Search results for: fibonacci sequence
735 Austenite Transformation in Duplex Stainless Steels under Fast Cooling Rates
Authors: L. O. Luengas, E. V. Morales, L. F. G. De Souza, I. S. Bott
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Duplex Stainless Steels are well known for its good mechanical properties, and corrosion resistance. However, when submitted to heating, these features can be lost since the good properties are strongly dependent on the austenite-ferrite phase ratio which has to be approximately 1:1 to keep the phase balance. In a welded joint, the transformation kinetics at the heat affected zone (HAZ) is a function of the cooling rates applied which in turn are dependent on the heat input. The HAZ is usually ferritized at these temperatures, and it has been argued that small variations of the chemical composition can play a role in the solid state transformation sequence of ferrite to austenite during cooling. The δ → γ transformation has been reported to be massive and diffusionless due to the fast cooling rate, but it is also considered a diffusion controlled transformation. The aim of this work is to evaluate the effect of different heat inputs on the HAZ of two duplex stainless steels UNS S32304 and S32750, obtained by physical simulation.Keywords: duplex stainless steels, HAZ, microstructural characterization, physical simulation
Procedia PDF Downloads 277734 Molecular Characterization, Host Plant Resistance and Epidemiology of Bean Common Mosaic Virus Infecting Cowpea (Vigna unguiculata L. Walp)
Authors: N. Manjunatha, K. T. Rangswamy, N. Nagaraju, H. A. Prameela, P. Rudraswamy, M. Krishnareddy
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The identification of virus in cowpea especially potyviruses is confusing. Even though there are several studies on viruses causing diseases in cowpea, difficult to distinguish based on symptoms and serological detection. The differentiation of potyviruses considering as a constraint, the present study is initiated for molecular characterization, host plant resistance and epidemiology of the BCMV infecting cowpea. The etiological agent causing cowpea mosaic was identified as Bean Common Mosaic Virus (BCMV) on the basis of RT-PCR and electron microscopy. An approximately 750bp PCR product corresponding to coat protein (CP) region of the virus and the presence of long flexuous filamentous particles measuring about 952 nm in size typical to genus potyvirus were observed under electron microscope. The characterized virus isolate genome had 10054 nucleotides, excluding the 3’ terminal poly (A) tail. Comparison of polyprotein of the virus with other potyviruses showed similar genome organization with 9 cleavage sites resulted in 10 functional proteins. The pairwise sequence comparison of individual genes, P1 showed most divergent, but CP gene was less divergent at nucleotide and amino acid level. A phylogenetic tree constructed based on multiple sequence alignments of the polyprotein nucleotide and amino acid sequences of cowpea BCMV and potyviruses showed virus is closely related to BCMV-HB. Whereas, Soybean variant of china (KJ807806) and NL1 isolate (AY112735) showed 93.8 % (5’UTR) and 94.9 % (3’UTR) homology respectively with other BCMV isolates. This virus transmitted to different leguminous plant species and produced systemic symptoms under greenhouse conditions. Out of 100 cowpea genotypes screened, three genotypes viz., IC 8966, V 5 and IC 202806 showed immune reaction in both field and greenhouse conditions. Single marker analysis (SMA) was revealed out of 4 SSR markers linked to BCMV resistance, M135 marker explains 28.2 % of phenotypic variation (R2) and Polymorphic information content (PIC) value of these markers was ranged from 0.23 to 0.37. The correlation and regression analysis showed rainfall, and minimum temperature had significant negative impact and strong relationship with aphid population, whereas weak correlation was observed with disease incidence. Path coefficient analysis revealed most of the weather parameters exerted their indirect contributions to the aphid population and disease incidence except minimum temperature. This study helps to identify specific gaps in knowledge for researchers who may wish to further analyse the science behind complex interactions between vector-virus and host in relation to the environment. The resistant genotypes identified are could be effectively used in resistance breeding programme.Keywords: cowpea, epidemiology, genotypes, virus
Procedia PDF Downloads 236733 Development of Loop-Mediated Isothermal Amplification for Detection of Garlic in Food
Authors: Ting-Ying Su, Meng-Shiou Lee, Shyang-Chwen Sheu
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Garlic is used commonly as a seasoning around the world. But some people suffer from allergy to garlic. Garlic may also cause burning of mouth, stomach, and throat. In some Buddhist traditions, consuming garlic is not allowed. The objective of this study is to develop a LAMP based method for detection of garlic in food. We designed specific primers targeted on ITS1-5.8S rRNA-ITS2 sequence of garlic DNA. The LAMP assay was performed using a set of four different primers F3, B3, FIP and BIP at 60˚C in less than 60 mins. Results showed that the primer was not cross-reactive to other commonly used spice including Chinese leek, Chinese onion, green onion, onion, pepper, basil, parsley, pepper and ginger. As low as 2% of garlic DNA could be detected. Garlic still could be detected by developed LAMP after boiled at 100˚C for 80 minutes and autoclaved at 121˚C for 60 minutes. Commercial products labeled with garlic ingredient could be identified by the developed method.Keywords: garlic, loop-mediated isothermal amplification, processing, DNA
Procedia PDF Downloads 303732 Active Control of Multiferroic Composite Shells Using 1-3 Piezoelectric Composites
Authors: S. C. Kattimani
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This article deals with the analysis of active constrained layer damping (ACLD) of smart multiferroic or magneto-electro-elastic doubly curved shells. The kinematics of deformations of the multiferroic doubly curved shell is described by a layer-wise shear deformation theory. A three-dimensional finite element model of multiferroic shells has been developed taking into account the electro-elastic and magneto-elastic couplings. A simple velocity feedback control law is employed to incorporate the active damping. Influence of layer stacking sequence and boundary conditions on the response of the multiferroic doubly curved shell has been studied. In addition, for the different orientation of the fibers of the constraining layer, the performance of the ACLD treatment has been studied.Keywords: active constrained layer damping (ACLD), doubly curved shells, magneto-electro-elastic, multiferroic composite, smart structures
Procedia PDF Downloads 311731 Clustered Regularly Interspaced Short Palindromic Repeats Interference (CRISPRi): An Approach to Inhibit Microbial Biofilm
Authors: Azna Zuberi
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Biofilm is a sessile bacterial accretion in which bacteria adapts different physiological and morphological behavior from planktonic form. It is the root cause of about 80% microbial infections in human. Among them, E. coli biofilms are most prevalent in medical devices associated nosocomial infections. The objective of this study was to inhibit biofilm formation by targeting LuxS gene, involved in quorum sensing using CRISPRi. luxS is a synthase, involved in the synthesis of Autoinducer-2(AI-2), which in turn guides the initial stage of biofilm formation. To implement CRISPRi system, we have synthesized complementary sgRNA to target gene sequence and co-expressed with dCas9. Suppression of luxS was confirmed through qRT-PCR. The effect of luxS gene on biofilm inhibition was studied through crystal violet assay, XTT reduction assay and scanning electron microscopy. We conclude that CRISPRi system could be a potential strategy to inhibit bacterial biofilm through mechanism base approach.Keywords: biofilm, CRISPRi, luxS, microbial
