The aim of this study is to answer to questions of how the null subject parameter properties in Turkish are reorganized by Turkish learners of English and whether there is a relationship between the null subject parameter properties in acquiring them. Firstly, a pilot study was conducted to detect the possible inadequacy in data collecting methods. Following the pilot study, a main study was conducted in order to answer the research questions.Thirty-four intermediate and thirty-four upper-intermediate students from METU English Preparation Department participated in the study. Along with these two proficiency groups, a control group of native speakers also contributed to the study whose answers were taken as criteria in evaluating students answers. Two types of tests were used: a 30item grammaticality judgment test and a 17item dialogue task. the test results were analyzed using a statistical program. In the end, it was found that students acquire the properties independently and as their proficiency levels increase, the acquisition of those properties also increases. However, it was also seen that students were not able to acquire these properties which was thought to be a result of parametric difference between Turkish and English. In order to overcome these acquisition problems, some teaching techniques were suggested in the conclusion part.

The Lake Malawi cichlid fishes are a pre-eminent example of adaptive evolutionary radiation. The diversity of species (nearly 1000 extant) is mirrored by an array of variation in dozens of phenotypes (e.g. trophic morphology, tooth shape, color patterns, behavior, development). The unique characteristics of this system have produced unparalleled diversity with very little genetic differentiation between species. This dissertation is composed of four studies addressing different aspects of the variation in the LM cichlids and the mechanisms generating and maintaining this level of diversity at multiple biological levels. Community-level diversity is investigated using null model analysis of species co-occurrence data. We detect signals of non-random community assembly at only the broadest and finest spatial scales. Based on the unique ecological and evolutionary characteristics of this assemblage we suggest that different mechanisms are responsible for these patterns. A core‟ group of species is posited to act as a foundation on which these diverse communities are created as a result of fine-scale species interactions. We identify both positive and negative depth-based correlations between species and suggest these interactions play an important role in species diversity in these fish. The Lake Malawi cichlids exhibit an array of trophic morphologies which may play a role in the fine-scale species interactions described in chapter one. In the second chapter we build a genetic model to predict the evolution of jaw morphology and a complex functional jaw trait. We use a complex biomechanical system, the 4-bar jaw linkage, to simulate trait evolution during interspecific hybridizations. We find rampant transgression (trait values beyond parental distributions) in jaw function in a large proportion of potential crosses. This result is characterized by a lack of novel morphological components but rather is the result of recombinations of existing component traits thus producing functional novelty. In the third chapter we create a laboratory cross of one of the parental combinations suggested from the genetic model. The results of this study serve as a proof of principle to the simulations as we observe a large proportion of transgressive 4-bar function in the F2. As predicted this diversity is produced in the absence of transgressive morphology. We contrast these results between this complex system and data generated from several simple jaw lever traits and report differences in the patterns. Using quantitative trait locus (QTL) mapping approaches we examine the genetic basis for complex and simple jaw traits and discuss correlative patterns within and between systems. Finally we examine the genetic architecture of sex-determination and color morphs in this hybrid cross. We find both ZW and XY sex systems segregating as well as linkage to sex-specific color patterns. Several loci and epistatic interactions are associated with sex-determination and color morphs in this cross. The orange-blotch (OB) color is found associated with ZW as predicted from previous work but a previously undescribed (in these species) male nuptial color (blue) is found associated with both ZW and XY genetic systems as well as other loci segregating for sex-determination. These results are discussed in the context of models of sex chromosome evolution as a result of sexual conflict and the potential importance of sexual selection in the diversification of Lake Malawi cichlids. Overall we observe various mechanisms generating and maintaining diversity at different levels of biological organization. We use community co-occurrence analyses, genetic simulation, and QTL analysis of an F2 hybrid population to examine these mechanisms in this rapidly radiating assemblage. These results bolster our understanding of the origins of diversity and the interplay between variation and aspects of evolution in all biological systems.

Isolated and Dynamical horizons are used to generate boundary conditions upon the lapse and shift vectors. Numerous results involving the Hamiltonian of General relativity are derived, including a self-contained derivation of the Hamiltonian equations of general relativity using both a direct 'brute force' method of directly computing Lie derivatives, as well as the standard Hamil- tonian approach. Conclusions are compared to numerous examples, including the Kerr, Schwarzschild-De Sitter, McVittie, and Vaiyda spacetimes. / text

The purpose of this survey is to describe how selected United States Government agencies provide information to the public via Internet services. With more than 2,000 Federal library and information centers located throughout the world this effort, of necessity, is selective and findings neither represent all libraries nor do they identify all approaches currently used to present information via the Web. An effort has been made to describe services without attributing values to particular site characteristics. This report provides a brief snapshot in time of a complex and rapidly evolving world. While not definitive in scope, it is hoped that this report will provide a baseline for anyone who may wish to revisit some of these sites in the future to determine how services may have been expanded, reduced, or refined.

