408 research outputs found
FIGURE 3. Rubus micropetalus Gardner. A in Taxonomic delineation of two closely allied Rubus L. (Rosaceae) species with notes on the typification of the name R. fairholmianus
No full textFIGURE 3. Rubus micropetalus Gardner. A. Habitat; B. Inflorescence; C. Abaxial surface of leaves; D. Flower; E. Fruits; F & G. Stipules (showing adaxial and abaxial surface); H & I. Sepals (showing adaxial and abaxial surface); J. Petal; K & L. Bracts (showing adaxial and abaxial surface); M. Drupelet. (Photos: Bhavadas N).Published as part of <i>Narayanan, Bhavadas, Prabhukumar, Konickal Mambetta, Kumar, Vannaratta Veetil Naveen, Harinarayanan, C.M., Chinnappan, Satheshkumar & Umesh, Balakrishnan Thara, 2023, Taxonomic delineation of two closely allied Rubus L. (Rosaceae) species with notes on the typification of the name R. fairholmianus, pp. 271-280 in Phytotaxa 622 (5)</i> on page 276, DOI: 10.11646/phytotaxa.622.5.1, <a href="http://zenodo.org/record/10150576">http://zenodo.org/record/10150576</a>
Large and detached eddy simulation of separated flow over 3D hill geometries with surface roughness to mimic flows over complex terrains
No full textWith the push to making wind power a significant contributor to the energy portfolio in the U.S. and Europe, there is considerable effort to deploy the currently available peta-scale computational resources to assess and improve well known simulation techniques, such as the large eddy simulation (LES) and detached eddy simulation (DES) techniques, to model the complex flows in wind farms, taken as a whole, as opposed to individual wind turbines. Simulating turbulent flows in wind farms, consisting of arrays of wind turbines, begins with the modeling and simulation of the atmospheric boundary layer (ABL) over complex terrain that is characterized by regions of separated flow with a high degree of turbulence anisotropy. Over the years there has been considerable work on applying LES and Reynolds Averaged Navier--Stokes (RANS) simulations over terrain geometries, such as the Askervein Hill, to understand turbulence closure models for flow over complex terrain. Such studies, however, have had limited success due to difficulties associated with the closure models in the near wall region of the flow. At the same time, turbulence simulations over \emph{canonical} geometries, such as the periodic and axisymmetric hills, have been shown to compare well with data obtained from laboratory scale experiments, where the inflow turbulence and boundary conditions are better characterized and defined respectively. In an effort to extend these canonical flows to be more representative of flows over complex terrain, this paper aims to present results of large and detached eddy simulations of separated flow over three dimensional hill geometries with roughness parametrization, with the objective of developing better closure models for flow over complex terrain
On defect CFT and path integral methods for entanglement in quantum field theories
No full textIn the first few chapters of the thesis, we will study defect CFT methods based on the replica trick for characterizing quantum information in quantum field theories. We calculate a coefficient that characterizes the strength of the two point function of the displacement operator in the replica twist defect placed in a holographic CFT, which controls the second order shape dependence of Renyi entropy. We introduce defect CFT methods for calculating correlation functions involving the modular Hamiltonian together with probe operators inserted at lightcone separation. We use these methods to further calculate correlation functions involving modular flows of these probe operators. Tomita-Takesaki theory constrains these correlation functions, which when combined with our defect CFT calculations, provides a proof of the Quantum Null Energy Condition.
