Human uracil DNA N-glycosidase: studies in normal and repair defective cultured fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Kuhnlein, U; Lee, B; Linn, S

1978-01-01

Uracil DNA N-glycosidase, an enzyme which participates in the excision of uracil from DNA, was measured in extracts from fibroblast lines cultured from normal subjects, from several subjects with the genetic disease xeroderma pigmentosum, and from a subject with ataxia telangiectasia. The cell lines representative of complementation groups A and D of xeroderma pigmentosum and of ataxia telangiectasia had roughly the same level of activity as did the normal cells. On the other hand, cells from two xeroderma pigmentosum variants (XP4BE and XP13BE) had roughly half the normal level of activity, and cells from the heterozygous mother of XP4BE had an intermediate level of activity. In spite of these quantitative differences, no systematic alterations in reaction characteristics, apparent K/sub m/ for substrate, or purification characteristics were noted for enzyme from any of the lines. Thus a causal relationship, if any, between levels of activity and the disease symptoms is equivocal.

Thermosensitive mutant of Bacillus subtilis deficient in uracil and cell division

Energy Technology Data Exchange (ETDEWEB)

Nagai, K; Some, H; Tamura, G

1976-01-01

Thermonsensitive division mutants were derived from Bacillus subtilis Marburg 168 thy trp/sub 2/ by means of membrane filtration after nitrosoguanidine mutagenesis. Among them, ts42 requiring uracil for normal growth at 48/sup 0/C was investigated. In the absence of uracil, the mutant cells grew normally at 37/sup 0/C and stopped dividing after temperature shift to 48/sup 0/C resulting in filaments of two to four times length of normal rods. The total cell number after the temperature shift increased two to three fold in 90 min and remained constant thereafter. The viable count after the temperature shift to 48/sup 0/C, increased 1.5 to 2 fold in initial 60 min and then decreased exponentially. A rapid restoration of colony forming ability was shown when the mutant cells were shifted back to the permissive temperature after 120 to 180 min of incubation at 48/sup 0/C or when uracil was introduced to the culture at 48/sup 0/C. This recovery of viability was partly observed even in the presence of chloramphenicol. The synthesis of RNA of this mutant was shown to decline 20 min after the temperature shift to 48/sup 0/C whereas the syntheses of DNA and protein proceeded for more than 80 min at that temperature. No newly isolated uracil requiring mutants formed filaments in the medium lacking uracil or showed growth pattern like ts42.

Isolation and characterization of the human uracil DNA glycosylase gene

International Nuclear Information System (INIS)

Vollberg, T.M.; Siegler, K.M.; Cool, B.L.; Sirover, M.A.

1989-01-01

A series of anti-human placental uracil DNA glycosylase monoclonal antibodies was used to screen a human placental cDNA library in phage λgt11. Twenty-seven immunopositive plaques were detected and purified. One clone containing a 1.2-kilobase (kb) human cDNA insert was chosen for further study by insertion into pUC8. The resultant recombinant plasmid selected by hybridization a human placental mRNA that encoded a 37-kDa polypeptide. This protein was immunoprecipitated specifically by an anti-human placenta uracil DNA glycosylase monoclonal antibody. RNA blot-hybridization (Northern) analysis using placental poly(A) + RNA or total RNA from four different human fibroblast cell strains revealed a single 1.6-kb transcript. Genomic blots using DNA from each cell strain digested with either EcoRI or PstI revealed a complex pattern of cDNA-hydridizing restriction fragments. The genomic analysis for each enzyme was highly similar in all four human cell strains. In contrast, a single band was observed when genomic analysis was performed with the identical DNA digests with an actin gene probe. During cell proliferation there was an increase in the level of glycosylase mRNA that paralleled the increase in uracil DNA glycosylase enzyme activity. The isolation of the human uracil DNA glycosylase gene permits an examination of the structure, organization, and expression of a human DNA repair gene

Compartmentalized self-replication (CSR) selection of Thermococcus litoralis Sh1B DNA polymerase for diminished uracil binding.

Science.gov (United States)

Tubeleviciute, Agne; Skirgaila, Remigijus

2010-08-01

The thermostable archaeal DNA polymerase Sh1B from Thermococcus litoralis has a typical uracil-binding pocket, which in nature plays an essential role in preventing the accumulation of mutations caused by cytosine deamination to uracil and subsequent G-C base pair transition to A-T during the genomic DNA replication. The uracil-binding pocket recognizes and binds uracil base in a template strand trapping the polymerase. Since DNA replication stops, the repair systems have a chance to correct the promutagenic event. Archaeal family B DNA polymerases are employed in various PCR applications. Contrary to nature, in PCR the uracil-binding property of archaeal polymerases is disadvantageous and results in decreased DNA amplification yields and lowered sensitivity. Furthermore, in diagnostics qPCR, RT-qPCR and end-point PCR are performed using dNTP mixtures, where dTTP is partially or fully replaced by dUTP. Uracil-DNA glycosylase treatment and subsequent heating of the samples is used to degrade the DNA containing uracil and prevent carryover contamination, which is the main concern in diagnostic laboratories. A thermostable archaeal DNA polymerase with the abolished uracil binding would be a highly desirable and commercially interesting product. An attempt to disable uracil binding in DNA polymerase Sh1B from T. litoralis by generating site-specific mutants did not yield satisfactory results. However, a combination of random mutagenesis of the whole polymerase gene and compartmentalized self-replication was successfully used to select variants of thermostable Sh1B polymerase capable of performing PCR with dUTP instead of dTTP.

A mutant Pfu DNA polymerase designed for advanced uracil-excision DNA engineering.

Science.gov (United States)

Nørholm, Morten H H

2010-03-16

The combined use of restriction enzymes with PCR has revolutionized molecular cloning, but is inherently restricted by the content of the manipulated DNA sequences. Uracil-excision based cloning is ligase and sequence independent and allows seamless fusion of multiple DNA sequences in simple one-tube reactions, with higher accuracy than overlapping PCR. Here, the addition of a highly efficient DNA polymerase and a low-background-, large-insertion- compatible site-directed mutagenesis protocol is described, largely expanding the versatility of uracil-excision DNA engineering. The different uracil-excision based molecular tools that have been developed in an open-source fashion, constitute a comprehensive, yet simple and inexpensive toolkit for any need in molecular cloning.

Escherichia coli-Derived Uracil Increases the Antibacterial Activity and Growth Rate of Lactobacillus plantarum.

Science.gov (United States)

Ha, Eun-Mi

2016-05-28

Lactobacillus plantarum (L. plantarum) is a representative probiotic. In particular, L. plantarum is the first commensal bacterium to colonize the intestine of infants. For this reason, the initial settlement of L. plantarum can play an important role in determining an infant's health as well as their eventual health status as an adult. In addition, L. plantarum combats pathogenic infections (such as Escherichia coli (E. coli), one of the early pathogenic colonizers in an unhealthy infant gut) by secreting antimicrobial substances. The aim of this research was to determine how L. plantarum combats E. coli infection and why it is a representative probiotic in the intestine. Consequently, this research observed that E. coli releases uracil. L. plantarum specifically recognizes E. coli-derived uracil, which increases the growth rate and production of antimicrobial substance of L. plantarum. In addition, through the inhibitory activity test, this study postulates that the antimicrobial substance is a protein and can be considered a bacteriocin-like substance. Therefore, this research assumes that L. plantarum exerts its antibacterial ability by recognizing E. coli and increasing its growth rate as a result, and this phenomenon could be one of the reasons for L. plantarum settling in the intestine of infants as a beneficial bacterium.

DFT study on metal-mediated uracil base pair complexes

Directory of Open Access Journals (Sweden)

Ayhan Üngördü

2017-11-01

Full Text Available The most stable of metal-mediated uracil base pair complexes were determined. Method was used density functional theory, B3LYP. The calculations of systems containing C, H, N, O were described by 6-311++G(d,p and cc-PVTZ basis sets and LANL2DZ and SDD basis sets was used for transition metals. Then Egap values of complexes were calculated and the electrical conductivity of the complexes for single nanowires was studied by band theory. Metal-mediated uracil base pair complexes which will be used as conductive wires in nanotechnology were predicted. In nanoworld, this study is expected to show a way for practical applications.

New uracil derivatives and their biological activity

International Nuclear Information System (INIS)

Hudecova, D.; Striganova, J.; Chovanec, P.; Uher, M.

1998-01-01

Present study is concentrated to the research of antimicrobial activity of some derivatives of the uracil and 1,3-dimethyluracyl. The antimicrobial effects of these compounds have been tested on various strains of bacteria, yeasts, and filamentous fungi. The highest antimicrobial effects were found with dithiocarbamato-derivatives, which were effective against pathogenic and non-pathogenic bacteria (IC 50 = 7-25 μg cm -3 ), yeasts (IC 50 = 9-60 μg cm -3 ) and filamentous fungi.The most sensitive fungus to dithiocarbamato-derivatives was Botritis cinerea. It seems to be apparent that the presence of the -NH-C(S)-S- group in molecules of derivatives of uracil and and 1,3-dimethyluracyl influencing the incorporation rate [ 14 ]-adenine and 14 ]-leucine into the biomolecules and also markedly inhibits oxygen consumption (IC 50 = 58 μg cm -3 ). The same derivative demonstrated no mutagenic activity. (authors)

Uracil Excision for Assembly of Complex Pathways

DEFF Research Database (Denmark)

Cavaleiro, Mafalda; Nielsen, Morten Thrane; Kim, Se Hyeuk

2015-01-01

Despite decreasing prices on synthetic DNA constructs, higher-order assembly of PCR-generated DNA continues to be an important exercise in molecular and synthetic biology. Simplicity and robustness are attractive features met by the uracil excision DNA assembly method, which is one of the most in...

Insight on specificity of uracil permeases of the NAT/NCS2 family from analysis of the transporter encoded in the pyrimidine utilization operon of Escherichia coli.

Science.gov (United States)

Botou, Maria; Lazou, Panayiota; Papakostas, Konstantinos; Lambrinidis, George; Evangelidis, Thomas; Mikros, Emmanuel; Frillingos, Stathis

2018-04-01

The uracil permease UraA of Escherichia coli is a structurally known prototype for the ubiquitous Nucleobase-Ascorbate Transporter (NAT) or Nucleobase-Cation Symporter-2 (NCS2) family and represents a well-defined subgroup of bacterial homologs that remain functionally unstudied. Here, we analyze four of these homologs, including RutG of E. coli which shares 35% identity with UraA and is encoded in the catabolic rut (pyrimidine utilization) operon. Using amplified expression in E. coli K-12, we show that RutG is a high-affinity permease for uracil, thymine and, at low efficiency, xanthine and recognizes also 5-fluorouracil and oxypurinol. In contrast, UraA and the homologs from Acinetobacter calcoaceticus and Aeromonas veronii are permeases specific for uracil and 5-fluorouracil. Molecular docking indicates that thymine is hindered from binding to UraA by a highly conserved Phe residue which is absent in RutG. Site-directed replacement of this Phe with Ala in the three uracil-specific homologs allows high-affinity recognition and/or transport of thymine, emulating the RutG profile. Furthermore, all RutG orthologs from enterobacteria retain an Ala at this position, implying that they can use both uracil and thymine and, possibly, xanthine as substrates and provide the bacterial cell with a range of catabolizable nucleobases. © 2018 John Wiley & Sons Ltd.

Scaffold hopping: exploration of acetanilide-containing uracil analogues as potential NNRTIs.

Science.gov (United States)

Babkov, Denis A; Valuev-Elliston, Vladimir T; Paramonova, Maria P; Ozerov, Alexander A; Ivanov, Alexander V; Chizhov, Alexander O; Khandazhinskaya, Anastasia L; Kochetkov, Sergey N; Balzarini, Jan; Daelemans, Dirk; Pannecouque, Christophe; Seley-Radtke, Katherine L; Novikov, Mikhail S

2015-03-01

In order to identify novel nonnucleoside inhibitors of HIV-1 reverse transcriptase two series of amide-containing uracil derivatives were designed as hybrids of two scaffolds of previously reported inhibitors. Subsequent biological evaluation confirmed acetamide uracil derivatives 15a-k as selective micromolar NNRTIs with a first generation-like resistance profile. Molecular modeling of the most active compounds 15c and 15i was employed to provide insight on their inhibitory properties and direct future design efforts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Uracil-ftorafur: an oral fluoropyrimidine active in colorectal cancer.

