Search results for: feature combination
1717 Safe Zone: A Framework for Detecting and Preventing Drones Misuse
Authors: AlHanoof A. Alharbi, Fatima M. Alamoudi, Razan A. Albrahim, Sarah F. Alharbi, Abdullah M Almuhaideb, Norah A. Almubairik, Abdulrahman Alharby, Naya M. Nagy
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Recently, drones received a rapid interest in different industries worldwide due to its powerful impact. However, limitations still exist in this emerging technology, especially privacy violation. These aircrafts consistently threaten the security of entities by entering restricted areas accidentally or deliberately. Therefore, this research project aims to develop drone detection and prevention mechanism to protect the restricted area. Until now, none of the solutions have met the optimal requirements of detection which are cost-effectiveness, high accuracy, long range, convenience, unaffected by noise and generalization. In terms of prevention, the existing methods are focusing on impractical solutions such as catching a drone by a larger drone, training an eagle or a gun. In addition, the practical solutions have limitations, such as the No-Fly Zone and PITBULL jammers. According to our study and analysis of previous related works, none of the solutions includes detection and prevention at the same time. The proposed solution is a combination of detection and prevention methods. To implement the detection system, a passive radar will be used to properly identify the drone against any possible flying objects. As for the prevention, jamming signals and forceful safe landing of the drone integrated together to stop the drone’s operation. We believe that applying this mechanism will limit the drone’s invasion of privacy incidents against highly restricted properties. Consequently, it effectively accelerates drones‘ usages at personal and governmental levels.Keywords: detection, drone, jamming, prevention, privacy, RF, radar, UAV
Procedia PDF Downloads 2111716 Railway Process Automation to Ensure Human Safety with the Aid of IoT and Image Processing
Authors: K. S. Vedasingha, K. K. M. T. Perera, K. I. Hathurusinghe, H. W. I. Akalanka, Nelum Chathuranga Amarasena, Nalaka R. Dissanayake
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Railways provide the most convenient and economically beneficial mode of transportation, and it has been the most popular transportation method among all. According to the past analyzed data, it reveals a considerable number of accidents which occurred at railways and caused damages to not only precious lives but also to the economy of the countries. There are some major issues which need to be addressed in railways of South Asian countries since they fall under the developing category. The goal of this research is to minimize the influencing aspect of railway level crossing accidents by developing the “railway process automation system”, as there are high-risk areas that are prone to accidents, and safety at these places is of utmost significance. This paper describes the implementation methodology and the success of the study. The main purpose of the system is to ensure human safety by using the Internet of Things (IoT) and image processing techniques. The system can detect the current location of the train and close the railway gate automatically. And it is possible to do the above-mentioned process through a decision-making system by using past data. The specialty is both processes working parallel. As usual, if the system fails to close the railway gate due to technical or a network failure, the proposed system can identify the current location and close the railway gate through a decision-making system, which is a revolutionary feature. The proposed system introduces further two features to reduce the causes of railway accidents. Railway track crack detection and motion detection are those features which play a significant role in reducing the risk of railway accidents. Moreover, the system is capable of detecting rule violations at a level crossing by using sensors. The proposed system is implemented through a prototype, and it is tested with real-world scenarios to gain the above 90% of accuracy.Keywords: crack detection, decision-making, image processing, Internet of Things, motion detection, prototype, sensors
Procedia PDF Downloads 1771715 Dimension of Water Accessibility in the Southern Part of Niger State, Nigeria
Authors: Kudu Dangana, Pai H. Halilu, Osesienemo R. Asiribo-Sallau, Garba Inuwa Kuta
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The study examined the determinants of household water accessibility in Southern part of Niger State, Nigeria. Data for the study was obtained from primary and secondary sources using questionnaire, interview, personal observation and documents. 1,192 questionnaires were administered; sampling techniques adopted are combination of purposive, stratified and simple random. Purposive sampling technique was used to determine sample frame; sample unit was determined using stratified sampling method and simple random technique was used in administering questionnaires. The result was analyzed within the scope of “WHO” water accessibility indicators using descriptive statistics. Major sources of water in the area are well; hand and electric pump borehole and streams. These sources account for over 90% of household’s water. Average per capita water consumption in the area is 22 liters per day, while location efficiency of facilities revealed an average of 80 people per borehole. Household water accessibility is affected mainly by the factors of distances, time spent to obtain water, low income status of the majority of respondents to access modern water infrastructure, and to a lesser extent household size. Recommendations includes, all tiers of government to intensify efforts in providing water infrastructures and existing ones through budgetary provisions, and communities should organize fund raising bazaar, so as to raise fund to improve water infrastructures in the area.Keywords: accessibility, determined, stratified, scope
Procedia PDF Downloads 3921714 Robustness of the Deep Chroma Extractor and Locally-Normalized Quarter Tone Filters in Automatic Chord Estimation under Reverberant Conditions
Authors: Luis Alvarado, Victor Poblete, Isaac Gonzalez, Yetzabeth Gonzalez
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In MIREX 2016 (http://www.music-ir.org/mirex), the deep neural network (DNN)-Deep Chroma Extractor, proposed by Korzeniowski and Wiedmer, reached the highest score in an audio chord recognition task. In the present paper, this tool is assessed under acoustic reverberant environments and distinct source-microphone distances. The evaluation dataset comprises The Beatles and Queen datasets. These datasets are sequentially re-recorded with a single microphone in a real reverberant chamber at four reverberation times (0 -anechoic-, 1, 2, and 3 s, approximately), as well as four source-microphone distances (32, 64, 128, and 256 cm). It is expected that the performance of the trained DNN will dramatically decrease under these acoustic conditions with signals degraded by room reverberation and distance to the source. Recently, the effect of the bio-inspired Locally-Normalized Cepstral Coefficients (LNCC), has been assessed in a text independent speaker verification task using speech signals degraded by additive noise at different signal-to-noise ratios with variations of recording distance, and it has also been assessed under reverberant conditions with variations of recording distance. LNCC showed a performance so high as the state-of-the-art Mel Frequency Cepstral Coefficient filters. Based on these results, this paper proposes a variation of locally-normalized triangular filters called Locally-Normalized Quarter Tone (LNQT) filters. By using the LNQT spectrogram, robustness improvements of the trained Deep Chroma Extractor are expected, compared with classical triangular filters, and thus compensating the music signal degradation improving the accuracy of the chord recognition system.Keywords: chord recognition, deep neural networks, feature extraction, music information retrieval
