Search results for: Sir Geoffrey Jackson

Authors: W. Wen, G. Jackson, S. Maskill, D. G. McCartney, W. Sun

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CoNiCrAlY alloys have been widely used as bond coats for thermal barrier coating (TBC) systems because of low cost, improved control of composition, and the feasibility to tailor the coatings microstructures. Coatings are in general very thin structures, and therefore it is impossible to characterize the mechanical responses of the materials via conventional mechanical testing methods. Due to this reason, miniature specimen testing methods, such as the small punch test technique, have been developed. This paper presents some of the recent research in evaluating the mechanical properties of the CoNiCrAlY coatings at room and high temperatures, through the use of small punch testing and the developed miniature specimen tensile testing, applicable to a range of temperature, to investigate the elastic-plastic and creep behavior as well as ductile-brittle transition temperature (DBTT) behavior. An inverse procedure was developed to derive the mechanical properties from such tests for the coating materials. A two-layer specimen test method is also described. The key findings include: 1) the temperature-dependent coating properties can be accurately determined by the miniature tensile testing within a wide range of temperature; 2) consistent DBTTs can be identified by both the SPT and miniature tensile tests (~ 650 °C); and 3) the FE SPT modelling has shown good capability of simulating the early local cracking. In general, the temperature-dependent material behaviors of the CoNiCrAlY coating has been effectively characterized using miniature specimen testing and inverse method.

Keywords: NiCoCrAlY coatings, mechanical properties, DBTT, miniature specimen testing

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Authors: Mojgan Rabiey, Shyamali Roy, Billy Quilty, Ryan Creeth, George Sundin, Robert W. Jackson

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Bacterial canker is a major disease of Prunus species such as cherry (Prunus avium). It is caused by Pseudomonas syringae species including P. syringae pv. syringae (Pss) and P. syringae pv. morsprunorum race 1 (Psm1) and race 2 (Psm2). Concerns over the environmental impact of, and developing resistance to, copper controls call for alternative approaches to disease management. One method of control could be achieved using naturally occurring bacteriophage (phage) infective to the bacterial pathogens. Phages were isolated from soil, leaf, and bark of cherry trees in five locations in the South East of England. The phages were assessed for their host range against strains of Pss, Psm1, and Psm2. The phages exhibited a differential ability to infect and lyse different Pss and Psm isolates as well as some other P. syringae pathovars. However, the phages were unable to infect beneficial bacteria such as Pseudomonas fluorescens. A subset of 18 of these phages were further characterised genetically (Random Amplification of Polymorphic DNA-PCR fingerprinting and sequencing) and using electron microscopy. The phages are tentatively identified as belonging to the order Caudovirales and the families Myoviridae, Podoviridae, and Siphoviridae, with genetic material being dsDNA. Future research will fully sequence the phage genomes. The efficacy of the phage, both individually and in cocktails, to reduce disease progression in vivo will be investigated to understand the potential for practical use of these phages as biocontrol agents.

Keywords: bacteriophage, pseudomonas, bacterial cancker, biological control

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Authors: Hainan Chen, Jina Qing, Xiao Zhu, Ling Gao, Ampadu O. Jackson, Min Zhang, Kai Yin

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Objective: Editing macrophage activation to dampen inflammatory diseases by promoting the repolarization of inflammatory (M1) macrophages to anti-inflammatory (M2) macrophages is highly associated with mitochondrial respiration. Recent studies have suggested that mitochondrial apolipoprotein A-1 binding protein (APOA1BP) was essential for the cellular metabolite NADHX repair to NADH, which is necessary for the mitochondrial function. The exact role of APOA1BP in the repolarization of M1 to M2, however, is uncertain. Material and method: THP-1-derived macrophages were incubated with LPS (10 ng/ml) or/and IL-4 (100 U/ml) for 24 hours. Biochemical parameters of oxidative phosphorylation and M1/M2 markers were analyzed after overexpression of APOA1BP in cells. Results: Compared with control and IL-4-exposed M2 cells, APOA1BP was downregulated in M1 macrophages. APOA1BP restored the decline in mitochondrial function to improve metabolic and phenotypic reprogramming of M1 to M2 macrophages. Blocking oxidative phosphorylation by oligomycin blunts the effects of APOA1BP on M1 to M2 repolarization. Mechanistically, LPS triggered the hydration of NADH and increased its hydrate NADHX which inhibit cellular NADH dehydrogenases, a key component of electron transport chain for oxidative phosphorylation. APOA1BP decreased the level of NADHX via converting R-NADHX to biologically useful S-NADHX. The mutant of APOA1BP aspartate188, the binding site of NADHX, fail to repair oxidative phosphorylation, thereby preventing repolarization. Conclusions: Restoring mitochondrial function by increasing mitochondrial APOA1BP might be useful to improve the reprogramming of inflammatory macrophages into anti-inflammatory cells to control inflammatory diseases.

Keywords: inflammatory diseases, macrophage repolarization, mitochondrial respiration, apolipoprotein A-1 binding protein, NADHX, NADH

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Authors: Harriet Kebirungi, Majaliwa Jackson-Gilbert Mwanjalolo, S. Livingstone Luboobi, Richard Joseph Kimwaga, Consolata Kabonesa

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This paper assessed gender responsiveness of water and sanitation policies and legal frameworks at Makerere University, Uganda. The objectives of the study were to i) examine the gender responsiveness of water and sanitation related policies and frameworks implemented at Makerere University; and ii) assess the challenges faced by the University in customizing national water and sanitation policies and legal frameworks into University policies. A cross-sectional gender-focused study design was adopted. A checklist was developed to analyze national water and sanitation policies and legal frameworks and University based policies. In addition, primary data was obtained from Key informants at the Ministry of Water and Environment and Makerere University. A gender responsive five-step analytical framework was used to analyze the collected data. Key findings indicated that the policies did not adequately address issues of gender, water and sanitation and the policies were gender neutral consistently. The national policy formulation process was found to be gender blind and not backed by situation analysis of different stakeholders including higher education institutions like Universities. At Makerere University, due to lack of customized and gender responsive water and sanitation policy and implementation framework, there were gender differences and deficiencies in access to and utilization of water and sanitation facilities. The University should take advantage of existing expertise within them to customize existing national water policies and gender, and water and sanitation sub-sector strategy. This will help the University to design gender responsive, culturally acceptable and environmental friendly water and sanitation systems that provide adequate water and sanitation facilities that address the needs and interests of male and female students.

Keywords: gender, Makerere University, policies, water, sanitation

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Authors: Tingting Huang, Sha Li, Geoffrey Griffiths, Martin Lukac, Jianning Zhu

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Territorial landscapes have experienced a gradual loss of their typical characteristics during long-term human activities. In order to protect the integrity of regional landscapes, it is necessary to characterize, evaluate and protect them in a graded manner. The study takes Fujian, China, as an example and classifies the landscape characters of the site at the regional scale, middle scale, and detailed scale. A multi-scale approach combining parametric and holistic approaches is used to classify and partition the landscape character types (LCTs) and landscape character areas (LCAs) at different scales, and a multi-element landscape assessment approach is adopted to explore the conservation strategies of the landscape character. Firstly, multiple fields and multiple elements of geography, nature and humanities were selected as the basis of assessment according to the scales. Secondly, the study takes a parametric approach to the classification and partitioning of landscape character, Principal Component Analysis, and two-stage cluster analysis (K-means and GMM) in MATLAB software to obtain LCTs, combines with Canny Operator Edge Detection Algorithm to obtain landscape character contours and corrects LCTs and LCAs by field survey and manual identification methods. Finally, the study adopts the Landscape Sensitivity Assessment method to perform landscape character conservation analysis and formulates five strategies for different LCAs: conservation, enhancement, restoration, creation, and combination. This multi-scale identification approach can efficiently integrate multiple types of landscape character elements, reduce the difficulty of broad-scale operations in the process of landscape character conservation, and provide a basis for landscape character conservation strategies. Based on the natural background and the restoration of regional characteristics, the results of landscape character assessment are scientific and objective and can provide a strong reference in regional and national scale territorial spatial planning.

