Dissertations / Theses: 'LOCONT'

1

Jones, Ryan C. "Hopper Bands: Locust Aggregation." Scholarship @ Claremont, 2016. https://scholarship.claremont.edu/hmc_theses/81.

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Locust swarms cause famine and hunger in parts of Sub-Saharan Africa as they travel across croplands and eat vegetation. Current models start with biological properties of locusts and analyze the macroscopic behavior of the system. These models exhibit the desired migratory behavior, but do so with too many parameters. To account for this, a new model, the Alignment and Intermittent Motion (AIM) model, is derived with minimal assumptions. AIM is constructed with regards to locust biology, allowing it to elicit biologically correct locust behavior: the most noteworthy being the fingering of hopper bands. A Particle-in-Cell method is used to optimize simulations, allowing for trials of up to 106 particles over reasonable timescales. We analyze the shapes of these swarms, note the similarities between simulations of large and small swarms, and propose possible methods for analyzing simulation metrics.

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Pelletier, de Chambure-Baguenier Desormeaux Marie. "René Lochon : inventaire de l'oeuvre gravé conservé à la Bibliothèque nationale : suivi de Inventaire de l'oeuvre gravé de Pierre Lochon /." Paris : Paris 4, 1994. http://catalogue.bnf.fr/ark:/12148/cb358486345.

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3

Cofer, David Wayne. "Neuromechanical Analysis of Locust Jumping." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/biology_diss/57.

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The nervous systems of animals evolved to exert dynamic control of behavior in response to the needs of the animal and changing signals from the environment. To understand the mechanisms of dynamic control, we need a means of predicting how individual neural and body elements will interact to produce the performance of the entire system. We have developed a neuromechanical application named AnimatLab that addresses this problem through simulation. A computational model of a body and nervous system can be constructed from simple components and situated in a virtual world for testing. Simulations and live experiments were used to investigate questions about locust jumping. The neural circuitry and biomechanics of kicking in locusts have been extensively studied. It has been hypothesized that the same neural circuit and biomechanics governed both behaviors, but this hypothesis was not testable with current technology. We built a neuromechanical model to test this and to gain a better understanding of the role of the semi-lunar process (SLP) in jump dynamics. The SLP are bands of cuticle that store energy for use during jumping. The results of the model were compared to a variety of published data and were similar. The SLP significantly increased jump distance, power, total energy, and duration of the jump impulse. Locust can jump precisely to a target, but also exhibit tumbling. We proposed two mechanisms for controlling tumbling during the jump. The first was that locusts adjust the pitch of their body prior to the jump to move the center of mass closer to the thrust vector. The second was that contraction of the abdominal muscles during the jump produced torques that countered the torque due to thrust. There was a strong correlation relating increased pitch and takeoff angle. In simulations there was an optimal pitch-takeoff combination that minimized tumbling that was similar to the live data. The direction and magnitude of tumbling could be controlled by adjusting abdominal tension. Tumbling also influenced jump elevation. Neuromechanical simulation addressed problems that would be difficult to examine using traditional physiological approaches. It is a powerful tool for understanding the neural basis of behavior.

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Wang, Haikou Physical Environmental &amp Mathematical Sciences Australian Defence Force Academy UNSW. "Evaluation of insect monitoring radar technology for monitoring locust migrations in inland Eastern Australia." Awarded by:University of New South Wales - Australian Defence Force Academy, 2008. http://handle.unsw.edu.au/1959.4/38923.