Procedia PDF Downloads 2321713 Augmentation of Conventional Medicine for Post-concussion Syndrome with Cognitive Behavioral Therapy Accelerates Symptomatic Relief in Affected Individuals
Authors: Waqas Mehdi, Muhammad Umar Hassan, Khadeeja Mustafa
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Objective: Post-concussion syndrome (PCS) is a medical term used to point out the complicated combination of physical, emotional, cognitive and behavioral signs and symptoms associated with Mild Traumatic Brain Injury(mTBI). This study was conducted to assess the improvement or debilitating effect of behavioral therapy in addition to the conventional treatment and to document these results for increasing the efficiency of treatment provided to such cases. Method: This was primarily an interventional prospective cohort study which was conducted in the Department of Neurosurgery, Mayo Hospital Lahore. The sample size was 200 patients who were randomly distributed into two groups. The interventional group with Cognitive behavioral therapy was added in addition to the conventional treatment regimen and the Control group receiving only conventional treatment. Results were noted initially as well as after two weeks of the follow-up period. Data were subsequently analyzed by Statistical Package for Social Sciences (SPSS) software and associations worked out. Result and conclusion: Among the patients that were given therapy sessions along with conventional medicine, there was a significant improvement in the symptoms and their overall quality of life. It is also important to notice that the time period taken for these effects to wane is cut down by psychiatric solutions too. So we can conclude that CBT sessions not only speed up recovery in patients with post-concussion syndrome they also aid in the efficiency improvement in functional capability and quality of life.Keywords: neurosurgery, CBT, PCS, mTBI
Procedia PDF Downloads 1641712 Methods for Enhancing Ensemble Learning or Improving Classifiers of This Technique in the Analysis and Classification of Brain Signals
Authors: Seyed Mehdi Ghezi, Hesam Hasanpoor
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This scientific article explores enhancement methods for ensemble learning with the aim of improving the performance of classifiers in the analysis and classification of brain signals. The research approach in this field consists of two main parts, each with its own strengths and weaknesses. The choice of approach depends on the specific research question and available resources. By combining these approaches and leveraging their respective strengths, researchers can enhance the accuracy and reliability of classification results, consequently advancing our understanding of the brain and its functions. The first approach focuses on utilizing machine learning methods to identify the best features among the vast array of features present in brain signals. The selection of features varies depending on the research objective, and different techniques have been employed for this purpose. For instance, the genetic algorithm has been used in some studies to identify the best features, while optimization methods have been utilized in others to identify the most influential features. Additionally, machine learning techniques have been applied to determine the influential electrodes in classification. Ensemble learning plays a crucial role in identifying the best features that contribute to learning, thereby improving the overall results. The second approach concentrates on designing and implementing methods for selecting the best classifier or utilizing meta-classifiers to enhance the final results in ensemble learning. In a different section of the research, a single classifier is used instead of multiple classifiers, employing different sets of features to improve the results. The article provides an in-depth examination of each technique, highlighting their advantages and limitations. By integrating these techniques, researchers can enhance the performance of classifiers in the analysis and classification of brain signals. This advancement in ensemble learning methodologies contributes to a better understanding of the brain and its functions, ultimately leading to improved accuracy and reliability in brain signal analysis and classification.Keywords: ensemble learning, brain signals, classification, feature selection, machine learning, genetic algorithm, optimization methods, influential features, influential electrodes, meta-classifiers
Procedia PDF Downloads 751711 First Rank Symptoms in Mania: An Indistinct Diagnostic Strand
Authors: Afshan Channa, Sameeha Aleem, Harim Mohsin
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First rank symptoms (FRS) are considered to be pathognomic for Schizophrenia. However, FRS is not a distinctive feature of Schizophrenia. It has also been noticed in affective disorder, albeit not inclusive in diagnostic criteria. The presence of FRS in Mania leads to misdiagnosis of psychotic illness, further complicating the management and delay of appropriate treatment. FRS in Mania is associated with poor clinical and functional outcome. Its existence in the first episode of bipolar disorder may be a predictor of poor short-term outcome and decompensating course of illness. FRS in Mania is studied in west. However, the cultural divergence and detriments make it pertinent to study the frequency of FRS in affective disorder independently in Pakistan. Objective: The frequency of first rank symptoms in manic patients, who were under treatment at psychiatric services of tertiary care hospital. Method: The cross sectional study was done at psychiatric services of Aga Khan University Hospital, Karachi, Pakistan. One hundred and twenty manic patients were recruited from November 2014 to May 2015. The patients who were unable to comprehend Urdu or had comorbid psychiatric or organic disorder were excluded. FRS was assessed by administration of validated Urdu version of Present State Examination (PSE) tool. Result: The mean age of the patients was 37.62 + 12.51. The mean number of previous manic episode was 2.17 + 2.23. 11.2% males and 30.6% females had FRS. This association of first rank symptoms with gender in patients of mania was found to be significant with a p-value of 0.008. All-inclusive, 19.2% exhibited FRS in their course of illness. 43.5% had thought broadcasting, made feeling, impulses, action and somatic passivity. 39.1% had thought insertion, 30.4% had auditory perceptual distortion, and 17.4% had thought withdrawal. However, none displayed delusional perception. Conclusion: The study confirms the presence of FRS in mania in both male and female, irrespective of the duration of current manic illness or previous number of manic episodes. A substantial difference was established between both the genders. Being married had no protective effect on the presence of FRS.Keywords: first rank symptoms, Mania, psychosis, present state examination
Procedia PDF Downloads 3791710 Modelling Heat Transfer Characteristics in the Pasteurization Process of Medium Long Necked Bottled Beers
Authors: S. K. Fasogbon, O. E. Oguegbu
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Pasteurization is one of the most important steps in the preservation of beer products, which improves its shelf life by inactivating almost all the spoilage organisms present in it. However, there is no gain saying the fact that it is always difficult to determine the slowest heating zone, the temperature profile and pasteurization units inside bottled beer during pasteurization, hence there had been significant experimental and ANSYS fluent approaches on the problem. This work now developed Computational fluid dynamics model using COMSOL Multiphysics. The model was simulated to determine the slowest heating zone, temperature profile and pasteurization units inside the bottled beer during the pasteurization process. The results of the simulation were compared with the existing data in the literature. The results showed that, the location and size of the slowest heating zone is dependent on the time-temperature combination of each zone. The results also showed that the temperature profile of the bottled beer was found to be affected by the natural convection resulting from variation in density during pasteurization process and that the pasteurization unit increases with time subject to the temperature reached by the beer. Although the results of this work agreed with literatures in the aspects of slowest heating zone and temperature profiles, the results of pasteurization unit however did not agree. It was suspected that this must have been greatly affected by the bottle geometry, specific heat capacity and density of the beer in question. The work concludes that for effective pasteurization to be achieved, there is a need to optimize the spray water temperature and the time spent by the bottled product in each of the pasteurization zones.Keywords: modeling, heat transfer, temperature profile, pasteurization process, bottled beer