Procedia PDF Downloads 183730 The Relationship between Confidence, Accuracy, and Decision Making in a Mobile Review Program
Authors: Carla Van De Sande, Jana Vandenberg
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Just like physical skills, cognitive skills grow rusty over time unless they are regularly used and practiced, so academic breaks can have negative consequences on student learning and success. The Keeping in School Shape (KiSS) program is an engaging, accessible, and cost-effective intervention that harnesses the benefits of retrieval practice by using technology to help students maintain proficiency over breaks from school by delivering a daily review problem via text message or email. A growth mindset is promoted through feedback messages encouraging students to try again if they get a problem wrong and to take on a challenging problem if they get a problem correct. This paper reports on the relationship between confidence, accuracy, and decision-making during the implementation of the KiSS Program at a large university during winter break for students enrolled in an engineering introductory Calculus course sequence.Keywords: growth mindset, learning loss, on-the-go learning, retrieval practice
Procedia PDF Downloads 205729 Passive Attenuation with Multiple Resonator Rings for Musical Instruments Equalization
Authors: Lorenzo Bonoldi, Gianluca Memoli, Abdelhalim Azbaid El Ouahabi
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In this paper, a series of ring-shaped attenuators utilizing Helmholtz and quarter wavelength resonators in variable, fixed, and combined configurations have been manufactured using a 3D printer. We illustrate possible uses by incorporating such devices into musical instruments (e.g. in acoustic guitar sound holes) and audio speakers with a view to controlling such devices tonal emissions without electronic equalization systems. Numerical investigations into the transmission loss values of these ring-shaped attenuators using finite element method simulations (COMSOL Multiphysics) have been presented in the frequency range of 100– 1000 Hz. We compare such results for each attenuator model with experimental measurements using different driving sources such as white noise, a maximum-length sequence (MLS), square and sine sweep pulses, and point scans in the frequency domain. Finally, we present a preliminary discussion on the comparison of numerical and experimental results.Keywords: equaliser, metamaterials, musical, instruments
Procedia PDF Downloads 174728 Taxonomic Classification for Living Organisms Using Convolutional Neural Networks
Authors: Saed Khawaldeh, Mohamed Elsharnouby, Alaa Eddin Alchalabi, Usama Pervaiz, Tajwar Aleef, Vu Hoang Minh
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Taxonomic classification has a wide-range of applications such as finding out more about the evolutionary history of organisms that can be done by making a comparison between species living now and species that lived in the past. This comparison can be made using different kinds of extracted species’ data which include DNA sequences. Compared to the estimated number of the organisms that nature harbours, humanity does not have a thorough comprehension of which specific species they all belong to, in spite of the significant development of science and scientific knowledge over many years. One of the methods that can be applied to extract information out of the study of organisms in this regard is to use the DNA sequence of a living organism as a marker, thus making it available to classify it into a taxonomy. The classification of living organisms can be done in many machine learning techniques including Neural Networks (NNs). In this study, DNA sequences classification is performed using Convolutional Neural Networks (CNNs) which is a special type of NNs.Keywords: deep networks, convolutional neural networks, taxonomic classification, DNA sequences classification
Procedia PDF Downloads 442727 Incorporating Information Gain in Regular Expressions Based Classifiers
Authors: Rosa L. Figueroa, Christopher A. Flores, Qing Zeng-Treitler
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A regular expression consists of sequence characters which allow describing a text path. Usually, in clinical research, regular expressions are manually created by programmers together with domain experts. Lately, there have been several efforts to investigate how to generate them automatically. This article presents a text classification algorithm based on regexes. The algorithm named REX was designed, and then, implemented as a simplified method to create regexes to classify Spanish text automatically. In order to classify ambiguous cases, such as, when multiple labels are assigned to a testing example, REX includes an information gain method Two sets of data were used to evaluate the algorithm’s effectiveness in clinical text classification tasks. The results indicate that the regular expression based classifier proposed in this work performs statically better regarding accuracy and F-measure than Support Vector Machine and Naïve Bayes for both datasets.Keywords: information gain, regular expressions, smith-waterman algorithm, text classification
Procedia PDF Downloads 320726 Modeling Football Penalty Shootouts: How Improving Individual Performance Affects Team Performance and the Fairness of the ABAB Sequence
Authors: Pablo Enrique Sartor Del Giudice
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Penalty shootouts often decide the outcome of important soccer matches. Although usually referred to as ”lotteries”, there is evidence that some national teams and clubs consistently perform better than others. The outcomes are therefore not explained just by mere luck, and therefore there are ways to improve the average performance of players, naturally at the expense of some sort of effort. In this article we study the payoff of player performance improvements in terms of the performance of the team as a whole. To do so we develop an analytical model with static individual performances, as well as Monte Carlo models that take into account the known influence of partial score and round number on individual performances. We find that within a range of usual values, the team performance improves above 70% faster than individual performances do. Using these models, we also estimate that the new ABBA penalty shootout ordering under test reduces almost all the known bias in favor of the first-shooting team under the current ABAB system.Keywords: football, penalty shootouts, Montecarlo simulation, ABBA
Procedia PDF Downloads 162725 High Impact Biosratigraphic Study Of Amama-1 and Bara-1 Wells In Parts of Anambra Basin
Authors: J. O. Njoku, G. C. Soronnadi-ononiwu, E. J. Acrra, C. C. Agoha, T. C. Anyawu