Keywords: parameterization, multi-scale, landscape character identify, landscape character assessment

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Authors: Jackson Simon Lusagalika, Lai Hsin-Chih, Dai Yu-Tung

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Particles with an aerodynamic diameter of 2.5 meters or less are referred to as "fine particulate matter" (PM₂.₅) are easily inhaled and can go deeper into the lungs than other particles in the atmosphere, where it may have detrimental health consequences. In this study, we use a hybrid model that combined CMAQ and AERMOD as well as initial meteorological fields from the Weather Research and Forecasting (WRF) model to study the impact of power plant PM₂.₅ emissions in South Taiwan since it frequently experiences higher PM₂.₅ levels. A specific date of March 3, 2022, was chosen as a result of a power outage that prompted the bulk of power plants to shut down. In some way, it is not conceivable anywhere in the world to turn off the power for the sole purpose of doing research. Therefore, this catastrophe involving a power outage and the shutdown of power plants offers a great occasion to evaluate the impact of air pollution driven by this power sector. As a result, four numerical experiments were conducted in the study using the Continuous Emission Data System (CEMS), assuming that the power plants continued to function normally after the power outage. The hybrid model results revealed that power plants have a minor impact in the study region. However, we examined the accumulation of PM₂.₅ in the study and discovered that once the vortex at 925hPa was established and moved to the north of Taiwan's coast, the study region experienced higher observed PM₂.₅ concentrations influenced by meteorological factors. This study recommends that decision-makers take into account not only control techniques, specifically emission reductions, but also the atmospheric and meteorological implications for future investigations.

Keywords: PM₂.₅ concentration, powerplants, hybrid air quality model, CEMS, Vorticity

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Authors: Jackson Niyongabo

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This study addresses a notable gap in the existing literature on the relationship between energy consumption, economic growth, and CO₂ emissions, particularly within the African context. While numerous studies have explored these dynamics globally and regionally across various development levels, few have delved into the nuances of regions and income levels specific to African countries. Furthermore, the evaluation of the interplay between green growth policies, green energy technologies, and their impact on environmental quality has been underexplored. This research aims to fill these gaps by conducting a comprehensive analysis of the transition from conventional economic growth and energy consumption to a paradigm of green growth coupled with green energy utilization across the African continent from 1980 to 2018. The study is structured into three main parts: an empirical examination of the long-term effects of energy intensity, renewable energy consumption, and economic growth on CO₂ emissions across diverse African regions and income levels; an estimation of the long-term impact of green growth and green energy use on CO₂ emissions for countries implementing green policies within Africa, as well as at regional and global levels; and a comparative analysis of the impact of green growth policies on environmental degradation before and after implementation. Employing advanced econometric methods and panel estimators, the study utilizes a testing framework, panel unit tests, and various estimators to derive meaningful insights. The anticipated results and conclusions will be elucidated through causality tests, impulse response, and variance decomposition analyses, contributing valuable knowledge to the discourse on sustainable development in the African context.

Keywords: economic growth, green growth, energy consumption, CO₂ emissions, econometric models, green energy

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Authors: Viveka Jackson, Erouscilla Joseph, Denise Beckles, Thomas Christopher

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Sulphur Dioxide (SO2) has been defined as a non-flammable, non-explosive, colourless gas, having a pungent, irritating odour, and is one of the main gases emitted from volcanoes. Sulphur dioxide has been recorded in concentrations hazardous to humans (0.25 – 0.5 ppm (~650 – 1300 μg/m3), downwind of many volcanoes and hence warrants constant air-quality monitoring around these sites. It has been linked to an increase in chronic respiratory disease attributed to long-term exposures and alteration in lung and other physiological functions attributed to short-term exposures. Sulphur Springs in Saint Lucia is a highly active geothermal area, located within the Soufrière Volcanic Centre, and is a park widely visited by tourists and locals. It is also a current source of continuous volcanic emissions via its many fumaroles and bubbling pools, warranting concern by residents and visitors to the park regarding the effects of exposure to these gases. In this study, we introduce a novel SO2 measurement system for the monitoring and quantification of ambient levels of airborne volcanic SO2 using low-cost technology. This work involves the extensive production of low-cost SO2 monitors/samplers, as well as field examination in tandem with standard commercial samplers (SO2 diffusion tubes). It also incorporates community involvement in the volcanic monitoring process as non-professional users of the instrument. We intend to present the preliminary monitoring results obtained from the low-cost samplers, to identify the areas in the Park exposed to high concentrations of ambient SO2, and to assess the feasibility of the instrument for non-professional use and application in volcanic settings

Keywords: ambient SO2, community-based monitoring, risk-reduction, sulphur springs, low-cost

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Authors: Allan Kiptanui Kimisto, Geoffrey Odhiambo Ongondo, Anastasia Wairimu Muia, Cyrus Ndungu Kimani

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The major challenge to proper sewage sludge treatment processes is the poor understanding of sludge microbiome diversities. This study applied the whole-genome. shotgun metagenomics technique to profile the microbial composition of sewage sludge in two active digestion lagoons at the Nyeri-Kangemi Wastewater Treatment Plant in Nyeri County, Kenya. Total microbial community DNA was extracted from samples using the available ZymoBIOMICS™ DNA Miniprep Kit and sequenced using Shotgun metagenomics. Samples were analyzed using MG-RAST software (Project ID: mgp100988), which allowed for comparing taxonomic diversity before β-diversities studies for Bacteria, Archaea and Eukaryotes. The study identified 57 phyla, 145 classes, 301 orders, 506 families, 963 genera, and 1980 species. Bacteria dominated the microbes and comprised 28 species, 51 classes, 110 orders, 243 families, 597 genera, and 1518 species. The Bacteroides(6.77%) were dominant, followed by Acinetobacter(1.44%) belonging to the Gammaproteobacteria and Acidororax (1.36%), Bacillus (1.24%) and Clostridium (1.02%) belonging to Betaproteobacteria. Archaea recorded 5 phyla, 13 classes, 19 orders, 29 families, 60 genera,and87 species, with the dominant genera being Methanospirillum (16.01%), methanosarcina (15.70%), and Methanoregula(14.80%) and Methanosaeta (8.74%), Methanosphaerula(5.48%) and Methanobrevibacter(5.03%) being the subdominant group. The eukaryotes were the least in abundance and comprised 24 phyla, 81 classes, 301 orders, 506 families, 963 genera, and 980 species. Arabidopsis (4.91%) and Caenorhabditis (4.81%) dominated the eukaryotes, while Dityostelium (3.63%) and Drosophila(2.08%) were the subdominant genera. All these microbes play distinct roles in the anaerobic treatment process of sewage sludge. The local sludge microbial composition and abundance variations may be due to age difference differences between the two digestion lagoons in operation at the plant and the different degradation rales played by the taxa. The information presented in this study can help in the genetic manipulation or formulation of optimal microbial ratios to improve their effectiveness in sewage sludge treatment. This study recommends further research on how the different taxa respond to environmental changes over time and space.