Procedia PDF Downloads 2031709 Enhancing Robustness in Federated Learning through Decentralized Oracle Consensus and Adaptive Evaluation
Authors: Peiming Li
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This paper presents an innovative blockchain-based approach to enhance the reliability and efficiency of federated learning systems. By integrating a decentralized oracle consensus mechanism into the federated learning framework, we address key challenges of data and model integrity. Our approach utilizes a network of redundant oracles, functioning as independent validators within an epoch-based training system in the federated learning model. In federated learning, data is decentralized, residing on various participants' devices. This scenario often leads to concerns about data integrity and model quality. Our solution employs blockchain technology to establish a transparent and tamper-proof environment, ensuring secure data sharing and aggregation. The decentralized oracles, a concept borrowed from blockchain systems, act as unbiased validators. They assess the contributions of each participant using a Hidden Markov Model (HMM), which is crucial for evaluating the consistency of participant inputs and safeguarding against model poisoning and malicious activities. Our methodology's distinct feature is its epoch-based training. An epoch here refers to a specific training phase where data is updated and assessed for quality and relevance. The redundant oracles work in concert to validate data updates during these epochs, enhancing the system's resilience to security threats and data corruption. The effectiveness of this system was tested using the Mnist dataset, a standard in machine learning for benchmarking. Results demonstrate that our blockchain-oriented federated learning approach significantly boosts system resilience, addressing the common challenges of federated environments. This paper aims to make these advanced concepts accessible, even to those with a limited background in blockchain or federated learning. We provide a foundational understanding of how blockchain technology can revolutionize data integrity in decentralized systems and explain the role of oracles in maintaining model accuracy and reliability.Keywords: federated learning system, block chain, decentralized oracles, hidden markov model
Procedia PDF Downloads 631708 Investigating the Combined Medicinal Effects of Withania Somnifera (Ashwaghandha) and Murraya Koenigii (Curry Pata) in Vitro
Authors: Sadia Roshan, Kulsoom Sughra, Shazia Shamas, Shamaila Irum, Haleema Sadia
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To evaluate synergistic medicinal effects of Withania somnifera (Ashwaghandha) and Murraya koenigii (Curry pata) in vitro. Antimicrobial activity was determined using the disc diffusion method against five bacterial and two fungal strains. The antioxidant activity was evaluated by the DPPH assay. The antidiabetic activity was evaluated by alpha-glucosidase inhibition assay and alpha-amylase inhibition assay. Synergistic antibacterial activity was observed against all the strains of bacteria, either Gram-positive or Gram-negative and fungi under study conditions. The maximum antibacterial activity was displayed by combined extract against E. coli i.e. 26±0.4mm. Maximum antifungal activity was shown by combined extract against Aspergillus niger, i.e., 17.3±0.5mm. The antioxidant activity of the combined extract was also significant. Alpha-glucosidase inhibition and alpha-amylase inhibition assays also showed synergism. Results indicate that Withania somnifera and Murraya koengii have medicinal properties. The combined extract of both plants is more potent than their individual extracts, suggesting that these can work in synergism. The research suggests that different plant extracts could be used in combination to increase their medicinal activities by many folds, thus giving an insight into future use of herbal medication.Keywords: withania somnifera, murraya koenigii, antimicrobial activity, gram-positive bacetria, gram-negative bacteria
Procedia PDF Downloads 791707 Neo-Adjuvant B-CAT Chemotherapy in Triple Negative Breast Cancer
Authors: Muneeb Nasir, Misbah Masood, Farrukh Rashid, Abubabakar Shahid
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Introduction: Neo-adjuvant chemotherapy is a potent option for triple negative breast cancer (TNBC) as these tumours lack a clearly defined therapeutic target. Several recent studies lend support that pathological complete remission (pCR) is associated with improved disease free survival (DFS) and overall survival (OS) and could be used as surrogate marker for DFS and OS in breast cancer patients. Methods: We have used a four-drug protocol in T3 and T4 TNBC patients either N+ or N- in the neo-adjuvant setting. The 15 patients enrolled in this study had a median age of 45 years. 12 patients went on to complete four planned cycles of B-CAT protocol. The chemotherapy regimen included inj. Bevacizumab 5mg/kg D1, inj. Adriamycin 50mg/m2 D1 and Docetaxel 65mg/m2 on D1. Inj. Cisplatin 60mg/m2 on D2. All patients received GCF support from D4 to D9 of each cycle. Results: Radiological assessment using ultrasound and PET-CT revealed a high percentage of responses. Radiological CR was documented in half of the patients (6/12) after four cycles. Remaining patients went on to receive 2 more cycles before undergoing radical surgery. pCR was documented in 7/12 patients and 3 more had a good partial response. The regimen was toxic and grade ¾ neutropenia was seen in 58% of patients. Four episodes of febrile neutropenia were reported and managed. Non-hematatological toxicities were common with mucositis, diarrhea, asthenia and neuropathy topping the list. Conclusion: B-CAT is a very active combination with very high pCR rates in TNBC. Toxicities though frequent, were manageable on outpatient basis. This protocol warrants further investigation.Keywords: B-CAT:bevacizumab, cisplatin, adriamycin, taxotere, CR: complete response, pCR: pathological complete response, TNBC: triple negative breast cancer
Procedia PDF Downloads 2601706 Developing a Virtual Reality System to Assist in Anatomy Teaching and Evaluating the Effectiveness of That System
Authors: Tarek Abdelkader, Suresh Selvaraj, Prasad Iyer, Yong Mun Hin, Hajmath Begum, P. Gopalakrishnakone
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Nowadays, more and more educational institutes, as well as students, rely on 3D anatomy programs as an important tool that helps students correlate the actual locations of anatomical structures in a 3D dimension. Lately, virtual reality (VR) is gaining more favor from the younger generations due to its higher interactive mode. As a result, using virtual reality as a gamified learning platform for anatomy became the current goal. We present a model where a Virtual Human Anatomy Program (VHAP) was developed to assist with the anatomy learning experience of students. The anatomy module has been built, mostly, from real patient CT scans. Segmentation and surface rendering were used to create the 3D model by direct segmentation of CT scans for each organ individually and exporting that model as a 3D file. After acquiring the 3D files for all needed organs, all the files were introduced into a Virtual Reality environment as a complete body anatomy model. In this ongoing experiment, students from different Allied Health orientations are testing the VHAP. Specifically, the cardiovascular system has been selected as the focus system of study since all of our students finished learning about it in the 1st trimester. The initial results suggest that the VHAP system is adding value to the learning process of our students, encouraging them to get more involved and to ask more questions. Involved students comments show that they are excited about the VHAP system with comments about its interactivity as well as the ability to use it solo as a self-learning aid in combination with the lectures. Some students also experienced minor side effects like dizziness.Keywords: 3D construction, health sciences, teaching pedagogy, virtual reality
