterns of Stopping and Starting
Authors: Dean Jeffrey , Wendler Gernot 
Published: April 2021

ABSTRACT
The relationship between standing and steady walking was investigated for stick insects walking on a wheel. Normal hexapod coordination patterns ensure that each point in the gait cycle has static stability. Nevertheless, stick insects show preferred stopping sequences: the final protraction in ipsilateral metachronal sequences is most often by a front leg and least often by a rear leg (Fig. 1, Table 1). The associated preferred stance is one in which front, middle, and rear legs are spread apart (Fig. 2). This preferred stance does not conform precisely to those of steady walking, necessitating small adjustments to the walk in the final steps. First, the final leg protraction often occurs in the absence of strong retraction by the supporting legs. Second, the insect often takes advantage of the left/right asymmetry, letting rear and middle legs on the leading side retract beyond their normal endpoints while completing the metachronal sequence on the trailing side. Walking typically resumes with an initial retraction by all legs. Stances are close enough to leg configurations of steady walking that metachronal rhythms are often continuous across pauses, a feature which suggests that leg coordination is affected by peripheral parameters, such as leg position.
Studies on the Mode of Action of Octopamine, 5-Hydroxytryptamine And Proctolin on A Myogenic Rhythm in the Locust
Authors: Evans Peter D. 
Published: April 2021

ABSTRACTThe modes of action of the modulatory compounds octopamine, 5-hydroxytryptamine (5-HT) and proctolin on the frequency of the myogenic rhythm of the extensor-tibiae muscle of the hindleg of the locust, Schisto-cerca americana gregaria, have been investigated. 5-HT and proctolin increase the frequency of the myogenic rhythm and the results of the present study suggest that they may mediate their effects by increasing the levels of cyclic AMP in the pacemaker of the myogenic bundle. In contrast, octopamine reduces the frequency of the myogenic rhythm and appears to mediate its effects by a mechanism that does not involve an elevation of cyclic AMP. A number of other possible mechanisms for the action of octopamine are discussed.
Feeding And Excretion In The Scorpion Paruroctonus Mesaensis: Water And Material Balance
Authors: D.Yokota Stanley 
Published: April 2021

ABSTRACT
Scorpions feed by a process involving the external grinding and digestion of prey, with the ingestion of only the soluble fraction. The water obtained from the prey represents the most important source of water intake for scorpions inhabiting arid regions, placing great importance on the animals’ ability to utilize prey water effectively. The scorpionParuroctonus mesaensis (Stahnke) was found to ingest a mean of 88 % of the body water of selected prey. However, the scorpion loses 0·37 ml of its own body water per ml of prey water extracted, resulting in a net water gain of 0·51 ml water for every ml of prey water. Fluid uptake by the scorpion has been ascribed to a pharyngeal pumping mechanism. Direct measurements of the suction generated by the pharynx yielded a minimal estimate of its pumping capability of 130 mmHg.
The uptake and excretion of nitrogen and electrolytes by Paruroctonus mesaensis on a diet of Tenebrio molitor adults were also analysed. Almost all the potassium ingested was excreted, whereas most of the sodium and chloride were retained, possibly serving to expand haemolymph volume. Assuming a steady state for nitrogen, it was estimated that the net utilizable water obtained from prey, that is the water intake minus the excretory water necessitated by nitrogen excretion, was equivalent to about 35 % of the initial prey water or 69 % of the water ingested.
Characterization Of The Intermittent Breathing Pattern In Xenopus Laevis
Authors: Boutilier Robert G. 
Published: April 2021

ABSTRACT
Xenopus laevis exhibits an extensive repertoire of breathing patterns during voluntary diving-emergence behaviour. In experiments where animals surfaced to breathe at a blowhole fitted with a pneumotachograph, two noticeably different patterns of breathing were observed. In the first (burst breathing), long periods of diving were periodically interrupted by short visits to the surface when a discrete series of evenly spaced ventilations occurred. On other occasions, the same animal might rise to the surface and begin ventilating its lungs, not in discrete bursts, but intermittently over a long period of time (a breathing bout). Minute ventilation during a breathing burst was more than double that of a bout and represents a more active diving-emergence behaviour on the part of the animal. Regulation of the amount of gas exchanged in both breathing styles appears to be due to manipulation of the temporal pattern of lung ventilations (i.e. the breathhold durations), rather than to an alteration in the overall depth of breathing; the latter is possible to some extent, however, through adjustments in the composition of individual ventilations.
Maintenance of Isolated Smooth Muscle Cells of the Ctenophore Mnemiopsis
Authors: Stein P. G. , Anderson P. A. V. 
Published: April 2021

ABSTRACT
Progress toward understanding the physiology of smooth muscle has been slow for several reasons. In most smooth muscle tissues, the cells are extremely small, electrically coupled to one another, often spontaneously active and complexed with large amounts of inelastic connective tissue. The technical problems posed by these factors are numerous and have been reviewed extensively (Tomita, 1970; Anderson, 1977; Attwell & Cohen, 1977; Beeler & McGuigan, 1978). It is clear that the nature of the tissue severely limits the types of experiments which can be performed and the interpretation of any data obtained. Recent efforts to circumvent these problems have increasingly focused on the development of isolated, single cell models. Thus far, isolated cells from Bufo (Bagby et al. 1971; Fay & Delise, 1973; Singer & Walsh, 1980), Mytilus (Ishii & Takahashi, 1982), Beroe (Hernandez-Nicaise, Mackie & Meech, 1980; Hernandez-Nicaise, Bilbaut, Malaval & Nicaise, 1982; Nicaise, Hernandez-Nicaise & Malaval, 1982) and Mnemiopsis (Anderson, 1984; Stein & Anderson, 1984) have been studied. These preparations have eliminated many of the complicating variables mentioned above and they have allowed the first simplified examination of smooth muscle cellular physiology.
The Physiology of Wandering Behaviour in Manduca Sexta: I. Temporal Organization and the Influence of the Internal and External Environments
Authors: Dominick Oliver S. , Truman James W. 
Published: April 2021

