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2020

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Articles 1621 - 1650 of 15208

Full-Text Articles in Physical Sciences and Mathematics

Drastic Vegetation Change In The Guajira Peninsula (Colombia) During The Neogene, Carlos Jaramillo, Pierre Sepulchre, Damian Cardenas, Francisca Oboh-Ikuenobe, For Full List Of Authors, See Publisher's Website. Nov 2020

Drastic Vegetation Change In The Guajira Peninsula (Colombia) During The Neogene, Carlos Jaramillo, Pierre Sepulchre, Damian Cardenas, Francisca Oboh-Ikuenobe, For Full List Of Authors, See Publisher's Website.

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Dry biomes occupy ~35% of the landscape in the Neotropics, but these are heavily human-disturbed. In spite of their importance, we still do not fully understand their origins and how they are sustained. The Guajira Peninsula in northern Colombia is dominated by dry biomes and has a rich Neogene fossil record. Here, we have analyzed its changes in vegetation and precipitation during the Neogene using a fossil pollen and spore dataset of 20 samples taken from a well and we also dated the stratigraphic sequence using microfossils. In addition, we analyzed the pollen and spore contents of 10 Holocene samples …


Lead Complexation By Humic Acids And Their Analogs: A Voltammetric Study, Spencer Steinberg, Vernon Hodge Nov 2020

Lead Complexation By Humic Acids And Their Analogs: A Voltammetric Study, Spencer Steinberg, Vernon Hodge

Chemistry and Biochemistry Faculty Research

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Differential pulse polarography (DPP) was used to assess the interaction of Pb2+ with various humic acid analogs and several humic acids. DPP analysis demonstrated that the reduction peak maximum (Ep) for Pb2+ shifted to more negative values in the presence of humic acids and humic acid analogs. The observed Ep for Pb2+ in the presence of humic acids and humic acid analogs is influenced by ligand concentration, solution pH and Pb2+ concentration. Shifts in the Ep for Pb2+ are related to the reduction potential and can be rationalized using the Lingane …


Distinct Clinicopathologic Clusters Of Persons With Tdp-43 Proteinopathy, Yuriko Katsumata, Erin L. Abner, Shama Karanth, Merilee A. Teylan, Charles N. Mock, Matthew D. Cykowski, Edward B. Lee, Kevin L. Boehme, Shubhabrata Mukherjee, John S. K. Kauwe, Richard J. Kryscio, Frederick A. Schmitt, David W. Fardo, Peter T. Nelson Nov 2020

Distinct Clinicopathologic Clusters Of Persons With Tdp-43 Proteinopathy, Yuriko Katsumata, Erin L. Abner, Shama Karanth, Merilee A. Teylan, Charles N. Mock, Matthew D. Cykowski, Edward B. Lee, Kevin L. Boehme, Shubhabrata Mukherjee, John S. K. Kauwe, Richard J. Kryscio, Frederick A. Schmitt, David W. Fardo, Peter T. Nelson

Biostatistics Faculty Publications

To better understand clinical and neuropathological features of TDP-43 proteinopathies, data were analyzed from autopsied research volunteers who were followed in the National Alzheimer’s Coordinating Center (NACC) data set. All subjects (n = 495) had autopsy-proven TDP-43 proteinopathy as an inclusion criterion. Subjects underwent comprehensive longitudinal clinical evaluations yearly for 6.9 years before death on average. We tested whether an unsupervised clustering algorithm could detect coherent groups of TDP-43 immunopositive cases based on age at death and extensive neuropathologic data. Although many of the brains had mixed pathologies, four discernible clusters were identified. Key differentiating features were age at …


Literature Retrieval For Precision Medicine With Neural Matching And Faceted Summarization, Jiho Noh, Ramakanth Kavuluru Nov 2020

Literature Retrieval For Precision Medicine With Neural Matching And Faceted Summarization, Jiho Noh, Ramakanth Kavuluru

