• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4122
  • 1594
  • 478
  • 402
  • 376
  • 286
  • 239
  • 170
  • 163
  • 143
  • 140
  • 119
  • 77
  • 74
  • 44
  • Tagged with
  • 9858
  • 1797
  • 1566
  • 1094
  • 823
  • 750
  • 573
  • 568
  • 546
  • 540
  • 487
  • 459
  • 455
  • 455
  • 429
  • 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.
311

Measuring the factor content of trade

May, Sharon L. 08 August 2006 (has links)
No description available.
312

Isolation, purification and immunochemical characterization of an Rh₀ (D) active lipoidal material from human erythrocytes /

Traul, Karl A. January 1969 (has links)
No description available.
313

STRUCTURAL FACTORIZATION OF SQUARES IN STRINGS

Bai, Haoyue 05 1900 (has links)
A balanced double square in a string x consists of two squares starting in the same position and of comparable lengths. We present a unique fac- torization of the longer square into primitive components refereed to as the canonical factorization and analyze its properties. In particular, we examine the inversion factors and the right and left inversion subfactors. All three substrings are collectively referred to as rare factors as they occur only twice in a signi cant portion of the larger square. The inversion factors were es- sential for determining the classi cation of mutual con gurations of double squares and thus providing the best-to-date upper bound of 11n=6 for the number of distinct squares in a string of length n by Deza, Franek, and Thierry. The right and left inversion subfactors have the advantage of being half the length of the inversion factors, thus providing a stronger dis- crimination property for a possible third square. This part of the thesis was published by Bai, Franek, and Smyth. The canonical factorization and the right and left inversion subfactors are used to formulate and prove a signi cantly stronger version of the New Periodicity Lemma by Fan, Puglisi, Smyth, and Turpin, 2006, that basically restricts what kind of a third square can exists in a balanced double square. This part of the thesis was published by Bai, Franek, and Smyth. The canonical factorization and the inversion factors are applied to for- mulate and prove a stronger version of the Three Squares Lemma by Crochemore and Rytter. This part of the thesis was published by Bai, Deza, and Franek. / Thesis / Doctor of Philosophy (PhD)
314

FUNCTIONS OF MULTIMERIN 1 (MMRN1) IN PLATELET ADHESION AND THROMBUS FORMATION, THROUGH INTERACTIONS WITH VON WILLEBRAND FACTOR (VWF) / FUNCTIONS OF MMRN1 IN PLATELET ADHESION & THROMBUS FORMATION

PARKER, D'ANDRA 11 1900 (has links)
Multimerin 1 (MMRN1) is a massive, homopolymeric platelet and endothelial cell protein with functions that are emerging to support platelet adhesive processes. MMRN1 supports platelet adhesion under arterial flow conditions by a mechanism dependent on interactions with von Willebrand factor (VWF). The goals of this thesis were to further define the platelet adhesive functions of MMRN1 by: 1) characterizing the molecular mechanisms of VWF interactions with MMRN1; and 2) investigating if multimerin 1 is important for platelet adhesive functions using mice with and without a selective multimerin 1 (Mmrn1) deficiency. Studies of the mechanism of MMRN1-VWF binding indicated that MMRN1 bound to shear exposed VWF, and that MMRN1 interacted with the A1 and A3 domains in the VWF A1A2A3 region. VWF A1A2A3 also bound to MMRN1 with a physiologically relevant binding affinity, and supported platelet adhesion to MMRN1 at a high shear rate. The selective loss of Mmrn1 in mice had limited effects on tail bleeding times, although it impaired collagen-induced aggregation of washed platelets, as well as high shear platelet adhesion of whole blood on collagen surfaces, in vitro. Additionally, the selective loss of Mmrn1 in mice was associated with impaired and delayed platelet-rich thrombus formation in vivo, in arterioles treated with ferric chloride. These findings provide new insights on platelet adhesive, haemostatic functions at arterial shear rates, and the involvement of the platelet and endothelial cell protein, multimerin 1, to support these processes. / Thesis / Doctor of Philosophy (PhD)
315