Keywords: shotgun metagenomics, sludge, bacteria, archaea, eukaryotes

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Authors: Milton Ixquiac, Erick Montenegro, Francisco Reynoso, Matthew Schmidt, Thomas Mazur, Tianyu Zhao, Hiram Gay, Geoffrey Hugo, Lauren Henke, Jeff Michael Michalski, Angel Velarde, Vicky de Falla, Franky Reyes, Osmar Hernandez, Edgar Aparicio Ruiz, Baozhou Sun

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Purpose: Radiotherapy departments in low- and middle-income countries (LMICs) like Guatemala have recently introduced intensity-modulated radiotherapy (IMRT). IMRT has become the standard of care in high-income countries (HIC) due to reduced toxicity and improved outcomes in some cancers. The purpose of this work is to show the agreement between the dosimetric results shown in the Dose Volume Histograms (DVH) to the objectives proposed in the adopted protocol. This is the initial experience with an O-ring Linac. Methods and Materials: An O-Linac Linac was installed at our clinic in Guatemala in 2019 and has been used to treat approximately 90 patients daily with IMRT. This Linac is a completely Image Guided Device since to deliver each radiotherapy session must take a Mega Voltage Cone Beam Computerized Tomography (MVCBCT). In each MVCBCT, the Linac deliver 9 UM, and they are taken into account while performing the planning. To start the standardization, the TG263 was employed in the nomenclature and adopted a hypofractionated protocol to treat ChestWall, including supraclavicular nodes achieving 40.05Gy in 15 fractions. The planning was developed using 4 semiarcs from 179-305 degrees. The planner must create optimization volumes for targets and Organs at Risk (OARs); the difficulty for the planner was the dose base due to the MVCBCT. To evaluate the planning modality, we used 30 chestwall cases. Results: The plans created manually achieve the protocol objectives. The protocol objectives are the same as the RTOG1005, and the DHV curves look clinically acceptable. Conclusions: Despite the O-ring Linac doesn´t have the capacity to obtain kv images, the cone beam CT was created using MV energy, the dose delivered by the daily image setup process still without affect the dosimetric quality of the plans, and the dose distribution is acceptable achieving the protocol objectives.

Keywords: hypofrationation, VMAT, chestwall, radiotherapy planning

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Authors: Maurício N. Kleinberg, Ana P. R. N. Barroso, Frederico R. Silva, Natasha l. Gomes, Rodrigo F. Guimarães, Marcelo M. V. Parente, Jackson Q. Malveira

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Increased production of biofuels, especially biodiesel, as an option to replace the diesel derived from oil is already a reality in countries seeking a renewable and environmentally friendly fuel, as is the case in Brazil. However, it is known that the use of fuels, renewable or not, implies that it is in contact with various metallic materials which may cause corrosion. In the search for more corrosion resistant materials has been experimentally observed that the addition of molybdenum in ferritic steels increases their protective character without significantly burdening the cost of production. In order to evaluate the effect of adding molybdenum, samples of commercial steel (austenitic, ferritic and carbon steel) and the experimental ferritic alloy with a high molybdenum content (5.3%) were immersed separately into biodiesel derived from transesterification of soy oil to monitor the corrosion process of these metal samples, and in parallel to analyze the oxidative degradation of biodiesel itself. During the immersion time of 258 days, biodiesel samples were taken for analysis of acidity, kinematic viscosity, density and refraction. Likewise, the metal samples were taken from the biodiesel to be weighed and microstructurally analyzed by light microscopy. The results obtained at the end of 258 days shown that biodiesel presented a considerable increase on the values of the studied parameters for all the samples. However, this increase was not able to produce significant mass loss in metallic samples. As regards the microstructural analysis, it showed the onset of surface oxidation on the carbon steel sample. As for the other samples, no significant surface changes were shown. These results are consistent with literature for short immersion times. It is concluded that the increase in the values of the studied parameters is not significant yet, probably due to the low time of immersion and exposure of the samples. Thus, it is necessary to continue the tests so that the objectives of this work are achieved.

Keywords: biodiesel, corrosion, immersion, experimental alloy

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Authors: Hercules Argyropoulos, Thomas F. Johnson, Nigel B Jackson, Kalliopi Zourna, Daniel G. Bracewell

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Lipid encapsulation has become essential in drug delivery, notably for mRNA vaccines during the COVID-19 pandemic. However, their sterile filtration poses challenges due to the risk of deformation, filter fouling and product loss from adsorption onto the membrane. Choosing the right filtration membrane is crucial to maintain sterility and integrity while minimizing product loss. The objective of this study is to develop a rigorous analytical framework utilizing confocal microscopy and filtration blocking models to elucidate the fouling mechanisms of liposomes as a model system for this class of delivery vehicle during sterile filtration, particularly in response to variations in transmembrane pressure (TMP) during the filtration process. Experiments were conducted using fluorescent Lipoid S100 PC liposomes formulated by micro fluidization and characterized by Multi-Angle Dynamic Light Scattering. Dual-layer PES/PES and PES/PVDF membranes with 0.2 μm pores were used for filtration under constant pressure, cycling from 30 psi to 5 psi and back to 30 psi, with 5, 6, and 5-minute intervals. Cross-sectional membrane samples were prepared by microtome slicing and analyzed with confocal microscopy. Liposome characterization revealed a particle size range of 100-140 nm and an average concentration of 2.93x10¹¹ particles/mL. Goodness-of-fit analysis of flux decline data at varying TMPs identified the intermediate blocking model as most accurate at 30 psi and the cake filtration model at 5 psi. Membrane resistance analysis showed atypical behavior compared to therapeutic proteins, with resistance remaining below 1.38×10¹¹ m⁻¹ at 30 psi, increasing over fourfold at 5 psi, and then decreasing to 1-1.3-fold when pressure was returned to 30 psi. This suggests that increased flow/shear deforms liposomes enabling them to more effectively navigate membrane pores. Confocal microscopy indicated that liposome fouling mainly occurred in the upper parts of the dual-layer membrane.

Keywords: sterile filtration, membrane resistance, microfluidization, confocal microscopy, liposomes, filtration blocking models

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Authors: Bambang Antoro, Lasito Soebari, Geoffrey de Jong, Fernandy Meiriyanto, Michael Siahaan, Eko Wibowo, Pormando Silalahi, Ruswanto, Adi Budirumantyo

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The Ertsberg East Skarn System (EESS) is located in the Ertsberg Mining District, Papua, Indonesia. EESS is a sub-vertical zone of copper-gold mineralization hosted in both diorite (vein-style mineralization) and skarn (disseminated and vein style mineralization). Deep Mill Level Zone (DMLZ) is a mining zone in the lower part of East Ertsberg Skarn System (EESS) that product copper and gold. The Deep Mill Level Zone deposit is located below the Deep Ore Zone deposit between the 3125m to 2590m elevation, measures roughly 1,200m in length and is between 350 and 500m in width. DMLZ planned start mined on Q2-2015, being mined at an ore extraction rate about 60,000 tpd by the block cave mine method (the block cave contain 516 Mt). Mineralization and associated hydrothermal alteration in the DMLZ is hosted and enclosed by a large stock (The Main Ertsberg Intrusion) that is barren on all sides and above the DMLZ. Late porphyry dikes that cut through the Main Ertsberg Intrusion are spatially associated with the center of the DMLZ hydrothermal system. DMLZ orebody hosted in diorite and skarn, both dominantly by vein style mineralization. Percentage Material Mined at DMLZ compare with current Reserves are diorite 46% (with 0.46% Cu; 0.56 ppm Au; and 0.83% EqCu); Skarn is 39% (with 1.4% Cu; 0.95 ppm Au; and 2.05% EqCu); Hornfels is 8% (with 0.84% Cu; 0.82 ppm Au; and 1.39% EqCu); and Marble 7 % possible mined waste. Correlation between Ertsberg intrusion, major structure, and vein style mineralization is important to determine characteristic orebody in DMLZ Mine. Generally Deep Mill Level Zone has 2 type of vein filling mineralization from both hosted (diorite and skarn), in diorite hosted the vein system filled by chalcopyrite-bornite-quartz and pyrite, in skarn hosted the vein filled by chalcopyrite-bornite-pyrite and magnetite without quartz. Based on orientation the stockwork vein at diorite hosted and shallow vein in skarn hosted was generally NW-SE trending and NE-SW trending with shallow-moderate dipping. Deep Mill Level Zone control by two main major faults, geologist founded and verified local structure between major structure with NW-SE trending and NE-SW trending with characteristics slickenside, shearing, gauge, water-gas channel, and some has been re-healed.