Institute for Biomedical Informatics Faculty Publications

Information retrieval (IR) for precision medicine (PM) often involves looking for multiple pieces of evidence that characterize a patient case. This typically includes at least the name of a condition and a genetic variation that applies to the patient. Other factors such as demographic attributes, comorbidities, and social determinants may also be pertinent. As such, the retrieval problem is often formulated as ad hoc search but with multiple facets (e.g., disease, mutation) that may need to be incorporated. In this paper, we present a document reranking approach that combines neural query-document matching and text summarization toward such retrieval scenarios. Our …


Oer Outdoor Ellipse Multicultural (Easter Island) Activity, Cynthia Huffman Ph.D. Nov 2020

Oer Outdoor Ellipse Multicultural (Easter Island) Activity, Cynthia Huffman Ph.D.

Faculty Submissions

This activity would fit in with a secondary or college algebra class studying conic sections, in particular ellipses, and gives students a multicultural hands-on application of the definition of an ellipse, while tracing out a full-scale model of the foundation of a hare paenga (boat house) from prehistoric Easter Island (Rapa Nui)..


Spotted Owls And Forest Fire: Comment, Gavin M. Jones, R. J. Gutiérrez, William M. Block, Peter C. Carlson, Emily J. Comfort, Samuel A. Cushman, Raymond J. Davis, Stephanie A. Eyes, Alan B. Franklin, Joseph L. Ganey, Shaula Hedwall, John J. Keane, Rodd Kelsey, Damon B, Lesmeister, Malcolm P. North, Susan L. Roberts, Jeremy T. Rockweit, Jamie S. Sanderlin, Sarah C. Sawyer, Ben Solvesky, Douglas J. Tempel, Ho Yi Wan, A. Leroy Westerling, Gary C. White, M. Zachariah Peery Nov 2020

Spotted Owls And Forest Fire: Comment, Gavin M. Jones, R. J. Gutiérrez, William M. Block, Peter C. Carlson, Emily J. Comfort, Samuel A. Cushman, Raymond J. Davis, Stephanie A. Eyes, Alan B. Franklin, Joseph L. Ganey, Shaula Hedwall, John J. Keane, Rodd Kelsey, Damon B, Lesmeister, Malcolm P. North, Susan L. Roberts, Jeremy T. Rockweit, Jamie S. Sanderlin, Sarah C. Sawyer, Ben Solvesky, Douglas J. Tempel, Ho Yi Wan, A. Leroy Westerling, Gary C. White, M. Zachariah Peery

United States Department of Agriculture Wildlife Services: Staff Publications

Western North American forest ecosystems are experiencing rapid changes in disturbance regimes because of climate change and land use legacies (Littell et al. 2018). In many of these forests, the accumulation of surface and ladder fuels from a century of fire suppression, coupled with a warming and drying climate, has led to increases in the number of large fires (Westerling 2016) and the proportion of areas burning at higher severity (Safford and Stevens 2017, Singleton et al. 2018). While the annual area burned by fire is still below historical levels (Taylor et al. 2016), some forest types in the west …


Seasonal Grassland Productivity Forecast For The U.S. Great Plains Using Grass-Cast, Melannie D. Hartman, William J. Parton, Justin D. Derner, Darin K. Schulte, William K. Smith, Dannele E. Peck, Ken A. Day, Stephen J. Del Grosso, Susan Lutz, Brian Fuchs, Maosi Chen, Wei Gao Nov 2020

Seasonal Grassland Productivity Forecast For The U.S. Great Plains Using Grass-Cast, Melannie D. Hartman, William J. Parton, Justin D. Derner, Darin K. Schulte, William K. Smith, Dannele E. Peck, Ken A. Day, Stephen J. Del Grosso, Susan Lutz, Brian Fuchs, Maosi Chen, Wei Gao

