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Sample records for melanogaster integrating experimental

  1. Drosophila Melanogaster as an Experimental Organism.

    Science.gov (United States)

    Rubin, Gerald M.

    1988-01-01

    Discusses the role of the fruit fly in genetics research requiring a multidisciplinary approach. Describes embryological and genetic methods used in the experimental analysis of this organism. Outlines the use of Drosophila in the study of the development and function of the nervous system. (RT)

  2. Experimental evolution under hyper-promiscuity in Drosophila melanogaster.

    Science.gov (United States)

    Perry, Jennifer C; Joag, Richa; Hosken, David J; Wedell, Nina; Radwan, Jacek; Wigby, Stuart

    2016-06-16

    The number of partners that individuals mate with over their lifetime is a defining feature of mating systems, and variation in mate number is thought to be a major driver of sexual evolution. Although previous research has investigated the evolutionary consequences of reductions in the number of mates, we know little about the costs and benefits of increased numbers of mates. Here, we use a genetic manipulation of mating frequency in Drosophila melanogaster to create a novel, highly promiscuous mating system. We generated D. melanogaster populations in which flies were deficient for the sex peptide receptor (SPR) gene - resulting in SPR- females that mated more frequently - and genetically-matched control populations, and allowed them to evolve for 55 generations. At several time-points during this experimental evolution, we assayed behavioural, morphological and transcriptional reproductive phenotypes expected to evolve in response to increased population mating frequencies. We found that males from the high mating frequency SPR- populations evolved decreased ability to inhibit the receptivity of their mates and decreased copulation duration, in line with predictions of decreased per-mating investment with increased sperm competition. Unexpectedly, SPR- population males also evolved weakly increased sex peptide (SP) gene expression. Males from SPR- populations initially (i.e., before experimental evolution) exhibited more frequent courtship and faster time until mating relative to controls, but over evolutionary time these differences diminished or reversed. In response to experimentally increased mating frequency, SPR- males evolved behavioural responses consistent with decreased male post-copulatory investment at each mating and decreased overall pre-copulatory performance. The trend towards increased SP gene expression might plausibly relate to functional differences in the two domains of the SP protein. Our study highlights the utility of genetic

  3. Experimental evolution of slowed cognitive aging in Drosophila melanogaster.

    Science.gov (United States)

    Zwoinska, Martyna K; Maklakov, Alexei A; Kawecki, Tadeusz J; Hollis, Brian

    2017-03-01

    Reproductive output and cognitive performance decline in parallel during aging, but it is unknown whether this reflects a shared genetic architecture or merely the declining force of natural selection acting independently on both traits. We used experimental evolution in Drosophila melanogaster to test for the presence of genetic variation for slowed cognitive aging, and assess its independence from that responsible for other traits' decline with age. Replicate experimental populations experienced either joint selection on learning and reproduction at old age (Old + Learning), selection on late-life reproduction alone (Old), or a standard two-week culture regime (Young). Within 20 generations, the Old + Learning populations evolved a slower decline in learning with age than both the Old and Young populations, revealing genetic variation for cognitive aging. We found little evidence for a genetic correlation between cognitive and demographic aging: although the Old + Learning populations tended to show higher late-life fecundity than Old populations, they did not live longer. Likewise, selection for late reproduction alone did not result in improved late-life learning. Our results demonstrate that Drosophila harbor genetic variation for cognitive aging that is largely independent from genetic variation for demographic aging and suggest that these two aspects of aging may not necessarily follow the same trajectories. © 2016 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

  4. The three-dimensional genome organization of Drosophila melanogaster through data integration.

    Science.gov (United States)

    Li, Qingjiao; Tjong, Harianto; Li, Xiao; Gong, Ke; Zhou, Xianghong Jasmine; Chiolo, Irene; Alber, Frank

    2017-07-31

    Genome structures are dynamic and non-randomly organized in the nucleus of higher eukaryotes. To maximize the accuracy and coverage of three-dimensional genome structural models, it is important to integrate all available sources of experimental information about a genome's organization. It remains a major challenge to integrate such data from various complementary experimental methods. Here, we present an approach for data integration to determine a population of complete three-dimensional genome structures that are statistically consistent with data from both genome-wide chromosome conformation capture (Hi-C) and lamina-DamID experiments. Our structures resolve the genome at the resolution of topological domains, and reproduce simultaneously both sets of experimental data. Importantly, this data deconvolution framework allows for structural heterogeneity between cells, and hence accounts for the expected plasticity of genome structures. As a case study we choose Drosophila melanogaster embryonic cells, for which both data types are available. Our three-dimensional genome structures have strong predictive power for structural features not directly visible in the initial data sets, and reproduce experimental hallmarks of the D. melanogaster genome organization from independent and our own imaging experiments. Also they reveal a number of new insights about genome organization and its functional relevance, including the preferred locations of heterochromatic satellites of different chromosomes, and observations about homologous pairing that cannot be directly observed in the original Hi-C or lamina-DamID data. Our approach allows systematic integration of Hi-C and lamina-DamID data for complete three-dimensional genome structure calculation, while also explicitly considering genome structural variability.

  5. Experimental integrated photovoltaic systems

    International Nuclear Information System (INIS)

    Pop-Jordanov, Jordan; Markovska, Natasha; Dimitrov, D.; Kocev, K.; Dimitrovski, D.

    2000-01-01

    Recently, the interest in building-integrated photovoltaic installations has started to increase within governmental and municipality authorities, as well as some industrial companies. To serve a national public-awareness program of solar electricity promotion and education, the indigenous solar energy potential, optimization of possible PV installation, and three test cases of building-integrated grid-connected experimental facilities have been studied. The results showed the feasibility and performance of the proposed concepts. (Original)

  6. Computational and experimental identification of mirtrons in Drosophila melanogaster and Caenorhabditis elegans

    Science.gov (United States)

    Chung, Wei-Jen; Agius, Phaedra; Westholm, Jakub O.; Chen, Michael; Okamura, Katsutomo; Robine, Nicolas; Leslie, Christina S.; Lai, Eric C.

    2011-01-01

    Mirtrons are intronic hairpin substrates of the dicing machinery that generate functional microRNAs. In this study, we describe experimental assays that defined the essential requirements for entry of introns into the mirtron pathway. These data informed a bioinformatic screen that effectively identified functional mirtrons from the Drosophila melanogaster transcriptome. These included 17 known and six confident novel mirtrons among the top 51 candidates, and additional candidates had limited read evidence in available small RNA data. Our computational model also proved effective on Caenorhabditis elegans, for which the identification of 14 cloned mirtrons among the top 22 candidates more than tripled the number of validated mirtrons in this species. A few low-scoring introns generated mirtron-like read patterns from atypical RNA structures, but their paucity suggests that relatively few such loci were not captured by our model. Unexpectedly, we uncovered examples of clustered mirtrons in both fly and worm genomes, including a <8-kb region in C. elegans harboring eight distinct mirtrons. Altogether, we demonstrate that discovery of functional mirtrons, unlike canonical miRNAs, is amenable to computational methods independent of evolutionary constraint. PMID:21177960

  7. Genetic consequences of the combined effect of ionizing radiation and copper vitriol on experimental Drosophila melanogaster populations

    International Nuclear Information System (INIS)

    Glushkova, I.V.; Anoshenko, I.P.; Malei, L.P.; Pechkovskaya, A.V.

    2004-01-01

    The paper studies the influence of the combined effect of gamma-irradiation (15 Gy/generation) and copper vitriol (1 mM concentration) on experimental Dr. melanogaster population with the help of the tests of morphogenetic variability and dominant lethal mutations (DLM). The frequency of morphogenetically changed phenotypes increased under the influence of mutagenic factors of diverse origin and their spectrum was practically unchanged. The DLM test has shown that irradiation and the combined effect of chemical and physical factors exerted a damaging effect, while Cu salt acted as sensitizer considerably intensifying radiation effect. (authors)

  8. Predictive regulatory models in Drosophila melanogaster by integrative inference of transcriptional networks.

    Science.gov (United States)

    Marbach, Daniel; Roy, Sushmita; Ay, Ferhat; Meyer, Patrick E; Candeias, Rogerio; Kahveci, Tamer; Bristow, Christopher A; Kellis, Manolis

    2012-07-01

    Gaining insights on gene regulation from large-scale functional data sets is a grand challenge in systems biology. In this article, we develop and apply methods for transcriptional regulatory network inference from diverse functional genomics data sets and demonstrate their value for gene function and gene expression prediction. We formulate the network inference problem in a machine-learning framework and use both supervised and unsupervised methods to predict regulatory edges by integrating transcription factor (TF) binding, evolutionarily conserved sequence motifs, gene expression, and chromatin modification data sets as input features. Applying these methods to Drosophila melanogaster, we predict ∼300,000 regulatory edges in a network of ∼600 TFs and 12,000 target genes. We validate our predictions using known regulatory interactions, gene functional annotations, tissue-specific expression, protein-protein interactions, and three-dimensional maps of chromosome conformation. We use the inferred network to identify putative functions for hundreds of previously uncharacterized genes, including many in nervous system development, which are independently confirmed based on their tissue-specific expression patterns. Last, we use the regulatory network to predict target gene expression levels as a function of TF expression, and find significantly higher predictive power for integrative networks than for motif or ChIP-based networks. Our work reveals the complementarity between physical evidence of regulatory interactions (TF binding, motif conservation) and functional evidence (coordinated expression or chromatin patterns) and demonstrates the power of data integration for network inference and studies of gene regulation at the systems level.

  9. Predictive regulatory models in Drosophila melanogaster by integrative inference of transcriptional networks

    Science.gov (United States)

    Marbach, Daniel; Roy, Sushmita; Ay, Ferhat; Meyer, Patrick E.; Candeias, Rogerio; Kahveci, Tamer; Bristow, Christopher A.; Kellis, Manolis

    2012-01-01

    Gaining insights on gene regulation from large-scale functional data sets is a grand challenge in systems biology. In this article, we develop and apply methods for transcriptional regulatory network inference from diverse functional genomics data sets and demonstrate their value for gene function and gene expression prediction. We formulate the network inference problem in a machine-learning framework and use both supervised and unsupervised methods to predict regulatory edges by integrating transcription factor (TF) binding, evolutionarily conserved sequence motifs, gene expression, and chromatin modification data sets as input features. Applying these methods to Drosophila melanogaster, we predict ∼300,000 regulatory edges in a network of ∼600 TFs and 12,000 target genes. We validate our predictions using known regulatory interactions, gene functional annotations, tissue-specific expression, protein–protein interactions, and three-dimensional maps of chromosome conformation. We use the inferred network to identify putative functions for hundreds of previously uncharacterized genes, including many in nervous system development, which are independently confirmed based on their tissue-specific expression patterns. Last, we use the regulatory network to predict target gene expression levels as a function of TF expression, and find significantly higher predictive power for integrative networks than for motif or ChIP-based networks. Our work reveals the complementarity between physical evidence of regulatory interactions (TF binding, motif conservation) and functional evidence (coordinated expression or chromatin patterns) and demonstrates the power of data integration for network inference and studies of gene regulation at the systems level. PMID:22456606

  10. Reduced Reproductive Success for a Conditioning Mutant in Experimental Populations of DROSOPHILA MELANOGASTER

    OpenAIRE

    Gailey, Donald A.; Hall, Jeffrey C.; Siegel, Richard W.

    1985-01-01

    Male Drosophila melanogaster that have courted newly-emerged males can modify their subsequent courtship behavior to avoid further courtship with immature males for up to 6 hr (previously reported). Here, it was hypothesized that such an experience-dependent modification would afford a mating advantage to normal males over males that carried a mutation that affects learning and memory. Coisogenic lines were constructed which varied at the dunce gene ( dnc+ and dncM14 alleles) in order to test...

  11. Population-based resequencing of experimentally evolved populations reveals the genetic basis of body size variation in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Thomas L Turner

    2011-03-01

    Full Text Available Body size is a classic quantitative trait with evolutionarily significant variation within many species. Locating the alleles responsible for this variation would help understand the maintenance of variation in body size in particular, as well as quantitative traits in general. However, successful genome-wide association of genotype and phenotype may require very large sample sizes if alleles have low population frequencies or modest effects. As a complementary approach, we propose that population-based resequencing of experimentally evolved populations allows for considerable power to map functional variation. Here, we use this technique to investigate the genetic basis of natural variation in body size in Drosophila melanogaster. Significant differentiation of hundreds of loci in replicate selection populations supports the hypothesis that the genetic basis of body size variation is very polygenic in D. melanogaster. Significantly differentiated variants are limited to single genes at some loci, allowing precise hypotheses to be formed regarding causal polymorphisms, while other significant regions are large and contain many genes. By using significantly associated polymorphisms as a priori candidates in follow-up studies, these data are expected to provide considerable power to determine the genetic basis of natural variation in body size.

  12. Integrating RNA-seq and ChIP-seq data to characterize long non-coding RNAs in Drosophila melanogaster.

    Science.gov (United States)

    Chen, Mei-Ju May; Chen, Li-Kai; Lai, Yu-Shing; Lin, Yu-Yu; Wu, Dung-Chi; Tung, Yi-An; Liu, Kwei-Yan; Shih, Hsueh-Tzu; Chen, Yi-Jyun; Lin, Yan-Liang; Ma, Li-Ting; Huang, Jian-Long; Wu, Po-Chun; Hong, Ming-Yi; Chu, Fang-Hua; Wu, June-Tai; Li, Wen-Hsiung; Chen, Chien-Yu

    2016-03-11

    characterization by integrating a large number of sequencing datasets (93 sets in total) from multiple sources (lncRNAs, RNA-seq and ChIP-seq). The RT-qPCR experiments demonstrated that RNA-seq is a reliable platform to discover lncRNAs. This set of curated lncRNAs with improved annotations can serve as an important resource for investigating the function of lncRNAs in D. melanogaster.

  13. Whole-Genome Resequencing of Experimental Populations Reveals Polygenic Basis of Egg-Size Variation in Drosophila melanogaster.

    Science.gov (United States)

    Jha, Aashish R; Miles, Cecelia M; Lippert, Nodia R; Brown, Christopher D; White, Kevin P; Kreitman, Martin

    2015-10-01

    Complete genome resequencing of populations holds great promise in deconstructing complex polygenic traits to elucidate molecular and developmental mechanisms of adaptation. Egg size is a classic adaptive trait in insects, birds, and other taxa, but its highly polygenic architecture has prevented high-resolution genetic analysis. We used replicated experimental evolution in Drosophila melanogaster and whole-genome sequencing to identify consistent signatures of polygenic egg-size adaptation. A generalized linear-mixed model revealed reproducible allele frequency differences between replicated experimental populations selected for large and small egg volumes at approximately 4,000 single nucleotide polymorphisms (SNPs). Several hundred distinct genomic regions contain clusters of these SNPs and have lower heterozygosity than the genomic background, consistent with selection acting on polymorphisms in these regions. These SNPs are also enriched among genes expressed in Drosophila ovaries and many of these genes have well-defined functions in Drosophila oogenesis. Additional genes regulating egg development, growth, and cell size show evidence of directional selection as genes regulating these biological processes are enriched for highly differentiated SNPs. Genetic crosses performed with a subset of candidate genes demonstrated that these genes influence egg size, at least in the large genetic background. These findings confirm the highly polygenic architecture of this adaptive trait, and suggest the involvement of many novel candidate genes in regulating egg size. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  14. Cytochrome c oxidase loses catalytic activity and structural integrity during the aging process in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Ren, Jian-Ching; Rebrin, Igor; Klichko, Vladimir; Orr, William C.; Sohal, Rajindar S.

    2010-01-01

    Research highlights: → Cytochrome c oxidase loses catalytic activity during the aging process. → Abundance of seven nuclear-encoded subunits of cytochrome c oxidase decreased with age in Drosophila. → Cytochrome c oxidase is specific intra-mitochondrial site of age-related deterioration. -- Abstract: The hypothesis, that structural deterioration of cytochrome c oxidase (CcO) is a causal factor in the age-related decline in mitochondrial respiratory activity and an increase in H 2 O 2 generation, was tested in Drosophila melanogaster. CcO activity and the levels of seven different nuclear DNA-encoded CcO subunits were determined at three different stages of adult life, namely, young-, middle-, and old-age. CcO activity declined progressively with age by 33%. Western blot analysis, using antibodies specific to Drosophila CcO subunits IV, Va, Vb, VIb, VIc, VIIc, and VIII, indicated that the abundance these polypeptides decreased, ranging from 11% to 40%, during aging. These and previous results suggest that CcO is a specific intra-mitochondrial site of age-related deterioration, which may have a broad impact on mitochondrial physiology.

  15. Cytochrome c oxidase loses catalytic activity and structural integrity during the aging process in Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Jian-Ching; Rebrin, Igor [Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90033 (United States); Klichko, Vladimir; Orr, William C. [Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275 (United States); Sohal, Rajindar S., E-mail: sohal@usc.edu [Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90033 (United States)

    2010-10-08

    Research highlights: {yields} Cytochrome c oxidase loses catalytic activity during the aging process. {yields} Abundance of seven nuclear-encoded subunits of cytochrome c oxidase decreased with age in Drosophila. {yields} Cytochrome c oxidase is specific intra-mitochondrial site of age-related deterioration. -- Abstract: The hypothesis, that structural deterioration of cytochrome c oxidase (CcO) is a causal factor in the age-related decline in mitochondrial respiratory activity and an increase in H{sub 2}O{sub 2} generation, was tested in Drosophila melanogaster. CcO activity and the levels of seven different nuclear DNA-encoded CcO subunits were determined at three different stages of adult life, namely, young-, middle-, and old-age. CcO activity declined progressively with age by 33%. Western blot analysis, using antibodies specific to Drosophila CcO subunits IV, Va, Vb, VIb, VIc, VIIc, and VIII, indicated that the abundance these polypeptides decreased, ranging from 11% to 40%, during aging. These and previous results suggest that CcO is a specific intra-mitochondrial site of age-related deterioration, which may have a broad impact on mitochondrial physiology.

  16. Inhalation toxicity of indoor air pollutants in Drosophila melanogaster using integrated transcriptomics and computational behavior analyses

    Science.gov (United States)

    Eom, Hyun-Jeong; Liu, Yuedan; Kwak, Gyu-Suk; Heo, Muyoung; Song, Kyung Seuk; Chung, Yun Doo; Chon, Tae-Soo; Choi, Jinhee

    2017-06-01

    We conducted an inhalation toxicity test on the alternative animal model, Drosophila melanogaster, to investigate potential hazards of indoor air pollution. The inhalation toxicity of toluene and formaldehyde was investigated using comprehensive transcriptomics and computational behavior analyses. The ingenuity pathway analysis (IPA) based on microarray data suggests the involvement of pathways related to immune response, stress response, and metabolism in formaldehyde and toluene exposure based on hub molecules. We conducted a toxicity test using mutants of the representative genes in these pathways to explore the toxicological consequences of alterations of these pathways. Furthermore, extensive computational behavior analysis showed that exposure to either toluene or formaldehyde reduced most of the behavioral parameters of both wild-type and mutants. Interestingly, behavioral alteration caused by toluene or formaldehyde exposure was most severe in the p38b mutant, suggesting that the defects in the p38 pathway underlie behavioral alteration. Overall, the results indicate that exposure to toluene and formaldehyde via inhalation causes severe toxicity in Drosophila, by inducing significant alterations in gene expression and behavior, suggesting that Drosophila can be used as a potential alternative model in inhalation toxicity screening.

  17. An integrated optical coherence microscopy imaging and optical stimulation system for optogenetic pacing in Drosophila melanogaster (Conference Presentation)

    Science.gov (United States)

    Alex, Aneesh; Li, Airong; Men, Jing; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

    2016-03-01

    Electrical stimulation is the clinical standard for cardiac pacing. Although highly effective in controlling cardiac rhythm, the invasive nature, non-specificity to cardiac tissues and possible tissue damage limits its applications. Optogenetic pacing of the heart is a promising alternative, which is non-invasive and more specific, has high spatial and temporal precision, and avoids the shortcomings in electrical stimulation. Drosophila melanogaster, which is a powerful model organism with orthologs of nearly 75% of human disease genes, has not been studied for optogenetic pacing in the heart. Here, we developed a non-invasive integrated optical pacing and optical coherence microscopy (OCM) imaging system to control the heart rhythm of Drosophila at different developmental stages using light. The OCM system is capable of providing high imaging speed (130 frames/s) and ultrahigh imaging resolutions (1.5 μm and 3.9 μm for axial and transverse resolutions, respectively). A light-sensitive pacemaker was developed in Drosophila by specifically expressing the light-gated cation channel, channelrhodopsin-2 (ChR2) in transgenic Drosophila heart. We achieved non-invasive and specific optical control of the Drosophila heart rhythm throughout the fly's life cycle (larva, pupa, and adult) by stimulating the heart with 475 nm pulsed laser light. Heart response to stimulation pulses was monitored non-invasively with OCM. This integrated non-invasive optogenetic control and in vivo imaging technique provides a novel platform for performing research studies in developmental cardiology.

  18. Transgenesis in Drosophila melanogaster.

    Science.gov (United States)

    Ringrose, Leonie

    2009-01-01

    Transgenesis in Drosophila melanogaster relies upon direct microinjection of embryos and subsequent crossing of surviving adults. The necessity of crossing single flies to screen for transgenic events limits the range of useful transgenesis techniques to those that have a very high frequency of integration, so that about 1 in 10 to 1 in 100 surviving adult flies carry a transgene. Until recently, only random P-element transgenesis fulfilled these criteria. However, recent advances have brought homologous recombination and site-directed integration up to and beyond this level of efficiency. For all transgenesis techniques in Drosophila melanogaster, microinjection of embryos is the central procedure. This chapter gives a detailed protocol for microinjection, and aims to enable the reader to use it for both site-directed integration and for P-element transgenesis.

  19. Experimental population genetics of meiotic drive systems. I. Pseudo-Y chromosomal drive as a means of eliminating cage populations of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Lyttle, T.W.

    1977-01-01

    The experimental population genetics of Y-chromosome drive in Drosophila melanogaster is approximated by studying the behavior of T(Y;2),SD lines. These exhibit ''pseudo-Y'' drive through the effective coupling of the Y chromosome to the second chromosome meiotic drive locus, segregation distorter (SD). T(Y;2),SD males consequently produce only male offspring. When such lines are allowed to compete against structurally normal SD+ flies in population cages, T(Y;2),SD males increase in frequency according to the dynamics of a simple haploid selection model until the cage population is eliminated as a result of a deficiency in the number of adult females. Cage population extinction generally occurs within about seven generations

  20. A genome-wide gene function prediction resource for Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Han Yan

    2010-08-01

    Full Text Available Predicting gene functions by integrating large-scale biological data remains a challenge for systems biology. Here we present a resource for Drosophila melanogaster gene function predictions. We trained function-specific classifiers to optimize the influence of different biological datasets for each functional category. Our model predicted GO terms and KEGG pathway memberships for Drosophila melanogaster genes with high accuracy, as affirmed by cross-validation, supporting literature evidence, and large-scale RNAi screens. The resulting resource of prioritized associations between Drosophila genes and their potential functions offers a guide for experimental investigations.

  1. Deep sequencing of natural and experimental populations of Drosophila melanogaster reveals biases in the spectrum of new mutations.

    Science.gov (United States)

    Assaf, Zoe June; Tilk, Susanne; Park, Jane; Siegal, Mark L; Petrov, Dmitri A

    2017-12-01

    Mutations provide the raw material of evolution, and thus our ability to study evolution depends fundamentally on having precise measurements of mutational rates and patterns. We generate a data set for this purpose using (1) de novo mutations from mutation accumulation experiments and (2) extremely rare polymorphisms from natural populations. The first, mutation accumulation (MA) lines are the product of maintaining flies in tiny populations for many generations, therefore rendering natural selection ineffective and allowing new mutations to accrue in the genome. The second, rare genetic variation from natural populations allows the study of mutation because extremely rare polymorphisms are relatively unaffected by the filter of natural selection. We use both methods in Drosophila melanogaster , first generating our own novel data set of sequenced MA lines and performing a meta-analysis of all published MA mutations (∼2000 events) and then identifying a high quality set of ∼70,000 extremely rare (≤0.1%) polymorphisms that are fully validated with resequencing. We use these data sets to precisely measure mutational rates and patterns. Highlights of our results include: a high rate of multinucleotide mutation events at both short (∼5 bp) and long (∼1 kb) genomic distances, showing that mutation drives GC content lower in already GC-poor regions, and using our precise context-dependent mutation rates to predict long-term evolutionary patterns at synonymous sites. We also show that de novo mutations from independent MA experiments display similar patterns of single nucleotide mutation and well match the patterns of mutation found in natural populations. © 2017 Assaf et al.; Published by Cold Spring Harbor Laboratory Press.

  2. Experimental Support That Natural Selection Has Shaped the Latitudinal Distribution of Mitochondrial Haplotypes in Australian Drosophila melanogaster.

    Science.gov (United States)

    Camus, M Florencia; Wolff, Jonci N; Sgrò, Carla M; Dowling, Damian K

    2017-10-01

    Cellular metabolism is regulated by enzyme complexes within the mitochondrion, the function of which are sensitive to the prevailing temperature. Such thermal sensitivity, coupled with the observation that population frequencies of mitochondrial haplotypes tend to associate with latitude, altitude, or climatic regions across species distributions, led to the hypothesis that thermal selection has played a role in shaping standing variation in the mitochondrial DNA (mtDNA) sequence. This hypothesis, however, remains controversial, and requires evidence that the distribution of haplotypes observed in nature corresponds with the capacity of these haplotypes to confer differences in thermal tolerance. Specifically, haplotypes predominating in tropical climates are predicted to encode increased tolerance to heat stress, but decreased tolerance to cold stress. We present direct evidence for these predictions, using mtDNA haplotypes sampled from the Australian distribution of Drosophila melanogaster. We show that the ability of flies to tolerate extreme thermal challenges is affected by sequence variation across mtDNA haplotypes, and that the thermal performance associated with each haplotype corresponds with its latitudinal prevalence. The haplotype that predominates at low (subtropical) latitudes confers greater resilience to heat stress, but lower resilience to cold stress, than haplotypes predominating at higher (temperate) latitudes. We explore molecular mechanisms that might underlie these responses, presenting evidence that the effects are in part regulated by SNPs that do not change the protein sequence. Our findings suggest that standing variation in the mitochondrial genome can be shaped by thermal selection, and could therefore contribute to evolutionary adaptation under climatic stress. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e

  3. Investigations of the fate of radiation-induced mutations in dependence of selection and recombination with recessive gene marks in experimental populations of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Pfriem, P.

    1978-01-01

    Three dichromosomal experimental populations of Drosophila melanogaster were started with heterozygons dp b/+ +- animals with identical dp b- and + +- II-chromosomes for all three populations. The male ++/++- parents had been exposed to 9000 r prior to the experiments. In 7 random samples of the first 15 generations of the experiment, the incidence of the mutant alleles dp and b, the exchange inequilibrium between the alleles of the two labelled loci, and the letthal factor frequency were investigatet. It was found that - The b allele had an equilibrium frequency of about 57% in all populations, while the frequency of the dp allele decreased to about 10% within the first 15 generations. - The association values a as measures of an exchange inequilibrium showed a fast development towards exchange inequilibrium within these 15 generations for the three populations. - The incidence of lethal factors remained constant throughout the generations for the tested type ++ and + b chromosomes, in irradiated ++- chromosomes, it was higher on an average than in the + b- chromosomes. The total lethal factor incidence was about 30%. - The alleling rate of lethal factors and the viability values of several distinguishable genotypes indicated individualities of the three populations in spite of their identical behaviour. In two of the three populations, the near-constant incidence of lethal factors was supposed to be due to a small number of lethal which accurred with high frequency. (orig.) [de

  4. From integrated control to integrated farming, an experimental approach

    NARCIS (Netherlands)

    Vereijken, P.H.

    1989-01-01

    Integrated control or integrated pest management (IPM), as envisaged originally, is not being practised to any large extent in arable farming, notwithstanding considerable research efforts. The reasons for this are discussed. A more basic approach called integrated farming is suggested. Preliminary

  5. Genetically controlled environmental variance for sternopleural bristles in Drosophila melanogaster - an experimental test of a heterogeneous variance model

    DEFF Research Database (Denmark)

    Sørensen, Anders Christian; Kristensen, Torsten Nygård; Loeschcke, Volker

    2007-01-01

    The objective of this study was to test the hypothesis that the environmental variance of sternopleural bristle number in Drosophila melanogaster is partly under genetic control. We used data from 20 inbred lines and 10 control lines to test this hypothesis. Two models were used: a standard quant...... as genes affecting the environmental variance may be important for adaptation to changing environmental conditions...

  6. Experimental Validation of an Integrated Controls-Structures Design Methodology

    Science.gov (United States)

    Maghami, Peiman G.; Gupta, Sandeep; Elliot, Kenny B.; Walz, Joseph E.

    1996-01-01

    The first experimental validation of an integrated controls-structures design methodology for a class of large order, flexible space structures is described. Integrated redesign of the controls-structures-interaction evolutionary model, a laboratory testbed at NASA Langley, was described earlier. The redesigned structure was fabricated, assembled in the laboratory, and experimentally tested against the original structure. Experimental results indicate that the structure redesigned using the integrated design methodology requires significantly less average control power than the nominal structure with control-optimized designs, while maintaining the required line-of-sight pointing performance. Thus, the superiority of the integrated design methodology over the conventional design approach is experimentally demonstrated. Furthermore, amenability of the integrated design structure to other control strategies is evaluated, both analytically and experimentally. Using Linear-Quadratic-Guassian optimal dissipative controllers, it is observed that the redesigned structure leads to significantly improved performance with alternate controllers as well.

  7. Mapping selection within Drosophila melanogaster embryo's anatomy

    DEFF Research Database (Denmark)

    Salvador-Martínez, Irepan; Coronado-Zamora, Marta; Castellano, David

    2018-01-01

    We present a survey of selection across Drosophila melanogaster embryonic anatomy. Our approach integrates genomic variation, spatial gene expression patterns and development, with the aim of mapping adaptation over the entire embryo's anatomy. Our adaptation map is based on analyzing spatial gen...

  8. Proteome reference map of Drosophila melanogaster head.

    Science.gov (United States)

    Lee, Tian-Ren; Huang, Shun-Hong; Lee, Chi-Ching; Lee, Hsiao-Yun; Chan, Hsin-Tzu; Lin, Kuo-Sen; Chan, Hong-Lin; Lyu, Ping-Chiang

    2012-06-01

    Drosophila melanogaster has been used as a genetic model organism to understand the fundamental molecular mechanisms in human biology including memory formation that has been reported involving protein synthesis and/or post-translational modification. In this study, we employed a proteomic platform based on fluorescent 2DE and MALDI-TOF MS to build a standard D. melanogaster head proteome map for proteome-proteome comparison. In order to facilitate the comparison, an interactive database has been constructed for systematically integrating and analyzing the proteomes from different conditions and further implicated to study human diseases related to D. melanogaster model. In summary, the fundamental head proteomic database and bioinformatic analysis will be useful for further elucidating the biological mechanisms such as memory formation and neurodegenerative diseases. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... As an experimental model system, the fruit fly Drosophila melanogaster has been seminal in shaping our understanding of the circadian clockwork. The wealth of genetic tools at our disposal over the past four decades has enabled discovery of the genetic and molecular bases of circadian rhythmicity.

  10. Sexual selection on wing interference patterns in Drosophila melanogaster.

    Science.gov (United States)

    Katayama, Natsu; Abbott, Jessica K; Kjærandsen, Jostein; Takahashi, Yuma; Svensson, Erik I

    2014-10-21

    Animals with color vision use color information in intra- and interspecific communication, which in turn may drive the evolution of conspicuous colored body traits via natural and sexual selection. A recent study found that the transparent wings of small flies and wasps in lower-reflectance light environments display vivid and stable structural color patterns, called "wing interference patterns" (WIPs). Such WIPs were hypothesized to function in sexual selection among small insects with wing displays, but this has not been experimentally verified. Here, to our knowledge we present the first experimental evidence that WIPs in males of Drosophila melanogaster are targets of mate choice from females, and that two different color traits--saturation and hue--experience directional and stabilizing sexual selection, respectively. Using isogenic lines from the D. melanogaster Genetic Reference Panel, we compare attractiveness of different male WIPs against black and white visual backgrounds. We show that males with more vivid wings are more attractive to females than are males with dull wings. Wings with a large magenta area (i.e., intermediate trait values) were also preferred over those with a large blue or yellow area. These experimental results add a visual element to the Drosophila mating array, integrating sexual selection with elements of genetics and evo-devo, potentially applicable to a wide array of small insects with hyaline wings. Our results further underscore that the mode of sexual selection on such visual signals can differ profoundly between different color components, in this case hue and saturation.

  11. Targeted Integration of Single-Copy Transgenes in Drosophila melanogaster Tissue-Culture Cells Using Recombination-Mediated Cassette Exchange.

    Science.gov (United States)

    Manivannan, Sathiya N; Jacobsen, Thomas L; Lyon, Peter; Selvaraj, Bhavani; Halpin, Peter; Simcox, Amanda

    2015-12-01

    Transfection of transgenes into Drosophila cultured cells is a standard approach for studying gene function. However, the number of transgenes present in the cell following transient transfection or stable random integration varies, and the resulting differences in expression level affect interpretation. Here we developed a system for Drosophila cell lines that allows selection of cells with a single-copy transgene inserted at a specific genomic site using recombination-mediated cassette exchange (RMCE). We used the φC31 integrase and its target sites attP and attB for RMCE. Cell lines with an attP-flanked genomic cassette were transfected with donor plasmids containing a transgene of interest (UAS-x), a dihydrofolate reductase (UAS-DHFR) gene flanked by attB sequences, and a thymidine kinase (UAS-TK) gene in the plasmid backbone outside the attB sequences. In cells undergoing RMCE, UAS-x and UAS-DHFR were exchanged for the attP-flanked genomic cassette, and UAS-TK was excluded. These cells were selected using methotrexate, which requires DHFR expression, and ganciclovir, which causes death in cells expressing TK. Pure populations of cells with one copy of a stably integrated transgene were efficiently selected by cloning or mass culture in ∼6 weeks. Our results show that RMCE avoids the problems associated with current methods, where transgene number is not controlled, and facilitates the rapid generation of Drosophila cell lines in which expression from a single transgene can be studied. Copyright © 2015 by the Genetics Society of America.

  12. The effect of population density on the elimination dynamics of a recessive lethal mutation l(2)M167(DTS) from experimental populations of Drosophila melanogaster

    Czech Academy of Sciences Publication Activity Database

    Kulikov, A. M.; Marec, František; Mitrofanov, V. G.

    2005-01-01

    Roč. 41, č. 3 (2005), s. 249-255 ISSN 1022-7954 Grant - others:Russian Foundation for Basic Research(RU) 02-04-50021; Program of the Presidium of the Russian Academy of Sciences "Dynamics of Gene Pools in Plants, Animals, and Humans"(RU) 10002-251/P-24/154-150/2004-04 -111 Institutional research plan: CEZ:AV0Z50070508 Keywords : Drosophila melanogaster Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.240, year: 2005

  13. Comprehensive analysis of the chromatin landscape in Drosophila melanogaster.

    Science.gov (United States)

    Kharchenko, Peter V; Alekseyenko, Artyom A; Schwartz, Yuri B; Minoda, Aki; Riddle, Nicole C; Ernst, Jason; Sabo, Peter J; Larschan, Erica; Gorchakov, Andrey A; Gu, Tingting; Linder-Basso, Daniela; Plachetka, Annette; Shanower, Gregory; Tolstorukov, Michael Y; Luquette, Lovelace J; Xi, Ruibin; Jung, Youngsook L; Park, Richard W; Bishop, Eric P; Canfield, Theresa K; Sandstrom, Richard; Thurman, Robert E; MacAlpine, David M; Stamatoyannopoulos, John A; Kellis, Manolis; Elgin, Sarah C R; Kuroda, Mitzi I; Pirrotta, Vincenzo; Karpen, Gary H; Park, Peter J

    2011-03-24

    Chromatin is composed of DNA and a variety of modified histones and non-histone proteins, which have an impact on cell differentiation, gene regulation and other key cellular processes. Here we present a genome-wide chromatin landscape for Drosophila melanogaster based on eighteen histone modifications, summarized by nine prevalent combinatorial patterns. Integrative analysis with other data (non-histone chromatin proteins, DNase I hypersensitivity, GRO-Seq reads produced by engaged polymerase, short/long RNA products) reveals discrete characteristics of chromosomes, genes, regulatory elements and other functional domains. We find that active genes display distinct chromatin signatures that are correlated with disparate gene lengths, exon patterns, regulatory functions and genomic contexts. We also demonstrate a diversity of signatures among Polycomb targets that include a subset with paused polymerase. This systematic profiling and integrative analysis of chromatin signatures provides insights into how genomic elements are regulated, and will serve as a resource for future experimental investigations of genome structure and function.

  14. Experimental systems of integrated and organic wheat production

    NARCIS (Netherlands)

    Vereijken, P.H.

    1989-01-01

    The objectives and significance of integrated and organic farming are briefly discussed. In wheat production, the cropping methods involved are then described and compared to those of a conventional system. Initial results from an experimental farm at Nagele, The Netherlands, indicate that by an

  15. An experimental investigation of Fang's Ag superlens suitable for integration

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Nielsen, Rasmus Bundgaard; Xiao, Sanshui

    2009-01-01

    We report on experimental realization of the Fang Ag superlens structure [1] suitable for further processing and integration in bio-chips by replacing PMMA with a highly chemical resistant cyclo-olefin copolymer, mr-I T85 (Micro Resist Technology, Berlin, Germany). The superlens was able to resolve...

  16. Statistical Methodologies to Integrate Experimental and Computational Research

    Science.gov (United States)

    Parker, P. A.; Johnson, R. T.; Montgomery, D. C.

    2008-01-01

    Development of advanced algorithms for simulating engine flow paths requires the integration of fundamental experiments with the validation of enhanced mathematical models. In this paper, we provide an overview of statistical methods to strategically and efficiently conduct experiments and computational model refinement. Moreover, the integration of experimental and computational research efforts is emphasized. With a statistical engineering perspective, scientific and engineering expertise is combined with statistical sciences to gain deeper insights into experimental phenomenon and code development performance; supporting the overall research objectives. The particular statistical methods discussed are design of experiments, response surface methodology, and uncertainty analysis and planning. Their application is illustrated with a coaxial free jet experiment and a turbulence model refinement investigation. Our goal is to provide an overview, focusing on concepts rather than practice, to demonstrate the benefits of using statistical methods in research and development, thereby encouraging their broader and more systematic application.

  17. Visual Detection of Speckles in the Fish Xenotoca variata by the Predatory Snake Thamnophis melanogaster in Water of Different Turbidity.

    Science.gov (United States)

    Manjarrez, Javier; Rivas-González, Eric; Venegas-Barrera, Crystian S; Moyaho, Alejandro

    2015-01-01

    Semi-aquatic snakes integrate visual and chemical stimuli, and prey detection and capture success are therefore linked to the display of visual predatory behavior. The snake Thamnophis melanogaster responds preferentially to individuals of the fish Xenotoca variata with a greater number of bright, colorful spots (lateral speckles) compared with those with a smaller number; however, water turbidity can reduce underwater visibility and effect the vulnerability of fish. In this study, we tested whether the presence of iridescent speckles on the flanks of male X. variata interacted with water turbidity to modify the predatory behavior displayed by the snake T. melanogaster. We predicted that in an experimental laboratory test, the snakes would increase the frequency of their predatory behavior to the extent that the water turbidity decreases. The snakes were tested at six different levels of water turbidity, in combination with three categories of male fish (with few, a median number of, or many speckles). The results showed that in a pool with high or zero turbidity, the number of speckles is not a determining factor in the deployment of the predatory behavior of the snake T. melanogaster toward X. variata. Our findings suggest that snakes can view the fish at intermediate percentages of turbidity, but the number of speckles in male X. variata is irrelevant as an interspecific visual signal in environments with insufficient luminosity. The successful capture of aquatic prey is influenced by integration between chemical and visual signals, according to environmental factors that may influence the recognition of individual traits.

  18. Visual Detection of Speckles in the Fish Xenotoca variata by the Predatory Snake Thamnophis melanogaster in Water of Different Turbidity.

    Directory of Open Access Journals (Sweden)

    Javier Manjarrez

    Full Text Available Semi-aquatic snakes integrate visual and chemical stimuli, and prey detection and capture success are therefore linked to the display of visual predatory behavior. The snake Thamnophis melanogaster responds preferentially to individuals of the fish Xenotoca variata with a greater number of bright, colorful spots (lateral speckles compared with those with a smaller number; however, water turbidity can reduce underwater visibility and effect the vulnerability of fish. In this study, we tested whether the presence of iridescent speckles on the flanks of male X. variata interacted with water turbidity to modify the predatory behavior displayed by the snake T. melanogaster. We predicted that in an experimental laboratory test, the snakes would increase the frequency of their predatory behavior to the extent that the water turbidity decreases. The snakes were tested at six different levels of water turbidity, in combination with three categories of male fish (with few, a median number of, or many speckles. The results showed that in a pool with high or zero turbidity, the number of speckles is not a determining factor in the deployment of the predatory behavior of the snake T. melanogaster toward X. variata. Our findings suggest that snakes can view the fish at intermediate percentages of turbidity, but the number of speckles in male X. variata is irrelevant as an interspecific visual signal in environments with insufficient luminosity. The successful capture of aquatic prey is influenced by integration between chemical and visual signals, according to environmental factors that may influence the recognition of individual traits.

  19. Systematic integration of experimental data and models in systems biology.

    Science.gov (United States)

    Li, Peter; Dada, Joseph O; Jameson, Daniel; Spasic, Irena; Swainston, Neil; Carroll, Kathleen; Dunn, Warwick; Khan, Farid; Malys, Naglis; Messiha, Hanan L; Simeonidis, Evangelos; Weichart, Dieter; Winder, Catherine; Wishart, Jill; Broomhead, David S; Goble, Carole A; Gaskell, Simon J; Kell, Douglas B; Westerhoff, Hans V; Mendes, Pedro; Paton, Norman W

    2010-11-29

    The behaviour of biological systems can be deduced from their mathematical models. However, multiple sources of data in diverse forms are required in the construction of a model in order to define its components and their biochemical reactions, and corresponding parameters. Automating the assembly and use of systems biology models is dependent upon data integration processes involving the interoperation of data and analytical resources. Taverna workflows have been developed for the automated assembly of quantitative parameterised metabolic networks in the Systems Biology Markup Language (SBML). A SBML model is built in a systematic fashion by the workflows which starts with the construction of a qualitative network using data from a MIRIAM-compliant genome-scale model of yeast metabolism. This is followed by parameterisation of the SBML model with experimental data from two repositories, the SABIO-RK enzyme kinetics database and a database of quantitative experimental results. The models are then calibrated and simulated in workflows that call out to COPASIWS, the web service interface to the COPASI software application for analysing biochemical networks. These systems biology workflows were evaluated for their ability to construct a parameterised model of yeast glycolysis. Distributed information about metabolic reactions that have been described to MIRIAM standards enables the automated assembly of quantitative systems biology models of metabolic networks based on user-defined criteria. Such data integration processes can be implemented as Taverna workflows to provide a rapid overview of the components and their relationships within a biochemical system.

  20. Neurogenetics of female reproductive behaviors in Drosophila melanogaster.

    Science.gov (United States)

    Laturney, Meghan; Billeter, Jean-Christophe

    2014-01-01

    We follow an adult Drosophila melanogaster female through the major reproductive decisions she makes during her lifetime, including habitat selection, precopulatory mate choice, postcopulatory physiological changes, polyandry, and egg-laying site selection. In the process, we review the molecular and neuronal mechanisms allowing females to integrate signals from both environmental and social sources to produce those behavioral outputs. We pay attention to how an understanding of D. melanogaster female reproductive behaviors contributes to a wider understanding of evolutionary processes such as pre- and postcopulatory sexual selection as well as sexual conflict. Within each section, we attempt to connect the theories that pertain to the evolution of female reproductive behaviors with the molecular and neurobiological data that support these theories. We draw attention to the fact that the evolutionary and mechanistic basis of female reproductive behaviors, even in a species as extensively studied as D. melanogaster, remains poorly understood. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. DIRECT SELECTION ON LIFE-SPAN IN DROSOPHILA-MELANOGASTER

    NARCIS (Netherlands)

    ZWAAN, B; BIJLSMA, R; HOEKSTRA, RE

    An important issue in the study of the evolution of aging in Drosophila melanogaster is whether decreased early fecundity is inextricably coupled with increased life span in selection experiments on age at reproduction. Here, this problem has been tackled using an experimental design in which

  2. Exquisite light sensitivity of Drosophila melanogaster cryptochrome.

    Directory of Open Access Journals (Sweden)

    Pooja Vinayak

    Full Text Available Drosophila melanogaster shows exquisite light sensitivity for modulation of circadian functions in vivo, yet the activities of the Drosophila circadian photopigment cryptochrome (CRY have only been observed at high light levels. We studied intensity/duration parameters for light pulse induced circadian phase shifts under dim light conditions in vivo. Flies show far greater light sensitivity than previously appreciated, and show a surprising sensitivity increase with pulse duration, implying a process of photic integration active up to at least 6 hours. The CRY target timeless (TIM shows dim light dependent degradation in circadian pacemaker neurons that parallels phase shift amplitude, indicating that integration occurs at this step, with the strongest effect in a single identified pacemaker neuron. Our findings indicate that CRY compensates for limited light sensitivity in vivo by photon integration over extraordinarily long times, and point to select circadian pacemaker neurons as having important roles.

  3. Integral Reactor Containment Condensation Model and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiao [Oregon State Univ., Corvallis, OR (United States); Corradini, Michael [Univ. of Wisconsin, Madison, WI (United States)

    2016-05-02

    plate may have been underestimated and thus the heat flux had been underestimated. The MELCOR model predicts a film thickness on the order of 100 microns, which agrees very well with film flow model developed in this study for scaling analysis. However, the expected differences in film thicknesses for near vacuum and near atmospheric test conditions are not significant. Further study on the behavior of condensate film is expected to refine the simulation results. Possible refinements include but are not limited to, the followings: CFD simulation focusing on the liquid film behavior and benchmarking with experimental analyses for simpler geometries. 16 1 INTRODUCTION This NEUP funded project, NEUP 12-3630, is for experimental, numerical and analytical studies on high-pressure steam condensation phenomena in a steel containment vessel connected to a water cooling tank, carried out at Oregon State University (OrSU) and the University of Wisconsin at Madison (UW-Madison). The experimental results are employed to validate the containment condensation model in reactor containment system safety analysis code for integral SMRs. Such a containment condensation model is important to demonstrate the adequate cooling. In the three years of investigation, following the original proposal, the following planned tasks have been completed: (1) Performed a scaling study for the full pressure test facility applicable to the reference design for the condensation heat transfer process during design basis accidents (DBAs), modified the existing test facility to route the steady-state secondary steam flow into the high pressure containment for controllable condensation tests, and extended the operations at negative gage pressure conditions (OrSU). (2) Conducted a series of DBA and quasi-steady experiments using the full pressure test facility to provide a reliable high pressure condensation database (OrSU). (3) Analyzed experimental data and evaluated condensation model for the experimental

  4. Experimental Investigation of Integrated Optical Intensive Impulse Electric Field Sensors

    International Nuclear Information System (INIS)

    Bao, Sun; Fu-Shen, Chen

    2009-01-01

    We design and fabricate an integrated optical electric field sensor with segmented electrode for intensive impulse electric field measurement. The integrated optical sensor is based on a Mach–Zehnder interferometer with segmented electrodes. The output/input character of the sensing system is analysed and measured. The maximal detectable electric field range (−75 kV/m to 245 kV/m) is obtained by analysing the results. As a result, the integrated optics electric field sensing system is suitable for transient intensive electric field measurement investigation

  5. Mapping of gene mutations in drosophila melanogaster

    OpenAIRE

    Halvorsen, Charlotte Marie

    2004-01-01

    In this experiment, mutant genes of a given unknown mutant strain of Drosophila melanogaster were mapped to specific chromosomes. Drosophila melanogaster, commonly known as the fruit fly, was the appropriate choice for the organism to use in this specific experiment because of its relatively rapid life cycle of 10-14 days and because of the small amount of space and food neccessary for maintaining thousands of flies. The D. Melanogaster unknown strain specifically used in this experiment wa...

  6. Experimental Evaluation of a Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Frandsen, Tommy; Jensen, Kasper Køtter

    2011-01-01

    This paper presents test results of a new motor integrated permanent magnet gear and clarifies a path for future optimizations. The prototype, which fabrication also is described, is initially targeting electrical traction for vehicles. Basic measured parameters in form of back-emf, stall torque...

  7. Biobetters From an Integrated Computational/Experimental Approach

    Directory of Open Access Journals (Sweden)

    Serdar Kuyucak

    2017-01-01

    Full Text Available Biobetters are new drugs designed from existing peptide or protein-based therapeutics by improving their properties such as affinity and selectivity for the target epitope, and stability against degradation. Computational methods can play a key role in such design problems—by predicting the changes that are most likely to succeed, they can drastically reduce the number of experiments to be performed. Here we discuss the computational and experimental methods commonly used in drug design problems, focusing on the inverse relationship between the two, namely, the more accurate the computational predictions means the less experimental effort is needed for testing. Examples discussed include efforts to design selective analogs from toxin peptides targeting ion channels for treatment of autoimmune diseases and monoclonal antibodies which are the fastest growing class of therapeutic agents particularly for cancers and autoimmune diseases.

  8. Experimental assessment of computer codes used for safety analysis of integral reactors

    Energy Technology Data Exchange (ETDEWEB)

    Falkov, A.A.; Kuul, V.S.; Samoilov, O.B. [OKB Mechanical Engineering, Nizhny Novgorod (Russian Federation)

    1995-09-01

    Peculiarities of integral reactor thermohydraulics in accidents are associated with presence of noncondensable gas in built-in pressurizer, absence of pumped ECCS, use of guard vessel for LOCAs localisation and passive RHRS through in-reactor HX`s. These features defined the main trends in experimental investigations and verification efforts for computer codes applied. The paper reviews briefly the performed experimental investigation of thermohydraulics of AST-500, VPBER600-type integral reactors. The characteristic of UROVEN/MB-3 code for LOCAs analysis in integral reactors and results of its verification are given. The assessment of RELAP5/mod3 applicability for accident analysis in integral reactor is presented.

  9. Mechanisms of LTR-Retroelement Transposition: Lessons from Drosophila melanogaster.

    Science.gov (United States)

    Nefedova, Lidia; Kim, Alexander

    2017-04-16

    Long terminal repeat (LTR) retrotransposons occupy a special place among all mobile genetic element families. The structure of LTR retrotransposons that have three open reading frames is identical to DNA forms of retroviruses that are integrated into the host genome. Several lines of evidence suggest that LTR retrotransposons share a common ancestry with retroviruses and thus are highly relevant to understanding mechanisms of transposition. Drosophila melanogaster is an exceptionally convenient model for studying the mechanisms of retrotransposon movement because many such elements in its genome are transpositionally active. Moreover, two LTRretrotransposons of D. melanogaster, gypsy and ZAM, have been found to have infectious properties and have been classified as errantiviruses. Despite numerous studies focusing on retroviral integration process, there is still no clear understanding of integration specificity in a target site. Most LTR retrotransposons non-specifically integrate into a target site. Site-specificity of integration at vertebrate retroviruses is rather relative. At the same time, sequence-specific integration is the exclusive property of errantiviruses and their derivatives with two open reading frames. The possible basis for the errantivirus integration specificity is discussed in the present review.

  10. Experimental error on integral data of reactor physics experiments at FCA

    International Nuclear Information System (INIS)

    Osugi, Toshitaka; Iijima, Susumu

    1989-01-01

    The procedures to estimate the experimental errors on integral data are discussed: Examples are taken from the measurements such as the criticality, the reactivity worth and the reaction rate ratio at FCA-XIV-1 core. (author)

  11. The developmental transcriptome of Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    University of Connecticut; Graveley, Brenton R.; Brooks, Angela N.; Carlson, Joseph W.; Duff, Michael O.; Landolin, Jane M.; Yang, Li; Artieri, Carlo G.; van Baren, Marijke J.; Boley, Nathan; Booth, Benjamin W.; Brown, James B.; Cherbas, Lucy; Davis, Carrie A.; Dobin, Alex; Li, Renhua; Lin, Wei; Malone, John H.; Mattiuzzo, Nicolas R.; Miller, David; Sturgill, David; Tuch, Brian B.; Zaleski, Chris; Zhang, Dayu; Blanchette, Marco; Dudoit, Sandrine; Eads, Brian; Green, Richard E.; Hammonds, Ann; Jiang, Lichun; Kapranov, Phil; Langton, Laura; Perrimon, Norbert; Sandler, Jeremy E.; Wan, Kenneth H.; Willingham, Aarron; Zhang, Yu; Zou, Yi; Andrews, Justen; Bicke, Peter J.; Brenner, Steven E.; Brent, Michael R.; Cherbas, Peter; Gingeras, Thomas R.; Hoskins, Roger A.; Kaufman, Thomas C.; Oliver, Brian; Celniker, Susan E.

    2010-12-02

    Drosophila melanogaster is one of the most well studied genetic model organisms; nonetheless, its genome still contains unannotated coding and non-coding genes, transcripts, exons and RNA editing sites. Full discovery and annotation are pre-requisites for understanding how the regulation of transcription, splicing and RNA editing directs the development of this complex organism. Here we used RNA-Seq, tiling microarrays and cDNA sequencing to explore the transcriptome in 30 distinct developmental stages. We identified 111,195 new elements, including thousands of genes, coding and non-coding transcripts, exons, splicing and editing events, and inferred protein isoforms that previously eluded discovery using established experimental, prediction and conservation-based approaches. These data substantially expand the number of known transcribed elements in the Drosophila genome and provide a high-resolution view of transcriptome dynamics throughout development. Drosophila melanogaster is an important non-mammalian model system that has had a critical role in basic biological discoveries, such as identifying chromosomes as the carriers of genetic information and uncovering the role of genes in development. Because it shares a substantial genic content with humans, Drosophila is increasingly used as a translational model for human development, homeostasis and disease. High-quality maps are needed for all functional genomic elements. Previous studies demonstrated that a rich collection of genes is deployed during the life cycle of the fly. Although expression profiling using microarrays has revealed the expression of, 13,000 annotated genes, it is difficult to map splice junctions and individual base modifications generated by RNA editing using such approaches. Single-base resolution is essential to define precisely the elements that comprise the Drosophila transcriptome. Estimates of the number of transcript isoforms are less accurate than estimates of the number of genes

  12. Experimental Evaluation of Integral Transformations for Engineering Drawings Vectorization

    Science.gov (United States)

    Vaský, Jozef; Gramblička, Matúš

    2014-12-01

    The concept of digital manufacturing supposes application of digital technologies in the whole product life cycle. Direct digital manufacturing includes such information technology processes, where products are directly manufactured from 3D CAD model. In digital manufacturing, engineering drawing is replaced by CAD product model. In the contemporary practice, lots of engineering paper-based drawings are still archived. They could be digitalized by scanner and stored to one of the raster graphics format and after that vectorized for interactive editing in the specific software system for technical drawing or for archiving in some of the standard vector graphics file format. The vector format is suitable for 3D model generating, too.The article deals with using of selected integral transformations (Fourier, Hough) in the phase of digitalized raster engineering drawings vectorization.

  13. Experimental Evaluation of Integral Transformations for Engineering Drawings Vectorization

    Directory of Open Access Journals (Sweden)

    Vaský Jozef

    2014-12-01

    Full Text Available The concept of digital manufacturing supposes application of digital technologies in the whole product life cycle. Direct digital manufacturing includes such information technology processes, where products are directly manufactured from 3D CAD model. In digital manufacturing, engineering drawing is replaced by CAD product model. In the contemporary practice, lots of engineering paper-based drawings are still archived. They could be digitalized by scanner and stored to one of the raster graphics format and after that vectorized for interactive editing in the specific software system for technical drawing or for archiving in some of the standard vector graphics file format. The vector format is suitable for 3D model generating, too.The article deals with using of selected integral transformations (Fourier, Hough in the phase of digitalized raster engineering drawings vectorization.

  14. MTG16 contributes to colonic epithelial integrity in experimental colitis

    Science.gov (United States)

    Williams, Christopher S; Bradley, Amber M; Chaturvedi, Rupesh; Singh, Kshipra; Piazuelo, Maria B; Chen, Xi; McDonough, Elizabeth M; Schwartz, David A; Brown, Caroline T; Allaman, Margaret M; Coburn, Lori A; Horst, Sara N; Beaulieu, Dawn B; Choksi, Yash A; Washington, Mary Kay; Williams, Amanda D; Fisher, Melissa A; Zinkel, Sandra S; Peek, Richard M; Wilson, Keith T; Hiebert, Scott W

    2013-01-01

    Objective The myeloid translocation genes (MTGs) are transcriptional corepressors with both Mtg8−/− and Mtgr1−/− mice showing developmental and/or differentiation defects in the intestine. We sought to determine the role of MTG16 in intestinal integrity. Methods Baseline and stress induced colonic phenotypes were examined in Mtg16−/− mice. To unmask phenotypes, we treated Mtg16−/− mice with dextran sodium sulphate (DSS) or infected them with Citrobacter rodentium and the colons were examined for ulceration and for changes in proliferation, apoptosis and inflammation. Results Mtg16−/− mice have altered immune subsets, suggesting priming towards Th1 responses. Mtg16−/− mice developed increased weight loss, diarrhoea, mortality and histological colitis and there were increased innate (Gr1+, F4/80+, CD11c+ and MHCII+; CD11c+) and Th1 adaptive (CD4) immune cells in Mtg16−/− colons after DSS treatment. Additionally, there was increased apoptosis and a compensatory increased proliferation in Mtg16−/− colons. Compared with wild-type mice, Mtg16−/− mice exhibited increased colonic CD4;IFN-γ cells in vehicle-treated and DSS-treated mice. Adoptive transfer of wildtype marrow into Mtg16−/− recipients did not rescue the Mtg16−/− injury phenotype. Isolated colonic epithelial cells from DSS-treated Mtg16−/− mice exhibited increased KC (Cxcl1) mRNA expression when compared with wild-type mice. Mtg16−/− mice infected with C rodentium had more severe colitis and greater bacterial colonisation. Last, MTG16 mRNA levels were reduced in human ulcerative colitis versus normal colon tissues. Conclusions These observations indicate that MTG16 is critical for colonocyte survival and regeneration in response to intestinal injury and provide evidence that this transcriptional corepressor regulates inflammatory recruitment in response to injury. PMID:22833394

  15. Effect of curcumin on aged Drosophila melanogaster: a pathway prediction analysis.

    Science.gov (United States)

    Zhang, Zhi-guo; Niu, Xu-yan; Lu, Ai-ping; Xiao, Gary Guishan

    2015-02-01

    To re-analyze the data published in order to explore plausible biological pathways that can be used to explain the anti-aging effect of curcumin. Microarray data generated from other study aiming to investigate effect of curcumin on extending lifespan of Drosophila melanogaster were further used for pathway prediction analysis. The differentially expressed genes were identified by using GeneSpring GX with a criterion of 3.0-fold change. Two Cytoscape plugins including BisoGenet and molecular complex detection (MCODE) were used to establish the protein-protein interaction (PPI) network based upon differential genes in order to detect highly connected regions. The function annotation clustering tool of Database for Annotation, Visualization and Integrated Discovery (DAVID) was used for pathway analysis. A total of 87 genes expressed differentially in D. melanogaster melanogaster treated with curcumin were identified, among which 50 were up-regulated significantly and 37 were remarkably down-regulated in D. melanogaster melanogaster treated with curcumin. Based upon these differential genes, PPI network was constructed with 1,082 nodes and 2,412 edges. Five highly connected regions in PPI networks were detected by MCODE algorithm, suggesting anti-aging effect of curcumin may be underlined through five different pathways including Notch signaling pathway, basal transcription factors, cell cycle regulation, ribosome, Wnt signaling pathway, and p53 pathway. Genes and their associated pathways in D. melanogaster melanogaster treated with anti-aging agent curcumin were identified using PPI network and MCODE algorithm, suggesting that curcumin may be developed as an alternative therapeutic medicine for treating aging-associated diseases.

  16. In vivo imaging of the Drosophila Melanogaster heart using a novel optical coherence tomography microscope

    Science.gov (United States)

    Izatt, Susan D.; Choma, Michael A.; Israel, Steven; Wessells, Robert J.; Bodmer, Rolf; Izatt, Joseph A.

    2005-03-01

    Real time in vivo optical coherence tomography (OCT) imaging of the adult fruit fly Drosophila melanogaster heart using a newly designed OCT microscope allows accurate assessment of cardiac anatomy and function. D. melanogaster has been used extensively in genetic research for over a century, but in vivo evaluation of the heart has been limited by available imaging technology. The ability to assess phenotypic changes with micrometer-scale resolution noninvasively in genetic models such as D. melanogaster is needed in the advancing fields of developmental biology and genetics. We have developed a dedicated small animal OCT imaging system incorporating a state-of-the-art, real time OCT scanner integrated into a standard stereo zoom microscope which allows for simultaneous OCT and video imaging. System capabilities include A-scan, B-scan, and M-scan imaging as well as automated 3D volumetric acquisition and visualization. Transverse and sagittal B-mode scans of the four chambered D. melanogaster heart have been obtained with the OCT microscope and are consistent with detailed anatomical studies from the literature. Further analysis by M-mode scanning is currently under way to assess cardiac function as a function of age and sex by determination of shortening fraction and ejection fraction. These studies create control cardiac data on the wild type D. melanogaster, allowing subsequent evaluation of phenotypic cardiac changes in this model after regulated genetic mutation.

  17. Drosophila melanogaster gene expression changes after spaceflight.

    Data.gov (United States)

    National Aeronautics and Space Administration — Gene expression levels were determined in 3rd instar and adult Drosophila melanogaster reared during spaceflight to elucidate the genetic and molecular mechanisms...

  18. Ecdysteroid receptors in Drosophila melanogaster adult females

    Science.gov (United States)

    Ecdysteroid receptors were identified and partially characterized from total cell extracts of whole animals and dissected tissues from Drosophila melanogaster adult females. Binding studies indicated the presence of two ecdysteroid binding components having high affinity and specificity consistent w...

  19. The Drosophila melanogaster host model

    Science.gov (United States)

    Igboin, Christina O.; Griffen, Ann L.; Leys, Eugene J.

    2012-01-01

    The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed. PMID:22368770

  20. Gustatory Processing in Drosophila melanogaster.

    Science.gov (United States)

    Scott, Kristin

    2018-01-07

    The ability to identify nutrient-rich food and avoid toxic substances is essential for an animal's survival. Although olfaction and vision contribute to food detection, the gustatory system acts as a final checkpoint control for food acceptance or rejection. The vinegar fly Drosophila melanogaster tastes many of the same stimuli as mammals and provides an excellent model system for comparative studies of taste detection. The relative simplicity of the fly brain and behaviors, along with the molecular genetic and functional approaches available in this system, allow the examination of gustatory neural circuits from sensory input to motor output. This review discusses the molecules and cells that detect taste compounds in the periphery and the circuits that process taste information in the brain. These studies are providing insight into how the detection of taste compounds regulates feeding decisions.

  1. Ferritin Assembly in Enterocytes of Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Abraham Rosas-Arellano

    2016-02-01

    Full Text Available Ferritins are protein nanocages that accumulate inside their cavity thousands of oxidized iron atoms bound to oxygen and phosphates. Both characteristic types of eukaryotic ferritin subunits are present in secreted ferritins from insects, but here dimers between Ferritin 1 Heavy Chain Homolog (Fer1HCH and Ferritin 2 Light Chain Homolog (Fer2LCH are further stabilized by disulfide-bridge in the 24-subunit complex. We addressed ferritin assembly and iron loading in vivo using novel transgenic strains of Drosophila melanogaster. We concentrated on the intestine, where the ferritin induction process can be controlled experimentally by dietary iron manipulation. We showed that the expression pattern of Fer2LCH-Gal4 lines recapitulated iron-dependent endogenous expression of the ferritin subunits and used these lines to drive expression from UAS-mCherry-Fer2LCH transgenes. We found that the Gal4-mediated induction of mCherry-Fer2LCH subunits was too slow to effectively introduce them into newly formed ferritin complexes. Endogenous Fer2LCH and Fer1HCH assembled and stored excess dietary iron, instead. In contrast, when flies were genetically manipulated to co-express Fer2LCH and mCherry-Fer2LCH simultaneously, both subunits were incorporated with Fer1HCH in iron-loaded ferritin complexes. Our study provides fresh evidence that, in insects, ferritin assembly and iron loading in vivo are tightly regulated.

  2. An integral parametrization of the bacterial growth curve experimental demonstration with E. coli C600 bacteria

    International Nuclear Information System (INIS)

    Garces, F.; Vidania, R. de

    1984-01-01

    In this work an integral parametrization of the bacterial growth curve is presented. The values of the parameters are obtained by fitting to the experimental data. Those parameters, with allow to describe the growth in its different phases, are the followings: slopes of the curve in its three parts and the time which divides the last two phases of the bacterial growth. The experimental data are bacterial densities measured by optical methods. The bacteria used was the E. coli C 6 00. (Author)

  3. Stochastic model for gene transcription on Drosophila melanogaster embryos

    Science.gov (United States)

    Prata, Guilherme N.; Hornos, José Eduardo M.; Ramos, Alexandre F.

    2016-02-01

    We examine immunostaining experimental data for the formation of stripe 2 of even-skipped (eve) transcripts on D. melanogaster embryos. An estimate of the factor converting immunofluorescence intensity units into molecular numbers is given. The analysis of the eve dynamics at the region of stripe 2 suggests that the promoter site of the gene has two distinct regimes: an earlier phase when it is predominantly activated until a critical time when it becomes mainly repressed. That suggests proposing a stochastic binary model for gene transcription on D. melanogaster embryos. Our model has two random variables: the transcripts number and the state of the source of mRNAs given as active or repressed. We are able to reproduce available experimental data for the average number of transcripts. An analysis of the random fluctuations on the number of eves and their consequences on the spatial precision of stripe 2 is presented. We show that the position of the anterior or posterior borders fluctuate around their average position by ˜1 % of the embryo length, which is similar to what is found experimentally. The fitting of data by such a simple model suggests that it can be useful to understand the functions of randomness during developmental processes.

  4. OSMOSE: An experimental program for the qualification of integral cross sections of actinides

    International Nuclear Information System (INIS)

    Hudelot, J. P.; Klann, R.; Fougeras, P.; Jorion, F.; Drin, N.; Donnet, L.

    2004-01-01

    The accurate integral cross sectional reaction rates in representative spectra for the actinides are discussed at OSMOSE program. The first step in obtaining better nuclear data consists of measuring accurate integral data and comparing it to integrated energy dependent data: this comparison provides a direct assessment of the effect of deficiencies in the differential data. The OSMOSE program includes a complete analytical program associated with experimental measurement program and aims at understanding and resolving discrepancies between calculated and measured values. The measurement covers a wide range of neutron spectra, from over-moderate thermal spectra to fast spectra. (authors)

  5. Large-scale discovery of promoter motifs in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Thomas A Down

    2007-01-01

    Full Text Available A key step in understanding gene regulation is to identify the repertoire of transcription factor binding motifs (TFBMs that form the building blocks of promoters and other regulatory elements. Identifying these experimentally is very laborious, and the number of TFBMs discovered remains relatively small, especially when compared with the hundreds of transcription factor genes predicted in metazoan genomes. We have used a recently developed statistical motif discovery approach, NestedMICA, to detect candidate TFBMs from a large set of Drosophila melanogaster promoter regions. Of the 120 motifs inferred in our initial analysis, 25 were statistically significant matches to previously reported motifs, while 87 appeared to be novel. Analysis of sequence conservation and motif positioning suggested that the great majority of these discovered motifs are predictive of functional elements in the genome. Many motifs showed associations with specific patterns of gene expression in the D. melanogaster embryo, and we were able to obtain confident annotation of expression patterns for 25 of our motifs, including eight of the novel motifs. The motifs are available through Tiffin, a new database of DNA sequence motifs. We have discovered many new motifs that are overrepresented in D. melanogaster promoter regions, and offer several independent lines of evidence that these are novel TFBMs. Our motif dictionary provides a solid foundation for further investigation of regulatory elements in Drosophila, and demonstrates techniques that should be applicable in other species. We suggest that further improvements in computational motif discovery should narrow the gap between the set of known motifs and the total number of transcription factors in metazoan genomes.

  6. Direction and Integration of Experimental Ground Test Capabilities and Computational Methods

    Science.gov (United States)

    Dunn, Steven C.

    2016-01-01

    This paper groups and summarizes the salient points and findings from two AIAA conference panels targeted at defining the direction, with associated key issues and recommendations, for the integration of experimental ground testing and computational methods. Each panel session utilized rapporteurs to capture comments from both the panel members and the audience. Additionally, a virtual panel of several experts were consulted between the two sessions and their comments were also captured. The information is organized into three time-based groupings, as well as by subject area. These panel sessions were designed to provide guidance to both researchers/developers and experimental/computational service providers in defining the future of ground testing, which will be inextricably integrated with the advancement of computational tools.

  7. An Experimental Study on Effectiveness of Integrated Curriculum Model (ICM) in Social Studies Education for Gifted and Talented Learners

    Science.gov (United States)

    Atalay, Özlem; Kahveci, Nihat Gürel

    2015-01-01

    This experimental study examines the effects of Integrated Curriculum Model (ICM) on 4th grade elementary gifted and talented students' academic achievement, creativity and critical thinking (Control Group N= 10, Experimental Group N= 11) in the social studies classroom context, in Istanbul, Turkey. Integrated Curriculum Model was utilized to…

  8. Experimental evaluation of contour J integral and energy dissipated in the fracture process zone

    Czech Academy of Sciences Publication Activity Database

    Vavřík, Daniel; Jandejsek, Ivan

    2014-01-01

    Roč. 129, October (2014), s. 14-25 ISSN 0013-7944 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0060; GA ČR(CZ) GBP105/12/G059 Institutional support: RVO:68378297 Keywords : experimental stress analysis * thin wall material * cohesive zone * J integral * fracture process zone Subject RIV: JN - Civil Engineering Impact factor: 1.767, year: 2014 http://www.sciencedirect.com/science/article/pii/S0013794414000988

  9. Experimental determination of neutron capture cross sections of fast reactor structure materials integrated in intermediate energy spectra. Vol. 2: description of experimental structure

    International Nuclear Information System (INIS)

    Tassan, S.