Science.gov (United States)

Sulkes, A; Benner, S E; Canetta, R M

1998-10-01

This review describes the early clinical development of uracil-ftorafur (UFT), an oral fluoropyrimidine, designed in 1978 by adding uracil to ftorafur. The review focuses on the treatment of colorectal cancer and summarizes the Japanese experience and the phase I and II trials performed in the United States and Europe. Clinical trials of UFT published in the Western world have included 581 patients with colorectal cancer. UFT has been administered in these trials as a single agent or biomodulated by leucovorin (LV). UFT was administered daily in split doses for periods that ranged from 14 to 28 days. The activity of oral UFT in large-bowel cancer when administered with oral LV (approximately 50 mg/dose) has resulted in objective response rates of approximately 40%. Response rates of approximately 25% (range, 17% to 39%) were reported when UFT was administered as a single agent or with lower doses of LV. The highest dose-intensities of UFT are achieved with 28-day schedules of administration. The maximum-tolerated dose (MTD) of UFT with this schedule, when administered concomitantly with oral LV 150 mg daily, is 300 mg/m2 daily. The dose-limiting toxicity (DLT) of UFT has generally been diarrhea. Other commonly described toxicities include nausea and vomiting, fatigue, and stomatitis. Myelosuppression occurs infrequently. Typically, hand-foot syndrome and neurologic toxicity are lacking. UFT is a fluoropyrimidine active in colorectal cancer. The oral route of administration and improved safety profile represent important advantages over both conventional and infusional fluorouracil (5-FU) regimens.

Identifying and representing elements of local contexts in Namibia

DEFF Research Database (Denmark)

Rodil, Kasper; Jensen, Kasper Løvborg; Rehm, Matthias

2013-01-01

In an attempt to represent local context in a 3D visualisa- tionfor rural elders in Namibia we have foundmajor dierences in thecon- ceptualizationof this context between external and local partners in the co-creation process. Through the evaluation of a mobile context capture tool we found a clea...

An unconventional family 1 uracil DNA glycosylase in Nitratifractor salsuginis.

Science.gov (United States)

Li, Jing; Chen, Ran; Yang, Ye; Zhang, Zhemin; Fang, Guang-Chen; Xie, Wei; Cao, Weiguo

2017-12-01

The uracil DNA glycosylase superfamily consists of at least six families with a diverse specificity toward DNA base damage. Family 1 uracil N-glycosylase (UNG) exhibits exclusive specificity on uracil-containing DNA. Here, we report a family 1 UNG homolog from Nitratifractor salsuginis with distinct biochemical features that differentiate it from conventional family 1 UNGs. Globally, the crystal structure of N. salsuginisUNG shows a few additional secondary structural elements. Biochemical and enzyme kinetic analysis, coupled with structural determination, molecular modeling, and molecular dynamics simulations, shows that N. salsuginisUNG contains a salt bridge network that plays an important role in DNA backbone interactions. Disruption of the amino acid residues involved in the salt bridges greatly impedes the enzymatic activity. A tyrosine residue in motif 1 (GQDPY) is one of the distinct sequence features setting family 1 UNG apart from other families. The crystal structure of Y81G mutant indicates that several subtle changes may account for its inactivity. Unlike the conventional family 1 UNG enzymes, N. salsuginisUNG is not inhibited by Ugi, a potent inhibitor specific for family 1 UNG. This study underscores the diversity of paths that a uracil DNA glycosylase may take to acquire its unique structural and biochemical properties during evolution. Structure data are available in the PDB under accession numbers 5X3G and 5X3H. © 2017 Federation of European Biochemical Societies.

Genomic uracil and human disease

DEFF Research Database (Denmark)

Hagen, Lars; Pena Diaz, Javier; Kavli, Bodil

2006-01-01

Uracil is present in small amounts in DNA due to spontaneous deamination of cytosine and incorporation of dUMP during replication. While deamination generates mutagenic U:G mismatches, incorporated dUMP results in U:A pairs that are not directly mutagenic, but may be cytotoxic. In most cells, mut...... retroviral infections. Ung(-/-) mice have a similar phenotype and develop B-cell lymphomas late in life. However, there is no evidence indicating that UNG deficiency causes lymphomas in humans....

Uracil and beta-alanine degradation in Saccharomyces Kluyveri - discovery of a novel catabolic pathway

DEFF Research Database (Denmark)

Andersen, Gorm

2006-01-01

’en i gær og de genetiske forudsætninger for uracil og beta-alanine (BAL) katabolisme i S. kluyveri undersøgt. Evnen til at bruge uracil, dihydrouracil (DHU), beta-ureidopropionate (BUP) og BAL som nitrogenkilde blev studeret i 38 gær arter. Disse var udvalgt, så de dækkede “Saccharomyces komplekset...

Experimental thermochemical study of fluoro-, chloro-, and bromo-derivatives of uracil

International Nuclear Information System (INIS)

Ribeiro da Silva, Manuel A.V.; Amaral, Luísa M.P.F.; Szterner, Piotr

2012-01-01

Highlights: ► Combustion calorimetry was used to determine Δ f H m ∘ (cr) of halo derivatives of uracil. ► Gas-phase Δ f H m ∘ of the studied compounds have been derived. ► The influence of the halogen atoms on the enthalpic stability of the halo-uracils is discussed. - Abstract: The values of the standard molar enthalpies of formation, of 5-fluorouracil, 5-chlorouracil, 5-bromouracil, and 6-chlorouracil, in the crystalline phase, at T = 298.15 K, were derived from the standard massic energies of combustion, in oxygen, at T = 298.15 K, measured by rotating bomb combustion calorimetry. The combination of the derived values of the standard molar enthalpies of formation, in the crystalline phase, and the literature values of the standard molar enthalpies of sublimation, allowed the calculation of the standard molar enthalpies of formation, in the gaseous phase, at T = 298.15 K, which are interpreted in terms of the influence of the halogen atoms upon the enthalpic stability of the halogen derivatives of uracil.

Efficacy of tegafur-uracil in advanced urothelial cancer patients after the treatment failure of platinum-based chemotherapy.

Science.gov (United States)

Maolake, Aerken; Izumi, Kouji; Takahashi, Rie; Itai, Shingo; Machioka, Kazuaki; Yaegashi, Hiroshi; Nohara, Takahiro; Kitagawa, Yasuhide; Kadono, Yoshifumi; Konaka, Hiroyuki; Mizokami, Atsushi; Namiki, Mikio

2015-03-01

Platinum-based chemotherapy is the first-line treatment for advanced urinary tract urothelial cancers. However, the optimal second-line treatment is unclear. Although tegafur-uracil is sometimes used for advanced urothelial cancer patients after the treatment failure of platinum-based chemotherapy, there is little evidence regarding its use as a second-line treatment. Advanced urothelial cancer patients previously treated with platinum-based chemotherapy were retrospectively analyzed. Overall survival (OS) was compared between patients with and without tegafur-uracil treatment. Thirty-one patients (27 and 4 patients with and without tegafur-uracil treatment, respectively) were analyzed. OS from the last day of the final chemotherapy course was better in patients with tegafur-uracil treatment than in those without (p<0.001, 358 and 66.5 days of the median survival time, respectively). Tegafur-uracil may be a candidate for the secondary treatment of advanced urothelial cancer patients after the treatment failure of platinum-based chemotherapy. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Expression of a natural fusion gene for uracil ...

African Journals Online (AJOL)

STORAGESEVER

2010-03-01

Mar 1, 2010 ... and UK enzyme from rice and the analysis of its function to investigate the pyrimidine ... Amp in the presence of 5-FU and 5-FD and grown at 37°C with shaking. The bacterial ..... O'sullivan WJ (1994). Properties of uracil.

Base excision repair of both uracil and oxidatively damaged bases contribute to thymidine deprivation-induced radiosensitization

International Nuclear Information System (INIS)

Allen, Bryan G.; Johnson, Monika; Marsh, Anne E.; Dornfeld, Kenneth J.

2006-01-01

Purpose: Increased cellular sensitivity to ionizing radiation due to thymidine depletion is the basis of radiosensitization with fluoropyrimidine and methotrexate. The mechanism responsible for cytotoxicity has not been fully elucidated but appears to involve both the introduction of uracil into, and its removal from, DNA. The role of base excision repair of uracil and oxidatively damaged bases in creating the increased radiosensitization during thymidine depletion is examined. Methods and Materials: Isogenic strains of S. cerevisiae differing only at loci involved in DNA repair functions were exposed to aminopterin and sulfanilamide to induce thymidine deprivation. Cultures were irradiated and survival determined by clonogenic survival assay. Results: Strains lacking uracil base excision repair (BER) activities demonstrated less radiosensitization than the parental strain. Mutant strains continued to show partial radiosensitization with aminopterin treatment. Mutants deficient in BER of both uracil and oxidatively damaged bases did not demonstrate radiosensitization. A recombination deficient rad52 mutant strain was markedly sensitive to radiation; addition of aminopterin increased radiosensitivity only slightly. Radiosensitization observed in rad52 mutants was also abolished by deletion of the APN1, NTG1, and NTG2 genes. Conclusion: These data suggest radiosensitization during thymidine depletion is the result of BER activities directed at both uracil and oxidatively damaged bases

Beta Glucan Production from Two Strains of Agrobacterium sp in Medium Containing of Molases and Uracil Combine

Directory of Open Access Journals (Sweden)

KUSMIATI

2007-04-01

Full Text Available Production of β-glucan by Agrobacterium sp is influenced by the composition of nutrition in the fermentation media. Molases has been used successfully by others in the fermentation media of S. cerevisiae to increase the yield of -glucan, and similarly, uracil has been used in the fermentation media of Agrobacterium sp to increase the yield of -glucan. Investigations to increase the yield of -glucan by two strains of Agrobacterium sp, i.e. A1.5 (reference and B4.4 (local strain, have been carried out by addition of various combination of molases and uracil into fermentation media, i.e. 5%(v/v molase-0,05%(b/v uracil; 5% molase-0,025% uracil; 10% molase-0,05% uracil; and 10% molase-0,025% uracil. The β-1,3-glucan and β-1,2-glucan fractions were separated by extraction method. Beta-glucan concentration was determined as the glucose monomer using the phenol-sulphate spectrophotometric method at 490 nm. The protein content was determined by a modified Lowry-spectrophotometric method at 750 nm. The results showed that all combination of molases and uracil in the fermentation media of Agrobacterium sp A1.5 and B4.4 strains have increased both the dry-weight yield of β-glucan (crude and the β¬glucan content, with the highest was in a medium containing 10% molases-0,025% uracil combination. In the above medium, the A1.5 strain produced the highest β-glucan (7,5% with the lowest protein content ( 8,4% in the β-1,3-glucan fraction, while the β-glucan content in the β-1,2-glucan fraction were all lower than in the control media, while the protein content were all higher than in the control media. In the above media, the B4.4 strain produced the highest β-glucan, 7,2% in the β-1,3-glucan fraction, and 13,1% in β-1,2-glucan fraction, while the lowest protein content ( 8,4% was in the β-1,3-glucan fraction. In conclusion, fermentation media of Agrobacterium sp A1.5 strain or B4.4 strain containing molase and uracil combination have increased both

Synthesis of acyclic nucleoside 5-o-carboranyl uracil derivative ...

African Journals Online (AJOL)

carboranyl uracil 7 as potentially antiviral agent and a suitable candidate for BNCT is described starting from 5,5- dihydroxymethyl-1,3-dioxane 1, an intermediate 2,2,2-triacetoxymethyl ethoxymethyl acetyl 2 was synthesized and coupled with ...

Palladium-catalyzed C-H olefination of uracils and caffeines using molecular oxygen as the sole oxidant.

Science.gov (United States)

Zhang, Xinyu; Su, Lv; Qiu, Lin; Fan, Zhenwei; Zhang, Xiaofeng; Lin, Shen; Huang, Qiufeng

2017-04-18

The palladium-catalyzed oxidative C-H olefination of uracils or caffeines with alkenes using an atmospheric pressure of molecular oxygen as the sole oxidant has been disclosed. This novel strategy offers an efficient and environmentally friendly method to biologically important C5-alkene uracil derivatives or C8-alkene caffeine derivatives.

UV-Photodimerization in Uracil-substituted dendrimers for high density data storage

DEFF Research Database (Denmark)

Lohse, Brian; Vestberg, Robert; Ivanov, Mario Tonev

2007-01-01

Two series of uracil-functionalized dendritic macromolecules based on poly (amidoamine) PAMAM and 2,2-bis(hydroxymethylpropionic acid) bis-MPA backbones were prepared and their photoinduced (2 pi+2 pi) cycloaddition reactions upon exposure to UV light at 257 nm examined. Dendrimers up to 4th...... generation were synthesized and investigated as potential materials for high capacity optical data storage with their dimerization efficiency compared to uracil as a reference compound. This allows the impact of increasing the generation number of the dendrimers, both the number of chromophores, as well...... nm with an intensity of 70 mW/cm(2) could be obtained suggesting future use as recording media for optical data storage. (c) 2007 Wiley Periodicals, Inc....

