570 research outputs found
The effect of data preprocessing on the performance of artificial neural networks techniques for classification problems
The artificial neural network (ANN) has recently been applied in many areas, such as
medical, biology, financial, economy, engineering and so on. It is known as an excellent
classifier of nonlinear input and output numerical data. Improving training efficiency of
ANN based algorithm is an active area of research and numerous papers have been
reviewed in the literature. The performance of Multi-layer Perceptron (MLP) trained
with back-propagation artificial neural network (BP-ANN) method is highly influenced
by the size of the data-sets and the data-preprocessing techniques used. This work
analyzes the advantages of using pre-processing datasets using different techniques in
order to improve the ANN convergence. Specifically Min-Max, Z-Score and Decimal
Scaling Normalization preprocessing techniques were evaluated. The simulation results
showed that the computational efficiency of ANN training process is highly enhanced
when coupled with different preprocessing techniques
An Enhanced Computer Vision By Using MLP Approach To Forensic Face Sketch Recognition System
Technologies for suspect identification, detection, and recognition have become more critical in recent years. As a result, face recognition is an almost commonly used biometric technique. Investigators for Criminal and forensic computer vision researchers are interested in the human-recognized face sketches were drawn by artists. Hand-drawn face sketches are, according to studies, still extremely rare, both in terms of artists and number of drawings, since forensic artists prepare victim drawings based on descriptions were provided by eyewitnesses following an incident. Masks are sometimes used to conceal standard facial features such as noses, eyes, lips, and skin color, but face biometrics' outliner features are impossible to conceal. This paper concentrated on a particular face-geometrical feature that could calculate some similarity ratios between composite template photos and forensic sketches. Computer vision techniques such as Two-Dimensional Discrete Cosine Transform (2D-DCT) and the Self-Organizing Map (SOM) Neural Network are used to design a system for composite and forensic face sketch recognition
Hyperthermophilic archaea as a source for novel enzyme discovery
The Archaea are a group of microorganisms that are phylogenetically distinct to the Bacteria and Eucarya. Their size and shape resemble bacteria, but display stark differences in the structure of their membrane lipids and machinery that are responsible for DNA replication and transcription. In addition, Archaea seem to utilize metabolic pathways that differ to previously recognized, classical pathways in bacteria and eukaryotes. Based on the genome sequences of the Archaea, there are many cases in which a particular metabolic pathway seems to be absent or incomplete. The search for these “missing” pathways or enzymes has been an exciting field of research in the Archaea, and has led to the discovery of structurally novel enzymes or enzymes with novel activity. Until now, we have been focused on the metabolism of the hyperthermophilic archaeon Thermococcus kodakarensis. The organism is an obligate anaerobe and heterotroph, utilizing a wide range of organic compounds including peptides/amino acids, starch and maltooligosaccharides, and organic acids such as pyruvate. By searching for missing genes, we have identified a structurally novel fructose-1,6-bisphosphatase [1], a key enzyme in gluconeogenesis, and enzymes with novel activity, such as pantoate kinase and phosphopantothenate synthetase, both involved in coenzyme A biosynthesis in T. kodakarensis [2].
A number of genes predicted to encode kinases are present on the T. kodakarensis genome. Although more than half display similarity to characterized enzymes high enough to predict their substrates, there are still nearly 20 genes whose substrates are unknown. One of them turned out to be a myo-inositol 3-kinase [3]. Another was found to display an ADP-dependent ribose-1-phosphate kinase activity, which participates in a pentose bisphosphate pathway, a previously unidentified route to direct the ribose moieties of nucleosides to central carbon metabolism [4]. Another kinase was identified through studies on serine and cysteine metabolism in T. kodakarensis. The protein was initially annotated as a chromosome-partitioning protein ParB, but displayed ADP-dependent serine kinase activity. The enzyme was necessary for the conversion of Ser to Cys in vivo, and is most likely involved in Ser assimilation in this archaeon [5]. The structure of the enzyme explains the specificity of the enzyme towards Ser and ADP, and raises the possibility that structurally related proteins may also be present not only in archaea but also in bacteria [6]. These studies indicate the potential of archaea as a source for novel enzyme discovery demonstrate various means to identify gene function through genome sequence information.
[1] Rashid N, Imanaka H, Kanai T, Fukui T, Atomi H, Imanaka T. A novel candidate for the true fructose-1,6-bisphosphatase in archaea. J. Biol. Chem., 277(34):30649-30655, 2002.
