Reproduction de : Thèse d'exercice : Médecine vétérinaire : Toulouse 3 : 2007. / Titre provenant de l'écran titre. Bibliogr. f. 48-50.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 110-118).

Thesis (Ph.D.) -- University of Texas at Arlington, 2008.

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains v, 72 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 70-72).

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 107-113). Also available in electronic version. Access restricted to campus users.

A common issue noted by detractors of the traditional scoring of Multiple Choice (MC) tests is the confounding of guessing or other false positives with partial knowledge and full knowledge. The current study provides a review of classical test theory (CTT) approaches to handling guessing and partial knowledge. When those methods are rejected, the item response theory (IRT) and cognitive diagnostic modeling (CDM) approaches, and their relative strengths and weaknesses, are considered. Finally, a generalization of the Multicomponent Latent Trait Model for Diagnosis (MLTM-D; Embretson & Yang, 2013) is proposed. The results of a simulation study are presented, which indicate that, in the presence of guessing, the proposed model has more reliable and accurate item parameter estimates than the MLTM-D, generally yielding better recovery of person parameters. Discussion of the methods and findings, as well as some suggested directions for further study, is included.

Recent research has shifted the focus of pronunciation instruction from achieving native-like speech in learners to correcting issues that affect the intelligibility of the learners’ speech. Research also suggests that suprasegmental features of pronunciation, such as intonation, rhythm, and stress, have a considerable influence on intelligibility. By using Dickerson’s (1989) Covert Rehearsal Model, which includes predictive strategies that encourage learner autonomy, instructors have the tools necessary to effectively help learners improve their intelligibility. However, the question as to which instructional targets should be taught in the classroom still remains. This report outlines one way in which instructors can use a diagnostic assessment in order to discover which instructional targets are most appropriate for their learners. / text

Introduction Cerebral glioma is the most prevalent primary brain tumour, of which the majority are high grade gliomas. High grade gliomas possess a poor prognosis, and glioblastoma patients survive less than one year after diagnosis. To date, histological grading is used as the standard technique for diagnosis and survival prediction. Previous studies using advanced techniques such as MR Perfusion have achieved a high sensitivity but a low specificity in identifying high grade gliomas. Moreover, they have failed to distinguish glioblastoma from anaplastic glioma. The purpose of the study presented here is to assess the diagnostic and prognostic value for cerebral glioma of cerebral blood volume maps derived from MR perfusion. Methods This retrospective study was approved by the local research ethics committee and clinical audit office. This study included 123 patients with newly diagnosed cerebral glioma, of all grades. Histological diagnosis was used as the standard reference for all potential patients. The relative tumour blood volume (rTBVmax) derived from MR perfusion was used for radiological grading of cerebral glioma. Receiver operating characteristics (ROC) were used to define the best threshold value in distinguishing the glioma grades and in determining the accuracy values (sensitivity, specificity, and positive and negative predictive values). For survival analysis, Kaplan-Meier was used to illustrate and compare the discriminatory value of the histological and radiological classifications. A multiple Cox regression model was used to assess the prognostic value of both classifications in addition to other tested demographic and clinical variables. Finally, the influence of potential moderators was assessed using ANOVA, to assess whether the variation in rTBVmax was only due to the difference in tumour grades. Results A model data set (n = 50) produced a 7-fold increase of TBVmax in tumour versus white matter and provided sensitivity and specificity of 97% and 94%, respectively, in distinguishing high versus low grade glioma. Moreover, a threshold value of 9.6 provided sensitivity and specificity of 100% and 56% in differentiating glioblastoma within the group of high grade gliomas. These threshold values were applied to the second group (n = 73) and provided sensitivity and specificity of 96% and 95% in distinguishing high versus low grade glioma, and 97% and 73% in differentiating, within the high grade gliomas, glioblastoma from anaplastic glioma. Using these two thresholds for a three-tier radiological classification, both the Kaplan-Meier plots and the multiple Cox regression showed that radiological classification was the most independent predictor of survival and tumour progression. The proposed radiological classification system was better than histological classification in predicting glioma patients survival especially noted in a group of moderately hyperaemic rTBVmax. Conclusion MR perfusion is a non-invasive and robust technique in glioma grading and survival prediction. The diagnostic value of rTBVmax derived from MR perfusion in differentiating high versus low grade glioma is promising. It may have a role in the future in defining the appropriate treatment. However, the proposed radiological classification was inferior in differentiating anaplastic glioma from glioblastoma multiforme. In the future, a more advanced multimodal MR, such as MR spectroscopy and MR diffusion, may be studied, besides MR perfusion, in order to improve this diagnostic accuracy.

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Multiplex polymerase chain reaction (PCR) assays were designed that incorporated primer pairs for the sex determining region on the Y chromosome, Sry, and one or two control sequences. A triplex and a duplex assay were created involving Sry and Dax, a single copy X chromosome gene which is involved in the female sex determination pathway. The third sequence in the triplex assay was a repetitive Y chromosome sequence, YR. A minimum of 2.5 x 10-3 to 2.5 x 10 -4 m g/ m L of male DNA and 2.5 x 10-5 m g/ m L of female DNA was required if a single multiplex PCR was performed. To demonstrate that sex determination of preimplantation porcine embryos is possible, morulae were collected 5 d post insemination from pregnant mare serum gonadotrophin (PMSG)/human chorionic gonadotrophin (hCG)-treated 60--70 kg prepubertal gilts. Embryos were biopsied using a micromanipulator and cells were placed into individual microcentrifuge tubes for further analysis. Embryos were then cultured to the blastocyst stage. A total of 315 embryos were sexed via the PCR assay with a resultant female/male (%) ratio of 73/27. When 94 embryos from heavier gilts (90--100 kg) were sexed in a similar assay, the resultant female/male ratio was 60/40. Attempts were made to correlate these results with karyotypes. Five transfers of sexed embryos into synchronized recipients were attempted. None of these resulted in pregnancies; although return to estrus was delayed by two to eight days, in four out of the five recipients. Our findings suggest that PCR amplification of the Sry gene can be a reliable method for sexing porcine embryos. It does appear that embryo quality is critical for both the PCR assay and subsequent successful culture. (Abstract shortened by UMI.)