Reports results of a study to explore how well six popular Web search engines performed in retrieving specific electronic finding aids mounted on the World Wide Web. A random sample of online finding aids was selected and then searched using AltaVista, Excite, Fast Search, Google, Hotbot and Northern Light, employing both word and phrase searching. As of February 2000, approximately 8 percent of repositories listed at the 'Repositories of Primary Resources' Web site had mounted at least four full finding aids on the Web. The most striking finding of this study was the importance of using phrase searches whenever possible, rather than word searches. Also of significance was the fact that if a finding aid were to be found using any search engine, it was generally found in the first ten or twenty items at most. The study identifies the best performers among the six chosen search engines. Combinations of search engines often produced much better results than did the search engines individually, evidence that there may be little overlap among the top hits provided by individual engines.

Sleep disturbances are common in patients with schizophrenia. Mice lacking the cytoskeletal-associated protein Stable Tubule Only Polypeptide (STOP) display cognitive, behavioural and neurobiological deficits that mimic those seen in schizophrenia, but there is little evidence of sleep changes in these mice. To investigate their sleep patterns, electroencephalogram (EEG) and electromyogram were recorded under a 12:12 light:dark cycle in adult male STOP-null (KO; n=7) and wild-type (WT; n=8) mice, during a 24 h baseline period, followed by 6 h of sleep deprivation, and a 24 h recovery period. In the baseline period, KO mice spent more time awake and less time in non-rapid eye movement (NREM) and REM sleep compared to WT mice. Particularly in the dark phase, KO mice had more wake and NREM sleep episodes, and shorter NREM and REM sleep episodes relative to WT mice. Following sleep deprivation, during the first 12 h of recovery (i.e. dark phase), both groups showed similar increases in NREM and REM sleep amounts and NREM EEG delta power relative to corresponding baseline periods. These findings indicate that the STOP-null mice sleep less and their sleep is more fragmented compared to WT mice. These features are consistent with the sleep abnormalities found in individuals with schizophrenia.

Recent retrospectives of classic psychology articles by Meehl (1978) and Wachtel (1980), concerning problems with psychology’s research paradigm, have been viewed by commentators, on the whole, as germane as when first published. However, no similar examination of Lykken’s (1991) classic criticisms of psychology’s dominant research tradition has been undertaken. Twenty years on, this thesis investigates whether Lykken’s criticisms and conclusions are still valid via an exposition of three contentious issues in psychological science: the measurement problem, null hypothesis significance testing, and the granularity of research methods. Though finding that little progress has been made, Observation Oriented Modelling is advanced as a promising methodological solution for improving psychological research.

Coral reefs are the most diverse marine ecosystem, but are increasingly threatened by local and global anthropogenic changes. In this thesis, I examine the impact of local stressors on the spatial variability of coral reef fish community composition by modeling the !-diversity of 35 islands across the Pacific Ocean that are characterized by either low or high human disturbance. By examining !-diversity across three spatial scales (within island, within island group, and across island group), and using null models to control for differences in alpha-diversity or abundance, I reveal previously undocumented effects of human disturbance on coral reef fish assemblages. At all scales, human disturbances alter !-diversity. At the largest-scale, islands with high human disturbance have lower incidence- and abundance-based !-diversity, consistent with biotic homogenization. This pattern was driven by both species with high and low abundances that differed across islands. At the smaller two scales (within islands or island groups), the presence of low abundance species is more variable on islands with high human disturbance (manifest in greater incidence-based !-diversity), but these islands have lower abundance-based !- diversity driven by moderately abundant and widespread species. Multivariate techniques show that islands with high human disturbance have a weaker species-environment relationship, and as such, I suggest that homogenization of coral reef fish assemblages by human disturbances is resulting in greater stochasticity of species composition. / Graduate / 0329 / wiwchar@uvic.ca

De type parabolique et soumis à l’action d’un couple de contrôles (h, k) où h et k jouent des rôles différents ; le contrôle k étant de type "contrôlabilité" et h de type "contrôle optimal".Il est alors naturel de considérer un problème d’optimisation multi-critères. Il existe plusieurs façons d’étudier de tels problèmes. Nous proposons, dans cette thèse, le contrôle de Stackelberg. Il s’agit d’une notion d’optimisation hiérarchique avec, ici, h qui est le "Leader" et k le "Follower". / In this thesis, we are interested in evolution problems governed by parabolic equations subjected to the action of a pair of controls (h, k) where h and k play different roles : the control k being of "controllability" type and h of "optimal control" type.It is then natural to consider a multi-criteria optimization problem. There are several ways to study such problems. We propose in this thesis, the Stackelberg control which is a notion of hierarchical optimization with here, h which is the "Leader" and k the "Follower".