In the last few chapters of this thesis, we will calculate entanglement measures for states that are defined by a Euclidean path integral together with a source for an operator inserted in the path integral. We provide a purely Lorentzian formula for the modular Hamiltonians for these states for flat entangling cuts which systematizes the task of writing time-ordered expressions for relative entropy of these states with respect to the vacuum to all orders in the source. We further apply this method to calculate a formula for shape deformed modular Hamiltonian for the vacuum state to all orders in the shape deformation. In the case of null shape deformation, we recover the formula for the vacuum modular Hamiltonian for null cuts. We then calculate the shape deformation of relative entropy and provide evidence for the presence of a shock in the stress tensor expectation value when one performs the Connes cocycle flow of the state.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2023-12-01The student, Srivatsan Balakrishnan, accepted the attached license on 2021-07-16 at 15:10.The student, Srivatsan Balakrishnan, submitted this Dissertation for approval on 2021-07-16 at 15:25.This Dissertation was approved for publication on 2021-07-19 at 10:22.DSpace SAF Submission Ingestion Package generated from Vireo submission #16990 on 2022-04-06 at 17:16:09Made available in DSpace on 2022-04-29T21:41:38Z (GMT). No. of bitstreams: 3
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Previous issue date: 2021-07-19Embargo set by: Seth Robbins for item 123298
Lift date: 2024-04-29T21:41:44Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 123298
Lift date: 2024-04-29T21:42:24Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 123298
Lift date: 2024-04-29T21:43:01Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 123298
Lift date: 2024-04-29T21:44:44Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 123298
Lift date: 2024-04-29T21:46:25Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 123298
Lift date: 2024-04-29T21:47:53Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Onl
Integrated Model for Hepatitis C Screening and Linkage to Care in Homeless Population
No full textThe 57th Annual Medical Student Research Forum at UT Southwestern Medical Center (Tuesday, January 22, 2019, 3-6 p.m., D1.600)BACKGROUND: Hepatitis C is a major cause of morbidity and mortality as up to 46% of people infected with Hepatitis C develop cirrhosis and up to 20% develop hepatocellular carcinoma. Over the past year, a new initiative through the DFW Hep B Free organization at the University of Texas Southwestern (UTSW) was formed to target Hepatitis C among the homeless population, starting with screening at the Union Gospel Mission's Calvert Place homeless shelter. This underserved population is vulnerable because of inadequate healthcare access and resources, in addition to other risk factors such as former incarceration and injection drug usage. The main barriers to care for a transient, homeless population are 1) their lack of access to regular healthcare and screenings, 2) their inability to receive screening results via phone or mail, and 3) the difficulty of linking patients to affordable, accessible healthcare and treatment.
METHODS: Our model integrates a student-run screening program, an on-site clinic at the shelter, and specialized hepatology services at Parkland Health Hospital System (PHHS), a local safety-net provider, to maximize the strengths that each component offers. Using OraQuick Rapid Hepatitis C Virus (HCV) tests, which screen for HCV antibodies and produce results in 20 minutes, we can deliver test results and provide counseling on the screening day. Under an IRB through a faculty hepatologist, patients that test positive are registered into Parkland Hospital's hepatitis surveillance program. The program then provides patient navigation, financial support, and treatment.
RESULTS: On average, the HCV antibody positive rate from screenings at Calvert Place is 12.7% (N=126). 100% of positive patients were contacted with their result. For patients who tested positive (n=16), 2 (12.5%) did not need care (resolved HCV). From the 14 of 16 that had active HCV infections, 50% were lost to follow up and 50% were linked to care at Parkland hepatology clinic.