    1978-01-01

    A selection of technical documents is given concerning the experimental determination of the neutron capture cross-sections of fast reactor structural materials (Fe, Cr, Ni...) integrated over the intermediate energy spectra. The experimental structure project and modifications of the reactor RB2 for this experiment, together with criticality and safety calculations, are presented

  10. From experimental zoology to big data: Observation and integration in the study of animal development.

    Science.gov (United States)

    Bolker, Jessica; Brauckmann, Sabine

    2015-06-01

    The founding of the Journal of Experimental Zoology in 1904 was inspired by a widespread turn toward experimental biology in the 19th century. The founding editors sought to promote experimental, laboratory-based approaches, particularly in developmental biology. This agenda raised key practical and epistemological questions about how and where to study development: Does the environment matter? How do we know that a cell or embryo isolated to facilitate observation reveals normal developmental processes? How can we integrate descriptive and experimental data? R.G. Harrison, the journal's first editor, grappled with these questions in justifying his use of cell culture to study neural patterning. Others confronted them in different contexts: for example, F.B. Sumner insisted on the primacy of fieldwork in his studies on adaptation, but also performed breeding experiments using wild-collected animals. The work of Harrison, Sumner, and other early contributors exemplified both the power of new techniques, and the meticulous explanation of practice and epistemology that was marshaled to promote experimental approaches. A century later, experimentation is widely viewed as the standard way to study development; yet at the same time, cutting-edge "big data" projects are essentially descriptive, closer to natural history than to the approaches championed by Harrison et al. Thus, the original questions about how and where we can best learn about development are still with us. Examining their history can inform current efforts to incorporate data from experiment and description, lab and field, and a broad range of organisms and disciplines, into an integrated understanding of animal development. © 2015 Wiley Periodicals, Inc.

  11. Integrated experimental and computational approach to laser machining of structural bone.

    Science.gov (United States)

    Dahotre, Narendra B; Santhanakrishnan, Soundarapandian; Joshi, Sameehan S; Khan, Riaz J K; Fick, Daniel P; Robertson, William B; Sheh, Raymond K; Ironside, Charlie N

    2018-01-01

    This study describes the fundamentals of laser-bone interaction during bone machining through an integrated experimental-computational approach. Two groups of laser machining parameters identified the effects of process thermodynamics and kinetics on machining attributes at micro to macro. A continuous wave Yb-fiber Nd:YAG laser (wavelength 1070 nm) with fluences in the range of 3.18 J/mm 2 -8.48 J/mm 2 in combination of laser power (300 W-700 W) and machining speed (110 mm/s-250 mm/s) were considered for machining trials. The machining attributes were evaluated through scanning electron microscopy observations and compared with finite element based multiphysics-multicomponent computational model predicted values. For both groups of laser machining parameters, experimentally evaluated and computationally predicted depths and widths increased with increased laser energy input and computationally predicted widths remained higher than experimentally measured widths whereas computationally predicted depths were slightly higher than experimentally measured depths and reversed this trend for the laser fluence >6 J/mm 2 . While in both groups, the machining rate increased with increased laser fluence, experimentally derived machining rate remained lower than the computationally predicted values for the laser fluences lower than ∼4.75 J/mm 2 for one group and ∼5.8 J/mm 2 for other group and reversed in this trend thereafter. The integrated experimental-computational approach identified the physical processes affecting machining attributes. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    2008-12-07

    Dec 7, 2008 ... system for the study of circadian rhythms primarily due to the availability of molecular genetic tools that enabled iden- tification of genes, proteins and neuronal groups that are es- sential components of the circadian machinery. Further, D. melanogaster exhibits robust and relatively easily measur-.

  13. Radioresistance and radiosensitivity in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Reguly, M.L.

    1983-01-01

    Studying the mechanisms controlling radioresistant in Drosophila the sensibility of four strains of Drosophila melanogaster to sex-linked recessive lethal mutations induced by 5kR Cobalt-60 gamma radiation and 0,006 M EMS or 0,25% of caffeine was determined. (M.A.C.) [pt

  14. Radioresistance and radiosensitivity in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Reguly, M.L.; Marques, E.K.

    1987-01-01

    The mechanisms of radioresistance in Drosophila are studied. The mutagenic effects of 5KR of 60 Cobalt gamma radiation and of 0,006M dose of ethyl methanesulfonate (EMS) on four D. Melanogaster strains (RC 1 , CO 3 , BUE and LEN) are investigated. (M.A.C.) [pt

  15. Drosophila melanogaster deoxyribonucleoside kinase activates gemcitabine

    DEFF Research Database (Denmark)

    Knecht, Wolfgang; Mikkelsen, N.E.; Clausen, A.R.

    2009-01-01

    Drosophila melanogaster multisubstrate deoxyribonucleoside kinase (Dm-dNK) can additionally sensitize human cancer cell lines towards the anti-cancer drug gemcitabine. We show that this property is based on the Dm-dNK ability to efficiently phosphorylate gemcitabine. The 2.2 angstrom resolution...

  16. Intersex (ix) mutations of Drosophila melanogaster cause ...

    Indian Academy of Sciences (India)

    In Drosophila melanogaster, the intersex (ix) is a terminally positioned gene in somatic sex determination hierarchy and function with the female specific product of double sex (DSXF) to implement female sexual differentiation. The null phenotype of ix is to transform diplo-X individuals into intersexes while leaving haplo-X ...

  17. Quantifying Abdominal Pigmentation in Drosophila melanogaster.

    Science.gov (United States)

    Saleh Ziabari, Omid; Shingleton, Alexander W

    2017-06-01

    Pigmentation is a morphologically simple but highly variable trait that often has adaptive significance. It has served extensively as a model for understanding the development and evolution of morphological phenotypes. Abdominal pigmentation in Drosophila melanogaster has been particularly useful, allowing researchers to identify the loci that underlie inter- and intraspecific variations in morphology. Hitherto, however, D. melanogaster abdominal pigmentation has been largely assayed qualitatively, through scoring, rather than quantitatively, which limits the forms of statistical analysis that can be applied to pigmentation data. This work describes a new methodology that allows for the quantification of various aspects of the abdominal pigmentation pattern of adult D. melanogaster. The protocol includes specimen mounting, image capture, data extraction, and analysis. All the software used for image capture and analysis feature macros written for open-source image analysis. The advantage of this approach is the ability to precisely measure pigmentation traits using a methodology that is highly reproducible across different imaging systems. While the technique has been used to measure variation in the tergal pigmentation patterns of adult D. melanogaster, the methodology is flexible and broadly applicable to pigmentation patterns in myriad different organisms.

  18. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    More recently, detailed investigation leading to the anatomical, neurochemical and electrophysiological characterization of the various neuronal subgroups that comprise the circadian machinery has revealed pathways through which these neurons come together to act as a neuronal circuit. Thus the D. melanogaster ...

  19. Integrated visualization of simulation results and experimental devices in virtual-reality space

    International Nuclear Information System (INIS)

    Ohtani, Hiroaki; Ishiguro, Seiji; Shohji, Mamoru; Kageyama, Akira; Tamura, Yuichi

    2011-01-01

    We succeeded in integrating the visualization of both simulation results and experimental device data in virtual-reality (VR) space using CAVE system. Simulation results are shown using Virtual LHD software, which can show magnetic field line, particle trajectory, and isosurface of plasma pressure of the Large Helical Device (LHD) based on data from the magnetohydrodynamics equilibrium simulation. A three-dimensional mouse, or wand, determines the initial position and pitch angle of a drift particle or the starting point of a magnetic field line, interactively in the VR space. The trajectory of a particle and the stream-line of magnetic field are calculated using the Runge-Kutta-Huta integration method on the basis of the results obtained after pointing the initial condition. The LHD vessel is objectively visualized based on CAD-data. By using these results and data, the simulated LHD plasma can be interactively drawn in the objective description of the LHD experimental vessel. Through this integrated visualization, it is possible to grasp the three-dimensional relationship of the positions between the device and plasma in the VR space, opening a new path in contribution to future research. (author)

  20. Experimental analysis of ammonia condensation on smooth and integral-fin titanium tubes

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose; Uhia, Francisco J.; Diz, Ruben [Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, University of Vigo, Campus Lagoas-Marcosende No 9, 36310 Vigo (Spain)

    2009-09-15

    This paper reports on the experimental research conducted to study the condensation of ammonia on smooth and integral-fin (32 fpi) titanium tubes of 19.05 mm outer diameter. Experiments were carried out at saturation temperatures of 30, 35, 40 and 45 C and wall subcoolings from 1 to 8 C. The results show that the condensation coefficients on the smooth tubes are well predicted by the Nusselt theory with an average error of +0.66% and within a deviation between -6.6% and +8.3%. The enhancement factors provided by the integral-fin tubes range from 0.77 to 1.22. The low enhancement factors are due to the high condensate retention between fins, which brings about flooded fractions of the tube perimeter from 62.9% to 73.2%, and the low thermal conductivity of titanium. The Briggs and Rose [1994. Effect of fin efficiency on a model for condensation heat transfer on a horizontal, integral-fin tube. Int. J. Heat Mass Transfer 37, 457-463.] model, which accounts for the conduction in the fins, predicts the experimental data with a mean overestimation of 20%. The analysis of the partial thermal resistances in the overall heat transfer process points out the convenience of enhancing the outside ammonia condensation when high water velocities are considered inside the tubes. (author)

  1. Experimental study on design verification of new concept for integral reactor safety system

    International Nuclear Information System (INIS)

    Chung, Moon Ki; Choi, Ki Yong; Park, Hyun Sik; Cho, Seok; Park, Choon Kyung; Lee, Sung Jae; Song, Chul Hwa

    2004-01-01

    The pressurized light water cooled, medium power (330 MWt) SMART (System-integrated Modular Advanced ReacTor) has been under development at KAERI for a dual purpose : seawater desalination and electricity generation. The SMART design verification phase was followed to conduct various separate effects tests and comprehensive integral effect tests. The high temperature / high pressure thermal-hydraulic test facility, VISTA(Experimental Verification by Integral Simulation of Transient and Accidents) has been constructed to simulate the SMART-P (the one fifth scaled pilot plant) by KAERI. Experimental tests have been performed to investigate the thermal-hydraulic dynamic characteristics of the primary and the secondary systems. Heat transfer characteristics and natural circulation performance of the PRHRS (Passive Residual Heat Removal System) of SMART-P were also investigated using the VISTA facility. The coolant flows steadily in the natural circulation loop which is composed of the Steam Generator (SG) primary side, the secondary system, and the PRHRS. The heat transfers through the PRHRS heat exchanger and ECT are sufficient enough to enable the natural circulation of the coolant

  2. Theoretical modeling and experimental analysis of solar still integrated with evacuated tubes

    Science.gov (United States)

    Panchal, Hitesh; Awasthi, Anuradha

    2017-06-01

    In this present research work, theoretical modeling of single slope, single basin solar still integrated with evacuated tubes has been performed based on energy balance equations. Major variables like water temperature, inner glass cover temperature and distillate output has been computed based on theoretical modeling. The experimental setup has been made from locally available materials and installed at Gujarat Power Engineering and Research Institute, Mehsana, Gujarat, India (23.5880°N, 72.3693°E) with 0.04 m depth during 6 months of time interval. From the series of experiments, it is found considerable increment in average distillate output of a solar still when integrated with evacuated tubes not only during daytime but also from night time. In all experimental cases, the correlation of coefficient (r) and root mean square percentage deviation of theoretical modeling and experimental study found good agreement with 0.97 < r < 0.98 and 10.22 < e < 38.4% respectively.

  3. Numerical simulation and experimental research of the integrated high-power LED radiator

    Science.gov (United States)

    Xiang, J. H.; Zhang, C. L.; Gan, Z. J.; Zhou, C.; Chen, C. G.; Chen, S.

    2017-01-01

    The thermal management has become an urgent problem to be solved with the increasing power and the improving integration of the LED (light emitting diode) chip. In order to eliminate the contact resistance of the radiator, this paper presented an integrated high-power LED radiator based on phase-change heat transfer, which realized the seamless connection between the vapor chamber and the cooling fins. The radiator was optimized by combining the numerical simulation and the experimental research. The effects of the chamber diameter and the parameters of fin on the heat dissipation performance were analyzed. The numerical simulation results were compared with the measured values by experiment. The results showed that the fin thickness, the fin number, the fin height and the chamber diameter were the factors which affected the performance of radiator from primary to secondary.

  4. Experimental Study on Shortwave Communication and OTHR Integrated System Based on OFDM Waveform

    Directory of Open Access Journals (Sweden)

    Shao Qi-hong

    2012-12-01

    Full Text Available Based on the recently developed active-passive multifunctional all-digital HF surface wave radar hardware platform of Wuhan University, an experiment study of integrated technology for shortwave communication and Over-The-Horizon Radar (OTHR application is carried out. Firstly, from the point of communication are demonstrated the key technologies of orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM in the short-wave communication. Secondly, from the point of radar detection are analyzed OFDM parameters design guidelines and its impact on the over-the-horizon radar detection performance. After the description of some key technologies related to communication signal demodulation and radar signal processing, the configuration parameters of hardware platform and experimental results are provided. The results show that the OFDM wave is done well in radar-communication integration systems, which is of great significance on the netted OTHR detection research.

  5. Integrating mind and brain: Warren S. McCulloch, cerebral localization, and experimental epistemology.

    Science.gov (United States)

    Abraham, Tara H

    2003-03-01

    Recently, historians have focused on Warren S. McCulloch's role in the cybernetics movement during the 1940s and 1950s, and his contributions to the development of computer science and communication theory. What has received less attention is McCulloch's early work in neurophysiology, and its relationship to his philosophical quest for an 'experimental epistemology' - a physiological theory of knowledge. McCulloch's early laboratory work during the 1930s addressed the problem of cerebral localization: localizing aspects of behaviour in the cerebral cortex of the brain. Most of this research was done with the Dutch neurophysiologist J.G. Dusser de Barenne at Yale University. The connection between McCulloch's philosophical interests and his experimental work can be expressed as a search for a physiological a priori, an integrated mechanism of sensation.

  6. Versatile P(acman) BAC Libraries for Transgenesis Studies in Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Venken, Koen J.T.; Carlson, Joseph W.; Schulze, Karen L.; Pan, Hongling; He, Yuchun; Spokony, Rebecca; Wan, Kenneth H.; Koriabine, Maxim; de Jong, Pieter J.; White, Kevin P.; Bellen, Hugo J.; Hoskins, Roger A.

    2009-04-21

    We constructed Drosophila melanogaster BAC libraries with 21-kb and 83-kb inserts in the P(acman) system. Clones representing 12-fold coverage and encompassing more than 95percent of annotated genes were mapped onto the reference genome. These clones can be integrated into predetermined attP sites in the genome using Phi C31 integrase to rescue mutations. They can be modified through recombineering, for example to incorporate protein tags and assess expression patterns.

  7. CDApps: integrated software for experimental planning and data processing at beamline B23, Diamond Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Rohanah, E-mail: rohanah.hussain@diamond.ac.uk; Benning, Kristian; Javorfi, Tamas; Longo, Edoardo; Rudd, Timothy R.; Pulford, Bill; Siligardi, Giuliano, E-mail: rohanah.hussain@diamond.ac.uk [Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2015-01-31

    CDApps software at Diamond B23 SRCD beamline is presented. The B23 Circular Dichroism beamline at Diamond Light Source has been operational since 2009 and has seen visits from more than 200 user groups, who have generated large amounts of data. Based on the experience of overseeing the users’ progress at B23, four key areas requiring the most assistance are identified: planning of experiments and note-keeping; designing titration experiments; processing and analysis of the collected data; and production of experimental reports. To streamline these processes an integrated software package has been developed and made available for the users. The subsequent article summarizes the main features of the software.

  8. CDApps: integrated software for experimental planning and data processing at beamline B23, Diamond Light Source.

    Science.gov (United States)

    Hussain, Rohanah; Benning, Kristian; Javorfi, Tamas; Longo, Edoardo; Rudd, Timothy R; Pulford, Bill; Siligardi, Giuliano

    2015-03-01

    The B23 Circular Dichroism beamline at Diamond Light Source has been operational since 2009 and has seen visits from more than 200 user groups, who have generated large amounts of data. Based on the experience of overseeing the users' progress at B23, four key areas requiring the most assistance are identified: planning of experiments and note-keeping; designing titration experiments; processing and analysis of the collected data; and production of experimental reports. To streamline these processes an integrated software package has been developed and made available for the users. The subsequent article summarizes the main features of the software.

  9. Integral method of treatment of experimental data from radiochemical solar neutrino detectors

    International Nuclear Information System (INIS)

    Gavrin, V.N.; Kopylov, A.V.; Streltsov, A.V.

    1985-01-01

    An analysis is made of the statistical errors in solar neutrino detection by radiochemical detectors at different times of exposure. It is shown that short exposures (tau/sub e/ = one-half to one half-life) give minimal one-year error. The possibility is considered of the detection of the solar neutrino flux variation due to annual changes of the Earth-Sun distance. The integral method of treatment of the experimental data is described. Results are given of the statistical treatment of computer simulated data

  10. Scaling Analysis Techniques to Establish Experimental Infrastructure for Component, Subsystem, and Integrated System Testing

    Energy Technology Data Exchange (ETDEWEB)

    Sabharwall, Piyush [Idaho National Laboratory (INL), Idaho Falls, ID (United States); O' Brien, James E. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); McKellar, Michael G. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Housley, Gregory K. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Bragg-Sitton, Shannon M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2015-03-01

    Hybrid energy system research has the potential to expand the application for nuclear reactor technology beyond electricity. The purpose of this research is to reduce both technical and economic risks associated with energy systems of the future. Nuclear hybrid energy systems (NHES) mitigate the variability of renewable energy sources, provide opportunities to produce revenue from different product streams, and avoid capital inefficiencies by matching electrical output to demand by using excess generation capacity for other purposes when it is available. An essential step in the commercialization and deployment of this advanced technology is scaled testing to demonstrate integrated dynamic performance of advanced systems and components when risks cannot be mitigated adequately by analysis or simulation. Further testing in a prototypical environment is needed for validation and higher confidence. This research supports the development of advanced nuclear reactor technology and NHES, and their adaptation to commercial industrial applications that will potentially advance U.S. energy security, economy, and reliability and further reduce carbon emissions. Experimental infrastructure development for testing and feasibility studies of coupled systems can similarly support other projects having similar developmental needs and can generate data required for validation of models in thermal energy storage and transport, energy, and conversion process development. Experiments performed in the Systems Integration Laboratory will acquire performance data, identify scalability issues, and quantify technology gaps and needs for various hybrid or other energy systems. This report discusses detailed scaling (component and integrated system) and heat transfer figures of merit that will establish the experimental infrastructure for component, subsystem, and integrated system testing to advance the technology readiness of components and systems to the level required for commercial

  11. INTERACTION BETWEEN THE ADH AND ALPHA-GPDH LOCI IN DROSOPHILA-MELANOGASTER - ADULT SURVIVAL AT HIGH-TEMPERATURE

    NARCIS (Netherlands)

    OUDMAN, L; VANDELDEN, W; KAMPING, A; BIJLSMA, R

    The role of high temperature resistance in the world-wide cline of Adh and alpha-Gpdh allele frequencies of Drosophila melanogaster was investigated. Experimental strains were used with different combinations of Adh and alpha-Gpdh alleles but with similar genetic background. The survival time of

  12. Effect of gamma irradiation on lifespan and offspring physiology of male drosophila melanogaster

    International Nuclear Information System (INIS)

    Hou Jiangyu; Gu Wei; Jiang Fangping; Han Hetong

    2010-01-01

    This study aimed to investigate the effects of γ-rays irradiation on adult longevity and physiological changes in F 1 generation.Male Drosophila melanogaster at 1 ∼ 2 days old were irradiated by γ-rays with doses of 5, 10, 15 and 30 Gy. In all experimental groups, mean lifespan, maximum lifespan and 90% of lethaldeath irradiated flies were reduced(at P 1 generation of irradiated group, body weight increased, but the capacity of physiological stress declined. (authors)

  13. The effect of Emblica officinalis diet on lifespan, sexual behavior, and fitness characters in Drosophila melanogaster

    OpenAIRE

    Pathak, Pankaj; Prasad, B. R. Guru; Murthy, N. Anjaneya; Hegde, S. N.

    2011-01-01

    Drosophila is an excellent organism to test Ayurvedic medicines. The objective of our study was to explore the potential of Emblica officinalis drug on longevity, sexual behavior, and reproductive fitness of Drosophila melanogaster using adult feeding method. Increase in the lifespan, fecundity, fertility, ovarioles number, and developmental time was observed in both parents and F1 generation, but not in the F2 generation in experimental culture (control + E. officinalis). According to the Du...

  14. Drosophila melanogaster as a Model Organism of Brain Diseases

    Directory of Open Access Journals (Sweden)

    Werner Paulus

    2009-02-01

    Full Text Available Drosophila melanogaster has been utilized to model human brain diseases. In most of these invertebrate transgenic models, some aspects of human disease are reproduced. Although investigation of rodent models has been of significant impact, invertebrate models offer a wide variety of experimental tools that can potentially address some of the outstanding questions underlying neurological disease. This review considers what has been gleaned from invertebrate models of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, metabolic diseases such as Leigh disease, Niemann-Pick disease and ceroid lipofuscinoses, tumor syndromes such as neurofibromatosis and tuberous sclerosis, epilepsy as well as CNS injury. It is to be expected that genetic tools in Drosophila will reveal new pathways and interactions, which hopefully will result in molecular based therapy approaches.

  15. Impact of the resident microbiota on the nutritional phenotype of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Emma V Ridley

    Full Text Available Animals are chronically infected by benign and beneficial microorganisms that generally promote animal health through their effects on the nutrition, immune function and other physiological systems of the host. Insight into the host-microbial interactions can be obtained by comparing the traits of animals experimentally deprived of their microbiota and untreated animals. Drosophila melanogaster is an experimentally tractable system to study host-microbial interactions.The nutritional significance of the microbiota was investigated in D. melanogaster bearing unmanipulated microbiota, demonstrated by 454 sequencing of 16S rRNA amplicons to be dominated by the α-proteobacterium Acetobacter, and experimentally deprived of the microbiota by egg dechorionation (conventional and axenic flies, respectively. In axenic flies, larval development rate was depressed with no effect on adult size relative to conventional flies, indicating that the microbiota promotes larval growth rates. Female fecundity did not differ significantly between conventional and axenic flies, but axenic flies had significantly reduced metabolic rate and altered carbohydrate allocation, including elevated glucose levels.We have shown that elimination of the resident microbiota extends larval development and perturbs energy homeostasis and carbohydrate allocation patterns of of D. melanogaster. Our results indicate that the resident microbiota promotes host nutrition and interacts with the regulation of host metabolism.

  16. Understanding electricity generation in osmotic microbial fuel cells through integrated experimental investigation and mathematical modeling.

    Science.gov (United States)

    Qin, Mohan; Ping, Qingyun; Lu, Yaobin; Abu-Reesh, Ibrahim M; He, Zhen

    2015-11-01

    Osmotic microbial fuel cells (OsMFCs) are a new type of MFCs with integrating forward osmosis (FO). However, it is not well understood why electricity generation is improved in OsMFCs compared to regular MFCs. Herein, an approach integrating experimental investigation and mathematical model was adopted to address the question. Both an OsMFC and an MFC achieved similar organic removal efficiency, but the OsMFC generated higher current than the MFC with or without water flux, resulting from the lower resistance of FO membrane. Combining NaCl and glucose as a catholyte demonstrated that the catholyte conductivity affected the electricity generation in the OsMFC. A mathematical model of OsMFCs was developed and validated with the experimental data. The model predicated the variation of internal resistance with increasing water flux, and confirmed the importance of membrane resistance. Increasing water flux with higher catholyte conductivity could decrease the membrane resistance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. The dynamical integrity concept for interpreting/ predicting experimental behaviour: from macro- to nano-mechanics.

    Science.gov (United States)

    Lenci, Stefano; Rega, Giuseppe; Ruzziconi, Laura

    2013-06-28

    The dynamical integrity, a new concept proposed by J.M.T. Thompson, and developed by the authors, is used to interpret experimental results. After reviewing the main issues involved in this analysis, including the proposal of a new integrity measure able to capture in an easy way the safe part of basins, attention is dedicated to two experiments, a rotating pendulum and a micro-electro-mechanical system, where the theoretical predictions are not fulfilled. These mechanical systems, the former at the macro-scale and the latter at the micro-scale, permit a comparative analysis of different mechanical and dynamical behaviours. The fact that in both cases the dynamical integrity permits one to justify the difference between experimental and theoretical results, which is the main achievement of this paper, shows the effectiveness of this new approach and suggests its use in practical situations. The men of experiment are like the ant, they only collect and use; the reasoners resemble spiders, who make cobwebs out of their own substance. But the bee takes the middle course: it gathers its material from the flowers of the garden and field, but transforms and digests it by a power of its own. Not unlike this is the true business of philosophy (science); for it neither relies solely or chiefly on the powers of the mind, nor does it take the matter which it gathers from natural history and mechanical experiments and lay up in the memory whole, as it finds it, but lays it up in the understanding altered and digested. Therefore, from a closer and purer league between these two faculties, the experimental and the rational (such as has never been made), much may be hoped. (Francis Bacon 1561-1626) But are we sure of our observational facts? Scientific men are rather fond of saying pontifically that one ought to be quite sure of one's observational facts before embarking on theory. Fortunately those who give this advice do not practice what they preach. Observation and theory get

  18. Cartilage integrity and proteoglycan turnover are comparable in canine experimentally induced and human joint degeneration

    Directory of Open Access Journals (Sweden)

    Femke Intema

    2010-10-01

    Full Text Available The value of experimental models of osteoarthritis (OA largely depends on the ability to translate observations to human OA. Surprisingly, direct comparison of characteristics of human and experimental OA is scarce. In the present study, cartilage integrity and matrix turnover in a canine model of joint degeneration were compared to human clinical OA. In 23 Beagle dogs, joint degeneration was induced in one knee, the contra-lateral knee served as a control. For comparison, human osteoarthritic and healthy knee cartilage were obtained at arthroplasty (n=14 and post-mortem (n=13. Cartilage was analyzed by histology and biochemistry. Values for cartilage integrity and proteoglycan (PG synthesis showed species specific differences; GAG content of healthy cartilage was 2-fold higher in canine cartilage and PG synthesis even 8-fold. However, the relative decrease in PG content between healthy and OA cartilage was similar for humans and canines (-17% vs. -15%, respectively, as was the histological damage (+7.0 vs. +6.1, respectively and the increase of PG synthesis (+100% vs. +70%, respectively. Remarkably, the percentage release of total and of newly formed PGs in human and canine controls was similar, as was the increase due to degeneration (+65% vs. +81% and +91% vs. +52%, respectively. Despite differences in control conditions, the observed changes in characteristics of cartilage integrity and matrix turnover are similar in a canine model of joint degeneration and human clinical OA. The canine Groove model shows that its characteristics reflect those of human OA which makes the model appropriate for studying human OA.

  19. The translation factors of Drosophila melanogaster.

    Science.gov (United States)

    Marygold, Steven J; Attrill, Helen; Lasko, Paul

    2017-01-02

    Synthesis of polypeptides from mRNA (translation) is a fundamental cellular process that is coordinated and catalyzed by a set of canonical 'translation factors'. Surprisingly, the translation factors of Drosophila melanogaster have not yet been systematically identified, leading to inconsistencies in their nomenclature and shortcomings in functional (Gene Ontology, GO) annotations. Here, we describe the complete set of translation factors in D. melanogaster, applying nomenclature already in widespread use in other species, and revising their functional annotation. The collection comprises 43 initiation factors, 12 elongation factors, 3 release factors and 6 recycling factors, totaling 64 of which 55 are cytoplasmic and 9 are mitochondrial. We also provide an overview of notable findings and particular insights derived from Drosophila about these factors. This catalog, together with the incorporation of the improved nomenclature and GO annotation into FlyBase, will greatly facilitate access to information about the functional roles of these important proteins.

  20. Die induzierbare antivirale Immunantwort von Drosophila melanogaster

    OpenAIRE

    Kemp, Cordula

    2010-01-01

    In der vorliegenden Arbeit wurde Drosophila melanogaster als Modell ge- nutzt, um die angeborene Immunantwort gegen virale Infektionen zu studie- ren. Wir untersuchten mit Hilfe von genomweiten microarrays das Transkriptom von Fliegen, welche entweder mit dem Drosophila C Virus (DCV), dem Flock- house Virus (FHV) oder dem Sindbis Virus (SINV) infiziert waren. Infektion mit diesen drei positiv orientierten Einzelstrang RNS Viren führte zu einer starken transkriptionellen Antwort, welche deutlic...

  1. Flavonoids and oxidative stress in Drosophila melanogaster.

    Science.gov (United States)

    Sotibrán, América Nitxin Castañeda; Ordaz-Téllez, María Guadalupe; Rodríguez-Arnaiz, Rosario

    2011-11-27

    Flavonoids are a family of antioxidants that are widely represented in fruits, vegetables, dry legumes, and chocolate, as well as in popular beverages, such as red wine, coffee, and tea. The flavonoids chlorogenic acid, kaempferol, quercetin and quercetin 3β-d-glycoside were investigated for genotoxicity using the wing somatic mutation and recombination test (SMART). This test makes use of two recessive wing cell markers: multiple wing hairs (mwh) and flare (flr(3)), which are mutations located on the left arm of chromosome 3 of Drosophila melanogaster and are indicative of both mitotic recombination and various types of mutational events. In order to test the antioxidant capacities of the flavonoids, experiments were conducted with various combinations of oxidants and polyphenols. Oxidative stress was induced using hydrogen peroxide, the Fenton reaction and paraquat. Third-instar transheterozygous larvae were chronically treated for all experiments. The data obtained in this study showed that, at the concentrations tested, the flavonoids did not induce somatic mutations or recombination in D. melanogaster with the exception of quercetin, which proved to be genotoxic at only one concentration. The oxidants hydrogen peroxide and the Fenton reaction did not induce mutations in the wing somatic assay of D. melanogaster, while paraquat and combinations of flavonoids produced significant numbers of small single spots. Quercetin 3β-d-glycoside mixed with paraquat was shown to be desmutagenic. Combinations of the oxidants with the other flavonoids did not show any antioxidant activity. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. C5a alters blood-brain barrier integrity in experimental lupus

    Science.gov (United States)

    Jacob, Alexander; Hack, Bradley; Chiang, Eddie; Garcia, Joe G. N.; Quigg, Richard J.; Alexander, Jessy J.

    2010-01-01

    .—Jacob, A., Hack, B., Chiang, E., Garcia, J. G. N., Quigg, R. J., Alexander, J. J. C5a alters blood-brain barrier integrity in experimental lupus. PMID:20065106

  3. Biophysical Interactions in Porous Media: an Integrated Experimental and Modelling Approach

    Science.gov (United States)

    Otten, W.; Baveye, P.; Falconer, R.

    2012-12-01

    A critical feature of porous media is that the geometry provides habitats of a complexity that is not seen above ground, offering shelter, food water and gasses to microorganisms, who's spatial and temporal dynamics are shaped by this microscopic heterogeneity. The microbial dynamics, including fungal and bacterial growth, in turn affect the geometry and the hydrological properties, shaping the pore architecture at short and long time scales, altering surface tension, and (partially) blocking pores, thereby affecting the flow paths of water through a structure. Crucially, the majority of these processes occur at microscopic scales with impact on larger scale ecological processes and ecosystem services. The complexity of these interacting processes and feed-back mechanisms at first may seem overwhelming. However, we show in this paper how with recent progress in experimental techniques, integrated with a modelling approach we can begin to understand the importance of microscopic heterogeneity on microbial dynamics. We will demonstrate this integrated approach for fungal dynamics in porous media such as soil through a combination of novel experimental tools and mathematical modelling. Using benchtop X-ray CT systems we present the finer detail of pore structure at scales relevant for microbial processes, and present our recent advances in the use of theoretical tools to rigorously characterise, and quantitatively describe this environment, and present the state-of-the art with respect to visualization of water in porous media. Severe challenges remain with studying the spatial distribution of microorganisms. We present how biological thin sectioning techniques offer a way forward to study the spatial distribution of fungi and bacteria within pore geometries. Through a series of detailed experiments we show how pathways, resulting from connected pore volumes and distribution of water within them, are preferentially explored during fungal invasion. We complement the

  4. Anti-Aging Effect of Riboflavin Via Endogenous Antioxidant in Fruit fly Drosophila Melanogaster.

    Science.gov (United States)

    Zou, Y-X; Ruan, M-H; Luan, J; Feng, X; Chen, S; Chu, Z-Y

    2017-01-01

    This study investigated the effect of riboflavin on aging in Drosophila melanogaster (fruit fly). Experimental study. Naval Medical Research Institute. Fruit fly Drosophila melanogaster. After lifelong supplement of riboflavin, the lifespan and the reproduction of fruit flies were observed. Hydrogen peroxide (H2O2) was used to mimic oxidative stress damage to fruit flies and the survival time was recorded. The activity of copper-zinc-containing superoxide dismutase (SOD1), manganese containing SOD (SOD2) and catalase (CAT) and lipofuscin (LF) content were determined. Riboflavin significantly prolonged the lifespan (Log rank χ2=16.677, Priboflavin supplement. Riboflavin prolonged the lifespan and increased the reproduction of fruit flies through anti-oxidative stress pathway involving enhancing the activity of SOD1 and CAT and inhibiting LF accumulation. Riboflavin deserves more attention for slowing human aging.

  5. An integrated experimental and economic evaluation of cell therapy affinity purification technologies.

    Science.gov (United States)

    Weil, Benjamin D; Jenkins, Michael J; Uddin, Siddique; Bracewell, Daniel G; Wellings, Donald; Farid, Suzanne S; Veraitch, Farlan

    2017-04-01

    To present an integrated techno-economic analysis assessing the feasibility of affinity purification technologies using the manufacture of induced pluripotent stem cell-derived progenitor photoreceptors for retinal dystrophies as a case study. Sort purity, progenitor yield and viable cell recovery were investigated for three cell sorting techniques: fluorescent-activated cell sorting (FACS); magnetic-activated cell sorting (MACS); and a novel technology SpheriTech beads. Experimentally derived metrics were incorporated into an advanced bioprocess economics tool to determine cost of goods per dose for each technology. Technical and bioprocess benefits were noted with SpheriTech beads which, unlike FACS and MACS, require no cell labeling. This simplifies the bioprocess, reduces cell loss and leaves target cells label free. The economic tool predicted cost drivers and a critical dose (7 × 10 7 cells per dose) shifting the most cost-effective technology from FACS to MACS. Process optimization is required for SpheriTech to compete economically.

  6. The Local Integrity Approach for Urban Contexts: Definition and Vehicular Experimental Assessment

    Directory of Open Access Journals (Sweden)

    Davide Margaria

    2016-01-01

    Full Text Available A novel cooperative integrity monitoring concept, called “local integrity”, suitable to automotive applications in urban scenarios, is discussed in this paper. The idea is to take advantage of a collaborative Vehicular Ad hoc NETwork (VANET architecture in order to perform a spatial/temporal characterization of possible degradations of Global Navigation Satellite System (GNSS signals. Such characterization enables the computation of the so-called “Local Protection Levels”, taking into account local impairments to the received signals. Starting from theoretical concepts, this paper describes the experimental validation by means of a measurement campaign and the real-time implementation of the algorithm on a vehicular prototype. A live demonstration in a real scenario has been successfully carried out, highlighting effectiveness and performance of the proposed approach.

  7. EBR-2 [Experimental Breeder Reactor-2], IFR [Integral Fast Reactor] prototype testing programs

    International Nuclear Information System (INIS)

    Lehto, W.K.; Sackett, J.I.; Lindsay, R.W.; Planchon, H.P.; Lambert, J.D.B.

    1990-01-01

    The Experimental Breeder Reactor-2 (EBR-2) is a sodium cooled power reactor supplying about 20 MWe to the Idaho National Engineering Laboratory (INEL) grid and, in addition, is the key component in the development of the Integral Fast Reactor (IFR). EBR-2's testing capability is extensive and has seen four major phases: (1) demonstration of LMFBR power plant feasibility, (2) irradiation testing for fuel and material development. (3) testing the off-normal performance of fuel and plant systems and (4) operation as the IFR prototype, developing and demonstrating the IFR technology associated with fuel and plant design. Specific programs being carried out in support of the IFR include advanced fuels and materials development and component testing. This paper discusses EBR-2 as the IFR prototype and the associated testing programs. 29 refs

  8. Antioxidants and embryo phenotype: is there experimental evidence for strong integration of the antioxidant system?

    Science.gov (United States)

    Possenti, Cristina Daniela; Karadas, Filiz; Colombo, Graziano; Caprioli, Manuela; Rubolini, Diego; Milzani, Aldo; Donne, Isabella Dalle; Saino, Nicola; Parolini, Marco

    2017-02-15

    Organisms have evolved complex defense systems against oxidative stress. Bird eggs contain maternally derived antioxidants that protect embryos from oxidative damage. The antioxidant system components are thought to be integrated, but few studies have analyzed the covariation between antioxidant concentrations, embryo 'oxidative status' and morphology. In addition, no study has tested the effects of experimental change in yolk antioxidant concentration on other antioxidants, on their reciprocal relationships and on their relationships with embryo oxidative status or growth, which are expected if antioxidants defenses are integrated. In yellow-legged gull ( Larus michahellis ) embryos, we analyzed the covariation between several antioxidants, markers of 'oxidative status' [total antioxidant capacity (TAC), concentration of pro-oxidants (TOS), lipid peroxidation (LPO) and protein carbonylation (PC)] in the yolk, liver and brain, and morphology. Yolk and liver antioxidant concentrations were positively correlated reciprocally and with embryo size, and positively predicted TAC but not oxidative status. TOS and LPO were positively correlated in the liver, while TAC and LPO were negatively correlated in the brain. Weak relationships existed between antioxidants and TOS, PC and LPO. The effects of antioxidants on oxidative status and morphology were non-synergistic. An experimental physiological increase in yolk vitamin E had very weak effects on the relationships between other antioxidants or oxidative status and vitamin E concentration, the concentration of other antioxidants or oxidative status; the covariation between other antioxidants and oxidative status, and relationships between morphology or oxidative status and other antioxidants, challenging the common wisdom of strong functional relationships among antioxidants, at least for embryos in the wild. © 2017. Published by The Company of Biologists Ltd.

  9. Integral test of JENDL dosimetry file using fast neutron field in the Experimental Fast Reactor JOYO

    International Nuclear Information System (INIS)

    Aoyama, Takafumi; Sekine, Takashi

    1999-09-01

    In order to evaluate the applicability of the JENDL dosimetry file, an integral test using a fast neutron spectrum field in the Experimental Fast Reactor JOYO Mark-II core was performed. The dosimeter set consisting of eight reactions of 46 Ti(n,p) 46 Sc, 54 Fe(n,p) 54 Mn, 58 Fe(n,γ) 59 Fe, 58 Ni(n,p) 58 Co, 59 Co(n,γ) 60 Co, 63 Cu(n,α) 60 Co, 238 U fission and 237 Np fission was irradiated for approximately 30 days near the core center of the JOYO Mk-II. Neutron flux at the dosimeter position was calculated using the two dimensional discrete ordinate transport code 'DORT'. The core configuration was modeled in XY geometry, and the 100 group cross section set of JSD-J2 / JFT-J2, which was processed from JENDL-2, was utilized. The absolute value of neutron flux was normalized so that the 235 U fission rate using the calculated neutron spectrum agreed with the measured reaction rate. The 103 group cross section data were processed by 'NJOY' code for nuclides to be used in the JOYO dosimetry. As the results of integral test for JENDL/D-99 (new file) and JENDL/D-91 (previous file), calculated values by JENDL/D-99 agreed well with the experimental values, and the C/E ratios ranged from 0.95 to 1.22. By comparing the results between JENDL/D-99 and JENDL/D-91, small differences exist, except for 58 Fe(n, γ) 59 Fe reaction, which was improved significantly in JENDL/D-99. (author)

  10. Integrating local research watersheds into hydrologic education: Lessons from the Dry Creek Experimental Watershed

    Science.gov (United States)

    McNamara, J. P.; Aishlin, P. S.; Flores, A. N.; Benner, S. G.; Marshall, H. P.; Pierce, J. L.

    2014-12-01

    While a proliferation of instrumented research watersheds and new data sharing technologies has transformed hydrologic research in recent decades, similar advances have not been realized in hydrologic education. Long-standing problems in hydrologic education include discontinuity of hydrologic topics from introductory to advanced courses, inconsistency of content across academic departments, and difficulties in development of laboratory and homework assignments utilizing large time series and spatial data sets. Hydrologic problems are typically not amenable to "back-of-the-chapter" examples. Local, long-term research watersheds offer solutions to these problems. Here, we describe our integration of research and monitoring programs in the Dry Creek Experimental Watershed into undergraduate and graduate hydrology programs at Boise State University. We developed a suite of watershed-based exercises into courses and curriculums using real, tangible datasets from the watershed to teach concepts not amenable to traditional textbook and lecture methods. The aggregation of exercises throughout a course or degree allows for scaffolding of concepts with progressive exposure of advanced concepts throughout a course or degree. The need for exercises of this type is growing as traditional lecture-based classes (passive learning from a local authoritative source) are being replaced with active learning courses that integrate many sources of information through situational factors.

  11. Integration of experimental and computational methods for identifying geometric, thermal and diffusive properties of biomaterials

    Science.gov (United States)

    Weres, Jerzy; Kujawa, Sebastian; Olek, Wiesław; Czajkowski, Łukasz

    2016-04-01

    Knowledge of physical properties of biomaterials is important in understanding and designing agri-food and wood processing industries. In the study presented in this paper computational methods were developed and combined with experiments to enhance identification of agri-food and forest product properties, and to predict heat and water transport in such products. They were based on the finite element model of heat and water transport and supplemented with experimental data. Algorithms were proposed for image processing, geometry meshing, and inverse/direct finite element modelling. The resulting software system was composed of integrated subsystems for 3D geometry data acquisition and mesh generation, for 3D geometry modelling and visualization, and for inverse/direct problem computations for the heat and water transport processes. Auxiliary packages were developed to assess performance, accuracy and unification of data access. The software was validated by identifying selected properties and using the estimated values to predict the examined processes, and then comparing predictions to experimental data. The geometry, thermal conductivity, specific heat, coefficient of water diffusion, equilibrium water content and convective heat and water transfer coefficients in the boundary layer were analysed. The estimated values, used as an input for simulation of the examined processes, enabled reduction in the uncertainty associated with predictions.

  12. Gene regulatory network reconstruction by Bayesian integration of prior knowledge and/or different experimental conditions.

    Science.gov (United States)

    Werhli, Adriano V; Husmeier, Dirk

    2008-06-01

    There have been various attempts to improve the reconstruction of gene regulatory networks from microarray data by the systematic integration of biological prior knowledge. Our approach is based on pioneering work by Imoto et al. where the prior knowledge is expressed in terms of energy functions, from which a prior distribution over network structures is obtained in the form of a Gibbs distribution. The hyperparameters of this distribution represent the weights associated with the prior knowledge relative to the data. We have derived and tested a Markov chain Monte Carlo (MCMC) scheme for sampling networks and hyperparameters simultaneously from the posterior distribution, thereby automatically learning how to trade off information from the prior knowledge and the data. We have extended this approach to a Bayesian coupling scheme for learning gene regulatory networks from a combination of related data sets, which were obtained under different experimental conditions and are therefore potentially associated with different active subpathways. The proposed coupling scheme is a compromise between (1) learning networks from the different subsets separately, whereby no information between the different experiments is shared; and (2) learning networks from a monolithic fusion of the individual data sets, which does not provide any mechanism for uncovering differences between the network structures associated with the different experimental conditions. We have assessed the viability of all proposed methods on data related to the Raf signaling pathway, generated both synthetically and in cytometry experiments.

  13. Integrated experimental and modeling assessment of potential effects of gas leakages on groundwater composition

    Science.gov (United States)

    Berta, Marton; Dethlefsen, Frank; Ebert, Markus; Schäfer, Dirk

    2017-04-01

    Storing renewably produced energy is one of the major challenges for the energy systems of the upcoming decades. Power-to-gas technologies coupled to geological storage of compressed air, methane, and hydrogen offer a comparatively safe and cost-efficient way for large-scale energy storage. However, the stored gases can potentially escape from their geological reservoir and may thus affect protected natural goods such as groundwater. The geochemical reactions responsible for these composition changes are usually investigated separately in experiments and numerical models. Here we present the outcomes of an integrated experimental and modeling approach through the example of a compressed air leakage scenario. A main consequence of the presence of oxygen to be assessed in an aquifer is pyrite oxidation, well known from acid mine drainage sites. However, in contrast to acid mine drainage sites exhibiting unsaturated sediments and fed by meteoric low-carbonate water, aquifers such as in Northern Germany contain a considerable amount of solid and dissolved inorganic carbon species potentially buffering pH changes. High pressure flow-through column experiments representing an intrusion of compressed air into an aquifer were carried out to quantify pyrite oxidation kinetics and to incorporate the observations into a descriptive reaction model. Surface passivation was found to decrease the reactivity of pyrite by more than 90% after a few months of experimental run time. We propose that the carbonate buffer system enables the precipitation of a passivating mineral layer on the pyrite surface reducing the overall reaction rate significantly. Consequently, an established rate law from the literature was extended by a reactive surface passivation term[1]. This improved reaction rate equation was incorporated into a 3D numerical model using OpenGeoSys with parameters representing similarly typical aquifer conditions the experiments had characterized. These boundaries include

  14. Integrated assessment of thermal hydraulic processes in W7-X fusion experimental facility

    Energy Technology Data Exchange (ETDEWEB)

    Kaliatka, T., E-mail: tadas.kaliatka@lei.lt; Uspuras, E.; Kaliatka, A.

    2017-02-15

    Highlights: • The model of Ingress of Coolant Event experiment facility was developed using the RELAP5 code. • Calculation results were compared with Ingress of Coolant Event experiment data. • Using gained experience, the numerical model of Wendelstein 7-X facility was developed. • Performed analysis approved pressure increase protection system for LOCA event. - Abstract: Energy received from the nuclear fusion reaction is one of the most promising options for generating large amounts of carbon-free energy in the future. However, physical and technical problems existing in this technology are complicated. Several experimental nuclear fusion devices around the world have already been constructed, and several are under construction. However, the processes in the cooling system of the in-vessel components, vacuum vessel and pressure increase protection system of nuclear fusion devices are not widely studied. The largest amount of radioactive materials is concentrated in the vacuum vessel of the fusion device. Vacuum vessel is designed for the vacuum conditions inside the vessel. Rupture of the in-vessel components of the cooling system pipe may lead to a sharp pressure increase and possible damage of the vacuum vessel. To prevent the overpressure, the pressure increase protection system should be designed and implemented. Therefore, systematic and detailed experimental and numerical studies, regarding the thermal-hydraulic processes in cooling system, vacuum vessel and pressure increase protection system, are important and relevant. In this article, the numerical investigation of thermal-hydraulic processes in cooling systems of in-vessel components, vacuum vessels and pressure increase protection system of fusion devices is presented. Using the experience gained from the modelling of “Ingress of Coolant Event” experimental facilities, the numerical model of Wendelstein 7-X (W7-X) experimental fusion device was developed. The integrated analysis of the

  15. The Risa R/Bioconductor package: integrative data analysis from experimental metadata and back again.

    Science.gov (United States)

    González-Beltrán, Alejandra; Neumann, Steffen; Maguire, Eamonn; Sansone, Susanna-Assunta; Rocca-Serra, Philippe

    2014-01-01

    The ISA-Tab format and software suite have been developed to break the silo effect induced by technology-specific formats for a variety of data types and to better support experimental metadata tracking. Experimentalists seldom use a single technique to monitor biological signals. Providing a multi-purpose, pragmatic and accessible format that abstracts away common constructs for describing Investigations, Studies and Assays, ISA is increasingly popular. To attract further interest towards the format and extend support to ensure reproducible research and reusable data, we present the Risa package, which delivers a central component to support the ISA format by enabling effortless integration with R, the popular, open source data crunching environment. The Risa package bridges the gap between the metadata collection and curation in an ISA-compliant way and the data analysis using the widely used statistical computing environment R. The package offers functionality for: i) parsing ISA-Tab datasets into R objects, ii) augmenting annotation with extra metadata not explicitly stated in the ISA syntax; iii) interfacing with domain specific R packages iv) suggesting potentially useful R packages available in Bioconductor for subsequent processing of the experimental data described in the ISA format; and finally v) saving back to ISA-Tab files augmented with analysis specific metadata from R. We demonstrate these features by presenting use cases for mass spectrometry data and DNA microarray data. The Risa package is open source (with LGPL license) and freely available through Bioconductor. By making Risa available, we aim to facilitate the task of processing experimental data, encouraging a uniform representation of experimental information and results while delivering tools for ensuring traceability and provenance tracking. The Risa package is available since Bioconductor 2.11 (version 1.0.0) and version 1.2.1 appeared in Bioconductor 2.12, both along with documentation

  16. Drosophila melanogaster deoxyribonucleoside kinase activates gemcitabine

    Energy Technology Data Exchange (ETDEWEB)

    Knecht, Wolfgang [BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby (Denmark); Mikkelsen, Nils Egil [Department of Molecular Biology, Swedish University of Agricultural Sciences, Biomedical Centre, SE-751 24 Uppsala (Sweden); Clausen, Anders Ranegaard [Cell and Organism Biology, Lund University, Soelvegatan 35, SE-22362 Lund (Sweden); Willer, Mette [ZGene A/S, Agern Alle 7, DK-2970 Horsholm (Denmark); Eklund, Hans [Department of Molecular Biology, Swedish University of Agricultural Sciences, Biomedical Centre, SE-751 24 Uppsala (Sweden); Gojkovic, Zoran [ZGene A/S, Agern Alle 7, DK-2970 Horsholm (Denmark); Piskur, Jure, E-mail: Jure.Piskur@cob.lu.se [BioCentrum-DTU, Technical University of Denmark, DK-2800 Lyngby (Denmark); Cell and Organism Biology, Lund University, Soelvegatan 35, SE-22362 Lund (Sweden)

    2009-05-01

    Drosophila melanogaster multisubstrate deoxyribonucleoside kinase (Dm-dNK) can additionally sensitize human cancer cell lines towards the anti-cancer drug gemcitabine. We show that this property is based on the Dm-dNK ability to efficiently phosphorylate gemcitabine. The 2.2 A resolution structure of Dm-dNK in complex with gemcitabine shows that the residues Tyr70 and Arg105 play a crucial role in the firm positioning of gemcitabine by extra interactions made by the fluoride atoms. This explains why gemcitabine is a good substrate for Dm-dNK.

  17. Crystal structure of enolase from Drosophila melanogaster.

    Science.gov (United States)

    Sun, Congcong; Xu, Baokui; Liu, Xueyan; Zhang, Zhen; Su, Zhongliang

    2017-04-01

    Enolase is an important enzyme in glycolysis and various biological processes. Its dysfunction is closely associated with diseases. Here, the enolase from Drosophila melanogaster (DmENO) was purified and crystallized. A crystal of DmENO diffracted to 2.0 Å resolution and belonged to space group R32. The structure was solved by molecular replacement. Like most enolases, DmENO forms a homodimer with conserved residues in the dimer interface. DmENO possesses an open conformation in this structure and contains conserved elements for catalytic activity. This work provides a structural basis for further functional and evolutionary studies of enolase.

  18. Integrated experimental test program on waterhammer pressure pulses and associated structural responses within a feedwater sparger

    Energy Technology Data Exchange (ETDEWEB)

    Nurkkala, P.; Hoikkanen, J. [Imatran Voima Oy, Vantaa (Finland)

    1997-12-31

    This paper describes the methods and systems as utilized in an integrated experimental thermohydraulic/mechanics analysis test program on waterhammer pressure pulses within a revised feedwater sparger of a Loviisa generation VVER-440-type reactor. This program was carried out in two stages: (1) measurements with a strictly limited set of operating parameters at Loviisa NPP, and (2) measurements with the full set of operating parameters on a test article simulating the revised feedwater sparger. The experiments at Loviisa NPS served as an invaluable source of information on the nature of waterhammer pressure pulses and structural responses. These tests thus helped to set the objectives and formulate the concept for series of tests on a test article to study the water hammer phenomena. The heavily instrumented full size test article of a steam generator feedwater sparger was placed within a pressure vessel simulating the steam generator. The feedwater sparger was subjected to the full range of operating parameters which were to result in waterhammer pressure pulse trains of various magnitudes and duration. Two different designs of revised feedwater sparger were investigated (i.e. `grounded` and `with goose neck`). The following objects were to be met within this program: (1) establish the thermohydraulic parameters that facilitate the occurrence of water hammer pressure pulses, (2) provide a database for further analysis of the pressure pulse phenomena, (3) establish location and severity of these water hammer pressure pulses, (4) establish the structural response due to these pressure pulses, (5) provide input data for structural integrity analysis. (orig.). 3 refs.

  19. Experimental study on comprehensive utilization of solar energy and energy balance in an integrated solar house

    International Nuclear Information System (INIS)

    Chang, Huawei; Liu, Yuting; Shen, Jinqiu; Xiang, Can; He, Sinian; Wan, Zhongmin; Jiang, Meng; Duan, Chen; Shu, Shuiming

    2015-01-01

    Highlights: • Active and passive solar house technology is integrated in the solar house. • Solar thermal system and solar photoelectric system are measured and analyzed. • Energy balance and energy consumption are analyzed with valuable experimental data. • “Zero energy consumption” is truly achieved with the solar supply rate of 1.19 in winter. - Abstract: An integrated solar house with numerous advanced envelops is designed and constructed to investigate the comprehensive utilization of solar energy, energy efficiency and energy balance, which combines active solar house technology with passive solar house technology including solar photovoltaic system, solar water heating system, direct-gain door and windows. Solar radiation intensity, performance of the photovoltaic system, water temperature, and indoor and outdoor temperature are measured, results of the experiments indicate that solar glass window on the south wall can maintain the average indoor temperature at 21.4 °C in the case of average outdoor temperature at 11.2 °C without any external heat supply. The output current of the solar photovoltaic system shows the same trend as solar radiation intensity. When the intensity is 619.7 W/m 2 , the instantaneous generation power could reach a value of 781.9 W, cumulative capacity throughout the day achieves 4.56 kW h and photovoltaic conversion efficiency 9.8%. When the average intensity throughout a day is 358 W/m 2 , the solar water heating system could help to raise the temperature of 450 L water by 30 °C with its heat collecting efficiency being 37.4%. Through the analysis of the overall energy system in the solar house, it can be derived that this solar house could achieve “zero energy consumption” in winter with the solar supply rate at 1.19.

  20. Trehalose as an indicator of desiccation stress in Drosophila melanogaster larvae: A potential marker of anhydrobiosis

    Energy Technology Data Exchange (ETDEWEB)

    Thorat, Leena J. [Centre for Advanced Studies, Department of Zoology, University of Pune, Pune 411007 (India); Gaikwad, Sushama M. [Division of Biochemical Sciences, National Chemical Laboratory, Pune 411008 (India); Nath, Bimalendu B., E-mail: bbnath@unipune.ac.in [Centre for Advanced Studies, Department of Zoology, University of Pune, Pune 411007 (India)

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer First report confirming anhydrobiosis in Drosophila melanogaster larvae. Black-Right-Pointing-Pointer Trehalose synthesis and accumulation in larvae that hydrolyzed on rehydration. Black-Right-Pointing-Pointer Trehalose synthesis in concert with the enzymes involved in trehalose metabolism. Black-Right-Pointing-Pointer Inhibition of trehalose hydrolysis in presence of a specific trehalase inhibitor. Black-Right-Pointing-Pointer Trehalose proposed as a reliable marker for biomonitoring of climate change studies. -- Abstract: In the current scenario of global climate change, desiccation is considered as one of the major environmental stressors for the biota exposed to altered levels of ambient temperature and humidity. Drosophila melanogaster, a cosmopolitan terrestrial insect has been chosen as a humidity-sensitive bioindicator model for the present study since its habitat undergoes frequent stochastic and/or seasonally aggravated dehydration regimes. We report here for the first time the occurrence of anhydrobiosis in D. melanogaster larvae by subjecting them to desiccation stress under laboratory conditions. Larvae desiccated for ten hours at <5% relative humidity could enter anhydrobiosis and could revive upon rehydration followed by resumption of active metabolism. As revealed by FTIR and HPLC analyzes, our findings strongly indicated the synthesis and accumulation of trehalose in the desiccating larvae. Biochemical measurements pointed out the desiccation-responsive trehalose metabolic pathway that was found to be coordinated in concert with the enzymes trehalose 6-phosphate synthase and trehalase. Further, an inhibitor-based experimental approach using deoxynojirimycin, a specific trehalase inhibitor, demonstrated the pivotal role of trehalose in larval anhydrobiosis of D. melanogaster. We therefore propose trehalose as a potential marker for the assessment of anhydrobiosis in Drosophila. The present findings thus add

  1. Trehalose as an indicator of desiccation stress in Drosophila melanogaster larvae: A potential marker of anhydrobiosis

    International Nuclear Information System (INIS)

    Thorat, Leena J.; Gaikwad, Sushama M.; Nath, Bimalendu B.

    2012-01-01

    Highlights: ► First report confirming anhydrobiosis in Drosophila melanogaster larvae. ► Trehalose synthesis and accumulation in larvae that hydrolyzed on rehydration. ► Trehalose synthesis in concert with the enzymes involved in trehalose metabolism. ► Inhibition of trehalose hydrolysis in presence of a specific trehalase inhibitor. ► Trehalose proposed as a reliable marker for biomonitoring of climate change studies. -- Abstract: In the current scenario of global climate change, desiccation is considered as one of the major environmental stressors for the biota exposed to altered levels of ambient temperature and humidity. Drosophila melanogaster, a cosmopolitan terrestrial insect has been chosen as a humidity-sensitive bioindicator model for the present study since its habitat undergoes frequent stochastic and/or seasonally aggravated dehydration regimes. We report here for the first time the occurrence of anhydrobiosis in D. melanogaster larvae by subjecting them to desiccation stress under laboratory conditions. Larvae desiccated for ten hours at <5% relative humidity could enter anhydrobiosis and could revive upon rehydration followed by resumption of active metabolism. As revealed by FTIR and HPLC analyzes, our findings strongly indicated the synthesis and accumulation of trehalose in the desiccating larvae. Biochemical measurements pointed out the desiccation-responsive trehalose metabolic pathway that was found to be coordinated in concert with the enzymes trehalose 6-phosphate synthase and trehalase. Further, an inhibitor-based experimental approach using deoxynojirimycin, a specific trehalase inhibitor, demonstrated the pivotal role of trehalose in larval anhydrobiosis of D. melanogaster. We therefore propose trehalose as a potential marker for the assessment of anhydrobiosis in Drosophila. The present findings thus add to the growing list of novel biochemical markers in specific bioindicator organisms for fulfilling the urgent need of

  2. Integrated modeling and experimental approach for determining transcription factor profiles from fluorescent reporter data

    Directory of Open Access Journals (Sweden)

    Jayaraman Arul

    2008-07-01

    Full Text Available Abstract Background The development of quantitative models of signal transduction, as well as parameter estimation to improve existing models, depends on the ability to obtain quantitative information about various proteins that are part of the signaling pathway. However, commonly-used measurement techniques such as Western blots and mobility shift assays provide only qualitative or semi-quantitative data which cannot be used for estimating parameters. Thus there is a clear need for techniques that enable quantitative determination of signal transduction intermediates. Results This paper presents an integrated modeling and experimental approach for quantitatively determining transcription factor profiles from green fluorescent protein (GFP reporter data. The technique consists of three steps: (1 creating data sets for green fluorescent reporter systems upon stimulation, (2 analyzing the fluorescence images to determine fluorescence intensity profiles using principal component analysis (PCA and K-means clustering, and (3 computing the transcription factor concentration from the fluorescence intensity profiles by inverting a model describing transcription, translation, and activation of green fluorescent proteins. We have used this technique to quantitatively characterize activation of the transcription factor NF-κB by the cytokine TNF-α. In addition, we have applied the quantitative NF-κB profiles obtained from our technique to develop a model for TNF-α signal transduction where the parameters were estimated from the obtained data. Conclusion The technique presented here for computing transcription factor profiles from fluorescence microscopy images of reporter cells generated quantitative data on the magnitude and dynamics of NF-κB activation by TNF-α. The obtained results are in good agreement with qualitative descriptions of NF-κB activation as well as semi-quantitative experimental data from the literature. The profiles computed from

  3. Analytical and experimental investigation of thermal transport in three-dimensional integrated circuits (3D ICs)

    Science.gov (United States)

    Choobineh, Leila

    Thermal management of three-dimensional integrated circuits (3D ICs) is recognized to be one of the foremost technological and research challenges currently blocking the widespread adoption of this promising technology. The computation of steady-state temperature fields in a 3D IC is critical for determining the thermal characteristics of a 3D IC and for evaluating any candidate thermal management technology. An analytical solution for the three-dimensional temperature field in a 3D IC based on solution of the governing energy equations using Fourier series expansion for steady-state temperature fields is studied. Comparison of the predicted temperature fields with finite-element simulation shows excellent agreement. The model is used to compute the temperature field in a 3D IC, and it is shown that by utilizing a thermal-friendly floorplanning approach, the maximum temperature of the 3D IC is reduced significantly. Several 3D IC manufacturing and packaging approaches require adjacent die sizes to be different from one another since this enables differentiated manufacturing and design. However, it is expected that unequally-sized die may cause deteriorated thermal performance due to heat spreading and constriction. Heat transfer model for predicting the three-dimensional temperature field in a multi-die 3D IC with unequally-sized die is studied. The model is used to compare the thermal performance of unequally-sized die stacks with a uniformly-sized die stack. Results indicate that the greater the degree of non-uniformity in the die stack, the greater in the peak temperature rise. An analytical modeling of heat transfer in interposer-based microelectronic systems is described. The analytical model is developed to study the effect of various parameters on the temperature field in an interposer system. A non-iterative, analytical heat transfer model for computing three-dimensional temperature fields in a 3D IC has been proposed. The governing energy equations with

  4. Grapes (Vitis vinifera) drying by semitransparent photovoltaic module (SPVM) integrated solar dryer: an experimental study

    Science.gov (United States)

    Tiwari, Sumit; Tiwari, G. N.

    2017-12-01

    In present research paper, semi-transparent photovoltaic module (SPVM) integrated greenhouse solar drying system has been used for grapes (Vitis vinifera) drying. Based on hourly experimental information namely solar intensity, moisture evaporated, ambient air temperature, grape surface temperatures, relative humidity and greenhouse air temperature etc. heat and mass transfer coefficient for the SPVM drying system have been evaluated. It has been seen that the convective heat transfer coefficients for grapes found between 3.1-0.84 W/m2 K. Also, there is a fair agreement between theoretical and practical mass transfer (moisture evaporated) during drying of grapes with a correlation coefficient (r) and root mean square percentage deviation (e) of 0.88 and 11.56 respectively. Further, nonlinear regression procedure has been used to fit various drying models namely Henderson and Pabis model, Newton's model, and Page's model. From the analysis, it was found that Page's model is best fitted for grapes drying in SPV greenhouse as well as open sun drying. Further, net electrical energy, thermal energy and equivalent thermal energy were found to be 3.61, 17.66 and 27.15 kWh during six days of drying respectively.

  5. Experimental and clinical transplantation: a commitment to integrity, accountability, and ethics in publication.

    Science.gov (United States)

    Haberal, Mehmet; Masri, Marwan; Ghods, Ahad J; Rizvi, Sadibul Hasan; Shaheen, Faissal A M

    2013-02-01

    For the past few years, the social, economic, and political issues surrounding the field of organ transplantation have entered into many ethical discussions. Transplant tourism, and organ trade in particular, have finally received the attention they deserve and many commendable developments have ensued. The "Declaration of Istanbul on Organ Trafficking and Transplant Tourism," the result of a collective effort by hundreds of transplant professionals the world over, is one such example and is now considered the universal charter for ethical conduct in the field of transplantation. The Middle East Society for Organ Transplantation and its official journal Experimental and Clinical Transplantation were among its first endorsers, and it is our policy to ensure that all authors of articles published in our Journal adhere fully to the rules and regulations stated in The Declaration of Istanbul and by the Committee on Publication Ethics. We believe that the medical community must ensure that a foundation of ethical conduct and scientific integrity is maintained throughout the field, and we must strive toward this goal in all our clinical and scholarly efforts.

  6. Experimental and Computational Investigation of Structural Integrity of Dissimilar Metal Weld Between Ferritic and Austenitic Steel

    Science.gov (United States)

    Santosh, R.; Das, G.; Kumar, S.; Singh, P. K.; Ghosh, M.

    2018-03-01

    The structural integrity of dissimilar metal welded (DMW) joint consisting of low-alloy steel and 304LN austenitic stainless steel was examined by evaluating mechanical properties and metallurgical characteristics. INCONEL 82 and 182 were used as buttering and filler materials, respectively. Experimental findings were substantiated through thermomechanical simulation of the weld. During simulation, the effect of thermal state and stress distribution was pondered based on the real-time nuclear power plant environment. The simulation results were co-related with mechanical and microstructural characteristics. Material properties were varied significantly at different fusion boundaries across the weld line and associated with complex microstructure. During in-situ deformation testing in a scanning electron microscope, failure occurred through the buttering material. This indicated that microstructure and material properties synergistically contributed to altering the strength of DMW joints. Simulation results also depicted that the stress was maximum within the buttering material and made its weakest zone across the welded joint during service exposure. Various factors for the failure of dissimilar metal weld were analyzed. It was found that the use of IN 82 alloy as the buttering material provided a significant improvement in the joint strength and became a promising material for the fabrication of DMW joint.

  7. Wolbachia influences the maternal transmission of the gypsy endogenous retrovirus in Drosophila melanogaster.

    Science.gov (United States)

    Touret, Franck; Guiguen, François; Terzian, Christophe

    2014-09-02

    The endosymbiotic bacteria of the genus Wolbachia are present in most insects and are maternally transmitted through the germline. Moreover, these intracellular bacteria exert antiviral activity against insect RNA viruses, as in Drosophila melanogaster, which could explain the prevalence of Wolbachia bacteria in natural populations. Wolbachia is maternally transmitted in D. melanogaster through a mechanism that involves distribution at the posterior pole of mature oocytes and then incorporation into the pole cells of the embryos. In parallel, maternal transmission of several endogenous retroviruses is well documented in D. melanogaster. Notably, gypsy retrovirus is expressed in permissive follicle cells and transferred to the oocyte and then to the offspring by integrating into their genomes. Here, we show that the presence of Wolbachia wMel reduces the rate of gypsy insertion into the ovo gene. However, the presence of Wolbachia does not modify the expression levels of gypsy RNA and envelope glycoprotein from either permissive or restrictive ovaries. Moreover, Wolbachia affects the pattern of distribution of the retroviral particles and the gypsy envelope protein in permissive follicle cells. Altogether, our results enlarge the knowledge of the antiviral activity of Wolbachia to include reducing the maternal transmission of endogenous retroviruses in D. melanogaster. Animals have established complex relationships with bacteria and viruses that spread horizontally among individuals or are vertically transmitted, i.e., from parents to offspring. It is well established that members of the genus Wolbachia, maternally inherited symbiotic bacteria present mainly in arthropods, reduce the replication of several RNA viruses transmitted horizontally. Here, we demonstrate for the first time that Wolbachia diminishes the maternal transmission of gypsy, an endogenous retrovirus in Drosophila melanogaster. We hypothesize that gypsy cannot efficiently integrate into the germ

  8. Structure of PCNA from Drosophila melanogaster

    International Nuclear Information System (INIS)

    Wang, Ke; Shi, Zhubing; Zhang, Min; Cheng, Dianlin

    2013-01-01

    Proliferating cell nuclear antigen (PCNA) plays essential roles in DNA replication, DNA repair, cell-cycle regulation and chromatin metabolism. The PCNA from Drosophila melanogaster (DmPCNA) has been purified and crystallized. Proliferating cell nuclear antigen (PCNA) plays essential roles in DNA replication, DNA repair, cell-cycle regulation and chromatin metabolism. The PCNA from Drosophila melanogaster (DmPCNA) was purified and crystallized. The crystal of DmPCNA diffracted to 2.0 Å resolution and belonged to space group H3, with unit-cell parameters a = b = 151.16, c = 38.28 Å. The structure of DmPCNA was determined by molecular replacement. DmPCNA forms a symmetric homotrimer in a head-to-tail manner. An interdomain connector loop (IDCL) links the N- and C-terminal domains. Additionally, the N-terminal and C-terminal domains contact each other through hydrophobic associations. Compared with human PCNA, the IDCL of DmPCNA has conformational changes, which may explain their difference in function. This work provides a structural basis for further functional and evolutionary studies of PCNA

  9. A computational search for box C/D snoRNA genes in the Drosophila melanogaster genome.

    Science.gov (United States)

    Accardo, M C; Giordano, E; Riccardo, S; Digilio, F A; Iazzetti, G; Calogero, R A; Furia, M

    2004-12-12

    In eukaryotes, the family of non-coding RNA genes includes a number of genes encoding small nucleolar RNAs (mainly C/D and H/ACA snoRNAs), which act as guides in the maturation or post-transcriptional modifications of target RNA molecules. Since in Drosophila melanogaster (Dm) only few examples of snoRNAs have been identified so far by cDNA libraries screening, integration of the molecular data with in silico identification of these types of genes could throw light on their organization in the Dm genome. We have performed a computational screening of the Dm genome for C/D snoRNA genes, followed by experimental validation of the putative candidates. Few of the 26 confirmed snoRNAs had been recognized by cDNA library analysis. Organization of the Dm genome was also found to be more variegated than previously suspected, with snoRNA genes nested in both the introns and exons of protein-coding genes. This finding suggests that the presence of additional mechanisms of snoRNA biogenesis based on the alternative production of overlapping mRNA/snoRNA molecules. Additional information is available at http://www.bioinformatica.unito.it/bioinformatics/snoRNAs.

  10. Bioregenerative Life Support Experiment for 90-days in a Closed Integrative Experimental Facility LUNAR PALACE 1

    Science.gov (United States)

    Liu, Hong

    A 90-day bioregenerative life support experiment with three-member crew was carried out in the closed integrative experimental facility, LUNAR PALACE 1 regenerating basic living necessities and disposing wastes to provide life support for crew. It was composed of higher plant module, animal module, and waste treatment module. The higher plant module included wheat, chufa, pea, carrot and green leafy vegetables, with aim to satisfy requirement of 60% plant food and 100% O2 and water for crew. The yellow mealworm was selected as animal module to provide partial animal protein for crew, and reared on plant inedible biomass. The higher plant and yellow mealworm were both cultivated and harvested in the conveyor-type manner. The partial plant inedible biomass and human feces were mixed and co- fermented in the waste treatment module for preparation of soil-like substrate by bioconversion, maintaining gas balance and increasing closure degree. Meanwhile, in the waste treatment module, the water and partial nitrogen from human urine were recovered by physical-chemical means. Circulation of O2 and water as well as food supply from crops cultivated in the LUNAR PALACE 1 were investigated and calculated, and simultaneously gas exchange, mass flow among different components and system closure degree were also analyzed, respectively. Furthermore, the system robustness with respect to internal variation was tested and evaluated by sensitivity analysis of the aggregative index consisting of key performance indicators like crop yield, gaseous equilibrium concentration, microbial community composition, biogenic elements dynamics, etc., and comprehensively evaluating the operating state, to number change of crew from 2 to 4 during the 90-day closed experiment period.