Procedia PDF Downloads 1561705 Series Connected GaN Resonant Tunneling Diodes for Multiple-Valued Logic
Authors: Fang Liu, JunShuai Xue, JiaJia Yao, XueYan Yang, ZuMao Li, GuanLin Wu, HePeng Zhang, ZhiPeng Sun
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III-Nitride resonant tunneling diode (RTD) is one of the most promising candidates for multiple-valued logic (MVL) elements. Here, we report a monolithic integration of GaN resonant tunneling diodes to realize multiple negative differential resistance (NDR) regions for MVL application. GaN RTDs, composed of a 2 nm quantum well embedded in two 1 nm quantum barriers, are grown by plasma-assisted molecular beam epitaxy on free-standing c-plane GaN substrates. Negative differential resistance characteristic with a peak current density of 178 kA/cm² in conjunction with a peak-to-valley current ratio (PVCR) of 2.07 is observed. Statistical properties exhibit high consistency showing a peak current density standard deviation of almost 1%, laying the foundation for the monolithic integration. After complete electrical isolation, two diodes of the designed same area are connected in series. By solving the Poisson equation and Schrodinger equation in one dimension, the energy band structure is calculated to explain the transport mechanism of the differential negative resistance phenomenon. Resonant tunneling events in a sequence of the series-connected RTD pair (SCRTD) form multiple NDR regions with nearly equal peak current, obtaining three stable operating states corresponding to ternary logic. A frequency multiplier circuit achieved using this integration is demonstrated, attesting to the robustness of this multiple peaks feature. This article presents a monolithic integration of SCRTD with multiple NDR regions driven by the resonant tunneling mechanism, which can be applied to a multiple-valued logic field, promising a fast operation speed and a great reduction of circuit complexity and demonstrating a new solution for nitride devices to break through the limitations of binary logic.Keywords: GaN resonant tunneling diode, multiple-valued logic system, frequency multiplier, negative differential resistance, peak-to-valley current ratio
Procedia PDF Downloads 811704 Influence of Precipitation and Land Use on Extreme Flow in Prek Thnot River Basin of Mekong River in Cambodia
Authors: Chhordaneath Hen, Ty Sok, Ilan Ich, Ratboren Chan, Chantha Oeurng
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The damages caused by hydrological extremes such as flooding have been severe globally, and several research studies indicated extreme precipitations play a crucial role. Cambodia is one of the most vulnerable countries exposed to floods and drought as consequences of climate impact. Prek Thnot River Basin in the southwest part of Cambodia, which is in the plate and plateau region and a part of the Mekong Delta, was selected to investigate the changes in extreme precipitation and hydrological extreme. Furthermore, to develop a statistical relationship between these phenomena in this basin from 1995 to 2020 using Multiple Linear Regression. The precipitation and hydrological extreme were assessed via the attributes and trends of rainfall patterns during the study periods. The extreme flow was defined as a dependent variable, while the independent variables are various extreme precipitation indices. The study showed that all extreme precipitations indices (R10, R20, R35, CWD, R95p, R99p, and PRCPTOT) had increasing decency. However, the number of rain days per year had a decreasing tendency, which can conclude that extreme rainfall was more intense in a shorter period of the year. The study showed a similar relationship between extreme precipitation and hydrological extreme and land use change association with hydrological extreme. The direct combination of land use and precipitation equals 37% of the flood causes in this river. This study provided information on these two causes of flood events and an understanding of expectations of climate change consequences for flood and water resources management.Keywords: extreme precipitation, hydrological extreme, land use, land cover, Prek Thnot river basin
Procedia PDF Downloads 1111703 Seismic Response of Structures of Reinforced Concrete Buildings: Regular and Irregular Configurations
Authors: Abdelhammid Chibane
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Often, for architectural reasons or designs, several buildings have a non-uniform profile in elevation. Depending on the configuration of the construction and the arrangements structural elements, the non-uniform profile in elevation (the recess) is considered concept of a combination of non-uniform distributions of strength, stiffness, weight and geometry along the height of irregular structures. Therefore, this type of configuration can induce irregular distribution load causing a serious concentration stresses at the discontinuity. This therefore requires a serious behavioral treatment buildings in an earthquake. If appropriate measures are not taken into account, structural irregularity may become a major source of damage during earthquakesEarth. In the past, several research investigations have identified differences in dynamic response of irregular and regular porches. Among the most notable differences are the increments of displacements and ductility applications in floors located above the level of the shoulder and an increase in the contribution of the higher modes cisaillement1 efforts, ..., 10. The para -ssismiques codes recommend the methods of analysis Dynamic (or modal history) to establish the forces of calculation instead of the static method equivalent, which is basically applicable only to regular structures without major discontinuities in the mass, rigidity and strength along the height 11, 12 .To investigate the effects of irregular profiles on the structures, the main objective of this study was the assessment of the inelastic response, in terms of applications of ductility four types of non-uniform multi-stage structures subjected to relatively severe earthquakes. In the This study, only the parallel responses are analyzed setback.Keywords: buildings, concentration stresses, ductility, ductility, designs, irregular structures
Procedia PDF Downloads 2621702 Cost Valuation Method for Development Concurrent, Phase Appropriate Requirement Valuation Using the Example of Load Carrier Development in the Lithium-Ion-Battery Production
Authors: Achim Kampker, Christoph Deutskens, Heiner Hans Heimes, Mathias Ordung, Felix Optehostert
