• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 120
  • 10
  • 10
  • 10
  • 10
  • 10
  • 10
  • 10
  • 9
  • 6
  • 5
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 211
  • 35
  • 27
  • 24
  • 22
  • 19
  • 18
  • 17
  • 17
  • 16
  • 15
  • 15
  • 15
  • 12
  • 11
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Coding of Bat-like Auditory Features in the AN2 Interneuron of the Pacific Field Cricket, Teleogryllus oceanicus and its Relation to Decreasing the Conspicuousness of Synthetic Bat Echolocation Calls

Asi, Navdeep Singh 14 December 2010 (has links)
Many insects have auditory systems capable of detecting the ultrasonic calls of insectivorous bats and use these cues to evade capture. I tested the hypothesis that bats can decrease the conspicuousness of their echolocation calls by varying three call features: duration, repetition rate and ramp times. This was done by examining the AN2 command interneuron’s response to these features in the cricket, Teleogryllus oceanicus, after describing the firing pattern necessary for evasive behaviour. Past studies on duration and repetition rate suggest increased thresholds for short durations and low repetition rates. Measurements of the AN2 response, which controls evasive behaviour, indicated that increased thresholds were a result of a decrease in bursting, raw spike numbers and an increase in latencies in the AN2. Results suggest that there is pressure on bats to evade early detection and that this can be done by employing large ramp times in search phase echolocation calls.
162

Bradman : representation, meaning and Australian culture

Hutchins, Brett. Unknown Date (has links)
No description available.
163

Cumulative mild head injury in rugby: cognitive test profiles of professional rugby and cricket players

Ancer, Ruth Lauren January 1999 (has links)
This study investigates the effects of cumulative concussive and subconcussive mild head injury on the cognitive functioning of professional rugby players. A comprehensive battery of neuropsychological tests was administered to 26 professional rugby players and a noncontact sport control group of 21 professional cricket players. The test performances of the rugby players were compared to those of the cricket players. Within the rugby group, forward and backline players were compared. An analysis of mean score differences between the rugby and cricket group failed to support the presence of brain damage effects in the rugby group. However, there was significantly increased variability of scores for the rugby players compared with the cricket players on tests particularly sensitive to cognitive deficit associated with mild head injury. This invalidates the null indications of average effects, indicating that a notable proportion of rugby players’ performances were falling off relative to the rest of the rugby players on tests vulnerable to the cognitive effects of diffuse brain damage. Mean score comparisons within the rugby group indicated that it was the subgroup of forward players, in particular, whose test performances revealed deficits suggestive of cerebral damage. Specifically, deficits were found in working memory, visuoperceptual tracking, verbal memory and visual memory, a pattern of deficits commensurate with cumulative mild head injury. The theoretical perspectives of Satz’s (1997) Brain Reserve Capacity Theory and Jordan’s (1997) ‘Shuttle’ model of variability are drawn upon in order to elucidate research findings and suggestions for future research are provided.
164

A psycho-educational intervention program to enhance the mental toughness of secondary school cricket players

Griffith, William Charles 11 1900 (has links)
The purpose of this study was to investigate the influence of a psycho-educational intervention program on the mental toughness of secondary school cricketers. The general aim of the study was to use psychological skills and psychological techniques to enhance the mental toughness of secondary school cricketers, within a psycho-educational framework. This general aim of the study was actualised by employing the following specific aims: • A literature review was conducted to explore the psycho-educational model. It was found that the psycho-educational model was an appropriate model to use as the framework of the intervention program. • The literature review investigated and evaluated different psychological skills and psychological techniques that influenced the mental toughness of cricketers positively. • A questionnaire was designed. This questionnaire (CMTQ) fulfilled the role of a psychological skills measuring tool. • A psycho-educational intervention program was designed around the findings of the literature study. • Guidelines were compiled to follow when coaching mental toughness to secondary school cricketers. • The intervention program was presented over a six week period. • An empirical study was conducted to evaluate the successfulness of the intervention program. The first phase of the empirical study was done before the presentation of the psycho-educational intervention program. The data suggest that Confidence and Motivation were the two main psychological skills that the participants employed in their mental game of cricket. The second phase of the empirical study was only done after the completion of the six week intervention program. The selected data analysis method employed to evaluate the effectiveness of the program was the t-test for dependant groups. v The results of the data analysis indicated that the participants in the experimental group improved in their mental toughness performance significantly. When the findings of the literature review and the results of the empirical study are combined, it appears as if this intervention program will have a positive influence on the cricket performance of secondary school cricketers. / Psychology of Education / D. Ed. (Psychology of Education)
165

Tackling mild head injury in rugby: a comparison of the cognitive profiles of professional rugby and cricket players