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To evaluate the utility of insect monitoring radar (IMR) technology for long-term monitoring of insect migration, a mini-network of two IMR units in Bourke, NSW, and Thargomindah, Qld, and a base-station server in Canberra, ACT, was set up in eastern Australia. The IMR operated automatically every night under the control of a personal computer that also conducted data acquisition and processing. Digitisation of radar signals, their analysis (delimitation of echoes from background noise and adjoining echoes, followed by extraction of estimates for each target's speed, displacement direction, body alignment, radar cross-section, and wingbeat frequency and modulation pattern), and generation of observation summaries were implemented as a fully automated procedure. Wingbeat frequency was found to be retrievable from the IMR's rotary-beam signals, and this allowed each individual target to be characterised by its wingbeat as well as its size and shape. By drawing on ancillary information from the Australian Plague Locust Commission's database of field survey and light trap records, the echo characters indicative of Australian plague locust, Chortoicetes terminifera (Walker), were identified. Using these, about 140 nights with detectable plague locust migrations were identified for the Bourke IMR site during 1998 - 2001 and 31 nights for Thargomindah during 1999 - 2000. Analysis of these nights confirmed that C. terminifera migrates in association with disturbed weather, especially tropical troughs, in eastern Australia. Trajectory simulation based on IMR-derived displacement directions and flight speeds allowed the identification of population movements likely to reach favourable habitats and thus to develop rapidly and possibly cause a plague. The outbreak during 1999 - 2001 most likely originated from the southeastern agricultural belt after migrations and multiplications over several generations. The IMR observations demonstrated that C. terminifera migrates over long distances with the wind at night and indicated that it may have an orientation behaviour that prevents it from being taken too far into the arid inland, a trait that could be highly adaptive in this environment. The two IMRs were operational for more than 85% of scheduled time during the study period and provided a wealth of information of potential value for locust management and migration research

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5

wei, Jonny, and Pär Palmebäck. "Locust System Integration into Demo Vechicles." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8252.

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This thesis project was carried out at Volvo Car Corporation. It is based on an EU project called Locust in which a bio-inspired visual sensor system (the Locust sensor system) for automotive collision avoidance was developed. The Locust sensor system is designed to emulate the collision avoidance functionality of the Locust grasshopper, which is well-known for its extraordinary vision based collision avoidance ability, in particular with regard to its fast reaction times to perceived threats. Volvo Car Corporation is interested in the possibility of using the bio-inspired technology developed in the Locust project to improve its already existing collision avoidance systems. Pedestrian collision avoidance is of high interest, for which the properties of the Locust grasshopper are desirable.

The purpose of this thesis project is to develop two demonstrator vehicles to test the performance of the Locust sensor system, carry out the testing, and evaluate its usability for Volvo Car Corporation. The first vehicle is a scale 1:5 model car that was originally developed in a thesis project at KTH, and the second a full scale Volvo XC90.

It was found in the testing that the Locust sensor system is promising for pedestrian collision avoidance applications. The results for detecting other vehicles were also acceptable, but Volvo Car Corporation already has other collision avoidance systems with better performance in this regard. In general the test results were very good for speeds up to about 40 km/h. This indicates that the Locust sensor system would be most usable in a city driving environment, parking lot situations, and for driving in residential areas.

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6

Cooke, Rachel Anne. "Opioid-like peptides in the locust." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386397.

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7

Miller, B. A. "Potassium channels in cultured locust muscle." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384270.

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8

Shah, Parin. "Economic Subterfuge and the NBA Lockout." Thesis, Boston College, 2012. http://hdl.handle.net/2345/2641.

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Thesis advisor: Richard, S.J. McGowan
At the very core of the National Basketball Association’s labor negotiations between the owners and the players during the 2011 lockout was the league’s argument that its economic structure was broken. Owners contended that the NBA’s soft salary cap system, and the resulting payroll disparity, has put small-market franchises at a talent disadvantage and produced a league of haves and have-nots. To remedy this purported competitive balance problem, the owners demanded severe policy measures to decrease the pay dispersion among teams. However, the players union cautioned that these hardline provisions were merely an attempt to transfer wealth from players to owners. This charge warranted further analysis. Existing literature on this topic is either outdated or insufficient in scope. As such, using regression analysis, this thesis evaluated the league’s argument and determined to what extent the league’s soft salary cap system has contributed to its competitive imbalance.The empirical analysis of this thesis produced several meaningful conclusions. While the NBA has relative imbalance, it does not affect consumer demand for the regular season product. Moreover, while pay dispersion exists, additional salary expenditures only marginally add to a team’s winning percentage. There is no significant relationship between payroll disparity and competitive balance. Finally, with the escalating importance of media rights contracts and the historical appreciation of franchise valuation, the league overstated the financial distress of most of its small-market owners. Overall, the NBA and its owners used deceptive rhetoric and misleading economic policies to decrease player salaries, not to increase competitive balance, in a collusive effort to maximize profits and reassert its diminishing monopsony power in an increasingly star-driven league
Thesis (BS) — Boston College, 2012
Submitted to: Boston College. Carroll School of Management
Discipline: Carroll School of Management Honors Program
Discipline: Economics

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9

Wilson, Emma. "Force response of locust skeletal muscle." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/190857/.

