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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.
81

The Cyclopropylmethyl Free Radical Clock. Calibration for the Range 30-90°C

Mathew, Lukose K. 02 May 2016 (has links)
<p> The Arrhenius equation for the ring opening isomerization of cyclopropylmethyl radicals (R•) to 3-buten-1-yl radicals (R•') for the 303-362 K temperature range was determined by thermolysis of cyclopropylmethyl [1-hydroxy-1-methylethyl] diazene in the presence of excess 1,1,3,3-tetra-methylisoindolin-2-yloxyl (Y•).</p> <p> Rate constants for coupling of R• with Y• were assumed to be proportional to diffusion controlled rate constants (kd) and rate constants (ki) for the isomerization were calculated from kd (corrected) and product ratios (RY/R'Y). The temperature dependence of ki, given by log(ki/s^-1) = (13.9 ± 0.4) - (7.6 ± 0.1)/θ, is significantly different from that determined by Ingold and co-workers by kinetic epr spectroscopy in the temperature range 128-153 K; log(ki/s^-1) = (11.34 ± 0.85) - (5.94 ± 0.57)/θ, where θ = 2.3 RT kcal mol^-1.</p> / Thesis / Master of Science (MSc)
82

Bmal1 Regulates Prostate Growth via Cell-Cycle Modulation / Bmal1は細胞周期の調節を介して前立腺の増殖を制御する

Ueda, Masakatsu 25 September 2023 (has links)
京都大学 / 新制・論文博士 / 博士(医学) / 乙第13572号 / 論医博第2298号 / 新制||医||1069(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 藤田 恭之, 教授 武藤 学, 教授 伊藤 貴浩 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM
83

Water loss comparison of Arabidopsis thaliana and Populus sp. genotypes / Jämförelse av vattenförlust hos olika genotyper av Arabidopsis thaliana och Populus sp.

Brändström, Kajsa January 2024 (has links)
In this study, the magnitude of stomatal water loss was compared between different Arabidopsis thaliana mutants. The stomatal water loss among different mutants of Populus sp. was also examined in this study. Fourteen different Arabidopsis thaliana mutants were sown and later genotyped using DNA-extraction, PCR, and gel electrophoresis. Leaf water loss analysis was made on both Arabidopsis thaliana and Populus sp. The data was then used in statistical tests, to find if there was a significant difference in rate of stomatal water loss between different genotypes. The result showed a significant difference in water loss when comparing the toc1-5 and T89 genotypes and the toc1-5 and 1119-4 genotypes in Populus sp. There was no significant difference between the 1119-4 and T89 genotypes in Populus sp. The result also showed that there was a significant difference between 25 combinations of the Arabidopsis thaliana genotypes. A conclusion was that TOC1 reduces water loss in Arabidopsis thaliana, indicating a role in stomatal clousure. Future research is needed to examine differences between genotypes among both species included in the study.
84

MODELING AND SIMULATION OF CLOCK DISTRIBUTION NETWORKS USING DELAY-LOCKED LOOPS

RAVI, MAHESWARI S. 02 October 2006 (has links)
No description available.
85

DESIGN AND TEST GENERATION FOR CLOCK SKEW FAULTS OF CLOCK-DELAYED DOMINO LOGIC CIRCUITS

MAO, WUJIN 08 October 2007 (has links)
No description available.
86

A Full Digital Phase Locked Loop

Thomas, Renji George 24 August 2010 (has links)
No description available.
87

Characterization of Exosomes from Mammalian Circadian Clock Cells

Zhao, Dan 07 May 2016 (has links)
Suprachiasmatic nuclei (SCN) is the master circadian pacemaker that generates coordinated rhythms and drives oscillations in other peripheral tissues. Extracellular vesicles (exosomes) have been implicated in cell-to-cell communication and the regulation of circadian clock. However, mammalian clock-derived exosomes have not been characterized. This thesis examine the contents of exosome released from SCN2.2 cells in vitro using a combination of proteomics, next-generation sequencing, and bioinformatic analyses. SCN2.2 cells-derived exosomes, that carry unique microRNAs and proteins, could be taken up by fibroblast cells in vitro. Interestingly, several unique microRNAs and proteins found in SCN2.2 cells-derived exosomes have shown circadian rhythmicity in other cells. In addition, differential expressed microRNAs secreted by SCN cells were also observed outside of exosomes. Taken together, these studies demonstrate that exosomes, containing small RNAs, RNAs and proteins, are released from SCN2.2 cells and likely have a biological role in circadian regulation of metabolism in downstream cells.
88