Generation of a Uracil Auxotroph Strain of the Probiotic Yeast Saccharomyces boulardii as a Host for the Recombinant Protein Production

Science.gov (United States)

Hamedi, Hassan; Misaghi, Ali; Modarressi, Mohammad Hossein; Salehi, Taghi Zahraei; Khorasanizadeh, Dorsa; Khalaj, Vahid

2013-01-01

Background Saccharomyces boulardii (S. boulardii) is the best known probiotic yeast. The genetic engineering of this probiotic strain requires the availability of appropriate mutants to accept various gene constructs carrying different selection markers. As the auxotrophy selection markers are under focus, we have generated a ura3 auxotroph mutant of S. boulardii for use in further genetic manipulations. Methods Classical UV mutagenesis was used for the generation of auxotroph mutants. The mutants were selected in the presence of 5-FOA (5-Fluoroorotic acid), uracil and uridine. Uracil auxotrophy phenotype was confirmed by the ability of mutants to grow in the presence of uracil and the lack of growth in the absence of this compound. To test whether the uracil auxotrophy phenotype is due to the inactivation of URA3, the mutants were transformed with a plasmid carrying the gene. An in vitro assay was used for the analysis of acid and bile resistance capacity of these mutants. Results Three mutants were found to be ura3 auxotroph as they were able to grow only in the presence of uracil. When the URA3 gene was added, these mutants were able to grow normally in the absence of uracil. Further in vitro analysis showed that the acid and bile resistance capacity of one of these mutants is intact and similar to the wild type. Conclusion A uracil auxotroph mutant of the probiotic yeast, S. boulardii, was generated and characterized. This auxotroph strain may have potential applications in the production and delivery of the recombinant pharmacuetics into the intestinal lumen. PMID:23626874

An N-Glycosidase from Escherichia coli That Releases Free Uracil from DNA Containing Deaminated Cytosine Residues

Science.gov (United States)

Lindahl, Tomas

1974-01-01

An enzyme that liberates uracil from single-stranded and double-stranded DNA containing deaminated cytosine residues and from deoxycytidylate-deoxyuridylate copolymers in the absence of Mg++ has been purified 30-fold from cell extracts of E. coli. The enzyme does not release uracil from deoxyuridine, dUMP, uridine, or RNA, nor does it liberate the normally occurring pyrimidine bases, cytosine and thymine, from DNA. The enzymatic cleavage of N-glycosidic bonds in DNA occurs without concomitant cleavage of phosphodiester bonds, resulting in the formation of free uracil and DNA strands of unaltered chain length that contain apyrimidinic sites as reaction products. The enzyme may be active in DNA repair, converting deaminated dCMP residues to an easily repairable form. PMID:4610583

Structural plasticity in Mycobacterium tuberculosis uracil-DNA glycosylase (MtUng) and its functional implications.

Science.gov (United States)

Arif, S M; Geethanandan, K; Mishra, P; Surolia, A; Varshney, U; Vijayan, M

2015-07-01

17 independent crystal structures of family I uracil-DNA glycosylase from Mycobacterium tuberculosis (MtUng) and its complexes with uracil and its derivatives, distributed among five distinct crystal forms, have been determined. Thermodynamic parameters of binding in the complexes have been measured using isothermal titration calorimetry. The two-domain protein exhibits open and closed conformations, suggesting that the closure of the domain on DNA binding involves conformational selection. Segmental mobility in the enzyme molecule is confined to a 32-residue stretch which plays a major role in DNA binding. Uracil and its derivatives can bind to the protein in two possible orientations. Only one of them is possible when there is a bulky substituent at the 5' position. The crystal structures of the complexes provide a reasonable rationale for the observed thermodynamic parameters. In addition to providing fresh insights into the structure, plasticity and interactions of the protein molecule, the results of the present investigation provide a platform for structure-based inhibitor design.

Intermolecular proton transfer in anionic complexes of uracil with alcohols

International Nuclear Information System (INIS)

Haranczyk, Maciej; Rak, Janusz; Gutowski, Maciej S.; Radisic, Dunja; Stokes, Sarah T.; Bowen, Kit H.

2005-01-01

A series of eighteen alcohols (ROH) has been designed with an enthalpy of deprotonation (H DP ) in a range of 13.8-16.3 eV. The effects of excess electron attachment to the binary alcohol-uracil (ROH...U) complexes have been studied at the density functional level with a B3LYP exchange-correlation functional and at the second order Moeller-Plesset perturbation theory level. The photoelectron spectra of anionic complexes of uracil with three alcohols (ethanol, 2,2,3,3,3-pentafluoroethanol and 1,1,1,3,3,3-hexafluoro-2-propanol) have been measured with 2.54 eV photons. For ROHs with deprotonation enthalpies larger than 14.8 eV only the ROH...U - minimum exists on the potential energy surface of the anionic complex. For alcohols with deprotonation enthalpies in a range of 14.3-14.8 eV two minima might exist on the anionic potential energy surface, which correspond to the RO - ...HU . and ROH...U - structures. For ROHs with deprotonation enthalpies smaller than 14.3 eV, the excess electron attachment to the ROH...U complex always induces a barrier-free proton transfer from the hydroxyl group of ROH to the O8 atom of U, with the product being RO - ...HU . . A driving force for the intermolecular proton transfer is to stabilize the excess negative charge localized on a orbital of uracil. Therefore, these complexes with proton transferred to the anionic uracil are characterized by larger values of electron vertical detachment energy (VDE). The values of VDE for anionic complexes span a range from 1.0 to 2.3 eV and roughly correlate with the acidity of alcohols. However, there is a gap of ∼0.5 eV in the values of VDE, which separates the two families, ROH...U - and RO - ...HU . , of anionic complexes. The energy of stabilization for the anionic complexes spans a range from 0.6 to 1.7 eV and roughly correlates with the acidity of alcohols. The measured photoelectron spectra are in good agreement with the theoretical predictions

Electron-induced hydrogen loss in uracil in a water cluster environment

International Nuclear Information System (INIS)

Smyth, M.; Kohanoff, J.; Fabrikant, I. I.

2014-01-01

Low-energy electron-impact hydrogen loss due to dissociative electron attachment (DEA) to the uracil and thymine molecules in a water cluster environment is investigated theoretically. Only the A ′ -resonance contribution, describing the near-threshold behavior of DEA, is incorporated. Calculations are based on the nonlocal complex potential theory and the multiple scattering theory, and are performed for a model target with basic properties of uracil and thymine, surrounded by five water molecules. The DEA cross section is strongly enhanced when the attaching molecule is embedded in a water cluster. This growth is due to two effects: the increase of the resonance lifetime and the negative shift in the resonance position due to interaction of the intermediate negative ion with the surrounding water molecules. A similar effect was earlier found in DEA to chlorofluorocarbons

Theoretical investigation of the ultrafast dissociation of core-ionized water and uracil molecules immersed in liquid water

Energy Technology Data Exchange (ETDEWEB)

Stia, C.R.; Fojon, O.A. [Instituto de Fisica Rosario - CONICET-Universidad Nacional de Rosario, Rosario (Argentina); Gaigeot, M.P. [Laboratoire Analyse et Modelisation pour la Biologie et l' Environnement, LAMBE, UMR-CNRS 8587, Universite d' Evry-Val-d' Essonne, 91 - Evry (France); Institut Universitaire de France, 75 - Paris (France); Vuilleumier, R. [Departement de chimie, Ecole Normale Superieure, 75 - Paris (France); Herve du Penhoat, M.A.; Politis, M.F. [Institut de Mineralogie et de Physique des Milieux Condenses, IMPMC, UMR-CNRS 7590, Universite Pierre et Marie Curie, 75 - Paris (France)

2010-10-15

We present a series of ab initio density functional based calculations of the fragmentation dynamics of core-ionized biomolecules. The computations are performed for pure liquid water, aqueous and isolated Uracil. Core ionization is described by replacing the 1s{sup 2} pseudopotential of one atom of the target molecule (C, N or O) with a pseudopotential for a 1s{sup 1} core-hole state. Our results predict that the dissociation of core-ionized water molecules may be reached during the lifetime of inner-shell vacancy (less than 10 fs), leading to OH bond breakage as a primary outcome. We also observe a second fragmentation channel in which total Coulomb explosion of the ionized water molecule occurs. Fragmentation pathways are found similar for pure water or when the water molecule is in the primary hydration shell of the uracil molecule. In the latter case, the proton may be transferred towards the uracil oxygen atoms. When the core hole is located on the uracil molecule, ultrafast dissociation is only observed in the aqueous environment and for nitrogen-K vacancies, resulting in proton transfers towards the hydrogen-bonded water molecule. (authors)

Tools and drugs for uracil nucleotide-activated P2Y receptors.

Science.gov (United States)

Rafehi, Muhammad; Müller, Christa E

2018-04-13

P2Y receptors (P2YRs) are a family of G protein-coupled receptors activated by extracellular nucleotides. Physiological P2YR agonists include purine and pyrimidine nucleoside di- and triphosphates, such as ATP, ADP, UTP, UDP, nucleotide sugars, and dinucleotides. Eight subtypes exist, P2Y 1 , P2Y 2 , P2Y 4 , P2Y 6 , P2Y 11 , P2Y 12 , P2Y 13 , and P2Y 14 , which represent current or potential future drug targets. Here we provide a comprehensive overview of ligands for the subgroup of the P2YR family that is activated by uracil nucleotides: P2Y 2 (UTP, also ATP and dinucleotides), P2Y 4 (UTP), P2Y 6 (UDP), and P2Y 14 (UDP, UDP-glucose, UDP-galactose). The physiological agonists are metabolically unstable due to their fast hydrolysis by ectonucleotidases. A number of agonists with increased potency, subtype-selectivity and/or enzymatic stability have been developed in recent years. Useful P2Y 2 R agonists include MRS2698 (6-01, highly selective) and PSB-1114 (6-05, increased metabolic stability). A potent and selective P2Y 2 R antagonist is AR-C118925 (10-01). For studies of the P2Y 4 R, MRS4062 (3-15) may be used as a selective agonist, while PSB-16133 (10-06) represents a selective antagonist. Several potent P2Y 6 R agonists have been developed including 5-methoxyuridine 5'-O-((R p )α-boranodiphosphate) (6-12), PSB-0474 (3-11), and MRS2693 (3-26). The isocyanate MRS2578 (10-08) is used as a selective P2Y 6 R antagonist, although its reactivity and low water-solubility are limiting. With MRS2905 (6-08), a potent and metabolically stable P2Y 14 R agonist is available, while PPTN (10-14) represents a potent and selective P2Y 14 R antagonist. The radioligand [ 3 H]UDP can be used to label P2Y 14 Rs. In addition, several fluorescent probes have been developed. Uracil nucleotide-activated P2YRs show great potential as drug targets, especially in inflammation, cancer, cardiovascular and neurodegenerative diseases. Copyright © 2018. Published by Elsevier Inc.

Electron-induced hydrogen loss in uracil in a water cluster environment

Energy Technology Data Exchange (ETDEWEB)

Smyth, M.; Kohanoff, J. [Atomistic Simulation Centre, Queen' s University Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom); Fabrikant, I. I., E-mail: ifabrikant1@unl.edu [Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, USA and Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

2014-05-14

Low-energy electron-impact hydrogen loss due to dissociative electron attachment (DEA) to the uracil and thymine molecules in a water cluster environment is investigated theoretically. Only the A{sup ′}-resonance contribution, describing the near-threshold behavior of DEA, is incorporated. Calculations are based on the nonlocal complex potential theory and the multiple scattering theory, and are performed for a model target with basic properties of uracil and thymine, surrounded by five water molecules. The DEA cross section is strongly enhanced when the attaching molecule is embedded in a water cluster. This growth is due to two effects: the increase of the resonance lifetime and the negative shift in the resonance position due to interaction of the intermediate negative ion with the surrounding water molecules. A similar effect was earlier found in DEA to chlorofluorocarbons.

Uracil phosphoribosyltransferase from the extreme thermoacidophilic archaebacterium Sulfolobus shibatae is an allosteric enzyme, activated by GTP and inhibited by CTP

DEFF Research Database (Denmark)

Linde, Lise; Jensen, Kaj Frank

1996-01-01

Uracil phosphoribosyltransferase, which catalyses the formation of UMP and pyrophosphate from uracil and 5-phosphoribosyl a-1-pyrophosphate (PRPP), was partly purified from the extreme thermophilic archaebacterium Sulfolobus shibatae. The enzyme required divalent metal ions for activity...... and it showed the highest activity at pH 6.4. The specific activity of the enzyme was 50-times higher at 95°C than at 37°C, but the functional half-life was short at 95°C. The activity of uracil phosphoribosyltransferase was strongly activated by GTP, which increased Vmax of the reaction by approximately 20......-fold without much effect on Km for the substrates. The concentration of GTP required for half-maximal activation was about 80 µM. CTP was a strong inhibitor and acted by raising the concentration of GTP needed for half-maximal activation of the enzyme. We conclude that uracil phosphoribosyltransferase...