Drought Mitigation Center: Faculty Publications

Every spring, ranchers in the drought-prone U.S. Great Plains face the same difficult challenge —trying to estimate how much forage will be available for livestock to graze during the upcoming summer grazing season. To reduce this uncertainty in predicting forage availability, we developed an innovative new grassland productivity forecast system, named Grass-Cast, to provide science-informed estimates of growing season aboveground net primary production (ANPP). Grass-Cast uses over 30 yr of historical data including weather and the satellite-derived normalized vegetation difference index (NDVI)—combined with ecosystem modeling and seasonal precipitation forecasts—to predict if rangelands in individual counties are likely to produce below-normal, …


A Stable Version Of Harbourne's Conjecture And The Containment Problem For Space Monomial Curves, Eloísa Grifo Nov 2020

A Stable Version Of Harbourne's Conjecture And The Containment Problem For Space Monomial Curves, Eloísa Grifo

Department of Mathematics: Faculty Publications

The symbolic powers I(n) of a radical ideal I in a polynomial ring consist of the functions that vanish up to order n in the variety defined by I. These do not necessarily coincide with the ordinary algebraic powers In, but it is natural to compare the two notions. The containment problem consists of determining the values of n and m for which I(n)Im holds. When I is an ideal of height 2 in a regular ring, I(3)I2 may fail, but we …


Set Operation Aided Network For Action Units Detection, Huiyuan Yang, Taoyue Wang, Lijun Yin Nov 2020

Set Operation Aided Network For Action Units Detection, Huiyuan Yang, Taoyue Wang, Lijun Yin

Computer Science Faculty Research & Creative Works

As a large number of parameters exist in deep model-based methods, training such models usually requires many fully AU-annotated facial images. This is true with regard to the number of frames in two widely used datasets: BP4D [31] and DISFA [18], while those frames were captured from a small number of subjects (41, 27 respectively). This is problematic, as subjects produce highly consistent facial muscle movements, adding more frames per subject would only adds more close points in the feature space, and thus the classifier does not benefit from those extra frames. Data augmentation methods can be applied to alleviate …


Photodissociation Of Aqueous I 3 - Observed With Liquid-Phase Ultrafast Mega-Electron-Volt Electron Diffraction, K. Ledbetter, E. Biasin, J. P.F. Nunes, Martin Centurion, K. J. Gaffney, M. Kozina, M. F. Lin, X. Shen, J. Yang, X. J. Wang, T. J. A. Wolf, A. A. Cordones Nov 2020

Photodissociation Of Aqueous I 3 - Observed With Liquid-Phase Ultrafast Mega-Electron-Volt Electron Diffraction, K. Ledbetter, E. Biasin, J. P.F. Nunes, Martin Centurion, K. J. Gaffney, M. Kozina, M. F. Lin, X. Shen, J. Yang, X. J. Wang, T. J. A. Wolf, A. A. Cordones

Martin Centurion Publications

Developing femtosecond resolution methods for directly observing structural dynamics is critical to understanding complex photochemical reaction mechanisms in solution. We have used two recent developments, ultrafast mega-electron-volt electron sources and vacuum compatible sub-micron thick liquid sheet jets, to enable liquid-phase ultrafast electron diffraction (LUED). We have demonstrated the viability of LUED by investigating the photodissociation of tri-iodide initiated with a 400 nm laser pulse. This has enabled the average speed of the bond expansion to be measured during the first 750 fs of dissociation and the geminate recombination to be directly captured on the picosecond time scale.


Challenges To Select Suitable Habitats And Demonstrate ‘Additionality’ In Blue Carbon Projects: A Seagrass Case Study, Anna Lafratta, Oscar Serrano, Pere Masqué, Miguel A. Mateo, Milena Fernandes, Sam Gaylard, Paul S. Lavery Nov 2020

Challenges To Select Suitable Habitats And Demonstrate ‘Additionality’ In Blue Carbon Projects: A Seagrass Case Study, Anna Lafratta, Oscar Serrano, Pere Masqué, Miguel A. Mateo, Milena Fernandes, Sam Gaylard, Paul S. Lavery

