115 research outputs found

    Microarray time-series data clustering via gene expression profile alignment

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    Clustering gene expression data given In terms of time-series is a challenging problem that imposes its own particular constraints, namely, exchanging two or more time points is not possible as it would deliver quite different results and would lead to erroneous biological conclusions. In this thesis, clustering methods introducing the concept of multiple alignment of natural cubic spline representations of gene expression profiles are presented. The multiple alignment is achieved by minimizing the sum of integrated squared errors over a time-interval, defined on a set of profiles. The proposed approach with flat clustering algorithms like k-means and EM are shown to cluster microarray time-series profiles efficiently and reduce the computational time significantly. The effectiveness of the approaches is experimented on six data sets. Experiments have also been carried out in order to determine the number of clusters and to determine the accuracies of the proposed approaches

    Iron Intermetallic Compounds (IMCs) Formation Mechanism in the Molten Aluminium Zinc (Al-Zn) Coating Alloy

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    To prevent corrosion of steel products, the steel industry often relies on Al-Zn based alloy coatings, applied through hot-dip coating technology. Despite this, a long-standing problem in the galvanizing industry involves the formation of Fe-based intermetallic compounds (IMCs) in the Al-Zn coating bath, caused by iron dissolution from steel products. Such IMCs are the primary source of dross formation in the Al-Zn bath, which inevitably leads to metal spot defects in the coated steel products and bottom dross build-up in the Al-Zn bath. The present research aims to investigate the mechanism of Fe transformation into IMCs. To achieve this, Fe saturated and unsaturated Al-Zn alloys were doped with low carbon steel at a temperature of 600 °C. The samples were collected at regular intervals and quenched in water. The optical microscopy (OM) and scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS) were used to study the transformation of steel strips into Fe-IMCs particles in molten Al-Zn alloys. The study findings suggest that the Fe transformation into Fe-IMCs is a complex process, where the steel strip surface is initially oxidized, and Al5Fe2 and Al3Fe are formed, which finally transform into Al8Fe2Si(Zn) (τ5c) IMCs particles. These results can assist galvanizers in understanding formation of Fe-IMCs and bottom dross build up in the costing pots

    Biochemistry and Molecular Biology Developmentally Regulated Production of meso- Zeaxanthin in Chicken Retinal Pigment Epithelium/ Choroid and Retina

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    PURPOSE. meso-Zeaxanthin is a carotenoid that is rarely encountered in nature outside of the vertebrate eye. It is not a constituent of a normal human diet, yet this carotenoid comprises onethird of the primate macular pigment. In the current study, we undertook a systematic approach to biochemically characterize the production of meso-zeaxanthin in the vertebrate eye. METHODS. Fertilized White Leghorn chicken eggs were analyzed for the presence of carotenoids during development. Yolk, liver, brain, serum, retina, and RPE/choroid were isolated, and carotenoids were extracted. The samples were analyzed on C-30 or chiral HPLC columns to determine the carotenoid composition. RESULTS. Lutein and zeaxanthin were found in all studied nonocular tissues, but no mesozeaxanthin was ever detected. Among the ocular tissues, the presence of meso-zeaxanthin was consistently observed starting at embryonic day 17 (E17) in the RPE/choroid, several days before its consistent detection in the retina. If RPE/choroid of an embryo was devoid of mesozeaxanthin, the corresponding retina was always negative as well. CONCLUSIONS. This is the first report of developmentally regulated synthesis of mesozeaxanthin in a vertebrate system. Our observations suggest that the RPE/choroid is the primary site of meso-zeaxanthin synthesis. Identification of meso-zeaxanthin isomerase enzyme in the developing chicken embryo will facilitate our ability to determine the biochemical mechanisms responsible for production of this unique carotenoid in other higher vertebrates, such as humans

    Sugar-sweetened carbonated beverage consumption correlates with BMI, waist circumference, and poor dietary choices in school children