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The force response of the locust hind leg extensor muscle to input excitation pulses is modelled. Despite the processes behind muscle contraction being well established, no broadly valid method of modelling skeletal muscle exists. Studies that compare the merits of existing models are extremely scarce and researchers make various assumptions in order to simplify the complex, nonlinear behaviour of the muscle. Locusts provide an opportunity to develop a muscle model in a simpler system, that will still show similar properties to that of mammalian muscles. In developing a model previous work is considered, and complexity is introduced in the experimental conditions in stages. This meant a model could be built up in parts. This approach reduces the need for questionably valid assumptions. The main focus of this work is modelling activated isometric muscle. Experimental data was collected by stimulating the extensor muscle and measuring the force generated at the tibia. In the first instance the response to individual stimulus pulses is modelled. This is extended to develop a predictive model capable of estimating the isometric force response to general pulse train inputs. In developing the model, data was fit to existing models, and from this an improved isometric model developed. The effect of changing the isometric muscle length is considered. Commonly changing the muscle length is assumed to just scale the force response. This assumption is poor. The dynamics of the force response were found to be modifed by the change in muscle length, and the isometric model adapted to include this dependency. Results related to the non-isometric behaviour are also presented. Passive muscle is usually just modelled over the lengthening period, however, the whole stretch-shorten cycle is considered here. A model, adapted from the standard linear model, is developed to describe the passive force response.

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10

Farivar, Shabnam Sarah Laurent Gilles. "Cytoarchitecture of the locust olfactory system /." Diss., Pasadena, Calif. : California Institute of Technology, 2005. http://resolver.caltech.edu/CaltechETD:etd-04212005-143332.

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11

Zanotto, Flavia Pinheiro. "Physiological and biochemical aspects of nutritional homeostasis in locusts." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306907.

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12

Nasiruddin, Munira. "The effects of azadirachtin and analogues upon feeding and development in locusts." Thesis, University of Aberdeen, 1993. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU553862.

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The antifeedant and insect growth regulatory (KGR) activities of azadirachtin, its natural analogue 3-tigloylazadirachtol and its synthetic analogues 22,23-dihydroazadirachtin and 22-alpha-bromo-22,23-dihydro-23-alpha,beta-ethoxyazadirachtin were investigated using different bioassays on Schistocera gregaria (F.) and Locusta migratoria (R &38 F). The effects of azadirachtin on midgut histology were studied at the light microscopical and electron microscopical level. Light microscopy revealed that azadirachtin affected midgut histology in a dose and time dependent manner. Increasing effects were seen at doses of 5-15 mug g-1 body weight. With a dose of 1 mug g -1, effects were apparent but recovery occurred after three days. Azadirachtin caused the normal elongated midgut epithelial cells to become cuboidal; thickening of the connective tissue with invading regenerative cells. The gut musculature was swollen. Electron microscopy showed the midgut cells to undergo necrosis with swelling of the mitochondria and endoplasmic reticulum, reduction in glycogen granules and increaesd autophagic vacuoles. Bursting and disruption of the cell contents was sometimes seen. Such effects were not seen in starved insects. Feeding activities, measured in terms of antifeedant indices (AI) and consumption rates (CR) in binary choice bioassays on fifth instar nymphs demonstrated dose-dependent variations for all the compounds in both species of insects. S.gregaria was more discriminatory and more sensitive to azadirachtin and its analogues than was L.migratoria. ED_50's were measured for all compounds tested. Ingestion rates of the compounds showed a dose-dependent decrease with increasing dose. The highest intake of the compounds was observed mostly at an AI of 50-60&'37. The short- and long-term effects of topical application and low doses (0.1 and 1.0 mug g-1 body weight) of azadirachtin, the analogues and an additional unidentified compound X (related to bromeothoxyazadirachtin) were measured in S.gregaria. The effects on growth were reduced body weight and reduced feeding as measured by faecal pellet production. Azadirachtin induced the highest mortality and most deaths occurred within the first few days of treatment; the analogues were less acutely toxic. Mortalities at the moults were also dose related. In all the insects which survived, none of the compounds exerted any significant effects on dry body or ovary weights, egg size or fecundity. Thus once toxic effects were overcome, the insects matured and reproduced normally; none of the compounds had any long term accumulative effects.