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The High Impact Biostratigrapgic Study of parts of Anambra basin was carried out using samples from two exploration wells (Amama-1 and Bara-1), Amama-1 (219M–1829M) and Bara-1 (317M-1594M). Palynological and Paleontological analyses were carried out on 100 ditch cutting samples. The faunal and floral succession were of terrestrial and marine origin as described and logged. The well penetrated four stratigraphic units in Anambra Basin (the Nkporo, Mamu, Ajali and Nsukka) the wells yielded well preserved formanifera and palynormorphs. The well yielded 53 species of foram and 69 species of palynomorphs, with 12 genera Bara-1 (25 Species of foram and 101 species of palynormorphs). Amama-1permitted the recognition of 21 genera with 31 formainiferal assemblage zones, 32 pollen and 37 spores assemblage zones, and dinoflagellate cyst, biozonation, ranging from late Campanian – early Paleocene. Bara-1 yielded (60 pollen, 41 spore assemblage zone and 18 dinoflagellate cyst).The zones, in stratigraphically ascending order for the foraminifera and palynomorphs are as follows. Amama Biozone A-Globotruncanella havanensis zone: Late Campanian –Maastrichtian (695 – 1829m) Biozone B-Morozovella velascoensis zone: Early Paleocene(165–695m) Bara-1 Biozone A-Globotruncanella havanensis zone: Late Campanian(1512m) Biozone B-Bolivina afra, B. explicate zone: Maastrichtian (634–1204m) Biozone C - Indeterminate (305 – 634m) palynomorphs Amama-1 A.Ctenolophonidites costatus zone:Early Maastrichtian (1829m) B-Retidiporites miniporatus Zone: Late Maastrichtian (1274m) Constructipollenites ineffectus Zone: Early Paleocene(695m) Bara-1 Droseridites senonicus Zone: Late Campanian (994– 1600m) B. Ctenolophonidites costatus Zone: Early Maastrichtian (713–994m) C. Retidiporites miniporatus Zone: Late Maastrichtian (305 –713m) The paleo – environment of deposition were determined to range from non-marine to outer netritic. A detailed categorization of the palynormorphs into terrestrially derived palynormorphs and marine derived palynormorphs based on the distribution of three broad vegetational types; mangrove, fresh water swamps and hintherland communities were used to evaluate sea level fluctuations with respect to sediments deposited in the basins and linked with a particular depositional system tract. Amama-1 recorded 4 maximum flooding surface(MFS) at depth 165-1829, dated b/w 61ma-76ma and three sequence boundary(SB) at depth1048m - 1533m and 1581 dated b/w 634m - 1387m, dated 69.5ma - 82ma and four sequence boundary(SB) at 552m-876m, dated 68ma-77.5ma respectively. The application of ecostratigraphic description is characterised by the prominent expansion of the hinterland component consisting of the Mangrove to Lowland Rainforest and Afromontane – Savannah vegetation.Keywords: formanifera, palynomorphs. campanian, maastritchian, ecostratigraphic, anambra
Procedia PDF Downloads 14724 TMIF: Transformer-Based Multi-Modal Interactive Fusion for Rumor Detection
Authors: Jiandong Lv, Xingang Wang, Cuiling Shao
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The rapid development of social media platforms has made it one of the important news sources. While it provides people with convenient real-time communication channels, fake news and rumors are also spread rapidly through social media platforms, misleading the public and even causing bad social impact in view of the slow speed and poor consistency of artificial rumor detection. We propose an end-to-end rumor detection model-TIMF, which captures the dependencies between multimodal data based on the interactive attention mechanism, uses a transformer for cross-modal feature sequence mapping and combines hybrid fusion strategies to obtain decision results. This paper verifies two multi-modal rumor detection datasets and proves the superior performance and early detection performance of the proposed model.Keywords: hybrid fusion, multimodal fusion, rumor detection, social media, transformer
Procedia PDF Downloads 246723 Co-Movement between Financial Assets: An Empirical Study on Effects of the Depreciation of Yen on Asia Markets
Authors: Yih-Wenn Laih
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In recent times, the dependence and co-movement among international financial markets have become stronger than in the past, as evidenced by commentaries in the news media and the financial sections of newspapers. Studying the co-movement between returns in financial markets is an important issue for portfolio management and risk management. The realization of co-movement helps investors to identify the opportunities for international portfolio management in terms of asset allocation and pricing. Since the election of the new Prime Minister, Shinzo Abe, in November 2012, the yen has weakened against the US dollar from the 80 to the 120 level. The policies, known as “Abenomics,” are to encourage private investment through a more aggressive mix of monetary and fiscal policy. Given the close economic relations and competitions among Asia markets, it is interesting to discover the co-movement relations, affected by the depreciation of yen, between stock market of Japan and 5 major Asia stock markets, including China, Hong Kong, Korea, Singapore, and Taiwan. Specifically, we devote ourselves to measure the co-movement of stock markets between Japan and each one of the 5 Asia stock markets in terms of rank correlation coefficients. To compute the coefficients, return series of each stock market is first fitted by a skewed-t GARCH (generalized autoregressive conditional heteroscedasticity) model. Secondly, to measure the dependence structure between matched stock markets, we employ the symmetrized Joe-Clayton (SJC) copula to calculate the probability density function of paired skewed-t distributions. The joint probability density function is then utilized as the scoring scheme to optimize the sequence alignment by dynamic programming method. Finally, we compute the rank correlation coefficients (Kendall's and Spearman's ) between matched stock markets based on their aligned sequences. We collect empirical data of 6 stock indexes from Taiwan Economic Journal. The data is sampled at a daily frequency covering the period from January 1, 2013 to July 31, 2015. The empirical distributions of returns indicate fatter tails than the normal distribution. Therefore, the skewed-t distribution and SJC copula are appropriate for characterizing the data. According to the computed Kendall’s τ, Korea has the strongest co-movement relation with Japan, followed by Taiwan, China, and Singapore; the weakest is Hong Kong. On the other hand, the Spearman’s ρ reveals that the strength of co-movement between markets with Japan in decreasing order are Korea, China, Taiwan, Singapore, and Hong Kong. We explore the effects of “Abenomics” on Asia stock markets by measuring the co-movement relation between Japan and five major Asia stock markets in terms of rank correlation coefficients. The matched markets are aligned by a hybrid method consisting of GARCH, copula and sequence alignment. Empirical experiments indicate that Korea has the strongest co-movement relation with Japan. The strength of China and Taiwan are better than Singapore. The Hong Kong market has the weakest co-movement relation with Japan.Keywords: co-movement, depreciation of Yen, rank correlation, stock market
Procedia PDF Downloads 231722 Phylogenetic Relationships of the Malaysian Primates Cercopithecine Based on COI Gene Sequences
Authors: B. M. Md-Zain, N. A. Rahman, M. A. B. Abdul-Latiff, W. M. R. Idris
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We conducted molecular research to portray phylogenetic relationships of Malaysian primates particularly in the genus of Macaca. We have sequenced cytochrome C oxidase subunit I (COI) of mitochondrial DNA of several individuals from M. fascicularis and M. arctoides. PCR amplifications were performed and COI DNA sequences were aligned using ClustalW. Phylogenetic trees were constructed using distance analyses by employing neighbor-joining algorithm (NJ). We managed to sequence 700 bp of COI DNA sequences. The tree topology showed that M. fascicularis did not clump based on phyleogeography division in Peninsular Malaysia. Individuals from Negeri Sembilan merged together with samples from Perak and Penang into one clade. In addition, phylogenetic analyses indicated that M. arctoides was classified into sinica group instead of fascicularis group supported by genetic distance data. COI gene is an effective locus to clarify phylogenetic position of M. arctoides but not in discriminating M. fascicularis population in Peninsular Malaysia.Keywords: cercopithecine, long-tailed macaque, Macaca fascicularis, Macaca arctoides