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    <p>Abstract</p> <p>Background</p> <p>The prevalence of obesity and overweight is increasing globally. Frequently coexisting with under-nutrition in developing countries, obesity is a major contributor to chronic disease, and will become a serious healthcare burden especially in countries with a larger percentage of youthful population. 35% of the population of Saudi Arabia are under the age of 16, and adult dietary preferences are often established during early childhood years. Our objective was to examine the dietary habits in relation to body-mass-index (BMI) and waist circumference (W_C), together with exercise and sleep patterns in a cohort of male and female Saudi school children, in order to ascertain whether dietary patterns are associated with obesity phenotypes in this population.</p> <p>Methods</p> <p>5033 boys and 4400 girls aged 10 to 19 years old participated in a designed Food Frequency Questionnaire. BMI and W_C measurements were obtained and correlated with dietary intake.</p> <p>Results</p> <p>The overall prevalence of overweight and obesity was 12.2% and 27.0% respectively, with boys having higher obesity rates than girls (P ≤ 0.001). W_C and BMI was positively correlated with sugar-sweetened carbonated beverage (SSCB) intake in boys only. The association between male BMI and SSCB consumption was significant in a multivariate regression model (P < 0.0001). SSCB intake was positively associated with poor dietary choices in both males and females. Fast food meal intake, savory snacks, iced desserts and total sugar consumption correlated with SSCB intake in both boys (r = 0.39, 0.13, 0.10 and 0.52 respectively, P < 0.001) and girls (r = 0.45, 0.23, 0.16 and 0.55 respectively, P < 0.001). Older children reported eating significantly less fruit and vegetables than younger children; and less eggs, fish and cereals. Conversely, consumption of SSCB and sugar-sweetened hot beverages were higher in older versus younger children (P < 0.001). BMI and W_C were negatively correlated with hours of night-time sleep and exercise in boys, but only with night time sleep in girls, who also showed the lowest frequency of exercise.</p> <p>Conclusions</p> <p>A higher intake of SSCB is associated with poor dietary choices. Male SSCB intake correlates with a higher W_C and BMI. Limiting exposure to SSCB could therefore have a large public health impact.</p

    Genomic insights into rapid speciation within the world's largest tree genus Syzygium

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    The relative importance of the mechanisms underlying species radiation remains unclear. Here, the authors combine reference genome assembly and population genetics analyses to show that neutral forces have contributed to the radiation of the most species-rich tree genus Syzygium. Species radiations, despite immense phenotypic variation, can be difficult to resolve phylogenetically when genetic change poorly matches the rapidity of diversification. Genomic potential furnished by palaeopolyploidy, and relative roles for adaptation, random drift and hybridisation in the apportionment of genetic variation, remain poorly understood factors. Here, we study these aspects in a model radiation, Syzygium, the most species-rich tree genus worldwide. Genomes of 182 distinct species and 58 unidentified taxa are compared against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that while Syzygium shares an ancient genome doubling event with other Myrtales, little evidence exists for recent polyploidy events. Phylogenomics confirms that Syzygium originated in Australia-New Guinea and diversified in multiple migrations, eastward to the Pacific and westward to India and Africa, in bursts of speciation visible as poorly resolved branches on phylogenies. Furthermore, some sublineages demonstrate genomic clines that recapitulate cladogenetic events, suggesting that stepwise geographic speciation, a neutral process, has been important in Syzygium diversification.Peer reviewe

    Genomic insights into rapid speciation within the world's largest tree genus Syzygium