Keywords: copper-gold, DMLZ, skarn, structure

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Authors: Samson Obiene, Khamati Shilabukha, Geoffrey Muga, James Kairo

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Mangroves play a vital role in the achievement of multiple goals of global sustainable development (SDG’s), particularly SDG SDG 14 (life under water). Their management, however, is faced with several shortcomings arising from inadequate knowledge on the perceptions of their ecosystem services, hence a need to map mangrove goods and services within SDGs while interrogating the disaggregated perceptions. This study therefore aimed at exploring the parities and disparities in attitudes and perceptions of mangrove ecosystem services among community members of Vanga and the link of the ecosystem services (ESs) to specific SDG targets. The study was based at the Kenya-Tanzania transboundary area in Vanga; where a carbon-offset project on mangroves is being up scaled. Mixed methods approach employing surveys, focus group discussions (FGDs) and reviews of secondary data were used in the study. A two stage cluster samplings was used to select the study population and the sample size. FGDs were conducted purposively selecting active participants in mangrove related activities with distinct socio-demographic characteristics. Sampled respondents comprised of males and females of different occupations and age groups. Secondary data review was used to select specific SDG targets against which mangrove ecosystem services identified through a value chain analysis were mapped. In Vanga, 20 ecosystem services were identified and categorized under supporting, cultural and aesthetic, provisioning and regulating services. According to the findings of this study, 63.9% (95% ci 56.6-69.3) perceived of the ESs as very important for economic development, 10.3% (95% ci 0-21.3) viewed them as important for environmental and ecological development while 25.8% (95% ci 2.2-32.8) were not sure of any role they play in development. In the social-economic disaggregation, ecosystem service values were found to vary with the level of interaction with the ecosystem which depended on gender and other social-economic classes within the study area. The youths, low income earners, women and those with low education levels were also identified as the primary beneficiaries of mangrove ecosystem services. The study also found that of the 17 SDGs, mangroves have a potential of influencing the achievement 12, including, SDGs 1, 2, 3, 4, 6, 8 10, 12, 13, 14, 15 and 17 either directly or indirectly. Generally therefore, the local community is aware of the critical importance mangroves for enhanced livelihood and ecological services but challenges in sustainability still occur as a result the diverse values and of the services and the contradicting interests of the different actors around the ecosystem. It is therefore important to consider parities in values and perception to avoid a ‘tragedy of the commons’ while striving to enhance sustainability of the Mangrove ecosystem.

Keywords: sustainable development, community values, socio-demographics, Vanga, mangrove ecosystem services

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Authors: Cait M. Henry, Sarah Jackson

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Abstract-This study is built from the culmination of four years of research into the cultural interpretation of Civil War heritage at a National Park Service (NPS) site, namely the Manassas National Battlefield Park, within an increasingly contentious political landscape surrounding the U.S. Civil War. Originating as questions regarding the relevancy of historic battlefields to the current culture within the United States soon evolved into more philosophical questions about what it means to feel welcome at a battlefield site, and what are considered appropriate actions and behaviors at what was once a mass gravesite. In trying to answer these questions, this work aims to critically analyze the confluence between the cultural authority of the NPS and collective memories of the U.S. Civil War. Operationalizing trauma as repeated violent acts within public spaces, the authors posit that the normalization of violence from white or white-passing men partially stems from the glorification of heroic white masculinity at National Park Service Civil War battlefield sites—especially those which also commemorate Confederate military strategy and prowess. From here the study moves outward to focus on the prevalence of heroic white masculinity within the nation’s current social zeitgeist, and particularly the notion that to take back masculinity one must utilize violence as a means of symbolic restoration from perceptions of white victimhood. The study ends with case studies of dark tourism framing at international battlefields as models for expanding heritage interpretation at the NPS site to foster narratives of empathy and responsibility within an increasingly contentious political landscape within the United States of America. Visitors do not leave Manassas National Battlefield Park with answers about the social and moral implications of the U.S. Civil War, but the tools for championing their own (predominantly white) heroic masculinity. As such, it is only logical that one common reaction when masculinity is symbolically threatened is to enact violence against Others as a restorative force within the United States.

Keywords: confederate heritage, military history, national park service, trauma, United States civil war

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Authors: Macie Matta, Ahmad Jabri, Stephanie Jackson

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Introduction: In the absence of hypotension, pulmonary embolism (PE) causing right ventricular dysfunction or strain, whether confirmed by imaging or cardiac biomarkers, is deemed to be an intermediate-risk category. Urgent treatment of intermediate-risk PE can prevent progression to hemodynamic instability and death. Management options include thrombolysis, thrombectomy, or systemic anticoagulation. We aim to evaluate the short-term outcomes of a half-dose tissue plasminogen activator (tPA) for the management of intermediate-risk PE. Methods: We retrospectively identified adult patients diagnosed with intermediate-risk PE between the years 2000 and 2021. Demographic data, lab values, imaging, treatment choice, and outcomes were all obtained through chart review. Primary outcomes measured include major bleeding events and in-hospital mortality. Patients on standard systemic anticoagulation without receiving thrombolysis or thrombectomy served as controls. Patient data were analyzed using SAS®️ Software (version 9.4; Cary, NC) to compare individuals that received half-dose tPA with controls, and statistical significance was set at a p-value of 0.05. Results: We included 57 patients in our final analysis, with 19 receiving tPA. Patient characteristics and comorbidities were comparable between both groups. There was a significant difference between PE location, presence of acute deep vein thrombosis, and peak troponin level between both groups. The thrombolytic cohort was more likely to demonstrate a 60/60 sign and thrombus in transit finding on echocardiography than controls. The thrombolytic group was more likely to have major bleeding (17% vs 7.9%, p= 0.4) and in-hospital mortality (5.3% vs 0%, p=0.3); however, this was not statistically significant. Patients who received half-dose tPA had non-significantly higher rates of major bleeding and in-hospital mortality. Larger scale, randomized control trials are needed to establish the benefit and safety of thrombolytics in patients with intermediate-risk PE.

Keywords: pulmonary embolism, half dose thrombolysis, tissue plasminogen activator, cardiac biomarkers, echocardiographic findings, major bleeding event

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Authors: Todd Jackson

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In this randomized control trial, we tested the effectiveness of a peer-facilitated version of the Body Project (BP) intervention among body-dissatisfied young women in China. Participants were randomly assigned to a peer-facilitator BP condition (N = 94) versus an educational video minimal intervention control condition (N = 89). Questionnaire measures of two primary outcomes (i.e., disordered eating and body dissatisfaction) and six secondary outcomes (thin-ideal internalization, pressure to be thin, negative affect, body surveillance, body shame, body appreciation and interest in cosmetic surgery) were administered at a pre-treatment baseline, a post-treatment assessment, and at a 12-month follow-up. A series of 2 (Group) x 2 (Time) analyses of variance indicated women in the peer-facilitated BP condition reported significant improvements in primary outcome measures of disordered eating and body dissatisfaction compared to women in the educational video control condition following treatment and at the 12-month follow-up. Furthermore, women in the peer-facilitated BP condition reported significant improvements in measures of body surveillance, body shame and body appreciation) compared to educational video controls that extended to the 12-month follow-up. Finally, although women in the peer-facilitated BP condition showed significant post-treatment improvements in thin-ideal internalization, negative affect, perceived pressure to be thin, and interest in cosmetic surgery compared to video controls, these differences were no longer statistically significant at the 12-month follow-up. In conclusion, findings supported the overall effectiveness of a peer-facilitated group version of the BP as an intervention for reducing disordered eating and several associated risk factors among at-risk young women in China.