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In the past years electric mobility became part of a public discussion. The trend to fully electrified vehicles instead of vehicles fueled with fossil energy has notably gained momentum. Today nearly every big car manufacturer produces and sells fully electrified vehicles, but electrified vehicles are still not as competitive as conventional powered vehicles. As the traction battery states the largest cost driver, lowering its price is a crucial objective. In addition to improvements in product and production processes a non-negligible, but widely underestimated cost driver of production can be found in logistics, since the production technology is not continuous yet and neither are the logistics systems. This paper presents an approach to evaluate cost factors on different designs of load carrier systems. Due to numerous interdependencies, the combination of costs factors for a particular scenario is not transparent. This is effecting actions for cost reduction negatively, but still cost reduction is one of the major goals for simultaneous engineering processes. Therefore a concurrent and phase appropriate cost valuation method is necessary to serve cost transparency. In this paper the four phases of this cost valuation method are defined and explained, which based upon a new approach integrating the logistics development process in to the integrated product and process development.Keywords: research and development, technology and innovation, lithium-ion-battery production, load carrier development process, cost valuation method
Procedia PDF Downloads 5941701 The Sociology of the Facebook: An Exploratory Study
Authors: Liana Melissa E. de la Rosa, Jayson P. Ada
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This exploratory study was conducted to determine the sociology of the Facebook. Specifically, it aimed to know the socio-demographic profile of the respondents in terms of age, sex, year level and monthly allowance; find out the common usage of Facebook to the respondents; identify the features of Facebook that are commonly used by the respondents; understand the benefits and risks of using the Facebook; determine how frequent the respondents use the Facebook; and find out if there is a significant relationship between socio-demographic profile of the respondents and their Facebook usage. This study used the exploratory research design and correlational design employing research survey questionnaire as its main data gathering instrument. Students of the University of Eastern Philippines were selected as the respondents of this study through quota sampling. Ten (10) students were randomly selected from each college of the university. Based on the findings of this study, the following conclusion were drawn: The majority of the respondents are aged 18 and 21 old, female, are third year students, and have monthly allowance of P 2,000 above. On the respondents’ usage of Facebook, the majority of use the Facebook on a daily basis for one to two (1-2) hours everyday. And most users used Facebook by renting a computer in an internet cafe. On the use of Facebook, most users have created their profiles mainly to connect with people and gain new friends. The most commonly used features of Facebook, are: photos application, like button, wall, notification, friend, chat, network, groups and “like” pages status updates, messages and inbox and events. While the other Facebook features that are seldom used by the respondents are games, news feed, user name, video sharing and notes. And the least used Facebook features are questions, poke feature, credits and the market place. The respondents stated that the major benefit that the Facebook has given to its users is its ability to keep in touch with family members or friends while the main risk identified is that the users can become addicted to the Internet. On the tests of relationships between the respondents’ use of Facebook and the four (4) socio-demographic profile variables: age, sex, year level, and month allowance, were found to be not significantly related to the respondents’ use of the Facebook. While the variable found to be significantly related was gender.Keywords: Facebook, sociology, social networking, exploratory study
Procedia PDF Downloads 2891700 Histone Deacetylases Inhibitor - Valproic Acid Sensitizes Human Melanoma Cells for alkylating agent and PARP inhibitor
Authors: Małgorzata Drzewiecka, Tomasz Śliwiński, Maciej Radek
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The inhibition of histone deacetyles (HDACs) holds promise as a potential anti-cancer therapy because histone and non-histone protein acetylation is frequently disrupted in cancer, leading to cancer initiation and progression. Additionally, histone deacetylase inhibitors (HDACi) such as class I HDAC inhibitor - valproic acid (VPA) have been shown to enhance the effectiveness of DNA-damaging factors, such as cisplatin or radiation. In this study, we found that, using of VPA in combination with talazoparib (BMN-637 – PARP1 inhibitor – PARPi) and/or Dacarabazine (DTIC - alkylating agent) resulted in increased DNA double strand break (DSB) and reduced survival (while not affecting primary melanocytes )and proliferation of melanoma cells. Furthermore, pharmacologic inhibition of class I HDACs sensitizes melanoma cells to apoptosis following exposure to DTIC and BMN-637. In addition, inhibition of HDAC caused sensitization of melanoma cells to dacarbazine and BMN-637 in melanoma xenografts in vivo. At the mRNA and protein level histone deacetylase inhibitor downregulated RAD51 and FANCD2. This study provides that combining HDACi, alkylating agent and PARPi could potentially enhance the treatment of melanoma, which is known for being one of the most aggressive malignant tumors. The findings presented here point to a scenario in which HDAC via enhancing the HR-dependent repair of DSBs created during the processing of DNA lesions, are essential nodes in the resistance of malignant melanoma cells to methylating agent-based therapies.Keywords: melanoma, hdac, parp inhibitor, valproic acid
Procedia PDF Downloads 821699 Pattern of Bacterial Isolates and Antimicrobial Resistance at Ayder Comprehensive Specialized Referral Hospital in Northern Ethiopia: A Retrospective Study
Authors: Solomon Gebremariam, Mulugeta Naizigi, Aregawi Haileselassie
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Background: Knowledge of the pattern of bacterial isolates and their antimicrobial susceptibility is crucial for guiding empirical treatment and infection prevention and control measures. Objective: The aim of this study was to analyze the pattern of bacterial isolates and their susceptibility patterns from various specimens. Methods: Retrospectively, a total of 1067 microbiological culture results that were isolated, characterized, and identified by standard microbiological methods and whose antibiotic susceptibility was determined using CLSI guidelines between 2017 and 2019 were retrieved and analyzed. Data were entered and analyzed using the Stata release 10.1 statistical package. Result: The positivity rate of culture was 26.04% (419/1609). The most common bacteria isolated were S. aureus 23.8% (94), E. coli 15.1% (60), Klebsiella pneumonia 14.1% (56), Pseudomonas aeruginosa 8.5% (34), and CONS 7.3% (29). S. aureus and CONS showed a high (58.1% - 96.2%) rate of resistance to most antibiotics tested. They were less resistant to Vancomycin which is 18.6% (13/70) and 11.8% (2/17), respectively. Similarly, the resistance of E. coli, Klebsella pneumonia, and Pseudomonas aeruginosa was high (69.4% - 100%) to most antibiotics. They were less resistant to Ciprofloxacilin, which is 41.1% (23/56), 19.2% (10/52), and 16.1% (5/31), respectively. Conclusion: This study has shown that there is a high rate of antibiotic resistance among bacterial isolates in this hospital. A combination of Vancomycin and Ciprofloxacin should be considered in the choice of antibiotics for empirical treatment of suspected infections due to S. aureus, CONS, E. coli, Klebsiella pneumonia, Pseudomonas such as in infections within hospital setup.Keywords: antimicrobial, resistance, bacteria, hospital
Procedia PDF Downloads 741698 Identification of Associated-Virulence Genes in Quinolone-Resistant Escherichia coli Strains Recovered from an Urban Wastewater Treatment Plant
Authors: Alouache Souhila, Messai Yamina, Torres Carmen, Bakour Rabah