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13

Jordan, Lars. "Protokolldiskussion Jabber vs. Locom." Universitätsbibliothek Chemnitz, 2000. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200000387.

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Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme (Fakultaet fuer Informatik) der TU Chemnitz. Workshop-Thema: Infrastruktur der ¨Digitalen Universitaet¨ Zur unmittelbaren Kommunikation zweier oder mehrerer Kommunikationspartner werden heute sogenannte Instant Messaging Systeme eingesetzt. Der Vortrag zeigt zwei moegliche Ansaetze fuer ein Protokoll, das diese Art von Kommunikation bewerkstelligen kann. Zum einen handelt es sich um das Protokoll einer freien Implementierung eines IM Systems, Jabber. Zum anderen ist dies das Protokoll eines im Rahmen einer Diplomarbeit an der Fakultaet fuer Informatik entstandenen IM Systems, Locom.

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14

Whim, Matthew Dominic. "Octopaminergic modulation of the locust flight system." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257169.

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15

Miller, Gabriel A. "Immunity, nutrition and phenotype in locust ecology." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497052.

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16

Locane, Elina [Verfasser]. "Switching processes in mesoscopic systems / Elina Locane." Berlin : Freie Universität Berlin, 2018. http://d-nb.info/115576112X/34.

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17

Newman, T. M. "Membrane specialisations of the locust neuromuscular system." Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371131.

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18

Zhang, Jialun. "Dynamics and Clustering in Locust Hopper Bands." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/hmc_theses/93.

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In recent years, technological advances in animal tracking have renewed interests in collective animal behavior, and in particular, locust swarms. These swarms pose a major threat to agriculture in northern Africa, the Middle East, and other regions. In their early life stages, locusts move in hopper bands, which are huge aggregations traveling on the ground. Our main goal is to understand the underlying mechanisms for the emergence and organization of these bands. We construct an agent-based model that tracks individual locusts and a continuum model that tracks the evolution of locust density. Both these models are motivated by experimental observations of individuals’ behavior. The macroscopic emergent behavior of the group is studied through numerical simulation of these models.

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Jiang, Xingcong [Verfasser], and Heinz [Akademischer Betreuer] Breer. "Molecular elements involved in locust olfaction : gene families in the desert locust Schistocerca gregaria / Xingcong Jiang ; Betreuer: Heinz Breer." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2018. http://d-nb.info/1166752844/34.

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20

Barker, Peter Douglas Robertson. "Statistics of spike discharges from a visual unit in the locust." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279163.

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Buckingham, S. D. "The motor organisation of a proximal joint in the hindleg of the locust." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233702.

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Hill-Venning, Claire. "The neural control of ventilation in the desert locust Schistocerca gregaria forskal." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280031.

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Seymour, Kathyrn Jane. "The neural control of oviposition in the locust Schistocerca Gregaria." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335246.

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Bates, Susan Elizabeth. "Aspects of neurotransmitter release at insect glutamatergic synapses." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238239.

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Stettin, Katja. "Mechanisms driving the acquisition and maintenance of gregarious behaviour in the desert locust (Schistocerca gregaria)." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708550.

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26

Duggan, Michael John. "Studies on the muscarinic acetylcholine receptors of the locust." Thesis, University of Bath, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378138.

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Anstey, Michael L. "Serotonin mediates behavioural gregarization in the desert locust." Thesis, University of Oxford, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504285.

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Marshall, John. "Molecular characteristics of the locust nicotinic acetylocholine receptor." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315055.

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Herbert, Rolf China. "Modelling insect wings using the finite element method." Thesis, University of Exeter, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370012.

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Banner, S. E. "Neurotransmitter receptors in the gut of the locust Schistocerca gregaria." Thesis, University of the West of England, Bristol, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383628.

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31

Armstrong, G. "Factors determining the metabolic rate of flying locusts." Thesis, University of Aberdeen, 1988. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU010220.