  11. Learning protein-DNA interaction landscapes by integrating experimental data through computational models.

    Science.gov (United States)

    Zhong, Jianling; Wasson, Todd; Hartemink, Alexander J

    2014-10-15

    Transcriptional regulation is directly enacted by the interactions between DNA and many proteins, including transcription factors (TFs), nucleosomes and polymerases. A critical step in deciphering transcriptional regulation is to infer, and eventually predict, the precise locations of these interactions, along with their strength and frequency. While recent datasets yield great insight into these interactions, individual data sources often provide only partial information regarding one aspect of the complete interaction landscape. For example, chromatin immunoprecipitation (ChIP) reveals the binding positions of a protein, but only for one protein at a time. In contrast, nucleases like MNase and DNase can be used to reveal binding positions for many different proteins at once, but cannot easily determine the identities of those proteins. Currently, few statistical frameworks jointly model these different data sources to reveal an accurate, holistic view of the in vivo protein-DNA interaction landscape. Here, we develop a novel statistical framework that integrates different sources of experimental information within a thermodynamic model of competitive binding to jointly learn a holistic view of the in vivo protein-DNA interaction landscape. We show that our framework learns an interaction landscape with increased accuracy, explaining multiple sets of data in accordance with thermodynamic principles of competitive DNA binding. The resulting model of genomic occupancy provides a precise mechanistic vantage point from which to explore the role of protein-DNA interactions in transcriptional regulation. The C source code for compete and Python source code for MCMC-based inference are available at http://www.cs.duke.edu/∼amink. amink@cs.duke.edu Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. Integrated Experimental and Computational Study of Hydraulic Fracturing and the Use of Alternative Fracking Fluids

    Science.gov (United States)

    Viswanathan, H.; Carey, J. W.; Karra, S.; Porter, M. L.; Rougier, E.; Zhang, D.; Makedonska, N.; Middleton, R. S.; Currier, R.; Gupta, R.; Lei, Z.; Kang, Q.; O'Malley, D.; Hyman, J.

    2014-12-01

    Shale gas is an unconventional fossil energy resource that is already having a profound impact on US energy independence and is projected to last for at least 100 years. Production of methane and other hydrocarbons from low permeability shale involves hydrofracturing of rock, establishing fracture connectivity, and multiphase fluid-flow and reaction processes all of which are poorly understood. The result is inefficient extraction with many environmental concerns. A science-based capability is required to quantify the governing mesoscale fluid-solid interactions, including microstructural control of fracture patterns and the interaction of engineered fluids with hydrocarbon flow. These interactions depend on coupled thermo-hydro-mechanical-chemical (THMC) processes over scales from microns to tens of meters. Determining the key mechanisms in subsurface THMC systems has been impeded due to the lack of sophisticated experimental methods to measure fracture aperture and connectivity, multiphase permeability, and chemical exchange capacities at the high temperature, pressure, and stresses present in the subsurface. This project uses innovative high-pressure microfluidic and triaxial core flood experiments on shale to explore fracture-permeability relations and the extraction of hydrocarbon. These data are integrated with simulations including lattice Boltzmann modeling of pore-scale processes, finite-element/discrete element models of fracture development in the near-well environment, discrete-fracture modeling of the reservoir, and system-scale models to assess the economics of alternative fracturing fluids. The ultimate goal is to make the necessary measurements to develop models that can be used to determine the reservoir operating conditions necessary to gain a degree of control over fracture generation, fluid flow, and interfacial processes over a range of subsurface conditions.

  13. Neurogenetics of female reproductive behaviors in Drosophila melanogaster

    NARCIS (Netherlands)

    Laturney, Meghan; Billeter, Jean-Christophe; Friedmann, T; Dunlap, JC; Goodwin, SF

    2014-01-01

    We follow an adult Drosophila melanogaster female through the major reproductive decisions she makes during her lifetime, including habitat selection, precopulatory mate choice, postcopulatory physiological changes, polyandry, and egg-laying site selection. In the process, we review the molecular

  14. Induction of morphological aberrations by enzyme inhibition in Drosophila melanogaster

    NARCIS (Netherlands)

    Bos, M.; Scharloo, W.; Bijlsma, R.; de Boer, I.M.; den Hollander, J.

    1969-01-01

    Zusatz zum Futter vonDrosophila melanogaster von 5-Fluoro-2-deoxyuridin oder Aminopterin induziert überzählige Skutellar- und Dorsozentralborsten sowie gekerbte Flügel. Diese Modifikationen wurden als Konsequenz von Enzymhemmung interpretiert.

  15. Visual Detection of Speckles in the Fish Xenotoca variata by the Predatory Snake Thamnophis melanogaster in Water of Different Turbidity

    OpenAIRE

    Manjarrez, Javier; Rivas-Gonz?lez, Eric; Venegas-Barrera, Crystian S.; Moyaho, Alejandro

    2015-01-01

    Semi-aquatic snakes integrate visual and chemical stimuli, and prey detection and capture success are therefore linked to the display of visual predatory behavior. The snake Thamnophis melanogaster responds preferentially to individuals of the fish Xenotoca variata with a greater number of bright, colorful spots (lateral speckles) compared with those with a smaller number; however, water turbidity can reduce underwater visibility and effect the vulnerability of fish. In this study, we tested ...

  16. POLYMORPHISM AT THE ADH AND ALPHA-GPDH LOCI IN DROSOPHILA-MELANOGASTER - EFFECTS OF REARING TEMPERATURE ON DEVELOPMENTAL RATE, BODY-WEIGHT, AND SOME BIOCHEMICAL PARAMETERS

    NARCIS (Netherlands)

    OUDMAN, L; VANDELDEN, W; KAMPING, A; BIJLSMA, R

    The role of developmental time in the world-wide cline of Adh and alpha-Gpdh allele frequencies of Drosophila melanogaster, and the relationship with weight and some biochemical characters, were investigated. Experimental strains were constructed with different combinations of Adh and alpha-Gpdh

  17. A high-quality catalog of the Drosophila melanogaster proteome

    DEFF Research Database (Denmark)

    Brunner, Erich; Ahrens, Christian H.; Mohanty, Sonaly

    2007-01-01

    % of the predicted Drosophila melanogaster proteome by detecting 9,124 proteins from 498,000 redundant and 72,281 distinct peptide identifications. This unprecedented high proteome coverage for a complex eukaryote was achieved by combining sample diversity, multidimensional biochemical fractionation and analysis...... matching approximately 50% of D. melanogaster gene models. This library of proteotypic peptides should enable fast, targeted and quantitative proteomic studies to elucidate the systems biology of this model organism....

  18. Integrating experimental and observational personality research--the contributions of Hans Eysenck.

    Science.gov (United States)

    Revelle, William; Oehlberg, Katherine

    2008-12-01

    A fundamental aspect of Hans Eysenck's research was his emphasis upon using all the tools available to the researcher to study personality. This included correlational, experimental, physiological, and genetic approaches. Fifty years after Cronbach's call for the reunification of the two disciplines of psychology (Cronbach, 1957) and 40 years after Eysenck's plea for experimental approaches to personality research (H. J. Eysenck, 1966), what is the status of the unification? Should personality researchers use experimental techniques? Do experimental techniques allow us to tease out causality, and are we communicating the advantages of combining experimental with multivariate correlational techniques? We review the progress made since Cronbach's and Eysenck's original papers and suggest that although it is still uncommon to find experimental studies of personality, psychology would benefit from the joint use of correlational and experimental approaches.

  19. The measurement respiration selected mutants at a fruit fly (Drosophila melanogaster)

    OpenAIRE

    DOULOVÁ, Lucie

    2015-01-01

    The Bachelor´s thesis is concentrated in an experimental way. The main target was to compare the respiration and to find out the differences in the quantity of the produced carbon dioxide at the chosen lines of a fruit fly, Drosophila melanogaster (class insect, order dipterous). Two concrete checking lines CantonS (a wild type) and White eyed (a white-eyed line) were compared with a mutant line AdoR- (a fruit fly with the mutation in adenosine receptor). It was supposed the control lines wil...

  20. Integrated Program of Experimental Diagnostics at the NNSS: An Integrated, Prioritized Work Plan for Diagnostic Development and Maintenance and Supporting Capability

    International Nuclear Information System (INIS)

    2010-01-01

    This Integrated Program of Experimental Diagnostics at the NNSS is an integrated prioritized work plan for the Nevada National Security Site (NNSS), formerly the Nevada Test Site (NTS), program that is independent of individual National Security Enterprise Laboratories (Labs) requests or specific Subprograms being supported. This prioritized work plan is influenced by national priorities presented in the Predictive Capability Framework (PCF) and other strategy documents (Primary and Secondary Assessment Technologies Plans and the Plutonium Experiments Plan). This document satisfies completion criteria for FY 2010 MRT milestone No.3496: Document an integrated, prioritized work plan for diagnostic development, maintenance, and supporting capability. This document is an update of the 3-year NNSS plan written a year ago, September 21, 2009, to define and understand Lab requests for diagnostic implementation. This plan is consistent with Lab interpretations of the PCF, Primary Assessment Technologies, and Plutonium Experiment plans.

  1. Integrated Program of Experimental Diagnostics at the NNSS. An Integrated, Prioritized Work Plan for Diagnostic Development and Maintenance and Supporting Capability

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2010-09-01

    This Integrated Program of Experimental Diagnostics at the NNSS is an integrated prioritized work plan for the Nevada National Security Site (NNSS), formerly the Nevada Test Site (NTS), program that is independent of individual National Security Enterprise Laboratories’ (Labs) requests or specific Subprograms being supported. This prioritized work plan is influenced by national priorities presented in the Predictive Capability Framework (PCF) and other strategy documents (Primary and Secondary Assessment Technologies Plans and the Plutonium Experiments Plan). This document satisfies completion criteria for FY 2010 MRT milestone #3496: Document an integrated, prioritized work plan for diagnostic development, maintenance, and supporting capability. This document is an update of the 3-year NNSS plan written a year ago, September 21, 2009, to define and understand Lab requests for diagnostic implementation. This plan is consistent with Lab interpretations of the PCF, Primary Assessment Technologies, and Plutonium Experiment plans.

  2. Maintenance of a Drosophila melanogaster Population Cage.

    Science.gov (United States)

    Caravaca, Juan Manuel; Lei, Elissa P

    2016-03-15

    Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life cycle of Drosophila enables collection of large quantities of material from embryos, larvae, pupae and adult flies, in a synchronized way, at a low economic cost. A major strategy for propagating large numbers of flies is the use of a fly population cage. This useful and common tool in the Drososphila community is an efficient way to regularly produce milligrams to tens of grams of embryos, depending on uniformity of developmental stage desired. While a population cage can be time consuming to set up, maintaining a cage over months takes much less time and enables rapid collection of biological material in a short period. This paper describes a detailed and flexible protocol for the maintenance of a Drosophila melanogaster population cage, starting with 1.5 g of harvested material from the previous cycle.

  3. MicroRNA function in Drosophila melanogaster.

    Science.gov (United States)

    Carthew, Richard W; Agbu, Pamela; Giri, Ritika

    2017-05-01

    Over the last decade, microRNAs have emerged as critical regulators in the expression and function of animal genomes. This review article discusses the relationship between microRNA-mediated regulation and the biology of the fruit fly Drosophila melanogaster. We focus on the roles that microRNAs play in tissue growth, germ cell development, hormone action, and the development and activity of the central nervous system. We also discuss the ways in which microRNAs affect robustness. Many gene regulatory networks are robust; they are relatively insensitive to the precise values of reaction constants and concentrations of molecules acting within the networks. MicroRNAs involved in robustness appear to be nonessential under uniform conditions used in conventional laboratory experiments. However, the robust functions of microRNAs can be revealed when environmental or genetic variation otherwise has an impact on developmental outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Resources for Functional Genomics Studies in Drosophila melanogaster

    Science.gov (United States)

    Mohr, Stephanie E.; Hu, Yanhui; Kim, Kevin; Housden, Benjamin E.; Perrimon, Norbert

    2014-01-01

    Drosophila melanogaster has become a system of choice for functional genomic studies. Many resources, including online databases and software tools, are now available to support design or identification of relevant fly stocks and reagents or analysis and mining of existing functional genomic, transcriptomic, proteomic, etc. datasets. These include large community collections of fly stocks and plasmid clones, “meta” information sites like FlyBase and FlyMine, and an increasing number of more specialized reagents, databases, and online tools. Here, we introduce key resources useful to plan large-scale functional genomics studies in Drosophila and to analyze, integrate, and mine the results of those studies in ways that facilitate identification of highest-confidence results and generation of new hypotheses. We also discuss ways in which existing resources can be used and might be improved and suggest a few areas of future development that would further support large- and small-scale studies in Drosophila and facilitate use of Drosophila information by the research community more generally. PMID:24653003

  5. Genome-wide analysis of promoter architecture in Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Hoskins, Roger A.; Landolin, Jane M.; Brown, James B.; Sandler, Jeremy E.; Takahashi, Hazuki; Lassmann, Timo; Yu, Charles; Booth, Benjamin W.; Zhang, Dayu; Wan, Kenneth H.; Yang, Li; Boley, Nathan; Andrews, Justen; Kaufman, Thomas C.; Graveley, Brenton R.; Bickel, Peter J.; Carninci, Piero; Carlson, Joseph W.; Celniker, Susan E.

    2010-10-20

    Core promoters are critical regions for gene regulation in higher eukaryotes. However, the boundaries of promoter regions, the relative rates of initiation at the transcription start sites (TSSs) distributed within them, and the functional significance of promoter architecture remain poorly understood. We produced a high-resolution map of promoters active in the Drosophila melanogaster embryo by integrating data from three independent and complementary methods: 21 million cap analysis of gene expression (CAGE) tags, 1.2 million RNA ligase mediated rapid amplification of cDNA ends (RLMRACE) reads, and 50,000 cap-trapped expressed sequence tags (ESTs). We defined 12,454 promoters of 8037 genes. Our analysis indicates that, due to non-promoter-associated RNA background signal, previous studies have likely overestimated the number of promoter-associated CAGE clusters by fivefold. We show that TSS distributions form a complex continuum of shapes, and that promoters active in the embryo and adult have highly similar shapes in 95% of cases. This suggests that these distributions are generally determined by static elements such as local DNA sequence and are not modulated by dynamic signals such as histone modifications. Transcription factor binding motifs are differentially enriched as a function of promoter shape, and peaked promoter shape is correlated with both temporal and spatial regulation of gene expression. Our results contribute to the emerging view that core promoters are functionally diverse and control patterning of gene expression in Drosophila and mammals.

  6. Organically grown food provides health benefits to Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Ria Chhabra

    Full Text Available The "organic food" market is the fastest growing food sector, yet it is unclear whether organically raised food is nutritionally superior to conventionally grown food and whether consuming organic food bestows health benefits. In order to evaluate potential health benefits of organic foods, we used the well-characterized fruit fly Drosophila melanogaster as a model system. Fruit flies were raised on a diets consisting of extracts of either conventionally or organically raised produce (bananas, potatoes, raisins, soy beans. Flies were then subjected to a variety of tests designed to assess overall fly health. Flies raised on diets made from organically grown produce had greater fertility and longevity. On certain food sources, greater activity and greater stress resistance was additionally observed, suggesting that organic food bestows positive effects on fly health. Our data show that Drosophila can be used as a convenient model system to experimentally test potential health effects of dietary components. Using this system, we provide evidence that organically raised food may provide animals with tangible benefits to overall health.

  7. Organically grown food provides health benefits to Drosophila melanogaster.

    Science.gov (United States)

    Chhabra, Ria; Kolli, Santharam; Bauer, Johannes H

    2013-01-01

    The "organic food" market is the fastest growing food sector, yet it is unclear whether organically raised food is nutritionally superior to conventionally grown food and whether consuming organic food bestows health benefits. In order to evaluate potential health benefits of organic foods, we used the well-characterized fruit fly Drosophila melanogaster as a model system. Fruit flies were raised on a diets consisting of extracts of either conventionally or organically raised produce (bananas, potatoes, raisins, soy beans). Flies were then subjected to a variety of tests designed to assess overall fly health. Flies raised on diets made from organically grown produce had greater fertility and longevity. On certain food sources, greater activity and greater stress resistance was additionally observed, suggesting that organic food bestows positive effects on fly health. Our data show that Drosophila can be used as a convenient model system to experimentally test potential health effects of dietary components. Using this system, we provide evidence that organically raised food may provide animals with tangible benefits to overall health.

  8. Experimental investigations on reactor pressure vessel penetration integrity under external vessel cooling in the Korean next generation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyoung Ho; Cho, Young Ro; Koo, Kil Mo; Park, Rae Joon; Kim, Sang Baik; Lee, Ki Young; Park, Jong Kyun

    2001-06-01

    An experimental study on the penetration integrity of the reactor vessel has been performed under external vessel cooling in the Korean Next Generation Reactor(KNGR). The experiments were carried out using only one penetration and 40 kg of Al2O3 melt as a corium simulant. The test section is a cylindrical shape with flat plate bottom. The thickness and material properties of the lower head vessel and the penetration including welding material are a coincident with those of the KNGR. In this study, the effect of coolant in the annulus between the ICI nozzle and the thimble tube on the integrity of the penetration has been estimated combined with the analytical study using the Modified Bulk Freezing(MBF) model. And also the experiments were performed for evaluating the effect of the external vessel cooling on the integrity of the penetration and the lower head vessel. The experimental results have shown that penetration is more damaged in the case of no external vessel cooling compared with the case of external vessel cooling. It could be inferred from the temperature histories of the lower head vessel and water in the tests with external vessel cooling that the outer surface of the vessel was effectively cooled down through the nucleate boiling in spite of the local heat up characterized by the film boiling beyond the Leidenfrost temperature. Synthesized the experimental results on the post-examination of the cross-sectional view and the thermal behavior of the test section, it is preliminarily concluded that the external vessel cooling is very effective measure for the improvement of the penetration integrity. Also it is confirmed from the experimental and calculated results that the coolant in the annulus reduces the melt penetration distance through the annulus and enhance the integrity of the reactor vessel penetration in the end.

  9. A framework for accelerated phototrophic bioprocess development: integration of parallelized microscale cultivation, laboratory automation and Kriging-assisted experimental design.

    Science.gov (United States)

    Morschett, Holger; Freier, Lars; Rohde, Jannis; Wiechert, Wolfgang; von Lieres, Eric; Oldiges, Marco

    2017-01-01

    Even though microalgae-derived biodiesel has regained interest within the last decade, industrial production is still challenging for economic reasons. Besides reactor design, as well as value chain and strain engineering, laborious and slow early-stage parameter optimization represents a major drawback. The present study introduces a framework for the accelerated development of phototrophic bioprocesses. A state-of-the-art micro-photobioreactor supported by a liquid-handling robot for automated medium preparation and product quantification was used. To take full advantage of the technology's experimental capacity, Kriging-assisted experimental design was integrated to enable highly efficient execution of screening applications. The resulting platform was used for medium optimization of a lipid production process using Chlorella vulgaris toward maximum volumetric productivity. Within only four experimental rounds, lipid production was increased approximately threefold to 212 ± 11 mg L -1  d -1 . Besides nitrogen availability as a key parameter, magnesium, calcium and various trace elements were shown to be of crucial importance. Here, synergistic multi-parameter interactions as revealed by the experimental design introduced significant further optimization potential. The integration of parallelized microscale cultivation, laboratory automation and Kriging-assisted experimental design proved to be a fruitful tool for the accelerated development of phototrophic bioprocesses. By means of the proposed technology, the targeted optimization task was conducted in a very timely and material-efficient manner.

  10. Drosophila melanogaster as a Versatile Model Organism in Food and Nutrition Research.

    Science.gov (United States)

    Staats, Stefanie; Lüersen, Kai; Wagner, Anika E; Rimbach, Gerald

    2018-04-18

    Drosophila melanogaster has been widely used in the biological sciences as a model organism. Drosophila has a relatively short life span of 60-80 days, which makes it attractive for life span studies. Moreover, approximately 60% of the fruit fly genes are orthologs to mammals. Thus, metabolic and signal transduction pathways are highly conserved. Maintenance and reproduction of Drosophila do not require sophisticated equipment and are rather cheap. Furthermore, there are fewer ethical issues involved in experimental Drosophila research compared with studies in laboratory rodents, such as rats and mice. Drosophila is increasingly recognized as a model organism in food and nutrition research. Drosophila is often fed complex solid diets based on yeast, corn, and agar. There are also so-called holidic diets available that are defined in terms of their amino acid, fatty acid, carbohydrate, vitamin, mineral, and trace element compositions. Feed intake, body composition, locomotor activity, intestinal barrier function, microbiota, cognition, fertility, aging, and life span can be systematically determined in Drosophila in response to dietary factors. Furthermore, diet-induced pathophysiological mechanisms including inflammation and stress responses may be evaluated in the fly under defined experimental conditions. Here, we critically evaluate Drosophila melanogaster as a versatile model organism in experimental food and nutrition research, review the corresponding data in the literature, and make suggestions for future directions of research.

  11. Neutralization of Bacterial Aerosols by Aerodynamic Shocks in a Novel Impactor System: An Integrated Computational and Experimental Study

    Science.gov (United States)

    2010-10-15

    Aerodynamic Shocks in a Novel Impactor: An Integrated Computational and Experimental Study. Chemical and Biologi - cal Defense Science and Technology...1990. [15] C. Di Giorgio, A. Krempff, H. Guiraud, P. Binder, C. Tiret, and G. Dume- nil. Atmospheric pollution by airborne microorganisms in the...suddenly exposed to a high-speed airstream. International Journal of Multiphase Flow, 25(6-7):1263-1303, 1999. [29] B. J. Jurcik, J. R. Brock , and I

  12. Volumetric integration model of the Stiles-Crawford effect of the first kind and its experimental verification.

    Science.gov (United States)

    Vohnsen, Brian; Carmichael, Alessandra; Sharmin, Najnin; Qaysi, Salihah; Valente, Denise

    2017-10-01

    The integrated Stiles-Crawford function is commonly used as apodization model for vision through the natural eye pupil. However, this method does not account for possible effects related to the retinal thickness, the large length-to-diameter aspect ratio of the photoreceptors, or the use of nonMaxwellian illumination. Here, we introduce a geometrical optics model to calculate the fraction of overlap between light at the retina and the photoreceptor outer segments where absorption triggers vision. The model, which does not account for photoreceptor waveguiding, is discussed for both Maxwellian and nonMaxwellian illumination. The integrated Stiles-Crawford effect is analyzed experimentally with a uniaxial pupil-size flicker methodology and we find that the psychophysical measurements match better to the geometrical optics predictions than direct integration of a Stiles-Crawford function.

  13. Design of high productivity antibody capture by protein A chromatography using an integrated experimental and modeling approach.

    Science.gov (United States)

    Ng, Candy K S; Osuna-Sanchez, Hector; Valéry, Eric; Sørensen, Eva; Bracewell, Daniel G

    2012-06-15

    An integrated experimental and modeling approach for the design of high productivity protein A chromatography is presented to maximize productivity in bioproduct manufacture. The approach consists of four steps: (1) small-scale experimentation, (2) model parameter estimation, (3) productivity optimization and (4) model validation with process verification. The integrated use of process experimentation and modeling enables fewer experiments to be performed, and thus minimizes the time and materials required in order to gain process understanding, which is of key importance during process development. The application of the approach is demonstrated for the capture of antibody by a novel silica-based high performance protein A adsorbent named AbSolute. In the example, a series of pulse injections and breakthrough experiments were performed to develop a lumped parameter model, which was then used to find the best design that optimizes the productivity of a batch protein A chromatographic process for human IgG capture. An optimum productivity of 2.9 kg L⁻¹ day⁻¹ for a column of 5mm diameter and 8.5 cm length was predicted, and subsequently verified experimentally, completing the whole process design approach in only 75 person-hours (or approximately 2 weeks). Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Integrated detoxification methodology of hazardous phenolic wastewaters in environmentally based trickle-bed reactors: Experimental investigation and CFD simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Rodrigo J.G., E-mail: rodrigo@eq.uc.pt [Centro de Investigacao em Engenharia dos Processos Quimicos e Produtos da Floresta (CIEPQPF), GERSE - Group on Environmental, Reaction and Separation Engineering, Department of Chemical Engineering, University of Coimbra, Rua Silvio Lima, Polo II - Pinhal de Marrocos, 3030-790 Coimbra (Portugal); Almeida, Teresa S.A.; Quinta-Ferreira, Rosa M. [Centro de Investigacao em Engenharia dos Processos Quimicos e Produtos da Floresta (CIEPQPF), GERSE - Group on Environmental, Reaction and Separation Engineering, Department of Chemical Engineering, University of Coimbra, Rua Silvio Lima, Polo II - Pinhal de Marrocos, 3030-790 Coimbra (Portugal)

    2011-05-15

    Centralized environmental regulations require the use of efficient detoxification technologies for the secure disposal of hazardous wastewaters. Guided by federal directives, existing plants need reengineering activities and careful analysis to improve their overall effectiveness and to become environmentally friendly. Here, we illustrate the application of an integrated methodology which encompasses the experimental investigation of catalytic wet air oxidation and CFD simulation of trickle-bed reactors. As long as trickle-bed reactors are determined by the flow environment coupled with chemical kinetics, first, on the optimization of prominent numerical solution parameters, the CFD model was validated with experimental data taken from a trickle bed pilot plant specifically designed for the catalytic wet oxidation of phenolic wastewaters. Second, several experimental and computational runs were carried out under unsteady-state operation to evaluate the dynamic performance addressing the TOC concentration and temperature profiles. CFD computations of total organic carbon conversion were found to agree better with experimental data at lower temperatures. Finally, the comparison of test data with simulation results demonstrated that this integrated framework was able to describe the mineralization of organic matter in trickle beds and the validated consequence model can be exploited to promote cleaner remediation technologies of contaminated waters.

  15. Integrated detoxification methodology of hazardous phenolic wastewaters in environmentally based trickle-bed reactors: Experimental investigation and CFD simulation

    International Nuclear Information System (INIS)

    Lopes, Rodrigo J.G.; Almeida, Teresa S.A.; Quinta-Ferreira, Rosa M.

    2011-01-01

    Centralized environmental regulations require the use of efficient detoxification technologies for the secure disposal of hazardous wastewaters. Guided by federal directives, existing plants need reengineering activities and careful analysis to improve their overall effectiveness and to become environmentally friendly. Here, we illustrate the application of an integrated methodology which encompasses the experimental investigation of catalytic wet air oxidation and CFD simulation of trickle-bed reactors. As long as trickle-bed reactors are determined by the flow environment coupled with chemical kinetics, first, on the optimization of prominent numerical solution parameters, the CFD model was validated with experimental data taken from a trickle bed pilot plant specifically designed for the catalytic wet oxidation of phenolic wastewaters. Second, several experimental and computational runs were carried out under unsteady-state operation to evaluate the dynamic performance addressing the TOC concentration and temperature profiles. CFD computations of total organic carbon conversion were found to agree better with experimental data at lower temperatures. Finally, the comparison of test data with simulation results demonstrated that this integrated framework was able to describe the mineralization of organic matter in trickle beds and the validated consequence model can be exploited to promote cleaner remediation technologies of contaminated waters.

  16. Experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solar absorber

    Directory of Open Access Journals (Sweden)

    Hejcik J.

    2013-04-01

    Full Text Available The paper deals with experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solarabsorber. The main purpose of heat storage in solar thermal systems is to store heat when the supply of solar heat exceeds demand and release it when otherwise. A number of heat storage materials can be used for this purpose; the phase change materials among them. Short-term latent heat thermal storage integrated with the solar absorber can stabilize the air temperature at the outlet of the collector on cloudy days when solar radiation intensity incident on a solar collector fluctuates significantly. Two experimental front-and-back pass solar air collectors of the same dimensions have been built for the experimental investigations. One collector had a “conventional” solar absorber made of a metal sheet while the solar absorber of the other collector consisted of containers filled with organic phase change material. The experimental collectors were positioned side by side during the investigations to ensure the same operating conditions (incident solar radiation, outdoor temperature.

  17. Integrated Reporting and Assurance of Sustainability Information: An Experimental Study on Professional Investors’ Information Processing

    NARCIS (Netherlands)

    Reimsbach, D.; Hahn, R.; Gürtürk, A.

    2018-01-01

    Sustainability-related non-financial information is increasingly deemed value relevant. Against this background, two recent trends in non-financial reporting are frequently discussed: integrated reporting and assurance of sustainability information. Using an established framework of information

  18. Experimental Demonstration of 7 Tb/s Switching Using Novel Silicon Photonic Integrated Circuit

    DEFF Research Database (Denmark)

    Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld

    2016-01-01

    We demonstrate BER performance <10^-9 for a 1 Tb/s/core transmission over 7-core fiber and SDM switching using a novel silicon photonic integrated circuit composed of a 7x7 fiber switch and low loss SDM couplers.......We demonstrate BER performance Tb/s/core transmission over 7-core fiber and SDM switching using a novel silicon photonic integrated circuit composed of a 7x7 fiber switch and low loss SDM couplers....

  19. Fly-DPI: database of protein interactomes for D. melanogaster in the approach of systems biology

    Directory of Open Access Journals (Sweden)

    Lin Chieh-Hua

    2006-12-01

    Full Text Available Abstract Background Proteins control and mediate many biological activities of cells by interacting with other protein partners. This work presents a statistical model to predict protein interaction networks of Drosophila melanogaster based on insight into domain interactions. Results Three high-throughput yeast two-hybrid experiments and the collection in FlyBase were used as our starting datasets. The co-occurrences of domains in these interactive events are converted into a probability score of domain-domain interaction. These scores are used to infer putative interaction among all available open reading frames (ORFs of fruit fly. Additionally, the likelihood function is used to estimate all potential protein-protein interactions. All parameters are successfully iterated and MLE is obtained for each pair of domains. Additionally, the maximized likelihood reaches its converged criteria and maintains the probability stable. The hybrid model achieves a high specificity with a loss of sensitivity, suggesting that the model may possess major features of protein-protein interactions. Several putative interactions predicted by the proposed hybrid model are supported by literatures, while experimental data with a low probability score indicate an uncertain reliability and require further proof of interaction. Fly-DPI is the online database used to present this work. It is an integrated proteomics tool with comprehensive protein annotation information from major databases as well as an effective means of predicting protein-protein interactions. As a novel search strategy, the ping-pong search is a naïve path map between two chosen proteins based on pre-computed shortest paths. Adopting effective filtering strategies will facilitate researchers in depicting the bird's eye view of the network of interest. Fly-DPI can be accessed at http://flydpi.nhri.org.tw. Conclusion This work provides two reference systems, statistical and biological, to evaluate

  20. Clinical trial of an experimental cleaning solution: antibiofilm effect and integrity of a silicone-based denture liner.

    Science.gov (United States)

    Segundo, Antonio de Luna Malheiros; Pisani, Marina Xavier; Nascimento, Céssio do; Souza, Raphael Freitas; Paranhos, Helena de Freitas Oliveira; Silva-Lovato, Cléudia Helena

    2014-09-01

    This study evaluated the antibiofilm effect of an experimental solution of 2% Ricinus communis (R. communis) on a silicone-based denture liner by means of a randomized clinical trial, as well as the integrity of such liner following a cleansing regimen with such solution. About 30 complete denture wearers had their lower dentures relined with a silicone-based denture liner and randomly allocated to cleanse their dentures by means of: (A) a specific toothbrush for complete dentures and dentifrice; (B) soaking in an experimental 2% R. communis solution; and (C) association of A and B. Considered outcomes were biofilm coverage area (%), microbial counts by means of the deoxy-ribonucleic acid (DNA) checkerboard hybridization technique and physical integrity of the soft liner, assessed during a time interval of 60 days. Mean group values were compared by analysis of variance (ANOVA) and Tukey tests or generalized linear method (α = 0.05). The mechanical method presented the lowest biofilm percentage (1.45 ± 1.03) if compared to the chemical method (2.96 ± 1.98) and the associated one (2.71 ± 1.76). After 60 days (3.37 ± 2.04), biofilm accumulation was higher than at 15 days (1.28 ± 0.77) and 30 days (2.46 ± 1.54). The denture liner was less deteriorated and kept its physical integrity when the mechanical method was applied. The chemical method presented higher effectiveness against microorganisms, including some Candida species. The 2% R. communis solution presented stronger antimicrobial capacity than brushing on a silicone-based denture liner after immersion. However, it was not superior to the mechanical method in preserving the physical integrity of the material and in biofilm removal. Soft denture liners hygiene is a very important issue and not conclusive in the literature. The experimental solution of 2% R. communis evaluated presented promising antimicrobial potential and should be more explored to be recommended as cleanser.

  1. Experimental simulation of the Paks-2 cleaning tank incident through separate effect and integral tests

    Energy Technology Data Exchange (ETDEWEB)

    Hozer, Z., E-mail: hozer@aeki.kfki.h [Hungarian Academy of Sciences KFKI Atomic Energy Research Institute, H-1525 Budapest, P.O. Box 49 (Hungary); Horvath, M.; Kunstar, M.; Matus, L.; Nagy, I.; Novotny, T.; Perez-Fero, E.; Pinter-Csordas, A.; Ver, N.; Vimi, A.; Windberg, P. [Hungarian Academy of Sciences KFKI Atomic Energy Research Institute, H-1525 Budapest, P.O. Box 49 (Hungary)

    2011-03-15

    Following the ex-core cleaning of VVER type fuel assemblies, a severe fuel damage took place at the Paks NPP. Assemblies with high decay heat remained without cooling for 7 h. As a common result of high temperature oxidation and final water quenching the assemblies were broken and the fuel rods fragmented. In order to improve the understanding of the phenomena that took place during the Paks-2 incident, several series of separate effect and integral tests have been carried out. The separate effect tests investigated the phenomena related to the upward shift of fuel assemblies, to the role of the spacer grid and the spring in the loss of cladding integrity, and to the importance of high hydrogen content in the vessel's atmosphere on the embrittlement of zirconium. Integral tests were carried out in the CODEX facility to simulate the whole scenario of the incident using electrically heated fuel rods.

  2. [Evaluation of the dustiness of a bakery: an integrated system with an experimental electronic device].

    Science.gov (United States)

    Dario, R; Uva, J; Trani, G; Falco, S; Ancona, V; Petrera, L

    2012-01-01

    In this paper we describe a novel approach to environmental control in a bakery, based on an integration system of qualitative and quantitative information. The aim is to identify prevention policy for allergic disease. Specifically, the dust concentration evaluated continuously by deposimeters and the realization of chemical-analytical investigations on flours samples, used in the production cycle, have given qualitative evaluation on powders dispersion; the integration of an electronic device, characterized by measurement reliability and low cost implementation, supported the development and evaluation of an environmental monitoring system in a bakery. The environmental control system could be used in other work environments where occupational asthma occurred.

  3. Gut-associated microbes of Drosophila melanogaster

    Science.gov (United States)

    Broderick, Nichole; Lemaitre, Bruno

    2012-01-01

    There is growing interest in using Drosophila melanogaster to elucidate mechanisms that underlie the complex relationships between a host and its microbiota. In addition to the many genetic resources and tools Drosophila provides, its associated microbiota is relatively simple (1–30 taxa), in contrast to the complex diversity associated with vertebrates (> 500 taxa). These attributes highlight the potential of this system to dissect the complex cellular and molecular interactions that occur between a host and its microbiota. In this review, we summarize what is known regarding the composition of gut-associated microbes of Drosophila and their impact on host physiology. We also discuss these interactions in the context of their natural history and ecology and describe some recent insights into mechanisms by which Drosophila and its gut microbiota interact. “Workers with Drosophila have been considered fortunate in that they deal with the first multicellular invertebrate to be cultured monoxenically (Delcourt and Guyenot, 1910); the first to be handled axenically on a semisynthetic diet (Guyenot, 1917); and the first to be grown on a defined diet (Schultz et al., 1946). This list of advantages is somewhat embarrassing, since it implies an interest in nutrition that, in reality, was only secondary. The very first studies were concerned with the reduction of variability in genetic experiments (Delcourt and Guyenot, 1910) and standardization of the nutritional environment.” -James Sang, 1959 Ann NY Acad 1 PMID:22572876

  4. The sexually antagonistic genes of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Paolo Innocenti

    2010-03-01

    Full Text Available When selective pressures differ between males and females, the genes experiencing these conflicting evolutionary forces are said to be sexually antagonistic. Although the phenotypic effect of these genes has been documented in both wild and laboratory populations, their identity, number, and location remains unknown. Here, by combining data on sex-specific fitness and genome-wide transcript abundance in a quantitative genetic framework, we identified a group of candidate genes experiencing sexually antagonistic selection in the adult, which correspond to 8% of Drosophila melanogaster genes. As predicted, the X chromosome is enriched for these genes, but surprisingly they represent only a small proportion of the total number of sex-biased transcripts, indicating that the latter is a poor predictor of sexual antagonism. Furthermore, the majority of genes whose expression profiles showed a significant relationship with either male or female adult fitness are also sexually antagonistic. These results provide a first insight into the genetic basis of intralocus sexual conflict and indicate that genetic variation for fitness is dominated and maintained by sexual antagonism, potentially neutralizing any indirect genetic benefits of sexual selection.

  5. Characterization of Autophagic Responses in Drosophila melanogaster.

    Science.gov (United States)

    Xu, T; Kumar, S; Denton, D

    2017-01-01

    Drosophila is an excellent model system for studying autophagy during animal development due to the availability of genetic reagents and opportunity for in vivo cell biological analysis. The regulation and mechanism of autophagy are highly evolutionarily conserved and the role of autophagy has been characterized during various stages of Drosophila development as well as following starvation. Studies in Drosophila have revealed novel insights into the role of distinct components of the autophagy machinery. This chapter describes protocols for examining autophagy during Drosophila development. A crucial step in the induction of autophagy is the incorporation of Atg8a into the autophagosome. This can be measured as autophagic puncta using live fluorescent imaging, immunostaining, or immunoblot analysis of LC3/Atg8a processing. The level of autophagy can also be examined using other specific components of the autophagy pathway as markers detected by immunofluorescent imaging. Based on the distinct morphology of autophagy, it can also be examined by transmission electron microscopy. In addition, one of the advantages of using Drosophila as a model is the ability to undertake genetic analysis of individual components of the autophagy machinery. Current approaches that can be used to monitor autophagy, including the overall flux and individual steps in Drosophila melanogaster, will be discussed. © 2017 Elsevier Inc. All rights reserved.

  6. The Ran pathway in Drosophila melanogaster mitosis

    Directory of Open Access Journals (Sweden)

    James G Wakefield

    2015-11-01

    Full Text Available Over the last two decades, the small GTPase Ran has emerged as a central regulator of both mitosis and meiosis, particularly in the generation, maintenance and regulation of the microtubule (MT-based bipolar spindle. Ran-regulated pathways in mitosis bear many similarities to the well-characterized functions of Ran in nuclear transport and, as with transport, the majority of these mitotic effects are mediated through affecting the physical interaction between karyopherins and Spindle Assembly Factors (SAFs - a loose term describing proteins or protein complexes involved in spindle assembly through promoting nucleation, stabilization, and/or depolymerization of MTs, through anchoring MTs to specific structures such as centrosomes, chromatin or kinetochores, or through sliding MTs along each other to generate the force required to achieve bipolarity. As such, the Ran-mediated pathway represents a crucial functional module within the wider spindle assembly landscape. Research into mitosis using the model organism Drosophila melanogaster has contributed substantially to our understanding of centrosome and spindle function. However, in comparison to mammalian systems, very little is known about the contribution of Ran-mediated pathways in Drosophila mitosis. This article sets out to summarize our understanding of the roles of the Ran pathway components in Drosophila mitosis, focusing on the syncytial blastoderm embryo, arguing that, far from being superfluous, it can provide important insights into the conserved functions on Ran during spindle formation.

  7. Experimental Validation of Energy Resources Integration in Microgrids via Distributed Predictive Control

    DEFF Research Database (Denmark)

    Mantovani, Giancarlo; Costanzo, Giuseppe Tommaso; Marinelli, Mattia

    2014-01-01

    This paper presents an innovative control scheme for the management of energy consumption in commercial build- ings with local energy production, such as photovoltaic panels or wind turbine and an energy storage unit. The presented scheme is based on distributed model predictive controllers, which...... manage the storage system and the building space heating and cooling. The proposed approach is implemented and tested in SYSLAB, the experimental facility for distributed energy systems at the Techni- cal University of Denmark, Risø Campus. The experimental setup consists of wind and solar renewable...

  8. The effects of integrative reminiscence on meaning in life: results of a quasi-experimental study

    NARCIS (Netherlands)

    Bohlmeijer, Ernst Thomas; Westerhof, Gerben Johan; Emmerik-de Jong, M.

    2008-01-01

    Objectives: Finding meaning in life is often cited as an important outcome of reminiscence, but this theoretical claim has not been empirically tested until now. A new intervention combining integrative reminiscence and elements of narrative therapy was developed and the effects on meaning in life

  9. Procedure and information displays in advanced nuclear control rooms: experimental evaluation of an integrated design.

    Science.gov (United States)

    Chen, Yue; Gao, Qin; Song, Fei; Li, Zhizhong; Wang, Yufan

    2017-08-01

    In the main control rooms of nuclear power plants, operators frequently have to switch between procedure displays and system information displays. In this study, we proposed an operation-unit-based integrated design, which combines the two displays to facilitate the synthesis of information. We grouped actions that complete a single goal into operation units and showed these operation units on the displays of system states. In addition, we used different levels of visual salience to highlight the current unit and provided a list of execution history records. A laboratory experiment, with 42 students performing a simulated procedure to deal with unexpected high pressuriser level, was conducted to compare this design against an action-based integrated design and the existing separated-displays design. The results indicate that our operation-unit-based integrated design yields the best performance in terms of time and completion rate and helped more participants to detect unexpected system failures. Practitioner Summary: In current nuclear control rooms, operators frequently have to switch between procedure and system information displays. We developed an integrated design that incorporates procedure information into system displays. A laboratory study showed that the proposed design significantly improved participants' performance and increased the probability of detecting unexpected system failures.

  10. Detection of tympanic membrane movement using film patch with integrated strain gauge, assessed by optical coherence tomography: experimental study.

    Science.gov (United States)

    Just, T; Zehlicke, T; Specht, O; Sass, W; Punke, C; Schmidt, W; Lankenau, E; Behrend, D; Pau, H W

    2011-05-01

    We report an ex vivo and in vivo experimental study of a device designed to measure tympanic membrane movement under normal and pathological conditions, assessed using optical coherence tomography. We designed two types of flexible, round film patch with integrated strain gauge, to be attached to the tympanic membrane in order to measure tympanic membrane movement. Tympanic membrane attachment was assessed using optical coherence tomography. The devices were tested experimentally using an ex vivo model with varying middle-ear pressure. Optical coherence tomography reliably assessed attachment of the film patch to the tympanic membrane, before and after middle-ear pressure changes. Strain gauge voltage changes were directly proportional to middle-ear pressure recordings, for low pressure changes. Tympanic membrane perforations smaller than 2 mm could be sealed off with the film patch. Attachment of the film patch with integrated strain gauge to the tympanic membrane was not ideal. Nevertheless, the strain gauge was able to precisely detect small pressure changes within the middle ear, in this experimental model.

  11. Integrated Planar Solid Oxide Fuel Cell: Steady-State Model of a Bundle and Validation through Single Tube Experimental Data

    Directory of Open Access Journals (Sweden)

    Paola Costamagna

    2015-11-01

    Full Text Available This work focuses on a steady-state model developed for an integrated planar solid oxide fuel cell (IP-SOFC bundle. In this geometry, several single IP-SOFCs are deposited on a tube and electrically connected in series through interconnections. Then, several tubes are coupled to one another to form a full-sized bundle. A previously-developed and validated electrochemical model is the basis for the development of the tube model, taking into account in detail the presence of active cells, interconnections and dead areas. Mass and energy balance equations are written for the IP-SOFC tube, in the classical form adopted for chemical reactors. Based on the single tube model, a bundle model is developed. Model validation is presented based on single tube current-voltage (I-V experimental data obtained in a wide range of experimental conditions, i.e., at different temperatures and for different H2/CO/CO2/CH4/H2O/N2 mixtures as the fuel feedstock. The error of the simulation results versus I-V experimental data is less than 1% in most cases, and it grows to a value of 8% only in one case, which is discussed in detail. Finally, we report model predictions of the current density distribution and temperature distribution in a bundle, the latter being a key aspect in view of the mechanical integrity of the IP-SOFC structure.

  12. Transplant rejection and tolerance – advancing the field through integration of computational and experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Raimondi, Giorgio [Johns Hopkins Univ., Baltimore, MD (United States); Wood, Kathryn [Univ. of Oxford (United Kingdom); Perelson, Alan S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Arciero, Julia C [Indiana Univ.-Purdue Univ., Indianapolis, IN (United States)

    2017-05-31

    This Research Topic provides a venue for stimulating these interdisciplinary conversations in the context of transplantation. The articles collected under this Research Topic introduce new theoretical and experimental studies that describe novel techniques and methods for understanding the interactions between the immune response and transplants and for establishing more effective strategies of diagnosis and intervention that will promote transplant tolerance.

  13. Consequences of fragmentation for the ability to adapt to novel environments in experimental Drosophila metapopulations

    NARCIS (Netherlands)

    Bakker, Joke; van Rijswijk, Maria; Weissing, F. J.; Bijlsma, R.

    We used experimental populations of Drosophila melanogaster, which had either been subdivided (metapopulations) or kept undivided for 40 generations, to study the consequences of population subdivision for the tolerance and adaptive response after six generations of exposure to novel environmental

  14. Courtship initiation is stimulated by acoustic signals in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Aki Ejima

    2008-09-01

    Full Text Available Finding a mating partner is a critical task for many organisms. It is in the interest of males to employ multiple sensory modalities to search for females. In Drosophila melanogaster, vision is thought to be the most important courtship stimulating cue at long distance, while chemosensory cues are used at relatively short distance. In this report, we show that when visual cues are not available, sounds produced by the female allow the male to detect her presence in a large arena. When the target female was artificially immobilized, the male spent a prolonged time searching before starting courtship. This delay in courtship initiation was completely rescued by playing either white noise or recorded fly movement sounds to the male, indicating that the acoustic and/or seismic stimulus produced by movement stimulates courtship initiation, most likely by increasing the general arousal state of the male. Mutant males expressing tetanus toxin (TNT under the control of Gr68a-GAL4 had a defect in finding active females and a delay in courtship initiation in a large arena, but not in a small arena. Gr68a-GAL4 was found to be expressed pleiotropically not only in putative gustatory pheromone receptor neurons but also in mechanosensory neurons, suggesting that Gr68a-positive mechanosensory neurons, not gustatory neurons, provide motion detection necessary for courtship initiation. TNT/Gr68a males were capable of discriminating the copulation status and age of target females in courtship conditioning, indicating that female discrimination and formation of olfactory courtship memory are independent of the Gr68a-expressing neurons that subserve gustation and mechanosensation. This study suggests for the first time that mechanical signals generated by a female fly have a prominent effect on males' courtship in the dark and leads the way to studying how multimodal sensory information and arousal are integrated in behavioral decision making.

  15. Non Linearity in Dominant Lethals Induced with Irradiation in Drosophila Melanogaster Non Linearity in Dominant Lethals Induced with Irradiation in Drosophila Melanogaster

    Directory of Open Access Journals (Sweden)

    Hoenigsberg H. F.

    1964-12-01

    Full Text Available El nuevo diseño experimental aquí presentado hizo posible el estudio de cada uno de los grupos de células germinales en la espermatogénesis de Drosophila melanogaster Oregon R. Los recuentos de los letales dominantes inducidos con Irradiación X permitieron el análisis detallado de la hipótesis sobre dosis-frecuencia para anormalidades cromosómicas. The design in the experiments permitted the study of daily batches of sperm cells. Counts of dominant lethals induced with X-irradiation consented a more detail analysis of the dose-frequency hypothesis for chromosome abnormalities.

  16. A Multi-Modal Control Using a Hybrid Pole-Placement-Integral Resonant Controller (PPIR) with Experimental Investigations

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Basu, Biswajit

    2011-01-01

    vibrations e.g. caused by broad-band turbulent wind excitations. Hence, the proposed hybrid controller can effectively suppress complex multi-modal vibrations in flexible systems. Both numerical and experimental studies have been carried out to demonstrate the effectiveness of the proposed algorithm using......Control of multi-modal structural vibrations has been an important and challenging problem in flexible structural systems. This paper proposes a new vibration control algorithm for multi-modal structural control. The proposed algorithm combines a pole-placement controller with an integral resonant...... controller. The pole-placement controller is used to achieve a target equivalent modal viscous damping in the system and helps in the suppression of higher modes, which contribute to the vibration response of flexible structures. The integral resonant controller successfully reduces the low frequency...

  17. Experimental and numerical analyses on thermal performance of different typologies of PCMs integrated in the roof space

    DEFF Research Database (Denmark)

    Elarga, Hagar; Fantucci, Stefano; Serra, Valentina

    2017-01-01

    The study investigates the thermal performances of Phase Change Materials (PCM) integrated in a roof space to be used as a residential attic in Torino, Italy. Three different solutions were applied to a roof continuously monitored under summer climatic conditions. The roof was divided into three...... portions, one, the bare roof, representing the reference case without PCMs, the other two integrating two PCM's typologies with different melting/solidification temperatures range. A numerical model was furthermore developed implementing the equivalent capacitance numerical method to describe the substance...... phase transition and the measured data set were used for its validation. The study demonstrates that PCM-enhanced components are a promising solution toward a higher thermal performance efficiency in roof attic spaces during the summer season. Experimental results showed a reduction of the ongoing heat...

  18. The educational relationship as a place of integration and prevention: First results of an experimental path

    Directory of Open Access Journals (Sweden)

    Loredana Teresa Pedata

    2012-12-01

    Full Text Available The path and the pilot study presented here come from a synergy between a pharmaceutical, universities and institutions in the area. The intervention evaluation wants to establish itself as a means of "re-thinking" youth intervention benefited: the assumption that the integration of knowledge can constitute an enrichment of the whole person, we believe that such enrichment is more likely to occur in group in comparison with others and the development of social skills and human resources.

  19. Experimental study of surface integrity and fatigue life in the face milling of inconel 718

    Science.gov (United States)

    Wang, Xiangyu; Huang, Chuanzhen; Zou, Bin; Liu, Guoliang; Zhu, Hongtao; Wang, Jun

    2017-12-01

    The Inconel 718 alloy is widely used in the aerospace and power industries. The machining-induced surface integrity and fatigue life of this material are important factors for consideration due to high reliability and safety requirements. In this work, the milling of Inconel 718 was conducted at different cutting speeds and feed rates. Surface integrity and fatigue life were measured directly. The effects of cutting speed and feed rate on surface integrity and their further influences on fatigue life were analyzed. Within the chosen parameter range, the cutting speed barely affected the surface roughness, whereas the feed rate increased the surface roughness through the ideal residual height. The surface hardness increased as the cutting speed and feed rate increased. Tensile residual stress was observed on the machined surface, which showed improvement with the increasing feed rate. The cutting speed was not an influencing factor on fatigue life, but the feed rate affected fatigue life through the surface roughness. The high surface roughness resulting from the high feed rate could result in a high stress concentration factor and lead to a low fatigue life.

  20. Integration of computational modeling and experimental techniques to design fuel surrogates

    DEFF Research Database (Denmark)

    Choudhury, H.A.; Intikhab, S.; Kalakul, Sawitree

    2017-01-01

    Virtual Process-Product Design Laboratory (VPPD-Lab) are applied onto the defined compositions of the surrogate gasoline. The aim is to primarily verify the defined composition of gasoline by means of VPPD-Lab. ρ, η and RVP are calculated with more accuracy and constraints such as distillation curve...... and flash point on the blend design are also considered. A post-design experiment-based verification step is proposed to further improve and fine-tune the “best” selected gasoline blends following the computation work. Here, advanced experimental techniques are used to measure the RVP, ρ, η, RON...... and distillation temperatures. The experimental results are compared with the model predictions as well as the extended calculations in VPPD-Lab....

  1. How to Integrate Experimental Research Approaches in Ecological and Environmental Studies: AnaEE France as an Example

    Directory of Open Access Journals (Sweden)

    Jean Clobert

    2018-04-01

    Full Text Available Human activities have altered continental ecosystems worldwide and generated a major environmental crisis, prompting urgent societal questions on how to best produce goods while at the same time securing sustainable ecological services and raising needs to better understand and predict biodiversity and ecosystems dynamics under global changes. To tackle these questions, experimentation on ecosystems is necessary to improve our knowledge of processes and to propose scientifically sound management strategies. Experimental platforms able to manipulate key factors of global change and including state of the art observation methodologies are available worldwide but how to best integrate them has been rarely addressed. Here, we present and discuss the case of the national research infrastructure AnaEE France dedicated to the study of continental ecosystems and designed to congregate complementary experimental approaches in order to facilitate their access and use through a range of distributed and shared services. The conceptual design of AnaEE France includes five modules. Three modules gather experimental facilities along a gradient of experimental control ranging from highly controlled Ecotron facilities, semi-natural field mesocosms to in natura experimental sites covering major continental ecosystems (forests, croplands, grasslands, and lakes. In addition, AnaEE France also includes shared instruments that can be implemented in experiments and analytical platforms specifically dedicated to environmental biology. To promote reuse of data, generalize results and improve predictive models, AnaEE France further gathers modeling and information systems. The implementation of AnaEE France allowed for mutual synergies, improved the technical skills, stimulated new experiments and helped our scientific community to enter into the big data sharing era.

  2. Mutagenic effects of irradiated glucose in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Varma, M.B.; Rao, K.P.; Nandan, S.D.; Rao, M.S.

    1982-01-01

    The mutagenic effects of irradiated glucose were studied using the sex-linked recessive lethal test in Drosophila melanogaster. Oregon K males of D. melanogaster reared on a medium containing 20 or 40% glucose irradiated with a dose of 0.02, 0.10, 0.20, 2 or 5 Mrad #betta#-rays were scored for the induction of sex-linked recessive lethals. The results showed no significant increase in the frequency of X-lethals in Drosophila at any of the dose levels. (author)

  3. Analysis of temporal transcription expression profiles reveal links between protein function and developmental stages of Drosophila melanogaster.

    Science.gov (United States)

    Wan, Cen; Lees, Jonathan G; Minneci, Federico; Orengo, Christine A; Jones, David T

    2017-10-01

    Accurate gene or protein function prediction is a key challenge in the post-genome era. Most current methods perform well on molecular function prediction, but struggle to provide useful annotations relating to biological process functions due to the limited power of sequence-based features in that functional domain. In this work, we systematically evaluate the predictive power of temporal transcription expression profiles for protein function prediction in Drosophila melanogaster. Our results show significantly better performance on predicting protein function when transcription expression profile-based features are integrated with sequence-derived features, compared with the sequence-derived features alone. We also observe that the combination of expression-based and sequence-based features leads to further improvement of accuracy on predicting all three domains of gene function. Based on the optimal feature combinations, we then propose a novel multi-classifier-based function prediction method for Drosophila melanogaster proteins, FFPred-fly+. Interpreting our machine learning models also allows us to identify some of the underlying links between biological processes and developmental stages of Drosophila melanogaster.

  4. Analysis of temporal transcription expression profiles reveal links between protein function and developmental stages of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Cen Wan

    2017-10-01

    Full Text Available Accurate gene or protein function prediction is a key challenge in the post-genome era. Most current methods perform well on molecular function prediction, but struggle to provide useful annotations relating to biological process functions due to the limited power of sequence-based features in that functional domain. In this work, we systematically evaluate the predictive power of temporal transcription expression profiles for protein function prediction in Drosophila melanogaster. Our results show significantly better performance on predicting protein function when transcription expression profile-based features are integrated with sequence-derived features, compared with the sequence-derived features alone. We also observe that the combination of expression-based and sequence-based features leads to further improvement of accuracy on predicting all three domains of gene function. Based on the optimal feature combinations, we then propose a novel multi-classifier-based function prediction method for Drosophila melanogaster proteins, FFPred-fly+. Interpreting our machine learning models also allows us to identify some of the underlying links between biological processes and developmental stages of Drosophila melanogaster.

  5. Optogenetic pacing in Drosophila melanogaster (Conference Presentation)

    Science.gov (United States)

    Alex, Aneesh; Li, Airong; Men, Jing; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

    2016-03-01

    A non-invasive, contact-less cardiac pacing technology can be a powerful tool in basic cardiac research and in clinics. Currently, electrical pacing is the gold standard for cardiac pacing. Although highly effective in controlling the cardiac function, the invasive nature, non-specificity to cardiac tissues and possible tissue damage limits its capabilities. Optical pacing of heart is a promising alternative, which is non-invasive and more specific, has high spatial and temporal precision, and avoids shortcomings in electrical stimulation. Optical coherence tomography has been proved to be an effective technique in non-invasive imaging in vivo with ultrahigh resolution and imaging speed. In the last several years, non-invasive specific optical pacing in animal hearts has been reported in quail, zebrafish, and rabbit models. However, Drosophila Melanogaster, which is a significant model with orthologs of 75% of human disease genes, has rarely been studied concerning their optical pacing in heart. Here, we combined optogenetic control of Drosophila heartbeat with optical coherence microscopy (OCM) technique for the first time. The light-gated cation channel, channelrhodopsin-2 (ChR2) was specifically expressed by transgene as a pacemaker in drosophila heart. By stimulating the pacemaker with 472 nm pulsed laser light at different frequencies, we achieved non-invasive and more specific optical control of the Drosophila heart rhythm, which demonstrates the wide potential of optical pacing for studying cardiac dynamics and development. Imaging capability of our customized OCM system was also involved to observe the pacing effect visually. No tissue damage was found after long exposure to laser pulses, which proved the safety of optogenetic control of Drosophila heart.

  6. Experimental investigation on an integrated thermal management system with heat pipe heat exchanger for electric vehicle

    International Nuclear Information System (INIS)

    Zou, Huiming; Wang, Wei; Zhang, Guiying; Qin, Fei; Tian, Changqing; Yan, Yuying

    2016-01-01

    Highlights: • An integrated thermal management system is proposed for electric vehicle. • The parallel branch of battery chiller can supply additional cooling capacity. • Heat pipe performance on preheating mode is better than that on cooling mode. • Heat pipe heat exchanger is a feasible choice for battery thermal management. - Abstract: An integrated thermal management system combining a heat pipe battery cooling/preheating system with the heat pump air conditioning system is presented to fulfill the comprehensive energy utilization for electric vehicles. A test bench with battery heat pipe heat exchanger and heat pump air conditioning for a regular five-chair electric car is set up to research the performance of this integrated system under different working conditions. The investigation results show that as the system is designed to meet the basic cabinet cooling demand, the additional parallel branch of battery chiller is a good way to solve the battery group cooling problem, which can supply about 20% additional cooling capacity without input power increase. Its coefficient of performance for cabinet heating is around 1.34 at −20 °C out-car temperature and 20 °C in-car temperature. The specific heat of the battery group is tested about 1.24 kJ/kg °C. There exists a necessary temperature condition for the heat pipe heat exchanger to start action. The heat pipe heat transfer performance is around 0.87 W/°C on cooling mode and 1.11 W/°C on preheating mode. The gravity role makes the heat transfer performance of the heat pipe on preheating mode better than that on cooling mode.

  7. Adaptation to fluctuating environments in a selection experiment withDrosophila melanogaster.

    Science.gov (United States)

    Kubrak, Olga I; Nylin, Sören; Flatt, Thomas; Nässel, Dick R; Leimar, Olof

    2017-06-01

    A fundamental question in life-history evolution is how organisms cope with fluctuating environments, including variation between stressful and benign conditions. For short-lived organisms, environments commonly vary between generations. Using a novel experimental design, we exposed wild-derived Drosophila melanogaster to three different selection regimes: one where generations alternated between starvation and benign conditions, and starvation was always preceded by early exposure to cold; another where starvation and benign conditions alternated in the same way, but cold shock sometimes preceded starvation and sometimes benign conditions; and a third where conditions were always benign. Using six replicate populations per selection regime, we found that selected flies increased their starvation resistance, most strongly for the regime where cold and starvation were reliably combined, and this occurred without decreased fecundity or extended developmental time. The selected flies became stress resistant, displayed a pronounced increase in early life food intake and resource storage. In contrast to previous experiments selecting for increased starvation resistance in D. melanogaster , we did not find increased storage of lipids as the main response, but instead that, in particular for females, storage of carbohydrates was more pronounced. We argue that faster mobilization of carbohydrates is advantageous in fluctuating environments and conclude that the phenotype that evolved in our experiment corresponds to a compromise between the requirements of stressful and benign environments.

  8. Spectral Libraries for SWATH-MS Assays for Drosophila melanogaster and Solanum lycopersicum.

    Science.gov (United States)

    Fabre, Bertrand; Korona, Dagmara; Mata, Clara I; Parsons, Harriet T; Deery, Michael J; Hertog, Maarten L A T M; Nicolaï, Bart M; Russell, Steven; Lilley, Kathryn S

    2017-11-01

    Quantitative proteomics methods have emerged as powerful tools for measuring protein expression changes at the proteome level. Using MS-based approaches, it is now possible to routinely quantify thousands of proteins. However, prefractionation of the samples at the protein or peptide level is usually necessary to go deep into the proteome, increasing both MS analysis time and technical variability. Recently, a new MS acquisition method named SWATH is introduced with the potential to provide good coverage of the proteome as well as a good measurement precision without prior sample fractionation. In contrast to shotgun-based MS however, a library containing experimental acquired spectra is necessary for the bioinformatics analysis of SWATH data. In this study, spectral libraries for two widely used models are built to study crop ripening or animal embryogenesis, Solanum lycopersicum (tomato) and Drosophila melanogaster, respectively. The spectral libraries comprise fragments for 5197 and 6040 proteins for S. lycopersicum and D. melanogaster, respectively, and allow reproducible quantification for thousands of peptides per MS analysis. The spectral libraries and all MS data are available in the MassIVE repository with the dataset identifiers MSV000081074 and MSV000081075 and the PRIDE repository with the dataset identifiers PXD006493 and PXD006495. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Metabolomics with Nuclear Magnetic Resonance Spectroscopy in a Drosophila melanogaster Model of Surviving Sepsis

    Science.gov (United States)

    Bakalov, Veli; Amathieu, Roland; Triba, Mohamed N.; Clément, Marie-Jeanne; Reyes Uribe, Laura; Le Moyec, Laurence; Kaynar, Ata Murat

    2016-01-01

    Patients surviving sepsis demonstrate sustained inflammation, which has been associated with long-term complications. One of the main mechanisms behind sustained inflammation is a metabolic switch in parenchymal and immune cells, thus understanding metabolic alterations after sepsis may provide important insights to the pathophysiology of sepsis recovery. In this study, we explored metabolomics in a novel Drosophila melanogaster model of surviving sepsis using Nuclear Magnetic Resonance (NMR), to determine metabolite profiles. We used a model of percutaneous infection in Drosophila melanogaster to mimic sepsis. We had three experimental groups: sepsis survivors (infected with Staphylococcus aureus and treated with oral linezolid), sham (pricked with an aseptic needle), and unmanipulated (positive control). We performed metabolic measurements seven days after sepsis. We then implemented metabolites detected in NMR spectra into the MetExplore web server in order to identify the metabolic pathway alterations in sepsis surviving Drosophila. Our NMR metabolomic approach in a Drosophila model of recovery from sepsis clearly distinguished between all three groups and showed two different metabolomic signatures of inflammation. Sham flies had decreased levels of maltose, alanine, and glutamine, while their level of choline was increased. Sepsis survivors had a metabolic signature characterized by decreased glucose, maltose, tyrosine, beta-alanine, acetate, glutamine, and succinate. PMID:28009836

  10. Experimental investigation of two-stage thermoelectric generator system integrated with phase change materials

    DEFF Research Database (Denmark)

    Ahmadi Atouei, Saeed; Ranjbar, Ali Akbar; Rezaniakolaei, Alireza

    2017-01-01

    experimentally. In the first stage, a TEG module installed between a phase change material (PCM) heat sink, as cooling system, and an electrical heater, as the heat source. Because of the inherent characteristics of PCMs to save the thermal energy as latent heat, the PCM heat sink is used as the heat source...... of the second stage TEGs. In the second stage, five smaller TEG modules are installed around the PCM with individual heat sinks for cooling with natural convection. In order to have a comparison between a common TEG system and the proposed two-stage TEG system, a one-stage thermoelectric generator with forced...

  11. Integrated trimodal SSEP experimental setup for visual, auditory and tactile stimulation

    Science.gov (United States)

    Kuś, Rafał; Spustek, Tomasz; Zieleniewska, Magdalena; Duszyk, Anna; Rogowski, Piotr; Suffczyński, Piotr

    2017-12-01

    Objective. Steady-state evoked potentials (SSEPs), the brain responses to repetitive stimulation, are commonly used in both clinical practice and scientific research. Particular brain mechanisms underlying SSEPs in different modalities (i.e. visual, auditory and tactile) are very complex and still not completely understood. Each response has distinct resonant frequencies and exhibits a particular brain topography. Moreover, the topography can be frequency-dependent, as in case of auditory potentials. However, to study each modality separately and also to investigate multisensory interactions through multimodal experiments, a proper experimental setup appears to be of critical importance. The aim of this study was to design and evaluate a novel SSEP experimental setup providing a repetitive stimulation in three different modalities (visual, tactile and auditory) with a precise control of stimuli parameters. Results from a pilot study with a stimulation in a particular modality and in two modalities simultaneously prove the feasibility of the device to study SSEP phenomenon. Approach. We developed a setup of three separate stimulators that allows for a precise generation of repetitive stimuli. Besides sequential stimulation in a particular modality, parallel stimulation in up to three different modalities can be delivered. Stimulus in each modality is characterized by a stimulation frequency and a waveform (sine or square wave). We also present a novel methodology for the analysis of SSEPs. Main results. Apart from constructing the experimental setup, we conducted a pilot study with both sequential and simultaneous stimulation paradigms. EEG signals recorded during this study were analyzed with advanced methodology based on spatial filtering and adaptive approximation, followed by statistical evaluation. Significance. We developed a novel experimental setup for performing SSEP experiments. In this sense our study continues the ongoing research in this field. On the

  12. Experimental study of structural and optical properties of integrated MOCVD GaAs/Si(001) heterostructures

    Science.gov (United States)

    Seredin, P. V.; Lenshin, A. S.; Zolotukhin, D. S.; Arsentyev, I. N.; Nikolaev, D. N.; Zhabotinskiy, A. V.

    2018-02-01

    This is the first report of the control of the structural and optical functional characteristics of integrated GaAs/Si(001) heterostructures due to the use of misoriented Si(001) substrates with protoporous sublayer. The growth of the epitaxial GaAs layer on silicon substrates without formation of the antiphase domains can be performed on substrates deviating less than 4°-6° from the singular (001) plane or without the use of a transition layer of GaAs nano-columns. Preliminary etching of the silicon substrate with protoporous Si sublayer formation facilitated the acquisition of an epitaxial GaAs film in a single-crystalline state with a considerably less residual strain factor using MOCVD, which has a positive effect on the structural quality of the film. These data are in a good agreement with the results of IR reflection spectroscopy as well as PL and UV spectroscopy. The optical properties of the integrated GaAs/Si (001) heterostructures in the IR and UV spectral regions were also determined by the residual strain value.

  13. Aufbau eines Teststandes zur Integration von Silizium-Streifenmodulen in den Vorwaertsbereich des CMS-Experimentes

    CERN Document Server

    Floßdorf, Alexander; Flügge, Günter; Pooth, Oliver

    2004-01-01

    The Large Hadron Collider at CERN will collide protons with energies of up to 14 TeV, thereby offering the opportunity to investigate a wide range of physics processes. One of the experiments designed for the analysis of these high energetic proton collisions is the Compact Muon Solenoid (CMS). For the measurement of charged particles’ tracks, CMS utilises a silicon strip tracker, which is completed by a tracker end cap on each side. Each of the end caps is built from sub-structures called petals, which comprise the silicon strip modules as well as steering and power supply circuits. The assembly of a petal is done at an integration test stand, at which all connections and readout channels are checked for proper operation. As the tracker will be operated at a temperature of -10°C, each completed petal has to undergo a long term test at low temperatures in which its functionality is monitored. This thesis describes the construction and operation of an integration and a long term test stand, and the results ...

  14. Experimental investigation of integrated refrigeration system (IRS) with gas engine, compression chiller and absorption chiller

    International Nuclear Information System (INIS)

    Sun, Z.G.

    2008-01-01

    An integrated refrigeration system (IRS) with a gas engine, a vapor-compression chiller and an absorption chiller is set up and tested. The vapor-compression refrigeration cycle is operated directly by the gas engine. The waste heat from the gas engine operates the absorption refrigeration cycle, which provides additional cooling. The performance of the IRS is described. The cooling capacity of the IRS is about 596 kW, and primary energy ratio (PER) reaches 1.84 at air-conditioning rated conditions. The refrigerating capacity of the prototype increased and PER of prototype decreased with the increase of the gas engine speed. The gas engine speed was preferably regulated at part load condition in order to operate the prototype at high-energy efficiency. The refrigerating capacity and PER of the prototype increased with the increase of the outlet temperature of chilled water or the decrease of the inlet temperature of cooling water. The integrated refrigeration chiller in this work saves running costs as compared to the conventional refrigeration system by using the waste heat

  15. System integration of RF based negative ion experimental facility at IPR

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, G; Bandyopadhyay, M; Singh, M J; Gahlaut, A; Soni, J; Pandya, K; Parmar, K G; Sonara, J; Chakraborty, A, E-mail: bansal@ipr.res.i [Institute for Plasma Research, Bhat, Gandhinagar (Gujarat) 382 428 (India)

    2010-02-01

    The setting up of RF based negative ion experimental facility shall witness the beginning of experiments on the negative ion source fusion applications in India. A 1 MHz RF generator shall launch 100 kW RF power into a single driver on the plasma source to produce a plasma of density {approx}5 x 10{sup 12} cm{sup -3}. The source can deliver a negative ion beam of {approx}10 A with a current density of {approx}30 mA/cm{sup 2} and accelerated to 35 kV through an electrostatic ion accelerator. The experimental system is similar to a RF based negative ion source, BATMAN, presently operating at IPP. The subsystems for source operation are designed and procured principally from indigenous resources, keeping the IPP configuration as a base line. The operation of negative ion source is supported by many subsystems e.g. vacuum pumping system with gate valves, cooling water system, gas feed system, cesium delivery system, RF generator, high voltage power supplies, data acquisition and control system, and different diagnostics. The first experiments of negative ion source are expected to start at IPR from the middle of 2009.

  16. System integration of RF based negative ion experimental facility at IPR

    Science.gov (United States)

    Bansal, G.; Bandyopadhyay, M.; Singh, M. J.; Gahlaut, A.; Soni, J.; Pandya, K.; Parmar, K. G.; Sonara, J.; Chakraborty, A.

    2010-02-01

    The setting up of RF based negative ion experimental facility shall witness the beginning of experiments on the negative ion source fusion applications in India. A 1 MHz RF generator shall launch 100 kW RF power into a single driver on the plasma source to produce a plasma of density ~5 × 1012 cm-3. The source can deliver a negative ion beam of ~10 A with a current density of ~30 mA/cm2 and accelerated to 35 kV through an electrostatic ion accelerator. The experimental system is similar to a RF based negative ion source, BATMAN, presently operating at IPP. The subsystems for source operation are designed and procured principally from indigenous resources, keeping the IPP configuration as a base line. The operation of negative ion source is supported by many subsystems e.g. vacuum pumping system with gate valves, cooling water system, gas feed system, cesium delivery system, RF generator, high voltage power supplies, data acquisition and control system, and different diagnostics. The first experiments of negative ion source are expected to start at IPR from the middle of 2009.