[2] Yokooji Y, Tomita H, Atomi H, Imanaka T. Pantoate kinase and phosphopantothenate synthetase, two novel enzymes necessary for CoA biosynthesis in the Archaea. J. Biol. Chem., 284(41):28137-28145, 2009.
[3] Sato T, Fujihashi M, Miyamoto Y, Kuwata K, Kusaka E, Fujita H, Miki K, Atomi H. An uncharacterized member of the ribokinase family in Thermococcus kodakarensis exhibits myo-inositol kinase activity. J. Biol. Chem., 288(29):20856-20867, 2013.
[4] Aono R, Sato T, Imanaka T, Atomi H. A pentose bisphosphate pathway for nucleoside degradation in Archaea. Nat. Chem. Biol., 11(5):355-360, 2015.
[5] Makino Y, Sato T, Kawamura H, Hachisuka SI, Takeno R, Imanaka T, Atomi H. An archaeal ADP-dependent serine kinase involved in cysteine biosynthesis and serine metabolism. Nat. Commun., 7:13446, 2016.
[6] Nagata R, Fujihashi M, Kawamura H, Sato T, Fujita T, Atomi H, Miki K. Structural study on the reaction mechanism of a free serine kinase involved in cysteine biosynthesis. ACS Chem. Biol. Article ASAP, 2017. doi:10.1021/acschembio.7b00064
転倒の自己認知は身体的危機に関連する脳領域を活性化させる
While bipedalism is a fundamental evolutionary adaptation thought to be essential for the development of the human brain, the erect body is always an inch or two away from falling. Although the neural mechanism for automatically detecting one’s own body instability is an important consideration, there have thus far been few functional neuroimaging studies because of the restrictions placed on participants’ movements. Here, we used functional magnetic resonance imaging to investigate the neural substrate underlying whole body instability, based on the self-recognition paradigm that uses video stimuli consisting of one’s own and others’ whole bodies depicted in stable and unstable states. Analyses revealed significant activity in the regions which would be activated during genuine unstable bodily states: The right parieto-insular vestibular cortex, inferior frontal junction, posterior insula and parabrachial nucleus. We argue that these right-lateralized cortical and brainstem regions mediate vestibular information processing for detection of vestibular anomalies, defensive motor responding in which the necessary motor responses are automatically prepared/simulated to protect one’s own body, and sympathetic activity as a form of alarm response during whole body instability.首都大学東京, 2016-03-25, 博士(健康科学), 甲第633号首都大学東
Isolation of the Gene Encoding Yeast Peroxisomal Isocitrate Lyase by a Combination of the Plaque Hybridization with Non-Radioactive Probes and the Amplification of Phages in a Small Scale
A genomic DNA encoding isocitrate lyase, one of peroxisomal enzymes, was successfully isolated from an n-alkane-utilizable yeast genomic library prepared in a λEMBL phage by a combination of the plaque hybridization with a non-radioactive, biotin labeled, cDNA and the amplification of the phages in a small scale. Three clones, partially overlapping, with sizes of about 11, 13 and 16 kbp respectively were finally obtained. The genomic Southern blot analysis using the biotin-labeled probe suggested the presence of one isocitrate lyase gene in the genomic DNA
Expression Cloning of Catalase Genomic Gene : Genomic DNA Expression Library of Candida boidinii in Saccharomyces cerevisiae
The genomic DNA expression library of a methylotrophic yeast, Candida boidinii (Kloeckera sp.) 2201, was prepared in Saccharomyces cerevisiae by the electroporation method. Five transformants harbouring a catalase gene were independently isolated with an anti-C. boidinii catalase antibody from this library. Furthermore, exhibition of catalase activity in these transformants demonstrated that C. boidinii genes could sufficiently function even in S. cerevisiae
Arab students' beliefs about using English language / Mayson Badar Atomi
English is a language that relishes a prestigious status in many countries and it is clear that English language has become more dominant around the world. This study aims to identify Arab students' beliefs about using English language, to identify the language skills that Arab students find difficult to learn and to understand the environmental factors that hinder the students from using the language in teaching and learning interaction and how they overcome these obstacles. It also aims to examine whether there is a difference between students' beliefs, difficulty in the different language skills, factors that hinder students from using the language in teaching and learning interaction, and their proficiency level in English language. A questionnaire was the main research tool; some of the items have been adapted from "Beliefs about Language Learning Inventory (BALLI)" (Horwitz, 1987). 60 Arab university students from different areas of study were selected from seven Malaysian universities. Data gathered in the study have been analyzed statistically; standard deviation and one way ANOVA were used to examine significant differences between students' beliefs about language learning and their proficiency level. Qualitative data of the study has been converted into numerical data for analysis purposes. The findings indicate that Arab students' beliefs about using English language are quiet similar regardless of their level of proficiency as they face similar problems and difficulties in using English language. The study has served as a useful reminder that English language proficiency does not affect learners' beliefs about language learning and problems and difficulties faced in learning the English language