The Identification of Prognostic Factors in Patients Suffering from Thromboembolic Stroke

Duku, Eric 07 1900 (has links)
In this project stroke data were analyzed with the use of survival techniques and incomplete principal component cox analysis. The data set resulted from a multi-center randomised controlled trial coordinated by investigators from the Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton with 438 patients. It was found that among stroke survivors, congestive heart failure along with other cardiac impairments post the major risks. Other factors found to be important were patient age, previous TIAs, presence of ulcers, diabetes and sex. / Thesis / Master of Science (MS)
316

Advanced Integrated Single-Stage Power Factor Correction Techniques

Zhang, Jindong 10 April 2001 (has links)
This dissertation presents the in-depth study and innovative solutions of the advanced integrated single-stage power-factor-correction (S2PFC) techniques, which target at the low- to medium-level power supplies, for wide range of applications, from power adapters and computers to various communication equipment. To limit the undesirable power converter input-current-harmonic's impact on the power line and other electronics equipment, stringent current harmonic regulations such as IEC 61000-3-2 have already been enforced. The S2PFC techniques have been proposed and intensively studied, in order to comply these regulations with minimal additional component count and cost. This dissertation provides a systematic study of the S2PFC input-current-shaping (ICS) mechanism, circuit topology generalization and variation, bulk capacitor voltage stress and switch current stress, converter design and optimization, and evaluation of the state-of-the-art S2PFC techniques with universal-line input. Besides, this presentation also presents the development of novel S2PFC techniques with a voltage-doubler-rectifier front end to both improve the performance and reduce the cost of S2PFC converters for (international voltage range) universal-line applications. The calculation and experimental results show that the proposed techniques offer a more cost-effective and efficient solution than industries' current practice, with universal-line input and converter power level up to 600 W. Finally, further improved technique is also presented with reduced filter inductor size and increased power density. / Ph. D.
317

Role of RNA Processing Factors in the Expression of Flt-1 and its Secreted Variant, sFlt-1

Roche, Rebecca I. 21 November 2005 (has links)
Vascular endothelial growth factor (VEGF) is an endothelial cell mitogen involved in angiogenesis, the formation of new blood vessels. sFlt-1, a secreted form of the signal-transducing VEGF receptor Flt-1, can inhibit cellular responses to VEGF both in vitro and in vivo. sFlt-1 is generated by alternative pre-mRNA processing; removal of Flt-1 intron 13 by splicing produces the mRNA for transmembrane Flt-1, whereas cleavage/polyadenylation within this intron, preserving the exon 13/intron 13 junction, yields sFlt-1 mRNA. Despite the likely importance of sFlt-1 in VEGF signaling, little is known about the regulation of its expression. Previous studies using an Flt-1 minigene (pFIN13) revealed that intronic cleavage/polyadenylation signals can affect Flt-1 expression, and, conversely, that 3' intronic splice signals can affect sFlt-1 expression. The goal of present work was to test the hypothesis that splicing and cleavage/polyadenylation factors compete functionally on Flt-1 transcripts, by 1) assessing the influence of exon 13/14 splicing determinants on expression of Flt-1 RNA processing variants in a transfected cell model system; 2) determining the effects of altering the relative abundance of proteins principally involved in splicing or cleavage/polyadenylation; and 3) characterizing a previously-unknown splice variant, predicted to encode a novel sFlt-1 protein isoform, in cells overexpressing the spliceosomal RNA binding protein U2AF65. When the upstream exon in pFIN13 was decreased from 2135 to 309 bp, the sFlt-1:Flt-1 mRNA ratio decreased 8.9-fold and an aberrant 5'UTR/exon 14 splice decreased 60-fold, indicating that "exon definition" is a key parameter of successful Flt-1 RNA processing. Mutation of 5' or 3' intronic splice signals had little effect on Long sFlt-1:Total sFlt-1 mRNA ratio, suggesting that splicing and cleavage/polyadenylation factors may not compete physically for Flt-1 transcripts. Although co-transfection with RNA processing factor cDNAs did not generally produce the predicted pattern of effects on sFlt-1:Flt-1 mRNA ratio, a cryptic exon within intron 13 was revealed in cells overexpressing U2AF65. sFlt-1 protein apparently can be encoded by mRNAs either cleaved/polyadenylated within intron 13 or, surprisingly, by splicing of the cryptic exon "13b." Thus, the cellular decision to produce sFlt-1 or Flt-1 from a nascent RNA can no longer be viewed as a simple choice between cleavage/polyadenylation and splicing. / Ph. D.
318