  17. Theoretical and experimental studies on in-plane stiffness of integrated container structure

    Directory of Open Access Journals (Sweden)

    Xiaoxiong Zha

    2016-03-01

    Full Text Available This article presents analytical, numerical, and experimental studies on the in-plane stiffness of container buildings. First, based on diaphragm theory, parallel corrugated direction stiffness of corrugated sheet has been deduced, and based on energy method, shear modulus of two elastic principal directions of orthotropic plate has been deduced, and through stiffness conversion method, the stiffness relationship between parallel corrugated direction and vertical corrugated direction has been obtained. Combined with container frame, the container stiffness of loading end and non-loading end, as bottom side beam fixed, has been obtained. Second, through the software Abaqus, full-scale container model has been established. The loading–displacement curve of finite element model has been compared with theoretical analysis and has a good agreement. Third, through 20 and 40 ft container, corresponding experimental verification has been done, and by comparison of container stiffness, the theoretical analysis and finite element simulation have been verified. Finally, based on verified finite element model, parametric analysis of corrugated sheet size, corrugated sheeting cross section, elasticity modulus of top side beam, and every plate action for container stiffness have been given. Research result has made feasible in design and construction of container buildings and can provide some references to corresponding specification preparation.

  18. Experimental and numerical study of heat transfer across insulation wall of a refrigerated integral panel van

    International Nuclear Information System (INIS)

    Glouannec, Patrick; Michel, Benoit; Delamarre, Guillaume; Grohens, Yves

    2014-01-01

    This paper presents an experimental and numerical design study of an insulation wall for refrigerated vans. The thermophysical properties of the insulating multilayer panel, the external environment impact (solar irradiation, temperature, etc.) and durability are taken into account. Different tools are used to characterize the thermal performances of the insulation walls and the thermal properties of the insulation materials are measured. In addition, an experiment at the wall scale is carried out and a 2D FEM model of heat and mass transfer within the wall is formulated. Three configurations are studied with this design approach. Multilayer insulation walls containing reflective multi-foil insulation, aerogel and phase change materials (PCM) are tested. Promising results are obtained with these materials, especially the reduction of peak heat transfer and energy consumption during the daytime period. Furthermore, the major influence of solar irradiation is highlighted as it can increase the peak heat transfer crossing the insulation wall by up to 43%. Nevertheless, we showed that the use of reflective multi-foil insulation and aerogel layers allowed decreasing this impact by 27%. - Highlights: • A design study of an insulation wall for a refrigerated van is carried out. • Experimental and numerical studies of multilayer insulation walls are performed. • The major influence of solar irradiation is highlighted. • New insulation materials (reflective multi-foil, aerogel and PCM) are tested

  19. Experimental performance and parametric analysis of heat pipe heat exchanger for air conditioning application integrated with evaporative cooling

    Science.gov (United States)

    Jadhav, Tushar S.; Lele, Mandar M.

    2017-11-01

    The experimental performance of different heat pipe heat exchanger (HPHX) configurations using distilled water as the working fluid is reported in the present study. The three HPHX configurations in the present investigation include HPHX with single wick structure (HPHX 1), HPHX with composite wick structure (HPHX 2) and hybrid HPHX (HPHX 3) which is the combination of HPHX 1 and HPHX 2. The parameters considered for the parametric analysis of HPHX in all the three configurations are outdoor air dry bulb temperature entering the evaporator section of HPHX (OADBT), return air dry bulb temperature entering the condenser section of HPHX (RADBT), outdoor air velocity (Ve) and return air velocity (Vc). The OADBT is varied between 40 and 24 °C and the outdoor & return air velocities between 0.6 and 2.4 m/s. The parametric analysis of HPHX without evaporative cooling is studied for RADBT = 24 °C whereas RADBT is maintained at 20 °C for the parametric analysis of HPHX integrated with evaporative cooling. In comparison with HPHX without evaporative cooling, the performance of HPHX with evaporative cooling is enhanced by 17% for single wick structure (HPHX 1), 47% for composite wick structure (HPHX 2) and 59% for hybrid HPHX (HPHX 3) for OADBT = 40 °C and at Ve = Vc of 0.6 m/s. The results of the experimental analysis highlights the benefits of HPHX integrated with evaporative cooling for achieving significant energy savings in air conditioning application.

  20. An experimental low-pressure facility to study boron transients in the pressurizer of an integral modular nuclear reactor

    International Nuclear Information System (INIS)

    Nascimento, Samira R. V.; Lira, Carlos A.B.O.; Silva, Mario A.B.; Bezerra, Jair L.; Lima, Fernando R.A.; Barroso, Antonio C.O.

    2013-01-01

    Small and medium size modular reactors offer many advantages when compared with typical nuclear plants in various circumstances, such as offering greater simplicity of design, economy of mass production, and reducing siting costs. The integral configuration is characterized by having most of its components inside the pressure vessel, eliminating the probability of accidents. However, for this configuration there is no spray system for boron homogenization, which may cause power transients. Thus, it is necessary to investigate boron mixing. The Federal University of Pernambuco (UFPE), in a partnership with the Regional Center of Nuclear Sciences of Northeast (CRCN-NE) and the Nuclear Engineering Institute (IEN/CNEN-RJ), is developing a project that aims to analyze transients in a compact modular integral reactor. This analysis will be made by using the data obtained from one experimental bench that is mounted at CRCN-NE. A study accomplished in 2012 using a simplified bench (built in reduced scale with a test section manufactured with transparent acrylic) showed that it was possible to obtain preliminary experimental results for the boron homogenizing process. (author)

  1. Experimental and analytical studies on the passive residual heat removal system for the advanced integral type reactor

    International Nuclear Information System (INIS)

    Park, Hyun-Sik; Choi, Ki-Yong; Cho, Seok; Park, Choon-Kyung; Lee, Sung-Jae; Song, Chul-Hwa; Chung, Moon-Ki

    2004-01-01

    An experiment on the thermal-hydraulic characteristics of the passive residual heat removal system (PRHRS) for an advanced integral type reactor, SMART-P, has been performed, and its experimental results have been analyzed using a best-estimated system analysis code, MARS. The experiment is performed to investigate the performance of the passive residual heat removal system using the high temperature and high pressure thermal-hydraulic test facility (VISTA) which simulates the SMART-P. The natural circulation performance of the PRHRS, the heat transfer characteristics of the PRHRS heat exchangers and the emergency cooldown tank (ECT), and the thermal-hydraulic behavior of the primary loop are investigated. The experimental results show that the coolant flows steadily in the PRHRS loop and the heat transfer through the PRHRS heat exchanger in the emergency cooldown tank is sufficient enough to enable a natural circulation of the coolant. Analysis on a typical PRHRS test has been carried out using the MARS code. The overall trends of the calculated flow rate, pressure, temperature, and heat transfer rate in the PRHRS are similar to the experimental data. There is good agreement between the experimental data and the calculated one for the fluid temperature in the PRHRS steam line. However, the calculated fluid temperature in the PRHRS condensate line is higher, the calculated coolant outlet temperature is lower, and the heat transfer rate through the PRHRS heat exchanger is lower than the experimental data. It seems that it is due to an insufficient heat transfer modeling in the pool such as the emergency cooldown tank in the MARS calculation. (author)

  2. Experimental integration of quantum key distribution and gigabit-capable passive optical network

    Science.gov (United States)

    Sun, Wei; Wang, Liu-Jun; Sun, Xiang-Xiang; Mao, Yingqiu; Yin, Hua-Lei; Wang, Bi-Xiao; Chen, Teng-Yun; Pan, Jian-Wei

    2018-01-01

    Quantum key distribution (QKD) ensures information-theoretic security for the distribution of random bits between two remote parties. To extend QKD applications to fiber-to-the-home optical communications, such as gigabit-capable passive optical networks (GPONs), an effective method is the use of wavelength-division multiplexing. However, the Raman scattering noise from intensive classical traffic and the huge loss introduced by the beam splitter in a GPON severely limits the performance of QKD. Here, we demonstrate the integration of QKD and a commercial GPON system with fiber lengths up to 14 km, in which the maximum splitting ratio of the beam splitter reaches 1:64. By placing the QKD transmitter on the optical line terminal side, we reduce the Raman noise collected at the QKD receiver. Using a bypass structure, the loss of the beam splitter is circumvented effectively. Our results pave the way to extending the applications of QKD to last-mile communications.

  3. Integration of the Omega-3 readout chip into a high energy physics experimental data acquisition system

    Energy Technology Data Exchange (ETDEWEB)

    Beker, H.; Chesi, E.; Martinengo, P. [European Organization for Nuclear Research, Geneva (Switzerland)

    1997-08-21

    The Omega-3 readout chip is presented in detail elsewhere in the same proceedings. We here describe the integration of the chip into present and future experiments describing both hardware and software aspects. We cover preliminary tests in the laboratory and on the beam. The WA97 experiment has already used a pixel telescope in the past and intends to upgrade to the Omega-3 chip. A newly proposed experiment at CERN studying strangeness production in heavy ion collisions also plans to use a similar telescope. Finally, we give an outlook on the ongoing developments in the pixel readout architecture in the context of ALICE, the heavy ion experiment at the LHC collider. (orig.). 11 refs.

  4. Detection of hepatocarcinoma in rats by integration of the fluorescence spectrum: Experimental model

    Science.gov (United States)

    Marcassa, J. C.; Ferreira, J.; Zucoloto, S.; Castro E Silva, O., Jr.; Marcassa, L. G.; Bagnato, V. S.

    2006-05-01

    The incorporation of spectroscopic techniques into diagnostic procedures may greatly improve the chances for precise diagnostics. One promising technique is fluorescence spectroscopy, which has recently been used to detect many different types of diseases. In this work, we use laser-induced tissue fluorescence to detect hepatocarcinoma in rats using excitation light at wavelengths of 443 and 532 nm. Hepatocarcinoma was induced chemically in Wistar rats. The collected fluorescence spectrum ranges from the excitation wavelength up to 850 nm. A mathematical procedure carried out on the spectrum determines a figure of merit value, which allows the detection of hepatocarcinoma. The figure of merit involves a procedure which evaluates the ratio between the backscattered excitation wavelength and the broad emission fluorescence band. We demonstrate that a normalization allowed by integration of the fluorescence spectra is a simple operation that may allow the detection of hepatocarcinoma.

  5. Strain measurement on stiff structures: experimental evaluation of three integrated measurement principles

    Science.gov (United States)

    Rausch, J.; Hatzfeld, C.; Karsten, R.; Kraus, R.; Millitzer, J.; Werthschützky, R.

    2012-06-01

    This paper presents an experimental evaluation of three different strain measuring principles. Mounted on a steel beam resembling a car engine mount, metal foil strain gauges, piezoresistive silicon strain gauges and piezoelectric patches are investigated to measure structure-borne forces to control an active mounting structure. FEA simulation determines strains to be measured in the range of 10-8 up to 10-5 m × m-1. These low strains cannot be measured with conventional metal foil strain gauges, as shown in the experiment conducted. Both piezoresistive and piezoelectric gauges show good results compared to a conventional piezoelectric force sensor. Depending on bandwidth, overload capacity and primary electronic costs, these principles seem to be worth considering in an adaptronic system design. These parameters are described in detail for the principles investigated.

  6. Non-concentrating and asymmetric compound parabolic concentrating building facade integrated photovoltaics: An experimental comparison

    Energy Technology Data Exchange (ETDEWEB)

    Mallick, Tapas K.; Eames, Philip C. [Centre for Sustainable Technologies, School of Built Environment, University of Ulster, Newtownabbey BT37 0QB, N.I (United Kingdom); Norton, Brian [Dublin Institute of Technology, Aungier Street, Dublin-2 (Ireland)

    2006-07-15

    Concentration of solar energy increases the illuminated flux on the photovoltaic (PV) surface thus less PV material is required. A novel asymmetric compound parabolic photovoltaic concentrator has been characterised experimentally with a similar non-concentrating system. Different numbers of PV strings connected within the system have been analysed and a power ratio of 1.62 measured compared to a similar non-concentrating PV panel with the same cell area. The solar to electrical conversion efficiency of 8.6% and 6.8% was achieved for the non-concentrating panel the concentrating system, respectively. The measured average solar cell temperature of the PV in the concentrator system was only 12{sup o}C higher than that of the similar non-concentrating system with same cell area. (author)

  7. Non-steady experimental investigation on an integrated thermal management system for power battery with phase change materials

    International Nuclear Information System (INIS)

    Shi, Shang; Xie, Yongqi; Li, Ming; Yuan, Yanping; Yu, Jianzu; Wu, Hongwei; Liu, Bin; Liu, Nan

    2017-01-01

    Highlights: • An integrated thermal management system for power battery is designed. • The battery temperature rise is a non-steady process for charge and discharge. • A mathematical model can accurately represent temperature rise characteristics. • The heat generation power of the battery is calculated theoretically. • The excess temperatures and thermal resistances affect the system performance. - Abstract: A large amount of heat inside the power battery must be dissipated to maintain the temperature in a safe range for the hybrid power train during high-current charging/discharging processes. In this article, a combined experimental and theoretical study has been conducted to investigate a newly designed thermal management system integrating phase change material with air cooling. An unsteady mathematical model was developed for the battery with the integrated thermal management system. Meanwhile, the heat generation power, thermal resistance, and time constant were calculated. The effect of several control parameters, such as thermal resistance, initial temperature, melting temperature and ambient temperature, on the performance of the integrated thermal management system were analyzed. The results indicated that: (1) the calculated temperature rise of the battery was in good agreement with the experimental data. The appropriate operation temperature of the battery was attained by the action of the phase change storage energy unit which is composed of copper foam and n-Eicosane, (2) the remarkable decrease of the battery temperature can be achieved by reducing the convection thermal resistance or increasing the conductivity of the phase change storage energy unit, where the latter could be the better option due to no additional energy consumption. When convective resistance and thermal resistance between the battery surface and the phase change storage energy unit are less than 2.03 K/W and 1.85 K/W, respectively, the battery will not exceed the

  8. Effect of Hawthorn on Drosophila Melanogaster Antioxidant-Related ...

    African Journals Online (AJOL)

    Purpose: To study the effects of various doses of hawthorn extract on Drosophila lifespan, antioxidant enzyme activity and expression of antioxidant-related regulation genes. Methods: Experiments with Drosophila as an animal model were conducted. The effects of hawthorn on Drosophila melanogaster antioxidant related ...

  9. Latitudinal clines in Drosophila melanogaster: body size, allozyme ...

    Indian Academy of Sciences (India)

    Unknown

    latitude temperate populations of D. melanogaster (Eanes. 1999; Verrelli and Eanes 2001b). It is surmised that the higher ADH and α-GPDH activities facilitate lipid stor- age. Higher lipid storage might increase longevity or fecundity. Higher PGM activity is strongly related to higher glycogen content in adult flies (Verrelli and ...

  10. Latitudinal clines in Drosophila melanogaster: body size, allozyme ...

    Indian Academy of Sciences (India)

    It is argued that adult body size clines, inversion frequency clines, and clines in allele frequency at loci involved in glycolysis and glycogen storage are part of the same adaptive strategy. Selection pressure is expected to differ at opposite ends of the clines. At high latitudes, selection on D. melanogaster would favour high ...

  11. Latitudinal clines in Drosophila melanogaster: body size, allozyme ...

    Indian Academy of Sciences (India)

    Unknown

    Body size may be measured as fresh weight, wing length, wing area or thorax length. .... starvation resistance. Indeed, a latitudinal cline for star- vation resistance and desiccation resistance is present in. Indian populations of D. melanogaster (Karan et al. 1998). ..... 215 effects. Loss-of-function mutations in any of the insulin-.

  12. Geographical analysis of diapause inducibility in European Drosophila melanogaster populations.

    Science.gov (United States)

    Pegoraro, Mirko; Zonato, Valeria; Tyler, Elizabeth R; Fedele, Giorgio; Kyriacou, Charalambos P; Tauber, Eran

    2017-04-01

    Seasonal overwintering in insects represents an adaptation to stressful environments and in European Drosophila melanogaster females, low temperatures and short photoperiods can induce an ovarian diapause. Diapause may represent a recent (melanogaster from tropical sub-Saharan Africa, because African D. melanogaster and the sibling species D. simulans, have been reported to fail to undergo diapause. Over the past few centuries, D. melanogaster have also invaded North America and Australia, and eastern populations on both continents show a predictable latitudinal cline in diapause induction. In Europe however, a new diapause-enhancing timeless allele, ls-tim, is observed at high levels in southern Italy (∼80%), where it appears to have arisen and has spread throughout the continent with a frequency of ∼20% in Scandinavia. Given the phenotype of ls-tim and its geographical distribution, we might predict that it would work against any latitudinal cline in diapause induction within Europe. Indeed we reveal that any latitudinal cline for diapause in Europe is very weak, as predicted by ls-tim frequencies. In contrast, we determine ls-tim frequencies in North America and observe that they would be expected to strengthen the latitudinal pattern of diapause. Our results reveal how a newly arisen mutation, can, via the stochastic nature of where it initially arose, blur an otherwise adaptive geographical pattern. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Nearly Neutral Evolution Across the Drosophila melanogaster Genome

    DEFF Research Database (Denmark)

    Esteve, David Castellano; James, Jennifer; Eyre-Walker, Adam

    2017-01-01

    Under the nearly neutral theory of molecular evolution the proportion of effectively neutral mutations is expected to depend upon the effective population size (Ne). Here we investigate whether this is the case across the genome of Drosophila melanogaster using polymorphism data from 128 North...

  14. P element excision in drosophila melanogaster and related drosophilids

    Science.gov (United States)

    The frequency of P element excision and the structure of the resulting excision products were determined in three drosophilid species, Drosophila melanogaster, D. virilis, and Chymomyza procnemis. A transient P element mobility assay was conducted in the cells of developing insect embryos, but unlik...

  15. mutations of Drosophila melanogaster cause nonrandom cell death ...

    Indian Academy of Sciences (India)

    In Drosophila melanogaster, the intersex (ix) is a terminally positioned gene in somatic sex determination hierarchy and function with the female specific product of double sex (DSXF) to implement female sexual differentiation. The null phenotype of ix is to transform diplo-X individuals into intersexes while leaving haplo-X ...

  16. The metabolic profile of long-lived Drosophila melanogaster

    DEFF Research Database (Denmark)

    Sarup, Pernille Merete; Pedersen, Simon Metz Mariendal; Nielsen, Niels Chr

    2012-01-01

    We investigated the age-related changes in the metabolic profile of male Drosophila melanogaster and compared the metabolic profile of flies selected for increased longevity to that of control flies of equal age. We found clear differences in metabolite composition between selection regimes...

  17. Ionizing radiation causes the stress response in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Gruntenko, N.E.; Zakharenko, L.P.; Raushenbakh, I.Yu.

    1998-01-01

    Potentiality of the stress-reaction arising in Drosophila melanogaster under gamma-irradiation of the source with 137 Cs (irradiation dose is 10 Gy , radiation dose rate amounts 180 c Gy/min) is studied. It is shown that radiation induces the stress-reaction in Drosophila resulting in alterations in energetic metabolism (biogenic amines metabolic system) and in reproductive function [ru

  18. Inbreeding affects locomotor activity in Drosophila melanogaster at different ages

    DEFF Research Database (Denmark)

    Manenti, Tommaso; Pertoldi, Cino; Nasiri Moghadam, Neda

    2015-01-01

    The ability to move is essential for many behavioural traits closely related to fitness. Here we studied the effect of inbreeding on locomotor activity (LA) of Drosophila melanogaster at different ages under both dark and light regimes. We expected to find a decreased LA in inbred lines compared...

  19. Characterization of reproductive dormancy in male Drosophila melanogaster

    Czech Academy of Sciences Publication Activity Database

    Kubrak, O. I.; Kučerová, Lucie; Theopold, U.; Nylin, S.; Nässel, D. R.

    2016-01-01

    Roč. 7, NOV 24 (2016), č. článku 572. ISSN 1664-042X Institutional support: RVO:60077344 Keywords : Drosophila melanogaster * diapause * reproduction Subject RIV: ED - Physiology Impact factor: 4.134, year: 2016 http://journal.frontiersin.org/article/10.3389/fphys.2016.00572/full

  20. Experimental study on the performance of a multi-functional domestic air conditioner with integrated water heater

    International Nuclear Information System (INIS)

    Dong, Jiankai; Li, Hui; Yao, Yang; Jiang, Yiqiang; Zhang, Xinran

    2017-01-01

    Highlights: • A novel MDACWH was presented and experimentally studied. • MDACWH has high performance on making domestic hot water and air conditioning. • The time for heating water reduced to 22.0 min after modification. • Average COP reached 4.32, which was 1.58 times higher than the unmodified unit. - Abstract: The recovery of condenser heat is concerned one of the most effective methods to curb energy consumption in residential dwellings. Aiming at recovering the condenser heat of domestic air conditioner, this paper experimentally studied a multi-functional domestic air conditioner with integrated water heater (MDACWH) which can effectively provide space – cooling and domestic hot water simultaneously. The dynamic operation characteristics, such as hot water supply and energy efficiency were tested to verify the availability of the MDACWH. The results showed that the MDACWH can effectively heat the domestic hot water without losing its cooling capacity. It was also found that with the use of MDACWH, the coefficient of comprehensive energy performance of the MDACWH was about 1.58 times higher than that of the unmodified experimental unit. Furthermore, the water-heating time was shorten remarkably from 128.5 min to 22.0 min. The novel domestic air conditioner, compared with the unmodified initial prototype, can be more practical and provide significant energy savings in space-cooling and hot water supply.

  1. Integration

    DEFF Research Database (Denmark)

    Emerek, Ruth

    2004-01-01

    Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration......Bidraget diskuterer de forskellige intergrationsopfattelse i Danmark - og hvad der kan forstås ved vellykket integration...

  2. Genetic effects of radon 222 in a population of Drosophila melanogaster chronically exposed; Efectos geneticos del radon 222 en una poblacion de Drosophila melanogaster cronicamente expuesta

    Energy Technology Data Exchange (ETDEWEB)

    Salceda, V.M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico). Dept. de Biologia

    1997-07-01

    It was investigated the mutagenic effect of Radon 222 during a experimental period of 11 generations. In this lapse Drosophila melanogaster larvae line Canton-S were maintained in a radon atmosphere. In each test generation had been extracted males, consequently exposed to radiation which were subjected to a crossing series with a bearer marker genes of according to the Wallace experimental design (1956). Due to the experimental conditions it only was determined the recessive lethal mutations frequency for the second chromosome in the 1,4,7 and 11 generations. Of all study it was conduced in parallel way a non-treated witness population. The concentrations at which was subjected the experimental population varied of generation to generation from 12 {+-} 2 to 43 {+-} 5 kBq/m{sup 3}. Our analysis correspond to lethality determination in 1182 second chromosomes distributed between two populations and the different exposition generations. The study allow to determine the respective frequencies of recessive lethal genes varying according to the population and/or generation between 10.53 and 22.02%. The statistical analysis of data did not show significant differences among the different populations. (Author)

  3. Integrating local knowledge with experimental research: case studies on managing cropping systems in Italy and Australia

    Directory of Open Access Journals (Sweden)

    Catherine Allan

    2013-06-01

    Full Text Available The sustainable development of agricultural systems is currently challenged by many complex agro-environmental issues. These are characterized by an incomplete understanding of the situation and the problems that arise, and the conflicting opinions that result, issues over boundaries that are often difficult to define, and controversy over the multiple goals and uncertain outcomes. Added to these characteristics, we also have the slow and often inadequate uptake and implementation of research outcomes in this complex, real world. In order to improve sustainability of agro-ecosystems, agronomic research must move away from the linear research approaches and extension practices adopted so far that have focused purely on biophysical agroecosystems. The theoretical operational space of agronomic research must be transformed by considering agronomic issues as part of a broader social-agro-ecosystem. One aspect of this transformation is the inclusion of knowledge collected on a local level with the participation of farmers on the ground. The integration of local experiential knowledge with traditional agronomic research is by necessity based on the participation of many different stakeholders and there can be no single blueprint for how best to develop and use the input received. However, agronomists and policy advisors require general guidelines drawn up from actual experience in order to accelerate positive agronomic change. We address this need through a comparative analysis of two case studies; one involves multi-stakeholder research in a cropping system in the dairy district of Arborea, Sardinia, Italy. The central question was: How can high crop production be maintained while also achieving the EU target water quality and minimizing the production costs? The second case is a multi-stakeholder soil health project from south-eastern Australia. Here the central question was: How can soil decline be prevented and reversed in this district, and soils

  4. Development of the Asphalt Multi-Integrated Roller Field and Experimental Studies

    Directory of Open Access Journals (Sweden)

    Abd El Halim Omar Abd El Halim

    2015-01-01

    Full Text Available Asphalt pavements have been compacted using steel drum rollers for a century. However, the problems that are observed today on these pavements are universal with no solution in sight. Intensive research work has been invested to identify the mechanisms that cause these problems. A recent development was the introduction of SuperPave mix design, GP asphalt cements, and the use of reinforcing elements ranging from polymer to steel bars. Yet it seems that none of these solutions have succeeded in eliminating any of the old problems. The pavements suffer from serious distresses regardless of the geographic location of the pavements and its design, materials, traffic loads, and climate condition. This paper presents a new approach to deal with the problems facing the asphalt pavements. While the research efforts to date concentrated on materials-related solutions, this paper identifies conventional compaction equipment as the cause of many problems observed on the pavements. The paper provides the development of the new Asphalt Multi-Integrated Roller, AMIR, and discusses new developments leading to a number of commercial field trials on several Ontario highways. The paper concludes that current compactors must be replaced with soft flat plates in order to achieve the required specifications for long term performance.

  5. Experimentally verified inductance extraction and parameter study for superconductive integrated circuit wires crossing ground plane holes

    International Nuclear Information System (INIS)

    Fourie, Coenrad J; Wetzstein, Olaf; Kunert, Juergen; Meyer, Hans-Georg; Toepfer, Hannes

    2013-01-01

    As the complexity of rapid single flux quantum (RSFQ) circuits increases, both current and power consumption of the circuits become important design criteria. Various new concepts such as inductive biasing for energy efficient RSFQ circuits and inductively coupled RSFQ cells for current recycling have been proposed to overcome increasingly severe design problems. Both of these techniques use ground plane holes to increase the inductance or coupling factor of superconducting integrated circuit wires. New design tools are consequently required to handle the new topographies. One important issue in such circuit design is the accurate calculation of networks of inductances even in the presence of finite holes in the ground plane. We show how a fast network extraction method using InductEx, which is a pre- and post-processor for the magnetoquasistatic field solver FastHenry, is used to calculate the inductances of a set of SQUIDs (superconducting quantum interference devices) with ground plane holes of different sizes. The results are compared to measurements of physical structures fabricated with the IPHT Jena 1 kA cm −2 RSFQ niobium process to verify accuracy. We then do a parameter study and derive empirical equations for fast and useful estimation of the inductance of wires surrounded by ground plane holes. We also investigate practical circuits and show excellent accuracy. (paper)

  6. Experimental study on high-power LEDs integrated with micro heat pipe

    Science.gov (United States)

    LI, Cong-ming; Zhou, Chuan-peng; Luo, Yi; Hamidnia, Mohammad; Wang, Xiao-dong; You, Bo

    2016-01-01

    Micro heat pipe (MHP) is applied to implement the efficient heat transfer of light emitting diode (LED) device. The fabrication of MHP is based on micro-electro-mechanical-system (MEMS) technique, 15 micro grooves were etched on one side of silicon (Si) substrate, which was then packaged with aluminum heat sink to form an MHP. On the other side of Si substrate, three LED chips were fixed by die bonding. Then experiments were performed to study the thermal performance of this LED device. The results show that the LED device with higher filling ratio is better when the input power is 1.0 W; with the increase of input power, the optimum filling ratio changes from 30% to 48%, and the time reaching stable state is reduced; when the input power is equal to 2.5 W, only the LED device with filling ratio of 48% can work normally. So integrating MHP into high-power LED device can implement the effective control of junction temperature.

  7. Mechanism of cysteine oxidation by peroxynitrite: An integrated experimental and theoretical study.

    Science.gov (United States)

    Zeida, Ari; González Lebrero, Mariano C; Radi, Rafael; Trujillo, Madia; Estrin, Darío A

    2013-11-01

    Since peroxynitrite was identified as a pathophysiological agent it has been implicated in a great variety of cellular processes. Particularly, peroxynitrite mediated oxidation of cellular thiol-containing compounds such as Cys residues, is a key event which has been extensively studied. Although great advances have been accomplished, the reaction is not completely understood at the atomic level. Aiming to shed light on this subject, we present an integrated kinetic and theoretical study of the oxidation of free Cys by peroxynitrite. We determined pH-independent thermodynamic activation parameters, namely those corresponding to the reaction between the reactive species: Cys thiolate and peroxynitrous acid. We found a pH-independent activation energy of 8.2 ± 0.6 kcal/mol. Simulations were performed using state of the art hybrid quantum-classical (QM-MM) molecular dynamics simulations. Our results are consistent with a SN2 mechanism, with Cys sulfenic acid and nitrite anion as products. The activation barrier is mostly due to the alignment of sulfur's thiolate atom with the oxygen atoms of the peroxide, along with the concomitant charge reorganization and important changes in the solvation profile. This work provides an atomic detailed description of the reaction mechanism and a framework to understand the environment effects on peroxynitrite reactivity with protein thiols. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Preliminary experimental study of post-combustion carbon capture integrated with solar thermal collectors

    International Nuclear Information System (INIS)

    Wang, Fu; Zhao, Jun; Li, Hailong; Deng, Shuai; Yan, Jinyue

    2017-01-01

    Highlights: • A solar assisted chemical absorption pilot system with two types of collectors (parabolic trough and linear Fresnel reflector) has been constructed. • Performance of two types of solar collectors has been investigated and compared at steady and transient states. • The operations of the pilot system with and without solar assisted have been tested. • The pilot system responds to the temperature of the heat transfer fluid regularly. - Abstract: The amine-based chemical absorption for CO 2 capture normally needs to extract steam from the steam turbine cycle for solvent regeneration. Integrating solar thermal energy enables the reduction of steam extraction and therefore, can reduce the energy penalty caused by CO 2 capture. In this paper, a pilot system of the solar thermal energy assisted chemical absorption was built to investigate the system performance. Two types of solar thermal energy collectors, parabolic trough and linear Fresnel reflector, were tested. It was found that the values of operation parameters can meet the requirements of designed setting parameters, and the solar collectors can provide the thermal energy required by the reboiler, while its contribution was mainly determined by solar irradiation. The solvent regeneration was investigated by varying the heat input. The results show that the response time of the reboiler heat duty is longer than those of the reboiler temperature and desorber pressure. This work provides a better understanding about the overall operation and control of the system.

  9. An Integrated Numerical and Experimental Analysis for Enhancing the Performance of the Hidden Ceiling Fan

    Directory of Open Access Journals (Sweden)

    Sheam-Chyun Lin

    2014-02-01

    Full Text Available Since the inlet and outlet of hidden ceiling fan are almost located at the same Plane; thus, an improper housing may cause inhale-return phenomenon which significantly affects its power consumption and performance. In this study, a comprehensive investigation by numerical and experimental techniques was used to predict and identify the flow pattern, airflow rate, efficiency, and noise for ceiling fans with different design parameters. The results showed that the unique inhale-return phenomenon happens for an inappropriate housing. Several key parameters, such as fan guard, housing ring, inlet-to-outlet area ratio, and blockage height, are evaluated for finding out the criterion to avoid the inhale-return flow. Consequently the study finds that fan guard changes the airflow to a wider distribution with a lower velocity. A minimum blockage distance and a maximum height of ring-plate are set at 80 mm and 30 mm, respectively. Also, it is suggested that the inlet area must be bigger than the outlet area. Moreover, all the parameters show the same trend under various rotational speeds. In conclusion, this systematic investigation not only provides the fan engineer's design ability to avoid the inhale-return phenomenon, but also the predicting capability on its aerodynamic and acoustic performances.

  10. Experimental Verification of Integrity of Low-Pressure Injection Piles Structure - Pile Internal Capacity

    Science.gov (United States)

    Pachla, Henryk

    2017-12-01

    The idea of strengthening the foundation using injection piles lies in transferring loads from the foundation to the piles anchorage in existing structure and formed in the soil. Such a system has to be able to transfer loads from the foundation to the pile and from the pile onto the soil. Pile structure often reinforced with steel element has to also be able to transfer such a loading. According to the rules of continuum mechanics, the bearing capacity of such a system and a deformation of its individual elements can be determined by way of an analysis of the contact problem of three interfaces. Each of these surfaces is determined by different couples of materials. Those surfaces create: pile-foundation anchorage, bonding between reinforcement and material from which the pile is formed and pilesoil interface. What is essential is that on the contact surfaces the deformation of materials which adhere to each other can vary and depends on the mechanical properties and geometry of these surfaces. Engineering practice and experimental research point out that the failure in such structures occurs at interfaces. The paper is concentrating on presenting the experiments on interaction between cement grout and various types of steel reinforcement. The tests were conducted on the special low pressure injection piles widely used to strengthen foundations of already existing structures of historical buildings due to the technology of formation and injection pressure.

  11. Experimental Verification of Integrity of Low-Pressure Injection Piles Structure – Pile Internal Capacity

    Directory of Open Access Journals (Sweden)

    Pachla Henryk

    2017-12-01

    Full Text Available The idea of strengthening the foundation using injection piles lies in transferring loads from the foundation to the piles anchorage in existing structure and formed in the soil. Such a system has to be able to transfer loads from the foundation to the pile and from the pile onto the soil. Pile structure often reinforced with steel element has to also be able to transfer such a loading. According to the rules of continuum mechanics, the bearing capacity of such a system and a deformation of its individual elements can be determined by way of an analysis of the contact problem of three interfaces. Each of these surfaces is determined by different couples of materials. Those surfaces create: pile-foundation anchorage, bonding between reinforcement and material from which the pile is formed and pilesoil interface. What is essential is that on the contact surfaces the deformation of materials which adhere to each other can vary and depends on the mechanical properties and geometry of these surfaces. Engineering practice and experimental research point out that the failure in such structures occurs at interfaces. The paper is concentrating on presenting the experiments on interaction between cement grout and various types of steel reinforcement. The tests were conducted on the special low pressure injection piles widely used to strengthen foundations of already existing structures of historical buildings due to the technology of formation and injection pressure.

  12. Metabolomic analysis of the selection response of Drosophila melanogaster to environmental stress: are there links to gene expression and phenotypic traits?

    Science.gov (United States)

    Malmendal, Anders; Sørensen, Jesper Givskov; Overgaard, Johannes; Holmstrup, Martin; Nielsen, Niels Chr.; Loeschcke, Volker

    2013-05-01

    We investigated the global metabolite response to artificial selection for tolerance to stressful conditions such as cold, heat, starvation, and desiccation, and for longevity in Drosophila melanogaster. Our findings were compared to data from other levels of biological organization, including gene expression, physiological traits, and organismal stress tolerance phenotype. Overall, we found that selection for environmental stress tolerance changes the metabolomic 1H NMR fingerprint largely in a similar manner independent of the trait selected for, indicating that experimental evolution led to a general stress selection response at the metabolomic level. Integrative analyses across data sets showed little similarity when general correlations between selection effects at the level of the metabolome and gene expression were compared. This is likely due to the fact that the changes caused by these selection regimes were rather mild and/or that the dominating determinants for gene expression and metabolite levels were different. However, expression of a number of genes was correlated with the metabolite data. Many of the identified genes were general stress response genes that are down-regulated in response to selection for some of the stresses in this study. Overall, the results illustrate that selection markedly alters the metabolite profile and that the coupling between different levels of biological organization indeed is present though not very strong for stress selection at this level. The results highlight the extreme complexity of environmental stress adaptation and the difficulty of extrapolating and interpreting responses across levels of biological organization.

  13. Experimental investigation of a two-inlet air-based building integrated photovoltaic/thermal (BIPV/T) system

    International Nuclear Information System (INIS)

    Yang, Tingting; Athienitis, Andreas K.

    2015-01-01

    Highlights: • BIPV/T system thermal efficiency is 5% higher using two inlets compared to one. • BIPV/T thermal efficiency is 7.6% higher using semi-transparent than opaque PV. • Detailed air temperature profile in BIPV/T channel is obtained. • Nusselt number correlations are developed. - Abstract: An experimental study of thermal characteristics of a novel two-inlet air-based open-loop building integrated photovoltaic/thermal (BIPV/T) system using a full-scale solar simulator is presented. Experimental prototypes of one-inlet and two-inlet BIPV/T systems were constructed for conducting comparative experiments. Variations of BIPV/T systems are also investigated including systems employing opaque mono-crystalline silicon photovoltaic (PV) panels and systems employing semi-transparent mono-crystalline PV panels. Experimental results demonstrate that an equivalent two-inlet system with frameless PV panels can increase the thermal efficiency by 5% compared to a conventional one-inlet system, and that the BIPV/T system with semi-transparent PV panels achieves 7.6% higher thermal efficiency due to the absorption of some solar radiation at the bottom surface in the BIPV/T system cavity. Also, the two-inlet BIPV/T design is easily implemented and does not add significant cost. Detailed air temperature measurements reveal that the mixing of the warm outlet air from the first section and the cool ambient air drawn in from the second inlet contributes to the improved performance of the two-inlet system. Based on a thermal network model of the BIPV/T system and experimental data, correlations are developed for the convective heat transfer coefficients in the two sections. These are necessary for further analysis and development of BIPV/T system with multiple inlets.

  14. Integrated Experimental and Computational Approach to Understand the Effects of Heavy Ion Radiation on Skin Homeostasis.

    Energy Technology Data Exchange (ETDEWEB)

    von Neubeck, Claere; Shankaran, Harish; Geniza, Matthew; Kauer, Paula M.; Robinson, Robert J.; Chrisler, William B.; Sowa, Marianne B.

    2013-08-08

    The effects of low dose high linear energy transfer (LET) radiation on human health are of concern for both space and clinical exposures. As epidemiological data for such radiation exposures are scarce for making relevant predictions, we need to understand the mechanism of response especially in normal tissues. Our objective here is to understand the effects of heavy ion radiation on tissue homeostasis in a realistic model system. Towards this end, we exposed an in vitro three dimensional skin equivalent to low fluences of Neon (Ne) ions (300 MeV/u), and determined the differentiation profile as a function of time following exposure using immunohistochemistry. We found that Ne ion exposures resulted in transient increases in the tissue regions expressing the differentiation markers keratin 10, and filaggrin, and more subtle time-dependent effects on the number of basal cells in the epidermis. We analyzed the data using a mathematical model of the skin equivalent, to quantify the effect of radiation on cell proliferation and differentiation. The agent-based mathematical model for the epidermal layer treats the epidermis as a collection of heterogeneous cell types with different proliferation/differentiation properties. We obtained model parameters from the literature where available, and calibrated the unknown parameters to match the observed properties in unirradiated skin. We then used the model to rigorously examine alternate hypotheses regarding the effects of high LET radiation on the tissue. Our analysis indicates that Ne ion exposures induce rapid, but transient, changes in cell division, differentiation and proliferation. We have validated the modeling results by histology and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The integrated approach presented here can be used as a general framework to understand the responses of multicellular systems, and can be adapted to other epithelial tissues.

  15. Experimental simulation on the integration of solid oxide fuel cell and micro-turbine generation system

    Science.gov (United States)

    Lai, Wei-Hsiang; Hsiao, Chi-An; Lee, Chien-Hsiung; Chyou, Yau-Pin; Tsai, Yu-Ching

    Solid oxide fuel cell (SOFC) is characterized in high performance and high temperature exhaust, and it has potential to reach 70% efficiency if combined with gas turbine engine (GT). Because the SOFC is in developing stage, it is too expensive to obtain. This paper proposes a feasibility study by using a burner (Comb A) to simulate the high temperature exhaust gas of SOFC. The second burner (Comb B) is connected downstream of Comb A, and preheated hydrogen is injected to simulate the condition of sequential burner (SeqB). A turbocharger and a water injection system are also integrated in order to simulate the situation of a real SOFC/GT hybrid system. The water injection system is used to simulate the water mist addition at external reformer. Results show that this configuration can simulate the SOFT/GT hybrid system successfully. Water mist addition will increase the GT rotational speed, but an optimal amount exists during the variation of water injection. In residual fuel addition test, hydrogen shows good combustion efficiency and preheating temperature is the dominant parameter for hydrogen burning in SeqB even without flame holding mechanism in it. When preheating temperature is among 450-600 °C, hydrogen will have almost 100% combustion efficiency at 90% engine loading, and GT will get a higher rotational speed for the same energy input. But when the engine operates at 100% loading, the combustion efficiency will decrease while fuel utilization (U f) setting is increasing. When raising the preheated temperature to 650-700 °C, the combustion efficiency will increase rapidly.

  16. Linac-integrated 4D cone beam CT: first experimental results

    Science.gov (United States)

    Dietrich, Lars; Jetter, Siri; Tücking, Thomas; Nill, Simeon; Oelfke, Uwe

    2006-06-01

    A new online imaging approach, linac-integrated cone beam CT (CBCT), has been developed over the past few years. It has the advantage that a patient can be examined in their treatment position directly before or during a radiotherapy treatment. Unfortunately, respiratory organ motion, one of the largest intrafractional organ motions, often leads to artefacts in the reconstructed 3D images. One way to take this into account is to register the breathing phase during image acquisition for a phase-correlated image reconstruction. Therefore, the main focus of this work is to present a system which has the potential to investigate the correlation between internal (movement of the diaphragm) and external (data of a respiratory gating system) information about breathing phase and amplitude using an inline CBCT scanner. This also includes a feasibility study about using the acquired information for a respiratory-correlated 4D CBCT reconstruction. First, a moving lung phantom was used to develop and to specify the required methods which are based on an image reconstruction using only projections belonging to a certain moving phase. For that purpose, the corresponding phase has to be detected for each projection. In the case of the phantom, an electrical signal allows one to track the movement in real time. The number of projections available for the image reconstruction depends on the breathing phase and the size of the position range from which projections should be used for the reconstruction. The narrower this range is, the better the inner structures can be located, but also the noise of the images increases due to the limited number of projections. This correlation has also been analysed. In a second step, the methods were clinically applied using data sets of patients with lung tumours. In this case, the breathing phase was detected by an external gating system (AZ-733V, Anzai Medical Co.) based on a pressure sensor attached to the patient's abdominal region with a

  17. GeneLab Phase 2: Integrated Search Data Federation of Space Biology Experimental Data

    Science.gov (United States)

    Tran, P. B.; Berrios, D. C.; Gurram, M. M.; Hashim, J. C. M.; Raghunandan, S.; Lin, S. Y.; Le, T. Q.; Heher, D. M.; Thai, H. T.; Welch, J. D.; hide

    2016-01-01

    The GeneLab project is a science initiative to maximize the scientific return of omics data collected from spaceflight and from ground simulations of microgravity and radiation experiments, supported by a data system for a public bioinformatics repository and collaborative analysis tools for these data. The mission of GeneLab is to maximize the utilization of the valuable biological research resources aboard the ISS by collecting genomic, transcriptomic, proteomic and metabolomic (so-called omics) data to enable the exploration of the molecular network responses of terrestrial biology to space environments using a systems biology approach. All GeneLab data are made available to a worldwide network of researchers through its open-access data system. GeneLab is currently being developed by NASA to support Open Science biomedical research in order to enable the human exploration of space and improve life on earth. Open access to Phase 1 of the GeneLab Data Systems (GLDS) was implemented in April 2015. Download volumes have grown steadily, mirroring the growth in curated space biology research data sets (61 as of June 2016), now exceeding 10 TB/month, with over 10,000 file downloads since the start of Phase 1. For the period April 2015 to May 2016, most frequently downloaded were data from studies of Mus musculus (39) followed closely by Arabidopsis thaliana (30), with the remaining downloads roughly equally split across 12 other organisms (each 10 of total downloads). GLDS Phase 2 is focusing on interoperability, supporting data federation, including integrated search capabilities, of GLDS-housed data sets with external data sources, such as gene expression data from NIHNCBIs Gene Expression Omnibus (GEO), proteomic data from EBIs PRIDE system, and metagenomic data from Argonne National Laboratory's MG-RAST. GEO and MG-RAST employ specifications for investigation metadata that are different from those used by the GLDS and PRIDE (e.g., ISA-Tab). The GLDS Phase 2 system

  18. Polyhydroxybutyrate/valerate/polycaprolactone small-diameter vascular graft: Experimental study of integration into organism

    Energy Technology Data Exchange (ETDEWEB)

    Antonova, L. V., E-mail: antonova.la@mail.ru; Burago, A. Yu.; Matveeva, V. G.; Velikanova, E. A.; Mukhamadiyarov, R. A.; Glushkova, T. V.; Kudryavtseva, Y. A.; Barbarash, O. L.; Barbarash, L. S. [Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo (Russian Federation); Mironov, A. V. [Kemerovo Cardiology Dispensary, Kemerovo (Russian Federation)

    2015-10-27

    We prepared polyhydroxybutyrate/valerate (PHBV)/polylcaprolactone (PCL) small-diameter vascular grafts using electrospinning. Surface structure was assessed by scanning electron microscopy whilst physicomechanical properties were investigated by longitudinal uniaxial tension testing. Patency of grafts implanted into the rat abdominal aorta was evaluated using a Doppler ultrasonography at 2 week, 1 month and 12 month postimplantation. In addition, we assessed local histological features, along with IL-1β, IL-2, IL-4, IL-10, TNFa, TGF-β1, and VEGF serum levels. We revealed that only 2 (25%) grafts were not thrombosed at 2 week and 1 month postimplantation. However, at 12 month postimplantation a satisfactory histological pattern was observed in 50% of all cases, and we detected a monolayer of endothelial cells on the inner graft surface in half the cases. Regarding other grafts, we revealed minor connective tissue hyperplasia in 41.7% of the grafts and an inflammatory infiltrate in the part of the arterial wall in 8.3% of the grafts. We found that the IL-1β serum level was 3.5-fold higher in the group of experimental rats at 12 month postimplantation (p < 0.01). In addition, the IL-2 and IL-4 serum levels at 12 month postimplantation were 2- and 2.8-fold higher as compared to short-term implantation (2 weeks and 1 month) and control rats (p < 0.05) whilst the IL-10 serum level at 1 and 12 month postimplantation was more than 100-fold higher in comparison with 2 week postimplantation and control rats (p < 0.001). Serum VEGF was detected only at 12 month postimplantation. All in all, we created a biocompatible PHBV/PCL small-diameter vascular graft with a high surface area to volume ratio. A long-term patency of biodegradable vascular grafts after implantation into the rat abdominal aorta and the absence of a considerable immune response confirmed a high biocompatibility of such construct and the possibility of its use as a vascular graft.

  19. Polyhydroxybutyrate/valerate/polycaprolactone small-diameter vascular graft: Experimental study of integration into organism

    Science.gov (United States)

    Antonova, L. V.; Burago, A. Yu.; Mironov, A. V.; Matveeva, V. G.; Velikanova, E. A.; Mukhamadiyarov, R. A.; Glushkova, T. V.; Kudryavtseva, Y. A.; Barbarash, O. L.; Barbarash, L. S.

    2015-10-01

    We prepared polyhydroxybutyrate/valerate (PHBV)/polylcaprolactone (PCL) small-diameter vascular grafts using electrospinning. Surface structure was assessed by scanning electron microscopy whilst physicomechanical properties were investigated by longitudinal uniaxial tension testing. Patency of grafts implanted into the rat abdominal aorta was evaluated using a Doppler ultrasonography at 2 week, 1 month and 12 month postimplantation. In addition, we assessed local histological features, along with IL-1β, IL-2, IL-4, IL-10, TNFa, TGF-β1, and VEGF serum levels. We revealed that only 2 (25%) grafts were not thrombosed at 2 week and 1 month postimplantation. However, at 12 month postimplantation a satisfactory histological pattern was observed in 50% of all cases, and we detected a monolayer of endothelial cells on the inner graft surface in half the cases. Regarding other grafts, we revealed minor connective tissue hyperplasia in 41.7% of the grafts and an inflammatory infiltrate in the part of the arterial wall in 8.3% of the grafts. We found that the IL-1β serum level was 3.5-fold higher in the group of experimental rats at 12 month postimplantation (p < 0.01). In addition, the IL-2 and IL-4 serum levels at 12 month postimplantation were 2- and 2.8-fold higher as compared to short-term implantation (2 weeks and 1 month) and control rats (p < 0.05) whilst the IL-10 serum level at 1 and 12 month postimplantation was more than 100-fold higher in comparison with 2 week postimplantation and control rats (p < 0.001). Serum VEGF was detected only at 12 month postimplantation. All in all, we created a biocompatible PHBV/PCL small-diameter vascular graft with a high surface area to volume ratio. A long-term patency of biodegradable vascular grafts after implantation into the rat abdominal aorta and the absence of a considerable immune response confirmed a high biocompatibility of such construct and the possibility of its use as a vascular graft.

  20. Numerical and Experimental Investigation of Natural Convection in Open-Ended Channels with Application to Building Integrated Photovoltaic (BIPV Systems

    Directory of Open Access Journals (Sweden)

    Timchenko V.

    2015-01-01

    Full Text Available Numerical and experimental investigations of the flow and heat transfer in open-ended channel formed by the double skin façade have been undertaken in order to improve understanding of the phenomena and to apply it to passive cooling of building integrated photovoltaic systems. Both uniform heating and non-uniform heating configurations in which heat sources alternated with unheated zones on both skins were studied. Different periodic and asymmetric heating modes have been considered for the same aspect ratio 1/15 of wall distance to wall height and for periodicity 1/15 and 4/15 of heated/unheated zones and heat input, 220 W/m2. In computational study three dimensional transient LES simulation was carried out. It is shown that in comparison to uniformly heating configuration, non-uniformly heating configuration enhances both convective heat transfer and chimney effect.

  1. Critical need for family-based, quasi-experimental designs in integrating genetic and social science research.

    Science.gov (United States)

    D'Onofrio, Brian M; Lahey, Benjamin B; Turkheimer, Eric; Lichtenstein, Paul

    2013-10-01

    Researchers have identified environmental risks that predict subsequent psychological and medical problems. Based on these correlational findings, researchers have developed and tested complex developmental models and have examined biological moderating factors (e.g., gene-environment interactions). In this context, we stress the critical need for researchers to use family-based, quasi-experimental designs when trying to integrate genetic and social science research involving environmental variables because these designs rigorously examine causal inferences by testing competing hypotheses. We argue that sibling comparison, offspring of twins or siblings, in vitro fertilization designs, and other genetically informed approaches play a unique role in bridging gaps between basic biological and social science research. We use studies on maternal smoking during pregnancy to exemplify these principles.

  2. CONTENT AND LANGUAGE INTEGRATED LEARNING (CLIL: AN EXPERIMENTAL STUDY ON CLIL COMPATIBILITY WITH THE MODERN GREEK EDUCATIONAL SYSTEM

    Directory of Open Access Journals (Sweden)

    Catherine Georgopoulou Theodosiou

    2016-06-01

    Full Text Available This paper focuses on the Content and Language Integrated Learning (CLIL method for (foreign language teaching. The CLIL approach is rapidly gaining momentum across Europe and all over the world. It is the result of recent European Union efforts to develop and apply innovative educational practices of interdisciplinary character in order to bridge the gap between foreign language education and optimum learning outcomes. In order to investigate the compatibility of CLIL with the contemporary Greek educational reality, a small-scale experimental research study was set up, including the development of original e-learning material, a pilot class instruction based on this material and the evaluation of the results. The class instruction was based on Project-Based Learning whereas Collaborative Learning was supported by the Edmodo e-learning platform. Information on the progress of the pilot class instruction and the learning outcomes achieved was disseminated through a wiki set up for this task.

  3. Experimental Peptide Identification Repository (EPIR): an integrated peptide-centric platform for validation and mining of tandem mass spectrometry data

    DEFF Research Database (Denmark)

    Kristensen, Dan Bach; Brønd, Jan Christian; Nielsen, Peter Aagaard

    2004-01-01

    LC MS/MS has become an established technology in proteomic studies, and with the maturation of the technology the bottleneck has shifted from data generation to data validation and mining. To address this bottleneck we developed Experimental Peptide Identification Repository (EPIR), which...... is an integrated software platform for storage, validation, and mining of LC MS/MS-derived peptide evidence. EPIR is a cumulative data repository where precursor ions are linked to peptide assignments and protein associations returned by a search engine (e.g. Mascot, Sequest, or PepSea). Any number of datasets can...... be parsed into EPIR and subsequently validated and mined using a set of software modules that overlay the database. These include a peptide validation module, a protein grouping module, a generic module for extracting quantitative data, a comparative module, and additional modules for extracting statistical...

  4. Clayey cap-rocks reactivity in presence of CO2 in deep geological storage conditions: experimentation/modeling integrated approach

    International Nuclear Information System (INIS)

    Credoz, A.

    2009-10-01

    CO 2 capture, transport and geological storage is one of the main solutions considered in the short and medium term to reduce CO 2 and others greenhouse gases emissions towards the atmosphere, by storing CO 2 in deeper geological reservoirs during 100 to 10 000 years. This Ph-D study offers a multi-scale vision of complex clayey cap-rocks reactivity and evolution. These formations are identified for the CO 2 containment and sealing into the reservoir. From the experimental scale on purified clay minerals to integrative modeling at high space and time scales, the strategy developed allowed identifying the main geochemical processes, to check the good agreement between experiment and modeling, and to lay emphasis the operational impacts on long-term cap-rocks integrity. Carbonated cements alteration is likely to open cap-rock porosity and to create preferential reactive pathway for reactive fluid flow. Besides, this could alter the cap-rock structure and the global geo-mechanic properties. Clay minerals alteration, including the illitization process, reduces the clay fraction volume but considerably limits the porosity increase. The illitization process in acidic conditions determined experimentally and by modeling at low and high scale, is coupled with silica precipitation. The final porosity increase control results of these two reactive processes balance. By a fundamental side, this study reveals new kinetic parameters of clay minerals and highlights new structural transformations. By an operational side, this study contributes to the acquisition of qualitative data (long-term reactive pathways of clayey cap-rocks, coupled reactivity carbonates/clays) and quantitative data (CO 2 penetration distance into the cap-rock) to partly answer to the performance and safety assessment CO 2 capture and geological storage. (author)

  5. Experimental coccidiosis influences the expression of the ABCB1 gene, a physiological important functional marker of intestinal integrity in chickens.

    Science.gov (United States)

    Haritova, Aneliya; Koinarski, Vencislav; Stanilova, Spaska

    2013-01-01

    Efflux transporters belonging to the family of ABC transporters have an important functional role in the maintenance of the intestinal barrier. As efflux transporters they prevent the absorption of toxic substances from feed, while at the same time facilitating the excretion of metabolic waste products as well as drugs from the circulation into the intestinal lumen. As Eimeria tenella infection significantly affects the integrity of caecum, the effects of experimental E. tenella infection on the levels of expression of ABCB1 mRNAs in the intestines and livers of broilers were evaluated. ABCB1 mRNA expression was quantified by qRT-PCR. Its expression levels were significantly down-regulated in the caecum of infected animals. The levels of ABCB1 mRNA were not changed in the duodenum and the liver. After treatment of the animals with sulfapyrazine for three days, not only a significant improvement of the clinical appearance but also a normalization of the P-gp expression was noticed. Although the current study cannot distinguish between the direct effect of the drug on the host and the drug action on the parasite, these results suggest that the treatment of coccidiosis with sulfachlorpyrazine also restored the expression of the investigated efflux transporter in the caecum. This is of clinical significance as P-glycoproteins contribute to the integrity of intestines and their function as important biological barriers, protecting poultry from pathogens and toxic compounds in animal feeds.

  6. An integrated experimental and first-principles computational study of carbon dioxide mineral carbonation reactions in olivine and serpentine

    Science.gov (United States)

    Gormley, Deirdre Marie

    This dissertation is a unique integration of experimental and theoretical methods. The central issue that is being addressed is to find a long term and economically viable solution to the disposal of carbon dioxide gas from coal power plants. Mineral carbonation reactions have emerged as a permanent solution to the well-known "Greenhouse Gas" issue. Our group here at ASU along with groups at Los Alamos National Laboratory (LANL), National Energy Technology Laboratory (NETL), Pennsylvania State in Utah (SAIC), and the Albany Research Center (ARC) comprise the working group managed by the US Department of Energy (DOE). We have been collaborating to develop a fundamental understanding of the carbonation reactions of candidate minerals which will ultimately be used to develop a pilot plant process. Two of the candidate minerals used in mineral sequestration processes are forsterite (olivine) and lizardite (serpentine). Both candidates require pre-treatment prior to reaction with carbon dioxide. Forsterite requires attrition (grinding), while lizardite requires a pre-heat treatment (dehydroxylation) step which removes chemically bound water. In Chapter 3 of this thesis, the thermodynamic properties of seven primary oxides involved in reactions with forsterite and lizardite are compared. A novel method was developed using a theoretical molecular quantum physics approach which reproduced experimental results with great accuracy. This method can now be used for other systems where experimental thermodynamic data is unavailable. In Chapters 4 and 5, the dehydroxylation mechanism for lizardite is studied using theoretical models in conjunction with experimental results. A possible mechanism for the dehydroxylation pathway is suggested. This long-awaited result may provide new insight regarding carbonation reactions in lizardite. Chapters 6 and 7 explore the carbonation reactions in forsterite. With the help of high resolution electron microscopy images and extremely large

  7. In between: Gypsy in Drosophila melanogaster Reveals New Insights into Endogenous Retrovirus Evolution

    Directory of Open Access Journals (Sweden)

    Franck Touret

    2014-12-01

    Full Text Available Retroviruses are RNA viruses that are able to synthesize a DNA copy of their genome and insert it into a chromosome of the host cell. Sequencing of different eukaryote genomes has revealed the presence of many such endogenous retroviral sequences. The mechanisms by which these retroviral sequences have colonized the genome are still unknown, and the endogenous retrovirus gypsy of Drosophila melanogaster is a powerful experimental model for deciphering this process in vivo. Gypsy is expressed in a layer of somatic cells, and then transferred into the oocyte by an unknown mechanism. This critical step is the start of the endogenization process. Moreover gypsy has been shown to have infectious properties, probably due to its envelope gene acquired from a baculovirus. Recently we have also shown that gypsy maternal transmission is reduced in the presence of the endosymbiotic bacterium Wolbachia. These studies demonstrate that gypsy is a unique and powerful model for understanding the endogenization of retroviruses.

  8. Metabolic and functional phenotypic profiling of Drosophila melanogaster reveals reduced sex differentiation under stressful environmental conditions

    DEFF Research Database (Denmark)

    Ørsted, Michael; Malmendal, Anders; Muñoz, Joaquin

    2017-01-01

    Strong sexual dimorphism is commonly observed across species and e.g. trade-offs between reproduction and maintenance are thought to explain this dimorphism. Here we test how the metabolic and functional phenotypic responses to varying types of environmental stress differ in male and female...... rearing regimes were investigated using NMR metabolomics and assessed for body mass and viability. Our results showed that environmental stress leads to reduced sexual dimorphism in both metabolic composition and body mass compared to the level of dimorphism observed at benign conditions. This reduced...... Drosophila melanogaster (Diptera: Drosophilidae), and how this impacts the magnitude of sexual dimorphism. Experimental stressors that we exposed flies to during development were heat stress, poor nutrition, high acidity, high levels of ammonia and ethanol. Emerged male and female flies from the different...

  9. Mapping Second Chromosome Mutations to Defined Genomic Regions in Drosophila melanogaster.

    Science.gov (United States)

    Kahsai, Lily; Cook, Kevin R

    2018-01-04

    Hundreds of Drosophila melanogaster stocks are currently maintained at the Bloomington Drosophila Stock Center with mutations that have not been associated with sequence-defined genes. They have been preserved because they have interesting loss-of-function phenotypes. The experimental value of these mutations would be increased by tying them to specific genomic intervals so that geneticists can more easily associate them with annotated genes. Here, we report the mapping of 85 second chromosome complementation groups in the Bloomington collection to specific, small clusters of contiguous genes or individual genes in the sequenced genome. This information should prove valuable to Drosophila geneticists interested in processes associated with particular phenotypes and those searching for mutations affecting specific sequence-defined genes. Copyright © 2018 Kahsai,Cook.

  10. Mapping Second Chromosome Mutations to Defined Genomic Regions in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Lily Kahsai

    2018-01-01

    Full Text Available Hundreds of Drosophila melanogaster stocks are currently maintained at the Bloomington Drosophila Stock Center with mutations that have not been associated with sequence-defined genes. They have been preserved because they have interesting loss-of-function phenotypes. The experimental value of these mutations would be increased by tying them to specific genomic intervals so that geneticists can more easily associate them with annotated genes. Here, we report the mapping of 85 second chromosome complementation groups in the Bloomington collection to specific, small clusters of contiguous genes or individual genes in the sequenced genome. This information should prove valuable to Drosophila geneticists interested in processes associated with particular phenotypes and those searching for mutations affecting specific sequence-defined genes.

  11. Experimental Investigation of an Automobile Air-Conditioning System using Integrated Brushless Direct Current Motor Rotary Compressor

    Directory of Open Access Journals (Sweden)

    Sukri M.F.

    2016-01-01

    Full Text Available The present study presents an experimental investigation on the effect of condenser air inlet temperature and dimensionless parameter of X on the performance of automobile air-conditioning (AAC system using integrated brushless direct current motor-rotary compressor and electronic expansion valve. The other components of AAC system are from original component of AAC system used for medium size passenger car. The experimental results showed that the increment of the condenser air inlet temperature and X caused an increase in condensing temperature, cooling capacity and compressor work, while decreasing the coefficient of performance (COP. Meanwhile, the evaporating temperature increase with the increment of condenser air inlet temperature, but decrease with decrement of X. In general, AAC system have to work at higher value of X in order to produce more cooling capacity, thereby increment in compressor work also occurs due to energy balance. However, at higher value of X, the COP of the system dropped due to dominant increase in compressor power, as opposed to a rise in cooling capacity. Due to this reason, the best operation of this compressor occurs at X = 4.96 for constant T5 (35ºC, or at T5 = 30ºC for constant X (4.96.

  12. Numerical and Experimental Study on Integration of Control Actions into the Finite Element Solutions in Smart Structures

    Directory of Open Access Journals (Sweden)

    L. Malgaca

    2009-01-01

    Full Text Available Piezoelectric smart structures can be modeled using commercial finite element packages. Integration of control actions into the finite element model solutions (ICFES can be done in ANSYS by using parametric design language. Simulation results can be obtained easily in smart structures by this method. In this work, cantilever smart structures consisting of aluminum beams and lead-zirconate-titanate (PZT patches are considered. Two cases are studied numerically and experimentally in parallel. In the first case, a smart structure with a single PZT patch is used for the free vibration control under an initial tip displacement. In the second case, a smart structure with two PZT patches is used for the forced vibration control under harmonic excitation, where one of the PZT patches is used as vibration generating shaker while the other is used as vibration controlling actuator. For the two cases, modal analyses are done using chirp signals; Control OFF and Control ON responses in the time domain are obtained for various controller gains. A non-contact laser displacement sensor and strain gauges are utilized for the feedback signals. It is observed that all the simulation results agree with the experimental results.

  13. SHOW. A program for the integrated analysis of the data produced in a nuclear fusion experimental device

    Energy Technology Data Exchange (ETDEWEB)

    Bracco, G.; Tudisco, O. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Energia

    1998-03-01

    The report describes the program SHOW, an application devoted to the integrated analysis of the data produced in nuclear fusion experimental devices. The program is currently used for the analysis of the FTU data and a version is also available at JET. The code is written in FORTRAN 77, runs on IBM mainframes under MVS operating system and makes use of the GDDM graphical package. The program, that operates both in batch and interactive modes, permits to perform a graphical analysis of the data collected in the experimental databases. The report contains as appendixes the detailed description of all the program options together with a short illustration of the FTU databases. [Italiano] Il rapporto descrive il programma SHOW. Si tratta di una applicazione che permette l`analisi integrata dei dati prodotti da apparati sperimentali dedicati allo studio della fusione nucleare controllata. Il programma e` utilizzato per l`analisi dei dati di FTU (Frascati Tokamak Upgrade) e una versione e` disponibile anche al JET (Joint European Torus). Il codice e` scritto in FORTRAN 77 per mainframes IBM con sistema operativo MVS ed utilizza il pacchetto grafico GDDM. Il programma puo` funzionare sia in modo batch che in modo interattivo e permette di compiere l`elaborazione grafica dei dati raccolti nelle basi di dati sperimentali. Il rapporto contiene come appendici la descrizione dettagliata di tutte le opzioni del programma e una breve illustrazione delle basi di dati disponibili per FTU.

  14. Experimental investigation of an indirect solar dryer integrated with phase change material for drying valeriana jatamansi (medicinal herb

    Directory of Open Access Journals (Sweden)

    A.K. Bhardwaj

    2017-09-01

    Full Text Available In this study, an experimental investigation of an indirect solar dryer integrated with phase change material has been carried out for drying Valeriana Jatamansi. The experimentation has been performed under the climatic conditions of Himalayan region, Solan (latitude − 30.91°N, longitude − 77.09°E, Himachal Pradesh (India in the month of October-November 2016. Paraffin RT-42 has been used as a phase change material in the dryer. Using this system, the moisture content of rhizomes reduced from 89% to 9% in 5 days as compared to heat pump drying and shade drying, which took 8 days and 14 days, respectively. Results of present study infer that the drying time using phase change material in this setup has reduced by 37.50% and 64.29% when compared to heat pump drying and shade drying, respectively. The dried rhizomes obtained are of superior quality in terms of colour, texture, aroma and bio-medical constituents. Analyses show that by using present setup, total valepotriates obtained were 3.47% as compared to traditional shade drying which yield 3.31%.

  15. Microgravity effects on Drosophila melanogaster development and aging: comparative analysis of the results of the Fly experiment in the Biokosmos 9 biosatellite flight.

    Science.gov (United States)

    Marco, R; González-Jurado, J; Calleja, M; Garesse, R; Maroto, M; Ramírez, E; Holgado, M C; de Juan, E; Miquel, J

    1992-01-01

    The results are presented of the exposure of Drosophila melanogaster to microgravity conditions during a 15-day biosatellite flight, Biokosmos 9, in a joint ESA-URSS project. The experimental containers were loaded before launch with a set of Drosophila melanogaster Oregon R larvae so that imagoes were due to emerge half-way through the flight. A large number of normally developed larvae were recovered from the space-flown containers. These larvae were able to develop into normal adults confirming earlier results that Drosophila melanogaster of a wild-type constitution can develop normally in the absence of gravity. However, microgravity exposure clearly enhances the number of growing embryos laid by the flies and possibly slows down the developmental pace of the microgravity-exposed animals. Due to some problems in the experimental set-up, this slowing down needs to be verified in future experiments. No live adult that had been exposed to microgravity was recovered from the experiment, so that no life span studies could be carried out, but adult males emerged from the recovered embyros showed a slight shortening in life span and a lower performance in other experimental tests of aging. This agrees with the results of previous experiments performed by our groups.

  16. Dynamic modeling, experimental evaluation, optimal design and control of integrated fuel cell system and hybrid energy systems for building demands

    Science.gov (United States)

    Nguyen, Gia Luong Huu

    Fuel cells can produce electricity with high efficiency, low pollutants, and low noise. With the advent of fuel cell technologies, fuel cell systems have since been demonstrated as reliable power generators with power outputs from a few watts to a few megawatts. With proper equipment, fuel cell systems can produce heating and cooling, thus increased its overall efficiency. To increase the acceptance from electrical utilities and building owners, fuel cell systems must operate more dynamically and integrate well with renewable energy resources. This research studies the dynamic performance of fuel cells and the integration of fuel cells with other equipment in three levels: (i) the fuel cell stack operating on hydrogen and reformate gases, (ii) the fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit, and (iii) the hybrid energy system consisting of photovoltaic panels, fuel cell system, and energy storage. In the first part, this research studied the steady-state and dynamic performance of a high temperature PEM fuel cell stack. Collaborators at Aalborg University (Aalborg, Denmark) conducted experiments on a high temperature PEM fuel cell short stack at steady-state and transients. Along with the experimental activities, this research developed a first-principles dynamic model of a fuel cell stack. The dynamic model developed in this research was compared to the experimental results when operating on different reformate concentrations. Finally, the dynamic performance of the fuel cell stack for a rapid increase and rapid decrease in power was evaluated. The dynamic model well predicted the performance of the well-performing cells in the experimental fuel cell stack. The second part of the research studied the dynamic response of a high temperature PEM fuel cell system consisting of a fuel reformer, a fuel cell stack, and a heat recovery unit with high thermal integration. After verifying the model performance with the

  17. Single Nucleotide Polymorphism Markers for Genetic Mapping in Drosophila melanogaster

    OpenAIRE

    Hoskins, Roger A.; Phan, Alexander C.; Naeemuddin, Mohammed; Mapa, Felipa A.; Ruddy, David A.; Ryan, Jessica J.; Young, Lynn M.; Wells, Trent; Kopczynski, Casey; Ellis, Michael C.

    2001-01-01

    For nearly a century, genetic analysis in Drosophila melanogaster has been a powerful tool for analyzing gene function, yet Drosophila lacks the molecular genetic mapping tools that recently have revolutionized human, mouse, and plant genetics. Here, we describe the systematic characterization of a dense set of molecular markers in Drosophila by using a sequence tagged site-based physical map of the genome. We identify 474 biallelic markers in standard laboratory strains of Drosophila that sp...