A unique DNase activity shares the active site with ATPase activity of the RecA/Rad51 homologue (Pk-REC) from a hyperthermophilic archaeon
AbstractA RecA/Rad51 homologue from Pyrococcus kodakaraensis KOD1 (Pk-REC) is the smallest protein among various RecA/Rad51 homologues. Nevertheless, Pk-Rec is a super multifunctional protein and shows a deoxyribonuclease activity. This deoxyribonuclease activity was inhibited by 3 mM or more ATP, suggesting that the catalytic centers of the ATPase and deoxyribonuclease activities are overlapped. To examine whether these two enzymatic activities share the same active site, a number of site-directed mutations were introduced into Pk-REC and the ATPase and deoxyribonuclease activities of the mutant proteins were determined. The mutant enzyme in which double mutations Lys-33 to Ala and Thr-34 to Ala were introduced, fully lost both of these activities, indicating that Lys-33 and/or Thr-34 are important for both ATPase and deoxyribonuclease activities. The mutation of Asp-112 to Ala slightly and almost equally reduced both ATPase and deoxyribonuclease activities. In addition, the mutation of Glu-54 to Gln did not seriously affect the ATPase, deoxyribonuclease, and UV tolerant activities. These results strongly suggest that the active sites of the ATPase and deoxyribonuclease activities of Pk-REC are common. It is noted that unlike Glu-96 in Escherichia coli RecA, which has been proposed to be a catalytic residue for the ATPase activity, the corresponding residual Glu-54 in Pk-REC is not involved in the catalytic function of the protein
Matrilysin (MMP-7) as a significant determinant of malignant potential of early invasive colorectal carcinomas
Matrix metalloproteinases play a crucial role in tumour invasion and mestasis. Matrilysin (MMP-7) has been shown to correlate with nodal or distant metastasis in colorectal carcinomas; however, its implication in early invasive colorectal carcinomas has not been determined. This study was undertaken to clarify the association of matrilysin expression with clinicopathologic parameters in early invasive colorectal carcinomas. 38 early invasive colorectal carcinomas treated by local excision or radical surgery were examined. Tumour budding was evaluated as the number of dedifferentiation units along the entire invasive margin. Matrilysin protein levels were determined using immunohistochemical study. Univariate analysis showed that matrilysin expression alone was significantly associated with distant metastasis (P= 0.0339), and both tumour budding and matrilysin expression were significantly associated with adverse outcome (P= 0.0005, 0.0341). Histological differentiation, vessel invasion, and depth of invasion were not significantly associated with either distant metastasis or adverse outcome. Multivariate analysis confirmed that tumour budding and matrilysin expression were independently associated with adverse outcome, although the significance of matrilysin expression was marginal (P= 0.0488). Tumour budding at the invasive margin and matrilysin expression are more useful in identifying high-risk groups for adverse outcome in patients with early invasive colorectal carcinomas. © 2001 Cancer Research Campaign www.bjcancer.co
Molecular bases of thermophily in hyperthermophiles
I reflect on some of our studies on the hyperthermophilic archaeon, Thermococcus kodakarensis KOD1 and its enzymes. The strain can grow at temperatures up to 100 ℃, and also represents one of the simplest forms of life. As expected, all enzymes, DNA, RNA, cytoplasmic membrane, and cytoplasmic solute displayed remarkable thermostability, and we have determined some of the basic principles that govern this feature. To our delight, many of the enzymes exhibited unique biochemical properties and novel structures not found in mesophilic proteins. Here, I will focus on some enzymes whose three-dimensional structures are characteristic of thermostable enzymes. I will also add some examples on the stabilization of DNA, RNA, cytoplasmic membrane, and cytoplasmic solute
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