Keywords: body project, disordered eating, body dissatisfaction, risk factors, prevention, China

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Authors: N. Dunleavy, E. Lovemore, K. Siljeur, D. Jackson, M. Hendricks, M. Hoosain, N. Plastow, S. Marais

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Background: The work requirements of sewing machine operators cause physical and emotional strain. Past ergonomic interventions have been provided to alleviate physical concerns; however, a holistic, multimodal intervention was needed to improve these factors. Aim: The study aimed to examine the effect of an occupational therapy programme on sewing machine operators’ pain, mental health, and productivity within a factory in the South African context. Methods: A pilot randomised control trial was conducted with 22 sewing machine operators within a single factory. Stratified randomisation was used to determine the experimental (EG) and control groups (CG), using measures for pain intensity, level of depression (mental health), and productivity rates as stratification variables. The EG received the multimodal intervention, incorporating education, seating adaptations, and mental health intervention. In three months, the CG will receive the same intervention. Pre- and post-intervention testing have occurred with upcoming three- and six-month follow-ups. Results: Immediate results indicate a statistically significant decrease in pain in both experimental and control groups; no change in productivity scores and depression between the two groups. This may be attributed to external factors. The values for depression further showed no statistical significance between the two groups and within pre-and post-test results. The Statistical Program for Social Sciences (SPSS) version-24 was used as the data analysis testing, where all the tests will be evaluated at a 5% significance level. Contribution of research: The research adds to the body of knowledge informing the Occupational Therapy role in work settings, providing evidence on the effectiveness of workplace-based multimodal interventions. Conclusion: The study provides initial data on the effectiveness of a pilot randomised control trial on pain and mental health in South Africa. Results indicated no quantitative change between the experimental and control groups; however, qualitative data suggest a clinical significance of the findings.

Keywords: ergonomics programme, occupational therapy, sewing machine operators, workplace-based multimodal interventions

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Authors: Jackson Andreas Theo Pola, Leksono Mucharam, Hari Oetomo, Budi Susanto, Wisnu Nugraha

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About half of the world oil reserves are located in carbonate reservoirs, where 65% of the total carbonate reservoirs are oil wet and 12% intermediate wet [1]. Oil recovery in oil wet or mixed wet carbonate reservoirs can be increased by dissolving surfactant to injected water to change the rock wettability from oil wet to more water wet. The Wakamuk Field operated by PetroChina International (Bermuda) Ltd. and PT. Pertamina EP in Papua, produces from main reservoir of Miocene Kais Limestone. First production commenced on August, 2004 and the peak field production of 1456 BOPD occurred in August, 2010. It was found that is a complex reservoir system and until 2014 cumulative oil production was 2.07 MMBO, less than 9% of OOIP. This performance is indicative of presence of secondary porosity, other than matrix porosity which is of low average porosity 13% and permeability less than 7 mD. Implementing chemical EOR in this case is the best way to increase oil production. However, the selected chemical must be able to lower the interfacial tension (IFT), reduce oil viscosity, and alter the wettability; thus a special chemical treatment named SeMAR has been proposed. Numerous laboratory tests such as phase behavior test, core compatibility test, mixture viscosity, contact angle measurement, IFT, imbibitions test and core flooding were conducted on Wakamuk field samples. Based on the spontaneous imbibitions results for Wakamuk field core, formulation of SeMAR with compositional S12A gave oil recovery 43.94% at 1wt% concentration and maximum percentage of oil recovery 87.3% at 3wt% concentration respectively. In addition, the results for first scenario of core flooding test gave oil recovery 60.32% at 1 wt% concentration S12A and the second scenario gave 96.78% of oil recovery at concentration 3 wt% respectively. The soaking time of chemicals has a significant effect on the recovery and higher chemical concentrations affect larger areas for wettability and therefore, higher oil recovery. The chemical that gives best overall results from laboratory tests study will also be a consideration for Huff and Puff injections trial (pilot project) for increasing oil recovery from Wakamuk Field

Keywords: Wakamuk field, chemical treatment, oil recovery, viscosity

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Authors: Gerald Steyn

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Despite the huge number of identical, tiny, boxy, freestanding houses built by the South African government after the advent of democracy in 1994, squatter camps continue to mushroom, and there is no evidence that the backlog is being reduced. Not only is the wasteful low-density detached-unit approach of the past being perpetuated, but the social, spatial, and economic marginalization is worse than before 1994. The situation is precarious since squatters are vulnerable to fires and flooding. At the same time, the occupants of the housing schemes are trapped far from employment opportunities or any public amenities. Despite these insecurities, the architectural, urban design, and city planning professions are puzzlingly quiet. Design projects address these issues only at the universities, albeit inevitably with somewhat Utopian notions. Geoffrey Payne, the renowned urban housing and urban development consultant and researcher focusing on issues in the Global South, once proclaimed that “we do not have a housing problem – we have a settlement problem.” This dictum was used as the guiding philosophy to conceptualize urban design and architectural principles that foreground the needs of low-income households and allow them to be fully integrated into the larger conurbation. Information was derived from intensive research over two decades, involving frequent visits to informal settlements, historic Black townships, and rural villages. Observations, measured site surveys, and interviews resulted in several scholarly articles from which a set of desirable urban and architectural criteria could be extracted. To formulate culturally appropriate design principles, existing vernacular and informal patterns were analyzed, reconciled with contemporary designs that align with the requirements for the envisaged settlement attributes, and reimagined as residential design principles. Five interrelated design principles are proposed, ranging in scale from (1) Integrating informal settlements into the city, (2) linear neighborhoods, (3) market streets as wards, (4) linear neighborhoods, and (5) typologies and densities for clustered and aggregated patios and courtyards. Each design principle is described, first in terms of its context and associated issues of concern, followed by a discussion of the patterns available to inform a possible solution, and finally, an explanation and graphic illustration of the proposed design. The approach is predominantly bottom-up since each of the five principles is unfolded from existing informal and vernacular practices studied in situ. They are, however, articulated and represented in terms of contemporary design language. Contrary to an idealized vision of housing for South Africa’s low-income urban households, this study proposes actual principles for critical assessment by peers in the tradition of architectural research in design.

Keywords: culturally appropriate design principles, informal settlements, South Africa’s housing backlog, squatter camps

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Authors: Mehak Burza

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As we pause to observe the Holocaust Remembrance Day each year on 27 January, it becomes important to consider how the Holocaust is witnessed, and its education is perceived across the globe. The dissemination of knowledge of the Holocaust becomes more pertinent in the countries that were not directly affected by it. The Holocaust education is not widespread in Asian countries and is thus not mandatory as an academic discipline for school and university students. One such Asian country that often considers Holocaust as an isolated event is India. Though the struggle for freedom began with the 1857 mutiny (the first war of Indian independence) but the freedom revolts gained momentum specifically during the years 1944-1947, when India was steeped in a battery of rebellions. However, freedom for the Indian subcontinent from the domination of British Raj came at the cost of partition of India that resulted in widespread bloodshed and immigration. For India, it is this backdrop of her freedom struggle that always outweighs the incidents of the Second World War, including the catastrophic event of the Holocaust. As a result, the knowledge about the Holocaust is available through secondary sources such as Holocaust documentaries and movies. Besides Anne Frank’s diary, the knowledge about the Holocaust is disseminated through the course readings in the universities. The most common literary acquaintances with the Jewish faith for university students are when they come across the Jewish characters in their course readings. The Prioress’s Tale in Geoffrey Chaucer’s Canterbury Tales, the character of Shylock in William Shakespeare’s The Merchant of Venice, and the Jewish protagonist, Barabas, in Christopher Marlow’s Jew of Malta. Apart from this, the school textbooks mention a detailed chapter on Holocaust and Hitler, which is an encouraging turn. However, there still exists a yawning gap between dissemination and sensitization of Holocaust education owing to different geographical locales. My paper presentation aims to trace the intersectional elements between India and the Holocaust that can serve as the required pivotal stand-board to foster sensitization towards Holocaust education in the Indian subcontinent. For instance, Maharaja Jam SahebDigvijaysinhjiRanjitsinhji, the ruler of Nawanagar, a princely state in British India, helped save thousand Polish Jewish children in 1945 at the time when India herself was steeped in its struggle for freedom. Famously known as the ‘Indian Oskar Schindler’ Polish government has named a street after him in Krakow, Poland. Another example that deserves mention is the spy princess, Noor Inayat Khan, a descendent of Tipu Sultan, who became the most celebrated British spyand fought against the Nazis. Additionally, by offering refuge to Jews, India has proved to be a distant haven for them. Researching further the domain of Jewish refugees in India will not only illuminate a dull/gray zone of investigation but also enable the educators to provide appropriate entry points for introducing the subject of Shoah/Holocaust in India, a subject which unfortunately hitherto is either seldom discussed or is equated with the Partition of India.

