58 research outputs found
Cellular decision making at the nanoscale
No full textThe well-established dependence of cell traction forces on the compliance of supporting matrices has been attributed to levels of force exerted on components in focal contacts. Here, use of novel, force-limited nanoscale tension gauges revealed that both force and substrate deformations govern cell decision-making during initial attachment to compliant substrates. We propose a mechanical model consistent with observed behavior. Upon formation of stable cell contacts, bond tension and tether rupture govern cell attachment, spreading, and focal adhesion maturation at force levels on individual receptors predicted by prior studies.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-08-01The student, Zainab Rahil, accepted the attached license on 2016-04-27 at 06:49.The student, Zainab Rahil, submitted this Thesis for approval on 2016-04-27 at 06:55.This Thesis was approved for publication on 2016-04-29 at 14:30.DSpace SAF Submission Ingestion Package generated from Vireo submission #9538 on 2017-09-29 at 11:12:58Made available in DSpace on 2017-09-29T17:52:42Z (GMT). No. of bitstreams: 2
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Previous issue date: 2016-04-29Embargo set by: Colleen Fallaw for item 103531
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Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 103531 on 2019-09-30T09:15:23Z
Cells and force transduction
No full textThis thesis studies mechanism involved in propagating force generated at cadherin complexes. The first part of this thesis demonstrates that mechanotransduction at classical cadherin complexes is not only ligand-dependent but also dependent on the respective receptor tyrosine kinase (RTK) binding partner of cadherin. This involvement of RTKs at cadherin complexes is important in propagating force transduction globally, implying that force transduction at cadherin complexes is not restricted to cell-cell junctions but is also propagated globally via the mediation of its respective RTK binding partner. These results suggest that homophilic ligation in trans- and cadherin association with cognate receptor tyrosine kinase in cis comprises a combinatorial, mechano-chemical switch. That is, specific combinations of cadherin, ligand, and RTK is required for force-activated RTK-dependent signaling, activation of cell contractility, and cytoskeletal remodeling at perturbed cadherin adhesions. These findings confirm that cadherins form both homophilic and heterophilic bonds, but homophilic cadherin ligation selectively triggers cadherin-associated RTK signals that mechanically reinforce homophilic, but not heterophilic cadherin adhesions, thereby stabilizing homophilic adhesions and amplifying binding differences. This study demonstrates that this mechano-chemical switch is not governed by cadherin adhesion differences, but requires a specific combination of cadherin ligand in trans- and RTK expression in cis to actuate force transduction signaling on rigid surfaces to propagate force transduction at a global level.
For the second part of this study used novel, force-limited nanoscale tension gauges to investigate how force and substrate stiffness guide cellular decision-making during initial cell attachment and spreading on deformable substrates. The well-established dependence of cell traction and spreading on substrate stiffness has been attributed to levels of force exerted on molecular components in focal contacts. The molecular tension gauges used in this study enabled direct estimates of the threshold, pico Newton forces that instructed decision-making at different stages of cell attachment, spreading, and adhesion maturation. These results further confirm that the force thresholds controlling adhesion and spreading transitions depend on substrate stiffness. Reported findings agree semi-quantitatively with a proposed model that attributes rigidity-dependent differences in cell spreading to stiffness-dependent rates of competing biochemical processesSubmission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2020-12-01The student, Zainab Rahil, accepted the attached license on 2018-11-08 at 12:34.The student, Zainab Rahil, submitted this Dissertation for approval on 2018-11-08 at 12:48.This Dissertation was approved for publication on 2018-11-13 at 10:27.DSpace SAF Submission Ingestion Package generated from Vireo submission #13072 on 2019-02-08 at 11:38:31Made available in DSpace on 2019-02-08T18:39:44Z (GMT). No. of bitstreams: 2
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Previous issue date: 2018-11-13Embargo set by: Seth Robbins for item 109931