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Rate of oxygen consumption was used as a method of measuring the metabolic rate of flying locusts. The animals flew into an airstream from a wind tunnel while tethered to a balance so that lift could be determined. Wingbeat frequency was also recorded. The rate of oxygen consumption during flight was found to be determined principally by wingbeat frequency, but using mean values for steady flight good straight line correlations were also found between rate of oxygen consumption and lift, and wingbeat frequency and lift. However, the relationships between these three variables were seen to change during the early part of flight, when lift could be maintained while, in general, wingbeat frequency and rate of oxygen consumption declined. As wingbeat frequency decreased the amount of oxygen used with each wingbeat was found to remain fairly constant, but the amount of lift generated by each wingstroke increased. Therefore the proportion of the locust's total power output which was used to perform aerodynamic work was greater at the lower wingbeat frequency. It was considered that the action of adipokinetic hormone and the change from predominantly carbohydrate to lipid metabolism might be involved in the onset of the period of more economical, steady flight. However, no firm evidence of this was obtained from the experiments which were carried out. When locusts were injected with corpus cardiacum extract 1h before flight, their wingbeat frequency dropped more rapidly than that of saline injected animals. Injection of adipokinetic hormone immediately before flight had a detrimental effect on the locusts' flight performance.

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32

Flores, Galindo Carlos. "Sendero Luminoso, los locos, los otros." Anthropía, 2014. http://repositorio.pucp.edu.pe/index/handle/123456789/78054.

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Gaaboub, Ibrahim Abd Alla. "Neural processing of chemosensory information from the locust legs." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961248831.

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Tousson, Ehab Mostafa. "Neural processing of chemosensory information from the locust ovipositor." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=961892293.

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Peach, Jacqueline Lenore. "Substrate utilization and ammonia secretion in the locust ileum." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30270.

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Increases in chloride-dependent short-circuit current (ΔIsc; an indicator of the major energy-requiring membrane transport process) were used to determine which external substrates support aerobic respiration in locust ileum stimulated by cAMP and theophylline in vitro. At high bilateral concentrations, only glucose and 5 amino acids (alanine, asparagine, glutamine, proline and serine) sustained ileal ΔIsc, while trehalose, lipid (diolein) and all other amino acids normally found in locust haemolymph were not utilized. When individual substrates were provided unilaterally at physiological concentrations, the predominant source of substrates supporting ileal Isc was the luminal fluid, which is mostly derived in situ from Malpighian tubule secretion. Only proline was used almost equally well from both the lumen or haemolymph sides. This situation contrasts with locust rectum where luminal proline is by far the predominant source of respiratory substrate. An inhibitor of amino transferases, amino-oxyacetate, largely abolished ileal ΔIsc sustained by alanine, but not that sustained by either proline or glutamine. The 5 amino acids that caused an increase in chloride-dependent Isc were assayed for their effect on luminal secretion of ammonia (Jamm), with and without cAMP. A saline with alanine, asparagine, glutamine, proline and serine supported ileal Jamm not significantly different from with Jamm complete saline. Each of these 5 amino acids, when applied individually, resulted in a Jamm significantly above a substrate-free control. The remaining amino acids found in a complete physiological saline (arginine, glycine, histidine, lysine, and valine) that do not stimulate ileal Isc were combined in one saline and gave a Jamm value insignificant from the substrate-free control. Asparagine and glutamine have the greatest effect on Jamm with both bilateral and luminal presentation. The addition of cAMP caused an increase in Jamm when either the complete saline or the 5 amino acid saline were present bilaterally, but no significant effect on Jamm caused by a luminal addition of individual amino acids. Jamm was unaffected by changes in luminal pH from 4.5 to 7.5, Na⁺ substitution and amiloride addition, indicating that luminal Jamm is primarily occurring by NH₄⁺ transport and not by diffusion trapping (NH₃).
Science, Faculty of
Zoology, Department of
Graduate

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Clissold, Fiona J. (Fiona Jane) 1967. "Nutritional ecology of the Australian plague locust, Chortoicetes terminifera." Monash University, School of Biological Sciences, 2003. http://arrow.monash.edu.au/hdl/1959.1/5837.

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37

Patel, Alexandra Judith Frances. "Developmental plasticity in aimed scratching movements of a locust." Thesis, University of Leicester, 2010. http://hdl.handle.net/2381/10080.