Overexpression, purification, crystallization and preliminary X-ray analysis of uracil N-glycosylase from Mycobacterium tuberculosis in complex with a proteinaceous inhibitor

Energy Technology Data Exchange (ETDEWEB)

Singh, Prem [Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012 (India); Talawar, Ramappa K.; Krishna, P. D. V.; Varshney, Umesh [Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560 012 (India); Vijayan, M., E-mail: mv@mbu.iisc.ernet.in [Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012 (India)

2006-12-01

Uracil N-glycosylase from M. tuberculosis has been crystallized in complex with a proteinaceous inhibitor (Ugi) and X-ray diffraction data have been collected. Uracil N-glycosylase is an enzyme which initiates the pathway of uracil-excision repair of DNA. The enzyme from Mycobacterium tuberculosis was co-expressed with a proteinaceous inhibitor from Bacillus subtilis phage and was crystallized in monoclinic space group C2, with unit-cell parameters a = 201.14, b = 64.27, c = 203.68 Å, β = 109.7°. X-ray data from the crystal have been collected for structure analysis.

Overexpression, purification, crystallization and preliminary X-ray analysis of uracil N-glycosylase from Mycobacterium tuberculosis in complex with a proteinaceous inhibitor

International Nuclear Information System (INIS)

Singh, Prem; Talawar, Ramappa K.; Krishna, P. D. V.; Varshney, Umesh; Vijayan, M.

2006-01-01

Uracil N-glycosylase from M. tuberculosis has been crystallized in complex with a proteinaceous inhibitor (Ugi) and X-ray diffraction data have been collected. Uracil N-glycosylase is an enzyme which initiates the pathway of uracil-excision repair of DNA. The enzyme from Mycobacterium tuberculosis was co-expressed with a proteinaceous inhibitor from Bacillus subtilis phage and was crystallized in monoclinic space group C2, with unit-cell parameters a = 201.14, b = 64.27, c = 203.68 Å, β = 109.7°. X-ray data from the crystal have been collected for structure analysis

Investigation of the fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by certain substituted uracils

Energy Technology Data Exchange (ETDEWEB)

Anbazhagan, V. [School of Chemistry, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India); Renganathan, R. [School of Chemistry, Bharathidasan University, Tiruchirappalli 620024, Tamil Nadu (India)], E-mail: rrengas@yahoo.com

2009-04-15

The fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by a series of uracils has been studied in water and acetonitrile solvents using steady-state and time-resolved fluorescence techniques. The steady-state fluorescence quenching technique has been performed in three different pHs (i.e. 4, 8 and 12). The bimolecular quenching rate constant (k{sub q}) increases with increase in pH of uracils. In acidic pH, a pure hydrogen atom abstraction is proposed as the quenching mechanism. This is supported by a pronounced solvent deuterium isotope effect. Electron transfer from the anionic form of uracil to the excited state of DBO is proposed as a mechanism for quenching in basic pH on the basis of highly exergonic thermodynamics obtained from the Rehm-Weller equation. The variation of k{sub q} is explained on the basis of the electronic effect of substitution in uracils as well.

Investigation of the fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by certain substituted uracils

International Nuclear Information System (INIS)

Anbazhagan, V.; Renganathan, R.

2009-01-01

The fluorescence quenching of 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) by a series of uracils has been studied in water and acetonitrile solvents using steady-state and time-resolved fluorescence techniques. The steady-state fluorescence quenching technique has been performed in three different pHs (i.e. 4, 8 and 12). The bimolecular quenching rate constant (k q ) increases with increase in pH of uracils. In acidic pH, a pure hydrogen atom abstraction is proposed as the quenching mechanism. This is supported by a pronounced solvent deuterium isotope effect. Electron transfer from the anionic form of uracil to the excited state of DBO is proposed as a mechanism for quenching in basic pH on the basis of highly exergonic thermodynamics obtained from the Rehm-Weller equation. The variation of k q is explained on the basis of the electronic effect of substitution in uracils as well

Experimental study on the thermochemistry of some amino derivatives of uracil

International Nuclear Information System (INIS)

Ribeiro da Silva, Manuel A.V.; Amaral, Luisa M.P.F.; Szterner, Piotr

2011-01-01

Highlights: → Combustion calorimetry was used to determine Δ f H m 0 (cr) of amino derivatives of uracil. → Gas-phase Δ f H m 0 of amino derivatives of uracil have been derived. → The relative enthalpic stability of the title compounds is discussed in structural terms. - Abstract: Values of the standard (p 0 = 0.1 MPa) molar enthalpy of combustion, Δ c H m 0 , of four crystalline compounds: 5-aminouracil, 6-aminouracil, 6-amino-1-methyluracil, and 6-amino-1,3-dimethyluracil, were determined, at T = 298.15 K, using a static bomb combustion calorimeter. The values obtained of standard molar enthalpy of combustion were used to derive the standard molar enthalpy of formation of the compounds investigated in their condensed phase and together with literature values of the standard molar enthalpy of sublimation, yielded the standard molar enthalpies of formation in the gaseous phase. These are discussed in terms of the effects of the molecular structure on the relative enthalpic stability.

Analogues of uracil nucleosides with intrinsic fluorescence (NIF-analogues): synthesis and photophysical properties.

Science.gov (United States)

Segal, Meirav; Fischer, Bilha

2012-02-28

Uridine cannot be utilized as fluorescent probe due to its extremely low quantum yield. For improving the uracil fluorescence characteristics we extended the natural chromophore at the C5 position by coupling substituted aromatic rings directly or via an alkenyl or alkynyl linker to create fluorophores. Extension of the uracil base was achieved by treating 5-I-uridine with the appropriate boronic acid under the Suzuki coupling conditions. Analogues containing an alkynyl linker were obtained from 5-I-uridine and the suitable boronic acid in a Sonogashira coupling reaction. The uracil fluorescent analogues proposed here were designed to satisfy the following requirements: a minimal chemical modification at a position not involved in base-pairing, resulting in relatively long absorption and emission wavelengths and high quantum yield. 5-((4-Methoxy-phenyl)-trans-vinyl)-2'-deoxy-uridine, 6b, was found to be a promising fluorescent probe. Probe 6b exhibits a quantum yield that is 3000-fold larger than that of the natural chromophore (Φ 0.12), maximum emission (478 nm) which is 170 nm red shifted as compared to uridine, and a Stokes shift of 143 nm. In addition, since probe 6b adopts the anti conformation and S sugar puckering favored by B-DNA, it makes a promising nucleoside analogue to be incorporated in an oligonucleotide probe for detection of genetic material.

Hydrothermal synthesis of functionalized CdS nanoparticles and their application as fluorescence probes in the determination of uracil and thymine

International Nuclear Information System (INIS)

Lu Yaxiang; Li Li; Ding Yaping; Zhang Fenfen; Wang Yaping; Yu Weijun

2012-01-01

A novel, sensitive, and convenient method for the determination of uracil and thymine by functionalized CdS nanoparticles (NPs) was proposed. CdS NPs were prepared by hydrothermal process and modified with thioglycollic acid (TGA) in aqueous solution. The fluorescence intensity of functionalized CdS NPs was quenched in the presence of uracil or thymine. Under optimal conditions, the relative fluorescence intensity (F 0 /F) was proportional to the concentration in the range of 9.0x10 -6 -1.0x10 -4 mol/L for uracil (r=0.9985) and 8.8x10 -7 -1.5x10 -4 mol/L for thymine (r=0.9960). The corresponding detection limits were 9.6x10 -7 mol/L and 3.2x10 -7 mol/L, respectively. In addition, the possible quenching mechanism was also discussed. - Highlights: → Nano-CdS fluorescence probes were synthesized with good optical properties. → Uracil and thymine were successfully detected by CdS fluorescence probes. → Wide linear ranges and low detection limits were obtained.

Pms2 and uracil-DNA glycosylases act jointly in the mismatch repair pathway to generate Ig gene mutations at A-T base pairs.

Science.gov (United States)

Girelli Zubani, Giulia; Zivojnovic, Marija; De Smet, Annie; Albagli-Curiel, Olivier; Huetz, François; Weill, Jean-Claude; Reynaud, Claude-Agnès; Storck, Sébastien

2017-04-03

During somatic hypermutation (SHM) of immunoglobulin genes, uracils introduced by activation-induced cytidine deaminase are processed by uracil-DNA glycosylase (UNG) and mismatch repair (MMR) pathways to generate mutations at G-C and A-T base pairs, respectively. Paradoxically, the MMR-nicking complex Pms2/Mlh1 is apparently dispensable for A-T mutagenesis. Thus, how detection of U:G mismatches is translated into the single-strand nick required for error-prone synthesis is an open question. One model proposed that UNG could cooperate with MMR by excising a second uracil in the vicinity of the U:G mismatch, but it failed to explain the low impact of UNG inactivation on A-T mutagenesis. In this study, we show that uracils generated in the G1 phase in B cells can generate equal proportions of A-T and G-C mutations, which suggests that UNG and MMR can operate within the same time frame during SHM. Furthermore, we show that Ung -/- Pms2 -/- mice display a 50% reduction in mutations at A-T base pairs and that most remaining mutations at A-T bases depend on two additional uracil glycosylases, thymine-DNA glycosylase and SMUG1. These results demonstrate that Pms2/Mlh1 and multiple uracil glycosylases act jointly, each one with a distinct strand bias, to enlarge the immunoglobulin gene mutation spectrum from G-C to A-T bases. © 2017 Girelli Zubani et al.

QSAR Studies of 6-Amino Uracil Base Analogues: A Thymidine Phosphorylase Inhibitor in Cancer Therapy

Directory of Open Access Journals (Sweden)

Surya Prakash B. N. Gupta

2008-01-01

Full Text Available A novel series of 6-amino uracil base analogue were synthesized. QSAR study was used to relate the selective nonsubstrate inhibitory activity of 6-amino uracil base analogue with various physicochemical descriptors. Stepwise multiple regression analysis was performed to find out the correlation between various physicochemical descriptors and biological activity of the compounds by using Openstat 2 version 6.5.1 and valstat statistical software. Out of the several equations developed, the best equation having the highest significance was selected for further study. The equation is able to explain 60% of total variance and are more than 95% significant as revealed by the F value.

Increased uracil misincorporation in lymphocytes from folate-deficient rats

OpenAIRE

Duthie, S J; Grant, G; Narayanan, S

2000-01-01

The development of certain human cancers has been linked with inadequate intake of folates. The effects of folate deficiency in vivo on DNA stability (strand breakage, misincorporated uracil and oxidative base damage) in lymphocytes isolated from rats fed a diet deficient in folic acid was determined. Because the metabolic pathways of folate and other methyl donors are closely coupled, the effects of methionine and choline deficiency alone or in combination with folate deficiency were determi...

Combined effects of π-π stacking and hydrogen bonding on the (N1) acidity of uracil and hydrolysis of 2'-deoxyuridine.

Science.gov (United States)

Kellie, Jennifer L; Navarro-Whyte, Lex; Carvey, Matthew T; Wetmore, Stacey D

2012-03-01

M06-2X/6-31+G(d,p) is used to study the simultaneous effects of π-π stacking interactions with phenylalanine (modeled as benzene) and hydrogen bonding with small molecules (HF, H(2)O, and NH(3)) on the N1 acidity of uracil and the hydrolytic deglycosylation of 2'-deoxyuridine (dU) (facilitated by fully (OH(-)) or partially (HCOO(-)···H(2)O) activated water). When phenylalanine is complexed with isolated uracil, the proton affinity of all acceptor sites significantly increases (by up to 28 kJ mol(-1)), while the N1 acidity slightly decreases (by ~6 kJ mol(-1)). When small molecules are hydrogen bound to uracil, addition of the phenylalanine ring can increase or decrease the acidity of uracil depending on the number and nature (acidity) of the molecules bound. Furthermore, a strong correlation between the effects of π-π stacking on the acidity of U and the dU deglycosylation reaction energetics is found, where the hydrolysis barrier can increase or decrease depending on the nature and number of small molecules bound, the nucleophile considered (which dictates the negative charge on U in the transition state), and the polarity of the (bulk) environment. These findings emphasize that the catalytic (or anticatalytic) role of the active-site aromatic amino acid residues is highly dependent on the situation under consideration. In the case of uracil-DNA glycosylase (UNG), which catalyzes the hydrolytic excision of uracil from DNA, the type of discrete hydrogen-bonding interactions with U, the nature of the nucleophile, and the anticipated weak, nonpolar environment in the active site suggest that phenylalanine will be slightly anticatalytic in the chemical step, and therefore experimentally observed contributions to catalysis may entirely result from associated structural changes that occur prior to deglycosylation.

