874 research outputs found
Hierarchical Bayesian Modeling of Spatio-temporal Patterns of Lung Cancer Incidence Risk in Georgia, USA: 2000–2007
Lung cancer is the second most commonly diagnosed cancer in both men and women in Georgia, USA. However, the spatio-temporal patterns of lung cancer risk in Georgia have not been fully studied. Hierarchical Bayesian models are used here to explore the spatio-temporal patterns of lung cancer incidence risk by race and gender in Georgia for the period of 2000–2007. With the census tract level as the spatial scale and the 2-year period aggregation as the temporal scale, we compare a total of seven Bayesian spatio-temporal models including two under a separate modeling framework and five under a joint modeling framework. One joint model outperforms others based on the deviance information criterion. Results show that the northwest region of Georgia has consistently high lung cancer incidence risk for all population groups during the study period. In addition, there are inverse relationships between the socioeconomic status and the lung cancer incidence risk among all Georgian population groups, and the relationships in males are stronger than those in females. By mapping more reliable variations in lung cancer incidence risk at a relatively fine spatio-temporal scale for different Georgian population groups, our study aims to better support healthcare performance assessment, etiological hypothesis generation, and health policy making
COMPRESSIVE BEHAVIOR OF BULK METALLIC GLASS UNDER DIFFERENT CONDITIONS —— COUPLED EFFECT OF TEMPERATURE AND STRAIN RATE
Metallic glass was first reported in 1960 by rapid quenching of Au-Si alloys. But, due to the size limitation, this material did not attract remarkable interest until the development of bulk metallic glasses (BMGs) with specimen sizes in excess of 1 mm. BMGs are considered to be promising engineering materials because of their ultrahigh strength, high elastic limit and wear resistance. However, they usually suffer from a strong tendency for localized plastic deformation with catastrophic failure. Many basic questions, such as the origin of shear softening and the strain rate effect remain unclear. In this thesis, the mechanical behavior of the Zr55Al10Ni5Cu30 bulk metallic glass and a metallic glass composite is investigated.
The stress-strain relationship for Zr55Al10Ni5Cu30 over a wide range of strain rate (5 × 10-5 to 2 × 103s-1) was investigated in uniaxial compression loading using both MTS servo-hydraulic system (quasi-static) and compression Kolsky bar system (dy- namic). The effect of the strain rate on the fracture stress at room temperature was discussed. Based on the experimental results, the strain rate sensitivity of the bulk metallic glass changes from a positive value to a negative value at high strain rate, which is a consequence of the significant adiabatic temperature rise during the dynamic testing. In order to characterize the temperature effect on the mechanical behavior of the metallic glass, a synchronically assembled heating unit was designed to be attached onto the Kolsky bar system to perform high temperature and high strain rate mechanical testing. A transition from inhomogeneous deformation to homoge-
neous deformation has been observed during the quasi-static compressive experiments at testing temperatures close to the glass transition temperature. However, no tran- sition has been observed at high strain rates at all the testing temperatures. A free volume based model is applied to analyze the stress-strain behavior of the homoge- neous deformation. To further examine the inelastic deformation of the Zr-based bulk metallic glasses, instrumented nanoindentation experiments were performed. A tran- sition from discrete plastic deformation to continuous plastic deformation was found when strain rate is increased but still within the quasi-static strain rate region. Moti- vated by the metal matrix composite material, a tungsten reinforced BMG composite was investigated at quasi-static and dynamic strain rates. The mechanical behavior of the metallic glass matrix was improved significantly by the addition of W particles
Modular Capacitated Maximal Covering Location Problem for the Optimal Siting of Emergency Vehicles
To improve the application of the maximal covering location problem (MCLP), several capacitated MCLP models were proposed to consider the capacity limits of facilities. However, most of these models assume only one fixed capacity level for the facility at each potential site. This assumption may limit the application of the capacitated MCLP. In this article, a modular capacitated maximal covering location problem (MCMCLP) is proposed and formulated to allow several possible capacity levels for the facility at each potential site. To optimally site emergency vehicles, this new model also considers allocations of the demands beyond the service covering standard. Two situations of the model are discussed: the MCMCLP-facility-constraint (FC), which fixes the total number of facilities to be located, and the MCMCLP-non-facility-constraint (NFC), which does not. In addition to the model formulations, one important aspect of location modeling—spatial demand representation—is included in the analysis and discussion. As an example, the MCMCLP is applied with Geographic Information System (GIS) and optimization software packages to optimally site ambulances for the Emergency Medical Services (EMS) Region 10 in the State of Georgia. The limitations of the model are also discussed
Demonstration of upstream flexible 2-/4-PAM formats for practical PON deployments
Adaptive 2-/4-PAM modulation in PONs leverages the distribution of optical path losses to increase capacity. Upstream 2-/4-PAM burst transmission is demonstrated with a selectable fixed 4-tap FIR-filter, improving the performance of each gain mode of the burst-mode receive
The use of tibial Less Invasive Stabilization System (LISS) plate [AO-ASIF] for the treatment of paediatric supracondylar fracture of femur: a case report
Paediatric supracondylar fractures of the femur are not common. The treatment options depend on the age of child, the site of the fracture, the pattern of injury and the surgeon's preference. We report a case of an 11-year old boy who sustained a comminuted displaced supracondylar fracture of the femur and was treated with indirect reduction and internal fixation with the Less Invasive Stabilization System (LISS) tibial plate
Single-nucleus RNA-seq2 reveals functional crosstalk between liver zonation and ploidy.
