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1.
J Environ Manage ; 299: 113639, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34479146

ABSTRACT

Sustainability has become a focus area for practitioners and scholars due to the growing socio-economic issues. The sustainability of airport operations is being raised in various international platforms. This paper aims to identify the dimensions of sustainability and evaluate sustainable practices in airports of selected ASEAN countries. The various dimensions associated with the environmental aspect are energy management, emissions management, water and effluents management, solid waste management. It was understood that noise management, employee development, and community investment belong to the social dimension. Similarly, the factors such as economic contribution, passenger experience, airport safety, and security are inclined to economic dimensions of sustainability. It was found that environmentally sustainable practices have greater importance than social and economic initiatives in the airport context which provide quantifiable benefits for airports in the long term. Airport operators in South East Asia strived to mitigate carbon emissions, reduce waste and effluents, enhance the economic contribution, satisfy passengers, and meet employee needs. Compared to the total economic and social benefits obtained from these airports, the negative impacts of airport operation (such as noise emission from aircraft) are minimal but significant. The most common sustainable initiatives in airports, such as employee development, energy management, and passenger safety, supported sustainable development goals (SDG) 8, SDG 9, and SDG 11. A weak connection is observed between SDG 14 & SDG 15 and the airport's sustainable practices. The new technological innovations are concentrated in busy and profitable airports. A slow trend towards the adoption of new technologies for sustainable practices is observed in airports. The paper concludes that major airport operators in South-East Asia have effectively responded to the growing sustainability challenges in aviation markets. The sustainable dimensions and practices discussed will be valuable resource for airports striving to achieve sustainability goals.


Subject(s)
Airports , Waste Management , Aircraft , Solid Waste , Technology
2.
J Forensic Dent Sci ; 10(3): 143-150, 2018.
Article in English | MEDLINE | ID: mdl-31143063

ABSTRACT

CONTEXT: "Identity" is a set of physical characteristics, functional or psychic, normal or pathological, that defines an individual. Identification of an individual is a crucial and an exigent task in forensic investigation. AIMS: The aim of the present pilot study was to investigate the accuracy of various methods employed in gender determination such as lip prints, mandibular canine index (MCI), fingerprints, and correlation between them. SUBJECTS AND METHODS: The pilot study group consisted of 300 samples aged between 18 and 25 years. Lip prints, fingerprints, and impressions of lower mandibular arches were collected. STATISTICAL ANALYSIS USED: The results were analyzed using Chi-square test for lip prints and fingerprints with an independent sample t-test for the MCI. Intergroup comparison between the parameters was analyzed by ANNOVA test. RESULTS: Type II lip print pattern and loop pattern of fingerprints were the predominant patterns in both males and females, and mesiodistal width of right MCI has greater sexual dimorphism than left MCI. CONCLUSIONS: Although lip prints, fingerprints, and MCI had their own specifications, correlation of the three parameters did not show any significance.

3.
Bioorg Med Chem ; 24(18): 3986-3993, 2016 09 15.
Article in English | MEDLINE | ID: mdl-27372840

ABSTRACT

Metabolic disorders such as diabetes are known risk factors for developing cholesterol gallstone disease (CGD). Cholesterol gallstone disease is one of the most prevalent digestive diseases, leading to considerable financial and social burden worldwide. Ursodeoxycholic acid (UDCA) is the only bile acid drug approved by FDA for the non-surgical treatment of gallstones. However, the molecular link between UDCA and CGD is unclear. Previous data suggest that the farnesoid X receptor (FXR), a bile acid nuclear receptor, may protect against the development of CGD. In studies aimed at identifying the role of FXR, we recently identify a novel chemical tool, 6EUDCA (6-αethyl-ursodeoxycholic acid), a synthetic derivative of UDCA, for studying FXR. We found that 6EUDCA binds FXR stronger than UDCA in a TR-FRET binding assay. This result was supported by computational docking models that suggest 6EUDCA forms a more extensive hydrogen bound network with FXR. Interestingly, neither compound could activate FXR target genes in human nor mouse liver cells, suggesting UDCA and 6EUDCA activate non-genomic signals in an FXR-dependent manner. Overall these studies may lead to the identification of a novel mechanism by which bile acids regulate cell function, and 6EUDCA may be an effective targeted CGD therapeutic.