Archaeal DNA Polymerase-B as a DNA Template Guardian: Links between Polymerases and Base/Alternative Excision Repair Enzymes in Handling the Deaminated Bases Uracil and Hypoxanthine

Directory of Open Access Journals (Sweden)

Javier Abellón-Ruiz

2016-01-01

Full Text Available In Archaea repair of uracil and hypoxanthine, which arise by deamination of cytosine and adenine, respectively, is initiated by three enzymes: Uracil-DNA-glycosylase (UDG, which recognises uracil; Endonuclease V (EndoV, which recognises hypoxanthine; and Endonuclease Q (EndoQ, (which recognises both uracil and hypoxanthine. Two archaeal DNA polymerases, Pol-B and Pol-D, are inhibited by deaminated bases in template strands, a feature unique to this domain. Thus the three repair enzymes and the two polymerases show overlapping specificity for uracil and hypoxanthine. Here it is demonstrated that binding of Pol-D to primer-templates containing deaminated bases inhibits the activity of UDG, EndoV, and EndoQ. Similarly Pol-B almost completely turns off EndoQ, extending earlier work that demonstrated that Pol-B reduces catalysis by UDG and EndoV. Pol-B was observed to be a more potent inhibitor of the enzymes compared to Pol-D. Although Pol-D is directly inhibited by template strand uracil, the presence of Pol-B further suppresses any residual activity of Pol-D, to near-zero levels. The results are compatible with Pol-D acting as the replicative polymerase and Pol-B functioning primarily as a guardian preventing deaminated base-induced DNA mutations.

Interplay Between Capsule Expression and Uracil Metabolism in Streptococcus pneumoniae D39

DEFF Research Database (Denmark)

Carvalho, Sandra M.; Kloosterman, Tomas G.; Manzoor, Irfan

2018-01-01

. Importantly, Pcps expression is further decreased by mutating the first gene of the de novo synthesis of pyrimidines, carA. In contrast, the absence of uracil from the culture medium showed no effect on the spontaneous mutant strain. Co-cultivation of the wild-type and the mutant strain indicated...

Effect of salt on a thermosensitive mutant of Bacillus subtilis deficient in uracil and cell division

Energy Technology Data Exchange (ETDEWEB)

Miyazaki, N; Nagai, K; Tamura, G

1976-01-01

A thermosensitive uracil requiring mutant of Bacillus subtilis Marburg 168 thy trp/sub 2/ ts42 was examined as to the colony forming ability at the permissive and nonpermissive temperatures. The viability of the mutant cells decreased rapidly at the restrictive temperature in the modified Woese's (MW) medium. However, the cells retained viability when sodium succinate or potassium chloride was added to the medium at that temperature although uracil deficiency was unchanged. A little but significant incorporation of adenine-8-/sup 14/C into RNA still continued even after the incorporation of N-acetyl-/sup 3/H-D-glucosamine into acid insoluble fraction of the cells terminated in the MW medium at 48/sup 0/C. Both incorporations as well as increase of absorbance were slowed down in the presence of sodium succinate at 48/sup 0/C. This mutant, ts-42, was more sensitive to deoxycholate (DOC) than the parent strain. The restoration of colony forming ability after the temperature shift back to 37/sup 0/C was suppressed by the addition of DOC to the medium. However, the cell became resistant to DOC when uracil was added to the medium prior to the temperature shift.

Spectroscopic study of uracil, 1-methyluracil and 1-methyl-4-thiouracil: Hydrogen bond interactions in crystals and ab-initio molecular dynamics

Science.gov (United States)

Brela, Mateusz Z.; Boczar, Marek; Malec, Leszek M.; Wójcik, Marek J.; Nakajima, Takahito

2018-05-01

Hydrogen bond networks in uracil, 1-methyluracil and 1-methyl-4-thiouracil were studied by ab initio molecular dynamics as well as analysis of the orbital interactions. The power spectra calculated by ab initio molecular dynamics for atoms involved in hydrogen bonds were analyzed. We calculated spectra by using anharmonic approximation based on the autocorrelation function of the atom positions obtained from the Born-Oppenheimer simulations. Our results show the differences between hydrogen bond networks in uracil and its methylated derivatives. The studied methylated derivatives, 1-methyluracil as well as 1-methyl-4-thiouracil, form dimeric structures in the crystal phase, while uracil does not form that kind of structures. The presence of sulfur atom instead oxygen atom reflects weakness of the hydrogen bonds that build dimers.

The Role of Sarcosine, Uracil, and Kynurenic Acid Metabolism in Urine for Diagnosis and Progression Monitoring of Prostate Cancer

Directory of Open Access Journals (Sweden)

Georgios Gkotsos

2017-02-01

Full Text Available The aim of this pilot study is to evaluate sarcosine, uracil, and kynurenic acid in urine as potential biomarkers in prostate cancer detection and progression monitoring. Sarcosine, uracil, and kynurenic acid were measured in urine samples of 32 prostate cancer patients prior to radical prostatectomy, 101 patients with increased prostate-specific antigen prior to ultrasonographically-guided prostatic biopsy collected before and after prostatic massage, and 15 healthy volunteers (controls. The results were related to histopathologic data, Gleason score, and PSA (Prostate Specific Antigen. Metabolites were measured after analysis of urine samples with Ultra-High Performance Liquid Chromatography coupled to tandem mass spectrometry (UPLC-MS/MS instrumentation. Multivariate, nonparametric statistical tests including receiver operating characteristics analyses, one-way analysis of variance (Kruskal–Wallis test, parametric statistical analysis, and Pearson correlation, were performed to evaluate diagnostic performance. Decreased median sarcosine and kynurenic acid and increased uracil concentrations were observed for patients with prostate cancer compared to participants without malignancy. Results showed that there was no correlation between the concentration of the studied metabolites and the cancer grade (Gleason score <7 vs. ≥7 and the age of the patients. Evaluation of biomarkers by ROC (Receiving Operating Characteristics curve analysis showed that differentiation of prostate cancer patients from participants without malignancy was not enhanced by sarcosine or uracil levels in urine. In contrast to total PSA values, kynurenic acid was found a promising biomarker for the detection of prostate cancer particularly in cases where collection of urine samples was performed after prostatic massage. Sarcosine and uracil in urine samples of patients with prostate cancer were not found as significant biomarkers for the diagnosis of prostate cancer

Radiation damage to uracil and water by proton and electron impact

International Nuclear Information System (INIS)

Scheier, P.; Hanel, G.; Denifl, S; Gstir, B.; Maerk, T.D.; Farizon, B.; Farizon, M.; Coupier, B.

2002-01-01

Full text: The inelastic interaction of protons (in the energy range from 20 keV to 150 keV) and electrons (from thermal energies up to 20 eV) with water and uracil, the latter a building block of the RNA has been studied in two laboratories with specially designed experimental setups. These measurements are motivated from a present lack of understanding how on a molecular level damage to living cells and organisms is caused. A unique way of simultaneous detection of the product ions after swift proton (or hydrogen) impact and the analysis of the charge state of the projectile after the collision allows to distinguish between direct ionization (e.g., projectile remains a proton) and electron capture events (e.g., proton becomes neutralized). The latter process turns out to be more destructive, i.e. leads to a higher yield of fragmentation. For electrons both the formation of positively and negatively charged ions has been investigated. We discovered that already thermal electrons lead with a rather large cross section to a dissociation of the uracil molecule producing an anion and a fast hydrogen radical. (author)

Effect of uracil on the intracellular distribution of 1-(2-tetrahydrofuryl)-5-fluorouracil in the mouse tumor cells

Energy Technology Data Exchange (ETDEWEB)

Fujimoto, J.; Kosaki, G. (Osaka Univ. (Japan). Faculty of Medicine)

1980-12-01

Fifteen ..mu..g/g 1-(2-tetrahydrofuryl)-5-fluoro (-6-/sup 3/H) uracil (/sup 3/H-FT) were injected i.p. into mice bearing Fujimoto ascites tumor. Tumor cells were removed at various intervals and the autoradiographs were prepared. The specimens were treated first with chloroform before being coated with emulsion, so as to remove /sup 3/H-FT in the specimens and to preserve 5-fluoro (-6-/sup 3/H) uracil (/sup 3/H-FU) which was released from /sup 3/H-FT. Autoradiographs revealed a higher concentration of silver grains which localized over the nucleus, especially over the nucleoli, of tumor cells than over the cytoplasm. When 33.6 ..mu..g uracil/g was coadministered with 15.0 ..mu..g /sup 3/H-FT/g into tumor-bearing mice, intracellular distribution of /sup 3/H-FU released from /sup 3/H-FT was unchanged and an incorporation of /sup 3/H-FU into the tumor cells was higher than when /sup 3/H-FT alone.

Different organization of base excision repair of uracil in DNA in nuclei and mitochondria and selective upregulation of mitochondrial uracil-DNA glycosylase after oxidative stress

DEFF Research Database (Denmark)

Akbari, M; Otterlei, M; Pena Diaz, Javier

2007-01-01

, indicating regulatory effects of oxidative stress on mitochondrial BER. To examine the overall organization of uracil-BER in nuclei and mitochondria, we constructed cell lines expressing EYFP (enhanced yellow fluorescent protein) fused to UNG1 or UNG2. These were used to investigate the possible presence...... BER processes are differently organized. Furthermore, the upregulation of mRNA for mitochondrial UNG1 after oxidative stress indicates that it may have an important role in repair of oxidized pyrimidines....

Study on autoradiolysis of 5-hydroxymethyl[hydroxy-methyl-3H]uracil

International Nuclear Information System (INIS)

Mittag, E.; Noll, S.; Grosse, B.

1990-01-01

The autoradiolysis of 5-hydroxymethyl-[hydroxymethyl 3 H]uracil with a specific radioactivity of about 2200 GBq per mmol has been studied. The investigations were carried out in aqueous solutions with radiochemical concentrations between 70 and 1200 MBq/ml using UV-spectroscopy. Tritiated 5-hydroxymethyl-5,6-dihydrouracil in a first order respectively pseudo-first order reaction, was obtained. The determined rate constants were correlated with the radiochemical concentration. (author)

Theoretical investigation on hydrogen bond interaction of diketo/keto-enol form uracil and thymine tautomers with intercalators.

Science.gov (United States)

Anithaa, V S; Vijayakumar, S; Sudha, M; Shankar, R

2017-11-06

The interaction of diketo and keto-enol form of thymine and uracil tautomers with acridine (Acr), phenazine (Phen), benzo[c]cinnoline (Ben), 1,10-phenanthroline (1,10-Phe), and 4,7-phenenthroline (4,7-Phe) intercalating drug molecules was studied using density functional theory at B3LYP/6-311++G** and M05-2×/6-311++G** levels of theory. From the interaction energy, it is found that keto-enol form tautomers have stronger interaction with intercalators than diketone form tautomers. On complex formation of thymine and uracil tautomers with benzo[c]cinnoline the drug molecules have high interaction energy values of -20.14 (BenT3) and -20.55 (BenU3) kcal mol -1 , while phenazine has the least interaction energy values of -6.52 (PhenT2) and -6.67 (PhenU2) kcal mol -1 . The closed shell intermolecular type interaction between the molecules with minimum elliptical value of 0.018 and 0.019 a.u at both levels of theory has been found from topological analysis. The benzo[c]cinnoline drug molecule with thymine and uracil tautomers has short range intermolecular N-H…N, C-H…O, and O-H...N hydrogen bonds (H-bonds) resulting in higher stability than other drug molecules. The proper hydrogen bonds N-H..N and O-H..N have the frequency shifted toward the lower side (red shifted) with the elongation in their bond length while the improper hydrogen bond C-H...O has the frequency shifted toward the higher side (blue shifted) of the spectral region with the contraction in their bond length. Further, the charge transfer between proton acceptor and donor along with stability of the bond is studied using natural bond orbital (NBO) analysis. Graphical abstract Hydrogen bond interaction of diketo/keto-enol form uracil and thymine tautomers with intercalators.

Orbitofrontal Cortex Encodes Memories within Value-Based Schemas and Represents Contexts That Guide Memory Retrieval

Science.gov (United States)

Farovik, Anja; Place, Ryan J.; McKenzie, Sam; Porter, Blake; Munro, Catherine E.