A estrutura de comunidades em poças tem sido explicada por competição de recursos, predação e permanência da água. No presente estudo, eu avaliei o efeito do gradiente predação-hidroperíodo sobre a riqueza de espécies e composição de guildas de girinos em poças, e também a co-ocorrência das espécies, testando a existência de padrões segregados que podem ser atribuídos as interações competitivas. O estudo foi realizado no município de Caçapava do Sul, Rio Grande do Sul, sul do Brasil. Eu amostrei girinos e predadores invertebrados em 38 poças, com diferentes tamanhos e graus de permanência. As coletas foram realizadas em duas estações: na primavera de 2007 (novembro) e no verão de 2008 (janeiro). Eu medi a área e a profundidade das poças em cada evento de coleta e registrei a riqueza da vegetação aquática e das margens, assim como a abundância e riqueza de predadores. Eu classifiquei as espécies em guildas baseadas em oito características eco-morfológicas. As espécies foram agrupadas através de ligação completa, usando o coeficiente de Gower. Eu analisei a relação da riqueza de girinos com as variáveis ambientais através de regressão múltipla, e usei Análise de Correspondência Canônica para relacionar a composição das guildas com os descritores ambientais. A co-ocorrência dos girinos foi analisada através de três algoritmos de modelo nulo: linhas e colunas fixas, linhas fixas e colunas proporcionais descartando-se matrizes degeneradas, linhas fixas e colunas proporcionais incluindo matrizes degeneradas. Nove matrizes de presença ausência foram testadas: ocorrências totais (primavera e verão) do conjunto total de espécies, e distinguindo as espécies em duas guildas (bentônicos e nectônicos), e ocorrências de primavera e verão para o conjunto total e as duas guildas. Das 38 poças com água na primavera, somente 22 permaneceram com água na amostragem de verão. Ao todo 10852 indivíduos de 21 espécies foram coletados. As espécies foram classificadas em sete guildas: suspensor-raspador (Sr), nectônicos (N), suspensor-filtrador (Sf), bentônicos com ninho de espuma, com e sem agregação (BI e BII), e bentônicos sem ninho de espuma com olhos dorsais ou laterais (BIII e BIV). A riqueza de espécies cresceu com a abundância de predadores, que foi a única variável explanatória relacionada a mesma. A composição das guildas foi explicada pela abundância de predadores e a profundidade média registrada na primavera. A co-ocorrência dos girinos mostrou padrões segregados para 14 dos 25 modelos testados. A maioria dos modelos com matrizes degeneradas rejeitou a hipótese nula. Os modelos com linhas e colunas fixas, e com as linhas fixas, colunas proporcionais e sem matrizes degeneradas mostraram muitos resultados similares. A segregação também foi influenciada pela combinação de espécies e estação consideradas. Em geral, para o conjunto total de espécies a coocorrência foi aleatória, para os bentônicos foi segregada para as ocorrências totais e de primavera, para os nectônicos apenas no verão. Os resultados das análises de gradiente e co-ocorrência sugerem que girinos são regulados pelos predadores que filtram a composição das guildas e podem reduzir a competição. Para girinos bentônicos, que ocupam poças com baixa abundância de predadores, competição pode ser um fator de estruturação importante. / The community structure of pond systems has been shown to be affected by resource competition, predation and permanency. Here, I evaluated the effect of the permanency-predation gradient in ponds on species richness and guild composition of tadpoles, and accessed the co-occurrence, searching segregated patterns that could be attributed to competitive interactions. The study was carried out Caçapava do Sul, Rio Grande do Sul state, southern Brazil. I sampled tadpoles and invertebrate predators in 38 ponds, with distinct sizes and permanency degrees. The collections were carried out twice: in spring 2007 (November) and summer, 2008 (January). I measured area and depth at each pond in each collection event, and recorded richness of aquatic and bank vegetation, and abundance and richness of predators. I conducted a guild classification of the species pool based on eight variables related to morphological and ecological features. Species were grouped through complete linkage agglomerative clustering method, using Gower coefficient. I evaluated the relation of tadpole richness with environmental variables using multiple regression, and Canonical Correspondence Analysis for guild composition. The tadpole co-occurrence was analyzed through three null models algorithm: fixed rows and columns; fixed rows, proportional columns, discharging degenerate matrices; and fixed rows, proportional columns, including degenerate matrices. Nine presence/absence matrices were tested: total occurrences (spring and summer) of the complete species pool, and distinguishing species of two tadpole guild (benthonic and nektonic), and spring and summer occurrence of total species pool and two guilds. Of the 38 ponds with water in the spring sampling, only 22 remained with water in the following summer sampling. A total of 10,852 individuals and 21 species of tadpoles were collected in the two sampling events. The species were classified into seven guilds: suspension-rasper (Sr), nektonics (N), suspension-feeder (Sf), benthonics with foam nests with and without school behavior (BI and BII), and benthonics without foam nests with lateral and dorsal eyes (BIII and BIV). Species richness increased with abundance of predators, which was the only explanatory variable related to it. Guild composition was explained by abundance of predators and mean depth recorded in spring, which was correlated with maximal depth. The tadpole co-occurrence showed a segregated pattern for 14 of the 25 tested models. Most models with degenerate matrices rejected the null hypothesis. The models with row and columns fixed, and row fixed, column proportional without degenerate matrices showed more similar results. Segregation was also influenced by the combination of species dataset and the season considered. In general, for the total species pool the co-occurrence was random, for benthonic species was segregated for the total and spring occurrences, and for nektonic in summer. The results of gradient and co-occurrence analysis suggest that tadpoles are regulated by predators that filter guild composition and could reduce competition. For benthonic species, which inhabit ponds with lower abundance of predators, competition can be a major structuring constraint.