CONCLUSION: Through our integrated model, we have created the foundations for a sustainable system to break down barriers to care while ultimately connecting HCV-positive homeless patients to treatment.Southwestern Medical Foundatio
Maximizing Water--Food--Energy Nexus Synergies at Basin Scale
No full textIn this short paper, we show how solutions for mitigating resource security in one sector can be found in another. We demonstrate—by means of a case study in Burkina Faso and Ghana—how investing in the electricity grid in the south leads to increase food security in the north. A new nexus framework was developed (‘MAXUS’) which was built to understand, simulate and optimize intersectoral (and international) development strategies in the water, food and energy sectors. We believe this new type of geospatial integral resource management, supported by the exponential increase of data availability of the twenty-first century, could finally turn nexus models into decision support tools.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Water Resource
Thiamin diphosphate catalysis in Escherichia coli pyruvate dehydrogenase multi-enzyme complex: activation, covalent electrophilic catalysis, and substrate channeling
No full textSpectroscopic identification and characterization of covalent and non-covalent intermediates on large enzyme complexes is an exciting and challenging area of modern enzymology. While nuclear magnetic resonance (NMR) methods which provide detailed chemical insights have been successfully employed previously, limited examples are available in the literature for large enzyme complexes. Enzymes utilizing cofactors provide promising examples for such studies when synthetic routes to labeled cofactor analogs and protocols for reconstitution of apo-enzymes with such analogs are readily available. Syntheses of key isotope enriched thiamin diphosphate (ThDP) analogs – [C2, C6’ – 13C2] ThDP, [N4’ – 15N]ThDP and [C2 – 13C]ThDP – enabled first detection of (i) various ionization/tautomerization states of ThDP during the catalytic cycle of three ThDP dependent enzymes using cross polarization magic angle spinning (CPMAS) solid state NMR (SSNMR) spectroscopy and (ii) [C2, C6’ – 13C2] ThDP covalent intermediates on the E1 component (E1p) during the catalytic cycle of E. coli pyruvate dehydrogenase multi-enzyme complex (PDHc) by filter experiments including solution 1-D 1H-13C HSQC NMR. Direct evidence was gathered for the 4’-aminopyrimidinium form (APH+) on ThDP molecules bound to (i) S. cerevisiae yeast pyruvate decarboxylase (YPDC) (ii) E1p and (iii) the E1 component of E. coli 2-oxoglutarate dehydrogenase complex (E1o) using 13C and 15N CPMAS SSNMR. The thiazolium C2-H bond was found to be slightly acidic in the cofactor bound to these enzymes. 15N SSNMR experiments confirmed the formation of the 1’,4’-iminopyrimidine tautomer in presence of substrate analogs; a mechanism is proposed for the stabilization of this biologically rare tautomer in enzyme active-sites. Using rapid chemical quench in conjunction with solution NMR, pre-steady state analyses were performed on the native PDHc and PDH complexes reconstituted with E1p active-site loop variants of very low PDHc activity. The C2-α-lactylThDP intermediate could not be detected under any of the conditions used, indicating that its formation is slower than its decarboxylation. The enamine intermediate accumulates at a rate 110 s-1 on E1p and PDHc, while the rates are 100-fold slower for the PDHc variants. 2-acetylThDP could be detected on E1p only during its reaction with pyruvate and the artificial electron acceptor DCPIP. Reductive acetylation of the lipoyl domain in a pre-steady state single turn-over experiment (a model for the E1p-E2p reductive acetyl transfer reaction) was determined by mass spectrometry. Combined, these kinetic results from artificial oxidation reactions suggest the enamine is very well stabilized by E1p and oxidation of the enamine and substrate channeling to E2p are favored by intact PDHc. These studies provide unprecedented insight into the acid-base and covalent electrophilic roles of ThDP in enzyme catalysis and the methods described herein are applicable to all such complexes.Ph.D.Includes bibliographical referencesIncludes vitaby Anand Balakrishna
Classifiers of massive and structured data problems: algorithms and applications
No full textThe last two decades have seen the emergence of vast and unprecedented data repositories. Extraordinary opportunities now present themselves for new data analysis methods that can harness these repositories. As larger and larger amounts of widely varying types of data are constantly being collected and assimilated, the
task of making use of such data opens up interesting and challenging avenues of research.