Subject(s)
Gallstones/drug therapy , Receptors, Cytoplasmic and Nuclear/metabolism , Ursodeoxycholic Acid/analogs & derivatives , Ursodeoxycholic Acid/pharmacology , Animals , Cells, Cultured , Drug Discovery , Gallstones/prevention & control , Hep G2 Cells , Hepatocytes/drug effects , Hepatocytes/metabolism , Humans , Mice , Mice, Inbred C57BL , Molecular Docking Simulation , Molecular Targeted Therapy , Protein Binding
4.
J Mol Model ; 20(1): 2077, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24464316

ABSTRACT

A quantitative feature-vector representation/model of tertiary structural motifs of proteins is presented. Multiclass logistic regression and a probabilistic neural network were employed to apply this representation to large data sets in order to classify them into major families of distinct motif types (including those of functional importance) with high statistical confidence. Scatter plots of random samples of these motifs were obtained through two-dimensional transformation of the feature vector by metric MDS (multidimensional scaling). The plots showed distinct clusters and shapes for different families and demonstrated the relevance and importance of the proposed quantitative feature-vector representation for characterizing protein tertiary structural motifs. The relative importance of the features was analyzed. The scope of the present work to investigate Nature's prioritization and optimization of functional motif structures is highlighted.


Subject(s)
Proteins/chemistry , Algorithms , Computer Simulation , Logistic Models , Models, Molecular , Neural Networks, Computer , Protein Structure, Secondary , Protein Structure, Tertiary
5.
Biochim Biophys Acta ; 1799(5-6): 353-64, 2010.
Article in English | MEDLINE | ID: mdl-20202486

ABSTRACT

O-linked beta-N-acetylglucosamine (O-GlcNAc) modification of nuclear and cytoplasmic proteins is important for many cellular processes, and the number of proteins that contain this modification is steadily increasing. This modification is dynamic and reversible, and in some cases competes for phosphorylation of the same residues. O-GlcNAc modification of proteins is regulated by cell cycle, nutrient metabolism, and other extracellular signals. Compared to protein phosphorylation, which is mediated by a large number of kinases, O-GlcNAc modification is catalyzed only by one enzyme called O-linked N-acetylglucosaminyl transferase or OGT. Removal of O-GlcNAc from proteins is catalyzed by the enzyme beta-N-acetylglucosaminidase (O-GlcNAcase or OGA). Altered O-linked GlcNAc modification levels contribute to the establishment of many diseases, such as cancer, diabetes, cardiovascular disease, and neurodegeneration. Many transcription factors have been shown to be modified by O-linked GlcNAc modification, which can influence their transcriptional activity, DNA binding, localization, stability, and interaction with other co-factors. This review focuses on modulation of transcription factor function by O-linked GlcNAc modification.


Subject(s)
Acetylglucosamine/chemistry , Acetylglucosamine/metabolism , Transcription Factors/chemistry , Transcription Factors/metabolism , Active Transport, Cell Nucleus , Animals , Cyclic AMP Response Element-Binding Protein/chemistry , Cyclic AMP Response Element-Binding Protein/metabolism , Glycosylation , Humans , Models, Biological , N-Acetylglucosaminyltransferases/metabolism , NF-kappa B/chemistry , NF-kappa B/metabolism , Protein Interaction Domains and Motifs , Protein Processing, Post-Translational , Protein Stability , Receptors, Estrogen/chemistry , Receptors, Estrogen/metabolism , STAT5 Transcription Factor/chemistry , STAT5 Transcription Factor/metabolism , Trans-Activators/chemistry , Trans-Activators/metabolism , Tumor Suppressor Protein p53/chemistry , Tumor Suppressor Protein p53/metabolism , YY1 Transcription Factor/chemistry , YY1 Transcription Factor/metabolism , beta-N-Acetylhexosaminidases/metabolism
6.
Biochem J ; 415(1): 1-10, 2008 Oct 01.
Article in English | MEDLINE | ID: mdl-18778246

