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  • 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.
61

Comportamento de Podium denticulatum F. Smith, 1856 (hymenoptera, Sphecidae) em ninhos-armadilha / Behavior of Podium denticulatum F. Smith, 1856 (Hymenoptera, Sphecidae) in trap-nests

Favi Ribeiro 24 March 2006 (has links)
Podium denticulatum é uma espécie de vespa solitária que pertence ao gênero Podium, família Sphecidae, sendo encontrada desde o México o Brasil. As fêmeas desse gênero são caçadoras, capturam e aprovisionam o ninho com baratas paralisadas. As espécies de Podium nidificam em cavidades preexistentes, como ninhos abandonados de outras espécies de vespas, cavidades em troncos e em ninhos-armadilha (NA). O principal objetivo do presente trabalho foi estudar os aspectos comportamentais das atividades realizadas pelas fêmeas de P.denticulatum no processo de nidificação, e a obtenção de dados do tempo de desenvolvimento, número de gerações por ano e novas informações sobre a biologia e fenologia da espécie, permitindo uma análise comparativa com aquelas reportadas por outros autores. O estudo foi realizado no Campus da USP de Ribeirão Preto, SP, onde o clima é tropical quente e úmido. Foram utilizados NA que consistiram de gomos de bambus, fechados em uma das extremidades pelo nó, com comprimentos e diâmetros variados. Esses NA foram inspecionados, frequentemente, de setembro de 2003 a setembro de 2005, para constatação de fêmeas trabalhando e coleta de dados. Com isso, pôde-se constatar que as fêmeas exibem comportamento de inspeção e escolha dos NA antes de começar a captura de presas, as quais são representantes da família Blattellidae. Os ovos são colocados entre o primeiro par de pernas da presa e o desenvolvimento total, ou seja, do ovo até o adulto, foi maior nas fêmeas que nos machos. Uma característica importante observada neste estudo é que as fêmeas fecham a célula ao final do dia caso não tenham completado o aprovisionamento, retornado no dia seguinte. Esse comportamento pode ser interpretado como uma forma de proteção ao alimento larval ou ovo. O material utilizado para fechar as células e o ninho consiste de barro coletado no campo. A parede de fechamento pode ser revestida com uma resina de origem desconhecida. A fêmea pode terminar o aprovisionamento de uma célula em até cinco dias; na conclusão do ninho, ela pode demorar até nove dias, e esse tempo está relacionado à fatores externos. Foram observadas 6 gerações e um período de diapausa e a razão sexual não diferiu significantemente da proporção de 1:1. As fêmeas foram produzidas preferencialmente nas primeiras células de cria, que são dispostas em série linear. Cada ninho continha de 1 a 6 células de cria e, em 43,8% dos ninhos a fêmea construiu uma célula vestibular. Foram encontradas ainda ninhos com célula intercalar e célula vazia de fundo. As paredes de fechamento do ninho foram significantemente mais espessas do que as partições celulares. Os casulos eram de coloração castanho-médio, fusiformes, flexíveis, lisos e mais ou menos brilhantes. Foram encontrados parasitóides da família Chrysididae e Eulophidae (Hymenoptera) e Tachinidae (Díptera) atacando ninhos de P. denticulatum. As atividades de nidificação das fêmeas só foram observadas no período quente e chuvoso. / Podium denticulatum it is a solitary wasp specie which belongs to the Podium class, Sphecidae, found from Mexico to Brazil. The females from this class are hunters, they catch and provide the nest with paralyzed cockroaches that are feed for their lavas. Podium species nesting in preexisting cavities, such as abandoned nests from other species, stem cavities and in nest traps. The major objective in this work it was to study the behavior aspects in detail from the P. denticulatum females, during the nesting process, besides the developing time, generation numbers by year and new information from the biology and phenology from the specie, allowing a comparative analysis from other authors. The study was done at the University of Sao Paulo, Ribeirao Preto Campus, where the weather is tropical, hot and humid showing two seasons will defined. Using trap-nests that were bamboo, tied in one end with a diversity of length and diameters. These trap-nests were inspected frequently, from September 2003 to September 2005, to assure that the females were working and to collect data. With this it was observed that the females show an inspection behavior to choose the nest-traps before the prey capture which are from the Blattellidae family. The eggs are placed between the first pair of legs from the prey and the whole development, from egg to adult, it was bigger among the females than the males. An important characteristic observed in this study is that the females close the cell at the end of the day if they didn?t complete the provision, returning next day. This behavior can be understood as a way to protect the lava feed or the egg. The material used to close the nest is mud collected in the country, which is casted by the female. The closing wall can be coated with a unknown resin. The female can finish the provision from one cell in a day or take up to five days, at the nest conclusion it can take up to nine days, and this time is related to outside factors. It was observed six generations and a period of day pause to the studied specie. The sexual cause wasn?t significantly different from the 1:1 proportion and the females were produced on the first brood cell. The cells are placed on a lineal series and the length and diameter in the trap-nests were diversified. Each nest had from one to six brood cell and in 43,8% of the nests the female built a vestibular cell. It was found nests with intercalary cells and empty space. The nest closing walls were significantly thicker than the cell division, fusiforme, flexible, plain and more less shiny. It was found parasitoids from the Chrysididae and Eulophidae (Hymenoptera) and Tachinidae (Diptera) attacking P. denticulatum nests. The nesting activities from the females were only observed at the hot and rainy days.
62