2015-01-01

There are a substantial number of studies showing that the orbitofrontal cortex links events to reward values, whereas the hippocampus links events to the context in which they occur. Here we asked how the orbitofrontal cortex contributes to memory where context determines the reward values associated with events. After rats learned object–reward associations that differed depending on the spatial context in which the objects were presented, neuronal ensembles in orbitofrontal cortex represented distinct value-based schemas, each composed of a systematic organization of the representations of objects in the contexts and positions where they were associated with reward or nonreward. Orbitofrontal ensembles also represent the different spatial contexts that define the mappings of stimuli to actions that lead to reward or nonreward. These findings, combined with observations on complementary memory representation within the hippocampus, suggest mechanisms through which prefrontal cortex and the hippocampus interact in support of context-guided memory. PMID:26019346

Uracil incorporation in the forespore and the mother cell during spore development in Bacillus subtilis

International Nuclear Information System (INIS)

Ryter, A.; Whitehouse, R.

1978-01-01

The transcriptional activity of the two genomes of the sporangium during spore formation was determined by pulse-labeling bacteria with 3 H-uracil at different times of sporulation and preparing them for high resolution autoradiography. The quantitative analysis of autoradiographs shows that uracile incorporation in the whole sporangium decreases considerably between stages II and IV. However, the variations of the transpcriptional activity are not identical in the mother cell and in the forespore. The one of the mother cell decreases rapidly between stages II and III and then remains stable until the end of stage IV, whereas that of the forespore which is low at stage II increases as the forespore grows ovoid and then quickly diminishes. It is very weak at the beginning of stage IV and negligible at the end of this stage. (orig.) [de

Concomitant Chemoradiotherapy Using Carboplatin, Tegafur-Uracil and Leucovorin for Stage III and IV Head-and-Neck Cancer: Results of GORTEC Phase II Study

International Nuclear Information System (INIS)

Fesneau, Melanie; Pointreau, Yoann; Chapet, Sophie; Martin, Laurent; Pommier, Pascal; Alfonsi, Marc; Laguerre, Brigitte; Feham, Nasreddine; Berger, Christine; Garaud, Pascal; Calais, Gilles

2010-01-01

Purpose: Concomitant chemoradiotherapy is the standard treatment of locally advanced, nonresectable, head-and-neck squamous cell carcinoma. However, the optimal chemotherapy regimen is still controversial. The objective of this Phase II study was to evaluate the feasibility and efficacy of a concomitant treatment using tegafur-uracil, leucovorin, carboplatin, and radiotherapy. Methods and Materials: A total of 77 patients with head-and-neck squamous cell carcinoma Stage III and IVA were enrolled between October 2003 and July 2005. Of the 77 patients, 72 were eligible. They were treated with tegafur-uracil (300 mg/m 2 /d) and leucovorin (75 mg/d) from Days 1 to 19 and from Days 29 to 47 and carboplatin (70 mg/m 2 intravenously for 4 consecutive days), in three cycles every 21 days. Conventional radiotherapy was delivered to a total dose of 70 Gy in 35 fractions. Results: With a mean follow-up of 22.8 months, the 3-year locoregional control, overall survival and disease-free survival actuarial rate was 33.1%, 41.9%, and 27.2%, respectively. The compliance of the treatment was correct. The main acute toxicity was mucositis, with 62% Grade 3-4. Three patients (4.2%) died of acute toxicity. The incidence and severity of late toxicity was acceptable, with 32% Grade 3 and no Grade 4 toxicity. Conclusion: The protocol of concomitant chemoradiotherapy using tegafur-uracil, leucovorin, and carboplatin for locally advanced unresectable head-and-neck squamous cell carcinoma is feasible. The compliance was correct. The incidence and severity of the acute and late toxicities were acceptable, but not improved. The efficacy of this regimen seems equivalent to the main protocols of concurrent chemoradiotherapy. It represents a possible alternative for patients without an intravenous catheter.

Structure determination of uracil-DNA N-glycosylase from Deinococcus radiodurans in complex with DNA.

Science.gov (United States)

Pedersen, Hege Lynum; Johnson, Kenneth A; McVey, Colin E; Leiros, Ingar; Moe, Elin

2015-10-01

Uracil-DNA N-glycosylase (UNG) is a DNA-repair enzyme in the base-excision repair (BER) pathway which removes uracil from DNA. Here, the crystal structure of UNG from the extremophilic bacterium Deinococcus radiodurans (DrUNG) in complex with DNA is reported at a resolution of 1.35 Å. Prior to the crystallization experiments, the affinity between DrUNG and different DNA oligonucleotides was tested by electrophoretic mobility shift assays (EMSAs). As a result of this analysis, two 16 nt double-stranded DNAs were chosen for the co-crystallization experiments, one of which (16 nt AU) resulted in well diffracting crystals. The DNA in the co-crystal structure contained an abasic site (substrate product) flipped into the active site of the enzyme, with no uracil in the active-site pocket. Despite the high resolution, it was not possible to fit all of the terminal nucleotides of the DNA complex into electron density owing to disorder caused by a lack of stabilizing interactions. However, the DNA which was in contact with the enzyme, close to the active site, was well ordered and allowed detailed analysis of the enzyme-DNA interaction. The complex revealed that the interaction between DrUNG and DNA is similar to that in the previously determined crystal structure of human UNG (hUNG) in complex with DNA [Slupphaug et al. (1996). Nature (London), 384, 87-92]. Substitutions in a (here defined) variable part of the leucine loop result in a shorter loop (eight residues instead of nine) in DrUNG compared with hUNG; regardless of this, it seems to fulfil its role and generate a stabilizing force with the minor groove upon flipping out of the damaged base into the active site. The structure also provides a rationale for the previously observed high catalytic efficiency of DrUNG caused by high substrate affinity by demonstrating an increased number of long-range electrostatic interactions between the enzyme and the DNA. Interestingly, specific interactions between residues

Synthesis of the derivatives of 6-amino-uracil labelled with C-14

Czech Academy of Sciences Publication Activity Database

Elbert, Tomáš; Hezký, Petr; Jansa, Petr

2016-01-01

Roč. 59, č. 14 (2016), s. 615-618 ISSN 0362-4803. [International Isotope Symposium on the Synthesis and Applications of Isotopes and Isotopically Labelled Compounds /12./. Princeton, 07.06.2015-11.06.2015] R&D Projects: GA MŠk LG13002 Institutional support: RVO:61388963 Keywords : 6-amino-uracil derivatives * specific activity assay using NMR * [C-14]cyanoacetic acid Subject RIV: CC - Organic Chemistry Impact factor: 1.745, year: 2016

Uracil DNA glycosylase counteracts APOBEC3G-induced hypermutation of hepatitis B viral genomes: excision repair of covalently closed circular DNA.

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Kouichi Kitamura

Full Text Available The covalently closed circular DNA (cccDNA of the hepatitis B virus (HBV plays an essential role in chronic hepatitis. The cellular repair system is proposed to convert cytoplasmic nucleocapsid (NC DNA (partially double-stranded DNA into cccDNA in the nucleus. Recently, antiviral cytidine deaminases, AID/APOBEC proteins, were shown to generate uracil residues in the NC-DNA through deamination, resulting in cytidine-to-uracil (C-to-U hypermutation of the viral genome. We investigated whether uracil residues in hepadnavirus DNA were excised by uracil-DNA glycosylase (UNG, a host factor for base excision repair (BER. When UNG activity was inhibited by the expression of the UNG inhibitory protein (UGI, hypermutation of NC-DNA induced by either APOBEC3G or interferon treatment was enhanced in a human hepatocyte cell line. To assess the effect of UNG on the cccDNA viral intermediate, we used the duck HBV (DHBV replication model. Sequence analyses of DHBV DNAs showed that cccDNA accumulated G-to-A or C-to-T mutations in APOBEC3G-expressing cells, and this was extensively enhanced by UNG inhibition. The cccDNA hypermutation generated many premature stop codons in the P gene. UNG inhibition also enhanced the APOBEC3G-mediated suppression of viral replication, including reduction of NC-DNA, pre-C mRNA, and secreted viral particle-associated DNA in prolonged culture. Enhancement of APOBEC3G-mediated suppression by UNG inhibition was not observed when the catalytic site of APOBEC3G was mutated. Transfection experiments of recloned cccDNAs revealed that the combination of UNG inhibition and APOBEC3G expression reduced the replication ability of cccDNA. Taken together, these data indicate that UNG excises uracil residues from the viral genome during or after cccDNA formation in the nucleus and imply that BER pathway activities decrease the antiviral effect of APOBEC3-mediated hypermutation.

A unique dual recognition hairpin probe mediated fluorescence amplification method for sensitive detection of uracil-DNA glycosylase and endonuclease IV activities.

Science.gov (United States)

Wu, Yushu; Yan, Ping; Xu, Xiaowen; Jiang, Wei

2016-03-07

Uracil-DNA glycosylase (UDG) and endonuclease IV (Endo IV) play cooperative roles in uracil base-excision repair (UBER) and inactivity of either will interrupt the UBER to cause disease. Detection of UDG and Endo IV activities is crucial to evaluate the UBER process in fundamental research and diagnostic application. Here, a unique dual recognition hairpin probe mediated fluorescence amplification method was developed for sensitively and selectively detecting UDG and Endo IV activities. For detecting UDG activity, the uracil base in the probe was excised by the target enzyme to generate an apurinic/apyrimidinic (AP) site, achieving the UDG recognition. Then, the AP site was cleaved by a tool enzyme Endo IV, releasing a primer to trigger rolling circle amplification (RCA) reaction. Finally, the RCA reaction produced numerous repeated G-quadruplex sequences, which interacted with N-methyl-mesoporphyrin IX to generate an enhanced fluorescence signal. Alternatively, for detecting Endo IV activity, the uracil base in the probe was first converted into an AP site by a tool enzyme UDG. Next, the AP site was cleaved by the target enzyme, achieving the Endo IV recognition. The signal was then generated and amplified in the same way as those in the UDG activity assay. The detection limits were as low as 0.00017 U mL(-1) for UDG and 0.11 U mL(-1) for Endo IV, respectively. Moreover, UDG and Endo IV can be well distinguished from their analogs. This method is beneficial for properly evaluating the UBER process in function studies and disease prognoses.

Synthesis of novel 1H-1,2,3-triazole tethered C-5 substituted uracil-isatin conjugates and their cytotoxic evaluation

KAUST Repository

Kumar, Kewal; Sagar, Sunil; Esau, Luke; Kaur, Mandeep; Kumar, Vipan

2012-01-01

The present manuscript describes the synthesis of uracil-isatin hybrids via azide-alkyne cycloadditions and their cytotoxic evaluation against three human cancer cell lines viz. HeLa (cervix), MCF-7 (breast) and DU145 (prostate) using MTT assay. The evaluation studies revealed the dependence of cytotoxicity on C-5 substituents of both uracil and isatin as well as the alkyl chain length with compounds 6g and 6k showing IC50 values 18.21 and 13.90 μM respectively against DU145 cell lines. Most of the synthesized conjugates exhibited considerable selectivity against MCF-7 and DU145 cell lines. © 2012 Elsevier Masson SAS. All rights reserved.

Synthesis of novel 1H-1,2,3-triazole tethered C-5 substituted uracil-isatin conjugates and their cytotoxic evaluation

KAUST Repository

Kumar, Kewal

2012-12-01

The present manuscript describes the synthesis of uracil-isatin hybrids via azide-alkyne cycloadditions and their cytotoxic evaluation against three human cancer cell lines viz. HeLa (cervix), MCF-7 (breast) and DU145 (prostate) using MTT assay. The evaluation studies revealed the dependence of cytotoxicity on C-5 substituents of both uracil and isatin as well as the alkyl chain length with compounds 6g and 6k showing IC50 values 18.21 and 13.90 μM respectively against DU145 cell lines. Most of the synthesized conjugates exhibited considerable selectivity against MCF-7 and DU145 cell lines. © 2012 Elsevier Masson SAS. All rights reserved.