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Objective: It has often been reported an association between antibiotic resistance and virulence. However, resistance to quinolones seems to be an exception, it tends instead to be associated with an attenuation of virulence, particularly in clinical strains. The purpose of this study was to evaluate the potential virulence of 28 quinolone-resistant E. coli strains recovered from water at the inflow (n=16) and outflow (n=12) of an urban wastewater treatment plant (WWTP). Methods: E. coli isolates were selected on Tergitol-7 agar supplemented with 2µg/ml of ciprofloxacin, they were screened by PCR for 11 virulence genes related to Extraintestinal pathogenic E. coli (ExPEC): papC, papG, afa/draBC, sfa/foc, kpsMTII, iutA, iroN, hlyF, ompT, iss and traT. The phylogenetic groups were determined by PCR and clonal relationship was evaluated by ERIC-PCR. Results: Genotyping by ERIC-PCR showed 7 and 12 DNA profiles among strains of wastewater (inflow) and treated water (outflow), respectively. Strains were assigned to the following phylogenetic groups: B2 (n = 1, 3.5%), D (n = 3, 10.7%), B1 (n = 10, 35.7%.) and A (n = 14, 50%). A total of 8 virulence-associated genes were detected, traT (n=19, 67.8%), iroN (n= 16, 57 .1%), hlyF (n=15, 53 .5%), ompT (n=15, 53 .5%), iss (n=14, 50%), iutA (n=9, 32.1%) , sfa/foc (n=7, 25%) and kpsMTII (n=2, 7.1%). Combination of virulence factors allowed to define 16 virulence profiles. The pathotype APEC was observed in 17.8% (D=1, B1=4) and human ExPEC in 7% (B2=1, D=1) of strains. Conclusion: The study showed that quinolone-resistant E. coli strains isolated from wastewater and treated water in WWTP harbored virulence genes with the presence of APEC and human ExPEC strains.Keywords: E. coli, quinolone-resistance, virulence, WWTP
Procedia PDF Downloads 4651697 Hand Gesture Detection via EmguCV Canny Pruning
Authors: N. N. Mosola, S. J. Molete, L. S. Masoebe, M. Letsae
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Hand gesture recognition is a technique used to locate, detect, and recognize a hand gesture. Detection and recognition are concepts of Artificial Intelligence (AI). AI concepts are applicable in Human Computer Interaction (HCI), Expert systems (ES), etc. Hand gesture recognition can be used in sign language interpretation. Sign language is a visual communication tool. This tool is used mostly by deaf societies and those with speech disorder. Communication barriers exist when societies with speech disorder interact with others. This research aims to build a hand recognition system for Lesotho’s Sesotho and English language interpretation. The system will help to bridge the communication problems encountered by the mentioned societies. The system has various processing modules. The modules consist of a hand detection engine, image processing engine, feature extraction, and sign recognition. Detection is a process of identifying an object. The proposed system uses Canny pruning Haar and Haarcascade detection algorithms. Canny pruning implements the Canny edge detection. This is an optimal image processing algorithm. It is used to detect edges of an object. The system employs a skin detection algorithm. The skin detection performs background subtraction, computes the convex hull, and the centroid to assist in the detection process. Recognition is a process of gesture classification. Template matching classifies each hand gesture in real-time. The system was tested using various experiments. The results obtained show that time, distance, and light are factors that affect the rate of detection and ultimately recognition. Detection rate is directly proportional to the distance of the hand from the camera. Different lighting conditions were considered. The more the light intensity, the faster the detection rate. Based on the results obtained from this research, the applied methodologies are efficient and provide a plausible solution towards a light-weight, inexpensive system which can be used for sign language interpretation.Keywords: canny pruning, hand recognition, machine learning, skin tracking
Procedia PDF Downloads 1851696 Building Information Modelling (BIM) and Unmanned Aerial Vehicles (UAV) Technologies in Road Construction Project Monitoring and Management: Case Study of a Project in Cyprus
Authors: Yiannis Vacanas, Kyriacos Themistocleous, Athos Agapiou, Diofantos Hadjimitsis
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Building Information Modelling (BIM) technology is considered by construction professionals as a very valuable process in modern design, procurement and project management. Construction professionals of all disciplines can use a single 3D model which BIM technology provides, to design a project accurately and furthermore monitor the progress of construction works effectively and efficiently. Unmanned Aerial Vehicles (UAVs), a technology initially developed for military applications, is now without any difficulty accessible and has already been used by commercial industries, including the construction industry. UAV technology has mainly been used for collection of images that allow visual monitoring of building and civil engineering projects conditions in various circumstances. UAVs, nevertheless, have undergone significant advances in equipment capabilities and now have the capacity to acquire high-resolution imagery from many angles in a cost effective manner, and by using photogrammetry methods, someone can determine characteristics such as distances, angles, areas, volumes and elevations of an area within overlapping images. In order to examine the potential of using a combination of BIM and UAV technologies in construction project management, this paper presents the results of a case study of a typical road construction project where the combined use of the two technologies was used in order to achieve efficient and accurate as-built data collection of the works progress, with outcomes such as volumes, and production of sections and 3D models, information necessary in project progress monitoring and efficient project management.Keywords: BIM, project management, project monitoring, UAV
Procedia PDF Downloads 3031695 Design and Development of a Safety Equipment and Accessory for Bicycle Users
Authors: Francine Siy, Stephen Buñi
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Safety plays a significant role in everyone’s life on a day-to-day basis. We wish ourselves and our loved ones their safety as we all venture out on our daily commute. The road is undeniably dangerous and unpredictable, with abundant traffic collisions and pedestrians experiencing various injuries. For bicycle users, the risk of accidents is even more exacerbated, and injuries may be severe. Even when cyclists try their best to be safe and protected, the possibility of encountering danger is always there. Despite being equipped with protective gear, safety is never guaranteed. Cyclists often settle for helmets and standard reflector vests to establish a presence on the road. There are different types of vests available, depending on the profession. However, traditional reflector vests, mostly seen on construction workers and traffic enforcers, were not designed for riders and their protection from injuries. With insufficient protection for riders, they need access to ergonomically designed equipment and accessories that suit the riders and cater to their needs. This research aimed to offer a protective vest with safety features for riders that is comfortable, effective, durable, and intuitive. This sheds light and addresses the safety of the biker population, which continuously grows through the years. The product was designed and developed by gathering data and using the cognitive mapping method to ensure that all qualitative and quantitative data were considered in this study to improve other existing products that do not have the proper design considerations. It is known that available equipment for cyclists is often sold separately or lacks the safety features for cyclists traversing open roads. Each safety feature like the headlights, reflectors, signal or rear lights, zipper pouch, body camera attachment, and wireless remote control all play a particular role in helping cyclists embark on their daily commute. These features aid in illumination, visibility, easy maneuvering, convenience, and security, allowing cyclists to go for a safer ride that is of use throughout the day. The product is designed and produced effectively and inexpensively without sacrificing the quality and purpose of its usage.Keywords: bicycle accessory, protective gear, safety, transport, visibility