Measuring Subtypes of Withdrawal in Children with Language Impairment

Coombs, Emma Maille 01 April 2017 (has links)
Children with language impairment (LI) often demonstrate increased levels of withdrawal, specifically the reticent and solitary-passive subtypes. Although it is recognized that there are several subtypes of withdrawal, the relationship between withdrawal and children with LI is complex and unclear. The aim of this study was to examine items on the Teacher Behavior Rating Scale (TBRS) to better understand the nature of withdrawal in children with LI. A factor analysis of TBRS scores of 355 participants was conducted to ensure that individual items on each subscale were measuring the same construct. An invariance analysis was also performed to ensure items were equally valid for both groups. Finally, a Pearson chi-square test was performed to see which items had the greatest power to separate typical and atypical children. Factor analysis confirmed that items on each subscale grouped together. All four reticence items were invariant, however only 3 of the 5 solitary-passive items were invariant across groups. Item analysis of the Reticence Subscale revealed that participants showed the greatest differences in items related to on-looking, unoccupied, and fearful behavior. Item analysis of the Solitary Passive Subscale revealed an increase in behavior related to a preference for solitary play. In accordance with previous work, children with LI displayed higher levels of both reticence and solitary-passive withdrawal than their typical peers. This study confirms the validity of using the TBRS as a tool to investigate the complex relationship between language and reticent behavior in future research.
63

CHEMOGENETIC & OPTOGENETIC METHODS FOR STUDYING THE ROLE OF THE NUCLEUS SOLITARY TRACT IN SATIATION

Kaitlyn E Gilland (7816811) 13 November 2019 (has links)
<div><div><div><p>Increased meal size on a western diet is a major contributor to development and maintenance of obesity. This also leads to decreased sensitivity to the satiating effects of the western diet. Excitation of cells during consumption of a meal in the caudal two-thirds of the nucleus solitary tract (cNTS) in the brainstem are thought to produce satiation and inhibit feeding. Currently, it is unknown how excitation of these cells inhibits feeding. A major obstacle has been the inability to selectively manipulate these cells without affecting intermixed cells that mediate other autonomic functions. We propose a novel approach using inducible, activity-dependent chemogenetics or optogenetics to test whether artificial excitation of cells in the caudal two-thirds of the nucleus solitary tract (cNTS) activated during satiation can reduce food intake and could contribute to preventing or reversing obesity in humans.</p><p>We tested four different mouse models with potential for answering this question: double transgenic mice with cFos-tTA & Tet-O-hM3Dq genes, a single transgenic cFos-tTA mouse with a virally delivered hM3Dq gene injected into the cNTS, a double transgenic mice with the TRAP2- tdTomato genes and double transgenic mice with c-Fos-tTA and ChEF genes. Evidence suggested that clozapine-N-oxide might activate satiation-related cells in the absence of the hM3Dq receptor and this should be taken into consideration for future experiments. All four models had promising aspects for studying feeding as well as serious limitations. These limitations will need to be considered when deciding to use any of these models to study any feeding behaviors, especially satiation.</p></div></div></div>
64

The Influence of Information on Public Support for Solitary Confinement: a Test of Belief Updating and Confirmation Bias