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Developmental changes may affect aimed limb movements by altering limb mass, muscle strength and musculo-skeletal resistance or changing the position of a target on the body relative to the responding limb. Scratching movements following stimulation of wings by 5th instars and adult Schistocerca gregaria were compared before and after the imaginal moult, during which the wings increase in length and rotate, presenting different wing surfaces to external contact. The arrangement of mechanosensory hairs on the wings of 5th instars and adults was determined and associated with the development of scratching behaviour. The neuronal projections of mechanosensory hairs on the hind wing projected intersegmentally to anterior ventral association centre (aVAC) of the metathoracic ganglion and continued intersegmentally to the mesothoracic aVAC. Scratching movements accommodated developmental changes that occurred between the 5th instar and adulthood of S. gregaria. There was no change in movement characteristics between 5th instars and adults, indicating that developmental changes in the muscle strength, limb mass and musculo-skeletal resistance were compensated. Movements were appropriately aimed to accommodate the increase in wing size, and were associated with stimulation of tactile hairs on different wing surfaces in 5th instars and adults, implying different synaptic connections onto post-synaptic interneurones. Therefore, changes in limb mass, muscle strength and musculo-skeletal resistance due to growth are be compensated for, possible mechanism are proprioceptive reflexes and dynamic joint stiffness. Changes in target position caused by body growth may be facilitated by the development of new mechanosensory hairs and different synaptic connections onto postsynaptic interneurones. Wing rotation is likely to be accommodated by the intersegmental projections of wing hair afferents, and the convergence of hind wing and fore wing sensory signals.

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38

Childs, Edward William. "The roles of the locust DCMD in collision detection." Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300191.

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Pickering, Alistair N. "Proton diffusion in locust muscle fibres : a microelectrode study." Thesis, University of Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.330055.

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40

Macallan, David Robert Edward. "Studies on the nicotinic acetylcholine receptor of the locust." Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760577.

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Brown, Michael Charles Simon. "The locust GABA receptor complex : the cage convulsant site." Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760579.

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McCorkell, Fergus. "Aerodynamic flow sensing in the desert locust (Schistocerca gregaria)." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:0bb72915-a937-4228-84be-ce3306a441ec.

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Insects are richly instrumented with sensors used in flight control. Whilst we have good knowledge of the basic physiology of these structures, in many cases we have only a cursory understanding of the likely stimuli each sensory system receives during flight or why these systems have evolved to perform their particular function. This thesis examines the role and optimisation of arrays of cephalic flow-sensitive hairs, called trichoid sensilla, in the flight control of the desert locust (Schistocerca gregaria). Particle image velocimetry and computational fluid dynamics are used to measure and simulate the airflows being received by the fields of sensilla during flight. The visualisations reveal distinct local flow conditions over each field and how these are modulated differently by perturbations. The geometry of every individual hair is captured using both benchtop and synchrotron based X-ray micro tomography (XMT). These scans enable three-dimensional measurement of each hair's direction of curvature, which represents the direction of peak sensitivity to airflow. By combining flow stimulus and directional sensitivity data, we provide strong evidence for separate fields being tuned for distinct roles: some as step detectors for monitoring stall at extreme angles of attack, others as graded sensors for angles of attack and sideslip, and possibly for monitoring airspeed. Finally, we examine the flight response of tethered locusts to varying aerodynamic stimuli by changing the angle of sideslip and selectively covering fields of sensilla from oncoming airflow. We demonstrate a clear role for the sensilla in modifying the forces and moments generated under varying sideslip, as well as in changing the underlying natural modes of motion of the system. We reveal the axes about which the locusts are unstable under our experimental conditions, and demonstrate the necessary additional sensory feedback required to stabilise the system fully. The combined data represent a comprehensive and thorough examination of the complete cephalic flow-sensing system, providing insights applicable to both further biological study on multi-modal flight control and the use of bio-inspired arrays of sensors for manmade applications.

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43

Costalago, Meruelo Alicia Costalago. "Tarsal intersegmental reflex responses in the locust hind leg." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/397373/.