Procedia PDF Downloads 357721 Genomic Adaptation to Local Climate Conditions in Native Cattle Using Whole Genome Sequencing Data
Authors: Rugang Tian
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In this study, we generated whole-genome sequence (WGS) data from110 native cattle. Together with whole-genome sequences from world-wide cattle populations, we estimated the genetic diversity and population genetic structure of different cattle populations. Our findings revealed clustering of cattle groups in line with their geographic locations. We identified noticeable genetic diversity between indigenous cattle breeds and commercial populations. Among all studied cattle groups, lower genetic diversity measures were found in commercial populations, however, high genetic diversity were detected in some local cattle, particularly in Rashoki and Mongolian breeds. Our search for potential genomic regions under selection in native cattle revealed several candidate genes related with immune response and cold shock protein on multiple chromosomes such as TRPM8, NMUR1, PRKAA2, SMTNL2 and OXR1 that are involved in energy metabolism and metabolic homeostasis.Keywords: cattle, whole-genome, population structure, adaptation
Procedia PDF Downloads 74720 Plasmonic Biosensor for Early Detection of Environmental DNA (eDNA) Combined with Enzyme Amplification
Authors: Monisha Elumalai, Joana Guerreiro, Joana Carvalho, Marta Prado
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DNA biosensors popularity has been increasing over the past few years. Traditional analytical techniques tend to require complex steps and expensive equipment however DNA biosensors have the advantage of getting simple, fast and economic. Additionally, the combination of DNA biosensors with nanomaterials offers the opportunity to improve the selectivity, sensitivity and the overall performance of the devices. DNA biosensors are based on oligonucleotides as sensing elements. These oligonucleotides are highly specific to complementary DNA sequences resulting in the hybridization of the strands. DNA biosensors are not only an advantage in the clinical field but also applicable in numerous research areas such as food analysis or environmental control. Zebra Mussels (ZM), Dreissena polymorpha are invasive species responsible for enormous negative impacts on the environment and ecosystems. Generally, the detection of ZM is made when the observation of adult or macroscopic larvae's is made however at this stage is too late to avoid the harmful effects. Therefore, there is a need to develop an analytical tool for the early detection of ZM. Here, we present a portable plasmonic biosensor for the detection of environmental DNA (eDNA) released to the environment from this invasive species. The plasmonic DNA biosensor combines gold nanoparticles, as transducer elements, due to their great optical properties and high sensitivity. The detection strategy is based on the immobilization of a short base pair DNA sequence on the nanoparticles surface followed by specific hybridization in the presence of a complementary target DNA. The hybridization events are tracked by the optical response provided by the nanospheres and their surrounding environment. The identification of the DNA sequences (synthetic target and probes) to detect Zebra mussel were designed by using Geneious software in order to maximize the specificity. Moreover, to increase the optical response enzyme amplification of DNA might be used. The gold nanospheres were synthesized and characterized by UV-visible spectrophotometry and transmission electron microscopy (TEM). The obtained nanospheres present the maximum localized surface plasmon resonance (LSPR) peak position are found to be around 519 nm and a diameter of 17nm. The DNA probes modified with a sulfur group at one end of the sequence were then loaded on the gold nanospheres at different ionic strengths and DNA probe concentrations. The optimal DNA probe loading will be selected based on the stability of the optical signal followed by the hybridization study. Hybridization process leads to either nanoparticle dispersion or aggregation based on the presence or absence of the target DNA. Finally, this detection system will be integrated into an optical sensing platform. Considering that the developed device will be used in the field, it should fulfill the inexpensive and portability requirements. The sensing devices based on specific DNA detection holds great potential and can be exploited for sensing applications in-loco.Keywords: ZM DNA, DNA probes, nicking enzyme, gold nanoparticles
Procedia PDF Downloads 245719 A First Order Shear Deformation Theory Approach for the Buckling Behavior of Nanocomposite Beams
Authors: P. Pramod Kumar, Madhu Salumari, V. V. Subba Rao
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Due to their high strength-to-weight ratio, carbon nanotube (CNTs) reinforced polymer composites are being considered as one of the most promising nanocomposites which can improve the performance when used in structural applications. The buckling behavior is one of the most important parameter needs to be considered in the design of structural members like beams and plates. In the present paper, the elastic constants of CNT reinforced polymer composites are evaluated by using Mori-Tanaka micromechanics approach. Knowing the elastic constants, an analytical study is being conducted to investigate the buckling behavior of nanocomposites for different CNT volume fractions at different boundary conditions using first-order shear deformation theory (FSDT). The effect of stacking sequence and CNT radius on the buckling of beam has also been presented. This study is being conducted primarily with an intension to find the stiffening effect of CNTs when used in polymer composites as reinforcement.Keywords: CNT, buckling, micromechanics, FSDT
Procedia PDF Downloads 279718 High Impact Ecostratigraphic and Biostratigrapgic Study of Amama-1 and Bara-1 Wells in Parts of Anambra Basin
Authors: J. O. Njoku, G. C. Soronnadi-Ononiwu, E. J. Acrra, C. C. Agoha, T. C. Anyawu
Abstract:
The high impact ecostratigraphic and biostratigrapgic study of parts of Anambra basin was carried out using samples from two exploration wells (Amama-1 and Bara-1), Amama-1 (219M–1829M) and Bara-1 (317M-1594M). Palynological and paleontological analyses were carried out on 100 ditch-cutting samples. The faunal and floral succession were of terrestrial and marine origin as described and logged. The well penetrated four stratigraphic units in Anambra Basin (the Nkporo, Mamu, Ajali and Nsukka) the wells yielded well preserved formanifera and palynormorphs. The well yielded 53 species of foram and 69 species of palynomorphs, with 12 genera Bara-1 (25 Species of foram and 101 species of palynormorphs). Amama-1 permitted the recognition of 21 genera with 31 formainiferal assemblage zones, 32 pollen and 37 spores assemblage zones, and dinoflagellate cyst, biozonation, ranging from late Campanian – early Paleocene. Bara-1 yielded (60 pollen, 41 spore assemblage zone and 18 dinoflagellate cyst). The zones, in stratigraphically ascending order for the foraminifera and palynomorphs are as follows: Amama Biozone A-Globotruncanella havanensis zone: Late Campanian –Maastrichtian (695 – 1829m) Biozone B-Morozovella velascoensis zone: Early Paleocene(165–695m) Bara-1 Biozone A-Globotruncanella havanensis zone: Late Campanian(1512m) Biozone B-Bolivina afra, B. explicate zone: Maastrichtian (634–1204m) Biozone C - Indeterminate (305 – 634m) palynomorphs Amama-1 A. Ctenolophonidites costatus zone: Early Maastrichtian (1829m) B-Retidiporites miniporatus Zone: Late Maastrichtian (1274m) Constructipollenites ineffectus Zone: Early Paleocene(695m) Bara-1 Droseridites senonicus Zone: Late Campanian (994– 1600m) B. Ctenolophonidites costatus Zone: Early Maastrichtian (713–994m) C. Retidiporites miniporatus Zone: Late Maastrichtian (305 –713m) The paleo-environment of deposition were determined to range from non-marine to outer netritic. A detailed categorization of the palynormorphs into terrestrially derived palynormorphs and marine derived palynormorphs based on the distribution of three broad vegetational types; mangrove, fresh water swamps and hintherland communities were used to evaluate sea level fluctuations with respect to sediments deposited in the basins and linked with a particular depositional system tract. Amama-1 recorded 4 maximum flooding surface(MFS) at depth 165-1829, dated b/w 61ma-76ma and three sequence boundary(SB) at depth1048m - 1533m and 1581 dated b/w 634m - 1387m, dated 69.5ma - 82ma and four sequence boundary(SB) at 552m-876m, dated 68ma-77.5ma respectively. The application of ecostratigraphic description is characterised by the prominent expansion of the hinterland component consisting of the Mangrove to Lowland Rainforest and Afromontane – Savannah vegetation.Keywords: foraminifera, palynomorphs, Campanian, Maastritchian, ecostratigraphic, Anambra
Procedia PDF Downloads 25717 High Impact Ecostratigraphic and Biostratigrapgic Study of Amama-1 and Bara-1 Wells in Parts of Anambra Basin
Authors: J. O. Njoku, G. C. Soronnadi-ononiwu, E. J. Acrra, C. C. Agoha, T. C. Anyawu
Abstract:
The High Impact Ecostratigraphic And Biostratigrapgic Study of parts of Anambra basin was carried out using samples from two exploration wells (Amama-1 and Bara-1), Amama-1 (219M–1829M) and Bara-1 (317M-1594M). Palynological and Paleontological analyses were carried out on 100 ditch cutting samples. The faunal and floral succession were of terrestrial and marine origin as described and logged. The well penetrated four stratigraphic units in Anambra Basin (the Nkporo, Mamu, Ajali and Nsukka) the wells yielded well preserved formanifera and palynormorphs. The well yielded 53 species of foram and 69 species of palynomorphs, with 12 genera Bara-1 (25 Species of foram and 101 species of palynormorphs). Amama-1permitted the recognition of 21 genera with 31 formainiferal assemblage zones, 32 pollen and 37 spores assemblage zones, and dinoflagellate cyst, biozonation, ranging from late Campanian – early Paleocene. Bara-1 yielded (60 pollen, 41 spore assemblage zone and 18 dinoflagellate cyst).The zones, in stratigraphically ascending order for the foraminifera and palynomorphs are as follows. Amama Biozone A-Globotruncanella havanensis zone: Late Campanian –Maastrichtian (695 – 1829m) Biozone B-Morozovella velascoensis zone: Early Paleocene(165–695m) Bara-1 Biozone A-Globotruncanella havanensis zone: Late Campanian(1512m) Biozone B-Bolivina afra, B. explicate zone: Maastrichtian (634–1204m) Biozone C - Indeterminate (305 – 634m) palynomorphs Amama-1 A.Ctenolophonidites costatus zone:Early Maastrichtian (1829m) B-Retidiporites miniporatus Zone: Late Maastrichtian (1274m) Constructipollenites ineffectus Zone: Early Paleocene(695m) Bara-1 Droseridites senonicus Zone: Late Campanian (994– 1600m) B. Ctenolophonidites costatus Zone: Early Maastrichtian (713–994m) C. Retidiporites miniporatus Zone: Late Maastrichtian (305 –713m) The paleo – environment of deposition were determined to range from non-marine to outer netritic. A detailed categorization of the palynormorphs into terrestrially derived palynormorphs and marine derived palynormorphs based on the distribution of three broad vegetational types; mangrove, fresh water swamps and hintherland communities were used to evaluate sea level fluctuations with respect to sediments deposited in the basins and linked with a particular depositional system tract. Amama-1 recorded 4 maximum flooding surface(MFS) at depth 165-1829, dated b/w 61ma-76ma and three sequence boundary(SB) at depth1048m - 1533m and 1581 dated b/w 634m - 1387m, dated 69.5ma - 82ma and four sequence boundary(SB) at 552m-876m, dated 68ma-77.5ma respectively. The application of ecostratigraphic description is characterised by the prominent expansion of the hinterland component consisting of the Mangrove to Lowland Rainforest and Afromontane – Savannah vegetation.Keywords: formanifera, palynomorphs. Campanian, Maastritchian, Ecostratigraphic, Anambra
Procedia PDF Downloads 18716 The Hyperbolic Smoothing Approach for Automatic Calibration of Rainfall-Runoff Models
Authors: Adilson Elias Xavier, Otto Corrêa Rotunno Filho, Paulo Canedo De Magalhães
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This paper addresses the issue of automatic parameter estimation in conceptual rainfall-runoff (CRR) models. Due to threshold structures commonly occurring in CRR models, the associated mathematical optimization problems have the significant characteristic of being strongly non-differentiable. In order to face this enormous task, the resolution method proposed adopts a smoothing strategy using a special C∞ differentiable class function. The final estimation solution is obtained by solving a sequence of differentiable subproblems which gradually approach the original conceptual problem. The use of this technique, called Hyperbolic Smoothing Method (HSM), makes possible the application of the most powerful minimization algorithms, and also allows for the main difficulties presented by the original CRR problem to be overcome. A set of computational experiments is presented for the purpose of illustrating both the reliability and the efficiency of the proposed approach.Keywords: rainfall-runoff models, automatic calibration, hyperbolic smoothing method
Procedia PDF Downloads 149715 Biological Treatment of a Mixture of Iodine-Containing Aromatic Compounds from Industrial Wastewaster
Authors: A. Elain, M. Le Fellic, A. Le Pemp, N. Hachet
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Iodinated Compounds (IC) are widely detected contaminants in most aquatic environments including sewage treatment plant, surface water, ground water and even drinking water, up to the µg.L-1 range. As IC contribute in the adsorbable organic halides (AOX) level, their removal or dehalogenation is expected. We report here on the biodegradability of a mixture of IC from an industrial effluent using a microbial consortium adapted to grow on IC as well as the native microorganisms. Both aerobic and anaerobic treatments were studied during batch experiments in 500-mL flasks. The degree of mineralization and recovery of iodide were monitored by HPLC-UV, TOC analysis and potentiometric titration. Providing ethanol as an electron acceptor was found to stimulate anaerobic reductive deiodination of IC while sodium chloride even at high concentration (22 g.l-1) had no influence on the degradation rates nor on the microbial viability. Phylogenetic analysis of 16S RNA gene sequence (MicroSeq®) was applied to provide a better understanding of the degradative microbial community.Keywords: iodinated compounds, biodegradability, deiodination, electron-accepting conditions, microbial consortium
Procedia PDF Downloads 329714 Comparison of Machine Learning-Based Models for Predicting Streptococcus pyogenes Virulence Factors and Antimicrobial Resistance
Authors: Fernanda Bravo Cornejo, Camilo Cerda Sarabia, Belén Díaz Díaz, Diego Santibañez Oyarce, Esteban Gómez Terán, Hugo Osses Prado, Raúl Caulier-Cisterna, Jorge Vergara-Quezada, Ana Moya-Beltrán