LaBranche, Kayla J. 31 May 2018 (has links)
There is limited research measuring public opinion about the correctional practice of solitary confinement (SC). Given that public opinion can influence policies, it is important to determine whether or not one's beliefs can be updated upon receiving information about the use and effect of SC. Prior research indicates that public opinion is malleable, and thus, may be susceptible to modification. Though, people may be more willing to update their beliefs when the information they receive confirms their existing beliefs (i.e., confirmation bias). This study used an experimental design in which participants were asked to provide their opinions on a series of statements designed to measure their support for SC. Participants were randomly assigned to one of two treatment conditions that provided differing messages about the use of SC through brief, informational videos. Participants were either told that SC is a necessary tool to maintain order within prisons, or that SC is harmful to those who experience it. Following the intervention, participants' support for SC was re-measured and their change in score was calculated. Analyses indicated that participants who received information stating that SC is harmful decreased their support for the practice, while those who received information stating it was necessary increased their support for its use. To test for confirmation bias, participants were presented a survey instrument designed to measure their existing support for punishment. The findings indicate that participants had greater belief changes when presented with disconfirming information. These effects were more pronounced when examining moderating demographic variables. The research and policy implications of this study's findings are discussed.
65

A Learning Approach To Obtain Efficient Testing Strategies In Medical Diagnosis

Fakih, Saif 15 March 2004 (has links)
Determining the most efficient use of diagnostic tests is one of the complex issues facing the medical practitioners. It is generally accepted that excessive use of tests is common practice in medical diagnosis. Many tests are performed even though the incremental knowledge gained does not affect the course of diagnosis. With the soaring cost of healthcare in the US, there is a critical need for cutting costs of diagnostic tests, while achieving a higher level of diagnostic accuracy. Various decision making tools assisting physicians in diagnosis management have been presented to the literature. One such method, called analytical hierarchy process, utilize a multilevel structure of decision criterion for sequential pair wise comparison of available test choices. Many of the decision-analytic methods are based on Bayes' theory and decision trees. These methods use threshold treatment probabilities and performance characteristics of the tests, such as true-positive rate and false-positive rates, to choose among the available alternatives. Sequential testing approaches tend to elongate the diagnosis process, whereas the parallel testing approach generally involves higher number of tests. This research is focused on developing a machine learning based methodology for finding an efficient testing strategy for medical diagnosis. The method, based on the patient parameters (both observed and tested), recommends test(s) with the objective of optimizing a measure of performance for the diagnosis process. The performance measure is a combined cost of the testing, the risk and discomfort associated with the tests and the time taken to reach diagnosis. The performance measure also considers the diagnostic ability of the tests. The methodology is developed combining tools from the fields of data mining (rough set theory, in particular), utility theory, Markov decision processes (MDP), and reinforcement learning (RL). The rough set theory is used in extracting diagnostic information in the form of rules from the medical databases. Utility theory is used to bring three non-homogenous measures (cost of testing, risk and discomfort and diagnostic ability) into one cost based measure of performance. The MDP framework along with an RL algorithm facilitates obtaining efficient testing strategies. The methodology is implemented on a sample problem of diagnosing Solitary Pulmonary Nodule (SPN). The results obtained are compared with those from four other approaches. It is shown that the RL based methodology holds significant promise in improving the performance of diagnostic process.
66

Ensamgravar och gravfält : olika begravningsmönster under romersk järnålder på Gotland / Solitary Graves and Grave Fields : different burial patterns during Roman Iron Age on Gotland

Stenström, Karin January 2011 (has links)
The aim of this thesis is to make a comparison between solitary graves and graves in grave fields from the Roman Iron Age on Gotland, Sweden. Differences in burial customs, morphology, dating, gender, age, grave-goods and social status are compared between 19 solitary graves and graves in three different grave fields in different parts of Gotland. An attempt is made to explain these differences and to discuss which functions the solitary graves had. Discussions about whether it is possible to distinguish social status and gender with the help of grave-goods are also made in connection to the determination of status and sex.
67

Laboratory and Numerical Study on Evolution of Interfacial Solitary Wave across Pseudo Slope-Shelf