  18. Thermal adaptation of cellular membranes in natural populations ofDrosophila melanogaster.

    Science.gov (United States)

    Cooper, Brandon S; Hammad, Loubna A; Montooth, Kristi L

    2014-08-01

    Changes in temperature disrupt the fluidity of cellular membranes, which can negatively impact membrane integrity and cellular processes. Many ectotherms, including Drosophila melanogaster (Meigen), adjust the glycerophospholipid composition of their membranes to restore optimal fluidity when temperatures change, a type of trait plasticity termed homeoviscous adaptation.Existing data suggest that plasticity in the relative abundances of the glycerophospholipids phosphatidylethanolamine (PE) and phosphatidylcholine (PC) underlies cellular adaptation to temporal variability in the thermal environment. For example, laboratory populations of D. melanogaster evolved in the presence of temporally variable temperatures have greater developmental plasticity of the ratio of PE to PC (PE/PC) and greater fecundity than do populations evolved at constant temperatures.Here, we extend this work to natural populations of D. melanogaster by evaluating thermal plasticity of glycerophospholipid composition at different life stages, in genotypes isolated from Vermont, Indiana and North Carolina, USA. We also quantify the covariance between developmental and adult (reversible) plasticity, and between adult responses of the membrane to cool and warm thermal shifts.As predicted by physiological models of homeoviscous adaptation, flies from all populations decrease PE/PC and the degree of lipid unsaturation in response to warm temperatures. Furthermore, these populations have diverged in their degree of membrane plasticity. Flies from the most variable thermal environment (Vermont, USA) decrease PE/PC to a greater extent than do other populations when developed at a warm temperature, a pattern that matches our previous observation in laboratory-evolved populations. We also find that developmental plasticity and adult plasticity of PE/PC covary across genotypes, but that adult responses to cool and warm thermal shifts do not.When combined with our previous observations of laboratory

  19. The neurogenetics of group behavior in Drosophila melanogaster.

    Science.gov (United States)

    Ramdya, Pavan; Schneider, Jonathan; Levine, Joel D

    2017-01-01

    Organisms rarely act in isolation. Their decisions and movements are often heavily influenced by direct and indirect interactions with conspecifics. For example, we each represent a single node within a social network of family and friends, and an even larger network of strangers. This group membership can affect our opinions and actions. Similarly, when in a crowd, we often coordinate our movements with others like fish in a school, or birds in a flock. Contributions of the group to individual behaviors are observed across a wide variety of taxa but their biological mechanisms remain largely unknown. With the advent of powerful computational tools as well as the unparalleled genetic accessibility and surprisingly rich social life of Drosophila melanogaster, researchers now have a unique opportunity to investigate molecular and neuronal determinants of group behavior. Conserved mechanisms and/or selective pressures in D. melanogaster can likely inform a much wider phylogenetic scale. Here, we highlight two examples to illustrate how quantitative and genetic tools can be combined to uncover mechanisms of two group behaviors in D. melanogaster: social network formation and collective behavior. Lastly, we discuss future challenges towards a full understanding how coordinated brain activity across many individuals gives rise to the behavioral patterns of animal societies. © 2017. Published by The Company of Biologists Ltd.

  20. Characterization of Reproductive Dormancy in MaleDrosophila melanogaster.

    Science.gov (United States)

    Kubrak, Olga I; Kučerová, Lucie; Theopold, Ulrich; Nylin, Sören; Nässel, Dick R

    2016-01-01

    Insects are known to respond to seasonal and adverse environmental changes by entering dormancy, also known as diapause. In some insect species, including Drosophila melanogaster , dormancy occurs in the adult organism and postpones reproduction. This adult dormancy has been studied in female flies where it is characterized by arrested development of ovaries, altered nutrient stores, lowered metabolism, increased stress and immune resistance and drastically extended lifespan. Male dormancy, however, has not been investigated in D. melanogaster , and its physiology is poorly known in most insects. Here we show that unmated 3-6 h old male flies placed at low temperature (11°C) and short photoperiod (10 Light:14 Dark) enter a state of dormancy with arrested spermatogenesis and development of testes and male accessory glands. Over 3 weeks of diapause we see a dynamic increase in stored carbohydrates and an initial increase and then a decrease in lipids. We also note an up-regulated expression of genes involved in metabolism, stress responses and innate immunity. Interestingly, we found that male flies that entered reproductive dormancy do not attempt to mate females kept under non-diapause conditions (25°C, 12L:12D), and conversely non-diapausing males do not mate females in dormancy. In summary, our study shows that male D. melanogaster can enter reproductive dormancy. However, our data suggest that dormant male flies deplete stored nutrients faster than females, studied earlier, and that males take longer to recover reproductive capacity after reintroduction to non-diapause conditions.

  1. Metabolic Activity of Radish Sprouts Derived Isothiocyanates in Drosophila melanogaster

    Science.gov (United States)

    Baenas, Nieves; Piegholdt, Stefanie; Schloesser, Anke; Moreno, Diego A.; García-Viguera, Cristina; Rimbach, Gerald; Wagner, Anika E.

    2016-01-01

    We used Drosophila melanogaster as a model system to study the absorption, metabolism and potential health benefits of plant bioactives derived from radish sprouts (Raphanus sativus cv. Rambo), a Brassicaceae species rich in glucosinolates and other phytochemicals. Flies were subjected to a diet supplemented with lyophilized radish sprouts (10.6 g/L) for 10 days, containing high amounts of glucoraphenin and glucoraphasatin, which can be hydrolyzed by myrosinase to the isothiocyanates sulforaphene and raphasatin, respectively. We demonstrate that Drosophila melanogaster takes up and metabolizes isothiocyanates from radish sprouts through the detection of the metabolite sulforaphane-cysteine in fly homogenates. Moreover, we report a decrease in the glucose content of flies, an upregulation of spargel expression, the Drosophila homolog of the mammalian PPARγ-coactivator 1 α, as well as the inhibition of α-amylase and α-glucosidase in vitro. Overall, we show that the consumption of radish sprouts affects energy metabolism in Drosophila melanogaster which is reflected by lower glucose levels and an increased expression of spargel, a central player in mitochondrial biogenesis. These processes are often affected in chronic diseases associated with aging, including type II diabetes mellitus. PMID:26901196

  2. Mdr65 decreases toxicity of multiple insecticides in Drosophila melanogaster.

    Science.gov (United States)

    Sun, Haina; Buchon, Nicolas; Scott, Jeffrey G

    2017-10-01

    ABC transporters are ubiquitous membrane-bound proteins, present in both prokaryotes and eukaryotes. The major function of eukaryotic ABC transporters is to mediate the efflux of a variety of substrates (including xenobiotics) out of cells. ABC transporters have been widely investigated in humans, particularly for their involvement in multidrug resistance (MDR). Considerably less is known about their roles in transport and/or excretion in insects. ABC transporters are only known to function as exporters in insects. Drosophila melanogaster has 56 ABC transporter genes, including eight which are phylogenetically most similar to the human Mdr genes (ABCB1 clade). We investigated the role of ABC transporters in the ABCB1 clade in modulating the susceptibility to insecticides. We took advantage of the GAL4/UAS system in D. melanogaster to knockdown the expression levels of Mdr65, Mdr50, Mdr49 and ABCB6 using transgenic UAS-RNAi lines and conditional driver lines. The most notable effects were increased sensitivities to nine different insecticides by silencing of Mdr65. Furthermore, a null mutation of Mdr65 decreased the malathion, malaoxon and fipronil LC 50 values by a factor of 1.9, 2.1 and 3.9, respectively. Altogether, this data demonstrates the critical role of ABC transporters, particularly Mdr65, in altering the toxicity of specific, structurally diverse, insecticides in D. melanogaster. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Drosophila Melanogaster as an Emerging Translational Model of Human Nephrolithiasis

    Science.gov (United States)

    Miller, Joe; Chi, Thomas; Kapahi, Pankaj; Kahn, Arnold J.; Kim, Man Su; Hirata, Taku; Romero, Michael F.; Dow, Julian A.T.; Stoller, Marshall L.

    2013-01-01

    Purpose The limitations imposed by human clinical studies and mammalian models of nephrolithiasis have hampered the development of effective medical treatments and preventative measures for decades. The simple but elegant Drosophila melanogaster is emerging as a powerful translational model of human disease, including nephrolithiasis and may provide important information essential to our understanding of stone formation. We present the current state of research using D. melanogaster as a model of human nephrolithiasis. Materials and Methods A comprehensive review of the English language literature was performed using PUBMED. When necessary, authoritative texts on relevant subtopics were consulted. Results The genetic composition, anatomic structure and physiologic function of Drosophila Malpighian tubules are remarkably similar to those of the human nephron. The direct effects of dietary manipulation, environmental alteration, and genetic variation on stone formation can be observed and quantified in a matter of days. Several Drosophila models of human nephrolithiasis, including genetically linked and environmentally induced stones, have been developed. A model of calcium oxalate stone formation is among the most recent fly models of human nephrolithiasis. Conclusions The ability to readily manipulate and quantify stone formation in D. melanogaster models of human nephrolithiasis presents the urologic community with a unique opportunity to increase our understanding of this enigmatic disease. PMID:23500641

  4. Differential sexual survival of Drosophila melanogaster on copper sulfate.

    Science.gov (United States)

    Balinski, Michael A; Woodruff, Ronny C

    2017-04-01

    Based on studies of the influence of X-chromosomes on the viability of Drosophila melanogaster exposed to cadmium, and on the role of X-linked genes on copper homeostasis, we examined the effect of copper sulfate (CuSO 4 ) on offspring viability using three independent, inbred D. melanogaster crosses (ensuring identical autosomes for males and females within each cross). Each cross was performed with attached X-chromosome females and males with a single X-chromosome. As female D. melanogaster have less metallothionein RNA expression than males, we predicted fewer female offspring than male offspring in crosses exposed to CuSO 4 , even though females have two copies of X-chromosome genes, possibly resulting in overdominant heterozygosity. In two of three crosses, CuSO 4 caused significantly higher numbers of male offspring compared to female offspring. We hypothesized that these gender-based viability differences to copper exposure are caused by X-chromosome ploidy and X-linked genetic variation affecting metallothionein expression. Observed differential offspring viability responses among crosses to copper exposure also showed that different genetic backgrounds (autosomal and/or X-chromosome) can result in significant differences in heavy metal and metallothionein regulation. These results suggest that the effect of copper on offspring viability depends on both genetic background and gender, as both factors can affect the regulation of metallothionein proteins as well as homeostasis of biologically necessary heavy metals.

  5. Integrated design of Nb-based superalloys: Ab initio calculations, computational thermodynamics and kinetics, and experimental results

    International Nuclear Information System (INIS)

    Ghosh, G.; Olson, G.B.

    2007-01-01

    An optimal integration of modern computational tools and efficient experimentation is presented for the accelerated design of Nb-based superalloys. Integrated within a systems engineering framework, we have used ab initio methods along with alloy theory tools to predict phase stability of solid solutions and intermetallics to accelerate assessment of thermodynamic and kinetic databases enabling comprehensive predictive design of multicomponent multiphase microstructures as dynamic systems. Such an approach is also applicable for the accelerated design and development of other high performance materials. Based on established principles underlying Ni-based superalloys, the central microstructural concept is a precipitation strengthened system in which coherent cubic aluminide phase(s) provide both creep strengthening and a source of Al for Al 2 O 3 passivation enabled by a Nb-based alloy matrix with required ductile-to-brittle transition temperature, atomic transport kinetics and oxygen solubility behaviors. Ultrasoft and PAW pseudopotentials, as implemented in VASP, are used to calculate total energy, density of states and bonding charge densities of aluminides with B2 and L2 1 structures relevant to this research. Characterization of prototype alloys by transmission and analytical electron microscopy demonstrates the precipitation of B2 or L2 1 aluminide in a (Nb) matrix. Employing Thermo-Calc and DICTRA software systems, thermodynamic and kinetic databases are developed for substitutional alloying elements and interstitial oxygen to enhance the diffusivity ratio of Al to O for promotion of Al 2 O 3 passivation. However, the oxidation study of a Nb-Hf-Al alloy, with enhanced solubility of Al in (Nb) than in binary Nb-Al alloys, at 1300 deg. C shows the presence of a mixed oxide layer of NbAlO 4 and HfO 2 exhibiting parabolic growth

  6. Development and integration of a 50 Hz pellet injection system for the Experimental Advanced Superconducting Tokamak (EAST)

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Xingjia [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230029 (China); Chen, Yue [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Hu, Jiansheng, E-mail: hujs@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Vinyar, Igor; Lukin, Alexander [PELIN, Saint-Petersburg (Russian Federation); Yuan, Xiaoling; Li, Changzheng; Liu, Haiqing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2017-01-15

    Highlights: • The design of the pumping system fits the operation requirement well not only theoretically but also experimentally. • The data showed that the averaged pellet injection velocity and propellant gas pressure had a relationship submitting to the power function. • The reliability of the injected pellet was mostly around 90% which is higher than the PI-20 system thanks to the improved pumping system and the new pellet fabrication and acceleration system. - Abstract: A 50 Hz pellet injection system, which is designed for edge-localized mode (ELM) control, has been successfully developed and integrated for the Experimental Advanced Superconducting Tokamak (EAST). Pellet injection is achieved by two separated injection system modules that can be operated independently from 1 to 25 Hz. The nominal injection velocity is 250 m/s with a scatter of ±50 m/s at a repetition rate of 50 Hz. A buffer tank and a two-stage differential pumping system of the pellet injection system was designed to increase hydrogen/deuterium ice quality and eliminate the influence of propellant gas on plasma operation, respectively. The pressure of the buffer tank could be pumped to 1 × 10{sup 2} Pa, and the pressure in the second differential chamber could reach 1 × 10{sup −4} Pa during the experiment. Engineering experiments, which consisted of 50 Hz pellet injection and guiding tube mock-up experiments, were also systematically carried out in a laboratory environment and demonstrated that the pellet injection system can reliably inject pellets at a repetitive frequency of 50 Hz.

  7. Genetic effects of radon 222 in a population of Drosophila melanogaster chronically exposed

    International Nuclear Information System (INIS)

    Salceda, V.M.

    1997-01-01

    It was investigated the mutagenic effect of Radon 222 during a experimental period of 11 generations. In this lapse Drosophila melanogaster larvae line Canton-S were maintained in a radon atmosphere. In each test generation had been extracted males, consequently exposed to radiation which were subjected to a crossing series with a bearer marker genes of according to the Wallace experimental design (1956). Due to the experimental conditions it only was determined the recessive lethal mutations frequency for the second chromosome in the 1,4,7 and 11 generations. Of all study it was conduced in parallel way a non-treated witness population. The concentrations at which was subjected the experimental population varied of generation to generation from 12 ± 2 to 43 ± 5 kBq/m 3 . Our analysis correspond to lethality determination in 1182 second chromosomes distributed between two populations and the different exposition generations. The study allow to determine the respective frequencies of recessive lethal genes varying according to the population and/or generation between 10.53 and 22.02%. The statistical analysis of data did not show significant differences among the different populations. (Author)

  8. Transcriptional profiling of human breast cancer cells cultured under microgravity conditions revealed the key role of genetic gravity sensors previously detected in Drosophila melanogaster

    Science.gov (United States)

    Valdivia-Silva, Julio E.; Lavan, David; Diego Orihuela-Tacuri, M.; Sanabria, Gabriela

    2016-07-01

    Currently, studies in Drosophila melanogaster has shown emerging evidence that microgravity stimuli can be detected at the genetic level. Analysis of the transcriptome in the pupal stage of the fruit flies under microgravity conditions versus ground controls has suggested the presence of a few candidate genes as "gravity sensors" which are experimentally validated. Additionally, several studies have shown that microgravity causes inhibitory effects in different types of cancer cells, although the genes involved and responsible for these effects are still unknown. Here, we demonstrate that the genes suggested as the sensors of gravitational waves in Drosophila melanogaster and their human counterpart (orthologous genes) are highly involved in carcinogenesis, proliferation, anti-apoptotic signals, invasiveness, and metastatic potential of breast cancer cell tumors. The transcriptome analyses suggested that the observed inhibitory effect in cancer cells could be due to changes in the genetic expression of these candidates. These results encourage the possibility of new therapeutic targets managed together and not in isolation.

  9. Menin links the stress response to genome stability in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Maria Papaconstantinou

    Full Text Available BACKGROUND: The multiple endocrine neoplasia type I gene functions as a tumor suppressor gene in humans and mouse models. In Drosophila melanogaster, mutants of the menin gene (Mnn1 are hypersensitive to mutagens or gamma irradiation and have profound defects in the response to several stresses including heat shock, hypoxia, hyperosmolarity and oxidative stress. However, it is not known if the function of menin in the stress response contributes to genome stability. The objective of this study was to examine the role of menin in the control of the stress response and genome stability. METHODOLOGY/PRINCIPAL FINDINGS: Using a test of loss-of-heterozygosity, we show that Drosophila strains lacking a functional Mnn1 gene or expressing a Mnn1 dsRNA display increased genome instability in response to non-lethal heat shock or hypoxia treatments. This is also true for strains lacking all Hsp70 genes, implying that a precise control of the stress response is required for genome stability. While menin is required for Hsp70 expression, the results of epistatic studies indicate that the increase in genome instability observed in Mnn1 lack-of-function mutants cannot be accounted for by mis-expression of Hsp70. Therefore, menin may promote genome stability by controlling the expression of other stress-responsive genes. In agreement with this notion, gene profiling reveals that Mnn1 is required for sustained expression of all heat shock protein genes but is dispensable for early induction of the heat shock response. CONCLUSIONS/SIGNIFICANCE: Mutants of the Mnn1 gene are hypersensitive to several stresses and display increased genome instability when subjected to conditions, such as heat shock, generally regarded as non-genotoxic. In this report, we describe a role for menin as a global regulator of heat shock gene expression and critical factor in the maintenance of genome integrity. Therefore, menin links the stress response to the control of genome stability

  10. Inhibition of Myeloperoxidase at the Peak of Experimental Autoimmune Encephalomyelitis Restores Blood-Brain-Barrier Integrity and Ameliorates Disease Severity.

    Science.gov (United States)

    Zhang, Hao; Ray, Avijit; Miller, Nichole M; Hartwig, Danielle; Pritchard, Kirkwood A; Dittel, Bonnie N

    2015-11-12

    Oxidative stress is thought to contribute to disease pathogenesis in the central nervous system (CNS) disease multiple sclerosis (MS). Myeloperoxidase (MPO), a potent peroxidase that generates toxic radicals and oxidants, is increased in the CNS during MS. However, the exact mechanism whereby MPO drives MS pathology is not known. We addressed this question by inhibiting MPO in mice with experimental autoimmune encephalomyelitis (EAE) using our non-toxic MPO inhibitor KYC. We found that therapeutic administration of KYC for five days starting at the peak of disease significantly attenuated EAE disease severity, reduced myeloid cell numbers and permeability of the blood-brain-barrier (BBB). These data indicate that inhibition of MPO by KYC restores BBB integrity thereby limiting migration of myeloid cells into the CNS that drive EAE pathogenesis. In addition, these observations indicate that KYC may be an effective therapeutic agent for the treatment of MS. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. Identification of novel adhesins of M. tuberculosis H37Rv using integrated approach of multiple computational algorithms and experimental analysis.

    Directory of Open Access Journals (Sweden)

    Sanjiv Kumar

    Full Text Available Pathogenic bacteria interacting with eukaryotic host express adhesins on their surface. These adhesins aid in bacterial attachment to the host cell receptors during colonization. A few adhesins such as Heparin binding hemagglutinin adhesin (HBHA, Apa, Malate Synthase of M. tuberculosis have been identified using specific experimental interaction models based on the biological knowledge of the pathogen. In the present work, we carried out computational screening for adhesins of M. tuberculosis. We used an integrated computational approach using SPAAN for predicting adhesins, PSORTb, SubLoc and LocTree for extracellular localization, and BLAST for verifying non-similarity to human proteins. These steps are among the first of reverse vaccinology. Multiple claims and attacks from different algorithms were processed through argumentative approach. Additional filtration criteria included selection for proteins with low molecular weights and absence of literature reports. We examined binding potential of the selected proteins using an image based ELISA. The protein Rv2599 (membrane protein binds to human fibronectin, laminin and collagen. Rv3717 (N-acetylmuramoyl-L-alanine amidase and Rv0309 (L,D-transpeptidase bind to fibronectin and laminin. We report Rv2599 (membrane protein, Rv0309 and Rv3717 as novel adhesins of M. tuberculosis H37Rv. Our results expand the number of known adhesins of M. tuberculosis and suggest their regulated expression in different stages.

  12. Integrated Microwave Photonic Isolators: Theory, Experimental Realization and Application in a Unidirectional Ring Mode-Locked Laser Diode

    Directory of Open Access Journals (Sweden)

    Martijn J.R. Heck

    2015-09-01

    Full Text Available A novel integrated microwave photonic isolator is presented. It is based on the timed drive of a pair of optical modulators, which transmit a pulsed or oscillating optical signal with low loss, when driven in phase. A signal in the reverse propagation direction will find the modulators out of phase and, hence, will experience high loss. Optical and microwave isolation ratios were simulated to be in the range up to 10 dB and 20 dB, respectively, using parameters representative for the indium phosphide platform. The experimental realization of this device in the hybrid silicon platform showed microwave isolation in the 9 dB–22 dB range. Furthermore, we present a design study on the use of these isolators inside a ring mode-locked laser cavity. Simulations show that unidirectional operation can be achieved, with a 30–50-dB suppression of the counter propagating mode, at limited driving voltages. The potentially low noise and feedback-insensitive operation of such a laser makes it a very promising candidate for use as on-chip microwave or comb generators.

  13. Comparative genomics of bacteria in the genus Providencia isolated from wild Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Galac Madeline R

    2012-11-01

    Full Text Available Abstract Background Comparative genomics can be an initial step in finding the genetic basis for phenotypic differences among bacterial strains and species. Bacteria belonging to the genus Providencia have been isolated from numerous and varied environments. We sequenced, annotated and compared draft genomes of P. rettgeri, P. sneebia, P. alcalifaciens, and P. burhodogranariea. These bacterial species that were all originally isolated as infections of wild Drosophila melanogaster and have been previously shown to vary in virulence to experimentally infected flies. Results We found that these Providencia species share a large core genome, but also possess distinct sets of genes that are unique to each isolate. We compared the genomes of these isolates to draft genomes of four Providencia isolated from the human gut and found that the core genome size does not substantially change upon inclusion of the human isolates. We found many adhesion related genes among those genes that were unique to each genome. We also found that each isolate has at least one type 3 secretion system (T3SS, a known virulence factor, though not all identified T3SS belong to the same family nor are they in syntenic genomic locations. Conclusions The Providencia species examined here are characterized by high degree of genomic similarity which will likely extend to other species and isolates within this genus. The presence of T3SS islands in all of the genomes reveal that their presence is not sufficient to indicate virulence towards D. melanogaster, since some of the T3SS-bearing isolates are known to cause little mortality. The variation in adhesion genes and the presence of T3SSs indicates that host cell adhesion is likely an important aspect of Providencia virulence.

  14. Experimental Research on heat transfer enhancement of lubricating-oil cooler with mixing integral pin-fin tubes and plain tubes

    International Nuclear Information System (INIS)

    Niu Guanglin; Yan Changqi; Sun Zhongning; Shi Shuai; Wang Lei

    2010-01-01

    A lot of comparison experimental research has been done to the lubricating-oil cooler with mixing integral pin-fin tubes and plain tubes. It is discovered that the mixing integral pin-fin tubes heat transfer capacity in unit volume is higher, pressure drop is lower, and the very strong heat transfer ability than plain tubes when oil volume flow rate is at constant value. The results show the performance of lubricating-oil cooler with mixing integral pin-fin tubes and plain tubes is superiority. So this can made lubricating-oil cooler miniaturize in the same Heat changing condition. (authors)

  15. 'Integration'

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2011-01-01

    , while the countries have adopted disparate policies and ideologies, differences in the actual treatment and attitudes towards immigrants and refugees in everyday life are less clear, due to parallel integration programmes based on strong similarities in the welfare systems and in cultural notions...

  16. 40 CFR 798.5955 - Heritable translocation test in drosophila melanogaster.

    Science.gov (United States)

    2010-07-01

    ... drosophila melanogaster. 798.5955 Section 798.5955 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....5955 Heritable translocation test in drosophila melanogaster. (a) Purpose. The heritable translocation test in Drosophila measures the induction of chromosomal translocations in germ cells of insects...

  17. An integral parametrization of the bacterial growth curve experimental demonstration with E. coli C{sub 6}00 bacteria; Parametrizacion integrada de la curva de crecimiento bacteriano. Comprobacion experimental para E. coli C{sub 6}00

    Energy Technology Data Exchange (ETDEWEB)

    Garces, F.; Vidania, R. de

    1984-07-01

    In this work an integral parametrization of the bacterial growth curve is presented. The values of the parameters are obtained by fitting to the experimental data. Those parameters, with allow to describe the growth in its different phases, are the followings: slopes of the curve in its three parts and the time which divides the last two phases of the bacterial growth. The experimental data are bacterial densities measured by optical methods. The bacteria used was the E. coli C{sub 6}00. (Author)

  18. Dispersão ativa em Drosophila melanogaster (Diptera; Drosophilidae

    Directory of Open Access Journals (Sweden)

    Salvador de Carvalho

    1988-07-01

    Full Text Available Em uma floresta remanescente do "mato grosso goiano" (Goiânia, GO, Brasil, moscas marcadas e mutantes "white" de Drosophila melanogaster foram soltos na intersecção de dois eixos ortogonais. Foram colocadas armadilhas a intervalos de 20 m nesses eixos. Coletas periódicas, a cada meia hora, das 08:30 às 17:00 hs foram realizadas, para estudar a dispersão das moscas no meio natural e para inferir a significância do componente genético nessa dispersão. Os dados obtidos sugerem as seguintes conclusões: foi detectada dispersão ativa; essa dispersão ativa depende do genótipo (foi maior no tipo selvagem que no mutante "white"; os padrões de dispersão mudaram de acordo com o tempo; uma mobilidade presumível de 120 m/h foi detectada; uma estimativa aproximada da densidade populacional sugere valores de cerca de 25.000 moscas/3.600m² para o grupo melanogaster e de cerca de 50.000 moscas/3.600m² para as Drosophila em geral; a freqüência da captura mudou durante o período.In a remaining wood of the "mato grosso goiano" (Goiânia, Go, Brazil, Drosophila melanogaster marked flies as well as "white" mutants were released at the inter-section of two orthogonal axis. Traps were disposed at intervals of 20m over these axis. Every half hour, from 08:30 to 17:00, periodics collects were performed to study the dispersion of the flies in natural environement as well as to infer about the significance of the genetic component in this dispersion. The obtained data suggest the following conclusions: acitve dispersion was detected; this active dispersion is genotype dependent (it was bigger in the wild type than the " white" mutante; the dispersion patterns changed according to time; a presumiblemobility potential of 120m/hour was detected; an approximate estimate of the population density suggest values of about 25,000 flies/3,600m² for the melanogaster group and about 50,000 flies 3,600m² for Drosophila in general; the frequence of capture

  19. Analysis of a new morphogenetic mutation in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mglinets, V.A.

    1987-01-01

    Somatic mosaicism for mutations monster and yellow was induced by gamma-irradiation of Drosophila melanogaster y/y; Dp(1; 2)sc 19 M(2)z/mn d embryos and larvae. Frequencies of mosaicism increased with the age of treated larvae, especially in the end of the 2nd larval instar. Autonomous expression of mn was observed throughout the whole range of larval age studied, though neither for all y/y spots nor for all parts of the spots. Dissimilarities in dynamics of mosaic spots and duplication induction suggest that the latter are not due to mn expression in somatic clones

  20. Host-microbe interactions in the gut of Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Takayuki eKuraishi

    2013-12-01

    Full Text Available Many insect species subsist on decaying and contaminated matter and are thus exposed to large quantities of microorganisms. To control beneficial commensals and combat infectious pathogens, insects must be armed with efficient systems for microbial recognition, signaling pathways, and effector molecules. The molecular mechanisms regulating these host-microbe interactions in insects have been largely clarified in Drosophila melanogaster with its powerful genetic and genomic tools. Here we review recent advances in this field, focusing mainly on the relationships between microbes and epithelial cells in the intestinal tract where the host exposure to the external environment is most frequent.

  1. Drosophila melanogaster as a model to explore the effects of methicillin-resistant Staphylococcus aureus strain type on virulence and response to linezolid treatment.

    Science.gov (United States)

    Ben-Ami, Ronen; Watson, Clay C; Lewis, Russell E; Albert, Nathaniel D; Arias, Cesar A; Raad, Issam I; Kontoyiannis, Dimitrios P

    2013-02-01

    USA300 is a uniquely successful methicillin-resistant Staphylococcus aureus (MRSA) clone that has been associated with Panton-Valentine leukocidin (PVL) production and severe infections. However, conflicting experimental and epidemiological data exist regarding the virulence of USA300 relative to other MRSA clones. We aimed to address this issue using Drosophila melanogaster as a model host to study strain and PVL-dependent variations in virulence among MRSA clinical isolates. We studied the relative virulence of 39 MRSA isolates: 17 (43%) were PFGE type USA300. Lethal MRSA infection was reproducibly induced both in wild-type (WT) and Toll-deficient D. melanogaster. USA300 strains had significantly lower lethality than non-USA300 strains in a WT background but not in Toll-deficient flies. PFGE type (USA300 versus non-USA300) and PVL status did not affect the response to treatment with linezolid. Virulence was similar in strains with high vancomycin MIC (≥2 μg/mL) versus those with vancomycin MIC<2 μg/mL. D. melanogaster is a potentially useful model host to study pathogenicity and response to antibiotic treatment in S. aureus. Our results imply that the attenuated virulence of PVL(+)/USA300 requires intact host innate immunity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Methane oxidation in contrasting soil types: responses to experimental warming with implication for landscape-integrated CH4budget.

    Science.gov (United States)

    D'Imperio, Ludovica; Nielsen, Cecilie Skov; Westergaard-Nielsen, Andreas; Michelsen, Anders; Elberling, Bo

    2017-02-01

    Arctic ecosystems are characterized by a wide range of soil moisture conditions and thermal regimes and contribute differently to the net methane (CH 4 ) budget. Yet, it is unclear how climate change will affect the capacity of those systems to act as a net source or sink of CH 4 . Here, we present results of in situ CH 4 flux measurements made during the growing season 2014 on Disko Island (west Greenland) and quantify the contribution of contrasting soil and landscape types to the net CH 4 budget and responses to summer warming. We compared gas flux measurements from a bare soil and a dry heath, at ambient conditions and increased air temperature, using open-top chambers (OTCs). Throughout the growing season, bare soil consumed 0.22 ± 0.03 g CH 4 -C m -2 (8.1 ± 1.2 g CO 2 -eq m -2 ) at ambient conditions, while the dry heath consumed 0.10 ± 0.02 g CH 4 -C m -2 (3.9 ± 0.6 g CO 2 -eq m -2 ). These uptake rates were subsequently scaled to the entire study area of 0.15 km 2 , a landscape also consisting of wetlands with a seasonally integrated methane release of 0.10 ± 0.01 g CH 4 -C m -2 (3.7 ± 1.2 g CO 2 -eq m -2 ). The result was a net landscape sink of 12.71 kg CH 4 -C (0.48 tonne CO 2 -eq) during the growing season. A nonsignificant trend was noticed in seasonal CH 4 uptake rates with experimental warming, corresponding to a 2% reduction at the bare soil, and 33% increase at the dry heath. This was due to the indirect effect of OTCs on soil moisture, which exerted the main control on CH 4 fluxes. Overall, the net landscape sink of CH 4 tended to increase by 20% with OTCs. Bare and dry tundra ecosystems should be considered in the net CH 4 budget of the Arctic due to their potential role in counterbalancing CH 4 emissions from wetlands - not the least when taking the future climatic scenarios of the Arctic into account. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  3. Genes involved in sex pheromone discrimination in Drosophila melanogaster and their background-dependent effect.

    Directory of Open Access Journals (Sweden)

    Benjamin Houot

    Full Text Available Mate choice is based on the comparison of the sensory quality of potential mating partners, and sex pheromones play an important role in this process. In Drosophila melanogaster, contact pheromones differ between male and female in their content and in their effects on male courtship, both inhibitory and stimulatory. To investigate the genetic basis of sex pheromone discrimination, we experimentally selected males showing either a higher or lower ability to discriminate sex pheromones over 20 generations. This experimental selection was carried out in parallel on two different genetic backgrounds: wild-type and desat1 mutant, in which parental males showed high and low sex pheromone discrimination ability respectively. Male perception of male and female pheromones was separately affected during the process of selection. A comparison of transcriptomic activity between high and low discrimination lines revealed genes not only that varied according to the starting genetic background, but varied reciprocally. Mutants in two of these genes, Shaker and quick-to-court, were capable of producing similar effects on discrimination on their own, in some instances mimicking the selected lines, in others not. This suggests that discrimination of sex pheromones depends on genes whose activity is sensitive to genetic context and provides a rare, genetically defined example of the phenomenon known as "allele flips," in which interactions have reciprocal effects on different genetic backgrounds.

  4. Variation in male mate choice in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Dominic A Edward

    Full Text Available Male mate choice has been reported in the fruit fly, Drosophila melanogaster, even though males of this species were previously thought to maximise their fitness by mating with all available females. To understand the evolution of male mate choice it is important to understand variation in male mating preferences. Two studies, using different stock populations and different methods, have reported contrasting patterns of variation in male mate choice in D. melanogaster. Two possible explanations are that there are evolved differences in each stock population or that the methods used to measure choice could have biased the results. We investigated these hypotheses here by repeating the methods used in one study in which variable male mate choice was found, using the stock population from the other study in which choice was not variable. The results showed a significant resource-independent male preference for less fecund, smaller females, which contrasts with previous observations of male mate choice. This indicates that different selection pressures between populations have resulted in evolved differences in the expression of male mate choice. It also reveals phenotypic plasticity in male mate choice in response to cues encountered in each choice environment. The results highlight the importance of variation in male mate choice, and of identifying mechanisms in order to understand the evolution of mate choice under varying ecological conditions.

  5. Sexual experience enhances Drosophila melanogaster male mating behavior and success.

    Directory of Open Access Journals (Sweden)

    Sehresh Saleem

    Full Text Available Competition for mates is a wide-spread phenomenon affecting individual reproductive success. The ability of animals to adjust their behaviors in response to changing social environment is important and well documented. Drosophila melanogaster males compete with one another for matings with females and modify their reproductive behaviors based on prior social interactions. However, it remains to be determined how male social experience that culminates in mating with a female impacts subsequent male reproductive behaviors and mating success. Here we show that sexual experience enhances future mating success. Previously mated D. melanogaster males adjust their courtship behaviors and out-compete sexually inexperienced males for copulations. Interestingly, courtship experience alone is not sufficient in providing this competitive advantage, indicating that copulation plays a role in reinforcing this social learning. We also show that females use their sense of hearing to preferentially mate with experienced males when given a choice. Our results demonstrate the ability of previously mated males to learn from their positive sexual experiences and adjust their behaviors to gain a mating advantage. These experienced-based changes in behavior reveal strategies that animals likely use to increase their fecundity in natural competitive environments.

  6. Individual variation of natural D.melanogaster-associated bacterial communities.

    Science.gov (United States)

    Wang, Yun; Staubach, Fabian

    2018-03-01

    Drosophila melanogaster has become an important model organism to study host-microbe interaction in the laboratory. However, the natural microbial communities that are associated with D. melanogaster have received less attention. Especially, information on inter-individual variation is still lacking, because most studies so far have used pooled material from several flies. Here, we collected bacterial 16S rRNA gene community profiles from a set of 32 individuals from a single population. We simulated pools from the individual data (i) to assess how well the microbiome of a host population is represented by pools, and (ii) to compare variation of Drosophila microbiomes within and between populations. Taxon richness was increased in simulated pools, suggesting that pools paint a more comprehensive picture of the taxa associated with a host population. Furthermore, microbiome composition varied less between pools than between individuals, indicating that differences even out in pools. Variation in microbiome composition was larger between populations than between simulated pools from a single population, adding to the notion that there are population-specific effects on the Drosophila microbiome. Surprisingly, samples from individuals clustered into two groups, suggesting that there are yet unknown factors that affect the composition of natural fly-associated microbial communities and need further research.

  7. Biological network analysis with CentiScaPe: centralities and experimental dataset integration [v2; ref status: indexed, http://f1000r.es/55u

    Directory of Open Access Journals (Sweden)

    Giovanni Scardoni

    2015-07-01

    Full Text Available The growing dimension and complexity of the available experimental data generating biological networks have increased the need for tools that help in categorizing nodes by their topological relevance. Here we present CentiScaPe, a Cytoscape app specifically designed to calculate centrality indexes used for the identification of the most important nodes in a network. CentiScaPe is a comprehensive suite of algorithms dedicated to network nodes centrality analysis, computing several centralities for undirected, directed and weighted networks. The results of the topological analysis can be integrated with data set from lab experiments, like expression or phosphorylation levels for each protein represented in the network. Our app opens new perspectives in the analysis of biological networks, since the integration of topological analysis with lab experimental data enhance the predictive power of the bioinformatics analysis.

  8. Male Drosophila melanogaster learn to prefer an arbitrary trait associated with female mating status

    DEFF Research Database (Denmark)

    Verzijden, Machteld Nicolette; Abbott, Jessica K.; Philipsborn, Anne von

    2015-01-01

    Although males are generally less discriminating than females when it comes to choosing a mate, they still benefit from distinguishing between mates that are receptive to courtship and those that are not, in order to avoid wasting time and energy. It is known that males of Drosophila melanogaster...... of the experiment was carried out in darkness.This is, to our knowledge 1) the first evidence that male D. melanogaster can use more arbitrary cues and 2) the first evidence that males use visual cues during mate choice learning. Our findings suggest that that D. melanogaster has untapped potential as a model...

  9. Experimental validation of numerical study on thermoelectric-based heating in an integrated centrifugal microfluidic platform for polymerase chain reaction amplification.

    Science.gov (United States)

    Amasia, Mary; Kang, Seok-Won; Banerjee, Debjyoti; Madou, Marc

    2013-01-01

    A comprehensive study involving numerical analysis and experimental validation of temperature transients within a microchamber was performed for thermocycling operation in an integrated centrifugal microfluidic platform for polymerase chain reaction (PCR) amplification. Controlled heating and cooling of biological samples are essential processes in many sample preparation and detection steps for micro-total analysis systems. Specifically, the PCR process relies on highly controllable and uniform heating of nucleic acid samples for successful and efficient amplification. In these miniaturized systems, the heating process is often performed more rapidly, making the temperature control more difficult, and adding complexity to the integrated hardware system. To gain further insight into the complex temperature profiles within the PCR microchamber, numerical simulations using computational fluid dynamics and computational heat transfer were performed. The designed integrated centrifugal microfluidics platform utilizes thermoelectrics for ice-valving and thermocycling for PCR amplification. Embedded micro-thermocouples were used to record the static and dynamic thermal responses in the experiments. The data collected was subsequently used for computational validation of the numerical predictions for the system response during thermocycling, and these simulations were found to be in agreement with the experimental data to within ∼97%. When thermal contact resistance values were incorporated in the simulations, the numerical predictions were found to be in agreement with the experimental data to within ∼99.9%. This in-depth numerical modeling and experimental validation of a complex single-sided heating platform provide insights into hardware and system design for multi-layered polymer microfluidic systems. In addition, the biological capability along with the practical feasibility of the integrated system is demonstrated by successfully performing PCR amplification of

  10. Allelic asymmetry of the Lethal hybrid rescue (Lhr) gene expression in the hybrid between Drosophila melanogaster and D. simulans: confirmation by using genetic variations of D. melanogaster.

    Science.gov (United States)

    Shirata, Mika; Araye, Quenta; Maehara, Kazunori; Enya, Sora; Takano-Shimizu, Toshiyuki; Sawamura, Kyoichi

    2014-02-01

    In the cross between Drosophila melanogaster females and D. simulans males, hybrid males die at the late larval stage, and the sibling females also die at later stages at high temperatures. Removing the D. simulans allele of the Lethal hybrid rescue gene (Lhr (sim) ) improves the hybrid incompatibility phenotypes. However, the loss-of-function mutation of Lhr (sim) (Lhr (sim0) ) does not rescue the hybrid males in crosses with several D. melanogaster strains. We first describe the genetic factor possessed by the D. melanogaster strains. It has been suggested that removing the D. melanogaster allele of Lhr (Lhr (mel) ), that is Lhr (mel0) , does not have the hybrid male rescue effect, contrasting to Lhr (sim0) . Because the expression level of the Lhr gene is known to be Lhr (sim) > Lhr (mel) in the hybrid, Lhr (mel0) may not lead to enough of a reduction in total Lhr expression. Then, there is a possibility that the D. melanogaster factor changes the expression level to Lhr (sim) Lhr (mel) in the hybrid irrespectively of the presence of the factor. At last, we showed that Lhr (mel0) slightly improves the viability of hybrid females, which was not realized previously. All of the present results are consistent with the allelic asymmetry model of the Lhr gene expression in the hybrid.

  11. Integrated system for production of neutronics and photonics calculational constants. Neutron-induced interactions: index of experimental data

    Energy Technology Data Exchange (ETDEWEB)

    MacGregor, M.H.; Cullen, D.E.; Howerton, R.J.; Perkins, S.T.

    1976-07-04

    Indexes to the neutron-induced interaction data in the Experimental Cross Section Information Library (ECSIL) as of July 4, 1976 are tabulated. The tabulation has two arrangements: isotope (ZA) order and reaction-number order.

  12. Integrated system for production of neutronics and photonics calculational constants. Neutron-induced interactions: bibliography of experimental data

    Energy Technology Data Exchange (ETDEWEB)

    MacGregor, M.H.; Cullen, D.E.; Howerton, R.J.; Perkins, S.T.

    1976-07-04

    The bibliographic citations in the Experimental Cross Section Information Library (ECSIL) as of July 4, 1976 are tabulated. The tabulation has three arrangements: alphabetically by author, alphabetically by publication, and numerically by reference number.

  13. Integrated system for production of neutronics and photonics calculational constants. Neutron-induced interactions: bibliography of experimental data

    International Nuclear Information System (INIS)

    MacGregor, M.H.; Cullen, D.E.; Howerton, R.J.; Perkins, S.T.

    1976-01-01

    The bibliographic citations in the Experimental Cross Section Information Library (ECSIL) as of July 4, 1976 are tabulated. The tabulation has three arrangements: alphabetically by author, alphabetically by publication, and numerically by reference number

  14. The Phenotypic Effects of Royal Jelly on Wild-Type D. melanogaster Are Strain-Specific.

    Directory of Open Access Journals (Sweden)

    Stefanie L Morgan

    Full Text Available The role for royal jelly (RJ in promoting caste differentiation of honeybee larvae into queens rather than workers is well characterized. A recent study demonstrated that this poorly understood complex nutrition drives strikingly similar phenotypic effects in Drosophila melanogaster, such as increased body size and reduced developmental time, making possible the use of D. melanogaster as a model system for the genetic analysis of the cellular mechanisms underlying RJ and caste differentiation. We demonstrate here that RJ increases the body size of some wild-type strains of D. melanogaster but not others, and report significant delays in developmental time in all flies reared on RJ. These findings suggest that cryptic genetic variation may be a factor in the D. melanogaster response to RJ, and should be considered when attempting to elucidate response mechanisms to environmental changes in non-honeybee species.

  15. Behavioural plasticity in support of a benefit for aggregation pheromone use in Drosophila melanogaster

    NARCIS (Netherlands)

    Wertheim, B; Dicke, Marcel; Vet, LEM

    We explored behavioural plasticity in the use of aggregation pheromone in the fruit fly Drosophila melanogaster Meigen (Diptera: Drosophilidae). Based on previous field observations, we formulated two hypotheses on a benefit of using aggregation pheromone for aggregated oviposition. One hypothesis

  16. Polymorphism patterns in two tightly linked developmental genes, Idgf1 and Idgf3, of Drosophila melanogaster

    Czech Academy of Sciences Publication Activity Database

    Žurovcová, Martina; Ayala, F. J.

    2002-01-01

    Roč. 162, - (2002), s. 177-188 ISSN 0016-6731 Institutional research plan: CEZ:AV0Z5007907 Keywords : Drosophila melanogaster Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.483, year: 2002

  17. Biological effect of the magnetic resonance on fruit flies, drosophila melanogaster

    International Nuclear Information System (INIS)

    Restrepo, Ana; Angel Karen; Lopez P, Monica; Sanabria, Ana I; Lopez, Maria I

    1992-01-01

    This article describes an investigation in which fruit flies, D. Melanogaster of the white and vestigial strains, were exposed to a magnetic resonance field for 171 hours, to determine possible genetic alterations

  18. Proteomic characterization of inbreeding-related cold sensitivity in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Vermeulen, Cornelis Joseph; Pedersen, Kamilla Sofie; Beck, Hans C

    2013-01-01

    insight into the molecular interplay between intrinsic stress responses, inbreeding depression and temperature tolerance, we performed a proteomic characterization of a well-defined conditional inbreeding effect in a single line of Drosophila melanogaster, which suffers from extreme cold sensitivity...

  19. Metabolic and functional characterization of effects of developmental temperature in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Schou, Mads F; Kristensen, Torsten Nygaard; Karlsson, Goran B

    2017-01-01

    , and in particular, how physiological stress at extreme temperatures may counteract beneficial acclimation responses at benign temperatures. We exposed Drosophila melanogaster to ten developmental temperatures covering their entire permissible temperature range. We obtained metabolic profiles and reaction norms...

  20. Genetic effects induced by neutrons in Drosophila melanogaster I. Determination of absorbed dose

    International Nuclear Information System (INIS)

    Delfin, A.; Paredes, L.C.; Zambrano, F.; Guzman-Rincon, J.; Urena-Nunez, F.

    2001-01-01

    A method to obtain the absorbed dose in Drosophila melanogaster irradiated in the thermal column facility of the Triga Mark III Reactor has been developed. The method is based on the measurements of neutron activation of gold foils produced by neutron capture to obtain the neutron fluxes. These fluxes, combined with the calculations of kinetic energy released per unit mass, enables one to obtain the absorbed doses in Drosophila melanogaster

  1. History and Structure of Sub-Saharan Populations of Drosophila melanogaster

    OpenAIRE

    Pool, John E.; Aquadro, Charles F.

    2006-01-01

    Drosophila melanogaster is an important model organism in evolutionary genetics, yet little is known about the population structure and the demographic history of this species within sub-Saharan Africa, which is thought to contain its ancestral range. We surveyed nucleotide variation at four 1-kb fragments in 240 individual lines representing 21 sub-Saharan and 4 Palearctic population samples of D. melanogaster. In agreement with recent studies, we find a small but significant level of geneti...

  2. Nuclear genomic control of naturally occurring variation in mitochondrial function in Drosophila melanogaster

    Science.gov (United States)

    2012-01-01

    . melanogaster. The integrative genomic approach used in our study allowed us to identify sls as a novel hub gene responsible for the regulation of mitochondrial respiration in muscle sarcomere and to provide evidence that sls might act via the electron transfer flavoprotein/ubiquinone oxidoreductase complex. PMID:23171078

  3. Promoting employee health by integrating health protection, health promotion, and continuous improvement: a longitudinal quasi-experimental intervention study.

    Science.gov (United States)

    von Thiele Schwarz, Ulrica; Augustsson, Hanna; Hasson, Henna; Stenfors-Hayes, Terese

    2015-02-01

    To test the effects of integrating health protection and health promotion with a continuous improvement system (Kaizen) on proximal employee outcomes (health promotion, integration, and Kaizen) and distal outcomes (workability, productivity, self-rated health and self-rated sickness absence). Twelve units in a county hospital in Sweden were randomized to control or intervention groups using a quasiexperimental study design. All staff (approximately 500) provided self-ratings in questionnaires at baseline, and a 12- and 24-month follow-up (response rate, 79% to 87.5%). There was a significant increase in the proximal outcomes over time in the intervention group compared with the control group, and a trend toward improvement in the distal outcomes workability and productivity. Integration seems to promote staff engagement in health protection and promotion, as well as to improve their understanding of the link between work and health.

  4. Phenomenon of life span instability in Drosophila melanogaster: Pt. 2

    International Nuclear Information System (INIS)

    Izmaylov, D.M.; Obukhova, L.K.; Okladnova, O.V.; Akifyev, A.P.

    1993-01-01

    The dynamics of life span (LS) have been studied in successive generations of postirradiation and control groups of Drosophila melanogaster, strain D-32, after a single exposure to Co 60 γ-quantum irradiation. It has been shown using mathematical procedures that in all postirradiation generations, with one exception, survival curves retain their canonical shape. This is indicative of the unchangeable nature of LS distribution. The means LS of the progeny of irradiated parents either coincides with control values or can be higher or lower. Moreover, single irradiation results in an altered time-scanning of LS variations in successive generations as compared with controls. The possible origin of LS instability is discussed. (author)

  5. A pulsed magnetic stress applied to Drosophila melanogaster flies

    International Nuclear Information System (INIS)

    Delle Side, D; Giuffreda, E; Nassisi, V; Velardi, L; Bozzetti, M P; Friscini, A; Specchia, V

    2014-01-01

    We report the development of a system to feed pulsed magnetic stress to biological samples. The device is based on a RLC circuit that transforms the energy stored in a high voltage capacitor into a magnetic field inside a coil. The field has been characterized and we found that charging the capacitor with 24 kV results in a peak field of 0.4 T. In order to test its effect, we applied such a stress to the Drosophila melanogaster model and we examined its bio-effects. We analysed, in the germ cells, the effects on the control of specific DNA repetitive sequences that are activated after different environmental stresses. The deregulation of these sequences causes genomic instability and chromosomes breaks leading to sterility. The magnetic field treatment did not produce effects on repetitive sequences in the germ cells of Drosophila. Hence, this field doesn't produce deleterious effects linked to repetitive sequences derepression.

  6. In vivo super-resolution RESOLFT microscopy of Drosophila melanogaster.

    Science.gov (United States)

    Schnorrenberg, Sebastian; Grotjohann, Tim; Vorbrüggen, Gerd; Herzig, Alf; Hell, Stefan W; Jakobs, Stefan

    2016-06-29

    Despite remarkable developments in diffraction unlimited super-resolution microscopy, in vivo nanoscopy of tissues and model organisms is still not satisfactorily established and rarely realized. RESOLFT nanoscopy is particularly suited for live cell imaging because it requires relatively low light levels to overcome the diffraction barrier. Previously, we introduced the reversibly switchable fluorescent protein rsEGFP2, which facilitated fast RESOLFT nanoscopy (Grotjohann et al., 2012). In that study, as in most other nanoscopy studies, only cultivated single cells were analyzed. Here, we report on the use of rsEGFP2 for live-cell RESOLFT nanoscopy of sub-cellular structures of intact Drosophila melanogaster larvae and of resected tissues. We generated flies expressing fusion proteins of alpha-tubulin and rsEGFP2 highlighting the microtubule cytoskeleton in all cells. By focusing through the intact larval cuticle, we achieved lateral resolution of.

  7. Estimating spontaneous mutation rates at enzyme loci in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mukai, Terumi; Yamazaki, Tsuneyuki; Harada, Ko; Kusakabe, Shin-ichi

    1990-04-01

    Spontaneous mutations were accumulated for 1,620,826 allele-generations on chromosomes that originated from six stem second chromosomes of Drosophila melanogaster. Only null-electromorph mutations were detected. Band-electromorph mutations were not found. The average rate of null-electromorph mutations was 2.71 x 10 -5 per locus per generation. The 95% confidence interval (μ n ) was 1.97 x 10 -5 n -5 per locus per generation. The upper 95% confidence limit of the band-electromorph mutation rate (μ B ) was 2.28 x 10 -6 per locus per generation. It appeared that null mutations were induced by movable genetic elements and that the mutation rates were different from chromosome to chromosome. (author)

  8. Drosophila melanogaster as a model organism to study nanotoxicity.

    Science.gov (United States)

    Ong, Cynthia; Yung, Lin-Yue Lanry; Cai, Yu; Bay, Boon-Huat; Baeg, Gyeong-Hun

    2015-05-01

    Drosophila melanogaster has been used as an in vivo model organism for the study of genetics and development since 100 years ago. Recently, the fruit fly Drosophila was also developed as an in vivo model organism for toxicology studies, in particular, the field of nanotoxicity. The incorporation of nanomaterials into consumer and biomedical products is a cause for concern as nanomaterials are often associated with toxicity in many in vitro studies. In vivo animal studies of the toxicity of nanomaterials with rodents and other mammals are, however, limited due to high operational cost and ethical objections. Hence, Drosophila, a genetically tractable organism with distinct developmental stages and short life cycle, serves as an ideal organism to study nanomaterial-mediated toxicity. This review discusses the basic biology of Drosophila, the toxicity of nanomaterials, as well as how the Drosophila model can be used to study the toxicity of various types of nanomaterials.

  9. Studies on mutagen-sensitive strains of Drosophila melanogaster. IV

    International Nuclear Information System (INIS)

    Ferro, W.

    1985-01-01

    The influence of defects in DNA repair processes on X-ray-induced genetic damage in post-meiotic male germ cell stages of Drosophila melanogaster was studied using the 'maternal effects approach'. Basc males were irradiated in N 2 , air or O 2 either as 48-h-old pupae (to sample spermatids) or as 3-4-day-old adults (to sample mature spermatozoa) and mated to females of 3 repair-deficient strains. Simultaneous controls involving mating of males to repair-proficient females (mei + ) were run. The frequencies of sex-linked recessive lethals and of autosomal translocations were determined following standard genetic procedures. The responses elicited in the different crosses with repair-deficient females were compared with those in mei + crosses. (Auth.)

  10. A pulsed magnetic stress applied to Drosophila melanogaster flies

    Science.gov (United States)

    Delle Side, D.; Bozzetti, M. P.; Friscini, A.; Giuffreda, E.; Nassisi, V.; Specchia, V.; Velardi, L.

    2014-04-01

    We report the development of a system to feed pulsed magnetic stress to biological samples. The device is based on a RLC circuit that transforms the energy stored in a high voltage capacitor into a magnetic field inside a coil. The field has been characterized and we found that charging the capacitor with 24 kV results in a peak field of 0.4 T. In order to test its effect, we applied such a stress to the Drosophila melanogaster model and we examined its bio-effects. We analysed, in the germ cells, the effects on the control of specific DNA repetitive sequences that are activated after different environmental stresses. The deregulation of these sequences causes genomic instability and chromosomes breaks leading to sterility. The magnetic field treatment did not produce effects on repetitive sequences in the germ cells of Drosophila. Hence, this field doesn't produce deleterious effects linked to repetitive sequences derepression.

  11. The effects of chronic low dose irradiation on drosophila melanogaster

    International Nuclear Information System (INIS)

    Zajnullin, V.G.; Moskalev, A.A.; Shaposhnikov, M.V.; Yuraneva, I.N.; Taskaev, A.I.

    2001-01-01

    It was investigated the influence of the chronic gamma-irradiation in the dose rate of 0.17 cGy/h on the rate of genetic variability and on the life-span in the laboratory strains of Drosophila melanogaster with genotypic distinguishes in mobile genetic elements and defects in the DNA repair processes. It is shown that the radiation-induced alteration of the traits under study depends from genotype of investigated strains. In the different strains we have observed an increase as well as a decrease of the mutation rate and life-span. Also it was established that irradiation leads to the frequencies of the GD-sterility and mutability of the snw and h(w+) in the P-M and H-E dysgenic crosses. The obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation. (author)

  12. Genetic effects of low-dose irradiation in Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Zajnulin, V.G.; Shaposhnikov, M.V.; Yuraneva, I.N.

    2000-01-01

    Influence of chronic γ-irradiation at the dose rate of 0.17 cGy/h on the rate of genetic variability in the laboratory strains of Drosophila Melanogaster with genotypic distinguishes by families of mobile genetic elements and of systems of hybrid disgenesis and also violations in reparation processes control mechanisms. It was shown that the rates of induction of recessive lethal mutations depended on genotype of investigated strains. In the different strains an increase as well as a decrease of the mutation rate were observed. Also in was established that irradiation leads to the increase in frequencies of the gonads sterility and mutability of the sn w and h(w + ) in the P-M and H-E dysgenic crosses. Obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation [ru

  13. GABAA receptor-expressing neurons promote consumption in Drosophila melanogaster.

    Science.gov (United States)

    Cheung, Samantha K; Scott, Kristin

    2017-01-01

    Feeding decisions are highly plastic and bidirectionally regulated by neurons that either promote or inhibit feeding. In Drosophila melanogaster, recent studies have identified four GABAergic interneurons that act as critical brakes to prevent incessant feeding. These GABAergic neurons may inhibit target neurons that drive consumption. Here, we tested this hypothesis by examining GABA receptors and neurons that promote consumption. We find that Resistance to dieldrin (RDL), a GABAA type receptor, is required for proper control of ingestion. Knockdown of Rdl in a subset of neurons causes overconsumption of tastants. Acute activation of these neurons is sufficient to drive consumption of appetitive substances and non-appetitive substances and acute silencing of these neurons decreases consumption. Taken together, these studies identify GABAA receptor-expressing neurons that promote Drosophila ingestive behavior and provide insight into feeding regulation.

  14. Cytological investigations in populations of D. melanogaster exposed to radiation

    International Nuclear Information System (INIS)

    Wienberg, J.

    1983-01-01

    The study described was carried out to investigate structural changes in the chromosomes of irradiated populations of D.melanogaster that can be analysed on the basis of cytological methods. It mainly dealt with two particular aspects of this subject: I. Different types of chromosomes (polytene chromosomes, mitotic and meiotic chromosomes) were used to examine whether and to which extent chromosomal variability would alter or remain unchanged under the influence of mutation. II. The prophase of the first division of female cells was analysed with respect to the role of resistance factor rar-2. In this connection, it was of interest whether the prophase of meiosis would show visible cytological changes in the interchromosomal structure that are caused by factor rar-2. (orig./MG) [de

  15. Conserved family of glycerol kinase loci in Drosophila melanogaster

    Science.gov (United States)

    Martinez Agosto, Julian A.; McCabe, Edward R.B.

    2009-01-01

    Glycerol kinase (GK) is an enzyme that catalyzes the formation of glycerol 3-phosphate from ATP and glycerol, the rate-limiting step in glycerol utilization. We analyzed the genome of the model organism Drosophila melanogaster and identified five GK orthologs, including two loci with sequence homology to the mammalian Xp21 GK protein. Using a combination of sequence analysis and evolutionary comparisons of orthologs between species, we characterized functional domains in the protein required for GK activity. Our findings include additional conserved domains that suggest novel nuclear and mitochondrial functions for glycerol kinase in apoptosis and transcriptional regulation. Investigation of GK function in Drosophila will inform us about the role of this enzyme in development and will provide us with a tool to examine genetic modifiers of human metabolic disorders. PMID:16545593

  16. Mechanisms Underlying the Risk to Develop Drug Addiction, Insights From Studies in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Julia Ryvkin

    2018-04-01

    Full Text Available The ability to adapt to environmental changes is an essential feature of biological systems, achieved in animals by a coordinated crosstalk between neuronal and hormonal programs that allow rapid and integrated organismal responses. Reward systems play a key role in mediating this adaptation by reinforcing behaviors that enhance immediate survival, such as eating or drinking, or those that ensure long-term survival, such as sexual behavior or caring for offspring. Drugs of abuse co-opt neuronal and molecular pathways that mediate natural rewards, which under certain circumstances can lead to addiction. Many factors can contribute to the transition from drug use to drug addiction, highlighting the need to discover mechanisms underlying the progression from initial drug use to drug addiction. Since similar responses to natural and drug rewards are present in very different animals, it is likely that the central systems that process reward stimuli originated early in evolution, and that common ancient biological principles and genes are involved in these processes. Thus, the neurobiology of natural and drug rewards can be studied using simpler model organisms that have their systems stripped of some of the immense complexity that exists in mammalian brains. In this paper we review studies in Drosophila melanogaster that model different aspects of natural and drug rewards, with an emphasis on how motivational states shape the value of the rewarding experience, as an entry point to understanding the mechanisms that contribute to the vulnerability of drug addiction.

  17. Whole genome resequencing reveals natural target site preferences of transposable elements in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Raquel S Linheiro

    Full Text Available Transposable elements are mobile DNA sequences that integrate into host genomes using diverse mechanisms with varying degrees of target site specificity. While the target site preferences of some engineered transposable elements are well studied, the natural target preferences of most transposable elements are poorly characterized. Using population genomic resequencing data from 166 strains of Drosophila melanogaster, we identified over 8,000 new insertion sites not present in the reference genome sequence that we used to decode the natural target preferences of 22 families of transposable element in this species. We found that terminal inverted repeat transposon and long terminal repeat retrotransposon families present clade-specific target site duplications and target site sequence motifs. Additionally, we found that the sequence motifs at transposable element target sites are always palindromes that extend beyond the target site duplication. Our results demonstrate the utility of population genomics data for high-throughput inference of transposable element targeting preferences in the wild and establish general rules for terminal inverted repeat transposon and long terminal repeat retrotransposon target site selection in eukaryotic genomes.

  18. Dietary protein content affects evolution for body size, body fat and viability in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Kristensen, Torsten N; Overgaard, Johannes; Loeschcke, Volker

    2011-01-01

    The ability to use different food sources is likely to be under strong selection if organisms are faced with natural variation in macro-nutrient (protein, carbohydrate and lipid) availabilities. Here, we use experimental evolution to study how variable dietary protein content affects adult body...... composition and developmental success in Drosophila melanogaster. We reared flies on either a standard diet or a protein-enriched diet for 17 generations before testing them on both diet types. Flies from lines selected on protein-rich diet produced phenotypes with higher total body mass and relative lipid...... content when compared with those selected on a standard diet, irrespective of which of the two diets they were tested on. However, selection on protein-rich diet incurred a cost as flies reared on this diet had markedly lower developmental success in terms of egg-to-adult viability on both medium types...

  19. Patterns of physiological decline due to age and selection in Drosophila melanogaster.

    Science.gov (United States)

    Shahrestani, Parvin; Wilson, Julian B; Mueller, Laurence D; Rose, Michael R

    2016-11-01

    In outbred sexually reproducing populations, age-specific mortality rates reach a plateau in late life following the exponential increase in mortality rates that marks aging. Little is known about what happens to physiology when cohorts transition from aging to late life. We measured age-specific values for starvation resistance, desiccation resistance, time-in-motion, and geotaxis in ten Drosophila melanogaster populations: five populations selected for rapid development and five control populations. Adulthood was divided into two stages, the aging phase and the late-life phase according to demographic data. Consistent with previous studies, we found that populations selected for rapid development entered the late-life phase at an earlier age than the controls. Age-specific rates of change for all physiological phenotypes showed differences between the aging phase and the late-life phase. This result suggests that late life is physiologically distinct from aging. The ages of transitions in physiological characteristics from aging to late life statistically match the age at which the demographic transition from aging to late life occurs, in all cases but one. These experimental results support evolutionary theories of late life that depend on patterns of decline and stabilization in the forces of natural selection. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  20. Large-scale assessment of olfactory preferences and learning in Drosophila melanogaster: behavioral and genetic components

    Directory of Open Access Journals (Sweden)

    Elisabetta Versace

    2015-09-01

    Full Text Available In the Evolve and Resequence method (E&R, experimental evolution and genomics are combined to investigate evolutionary dynamics and the genotype-phenotype link. As other genomic approaches, this methods requires many replicates with large population sizes, which imposes severe restrictions on the analysis of behavioral phenotypes. Aiming to use E&R for investigating the evolution of behavior in Drosophila, we have developed a simple and effective method to assess spontaneous olfactory preferences and learning in large samples of fruit flies using a T-maze. We tested this procedure on (a a large wild-caught population and (b 11 isofemale lines of Drosophila melanogaster. Compared to previous methods, this procedure reduces the environmental noise and allows for the analysis of large population samples. Consistent with previous results, we show that flies have a preference for orange vs. apple odor. With our procedure wild-derived flies exhibit olfactory learning in the absence of previous laboratory selection. Furthermore, we find genetic differences in the olfactory learning with relatively high heritability. We propose this large-scale method as an effective tool for E&R and genome-wide association studies on olfactory preferences and learning.

  1. Genotoxicity testing of Plantago major extracts in somatic cells of Drosophila melanogaster.

    Science.gov (United States)

    Pimenta, Vânia Maria Sartini Dutra; Nepomuceno, Júlio César

    2005-01-01

    Plantago major is used in many parts of the world for the treatment of diseases and to promote the healing of wounds. In the present study, the somatic mutation and recombination test (SMART) in Drosophila melanogaster was used to evaluate the genotoxic activity of an aqueous extract of P. major. The following Drosophila crosses were made: standard (ST) cross, in which virgin flare females (flr3/TM3, Bds) were mated with mwh/mwh males, and high-bioactivation (HB) cross, in which virgin ORR females (ORR/ORR; flr3/TM3, Bds) were mated with mwh/mwh males. Each cross produced two types of descendents, marker-transheterozygous (MH) (mwh +/+ flr3) and balancer-heterozygous (BH) (mwh +/+ TM3, Bds) flies. Three-day-old larvae of both types of descendents were treated with undiluted and diluted (1:1 and 1:2 in water) aqueous extracts of P. major. The extracts were genotoxic in both crosses, producing similar induced frequencies in ST and HB flies. Comparison of the frequencies of wing spots in the BH and MH descendents indicated that recombination was a major response. The results indicate that, under these experimental conditions, aqueous extracts of P. major are genotoxic (recombinagenic). 2004 Wiley-Liss, Inc.

  2. Genome-wide analysis of long-term evolutionary domestication in Drosophila melanogaster.

    Science.gov (United States)

    Phillips, Mark A; Long, Anthony D; Greenspan, Zachary S; Greer, Lee F; Burke, Molly K; Villeponteau, Bryant; Matsagas, Kennedy C; Rizza, Cristina L; Mueller, Laurence D; Rose, Michael R

    2016-12-22

    Experimental evolutionary genomics now allows biologists to test fundamental theories concerning the genetic basis of adaptation. We have conducted one of the longest laboratory evolution experiments with any sexually-reproducing metazoan, Drosophila melanogaster. We used next-generation resequencing data from this experiment to examine genome-wide patterns of genetic variation over an evolutionary time-scale that approaches 1,000 generations. We also compared measures of variation within and differentiation between our populations to simulations based on a variety of evolutionary scenarios. Our analysis yielded no clear evidence of hard selective sweeps, whereby natural selection acts to increase the frequency of a newly-arising mutation in a population until it becomes fixed. We do find evidence for selection acting on standing genetic variation, as independent replicate populations exhibit similar population-genetic dynamics, without obvious fixation of candidate alleles under selection. A hidden-Markov model test for selection also found widespread evidence for selection. We found more genetic variation genome-wide, and less differentiation between replicate populations genome-wide, than arose in any of our simulated evolutionary scenarios.

  3. Drosophila melanogaster Models of Metal-Related Human Diseases and Metal Toxicity.

    Science.gov (United States)

    Calap-Quintana, Pablo; González-Fernández, Javier; Sebastiá-Ortega, Noelia; Llorens, José Vicente; Moltó, María Dolores

    2017-07-06

    Iron, copper and zinc are transition metals essential for life because they are required in a multitude of biological processes. Organisms have evolved to acquire metals from nutrition and to maintain adequate levels of each metal to avoid damaging effects associated with its deficiency, excess or misplacement. Interestingly, the main components of metal homeostatic pathways are conserved, with many orthologues of the human metal-related genes having been identified and characterized in Drosophila melanogaster . Drosophila has gained appreciation as a useful model for studying human diseases, including those caused by mutations in pathways controlling cellular metal homeostasis. Flies have many advantages in the laboratory, such as a short life cycle, easy handling and inexpensive maintenance. Furthermore, they can be raised in a large number. In addition, flies are greatly appreciated because they offer a considerable number of genetic tools to address some of the unresolved questions concerning disease pathology, which in turn could contribute to our understanding of the metal metabolism and homeostasis. This review recapitulates the metabolism of the principal transition metals, namely iron, zinc and copper, in Drosophila and the utility of this organism as an experimental model to explore the role of metal dyshomeostasis in different human diseases. Finally, a summary of the contribution of Drosophila as a model for testing metal toxicity is provided.

  4. Genome-wide mapping of Painting of fourth on Drosophila melanogaster salivary gland polytene chromosomes.

    Science.gov (United States)

    Johansson, Anna-Mia; Larsson, Jan

    2014-12-01

    The protein Painting of fourth (POF) in Drosophila melanogaster specifically targets and stimulates expression output from the heterochromatic 4th chromosome, thereby representing an autosome specific protein [1,2]. Despite the high specificity for chromosome 4 genes, POF is occasionally observed binding to the cytological region 2L:31 in males and females [3] and two loci on the X-chromosome, PoX1 and PoX2 only in females [4]. Here we provide a detailed description of the experimental design and analysis of the tiling array data presented by Lundberg and colleagues in G3: Genes, Genomes, Genetics 2013 [4], where the female specific POF binding to PoX1 and PoX2 loci on the X chromosome was reported. We show the genome-wide high resolution binding profile of the POF protein where these different POF binding sites are detected. The complete data set is available at http://www.ncbi.nlm.nih.gov/geo/ (accession: GSE45402).

  5. The frequency of allelic lethals and complementation maps in natural populations of drosophila melanogaster from Mexico

    Directory of Open Access Journals (Sweden)

    Salceda Victor M.

    2004-01-01

    Full Text Available Departing from a previous study on the genetic loads affecting the second chromosome of Drosophila melanogaster in four natural populations, 171 lethal chromosomes were recovered and maintained as a balanced stocks in the condition Cy L / 1 (l=lethal; of those lethais 24 correspond to population A, 50 to populations B and C and 47 to population D. later on an intra-population allelism test for the four populations was performed for each one. A total of 3807 inter lethal crosses were done yielding a total of i 10 allelic combinations, from them the respective percentage of allelism for each population was calculated and they are as follow: 3.98 % for population A, 1.80 % for population B, 3.67 % for population C and 2.96 % for population D. the observed values for the frequency of allelism in these populations are not significantly different from those reported by other authors in similar studies in natural and/or experimental populations. Beside these values the frequency for singles, doubles, triplets and even quadruplets present in each population were determined, they shown the presence of various complementation maps due to the clustering of few different lethals: also a large complementation map formed by a large cluster involving the presence of 26 different lethals found in population D all of them combined constituting a single unit was found.

  6. Homology directed repair is unaffected by the absence of siRNAs in Drosophila melanogaster.

    Science.gov (United States)

    Schmidts, Ines; Böttcher, Romy; Mirkovic-Hösle, Milijana; Förstemann, Klaus

    2016-09-30

    Small interfering RNAs (siRNAs) defend the organism against harmful transcripts from exogenous (e.g. viral) or endogenous (e.g. transposons) sources. Recent publications describe the production of siRNAs induced by DNA double-strand breaks (DSB) in Neurospora crassa, Arabidopsis thaliana, Drosophila melanogaster and human cells, which suggests a conserved function. A current hypothesis is that break-induced small RNAs ensure efficient homologous recombination (HR). However, biogenesis of siRNAs is often intertwined with other small RNA species, such as microRNAs (miRNAs), which complicates interpretation of experimental results. In Drosophila, siRNAs are produced by Dcr-2 while miRNAs are processed by Dcr-1. Thus, it is possible to probe siRNA function without miRNA deregulation. We therefore examined DNA double-strand break repair after perturbation of siRNA biogenesis in cultured Drosophila cells as well as mutant flies. Our assays comprised reporters for the single-strand annealing pathway, homologous recombination and sensitivity to the DSB-inducing drug camptothecin. We could not detect any repair defects caused by the lack of siRNAs derived from the broken DNA locus. Since production of these siRNAs depends on local transcription, they may thus participate in RNA metabolism-an established function of siRNAs-rather than DNA repair. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  7. Lifespan Extension by the Antioxidant Curcumin in Drosophila Melanogaster

    Science.gov (United States)

    Suckow, Brianne K.; Suckow, Mark A.