Overlapped schedules with centralized clustering for wireless sensor networks

Ammar, Ibrahim A.M., Miskeen, Guzlan M.A., Awan, Irfan U. January 2013 (has links)
No / The main attributes that have been used to conserve the energy in wireless sensor networks (WSNs) are clustering, synchronization and low-duty-cycle operation. Clustering is an energy efficient mechanism that divides sensor nodes into many clusters. Clustering is a standard approach for achieving energy efficient and hence extending the network lifetime. Synchronize the schedules of these clusters is one of the primary challenges in WSNs. Several factors cause the synchronization errors. Among them, clock drift that is accommodated at each hop over the time. Synchronization by means of scheduling allows the nodes to cooperate and transmit data in a scheduled manner under the duty cycle mechanism. Duty cycle is the approach to efficiently utilize the limited energy supplies for the sensors. This concept is used to reduce idle listening. Duty cycle, nodes clustering and schedules synchronization are the main attributes we have considered for designing a new medium access control (MAC) protocol. The proposed OLS-MAC protocol designed with the target of making the schedules of the clusters to be overlapped with introducing a small shift time between the adjacent clusters schedules to compensate the clock drift. The OLS-MAC algorithm is simulated in NS-2 and compared to some S-MAC derived protocols. We verified that our proposed algorithm outperform these protocols in number of performance matrix.
89

DNA Sequence and Haplotype Variation Analyses of Circadian Clock Genes and Their Effects on Phenotypes in the Turkey, Meleagris gallopavo

Adikari Mudiyanselage, Jayantha Bandara Adikari 04 December 2012 (has links)
Present study was planned to compare the phenotypic variation of performances traits among commercial (CC) and heritage varieties of turkeys. Information about heritage turkey varieties continues to be limited. In addition, the emerging turkey genome sequence provides a unique opportunity to understand the DNA sequence variation and its associations with performance traits. The turClock, turPer3, turCry1 and turCry2 genes were screened and evaluated for its association with their performance traits. As expected, CC turkeys were superior to heritage birds in performance for most of the traits evaluated. However, heritage turkeys showed better reproductive performances compared to CC turkeys. A total of 41 SNPs were identified from the genes that screened. The haplogroups in the turClock gene were significantly associated with body weight (BW) at 309 d of age, feed conversion ratio (FCR) for 34 - 68 d and 69 - 159 d, egg production and average egg weight (P " 0.05). The haplogroups developed from turPeriod-3 gene were significantly associated with BW at 231 d of age, average daily gain (ADG) for 160 - 231 d, FCR for 69 - 159 d and 160 - 231 d, egg production traits, semen quality traits and plasma melatonin concentration (P " 0.05). In the turCry1 gene, haplogroups were significantly associated with ADG for 35 - 68 d, FCR for 160 - 231 d and 34 - 231 d, egg production and ejaculate volume (P " 0.05). The haplogroups identified from turCry2 gene were significantly associated with BW at 34, 68 and 231 d of age, ADG for 160 - 231 d, FCR for 34 - 68 d, average egg weight (P " 0.05). These findings reveal that phenotypic variation observed in growth and reproductive parameters among turkeys could be used for selecting birds for future breeding programs. DNA sequence variations at the nucleotide and haplotype levels are associated with some of growth, reproductive parameters and plasma melatonin of turkeys. Thus DNA sequence variations that identified of the circadian genes may have some regulatory role in the molecular mechanism of the circadian clock which may affect the circadian rhythm of the animal. / Ph. D.
90

Signatures of natural selection and local adaptation in Populus trichocarpa and Populus deltoides along latitudinal clines

Bawa, Rajesh K. 18 February 2013 (has links)
Trees, like many other organisms, decrease their rate of metabolic activities to cope up with harsh environments. This stage of "dormancy" is marked by shedding of leaves and bud-set in deciduous trees. Recent studies have revealed the role of the circadian clock in synchronizing the timing of dormancy and physiology for conferring fitness in trees. To better understand the possible role of natural selection on circadian clock-related genes in climatic adaptation, I took a candidate gene approach, selecting circadian clock genes, some of which had been functionally validated, and others hypothesized, to identify signatures of natural selection in Populus trichocarpa and P. deltoides. Using both frequency spectrum based tests and tests of heterogeneity, I identified genetic variants deviating from selective neutrality. Results reveal that photoreceptors and dormancy regulator genes may have been the targets of natural selection. Nearly the same levels of selective constraints were found in different functional groups of genes irrespective of pleiotropy. Further, upstream regions of all genes showed high selective constraint, with some of them (FT-2, PIF-4, FRIGIDA) showing significantly higher variation than the other genes, hinting at the role of non-coding regulatory regions in local adaption. In some cases, the same genes in both species appeared as outliers, including PIF-6, FRI, FT-2, SRR1, TIC, and CO, which might reflect their common role in adaptation across species boundaries. All of these results indicate a complex nature of phenology regulation and local adaptation in Populus species with photoreceptors and dormancy regulator genes playing key roles. / Master of Science

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