Cheng, Ming-hung 19 June 2011 (has links)
While shoaling from deepwater in a stratified ocean, an interfacial solitary wave (ISW) may experience waveform inversion on a continental margin. Although many oceanographers have believed that the inversion from depression to elevation may commence at the turning point where the upper and bottom layers are equal in depth, this phenomenon has not been fully verified in field observations nor in a laboratory. In this study, a series of laboratory experiments and numerical modeling were conducted on the evolution of an ISW of depression across uniform slope joining a horizontal plateau which resembles pseudo slope-shelf topography, in order to clarify this fascinating phenomenon and the variations of wave properties associated with the process. In the laboratory experiments, a depression ISW was produced by a collapse mechanism in a stratified two-layer fluid system within a steel-framed wave flume (12 m long, 0.7 m high by 0.5 m wide) at the National Sun Yat-sen University in Taiwan. The fluid density in the upper (fresh) and bottom (brine) layers was 996 and 1030 kg/m3, respectively. A series of experiments were conducted upon varying the magnitude of the most important physical factors (i.e., nominal thickness of pycnocline, depth ratio between upper and bottom layer, front gradient and shape of pseudo slope-shelf), from which the results are now discussed in four separate chapters in this thesis. Present laboratory results indicate that the process of waveform inversion took place after an ISW had experienced internal run-down, hydraulic jump, vortex motion and surge-up on the front slope, prior to its propagation onto the plateau. Moreover, the fundamental wave period of leading wave on the plateau was significantly smaller than that in the preceding sections on the front slope and the incident stage earlier, thus representing frequency downshift. Amongst the factors involved, the depth ratio between the upper and bottom layer was the most significant one for waveform inversion. Only when the upper layer was thicker than the bottom layer on the plateau of pseudo slope-shelf, waveform inversion could occur, besides the length of the plateau. On the other hand, the front gradient and shape of pseudo slope-shelf also affected the magnitude of the transmitted wave over the plateau as the wave across this specific topography. In the case of a steeper front gradient, waveform inversion became insignificant due to stronger wave reflection and intense energy dissipation caused by turbulent mixing while a depression ISW propagated over a slope-shelf; particularly against a submerged vertical cliff. As a depression ISW across pseudo slope-shelf with short plateau, intense wave breaking might occur again with vortex motion at its rear end as the newly inversed waveform reentering deep water. In this region, the upper layer was smaller than the bottom layer, hence it could not support the continuous existence of an ISW in elevation. Again, energy dissipation occurred due to turbulent mixing beyond the rear end of a short plateau. Finally, a different mode of ISW appeared within pycnocline, while its nominal thickness was larger than the amplitude of the incident wave. In addition to the laboratory investigations, numerical model was also adopted to study the variations in the flow field as an ISW propagated over a pseudo slope-shelf, in order to complement the experimental results. The results of numerical modeling revealed that the horizontal velocity in the bottom layer increased when the wave encountered the front slope, even if the depth of upper layer was thinner than that of the bottom layer on the plateau. Consequently, the velocity in the upper layer became less than that in the bottom layer when the former was thicker than that of the latter on the plateau. On the other hand, the vertical velocity within the self-generated vortex switched direction as waveform inversion commenced after the wave across the shoulder of pseudo slope-shelf where the local depth of the upper layer was larger than that of bottom part. Overall, the significance of the four pertinent factors (i.e., nominal thickness of pycnocline, water depth ratio, front slope, and plateau length) that affected a depression ISW across pseudo slope-shelf is discussed in detail in this thesis, as well as the variation of flow field calculated by the numerical mode presented.
68

Symbolic Computations of Exact Solutions to Nonlinear Integrable Di®erential Equations

Grupcev, Vladimir 10 April 2007 (has links)
In this thesis, first the tanh method, a method for obtaining exact traveling wave solutions to nonlinear differential equations, is introduced and described. Then the method is applied to two classes of Nonlinear Partial Differential Equations. The first one is a system of two (1 + 1)-dimensional nonlinear Korteweg-de Vries (KdV) type equations. The second one is a (3 + 1)-dimensional nonlinear wave equation. At the end, a few graphic representations of the obtained solitary wave solutions are provided, in correspondence to different values of the parameters used in the equations.
69

Lizdavietėse-gaudyklėse apsigyvenančių klosčiavapsvių (Hymenoptera: Vespidae: Eumeninae) vystymasis ir rūpinimosi palikuonimis elgsena / Development and nesting behaviour of trap-nesting wasps (Hymenoptera: Vespidae: Eumeninae)