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Streptococcus pyogenes is a gram-positive bacteria involved in a wide range of diseases and is a major-human-specific bacterial pathogen. In Chile, this year the 'Ministerio de Salud' declared an alert due to the increase in strains throughout the year. This increase can be attributed to the multitude of factors including antimicrobial resistance (AMR) and Virulence Factors (VF). Understanding these VF and AMR is crucial for developing effective strategies and improving public health responses. Moreover, experimental identification and characterization of these pathogenic mechanisms are labor-intensive and time-consuming. Therefore, new computational methods are required to provide robust techniques for accelerating this identification. Advances in Machine Learning (ML) algorithms represent the opportunity to refine and accelerate the discovery of VF associated with Streptococcus pyogenes. In this work, we evaluate the accuracy of various machine learning models in predicting the virulence factors and antimicrobial resistance of Streptococcus pyogenes, with the objective of providing new methods for identifying the pathogenic mechanisms of this organism.Our comprehensive approach involved the download of 32,798 genbank files of S. pyogenes from NCBI dataset, coupled with the incorporation of data from Virulence Factor Database (VFDB) and Antibiotic Resistance Database (CARD) which contains sequences of AMR gene sequence and resistance profiles. These datasets provided labeled examples of both virulent and non-virulent genes, enabling a robust foundation for feature extraction and model training. We employed preprocessing, characterization and feature extraction techniques on primary nucleotide/amino acid sequences and selected the optimal more for model training. The feature set was constructed using sequence-based descriptors (e.g., k-mers and One-hot encoding), and functional annotations based on database prediction. The ML models compared are logistic regression, decision trees, support vector machines, neural networks among others. The results of this work show some differences in accuracy between the algorithms, these differences allow us to identify different aspects that represent unique opportunities for a more precise and efficient characterization and identification of VF and AMR. This comparative analysis underscores the value of integrating machine learning techniques in predicting S. pyogenes virulence and AMR, offering potential pathways for more effective diagnostic and therapeutic strategies. Future work will focus on incorporating additional omics data, such as transcriptomics, and exploring advanced deep learning models to further enhance predictive capabilities.Keywords: antibiotic resistance, streptococcus pyogenes, virulence factors., machine learning
Procedia PDF Downloads 31713 Promissing Antifungal Chitinase from Marine Strain of Bacillus
Authors: Ben Amar Cheba, Taha Ibrahim Zaghloul, Mohamad Hisham El-Massry, Ahmad Rafik El-Mahdy
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Seventy two bacterial strains with ability to degrade chitin were isolated during a screening program. One of the most potent isolates (strain R2) was identified as Bacillus sp. using conventional methods as well as 16S rRNA technique and submitted in the Gen Bank sequence database as Bacillus sp. R2 with a given accession number DQ 923161. This strain was able to produce high levels of extracellular chitinase. The chitinase of Bacillus sp. R2 hydrolyzed several chitinous substrates preferentially and showed a maximum activity toward the β chitin such as Calmar pen and squid bone chitins with the folds 1.47 and 1.23 respectively. The enzyme also exhibited a substrate binding capacity of more than 70% for squid chitin, shrimp shell colloidal chitin, chitosan and prawn shell chitin. The chitinase showed a moderate antifungal activity against many phytopathogenic fungi such as Aspergillus niger, A. flavus, Penicillium degitatum and Fusarium calmorum.This strain could be a suitable candidate for chitinase production on an industrial scale for using as promising antifungal biopestecide.Keywords: antifungal activity, Bacillus sp. R2, chitinase, substrate specificity
Procedia PDF Downloads 501712 Elements of Creativity and Innovation
Authors: Fadwa Al Bawardi
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In March 2021, the Saudi Arabian Council of Ministers issued a decision to form a committee called the "Higher Committee for Research, Development and Innovation," a committee linked to the Council of Economic and Development Affairs, chaired by the Chairman of the Council of Economic and Development Affairs, and concerned with the development of the research, development and innovation sector in the Kingdom. In order to talk about the dimensions of this wonderful step, let us first try to answer the following questions. Is there a difference between creativity and innovation..? What are the factors of creativity in the individual. Are they mental genetic factors or are they factors that an individual acquires through learning..? The methodology included surveys that have been conducted on more than 500 individuals, males and females, between the ages of 18 till 60. And the answer is. "Creativity" is the creation of a new idea, while "Innovation" is the development of an already existing idea in a new, successful way. They are two sides of the same coin, as the "creative idea" needs to be developed and transformed into an "innovation" in order to achieve either strategic achievements at the level of countries and institutions to enhance organizational intelligence, or achievements at the level of individuals. For example, the beginning of smart phones was just a creative idea from IBM in 1994, but the actual successful innovation for the manufacture, development and marketing of these phones was through Apple later. Nor does creativity have to be hereditary. There are three basic factors for creativity: The first factor is "the presence of a challenge or an obstacle" that the individual faces and seeks thinking to find solutions to overcome, even if thinking requires a long time. The second factor is the "environment surrounding" of the individual, which includes science, training, experience gained, the ability to use techniques, as well as the ability to assess whether the idea is feasible or otherwise. To achieve this factor, the individual must be aware of own skills, strengths, hobbies, and aspects in which one can be creative, and the individual must also be self-confident and courageous enough to suggest those new ideas. The third factor is "Experience and the Ability to Accept Risk and Lack of Initial Success," and then learn from mistakes and try again tirelessly. There are some tools and techniques that help the individual to reach creative and innovative ideas, such as: Mind Maps tool, through which the available information is drawn by writing a short word for each piece of information and arranging all other relevant information through clear lines, which helps in logical thinking and correct vision. There is also a tool called "Flow Charts", which are graphics that show the sequence of data and expected results according to an ordered scenario of events and workflow steps, giving clarity to the ideas, their sequence, and what is expected of them. There are also other great tools such as the Six Hats tool, a useful tool to be applied by a group of people for effective planning and detailed logical thinking, and the Snowball tool. And all of them are tools that greatly help in organizing and arranging mental thoughts, and making the right decisions. It is also easy to learn, apply and use all those tools and techniques to reach creative and innovative solutions. The detailed figures and results of the conducted surveys are available upon request, with charts showing the %s based on gender, age groups, and job categories.Keywords: innovation, creativity, factors, tools