    2006-01-01

    The interest in health benefits associated with consumption of anti-oxidants has led to investigations examining the possibility that diets rich in anti-oxidants promote lifespan extension. Studies using the standard fruit fly (Drosophila melanogaster) model of longevity have shown that the antioxidants vitamin E and N-acetyl cysteine prolong lifespan. Turmeric is a spice which has been consumed and used for medicinal purposes for many centuries in Asia. Interestingly, turmeric contains the powerful antioxidant, curcumin. To test the hypothesis that dietary curcumin prolongs lifespan, groups of 30 male D. melanogaster were cultured on media containing 1) no additive; 2) 0.5 mg of curcumin/gram of media; 3) 1.0 mg of curumin/gram of media; 4) 1.0μg of the superoxide dismutase inhibitor, disulfiram/gram of media; 5) 10 g of disulfiram/gram of media; 6) 0.5 mg curcumin and 1.0 g disulfiram/ gram of media; 7) 1.0 mg curcumin and 1.0 g disulfiram/ gram of media; 8) 0.5 mg curcumin and 10 g disulfiram/gram of media; or 9) 1.0 mg curcumin and 10 g disulfiram/gram of media. The number of live fruitflies was noted daily and mean lifespan determined for each treatment group. A significant (P≤0.05) increase in mean lifespan was noted only for the fruitflies maintained on 1.0 mg of curcumin/gram of media; this effect was reversed by addition of disulfiram. These results demonstrate that dietary curcumin prolongs lifespan and that this effect is associated with enhanced superoxide dismutase activity. PMID:23675008

  8. Male killing Spiroplasma protects Drosophila melanogaster against two parasitoid wasps

    Science.gov (United States)

    Xie, J; Butler, S; Sanchez, G; Mateos, M

    2014-01-01

    Maternally transmitted associations between endosymbiotic bacteria and insects are diverse and widespread in nature. Owing to imperfect vertical transmission, many heritable microbes have evolved compensational mechanisms to enhance their persistence in host lineages, such as manipulating host reproduction and conferring fitness benefits to host. Symbiont-mediated defense against natural enemies of hosts is increasingly recognized as an important mechanism by which endosymbionts enhance host fitness. Members of the genus Spiroplasma associated with distantly related Drosophila hosts are known to engage in either reproductive parasitism (i.e., male killing) or defense against natural enemies (the parasitic wasp Leptopilina heterotoma and a nematode). A male-killing strain of Spiroplasma (strain Melanogaster Sex Ratio Organism (MSRO)) co-occurs with Wolbachia (strain wMel) in certain wild populations of the model organism Drosophila melanogaster. We examined the effects of Spiroplasma MSRO and Wolbachia wMel on Drosophila survival against parasitism by two common wasps, Leptopilina heterotoma and Leptopilina boulardi, that differ in their host ranges and host evasion strategies. The results indicate that Spiroplasma MSRO prevents successful development of both wasps, and confers a small, albeit significant, increase in larva-to-adult survival of flies subjected to wasp attacks. We modeled the conditions under which defense can contribute to Spiroplasma persistence. Wolbachia also confers a weak, but significant, survival advantage to flies attacked by L. heterotoma. The host protective effects exhibited by Spiroplasma and Wolbachia are additive and may provide the conditions for such cotransmitted symbionts to become mutualists. Occurrence of Spiroplasma-mediated protection against distinct parasitoids in divergent Drosophila hosts suggests a general protection mechanism. PMID:24281548

  9. Simulation and experimental validation of a SU-8 based PCR thermocycler chip with integrated heaters and temperature sensor

    DEFF Research Database (Denmark)

    El-Ali, Jamil; Perch-Nielsen, Ivan R.; Poulsen, Claus Riber

    2004-01-01

    and can allow on chip integration to other SU-8 based functional elements. Finite element modeling (FEM) and experiments show that the temperature distribution in the PCR chamber is homogeneous and that the chip is capable of fast thermal cycling. With heating and cooling rates of up to 50 and 30 degrees...

  10. Tissue integration of polyacrylamide hydrogel: an experimental study of periurethral, perivesical, and mammary gland tissue in the pig

    DEFF Research Database (Denmark)

    Christensen, Lise H; Nielsen, John B; Mouritsen, Lone

    2008-01-01

    With silicone gel as reference, PAAG tissue integration and migration was studied in a longitudinal study of the pig. MATERIALS AND METHODS Forty-one pigs were used. PAAG and silicone gel were injected into mammary tissue, and PAAG was injected into urethral or bladder wall or the anal canal. Tissues...

  11. Development and verification test of integral reactor major components - Development of MCP impeller design, performance prediction code and experimental verification

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Myung Kyoon; Oh, Woo Hyoung; Song, Jae Wook [Korea Advanced Institute of Science and Technology, Taejon (Korea)

    1999-03-01

    The present study is aimed at developing a computational code for design and performance prediction of an axial-flow pump. The proposed performance prediction method is tested against a model axial-flow pump streamline curvature method. The preliminary design is made by using the ideal velocity triangles at inlet and exit and the three dimensional blade shape is calculated by employing the free vortex design method. Then the detailed blading design is carried out by using experimental database of double circular arc cambered hydrofoils. To computationally determine the design incidence, deviation, blade camber, solidity and stagger angle, a number of correlation equations are developed form the experimental database and a theorical formula for the lift coefficient is adopted. A total of 8 equations are solved iteratively using an under-relaxation factor. An experimental measurement is conducted under a non-cavitating condition to obtain the off-design performance curve and also a cavitation test is carried out by reducing the suction pressure. The experimental results are very satisfactorily compared with the predictions by the streamline curvature method. 28 refs., 26 figs., 11 tabs. (Author)

  12. Genetic structure of populations of Drosophila melanogaster natives from Laguna Verde, Veracruz; Estructura genetica de poblaciones de Drosophila melanogaster originarias de Laguna Verde, Veracruz

    Energy Technology Data Exchange (ETDEWEB)

    Salceda, V.M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: vmss@nuclear.inin.mx

    2005-07-01

    The genetic variability hidden present in natural populations of Drosophila melanogaster, it has been broadly analyzed, and it is a tool that allows to detect differences among the different populations of this species, so much of natural nature as experimental. In this occasion we use it to see if differences exist in two neighboring populations inside the Laguna Verde nuclear power plant, Veracruz, and this way to suggest, of having differences in the mount of the relative frequencies of lethal genes, semi lethals and normal, be due to the radioactive emanations product of the reactors operation of the plant. Its were took samples of flies in both towns during three successive seasons and they were transported to the laboratory of the ININ where they were carried out the tests to determine the frequency of the different types of genes. This was made by means of the denominated technique C y L / Pm that allows by means of a cross series with a stump marker to obtain, in the third generation, in isolated form the different types of genes and this way to calculate their relative frequencies. The study understands the analysis of 299 chromosomes extracted from the populations, of those that 95 correspond at the control population and 204 to the experimental one. As a result of the analysis we find that 30.52 percent of the genes of the population witness contains detrimental genes (sum of the lethal plus the semi lethal genes) as long as in the experimental population this value corresponds to 23.03 percent. In accordance with this information was not significant difference among the studied populations. A similar analysis, but now comparing the seasons, (summer against winter), it showed significant difference to 5% with regard to the lethal genes frequency only in the population witness. These results indicate the absence of damage, however it is necessary to consider that this can be due to that indeed there is not him or that the investigation protocol is not

  13. SKRINING BAKTERI SIMBION PADA LALAT BUAH (Drosophilla melanogaster SEBAGAI KANDIDAT PENGHASIL SENYAWA ANTIBIOTIKA

    Directory of Open Access Journals (Sweden)

    Armini Syamsidi

    2014-12-01

    Full Text Available Now the emergence of bacterial resistance to antibiotics is a national and global issues that have a significant impact on public health. We report the screening of bacterial symbionts in fruit flies (Drosophilla melanogaster as a producer of new antibiotic compounds. This study aims to get antibiotic-producing bacterial symbionts in fruit flies (Drosophilla melanogaster. In this study used methods of isolation, purification and antibacterial testing using four test bacteria (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Salmonella thyposa. Isolation of fruit flies (Drosophilla melanogaster that uses peptone solution prepared dilutions to 10-9 and then purification is done by scraping the bacteria on NA medium by repeatedly to obtain pure isolates and subsequently antibacterial test. The results showed that the bacterial isolation 10-8 and 10-9 dilutions allegedly produce antibiotic-producing compound while the antibacterial test using test bacteria showed that the compound obtained from the insulation in the fruit fly (Drosophilla melanogaster showed the compound to inhibit the growth of bacteria Escherichia coli and Staphylococcus aureus. Keywords: fruit flies, Drosophilla melanogaster, antibiotics ABSTRAK Munculnya resistensi bakteri terhadap antibiotika saat ini merupakan masalah nasional dan global yang memiliki dampak signifikan bagi kesehatan masyarakat. Telah dilakukan penelitian mengenai skrining bakteri simbion pada lalat buah (Drosophilla melanogaster sebagai penghasil senyawa antibiotika baru. Penelitian ini bertujuan untuk mendapatkan bakteri simbion penghasil antibiotika pada lalat buah (Drosophilla melanogaster. Pada penelitian ini digunakan metode isolasi, pemurnian dan pengujian antibakteri dengan menggunakan 4 bakteri uji (Escherchia coli, Staphylococcus aureus, Bacillus subtilis, dan Salmonella thyposa. Isolasi lalat buah (Drosophilla melanogaster yang  menggunakan larutan pepton yang dibuat pengenceran

  14. Climate Dynamics and Experimental Prediction (CDEP) and Regional Integrated Science Assessments (RISA) Programs at NOAA Office of Global Programs

    Science.gov (United States)

    Bamzai, A.

    2003-04-01

    This talk will highlight science and application activities of the CDEP and RISA programs at NOAA OGP. CDEP, through a set of Applied Research Centers (ARCs), supports NOAA's program of quantitative assessments and predictions of global climate variability and its regional implications on time scales of seasons to centuries. The RISA program consolidates results from ongoing disciplinary process research under an integrative framework. Examples of joint CDEP-RISA activities will be presented. Future directions and programmatic challenges will also be discussed.

  15. Nutrition attitudes and knowledge in medical students after completion of an integrated nutrition curriculum compared to a dedicated nutrition curriculum: a quasi-experimental study.

    Science.gov (United States)

    Walsh, Carolyn O; Ziniel, Sonja I; Delichatsios, Helen K; Ludwig, David S

    2011-08-12

    Nutrition education has presented an ongoing challenge to medical educators. In the 2007-2008 academic year, Harvard Medical School replaced its dedicated Preventive Medicine and Nutrition course with an integrated curriculum. The objective of the current study was to assess the effect of the curriculum change on medical student attitudes and knowledge about nutrition. A survey was administered in a quasi-experimental design to students in the last class of the dedicated curriculum (n = 131) and the first class of the integrated curriculum (n = 135) two years after each class completed the required nutrition course. Main measures were attitude scores based on modified Nutrition in Patient care Survey and satisfaction ratings, performance on a nutrition knowledge test, and demographic variables. Two-tailed t-tests were performed. Response rates were 50.4% and 42.2%. There were no differences between the groups in attitude scores from the Nutrition in Patient care Survey (p = 0.43) or knowledge scores (p = 0.63). Students with the integrated curriculum were less satisfied with both the quantity (p nutrition education, and were more likely to have completed optional online nutrition training modules (p = 0.0089). Medical student attitudes and knowledge about nutrition were not affected by the model of nutrition education they receive, though students in an integrated curriculum may feel their education is inadequate and seek additional training.

  16. Functionalization of glassy carbon surface by means of aliphatic and aromatic amino acids. An experimental and theoretical integrated approach

    International Nuclear Information System (INIS)

    Vanossi, Davide; Benassi, Rois; Parenti, Francesca; Tassinari, Francesco; Giovanardi, Roberto; Florini, Nicola; De Renzi, Valentina; Arnaud, Gaelle; Fontanesi, Claudio

    2012-01-01

    Highlights: ► Glassy carbon is functionalized via electrochemical assisted grafting of amino acids. ► The grafting mechanism is suggested to involve the “zwitterionic” species. ► DFT calculations allowed to determine the electroactive species. ► An original grafting mechanism is proposed. - Abstract: Glassy carbon (GC) electrode surfaces are functionalized through electrochemical assisted grafting, in oxidation regime, of six amino acids (AA): β-alanine (β-Ala), L-aspartic acid (Asp), 11-aminoundecanoic acid (UA), 4-aminobenzoic acid (PABA), 4-(4-amino-phenyl)-butyric acid (PFB), 3-(4-amino-phenyl)-propionic acid (PFP). Thus, a GC/AA interface is produced featuring carboxylic groups facing the solution. Electrochemical (cyclic voltammetry and electrochemical impedance spectroscopy) and XPS techniques are used to experimentally characterize the grafting process and the surface state. The theoretical results are compared with the experimental evidence to determine, at a molecular level, the overall grafting mechanism. Ionization potentials, standard oxidation potentials, HOMO and electron spin distributions are calculated at the CCD/6-31G* level of the theory. The comparison of experimental and theoretical data suggests that the main electroactive species is the “zwitterionic” form for the three aliphatic amino acids, while the amino acids featuring the amino group bound to the phenyl aromatic moiety show a different behaviour. The comparison between experimental and theoretical results suggests that both the neutral and the zwitterionic forms are present in the acetonitrile solution in the case of 4-(4-amino-phenyl)-butyric acid (PFB) and 3-(4-amino-phenyl)-propionic acid.

  17. ShewRegDB: a Visualization Environment for Integration of Experimental and In Silico Derived Regulatory Information in Shewanella oneidensis MR-1

    Energy Technology Data Exchange (ETDEWEB)

    Syed, Mustafa H [ORNL; Karpinets, Tatiana V [ORNL; Leuze, Michael Rex [ORNL; Kora, Guruprasad H [ORNL; Romine, Margaret [Pacific Northwest National Laboratory (PNNL); Uberbacher, Edward C [ORNL

    2009-01-01

    Shewanella oneidensis MR-1 is an important model organism for environmental research as it has an exceptional metabolic and respiratory versatility regulated by a complex regulatory network. We have developed a database to collect experimental and computational data relating to regulation of gene and protein expression, and, a visualization environment that enables integration of these data types. The regulatory information in the database includes predictions of DNA regulator binding sites, sigma factor binding sites, transcription units, operons, promoters, and RNA regulators including non-coding RNAs, riboswitches, and different types of terminators.

  18. Numerical and experimental studies on a Building integrated Semi-transparent Photovoltaic Thermal (BiSPVT) system: Model validation with a prototype test setup

    International Nuclear Information System (INIS)

    Gaur, Ankita; Tiwari, G.N.; Ménézo, Christophe; Al-Helal, I.M.

    2016-01-01

    Highlights: • Mathematical models for c-Si BiSPVT systems are developed & verified experimentally. • Expressions for thermal and electrical parameters of BiSPVT system are derived. • Energy and exergy analysis are performed. • The system is optimized for various design parameters and number of air changes. - Abstract: The work concerns experimental and theoretical studies of building integrated semitransparent photovoltaic/thermal (BiSPVT) system. The analytical expressions for temperature dependent electrical efficiencies of the system have been established. It concerns a roof integrated semitransparent mono crystalline silicon (c-Si) PV with two options: (i) with air duct or (ii) without air duct. An experiment has been performed on a specially designed proto-type c-Si BiSPVT set up built in Indian Institute of Technology, New Delhi, India. Theoretically calculated results using derived expressions have been validated with experimentally measured thermal and electrical parameters for both cases. A fair agreement between theoretically calculated and experimentally measured values is observed. The characteristic curves, energy and exergy analysis have also been performed particularly under cold climatic conditions of Srinagar, India. Further, to maximize the electrical and thermal efficiencies, BiSPVT system has been optimized for various design parameters as cross sectional area of air duct, duct height, fluid flow velocity, packing factor and number of air change. Without air duct, the efficiency (η m ) and the average room temperature (T r ) are found to be 12% and 25 °C respectively, whereas with air duct the BiSPVT systems inflicted the efficiency (η m ) and temperature (T r ) to be 13.11% and 10.1 °C respectively.

  19. Germ-line transmission of lentiviral PGK-EGFP integrants in transgenic cattle: new perspectives for experimental embryology.

    Science.gov (United States)

    Reichenbach, Myriam; Lim, Tiongti; Reichenbach, Horst-Dieter; Guengoer, Tuna; Habermann, Felix A; Matthiesen, Marieke; Hofmann, Andreas; Weber, Frank; Zerbe, Holm; Grupp, Thomas; Sinowatz, Fred; Pfeifer, Alexander; Wolf, Eckhard

    2010-08-01

    Lentiviral vectors are a powerful tool for the genetic modification of livestock species. We previously generated transgenic founder cattle with lentiviral integrants carrying enhanced green fluorescent protein (EGFP) under the control of the phosphoglycerate kinase (PGK) promoter. In this study, we investigated the transmission of LV-PGK-EGFP integrants through the female and male germ line in cattle. A transgenic founder heifer (#562, Kiki) was subjected to superovulation treatment and inseminated with semen from a non-transgenic bull. Embryos were recovered and transferred to synchronized recipient heifers, resulting in the birth of a healthy male transgenic calf expressing EGFP as detected by in vivo imaging. Semen from a transgenic founder bull (#561, Jojo) was used for in vitro fertilization (IVF) of in vitro matured (IVM) oocytes from non-transgenic cows. The rates of cleavage and development to blastocyst in vitro corresponded to 52.0 +/- 4.1 and 24.5 +/- 4.4%, respectively. Expression of EGFP was observed at blastocyst stage (day 7 after IVF) and was seen in 93.0% (281/302) of the embryos. 24 EGFP-expressing embryos were transferred to 9 synchronized recipients. Analysis of 2 embryos, flushed from the uterus on day 15, two fetuses recovered on day 45, and a healthy male transgenic calf revealed consistent high-level expression of EGFP in all tissues investigated. Our study shows for the first time transmission of lentiviral integrants through the germ line of female and male transgenic founder cattle. The pattern of inheritance was consistent with Mendelian rules. Importantly, high fidelity expression of EGFP in embryos, fetuses, and offspring of founder #561 provides interesting tools for developmental studies in cattle, including interactions of gametes, embryos and fetuses with their maternal environment.

  20. Implementation challenges for designing integrated in vitro testing strategies (ITS) aiming at reducing and replacing animal experimentation.

    Science.gov (United States)

    De Wever, Bart; Fuchs, Horst W; Gaca, Marianna; Krul, Cyrille; Mikulowski, Stan; Poth, Albrecht; Roggen, Erwin L; Vilà, Maya R

    2012-04-01

    At the IVTIP (in vitro testing industrial platform) meeting of November 26th 2009 entitled 'Toxicology in the 21st century ('21C')--working our way towards a visionary reality' all delegates endorsed the emerging concept of the '21C' vision as the way forward to enable a thorough, reliable and systematic approach to future toxicity testing without the use of animals. One of the emerging concepts focused on integrating a defined number of tests modelling in vivo-relevant and well-characterised toxicity pathways representing mechanistic endpoints. At this meeting the importance of Integrated Testing Strategies (ITS) as tools towards reduction and eventually replacement of the animals currently used for hazard identification and risk assessment was recognised. A follow-up IVTIP Spring 2010 meeting entitled 'Integrated In Vitro Testing Strategies (ITS)--Implementation Challenges' was organised to address pending questions about ITS. This report is not a review of the ITS literature, but a summary of the discussions triggered by presented examples on how to develop and implement ITS. Contrasts between pharmaceutical and chemical industry, as well as a list of general but practical aspects to be considered while developing an ITS emerged from the discussions. In addition, current recommendations on the validation of ITS were discussed. In conclusion, the outcome of this workshop improved the understanding of the participants of some important factors that may impact the design of an ITS in function of its purpose (e.g., screening, or early decision making versus regulatory), the context in which they need to be applied (e.g., ICH guidelines, REACH) and the status and quality of the available tools. A set of recommendations of best practices was established and the importance of the applicability of the individual tests as well as the testing strategy itself was highlighted. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. The Adaptive Significance of Natural Genetic Variation in the DNA Damage Response of Drosophila melanogaster.

    Science.gov (United States)

    Svetec, Nicolas; Cridland, Julie M; Zhao, Li; Begun, David J

    2016-03-01

    Despite decades of work, our understanding of the distribution of fitness effects of segregating genetic variants in natural populations remains largely incomplete. One form of selection that can maintain genetic variation is spatially varying selection, such as that leading to latitudinal clines. While the introduction of population genomic approaches to understanding spatially varying selection has generated much excitement, little successful effort has been devoted to moving beyond genome scans for selection to experimental analysis of the relevant biology and the development of experimentally motivated hypotheses regarding the agents of selection; it remains an interesting question as to whether the vast majority of population genomic work will lead to satisfying biological insights. Here, motivated by population genomic results, we investigate how spatially varying selection in the genetic model system, Drosophila melanogaster, has led to genetic differences between populations in several components of the DNA damage response. UVB incidence, which is negatively correlated with latitude, is an important agent of DNA damage. We show that sensitivity of early embryos to UVB exposure is strongly correlated with latitude such that low latitude populations show much lower sensitivity to UVB. We then show that lines with lower embryo UVB sensitivity also exhibit increased capacity for repair of damaged sperm DNA by the oocyte. A comparison of the early embryo transcriptome in high and low latitude embryos provides evidence that one mechanism of adaptive DNA repair differences between populations is the greater abundance of DNA repair transcripts in the eggs of low latitude females. Finally, we use population genomic comparisons of high and low latitude samples to reveal evidence that multiple components of the DNA damage response and both coding and non-coding variation likely contribute to adaptive differences in DNA repair between populations.

  2. Improved prediction of RNA secondary structure by integrating the free energy model with restraints derived from experimental probing data.

    Science.gov (United States)

    Wu, Yang; Shi, Binbin; Ding, Xinqiang; Liu, Tong; Hu, Xihao; Yip, Kevin Y; Yang, Zheng Rong; Mathews, David H; Lu, Zhi John

    2015-09-03

    Recently, several experimental techniques have emerged for probing RNA structures based on high-throughput sequencing. However, most secondary structure prediction tools that incorporate probing data are designed and optimized for particular types of experiments. For example, RNAstructure-Fold is optimized for SHAPE data, while SeqFold is optimized for PARS data. Here, we report a new RNA secondary structure prediction method, restrained MaxExpect (RME), which can incorporate multiple types of experimental probing data and is based on a free energy model and an MEA (maximizing expected accuracy) algorithm. We first demonstrated that RME substantially improved secondary structure prediction with perfect restraints (base pair information of known structures). Next, we collected structure-probing data from diverse experiments (e.g. SHAPE, PARS and DMS-seq) and transformed them into a unified set of pairing probabilities with a posterior probabilistic model. By using the probability scores as restraints in RME, we compared its secondary structure prediction performance with two other well-known tools, RNAstructure-Fold (based on a free energy minimization algorithm) and SeqFold (based on a sampling algorithm). For SHAPE data, RME and RNAstructure-Fold performed better than SeqFold, because they markedly altered the energy model with the experimental restraints. For high-throughput data (e.g. PARS and DMS-seq) with lower probing efficiency, the secondary structure prediction performances of the tested tools were comparable, with performance improvements for only a portion of the tested RNAs. However, when the effects of tertiary structure and protein interactions were removed, RME showed the highest prediction accuracy in the DMS-accessible regions by incorporating in vivo DMS-seq data. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  3. Experimental techniques and theoretical models for the study of integral 14 MeV neutron cross sections

    International Nuclear Information System (INIS)

    Csikai, J.

    1981-01-01

    Owing to technical reasons, most of the data for fast neutron-induced reactions were measured at 14 MeV and the free parameters in nuclear reaction models have been determined at this energy. The discrepancies between experiment and theory are often due to the unmeasured or unreliable experimental data; therefore, it is important to survey the present techniques used for the measurement of total, elastic, nonelastic and partial nonelastic [(n,xn); (n,x charged); (n,f); (n,γ)] cross sections for 14 MeV neutrons. Systematics in the data as well as theoretical and semi-empirical models are also outlined. (author)

  4. Integrated modeling and experimental programs to predict brine and gas flow at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Beauheim, R.L.; Howarth, S.M.; Vaughn, P.; Webb, S.W.; Larson, K.W.

    1995-01-01

    Evaluation of the performance of the WIPP repository involves modeling of brine and gas flow in the host rocks of the Salado Formation, which consist of halite and anhydrite interbeds. Numerous physical, chemical, and structural processes, must be understood to perform this modeling. Gas generation within the repository is strongly coupled to the amount of brine inflow to the repository because brine aids in the corrosion of metals and associated generation of hydrogen gas. Increasing gas pressure in the repository decreases the rate of brine inflow. Ultimately, the gas pressure may exceed the brine pressure and gas may flow out of the repository. Relative-permeability curves and a correlation between threshold pressure and permeability taken from studies reported in the literature were used in PA models prior to being experimentally verified as appropriate for WIPP. In addition, interbed permeabilities were treated as constant and independent of effective stress in early models. Subsequently, the process of interbed fracturing (or fracture dilation) was recognized to limit gas pressures in the repository to values below lithostatic, and assumed (and unverified) relationships between porosity, permeability, and pore pressure were employed. Parameter-sensitivity studies performed using the simplified models identified important parameters for which site-specific data were needed. Unrealistic modeling results, such as room pressures substantially above lithostatic, showed the need to include additional processes in the models. Field and laboratory experimental programs have been initiated in conjunction with continued model development to provide information on important processes and parameters

  5. Experimental Study of Single Phase Flow in a Closed-Loop Cooling System with Integrated Mini-Channel Heat Sink

    Directory of Open Access Journals (Sweden)

    Lei Ma

    2016-06-01

    Full Text Available The flow and heat transfer characteristics of a closed-loop cooling system with a mini-channel heat sink for thermal management of electronics is studied experimentally. The heat sink is designed with corrugated fins to improve its heat dissipation capability. The experiments are performed using variable coolant volumetric flow rates and input heating powers. The experimental results show a high and reliable thermal performance using the heat sink with corrugated fins. The heat transfer capability is improved up to 30 W/cm2 when the base temperature is kept at a stable and acceptable level. Besides the heat transfer capability enhancement, the capability of the system to transfer heat for a long distance is also studied and a fast thermal response time to reach steady state is observed once the input heating power or the volume flow rate are varied. Under different input heat source powers and volumetric flow rates, our results suggest potential applications of the designed mini-channel heat sink in cooling microelectronics.

  6. Hormetic efficacy of rutin to promote longevity in Drosophila melanogaster.

    Science.gov (United States)

    Chattopadhyay, Debarati; Chitnis, Atith; Talekar, Aishwarya; Mulay, Prajakta; Makkar, Manyata; James, Joel; Thirumurugan, Kavitha

    2017-06-01

    Hormetins are compounds that mediate hormesis by being beneficial at low doses but detrimental at high doses. Recent studies have highlighted that many compounds that extended lifespan in model organisms did so by mediating hormesis. Rutin is a glycosylate conjugate of quercetin and rutinose and is abundant in citrus fruits and buckwheat seeds. Rutin possess ROS scavenging, anti-cancer, cardio-protective, skin-regenerative and neuro-protective properties. Drosophila melanogaster is an attractive model organism for longevity studies owing to its homology of organ and cellular-pathways with mammals. In this study, we aimed to understand the effect of rutin on extending longevity in Drosophila melanogaster. Male and female flies were administered with a range of rutin doses (100-800 µM) to analyse whether rutin mediated lifespan-extension by hormesis. Effect of rutin on physiological parameters like food intake, fecundity, climbing activity, development and resistance to various stresses was also studied. Lifespan assays showed that rutin at 200 and 400 µM significantly extended median lifespan in both male and female flies beyond which flies exhibited drastically reduced longevity. Increase in survival at 400 µM was associated with reduced food intake and fecundity. Flies exhibited improved climbing capability with both 200 and 400 µM rutin. Flies fed with 100 and 200 µM rutin exhibited enhanced survival upon exposure to oxidative stress with 400 µM rutin exhibiting no improvement in median lifespan following oxidative stress. Analysis of endogenous peroxide upon treatment with rutin (100-400 µM) with or without 5% H 2 O 2 showed elevated levels of endogenous peroxide with 400 µM rutin whereas no increase in hydrogen peroxide level was observed with rutin at 100 and 200 µM. Finally, gene expression studies in male flies revealed that rutin treatment at 200 and/or 400 µM elevated transcript levels of dFoxO, MnSod, Cat, dTsc1, dTsc2, Thor, dAtg1, d

  7. Deep Conservation of Genes Required for Both Drosophila melanogaster and Caenorhabditis elegans Sleep Includes a Role for Dopaminergic Signaling

    Science.gov (United States)

    Singh, Komudi; Ju, Jennifer Y.; Walsh, Melissa B.; DiIorio, Michael A.; Hart, Anne C.

    2014-01-01

    Objectives: Cross-species conservation of sleep-like behaviors predicts the presence of conserved molecular mechanisms underlying sleep. However, limited experimental evidence of conservation exists. Here, this prediction is tested directly. Measurements and Results: During lethargus, Caenorhabditis elegans spontaneously sleep in short bouts that are interspersed with bouts of spontaneous locomotion. We identified 26 genes required for Drosophila melanogaster sleep. Twenty orthologous C. elegans genes were selected based on similarity. Their effect on C. elegans sleep and arousal during the last larval lethargus was assessed. The 20 most similar genes altered both the quantity of sleep and arousal thresholds. In 18 cases, the direction of change was concordant with Drosophila studies published previously. Additionally, we delineated a conserved genetic pathway by which dopamine regulates sleep and arousal. In C. elegans neurons, G-alpha S, adenylyl cyclase, and protein kinase A act downstream of D1 dopamine receptors to regulate these behaviors. Finally, a quantitative analysis of genes examined herein revealed that C. elegans arousal thresholds were directly correlated with amount of sleep during lethargus. However, bout duration varies little and was not correlated with arousal thresholds. Conclusions: The comprehensive analysis presented here suggests that conserved genes and pathways are required for sleep in invertebrates and, likely, across the entire animal kingdom. The genetic pathway delineated in this study implicates G-alpha S and previously known genes downstream of dopamine signaling in sleep. Quantitative analysis of various components of quiescence suggests that interdependent or identical cellular and molecular mechanisms are likely to regulate both arousal and sleep entry. Citation: Singh K, Ju JY, Walsh MB, Dilorio MA, Hart AC. Deep conservation of genes required for both Drosophila melanogaster and Caenorhabditis elegans sleep includes a role for

  8. Comparison of experimental pulse-height distributions in germanium detectors with integrated-tiger-series-code predictions

    International Nuclear Information System (INIS)

    Beutler, D.E.; Halbleib, J.A.; Knott, D.P.

    1989-01-01

    This paper reports pulse-height distributions in two different types of Ge detectors measured for a variety of medium-energy x-ray bremsstrahlung spectra. These measurements have been compared to predictions using the integrated tiger series (ITS) Monte Carlo electron/photon transport code. In general, the authors find excellent agreement between experiments and predictions using no free parameters. These results demonstrate that the ITS codes can predict the combined bremsstrahlung production and energy deposition with good precision (within measurement uncertainties). The one region of disagreement observed occurs for low-energy (<50 keV) photons using low-energy bremsstrahlung spectra. In this case the ITS codes appear to underestimate the produced and/or absorbed radiation by almost an order of magnitude

  9. Integrated system for production of neutronics and photonics calculational constants. Major neutron-induced interactions (Z > 55): graphical, experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Cullen, D.E.; Howerton, R.J.; MacGregor, M.H.; Perkins, S.T.

    1976-07-04

    This report (vol. 7) presents graphs of major neutron-induced interaction cross sections in the Experimental Cross Section Information Library (ECSIL) as of July 4, 1976. It consists primarily of interactions where a single data set contains enough points to show cross section behavior. In contrast, vol. 8 of this UCRL-50400 series consists of interactions where more than one data set is needed to show cross section behavior. Thus, you can find the total, elastic, capture, and fission cross sections (along with the parameters ..nu.. bar, ..cap alpha.., and eta) in vol. 7 and all other reactions in vol. 8. Data are plotted with associated cross section error bars (when given) and compared with the Evaluated Nuclear Data Library (ENDL) as of July 4, 1976. The plots are arranged in ascending order of atomic number (Z) and atomic weight (A). Part A contains the plots for Z = 1 to 55; Part B contains the plots for Z is greater than 55.

  10. Integrating beneficiaries into assessment of ecosystem services from managed forests at the Hubbard Brook Experimental Forest, USA

    Directory of Open Access Journals (Sweden)

    Jesse Caputo

    2016-05-01

    Full Text Available Background: Forests contribute to human wellbeing through the provision of important ecosystem services. Methods: In this study, we investigated how the perceived importance of ecosystem services may impact the overall benefit provided by managed watersheds at the Hubbard Brook Experimental Forest over a 45-year period, using standardized measures of service capacity weighted by service importance weights derived from a survey of beneficiaries. Results: The capacity of watersheds to regulate water flow and quality was high in all watersheds throughout the study period, whereas cultural services such as scenic beauty declined after harvest. Impacts on greenhouse gas regulation depended on the efficiency with which harvested biomass was used. Surveys revealed that stakeholders placed high value on all ecosystem services, with regulating and cultural services seen as more important than provisioning services. When service metrics were weighted by survey responses and aggregated into a single measure, total service provision followed the same overall trend as greenhouse gas regulation. Where biomass use was less efficient in terms of greenhouse gas emissions, harvesting resulted in an overall “ecosystem service debt”; where use was more efficient, this “ecosystem service debt” was reduced. Beneficiaries’ educational backgrounds significantly affected overall assessment of service provision. Beneficiaries with college or university degrees incurred smaller “ecosystem service debts” and were less negatively affected by harvesting overall. Conclusions: This study highlights the importance of including empirical measures of beneficiary preference when attempting to quantify overall provision of ecosystem services to human beneficiaries over time. Keywords: Ecosystem services, Forests, Long-term ecological research, Hubbard Brook Experimental Forest, Regulating services

  11. Identification and characterization of novel natural pathogen of Drosophila melanogaster isolated from wild captured Drosophila spp.

    Science.gov (United States)

    Singh, Karan; Zulkifli, Mohammad; Prasad, N G

    2016-12-01

    Drosophila melanogaster is an emerging model system for the study of evolutionary ecology of immunity. However, a large number of studies have used non natural pathogens as very few natural pathogens have been isolated and identified. Our aim was to isolate and characterize natural pathogen/s of D. melanogaster. A bacterial pathogen was isolated from wild caught Drosophila spp., identified as a new strain of Staphylococcus succinus subsp. succinus and named PK-1. This strain induced substantial mortality (36-62%) in adults of several laboratory populations of D. melanogaster. PK-1 grew rapidly within the body of the flies post infection and both males and females had roughly same number of colony forming units. Mortality was affected by mode of infection and dosage of the pathogen. However mating status of the host had no effect on mortality post infection. Given that there are very few known natural bacterial pathogens of D. melanogaster and that PK-1 can establish a sustained infection across various outbred and inbred populations of D. melanogaster this new isolate is a potential resource for future studies on immunity. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  12. Parallel Evolution of Copy-Number Variation across Continents in Drosophila melanogaster

    Science.gov (United States)

    Schrider, Daniel R.; Hahn, Matthew W.; Begun, David J.

    2016-01-01

    Genetic differentiation across populations that is maintained in the presence of gene flow is a hallmark of spatially varying selection. In Drosophila melanogaster, the latitudinal clines across the eastern coasts of Australia and North America appear to be examples of this type of selection, with recent studies showing that a substantial portion of the D. melanogaster genome exhibits allele frequency differentiation with respect to latitude on both continents. As of yet there has been no genome-wide examination of differentiated copy-number variants (CNVs) in these geographic regions, despite their potential importance for phenotypic variation in Drosophila and other taxa. Here, we present an analysis of geographic variation in CNVs in D. melanogaster. We also present the first genomic analysis of geographic variation for copy-number variation in the sister species, D. simulans, in order to investigate patterns of parallel evolution in these close relatives. In D. melanogaster we find hundreds of CNVs, many of which show parallel patterns of geographic variation on both continents, lending support to the idea that they are influenced by spatially varying selection. These findings support the idea that polymorphic CNVs contribute to local adaptation in D. melanogaster. In contrast, we find very few CNVs in D. simulans that are geographically differentiated in parallel on both continents, consistent with earlier work suggesting that clinal patterns are weaker in this species. PMID:26809315

  13. Comparative population genomics of latitudinal variation in Drosophila simulans and Drosophila melanogaster.

    Science.gov (United States)

    Machado, Heather E; Bergland, Alan O; O'Brien, Katherine R; Behrman, Emily L; Schmidt, Paul S; Petrov, Dmitri A

    2016-02-01

    Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for understanding how spatially varying selection and demographic forces shape variation within species. Here, we examine the selective and demographic contributions to latitudinal variation through the largest comparative genomic study to date of Drosophila simulans and Drosophila melanogaster, with genomic sequence data from 382 individual fruit flies, collected across a spatial transect of 19 degrees latitude and at multiple time points over 2 years. Consistent with phenotypic studies, we find less clinal variation in D. simulans than D. melanogaster, particularly for the autosomes. Moreover, we find that clinally varying loci in D. simulans are less stable over multiple years than comparable clines in D. melanogaster. D. simulans shows a significantly weaker pattern of isolation by distance than D. melanogaster and we find evidence for a stronger contribution of migration to D. simulans population genetic structure. While population bottlenecks and migration can plausibly explain the differences in stability of clinal variation between the two species, we also observe a significant enrichment of shared clinal genes, suggesting that the selective forces associated with climate are acting on the same genes and phenotypes in D. simulans and D. melanogaster. © 2015 John Wiley & Sons Ltd.

  14. Assessing population and environmental effects on thermal resistance in Drosophila melanogaster using ecologically relevant assays

    DEFF Research Database (Denmark)

    Overgaard, Johannes; Hoffmann, Ary A; Kristensen, Torsten Nygård

    2011-01-01

    adult flies. We use this approach to assess upper and lower thermal limits and functional thermal scope for Drosophila melanogaster and also show that the method can be used to (1) detect a previously described latitudinal cline for cold tolerance in D. melanogaster populations collected along the east...

  15. Isolation of protease-free alcohol dehydrogenase (ADH) from Drosophila simulans and several homozygous and heterozygous Drosophila melanogaster variants

    NARCIS (Netherlands)

    Smilda, T; Lamme, DA; Collu, G; Jekel, PA; Reinders, P; Beintema, JJ

    The enzyme alcohol dehydrogenase (ADH) from several naturally occurring ADH variants of Drosophila melanogaster and Drosophila simulans Lc,as isolated. Affinity chromatography with the ligand Cibacron Blue and elution with NAD(+) showed similar behavior for D. melanogaster ADH-FF, ADH-71k, and D.

  16. Dopamine modulates metabolic rate and temperature sensitivity in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Taro Ueno

    Full Text Available Homeothermal animals, such as mammals, maintain their body temperature by heat generation and heat dissipation, while poikilothermal animals, such as insects, accomplish it by relocating to an environment of their favored temperature. Catecholamines are known to regulate thermogenesis and metabolic rate in mammals, but their roles in other animals are poorly understood. The fruit fly, Drosophila melanogaster, has been used as a model system for the genetic studies of temperature preference behavior. Here, we demonstrate that metabolic rate and temperature sensitivity of some temperature sensitive behaviors are regulated by dopamine in Drosophila. Temperature-sensitive molecules like dTrpA1 and shi(ts induce temperature-dependent behavioral changes, and the temperature at which the changes are induced were lowered in the dopamine transporter-defective mutant, fumin. The mutant also displays a preference for lower temperatures. This thermophobic phenotype was rescued by the genetic recovery of the dopamine transporter in dopamine neurons. Flies fed with a dopamine biosynthesis inhibitor (3-iodo-L-tyrosine, which diminishes dopamine signaling, exhibited preference for a higher temperature. Furthermore, we found that the metabolic rate is up-regulated in the fumin mutant. Taken together, dopamine has functions in the temperature sensitivity of behavioral changes and metabolic rate regulation in Drosophila, as well as its previously reported functions in arousal/sleep regulation.

  17. Image enhancement for tracking the translucent larvae of Drosophila melanogaster.

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    Sukant Khurana

    Full Text Available Drosophila melanogaster larvae are model systems for studies of development, synaptic transmission, sensory physiology, locomotion, drug discovery, and learning and memory. A detailed behavioral understanding of larvae can advance all these fields of neuroscience. Automated tracking can expand fine-grained behavioral analysis, yet its full potential remains to be implemented for the larvae. All published methods are unable to track the larvae near high contrast objects, including the petri-dish edges encountered in many behavioral paradigms. To alleviate these issues, we enhanced the larval contrast to obtain complete tracks. Our method employed a dual approach of optical-contrast boosting and post-hoc image processing for contrast enhancement. We reared larvae on black food media to enhance their optical contrast through darkening of their digestive tracts. For image processing we performed Frame Averaging followed by Subtraction then Thresholding (FAST. This algorithm can remove all static objects from the movie, including petri-dish edges prior to processing by the image-tracking module. This dual approach for contrast enhancement also succeeded in overcoming fluctuations in illumination caused by the alternating current power source. Our tracking method yields complete tracks, including at the edges of the behavioral arena and is computationally fast, hence suitable for high-throughput fine-grained behavioral measurements.

  18. Strong Purifying Selection at Synonymous Sites in D. melanogaster

    Science.gov (United States)

    Lawrie, David S.; Messer, Philipp W.; Hershberg, Ruth; Petrov, Dmitri A.

    2013-01-01

    Synonymous sites are generally assumed to be subject to weak selective constraint. For this reason, they are often neglected as a possible source of important functional variation. We use site frequency spectra from deep population sequencing data to show that, contrary to this expectation, 22% of four-fold synonymous (4D) sites in Drosophila melanogaster evolve under very strong selective constraint while few, if any, appear to be under weak constraint. Linking polymorphism with divergence data, we further find that the fraction of synonymous sites exposed to strong purifying selection is higher for those positions that show slower evolution on the Drosophila phylogeny. The function underlying the inferred strong constraint appears to be separate from splicing enhancers, nucleosome positioning, and the translational optimization generating canonical codon bias. The fraction of synonymous sites under strong constraint within a gene correlates well with gene expression, particularly in the mid-late embryo, pupae, and adult developmental stages. Genes enriched in strongly constrained synonymous sites tend to be particularly functionally important and are often involved in key developmental pathways. Given that the observed widespread constraint acting on synonymous sites is likely not limited to Drosophila, the role of synonymous sites in genetic disease and adaptation should be reevaluated. PMID:23737754

  19. Drosophila melanogaster White Mutant w1118 Undergo Retinal Degeneration

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    María José Ferreiro

    2018-01-01

    Full Text Available Key scientific discoveries have resulted from genetic studies of Drosophila melanogaster, using a multitude of transgenic fly strains, the majority of which are constructed in a genetic background containing mutations in the white gene. Here we report that white mutant flies from w1118 strain undergo retinal degeneration. We observed also that w1118 mutants have progressive loss of climbing ability, shortened life span, as well as impaired resistance to various forms of stress. Retinal degeneration was abolished by transgenic expression of mini-white+ in the white null background w1118. We conclude that beyond the classical eye-color phenotype, mutations in Drosophila white gene could impair several biological functions affecting parameters like mobility, life span and stress tolerance. Consequently, we suggest caution and attentiveness during the interpretation of old experiments employing white mutant flies and when planning new ones, especially within the research field of neurodegeneration and neuroprotection. We also encourage that the use of w1118 strain as a wild-type control should be avoided.

  20. Specialized Cortex Glial Cells Accumulate Lipid Droplets in Drosophila melanogaster

    Science.gov (United States)

    Kis, Viktor; Barti, Benjámin; Lippai, Mónika; Sass, Miklós

    2015-01-01

    Lipid droplets (LDs) are common organelles of the majority of eukaryotic cell types. Their biological significance has been extensively studied in mammalian liver cells and white adipose tissue. Although the central nervous system contains the highest relative amount and the largest number of different lipid species, neither the spatial nor the temporal distribution of LDs has been described. In this study, we used the brain of the fruitfly, Drosophila melanogaster, to investigate the neuroanatomy of LDs. We demonstrated that LDs are exclusively localised in glial cells but not in neurons in the larval nervous system. We showed that the brain’s LD pool, rather than being constant, changes dynamically during development and reaches its highest value at the beginning of metamorphosis. LDs are particularly enriched in cortex glial cells located close to the brain surface. These specialized superficial cortex glial cells contain the highest amount of LDs among glial cell types and encapsulate neuroblasts and their daughter cells. Superficial cortex glial cells, combined with subperineurial glial cells, express the Drosophila fatty acid binding protein (Dfabp), as we have demonstrated through light- and electron microscopic immunocytochemistry. To the best of our best knowledge this is the first study that describes LD neuroanatomy in the Drosophila larval brain. PMID:26148013

  1. Specialized Cortex Glial Cells Accumulate Lipid Droplets in Drosophila melanogaster.

    Science.gov (United States)

    Kis, Viktor; Barti, Benjámin; Lippai, Mónika; Sass, Miklós

    2015-01-01

    Lipid droplets (LDs) are common organelles of the majority of eukaryotic cell types. Their biological significance has been extensively studied in mammalian liver cells and white adipose tissue. Although the central nervous system contains the highest relative amount and the largest number of different lipid species, neither the spatial nor the temporal distribution of LDs has been described. In this study, we used the brain of the fruitfly, Drosophila melanogaster, to investigate the neuroanatomy of LDs. We demonstrated that LDs are exclusively localised in glial cells but not in neurons in the larval nervous system. We showed that the brain's LD pool, rather than being constant, changes dynamically during development and reaches its highest value at the beginning of metamorphosis. LDs are particularly enriched in cortex glial cells located close to the brain surface. These specialized superficial cortex glial cells contain the highest amount of LDs among glial cell types and encapsulate neuroblasts and their daughter cells. Superficial cortex glial cells, combined with subperineurial glial cells, express the Drosophila fatty acid binding protein (Dfabp), as we have demonstrated through light- and electron microscopic immunocytochemistry. To the best of our best knowledge this is the first study that describes LD neuroanatomy in the Drosophila larval brain.

  2. Plasticity of the chemoreceptor repertoire in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Shanshan Zhou

    2009-10-01

    Full Text Available For most organisms, chemosensation is critical for survival and is mediated by large families of chemoreceptor proteins, whose expression must be tuned appropriately to changes in the chemical environment. We asked whether expression of chemoreceptor genes that are clustered in the genome would be regulated independently; whether expression of certain chemoreceptor genes would be especially sensitive to environmental changes; whether groups of chemoreceptor genes undergo coordinated rexpression; and how plastic the expression of chemoreceptor genes is with regard to sex, development, reproductive state, and social context. To answer these questions we used Drosophila melanogaster, because its chemosensory systems are well characterized and both the genotype and environment can be controlled precisely. Using customized cDNA microarrays, we showed that chemoreceptor genes that are clustered in the genome undergo independent transcriptional regulation at different developmental stages and between sexes. Expression of distinct subgroups of chemoreceptor genes is sensitive to reproductive state and social interactions. Furthermore, exposure of flies only to odor of the opposite sex results in altered transcript abundance of chemoreceptor genes. These genes are distinct from those that show transcriptional plasticity when flies are allowed physical contact with same or opposite sex members. We analyzed covariance in transcript abundance of chemosensory genes across all environmental conditions and found that they segregated into 20 relatively small, biologically relevant modules of highly correlated transcripts. This finely pixilated modular organization of the chemosensory subgenome enables fine tuning of the expression of the chemoreceptor repertoire in response to ecologically relevant environmental and physiological conditions.

  3. Evolutionary consequences of altered atmospheric oxygen in Drosophila melanogaster.

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    Marc Charette

    Full Text Available Twelve replicate populations of Drosophila melanogaster, all derived from a common ancestor, were independently evolved for 34+ generations in one of three treatment environments of varying PO(2: hypoxia (5.0-10.1 kPa, normoxia (21.3 kPa, and hyperoxia (40.5 kPa. Several traits related to whole animal performance and metabolism were assayed at various stages via "common garden" and reciprocal transplant assays to directly compare evolved and acclimatory differences among treatments. Results clearly demonstrate the evolution of a greater tolerance to acute hypoxia in the hypoxia-evolved populations, consistent with adaptation to this environment. Greater hypoxia tolerance was associated with an increase in citrate synthase activity in fly homogenate when compared to normoxic (control populations, suggesting an increase in mitochondrial volume density in these populations. In contrast, no direct evidence of increased performance of the hyperoxia-evolved populations was detected, although a significant decrease in the tolerance of these populations to acute hypoxia suggests a cost to adaptation to hyperoxia. Hyperoxia-evolved populations had lower productivity overall (i.e., across treatment environments and there was no evidence that hypoxia or hyperoxia-evolved populations had greatest productivity or longevity in their respective treatment environments, suggesting that these assays failed to capture the components of fitness relevant to adaptation.

  4. Rhythmic changes in synapse numbers in Drosophila melanogaster motor terminals.

    Directory of Open Access Journals (Sweden)

    Santiago Ruiz

    Full Text Available Previous studies have shown that the morphology of the neuromuscular junction of the flight motor neuron MN5 in Drosophila melanogaster undergoes daily rhythmical changes, with smaller synaptic boutons during the night, when the fly is resting, than during the day, when the fly is active. With electron microscopy and laser confocal microscopy, we searched for a rhythmic change in synapse numbers in this neuron, both under light:darkness (LD cycles and constant darkness (DD. We expected the number of synapses to increase during the morning, when the fly has an intense phase of locomotion activity under LD and DD. Surprisingly, only our DD data were consistent with this hypothesis. In LD, we found more synapses at midnight than at midday. We propose that under LD conditions, there is a daily rhythm of formation of new synapses in the dark phase, when the fly is resting, and disassembly over the light phase, when the fly is active. Several parameters appeared to be light dependent, since they were affected differently under LD or DD. The great majority of boutons containing synapses had only one and very few had either two or more, with a 70∶25∶5 ratio (one, two and three or more synapses in LD and 75∶20∶5 in DD. Given the maintenance of this proportion even when both bouton and synapse numbers changed with time, we suggest that there is a homeostatic mechanism regulating synapse distribution among MN5 boutons.

  5. Physiological Effects of l-Theanine on Drosophila melanogaster

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    Lei Xue

    2013-10-01

    Full Text Available Green tea has been consumed as the most popular drink in East Asia for centuries, and is believed to have a wide range of health benefits. l-Theanine, the major component of the free amino acids in green tea, has been reported to display neuronal protection and tumor inhibition in vitro, but its physiological effects on animal development and behavior remain elusive. In this report, we used Drosophila melanogaster, the fruit fly, as a model organism to investigate the physiological effects of L-theanine. Flies were fed with three different concentrations of theanine as a dietary supplement after eclosion, and were examined for a variety of physiological parameters at different time points. We found theanine treatment results in significantly increased locomotion and courtship ability, and decreased resistance against wet and dry starvation in males, but not in females. Furthermore, theanine application diminished UV tolerance in females, but not in males. However, we did not perceive distinguishable effect of theanine on animal development, life span, weight, and tolerance of heat and anoxia. This work represents the first comprehensive physiological investigation of L-theanine at the whole animal level, and shall shed light on the mechanistic study of theanine in the future.

  6. Altered Gravity Induces Oxidative Stress in Drosophila Melanogaster

    Science.gov (United States)

    Bhattacharya, Sharmila; Hosamani, Ravikumar

    2015-01-01

    Altered gravity environments can induce increased oxidative stress in biological systems. Microarray data from our previous spaceflight experiment (FIT experiment on STS-121) indicated significant changes in the expression of oxidative stress genes in adult fruit flies after spaceflight. Currently, our lab is focused on elucidating the role of hypergravity-induced oxidative stress and its impact on the nervous system in Drosophila melanogaster. Biochemical, molecular, and genetic approaches were combined to study this effect on the ground. Adult flies (2-3 days old) exposed to acute hypergravity (3g, for 1 hour and 2 hours) showed significantly elevated levels of Reactive Oxygen Species (ROS) in fly brains compared to control samples. This data was supported by significant changes in mRNA expression of specific oxidative stress and antioxidant defense related genes. As anticipated, a stress-resistant mutant line, Indy302, was less vulnerable to hypergravity-induced oxidative stress compared to wild-type flies. Survival curves were generated to study the combined effect of hypergravity and pro-oxidant treatment. Interestingly, many of the oxidative stress changes that were measured in flies showed sex specific differences. Collectively, our data demonstrate that altered gravity significantly induces oxidative stress in Drosophila, and that one of the organs where this effect is evident is the brain.

  7. The cuticular nature of corneal lenses in Drosophila melanogaster.

    Science.gov (United States)

    Stahl, Aaron L; Charlton-Perkins, Mark; Buschbeck, Elke K; Cook, Tiffany A

    2017-07-01

    The dioptric visual system relies on precisely focusing lenses that project light onto a neural retina. While the proteins that constitute the lenses of many vertebrates are relatively well characterized, less is known about the proteins that constitute invertebrate lenses, especially the lens facets in insect compound eyes. To address this question, we used mass spectrophotometry to define the major proteins that comprise the corneal lenses from the adult Drosophila melanogaster compound eye. This led to the identification of four cuticular proteins: two previously identified lens proteins, drosocrystallin and retinin, and two newly identified proteins, Cpr66D and Cpr72Ec. To determine which ommatidial cells contribute each of these proteins to the lens, we conducted in situ hybridization at 50% pupal development, a key age for lens secretion. Our results confirm previous reports that drosocrystallin and retinin are expressed in the two primary corneagenous cells-cone cells and primary pigment cells. Cpr72Ec and Cpr66D, on the other hand, are more highly expressed in higher order interommatidial pigment cells. These data suggest that the complementary expression of cuticular proteins give rise to the center vs periphery of the corneal lens facet, possibly facilitating a refractive gradient that is known to reduce spherical aberration. Moreover, these studies provide a framework for future studies aimed at understanding the cuticular basis of corneal lens function in holometabolous insect eyes.

  8. Genetic analysis of the claret locus of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Sequeira, W.; Nelson, C.R.; Szauter, P.

    1989-01-01

    The claret (ca) locus of Drosophila melanogaster comprises two separately mutable domains, one responsible for eye color and one responsible for proper disjunction of chromosomes in meiosis and early cleavage divisions. Previously isolated alleles are of three types: (1) alleles of the claret (ca) type that affect eye color only, (2) alleles of the claret-nondisjunctional (ca nd ) type that affect eye color and chromosome behavior, and (3) a meiotic mutation, non-claret disjunctional (ncd), that affects chromosome behavior only. In order to investigate the genetic structure of the claret locus, the authors have isolated 19 radiation-induced alleles of claret on the basis of the eye color phenotype. Two of these 19 new alleles are of the ca nd type, while 17 are of the ca type, demonstrating that the two domains do not often act as a single target for mutagenesis. This suggests that the two separately mutable functions are likely to be encoded by separate or overlapping genes rather than by a single gene. One of the new alleles of the ca nd type is a chromosome rearrangement with a breakpoint at the position of the claret locus. If this breakpoint is the cause of the mutant phenotype and there are no other mutations associated with the rearrangement, the two functions must be encoded by overlapping genes

  9. Obp56h Modulates Mating Behavior in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    John R. Shorter

    2016-10-01

    Full Text Available Social interactions in insects are driven by conspecific chemical signals that are detected via olfactory and gustatory neurons. Odorant binding proteins (Obps transport volatile odorants to chemosensory receptors, but their effects on behaviors remain poorly characterized. Here, we report that RNAi knockdown of Obp56h gene expression in Drosophila melanogaster enhances mating behavior by reducing courtship latency. The change in mating behavior that results from inhibition of Obp56h expression is accompanied by significant alterations in cuticular hydrocarbon (CHC composition, including reduction in 5-tricosene (5-T, an inhibitory sex pheromone produced by males that increases copulation latency during courtship. Whole genome RNA sequencing confirms that expression of Obp56h is virtually abolished in Drosophila heads. Inhibition of Obp56h expression also affects expression of other chemoreception genes, including upregulation of lush in both sexes and Obp83ef in females, and reduction in expression of Obp19b and Or19b in males. In addition, several genes associated with lipid metabolism, which underlies the production of cuticular hydrocarbons, show altered transcript abundances. Our data show that modulation of mating behavior through reduction of Obp56h is accompanied by altered cuticular hydrocarbon profiles and implicate 5-T as a possible ligand for Obp56h.

  10. A Laboratory Experimental Study: An FBG-PVC Tube Integrated Device for Monitoring the Slip Surface of Landslides.

    Science.gov (United States)

    Wang, Kai; Zhang, Shaojie; Chen, Jiang; Teng, Pengxiao; Wei, Fangqiang; Chen, Qiao

    2017-10-30

    A new detection device was designed by integrating fiber Bragg grating (FBG) and polyvinyl chloride (PVC) tube in order to monitor the slip surface of a landslide. Using this new FBG-based device, a corresponding slope model with a pre-set slip surface was designed, and seven tests with different soil properties were carried out in laboratory conditions. The FBG sensing fibers were fixed on the PVC tube to measure strain distributions of PVC tube at different elevation. Test results indicated that the PVC tube could keep deformation compatible with soil mass. The new device was able to monitor slip surface location before sliding occurrence, and the location of monitored slip surface was about 1-2 cm above the pre-set slip surface, which basically agreed with presupposition results. The monitoring results are expected to be used to pre-estimate landslide volume and provide a beneficial option for evaluating the potential impact of landslides on shipping safety in the Three Gorges area.

  11. Experimental integrative muscular movement technique enhances cervical range of motion in patients with chronic neck pain: a pilot study.

    Science.gov (United States)

    Rohe, Benjamin G; Carter, Ronald; Thompson, William R; Duncan, Randall L; Cooper, Carlton R

    2015-04-01

    Neck pain presents a tremendous physical and financial burden. This study compared the efficacy of the complementary and alternative medical treatments of integrative muscular movement technique (IMMT) and Swedish massage on neck pain in women of occupation age, the largest demographic group with neck pain. A total of 38 women were assigned to IMMT (n=28) or Swedish massage (n=10) in a blinded manner. Both groups received eight 30-minute treatments over 4 weeks. Cervical range of motion (ROM) in flexion, extension, sidebending, and rotation was measured before and after treatment. Each patient's pain was assessed by using an analogue pain scale of 0-10. Compared with the Swedish massage group, patients receiving IMMT experienced a significant increase in ROM in cervical flexion (ppain for IMMT was -1.75 units compared with -0.3 units for Swedish massage (pneck pain may lead to decreased pain and increased cervical ROM. These positive effects of the IMMT intervention may have a role in enhancing functional outcomes in patients with neck pain.

  12. Towards an integrated experimental-theoretical approach for assessing the mechanistic basis of hair and feather morphogenesis.

    Science.gov (United States)

    Painter, K J; Hunt, G S; Wells, K L; Johansson, J A; Headon, D J

    2012-08-06

    In his seminal 1952 paper, 'The Chemical Basis of Morphogenesis', Alan Turing lays down a milestone in the application of theoretical approaches to understand complex biological processes. His deceptively simple demonstration that a system of reacting and diffusing chemicals could, under certain conditions, generate spatial patterning out of homogeneity provided an elegant solution to the problem of how one of nature's most intricate events occurs: the emergence of structure and form in the developing embryo. The molecular revolution that has taken place during the six decades following this landmark publication has now placed this generation of theoreticians and biologists in an excellent position to rigorously test the theory and, encouragingly, a number of systems have emerged that appear to conform to some of Turing's fundamental ideas. In this paper, we describe the history and more recent integration between experiment and theory in one of the key models for understanding pattern formation: the emergence of feathers and hair in the skins of birds and mammals.

  13. Modeling and Experimental Studies for the Thermal Performance of a Ground Heat Storage System Integrated with a Greenhouse

    International Nuclear Information System (INIS)

    Kooli, Sami; Lazaar, Mariem; Hazami, Majdi; Farhat, Abdelhamid; Belghith, Ali

    2009-01-01

    A thermal model has been developed to investigate the potential of using the stored thermal energy of the ground for greenhouse heating and cooling with the help of a ground heat storage system (GHSS) integrated with the greenhouse located in the premises of CRTEn, Tunis, Tunisia. Experiments were conducted extensively throughout the years 2006-2007, and the developed model was validated against several consecutive arbitrary days experiments. The predicted and measured values of the greenhouse air temperatures and humidities that were verified, in terms of root mean square deviation and correlation coefficient, exhibited fair agreement. The results of this study showed that the GHS system kept the inside air temperature 1-3 degree higher than that of outside air at nighttime. The main reason for this low efficiency is due to the weak heat transfer area of the water-air heat exchanger. The simulation results indicate that the GHSS does not yield any significant effect for cooling greenhouses during sunny daytime. The GHSS fulfils its full potential for a heat transfer area of 150 m 2 . With this area, there occurs 4-6 degree rise of temperature in greenhouse as compared to the temperatures without GHSS and respectively 5-7.5 degree rise in greenhouse as compared to outside air

  14. Integrated experimental investigation and mathematical modeling of brackish water desalination and wastewater treatment in microbial desalination cells.

    Science.gov (United States)

    Ping, Qingyun; Huang, Zuyi; Dosoretz, Carlos; He, Zhen

    2015-06-15

    Desalination of brackish water can provide freshwater for potable use or non potable applications such as agricultural irrigation. Brackish water desalination is especially attractive to microbial desalination cells (MDCs) because of its low salinity, but this has not been well studied before. Herein, three brackish waters prepared according to the compositions of actual brackish water in three locations in Israel were examined with domestic wastewater as an electron source in a bench-scale MDC. All three brackish waters could be effectively desalinated with simultaneous wastewater treatment. The MDC achieved the highest salt removal rate of 1.2 g L(-1) d(-1) with an initial salinity of 5.9 g L(-1) and a hydraulic retention time (HRT) of 0.8 d. The desalinated brackish water could meet the irrigation standard of both salinity (450 mg L(-1) TDS) and the concentrations of major ionic species, given a sufficient HRT. The MDC also accomplished nearly 70% removal of organic compounds in wastewater with Coulombic efficiency varied between 5 and 10%. A previously developed MDC model was improved for brackish water desalination, and could well predict salinity variation and the concentrations of individual ions. The model also simulated a staged operation mode with improved desalination performance. This integrated experiment and mathematical modeling approach provides an effective method to understand the key factors in brackish water desalination by MDCs towards further system development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. An Integrated Modeling and Experimental Approach to Study the Influence of Environmental Nutrients on Biofilm Formation of Pseudomonas aeruginosa.

    Science.gov (United States)

    Xu, Zhaobin; Islam, Sabina; Wood, Thomas K; Huang, Zuyi

    2015-01-01

    The availability of nutrient components in the environment was identified as a critical regulator of virulence and biofilm formation in Pseudomonas aeruginosa. This work proposes the first systems-biology approach to quantify microbial biofilm formation upon the change of nutrient availability in the environment. Specifically, the change of fluxes of metabolic reactions that were positively associated with P. aeruginosa biofilm formation was used to monitor the trend for P. aeruginosa to form a biofilm. The uptake rates of nutrient components were changed according to the change of the nutrient availability. We found that adding each of the eleven amino acids (Arg, Tyr, Phe, His, Iso, Orn, Pro, Glu, Leu, Val, and Asp) to minimal medium promoted P. aeruginosa biofilm formation. Both modeling and experimental approaches were further developed to quantify P. aeruginosa biofilm formation for four different availability levels for each of the three ions that include ferrous ions, sulfate, and phosphate. The developed modeling approach correctly predicted the amount of biofilm formation. By comparing reaction flux change upon the change of nutrient concentrations, metabolic reactions used by P. aeruginosa to regulate its biofilm formation are mainly involved in arginine metabolism, glutamate production, magnesium transport, acetate metabolism, and the TCA cycle.

  16. Path integral effects in heavy ion beam probe density measurements: A comparison of simulation results and experimental data

    International Nuclear Information System (INIS)

    Heard, J.W.; Crowley, T.P.; Ross, D.W.; Schoch, P.M.; Hickok, R.L. Jr.; Zhang, B.Z.

    1993-01-01

    The heavy ion beam probe (HIBP) signal used to measure local density fluctuations in a plasma is also sensitive to modulation due to density fluctuations along the entire beam trajectory. A modulation model of the HIBP experiment on the Texas experimental tokamak (TEXT) is presented. The model includes profile information for equilibrium and fluctuating parameters, allows for differences in the radial and poloidal characteristics of the fluctuations, and uses realistic beam trajectories. It is shown that profile effects are important in understanding HIBP modulation and that modulation does not simply increase with line average density in TEXT. In addition, calculations of the modulation effects show that only the terms which correspond to in-phase signals at the two sample volumes are significant. Therefore, the modulation effects can be approximated with a real parameter. Under these assumptions, it is shown that only long correlation length, low wave number modes will contribute significantly to the corruption of the measured signal. The calculation of the modulation effects are consistent with the experiment. It is illustrated herein how the measured data can be used to set limits on the modulation signal without doing extensive model calculations. These limits show that there must be long wavelength fluctuations in the plasma

  17. Mastitomics, the integrated omics of bovine milk in an experimental model of Streptococcus uberis mastitis: 3. Untargeted metabolomics.

    Science.gov (United States)

    Thomas, Funmilola Clara; Mudaliar, Manikhandan; Tassi, Riccardo; McNeilly, Tom N; Burchmore, Richard; Burgess, Karl; Herzyk, Pawel; Zadoks, Ruth N; Eckersall, P David

    2016-08-16

    Intramammary infection leading to bovine mastitis is the leading disease problem affecting dairy cows and has marked effects on the milk produced by infected udder quarters. An experimental model of Streptococcus uberis mastitis has previously been investigated for clinical, immunological and pathophysiological alteration in milk, and has been the subject of peptidomic and quantitative proteomic investigation. The same sample set has now been investigated with a metabolomics approach using liquid chromatography and mass spectrometry. The analysis revealed over 3000 chromatographic peaks, of which 690 were putatively annotated with a metabolite. Hierarchical clustering analysis and principal component analysis demonstrated that metabolite changes due to S. uberis infection were maximal at 81 hours post challenge with metabolites in the milk from the resolution phase at 312 hours post challenge being closest to the pre-challenge samples. Metabolic pathway analysis revealed that the majority of the metabolites mapped to carbohydrate and nucleotide metabolism show a decreasing trend in concentration up to 81 hours post-challenge whereas an increasing trend was found in lipid metabolites and di-, tri- and tetra-peptides up to the same time point. The increase in these peptides coincides with an increase in larger peptides found in the previous peptidomic analysis and is likely to be due to protease degradation of milk proteins. Components of bile acid metabolism, linked to the FXR pathway regulating inflammation, were also increased. Metabolomic analysis of the response in milk during mastitis provides an essential component to the full understanding of the mammary gland's response to infection.

  18. An Integrated Modeling and Experimental Approach to Study the Influence of Environmental Nutrients on Biofilm Formation of Pseudomonas aeruginosa

    Science.gov (United States)

    Xu, Zhaobin; Islam, Sabina; Wood, Thomas K.; Huang, Zuyi

    2015-01-01

    The availability of nutrient components in the environment was identified as a critical regulator of virulence and biofilm formation in Pseudomonas aeruginosa. This work proposes the first systems-biology approach to quantify microbial biofilm formation upon the change of nutrient availability in the environment. Specifically, the change of fluxes of metabolic reactions that were positively associated with P. aeruginosa biofilm formation was used to monitor the trend for P. aeruginosa to form a biofilm. The uptake rates of nutrient components were changed according to the change of the nutrient availability. We found that adding each of the eleven amino acids (Arg, Tyr, Phe, His, Iso, Orn, Pro, Glu, Leu, Val, and Asp) to minimal medium promoted P. aeruginosa biofilm formation. Both modeling and experimental approaches were further developed to quantify P. aeruginosa biofilm formation for four different availability levels for each of the three ions that include ferrous ions, sulfate, and phosphate. The developed modeling approach correctly predicted the amount of biofilm formation. By comparing reaction flux change upon the change of nutrient concentrations, metabolic reactions used by P. aeruginosa to regulate its biofilm formation are mainly involved in arginine metabolism, glutamate production, magnesium transport, acetate metabolism, and the TCA cycle. PMID:25954752

  19. PPD v1.0--an integrated, web-accessible database of experimentally determined protein pKa values.

    Science.gov (United States)

    Toseland, Christopher P; McSparron, Helen; Davies, Matthew N; Flower, Darren R

    2006-01-01

    The Protein pK(a) Database (PPD) v1.0 provides a compendium of protein residue-specific ionization equilibria (pK(a) values), as collated from the primary literature, in the form of a web-accessible postgreSQL relational database. Ionizable residues play key roles in the molecular mechanisms that underlie many biological phenomena, including protein folding and enzyme catalysis. The PPD serves as a general protein pK(a) archive and as a source of data that allows for the development and improvement of pK(a) prediction systems. The database is accessed through an HTML interface, which offers two fast, efficient search methods: an amino acid-based query and a Basic Local Alignment Search Tool search. Entries also give details of experimental techniques and links to other key databases, such as National Center for Biotechnology Information and the Protein Data Bank, providing the user with considerable background information. The database can be found at the following URL: http://www.jenner.ac.uk/PPD.

  20. Scaffold microstructure effects on functional and mechanical performance: Integration of theoretical and experimental approaches for bone tissue engineering applications.

    Science.gov (United States)

    Cavo, Marta; Scaglione, Silvia

    2016-11-01

    The really nontrivial goal of tissue engineering is combining all scaffold micro-architectural features, affecting both fluid-dynamical and mechanical performance, to obtain a fully functional implant. In this work we identified an optimal geometrical pattern for bone tissue engineering applications, best balancing several graft needs which correspond to competing design goals. In particular, we investigated the occurred changes in graft behavior by varying pore size (300μm, 600μm, 900μm), interpore distance (equal to pore size or 300μm fixed) and pores interconnection (absent, 45°-oriented, 90°-oriented). Mathematical considerations and Computational Fluid Dynamics (CFD) tools, here combined in a complete theoretical model, were carried out to this aim. Poly-lactic acid (PLA) based samples were realized by 3D printing, basing on the modeled architectures. A collagen (COL) coating was also realized on grafts surface and the interaction between PLA and COL, besides the protein contribution to graft bioactivity, was evaluated. Scaffolds were extensively characterized; human articular cells were used to test their biocompatibility and to evaluate the theoretical model predictions. Grafts fulfilled both the chemical and physical requirements. Finally, a good agreement was found between the theoretical model predictions and the experimental data, making these prototypes good candidates for bone graft replacements. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. An integrated theoretical and experimental investigation of insensitive munition compounds adsorption on cellulose, cellulose triacetate, chitin and chitosan surfaces.

    Science.gov (United States)

    Gurtowski, Luke A; Griggs, Chris S; Gude, Veera G; Shukla, Manoj K

    2018-02-01

    This manuscript reports results of combined computational chemistry and batch adsorption investigation of insensitive munition compounds, 2,4-dinitroanisole (DNAN), triaminotrinitrobenzene (TATB), 1,1-diamino-2,2-dinitroethene (FOX-7) and nitroguanidine (NQ), and traditional munition compound 2,4,6-trinitrotoluene (TNT) on the surfaces of cellulose, cellulose triacetate, chitin and chitosan biopolymers. Cellulose, cellulose triacetate, chitin and chitosan were modeled as trimeric form of the linear chain of 4 C 1 chair conformation of β-d-glucopyranos, its triacetate form, β-N-acetylglucosamine and D-glucosamine, respectively, in the 1➔4 linkage. Geometries were optimized at the M062X functional level of the density functional theory (DFT) using the 6-31G(d,p) basis set in the gas phase and in the bulk water solution using the conductor-like polarizable continuum model (CPCM) approach. The nature of potential energy surfaces of the optimized geometries were ascertained through the harmonic vibrational frequency analysis. The basis set superposition error (BSSE) corrected interaction energies were obtained using the 6-311G(d,p) basis set at the same theoretical level. The computed BSSE in the gas phase was used to correct interaction energy in the bulk water solution. Computed and experimental results regarding the ability of considered surfaces in adsorbing the insensitive munitions compounds are discussed. Copyright © 2017. Published by Elsevier B.V.