Research outputs 2014 to 2021

© 2020 Elsevier Ltd Seagrass restoration has been suggested as a Blue Carbon (BC) strategy for climate change mitigation. For Nationally Determined Contributions (NDC) and carbon crediting schemes, BC projects need to demonstrate ‘additionality’, that is enhanced CO2 sequestration and/or avoided greenhouse gas emissions following management actions. This typically requires determining soil carbon accumulation rates (CAR), which is often done using radionuclides or surface elevation tables to estimate sedimentation rates. Here we undertook a case study, using 210Pb and 14C dating, to detect possible changes in Corg stocks and CAR following the loss and partial recovery of Posidonia seagrass meadows …


Seeing The Insurgent In Transformative Planning Practices, Efadul Huq Nov 2020

Seeing The Insurgent In Transformative Planning Practices, Efadul Huq

Environmental Science and Policy: Faculty Publications

Insurgent planning and radical planning are two of the most popular conceptual frames of reference for progressive planners and theorists of transformative planning practices. In the past decades, scholars have extended these two planning conceptions to new geographies and realities to shed light on how planning can challenge structural injustices and marginalization. However, less attention has been given to how insurgent planning renovates radical planning practices in response to the crisis of neoliberal urbanization. While appreciating that radical and insurgent planning remain braided in practice, this article contributes to the literature on transformative planning by highlighting how insurgent planning builds …


The Gauge Principle From The Schrodinger-Born Wave Mechanics, P. T. Leung Nov 2020

The Gauge Principle From The Schrodinger-Born Wave Mechanics, P. T. Leung

Physics Faculty Publications and Presentations

We propose an elementary way of introducing the gauge principle to beginners with a background in only mechanics, electromagnetism, and quantum mechanics. This evolves from an apparent conflict in the Schrodinger-Born formulation of wave mechanics, and does not have to resort to advanced concepts like covariant derivative and minimal coupling. With such an approach, one would have appreciated how interactions can be dictated from consideration of internal symmetry of a physical system, which serves as a principle underlying the foundation of almost all modern physics. In addition, the gauge principle also serves as a resource providing consistency between the Born …


College Of Natural Sciences Newsletter, November 2020, College Of Natural Sciences Nov 2020

College Of Natural Sciences Newsletter, November 2020, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 1. Issue 10

Content:

Dean’s Update P.1
Awards & Recognition P.2
Student Club Spotlight P.3
Open PRAIRIE | Interest in Science P.4
Bioethics Lecture P.5
External Advisory Board P.6
Science as Art Competition P.7


Diversity Patterns Associated With Varying Dispersal Capabilities As A Function Of Spatial And Local Environmental Variables In Small Wetlands In Forested Ecosystems, Brett M. Tornwall, Amber L. Pitt, Bryan L. Brown, Joanna Hawley-Howard, Robert F. Baldwin Nov 2020

Diversity Patterns Associated With Varying Dispersal Capabilities As A Function Of Spatial And Local Environmental Variables In Small Wetlands In Forested Ecosystems, Brett M. Tornwall, Amber L. Pitt, Bryan L. Brown, Joanna Hawley-Howard, Robert F. Baldwin

Faculty Scholarship

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. The diversity of species on a landscape is a function of the relative contribution of diversity at local sites and species turnover between sites. Diversity partitioning refers to the relative contributions of alpha (local) and beta (species turnover) diversity to gamma (regional/landscape) diversity and can be influenced by the relationship between dispersal capability as well as spatial and local environmental variables. Ecological theory predicts that variation in the distribution of organisms that are strong dispersers will be less influenced by spatial properties such as topography and connectivity of a region and …


Analyzing Yankees And Red Sox Sentiment Over The Course Of A Season, Connor Koch Nov 2020

Analyzing Yankees And Red Sox Sentiment Over The Course Of A Season, Connor Koch

Honors Projects in Data Science

This paper investigates data collected on twitter which references the Yankees or Red Sox during the 2020 Major League Baseball (MLB) season. The objective is to analyze the sentiment of tweets referencing the Yankees and Red Sox over the course of the season. In addition, an investigation of the networks within the data and the topics that were prevalent will be conducted. The 2020 MLB season was started late because of the COVID-19 pandemic and was a season like no other. The expectation of a dataset revolving around baseball is that the topics discussed would be about baseball. The findings …


The Impact Of Covid-19 On Asian Businesses And The Economy, Havovi Joshi Nov 2020

The Impact Of Covid-19 On Asian Businesses And The Economy, Havovi Joshi

Asian Management Insights

The Covid-19 pandemic will likely end when a vaccine can be made available to everyone, or when we have achieved some measure of herd immunity. Unfortunately, both are as yet nowhere in sight.