ABSTRACT

Production and secretion of insulin from the beta-cells of the pancreas is very crucial in maintaining normoglycaemia. This is achieved by tight regulation of insulin synthesis and exocytosis from the beta-cells in response to changes in blood glucose levels. The synthesis of insulin is regulated by blood glucose levels at the transcriptional and post-transcriptional levels. Although many transcription factors have been implicated in the regulation of insulin gene transcription, three beta-cell-specific transcriptional regulators, Pdx-1 (pancreatic and duodenal homeobox-1), NeuroD1 (neurogenic differentiation 1) and MafA (V-maf musculoaponeurotic fibrosarcoma oncogene homologue A), have been demonstrated to play a crucial role in glucose induction of insulin gene transcription and pancreatic beta-cell function. These three transcription factors activate insulin gene expression in a co-ordinated and synergistic manner in response to increasing glucose levels. It has been shown that changes in glucose concentrations modulate the function of these beta-cell transcription factors at multiple levels. These include changes in expression levels, subcellular localization, DNA-binding activity, transactivation capability and interaction with other proteins. Furthermore, all three transcription factors are able to induce insulin gene expression when expressed in non-beta-cells, including liver and intestinal cells. The present review summarizes the recent findings on how glucose modulates the function of the beta-cell transcription factors Pdx-1, NeuroD1 and MafA, and thereby tightly regulates insulin synthesis in accordance with blood glucose levels.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/physiology , Blood Glucose/physiology , Homeodomain Proteins/physiology , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/physiology , Insulin/biosynthesis , Maf Transcription Factors, Large/physiology , Nerve Tissue Proteins/physiology , Trans-Activators/physiology , Animals , Gene Expression Regulation , Histone Deacetylases/physiology , Humans , Insulin/genetics , Protein Transport
7.
J Biol Chem ; 282(21): 15589-96, 2007 May 25.
Article in English | MEDLINE | ID: mdl-17403669

ABSTRACT

O-Linked GlcNAc modification of nuclear and cytosolic proteins has been shown to regulate the function of many cellular proteins. Increased O-linked glycosylation, observed under chronic hyperglycemia conditions, has been implicated in the pathogenesis of diabetes. However, the exact role of O-GlcNAc modification in regulating glucose homeostasis remains to be established. We report here that the subcellular localization of the pancreatic beta cell-specific transcription factor NeuroD1 is regulated by O-linked glycosylation in the mouse insulinoma cell line MIN6. Under low glucose conditions, NeuroD1 is mainly in the cytosol. However, treatment of MIN6 cells with high glucose results in O-linked GlcNAc modification of NeuroD1 and its subsequent translocation into the nucleus. Consistent with these data, treatment of MIN6 cells with O-(2-acetamido-2-deoxy-d-glucopyranosylidene)-amino N-phenylcarbamate, an inhibitor of O-GlcNAcase, causes Neuro-D1 localization to the nucleus and induction of insulin gene expression even on low glucose. Furthermore, we demonstrate that NeuroD1 interacts with the O-GlcNAc transferase, OGT only at high concentrations of glucose and depletion of OGT by using small interfering RNA oligos interferes with the nuclear localization of NeuroD1 on high glucose. On low glucose NeuroD1 interacts with the O-GlcNAcase and becomes deglycosylated, which is likely to be important for export of Neuro-D1 into cytosol in the presence of low glucose. In summary, the presented data suggest that glucose regulates the subcellular localization of NeuroD1 in pancreatic beta cells via O-linked GlcNAc modification of NeuroD1 by OGT.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/metabolism , Cell Nucleus/metabolism , Glucose/pharmacology , Insulin-Secreting Cells/metabolism , Protein Processing, Post-Translational/drug effects , Sweetening Agents/pharmacology , Acetylglucosamine/biosynthesis , Active Transport, Cell Nucleus/drug effects , Animals , Cell Line, Tumor , Cell Nucleus/pathology , Chronic Disease , Diabetes Mellitus/etiology , Diabetes Mellitus/metabolism , Diabetes Mellitus/pathology , Gene Expression Regulation/drug effects , Glucose/metabolism , Glycosylation/drug effects , Hyperglycemia/complications , Hyperglycemia/metabolism , Hyperglycemia/pathology , Insulin/biosynthesis , Insulin-Secreting Cells/pathology , Mice
8.
IET Syst Biol ; 1(1): 33-40, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17370427