Procedia PDF Downloads 55711 Nature of Forest Fragmentation Owing to Human Population along Elevation Gradient in Different Countries in Hindu Kush Himalaya Mountains
Authors: Pulakesh Das, Mukunda Dev Behera, Manchiraju Sri Ramachandra Murthy
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Large numbers of people living in and around the Hindu Kush Himalaya (HKH) region, depends on this diverse mountainous region for ecosystem services. Following the global trend, this region also experiencing rapid population growth, and demand for timber and agriculture land. The eight countries sharing the HKH region have different forest resources utilization and conservation policies that exert varying forces in the forest ecosystem. This created a variable spatial as well altitudinal gradient in rate of deforestation and corresponding forest patch fragmentation. The quantitative relationship between fragmentation and demography has not been established before for HKH vis-à-vis along elevation gradient. This current study was carried out to attribute the overall and different nature in landscape fragmentations along the altitudinal gradient with the demography of each sharing countries. We have used the tree canopy cover data derived from Landsat data to analyze the deforestation and afforestation rate, and corresponding landscape fragmentation observed during 2000 – 2010. Area-weighted mean radius of gyration (AMN radius of gyration) was computed owing to its advantage as spatial indicator of fragmentation over non-spatial fragmentation indices. Using the subtraction method, the change in fragmentation was computed during 2000 – 2010. Using the tree canopy cover data as a surrogate of forest cover, highest forest loss was observed in Myanmar followed by China, India, Bangladesh, Nepal, Pakistan, Bhutan, and Afghanistan. However, the sequence of fragmentation was different after the maximum fragmentation observed in Myanmar followed by India, China, Bangladesh, and Bhutan; whereas increase in fragmentation was seen following the sequence of as Nepal, Pakistan, and Afghanistan. Using SRTM-derived DEM, we observed higher rate of fragmentation up to 2400m that corroborated with high human population for the year 2000 and 2010. To derive the nature of fragmentation along the altitudinal gradients, the Statistica software was used, where the user defined function was utilized for regression applying the Gauss-Newton estimation method with 50 iterations. We observed overall logarithmic decrease in fragmentation change (area-weighted mean radius of gyration), forest cover loss and population growth during 2000-2010 along the elevation gradient with very high R2 values (i.e., 0.889, 0.895, 0.944 respectively). The observed negative logarithmic function with the major contribution in the initial elevation gradients suggest to gap filling afforestation in the lower altitudes to enhance the forest patch connectivity. Our finding on the pattern of forest fragmentation and human population across the elevation gradient in HKH region will have policy level implication for different nations and would help in characterizing hotspots of change. Availability of free satellite derived data products on forest cover and DEM, grid-data on demography, and utility of geospatial tools helped in quick evaluation of the forest fragmentation vis-a-vis human impact pattern along the elevation gradient in HKH.Keywords: area-weighted mean radius of gyration, fragmentation, human impact, tree canopy cover
Procedia PDF Downloads 215710 Public and Private Domains: Contradictions and Covenants in Evolution of Game Policy
Authors: Mingzhu Lyu, Runlei Ren, Xinyu Dai, Jiaxuan Pi, Kanghua Li
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The study of video game policy in China has been divided into two branches: "pedagogy" and "game industry". The binary perspective of policy reveals the "contradictory" side of policy performance. Based on this suspicion, this paper constructs a three-dimensional sequence of time, content and institutions of game policy, and establishes the "contradictory" aspects of policy performance between 1949 and 2019. A central-level database of game policies, clarifying that our game policies follow a shift from reactive response to proactive guidance, stigmatization and de-stigmatization, the evolutionary logic. The study found that the central government has always maintained a strict requirement and prudent guidance for game policy, and the deep contradictions in game policy stem from the essential conflict between the natural amusement of games and the seriousness of the educational system, and the Chinese government's use of the understanding of the public and private domains and the Managing of the conflict.Keywords: game industry, gaming policy, public domain, private domain
Procedia PDF Downloads 148709 Homoleptic Complexes of a Tetraphenylporphyrinatozinc(II)-conjugated 2,2':6',6"-Terpyridine
Authors: Angelo Lanzilotto, Martin Kuss-Petermann, Catherine E. Housecroft, Edwin C. Constable, Oliver S. Wenger
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We recently described the synthesis of a new tetraphenylporphyrinatozinc(II)-conjugated 2,2':6',6"-terpyridine (1) in which the tpy domain enables the molecule to act as a metalloligand. The synthetic route to 1 has been optimized, the importance of selecting a particular sequence of synthetic steps will be discussed. Three homoleptic complexes have been prepared, [Zn(1)₂]²⁺, [Fe(1)₂]²⁺ and [Ru(1)₂]²⁺, and have been isolated as the hexafluoridophosphate salts. Spectroelectrochemical measurements have been performed and the spectral changes ascribed to redox processes are partitioned on either the porphyrin or the terpyridine units. Compound 1 undergoes a reversible one-electron oxidation/reduction. The removal/gain of a second electron leads to a further irreversible chemical transformation. For the homoleptic [M(1)₂]²⁺ complexes, a suitable potential can be chosen at which both the oxidation and the reduction of the {ZnTPP} core are reversible. When the homoleptic complex contains a redox active metal such as Fe or Ru, spectroelectrochemistry has been used to investigate the metal to ligand charge transfer (MLCT) transition. The latter is sensitive to the oxidation state of the metal, and electrochemical oxidation of the metal center suppresses it. Detailed spectroelectrochemical studies will be presented.Keywords: homoleptic complexes, spectroelectrochemistry, tetraphenylporphyrinatozinc(II), 2, 2':6', 6"-terpyridine
Procedia PDF Downloads 220708 Why and When to Teach Definitions: Necessary and Unnecessary Discontinuities Resulting from the Definition of Mathematical Concepts
Authors: Josephine Shamash, Stuart Smith
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We examine reasons for introducing definitions in teaching mathematics in a number of different cases. We try to determine if, where, and when to provide a definition, and which definition to choose. We characterize different types of definitions and the different purposes we may have for formulating them, and detail examples of each type. Giving a definition at a certain stage can sometimes be detrimental to the development of the concept image. In such a case, it is advisable to delay the precise definition to a later stage. We describe two models, the 'successive approximation model', and the 'model of the extending definition' that fit such situations. Detailed examples that fit the different models are given based on material taken from a number of textbooks, and analysis of the way the concept is introduced, and where and how its definition is given. Our conclusions, based on this analysis, is that some of the definitions given may cause discontinuities in the learning sequence and constitute obstacles and unnecessary cognitive conflicts in the formation of the concept definition. However, in other cases, the discontinuity in passing from definition to definition actually serves a didactic purpose, is unavoidable for the mathematical evolution of the concept image, and is essential for students to deepen their understanding.Keywords: concept image, mathematical definitions, mathematics education, mathematics teaching