Lift date: 2021-02-08T18:40:00Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 109931
Lift date: 2021-02-08T18:42:23Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 109931
Lift date: 2021-02-08T18:43:54Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 109931
Lift date: 2021-02-08T18:44:50Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 109931 on 2021-02-09T10:15:38Z
Quantification of Imaging Biomarkers For Cardiovascular Disease in CT(A)
No full textFor better management of cardiovascular disease, it is of utmost importance to categorize the subjects into different risk groups. This categorization can be made based on cardiovascular risk factors including the family history of the subject. Imaging techniques play an increasing role in order to assess ardiovascular risk factors. In this thesis we set out to develop and evaluate automatic techniques for the extraction of quantitative imaging biomarkers for coronary artery disease (CAD). One of the important cardiovascular risk factor is the presence of calcium in the arteries. We presented an automatic method that can compute the amount of calcium scores for the whole heart as well as for each of the coronary arteries from CT data. The system also categorizes patients into different risk groups. This vessel specific calcium lesion information can be used for treatment planning and assessing progression of CAD in follow up studies. The possibility to assign calcium to individual coronary arteries was possible owing to the ’Coronary Density Estimate’. The second imaging biomarker is epicardial fat volume. We resent a method that can accurately quantify the amount of epicardial fat volume. It was demonstrated that the method performs as good as the manual observers, hence has great potential to be used in daily clinical practice. In a clinical study on 2298 subjects it was demonstrated that indeed larger volumes of epicardial fat volumes were related to larger volumes of calcified lesions in the various vessel beds. The potential of this biomarker will need to be established in multiple larger studies. The third imaging biomarker in CAD considered in this thesis is coronary artery stenosis grade. Accurate detection and quantification of coronary stenoses is of great importance, as this information is very important for the clinician in order to make accurate treatment selection and planning. We investigated the ability of detecting and quantifying coronary stenoses from CTA data. We demonstrated that the vessel lumen can be segmented with a precision similar to the human observers, but that it is still a challenge to be able to distinguish between significant and non-significant lesions. Quantitative imaging biomarkers in CAD may provide both anatomical and functional information, and are often obtained from different imaging modalities. An important subject with respect to treatment planning is therefore the ability to combine information from different modalities in an integrated display. The SMARTVis system was introduced to fuse anatomical information from CTA scans and functional information from SPECT-MPI into one display. The integrated visualization proposed in the SMARTVis system enables a one-stop-shop visual exploration of cardiac anatomical and functional data, to maximally exploit the complementary information of multiple imaging modalities. It has been confirmed that such comprehensive visualizations allow to effectively relate perfusion defects and coronary lesions, and that fused integrated analysis leads to a more accurate diagnosis. Automatic image processing plays an increasingly important role. Not only to extract relevant quantitative imaging biomarkers from CT imaging data, but also establish with what accuracy they can be assessed. For a number of relevant cardiovascular quantitative imaging biomarkers, this thesis has provided the required methodology.Imaging Science & TechnologyApplied Science
Mechanism and performance evaluation of spent-coffee grounds-derived nanocomposite materials for highly efficient photocatalytic degradation of organic pollutant
No full textThe study demonstrates a facile and environmentally friendly method for synthesizing crystalline TiO2 nanoparticles on the surface of hydrochar generated from readily available biomass waste, i.e., spent coffee grounds (SCGs), using a simple sol–gel process. The hydrochar served as a support for TiO2, reducing the rate at which electrons and holes recombine during photocatalysis, thereby facilitating the effective binding of TiO2, enhancing its adsorption capacity, and the convenient separation of the photocatalyst after usage. The materials were tested in the photocatalytic degradation of an organic pollutant, methylene blue (MB) dye. TiO2-hydrochar obtained at 210 ⁰C has the best performance, giving a degradation efficiency of 98.5 % and a mineralization efficiency of 87.1 % in 90 min at neutral pH. Radical trapping experiments showed