  2. Dominant lethal mutations in Drosophila melanogaster natural populations flown on board ISS.

    Science.gov (United States)

    Larina, Olga; Bekker, Anna

    The resistance to mutagenic impacts represents an important issue of manned space missions. However the reasons of its individual variability as well as the factors which could induce mutations in space flight are not fully understood. Drosophila studies accomplished by several research teams at real space flights, revealed pronounced increase of mutations in somatic and reproductive cells, nonetheless, quite an opposite spaceflight effects also occurred, i.e., mei-41 laboratory strain showed postflight mutation rates lower than that in ground control. In order to monitor the influence of space flight on the mutational process, 4 series of space experiment with D. melanogaster wild type populations were performed at International Space Station (ISS). The appliance “Drosophila-2” used for breeding of drosophila in spaceflight conditions, enabled to conduct synchronous studies with two samples of fly populations. First instar drosophila larvae were placed into the experimental appliance 12 hours before the start of transport spacecraft. The duration of experiments was 7.9 through 19.7 days. In 19.7-day experiment, two generations of the flies were raised during the space flight, and then delivered to the earth. The frequency of dominant lethal mutations (DLM) was evaluated as the percentage of embryonic death in the progeny of experimental drosophila samples. DLM tests in VV-09 and Chas-09 natural populations, performed after the exposure to 10.9-day flight, showed the increase of DLM rate in Chas-09 (0.077 in flight series vs. 0.43 in earth-based control) while post-flight DLM value in VV-09 did not diverge from on-earth sample (0.025 and 0.027 correspondingly). The same results for VV-09 were obtained after the 14.7-day and 7.9-day flights with the only exception: 7.9-day flight experiment employed DLM measurements in two VV-09 spaceflight samples, differing by the age of the flies, and the above DLM rates were detected in “younger” VV-09 sample only. DLM

  3. The impact of green tea polyphenols on development and reproduction in Drosophila melanogaster.

    Science.gov (United States)

    Lopez, Terry E; Pham, Hoang M; Barbour, Julia; Tran, Phillip; Van Nguyen, Benjamin; Hogan, Sean P; Homo, Richelle L; Coskun, Volkan; Schriner, Samuel E; Jafari, Mahtab

    2016-01-01

    Although, green tea has numerous health benefits, adverse effects with excessive consumption have been reported. Using Drosophila melanogaster , a decrease in male fertility with green tea was evidenced. Here, the extent of green tea toxicity on development and reproduction was investigated. Drosophila melanogaster embryos and larvae were exposed to various doses of green tea polyphenols (GTP). Larvae exposed to 10 mg/mL GTP were slower to develop, emerged smaller, and exhibited a dramatic decline in the number of emerged offspring. GTP protected flies against desiccation but sensitized them to starvation and heat stress. Female offspring exhibited a decline in reproductive output and decreased survival while males were unaffected. GTP had a negative impact on reproductive organs in both males and females (e.g., atrophic testes in males, absence of mature eggs in females). Collectively, the data show that high doses of GTP adversely affect development and reproduction of Drosophila melanogaster .

  4. Light wavelength dependency of mating activity in the drosophila melanogaster species subgroup

    International Nuclear Information System (INIS)

    Sakai, Takaomi; Tomaru, Masatoshi; Oguma, Yuzuru; Isono, Kunio; Fukatami, Akishi

    2002-01-01

    The action spectra of mating activity among the six species of the Drosophila melanogaster species subgroup were compared to understand how light wavelength affects mating activity. The species fell into three groups with respect to the action spectrum of mating activity. We chose one representative species from each of the three types for detailed study: D. melanogaster, D. sechellia and D. yakuba. The mating activities were investigated under three different light intensities of three monochromatic lights stimulus. Each species showed a unique spectral and intensity response. To know the evolutionary meaning of the light wavelength dependency of mating activity, we superimposed the type of action spectrum of mating activity in these six species on a cladogram. Mating inhibition under UV was conserved in evolution among these species. Furthermore we clarified that D. melanogaster showed low mating activity under UV because males courted less under UV. (author)

  5. Genetic architecture of natural variation in cuticular hydrocarbon composition in Drosophila melanogaster.

    Science.gov (United States)

    Dembeck, Lauren M; Böröczky, Katalin; Huang, Wen; Schal, Coby; Anholt, Robert R H; Mackay, Trudy F C

    2015-11-14

    Insect cuticular hydrocarbons (CHCs) prevent desiccation and serve as chemical signals that mediate social interactions. Drosophila melanogaster CHCs have been studied extensively, but the genetic basis for individual variation in CHC composition is largely unknown. We quantified variation in CHC profiles in the D. melanogaster Genetic Reference Panel (DGRP) and identified novel CHCs. We used principal component (PC) analysis to extract PCs that explain the majority of CHC variation and identified polymorphisms in or near 305 and 173 genes in females and males, respectively, associated with variation in these PCs. In addition, 17 DGRP lines contain the functional Desat2 allele characteristic of African and Caribbean D. melanogaster females (more 5,9-C27:2 and less 7,11-C27:2, female sex pheromone isomers). Disruption of expression of 24 candidate genes affected CHC composition in at least one sex. These genes are associated with fatty acid metabolism and represent mechanistic targets for individual variation in CHC composition.

  6. Acetylcholine receptors and cholinergic ligands: biochemical and genetic aspects in Torpedo californica and Drosophila melanogaster

    International Nuclear Information System (INIS)

    Rosenthal, L.S.

    1987-01-01

    This study evaluates the biochemical and genetic aspects of the acetylcholine receptor proteins and cholinergic ligands in Drosophila melanogaster and Torpedo californica. Included are (1) a comparative study of nicotinic ligand-induced cation release from acetylcholine receptors isolated from Torpedo californica and from Drosophila melanogaster, (2) solution studies of the cholinergic ligands, nikethamide and ethamivan, aimed at measuring internal molecular rotational barriers in solvents of different polarity; and (3) the isolation and characterization of the gene(s) for the acetylcholine receptor in Drosophila melasogaster. Acetylcholine receptor proteins isolated from Drosphila melanogaster heads were found to behave kinetically similar (with regards to cholinergic ligand-induced 155 Eu: 3+ displacement from prelabeled proteins) to receptor proteins isolated from Torpedo californica electric tissue, providing additional biochemical evidence for the existence of a Drosophila acetylcholine receptor

  7. Gene expression profiles of Drosophila melanogaster exposed to an insecticidal extract of Piper nigrum.

    Science.gov (United States)

    Jensen, Helen R; Scott, Ian M; Sims, Steve; Trudeau, Vance L; Arnason, John Thor

    2006-02-22

    Black pepper, Piper nigrum L. (Piperaceae), has insecticidal properties and could potentially be utilized as an alternative to synthetic insecticides. Piperine extracted from P. nigrum has a biphasic effect upon cytochrome P450 monooxygenase activity with an initial suppression followed by induction. In this study, an ethyl acetate extract of P. nigrum seeds was tested for insecticidal activity toward adult Musca domestica and Drosophila melanogaster. The effect of this same P. nigrum extract upon differential gene expression in D. melanogaster was investigated using cDNA microarray analysis of 7380 genes. Treatment of D. melanogaster with P. nigrum extract led to a greater than 2-fold upregulation of transcription of the cytochrome P450 phase I metabolism genes Cyp 6a8, Cyp 9b2, and Cyp 12d1 as well as the glutathione-S-transferase phase II metabolism gene Gst-S1. These data suggests a complex effect of P. nigrum upon toxin metabolism.

  8. Experimental study of temperature stratification in an integrated collector-storage solar water heater with two horizontal tanks

    Energy Technology Data Exchange (ETDEWEB)

    Madhlopa, A. [Department of Physics and Biochemical Sciences, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi); Mgawi, R. [Department of Mechanical Engineering, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi); Taulo, J. [Malawi Industrial Research and Technology Development Centre, P.O. Box 357, Blantyre (Malawi)

    2006-08-15

    The effect of tank-interconnection geometry on temperature stratification in an integrated collector-storage solar water (ICSSW) heater with two horizontal cylindrical tanks has been studied. The tanks were parallel to each other, and separated horizontally and vertically, with the lower tank fitted directly below a glass cover, and half of the upper tank insulated. In addition, a truncated parabolic concentrator was fitted below the tanks, with its focal line along the axis of the upper tank. The heater was tested outdoors with the two tanks connected in parallel (P), and S1- and S2-series configurations, with and without hot water draw-off. Water temperature was monitored during solar collection and hot water draw-offs. For the heat charging process, it was found that only the lower tank exhibited temperature stratification in the P- and S1-tank modes of operation. There was satisfactory temperature stratification in both tanks in the S2-tank configuration. For the hot water draining process, the P-tank configuration exhibited some degree of stratification in both tanks. A significant loss of stratification was observed in the lower tank, with the upper tank exhibiting practical stratification, when the system was operated in the S1-tank mode. The S2-tank interconnection maintained a satisfactory degree of temperature stratification in both tanks. So, the S2-tank mode of operation was most effective in promoting practical temperature stratification in both tanks during solar collection and hot water draw-offs. Other results are presented and discussed in this paper. (author)

  9. Experimental performance and feasibility of a miniature single-degree-of-freedom rotary joint with integrated IPMC actuator

    Science.gov (United States)

    Manley, Sean; McDaid, Andrew; Aw, Kean; Xie, Shane; Haemmerle, Enrico

    2009-03-01

    Ionic Polymer Metal Composite (IPMC) materials are bending actuators that can achieve large tip displacements at voltages less than 10V, but with low force output. Their advantages over traditional actuators include very low mass and size; flexibility; direct conversion of electricity to mechanical energy; biocompatibility; and the potential to build integrated sensing/actuation devices, using their inherent sensing properties. It therefore makes sense to pursue them as a replacement to traditional actuators where the lack of force is less significant, such as micro-robotics; bio-mimetics; medical robotics; and non-contact applications such as positioning of sensors. However, little research has been carried out on using them to drive mechanisms such as the rotary joints. This research explores the potential for applying IPMC to driving a single degree-of-freedom rotary mechanism, for a small-force robotic manipulator or positioning system. Practical issues such as adequate force output and friction are identified and tackled in the development of the mechanical apparatus, to study the feasibility of the actuator once attached to the mechanism. Rigid extensions are then applied to the tip of the IPMC, as well as doubling- and tripling the actuators in a stack to increase force output. Finally, feasibility of the entire concept is considered by comparing the maximum achievable forces and combining the actuator with the mechanism. It is concluded that while the actuator is capable of moving the mechanism, it is non-repeatable and does not achieve a level that allows feedback control to be applied.

  10. Satellite Repeats Identify X Chromatin for Dosage Compensation in Drosophila melanogaster Males.

    Science.gov (United States)

    Joshi, Sonal S; Meller, Victoria H

    2017-05-22

    A common feature of sex chromosomes is coordinated regulation of X-linked genes in one sex. Drosophila melanogaster males have one X chromosome, whereas females have two. The resulting imbalance in gene dosage is corrected by increased expression from the single X chromosome of males, a process known as dosage compensation. In flies, compensation involves recruitment of the male-specific lethal (MSL) complex to X-linked genes and modification of chromatin to increase expression. The extraordinary selectivity of the MSL complex for the X chromosome has never been explained. We previously demonstrated that the small interfering RNA (siRNA) pathway and siRNA from a family of X-linked satellite repeats (1.688 X repeats) promote X recognition. Now, we test the ability of 1.688 X DNA to attract compensation to genes nearby and report that autosomal integration of 1.688 X repeats increases MSL recruitment and gene expression in surrounding regions. Placement of 1.688 X repeats opposite a lethal autosomal deletion achieves partial rescue of males, demonstrating functional compensation of autosomal chromatin. Females block formation of the MSL complex and are not rescued. The 1.688 X repeats are therefore cis-acting elements that guide dosage compensation. Furthermore, 1.688 X siRNA enhances rescue of males with a lethal deletion but only when repeat DNA is present on the intact homolog. We propose that the siRNA pathway promotes X recognition by enhancing the ability of 1.688 X DNA to attract compensation in cis. The dense and near-exclusive distribution of 1.688 X sequences along the X chromosome suggests that they play a primary role in determining X identity during dosage compensation. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  11. Canalization and control in automata networks: body segmentation in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Manuel Marques-Pita

    Full Text Available We present schema redescription as a methodology to characterize canalization in automata networks used to model biochemical regulation and signalling. In our formulation, canalization becomes synonymous with redundancy present in the logic of automata. This results in straightforward measures to quantify canalization in an automaton (micro-level, which is in turn integrated into a highly scalable framework to characterize the collective dynamics of large-scale automata networks (macro-level. This way, our approach provides a method to link micro- to macro-level dynamics--a crux of complexity. Several new results ensue from this methodology: uncovering of dynamical modularity (modules in the dynamics rather than in the structure of networks, identification of minimal conditions and critical nodes to control the convergence to attractors, simulation of dynamical behaviour from incomplete information about initial conditions, and measures of macro-level canalization and robustness to perturbations. We exemplify our methodology with a well-known model of the intra- and inter cellular genetic regulation of body segmentation in Drosophila melanogaster. We use this model to show that our analysis does not contradict any previous findings. But we also obtain new knowledge about its behaviour: a better understanding of the size of its wild-type attractor basin (larger than previously thought, the identification of novel minimal conditions and critical nodes that control wild-type behaviour, and the resilience of these to stochastic interventions. Our methodology is applicable to any complex network that can be modelled using automata, but we focus on biochemical regulation and signalling, towards a better understanding of the (decentralized control that orchestrates cellular activity--with the ultimate goal of explaining how do cells and tissues 'compute'.

  12. Canalization and Control in Automata Networks: Body Segmentation in Drosophila melanogaster

    Science.gov (United States)

    Marques-Pita, Manuel; Rocha, Luis M.

    2013-01-01

    We present schema redescription as a methodology to characterize canalization in automata networks used to model biochemical regulation and signalling. In our formulation, canalization becomes synonymous with redundancy present in the logic of automata. This results in straightforward measures to quantify canalization in an automaton (micro-level), which is in turn integrated into a highly scalable framework to characterize the collective dynamics of large-scale automata networks (macro-level). This way, our approach provides a method to link micro- to macro-level dynamics – a crux of complexity. Several new results ensue from this methodology: uncovering of dynamical modularity (modules in the dynamics rather than in the structure of networks), identification of minimal conditions and critical nodes to control the convergence to attractors, simulation of dynamical behaviour from incomplete information about initial conditions, and measures of macro-level canalization and robustness to perturbations. We exemplify our methodology with a well-known model of the intra- and inter cellular genetic regulation of body segmentation in Drosophila melanogaster. We use this model to show that our analysis does not contradict any previous findings. But we also obtain new knowledge about its behaviour: a better understanding of the size of its wild-type attractor basin (larger than previously thought), the identification of novel minimal conditions and critical nodes that control wild-type behaviour, and the resilience of these to stochastic interventions. Our methodology is applicable to any complex network that can be modelled using automata, but we focus on biochemical regulation and signalling, towards a better understanding of the (decentralized) control that orchestrates cellular activity – with the ultimate goal of explaining how do cells and tissues ‘compute’. PMID:23520449

  13. Identification of a novel gene, anorexia, regulating feeding activity via insulin signaling in Drosophila melanogaster.

    Science.gov (United States)

    Ryuda, Masasuke; Tsuzuki, Seiji; Matsumoto, Hitoshi; Oda, Yasunori; Tanimura, Teiichi; Hayakawa, Yoichi

    2011-11-04

    Feeding activities of animals, including insects, are influenced by various signals from the external environment, internal energy status, and physiological conditions. Full understanding of how such signals are integrated to regulate feeding activities has, however, been hampered by a lack of knowledge about the genes involved. Here, we identified an anorexic Drosophila melanogaster mutant (GS1189) in which the expression of a newly identified gene, Anorexia (Anox), is mutated. In Drosophila larvae, Anox encodes an acyl-CoA binding protein with an ankyrin repeat domain that is expressed in the cephalic chemosensory organs and various neurons in the central nervous system (CNS). Loss of its expression or disturbance of neural transmission in Anox-expressing cells decreased feeding activity. Conversely, overexpression of Anox in the CNS increased food intake. We further found that Anox regulates expression of the insulin receptor gene (dInR); overexpression and knockdown of Anox in the CNS, respectively, elevated and repressed dInR expression, which altered larval feeding activity in parallel with Anox expression levels. Anox mutant adults also showed significant repression of sugar-induced nerve responses and feeding potencies. Although Anox expression levels did not depend on the fasting and feeding states cycle, stressors such as high temperature and desiccation significantly repressed its expression levels. These results strongly suggest that Anox is essential for gustatory sensation and food intake of Drosophila through regulation of the insulin signaling activity that is directly regulated by internal nutrition status. Therefore, the mutant strain lacking Anox expression cannot enhance feeding potencies even under starvation.

  14. Oxidative stress contributes to outcome severity in a Drosophila melanogaster model of classic galactosemia

    Directory of Open Access Journals (Sweden)

    Patricia P. Jumbo-Lucioni

    2013-01-01

    Classic galactosemia is a genetic disorder that results from profound loss of galactose-1P-uridylyltransferase (GALT. Affected infants experience a rapid escalation of potentially lethal acute symptoms following exposure to milk. Dietary restriction of galactose prevents or resolves the acute sequelae; however, many patients experience profound long-term complications. Despite decades of research, the mechanisms that underlie pathophysiology in classic galactosemia remain unclear. Recently, we developed a Drosophila melanogaster model of classic galactosemia and demonstrated that, like patients, GALT-null Drosophila succumb in development if exposed to galactose but live if maintained on a galactose-restricted diet. Prior models of experimental galactosemia have implicated a possible association between galactose exposure and oxidative stress. Here we describe application of our fly genetic model of galactosemia to the question of whether oxidative stress contributes to the acute galactose sensitivity of GALT-null animals. Our first approach tested the impact of pro- and antioxidant food supplements on the survival of GALT-null and control larvae. We observed a clear pattern: the oxidants paraquat and DMSO each had a negative impact on the survival of mutant but not control animals exposed to galactose, and the antioxidants vitamin C and α-mangostin each had the opposite effect. Biochemical markers also confirmed that galactose and paraquat synergistically increased oxidative stress on all cohorts tested but, interestingly, the mutant animals showed a decreased response relative to controls. Finally, we tested the expression levels of two transcripts responsive to oxidative stress, GSTD6 and GSTE7, in mutant and control larvae exposed to galactose and found that both genes were induced, one by more than 40-fold. Combined, these results implicate oxidative stress and response as contributing factors in the acute galactose sensitivity of GALT-null Drosophila and, by

  15. Facilitating Neuron-Specific Genetic Manipulations in Drosophila melanogaster Using a Split GAL4 Repressor.

    Science.gov (United States)

    Dolan, Michael-John; Luan, Haojiang; Shropshire, William C; Sutcliffe, Ben; Cocanougher, Benjamin; Scott, Robert L; Frechter, Shahar; Zlatic, Marta; Jefferis, Gregory S X E; White, Benjamin H

    2017-06-01

    Efforts to map neural circuits have been galvanized by the development of genetic technologies that permit the manipulation of targeted sets of neurons in the brains of freely behaving animals. The success of these efforts relies on the experimenter's ability to target arbitrarily small subsets of neurons for manipulation, but such specificity of targeting cannot routinely be achieved using existing methods. In Drosophila melanogaster , a widely-used technique for refined cell type-specific manipulation is the Split GAL4 system, which augments the targeting specificity of the binary GAL4-UAS (Upstream Activating Sequence) system by making GAL4 transcriptional activity contingent upon two enhancers, rather than one. To permit more refined targeting, we introduce here the "Killer Zipper" (KZip + ), a suppressor that makes Split GAL4 targeting contingent upon a third enhancer. KZip + acts by disrupting both the formation and activity of Split GAL4 heterodimers, and we show how this added layer of control can be used to selectively remove unwanted cells from a Split GAL4 expression pattern or to subtract neurons of interest from a pattern to determine their requirement in generating a given phenotype. To facilitate application of the KZip + technology, we have developed a versatile set of LexA op -KZip + fly lines that can be used directly with the large number of LexA driver lines with known expression patterns. KZip + significantly sharpens the precision of neuronal genetic control available in Drosophila and may be extended to other organisms where Split GAL4-like systems are used. Copyright © 2017 Dolan et al.

  16. Pulsed Light Stimulation Increases Boundary Preference and Periodicity of Episodic Motor Activity in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Shuang Qiu

    Full Text Available There is considerable interest in the therapeutic benefits of long-term sensory stimulation for improving cognitive abilities and motor performance of stroke patients. The rationale is that such stimulation would activate mechanisms of neural plasticity to promote enhanced coordination and associated circuit functions. Experimental approaches to characterize such mechanisms are needed. Drosophila melanogaster is one of the most attractive model organisms to investigate neural mechanisms responsible for stimulation-induced behaviors with its powerful accessibility to genetic analysis. In this study, the effect of chronic sensory stimulation (pulsed light stimulation on motor activity in w1118 flies was investigated. Flies were exposed to a chronic pulsed light stimulation protocol prior to testing their performance in a standard locomotion assay. Flies responded to pulsed light stimulation with increased boundary preference and travel distance in a circular arena. In addition, pulsed light stimulation increased the power of extracellular electrical activity, leading to the enhancement of periodic electrical activity which was associated with a centrally-generated motor pattern (struggling behavior. In contrast, such periodic events were largely missing in w1118 flies without pulsed light treatment. These data suggest that the sensory stimulation induced a response in motor activity associated with the modifications of electrical activity in the central nervous system (CNS. Finally, without pulsed light treatment, the wild-type genetic background was associated with the occurrence of the periodic activity in wild-type Canton S (CS flies, and w+ modulated the consistency of periodicity. We conclude that pulsed light stimulation modifies behavioral and electrophysiological activities in w1118 flies. These data provide a foundation for future research on the genetic mechanisms of neural plasticity underlying such behavioral modification.

  17. Concentration-dependent, size-independent toxicity of citrate capped AuNPs in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Giuseppe Vecchio

    Full Text Available The expected potential benefits promised by nanotechnology in various fields have led to a rapid increase of the presence of engineered nanomaterials in a high number of commercial goods. This is generating increasing questions about possible risks for human health and environment, due to the lack of an in-depth assessment of the physical/chemical factors responsible for their toxic effects. In this work, we evaluated the toxicity of monodisperse citrate-capped gold nanoparticles (AuNPs of different sizes (5, 15, 40, and 80 nm in the model organism Drosophila melanogaster, upon ingestion. To properly evaluate and distinguish the possible dose- and/or size-dependent toxicity of the AuNPs, we performed a thorough assessment of their biological effects, using two different dose-metrics. In the first approach, we kept constant the total surface area of the differently sized AuNPs (Total Exposed Surface area approach, TES, while, in the second approach, we used the same number concentration of the four different sizes of AuNPs (Total Number of Nanoparticles approach, TNN. We observed a significant AuNPs-induced toxicity in vivo, namely a strong reduction of Drosophila lifespan and fertility performance, presence of DNA fragmentation, as well as a significant modification in the expression levels of genes involved in stress responses, DNA damage recognition and apoptosis pathway. Interestingly, we found that, within the investigated experimental conditions, the toxic effects in the exposed organisms were directly related to the concentration of the AuNPs administered, irrespective of their size.

  18. A Comprehensive Toolbox for Genome Editing in Cultured Drosophila melanogaster Cells

    Directory of Open Access Journals (Sweden)

    Stefan Kunzelmann

    2016-06-01

    Full Text Available Custom genome editing has become an essential element of molecular biology. In particular, the generation of fusion constructs with epitope tags or fluorescent proteins at the genomic locus facilitates the analysis of protein expression, localization, and interaction partners at physiologic levels. Following up on our initial publication, we now describe a considerably simplified, more efficient, and readily scalable experimental workflow for PCR-based genome editing in cultured Drosophila melanogaster cells. Our analysis at the act5C locus suggests that PCR-based homology arms of 60 bp are sufficient to reach targeting efficiencies of up to 80% after selection; extension to 80 bp (PCR or 500 bp (targeting vector did not further improve the yield. We have expanded our targeting system to N-terminal epitope tags; this also allows the generation of cell populations with heterologous expression control of the tagged locus via the copper-inducible mtnDE promoter. We present detailed, quantitative data on editing efficiencies for several genomic loci that may serve as positive controls or benchmarks in other laboratories. While our first PCR-based editing approach offered only blasticidin-resistance for selection, we now introduce puromycin-resistance as a second, independent selection marker; it is thus possible to edit two loci (e.g., for coimmunoprecipitation without marker removal. Finally, we describe a modified FLP recombinase expression plasmid that improves the efficiency of marker cassette FLP-out. In summary, our technique and reagents enable a flexible, robust, and cloning-free genome editing approach that can be parallelized for scale-up.

  19. Modeling of a Piezoelectric MEMS Micropump Dedicated to Insulin Delivery and Experimental Validation Using Integrated Pressure Sensors: Application to Partial Occlusion Management

    Directory of Open Access Journals (Sweden)

    S. Fournier

    2017-01-01

    Full Text Available A numerical model based on equivalent electrical networks has been built to simulate the dynamic behavior of a positive-displacement MEMS micropump dedicated to insulin delivery. This device comprises a reservoir in direct communication with the inlet check valve, a pumping membrane actuated by a piezo actuator, two integrated piezoresistive pressure sensors, an anti-free-flow check valve at the outlet, and finally a fluidic pathway up to the patient cannula. The pressure profiles delivered by the sensors are continuously analyzed during the therapy in order to detect failures like occlusion. The numerical modeling is a reliable way to better understand the behavior of the micropump in case of failure. The experimental pressure profiles measured during the actuation phase have been used to validate the numerical modeling. The effect of partial occlusion on the pressure profiles has been also simulated. Based on this analysis, a new management of partial occlusion for MEMS micropump is finally proposed.

  20. The Integration of Family and Group Therapy as an Alternative to Juvenile Incarceration: A Quasi-Experimental Evaluation Using Parenting with Love and Limits.

    Science.gov (United States)

    Karam, Eli A; Sterrett, Emma M; Kiaer, Lynn

    2017-06-01

    The current study employed a quasi-experimental design using both intent-to-treat and protocol adherence analysis of 155 moderate- to high-risk juvenile offenders to evaluate the effectiveness of Parenting with Love and Limits® (PLL), an integrative group and family therapy approach. Youth completing PLL had significantly lower rates of recidivism than the comparison group. Parents also reported statistically significant improvements in youth behavior. Lengths of service were also significantly shorter for the treatment sample than the matched comparison group by an average of 4 months. This study contributes to the literature by suggesting that intensive community-based combined family and group treatment is effective in curbing recidivism among high-risk juveniles. © 2015 Family Process Institute.

  1. IMFIT Integrated Modeling Applications Supporting Experimental Analysis: Multiple Time-Slice Kinetic EFIT Reconstructions, MHD Stability Limits, and Energy and Momentum Flux Analyses

    Science.gov (United States)

    Collier, A.; Lao, L. L.; Abla, G.; Chu, M. S.; Prater, R.; Smith, S. P.; St. John, H. E.; Guo, W.; Li, G.; Pan, C.; Ren, Q.; Park, J. M.; Bisai, N.; Srinivasan, R.; Sun, A. P.; Liu, Y.; Worrall, M.

    2010-11-01

    This presentation summarizes several useful applications provided by the IMFIT integrated modeling framework to support DIII-D and EAST research. IMFIT is based on Python and utilizes modular task-flow architecture with a central manager and extensive GUI support to coordinate tasks among component modules. The kinetic-EFIT application allows multiple time-slice reconstructions by fetching pressure profile data directly from MDS+ or from ONETWO or PTRANSP. The stability application analyzes a given reference equilibrium for stability limits by performing parameter perturbation studies with MHD codes such as DCON, GATO, ELITE, or PEST3. The transport task includes construction of experimental energy and momentum fluxes from profile analysis and comparison against theoretical models such as MMM95, GLF23, or TGLF.

  2. [Mating behavior in mutant strains of Drosophila melanogaster at different population densities].

    Science.gov (United States)

    Volkova, N E; Sheremet, O Iu; Vorobieva, L I

    2006-04-01

    The effects of mutations and genetic background on the mating activity of male and receptivity of female Drosophila melanogaster have been studied at different population densities. Population density, as well as its combinations with other factors, significantly affects mating behavior of D. melanogaster. There are two distinct trends in the effect of this factor on mating behavior: the maximum larval overpopulation may cause either a significant suppression of the behaviors studied or an increase in their expressivity. The mating behaviors of wa and cn mutants against a certain genetic background changed similarly in response to varying population density.

  3. Análisis molecular del gen longitudinals lacking en Drosophila melanogaster

    OpenAIRE

    Cordobés Padilla, Eligio

    2016-01-01

    El gen longitudinals lacking (lola) desempeña un importante papel en el desarrollo del sistema nervioso de Drosophila melanogaster. Se ha comprobado su implicación en un elevado número de procesos relacionados con el crecimiento y la orientación de los axones. En el presente trabajo se realizó un análisis molecular de lola en D. melanogaster; para ello, se localizó el punto exacto de una inserción de un elemento P modificado (PlacW) que caracteriza la línea 5D2, y se observó la expresión espa...

  4. Establishing a web-based integrated surveillance system for early detection of infectious disease epidemic in rural China: a field experimental study.

    Science.gov (United States)

    Yan, Wei-rong; Nie, Shao-fa; Xu, Biao; Dong, Heng-jin; Palm, Lars; Diwan, Vinod K

    2012-02-03

    A crucial goal of infectious disease surveillance is the early detection of epidemics, which is essential for disease control. In China, the current surveillance system is based on confirmed case reports. In rural China, it is not practical for health units to perform laboratory tests to confirm disease and people are more likely to get 'old' and emerging infectious diseases due to poor living conditions and closer contacts with wild animals and poultry. Syndromic surveillance, which collects non-specific syndromes before diagnosis, has great advantages in promoting the early detection of epidemics and reducing the necessities of disease confirmation. It will be especially effective for surveillance in resource poor settings. This is a field experimental study. The experimental tool is an innovative electronic surveillance system, combining syndromic surveillance with the existing case report surveillance in four selected counties in China. In the added syndromic surveillance, three types of data are collected including patients' major symptoms from health clinics, pharmaceutical sales from pharmacies and absenteeism information from primary school. In order to evaluate the early warning capability of the new added syndromic surveillance, the timelines and validity of the alert signals will be analyzed in comparison with the traditional case reporting system. The acceptability, feasibility and economic evaluation of the whole integrated surveillance system will be conducted in a before and after study design. Although syndromic surveillance system has mostly been established in developed areas, there are opportunities and advantages of developing it in rural China. The project will contribute to knowledge, experience and evidence on the establishment of an integrated surveillance system, which aims to provide early warning of disease epidemics in developing countries.

  5. Establishing a web-based integrated surveillance system for early detection of infectious disease epidemic in rural China: a field experimental study

    Directory of Open Access Journals (Sweden)

    Yan Wei-rong

    2012-02-01

    Full Text Available Abstract Background A crucial goal of infectious disease surveillance is the early detection of epidemics, which is essential for disease control. In China, the current surveillance system is based on confirmed case reports. In rural China, it is not practical for health units to perform laboratory tests to confirm disease and people are more likely to get 'old' and emerging infectious diseases due to poor living conditions and closer contacts with wild animals and poultry. Syndromic surveillance, which collects non-specific syndromes before diagnosis, has great advantages in promoting the early detection of epidemics and reducing the necessities of disease confirmation. It will be especially effective for surveillance in resource poor settings. Methods/Design This is a field experimental study. The experimental tool is an innovative electronic surveillance system, combining syndromic surveillance with the existing case report surveillance in four selected counties in China. In the added syndromic surveillance, three types of data are collected including patients' major symptoms from health clinics, pharmaceutical sales from pharmacies and absenteeism information from primary school. In order to evaluate the early warning capability of the new added syndromic surveillance, the timelines and validity of the alert signals will be analyzed in comparison with the traditional case reporting system. The acceptability, feasibility and economic evaluation of the whole integrated surveillance system will be conducted in a before and after study design. Discussions Although syndromic surveillance system has mostly been established in developed areas, there are opportunities and advantages of developing it in rural China. The project will contribute to knowledge, experience and evidence on the establishment of an integrated surveillance system, which aims to provide early warning of disease epidemics in developing countries.

  6. Experimental study of ultra-thin films mechanical integrity by combined nanoindentation and nano-acoustic emission

    Science.gov (United States)

    Zhang, Zihou

    for this sorting. In the case wherein no excursion were present on the load-displacement curve, atypical case for adhesive failure only, the final indentation load along with the size of the blister were used to characterize the cohesive fracture energy. In the few cases wherein the film toughness was much higher than the substrate toughness, the unloading segment of the force-indentation depth curve showed a clear demarcation with a much lower slope. Such demarcation arises from the film buckling induced delamination. The delaminated buckled film unloads faster than the indentation process zone within the substrate and thereby become affected by the stored elastic strain energy within the film only. A simple model, utilizing the area under the force-indentation depth curve is derived to calculate the interfacial energy release rate of the film-substrate system. The model assessment is in good agreement with estimates done by four-point-bend testing on the same material system. The developed experimental protocol may become useful in identifying the prominent failure mechanisms for quick screening of film-substrate, as well as in providing some quantitative measures of the adhesive and cohesive fracture toughness.

  7. Improving health related quality of life among rural hypertensive patients through the integrative strategy of health services delivery: a quasi-experimental trial from Chongqing, China.

    Science.gov (United States)

    Miao, Yudong; Zhang, Liang; Sparring, Vibeke; Sandeep, Sandeep; Tang, Wenxi; Sun, Xiaowei; Feng, Da; Ye, Ting

    2016-08-23

    Integrative strategy of health services delivery has been proven to be effective in economically developed countries, where the healthcare systems have enough qualified primary care providers. However rural China lacks such providers to act as gatekeeper, besides, Chinese rural hypertensive patients are usually of old age, more likely to be exposed to health risk factors and they experience a greater socio-economic burden. All these Chinese rural setting specific features make the effectiveness of integrative strategy of health services in improving health related quality of life among Chinese rural hypertensive patients uncertain. In order to assess the impact of integrative strategy of health services delivery on health related quality of life among Chinese rural hypertensive patients, a two-year quasi-experimental trial was conducted in Chongqing, China. At baseline the sample enrolled 1006 hypertensive patients into intervention group and 420 hypertensive patients into control group. Physicians from village clinics, town hospitals and county hospitals worked collaboratively to deliver multidisciplinary health services for the intervention group, while physicians in the control group provided services without cooperation. The quality of life was studied by SF-36 Scale. Blood pressures were reported by town hospitals. The Difference-in-Differences model was used to estimate the differences in SF-36 score and blood pressure of both groups to assess the impact. The study showed that at baseline there was no statistical difference in SF-36 scores between both groups. While at follow-up the intervention group scored higher in overall SF-36, Role Physical, Body Pain, Social Functioning and Role Emotional than the control group. The Difference-in-Differences result demonstrated that there were statistical differences in SF-36 total score (p = 0.011), Role Physical (p = 0.027), Social Functioning (p = 0.000), Role Emotional (p = 0.002) between both

  8. Recovery Act: An Integrated Experimental and Numerical Study: Developing a Reaction Transport Model that Couples Chemical Reactions of Mineral Dissolution/Precipitation with Spatial and Temporal Flow Variations.

    Energy Technology Data Exchange (ETDEWEB)

    Saar, Martin O. [ETH Zurich (Switzerland); Univ. of Minnesota, Minneapolis, MN (United States); Seyfried, Jr., William E. [Univ. of Minnesota, Minneapolis, MN (United States); Longmire, Ellen K. [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-06-24

    A total of 12 publications and 23 abstracts were produced as a result of this study. In particular, the compilation of a thermodynamic database utilizing consistent, current thermodynamic data is a major step toward accurately modeling multi-phase fluid interactions with solids. Existing databases designed for aqueous fluids did not mesh well with existing solid phase databases. Addition of a second liquid phase (CO2) magnifies the inconsistencies between aqueous and solid thermodynamic databases. Overall, the combination of high temperature and pressure lab studies (task 1), using a purpose built apparatus, and solid characterization (task 2), using XRCT and more developed technologies, allowed observation of dissolution and precipitation processes under CO2 reservoir conditions. These observations were combined with results from PIV experiments on multi-phase fluids (task 3) in typical flow path geometries. The results of the tasks 1, 2, and 3 were compiled and integrated into numerical models utilizing Lattice-Boltzmann simulations (task 4) to realistically model the physical processes and were ultimately folded into TOUGH2 code for reservoir scale modeling (task 5). Compilation of the thermodynamic database assisted comparisons to PIV experiments (Task 3) and greatly improved Lattice Boltzmann (Task 4) and TOUGH2 simulations (Task 5). PIV (Task 3) and experimental apparatus (Task 1) have identified problem areas in TOUGHREACT code. Additional lab experiments and coding work has been integrated into an improved numerical modeling code.

  9. Genetic structure of populations of Drosophila melanogaster natives from Laguna Verde, Veracruz

    International Nuclear Information System (INIS)

    Salceda, V.M.

    2005-01-01

    The genetic variability hidden present in natural populations of Drosophila melanogaster, it has been broadly analyzed, and it is a tool that allows to detect differences among the different populations of this species, so much of natural nature as experimental. In this occasion we use it to see if differences exist in two neighboring populations inside the Laguna Verde nuclear power plant, Veracruz, and this way to suggest, of having differences in the mount of the relative frequencies of lethal genes, semi lethals and normal, be due to the radioactive emanations product of the reactors operation of the plant. Its were took samples of flies in both towns during three successive seasons and they were transported to the laboratory of the ININ where they were carried out the tests to determine the frequency of the different types of genes. This was made by means of the denominated technique C y L / Pm that allows by means of a cross series with a stump marker to obtain, in the third generation, in isolated form the different types of genes and this way to calculate their relative frequencies. The study understands the analysis of 299 chromosomes extracted from the populations, of those that 95 correspond at the control population and 204 to the experimental one. As a result of the analysis we find that 30.52 percent of the genes of the population witness contains detrimental genes (sum of the lethal plus the semi lethal genes) as long as in the experimental population this value corresponds to 23.03 percent. In accordance with this information was not significant difference among the studied populations. A similar analysis, but now comparing the seasons, (summer against winter), it showed significant difference to 5% with regard to the lethal genes frequency only in the population witness. These results indicate the absence of damage, however it is necessary to consider that this can be due to that indeed there is not him or that the investigation protocol is not

  10. Quantification of Histamine and Carcinine in Drosophila melanogaster Tissues.

    Science.gov (United States)

    Denno, Madelaine E; Privman, Eve; Borman, Ryan P; Wolin, Danielle C; Venton, B Jill

    2016-03-16

    Histamine is a neurotransmitter crucial to the visual processing of Drosophila melanogaster. It is inactivated by metabolism to carcinine, a β-alanyl derivative, and the same enzyme that controls that process also converts dopamine to N-β-alanyl-dopamine. Direct detection of histamine and carcinine has not been reported in single Drosophila brains. Here, we quantify histamine, carcinine, dopamine, and N-β-alanyl-dopamine in Drosophila tissues by capillary electrophoresis coupled to fast-scan cyclic voltammetry (CE-FSCV). Limits of detection were low, 4 ± 1 pg for histamine, 10 ± 4 pg for carcinine, 2.8 ± 0.3 pg for dopamine, and 9 ± 3 pg for N-β-alanyl-dopamine. Tissue content was compared in the brain, eyes, and cuticle from wild-type (Canton S) and mutant (tan(3) and ebony(1)) strains. In tan(3) mutants, the enzyme that produces histamine from carcinine is nonfunctional, whereas in ebony(1) mutants, the enzyme that produces carcinine from histamine is nonfunctional. In all fly strains, the neurotransmitter content was highest in the eyes and there were no strain differences for tissue content in the cuticle. The main finding was that carcinine levels changed significantly in the mutant flies, whereas histamine levels did not. In particular, tan(3) flies had significantly higher carcinine levels in the eyes and brain than Canton S or ebony(1) flies. N-β-Alanyl-dopamine was detected in tan(3) mutants but not in other strains. These results show the utility of CE-FSCV for sensitive detection of histamine and carcinine, which allows a better understanding of their content and metabolism in different types of tissues to be obtained.

  11. Calmodulin affects sensitization of Drosophila melanogaster odorant receptors

    Directory of Open Access Journals (Sweden)

    Latha eMukunda

    2016-02-01

    Full Text Available Flying insects have developed a remarkably sensitive olfactory system to detect faint and turbulent odor traces. This ability is linked to the olfactory receptors class of odorant receptors (ORs, occurring exclusively in winged insects. ORs form heteromeric complexes of an odorant specific receptor protein (OrX and a highly conserved co-receptor protein (Orco. The ORs form ligand gated ion channels that are tuned by intracellular signaling systems. Repetitive subthreshold odor stimulation of olfactory sensory neurons sensitizes insect ORs. This OR sensitization process requires Orco activity. In the present study we first asked whether OR sensitization can be monitored with heterologously expressed OR proteins. Using electrophysiological and calcium imaging methods we demonstrate that D. melanogaster OR proteins expressed in CHO cells show sensitization upon repeated weak stimulation. This was found for OR channels formed by Orco as well as by Or22a or Or56a and Orco. Moreover, we show that inhibition of calmodulin (CaM action on OR proteins, expressed in CHO cells, abolishes any sensitization. Finally, we investigated the sensitization phenomenon using an ex vivo preparation of olfactory sensory neurons (OSNs expressing Or22a inside the fly’s antenna. Using calcium imaging, we observed sensitization in the dendrites as well as in the soma. Inhibition of calmodulin with W7 disrupted the sensitization within the outer dendritic shaft, whereas the sensitization remained in the other OSN compartments. Taken together, our results suggest that CaM action is involved in sensitizing the OR complex and that this mechanisms accounts for the sensitization in the outer dendrites, whereas further mechanisms contribute to the sensitization observed in the other OSN compartments. The use of heterologously expressed OR proteins appears to be suitable for further investigations on the mechanistic basis of OR sensitization, while investigations on native

  12. Female mediation of competitive fertilization success in Drosophila melanogaster.

    Science.gov (United States)

    Lüpold, Stefan; Pitnick, Scott; Berben, Kirstin S; Blengini, Cecilia S; Belote, John M; Manier, Mollie K

    2013-06-25

    How females store and use sperm after remating can generate postcopulatory sexual selection on male ejaculate traits. Variation in ejaculate performance traits generally is thought to be intrinsic to males but is likely to interact with the environment in which sperm compete (e.g., the female reproductive tract). Our understanding of female contributions to competitive fertilization success is limited, however, in part because of the challenges involved in observing events within the reproductive tract of internally fertilizing species while discriminating among sperm from competing males. Here, we used females from crosses among isogenic lines of Drosophila melanogaster, each mated to two genetically standardized males (the first with green- and the second with red-tagged sperm heads) to demonstrate heritable variation in female remating interval, progeny production rate, sperm-storage organ morphology, and a number of sperm performance, storage, and handling traits. We then used multivariate analyses to examine relationships between this female-mediated variation and competitive paternity. In particular, the timing of female ejection of excess second-male and displaced first-male sperm was genetically variable and, by terminating the process of sperm displacement, significantly influenced the relative numbers of sperm from each male competing for fertilization, and consequently biased paternity. Our results demonstrate that females do not simply provide a static arena for sperm competition but rather play an active and pivotal role in postcopulatory processes. Resolving the adaptive significance of genetic variation in female-mediated mechanisms of sperm handling is critical for understanding sexual selection, sexual conflict, and the coevolution of male and female reproductive traits.

  13. Sexual selection and immune function in Drosophila melanogaster.

    Science.gov (United States)

    McKean, Kurt A; Nunney, Leonard

    2008-02-01

    The evolution of immune function depends not only on variation in genes contributing directly to the immune response, but also on genetic variation in other traits indirectly affecting immunocompetence. In particular, sexual selection is predicted to trade-off with immunocompetence because the extra investment of resources needed to increase sexual competitiveness reduces investment in immune function. Additional possible immunological consequences of intensifying sexual selection include an exaggeration of immunological sexual dimorphism, and the reduction of condition-dependent immunological costs due to selection of 'good genes' (the immunocompetence handicap hypothesis, ICHH). We tested for these evolutionary possibilities by increasing sexual selection in laboratory populations of Drosophila melanogaster for 58 generations by reestablishing a male-biased sex ratio at the start of each generation. Sexually selected flies were larger, took longer to develop, and the males were more sexually competitive than males from control (equal sex ratio) lines. We found support for the trade-off hypothesis: sexually selected males were found to have reduced immune function compared to control males. However, we found no evidence that sexual selection promoted immunological sexual dimorphism because females showed a similar reduction in immune function. We found no evidence of evolutionary changes in the condition-dependent expression of immunocompetence contrary to the expectations of the ICHH. Lastly, we compared males from the unselected base population that were either successful (IS) or unsuccessful (IU) in a competitive mating experiment. IS males showed reduced immune function relative to IU males, suggesting that patterns of phenotypic correlation largely mirror patterns of genetic correlation revealed by the selection experiment. Our results suggest increased disease susceptibility could be an important cost limiting increases in sexual competitiveness in

  14. Cytochrome P450-dependent metabolism of caffeine in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Alexandra Coelho

    Full Text Available Caffeine (1, 3, 7-trimethylxanthine, an alkaloid produced by plants, has antioxidant and insecticide properties that can affect metabolism and cognition. In vertebrates, the metabolites derived from caffeine have been identified, and their functions have been characterized. However, the metabolites of caffeine in insects remain unknown. Thus, using radiolabelled caffeine, we have identified some of the primary caffeine metabolites produced in the body of Drosophila melanogaster males, including theobromine, paraxanthine and theophylline. In contrast to mammals, theobromine was the predominant metabolite (paraxanthine in humans; theophylline in monkeys; 1, 3, 7-trimethyluric acid in rodents. A transcriptomic screen of Drosophila flies exposed to caffeine revealed the coordinated variation of a large set of genes that encode xenobiotic-metabolizing proteins, including several cytochromes P450s (CYPs that were highly overexpressed. Flies treated with metyrapone--an inhibitor of CYP enzymes--showed dramatically decreased caffeine metabolism, indicating that CYPs are involved in this process. Using interference RNA genetic silencing, we measured the metabolic and transcriptomic effect of three candidate CYPs. Silencing of CYP6d5 completely abolished theobromine synthesis, whereas CYP6a8 and CYP12d1 silencing induced different consequences on metabolism and gene expression. Therefore, we characterized several metabolic products and some enzymes potentially involved in the degradation of caffeine. In conclusion, this pioneer approach to caffeine metabolism in insects opens novel perspectives for the investigation of the physiological effects of caffeine metabolites. It also indicates that caffeine could be used as a biomarker to evaluate CYP phenotypes in Drosophila and other insects.

  15. Adaptive response in Drosophila melanogaster heat shock proteins mutant strains

    International Nuclear Information System (INIS)

    Shaposhnikov, M.V.; Moskalev, A.A.; Turysheva, E.V.

    2007-01-01

    Complete text of publication follows. The members of the heat shock proteins (Hsp) family function as molecular chaperones and assist intracellular folding of newly synthesized proteins. Also it is possible that molecular chaperones are induced during adaptive response to oxidative stress and radiation. The aim of our research was to exam the role of heat shock proteins in adaptive response to oxidative stress after low dose rate gamma-irradiation in Drosophila melanogaster. Drosophilamelanogaster strains were kindly provided by Bloomington Drosophila Stock Center (University of state of Indiana, Bloomington, USA). We used wild type strain (CS), heat shock protein mutant strains (Hsp22, Hsp70, Hsp83), and heat shock factor mutant strain (Hsf). Strains were chronically exposured to adaptive dose of gamma-irradiation in dose rate of 0.17 cGy/h during all stages of life history (from the embrional stage to the stage of matured imago). The rate of absorbed dose was 60 cGy. For oxidative-stress challenge twodays old flies were starved in empty vials for 6 h and then transferred to vials containing only filter paper soaked with 20 mM paraquat in 5% sucrose solution. Survival data were collected after 26 h of treatment. Dead flies were counted daily. The obtained data were subjected to survival analysis by Kaplan and Meier method and presented as survival curves. Statistical analysis was held by non-parametric methods. To test the significance of the difference between the two age distributions Kolmogorov-Smirnov test was applied. Gehan-Braslow- Wilcoxon and Cox-Mantel tests were used for estimation of median life span differences. In addition the minimal and maximal life span, time of 90% death, and mortality rate doubling time (MRDT) were estimated. The obtained results will be discussed in presentation.

  16. Studies on a photoreactivating enzyme from Drosophila melanogaster cultured cells

    International Nuclear Information System (INIS)

    Beck, L.A.

    1982-01-01

    A photoreactivating enzyme was purified from Schneider's Line No. 2 Drosophila melanogaster cultured cells. DEAE cellulose chromatography with high potassium phosphate buffer conditions was used to separate nucleic acids from the protein component of the crude cell extract. The protein pass-through fraction from DEAE cellulose was chromatographed on phosphocellulose followed by hydroxylapatite, using linear potassium phosphate gradients to elute the enzyme. Gel filtration chromatography on Sephacryl S-200 resulted in a 4500-fold purification of the enzyme with a final recovery of 4%. The enzyme has an apparent gel filtration molecular weight of 32,900 (+/- 1350 daltons) and an isoelectric pH of 4.9. Optimum ionic strength for activity is 0.17 at pH 6.5 in potassium phosphate buffer. The action spectrum for photoreactivation in Drosophila has an optimum at 365 nm with a response to wavelengths in the range of 313 to 465 nm. Drosophila photoreactivating enzyme contains an essential RNA that is necessary for activity in vitro. The ability of the enzyme to photoreactivate dimers in vitro is abolished by treatment of the enzyme with ribonucleases, or by disruption of the enzyme-RNA complex by electrophoresis or adsorption to DEAE cellulose. The essential RNA is heterogeneous in size but contains a 10-12 base region that may interact with the active site of the enzyme, and thus is protected from degradation by contaminating RNase activities during purification. The RNA is thought to stabilize the photoreactivating enzyme by maintaining the enzyme in the proper configuration for binding to dimer-containing DNA. It is not known whether this RNA is essential for in vivo photoreactivation

  17. Light-induced vitamin deficiency in Drosophila melanogaster.

    Science.gov (United States)

    Bruins, B G; Scharloo, W; Thörig, G E

    1997-01-01

    Illumination by visible light (400 Ix) of cultures containing larvae of Drosophila melanogaster can reduce survival (Bruins et al., Insect Biochemistry 21:535-539, 1991). Here we show that the effect of light depends on the presence of propionic or acetic acid in the food medium. We also show that survival is far more affected by illumination of the yeast food media than by direct illumination of the eggs and developing larvae. It is shown that addition of antioxidants to the food prevents light induced mortality. The action of antioxidants suggests that free radicals are important in light induced mortality. We also showed that both yeast and riboflavin (vitamin B2) solutions illuminated with visible light (400 Ix) generate hydrogen peroxide. Other vitamin and amino acid solutions do not produce peroxide in measurable amounts. However, the concentration of photogenerated hydrogen peroxide is far too low to explain the death of eggs and developing larvae upon exposure to light. A 400 Ix light treatment destroys the capability of yeast food media to support survival of larvae. Addition of vitamin C, carotene, tryptophan, nipagin, uric acid, or sucrose to the light treated medium does not restore viability. It is restored when riboflavin is added to the photo-inactivated yeast. A high concentration of pyridoxine also produced an improvement in survival. When riboflavin is treated with light, it cannot support survival on synthetic food media nor can it restore survival on light treated yeast food media. These results show that riboflavin (or a derivative) is a major light sensitive compound of yeast, which can be degraded by light. Light induced loss of riboflavin leads to mortality, because this is an essential dietary vitamin. The vitamin degradation can be prevented by dietary antioxidants. A chromatographic analysis confirms this conclusion.

  18. Female Meiosis: Synapsis, Recombination, and Segregation in Drosophila melanogaster

    Science.gov (United States)

    Hughes, Stacie E.; Miller, Danny E.; Miller, Angela L.; Hawley, R. Scott

    2018-01-01

    A century of genetic studies of the meiotic process in Drosophila melanogaster females has been greatly augmented by both modern molecular biology and major advances in cytology. These approaches, and the findings they have allowed, are the subject of this review. Specifically, these efforts have revealed that meiotic pairing in Drosophila females is not an extension of somatic pairing, but rather occurs by a poorly understood process during premeiotic mitoses. This process of meiotic pairing requires the function of several components of the synaptonemal complex (SC). When fully assembled, the SC also plays a critical role in maintaining homolog synapsis and in facilitating the maturation of double-strand breaks (DSBs) into mature crossover (CO) events. Considerable progress has been made in elucidating not only the structure, function, and assembly of the SC, but also the proteins that facilitate the formation and repair of DSBs into both COs and noncrossovers (NCOs). The events that control the decision to mature a DSB as either a CO or an NCO, as well as determining which of the two CO pathways (class I or class II) might be employed, are also being characterized by genetic and genomic approaches. These advances allow a reconsideration of meiotic phenomena such as interference and the centromere effect, which were previously described only by genetic studies. In delineating the mechanisms by which the oocyte controls the number and position of COs, it becomes possible to understand the role of CO position in ensuring the proper orientation of homologs on the first meiotic spindle. Studies of bivalent orientation have occurred in the context of numerous investigations into the assembly, structure, and function of the first meiotic spindle. Additionally, studies have examined the mechanisms ensuring the segregation of chromosomes that have failed to undergo crossing over. PMID:29487146

  19. Genomic Variation in Natural Populations of Drosophila melanogaster

    Science.gov (United States)

    Langley, Charles H.; Stevens, Kristian; Cardeno, Charis; Lee, Yuh Chwen G.; Schrider, Daniel R.; Pool, John E.; Langley, Sasha A.; Suarez, Charlyn; Corbett-Detig, Russell B.; Kolaczkowski, Bryan; Fang, Shu; Nista, Phillip M.; Holloway, Alisha K.; Kern, Andrew D.; Dewey, Colin N.; Song, Yun S.; Hahn, Matthew W.; Begun, David J.

    2012-01-01

    This report of independent genome sequences of two natural populations of Drosophila melanogaster (37 from North America and 6 from Africa) provides unique insight into forces shaping genomic polymorphism and divergence. Evidence of interactions between natural selection and genetic linkage is abundant not only in centromere- and telomere-proximal regions, but also throughout the euchromatic arms. Linkage disequilibrium, which decays within 1 kbp, exhibits a strong bias toward coupling of the more frequent alleles and provides a high-resolution map of recombination rate. The juxtaposition of population genetics statistics in small genomic windows with gene structures and chromatin states yields a rich, high-resolution annotation, including the following: (1) 5′- and 3′-UTRs are enriched for regions of reduced polymorphism relative to lineage-specific divergence; (2) exons overlap with windows of excess relative polymorphism; (3) epigenetic marks associated with active transcription initiation sites overlap with regions of reduced relative polymorphism and relatively reduced estimates of the rate of recombination; (4) the rate of adaptive nonsynonymous fixation increases with the rate of crossing over per base pair; and (5) both duplications and deletions are enriched near origins of replication and their density correlates negatively with the rate of crossing over. Available demographic models of X and autosome descent cannot account for the increased divergence on the X and loss of diversity associated with the out-of-Africa migration. Comparison of the variation among these genomes to variation among genomes from D. simulans suggests that many targets of directional selection are shared between these species. PMID:22673804

  20. The Release 6 reference sequence of the Drosophila melanogaster genome.

    Science.gov (United States)

    Hoskins, Roger A; Carlson, Joseph W; Wan, Kenneth H; Park, Soo; Mendez, Ivonne; Galle, Samuel E; Booth, Benjamin W; Pfeiffer, Barret D; George, Reed A; Svirskas, Robert; Krzywinski, Martin; Schein, Jacqueline; Accardo, Maria Carmela; Damia, Elisabetta; Messina, Giovanni; Méndez-Lago, María; de Pablos, Beatriz; Demakova, Olga V; Andreyeva, Evgeniya N; Boldyreva, Lidiya V; Marra, Marco; Carvalho, A Bernardo; Dimitri, Patrizio; Villasante, Alfredo; Zhimulev, Igor F; Rubin, Gerald M; Karpen, Gary H; Celniker, Susan E

    2015-03-01

    Drosophila melanogaster plays an important role in molecular, genetic, and genomic studies of heredity, development, metabolism, behavior, and human disease. The initial reference genome sequence reported more than a decade ago had a profound impact on progress in Drosophila research, and improving the accuracy and completeness of this sequence continues to be important to further progress. We previously described improvement of the 117-Mb sequence in the euchromatic portion of the genome and 21 Mb in the heterochromatic portion, using a whole-genome shotgun assembly, BAC physical mapping, and clone-based finishing. Here, we report an improved reference sequence of the single-copy and middle-repetitive regions of the genome, produced using cytogenetic mapping to mitotic and polytene chromosomes, clone-based finishing and BAC fingerprint verification, ordering of scaffolds by alignment to cDNA sequences, incorporation of other map and sequence data, and validation by whole-genome optical restriction mapping. These data substantially improve the accuracy and completeness of the reference sequence and the order and orientation of sequence scaffolds into chromosome arm assemblies. Representation of the Y chromosome and other heterochromatic regions is particularly improved. The new 143.9-Mb reference sequence, designated Release 6, effectively exhausts clone-based technologies for mapping and sequencing. Highly repeat-rich regions, including large satellite blocks and functional elements such as the ribosomal RNA genes and the centromeres, are largely inaccessible to current sequencing and assembly methods and remain poorly represented. Further significant improvements will require sequencing technologies that do not depend on molecular cloning and that produce very long reads. © 2015 Hoskins et al.; Published by Cold Spring Harbor Laboratory Press.

  1. Autosomal mutations affecting Y chromosome loops in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Petrucci Romano

    2008-04-01

    Full Text Available Abstract Background The Y chromosome of Drosophila melanogaster harbors several genes required for male fertility. The genes for these fertility factors are very large in size and contain conspicuous amounts of repetitive DNA and transposons. Three of these loci (ks-1, kl-3 and kl-5 have the ability to develop giant lampbrush-like loops in primary spermatocytes, a cytological manifestation of their active state in these cells. Y-loops bind a number of non-Y encoded proteins, but the mechanisms regulating their development and their specific functions are still to be elucidated. Results Here we report the results of a screen of 726 male sterile lines to identify novel autosomal genes controlling Y-loop function. We analyzed mutant testis preparations both in vivo and by immunofluorescence using antibodies directed against Y-loop-associated proteins. This screen enabled us to isolate 17 mutations at 15 loci whose wild-type function is required for proper Y-loop morphogenesis. Six of these loci are likely to specifically control loop development, while the others display pleiotropic effects on both loops and meiotic processes such as spermiogenesis, sperm development and maturation. We also determined the map position of the mutations affecting exclusively Y-loop morphology. Conclusion Our cytological screening permitted us to identify novel genetic functions required for male spermatogenesis, some of which show pleiotropic effects. Analysis of these mutations also shows that loop development can be uncoupled from meiosis progression. These data represent a useful framework for the characterization of Y-loop development at a molecular level and for the study of the genetic control of heterochromatin.

  2. Question of the total gene number in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Lefevre, G.; Watkins, W.

    1986-01-01

    A statistical analysis has been carried out on the distribution and allelism of nearly 500 sex-linked, X-ray-induced, cytologically normal and rearranged lethal mutations in Drosophila melanogaster that were obtained by G. Lefevre. The mutations were induced in four different regions of the X chromosome: (1) 1A1-3E8, (2) 6D1-8A5, (3) 9E1-11A7 and (4) 19A1-20F4, which together comprise more than one-third of the entire chromosome.--The analysis shows that the number of alleles found at different loci does not fit a Poisson distribution, even when the proper procedures are taken to accommodate the truncated nature of the data. However, the allele distribution fits a truncated negative binomial distribution quite well, with cytologically normal mutations fitting better than rearrangement mutations. This indicates that genes are not equimutable, as required for the data to fit a Poisson distribution.--Using the negative binomial parameters to estimate the number of genes that did not produce a detectable lethal mutation in our experiment (n0) gave a larger number than that derived from the use of the Poisson parameter. Unfortunately, we cannot estimate the total numbers of nonvital loci, loci with undetectable phenotypes and loci having extremely low mutabilities. In any event, our estimate of the total vital gene number was far short of the total number of bands in the analyzed regions; yet, in several short intervals, we have found more vital genes than bands; in other intervals, fewer. We conclude that the one-band, one-gene hypothesis, in its literal sense, is not true; furthermore, it is difficult to support, even approximately.--The question of the total gene number in Drosophila will, not doubt, eventually be solved by molecular analyses, not by statistical analysis of mutation data or saturation studies

  3. Pomegranate juice enhances healthy lifespan in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Padmavathy eVenkatasubramanian

    2014-12-01

    Full Text Available Exploring innovative ways to ensure healthy ageing of populations is a pre-requisite to contain rising healthcare costs. Scientific research into the principles and practices of traditional medicines can provide new insights and simple solutions to lead a healthy life. Rasayana is a dedicated branch of Ayurveda (an Indian medicine that deals with methods to increase vitality and delay aging through the use of diet, herbal supplements and other lifestyle practices. The life-span and health-span enhancing actions of the fruits of Pomegranate (Punica granatum L., a well-known Rasayana, were tested on Drosophila melanogaster (fruitfly model. Supplementation of standard corn meal with 10% (v/v pomegranate juice (PJ extended the life-span of male and female flies by 18% and 8% respectively. When male and female flies were mixed and reared together, there was 19% increase in the longevity of PJ fed flies, as assessed by MSD, the median survival day (24.8. MSD for control and resveratrol (RV groups was at 20.8 and 23.1 days respectively. A two-fold enhancement in fecundity, improved resistance to oxidative stress (H2O2 and paraquat induced and to Candida albicans infection were observed in PJ fed flies. Further, the flies in the PJ fed group were physically active over an extended period of time, as assessed by the climbing assay. PJ thus outperformed both control and RV groups in the life-span and health-span parameters tested. This study provides the scope to explore the potential of PJ as a nutraceutical to improve health span and lifespan in humans.

  4. Experimental verification on the integrity and performance of the passive residual heat removal system for a SMART design with VISTA-ITL

    International Nuclear Information System (INIS)

    Min, Byung-Yeon; Park, Hyun-Sik; Shin, Yong-Chul; Yi, Sung-Jae

    2014-01-01

    Highlights: • Performance of the passive residual heat removal system. • Thermal–hydraulic behavior during the steady state operation of the PRHRS. • Natural circulation flow rate. • Small-break loss of coolant accident. - Abstract: The purpose of this paper is to verify the integrity and performance of the passive residual heat removal system (PRHRS) for the SMART design during a steady state condition. The system’s overall thermal–hydraulic behavior during the steady state operation of the PRHRS of the SMART reactor was simulated using the VISTA-ITL, a small-scale integral effect test loop for the SMART design. The PRHRS is operated properly when the reactor is shutdown considering all the operating conditions of the SMART plant. The steady-state PRHRS performance tests are divided into three conditions of 100% scaled power, 20% scaled power, and hot standby condition. The experimental results show that PRHRS’s integrity and performance are proper for these three conditions. The steady state condition was well operated to satisfy the initial test conditions presented in the test requirement, and its boundary condition was properly simulated. The natural circulation flow rate in the primary system was about 10.0%, 10.6%, and 10.6% for 100% scaled power, 20% scaled power, and hot standby condition, respectively. The PRHRS’s natural circulation flow was formed as much as 10.1%, 11.7% and 9.1% for 100% scaled power, 20% scaled power and hot standby condition of its nominal value in the early stage of the PRHRS operation, respectively

  5. Vernonanthura polyanthes leaves aqueous extract enhances doxorubicin genotoxicity in somatic cells of Drosophila melanogaster and presents no antifungal activity against Candida spp.

    Directory of Open Access Journals (Sweden)

    I. J. Guerra-Santos

    Full Text Available Abstract Vernonanthura polyanthes (Spreng. A.J. Vega & Dematt. (Asteraceae, known as “assa-peixe”, has been used in ethnomedicine for the treatment of various diseases such as bronchitis, pneumonia, hemoptysis, persistent cough, internal abscesses, gastric and kidney stone pain. Moreover, some studies demonstrated that species of Genus Vernonia present antifungal activity. Due to the biological relevance of this species, the aim of this study was to investigate the toxic, genotoxic, antigenotoxic and antifungal potential of V. polyanthes leaves aqueous extract in somatic cells of Drosophila melanogaster or against Candida spp. The aqueous extract of the plant showed no toxic, genotoxic and antigenotoxic activity in the experimental conditions tested using the wing somatic mutation and recombination test (SMART/wing. However, when the extract was associated with doxorubicin, used in this work as a positive control, the mutagenic potential of doxorubicin was enhanced, increasing the number of mutations in D. melanogaster somatic cells. In the other hand, no inhibitory activity against Candida spp. was observed for V. polyanthes leaves aqueous extract using agar-well diffusion assay. More studies are necessary to reveal the components present in the V. polyanthes leaves aqueous extract that could contribute to potentiate the doxorubicin genotoxicity.

  6. Vernonanthura polyanthes leaves aqueous extract enhances doxorubicin genotoxicity in somatic cells of Drosophila melanogaster and presents no antifungal activity against Candida spp.

    Science.gov (United States)

    Guerra-Santos, I J; Rocha, J D; Vale, C R; Sousa, W C; Teles, A M; Chen-Chen, L; Carvalho, S; Bailão, E F L C

    2016-01-01

    Vernonanthura polyanthes (Spreng.) A.J. Vega & Dematt. (Asteraceae), known as "assa-peixe", has been used in ethnomedicine for the treatment of various diseases such as bronchitis, pneumonia, hemoptysis, persistent cough, internal abscesses, gastric and kidney stone pain. Moreover, some studies demonstrated that species of Genus Vernonia present antifungal activity. Due to the biological relevance of this species, the aim of this study was to investigate the toxic, genotoxic, antigenotoxic and antifungal potential of V. polyanthes leaves aqueous extract in somatic cells of Drosophila melanogaster or against Candida spp. The aqueous extract of the plant showed no toxic, genotoxic and antigenotoxic activity in the experimental conditions tested using the wing somatic mutation and recombination test (SMART/wing). However, when the extract was associated with doxorubicin, used in this work as a positive control, the mutagenic potential of doxorubicin was enhanced, increasing the number of mutations in D. melanogaster somatic cells. In the other hand, no inhibitory activity against Candida spp. was observed for V. polyanthes leaves aqueous extract using agar-well diffusion assay. More studies are necessary to reveal the components present in the V. polyanthes leaves aqueous extract that could contribute to potentiate the doxorubicin genotoxicity.

  7. The role of acetone in the [omim][BF4]-mediated adverse effects on tissues of mussels, human lymphocytes and the fruit fly Drosophila melanogaster.

    Science.gov (United States)

    Tsarpali, Vasiliki; Goutas, Andreas; Karyda, Anna; Efthimiou, Ioanna; Antonopoulou, Maria; Drosopoulou, Elena; Vlastos, Dimitrios; Konstantinou, Ioannis; Mavragani-Tsipidou, Penelope; Dailianis, Stefanos

    2017-07-05

    The present study investigated [omim][BF 4 ]-mediated adverse effects on biological models widely used in toxicological studies. Specifically, mussels of the genus Mytilus, human lymphocytes and fruit flies of the species Drosophila melanogaster, were exposed to [omim][BF 4 ] at concentrations ranging from micro- to milligrams per liter, with or without the presence of acetone as a carrier solvent and thereafter [omim][BF 4 ]-mediated adverse effects were analyzed appropriately (stress indices, such as lipid peroxidation byproducts, acetylcholinesterase/AChE activity and micronucleus/MN formation frequency, in mussel gills, Cytokinesis Block Micronucleus/CBMN assay and SMART test in human lymphocytes and fruit flies respectively). LC-MS-TOF analysis was also performed for elucidating [omim][BF 4 ] mode of action in the presence of the carrier solvent. The results showed the toxic potential of [omim][BF 4 ], as well as acetone's ability to attenuate [omim][BF 4 ]-mediated toxicity in almost all cases, probably due to the significant effect of acetone on the hydrophilic-lipophilic character and the viscosity of [omim][BF 4 ], as well as its interaction and permeability on the cell membranes. The slight involvement of acetone in the attenuation of [omim][BF 4 ]-mediated genotoxic effects on D. melanogaster could be due to species feeding experimental conditions, thus favoring the induction of antioxidant defense system against the [omim][BF 4 ]-mediated effects in all cases. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Used Nuclear Fuel Loading and Structural Performance Under Normal Conditions of Transport - Modeling, Simulation and Experimental Integration RD&D Plan

    Energy Technology Data Exchange (ETDEWEB)

    Adkins, Harold E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-04-01

    Under current U.S. Nuclear Regulatory Commission regulation, it is not sufficient for used nuclear fuel (UNF) to simply maintain its integrity during the storage period, it must maintain its integrity in such a way that it can withstand the physical forces of handling and transportation associated with restaging the fuel and moving it to treatment or recycling facilities, or a geologic repository. Hence it is necessary to understand the performance characteristics of aged UNF cladding and ancillary components under loadings stemming from transport initiatives. Researchers would like to demonstrate that enough information, including experimental support and modeling and simulation capabilities, exists to establish a preliminary determination of UNF structural performance under normal conditions of transport (NCT). This research, development and demonstration (RD&D) plan describes a methodology, including development and use of analytical models, to evaluate loading and associated mechanical responses of UNF rods and key structural components. This methodology will be used to provide a preliminary assessment of the performance characteristics of UNF cladding and ancillary components under rail-related NCT loading. The methodology couples modeling and simulation and experimental efforts currently under way within the Used Fuel Disposition Campaign (UFDC). The methodology will involve limited uncertainty quantification in the form of sensitivity evaluations focused around available fuel and ancillary fuel structure properties exclusively. The work includes collecting information via literature review, soliciting input/guidance from subject matter experts, performing computational analyses, planning experimental measurement and possible execution (depending on timing), and preparing a variety of supporting documents that will feed into and provide the basis for future initiatives. The methodology demonstration will focus on structural performance evaluation of

  9. Integrated Experimental and Modeling Studies of Mineral Carbonation as a Mechanism for Permanent Carbon Sequestration in Mafic/Ultramafic Rocks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhengrong [Yale Univ., New Haven, CT (United States); Qiu, Lin [Yale Univ., New Haven, CT (United States); Zhang, Shuang [Yale Univ., New Haven, CT (United States); Bolton, Edward [Yale Univ., New Haven, CT (United States); Bercovici, David [Yale Univ., New Haven, CT (United States); Ague, Jay [Yale Univ., New Haven, CT (United States); Karato, Shun-Ichiro [Yale Univ., New Haven, CT (United States); Oristaglio, Michael [Yale Univ., New Haven, CT (United States); Zhu, Wen-Iu [Univ. of Maryland, College Park, MD (United States); Lisabeth, Harry [Univ. of Maryland, College Park, MD (United States); Johnson, Kevin [Univ. of Hawaii, Honolulu, HI (United States)

    2014-09-30

    that could have been removed if the olivine initially present had fully dissolved and the cations released had subsequently precipitated in carbonate minerals. The carbonation fractions observed in batch experiments with olivine grains and powders varied significantly, from less than 0.01 (1%) to more than 0.5 (50%). Over time, the carbonation fractions reached an upper limit after about 24 to 72 hours of reaction, then stayed constant or decreased. The peak Final Scientific/Technical Report DE-FE0004275 | Mineral Carbonation | 4 coincided with the appearance of secondary magnesium-bearing silicate minerals, whose formation competes for magnesium ions in solution and can even promote conditions that dissolve magnesite. The highest carbonation fractions resulted from experiments with low ratios of concentrated solution to olivine, during which amorphous silica spheres or meshes formed, instead of secondary silicate minerals. The highest carbonation fractions appear to result from competing effects. Precipitation of silica layers on olivine reduces the reactive surface area and, thus, the rate of olivine dissolution (which ultimately limits the carbonation rate), but these same silica layers can also inhibit the formation of secondary silicate minerals that consume magnesite formed in earlier stages of carbonation. Simulation of these experiments with simple geochemical models using the software program EQ3/6 reproduces the general trends observed—especially the results for the carbonation fraction in short-run experiments. Although further experimentation and better models are needed, this study nevertheless provides a framework for understanding the optimal conditions for sequestering carbon dioxide by reacting CO2-bearing fluids with rocks containing olivine minerals. A series of experiments at the Rock Physics Laboratory at the University of Maryland studied the carbonation process during deformation of thermally cracked olivine-rich rock samples (dunite

  10. Experimental evolution reveals natural selection on standing genetic variation

    OpenAIRE

    Teotónio, H; Chelo, IM; Bradic, M; Rose, MR; Long, AD

    2009-01-01

    Evolution depends on genetic variation generated by mutation or recombination from standing genetic variation. In sexual organisms, little is known about the molecular population genetics of adaptation and reverse evolution(1-11). We carry out 50 generations of experimental reverse evolution in populations of Drosophila melanogaster, previously differentiated by forward evolution, and follow changes in the frequency of SNPs in both arms of the third chromosome. We characterize the effects of ...