Photodissociation dynamics of the iodide-uracil (I{sup −}U) complex

Energy Technology Data Exchange (ETDEWEB)

Li, Wei-Li; Kunin, Alice [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Matthews, Edward; Yoshikawa, Naruo; Dessent, Caroline E. H., E-mail: dneumark@berkeley.edu, E-mail: caroline.dessent@york.ac.uk [Department of Chemistry, University of York, Heslington, York YO10 5DD (United Kingdom); Neumark, Daniel M., E-mail: dneumark@berkeley.edu, E-mail: caroline.dessent@york.ac.uk [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2016-07-28

Photofragment action spectroscopy and femtosecond time-resolved photoelectron imaging are utilized to probe the dissociation channels in iodide-uracil (I{sup −} ⋅ U) binary clusters upon photoexcitation. The photofragment action spectra show strong I{sup −} and weak [U—H]{sup −} ion signal upon photoexcitation. The action spectra show two bands for I{sup −} and [U—H]{sup −} production peaking around 4.0 and 4.8 eV. Time-resolved experiments measured the rate of I{sup −} production resulting from excitation of the two bands. At 4.03 eV and 4.72 eV, the photoelectron signal from I{sup −} exhibits rise times of 86 ± 7 ps and 36 ± 3 ps, respectively. Electronic structure calculations indicate that the lower energy band, which encompasses the vertical detachment energy (4.11 eV) of I{sup −}U, corresponds to excitation of a dipole-bound state of the complex, while the higher energy band is primarily a π–π{sup ∗} excitation on the uracil moiety. Although the nature of the two excited states is very different, the long lifetimes for I{sup −} production suggest that this channel results from internal conversion to the I{sup −} ⋅ U ground state followed by evaporation of I{sup −}. This hypothesis was tested by comparing the dissociation rates to Rice-Ramsperger-Kassel-Marcus calculations.

Photoinduced electron transfer in a Watson-Crick base-paired, 2-aminopurine:uracil-C60 hydrogen bonding conjugate.

Science.gov (United States)

D'Souza, Francis; Gadde, Suresh; Islam, D-M Shafiqul; Pang, Siew-Cheng; Schumacher, Amy Lea; Zandler, Melvin E; Horie, Rumiko; Araki, Yasuyaki; Ito, Osamu

2007-02-07

A fluorescent reporter molecule, 2-aminopurine was self-assembled via Watson-Crick base-pairing to a uracil appended fullerene to form a donor-acceptor conjugate; efficient photoinduced charge separation was confirmed by time-resolved emission and transient absorption spectral studies.

Visual and light scattering spectrometric method for the detection of melamine using uracil 5‧-triphosphate sodium modified gold nanoparticles

Science.gov (United States)

Liang, Lijiao; Zhen, Shujun; Huang, Chengzhi

2017-02-01

A highly selective method was presented for colorimetric determination of melamine using uracil 5‧-triphosphate sodium modified gold nanoparticles (UTP-Au NPs) in this paper. Specific hydrogen-bonding interaction between uracil base (U) and melamine resulted in the aggregation of AuNPs, displaying variations of localized surface plasmon resonance (LSPR) features such as color change from red to blue and enhanced localized surface plasmon resonance light scattering (LSPR-LS) signals. Accordingly, the concentration of melamine could be quantified based on naked eye or a spectrometric method. This method was simple, inexpensive, environmental friendly and highly selective, which has been successfully used for the detection of melamine in pretreated liquid milk products with high recoveries.

Toehold-mediated strand displacement reaction-dependent fluorescent strategy for sensitive detection of uracil-DNA glycosylase activity.

Science.gov (United States)

Wu, Yushu; Wang, Lei; Jiang, Wei

2017-03-15

Sensitive detection of uracil-DNA glycosylase (UDG) activity is beneficial for evaluating the repairing process of DNA lesions. Here, toehold-mediated strand displacement reaction (TSDR)-dependent fluorescent strategy was constructed for sensitive detection of UDG activity. A single-stranded DNA (ssDNA) probe with two uracil bases and a trigger sequence were designed. A hairpin probe with toehold domain was designed, and a reporter probe was also designed. Under the action of UDG, two uracil bases were removed from ssDNA probe, generating apurinic/apyrimidinic (AP) sites. Then, the AP sites could inhibit the TSDR between ssDNA probe and hairpin probe, leaving the trigger sequence in ssDNA probe still free. Subsequently, the trigger sequence was annealed with the reporter probe, initiating the polymerization and nicking amplification reaction. As a result, numerous G-quadruplex (G4) structures were formed, which could bind with N-methyl-mesoporphyrin IX (NMM) to generate enhanced fluorescent signal. In the absence of UDG, the ssDNA probe could hybridize with the toehold domain of the hairpin probe to initiate TSDR, blocking the trigger sequence, and then the subsequent amplification reaction would not occur. The proposed strategy was successfully implemented for detecting UDG activity with a detection limit of 2.7×10 -5 U/mL. Moreover, the strategy could distinguish UDG well from other interference enzymes. Furthermore, the strategy was also applied for detecting UDG activity in HeLa cells lysate with low effect of cellular components. These results indicated that the proposed strategy offered a promising tool for sensitive quantification of UDG activity in UDG-related function study and disease prognosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Allosteric regulation of the GTP activated and CTP inhibited uracil phosphoribosyltransferase from the thermophilic archaeon Sulfolobus solfataricus

DEFF Research Database (Denmark)

Jensen, Kaj Frank; Arent, Susan; Larsen, Sine

2005-01-01

The upp gene, encoding uracil phosphoribosyltransferase (UPRTase) from the thermoacidophilic archaeon Sulfolobus solfataricus, was cloned and expressed in Escherichia coli. The enzyme was purified to homogeneity. It behaved as a tetramer in solution and showed optimal activity at pH 5.5 when...... assayed at 60 °C. Enzyme activity was strongly stimulated by GTP and inhibited by CTP. GTP caused an approximately 20-fold increase in the turnover number kcat and raised the Km values for 5-phosphoribosyl-1-diphosphate (PRPP) and uracil by two- and >10-fold, respectively. The inhibition by CTP...... was complex as it depended on the presence of the reaction product UMP. Neither CTP nor UMP were strong inhibitors of the enzyme, but when present in combination their inhibition was extremely powerful. Ligand binding analyses showed that GTP and PRPP bind cooperatively to the enzyme and that the inhibitors...

A Novel Synthesis of Fused Uracils: Indenopyrimidopyridazines, Pyrimidopyridazines, and Pyrazolopyrimidines for Antimicrobial and Antitumor Evalution

Directory of Open Access Journals (Sweden)

Samar El-Kalyoubi

2016-12-01

Full Text Available A variety of different compounds of fused uracils were prepared simply by the heating of 6-hydrazinyl-1-methyl-, 6-hydrazinyl-1-propyl-, or 6-hydrazinyl-1,3-dipropyluracil under reflux with ninhydrin, isatin, benzylidene malononitrile, benzylylidene ethyl cyanoacetate, benzil, and phenacyl bromide derivatives. The newly synthesized compounds were completely screened for antimicrobial and antitumor activity.

Retrospective analysis of an oral combination of dexamethasone, uracil plus tegafur and cyclophosphamide for hormone-refractory prostate cancer.

Science.gov (United States)

Hatano, Koji; Nonomura, Norio; Nishimura, Kazuo; Kawashima, Atsunari; Mukai, Masatoshi; Nagahara, Akira; Nakai, Yasutomo; Nakayama, Masashi; Takayama, Hitoshi; Tsujimura, Akira; Okuyama, Akihiko

2011-02-01

To evaluate the clinical utility of an oral combination of dexamethasone, uracil plus tegafur and cyclophosphamide as a treatment for patients with hormone-refractory prostate cancer. Fifty-seven patients with hormone-refractory prostate cancer were treated with an oral administration of dexamethasone (1.0 mg/day), uracil plus tegafur (400 mg/day) and cyclophosphamide (100 mg/day). The median patient age was 71 years. Sixteen patients had symptomatic bone metastasis, 31 had asymptomatic bone metastasis and 8 showed lymph node metastasis. Eight patients presented with only biochemical progression as evaluated by serum prostate-specific antigen levels. Thirty-six (63%) of 57 patients demonstrated a ≥50% decline in serum prostate-specific antigen levels. The median time to prostate-specific antigen progression was 7.2 months. In patients with a prostate-specific antigen decline of ≥50%, the median time to progression was 13.3 months. With respect to pre-treatment markers, the duration of response to initial hormonal treatment was associated with the time to prostate-specific antigen progression. In 11 of 16 (69%) patients who complained of bone pain, the pain improved and became stable in 5 of those patients (31%). Most adverse events were mild and only three (5%) patients showed neutropenia of Grade 3 or higher. The combination of dexamethasone, uracil plus tegafur and cyclophosphamide is an effective and well tolerated regimen for hormone-refractory prostate cancer. To evaluate the survival benefits, further randomized studies are required.

Mechanism for the abiotic synthesis of uracil via UV-induced oxidation of pyrimidine in pure H2O ices under astrophysical conditions

International Nuclear Information System (INIS)

Bera, Partha P.; Nuevo, Michel; Sandford, Scott A.; Lee, Timothy J.; Milam, Stefanie N.

2010-01-01

The UV photoirradiation of pyrimidine in pure H 2 O ices has been explored using second-order Moeller-Plesset perturbation theory and density functional theory methods, and compared with experimental results. Mechanisms studied include those starting with neutral pyrimidine or cationic pyrimidine radicals, and reacting with OH radical. The ab initio calculations reveal that the formation of some key species, including the nucleobase uracil, is energetically favored over others. The presence of one or several water molecules is necessary in order to abstract a proton which leads to the final products. Formation of many of the photoproducts in UV-irradiated H 2 O:pyrimidine=20:1 ice mixtures was established in a previous experimental study. Among all the products, uracil is predicted by quantum chemical calculations to be the most favored, and has been identified in experimental samples by two independent chromatography techniques. The results of the present study strongly support the scenario in which prebiotic molecules, such as the nucleobase uracil, can be formed under abiotic processes in astrophysically relevant environments, namely in condensed phase on the surface of icy, cold grains before being delivered to the telluric planets, like Earth.

Exploration of acetanilide derivatives of 1-(ω-phenoxyalkyl)uracils as novel inhibitors of Hepatitis C Virus replication.

Science.gov (United States)

Magri, Andrea; Ozerov, Alexander A; Tunitskaya, Vera L; Valuev-Elliston, Vladimir T; Wahid, Ahmed; Pirisi, Mario; Simmonds, Peter; Ivanov, Alexander V; Novikov, Mikhail S; Patel, Arvind H

2016-07-12

Hepatitis C Virus (HCV) is a major public health problem worldwide. While highly efficacious directly-acting antiviral agents have been developed in recent years, their high costs and relative inaccessibility make their use limited. Here, we describe new 1-(ω-phenoxyalkyl)uracils bearing acetanilide fragment in 3 position of pyrimidine ring as potential antiviral drugs against HCV. Using a combination of various biochemical assays and in vitro virus infection and replication models, we show that our compounds are able to significantly reduce viral genomic replication, independently of virus genotype, with their IC50 values in the nanomolar range. We also demonstrate that our compounds can block de novo RNA synthesis and that effect is dependent on a chemical structure of the compounds. A detailed structure-activity relationship revealed that the most active compounds were the N(3)-substituted uracil derivatives containing 6-(4-bromophenoxy)hexyl or 8-(4-bromophenoxy)octyl fragment at N(1) position.

Photochemical exchange reactions of thymine, uracil and their nucleosides with selected amino acids

International Nuclear Information System (INIS)

Shetlar, M.D.; Taylor, J.A.; Hom, K.

1984-01-01

The photoinduced exchange reactions of thymine with lysine at basic pH, using 254 nm light, have been studied. Three products have been isolated, namely, 6-amino-2-(1-thyminyl)hexanoic acid (Ia), 2-amino-6-(1-thyminyl)hexanoic acid (IIa) and 1-amino-5-(1-thyminyl)pentane (IIIa). Compound IIIa was shown to be a secondary product, produced by photochemical decarboxylation of Ia. Photochemical reaction of thymine with glycine and alanine at basic pH led, respectively, to formation of 2-(1-thyminyl)acetic acid (Ic) and 2-(1-thyminyl)propionic acid (Id). Compounds Ic and Id underwent photolysis to produce the decarboxylated secondary products 1-methylthymine and 1-ethylthymine, respectively. Thymidine reacts photochemically with glycine and alanine to produce the same products. Irradiation of DNA in the presence of lysine at basic pH led to the formation of the same products formed in the thymine-lysine system, namely Ia, IIa and IIIa. Uracil was found to undergo analogous photochemical exchange reactions with lysine to form 6-amino-2-(1-uracilyl)hexanoic acid (Ib), and 2-amino-6-(1-uracilyl)hexanoic acid (IIb). Compound Ib was found to undergo photodecarboxylation to form 1-amino-5-(1-uracilyl)pentane (IIIb), analogous to the secondary photoreaction of Ia. Photoreaction of uracil with 1,5-diaminopentane (cadaverine) likewise led to formation of IIIb. (author)

Capturing complex human behaviors in representative sports contexts with a single camera.

