53 research outputs found

    Induced hyperlipaemia and immune challenge in locusts

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    Injections of immunogens, such as β-1,3-glucan or lipopolysaccharide (LPS), bring about a marked hyperlipaemia with associated changes in lipophorins and apolipophorin-III in the haemolymph of Locusta migratoria. These changes are similar to those observed after injection of adipokinetic hormone (AKH). The possibility that endogenous AKH is released as part of the response to these immunogens is investigated using passive immunisation against AKH-I, and measurement of AKH-I titre in the haemolymph after injection of immunogens. The data presented show that, despite the similarity of the changes brought about by the presence of immunogens in the haemolymph to those brought about by AKH, there is no release of endogenous AKH after injection of laminarin or LPS. A direct effect of the immunogens on release of neutral lipids by the fat body cannot be demonstrated in vitro, and the mechanism by which hyperlipaemia is induced during immune challenge remains uncertain

    Habit Reversal Training and Educational group treatments for children with Tourette Syndrome: a preliminary randomised controlled trial.

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    Quality of life of children with Tourette Syndrome (TS) is impacted greatly by its symptoms and their social consequences. Habit Reversal Training (HRT) is effective but has not, until now, been empirically evaluated in groups. This randomised controlled trial evaluated feasibility and preliminary efficacy of eight HRT group sessions compared to eight Education group sessions. Thirty-three children aged 9-13 years with TS or Chronic Tic Disorder took part. Outcomes evaluated were tic severity and quality of life (QoL). Tic severity improvements were found in both groups. Motor tic severity (Yale Global Tic Severity Scale) showed greatest improvements in the HRT group. Both groups showed a strong tendency toward improvements in patient reported QoL. In conclusion, group-based treatments for TS are feasible and exposure to other children with tics did not increase tic expression. HRT led to greater reductions in tic severity than Education. Implications, such as cost-effectiveness of treatment delivery, are discussed

    Morphology, testes development and behaviour of unusual triploid males in microchromosome-carrying clones of Poecilia formosa.

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    In a microchromosome-carrying laboratory stock of the normally all-female Amazon molly Poecilia formosa triploid individuals were obtained, all of which spontaneously developed into males. A comparison of morphology of the external and internal insemination apparatus and the gonads, sperm ploidy and behaviour, to laboratory-bred F(1) hybrids revealed that the triploid P. formosa males, though producing mostly aneuploid sperm, are partly functional males that differ mainly in sperm maturation and sexual motivation from gonochoristic P. formosa males

    Consideration of Thermodynamic Processes Formation of Compressed-Air Foam in Design Compressed Air Foam Systems

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    The main problem with creating compressed air systems is to properly regulate the flow of water and the flow of air that is fed into the mixing chamber so as to continuously provide a foam that must have adequate fire-fighting properties and remain stable over time. The process of obtaining compression foam is a thermodynamic process, which depending on the specified technological factors can be both isothermal and adiabatic. The nature of the process determines both the geometric and physical properties of the foam, and its possible fluctuations can lead to changes in the physical characteristics of the foam. The work provides recommendations for determining the type of thermodynamic process, which makes it possible to improve the accuracy when creating mathematical models of mobile plants for the production of CAF.</jats:p

    Nonlethal effects of predation: Presence of insectivorous birds affects the behaviour and level of stress in insects

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    AbstractInsect exposure to their predators can affect individuals and community processes, through direct consumption or nonlethal (i.e., nonconsumptive) effects. However, the links between behavioural and physiological responses and stimuli needed for development of the fear are not clear. We therefore subjected the desert locusts (Schistocerca gregaria) to three nonlethal treatments, using the great tits (Parus major) as a potential predator. The treatments involved: (1) bird - presence of a live great tit and its calls, (2) call - great tit calls only, (3) control - without any treatment. In the first behavioural laboratory experiment, hungry locusts were kept in an experimental cage with a shelter and food on opposite sides of the cage. The duration of hiding and feeding were considered as an indicator of fear responses. In the second laboratory experiment with the same three treatments, levels of the adipokinetic hormone (AKH) were evaluated in the central nervous system (CNS) and haemolymph. In the third experiment in an outdoor aviary, birds were free to fly in larger distances from locusts, before hormone levels were measured as response to bird and control treatments. In the first behavioural experiment, the presence of tits and their call resulted in significantly longer hiding time and significantly shorter feeding time than in the call/control treatments. The proximity of birds and locusts in the laboratory experiment elicited a significant increase in the AKH levels in the CNS and haemolymph as compared to the call/control treatments. In the outdoor experiment, the AKH levels were significantly higher in the CNS of locusts exposed to the bird than to control; no difference was recorded in their haemolymph. We showed that predator exposure quickly affected behavioural responses and physiological processes of locusts. Playback of the avian calls was not an appropriate stimulus to induce stress responses in desert locusts.</jats:p

    Nonlethal Effects of Predation: The Presence of Insectivorous Birds (Parus major) Affects The Behavior and Level of Stress in Locusts (Schistocerca gregaria)

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    AbstractInsect exposure to their predators can affect individuals and community processes, through direct consumption or nonlethal effects. However, the links between behavioral and physiological responses and stimuli needed for the development of predator avoidance are not clear. We subjected desert locusts (Schistocerca gregaria) to three nonlethal treatments, using great tits (Parus major) as a predator. The treatments included: (1) bird—presence of a great tit and its calls, (2) call—great tit calls only, (3) control—absence of a great tit and its calls. In the first behavioral laboratory experiment, locusts were offered food and shelter in an open space. The duration of hiding versus feeding indicated predator responses. In the second laboratory experiment, locusts were subjected to the same three treatments, and adipokinetic hormone (AKH) levels were measured in the central nervous system (CNS) and hemolymph. In the third experiment in an outdoor aviary, birds were allowed to fly freely over locusts before we measured physiological response. During the first experiment, locusts hid for a significantly longer amount of time and fed for a significantly shorter amount of time when the bird was present and calls were played, compared to when only calls were played or compared to the control treatment. The proximity of birds to locusts in the laboratory experiment elicited a significant increase in AKH levels in the CNS and hemolymph compared to the call/control treatment. The physical proximity of the great tits affected both the behavioral and physiological responses of the locusts.</jats:p
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