Oer Indoor Ellipse Multicultural (Easter Island) Activity, Cynthia Huffman Ph.D. Nov 2020

Oer Indoor Ellipse Multicultural (Easter Island) Activity, Cynthia Huffman Ph.D.

Faculty Submissions

This activity would fit in with a secondary or college algebra class studying conic sections, in particular ellipses, and gives students a multicultural hands-on application of the definition of an ellipse, while tracing out a scale model of the foundation of a hare paenga (boat house) from prehistoric Easter Island (Rapa Nui)..


Divide And Slide: Layer-Wise Refinement For Output Range Analysis Of Deep Neural Networks, Chao Huang, Jiameng Fan, Xin Chen, Wenchao Li, Qi Zhu Nov 2020

Divide And Slide: Layer-Wise Refinement For Output Range Analysis Of Deep Neural Networks, Chao Huang, Jiameng Fan, Xin Chen, Wenchao Li, Qi Zhu

Computer Science Faculty Publications

In this article, we present a layer-wise refinement method for neural network output range analysis. While approaches such as nonlinear programming (NLP) can directly model the high nonlinearity brought by neural networks in output range analysis, they are known to be difficult to solve in general. We propose to use a convex polygonal relaxation (overapproximation) of the activation functions to cope with the nonlinearity. This allows us to encode the relaxed problem into a mixed-integer linear program (MILP), and control the tightness of the relaxation by adjusting the number of segments in the polygon. Starting with a segment number of …


The Genetic Algorithm: Using Biology To Compute Liquid Crystal Director Configurations, Shouzhuo Yang , '23, Peter J. Collings Nov 2020

The Genetic Algorithm: Using Biology To Compute Liquid Crystal Director Configurations, Shouzhuo Yang , '23, Peter J. Collings

Physics & Astronomy Faculty Works

The genetic algorithm is an optimization routine for finding the solution to a problem that requires a function to be minimized. It accomplishes this by creating a population of solutions and then producing “offspring” solutions from this population by combining two “parental” solutions in much the way that the DNA of biological parents is combined in the DNA of offspring. Strengths of the algorithm include that it is simple to implement, no trial solution is required, and the results are fairly accurate. Weaknesses include its slow computational speed and its tendency to find a local minimum that does not represent …


Temperature-Dependent Phonon Lifetimes And Thermal Conductivity Of Silicon By Inelastic Neutron Scattering And Ab Initio Calculations, D. S. Kim, O. Hellman, N. Shulumba, C. N. Saunders, J. Y. Y. Lin, Hillary L. Smith, J. E. Herriman, J. L. Niedziela, D. L. Abernathy, C. W. Li, B. Fultz Nov 2020

Temperature-Dependent Phonon Lifetimes And Thermal Conductivity Of Silicon By Inelastic Neutron Scattering And Ab Initio Calculations, D. S. Kim, O. Hellman, N. Shulumba, C. N. Saunders, J. Y. Y. Lin, Hillary L. Smith, J. E. Herriman, J. L. Niedziela, D. L. Abernathy, C. W. Li, B. Fultz

Physics & Astronomy Faculty Works

Inelastic neutron scattering on a single crystal of silicon was performed at temperatures from 100 to 1500 K. These experimental data were reduced to obtain phonon spectral intensity at all wave vectors →Q and frequencies ω in the first Brillouin zone. Thermal broadenings of the phonon peaks were obtained by fitting and by calculating with an iterative ab initio method that uses thermal atom displacements on an ensemble of superlattices. Agreement between the calculated and experimental broadenings was good, with possible discrepancies at the highest temperatures. Distributions of phonon widths versus phonon energy had similar shapes for computation and experiment. …