being the dominant species, followed by
. Besides, it showed superior stability with an activity loss of ∼ 9.2 % after five runs. The superior performance of the HCT210 was ascribed to the enhanced interfacial charge transfer kinetics between the TiO2 and hydrochar through
bond formation, better light absorption, and the high surface area of the materials. Performance metrics show that synthesized nanocomposites are promising photocatalysts, providing a biomass-assisted method for robust photocatalytic wastewater treatment.Killam TrustsNatural Science and Engineering Research Council (NSERC
House of Music : Festivity from city to seat
No full textHouse of Music : Festivity from city to seat.Concert HallArchitecture, Urbanism and Building Sciences | Interiors Buildings Citie
Reality, Dream and Hallucination in the Literary Works of Muhammad al-Qurmuti
No full textMuhammad al-Qurmuti is one of the most eminent of Omani writers. He was
born in al-Buraymi in 1955. He is the author of a single volume of short stories, entitled
Sa’at ar-rahil al-multahiba, which was published in Muscat in 1988. The unequivocally
innovative and surrealist short stories that are contained in the volume are filled with
the spirit of decadence and catastrophism. And here also the echoes of the philosophy
of Schopenhauer, Bergson and Nietzsche are strong. This collection is an
excellent example of how well western philosophy, thought and art has acclimatized to
the Arab world. Muhammad al-Qurmuti presents the reader with an ‘exciting hour
of travel’ to the land of dreams, desires, illusions, and hallucinations, to a world in which
the possible will within a second cease to exist
DNA Fingerprinting and Cultivar Identification of Olive (Olea europaea L.) using SSR markers
No full textBackground: Genetic diversity and population structure of the olive varieties cultivated in Pakistan are yet to be explored.Methods: In present study, we studied population structure and genetic diversity and developed DNA fingerprints of 13 olive varieties using 63 Simple Sequence Repeat markers.Results: Collectively 618 alleles were amplified among which 582 were polymorphic and 36 were monomorphic. High allelic diversity per locus was found among 63 SSR markers, i.e., one for GAPU-12 to 23 for UDO099-008 and GAPU-47 with an average 9.80 alleles per locus. On the basis of cluster analysis genotypes were grouped into two clusters. Cluster I contained varieties Manzanilla, Sohawa-selection, Koroneki, Bulkasar-selection, Arbequina, Arbosona, Chugtai-selection, whereas cluster II was comprised of varieties Bari-Zatoon, Coratina, Gemlik, Frontaio, Pendolino and Ottobratica. UDO-24 marker alone identified seven olive varieties. Similarly, DCA-07 and EMO-02 identified six olive varieties each.Conclusion: The findings of this manuscript will be helpful for future studies related to DNA fingerprinting and genetic diversity assessment for choice of SSR markers and identification of olive varieties. Keywords: Cluster analysis; Polymorphic Information Content; Structure analysis; Similarity matrix
The Use of Idioms in Novel Sun by Tere Liye
No full textBackground: Idioms play an important role in novels, especially in conversation
and writing. The novel Sun (2019) explores themes of friendship, adventure, and
life's journey. Analysis of this novel is important for understanding the meaning
and types of idioms used.
Objective: This study aims to identify, classify, and analyze idioms based on their
form and meaning in the novel Sun.
Method: This research uses a qualitative descriptive method. The author
collected data from a novel and analyzed it based on Boatner and Gates' theory,
which divides idioms into four forms: lexical idioms, phrasal idioms, frozen
idioms, and proverbs.
Results: This study shows that idioms can be found in various forms. This is
evidenced by the number of idioms identified in the novel: there are 42 idioms
classified into 4 forms, 32 lexical idioms, divided into 4 parts, 17 verbal idioms,
10 nominal idioms, 3 adjective idioms, and 2 adverbial idioms, 10 phrasal idioms,
no frozen idioms, and no proverbs.
Conclusion: The idioms in the novel Sun are well-structured and have a variety of
types. The themes raised contain moral messages related to human values,
friendship, family, courage, and the importance of protecting the environment.54 PagesKertas Karya Diplom
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