Keywords: awareness, dissemination, holocaust, India

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Authors: Petr Daniel Edward Kovarik, Malcolm Jackson, Charles Kelly, Rahul Patil, Shahid Iqbal

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Introduction: Recognition of the presence of extra capsular spread (ECS) has been a major change in the TNM 8th edition published by the American Joint Committee on Cancer in 2018. Irrespective of the size or number of lymph nodes, the presence of ECS makes N3b disease a stage IV disease. The objective of this retrospective observational study was to conduct a comparative analysis of survival outcomes in patients with lymph node-positive cutaneous head and neck squamous cell carcinoma (CHNSCC) based on their TNM 7th and TNM 8th editions classification. Materials and Methods: From January 2010 to December 2020, 71 patients with CHNSCC were identified from our centre’s database who were treated with radical surgery and adjuvant radiotherapy. All histopathological reports were reviewed, and comprehensive nodal mapping was performed. The data were collected retrospectively and survival outcomes were compared using TNM 7th and 8th editions. Results: The median age of the whole group of 71 patients was 78 years, range 54 – 94 years, 63 were male and 8 female. In total, 2246 lymph nodes were analysed; 195 were positive for cancer. ECS was present in 130 lymph nodes, which led to a change in TNM staging. The details on N-stage as per TNM 7th edition was as follows; pN1 = 23, pN2a = 14, pN2b = 32, pN2c = 0, pN3 = 2. After incorporating the TNM 8th edition criterion (presence of ECS), the details on N-stage were as follows; pN1 = 6, pN2a = 5, pN2b = 3, pN2c = 0, pN3a = 0, pN3b = 57. This showed an increase in overall stage. According to TNM 7th edition, there were 23 patients were with stage III and remaining 48 patients, stage IV. As per TNM 8th edition, there were only 6 patients with stage III as compared to 65 patients with stage IV. For all patients, 2-year disease specific survival (DSS) and overall survival (OS) were 70% and 46%. 5-year DSS and OS rates were 66% and 20% respectively. Comparing the survival between stage III and stage IV of the two cohorts using both TNM 7th and 8th editions, there is an obvious greater survival difference between the stages if TNM 8th staging is used. However, meaningful statistics were not possible as the majority of patients (n = 65) were with stage IV and only 6 patients were stage III in the TNM 8th cohort. Conclusion: Our study provides a comprehensive analysis on lymph node data mapping in this specific patient population. It shows a better differentiation between stage III and stage IV in the TNM 8th edition as compared to TNM 7th however meaningful statistics were not possible due to the imbalance of patients in the sub-cohorts of the groups.

Keywords: cutaneous head and neck squamous cell carcinoma, extra capsular spread, neck lymphadenopathy, TNM 7th and 8th editions

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Authors: Stefano Zaninotto, Geoffrey Farrugia, Johan Debattista, Jason Gauci

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The need to reduce fuel and noise during taxi operations in the airports with a scenario of constantly increasing air traffic has resulted in an effort by the aerospace industry to move towards electric taxiing. In fact, this is one of the problems that is currently being addressed by SESAR JU and two main solutions are being proposed. With the first solution, electric motors are installed in the main (or nose) landing gear of the aircraft. With the second solution, manned or unmanned electric tow trucks are used to tow aircraft from the gate to the runway (or vice-versa). The presence of the tow trucks results in an increase in vehicle traffic inside the airport. Therefore, it is important to design the system in a way that the workload of Air Traffic Control (ATC) is not increased and the system assists ATC in managing all ground operations. The aim of this work is to develop an electric taxiing system, based on the use of autonomous tow trucks, which optimizes aircraft ground operations while keeping ATC in the loop. This system will consist of two components: an optimization tool and a Graphical User Interface (GUI). The optimization tool will be responsible for determining the optimal path for arriving and departing aircraft; allocating a tow truck to each taxiing aircraft; detecting conflicts between aircraft and/or tow trucks; and proposing solutions to resolve any conflicts. There are two main optimization strategies proposed in the literature. With centralized optimization, a central authority coordinates and makes the decision for all ground movements, in order to find a global optimum. With the second strategy, called decentralized optimization or multi-agent system, the decision authority is distributed among several agents. These agents could be the aircraft, the tow trucks, and taxiway or runway intersections. This approach finds local optima; however, it scales better with the number of ground movements and is more robust to external disturbances (such as taxi delays or unscheduled events). The strategy proposed in this work is a hybrid system combining aspects of these two approaches. The GUI will provide information on the movement and status of each aircraft and tow truck, and alert ATC about any impending conflicts. It will also enable ATC to give taxi clearances and to modify the routes proposed by the system. The complete system will be tested via computer simulation of various taxi scenarios at multiple airports, including Malta International Airport, a major international airport, and a fictitious airport. These tests will involve actual Air Traffic Controllers in order to evaluate the GUI and assess the impact of the system on ATC workload and situation awareness. It is expected that the proposed system will increase the efficiency of taxi operations while reducing their environmental impact. Furthermore, it is envisaged that the system will facilitate various controller tasks and improve ATC situation awareness.

Keywords: air traffic control, electric taxiing, autonomous tow trucks, graphical user interface, ground operations, multi-agent, route optimization

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Authors: Animesh Pan, Geoffrey D. Bothun

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With the development of nanotechnology, research in multifunctional delivery systems has a new pace and dimension. An incipient challenge is to design an all-in-one delivery system that can be used for multiple purposes, including tumor targeting therapy, radio-frequency (RF-), near-infrared (NIR-), light-, or pH-induced controlled release, photothermal therapy (PTT), photodynamic therapy (PDT), and medical diagnosis. In this regard, various inorganic nanoparticles (NPs) are known to show great potential as the 'functional components' because of their fascinating and tunable physicochemical properties and the possibility of multiple theranostic modalities from individual NPs. Magnetic, luminescent, and plasmonic properties are the three most extensively studied and, more importantly biomedically exploitable properties of inorganic NPs. Although successful attempts of combining any two of them above mentioned functionalities have been made, integrating them in one system has remained challenge. Keeping those in mind, controlled designs of complex colloidal nanoparticle system are one of the most significant challenges in nanoscience and nanotechnology. Therefore, systematic and planned studies providing better revelation are demanded. We report a multifunctional delivery platform-based liposome loaded with drug, iron-oxide magnetic nanoparticles (MNPs), and a gold shell on the surface of liposomes, were synthesized using a lipid with polyelectrolyte (layersomes) templating technique. MNPs and the anti-cancer drug doxorubicin (DOX) were co-encapsulated inside liposomes composed by zwitterionic phophatidylcholine and anionic phosphatidylglycerol using reverse phase evaporation (REV) method. The liposomes were coated with positively charge polyelectrolyte (poly-L-lysine) to enrich the interface with gold anion, exposed to a reducing agent to form a gold nanoshell, and then capped with thio-terminated polyethylene glycol (SH-PEG2000). The core-shell nanostructures were characterized by different techniques like; UV-Vis/NIR scanning spectrophotometer, dynamic light scattering (DLS), transmission electron microscope (TEM). This multifunctional system achieves a variety of functions, such as radiofrequency (RF)-triggered release, chemo-hyperthermia, and NIR laser-triggered for photothermal therapy. Herein, we highlight some of the remaining major design challenges in combination with preliminary studies assessing therapeutic objectives. We demonstrate an efficient loading and delivery system to significant cell death of human cancer cells (A549) with therapeutic capabilities. Coupled with RF and NIR excitation to the doxorubicin-loaded core-shell nanostructure helped in securing targeted and controlled drug release to the cancer cells. The present core-shell multifunctional system with their multimodal imaging and therapeutic capabilities would be eminent candidates for cancer theranostics.