This thesis deals with specific problems in data mining and machine learning in this setting. In particular we describe algorithms and applications for classification problems where
computational restrictions become limiting (resource bounded algorithms and online/streaming algorithms) as well as models and algorithms for certain problems where the structure of the input is leveraged to provide not only accurate, but also interpretable classifiers.Ph.D.Includes bibliographical references
Recurrence-based models for improving coverage within GPS and satellite-denied mobile sensor networks
No full textThis Thesis was approved for publication on 2021-04-28 at 11:15.DSpace SAF Submission Ingestion Package generated from Vireo submission #16540 on 2021-09-16 at 17:05:08Made available in DSpace on 2021-09-17T02:34:46Z (GMT). No. of bitstreams: 3
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Previous issue date: 2021-04-28Adversarial GPS-denial and coordinate spoofing, as well as satellite jamming, serve as common obstacles to disaster-recovery and military-based teams. While such teams are often supported by UAVs that connect multiple personnel by serving as relay devices, UAV position schemes that rely on centralized controllers are also disrupted by such hurdles, as GPS and satellite-based denial will effect the ability of UAVs to communicate with the controller and drones outside line of sight. In this thesis, we design and implement a drone-relay system that allows drones to cooperatively maximize coverage in a GPS-denied and satellite-denied scenario. Here, we define coverage as the ability of one entity to speak to another entity using a drone network as an intermediate relay system and is measured as the ratio of fulfilled entity-to-entity connections to all possible entity-to-entity connections. We maximize coverage over an extended experiment duration, consisting of 300–1000 timesteps, by devising algorithms that rely on a centralized controller with full knowledge of drone and ground entity position. Particle Swarm Optimization (85% coverage), Reinforcement Learning on a Recurrent Neural Network (75% coverage), and a Time-Series based Inference Optimizer (71% coverage) were amongst the best performing movement algorithms, improving upon movement models in related works by up to 40%. We then design a distributed backend that disperses commands from a centralized controller using a distributed drone-to-drone communication scheme, also collecting observations made by each drone and relaying them to the centralized controller. This backend is additionally integrated with failure recovery and security-based protocols to ensure recovery in drone-downtime and drone-compromised scenarios; both systems feature minimal overhead, allowing drone recovery from downtime in 7% of the simulated episode length and featuring a constant time-addition from encryption that does not increase as drone count increases. Finally, we remove all notions of centrality by designing and implementing a fully decentralized system, where drones operate in squads and house their own models and decision-making protocols. In this system, drone squads are able to share observations of their surroundings with neighboring drone squads to improve predictive performance. This final system complies with GPS and satellite-denial limitations as drones only perform observations in a surrounding vision radius, assuming a camera to be mounted on each drone, and drones can only send messages to neighbors in a transmission radius, avoiding the need of sending satellite-based messages.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2023-05-01The student, Rahul Balakrishnan, accepted the attached license on 2021-04-23 at 19:58.The student, Rahul Balakrishnan, submitted this Thesis for approval on 2021-04-23 at 20:11.Embargo set by: Seth Robbins for item 118580
Lift date: 2023-09-17T02:34:57Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Onl
Mechanical properties of pressure-less sintered zirconia-magnesium aluminum silicate glass composite
No full textThe main objective of the present study was to develop a high-strength machinable ceramic based on zirconia (ZrO 2) and magnesium aluminum silicate (Mg 3Al 2Si 6O 18; MAS) glass system through pressure-less sintering. Pressure-less sintering of ZrO 2, 3 mol% yttria-stabilized (YSZ) was carried out at 1450°C in air, using 10 wt% MAS glass as a sintering additive. The influence of glass on the microstructure and mechanical properties of the composite was investigated. The presence of glass into the ZrO 2 matrix was substantiated using scanning electron microscopy (SEM). X-ray diffractometry (XRD) revealed no crystalline phases other than tetragonal ZrO 2. The flexural strength of the composite was found to be ∼30% higher than YSZ. The apparent crack resistance was determined by Vickers microindentations carried out at different loads ranging from 9.8 to 196 N. The apparent crack length on the surface at each load was found to be decreased (6-21%) in YSZ and the corresponding crack-resistance values increased by about 5-20%. Both YSZ and composite showed rising trend in crack-resistance values as the indentation load was increased. Improved properties of composite sample were attributed to the formation of a relatively larger process zone surrounding the crack, crack-arrest behavior due to the localized compressive stresses, and the crack-bridging phenomena. © The Author(s) 2011 Reprints and permissions: sagepub.co.uk/journalsPermissions. nav
