198 research outputs found
Systems physiology and nutrition in dairy cattle: applications of omics and bioinformatics to better understand the hepatic metabolomics and transcriptomics adaptations in transition dairy cows
No full textSubmission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-05-01The student, Khuram Shahzad, accepted the attached license on 2017-04-10 at 16:09.The student, Khuram Shahzad, submitted this Dissertation for approval on 2017-04-10 at 16:33.This Dissertation was approved for publication on 2017-04-18 at 08:56.DSpace SAF Submission Ingestion Package generated from Vireo submission #10688 on 2017-08-10 at 14:30:20Made available in DSpace on 2017-08-10T19:51:48Z (GMT). No. of bitstreams: 2
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Previous issue date: 2017-04-18Embargo set by: Colleen Fallaw for item 102607
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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
Author Correction: Mortality outcomes with hydroxychloroquine and chloroquine in COVID-19 from an international collaborative meta-analysis of randomized trials.
No full textThe original version of this Article contained an error in the spelling of the author Muhammad Shahzad, which was incorrectly given as Muhammad Shehzad. This has now been corrected in both the PDF and HTML versions of the Article
Understanding mechanisms of Ketamine-induced human urinary tract damage
No full textKetamine is a phencyclidine derivative N-Methyl D-Aspartate (NMDA) receptor antagonist used as an anaesthetic and analgesic. A florid non-bacterial cystitis condition known as ketamine-induced cystitis (KIC) has recently been reported in abusers and prescription users of ketamine. Whilst the aetiological agent in patients withKIC is known, the mechanism of disease development is unknown.
The aims of this study were to investigate the potential mechanisms of development of KIC and to establish potential links between KIC and other chronic non-bacterial cystitis conditions; interstitial cystitis (IC) and eosinophilic cystitis (EC).
These aims were pursued under the following objectives;
1. Investigate toxicity of ketamine and its primary metabolite nor-ketamine on normal human urothelial (NHU) cell cultures.
2. Describe human urothelial tissue damage caused by ketamine.
3. Assess a possible relationship between ketamine exposure and development of KIC.
The main findings were that;
Ketamine and nor-ketamine were equally toxic to NHU cells in a concentration dependent manner.
A specific NMDA receptor antagonist (MK-801) did not show any urothelial toxicity on its own but unexpectedly increased toxicity of ketamine when used in combination.
Immunolabelling of the three individual KIC tissue sections demonstrated epithelial denudation and stromal inflammation with oedematous blood vessels.
Results from a telephone questionnaire did not show any obvious relationship between prescription use of ketamine and development of KIC.
Literature review suggested considerable similarities between the reported symptoms and clinical investigation findings of KIC to mainly EC and to some extent to IC.
In conclusion, the study indicated that ketamine might cause human urinary tract damage by impairing the barrier function of urothelium, inducing inflammation and resultant development of KIC.
These experiments should form the basis for future research in to understanding the mechanisms of development of KIC and other difficult to treat chronic uropathies such as EC and IC
The Study of Fixed Point Theory for Various Multivalued Non-Self
No full textKARAPINAR, ERDAL/0000-0002-6798-3254; Shahzad, Naseer/0000-0001-7155-5917The basic motivation of this paper is to extend, generalize, and improve several fundamental results on the existence (and uniqueness) of coincidence points and fixed points for well-known maps in the literature such as Kannan type, Chatterjea type, Mizoguchi-Takahashi type, Berinde-Berinde type, Du type, and other types from the class of self-maps to the class of non-self-maps in the framework of the metric fixed point theory. We establish some fixed/coincidence point theorems for multivalued non-self-maps in the context of complete metric spaces.National Science Council of the Republic of China [NSC 101-2115-M-017-001]The first author was supported partially by grant no. NSC 101-2115-M-017-001 of the National Science Council of the Republic of China
Correction
No full textWhen this article was first published online, the affiliation of the last author ‘Malik
Shahzad Shabbir’ was set incorrectly. This has now been corrected as follows and
republished onlin
Scalable centralized and distributed spectral clustering
No full textSpectral clustering approaches have led to well-accepted algorithms for finding accurate clusters in a given dataset. However, their application to large-scale datasets has been hindered by the computational complexity of eigenvalue decompositions. Several algorithms have been proposed in the recent past to accelerate spectral clustering, however, they compromise on the accuracy of the spectral clustering to achieve faster speed. In this paper, we propose a novel spectral clustering algorithm based on a mixing process on a graph. Unlike the existing spectral clustering algorithms, our algorithm does not require computing eigenvectors. Specifically, it finds the equivalent of a linear combination of eigenvectors of the normalized similarity matrix weighted with corresponding eigenvalues. This linear combination is then used to partition the dataset into meaningful clusters. Simulations on real datasets show that partitioning datasets based on such linear combinations of eigenvectors achieve better accuracy than standard spectral clustering methods as the number of clusters increase. Our algorithm can easily be implemented for parallel processing.
