Search results for: combined loading
1327 Cannabidiol (CBD) Resistant Salmonella Strains Are Susceptible to Epsilon 34 Phage Tailspike Protein
Authors: Ibrahim Iddrisu, Joseph Ayariga, Junhuan Xu, Ayomide Adebanjo, Boakai K. Robertson, Michelle Samuel-Foo, Olufemi Ajayi
Abstract:
The rise of antimicrobial resistance is a global public health crisis that threatens the effective control and prevention of infections. Due to the emergence of pan drug-resistant bacteria, most antibiotics have lost their efficacy. Bacteriophages or their components are known to target bacterial cell walls, cell membranes, and lipopolysaccharides (LPS) and hydrolyze them. Bacteriophages, being the natural predators of pathogenic bacteria, are inevitably categorized as ‘human friends’, thus fulfilling the adage that ‘the enemy of my enemy is my friend’. Leveraging on their lethal capabilities against pathogenic bacteria, researchers are searching for more ways to overcome the current antibiotic resistance challenge. In this study, we expressed and purified epsilon 34 phage tail spike protein (E34 TSP) from the E34 TSP gene, then assessed the ability of this bacteriophage protein in the killing of two CBD-resistant strains of Salmonella spp. We also assessed the ability of the tail spike protein to cause bacteria membrane disruption and dehydrogenase depletion. We observed that the combined treatment of CBD-resistant strains of Salmonella with CBD and E34 TSP showed poor killing ability, whereas the mono treatment with E34 TSP showed considerably higher killing efficiency. This study demonstrates that the inhibition of the bacteria by E34 TSP was due in part to membrane disruption and dehydrogenase inactivation by the protein. The results of this work provide an interesting background to highlight the crucial role phage proteins such as E34 TSP could play in pathogenic bacterial control.Keywords: cannabidiol, resistance, Salmonella, antimicrobials, phages
Procedia PDF Downloads 711326 An Open-Source Guidance System for an Autonomous Planter Robot in Precision Agriculture
Authors: Nardjes Hamini, Mohamed Bachir Yagoubi
Abstract:
Precision agriculture has revolutionized farming by enabling farmers to monitor their crops remotely in real-time. By utilizing technologies such as sensors, farmers can detect the state of growth, hydration levels, and nutritional status and even identify diseases affecting their crops. With this information, farmers can make informed decisions regarding irrigation, fertilization, and pesticide application. Automated agricultural tasks, such as plowing, seeding, planting, and harvesting, are carried out by autonomous robots and have helped reduce costs and increase production. Despite the advantages of precision agriculture, its high cost makes it inaccessible to small and medium-sized farms. To address this issue, this paper presents an open-source guidance system for an autonomous planter robot. The system is composed of a Raspberry Pi-type nanocomputer equipped with Wi-Fi, a GPS module, a gyroscope, and a power supply module. The accompanying application allows users to enter and calibrate maps with at least four coordinates, enabling the localized contour of the parcel to be captured. The application comprises several modules, such as the mission entry module, which traces the planting trajectory and points, and the action plan entry module, which creates an ordered list of pre-established tasks such as loading, following the plan, returning to the garage, and entering sleep mode. A remote control module enables users to control the robot manually, visualize its location on the map, and use a real-time camera. Wi-Fi coverage is provided by an outdoor access point, covering a 2km circle. This open-source system offers a low-cost alternative for small and medium-sized farms, enabling them to benefit from the advantages of precision agriculture.Keywords: autonomous robot, guidance system, low-cost, medium farms, open-source system, planter robot, precision agriculture, real-time monitoring, remote control, small farms
Procedia PDF Downloads 1111325 Environmental Conditions Simulation Device for Evaluating Fungal Growth on Wooden Surfaces
Authors: Riccardo Cacciotti, Jiri Frankl, Benjamin Wolf, Michael Machacek
Abstract:
Moisture fluctuations govern the occurrence of fungi-related problems in buildings, which may impose significant health risks for users and even lead to structural failures. Several numerical engineering models attempt to capture the complexity of mold growth on building materials. From real life observations, in cases with suppressed daily variations of boundary conditions, e.g. in crawlspaces, mold growth model predictions well correspond with the observed mold growth. On the other hand, in cases with substantial diurnal variations of boundary conditions, e.g. in the ventilated cavity of a cold flat roof, mold growth predicted by the models is significantly overestimated. This study, founded by the Grant Agency of the Czech Republic (GAČR 20-12941S), aims at gaining a better understanding of mold growth behavior on solid wood, under varying boundary conditions. In particular, the experimental investigation focuses on the response of mold to changing conditions in the boundary layer and its influence on heat and moisture transfer across the surface. The main results include the design and construction at the facilities of ITAM (Prague, Czech Republic) of an innovative device allowing for the simulation of changing environmental conditions in buildings. It consists of a square section closed circuit with rough dimensions 200 × 180 cm and cross section roughly 30 × 30 cm. The circuit is thermally insulated and equipped with an electric fan to control air flow inside the tunnel, a heat and humidity exchange unit to control the internal RH and variations in temperature. Several measuring points, including an anemometer, temperature and humidity sensor, a loading cell in the test section for recording mass changes, are provided to monitor the variations of parameters during the experiments. The research is ongoing and it is expected to provide the final results of the experimental investigation at the end of 2022.Keywords: moisture, mold growth, testing, wood
Procedia PDF Downloads 1331324 Nanoparticulated (U,Gd)O2 Characterization
Authors: A. Fernandez Zuvich, I. Gana Watkins, H. Zolotucho, H. Troiani, A. Caneiro, M. Prado, A. L. Soldati
Abstract:
The study of actinide nanoparticles (NPs) has attracted the attention of the scientific community not only because the lack of information about their ecotoxicological effects but also because the use of NPs could open a new way in the production of nuclear energy. Indeed, it was recently demonstrated that UO2 NPs sintered pellets exhibit closed porosity with improved fission gas retention and radiation-tolerance , ameliorated mechanical properties, and less detriment of the thermal conductivity upon use, making them an interesting option for new nuclear fuels. In this work, we used a combination of diffraction and microscopy tools to characterize the morphology, the crystalline structure and the composition of UO2 nanoparticles doped with 10%wt Gd2O3. The particles were synthesized by a modified sol-gel method at low temperatures. X-ray Diffraction (XRD) studies determined the presence of a unique phase with the cubic structure and Fm3m spatial group, supporting that Gd atoms substitute U atoms in the fluorite structure of UO2. In addition, Field Emission Gun Scanning (FEG-SEM) and Transmission (FEG-TEM) Electron Microscopy images revealed the presence of micrometric agglomerates of nanoparticles, with rounded morphology and an average crystallite size < 50 nm. Energy Dispersive Spectroscopy (EDS) coupled to TEM determined the presence of Gd in all the analyzed crystallites. Besides, FEG-SEM-EDS showed a homogeneous concentration distribution at the micrometer scale indicating that the small size of the crystallites compensates the variation in composition by averaging a large number of crystallites. These techniques, as combined tools resulted thus essential to find out details of morphology and composition distribution at the sub-micrometer scale, and set a standard for developing and analyzing nanoparticulated nuclear fuels.Keywords: actinide nanoparticles, burnable poison, nuclear fuel, sol-gel