Procedia PDF Downloads 831694 Biaxial Fatigue Specimen Design and Testing Rig Development
Authors: Ahmed H. Elkholy
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An elastic analysis is developed to obtain the distribution of stresses, strains, bending moment and deformation for a thin hollow, variable thickness cylindrical specimen when subjected to different biaxial loadings. The specimen was subjected to a combination of internal pressure, axial tensile loading and external pressure. Several axial to circumferential stress ratios were investigated in detail. The analytical model was then validated using experimental results obtained from a test rig using several biaxial loadings. Based on the preliminary results obtained, the specimen was then modified geometrically to ensure uniform strain distribution through its wall thickness and along its gauge length. The new design of the specimen has a higher buckling strength and a maximum value of equivalent stress according to the maximum distortion energy theory. A cyclic function generator of the standard servo-controlled, electro-hydraulic testing machine is used to generate a specific signal shape (sine, square,…) at a certain frequency. The two independent controllers of the electronic circuit cause an independent movement to each servo-valve piston. The movement of each piston pressurizes the upper and lower sides of the actuators alternately. So, the specimen will be subjected to axial and diametral loads independent of each other. The hydraulic system has two different pressures: one pressure will be responsible for axial stress produced in the specimen and the other will be responsible for the tangential stress. Changing the two pressure ratios will change the stress ratios accordingly. The only restriction on the maximum stress obtained is the capacity of the testing system and specimen instability due to buckling.Keywords: biaxial, fatigue, stress, testing
Procedia PDF Downloads 1281693 Antibacterial Activity of Silver Nanoparticles of Extract of Leaf of Nauclea latifolia (Sm.) against Some Selected Clinical Isolates
Authors: Mustapha Abdulsalam, R. N. Ahmed
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Nauclea latifolia is one of the medicinal plants used in traditional Nigerian medicine in the treatment of various diseases such as fever, toothaches, malaria, diarrhea among several other conditions. Nauclea latifolia leaf extract acts as a capping and reducing agent in the formation of silver nanoparticles. Silver nanoparticles (AgNPs) were synthesized using a combination of aqueous extract of Nauclea latifolia and 1mM of silver nitrate (AgNO₃) solution to obtain concentrations of 100mg/ml-400mg/ml. Characterization of the particles was done by UV-Vis spectroscopy and Fourier transform infrared (FTIR). In this study, aqueous as well as ethanolic extract of leaf of Nauclea latifolia were investigated for antibacterial activity using the standard agar well diffusion technique against three clinical isolates (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa). The Minimum Inhibitory Concentration (MIC) was achieved by microbroth dilution method and Minimum Bactericidal Concentration (MBC) was also determined by plate assay. Characterization by UV-visible spectrometry revealed peak absorbance of 0.463 at 450.0nm, while FTIR showed the presence of two functional groups. At 400mg/ml, the highest inhibitory activities were observed with S.aureus and E.coli with zones of inhibition measuring 20mm and 18mm respectively. The MIC was obtained at 400mg/ml while MBC was at a higher concentration. The data from this study indicate the potential of silver nanoparticle of Nauclea latifolia as a suitable alternative antibacterial agent for incorporation into orthodox medicine in health care delivery in Nigeria.Keywords: agar well diffusion, antimicrobial activity, Nauclea latifolia, silver nanoparticles
Procedia PDF Downloads 2061692 Co-Design of Accessible Speech Recognition for Users with Dysarthric Speech
Authors: Elizabeth Howarth, Dawn Green, Sean Connolly, Geena Vabulas, Sara Smolley
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Through the EU Horizon 2020 Nuvoic Project, the project team recruited 70 individuals in the UK and Ireland to test the Voiceitt speech recognition app and provide user feedback to developers. The app is designed for people with dysarthric speech, to support communication with unfamiliar people and access to speech-driven technologies such as smart home equipment and smart assistants. Participants with atypical speech, due to a range of conditions such as cerebral palsy, acquired brain injury, Down syndrome, stroke and hearing impairment, were recruited, primarily through organisations supporting disabled people. Most had physical or learning disabilities in addition to dysarthric speech. The project team worked with individuals, their families and local support teams, to provide access to the app, including through additional assistive technologies where needed. Testing was user-led, with participants asked to identify and test use cases most relevant to their daily lives over a period of three months or more. Ongoing technical support and training were provided remotely and in-person throughout the testing period. Structured interviews were used to collect feedback on users' experiences, with delivery adapted to individuals' needs and preferences. Informal feedback was collected through ongoing contact between participants, their families and support teams and the project team. Focus groups were held to collect feedback on specific design proposals. User feedback shared with developers has led to improvements to the user interface and functionality, including faster voice training, simplified navigation, the introduction of gamification elements and of switch access as an alternative to touchscreen access, with other feature requests from users still in development. This work offers a case-study in successful and inclusive co-design with the disabled community.Keywords: co-design, assistive technology, dysarthria, inclusive speech recognition
Procedia PDF Downloads 1101691 MANIFEST-2, a Global, Phase 3, Randomized, Double-Blind, Active-Control Study of Pelabresib (CPI-0610) and Ruxolitinib vs. Placebo and Ruxolitinib in JAK Inhibitor-Naïve Myelofibrosis Patients
Authors: Claire Harrison, Raajit K. Rampal, Vikas Gupta, Srdan Verstovsek, Moshe Talpaz, Jean-Jacques Kiladjian, Ruben Mesa, Andrew Kuykendall, Alessandro Vannucchi, Francesca Palandri, Sebastian Grosicki, Timothy Devos, Eric Jourdan, Marielle J. Wondergem, Haifa Kathrin Al-Ali, Veronika Buxhofer-Ausch, Alberto Alvarez-Larrán, Sanjay Akhani, Rafael Muñoz-Carerras, Yury Sheykin, Gozde Colak, Morgan Harris, John Mascarenhas
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Myelofibrosis (MF) is characterized by bone marrow fibrosis, anemia, splenomegaly and constitutional symptoms. Progressive bone marrow fibrosis results from aberrant megakaryopoeisis and expression of proinflammatory cytokines, both of which are heavily influenced by bromodomain and extraterminal domain (BET)-mediated gene regulation and lead to myeloproliferation and cytopenias. Pelabresib (CPI-0610) is an oral small-molecule investigational inhibitor of BET protein bromodomains currently being developed for the treatment of patients with MF. It is designed to downregulate BET target genes and modify nuclear factor kappa B (NF-κB) signaling. MANIFEST-2 was initiated based on data from Arm 3 of the ongoing Phase 2 MANIFEST study (NCT02158858), which is evaluating the combination of pelabresib and ruxolitinib in Janus kinase inhibitor (JAKi) treatment-naïve patients with MF. Primary endpoint analyses showed splenic and symptom responses in 68% and 56% of 84 enrolled patients, respectively. MANIFEST-2 (NCT04603495) is a global, Phase 3, randomized, double-blind, active-control study of pelabresib and ruxolitinib versus placebo and ruxolitinib in JAKi treatment-naïve patients with primary MF, post-polycythemia vera MF or post-essential thrombocythemia MF. The aim of this study is to evaluate the efficacy and safety of pelabresib in combination with ruxolitinib. Here we report updates from a recent