ABSTRACT

Networks of signaling pathways provide a robust mechanism for cells to respond to various biological stimuli. Cell adaptation through the viewpoint of an organising principle between two interconnected pathways--mitogen-activated protein kinase (MAPK) and protein kinase C (PKC) is demonstrated. A multilevel system representation of the pathways is used to determine the pathway components contributing to the adaptive behaviour and coordination. The adaptation can be thought of as being manifested by a change in parameters of the coordinator. In silico experiments are conducted using MAPK-PKC mathematical model in the literature, which is modularised using biological functionality. Through extensive, guided parametric in silico experiments, the PLA2 subsystem is shown to be a coordinator. Results show that varying parameters of the coordinator not only activate the network of pathways where otherwise the pathway activity is very low, but also reveal the ability of the system to activate itself in the absence of the input, indicating relevance of the principle of bounded autonomy.


Subject(s)
Mitogen-Activated Protein Kinases/metabolism , Models, Biological , Signal Transduction/physiology , Computational Biology/methods , Protein Kinase C/metabolism , Systems Biology/methods
9.
J Biol Chem ; 282(3): 1577-84, 2007 Jan 19.
Article in English | MEDLINE | ID: mdl-17142462

ABSTRACT

MafA is a basic leucine zipper transcription factor that regulates gene expression in both the neuroretina and pancreas. Within the pancreas, MafA is exclusively expressed in the beta cells and is involved in insulin gene transcription, insulin secretion, and beta cell survival. The expression of the mafA gene within beta cells is known to increase in response to high glucose levels by an unknown mechanism. In this study, we demonstrate that pyruvate, which is produced by glycolysis from glucose, is not sufficient to induce mafA gene expression compared with high glucose. This suggests that the signal for MafA induction is independent of ATP levels and that a metabolic event occurring upstream of pyruvate production leads to the induction of MafA. Furthermore, insulin secretion mediated by high glucose is not important for MafA expression. However, the addition of glucosamine to beta cell lines stimulates MafA expression in the absence of high glucose, and inhibition of the hexosamine biosynthetic pathway in the presence of high glucose abolishes MafA induction. Moreover, we demonstrate that the expression of UDP-N-acetylglucosaminyl transferase, the enzyme mediating O-linked glycosylation of cytosolic and nuclear proteins, is essential for glucose-dependent MafA expression. Consistent with this observation, inhibition of N-acetylglucosaminidase, the enzyme involved in the removal of the O-GlcNAc modification from proteins, with O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino-N-phenylcarbamate stimulates MafA expression under low glucose conditions. The presented data suggest that MafA expression mediated by high glucose requires flux through the hexosamine biosynthetic pathway and the O-linked glycosylation of an unknown protein(s) by UDP-N-acetylglucosaminyl transferase.


Subject(s)
Gene Expression Regulation , Glucose/metabolism , Hexosamines/metabolism , Insulin-Secreting Cells/metabolism , Maf Transcription Factors, Large/biosynthesis , Animals , Cell Nucleus/metabolism , Cell Survival , Cytosol/metabolism , Glycosylation , Insulin/metabolism , Mice , Models, Biological , N-Acetylglucosaminyltransferases/metabolism , Tetrazolium Salts/pharmacology , Thiazoles/pharmacology
10.
Biochem Biophys Res Commun ; 337(1): 149-53, 2005 Nov 11.
Article in English | MEDLINE | ID: mdl-16182253

ABSTRACT

Several nuclear and cytoplasmic proteins in metazoans are modified by O-linked N-acetylglucosamine (O-GlcNAc). This modification is dynamic and reversible similar to phosphorylation and is catalyzed by the O-linked GlcNAc transferase (OGT). Hyperglycemia has been shown to increase O-GlcNAc levels in pancreatic beta cells, which appears to interfere with beta-cell function. To obtain a better understanding of the role of O-linked GlcNAc modification in beta cells, we have isolated OGT interacting proteins from a cDNA library made from the mouse insulinoma MIN6 cell line. We describe here the identification of Ataxin-10, encoded by the SCA10 (spinocerebellar ataxia type 10) gene as an OGT interacting protein. Mutations in the SCA10 gene cause progressive cerebellar ataxias and seizures. We demonstrate that SCA10 interacts with OGT in vivo and is modified by O-linked glycosylation in MIN6 cells, suggesting a novel role for the Ataxin-10 protein in pancreatic beta cells.