Procedia PDF Downloads 3331323 Numerical Simulations of Fire in Typical Air Conditioned Railway Coach
Authors: Manoj Sarda, Abhishek Agarwal, Juhi Kaushik, Vatsal Sanjay, Arup Kumar Das
Abstract:
Railways in India remain primary mode of transport having one of the largest networks in the world and catering to billions of transits yearly. Catastrophic economic damage and loss to life is encountered over the past few decades due to fire to locomotives. Study of fire dynamics and fire propagation plays an important role in evacuation planning and reducing losses. Simulation based study of propagation of fire and soot inside an air conditioned coach of Indian locomotive is done in this paper. Finite difference based solver, Fire Dynamic Simulator (FDS) version 6 has been used for analysis. A single air conditioned 3 tier coupe closed to ambient surroundings by glass windows having occupancy for 8 people is the basic unit of the domain. A system of three such coupes combined is taken to be fundamental unit for the entire study to resemble effect to an entire coach. Analysis of flame and soot contours and concentrations is done corresponding to variations in heat release rate per unit volume (HRRPUA) of fire source, variations in conditioned air velocity being circulated inside coupes by vents and an alternate fire initiation and propagation mechanism via ducts. Quantitative results of fractional area in top and front view of the three coupes under fire and smoke are obtained using MATLAB (IMT). Present simulations and its findings will be useful for organizations like Commission of Railway Safety and others in designing and implementing safety and evacuation measures.Keywords: air conditioned coaches, fire propagation, flame contour, soot flow, train fire
Procedia PDF Downloads 2851322 The Impact of Artesunate-Amodiaquine on Schistosoma mansoni Infection among Children Infected by Plasmodium in Rural Area of Lemfu, Kongo Central, Democratic Republic of the Congo
Authors: Mbanzulu Kennedy, Zanga Josue, Wumba Roger
Abstract:
Malaria and schistosomiasis remain life-threatening public health problems in sub-Saharan Africa. The infection pattern related to age indicates that preschool and school-age children are at the highest risk of malaria and schistosomiasis. Both parasitic infections, separately or combined, may have negative impacts on the haemoglobin concentration levels. The existing data revealed that artemisinin derivatives commonly used to cure malaria present also in antischistosomal activities. The current study investigated the impact of Artesunate-Amodiaquine (AS-AQ) on schistosomiasis when administered to treat malaria in rural area of Lemfu, DRC. A prospective longitudinal study including 171 coinfected children screened for anaemia, Schistosoma mansoni, and Plasmodium falciparum infections. The egg reduction rate and haemoglobin concentration were assessed four weeks after the treatment with AS-AQ, of all coinfected children of this series. One hundred and twenty-five (74.4%) out of 168 coinfected children treated and present during the assessment were found stool negative for S. mansoni eggs. Out of 43 (25.6%) children who remained positives, 37 (22%) showed a partial reduction of eggs amount, and no reduction was noted in 3.6% of coinfected. The mean of haemoglobin concentration and the prevalence of anaemia were, respectively, 10.74±1.5g/dl , 11.2±1.3g/dl, and 64.8%, 51.8%, respectively, before and after treatment, p<0.001. The AS-AQ commonly used against Plasmodium allowed curing S. mansoni in coinfected children and increasing the Hb level. For the future, the randomized and multicentric clinical trials are needed for a better understanding of the effectiveness of AS-AQ against Schistosoma spp. The trial registration number was 3487183.Keywords: paludisme, schistosomiase, as-aq, enfants lemfu
Procedia PDF Downloads 1031321 Development of the Religious Out-Group Aggression Scale
Authors: Rylle Evan Gabriel Zamora, Micah Dennise Malia, Abygail Deniese Villabona
Abstract:
When examining studies on aggression, the studies about individual aggression vastly outnumbers those studies on group aggression. Given the nature of aggression to be violent and cyclical, and the amount violent events that have occurred in the near present, the study of group aggression is relevant now more than ever. This discrepancy is parallel with the number of valid and reliable psychological tests that measure group aggression. Throughout history, one of the biggest causes of group based violence and aggression is religion. This is particularly true within the context of the Philippines as there are a large number of religious groups. Thus, this study aimed to develop a standardized test that measures an individual’s tendency to be aggressive to those who are in conflict with his or her religious beliefs. This study employs a test development design that employs a qualitative phase to ensure the validity of the scale. Thus, the study was divided into three phases. First is a pilot test wherein an instrument was designed from existing literature which was then administered to 173 respondents from the four largest religious groups in the Philippines. After extensive factor analysis and reliability testing, new items were then formed from the qualitative data collected from eight participants, consisting of two individuals per religious group. The final testing integrates all statistically significant items from the first phase, and the newly formed items from the second phase, which was then administered to 200 respondents. The results were then tested further for reliability using Cronbach’s alpha and validity through factor analysis. The items that were proven to be significant were then combined to create a final instrument that may be used by future studies.Keywords: religious aggression, group aggression, test development, psychological assessment, social psychology
Procedia PDF Downloads 2951320 Thematical and Critical Analysis of Answers of Saduddin Thafthazani and His Methodology in His Book Sharahul Aqaid
Authors: Muhsina Khadeeja
Abstract:
Introducing theological texts combined with philosophy will be useful in understanding the major difference between theology and philosophy and making a comparative study between these two epistemologies. SHARAHUL AQAID is one of them. Which originated in the Fourteenth century; the time was enriched with theological discourses and religious revisions. Meanwhile, visions of philosophy strengthened and its ideologies were discussed widely until it reflected on Islamic theology. Those philosophers initiated to interpretation of Islamic theology from a philosophical aspect. Some prominent Muslim theologists like Gazzali analyzed that this genre of interpretations and followed questions will threaten the existence of Islamic theology. Understanding these situations, prominent leaders defended Islamic theology through their intellectual works. SHARAHUL AQAID of SADUDDIN THATHAZANI is one of them, which is written as a commentary on UMAR NASAFI's work. The mentioned book is full of answers to the counters of philosophers and rectification of their interpretation. He adopted the philosophical method in this work rather than other methods to make philosophers understand his answers vividly. Because of that, the book is plentiful with philosophical terminologies. Common people can't grasp it without a deep reading. So, the researcher hopes that the analysis of this work will help to elaborate its meanings and make it graspable. The researcher chooses a thematical and critical analysis of the answers of SADUDDIN THAFTHAZANI in SHARAHUL AQAID and on his methodology. This analysis denotes theology and philosophy show similarities rather than contradictions. The researcher concludes this study by examining the difference between theology and philosophy, similarities and contradiction. Finally, researcher proves how both epistemologies coexist.Keywords: islamic theology, sharahul aqaid, saduddin thafthazani, philosophy
Procedia PDF Downloads 791319 Removal of Na₂SO₄ by Electro-Confinement on Nanoporous Carbon Membrane
Authors: Jing Ma, Guotong Qin
Abstract:
We reported electro-confinement desalination (ECMD), a desalination method combining electric field effects and confinement effects using nanoporous carbon membranes as electrode. A carbon membrane with average pore size of 8.3 nm was prepared by organic sol-gel method. The precursor of support was prepared by curing porous phenol resin tube. Resorcinol-formaldehyde sol was coated on porous tubular resin support. The membrane was obtained by carbonisation of coated support. A well-combined top layer with the thickness of 35 μm was supported by macroporous support. Measurements of molecular weight cut-off using polyethylene glycol showed the average pore size of 8.3 nm. High salt rejection can be achieved because the water molecules need not overcome high energy barriers in confined space, while huge inherent dehydration energy was required for hydrated ions to enter the nanochannels. Additionally, carbon membrane with additional electric field can be used as an integrated membrane electrode combining the effects of confinement and electric potential gradient. Such membrane electrode can repel co-ions and attract counter-ions using pressure as the driving force for mass transport. When the carbon membrane was set as cathode, the rejection of SO₄²⁻ was 94.89%, while the removal of Na⁺ was less than 20%. We set carbon membrane as anode chamber to treat the effluent water from the cathode chamber. The rejection of SO₄²⁻ and Na⁺ reached to 100% and 88.86%, respectively. ECMD will be a promising energy efficient method for salt rejection.Keywords: nanoporous carbon membrane, confined effect, electric field, desalination, membrane reactor
Procedia PDF Downloads 1271318 Soil Liquefaction Hazard Evaluation for Infrastructure in the New Bejaia Quai, Algeria
Authors: Mohamed Khiatine, Amal Medjnoun, Ramdane Bahar
Abstract:
The North Algeria is a highly seismic zone, as evidenced by the historical seismicity. During the past two decades, it has experienced several moderate to strong earthquakes. Therefore, the geotechnical engineering problems that involve dynamic loading of soils and soil-structure interaction system requires, in the presence of saturated loose sand formations, liquefaction studies. Bejaia city, located in North-East of Algiers, Algeria, is a part of the alluvial plain which covers an area of approximately 750 hectares. According to the Algerian seismic code, it is classified as moderate seismicity zone. This area had not experienced in the past urban development because of the different hazards identified by hydraulic and geotechnical studies conducted in the region. The low bearing capacity of the soil, its high compressibility and the risk of liquefaction and flooding are among these risks and are a constraint on urbanization. In this area, several cases of structures founded on shallow foundations have suffered damages. Hence, the soils need treatment to reduce the risk. Many field and laboratory investigations, core drilling, pressuremeter test, standard penetration test (SPT), cone penetrometer test (CPT) and geophysical down hole test, were performed in different locations of the area. The major part of the area consists of silty fine sand , sometimes heterogeneous, has not yet reached a sufficient degree of consolidation. The ground water depth changes between 1.5 and 4 m. These investigations show that the liquefaction phenomenon is one of the critical problems for geotechnical engineers and one of the obstacles found in design phase of projects. This paper presents an analysis to evaluate the liquefaction potential, using the empirical methods based on Standard Penetration Test (SPT), Cone Penetration Test (CPT) and shear wave velocity and numerical analysis. These liquefaction assessment procedures indicate that liquefaction can occur to considerable depths in silty sand of harbor zone of Bejaia.Keywords: earthquake, modeling, liquefaction potential, laboratory investigations
Procedia PDF Downloads 3531317 Agroforestry Practices on Soil Microbial Biomass Carbon and Organic Carbon in Southern Ethiopia
Authors: Nebiyou Masebo
Abstract:
The rapid conversion of an old aged agroforestry (AF) based agricultural system to monocropping farming system in southern Ethiopia is increasing. The consequence of this, combined with climate change, has been impaired biodiversity, soil microbial biomass carbon (MBC), and soil organic carbon (SOC). The AF system could curb such problems due it is an ecologically and economically sustainable strategies. This study was aimed to investigate different agroforestry practices (AFPs) on MBC and SOC in southern Ethiopia. Soil samples were collected from homegarden based agroforestry practice (HAFP), crop land based agroforestry practice (ClAFP), woodlot based agroforestry practice (WlAFP), and trees on soil and water conservation based agroforestry practice (TSWAFP) using two depth layer (0-30 & 30-60 cm) by systematic sampling. Moreover, woody species inventorywas also collected. The chloroform fumigation extraction method was employed to determine MBC from different AFP types. In this study, the value of MBC and SOC decreased significantly with soil depth (p< 0.05). Besides, AFP type, soil depth, woody species diversity, and key soil properties also strongly influenced MBC and SOC (p< 0.05). In this study, the MBC was the highest (786 mg kg⁻¹ soil) in HAFP, followed by WlAFP (592 mg kg⁻¹ soil), TSWAFP (421 mg kg⁻¹ soil), and ClAFP (357 mg kg⁻¹ soil). The highest mean value of SOC (43.5Mg C ha⁻¹) was recorded in HAFP, followed by WlAFP (35.1Mg C ha⁻¹), TSWAFP (22.3 Mg C ha⁻¹), while the lowest (21.8 Mg C ha⁻¹) was recorded in ClAFP. The HAFP had high woody species diversity, and the lowest was recorded in ClAFP. The finding indicated that SOC and MBC were significantly affected by land management practices, and HAFP has the potential to improve MBC and SOC through good management practices of AFP.Keywords: agroforestry practices, microbial biomass carbon, soil carbon, rapid conversion
Procedia PDF Downloads 1021316 Thin Films of Glassy Carbon Prepared by Cluster Deposition
Authors: Hatem Diaf, Patrice Melinon, Antonio Pereira, Bernard Moine, Nicholas Blanchard, Florent Bourquard, Florence Garrelie, Christophe Donnet
Abstract:
Glassy carbon exhibits excellent biological compatibility with live tissues meaning it has high potential for applications in life science. Moreover, glassy carbon has interesting properties including 'high temperature resistance', hardness, low density, low electrical resistance, low friction, and low thermal resistance. The structure of glassy carbon has long been a subject of debate. It is now admitted that glassy carbon is 100% sp2. This term is a little bit confusing as long sp2 hybridization defined from quantum chemistry is related to both properties: threefold configuration and pi bonding (parallel pz orbitals). Using plasma laser deposition of carbon clusters combined with pulsed nano/femto laser annealing, we are able to synthesize thin films of glassy carbon of good quality (probed by G band/ D disorder band ratio in Raman spectroscopy) without thermal post annealing. A careful inspecting of Raman signal, plasmon losses and structure performed by HRTEM (High Resolution Transmission Electron Microscopy) reveals that both properties (threefold and pi orbitals) cannot coexist together. The structure of the films is compared to models including schwarzites based from negatively curved surfaces at the opposite of onions or fullerene-like structures with positively curved surfaces. This study shows that a huge collection of porous carbon named vitreous carbon with different structures can coexist.Keywords: glassy carbon, cluster deposition, coating, electronic structure
Procedia PDF Downloads 3211315 The Study of Climate Change Effects on the Performance of Thermal Power Plants in Iran
Authors: Masoud Soltani Hosseini, Fereshteh Rahmani, Mohammad Tajik Mansouri, Ali Zolghadr
Abstract:
Climate change is accompanied with ambient temperature increase and water accessibility limitation. The main objective of this paper is to investigate the effects of climate change on thermal power plants including gas turbines, steam and combined cycle power plants in Iran. For this purpose, the ambient temperature increase and water accessibility will be analyzed and their effects on power output and efficiency of thermal power plants will be determined. According to the results, the ambient temperature has high effect on steam power plants with indirect cooling system (Heller). The efficiency of this type of power plants decreases by 0.55 percent per 1oC ambient temperature increase. This amount is 0.52 and 0.2 percent for once-through and wet cooling systems, respectively. The decrease in power output covers a range of 0.2% to 0.65% for steam power plant with wet cooling system and gas turbines per 1oC air temperature increase. Based on the thermal power plants distribution in Iran and different scenarios of climate change, the total amount of power output decrease falls between 413 and 1661 MW due to ambient temperature increase. Another limitation incurred by climate change is water accessibility. In optimistic scenario, the power output of steam plants decreases by 1450 MW in dry and hot climate areas throughout next decades. The remaining scenarios indicate that the amount of decrease in power output would be by 4152 MW in highlands and cold climate. Therefore, it is necessary to consider appropriate solutions to overcome these limitations. Considering all the climate change effects together, the actual power output falls in range of 2465 and 7294 MW and efficiency loss covers the range of 0.12 to .56 % in different scenarios.Keywords: climate, change, thermal, power plants
Procedia PDF Downloads 831314 Analytical Study of Symbolism in Literary Texts: A Pragma-Stylistic Approach
Authors: Hussain Hameed Mayuuf
Abstract:
We may find multiple functions that are required to exist in order for meaning, in any certain context, to manifest and act accordingly. Pragmatic function and symbolic function need to be contributing in a combined effort towards that manifestation in order for meaning to be acquired or achieved from within a structure too complex to detect meaning in it by employing any other means. This paper inspects symbolism pragma-stylistically in literary texts. Thus, it principally aims at showing the ways writers utilize symbolism to contribute to the themes of their works and, consequently, pinpointing the most frequently flouted maxim involved in symbolic interpretations in addition to the reason(s) behind the writer's exploitation of that maxim in the literary work. E. E. Cummings' play Him constitutes rich data for the present study. Thus, to achieve its aims, the present study hypothesizes that the descriptions of scenes, the playwright’s remarks, and the characters’ references are all manipulated symbolically to contribute to the themes of the play. It is also hypothesized that the maxim of manner is the most frequently flouted maxim involved in symbolic interpretations in the play, which comes as a result of the intended ambiguity and obscurity manipulated in the descriptions of the scenes, the playwright’s remarks and the characters’ references. In order to achieve the aims of the study and test its hypotheses, a theoretical background about symbolism in general and symbolism from pragma-stylistic points of view is presented. Then, (six) extracts of Him according to Eco’s (1984) model Semiotics and the Philosophy of Language are analyzed. The findings of the analysis verify the above-mentioned hypotheses.Keywords: pragmatic function, stylistic function, Symbolism, pragma-stylistics, Cummings
Procedia PDF Downloads 1681313 Data Compression in Ultrasonic Network Communication via Sparse Signal Processing
Authors: Beata Zima, Octavio A. Márquez Reyes, Masoud Mohammadgholiha, Jochen Moll, Luca de Marchi
Abstract:
This document presents the approach of using compressed sensing in signal encoding and information transferring within a guided wave sensor network, comprised of specially designed frequency steerable acoustic transducers (FSATs). Wave propagation in a damaged plate was simulated using commercial FEM-based software COMSOL. Guided waves were excited by means of FSATs, characterized by the special shape of its electrodes, and modeled using PIC255 piezoelectric material. The special shape of the FSAT, allows for focusing wave energy in a certain direction, accordingly to the frequency components of its actuation signal, which makes available a larger monitored area. The process begins when a FSAT detects and records reflection from damage in the structure, this signal is then encoded and prepared for transmission, using a combined approach, based on Compressed Sensing Matching Pursuit and Quadrature Amplitude Modulation (QAM). After codification of the signal is in binary chars the information is transmitted between the nodes in the network. The message reaches the last node, where it is finally decoded and processed, to be used for damage detection and localization purposes. The main aim of the investigation is to determine the location of detected damage using reconstructed signals. The study demonstrates that the special steerable capabilities of FSATs, not only facilitate the detection of damage but also permit transmitting the damage information to a chosen area in a specific direction of the investigated structure.Keywords: data compression, ultrasonic communication, guided waves, FEM analysis
Procedia PDF Downloads 1251312 Screening and Isolation of Lead Molecules from South Indian Plant Extracts against NDM-1 Producing Escherichia coli
Authors: B. Chandar, M. K. Ramasamy, P. Madasamy
Abstract:
The discovery and development of newer antibiotics are limited with the increase in resistance of such multi-drug resistant bacteria creating the need for alternative new therapeutic agents. The recently discovered New Delhi Metallo-betalactamase-1 (NDM-1), which confers antibiotic resistance to most of the currently available β-lactams, except colistin and tigecycline, is a global concern. Several antibacterial drugs approved are natural products or their semisynthetic derivatives, but plant extracts remain to be explored to find molecules that are effective against NDM-1 bacteria. Therefore, it is necessary to explore the possibility of finding new and effective antibacterial compounds against NDM-1 bacteria. In the present study, we have screened a diverse set South Indian plant species, and report most plant species as a potential source for antimicrobial compounds against NDM-1 bacteria. Ethanol extracts from the leaves of taxonomically diverse South Indian medicinal plants were screened for antibacterial activity against NDM-1 E. coli using streak plate method. Among the plant screened against NDM-1 E. coli, the ethanol extracts from many plant extracts showed minimum bactericidal concentration between 5 and 15 mg /ml and MIC between 2.54 and 5.12 mg/ml. These extracts also showed a potent synergistic effect when combined with antibiotics colistin and tetracycline. Combretum albidum that was effective was taken for further analysis. At 5mg/L concentration, these extracts inhibited the NDM-1 enzyme in vitro, and residual activity for Combretum albidum was 33.09%. Treatment of NDM-1 E. coli with the extracts disrupted the cell wall integrity and caused 89.7% cell death. The plant extract of Combretum albidum that was effective was subjected to fractionation and the fraction was further subjected to HPLC, LC-MS for identification of antibacterial compound.Keywords: antibacterial activity, combretum albidum, Escherichia coli, NDM-1
Procedia PDF Downloads 4571311 Porous Alumina-Carbon Nanotubes Nanocomposite Membranes Processed via Spark Plasma Sintering for Heavy Metal Removal from Contaminated Water
Authors: H. K. Shahzad, M. A. Hussein, F. Patel, N. Al-Aqeeli, T. Laoui
Abstract:
The purpose of the present study was to use the adsorption mechanism with microfiltration synergistically for efficient heavy metal removal from contaminated water. Alumina (Al2O3) is commonly used for ceramic membranes development while recently carbon nanotubes (CNTs) have been considered among the best adsorbent materials for heavy metals. In this work, we combined both of these materials to prepare porous Al2O3-CNTs nanocomposite membranes via Spark Plasma Sintering (SPS) technique. Alumina was used as a base matrix while CNTs were added as filler. The SPS process parameters i.e. applied pressure, temperature, heating rate, and holding time were varied to obtain the best combination of porosity (64%, measured according to ASTM c373-14a) and strength (3.2 MPa, measured by diametrical compression test) of the developed membranes. The prepared membranes were characterized using X-ray diffraction (XRD), field emission secondary electron microscopy (FE-SEM), contact angle and porosity measurements. The results showed that properties of the synthesized membranes were highly influenced by the SPS process parameters. FE-SEM images revealed that CNTs were reasonably dispersed in the alumina matrix. The porous membranes were evaluated for their water flux transport as well as their capacity to adsorb heavy metals ions. Selected membranes were able to remove about 97% cadmium from contaminated water. Further work is underway to enhance the removal efficiency of the developed membranes as well as to remove other heavy metals such as arsenic and mercury.Keywords: heavy metal removal, inorganic membrane, nanocomposite, spark plasma sintering
Procedia PDF Downloads 2621310 Simulating the Dynamics of E-waste Production from Mobile Phone: Model Development and Case Study of Rwanda
Authors: Rutebuka Evariste, Zhang Lixiao
Abstract:
Mobile phone sales and stocks showed an exponential growth in the past years globally and the number of mobile phones produced each year was surpassing one billion in 2007, this soaring growth of related e-waste deserves sufficient attentions paid to it regionally and globally as long as 40% of its total weight is made from metallic which 12 elements are identified to be highly hazardous and 12 are less harmful. Different research and methods have been used to estimate the obsolete mobile phones but none has developed a dynamic model and handle the discrepancy resulting from improper approach and error in the input data. The study aim was to develop a comprehensive dynamic system model for simulating the dynamism of e-waste production from mobile phone regardless the country or region and prevail over the previous errors. The logistic model method combined with STELLA program has been used to carry out this study. Then the simulation for Rwanda has been conducted and compared with others countries’ results as model testing and validation. Rwanda is about 1.5 million obsoletes mobile phone with 125 tons of waste in 2014 with e-waste production peak in 2017. It is expected to be 4.17 million obsoletes with 351.97 tons by 2020 along with environmental impact intensity of 21times to 2005. Thus, it is concluded through the model testing and validation that the present dynamic model is competent and able deal with mobile phone e-waste production the fact that it has responded to the previous studies questions from Czech Republic, Iran, and China.Keywords: carrying capacity, dematerialization, logistic model, mobile phone, obsolescence, similarity, Stella, system dynamics
Procedia PDF Downloads 3461309 Subsea Processing: Deepwater Operation and Production
Authors: Md Imtiaz, Sanchita Dei, Shubham Damke
Abstract:
In recent years, there has been a rapidly accelerating shift from traditional surface processing operations to subsea processing operation. This shift has been driven by a number of factors including the depletion of shallow fields around the world, technological advances in subsea processing equipment, the need for production from marginal fields, and lower initial upfront investment costs compared to traditional production facilities. Moving production facilities to the seafloor offers a number of advantage, including a reduction in field development costs, increased production rates from subsea wells, reduction in the need for chemical injection, minimization of risks to worker ,reduction in spills due to hurricane damage, and increased in oil production by enabling production from marginal fields. Subsea processing consists of a range of technologies for separation, pumping, compression that enables production from offshore well without the need for surface facilities. At present, there are two primary technologies being used for subsea processing: subsea multiphase pumping and subsea separation. Multiphase pumping is the most basic subsea processing technology. Multiphase pumping involves the use of boosting system to transport the multiphase mixture through pipelines to floating production vessels. The separation system is combined with single phase pumps or water would be removed and either pumped to the surface, re-injected, or discharged to the sea. Subsea processing can allow for an entire topside facility to be decommissioned and the processed fluids to be tied back to a new, more distant, host. This type of application reduces costs and increased both overall facility and integrity and recoverable reserve. In future, full subsea processing could be possible, thereby eliminating the need for surface facilities.Keywords: FPSO, marginal field, Subsea processing, SWAG
Procedia PDF Downloads 4151308 Impact of Vehicle Travel Characteristics on Level of Service: A Comparative Analysis of Rural and Urban Freeways
Authors: Anwaar Ahmed, Muhammad Bilal Khurshid, Samuel Labi
Abstract:
The effect of trucks on the level of service is determined by considering passenger car equivalents (PCE) of trucks. The current version of Highway Capacity Manual (HCM) uses a single PCE value for all tucks combined. However, the composition of truck traffic varies from location to location; therefore a single PCE-value for all trucks may not correctly represent the impact of truck traffic at specific locations. Consequently, present study developed separate PCE values for single-unit and combination trucks to replace the single value provided in the HCM on different freeways. Site specific PCE values, were developed using concept of spatial lagging headways (the distance from the rear bumper of a leading vehicle to the rear bumper of the following vehicle) measured from field traffic data. The study used data from four locations on a single urban freeway and three different rural freeways in Indiana. Three-stage-least-squares (3SLS) regression techniques were used to generate models that predicted lagging headways for passenger cars, single unit trucks (SUT), and combination trucks (CT). The estimated PCE values for single-unit and combination truck for basic urban freeways (level terrain) were: 1.35 and 1.60, respectively. For rural freeways the estimated PCE values for single-unit and combination truck were: 1.30 and 1.45, respectively. As expected, traffic variables such as vehicle flow rates and speed have significant impacts on vehicle headways. Study results revealed that the use of separate PCE values for different truck classes can have significant influence on the LOS estimation.Keywords: level of service, capacity analysis, lagging headway, trucks
Procedia PDF Downloads 3571307 Relationship and Associated Factors of Breastfeeding Self-efficacy among Postpartum Couples in Malawi: A Cross-sectional Study
Authors: Roselyn Chipojola, Shu-yu Kuo
Abstract:
Background: Breastfeeding self-efficacy in both mothers and fathers play a crucial role in improving exclusive breastfeeding rates. However, less is known on the relationship and predictors of paternal and maternal breastfeeding self-efficacy. This study aimed to examine the relationship and associated factors of breastfeeding self-efficacy (BSE) among mothers and fathers in Malawi. Methods: A cross-sectional study was conducted on 180 pairs of postpartum mothers and fathers at a tertiary maternity facility in central Malawi. BSE was measured using the Breastfeeding Self-Efficacy Scale Short-Form. Depressive symptoms were assessed by the Edinburgh Postnatal Depression Scale. A structured questionnaire was used to collect demographic and health variables. Data were analyzed using multivariable logistic regression and multinomial logistic regression. Results: A higher score of self-efficacy was found in mothers (mean=55.7, Standard Deviation (SD) =6.5) compared to fathers (mean=50.2, SD=11.9). A significant association between paternal and maternal breastfeeding self-efficacy was found (r= 0. 32). Age, employment status, mode of birth was significantly related to maternal and paternal BSE, respectively. Older age and caesarean section delivery were significant factors of combined BSE scores in couples. A higher BSE score in either the mother or her partner predicted higher exclusive breastfeeding rates. BSE scores were lower when couples’ depressive symptoms were high. Conclusion: BSE are highly correlated between Malawian mothers and fathers, with a relatively higher score in maternal BSE. Importantly, a high BSE in couples predicted higher odds of exclusive breastfeeding, which highlights the need to include both mothers and fathers in future breastfeeding promotion strategies.Keywords: paternal, maternal, exclusive breastfeeding, breastfeeding self‑efficacy, malawi
Procedia PDF Downloads 701306 Trends in Domestic Terms of Trade of Agricultural Sector of Pakistan
Authors: Anwar Hussain, Muhammad Iqbal
Abstract:
The changes in the prices of the agriculture commodities combined with changes in population and agriculture productivity affect farmers’ profitability and standard of living. This study intends to estimate various domestic terms of trade for agriculture sector and also to assess the volatility in the standard of living and profitability of farmers. The terms of trade has been estimated for Pakistan and its provinces using producer prices indices, consumer price indices, input prices indices and quantity indices using the data for the period 1990-91 to 2008-09. The domestic terms of trade of agriculture sector has been improved in terms of both approaches i.e. the ratio of producer prices indices to consumer prices indices and the real per capita income approach. However, the cross province estimates indicated that the terms of trade also improved for Khyber Pakhtunkhwa, Sindh and Punjab while Balochistan’s domestic terms of trade deteriorated drastically. In other words the standard of living of the farmers in Pakistan and its provinces except Balochistan improved. Using the input prices, the domestic terms of trade deteriorated for Pakistan as a whole and its provinces as well. This also explores that as a whole the profitability of the farmers reduced during the study period. The farmers pay more prices for inputs as compared to they receive for their produce. This further indicates that the poverty at the gross root level has been increased. Further, summing, the standard of living of the farmers improved but their profitability reduced, which indicates that the farmers do not completely rely on the farm income but also utilize some other sources of income for their livelihood. The study supports to give subsidies on farm inputs so as to improve the profitability of the farmers.Keywords: agricultural terms of trade, farmers’ profitability, farmers’ standard of living, consumer and producer price indices, quantity indices
Procedia PDF Downloads 4661305 Understanding the Effects of Lamina Stacking Sequence on Structural Response of Composite Laminates
Authors: Awlad Hossain
Abstract:
Structural weight reduction with improved functionality is one of the targeted desires of engineers, which drives materials and structures to be lighter. One way to achieve this objective is through the replacement of metallic structures with composites. The main advantages of composite materials are to be lightweight and to offer high specific strength and stiffness. Composite materials can be classified in various ways based on the fiber types and fiber orientations. Fiber reinforced composite laminates are prepared by stacking single sheet of continuous fibers impregnated with resin in different orientation to get the desired strength and stiffness. This research aims to understand the effects of Lamina Stacking Sequence (LSS) on the structural response of a symmetric composite laminate, defined by [0/60/-60]s. The Lamina Stacking Sequence (LSS) represents how the layers are stacked together in a composite laminate. The [0/60/-60]s laminate represents a composite plate consists of 6 layers of fibers, which are stacked at 0, 60, -60, -60, 60 and 0 degree orientations. This laminate is also called symmetric (defined by subscript s) as it consists of same material and having identical fiber orientations above and below the mid-plane. Therefore, the [0/60/-60]s, [0/-60/60]s, [60/-60/0]s, [-60/60/0]s, [60/0/-60]s, and [-60/0/60]s represent the same laminate but with different LSS. In this research, the effects of LSS on laminate in-plane and bending moduli was investigated first. The laminate moduli dictate the in-plane and bending deformations upon loading. This research also provided all the setup and techniques for measuring the in-plane and bending moduli, as well as how the stress distribution was assessed. Then, the laminate was subjected to in-plane force load and bending moment. The strain and stress distribution at each ply for different LSS was investigated using the concepts of Macro-Mechanics. Finally, several numerical simulations were conducted using the Finite Element Analysis (FEA) software ANSYS to investigate the effects of LSS on deformations and stress distribution. The FEA results were also compared to the Macro-Mechanics solutions obtained by MATLAB. The outcome of this research helps composite users to determine the optimum LSS requires to minimize the overall deformation and stresses. It would be beneficial to predict the structural response of composite laminates analytically and/or numerically before in-house fabrication.Keywords: composite, lamina, laminate, lamina stacking sequence, laminate moduli, laminate strength