Funder: Cancer Research UKSingle-cell RNA-seq reveals the role of pathogenic cell populations in development and progression of chronic diseases. In order to expand our knowledge on cellular heterogeneity, we have developed a single-nucleus RNA-seq2 method tailored for the comprehensive analysis of the nuclear transcriptome from frozen tissues, allowing the dissection of all cell types present in the liver, regardless of cell size or cellular fragility. We use this approach to characterize the transcriptional profile of individual hepatocytes with different levels of ploidy, and have discovered that ploidy states are associated with different metabolic potential, and gene expression in tetraploid mononucleated hepatocytes is conditioned by their position within the hepatic lobule. Our work reveals a remarkable crosstalk between gene dosage and spatial distribution of hepatocytes
Hybrid nanomaterials based on carbon nanotubes (CNTs) and nanofibers (CNFs) for electrocatalytic and biosensing application
As the field of materials science and engineering has become more well developed and advanced, the demand for highly functionalized materials with new characteristics for future purposes has risen. In particular, more and more new discoveries have merged from interdisciplinary into a central hub of hybrid nanomaterials and composites. Briefly, hybrid materials are a result of constituting with two or more components via formation of chemical and physical interactions, such as Van der Waal, hydrogen bonding, weak electrostatic interaction or covalent bonds. Herein, hybrid materials not only inherit some of merits and functions from those constituents, but also acquire some new physicochemical properties that were not present in individual components. Carbon based nanomaterials have attracted paramount attention in the materials and biosensor communities owing to a large number of their unique properties, including improved mechanical, electrical, thermal, biocompatibility and catalytic virtues. Among different allotropes of carbon ranged from 0D to 3D structures, 1D filamentous forms of carbon, in terms of carbon nanotubes (CNTs) and carbon nanofibers (CNFs), are very attractive materials for a broader research community, taking one of the striking advantages in their superior length to width ratio (>1,000) with a high specific area. Thus, there is an emerging opportunity to design and create multi-functional hybrid nanomaterials based on carbon nanomaterials with various organic/inorganic materials at the nanoscale or molecule level, exhibiting great potential in electronics, catalysis, sensors and energy conversion and storage. This dissertation includes three research thrusts using hybrid carbon nanomaterials. 1) We investigated the direct electrochemistry of glucose oxidase (GOx) entrapped into a single-wall carbon nanotubes (SWCNTs)-poly(ethylenimine) (PEI) matrix under presence of glucose. We found the direct electrochemistry and ET kinetics of the GOx were impacted by glucose and correlated to its concentration. This finding may offer a promising way for the development of reagentless or mediator-free glucose biosensors or biofuel cells. 2) We examined the synergistic effect of mingled binary metal oxide (MnO2/Co3O4) on well-aligned electrospun carbon nanofibers (WA-ECNFs) towards electrocatalytic oxidation of glucose and a non-enzymatic glucose sensor. The results demonstrate a superior electrocatalytic performance due to the nanostructure feature of the binary metal oxides interfaces. 3) We studied nitrogen dopant in ECNFs (NECNFs) for the nucleation of metal oxide nanoparticles (Co3O4) and exploited the electrochemical performance towards selective detection of dopamine. We found the N dopant could induce the nucleation and growth of cobalt oxide nanoparticles (nanograin morphology) via strong covalent coupling effect, sustaining improved catalytic effect in contrast to the smoothly deposited Co3O4 film without the N-dopant. The Co3O4@NECNFs electrode demonstrated rapid responsive and highly sensitive, in-situ, real-time monitoring dopamine secreted by living cells. In summary, the findings in this dissertation work present advanced knowledge associated with novel nanohybrid structures and the structure-property-performance. We hope this research can promote the development of new hybrid materials and composites, thereby benefiting our lives in human society. [This abstract has been edited to remove characters that will not display in this system. Please see the PDF for the full abstract.]]]>
2021
Carbon nanotubes
Carbon nanofibers
Electrocatalysis
Biosensors
Charge exchange
English
http://libres.uncg.edu/ir/uncg/f/Yin_uncg_0154D_13201.pdf
oai:libres.uncg.edu/35793
2021-07-09T21:05:59Z
UNCG
A study of Franz Liszt’s Variations on “Weinen, Klagen, Sorgen, Zagen”
NC DOCKS at The University of North Carolina at Greensboro
Yu, Xiuwei