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    Acknowledgements Y.W.L. was supported by a postgraduate scholarship research grant from the Ministry of National Development, Singapore awarded through the National Parks Board, Singapore (NParks; NParks’ Garden City Fund). Principal research funding from NParks and the School of Biological Sciences (SBS), Nanyang Technological University (NTU), Singapore, is acknowledged. We thank Peter Preiser, Associate Vice President for Biomedical and Life Sciences, for facilitating NTU support, and Kenneth Er, CEO of NParks, for facilitating research funding through that organisation. V.A.A. and C.L. were funded by SBS, NTU for a one-year research leave. V.A.A. and C.L. also acknowledge support from the United States National Science Foundation (grants 2030871 and 1854550, respectively). S.R. was supported by a postdoctoral research fellowship under the NTU Strategic Plant Programme. S.R. and N.R.W.C. acknowledge funding from NTU start-up and the Academy of Finland (decisions 318288, 319947) grants to J.S. Fieldwork conducted by Y.W.L. was supported by an Indonesian Government RISTEK research permit (Application ID: 1517217008) and an Access License from the Sabah State government [JKM/MBS.1000-2/2JLD.7(84)]. T.N.C.V. is grateful to the Assemblée de la Province Nord and Assemblée de la Province Sud (New Caledonia) for facilitating relevant collection permits. A.N. was partly supported by the Research Project Promotion Grant (Strategic Research Grant No. 17SP01302) from the University of the Ryukyus, and partly by the Environment Research and Technology Development Fund (JPMEERF20204003) from the Environmental Restoration and Conservation Agency of Japan. Fieldwork in Fiji conducted by R.B. was hosted and facilitated by Elina Nabubuniyaka-Young (The Pacific Community’s Centre for Pacific Crops and Trees, Fiji). We thank the NTU-Smithsonian Partnership for tree data obtained for the Bukit Timah Nature Reserve (BTNR) long-term forest dynamics plots. Administrative support provided by Mui Hwang Khoo-Woon and Peter Ang at the molecular laboratory of the Singapore Botanic Gardens (SBG) is acknowledged. Rosie Woods and Imalka Kahandawala (DNA and Tissue Bank, Royal Botanic Gardens, Kew) facilitated additional DNA samples. Daniel Thomas (SBG) and Yan Yu (Sichuan University) commented on biogeographical analyses. NovogeneAIT in Singapore is acknowledged for personalised sequencing service.Peer reviewedPublisher PD

    Внедрение и принцип работы системы сейсмического мониторинга горного массива для работы в условиях ООО "Шахта "Усковская"

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    The status of the Silicon Microvertex Detector (SMD) and its installation into the LEP-L3 experiment are presented, highlighting novel features and sophisticated techniques. Preliminary results based on 1993 data are given and compared with Monte Carlo predictions, to understand the detector performances and its tracking capabilities

    The Liverpool alcohol-related liver disease algorithm identifies twice as many emergency admissions compared to standard methods when applied to Hospital Episode Statistics for England

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    BackgroundEmergency admissions in England for alcohol-related liver disease (ArLD) have increased steadily for decades. Statistics based on administrative data typically focus on the ArLD-specific code as the primary diagnosis and are therefore at risk of excluding ArLD admissions defined by other coding combinations.AimTo deploy the Liverpool ArLD Algorithm (LAA), which accounts for alternative coding patterns (e.g., ArLD secondary diagnosis with alcohol/liver-related primary diagnosis), to national and local datasets in the context of studying trends in ArLD admissions before and during the COVID-19 pandemic.MethodsWe applied the standard approach and LAA to Hospital Episode Statistics for England (2013-21). The algorithm was also deployed at 28 hospitals to discharge coding for emergency admissions during a common 7-day period in 2019 and 2020, in which eligible patient records were reviewed manually to verify the diagnosis and extract data.ResultsNationally, LAA identified approximately 100% more monthly emergency admissions from 2013 to 2021 than the standard method. The annual number of ArLD-specific admissions increased by 30.4%. Of 39,667 admissions in 2020/21, only 19,949 were identified with standard approach, an estimated admission cost of £70 million in under-recorded cases. Within 28 local hospital datasets, 233 admissions were identified using the standard approach and a further 250 locally verified cases using the LAA (107% uplift). There was an 18% absolute increase in ArLD admissions in the seven-day evaluation period in 2020 versus 2019. There were no differences in disease severity or mortality, or in the proportion of admissions with decompensation of cirrhosis or alcoholic hepatitis.ConclusionsThe LAA can be applied successfully to local and national datasets. It consistently identifies approximately 100% more cases than the standard coding approach. The algorithm has revealed the true extent of ArLD admissions. The pandemic has compounded a long-term rise in ArLD admissions and mortality

    International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

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    Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist
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