Procedia PDF Downloads 141304 Fully Automated Methods for the Detection and Segmentation of Mitochondria in Microscopy Images
Authors: Blessing Ojeme, Frederick Quinn, Russell Karls, Shannon Quinn
Abstract:
The detection and segmentation of mitochondria from fluorescence microscopy are crucial for understanding the complex structure of the nervous system. However, the constant fission and fusion of mitochondria and image distortion in the background make the task of detection and segmentation challenging. In the literature, a number of open-source software tools and artificial intelligence (AI) methods have been described for analyzing mitochondrial images, achieving remarkable classification and quantitation results. However, the availability of combined expertise in the medical field and AI required to utilize these tools poses a challenge to its full adoption and use in clinical settings. Motivated by the advantages of automated methods in terms of good performance, minimum detection time, ease of implementation, and cross-platform compatibility, this study proposes a fully automated framework for the detection and segmentation of mitochondria using both image shape information and descriptive statistics. Using the low-cost, open-source python and openCV library, the algorithms are implemented in three stages: pre-processing, image binarization, and coarse-to-fine segmentation. The proposed model is validated using the mitochondrial fluorescence dataset. Ground truth labels generated using a Lab kit were also used to evaluate the performance of our detection and segmentation model. The study produces good detection and segmentation results and reports the challenges encountered during the image analysis of mitochondrial morphology from the fluorescence mitochondrial dataset. A discussion on the methods and future perspectives of fully automated frameworks conclude the paper.Keywords: 2D, binarization, CLAHE, detection, fluorescence microscopy, mitochondria, segmentation
Procedia PDF Downloads 3581303 Mechanical Responses to Hip Versus Knee Induced Muscle Fatigue in Patellofemoral Pain Syndrome
Authors: Eman Ahmed Ahmed, Ghada Abdelmoneim Mohamed, Hamada Ahmed Hamada, Nagui Sobhi Nassif
Abstract:
Impaired skeletal muscle endurance may be an important causal factor in the development of patellofemoral pain syndrome (PFPS). However, there is lack of information regarding the effect of hip versus knee muscle fatigue on isokinetic parameters, and myoelectric activity of hip and knee muscles in these patients. Purpose: The study was conducted to investigate the effect of hip abductors versus knee extensors fatigue protocol on knee proprioception, hip and knee muscle strength and their myoelectric activity in patients with PFPS. Methods: Fifteen female patients with PFPS participated in the study. They were tested randomly under two fatiguing conditions; hip abductors and knee extensors fatigue protocols. Isolated muscle fatigue of two muscles was induced isokinetically on the affected side in a two separate sessions with a rest interval of at least three days. After determining peak torque, patients performed continuous maximal concentric-eccentric contraction of the selected muscle until the torque output dropped below 50% of peak torque value for 3 consecutive repetitions. Knee proprioception, eccentric hip abductors' peak torque, eccentric knee extensors' peak torque, EMG ratio of vastus medialis obliquus (VMO) / vastus lateralis (VL), and EMG activity of gluteus medius (GM) muscle, were recorded before and immediately after each fatigue protocol using the Biodex Isokinetic system and EMG Myosystem. Results: Two-way within subject MANOVA revealed that eccentric knee extensors’ peak torque decreased significantly after hip abductors fatigue protocol compared to pre fatigue condition (p<0.05). On the other hand, there was no statistically significant difference in the eccentric hip abductors’ peak torque after admitting knee extensors fatigue protocol (p > 0.05). Moreover, no significant difference was found in knee proprioception, EMG ratio of VMO/VL, and EMG activity of GM muscle, after either hip or knee fatigue protocol (p>0.05). Conclusion: A hip focused rehabilitation program may be beneficial in improving knee function through correcting faulty kinematics and hence decrease knee loading in patients with PFPS.Keywords: electromyography, knee proprioception, mechanical responses, muscle fatigue, patellofemoral pain syndrome
Procedia PDF Downloads 3121302 Comparison Between Conventional Ultrafiltration Combined with Modified Ultrafiltration and Conventional Ultrafiltration Only for Adult Open-heart Surgery: Perspective from Systemic Inflammation, Vascular Resistance, and Cardiac Index
Authors: Ratna Farida Soenarto, Anas Alatas, Made Ryan Kharmayani
Abstract:
Background: Conventional ultrafiltration (CUF) system was shown to be helpful in reducing anti-inflammatory mediators for patients who underwent open heart surgery. Additionally, modified ultrafiltration (MUF) has been shown to reduce anti-inflammatory mediators further while reducing interstitial fluid volume at the same time. However, there has been minimal data concerning the efficacy of combining both ultrafiltration methods. This study aims to compare inflammation marker, vascular resistance, and cardiac index on CUF+MUF patients with CUF only patients undergoing open heart surgery. Method: This is a single blind randomized controlled trial on patients undergoing open heart surgery between June 2021 - October 2021 in CiptoMangunkusumo National Referral Hospital and Jakarta Heart Hospital. Patients wererandomized using block randomization into modified ultrafiltration following conventional ultrafiltration (CUF+MUF) and conventional ultrafiltration (CUF) only. Outcome assessed in this study were 24-hoursinterleukin-6 levels, systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), and cardiac index. Results: A total of 38patients were included (19 CUF+MUF and 19 CUF subjects). There was no difference in postoperative IL-6 level between groups (p > 0.05).No difference in PVR was observed between groups.Higher difference in SVR was observed in CUF+MUF group (-646 vs. -261dyn/s/cm-5, p < 0.05). Higher cardiac index was observed on CUF+MUF group (0.93 vs. 0.48, p < 0.05). Conclusion: Patients undergoing open heart surgery with modified ultrafiltration following conventional ultrafiltration had similar systemic inflammatory response and better cardiac response than those having conventional ultrafiltration.Keywords: open-heart, CUF, MUF, SVR, PVR, IL-6
Procedia PDF Downloads 1551301 Suppressing Vibration in a Three-axis Flexible Satellite: An Approach with Composite Control
Authors: Jalal Eddine Benmansour, Khouane Boulanoir, Nacera Bekhadda, Elhassen Benfriha
Abstract:
This paper introduces a novel composite control approach that addresses the challenge of stabilizing the three-axis attitude of a flexible satellite in the presence of vibrations caused by flexible appendages. The key contribution of this research lies in the development of a disturbance observer, which effectively observes and estimates the unwanted torques induced by the vibrations. By utilizing the estimated disturbance, the proposed approach enables efficient compensation for the detrimental effects of vibrations on the satellite system. To govern the attitude angles of the spacecraft, a proportional derivative controller (PD) is specifically designed and proposed. The PD controller ensures precise control over all attitude angles, facilitating stable and accurate spacecraft maneuvering. In order to demonstrate the global stability of the system, the Lyapunov method, a well-established technique in control theory, is employed. Through rigorous analysis, the Lyapunov method verifies the convergence of system dynamics, providing strong evidence of system stability. To evaluate the performance and efficacy of the proposed control algorithm, extensive simulations are conducted. The simulation results validate the effectiveness of the combined approach, showcasing significant improvements in the stabilization and control of the satellite's attitude, even in the presence of disruptive vibrations from flexible appendages. This novel composite control approach presented in this paper contributes to the advancement of satellite attitude control techniques, offering a promising solution for achieving enhanced stability and precision in challenging operational environments.Keywords: attitude control, flexible satellite, vibration control, disturbance observer
Procedia PDF Downloads 871300 The Perspectives of Preparing Psychology Practitioners in Armenian Universities
Authors: L. Petrosyan
Abstract:
The problem of psychologist training remains a key priority in Armenia. During the Soviet period, the notion of a psychologist was obscure not only in Armenia but also in other Soviet republics. The breakup of the Soviet Union triggered a gradual change in this area activating the cooperation with specialists from other countries. The need for recovery from the psychological trauma caused by the 1988 earthquake pushed forward the development of practical psychology in Armenia. This phenomenon led to positive changes in perception of and interest to a psychologist profession.Armenian universities started designing special programs for psychologists’ preparation. Armenian psychologists combined their efforts in the field of training relevant specialists. During the recent years, the Bologna educational system was introduced in Armenia which led to implementation of education quality improvement programs. Nevertheless, even today the issue of psychologists’ training is not yet settled in Armenian universities. So far graduate psychologists haven’t got a clear idea of personal and professional qualities of a psychologist. Recently, as a result of educational reforms, the psychology curricula underwent changes, but so far they have not led to a desired outcome. Almost all curricula in certain specialties are aimed to form professional competencies and strengthen practical skills. A survey conducted in Armenia aimed to identify what are the ideas of young psychology specialists on the image of a psychologist. The survey respondents were 45 specialists holding bachelor’s degree as well as 30 master degree graduates, who have not been working yet. The research reveals that we need to change the approach of preparing psychology practitioners in the universities of Armenia. Such an approach to psychologist training will make it possible to train qualified specialists for enhancement of modern psychology theory and practice.Keywords: practitioners, psychology degree, study, professional competencies
Procedia PDF Downloads 4531299 An Efficient Machine Learning Model to Detect Metastatic Cancer in Pathology Scans Using Principal Component Analysis Algorithm, Genetic Algorithm, and Classification Algorithms
Authors: Bliss Singhal
Abstract:
Machine learning (ML) is a branch of Artificial Intelligence (AI) where computers analyze data and find patterns in the data. The study focuses on the detection of metastatic cancer using ML. Metastatic cancer is the stage where cancer has spread to other parts of the body and is the cause of approximately 90% of cancer-related deaths. Normally, pathologists spend hours each day to manually classifying whether tumors are benign or malignant. This tedious task contributes to mislabeling metastasis being over 60% of the time and emphasizes the importance of being aware of human error and other inefficiencies. ML is a good candidate to improve the correct identification of metastatic cancer, saving thousands of lives and can also improve the speed and efficiency of the process, thereby taking fewer resources and time. So far, the deep learning methodology of AI has been used in research to detect cancer. This study is a novel approach to determining the potential of using preprocessing algorithms combined with classification algorithms in detecting metastatic cancer. The study used two preprocessing algorithms: principal component analysis (PCA) and the genetic algorithm, to reduce the dimensionality of the dataset and then used three classification algorithms: logistic regression, decision tree classifier, and k-nearest neighbors to detect metastatic cancer in the pathology scans. The highest accuracy of 71.14% was produced by the ML pipeline comprising of PCA, the genetic algorithm, and the k-nearest neighbor algorithm, suggesting that preprocessing and classification algorithms have great potential for detecting metastatic cancer.Keywords: breast cancer, principal component analysis, genetic algorithm, k-nearest neighbors, decision tree classifier, logistic regression
Procedia PDF Downloads 831298 DNA Prime/MVTT Boost Enhances Broadly Protective Immune Response against Mosaic HIV-1 Gag
Authors: Wan Liu, Haibo Wang, Cathy Huang, Zhiwu Tan, Zhiwei Chen
Abstract:
The tremendous diversity of HIV-1 has been a major challenge for an effective AIDS vaccine development. Mosaic approach presents the potential for vaccine design aiming for global protection. The mosaic antigen of HIV-1 Gag allows antigenic breadth for vaccine-elicited immune response against a wider spectrum of viral strains. However, the enhancement of immune response using vaccines is dependent on the strategy used. Heterologous prime/boost regimen has been shown to elicit high levels of immune responses. Here, we investigated whether priming using plasmid DNA with electroporation followed by boosting with the live replication-competent modified vaccinia virus vector TianTan (MVTT) combined with the mosaic antigenic sequence could elicit a greater and broader antigen-specific response against HIV-1 Gag in mice. When compared to DNA or MVTT alone, or MVTT/MVTT group, DNA/MVTT group resulted in coincidentally high frequencies of broadly reactive, Gag-specific, polyfunctional, long-lived, and cytotoxic CD8+ T cells and increased anti-Gag antibody titer. Meanwhile, the vaccination could upregulate PD-1+, and Tim-3+ CD8+ T cell, myeloid-derived suppressive cells and Treg cells to balance the stronger immune response induced. Importantly, the prime/boost vaccination could help control the EcoHIV and mesothelioma AB1-gag challenge. The stronger protective Gag-specific immunity induced by a Mosaic DNA/MVTT vaccine corroborate the promise of the mosaic approach, and the potential of two acceptably safe vectors to enhance anti-HIV immunity and cancer prevention.Keywords: DNA/MVTT vaccine, EcoHIV, mosaic antigen, mesothelioma AB1-gag
Procedia PDF Downloads 242