Development of the Posttraumatic Anger Scale

Sullivan, Connor Patrick 10 January 2016 (has links)
Anger is a pervasive problem after individuals experience traumatic stress that heightens the risk for violence, health problems, poor relationships, and poor treatment outcomes. Previous research has demonstrated a moderate relationship between anger and posttraumatic stress disorder (PTSD), yet this research also highlights that anger has not been rigorously measured in the context of PTSD. Thus, this study concerns the development of a complimentary measure to assess anger in the context of PTSD. Participants were 435 undergraduate students. The participants were given a battery including the proposed scale and measures of trauma exposure, PTSD, anger, depression, anxiety, and social desirability to assess. Exploratory factor analyses revealed that a hierarchical, four-factor model was the best model. The Posttraumatic Anger Scale appeared psychometrically sound, with excellent internal consistency, good evidence of validity, and good model fit. This scale may provide implications for clinical work, specifically for the assessment and tracking of anger symptoms connected to PTSD. Additionally, this scale may assist with research by predicting treatment outcomes, aggression, and PTSD. / Master of Science
319

Mathematical Model for Calibration of Potential Detection of Nonlinear Responses in Biological Media Exposed to RF Energy

See, Chan H., Abd-Alhameed, Raed, Mirza, Ahmed F., McEwan, Neil J., Excell, Peter S., Balzano, Q. 25 February 2015 (has links)
No / An efficient way to test for potential unsymmetrical nonlinear responses in biological tissue samples exposed to a microwave signal is to observe the second harmonic in a cavity resonant at the two frequencies, with collocated antinodes. Such a response would be of interest as being a mechanism that could enable demodulation of information-carrying waveforms. In this work, an electric circuit model is proposed to facilitate calibration of any putative nonlinear RF energy conversion inside a high quality-factor resonant cavity with a known nonlinear loading device. The first and second harmonic responses of the cavity due to loading with the nonlinear and lossy material are also demonstrated. The results from the proposed mathematical model give a good indication of the input power required to detect any very weak second harmonic signal in relation to the sensitivity of the measurement equipment. Hence, this proposed mathematical model will assist in determining the level of the second harmonic signal in the detector as a function of the specific input power applied. / EPSRC
320

Investigating the Role of the VAL1 Transcription Factor in Arabidopsis thaliana Embryo Development

Schneider, Andrew 05 October 2015 (has links)
Developing oilseeds accumulate oils and seed storage proteins synthesized by the pathways of primary metabolism. Seed development and metabolism are positively regulated at the transcriptional level through the transcription factors belonging to the LAFL regulatory network. The VAL genes encode repressors of the seed maturation program in germinating seeds, but they are also expressed during early stages of seed maturation. VAL1 was identified through a reverse genetics approach as a regulator of seed metabolism, as val1 mutant seeds accumulated elevated levels of storage proteins compared to the wild type. Two VAL1 splice variants were identified, yielding the canonical protein and a truncated protein lacking the plant-homeodomain-like domain important for epigenetic repression. Transcriptomics analysis also revealed that VAL1 is a global epigenetic and transcriptional repressor in developing embryos, though none of the transcripts encoding the LAFL network regulators, including FUSCA3, were affected in val1 embryos. However, VAL1 action is connected specifically to FUSCA3 as 38% of transcripts belonging to the FUSCA3 regulon, but not to other regulons, were largely de-repressed in the absence of VAL1. Based on our model, FUSCA3 activates expression of VAL1 to repress transcription of seed maturation genes without interfering with expression of the core LAFL regulators. / Ph. D.

Page generated in 0.0605 seconds