In the past few years, the size of a typical dataset has grown exponentially making it impossible to the store the data in a single system. Thus distributed systems are employed to store the data. Most of the clustering algorithms are tailored towards data stored in a centralized system which makes them inappropriate for the distributed system. Moreover, the large scale of the data prohibits us from moving it to a central location to use a centralized algorithm. Our approach to distributed spectral clustering works in two phases. In phase 1, individual machines generate a set of representative points of the local data and communicate it to a central machine. In phase 2, the central machine performs spectral clustering on the data and communicates the cluster assignment of the representative points to the corresponding nodes. We have explored various algorithms to generate the representative points and compare their trade-offs and accuracy. Our algorithm can easily be cast in the MapReduce framework.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2020-08-01The student, Shahzad Bhatti, accepted the attached license on 2018-06-24 at 19:39.The student, Shahzad Bhatti, submitted this Dissertation for approval on 2018-06-24 at 19:54.This Dissertation was approved for publication on 2018-06-26 at 09:00.DSpace SAF Submission Ingestion Package generated from Vireo submission #12667 on 2018-09-27 at 11:33:38Made available in DSpace on 2018-09-27T16:45:34Z (GMT). No. of bitstreams: 2
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Previous issue date: 2018-06-26Embargo set by: Seth Robbins for item 107869
Lift date: 2020-09-27T16:45:39Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 107869
Lift date: 2020-09-27T16:47:41Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 107869 on 2020-09-28T09:15:19Z
Correction
No full textArticle title: The dynamic role of sustainable development goals to eradicate the
multidimensional poverty: evidence from emerging economy
Authors: Yufei Cao, Aftab Hussain Tabasam, Syed Ahtsham Ali, Anam Ashiq, Carlos
Samuel Ramos-Meza, Vipin Jain and Malik Shahzad Shabbir
Journal: Economic Research-Ekonomska Istrazivanja
DOI: https://doi.org/10.1080/1331677X.2022.2153715
When this article was first published online, the affiliation of the last author ‘Malik
Shahzad Shabbir’ was set incorrectly. This has now been corrected as follows and
republished online.
‘Lahore Business School, University of Lahore, Pakistan
Permeability and Turbulence Over Perforated Plates
No full textWe perform direct numerical simulations of turbulent flow at friction Reynolds number Reτ≈ 500 - 2000 grazing over perforates plates with moderate viscous-scaled orifice diameter d+≈ 40 - 160 and analyse the relation between permeability and added drag. Unlike previous studies of turbulent flows over permeable surfaces, we find that the flow inside the orifices is dominated by inertial effects, and that the relevant permeability is the Forchheimer and not the Darcy one. We find evidence of a fully rough regime where the relevant length scale is the inverse of the Forchheimer coefficient, which can be regarded as the resistance experienced by the wall-normal flow. Moreover, we show that, for low porosities, the Forchheimer coefficient can be estimated with good accuracy using a simple analytical relation.In this article the author name Stefan Hickel was incorrectly written as Hickel Stefan. The original article has been corrected.Aerodynamic
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