Keywords: cancer thernostics, multifunctional nanostructure, photothermal therapy, radiofrequency targeting

Procedia PDF Downloads 128

Authors: Joseph Mwiti Marangu, Joseph Karanja Thiong'o, Jackson Muthengia Wachira

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The mechanical performance of hydrated cements mortars mainly depends on its compressive strength and setting time. These properties are crucial in the construction industry. Pozzolana based cements are mostly characterized by low 28 day compressive strength and long setting times. These are some of the major impediments to their production and diverse uses despite numerous technological and environmental benefits associated with them. The study investigated the effects of potential chemical activators on calcined clay- Portland cement blends with an aim to achieve high early compressive strength and shorter setting times in cement mortar. In addition, standard consistency, soundness and insoluble residue of all cement categories was determined. The test cement was made by blending calcined clays with Ordinary Portland Cement (OPC) at replacement levels from 35 to 50 percent by mass of the OPC to make test cement labeled PCC for the purposes of this study. Mortar prisms measuring 40mmx40mmx160mm were prepared and cured in accordance with KS EAS 148-3:2000 standard. Solutions of Na2SO4, NaOH, Na2SiO3 and Na2CO3 containing 0.5- 2.5M were separately added during casting. Compressive strength was determined at 2rd, 7th, 28th and 90th day of curing. For comparison purposes, commercial Portland Pozzolana cement (PPC) and Ordinary Portland Cement (OPC) were also investigated without activators under similar conditions. X-Ray Florescence (XRF) was used for chemical analysis while X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) were used for mineralogical analysis of the test samples. The results indicated that addition of activators significantly increased the 2nd and 7th day compressive strength but minimal increase on the 28th and 90th day compressive strength. A relatively linear relationship was observed between compressive strength and concentration of activator solutions up to 28th of curing. Addition of the said activators significantly reduced both initial and final setting time. Standard consistency and soundness varied with increased amount of clay in the test cement and concentration of activators. Amount of insoluble residues increased with increased replacement of OPC with calcined clays. Mineralogical studies showed that N-A-S-H is formed in addition to C-S-H. In conclusion, the concentration of 2 molar for all activator solutions produced the optimum compressive strength and greatly reduced the setting times for all cement mortars.

Keywords: activators, admixture, cement, clay, pozzolana

Procedia PDF Downloads 261

Authors: Pamela R. Jackson, Andrea Hawkins-Daarud, Cassandra R. Rickertsen, Kamala Clark-Swanson, Scott A. Whitmire, Kristin R. Swanson

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Glioblastoma Multiforme (GBM), the most common primary brain tumor, often presents with hyperintensity on T2-weighted or T2-weighted fluid attenuated inversion recovery (T2/FLAIR) magnetic resonance imaging (MRI). This hyperintensity corresponds with vasogenic edema, however there are likely many infiltrating tumor cells within the hyperintensity as well. While MRIs do not directly indicate tumor cells, MRIs do reflect the microenvironmental water abnormalities caused by the presence of tumor cells and edema. The inherent heterogeneity and resulting MRI features of GBMs complicate assessing disease response. To understand how hyperintensity on T2/FLAIR MRI may correlate with edema in the extracellular space (ECS), a multi-compartmental MRI signal equation which takes into account tissue compartments and their associated volumes with input coming from a mathematical model of glioma growth that incorporates edema formation was explored. The reasonableness of two possible extracellular space schema was evaluated by varying the T2 of the edema compartment and calculating the possible resulting T2s in tumor and peripheral edema. In the mathematical model, gliomas were comprised of vasculature and three tumor cellular phenotypes: normoxic, hypoxic, and necrotic. Edema was characterized as fluid leaking from abnormal tumor vessels. Spatial maps of tumor cell density and edema for virtual tumors were simulated with different rates of proliferation and invasion and various ECS expansion schemes. These spatial maps were then passed into a multi-compartmental MRI signal model for generating simulated T2/FLAIR MR images. Individual compartments’ T2 values in the signal equation were either from literature or estimated and the T2 for edema specifically was varied over a wide range (200 ms – 9200 ms). T2 maps were calculated from simulated images. T2 values based on simulated images were evaluated for regions of interest (ROIs) in normal appearing white matter, tumor, and peripheral edema. The ROI T2 values were compared to T2 values reported in literature. The expanding scheme of extracellular space is had T2 values similar to the literature calculated values. The static scheme of extracellular space had a much lower T2 values and no matter what T2 was associated with edema, the intensities did not come close to literature values. Expanding the extracellular space is necessary to achieve simulated edema intensities commiserate with acquired MRIs.

Keywords: extracellular space, glioblastoma multiforme, magnetic resonance imaging, mathematical modeling

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Authors: Ariyan S. Araghi, Guy C. Jackson, Stephen J. Bonsor

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Materials & Methods: A systematic literature search was undertaken using pre-determined inclusion and exclusion criteria. This review followed the Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA) statement. Several databases were used to search for randomised control trials and longitudinal cohort studies, which were published less than thirty years ago. A total of 54 studies met the predefined inclusion criteria. Four studies reviewed the success, survival, and failure characteristics of zirconia framework resin retained bridges, whilst two reviewed non-precious metal resin retained bridges. Results: The analysis of the studies revealed an overall survival rate of 95.9% for zirconia-based restorations compared to 90.7% for non-precious metal frameworks. Non-precious metal resin retained bridges displayed a higher overall failure rate of 11.9% compared to 4.6% for zirconia-based restorations in the analysed papers. The most frequent complications were wing debonding for the non-precious metal wing group, whereas substructure fracture and veneering ceramic fracture were more prevalent for the zirconia arm of the study. Conclusion: Both types of resin retained bridges provide effective medium to long-term survival. Zirconia-based frameworks will provide marginally increased success and survival and greatly improved aesthetics. However, catastrophic failure is more likely with zirconia-based restorations. Non-precious metal is time tested but performs worse than its zirconia counterpart with regards to longevity; it does not exhibit the same framework fractures as zirconia. Cement choice and attention to the adhesive bonding systems used appear to be paramount to restoration longevity with both restoration subtypes. Furthermore, improved longevity can be seen when air particle abrasion is incorporated into the adhesive protocol. Within the limitations of this study, it has been determined that zirconia-based resin retained bridges can be effectively used in anterior cantilever bridges. Clinical Significance: Zirconia-based resin retained bridges have been demonstrating promising results in terms of improved success and survival characteristics, together with improved aesthetics when compared to non-precious metal winged resin retained bridges. Their popularity is increasing in the age of digital dentistry as many restorations are manufactured using such technology. It is essential that clinicians understand the limitations of each material type and principles of adhesion to ensure restoration longevity.