Procedia PDF Downloads 129707 Aerobic Biodegradation of a Chlorinated Hydrocarbon by Bacillus Cereus 2479
Authors: Srijata Mitra, Mobina Parveen, Pranab Roy, Narayan Chandra Chattopadhyay
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Chlorinated hydrocarbon can be a major pollution problem in groundwater as well as soil. Many people interact with these chemicals on daily accidentally or by professionally in the laboratory. One of the most common sources for Chlorinated hydrocarbon contamination of soil and groundwater are industrial effluents. The wide use and discharge of Trichloroethylene (TCE), a volatile chlorohydrocarbon from chemical industry, led to major water pollution in rural areas. TCE is an mainly used as an industrial metal degreaser in industries. Biotransformation of TCE to the potent carcinogen vinyl chloride (VC) by consortia of anaerobic bacteria might have role for the above purpose. For these reasons, the aim of current study was to isolate and characterized the genes involved in TCE metabolism and also to investigate the in silico study of those genes. To our knowledge, only one aromatic dioxygenase system, the toluene dioxygenase in Pseudomonas putida F1 has been shown to be involved in TCE degradation. This is first instance where Bacillus cereus group being used in biodegradation of trichloroethylene. A novel bacterial strain 2479 was isolated from oil depot site at Rajbandh, Durgapur (West Bengal, India) by enrichment culture technique. It was identified based on polyphasic approach and ribotyping. The bacterium was gram positive, rod shaped, endospore forming and capable of degrading trichloroethylene as the sole carbon source. On the basis of phylogenetic data and Fatty Acid Methyl Ester Analysis, strain 2479 should be placed within the genus Bacillus and species cereus. However, the present isolate (strain 2479) is unique and sharply different from the usual Bacillus strains in its biodegrading nature. Fujiwara test was done to estimate that the strain 2479 could degrade TCE efficiently. The gene for TCE biodegradation was PCR amplified from genomic DNA of Bacillus cereus 2479 by using todC1 gene specific primers. The 600bp amplicon was cloned into expression vector pUC I8 in the E. coli host XL1-Blue and expressed under the control of lac promoter and nucleotide sequence was determined. The gene sequence was deposited at NCBI under the Accession no. GU183105. In Silico approach involved predicting the physico-chemical properties of deduced Tce1 protein by using ProtParam tool. The tce1 gene contained 342 bp long ORF encoding 114 amino acids with a predicted molecular weight 12.6 kDa and the theoretical pI value of the polypeptide was 5.17, molecular formula: C559H886N152O165S8, total number of atoms: 1770, aliphatic index: 101.93, instability index: 28.60, Grand Average of Hydropathicity (GRAVY): 0.152. Three differentially expressed proteins (97.1, 40 and 30 kDa) were directly involved in TCE biodegradation, found to react immunologically to the antibodies raised against TCE inducible proteins in Western blot analysis. The present study suggested that cloned gene product (TCE1) was capable of degrading TCE as verified chemically.Keywords: cloning, Bacillus cereus, in silico analysis, TCE
Procedia PDF Downloads 398706 A Genetic Identification of Candida Species Causing Intravenous Catheter-Associated Candidemia in Heart Failure Patients
Authors: Seyed Reza Aghili, Tahereh Shokohi, Shirin Sadat Hashemi Fesharaki, Mohammad Ali Boroumand, Bahar Salmanian
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Introduction: Intravenous catheter-associated fungal infection as nosocomial infection continue to be a deep problem among hospitalized patients, decreasing quality of life and adding healthcare costs. The capacity of catheters in the spread of candidemia in heart failure patients is obvious. The aim of this study was to evaluate the prevalence and genetic identification of Candida species in heart disorder patients. Material and Methods: This study was conducted in Tehran Hospital of Cardiology Center (Tehran, Iran, 2014) during 1.5 years on the patients hospitalized for at least 7 days and who had central or peripheral vein catheter. Culture of catheters, blood and skin of the location of catheter insertion were applied for detecting Candida colonies in 223 patients. Identification of Candida species was made on the basis of a combination of various phenotypic methods and confirmed by sequencing the ITS1-5.8S-ITS2 region amplified from the genomic DNA using PCR and the NCBI BLAST. Results: Of the 223 patients samples tested, we identified totally 15 Candida isolates obtained from 9 (4.04%) catheter cultures, 3 (1.35%) blood cultures and 2 (0.90%) skin cultures of the catheter insertion areas. On the base of ITS region sequencing, out of nine Candida isolates from catheter, 5(55.6%) C. albicans, 2(22.2%) C. glabrata, 1(11.1%) C. membranifiaciens and 1 (11.1%) C. tropicalis were identified. Among three Candida isolates from blood culture, C. tropicalis, C. carpophila and C. membranifiaciens were identified. Non-candida yeast isolated from one blood culture was Cryptococcus albidus. One case of C. glabrata and one case of Candida albicans were isolated from skin culture of the catheter insertion areas in patients with positive catheter culture. In these patients, ITS region of rDNA sequence showed a similarity between Candida isolated from the skin and catheter. However, the blood samples of these patients were negative for fungal growth. We report two cases of catheter-related candidemia caused by C. membranifiaciens and C. tropicalis on the base of genetic similarity of species isolated from blood and catheter which were treated successfully with intravenous fluconazole and catheter removal. In phenotypic identification methods, we could only identify C. albicans and C. tropicalis and other yeast isolates were diagnosed as Candida sp. Discussion: Although more than 200 species of Candida have been identified, only a few cause diseases in humans. There is some evidence that non-albicans infections are increasing. Many risk factors, including prior antibiotic therapy, use of a central venous catheter, surgery, and parenteral nutrition are considered to be associated with candidemia in hospitalized heart failure patients. Identifying the route of infection in candidemia is difficult. Non-albicans candida as the cause of candidemia is increasing dramatically. By using conventional method, many non-albicans isolates remain unidentified. So, using more sensitive and specific molecular genetic sequencing to clarify the aspects of epidemiology of the unknown candida species infections is essential. The positive blood and catheter cultures for candida isolates and high percentage of similarity of their ITS region of rDNA sequence in these two patients confirmed the diagnosis of intravenous catheter-associated candidemia.Keywords: catheter-associated infections, heart failure patient, molecular genetic sequencing, ITS region of rDNA, Candidemia
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