An Eeg-Based Multi-Modal Emotion Database With Both Posed And Authentic Facial Actions For Emotion Analysis, Xiaotian Li, Xiang Zhang, Huiyuan Yang, Wenna Duan, Weiying Dai, Lijun Yin Nov 2020

An Eeg-Based Multi-Modal Emotion Database With Both Posed And Authentic Facial Actions For Emotion Analysis, Xiaotian Li, Xiang Zhang, Huiyuan Yang, Wenna Duan, Weiying Dai, Lijun Yin

Computer Science Faculty Research & Creative Works

Emotion is an experience associated with a particular pattern of physiological activity along with different physiological, behavioral and cognitive changes. One behavioral change is facial expression, which has been studied extensively over the past few decades. Facial behavior varies with a person's emotion according to differences in terms of culture, personality, age, context, and environment. In recent years, physiological activities have been used to study emotional responses. A typical signal is the electroencephalogram (EEG), which measures brain activity. Most of existing EEG-based emotion analysis has overlooked the role of facial expression changes. There exits little research on the relationship between …


Introduction To Special Section: Integrated Geophysical Imaging, Irina Filina, Rao Yalamanchili, Simone Re, Daniele Colombo, Antony Price, Vsevolod Egorov, Guimin Liu Nov 2020

Introduction To Special Section: Integrated Geophysical Imaging, Irina Filina, Rao Yalamanchili, Simone Re, Daniele Colombo, Antony Price, Vsevolod Egorov, Guimin Liu

Department of Earth and Atmospheric Sciences: Faculty Publications

This special section illustrates the value of integration with nonseismic geophysical methods, namely potential fields (gravity and magnetics) and electric and electromagnetic techniques. The primary objective is to overcome the overall underappreciation of these methods as exploration tools. We provide their brief overview and present nine case studies illustrating how the integrative approach to geophysical data analysis influences the overall result and reduces the uncertainty of the derived solution.


Price Elasticity And Determinants Of Residential Water Consumption In Al Ain Region, Bara Mohamad Alrefai Nov 2020

Price Elasticity And Determinants Of Residential Water Consumption In Al Ain Region, Bara Mohamad Alrefai

Civil and Environmental Theses

This thesis is concerned with the effect of water price on residential water consumption in the Al Ain region. Water demand worldwide significantly increased due to high population growth, climate change, and lifestyle changes. Fulfilling the growing water demand by constantly increasing supply has several environmental and economic implications. Water management strategies assist in driving the water industry to develop better solutions to address the increase in water demand. The UAE recently shifted its water management strategies towards demand management to reduce the growing demand in the country. Water pricing is considered one of the important tools to reduce residential …


Establishing Blockchain-Related Security Controls, Maitha Ali Mohammed Hamad Al Ketbi Nov 2020

Establishing Blockchain-Related Security Controls, Maitha Ali Mohammed Hamad Al Ketbi

Theses

Blockchain technology is a secure and relatively new technology of distributed digital ledgers which is based on interlinked blocks of transactions. There is a rapid growth in the adoption of the blockchain technology in different solutions and applications and within different industries throughout the world, such as but not limited to, finance, supply chain, digital identity, energy, healthcare, real estate and government. Blockchain technology has great benefits such as decentralization, transparency, immutability and automation. Like any other emerging technology, the blockchain technology has also several risks and threats associated with its expected benefits which in turns could have a negative …


One-Pot O-Alkylation And C-C Cross-Coupling Reactions Involving Stabilized Phosphoranes, Areej Hashim Elamin Mohamed Ali Nov 2020

One-Pot O-Alkylation And C-C Cross-Coupling Reactions Involving Stabilized Phosphoranes, Areej Hashim Elamin Mohamed Ali