Assessing Self-Care Perception in Patients Living with Type 2 Diabetes and Their Physicians
No full textThe general metadata -- e.g., title, author, abstract, subject headings, etc. -- is publicly available, but access to the submitted files is restricted to UT Southwestern campus access and/or authorized UT Southwestern users.BACKGROUND: Type 2 diabetes mellitus (T2D) is chronic illness affecting millions in the United States. Patients living with T2D require highly individualized care and significant patient effort. This effort is comprised of the patient's self-care with regards to medication, diet, lifestyle, and mental health. Self-efficacy is a patient's ability to feel agency over their illness and therefore feel able to maintain self-care. Previous literature suggests that improving a patient's self-efficacy through various behavioral health interventions may improve a patient's ability to manage their T2D. Additionally, interventions on self-efficacy are thought to work regardless of health literacy level and might be a generalizable intervention. However, while validated surveys assessing patient diabetes distress, quality-of-life, social determinants of health, adverse childhood events, and more exist, no literature was found attempting to understand a patient's perspective on their self-care, and by extension, their self-efficacy. Under the premise that consistent beliefs between patient and physician regarding self-care are necessary to make meaningful plans promoting self-care and self-efficacy, the authors developed the term self-care perception consistency to assess relationship between patient and physician perceptions of a patient's self-care.
OBJECTIVE: The objective is to assess the consistency between patient and physician perceptions of patient self-care through a biopsychosocial and structural/social determinants of health lens.
METHODS: This study uses a cross-sectional, quantitative data set obtained by the Research Residency Network of Texas (RRNeT) through a 71-item survey study. This survey was completed across 12 Family Medicine residencies in Texas and included individuals between 18-75 who were living with T2D. Responses ranged from short free response to Likert-scale based questions and covered topics such as demographics, social determinants of health, patient self-care, diabetes distress, quality-of-life, adverse childhood events, and more. The physicians of each patient were asked to complete a shorter 10-item survey with broader analogous questions to the patient survey. This data was collected through RedCap and analyzed through RStudio.
RESULTS: The term self-care perception consistency was coined to describe the relationship between the patient's and physician's perception of the patient's self-care. Self-care perception consistency was found to be lacking 31.2% of the time. Only HgA1c (p<0.01) was inversely correlated with self-care perception consistency in both the univariate and multivariate analyses of demographic factors and social determinants of health. Additional analysis was completed to assess the relationship of HgA1c control, patient diabetes distress, patient quality-of-life, and the physician survey with self-care perception consistency. Self-care perception consistent and inconsistent groups were found to have significantly different HgA1c control distributions (p < 0.01) in the subset of patients that rated their self-care positively, but no significant difference was found in the group that rated their self-care negatively. Patient self-care ratings were best correlated with their diabetes distress (p<0.01) and HgA1c (p<0.01) while physician ratings of patient self-care were best correlated with their perception of HgA1c, perception of patient diabetes distress, perception of patient quality-of-life, and perception of patient social connectedness (p<0.01 for all). Notably, trending diabetes distress, quality-of-life, the physician survey, and social determinants of health across patient self-care ratings in self-care perception consistent versus inconsistent groups revealed that only the physician survey showed opposite trends across the consistent and inconsistent groups.
CONCLUSION: Self-care perception consistency was found to be lacking 31.2% of the time. Notably, HgA1c is correlated with patient and physician perceptions of patient self-care (p<0.01 for both); however, in instances of patient-physician self-care perception inconsistency, HgA1c is not correlated with patient self-care perception. Instead, diabetes distress remains predictive of patient self-care rating in all instances (p<0.01). Patient-physician self-care perception inconsistency is also associated with inconsistency in patient and physician perceptions of the patient's diabetes distress. As diabetes distress remains consistently correlated with patient self-care rating, using the validated diabetes distress survey-17 with an additional question regarding self-care may help physicians better understand patients and therefore target appropriate education and psychosocial interventions
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