Subject(s)
Carrier Proteins/metabolism , Islets of Langerhans/enzymology , N-Acetylglucosaminyltransferases/metabolism , Animals , Ataxin-10 , Cell Line, Tumor , Glucose/pharmacology , Humans , Islets of Langerhans/drug effects , Mice , Protein Interaction Mapping
11.
Biochem Soc Trans ; 33(Pt 3): 507-15, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15916553

ABSTRACT

A mathematical understanding of regulation, and, in particular, the role of feedback, has been central to the advance of the physical sciences and technology. In this article, the framework provided by systems biology is used to argue that the same can be true for molecular biology. In particular, and using basic modular methods of mathematical modelling which are standard in control theory, a set of dynamic models is developed for some illustrative cell signalling processes. These models, supported by recent experimental evidence, are used to argue that a control theoretical approach to the mechanisms of feedback in intracellular signalling is central to furthering our understanding of molecular communication. As a specific example, a MAPK (mitogen-activated protein kinase) signalling pathway is used to show how potential feedback mechanisms in the signalling process can be investigated in a simulated environment. Such 'what if' modelling/simulation studies have been an integral part of physical science research for many years. Using tools of control systems analysis, as embodied in the disciplines of systems biology, similar predictive modelling/simulation studies are now bearing fruit in cell signalling research.


Subject(s)
Cells/metabolism , Signal Transduction , Systems Biology , Computer Simulation , Models, Biological , Protein Transport
12.
Syst Biol (Stevenage) ; 1(1): 19-27, 2004 Jun.
Article in English | MEDLINE | ID: mdl-17052112

ABSTRACT

Due in large measure to the explosive progress in molecular biology, biology has become arguably the most exciting scientific field. The first half of the 21st century is sometimes referred to as the 'era of biology', analogous to the first half of the 20th century, which was considered to be the 'era of physics'. Yet, biology is facing a crisis--or is it an opportunity--reminiscent of the state of biology in pre-double-helix time. The principal challenge facing systems biology is complexity. According to Hood, 'Systems biology defines and analyses the interrelationships of all of the elements in a functioning system in order to understand how the system works.' With 30000+ genes in the human genome the study of all relationships simultaneously becomes a formidably complex problem. Hanahan and Weinberg raised the question as to whether progress will consist of 'adding further layers of complexity to a scientific literature that is already complex almost beyond measure' or whether the progress will lead to a 'science with a conceptual structure and logical coherence that rivals that of chemistry or physics.' At the core of the challenge is the need for a new approach, a shift from reductionism to a holistic perspective. However, more than just a pronouncement of a new approach is needed. We suggest that what is needed is to provide a conceptual framework for systems biology research. We propose that the concept of a complex system, i.e. a system of systems as defined in mathematical general systems theory (MGST), is central to provide such a framework. We further argue that for a deeper understanding in systems biology investigations should go beyond building numerical mathematical or computer models--important as they are. Biological phenomena cannot be predicted with the level of numerical precision as in classical physics. Explanations in terms of how the categories of systems are organised to function in ever changing conditions are more revealing. Non-numerical mathematical tools are appropriate for the task. Such a categorical perspective led us to propose that the core of understanding in systems biology depends on the search for organising principles rather than solely on construction of predictive descriptions (i.e. models) that exactly outline the evolution of systems in space and time. The search for organising principles requires an identification/discovery of new concepts and hypotheses. Some of them, such as coordination motifs for transcriptional regulatory networks and bounded autonomy of levccels in a hierarchy, are outlined in this article. Experimental designs are outlined to help verify the applicability of the interaction balance principle of coordination to transcriptional and posttranscriptional networks.


Subject(s)
Cell Physiological Phenomena , Models, Biological , Molecular Biology/methods , Molecular Biology/trends , Systems Biology/methods , Systems Biology/trends
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