Keywords: resin retained bridge, fixed partial denture, zirconia bridge, adhesive bridge

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Authors: Sonia Boscenco, Zihan Wang, Euclides José de Mendoça Filho, João Paulo Hoppe, Irina Pokhvisneva, Geoffrey B.C. Hall, Michael J. Meaney, Patricia Pelufo Silveira

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Entropy can be described as a measure of the number of states of a system, and when used in the context of physiological time-based signals, it serves as a measure of complexity. In functional connectivity data, entropy can account for the moment-to-moment variability that is neglected in traditional functional magnetic resonance imaging (fMRI) analyses. While brain fMRI resting state entropy has been associated with some pathological conditions like schizophrenia, no investigations have explored the association between brain entropy measures and individual differences in child behavior in healthy children. We describe a novel exploratory approach to evaluate brain fMRI resting state data in two child cohorts, and MAVAN (N=54, 4.5 years, 48% males) and GUSTO (N = 206, 4.5 years, 48% males) and its associations to child behavior, that can be used in future research in the context of child exposures and long-term health. Following rs-fMRI data pre-processing and Shannon entropy calculation across 32 network regions of interest to acquire 496 unique functional connections, partial correlation coefficient analysis adjusted for sex was performed to identify associations between entropy data and Strengths and Difficulties questionnaire in MAVAN and Child Behavior Checklist domains in GUSTO. Significance was set at p < 0.01, and we found eight significant associations in GUSTO. Negative associations were found between two frontoparietal regions and cerebellar posterior and oppositional defiant problems, (r = -0.212, p = 0.006) and (r = -0.200, p = 0.009). Positive associations were identified between somatic complaints and four default mode connections: salience insula (r = 0.202, p < 0.01), dorsal attention intraparietal sulcus (r = 0.231, p = 0.003), language inferior frontal gyrus (r = 0.207, p = 0.008) and language posterior superior temporal gyrus (r = 0.210, p = 0.008). Positive associations were also found between insula and frontoparietal connection and attention deficit / hyperactivity problems (r = 0.200, p < 0.01), and insula – default mode connection and pervasive developmental problems (r = 0.210, p = 0.007). In MAVAN, ten significant associations were identified. Two positive associations were found = with prosocial scores: the salience prefrontal cortex and dorsal attention connection (r = 0.474, p = 0.005) and the salience supramarginal gyrus and dorsal attention intraparietal sulcus (r = 0.447, p = 0.008). The insula and prefrontal connection were negatively associated with peer problems (r = -0.437, p < 0.01). Conduct problems were negatively associated with six separate connections, the left salience insula and right salience insula (r = -0.449, p = 0.008), left salience insula and right salience supramarginal gyrus (r = -0.512, p = 0.002), the default mode and visual network (r = -0.444, p = 0.009), dorsal attention and language network (r = -0.490, p = 0.003), and default mode and posterior parietal cortex (r = -0.546, p = 0.001). Entropy measures of resting state functional connectivity can be used to identify individual differences in brain function that are correlated with variation in behavioral problems in healthy children. Further studies applying this marker into the context of environmental exposures are warranted.

Keywords: child behaviour, functional connectivity, imaging, Shannon entropy

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Authors: D. Hilton

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The importance and significance of this research is based upon the fundamental knowledge reported in the scientific literature that physical activity is inversely associated with obesity. In addition, it is recognized there is a global epidemic of sedentariness while at the same time it is known that morbidity and mortality are associated with physical inactivity and as a result of overweight or obesity. Hence this small study in school students is an important area of research in our community. An application submitted in 2005 for the inaugural Public Health Education Research Trust [PHERT] Post Graduate Research Scholarship scheme organized by the Public Health Association of Australia [PHAA] was awarded 3rd place within Australia. The author and title was: D. Hilton, Methods to increase physical activity in school aged children [literature review, a trial using pedometers and a policy paper]. Third place is a good result, however this did not secure funding for the project, as only first place received $5000 funding. Some years later within Australia, a program commenced called the Global Children's Challenge [GCC]. Given details of the 2005 award above were included an application submission prepared for Parkhill Primary School [PPS] which is located in Victoria, Australia was successful. As a result, an excited combined grade 3/ 4 class at the school [27 students] in 2012 became recipients of these free pedometers. Ambassadors for the program were Mrs Catherine Freeman [OAM], Olympic Gold Medalist – Sydney 2000 [400 meters], while another ambassador was Mr Colin Jackson [CBE] who is a Welsh former sprint and hurdling athlete. In terms of PPS and other schools involved in 2012, website details show that the event started on 19th Sep 2012 and students were to wear the pedometer every day for 50 days [at home and at school] aiming for the recommended 15,000 steps/day recording steps taken in a booklet provided. After the finish, an analysis of the average step count for this school showed that the average steps taken / day was 14, 003 [however only a small percentage of students returned the booklets and units] as unfortunately the dates for the program coincided with school holidays so some students either forgot or misplaced the units / booklets. Unfortunately funding for this program ceased in 2013, however the lasting impact of the trial on student’s knowledge and awareness remains and in fact becomes a good grounding for students in how to monitor basic daily physical activity using a method that is easy, fun, low cost and readily accessible.

Keywords: walking, physical activity, exercise, Australian school

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Authors: Christi Jackson, Chuka Onaga

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Introduction: We report a case of delayed diagnosis of extra-pulmonary INH-mono-resistant Tuberculosis (TB) in a South African patient with drug-resistant HIV. Case Presentation: A 36-year old male was initiated on 1st line (NNRTI-based) anti-retroviral therapy (ART) in September 2009 and switched to 2nd line (PI-based) ART in 2011, according to local guidelines. He was following up at the outpatient wellness unit of a public hospital, where he was diagnosed with Protease Inhibitor resistant HIV in March 2016. He had an HIV viral load (HIVVL) of 737000 copies/mL, CD4-count of 10 cells/µL and presented with complaints of productive cough, weight loss, chronic diarrhoea and a septic buttock wound. Several investigations were done on sputum, stool and pus samples but all were negative for TB. The patient was treated with antibiotics and the cough and the buttock wound improved. He was subsequently started on a 3rd-line ART regimen of Darunavir, Ritonavir, Etravirine, Raltegravir, Tenofovir and Emtricitabine in May 2016. He continued losing weight, became too weak to stand unsupported and started complaining of abdominal pain. Further investigations were done in September 2016, including a urine specimen for Line Probe Assay (LPA), which showed M. tuberculosis sensitive to Rifampicin but resistant to INH. A lymph node biopsy also showed histological confirmation of TB. Management and outcome: He was started on Rifabutin, Pyrazinamide and Ethambutol in September 2016, and Etravirine was discontinued. After 6 months on ART and 2 months on TB treatment, his HIVVL had dropped to 286 copies/mL, CD4 improved to 179 cells/µL and he showed clinical improvement. Pharmacy supply of his individualised drugs was unreliable and presented some challenges to continuity of treatment. He successfully completed his treatment in June 2017 while still maintaining virological suppression. Discussion: Several laboratory-related factors delayed the diagnosis of TB, including the unavailability of urine-lipoarabinomannan (LAM) and urine-GeneXpert (GXP) tests at this facility. Once the diagnosis was made, it presented a treatment dilemma due to the expected drug-drug interactions between his 3rd-line ART regimen and his INH-resistant TB regimen, and specialist input was required. Conclusion: TB is more difficult to diagnose in patients with severe immunosuppression, therefore additional tests like urine-LAM and urine-GXP can be helpful in expediting the diagnosis in these cases. Patients with non-standard drug regimens should always be discussed with a specialist in order to avoid potentially harmful drug-drug interactions.

Keywords: drug-resistance, HIV, line probe assay, tuberculosis

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