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Locomotion is vital for vertebrates and invertebrates to survive. However, the mechanisms for locomotion are partially unknown. Central Pattern Generators and reflex systems have been shown to be the basis of most movements performed by arthropods. Much has been investigated lately on Central Pattern Generators, but little work has been done in reflex systems. Locomotion and motor output in feet (or tarsus in arthropods) has also been disregarded in research. Despite that feet are responsible for stability and agility in most animals, research on feet movements is scarce. In this thesis the tarsal intersegmental reflex of the locust hind leg is investigated. The tarsal reflex consists of a response in the tarsus when there is a change in the femoro-tibial joint. The main objective of the thesis is to describe the system and to develop mathematical and experimental methods to study, model and analyse it. Through a set of experiments is shown that as the knee joint is extended, the tarsus is depressed, and as the knee joint flexes, the tarsus levates. The experiments demonstrated that there is a purely neuronal link between the femoro-tibial joint position and the tibio-tarsal joint position. Moreover, it also reveals the effect of neuromodulatory compounds, such as dopamine, serotonin or octopamine. The tarsal reflex responses are fairly consistent across individuals, although significant variability across animals was found. To model a system where variability is an issue, a mathematical model with strong generalisation abilities is used: Artificial Neural Networks (ANNs). To design the ANNs, a metaheuristic algorithm has been implemented. The resulting ANNs are shown to be as accurate as other mathematical models used in physiology when used in a well known reflex system, the FETi responses. This results showed that ANNs are as good as Wiener methods in predicting responses and they outperform them in prediction of Gaussian inputs. Furthermore, they are able to predict responses in different animals, independently of the variability, with a more limited performance. New experimental methods are also designed to obtain accurate recordings of tarsal movements in response to knee joint changes. These experimental methods facilitate the data acquisition and its accuracy, reducing measurement errors. Using the mathematical methods validated, these responses are modelled and studied, showing responses to Gaussian and sinusoidal inputs, variability across individuals and effects of neuromodulators. With the tarsal reflex described and modelled, it can be used as a tool for further research in disciplines such as medicine, in the diagnose and treatment of euromuscular dysfunction or design of prosthesis and orthoses. This model can also be implemented in robotics to aid in stability when walking on irregular terrain.

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Hampton, Scott. "Genius loco." This title; PDF viewer required. Home page for entire collection, 2009. http://archives.udmercy.edu:8080/dspace/handle/10429/9.

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45

Lechleitner, Richard August. "Properties of ion and fluid transport and control in hindgut of the desert locust (Schistocerca gregaria)." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28855.

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Previous studies of selective reabsorption in insect excretory system have concentrated almost exclusively on the rectum, while the role of the ileum has been assumed to be minor. The properties and control of solute and fluid transport in two segments of the hindgut, the ileum and rectum, from the desert locust (Schistocerca gregaria) have been studied and compared in vitro using everted sac and flat sheet preparations. Everted sacs of locust ileum transported fluid from the lumen side to hemocoel side over a 5 h period at near constant rates of 3.0 to 3.5 μL-h⁻¹-ileum⁻¹ and tissue volume did not change. Inhibition by azide indicated metabolic dependence of fluid transport. Fluid absorption occurred against osmotic concentration differences of up to 600 mosmol. Fluid transport was stimulated by cAMP, both nervous and glandular lobes of corpus cardiacum (CC), and fifth ventral ganglia (VG) in a dose-dependent manner. All stimulants caused ilea to absorb against larger osmotic concentration differences than unstimulated sacs. The ileal absorbate remained hyperosmotic to the luminal saline under all conditions and stimulants increased absorbate osmolality. Unstimulated fluid transport was supported at 50% of control levels by any one of Na+, K+, or CI⁻. Stimulation of fluid transport by CC or VG was dependent on CI⁻ and maximal stimulation occurred when the Na+:K+ ratio was 1:1. Cyclic AMP, CC and VG all stimulated Na+,K+ and CI⁻ absorption across everted ileal sacs. This is the first direct demonstration that Na+ reabsorption is controlled in insect excretory systems. Stimulation resulted in a decrease in absorbate HCO₃⁻ levels and pH concurrently with an increase in absorbate CI⁻ levels. Stimulation of fluid transport was associated with a 3-fold increase in transepithelial potential (hemocoel negative) suggesting stimulation of electrogenic anion (CI⁻) movement to the hemocoel. Net Na+ absorption occurs largely by electroneutral active transport. NH₄+/Na+ exchange may account for one-third of stimulated net Na+ flux. Extracts from both CC and VG stimulated fluid, K+, and CI⁻ transport across everted rectal sacs, but only a small stimulation of Na+ flux was observed which was an order of magnitude less than that observed for stimulated ilea (0.4 versus 5.1 μequiv-h⁻¹ -cm⁻²). Unlike the rectum, the ileum did not transport proline transepithelially and ileal fluid transport was not stimulated by increasing concentrations of proline in the bathing saline. Rectal fluid transport was stimulated 50% by increasing external proline concentration from 1 to 80 mM. Stimulation of rectal fluid transport by proline also occurred in the absence of Na+, K+, and CI⁻ and occurred against larger osmotic concentration differences. These results are consistent with previous reports of a high capacity transport system for proline in locust rectum. The presence of anion-stimulated ATPase and Na+,K+-ATPase in locust hindgut was also investigated. Anion-stimulated ATPase activities were observed in microsomal fractions of both rectum and ileum. Microsomal fractions from both tissues had enriched specific activities of several plasma membrane marker enzymes and decreased activities of two mitochondrial markers as compared to homogenate enzyme activities. Na+,K+-ATPase activity was 20-fold higher in the rectum than in the ileum, associated with the greater development of the basolateral membrane in the rectum. Overall the results suggest that ion and fluid reabsorption in the locust ileum is much more important in the excretory process than previously supposed. Moreover, this reabsorption was shown to be under neuroendocrine control.
Science, Faculty of
Zoology, Department of
Graduate