Reid, Iain Robert January 1999 (has links)
The aim of this study was to investigate the effect of cumulative mild head injury on the cognitive functioning of professional rugby players. A comprehensive battery of neuropsychological tests was administered to 26 professional rugby players and to a comparison group of 21 professional cricket players. The group test results of the rugby, cricket, rugby forwards and rugby backline players were each compared with established normative data. Generally, the comparison of the rugby and cricket mean scores relative to the normative data did not reveal significant differences on tests known to be sensitive to the effects of mild head injury. However, the comparison of variability for each of the rugby and cricket playing groups relative to variability for the normative data, revealed a pattern of increased variability among the rugby players. This implies a bimodal distribution in which a significant number of rugby players were performing poorly across these tests whereas a significant proportion were not. This variability effect was accounted for by further mean score comparisons which revealed that, as a group, it was the forward players whose performances were disproportionately poor on tests sensitive to the effects of mild head injury. The implications of these results are developed theoretically within the context of brain reserve capacity theory and suggestions for future research are provided.
166

Estudo da História Natural do Grilo Cavernícola Strinatia Brevipennis (Ensifera: Phalangopsidae) em Laboratório / Natural History of Cave Cricket Strinatia brevipennis (Ensifera: Phalangopsidae) in Laboratory

Flavia Pellegatti Franco 13 February 1998 (has links)
Este estudo foi realizado em laboratório entre fevereiro de 1995 e dezembro de 1997. Os grilos (Strinatia brevipennis) foram coletados de diversas cavernas do Parque Estadual Intervales, no Vale do Ribeira, SP, e mantidos no porão do Edifício Ernesto Marcus, Departamento de Zoologia do IBUSP para estudo da história natural da espécie. Outra espécie de grilos (Endecous itatibensis) foi acompanhada devido a uma coleta acidental da mesma. As duas espécies foram mantidas separadamente, uma vez que a primeira não sobrevive em contato com a segunda. A reprodução de S. brevipennis ocorreu com sucesso em caixas de isopor, principalmente no verão. A reprodução de E. itatibensis, por outro lado, ocorreu apenas entre indivíduos mantidos livremente na câmara de criação, onde observou-se grande sucesso reprodutivo, com várias gerações e uma grande população proveniente de apenas uma fêmea. O período embrionário médio de S. brevipennis foi de 56 dias. O desenvolvimento pós-embrionário também foi acompanhado, onde observou-se provável variação no número de mudas (10 ou 11) antes de tornarem-se adultos. A identificação de macho e fêmea é facilmente observada nos três últimos instares ninfais e nos adultos através do surgimento do ovipositor (para ambas espécies) nas fêmeas, e das tégminas no último instar ninfal para S. brevipennis e no penúltimo para E. itatibensis nos machos. As fêmeas são ápteras nas duas espécies estudadas. A caracterização morfométrica mostra que os primeiros estágios da vida podem se confundir quanto às dimensões corporais para S. brevipennis. Nos últimos instares e adultos a caracterização torna-se mais facilitada através das medidas do comprimento do fêmur e da tíbia da perna III, e dos dimorfismos sexuais. / This study was conduced in laboratory between February 1995 and December 1997. The crickets (Strinatia brevipennis) have been collected in several caves from Parque Estadual Intervales, Ribeira Valley, São Paulo state. They were kapt in a room in the basement of Edifício Ernesto Marcus, Departamento de Aoologia IBUSP, to develop a study focusing their natural history. Another species of crickets (Endecous itatibensis) was studied due to an accidental collection. The two species were maintained in different compartments because the first did not survive whem in direct contact with the second. Reproduction of S. brevipennis was successful inside boxes, mainly during summer. Reproduction of E. itatibensis was only successful when animals were kept freely inside the compartment, where a large reproductive success for several generations was originated from a single female. S. brevipennis showed a mean period of embryonic development of 56 days. Post-embryonic development showed a variation of 10-11 molting events to achieve adulthood. Telling males from females is an easy task during the last three nymphal stages and among adults because of the development of ovipositor among females of both species; and development of mesothoracic wings during the last nymphal stage os S. brevipennis or the penultimate nymphal stage of E. itatibensis among males. Females are wingless in both species. Morphometric characterization showed that the first nymphal stages are hardly told from each other. Last stages and adults can be distinguished both from sexual dimorphisms and length of femur and tibia of leg III.
167

Proteases fúngicas produção utilizando farelo de soja e farinhas de banana, caracterização enzimática e aplicação em farinha de grilo /