Theses

This thesis is concerned with the one-pot reactions that are considered to be beneficial to preserve resources, save time, and are deemed a green chemistry strategy. To plan such one-pot reactions, it is important to combine two or more reactions that are compatible with each other and can be run under the same reaction conditions. In this work, possibilities of a combination of Wittig-olefination and Suzuki C-C-cross coupling reactions are explored further. Reaction sequences involve the combination of a Suzuki-reaction / Wittig olefination, a Suzuki reaction / Wittig olefination/hydrolysis, and a Suzuki-reaction / double Wittig olefination. In all cases, stabilized …


2d Audio Magnetotelluric (Amt) Data Inversion Of Al-Jaww Plain Area (Al-Ain, Uae) For Groundwater Aquifer Investigations, Ahmad Esam Alaran Nov 2020

2d Audio Magnetotelluric (Amt) Data Inversion Of Al-Jaww Plain Area (Al-Ain, Uae) For Groundwater Aquifer Investigations, Ahmad Esam Alaran

Theses

The United Arab Emirates (UAE) is considered within the arid climate zone having low rates of annual rainfall. The freshwater is mainly located in shallow groundwater aquifers. Understanding the depth and extent of such aquifers is an important issue for UAE local governments and environmental agencies. Hydrogeological conditions in the UAE are strongly related to the topographic features and are dominated by a mountain range in Oman at the eastern margin of the Arabian Platform. The alluvial plains such as Al-Jaww plain (eastern Al-Ain city) is considered as an important potential source of groundwater for the Al-Ain region. Al-Jaww plain …


Determination Of Vitamin D Metabolites And Their Epimers In Obese Emirati Population, Bashar Hiatham Alzohily Nov 2020

Determination Of Vitamin D Metabolites And Their Epimers In Obese Emirati Population, Bashar Hiatham Alzohily

Theses

Vitamin D deficiency is a global issue, and despite all-year-round sunshine, it is a big problem in the UAE. Obesity or overweight refers to an accumulation of excessive fat that may harm health so, it is considered a worldwide health concern. The accurate measurement of vitamin D active forms is a problematic issue. This study aimed to develop and validate a UHPLC-MS/MS method for the new method for determining vitamin D levels in the obese Emirati population. The vitamin D epimers and other metabolites were determined by UHPLC-MS/MS system, model 8060. The methods include the collection of blood samples from …


Determination Of Vitamin D Metabolites And Their Epimers In Obese Emirati Population, Bashar Hiatham Alzohily Nov 2020

Determination Of Vitamin D Metabolites And Their Epimers In Obese Emirati Population, Bashar Hiatham Alzohily

Theses

Vitamin D deficiency is a global issue, and despite all-year-round sunshine, it is a big problem in the UAE. Obesity or overweight refers to an accumulation of excessive fat that may harm health; so, it is considered a worldwide health concern. The accurate measurement of vitamin D active forms is a problematic issue. The aim of this study was to develop and validate a UHPLC-MS/MS method for the determination of vitamin D metabolites and their epimers and then apply the new method for the determination of vitamin D levels in the obese Emirati population. The vitamin D epimers and other …


Mass Spectrometric Determination Of Retinol In Emirati Population, Israa Samir Mohamed Shawky El-Konaissi Nov 2020

Mass Spectrometric Determination Of Retinol In Emirati Population, Israa Samir Mohamed Shawky El-Konaissi

Theses

This thesis is concerned with analysing vitamin A deficiency. Vitamin A is crucial for several functions, including vision, growth, and cell differentiation. the main aim is to develop and validate an LC-MS/MS method for the determination of vitamin A in plasma matrix and use the new method for the determination of vitamin A levels in the obese Emirati population. Methods: A positive ion electrospray ionisation (ESI) LC-MS/MS method was used in the Multiple Reaction Monitoring (MRM) mode for quantification. It involved i) LC-MS/MS, ii) a guard column together with C18 Ascentis Express F5 column iii) Internal standard, 25-Hydroxyvitamin D3 (6, …