  11. [Functional analysis of Grp and Iris, the gag and env domesticated errantivirus genes, in the Drosophila melanogaster genome].

    Science.gov (United States)

    Makhnovskii, P A; Kuzmin, I V; Nefedova, L N; Kima, A I

    2016-01-01

    Drosophila melanogaster is the only invertebrate that contains endogenous retroviruses, which are called errantiviruses. Two domesticated genes, Grp and Iris, which originate from errantivirus gag and env, respectively, have been found in the D. melanogaster genome. The functions performed by the genes in Drosophila are still unclear. To identify the functions of domesticated gag and env in the D. melanogaster genome, expression of Iris and Grp was studied in strains differing by the presence or absence of the functional gypsy errantivirus. In addition, the expression levels were measured after injection of gram-positive and gram-negative bacteria, which activate different immune response pathways, and exposure to various abiotic stress factors. The presence of functional D. melanogaster retrovirus gypsy was found to increase the Grp expression level in somatic tissues of the carcass, while exerting no effect on the Iris expression level. Activation of the immune response in D. melanogaster by bacteria Bacillus cereus increased the Grp expression level and did not affect Iris expression. As for the effects of abiotic stress factors (oxidative stress, starvation, and heat and cold stress), the Grp expression level increased in response to starvation in D. melanogaster females, and the Iris expression level was downregulated in heat shock and oxidative stress. Based on the findings, Grp was assumed to play a direct role in the immune response in D. melanogaster; Iris is not involved in immune responses, but and apparently performs a cell function that is inhibited in stress.

  12. Effect of low-level intensity EHF radiation on endurance and reproductivity of Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Shakhbazov, V.G.; Chepel', L.M.; Bulgakov, B.M.; Sirenko, S.P.; Belous, O.I.; Fisun, A.I.

    1999-01-01

    The effect of the low-intensity microwaves on three gene-radiations of the imago Drosophila Melanogaster has been investigated out. The radiation source was tuned from 37 to 53 GHz. The thermoimmunity and reproductivity of the first generation of females and males of imago after processing by radiation. The obtained effect can be considered as physiological heterosis

  13. allele of the noncoding hsrω gene of Drosophila melanogaster is not ...

    Indian Academy of Sciences (India)

    , Martinez P. et al. 2000 Identification of genes that modify ataxin-1-induced neurodegeneration. Nature 408, 101–. 106. Lakhotia S. C. 2003 The non-coding, developmentally active and stress inducible hsrω gene of Drosophila melanogaster ...

  14. EFFECTS ON ADH ACTIVITY AND DISTRIBUTION, FOLLOWING SELECTION FOR TOLERANCE TO ETHANOL IN DROSOPHILA-MELANOGASTER

    NARCIS (Netherlands)

    KERVER, JWM; WOLF, W; KAMPING, A; VANDELDEN, W

    1992-01-01

    Strains of Drosophila melanogaster homozygous for either the Adh(F) or the Adh(S) allele were kept on food supplemented with ethanol for 20 generations. These strains (FE and SE) were tested for tolerance to ethanol and compared with control strains (FN and SN). The E strains showed increased

  15. Male Mating Success: Preference or Prowess? Investigating Sexual Selection in the Laboratory Using "Drosophila melanogaster"

    Science.gov (United States)

    Coleman, Seth; Jensen, Jeffrey

    2007-01-01

    Sexual selection is the primary force affecting the evolution of the elaborate sexual displays common in animals, yet sexual selection experiments are largely absent from introductory biology laboratories. Here we describe the rationale, methodology, and results of several experiments using "Drosophila melanogaster" to demonstrate sexual selection…

  16. The nutritional and hedonic value of food modulate sexual receptivity in Drosophila melanogaster females

    NARCIS (Netherlands)

    Gorter, Jenke A; Jagadeesh, Samyukta; Gahr, Christoph; Boonekamp, Jelle J; Levine, Joel D; Billeter, Jean-Christophe

    2016-01-01

    Food and sex often go hand in hand because of the nutritional cost of reproduction. For Drosophila melanogaster females, this relationship is especially intimate because their offspring develop on food. Since yeast and sugars are important nutritional pillars for Drosophila, availability of these

  17. Drosophila melanogaster females change mating behaviour and offspring production based on social context

    NARCIS (Netherlands)

    Billeter, Jean-Christophe; Jagadeesh, Samyukta; Stepek, Nancy; Azanchi, Reza; Levine, Joel D.

    2012-01-01

    In Drosophila melanogaster, biological rhythms, aggression and mating are modulated by group size and composition. However, the fitness significance of this group effect is unknown. By varying the composition of groups of males and females, we show that social context affects reproductive behaviour

  18. Autosomal control of the Y-chromosome kl-3 loop of Drosophila melanogaster

    NARCIS (Netherlands)

    Piergentili, R.; Bonaccorsi, S.; Raffa, G.D.; Pisano, C.; Hackstein, J.H.P.; Mencarelli, C.

    2004-01-01

    The Y chromosome of Drosophila melanogaster carries a limited number of loci necessary for male fertility that possess a series of unconventional features that still hinder a definition of their biological role: they have extremely large sizes; accommodate huge amounts of repetitive DNA; and develop

  19. allele of the noncoding hsrω gene of Drosophila melanogaster is not ...

    Indian Academy of Sciences (India)

    Drosophila melanogaster is not responsible for male sterility as reported earlier ... gene, the pl alleles were brought in trans with hsrω05241 or with the ... The progeny hsrω05241/ry. − females were crossed with TM3/TM6B males (for details of the var- ious mutant genes and balancer chromosomes, see Lindslay and Zimm ...

  20. Consistent effects of a major QTL for thermal resistance in field-released Drosophila melanogaster

    DEFF Research Database (Denmark)

    Loeschcke, Volker; Kristensen, Torsten Nygård; Norry, Fabian M

    2011-01-01

    Molecular genetic markers can be used to identify quantitative trait loci (QTL) for thermal resistance and this has allowed characterization of a major QTL for knockdown resistance to high temperature in Drosophila melanogaster. The QTL showed trade-off associations with cold resistance under lab...

  1. Proteomic characterization of a temperature-sensitive conditional lethal in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Pedersen, Kamilla Sofie; Codrea, M.C; Vermeulen, Corneel

    2010-01-01

    Genetic variation that is expressed only under specific environmental conditions can contribute to additional adverse effects of inbreeding if environmental conditions change. We present a proteomic characterization of a conditional lethal found in an inbred line of Drosophila melanogaster. The l...

  2. Structural studies of nucleoside analog and feedback inhibitor binding to Drosophila melanogaster multisubstrate deoxyribonucleoside kinase

    DEFF Research Database (Denmark)

    Mikkelsen, Niels Egil; Munch-Petersen, Birgitte; Eklund, Hans

    2008-01-01

    The Drosophila Melanogaster multisubstrate deoxyribonucleoside kinase (dNK) has a high turnover rate and a wide substrate range that makes it a very good candidate for gene therapy. This concept is based on introducing a suicide gene into malignant cells in order to activate a pro...

  3. Bowman-Birk inhibitor affects pathways associated with energy metabolism in Drosophila melanogaster

    Science.gov (United States)

    Bowman-Birk inhibitor (BBI) is toxic when fed to certain insects, including the fruit fly, Drosophila melanogaster. Dietary BBI has been demonstrated to slow growth and increase insect mortality by inhibiting the digestive enzymes trypsin and chymotrypsin, resulting in a reduced supply of amino acid...

  4. Pharmacodynamic study on insomnia-curing effects of Shuangxia Decoction in Drosophila melanogaster.

    Science.gov (United States)

    Zhang, Zhi-Qian; Degejin; Geng, Di; Zhang, Qi; Tian, Yan; Xi, Yuan; Wang, Wen-Qi; Tang, Hua-Qi; Xu, Bing; Lin, Hong-Ying; Sun, Yi-Kun

    2016-09-01

    The present study aimed to establish a pharmacodynamic method using the pySolo software to explore the influence of freeze-dried powders of Shuangxia Decoction (SXD) on the sleep of normal Drosophila melanogaster and the Drosophila melanogaster whose sleep was divested by light. The dose-effect and the time-effect relationships of SXD on sleep were examined. The effect-onset concentration of SXD was 0.25%, the plateau appeared at the concentration of 2.5% and the total sleep time showed a downtrend when the concentration was greater than 2.5%. The sleep time was the longest on the fourth day after SXD was given. The fruit fly sleep deprivation model was repeated by light stimulation at night. The middle dosage group (2.5%) had the best insomnia-curing effect. In conclusion, using the pySolo software, an approach for the pharmacodynamics study was established with Drosophila melanogaster as a model organism to determine the insomnia-curing effects of the traditional Chinese medicine (TCM). Our results demonstrated the reliability of this method. The freeze-dried powders of SXD could effectively improve the sleep quality of Drosophila melanogaster. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  5. Study of radioadaptive response in Drosophila melanogaster at different oogenesis stages

    International Nuclear Information System (INIS)

    Glushkova, I.V.; Aksyutik, T.V.

    2005-01-01

    We study radioadaptive response in the Canton-S strain of Drosophila melanogaster at different oogenesis stages using the test of dominant lethal mutations (DLM). AR was not revealed at the stages of 14-7 and 7--1 oocytes in the studied Drosophila stock. It is likely to be associated with a genetic constitution of the Drosophila strain under study. (authors)

  6. Metabolomic analysis of the selection response of Drosophila melanogaster to environmental stress

    DEFF Research Database (Denmark)

    Malmendal, Anders; Sørensen, Jesper Givskov; Overgaard, Johannes

    2013-01-01

    We investigated the global metabolite response to artificial selection for tolerance to stressful conditions such as cold, heat, starvation, and desiccation, and for longevity in Drosophila melanogaster. Our findings were compared to data from other levels of biological organization, including gene...

  7. Transcriptional Signatures in Response to Wheat Germ Agglutinin and Starvation in Drosophila melanogaster Larval Midgut

    Science.gov (United States)

    One function of plant lectins such as wheat germ agglutinin (WGA) is to serve as defenses against herbivorous insects. The midgut is one critical site affected by dietary lectins. We observed marked cellular, structural, and gene expression changes in the midguts of Drosophila melanogaster third-i...

  8. Structure of glutaminyl cyclase from Drosophila melanogaster in space group I4

    Czech Academy of Sciences Publication Activity Database

    Kolenko, Petr; Koch, B.; Rahfeld, J.-U.; Schilling, S.; Demuth, H.-U.; Stubbs, M. T.

    2013-01-01

    Roč. 69, č. 4 (2013), s. 358-361 ISSN 1744-3091 R&D Projects: GA MŠk EE2.3.30.0029 Institutional support: RVO:61389013 Keywords : glutaminyl cyclases * Drosophila melanogaster * soaking Subject RIV: CE - Biochemistry Impact factor: 0.568, year: 2013

  9. Influence of incorporated radionuclides on the life span of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Koshel', N.M.; Vajserman, O.M.; Vojtenko, V.P.; Kutlakhmedov, Yu.O.; Mikhjejev, O.M.

    2004-01-01

    Influence of incorporated radionuclides ( 137 Cs and 90 Sr) on the life span of Drosophila melanogaster was studied. External irradiation modified the formation of cumulative dose of incorporated radionuclides. All influences leaded to significant (p 90 Sr was higher comparing to 137 Cs

  10. Somatic mutation and recombination induced by fast neutrons in the wing spot test of Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Guzman R, J.; Varela, A.; Policroniades, R.; Delfin, A.; Graf, U.

    1994-01-01

    In the last decades, a large number of studies have been undertaken to evaluate the biological effects of gamma and X rays in Drosophila melanogaster. The majority of these investigations were performed on female and male germ cells. However, comparatively little is known in relation to the biological effects of fast neutrons, and especially in relation to their effects in somatic cells. (Author)

  11. Metabolomic profiling of rapid cold hardening and cold shock in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Overgaard, Johannes; Malmendal, Anders; Sørensen, Jesper

    2007-01-01

    study used untargeted (1)H NMR metabolomic profiling to examine the metabolomic response in Drosophila melanogaster during the 72 h following RCH and cold shock treatment. These findings are discussed in relation to the costs and benefits of RCH that are measured in terms of survival and reproductive...

  12. Pervasive gene expression responses to a fluctuating diet in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Zandveld, Jelle; van den Heuvel, Joost; Mulder, Maarten

    2017-01-01

    Phenotypic plasticity is an important concept in life-history evolution, and most organisms, including Drosophila melanogaster, show a plastic life-history response to diet. However, little is known about how these life-history responses are mediated. In this study, we compared adult female flies...

  13. Molecular Mechanisms for High Hydrostatic Pressure-Induced Wing Mutagenesis in Drosophila melanogaster.

    Science.gov (United States)

    Wang, Hua; Wang, Kai; Xiao, Guanjun; Ma, Junfeng; Wang, Bingying; Shen, Sile; Fu, Xueqi; Zou, Guangtian; Zou, Bo

    2015-10-08

    Although High hydrostatic pressure (HHP) as an important physical and chemical tool has been increasingly applied to research of organism, the response mechanisms of organism to HHP have not been elucidated clearly thus far. To identify mutagenic mechanisms of HHP on organisms, here, we treated Drosophila melanogaster (D. melanogaster) eggs with HHP. Approximately 75% of the surviving flies showed significant morphological abnormalities from the egg to the adult stages compared with control flies (p melanogaster induced by HHP were used to investigate the mutagenic mechanisms of HHP on organism. Thus 285 differentially expressed genes associated with wing mutations were identified using Affymetrix Drosophila Genome Array 2.0 and verified with RT-PCR. We also compared wing development-related central genes in the mutant flies with control flies using DNA sequencing to show two point mutations in the vestigial (vg) gene. This study revealed the mutagenic mechanisms of HHP-induced mutagenesis in D. melanogaster and provided a new model for the study of evolution on organisms.

  14. Editor's Highlight: Genetic Targets of Acute Toluene Inhalation in Drosophila melanogaster

    Science.gov (United States)

    Interpretation and use of data from high-throughput assays for chemical toxicity require links between effects at molecular targets and adverse outcomes in whole animals. The well-characterized genome of Drosophila melanogaster provides a potential model system by which phenotypi...

  15. Lethality and Developmental Delay of Drosophila melanogaster Following Ingestion of Selected Pseudomonas fluorescens Strains

    Science.gov (United States)

    Pseudomonas fluorescens secretes antimicrobial compounds that promote plant health and provide protection from pathogens. We used a non-invasive feeding assay to study the toxicity of P. fluorescens strains Pf0-1, SBW25, and Pf-5 to Drosophila melanogaster. The three strains of P. fluorescens varie...

  16. Field tests reveal genetic variation for performance atlow temperatures in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Overgaard, Johannes; Sørensen, Jesper Givskov; Jensen, Louise Toft

    2010-01-01

    investigated a population of Drosophila melanogaster for performance at low temperature conditions in the field using release recapture assays and in the laboratory using standard cold resistance assays. The aim of the study was to get a better understanding of the nature and underlying mechanisms of the trait...

  17. The effects of inbreeding and heat stress on male sterility in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Pedersen, Louise Dybdahl; Pedersen, Asger Roer; Bijlsma, Kuke

    2011-01-01

    in benign and stressful environments using Drosophila melanogaster as a model organism. Male sterility was compared in 21 inbred lines and five non-inbred control lines at 25.0 and 29.0 °C. The effect of inbreeding on sterility was significant only at 29.0 °C. This stress-induced increase in sterility...

  18. Endosymbiont-based immunity in Drosophila melanogaster against parasitic nematode infection.

    Science.gov (United States)

    Yadav, Shruti; Frazer, Joanna; Banga, Ashima; Pruitt, Katherine; Harsh, Sneh; Jaenike, John; Eleftherianos, Ioannis

    2018-01-01

    Associations between endosymbiotic bacteria and their hosts represent a complex ecosystem within organisms ranging from humans to protozoa. Drosophila species are known to naturally harbor Wolbachia and Spiroplasma endosymbionts, which play a protective role against certain microbial infections. Here, we investigated whether the presence or absence of endosymbionts affects the immune response of Drosophila melanogaster larvae to infection by Steinernema carpocapsae nematodes carrying or lacking their mutualistic Gram-negative bacteria Xenorhabdus nematophila (symbiotic or axenic nematodes, respectively). We find that the presence of Wolbachia alone or together with Spiroplasma promotes the survival of larvae in response to infection with S. carpocapsae symbiotic nematodes, but not against axenic nematodes. We also find that Wolbachia numbers are reduced in Spiroplasma-free larvae infected with axenic compared to symbiotic nematodes, and they are also reduced in Spiroplasma-containing compared to Spiroplasma-free larvae infected with axenic nematodes. We further show that S. carpocapsae axenic nematode infection induces the Toll pathway in the absence of Wolbachia, and that symbiotic nematode infection leads to increased phenoloxidase activity in D. melanogaster larvae devoid of endosymbionts. Finally, infection with either type of nematode alters the metabolic status and the fat body lipid droplet size in D. melanogaster larvae containing only Wolbachia or both endosymbionts. Our results suggest an interaction between Wolbachia endosymbionts with the immune response of D. melanogaster against infection with the entomopathogenic nematodes S. carpocapsae. Results from this study indicate a complex interplay between insect hosts, endosymbiotic microbes and pathogenic organisms.

  19. Three Strains of Pseudomonas fluorescens Exhibit Differential Toxicity Against Drosophila melanogaster

    Science.gov (United States)

    Three strains of Pseudomonas fluorescens were tested for toxicity to Drosophila melanogaster in an insect feeding assay. Insect eggs were placed on the surface of a non-nutritive agar plate supplemented with a food source that was non-inoculated or inoculated with P. fluorescens Pf0-1, SBW25, or Pf-...

  20. The Drosophila melanogaster methuselah gene: a novel gene with ancient functions.

    Directory of Open Access Journals (Sweden)

    Ana Rita Araújo

    Full Text Available The Drosophila melanogaster G protein-coupled receptor gene, methuselah (mth, has been described as a novel gene that is less than 10 million years old. Nevertheless, it shows a highly specific expression pattern in embryos, larvae, and adults, and has been implicated in larval development, stress resistance, and in the setting of adult lifespan, among others. Although mth belongs to a gene subfamily with 16 members in D. melanogaster, there is no evidence for functional redundancy in this subfamily. Therefore, it is surprising that a novel gene influences so many traits. Here, we explore the alternative hypothesis that mth is an old gene. Under this hypothesis, in species distantly related to D. melanogaster, there should be a gene with features similar to those of mth. By performing detailed phylogenetic, synteny, protein structure, and gene expression analyses we show that the D. virilis GJ12490 gene is the orthologous of mth in species distantly related to D. melanogaster. We also show that, in D. americana (a species of the virilis group of Drosophila, a common amino acid polymorphism at the GJ12490 orthologous gene is significantly associated with developmental time, size, and lifespan differences. Our results imply that GJ12490 orthologous genes are candidates for developmental time and lifespan differences in Drosophila in general.

  1. Structural basis for the changed substrate specificity of Drosophila melanogaster deoxyribonucleoside kinase mutant N64D

    DEFF Research Database (Denmark)

    Welin, M.; Skovgaard, T.; Knecht, Wolfgang

    2005-01-01

    The Drosophila melanogaster deoxyribonucleoside kinase (Dm-dNK) double mutant N45D/N64D was identified during a previous directed evolution study. This mutant enzyme had a decreased activity towards the natural substrates and decreased feedback inhibition with dTTP, whereas the activity with 3...

  2. Onderzoek naar de mutagene werking van acrylamide en methacrylamide bij Drosophila melanogaster

    NARCIS (Netherlands)

    Kramers PGN; Groot MG; Mout HCA; Verharen HW

    1989-01-01

    Acrylamide is mutageen in de somatische mutatie- en recombinatietest (SMART) met Drosphila melanogaster na behandeling van larven vanaf het 2e en 3e larvale stadium tot aan de verpopping, bij concentraties van 1,0 ; 1,5 en 2,0 mM in gedistilleerd water. Concentraties van 1,5 en 2,0 mM acrylamide

  3. Circadian Rhythms and Sleep inDrosophila melanogaster.

    Science.gov (United States)

    Dubowy, Christine; Sehgal, Amita

    2017-04-01

    The advantages of the model organism Drosophila melanogaster , including low genetic redundancy, functional simplicity, and the ability to conduct large-scale genetic screens, have been essential for understanding the molecular nature of circadian (∼24 hr) rhythms, and continue to be valuable in discovering novel regulators of circadian rhythms and sleep. In this review, we discuss the current understanding of these interrelated biological processes in Drosophila and the wider implications of this research. Clock genes period and timeless were first discovered in large-scale Drosophila genetic screens developed in the 1970s. Feedback of period and timeless on their own transcription forms the core of the molecular clock, and accurately timed expression, localization, post-transcriptional modification, and function of these genes is thought to be critical for maintaining the circadian cycle. Regulators, including several phosphatases and kinases, act on different steps of this feedback loop to ensure strong and accurately timed rhythms. Approximately 150 neurons in the fly brain that contain the core components of the molecular clock act together to translate this intracellular cycling into rhythmic behavior. We discuss how different groups of clock neurons serve different functions in allowing clocks to entrain to environmental cues, driving behavioral outputs at different times of day, and allowing flexible behavioral responses in different environmental conditions. The neuropeptide PDF provides an important signal thought to synchronize clock neurons, although the details of how PDF accomplishes this function are still being explored. Secreted signals from clock neurons also influence rhythms in other tissues. SLEEP is, in part, regulated by the circadian clock, which ensures appropriate timing of sleep, but the amount and quality of sleep are also determined by other mechanisms that ensure a homeostatic balance between sleep and wake. Flies have been useful

  4. Developmental environment mediates male seminal protein investment in Drosophila melanogaster.

    Science.gov (United States)

    Wigby, Stuart; Perry, Jennifer C; Kim, Yon-Hee; Sirot, Laura K

    2016-03-01

    Males of many species fine-tune their ejaculates in response to sperm competition risk. Resource availability and the number of competitors during development can also strongly influence sperm production. However, despite the key role of seminal proteins in mediating reproductive processes, it is unclear whether seminal protein investment is dependent on the developmental environment.We manipulated the developmental environment of Drosophila melanogaster by rearing flies at low and high density. As expected, this resulted in large and small (i.e. high and low condition) adult phenotypes, respectively.As predicted, large males produced more of two key seminal proteins, sex peptide (SP) and ovulin, and were more successful at obtaining matings with both virgin and previously mated females. However, there was only a weak and non-significant trend for large males to transfer more absolute quantities of SP at mating, and thus, small males ejaculated proportionally more of their stored accessory gland SP resources.Males transferred more receptivity-inhibiting SP to large females. Despite this, large females remated more quickly than small females and thus responded to their developmental environment over and above the quantity of SP they received.The results are consistent with two non-mutually exclusive hypotheses. First, flies might respond to condition-dependent reproductive opportunities, with (i) small males investing heavily in ejaculates when mating opportunities arise and large males strategically partitioning SP resources and (ii) small females remating at reduced rates because they have higher mating costs or need to replenish sperm less often.Second, flies may be primed by their larval environment to deal with similar adult population densities, with (i) males perceiving high density as signalling increased competition, leading small males to invest proportionally more SP resources at mating and (ii) females perceiving high density as signalling abundant

  5. Estudio experimental del Sistema de Albañilería Integral en la construcción de viviendas sismorresistentes

    Directory of Open Access Journals (Sweden)

    Orta, B.

    2012-03-01

    Full Text Available This paper presents the application of the Integral Masonry System (IMS to the construction of earthquake resistant houses and its experimental study. To verify the security of this new type of building in seismic areas of the third world two prototypes have been tested, one with adobe and the other with hollow brick. In both cases it’s a two-story 6x6x6 m3 house built to scale 1/2. The tests are carried out at the Laboratory of Antiseismic Structures of the Department of Engineering, Pontifical Catholic University of Peru in Lima, in collaboration with the UPM (Technical University of Madrid. This article shows the design process of the prototypes to test, including the sizing of the reinforcements, the characteristics of the tests and the results obtained. These results show that the IMS with adobe or brick remains stable with no significant cracks faced with a severe earthquake, with an estimated acceleration of 1.8 g.

    Este artículo presenta una aplicación del Sistema de Albañilería Integral (SAI a la construcción de viviendas sismorresistentes y su estudio experimental. Para verificar su seguridad para su construcción en zonas sísmicas del tercer mundo se han ensayado dos prototipos, uno con adobe, y otro con ladrillo hueco. Se trata de una vivienda de 6x6x6 m3 y dos plantas que se construyen a escala 1/2. Los ensayos se realizaron en el Laboratorio de Estructuras Antisísmicas del Departamento de Ingeniería de la Pontificia Católica Universidad del Perú (PUCP de Lima en colaboración con la UPM (Universidad Politécnica de Madrid. Este artículo muestra el proceso de diseño de los prototipos a ensayar, incluido el dimensionado de los refuerzos, las características de los ensayos y los resultados obtenidos. Estos resultados muestran que el SAI con adobe o ladrillo permanece estable sin grietas significativas ante un sismo severo, con una aceleración estimada de 1,8 g.

  6. The Discovery, Distribution, and Evolution of Viruses Associated with Drosophila melanogaster.

    Science.gov (United States)

    Webster, Claire L; Waldron, Fergal M; Robertson, Shaun; Crowson, Daisy; Ferrari, Giada; Quintana, Juan F; Brouqui, Jean-Michel; Bayne, Elizabeth H; Longdon, Ben; Buck, Amy H; Lazzaro, Brian P; Akorli, Jewelna; Haddrill, Penelope R; Obbard, Darren J

    2015-07-01

    Drosophila melanogaster is a valuable invertebrate model for viral infection and antiviral immunity, and is a focus for studies of insect-virus coevolution. Here we use a metagenomic approach to identify more than 20 previously undetected RNA viruses and a DNA virus associated with wild D. melanogaster. These viruses not only include distant relatives of known insect pathogens but also novel groups of insect-infecting viruses. By sequencing virus-derived small RNAs, we show that the viruses represent active infections of Drosophila. We find that the RNA viruses differ in the number and properties of their small RNAs, and we detect both siRNAs and a novel miRNA from the DNA virus. Analysis of small RNAs also allows us to identify putative viral sequences that lack detectable sequence similarity to known viruses. By surveying >2,000 individually collected wild adult Drosophila we show that more than 30% of D. melanogaster carry a detectable virus, and more than 6% carry multiple viruses. However, despite a high prevalence of the Wolbachia endosymbiont--which is known to be protective against virus infections in Drosophila--we were unable to detect any relationship between the presence of Wolbachia and the presence of any virus. Using publicly available RNA-seq datasets, we show that the community of viruses in Drosophila laboratories is very different from that seen in the wild, but that some of the newly discovered viruses are nevertheless widespread in laboratory lines and are ubiquitous in cell culture. By sequencing viruses from individual wild-collected flies we show that some viruses are shared between D. melanogaster and D. simulans. Our results provide an essential evolutionary and ecological context for host-virus interaction in Drosophila, and the newly reported viral sequences will help develop D. melanogaster further as a model for molecular and evolutionary virus research.

  7. Comparative Analysis of Drosophila melanogaster Gut Microbiota with Respect to Host Strain, Sex, and Age.

    Science.gov (United States)

    Han, Gangsik; Lee, Hyo Jung; Jeong, Sang Eun; Jeon, Che Ok; Hyun, Seogang

    2017-07-01

    Microbiota has a significant impact on the health of the host individual. The complexity of the interactions between mammalian hosts and their microbiota highlights the value of using Drosophila melanogaster as a model organism, because of its relatively simple microbial community and ease of physiological and genetic manipulation. However, highly variable and sometimes inconsistent results regarding the microbiota of D. melanogaster have been reported for host samples collected from different geographical locations; discrepancies that may be because of the inherent physiological conditions of the D. melanogaster host. Here, we conducted a comparative analysis of the gut microbiota of two D. melanogaster laboratory strains, w 1118 and Canton S, with respect to the sex and age of the host, by pyrosequencing of the 16S rRNA gene. In addition to the widespread and abundant commensal bacterial genera Lactobacillus and Acetobacter, we identified Enterococcus and Leuconostoc as major host-strain-specific bacterial genera. The relative proportions of these bacterial genera, and those of the species within each, were found to differ markedly with respect to strain, sex, and age of the host, even though host individuals were reared under the same nutritional conditions. By using various bioinformatic tools, we uncovered several characteristic features of microbiota corresponding to specific categories of the flies: host-sex-bias association of specific bacteria, age-dependent alteration of microbiota across host species and sex, and uniqueness of the microbiota of female w 1118 flies. Our results, thus, help to further our understanding of host-microbe interactions in the D. melanogaster model.

  8. Parallel Evolution of Copy-Number Variation across Continents in Drosophila melanogaster.

    Science.gov (United States)

    Schrider, Daniel R; Hahn, Matthew W; Begun, David J

    2016-05-01

    Genetic differentiation across populations that is maintained in the presence of gene flow is a hallmark of spatially varying selection. In Drosophila melanogaster, the latitudinal clines across the eastern coasts of Australia and North America appear to be examples of this type of selection, with recent studies showing that a substantial portion of the D. melanogaster genome exhibits allele frequency differentiation with respect to latitude on both continents. As of yet there has been no genome-wide examination of differentiated copy-number variants (CNVs) in these geographic regions, despite their potential importance for phenotypic variation in Drosophila and other taxa. Here, we present an analysis of geographic variation in CNVs in D. melanogaster. We also present the first genomic analysis of geographic variation for copy-number variation in the sister species, D. simulans, in order to investigate patterns of parallel evolution in these close relatives. In D. melanogaster we find hundreds of CNVs, many of which show parallel patterns of geographic variation on both continents, lending support to the idea that they are influenced by spatially varying selection. These findings support the idea that polymorphic CNVs contribute to local adaptation in D. melanogaster In contrast, we find very few CNVs in D. simulans that are geographically differentiated in parallel on both continents, consistent with earlier work suggesting that clinal patterns are weaker in this species. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Structural design of shield-integrated thin-wall vacuum vessel and manufacturing qualification tests for International Thermonuclear Experimental Reactor (ITER)

    International Nuclear Information System (INIS)

    Shimizu, Katsusuke; Shibui, Masanao; Koizumi, Koichi; Kanamori, Naokazu; Nishio, Satoshi; Sasaki, Takashi; Tada, Eisuke

    1992-09-01

    Conceptual design of shield-integrated thin-wall vacuum vessel has been done for ITER (International Thermonuclear Experimental Reactor). The vacuum vessel concept is based on a thin-double-wall structure, which consists of inner and outer plates and rib stiffeners. Internal shielding structures, which provide neutron irradiation shielding to protect TF coils, are set up between the inner plate and the outer plate of the vessel to avoid complexity of machine systems such as supporting systems of blanket modules. The vacuum vessel is assembled/disassembled by remote handling, so that welding joints are chosen as on-site joint method from reliability of mechanical strength. From a view point of assembling TF coils, the vacuum vessel is separated at the side of port, and is divided into 32 segments similar to the ITER-CDA reference design. Separatrix sweeping coils are located in the vacuum vessel to reduce heat fluxes onto divertor plates. Here, the coil structure and attachment to the vacuum vessel have been investigated. A sectorized saddle-loop coil is available for assembling and disassembling the coil. To support electromagnetic loads on the coils, they are attached to the groove in the vacuum vessel by welding. Flexible multi-plate supporting structure (compression-type gravity support), which was designed during CDA, is optimized by investigating buckling and frequency response properties, and concept on manufacturing and fabrication of the gravity support are proposed. Partial model of the vacuum vessel is manufactured for trial, so that fundamental data on welding and fabrication are obtained. From mechanical property tests of weldment and partial models, mechanical intensity and behaviors of the weldment are obtained. Informations on FEM-modeling are obtained by comparing analysis results with experimental results. (author)

  10. Catalysis of GTP hydrolysis by small GTPases at atomic detail by integration of X-ray crystallography, experimental, and theoretical IR spectroscopy.

    Science.gov (United States)

    Rudack, Till; Jenrich, Sarah; Brucker, Sven; Vetter, Ingrid R; Gerwert, Klaus; Kötting, Carsten

    2015-10-02

    Small GTPases regulate key processes in cells. Malfunction of their GTPase reaction by mutations is involved in severe diseases. Here, we compare the GTPase reaction of the slower hydrolyzing GTPase Ran with Ras. By combination of time-resolved FTIR difference spectroscopy and QM/MM simulations we elucidate that the Mg(2+) coordination by the phosphate groups, which varies largely among the x-ray structures, is the same for Ran and Ras. A new x-ray structure of a Ran·RanBD1 complex with improved resolution confirmed this finding and revealed a general problem with the refinement of Mg(2+) in GTPases. The Mg(2+) coordination is not responsible for the much slower GTPase reaction of Ran. Instead, the location of the Tyr-39 side chain of Ran between the γ-phosphate and Gln-69 prevents the optimal positioning of the attacking water molecule by the Gln-69 relative to the γ-phosphate. This is confirmed in the RanY39A·RanBD1 crystal structure. The QM/MM simulations provide IR spectra of the catalytic center, which agree very nicely with the experimental ones. The combination of both methods can correlate spectra with structure at atomic detail. For example the FTIR difference spectra of RasA18T and RanT25A mutants show that spectral differences are mainly due to the hydrogen bond of Thr-25 to the α-phosphate in Ran. By integration of x-ray structure analysis, experimental, and theoretical IR spectroscopy the catalytic center of the x-ray structural models are further refined to sub-Å resolution, allowing an improved understanding of catalysis. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Revealing the Effects of the Herbal Pair of Euphorbia kansui and Glycyrrhiza on Hepatocellular Carcinoma Ascites with Integrating Network Target Analysis and Experimental Validation.

    Science.gov (United States)

    Zhang, Yanqiong; Lin, Ya; Zhao, Haiyu; Guo, Qiuyan; Yan, Chen; Lin, Na

    2016-01-01

    Although the herbal pair of Euphorbia kansui (GS) and Glycyrrhiza (GC) is one of the so-called "eighteen antagonistic medicaments" in Chinese medicinal literature, it is prescribed in a classic Traditional Chinese Medicine (TCM) formula Gansui-Banxia-Tang for cancerous ascites, suggesting that GS and GC may exhibit synergistic or antagonistic effects in different combination designs. Here, we modeled the effects of GS/GC combination with a target interaction network and clarified the associations between the network topologies involving the drug targets and the drug combination effects. Moreover, the "edge-betweenness" values, which is defined as the frequency with which edges are placed on the shortest paths between all pairs of modules in network, were calculated, and the ADRB1-PIK3CG interaction exhibited the greatest edge-betweenness value, suggesting its crucial role in connecting the other edges in the network. Because ADRB1 and PIK3CG were putative targets of GS and GC, respectively, and both had functional interactions with AVPR2 approved as known therapeutic target for ascites, we proposed that the ADRB1-PIK3CG-AVPR2 signal axis might be involved in the effects of the GS-GC combination on ascites. This proposal was further experimentally validated in a H22 hepatocellular carcinoma (HCC) ascites model. Collectively, this systems-level investigation integrated drug target prediction and network analysis to reveal the combination principles of the herbal pair of GS and GC. Experimental validation in an in vivo system provided convincing evidence that different combination designs of GS and GC might result in synergistic or antagonistic effects on HCC ascites that might be partially related to their regulation of the ADRB1-PIK3CG-AVPR2 signal axis.

  12. Estudo experimental da influência das dimensões dos grânulos de hidroxiapatita na integração óssea Influence od dimensions of hydroxiapatite granules upon bone integration: an experimental study

    Directory of Open Access Journals (Sweden)

    Adriana Santos Barone Moreira

    2003-12-01

    Full Text Available Foi realizado estudo experimental em ratos Wistar para a avaliação da integração óssea dos grânulos de hidroxiapatita de diferentes tamanhos (212µ, 500µ e 1000µ. Os animais foram divididos em três grupos experimentais (dois grupos com 15 animais e um grupo com 25 animais e foram sacrificados com 30, 90 e 180 dias após a implantação da hidroxiapatita, que foi utilizada para o preenchimento de falha óssea produzida no fêmur. Dez animais formaram o grupo controle, cujo falha produzida no fêmur não foi preenchida com a HA. Os animais foram avaliados por meio de estudo radiológico e histológico, utilizando-se microscopia de luz para a avaliação da interface entre o tecido ósseo e a hidroxiapatita. Foi observado que os grânulos de hidroxiapatita utilizados para o preenchimento da falha óssea foram biocompatíveis e que a restauração da falha óssea ocorreu mais rapidamente nas falhas ósseas preenchidas com a HA que apresentava grânulos de menor diâmetro (212µ.This trial was performed in Wistar rats to evaluate bone integration of hydroxyapatite (HA granules of different sizes (212 µm, 500 µm, and 1000 µm. The animals were divided into three experimental groups, that is, two groups of 15 animals and one group of 25 animals, which were killed, respectively, 30, 90 and 180 days after the implantation of the hydroxyapatite employed to fill the bone defects produced in the rats' femurs. Additionally, a control group included ten rats whose induced femur defects were not filled with HA. All animals were radiologically and histologically examined by light microscopy, in order to evaluate the bone tissue / hydroxyapatite interface. It was seen that the hydroxyapatite granules employed to fill the bone defects were biocompatible and that the bone defect was restored faster in the bone defects filled with HA whose granules had smaller diameters (212 µm.

  13. N p n bipolar-junction-transistor detector with integrated p n p biasing transistor—feasibility study, design and first experimental results

    Science.gov (United States)

    Verzellesi, Giovanni; Bergamini, Davide; Dalla Betta, Gian-Franco; Piemonte, Claudio; Boscardin, Maurizio; Bosisio, Luciano; Bettarini, Stefano; Batignani, Giovanni

    2006-02-01

    We propose a novel n-p-n BJT radiation detector on high-resistivity silicon with integrated p-n-p transistor providing the quiescent base current of the detector. The dc operational limits of the proposed detector are analysed by means of numerical device simulations, pointing out that, by properly distancing the base of the p-n-p transistor from the emitter of the n-p-n detector, the latch-up of the parasitic thyristor embedded within the detector-plus-biasing-transistor structure takes place at relatively high current levels, where detector operation should anyway be avoided in order to prevent the associated current-gain loss. Numerical simulations provides insight about the bias dependence of charge-collection waveforms, indicating that minimization of the collecting time requires the detector quiescent current to be adjusted at the highest value still allowing high-injection effects to be avoided. A small-signal equivalent circuit of the proposed structure is also derived, allowing the impact of p-n-p biasing transistor and load resistance on the charge-collecting time constant to be evaluated. First experimental results show that fabricated structures are immune from the latch-up of the parasitic thyristor throughout their high-current-gain operating region and feature a minimum charge-collecting time constant of 35 µs, as tested by pulsed laser illumination.

  14. Study of the variation of the nuclear transcriptional map during de initial development of Drosophyla melanogaster embryos

    International Nuclear Information System (INIS)

    Alonso, C.E.V.

    1987-01-01

    The variation of nuclear transcriptional map during the initial development of Drosophyla melanogaster embryos were studied. Thermic treatment, chromatographic techniques and liquid scintilation in embryos inoculated with radioactive uridine were used. (L.J.C.)

  15. Absence of genotoxic activity from milk and water boiled in microwave oven in somatic cells from Drosophila melanogaster; Ausencia da atividade genotoxica do leite e agua, fervidos com microondas, em celulas somaticas de Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Cristina das Dores. E-mail: crisddias@yahoo.com.br

    2003-07-01

    This paper reports an experiment for evaluation of the possible genotoxic effects of food prepared in a microwave oven, through the mutation test and somatic recombination, in wings of Drosophila melanogaster. Two crossing have been performed: a standard cross-ST and a high bioactivation cross - HB resulting in marked trans -heterozygote descendents (MH) and balanced heterozygotes (BH). The 72 hours larvas were fed with water and milk boiled both in the microwave oven and in the traditional way. The MH individual wings were analyzed, where the spots can be induced either by mutation or mitotic recombination. The experiment presented negative results related to the genotoxic effects of the water and milk boiled using the microwave oven, in MH descendents of both crossing. Therefore, under these experimental conditions, genotoxic activity were not presented by milk and water boiled in the microwave oven. However, an extensive study using different techniques is necessary to investigate the action of the food prepared in the microwave oven on the genetic material.

  16. Pseudomonas aeruginosa RhlR is required to neutralize the cellular immune response in a Drosophila melanogaster oral infection model

    OpenAIRE

    Limmer, Stefanie; Haller, Samantha; Drenkard, Eliana; Lee, Janice; Yu, Shen; Kocks, Christine; Ausubel, Frederick M.; Ferrandon, Dominique

    2011-01-01

    An in-depth mechanistic understanding of microbial infection necessitates a molecular dissection of host–pathogen relationships. Both Drosophila melanogaster and Pseudomonas aeruginosa have been intensively studied. Here, we analyze the infection of D. melanogaster by P. aeruginosa by using mutants in both host and pathogen. We show that orally ingested P. aeruginosa crosses the intestinal barrier and then proliferates in the hemolymph, thereby causing the infected flies to die of bacteremia....

  17. Effects of acclimation temperature on thermal tolerance and membrane phospholipid composition in the fruit fly Drosophila melanogaster

    DEFF Research Database (Denmark)

    Overgaard, Johannes; Tomcala, Ales; Sørensen, Jesper G

    2008-01-01

    and the composition of membrane GPLs in adult Drosophila melanogaster. Long-term cold survival was significantly improved by low acclimation temperature. After 60h at 0 degrees C, more than 80% of the 15 degrees C-acclimated flies survived while none of the 25 degrees C-acclimated flies survived. Cold shock tolerance...... acclimation temperature and correlated with the changes in GPL composition in membranes of adult D. melanogaster. Udgivelsesdato: 2008-Mar...

  18. Sequential gene activation by ecdysone in Drosophila melanogaster: the hierarchical equivalence of early and early late genes.

    Science.gov (United States)

    Huet, F; Ruiz, C; Richards, G

    1995-04-01

    Ecdysteroids are key regulators of insect development. In Drosophila melanogaster the late larval response to ecdysone is characterised by a precise sequential activation of members of the superfamily of nuclear receptors (DHR3, DHR39, EcR, E75, E78, FTZ-F1, usp). Many of these genes are localised in the polytene chromosome puffs of the salivary gland previously classified as intermoult, early or early-late puff loci. Ashburner et al. (Ashburner, M., Chihara, C., Meltzer, P. and Richards, G. (1974) Cold Spring Harbour Symp. Quant. Biol. 38, 655-662) proposed a formal model describing interactions between ecdysone, its receptor and the early and late puffs during this ecdysone response. To integrate transcripts from the intermoult and early-late puffs into this model, we have used a micro RT-PCR assay to study their hormonal regulation using salivary gland culture protocols first used in the puffing analyses. We show that transcripts from certain early-late puffs are induced in parallel with the early transcripts and are thus hierarchically equivalent. In vivo the profile of the increase in hormone titre, the sensitivity of different promoters to hormone and the rate of transcript accumulation must contribute to the temporal differences in expression observed between these two classes.

  19. Drosophila melanogaster dHCF interacts with both PcG and TrxG epigenetic regulators.

    Directory of Open Access Journals (Sweden)

    Sara Rodriguez-Jato

    Full Text Available Repression and activation of gene transcription involves multiprotein complexes that modify chromatin structure. The integration of these complexes at regulatory sites can be assisted by co-factors that link them to DNA-bound transcriptional regulators. In humans, one such co-factor is the herpes simplex virus host-cell factor 1 (HCF-1, which is implicated in both activation and repression of transcription. We show here that disruption of the gene encoding the Drosophila melanogaster homolog of HCF-1, dHCF, leads to a pleiotropic phenotype involving lethality, sterility, small size, apoptosis, and morphological defects. In Drosophila, repressed and activated transcriptional states of cell fate-determining genes are maintained throughout development by Polycomb Group (PcG and Trithorax Group (TrxG genes, respectively. dHCF mutant flies display morphological phenotypes typical of TrxG mutants and dHCF interacts genetically with both PcG and TrxG genes. Thus, dHCF inactivation enhances the mutant phenotypes of the Pc PcG as well as brm and mor TrxG genes, suggesting that dHCF possesses Enhancer of TrxG and PcG (ETP properties. Additionally, dHCF interacts with the previously established ETP gene skd. These pleiotropic phenotypes are consistent with broad roles for dHCF in both activation and repression of transcription during fly development.

  20. Non-invasive red light optogenetic pacing and optical coherence microscopy (OCM) imaging for drosophila melanogaster (Conference Presentation)

    Science.gov (United States)

    Men, Jing; Li, Airong; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

    2017-02-01

    Cardiac pacing could be a powerful tool for investigating mammalian cardiac electrical conduction systems as well as for treatment of certain cardiac pathologies. However, traditional electrical pacing using pacemaker requires an invasive surgical procedure. Electrical currents from the implanted electrodes can also cause damage to heart tissue, further restricting its utility. Optogenetic pacing has been developed as a promising, non-invasive alternative to electrical stimulation for controlling animal heart rhythms. It induces heart contractions by shining pulsed light on transgene-generated microbial opsins, which in turn activate the light gated ion channels in animal hearts. However, commonly used opsins in optogenetic pacing, such as channelrhodopsin-2 (ChR2), require short light wavelength stimulation (475 nm), which is strongly absorbed and scattered by tissue. Here, we performed optogenetic pacing by expression of recently engineered red-shifted microbial opsins, ReaChR and CsChrimson, in a well-established animal model, Drosophila melanogaster, using the 617 nm stimulation light pulses. The OCM technique enables non-invasive optical imaging of animal hearts with high speed and ultrahigh axial and transverse resolutions. We integrated a customized OCM system with the optical stimulation system to monitor the optogenetic pacing noninvasively. The use of red-sifted opsins enabled deeper penetration of simulating light at lower power, which is promising for applications of optogenetic pacing in mammalian cardiac pathology studies or clinical treatments in the future.

  1. Tests for the replication of an association between Egfr and natural variation in Drosophila melanogaster wing morphology

    Directory of Open Access Journals (Sweden)

    Dodgson James

    2005-08-01

    Full Text Available Abstract Background Quantitative differences between individuals stem from a combination of genetic and environmental factors, with the heritable variation being shaped by evolutionary forces. Drosophila wing shape has emerged as an attractive system for genetic dissection of multi-dimensional traits. We utilize several experimental genetic methods to validation of the contribution of several polymorphisms in the Epidermal growth factor receptor (Egfr gene to wing shape and size, that were previously mapped in populations of Drosophila melanogaster from North Carolina (NC and California (CA. This re-evaluation utilized different genetic testcrosses to generate heterozygous individuals with a variety of genetic backgrounds as well as sampling of new alleles from Kenyan stocks. Results Only one variant, in the Egfr promoter, had replicable effects in all new experiments. However, expanded genotyping of the initial sample of inbred lines rendered the association non-significant in the CA population, while it persisted in the NC sample, suggesting population specific modification of the quantitative trait nucleotide QTN effect. Conclusion Dissection of quantitative trait variation to the nucleotide level can identify sites with replicable effects as small as one percent of the segregating genetic variation. However, the testcross approach to validate QTNs is both labor intensive and time-consuming, and is probably less useful than resampling of large independent sets of outbred individuals.

  2. The NF-kB like factor DIF has weaker effects on Drosophila melanogaster immune defenses than previously thought.

    Science.gov (United States)

    Le Bourg, Eric

    2011-08-01

    The Toll pathway of Drosophila melanogaster, when activated by the Beauveria bassiana fungus, directs the expression of the drosomycin and metchnikowin antimicrobial peptide genes by inducing the translocation into the nucleus of the DIF transcription factor. Accordingly, DIF mutants have been reported to have a lower resistance to fungi than control flies. However, as the longevity of non-infected DIF flies has not been measured in previous studies, it could be that survival times after infection are constrained by a low longevity. In the present study, DIF flies reared in conditions similar to those used in these previous studies had much lower survival time after infection than the control flies, but the longevity of non-infected DIF flies was also very low. Using rearing conditions controlling larval crowding, age of parents and mating status of experimental flies increased longevity of non-infected flies and survival time after infection in both strains. However, DIF flies had a similar survival time after infection as control ones or a slightly lower one, which shows that the effect of DIF is weaker than previously thought.

  3. Absence of genotoxic activity from milk and water boiled in microwave oven in somatic cells from Drosophila melanogaster

    International Nuclear Information System (INIS)

    Dias, Cristina das Dores.

    2003-01-01

    This paper reports an experiment for evaluation of the possible genotoxic effects of food prepared in a microwave oven, through the mutation test and somatic recombination, in wings of Drosophila melanogaster. Two crossing have been performed: a standard cross-ST and a high bioactivation cross - HB resulting in marked trans -heterozygote descendents (MH) and balanced heterozygotes (BH). The 72 hours larvas were fed with water and milk boiled both in the microwave oven and in the traditional way. The MH individual wings were analyzed, where the spots can be induced either by mutation or mitotic recombination. The experiment presented negative results related to the genotoxic effects of the water and milk boiled using the microwave oven, in MH descendents of both crossing. Therefore, under these experimental conditions, genotoxic activity were not presented by milk and water boiled in the microwave oven. However, an extensive study using different techniques is necessary to investigate the action of the food prepared in the microwave oven on the genetic material

  4. Modulatory effect of Byrsonima verbascifolia (Malpighiaceae) against damage induced by doxorubicin in somatic cells of Drosophila melanogaster.

    Science.gov (United States)

    Mendanha, D M; Ferreira, H D; Felício, L P; Silva, E M; Pereira, D G; Nunes, W B; Carvalho, S

    2010-01-01

    Byrsonima verbascifolia, popularly known in Brazil as murici, is a medicinal plant widely used in the treatment of bacterial and viral infections, Chagas's disease, diarrhea, bronchitis, cough and fever, as well as for protection of the intestinal mucosa. Since chemotherapy and radiotherapy, broadly employed in the treatment of cancer, can have undesirable side effects, such as inducing DNA damage in normal cells, it would be useful to investigate compounds that inhibit or reduce these effects. A lyophilized water extract of murici, used at three different concentrations (25, 50, and 100 mg/mL), was tested to determine if it could reduce damage induced by the antineoplastic compound doxorubicin in somatic cells of Drosophila melanogaster, analyzed by SMART/wing. The frequency of mutant spots in descendants from standard and high bioactivation crosses was significantly reduced by treatment with murici extract. Further studies are needed using other experimental models, to determine if murici has the potential to be employed by cancer patients receiving chemotherapy.

  5. Non-Mendelian Dominant Maternal Effects Caused by CRISPR/Cas9 Transgenic Components in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Chun-Chieh Lin

    2016-11-01

    Full Text Available The CRISPR/Cas9 system has revolutionized genomic editing. The Cas9 endonuclease targets DNA via an experimentally determined guide RNA (gRNA. This results in a double-strand break at the target site . We generated transgenic Drosophila melanogaster in which the CRISPR/Cas9 system was used to target a GAL4 transgene in vivo. To our surprise, progeny whose genomes did not contain CRISPR/Cas9 components were still capable of mutating GAL4 sequences. We demonstrate this effect was caused by maternal deposition of Cas9 and gRNAs into the embryo, leading to extensive GAL4 mutations in both somatic and germline tissues. This serves as a cautionary observation on the effects of maternal contributions when conducting experiments using genomically encoded CRISPR/Cas9 components. These results also highlight a mode of artificial inheritance in which maternal contributions of DNA editing components lead to transmissible mutant defects even in animals whose genomes lack the editing components. We suggest calling this a dominant maternal effect to reflect it is caused by the gain of maternally contributed products. Models of CRISPR-mediated gene drive will need to incorporate dominant maternal effects in order to accurately predict the efficiency and dynamics of gene drive in a population.

  6. High Throughput Measurement of Locomotor Sensitization to Volatilized Cocaine in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Ana Filošević

    2018-02-01

    Full Text Available Drosophila melanogaster can be used to identify genes with novel functional roles in neuronal plasticity induced by repeated consumption of addictive drugs. Behavioral sensitization is a relatively simple behavioral output of plastic changes that occur in the brain after repeated exposures to drugs of abuse. The development of screening procedures for genes that control behavioral sensitization has stalled due to a lack of high-throughput behavioral tests that can be used in genetically tractable organism, such as Drosophila. We have developed a new behavioral test, FlyBong, which combines delivery of volatilized cocaine (vCOC to individually housed flies with objective quantification of their locomotor activity. There are two main advantages of FlyBong: it is high-throughput and it allows for comparisons of locomotor activity of individual flies before and after single or multiple exposures. At the population level, exposure to vCOC leads to transient and concentration-dependent increase in locomotor activity, representing sensitivity to an acute dose. A second exposure leads to further increase in locomotion, representing locomotor sensitization. We validate FlyBong by showing that locomotor sensitization at either the population or individual level is absent in the mutants for circadian genes period (per, Clock (Clk, and cycle (cyc. The locomotor sensitization that is present in timeless (tim and pigment dispersing factor (pdf mutant flies is in large part not cocaine specific, but derived from increased sensitivity to warm air. Circadian genes are not only integral part of the neural mechanism that is required for development of locomotor sensitization, but in addition, they modulate the intensity of locomotor sensitization as a function of the time of day. Motor-activating effects of cocaine are sexually dimorphic and require a functional dopaminergic transporter. FlyBong is a new and improved method for inducing and measuring locomotor

  7. Incompatibility between X chromosome factor and pericentric heterochromatic region causes lethality in hybrids between Drosophila melanogaster and its sibling species.

    Science.gov (United States)

    Cattani, M Victoria; Presgraves, Daven C

    2012-06-01

    The Dobzhansky-Muller model posits that postzygotic reproductive isolation results from the evolution of incompatible epistatic interactions between species: alleles that function in the genetic background of one species can cause sterility or lethality in the genetic background of another species. Progress in identifying and characterizing factors involved in postzygotic isolation in Drosophila has remained slow, mainly because Drosophila melanogaster, with all of its genetic tools, forms dead or sterile hybrids when crossed to its sister species, D. simulans, D. sechellia, and D. mauritiana. To circumvent this problem, we used chromosome deletions and duplications from D. melanogaster to map two hybrid incompatibility loci in F(1) hybrids with its sister species. We mapped a recessive factor to the pericentromeric heterochromatin of the X chromosome in D. simulans and D. mauritiana, which we call heterochromatin hybrid lethal (hhl), which causes lethality in F(1) hybrid females with D. melanogaster. As F(1) hybrid males hemizygous for a D. mauritiana (or D. simulans) X chromosome are viable, the lethality of deficiency hybrid females implies that a dominant incompatible partner locus exists on the D. melanogaster X. Using small segments of the D. melanogaster X chromosome duplicated onto the Y chromosome, we mapped a dominant factor that causes hybrid lethality to a small 24-gene region of the D. melanogaster X. We provide evidence suggesting that it interacts with hhl(mau). The location of hhl is consistent with the emerging theme that hybrid incompatibilities in Drosophila involve heterochromatic regions and factors that interact with the heterochromatin.

  8. Implementation of integration strategies between primary care units and a regional general hospital in Brazil to update and connect health care professionals: a quasi-experimental study protocol.

    Science.gov (United States)

    Bracco, Mario Maia; Mafra, Ana Carolina Cintra Nunes; Abdo, Alexandre Hannud; Colugnati, Fernando Antonio Basile; Dalla, Marcello Dala Bernardina; Demarzo, Marcelo Marcos Piva; Abrahamsohn, Ises; Rodrigues, Aline Pacífico; Delgado, Ana Violeta Ferreira de Almeida; Dos Prazeres, Glauber Alves; Teixeira, José Carlos; Possa, Silvio

    2016-08-12

    Better communication among field health care teams and points of care, together with investments focused on improving teamwork, individual management, and clinical skills, are strategies for achieving better outcomes in patient-oriented care. This research aims to implement and evaluate interventions focused on improving communication and knowledge among health teams based on points of care in a regional public health outreach network, assessing the following hypotheses: 1) A better-working communication process between hospitals and primary health care providers can improve the sharing of information on patients as well as patients' outcomes. 2) A skill-upgrading education tool offered to health providers at their work sites can improve patients' care and outcomes. A quasi-experimental study protocol with a mixed-methods approach (quantitative and qualitative) was developed to evaluate communication tools for health care professionals based in primary care units and in a general hospital in the southern region of São Paulo City, Brazil. The usefulness and implementation processes of the integration strategies will be evaluated, considering: 1) An Internet-based communication platform that facilitates continuity and integrality of care to patients, and 2) A tailored updating distance-learning course on ambulatory care sensitive conditions for clinical skills improvements. The observational study will evaluate a non-randomized cohort of adult patients, with historical controls. Hospitalized patients diagnosed with an ambulatory care sensitive condition will be selected and followed for 1 year after hospital discharge. Data will be collected using validated questionnaires and from patients' medical records. Health care professionals will be evaluated related to their use of education and communication tools and their demographic and psychological profiles. The primary outcome measured will be the patients' 30-day hospital readmission rates. A sample size of 560

  9. Data Integration and Applications of Functional Gene Networks in Drosophila Melanogaster

    Science.gov (United States)

    Costello, James Christopher

    2009-01-01

    Understanding the function of every gene in the genome is a central goal in the biological sciences. This includes full characterization of a genes phenotypic effects, molecular interactions, the evolutionary forces that shape its function(s), and how these functions interrelate. Despite a long history and considerable effort to understand all…

  10. Mastitomics, the integrated omics of bovine milk in an experimental model of Streptococcus uberis mastitis: 2. Label-free relative quantitative proteomics.

    Science.gov (United States)

    Mudaliar, Manikhandan; Tassi, Riccardo; Thomas, Funmilola C; McNeilly, Tom N; Weidt, Stefan K; McLaughlin, Mark; Wilson, David; Burchmore, Richard; Herzyk, Pawel; Eckersall, P David; Zadoks, Ruth N

    2016-08-16

    Mastitis, inflammation of the mammary gland, is the most common and costly disease of dairy cattle in the western world. It is primarily caused by bacteria, with Streptococcus uberis as one of the most prevalent causative agents. To characterize the proteome during Streptococcus uberis mastitis, an experimentally induced model of intramammary infection was used. Milk whey samples obtained from 6 cows at 6 time points were processed using label-free relative quantitative proteomics. This proteomic analysis complements clinical, bacteriological and immunological studies as well as peptidomic and metabolomic analysis of the same challenge model. A total of 2552 non-redundant bovine peptides were identified, and from these, 570 bovine proteins were quantified. Hierarchical cluster analysis and principal component analysis showed clear clustering of results by stage of infection, with similarities between pre-infection and resolution stages (0 and 312 h post challenge), early infection stages (36 and 42 h post challenge) and late infection stages (57 and 81 h post challenge). Ingenuity pathway analysis identified upregulation of acute phase protein pathways over the course of infection, with dominance of different acute phase proteins at different time points based on differential expression analysis. Antimicrobial peptides, notably cathelicidins and peptidoglycan recognition protein, were upregulated at all time points post challenge and peaked at 57 h, which coincided with 10 000-fold decrease in average bacterial counts. The integration of clinical, bacteriological, immunological and quantitative proteomics and other-omic data provides a more detailed systems level view of the host response to mastitis than has been achieved previously.

  11. Evaluation of the mutagenic potential of Cochlospermum regium in Drosophila melanogaster male germ cells

    Directory of Open Access Journals (Sweden)

    Nunes Wanderlene Blanco

    2003-01-01

    Full Text Available During the last few decades the search for medical treatments based on alternative medicine has increased significantly, making knowledge of the plants commonly used as folk medicines extremely important. The plant Cochlospermum regium, a member of the Cochlospermaceae found in the Brazilian cerrado (a type of savanna, is known to have high depurative activity and to be effective not only in treating skin problems such as pimples, boils and blotches but also in curing gastritis and ulcers. We prepared aqueous extracts using 13, 19 and 25 gL-1 of dried C. regium root and investigated these extracts for possible mutagenic effects on Drosophila melanogaster germ cells. Mutagenesis was assessed using the ring-X loss (RXL test which can detect chromosome mosaicism, partial loss of the ring X chromosome and chromosome non-disjunction. Our results showed that at the concentrations tested C. regium extracts did not induce ring-X loss in D. melanogaster.

  12. Simulating Evolution of Drosophila melanogaster Ebony Mutants Using a Genetic Algorithm

    DEFF Research Database (Denmark)

    Helles, Glennie

    2009-01-01

    Genetic algorithms are generally quite easy to understand and work with, and they are a popular choice in many cases. One area in which genetic algorithms are widely and successfully used is artificial life where they are used to simulate evolution of artificial creatures. However, despite...... their suggestive name, simplicity and popularity in artificial life, they do not seem to have gained a footing within the field of population genetics to simulate evolution of real organisms --- possibly because genetic algorithms are based on a rather crude simplification of the evolutionary mechanisms known...... today. However, in this paper we report how a standard genetic algorithm is used to successfully simulate evolution of ebony mutants in a population of Drosophila melanogaster (D.melanogaster). The results show a remarkable resemblance to the evolution observed in real biological experiments with ebony...

  13. Structure of glutaminyl cyclase from Drosophila melanogaster in space group I4

    International Nuclear Information System (INIS)

    Kolenko, Petr; Koch, Birgit; Rahfeld, Jens-Ulrich; Schilling, Stephan; Demuth, Hans-Ulrich; Stubbs, Milton T.

    2013-01-01

    The structure of ligand-free glutaminyl cyclase from D. melanogaster has been determined in a novel crystal form belonging to space group I4. The structure of ligand-free glutaminyl cyclase (QC) from Drosophila melanogaster (DmQC) has been determined in a novel crystal form. The protein crystallized in space group I4, with unit-cell parameters a = b = 122.3, c = 72.7 Å. The crystal diffracted to a resolution of 2 Å at the home source. The structure was solved by molecular replacement and was refined to an R factor of 0.169. DmQC exhibits a typical α/β-hydrolase fold. The electron density of three monosaccharides could be localized. The accessibility of the active site will facilitate structural studies of novel inhibitor-binding modes

  14. Starvation-Induced Dietary Behaviour in Drosophila melanogaster Larvae and Adults.

    Science.gov (United States)

    Ahmad, Muhammad; Chaudhary, Safee Ullah; Afzal, Ahmed Jawaad; Tariq, Muhammad

    2015-09-24

    Drosophila melanogaster larvae are classified as herbivores and known to feed on non-carnivorous diet under normal conditions. However, when nutritionally challenged these larvae exhibit cannibalistic behaviour by consuming a diet composed of larger conspecifics. Herein, we report that cannibalism in Drosophila larvae is confined not only to scavenging on conspecifics that are larger in size, but also on their eggs. Moreover, such cannibalistic larvae develop as normally as those grown on standard cornmeal medium. When stressed, Drosophila melanogaster larvae can also consume a carnivorous diet derived from carcasses of organisms belonging to diverse taxonomic groups, including Musca domestica, Apis mellifera, and Lycosidae sp. While adults are ill-equipped to devour conspecific carcasses, they selectively oviposit on them and also consume damaged cadavers of conspecifics. Thus, our results suggest that nutritionally stressed Drosophila show distinct as well as unusual feeding behaviours that can be classified as detritivorous, cannibalistic and/or carnivorous.

  15. The mechanisms underlying α-amanitin resistance in Drosophila melanogaster: a microarray analysis.

    Directory of Open Access Journals (Sweden)

    Chelsea L Mitchell

    Full Text Available The rapid evolution of toxin resistance in animals has important consequences for the ecology of species and our economy. Pesticide resistance in insects has been a subject of intensive study; however, very little is known about how Drosophila species became resistant to natural toxins with ecological relevance, such as α-amanitin that is produced in deadly poisonous mushrooms. Here we performed a microarray study to elucidate the genes, chromosomal loci, molecular functions, biological processes, and cellular components that contribute to the α-amanitin resistance phenotype in Drosophila melanogaster. We suggest that toxin entry blockage through the cuticle, phase I and II detoxification, sequestration in lipid particles, and proteolytic cleavage of α-amanitin contribute in concert to this quantitative trait. We speculate that the resistance to mushroom toxins in D. melanogaster and perhaps in mycophagous Drosophila species has evolved as cross-resistance to pesticides, other xenobiotic substances, or environmental stress factors.

  16. Functional Characterization of CCHamide and Muscarinic Acetylcholine Receptor Signalling in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Ren, Guilin Robin

    G-protein coupled receptors (GPCRs) constitute a large and ancient superfamily of membraneproteins responsible for the transduction of extracellular signals to the inside of the cells. In thisPh.D. thesis, Drosophila melanogaster (Dm) was used as a model organism to investigate a numberof topics...... is a newly discovered insect peptide hormone. The function of this novel peptide hasnot been well characterised. In this Ph.D. thesis, I identified CCHamide-2 peptides in endocrinecells of the gut and neurones of the brain of larvae and endocrine cells of the gut of adultDrosophila. Behavioural assays...... little is known about muscarinic acetylcholine receptorsignalling in insects. In this study, I found that two types of mAChRs occur in D. melanogaster, onecoupling to Gq (A-type) and the other to Gi (B-type). Both A- and B-type Dm-mAChRs can beactivated by acetylcholine (ACh), but the classical...

  17. Integration des sciences et de la langue: Creation et experimentation d'un modele pedagogique pour ameliorer l'apprentissage des sciences en milieu francophone minoritaire

    Science.gov (United States)

    Cormier, Marianne

    Les faibles resultats en sciences des eleves du milieu francophone minoritaire, lors d'epreuves au plan national et international, ont interpelle la recherche de solutions. Cette these avait pour but de creer et d'experimenter un modele pedagogique pour l'enseignement des sciences en milieu linguistique minoritaire. En raison de la presence de divers degres de francite chez la clientele scolaire de ce milieu, plusieurs elements langagiers (l'ecriture, la discussion et la lecture) ont ete integres a l'apprentissage scientifique. Nous avions recommande de commencer le processus d'apprentissage avec des elements langagiers plutot informels (redaction dans un journal, discussions en dyades...) pour progresser vers des activites langagieres plus formelles (redaction de rapports ou d'explications scientifiques). En ce qui a trait a l'apprentissage scientifique, le modele preconisait une demarche d'evolution conceptuelle d'inspiration socio-constructiviste tout en s'appuyant fortement sur l'apprentissage experientiel. Lors de l'experimentation du modele, nous voulions savoir si celui-ci provoquait une evolution conceptuelle chez les eleves, et si, simultanement, le vocabulaire scientifique de ces derniers s'enrichissait. Par ailleurs, nous cherchions a comprendre comment les eleves vivaient leurs apprentissages dans le cadre de ce modele pedagogique. Une classe de cinquieme annee de l'ecole de Grande-Digue, dans le Sud-est du Nouveau-Brunswick, a participe a la mise a l'essai du modele en etudiant les marais sales locaux. Lors d'entrevues initiales, nous avons remarque que les connaissances des eleves au sujet des marais sales etaient limitees. En effet, s'ils etaient conscients que les marais etaient des lieux naturels, ils ne pouvaient pas necessairement les decrire avec precision. Nous avons egalement constate que les eleves utilisaient surtout des mots communs (plantes, oiseaux, insectes) pour decrire le marais. Les resultats obtenus indiquent que les eleves ont

  18. Reduced learning ability as a consequence of evolutionary adaptation to nutritional stress in Drosophila melanogaster

    OpenAIRE

    Kolss, M.; Kawecki, T. J.

    2008-01-01

    Abstract. 1. Dietary conditions affect cognitive abilities of many species, but it is unclear to what extent this physiological effect translates into an evolutionary relationship.2. A reduction of competitive ability under nutritional stress has been reported as a correlated response to selection for learning ability in Drosophila melanogaster. Here we test whether the reverse holds as well, i.e. whether an evolutionary adaptation to poor food conditions leads to a decrease in learning capac...

  19. Related male Drosophila melanogaster reared together as larvae fight less and sire longer lived daughters

    OpenAIRE

    Carazo, Pau; Perry, Jennifer C; Johnson, Fern; Pizzari, Tommaso; Wigby, Stuart

    2015-01-01

    Competition over access to reproductive opportunities can lead males to harm females. However, recent work has shown that, in Drosophila melanogaster, male competition and male harm of females are both reduced under conditions simulating male-specific population viscosity (i.e., in groups where males are related and reared with each other as larvae). Here, we seek to replicate these findings and investigate whether male population viscosity can have repercussions for the fitness of offspring ...

  20. Surface Display of Recombinant Drosophila melanogaster Acetylcholinesterase for Detection of Organic Phosphorus and Carbamate Pesticides

    OpenAIRE

    Li, Jingquan; Qian Ba,; Yin, Jun; Wu, Songjie; Zhuan, Fangfang; Xu, Songci; Li, Junyang; Salazar, Joelle K.; Zhang, Wei; Wang, Hui

    2013-01-01

    Acetylcholinesterase (AChE) is commonly used for the detection of organophosphate (OP) and carbamate (CB) insecticides. However, the cost of this commercially available enzyme is high, making high-throughput insecticide detection improbable. In this study we constructed a new AChE yeast expression system in Saccharomyces cerevisiae for the expression of a highly reactive recombinant AChE originating from Drosophila melanogaster (DmAChE). Specifically, the coding sequence of DmAChE was fused w...