ABSTRACT
A stereotyped series of behavioural changes occurs in preparation for pupation in Manduca sexta. Feeding declines over an 8-h period, after which the larva coats its body with a labial gland secretion. The animal then begins a 10-to 30-h wandering behaviour during which it constructs a pupation chamber underground. Wandering behaviour starts during a specific temporal gate which is determined by an internal circadian timer. The scotophase of the day prior to wandering has the major influence on the timing of internal processes which activate the behaviour. Wandering duration is correlated with larval size, reflecting a possible influence of juvenile hormone. The larva appears to be irrevocably committed to begin wandering by an event that occurs about 15 h previously, a time that corresponds to the second of three prothoracicotropic hormone (PTTH) pulses and the accompanying elevation of ecdysteroids as measured by Gilbert et al. (1981). We conclude that both the initiation and duration of wandering behaviour are governed primarily by processes which are internal to the larva.
The Orientation of Pigeons at Gravity Anomalies
Authors: Lednor A. J. , Walcott C. 
Published: April 2021

ABSTRACT
The means by which homing pigeons determine the direction to their home loft when released in unfamiliar territory remains a mystery. Hypotheses involving the sun (Matthews, 1953, 1955), Coriolis force and the earth’s magnetic field (Yeagley, 1947, 1951), inertial cues (Barlow, 1964, 1966), infrasound (Kreithen & Quine, 1979), have been advanced but currently there is no strong empirical support for any of these hypotheses. Recently Papi (see Papi, 1976; Papi et al. 1980 for reviews) and Wallraff (1980) have proposed that olfactory cues are the basis of the pigeons’ position-finding ability but not all investigators are convinced by the evidence (see e.g. Able, 1980; Keeton, 1980; Schmidt-Koenig, 1979; Walcott & Lednor, 1983).
Nematocyst Inactivation During Feeding in Hydra Littoralis
Authors: Ruch R. J. , Cook C. B. 
Published: April 2021

ABSTRACT
Hydra littoralis uses stenotele nematocysts for prey-killing. Unused stenoteles are retained when prey-killing ceases. This inactivation results from an accumulation of soluble factors in the surrounding medium, and ends when hydra are placed in fresh culture solution. The inactivation factors are most probably released from the hydra during nematocyst discharge since stenotele activity is reduced by KCl solutions containing nematocyst factors and is enhanced by prey homogenate.
Correlations between structure and function in the design of the bat lung: a morphometric study
Authors: Maina J. N. , King A. S. 
Published: April 2021

ABSTRACT
The lungs of five species of bat Pipistrellus pipistrellus, Miniopterus minor (Peters), Tadarida mops (De Blainville), Cynopterus brachyotis (Muller) and Cheiromeles torquatus (Horstield) have been analysed by morphometric techniques. The mean body weight (W) ranged from 5 g in Pipistrellus pipistrellus to 173g in Cheiromeles torquatus; the lung volume (VL) ranged from 0·3 cm3 in Pipistrellus to 10 cm3 in Cheiromeles. The volume densities or the main components of the bat lung, namely the parenchyma [Vv(p,L)] (the gas exchange region) and the nonparenchyma [Vv(np,L)], were closely similar, the Vv(p,L) constituting a mean value of 84·2% and the Vv(np,L) 15·8% in the five species. The VL, the surface area of the blood-gas (tissue) barrier (St), the pulmonary capillary blood volume (Vc), and the total morphometric pulmonary diffusing capacity were all strongly correlated with body weight. The harmonic mean thickness of the blood-gas (tissue) barrier (τht) and the surface density of the blood-gas (tissue) barrier [Sv(t,p)] were poorly correlated with W. The bats had a remarkably higher VL than either birds or terrestrial mammals. The Vc in the bat lung was similar to that in the bird lung but higher than that of the terrestrial mammals. The bats had a more extensive St than either the birds or the terrestrial mammals. In the bats the τht was thicker than in the birds but thinner than that of the terrestrial mammals. These pulmonary structural adaptations culminated in a higher in the bat than either in the birds or in the terrestrial mammals. The superior morphometric properties of the bat lung coupled with the established physiological adaptations may help to explain how the bat lung is capable of providing the immense amount of oxygen demanded by flight.
Analysis of contact-rehydration in terrestrial gastropods: osmotic control of drinking behaviour
Authors: Prior David J. 
Published: April 2021

ABSTRACT
Contact-rehydration in slugs is mediated by a specific behavioural pattern in which dehydrated slugs move onto a moist surface, assume a flattened posture while water is absorbed through the surface of the foot and move off once they are rehydrated. ‘Drinking behaviour’ is initiated when slugs have been dehydrated to the threshold leyel of 60–70% of initial body weight (IBW). Drinking behaviour is terminated once slugs have rehydrated to their individual rehydration set-points. The mean ‘rehydration set-point’ for Limax is 93·6 ± 12·2% IBW (±S.D.). Slugs can achieve their individual set-point regardless of the extent of initial dehydration. Drinking behaviour can be initiated by injections of hyperosmotic mannitol solution and terminated by injections of dilute saline. This indicates that variation in the osmolality of the haemolymph is involved in the control of the behavioural sequence.