<![CDATA[Variations on “Weinen, Klagen, Sorgen, Zagen,” S. 180 is one of Franz Liszt’s most significant but understudied piano works. Written after Liszt joined the Third Order of Saint Francis and during a time of deep personal tragedy, this composition reflects both Liszt’s religious journey and his coping with suffering and shows daring explorations of chromaticism that pushed the limits of tonality. It was arranged for organ one year after the piano version was composed and became one of his best-known compositions for organ. This study will provide a comprehensive overview of relevant studies of this piece. The first chapter provides an introduction of Franz Liszt and Variations on “Weinen, Klagen, Sorgen, Zagen,” S.180. The second chapter summarizes Franz Liszt’s religious journey. The third chapter includes an analysis of this music. The fourth chapter shows a detailed comparison between the piano version and organ version. The last chapter concludes this study with a summary
On-Line Adaptive Radiation Therapy: Feasibility and Clinical Study
The purpose of this paper is to evaluate the feasibility and clinical dosimetric benefit of an on-line, that is, with the patient in the treatment position, Adaptive Radiation Therapy (ART) system for prostate cancer treatment based on daily cone-beam CT imaging and fast volumetric reoptimization of treatment plans. A fast intensity-modulated radiotherapy (IMRT) plan reoptimization algorithm is implemented and evaluated with clinical cases. The quality of these adapted plans is compared to the corresponding new plans generated by an experienced planner using a commercial treatment planning system and also evaluated by an in-house developed tool estimating achievable dose-volume histograms (DVHs) based on a database of existing treatment plans. In addition, a clinical implementation scheme for ART is designed and evaluated using clinical cases for its dosimetric qualities and efficiency
Deep sequencing identifies novel and conserved microRNAs in peanuts (Arachis hypogaea L.)
<p>Abstract</p> <p>Background</p> <p>MicroRNAs (miRNAs) are a new class of small, endogenous RNAs that play a regulatory role in the cell by negatively affecting gene expression at the post-transcriptional level. miRNAs have been shown to control numerous genes involved in various biological and metabolic processes. There have been extensive studies on discovering miRNAs and analyzing their functions in model species, such as <it>Arabidopsis </it>and rice. Increasing investigations have been performed on important agricultural crops including soybean, conifers, and <it>Phaselous vulgaris </it>but no studies have been reported on discovering peanut miRNAs using a cloning strategy.</p> <p>Results</p> <p>In this study, we employed the next generation high through-put Solexa sequencing technology to clone and identify both conserved and species-specific miRNAs in peanuts. Next generation high through-put Solexa sequencing showed that peanuts have a complex small RNA population and the length of small RNAs varied, 24-nt being the predominant length for a majority of the small RNAs. Combining the deep sequencing and bioinformatics, we discovered 14 novel miRNA families as well as 75 conserved miRNAs in peanuts. All 14 novel peanut miRNAs are considered to be species-specific because no homologs have been found in other plant species except ahy-miRn1, which has a homolog in soybean. qRT-PCR analysis demonstrated that both conserved and peanut-specific miRNAs are expressed in peanuts.</p> <p>Conclusions</p> <p>This study led to the discovery of 14 novel and 22 conserved miRNA families from peanut. These results show that regulatory miRNAs exist in agronomically important peanuts and may play an important role in peanut growth, development, and response to environmental stress.</p
Machine-Part cell formation through visual decipherable clustering of Self Organizing Map
Machine-part cell formation is used in cellular manufacturing in order to
process a large variety, quality, lower work in process levels, reducing
manufacturing lead-time and customer response time while retaining flexibility
for new products. This paper presents a new and novel approach for obtaining
machine cells and part families. In the cellular manufacturing the fundamental
problem is the formation of part families and machine cells. The present paper
deals with the Self Organising Map (SOM) method an unsupervised learning
algorithm in Artificial Intelligence, and has been used as a visually
decipherable clustering tool of machine-part cell formation. The objective of
the paper is to cluster the binary machine-part matrix through visually
decipherable cluster of SOM color-coding and labelling via the SOM map nodes in
such a way that the part families are processed in that machine cells. The
Umatrix, component plane, principal component projection, scatter plot and
histogram of SOM have been reported in the present work for the successful
visualization of the machine-part cell formation. Computational result with the
proposed algorithm on a set of group technology problems available in the
literature is also presented. The proposed SOM approach produced solutions with
a grouping efficacy that is at least as good as any results earlier reported in
the literature and improved the grouping efficacy for 70% of the problems and
found immensely useful to both industry practitioners and researchers.Comment: 18 pages,3 table, 4 figure
- …