protocol amendment. The MANIFEST-2 study schema is shown in Figure 1. Key eligibility criteria include a Dynamic International Prognostic Scoring System (DIPSS) score of Intermediate-1 or higher, platelet count ≥100 × 10^9/L, spleen volume ≥450 cc by computerized tomography or magnetic resonance imaging, ≥2 symptoms with an average score ≥3 or a Total Symptom Score (TSS) of ≥10 using the Myelofibrosis Symptom Assessment Form v4.0, peripheral blast count <5% and Eastern Cooperative Oncology Group performance status ≤2. Patient randomization will be stratified by DIPSS risk category (Intermediate-1 vs Intermediate-2 vs High), platelet count (>200 × 10^9/L vs 100–200 × 10^9/L) and spleen volume (≥1800 cm^3 vs <1800 cm^3). Double-blind treatment (pelabresib or matching placebo) will be administered once daily for 14 consecutive days, followed by a 7 day break, which is considered one cycle of treatment. Ruxolitinib will be administered twice daily for all 21 days of the cycle. The primary endpoint is SVR35 response (≥35% reduction in spleen volume from baseline) at Week 24, and the key secondary endpoint is TSS50 response (≥50% reduction in TSS from baseline) at Week 24. Other secondary endpoints include safety, pharmacokinetics, changes in bone marrow fibrosis, duration of SVR35 response, duration of TSS50 response, progression-free survival, overall survival, conversion from transfusion dependence to independence and rate of red blood cell transfusion for the first 24 weeks. Study recruitment is ongoing; 400 patients (200 per arm) from North America, Europe, Asia and Australia will be enrolled. The study opened for enrollment in November 2020. MANIFEST-2 was initiated based on data from the ongoing Phase 2 MANIFEST study with the aim of assessing the efficacy and safety of pelabresib and ruxolitinib in JAKi treatment-naïve patients with MF. MANIFEST-2 is currently open for enrollment.Keywords: CPI-0610, JAKi treatment-naïve, MANIFEST-2, myelofibrosis, pelabresib
Procedia PDF Downloads 2011690 Force Measurement for E-Cadherin-Mediated Intercellular Adhesion Probed by Protein Micropattern and Traction Force Microscopy
Authors: Chieh-Chung Tsou, Chun-Min Lo, Yeh-Shiu Chu
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Cell’s mechanical forces provide important physical cues in regulation of proper cellular functions, such as cell differentiation, proliferation and migration. It is believed that adhesive forces generated by cell-cell interaction are able to transmit to the interior of cell through filamentous cortical cytoskeleton. Prominent among other membrane receptors, Cadherins are prototypical adhesive molecules able to generate remarkable forces to regulate intercellular adhesion. However, the mechanistic steps of mechano-transduction in Cadherin-mediated adhesion remain very controversial. We are interested in understanding how Cadherin protein complexes enable force generation and transmission at cell-cell contact in the initial stage of intercellular adhesion. For providing a better control of time, space, and substrate stiffness, in this study, a combination of protein micropattern, micropipette manipulation, and traction force microscopy is used. Pair micropattern with different forms confines cell spreading area and the gaps in pairs varied from 2 to 8 microns are applied for monitoring the forces that cell pairs generated, measured by traction force microscopy. Moreover, cell clones obtained from epithelial cells undergone genome editing are used to score the importance for known components of Cadherin complexes in force generation. We believe that our results from this combinatory mechanobiological method will provide deep insights on understanding the biophysical principle governing mechano- transduction of Cadherin-mediated intercellular adhesion.Keywords: cadherin, intercellular adhesion, protein micropattern, traction force microscopy
Procedia PDF Downloads 2511689 Optical Variability of Faint Quasars
Authors: Kassa Endalamaw Rewnu
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The variability properties of a quasar sample, spectroscopically complete to magnitude J = 22.0, are investigated on a time baseline of 2 years using three different photometric bands (U, J and F). The original sample was obtained using a combination of different selection criteria: colors, slitless spectroscopy and variability, based on a time baseline of 1 yr. The main goals of this work are two-fold: first, to derive the percentage of variable quasars on a relatively short time baseline; secondly, to search for new quasar candidates missed by the other selection criteria; and, thus, to estimate the completeness of the spectroscopic sample. In order to achieve these goals, we have extracted all the candidate variable objects from a sample of about 1800 stellar or quasi-stellar objects with limiting magnitude J = 22.50 over an area of about 0.50 deg2. We find that > 65% of all the objects selected as possible variables are either confirmed quasars or quasar candidates on the basis of their colors. This percentage increases even further if we exclude from our lists of variable candidates a number of objects equal to that expected on the basis of `contamination' induced by our photometric errors. The percentage of variable quasars in the spectroscopic sample is also high, reaching about 50%. On the basis of these results, we can estimate that the incompleteness of the original spectroscopic sample is < 12%. We conclude that variability analysis of data with small photometric errors can be successfully used as an efficient and independent (or at least auxiliary) selection method in quasar surveys, even when the time baseline is relatively short. Finally, when corrected for the different intrinsic time lags corresponding to a fixed observed time baseline, our data do not show a statistically significant correlation between variability and either absolute luminosity or redshift.Keywords: nuclear activity, galaxies, active quasars, variability
Procedia PDF Downloads 811688 The Construction of the Bridge between Mrs Dalloway and to the Lighthouse: The Combination of Codes and Metaphors in the Structuring of the Plot in the Work of Virginia Woolf
Authors: María Rosa Mucci
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Tzvetan Todorov (1971) designs a model of narrative transformation where the plot is constituted by difference and resemblance. This binary opposition is a synthesis of a central figure within narrative discourse: metaphor. Narrative operates as a metaphor since it combines different actions through similarities within a common plot. However, it sounds paradoxical that metonymy and not metaphor should be the key figure within the narrative. It is a metonymy that keeps the movement of actions within the story through syntagmatic relations. By the same token, this articulation of verbs makes it possible for the reader to engage in a dynamic interaction with the text, responding to the plot and mediating meanings with the contradictory external world. As Roland Barthes (1957) points out, there are two codes that are irreversible within the process: the codes of actions and the codes of enigmas. Virginia Woolf constructs her plots through a process of symbolism; a scene is always enduring, not only because it stands for something else but also because it connotes it. The reader is forced to elaborate the meaning at a mythological level beyond the lines. In this research, we follow a qualitative content analysis to code language through the proairetic (actions) and hermeneutic (enigmas) codes in terms of Barthes. There are two novels in particular that engage the reader in this process of construction: Mrs Dalloway (1925) and To the Lighthouse (1927). The bridge from the first to the second brings memories of childhood, allowing for the discovery of these enigmas hidden between the lines. What survives? Who survives? It is the reader's task to unravel these codes and rethink this dialogue between plot and reader to contribute to the predominance of texts and the textuality of narratives.Keywords: metonymy, code, metaphor, myth, textuality
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