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46

Abisgold, J. D. "Compensation by locusts for changes in dietary nutrients : Behavioural and physiological mechanisms." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382635.

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47

Tjahjadi, Ir Nur. "Studies on predator - prey interactions in a grassland soil." Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320412.

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48

Svensson, Lars. "Storstrejken 1909 : Ur ett fackligt perspektiv i Landskrona." Thesis, Uppsala universitet, Historiska institutionen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267857.

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I denna uppsats belyses på ett lokalt plan i Landskrona den stora kraftmätning som ägde rum på den svenska arbetsmarknaden 1909 med omfattande lockouter och storstrejk. Sammanlagt drogs 300 000 arbetare in i konflikten som pågick från den 4 augusti till omkring den 6 september. Orsakerna till storkonflikten var en serie lockouter som iscensattes av arbetsgivarsidan och som den fackliga sidan mötte med en omfattande arbetsnedläggelse. I bakgrunden till konflikten fanns de stora samhällsförändringar som industrialismen orsakade. Det svenska samhället förändrades i snabb takt vilket bland annat resulterade i tillkomsten av en arbetarklass och en ökad polarisering av samhället. Därtill skall läggas de bakomliggande orsaker som bestod av upplysningens strävan att sätta människan i centrum och uppfattningen om alla människors lika värde vilket ledde till en kamp för allmän rösträtt och ökad demokrati. LO-ledningen var till en början försiktig och såg inte storstrejken som en lösning på problemen på arbetsmarknaden eftersom det saknades pengar för att understödja en större konflikt. Delvis mot LO-ledningens uppfattning drevs storstrejken fram av de fackligt organiserade arbetarna med motivet att en så omfattande arbetsnedläggelse skulle sätta hela samhället i gungning och tvinga fram en acceptabel uppgörelse med arbetsgivarparten. I denna uppsats studeras hur de tre fackliga organisationerna Landskrona Sömmerskefackförening, Fabriksarbetareförbundet Grovarbetaravdelning 4 och Jern och Metallarbetarförbundet avdelning 40 – samtliga representerade i Landskrona – påverkades av storstrejken. De tre förbunden organiserade arbetare på arbetsplatser i Landskrona inom en begynnande tekoindustri, konstgödnings- och sockerfabrik och inom verkstadsföretag samt den begynnande varvsnäringen. De frågor som ställs till materialet är: Vilka strategier användes av de fackliga organisationerna? Vilka var målsättningarna med den fackliga verksamheten? Hur förändrades dessa över tid? På vilket sätt utgjorde Landskronas fackliga verksamhet någonting särpräglat i jämförelse med verksamheten på nationell nivå? Hur uppfattades stridsåtgärderna på ett lokalt fackligt plan? Studien visar att de lokala fackföreningarna ställdes inför helt nya uppgifter när de gällde att administrera strejken, värna medlemmarnas intresse och organisera insatser för att minska den nöd som uppstod i arbetarhemmen.

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Bouaïchi, Abdelghani. "The behavioural and environmental bases of gregarization in the desert locust Schistocerca gregaria (Forskal)." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670251.

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Ali, Declan W. "On the aminergic innervation of locust (Locusta migratoria) salivary glands." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0006/NQ27867.pdf.

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Dissertations / Theses on the topic 'LOCONT'

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