Koike, Meliane Akemi January 2020 (has links)
Orientador: Luciana Francisco Fleuri / Resumo: Resíduos e subprodutos agroindustriais são extensivamente estudados a fim de se reaproveitar seu potencial biológico e agregar valor. A fermentação em estado sólido (FES) é uma das formas de utilizar estes resíduos e subprodutos para obtenção de enzimas, como as proteases. Este trabalho objetivou estudar a produção de proteases fúngicas por FES utilizando farelo de soja e farinhas de banana, caracterizar bioquimicamente as proteases mais promissoras e, por fim, aplicar na hidrólise da farinha de grilo (Gryllus assimilis), avaliando os produtos de hidrólise. O estudo da composição do meio de cultivo foi conduzido através de um delineamento experimental, o planejamento de misturas, para definir a proporção ótima de parte sólida dos substratos de fermentação. Posteriormente, realizou-se a cinética de produção de protease por FES, a caracterização bioquímica das proteases mais promissoras quanto ao pH e temperatura ótimos de atuação, bem como a influência de íons metálicos e L-cisteína em diferentes concentrações. Por meio de relargagem (salting-out), fez-se a purificação parcial das enzimas, seguida de diálise e liofilização, para então serem aplicadas na hidrólise da farinha de grilo. O fator de hidrólise, a atividade antioxidante e o perfil eletroforético dos produtos de hidrólise foram avaliados. O planejamento de misturas resultou em duas proporções com altas atividades proteolíticas, 50 % de farelo de soja (FS) e 50 % de farinha de casca de banana madura (FCBM) e um terço d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Agro-industrial waste and by-products are extensively studied aiming to add value and explore their full biological potential. Solid state fermentation (SSF) is a technique that use agro-industrial waste and by-products and may be used to obtain enzymes, such as proteases. This study aimed to produce fungal proteases by SSF using soybean bran and banana flours as substrate, characterize biochemically and apply most promising proteases to hydrolysis of cricket flour (Gryllus assimilis), and evaluate the hydrolysis products. The composition of the culture medium was evaluated through an experimental design to define the optimal proportion of solid part of the fermentation substrates. Subsequently, the protease production kinetics were performed by SSF, the most promising proteases were characterized biochemically according to the optimal pH and temperature, as well as according to the influence of metal ions and L-cysteine ​​in different concentrations. Proteases were partially purified by salting-out, followed by dialysis and lyophilization and applied in hydrolysis of the cricket flour. The hydrolysis factor, the antioxidant activity and the electrophoretic profile of the hydrolysis products were evaluated. The mixture design resulted in two combinations with high proteolytic activities, 50% soybean bran (SB) and 50% ripe banana peel flour (RBPF) and one third of each component (soybean bran, ripe banana peel flour and green banana flour) for the microorganisms Trichoderma ko... (Complete abstract click electronic access below) / Mestre
168

Should I stay or should I go? Complex environments drive the developmental plasticity of flight capacity and flight-related tradeoffs

Glass, Jordan R. 01 January 2018 (has links)
Animals must balance multiple, fitness-related traits in environments that are complex and characterized by co-varying factors, such as co-variation in temperature and food availability. Thus, experiments manipulating multiple environmental factors provide valuable insight into the role of the environment in shaping not only important traits (e.g., dispersal capacity or reproduction), but also trait-trait interactions (e.g., trade-offs between traits). We employed a multi-factorial design to manipulate variation in temperature (constant 28°C vs. 28±5°C daily cycle) and food availability (unlimited vs. intermittent access) throughout development in the sand field cricket, Gryllus firmus. We found that fitness-related, life-history traits and trait trade-offs can be developmentally plastic in response to variation in temperature and food availability. Variability in temperature and food availability influenced development, growth, body size, reproductive investment, and/or flight capacity, and food availability also affected survival to adulthood. Further, both constant temperature and unlimited food availability promoted investment into key components of somatic and reproductive tissues while reducing investment into flight capacity. We develop an experimental and statistical framework to reveal shifts in correlative patterns of investment into different life-history traits. This approach can be applied to a range of animal systems to investigate how environmental complexity influences traits and trait trade-offs.
169

Ecology Of Larra Bicolor (Hymenoptera: Sphecidae) In The Northern Gulf

Abraham, Cheri Muthirakalayil 13 December 2008 (has links)
Mole Crickets (Scapteriscus spp.) are the most destructive pests in southern turf and pasture grasses. In response to extensive losses from mole crickets, Florida formed a task force to identify natural enemies in the native range of these pests. Two parasitic insects, Larra bicolor and Ormia depleta, and Steinernema scapterisci, an entomopathogenic nematode, were imported and released. Of the two insects, only Larra bicolor has spread to other states infested with mole crickets in the southeast. The present study documents the seasonal biology of Larra bicolor in the northern Gulf region, ornamental plants that can be used as nectar sources, and the impact of these nectar sources on longevity of the wasp and parasitism of mole crickets. Results of field and laboratory experiments showed that the ornamental Pentas lanceolata attracted wasps in the field and provided comparable or better longevity than Spermacoce verticillata which was the only known nectar source.
170

Sensorimotor Integration And The Role Of The Cercal System In The Reproductive Behavior Of The Cricket, <i>Acheta Domesticus</i>

Snell, Lewis Casbeer 05 August 2005 (has links)
No description available.

Page generated in 0.0504 seconds