Nevronytė, Žaneta 28 December 2009 (has links)
Geluoninių plėviasparnių, apsigyvenančių lizdavietėse-gaudyklėse bendrijos, yra potencialūs ekologinių pokyčių ir buveinių kokybės bioindikatoriai sausumos ekosistemose, todėl vis dažniau naudojamos įvairiuose tyrimuose. Darbo tikslas buvo įvertinti lizdavietės rodiklių ir grobio, reikalingo palikuonims aprūpinti, gausumo įtaką lizdavietėse-gaudyklėse apsigyvenančių klosčiavapsvių rūpinimosi palikuonimis elgsenai. Tyrimų metu buvo ištirta lizdavietės skersmens ir gylio įtaka 13-kos lizdavietėse-gaudyklėse apsigyvenančių vapsvų rūšių lizdo struktūrai, palikuonių aprūpinimo maistu elgsenai ir lyčių santykiui; kai kurioms rūšims nustatyti optimalūs lizdavietės rodikliai. Taip pat buvo ištirtas, dažniausiai lizdavietėse-gaudyklėse pasitaikiusios rūšies, Symmorphus allobrogus vystymasis nuo kiaušinio iki suaugėlio; palyginti skirtingų lyčių individų augimo greičiai ir svorio pokyčiai vystymosi metu. Atliktas laboratorinis eksperimentas, kurio rezultatai parodė, kad akelių skaičius lizde būna didesnis, jeigu aplinkoje yra didesnis maisto, reikalingo palikuonims aprūpinti, kiekis. Taip pat įvertinta patelės amžiaus įtaka rūpinimosi palikuonimis elgsenai. Darbe taip pat pateikiamas sinantropinių, Lietuvoje lizdavietėse-gaudyklėse apsigyvenančių plėviasparnių rūšių sąrašas. / Since Hymenoptera Aculeate are known to be bioindicators, which are sensitive to environment change, fragmentation of habitats and antropogenous impact, these insects may have an importance in environment conservation. The purpose of our study was to establish impact of nesting cavity parameters and prey abundance on the nesting behaviour of solitary xylicolous wasps. We studied nest structure and the influence of nesting cavity width and length on progeny size and sex ratio in 13 wasp species. The development of the most common synanthropic xylicolous wasp in Lithuania, Symmorphus allobrogus, has been investigated: the assimilation of prey and weight loss during development from larva to adult in both sexes have been compared. Results of a laboratory experiment using S. allobrogus as a model species demonstrated that the amount of prey available in the environment affects the number of cells in the nest of solitary wasp. The list of solitary Hymenoptera inhabiting trap-nests in Lithuania are presented.
70

Development and nesting behaviour of trap-nesting wasps (Hymenoptera: Vespidae: Eumeninae) / Lizdavietėse-gaudyklėse apsigyvenančių klosčiavapsvių (Hymenoptera: Vespidae: Eumeninae) vystymasis ir rūpinimosi palikuonimis elgsena

Nevronytė, Žaneta 28 December 2009 (has links)
Since Hymenoptera Aculeate are known to be bioindicators, which are sensitive to environment change, fragmentation of habitats and antropogenous impact, these insects may have an importance in environment conservation. The purpose of our study was to establish impact of nesting cavity parameters and prey abundance on the nesting behaviour of solitary xylicolous wasps. We studied nest structure and the influence of nesting cavity width and length on progeny size and sex ratio in 13 wasp species. The development of the most common synanthropic xylicolous wasp in Lithuania, Symmorphus allobrogus, has been investigated: the assimilation of prey and weight loss during development from larva to adult in both sexes have been compared. Results of a laboratory experiment using S. allobrogus as a model species demonstrated that the amount of prey available in the environment affects the number of cells in the nest of solitary wasp. The list of solitary Hymenoptera inhabiting trap-nests in Lithuania are presented. / Geluoninių plėviasparnių, apsigyvenančių lizdavietėse-gaudyklėse bendrijos, yra potencialūs ekologinių pokyčių ir buveinių kokybės bioindikatoriai sausumos ekosistemose, todėl vis dažniau naudojamos įvairiuose tyrimuose. Darbo tikslas buvo įvertinti lizdavietės rodiklių ir grobio, reikalingo palikuonims aprūpinti, gausumo įtaką lizdavietėse-gaudyklėse apsigyvenančių klosčiavapsvių rūpinimosi palikuonimis elgsenai. Tyrimų metu buvo ištirta lizdavietės skersmens ir gylio įtaka 13-kos lizdavietėse-gaudyklėse apsigyvenančių vapsvų rūšių lizdo struktūrai, palikuonių aprūpinimo maistu elgsenai ir lyčių santykiui; kai kurioms rūšims nustatyti optimalūs lizdavietės rodikliai. Taip pat buvo ištirtas, dažniausiai lizdavietėse-gaudyklėse pasitaikiusios rūšies, Symmorphus allobrogus vystymasis nuo kiaušinio iki suaugėlio; palyginti skirtingų lyčių individų augimo greičiai ir svorio pokyčiai vystymosi metu. Atliktas laboratorinis eksperimentas, kurio rezultatai parodė, kad akelių skaičius lizde būna didesnis, jeigu aplinkoje yra didesnis maisto, reikalingo palikuonims aprūpinti, kiekis. Taip pat įvertinta patelės amžiaus įtaka rūpinimosi palikuonimis elgsenai. Darbe taip pat pateikiamas sinantropinių, Lietuvoje lizdavietėse-gaudyklėse apsigyvenančių plėviasparnių rūšių sąrašas.

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