Science.gov (United States)

Duarte, Ricardo; Araújo, Duarte; Fernandes, Orlando; Fonseca, Cristina; Correia, Vanda; Gazimba, Vítor; Travassos, Bruno; Esteves, Pedro; Vilar, Luís; Lopes, José

2010-01-01

In the last years, several motion analysis methods have been developed without considering representative contexts for sports performance. The purpose of this paper was to explain and underscore a straightforward method to measure human behavior in these contexts. Procedures combining manual video tracking (with TACTO device) and bidimensional reconstruction (through direct linear transformation) using a single camera were used in order to capture kinematic data required to compute collective variable(s) and control parameter(s). These procedures were applied to a 1vs1 association football task as an illustrative subphase of team sports and will be presented in a tutorial fashion. Preliminary analysis of distance and velocity data identified a collective variable (difference between the distance of the attacker and the defender to a target defensive area) and two nested control parameters (interpersonal distance and relative velocity). Findings demonstrated that the complementary use of TACTO software and direct linear transformation permit to capture and reconstruct complex human actions in their context in a low dimensional space (information reduction).

Investigation of tritium tracer in nucleic acid components by hydrogenolysis of corresponding precursors. 7. Preparation of tritiated uracil, uridine-5'-mono-, di- and triphosphates of high molar activity

Energy Technology Data Exchange (ETDEWEB)

Myasoedov, N F; Sidorov, G V; Kuznetsova, O B; Frank-Kamenetskaya, M D; Lazurkina, T Yu; Orlova, V A

1984-01-01

Preparation of (5,6-/sup 3/H) uracil by hydrogenolysis of 5-bromo-6-chlorouracil with molar activity (1.59-1.63)x10/sup 15/ Bg/mol has been described. Hydrogenolysis reaction kinetics is studied, effect of the reaction conditions on molar activity of dehalogenation product is considered. Using enzyme fraction, separated from the E.coli cells tritium-labelled preparations of UMP, UTP and UTP from (5.6-/sup 3/H) uracil are made. Kinetics of enzymatic reactions is studied and conditions, permitting to synthesize both UMP and UTP and a mixture of nucleotides of different degree of phosphorylation in approximately equal amounts are selected. Separation of nucleotides labelled with tritium is conducted using ion exchange chromatography on DEAE cellulose. Molar activity of nucleotides labelled with tritium equals molar activity of initial (5.6-/sup 3/H) uracil, and radiochemical purity constitutes more than 95%.

Electron-Impact Excitation of Uracil Luminescence on a Ceramic Surface

Science.gov (United States)

Shafranyosh, I. I.; Mitropolskiy, I. E.; Kuzma, V. V.; Svyda, Yu. Yu.; Sukhoviya, M. I.

2018-03-01

Photoelectron spectroscopy was applied to pyrimidine nitrogenous bases, an important class of six-membered heterocyclic compounds incorporated into nucleic acids. The emission spectrum of uracil adsorbed on a ceramic surface that was obtained by bombardment with 600-eV electrons in a high vacuum was analyzed. Broad bands with maxima at 335, 435, and 495 nm were observed in the UV and visible regions. The strongest band (λ = 335 nm) was attributed to fluorescence and corresponded to a singlet-singlet transition from the first excited electronic state into the molecular ground state. Electronic transitions from a triplet T1 into the ground state formed a weaker phosphorescence band (λ = 435 nm). The nature of the band maximum at 495 nm is discussed. The obtained luminescence spectrum was compared with photoluminescence spectra in various phases.

E. S. R. studies of halogenated pyrimidines in. gamma. -irradiated alkaline glasses. [Halogenated uracil bases; bromouridine; bromodeoxyuridine

Energy Technology Data Exchange (ETDEWEB)

Simpson, L D; Zimbrick, J D [Kansas Univ., Lawrence (USA)

1975-11-01

The reactions of mobile electrons (e/sup -//sub m/) and oxygen radical anions (O./sup -/) with halogenated bases and nucleosides have been studied in ..gamma..-irradiated alkaline glasses by e.s.r. and specific halogen-ion electrode techniques. It was shown that electrons react with halogenated uracil bases (XUr where X = Cl, Br, I but not F) by dissociative electron attachment to form uracil-5-yl radicals (U.) and halogen anions. The relative rates of reaction of e/sup -//sub m/ with XUr decreased in the sequence BrUr > ClUr > FUr > IUr. Thermal annealing studies carried out on U. in H/sub 2/O and D/sub 2/O matrices supported the hypothesis that U. in H/sub 2/O hydrates across the 5-6 double bond in the temperature region 135/sup 0/ to 155/sup 0/ K, and deuterates to a much smaller extent in D/sub 2/O at temperatures above 155/sup 0/ K. Studies on bromouridine and bromodeoxyuridine suggested that e/sup -/sub(m) reacts with the base moieties to form U. type radicals which abstract H. from the sugar moieties of adjacent nucleosides.

Structural and kinetic studies of the allosteric transition in Sulfolobus solfataricus uracil phosphoribosyltransferase: Permanent activation by engineering of the C-terminus

DEFF Research Database (Denmark)

Christoffersen, Stig; Kadziola, Anders; Johansson, Eva

2009-01-01

and PPi, in the other sites. Combined with three existing structures of uracil phosphoribosyltransferase in complex with UMP and the allosteric inhibitor cytidine triphosphate (CTP), these structures provide valuable insight into the mechanism of allosteric transition from inhibited to active enzyme...

Effect of salt on a thermosensitive mutant of Bacillus subtilis deficient in uracil and cell division

International Nuclear Information System (INIS)

Miyazaki, Nobuyoshi; Nagai, Kazuo; Tamura, Gakuzo

1976-01-01

A thermosensitive mutant ts 42, of Bacillus subtilis Marburg 168 thy trp2 which requires uracil, was examined as to the colony-forming ability at the permissive and nonpermissive temperatures. The viability of the mutant cells decreased rapidly at the restrictive temperature in modified woese's medium. However, the cells retained the viability when sodium succinate or potassium chloride was added to the medium at that temperature, although uranil deficiency was unchanged. A little but significant incorporation of adenine-8- 14 C into RNA still continued even after the incorporation of N-acetyl- 3 H-D-glucosamine into the acid-insoluble fraction of the cells terminated in the modified Woese's medium at 48 0 C. Both incorporations as well as the increase of absorbance were slowed down in the presence of sodium succinate at 48 0 C. This mutant, ts42, was more sensitive to deoxycholate than the parent wild strain. The resoration of the colony-forming ability after the temperature shifted back from 48 0 to 37 0 C was suppressed by the addition of deoxycholate to the medium. However, the cells became resistant to deoxycholate when uracil had been added to the medium prior to the temperature shift. (Kobatake, H.)

A framework for extracting and representing project knowledge contexts using topic models and dynamic knowledge maps

Science.gov (United States)

Xu, Jin; Li, Zheng; Li, Shuliang; Zhang, Yanyan

2015-07-01

There is still a lack of effective paradigms and tools for analysing and discovering the contents and relationships of project knowledge contexts in the field of project management. In this paper, a new framework for extracting and representing project knowledge contexts using topic models and dynamic knowledge maps under big data environments is proposed and developed. The conceptual paradigm, theoretical underpinning, extended topic model, and illustration examples of the ontology model for project knowledge maps are presented, with further research work envisaged.

A new and efficient approach for construction of uridine/uracil auxotrophic mutants in the filamentous fungus Aspergillus oryzae using Agrobacterium tumefaciens-mediated transformation.

Science.gov (United States)

Nguyen, Khuyen Thi; Ho, Quynh Ngoc; Do, Loc Thi Binh Xuan; Mai, Linh Thi Dam; Pham, Duc-Ngoc; Tran, Huyen Thi Thanh; Le, Diep Hong; Nguyen, Huy Quang; Tran, Van-Tuan

2017-06-01

Aspergillus oryzae is a filamentous fungus widely used in food industry and as a microbial cell factory for recombinant protein production. Due to the inherent resistance of A. oryzae to common antifungal compounds, genetic transformation of this mold usually requires auxotrophic mutants. In this study, we show that Agrobacterium tumefaciens-mediated transformation (ATMT) method is very efficient for deletion of the pyrG gene in different Aspergillus oryzae wild-type strains to generate uridine/uracil auxotrophic mutants. Our data indicated that all the obtained uridine/uracil auxotrophic transformants, which are 5- fluoroorotic acid (5-FOA) resistant, exist as the pyrG deletion mutants. Using these auxotrophic mutants and the pyrG selectable marker for genetic transformation via A. tumefaciens, we could get about 1060 transformants per 10 6 fungal spores. In addition, these A. oryzae mutants were also used successfully for expression of the DsRed fluorescent reporter gene under control of the A. oryzae amyB promoter by the ATMT method, which resulted in obvious red transformants on agar plates. Our work provides a new and effective approach for constructing the uridine/uracil auxotrophic mutants in the importantly industrial fungus A. oryzae. This strategy appears to be applicable to other filamentous fungi to develop similar genetic transformation systems based on auxotrophic/nutritional markers for food-grade recombinant applications.

Human cytomegalovirus uracil DNA glycosylase associates with ppUL44 and accelerates the accumulation of viral DNA

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Dixon Melissa

2005-07-01

Full Text Available Abstract Background Human cytomegalovirus UL114 encodes a uracil-DNA glycosylase homolog that is highly conserved in all characterized herpesviruses that infect mammals. Previous studies demonstrated that the deletion of this nonessential gene delays significantly the onset of viral DNA synthesis and results in a prolonged replication cycle. The gene product, pUL114, also appears to be important in late phase DNA synthesis presumably by introducing single stranded breaks. Results A series of experiments was performed to formally assign the observed phenotype to pUL114 and to characterize the function of the protein in viral replication. A cell line expressing pUL114 complemented the observed phenotype of a UL114 deletion virus in trans, confirming that the observed defects were the result of a deficiency in this gene product. Stocks of recombinant viruses without elevated levels of uracil were produced in the complementing cells; however they retained the phenotype of poor growth in normal fibroblasts suggesting that poor replication was unrelated to uracil content of input genomes. Recombinant viruses expressing epitope tagged versions of this gene demonstrated that pUL114 was expressed at early times and that it localized to viral replication compartments. This protein also coprecipitated with the DNA polymerase processivity factor, ppUL44 suggesting that these proteins associate in infected cells. This apparent interaction did not appear to require other viral proteins since ppUL44 could recruit pUL114 to the nucleus in uninfected cells. An analysis of DNA replication kinetics revealed that the initial rate of DNA synthesis and the accumulation of progeny viral genomes were significantly reduced compared to the parent virus. Conclusion These data suggest that pUL114 associates with ppUL44 and that it functions as part of the viral DNA replication complex to increase the efficiency of both early and late phase viral DNA synthesis.

E. s. r. of free radicals in irradiated uracil-. beta. -D-arabinofuranoside

Energy Technology Data Exchange (ETDEWEB)

Bergene, R [Oslo Univ. (Norway). Fysisk Institutt; Vaughan, R A

1976-02-01

Electron-spin-resonance measurements have been made on single crystals of uracil-..beta..-D-arabinofuranoside, which were irradiated by 4.0 MeV electrons at 77 K. At low temperatures, two radicals have been identified, one attributed to a hydrogen abstraction of 05' in the sugar moiety and the other to a radical anion located on the pyrimidine ring. The former was very unstable and seemed to act as a precursor to other unidentified radical species stable at 77 K. At room temperature, the main resonance was due to hydrogen addition to C5 and was probably produced by protonation of the anion. This same radical was also produced by irradiation at room temperature.

Photoelectron spectrum of valence anions of uracil and first-principles calculations of excess electron binding energies.

Science.gov (United States)

Bachorz, Rafał A; Klopper, Wim; Gutowski, Maciej; Li, Xiang; Bowen, Kit H

2008-08-07

The photoelectron spectrum (PES) of the uracil anion is reported and discussed from the perspective of quantum chemical calculations of the vertical detachment energies (VDEs) of the anions of various tautomers of uracil. The PES peak maximum is found at an electron binding energy of 2.4 eV, and the width of the main feature suggests that the parent anions are in a valence rather than a dipole-bound state. The canonical tautomer as well as four tautomers that result from proton transfer from an NH group to a C atom were investigated computationally. At the Hartree-Fock and second-order Moller-Plesset perturbation theory levels, the adiabatic electron affinity (AEA) and the VDE have been converged to the limit of a complete basis set to within +/-1 meV. Post-MP2 electron-correlation effects have been determined at the coupled-cluster level of theory including single, double, and noniterative triple excitations. The quantum chemical calculations suggest that the most stable valence anion of uracil is the anion of a tautomer that results from a proton transfer from N1H to C5. It is characterized by an AEA of 135 meV and a VDE of 1.38 eV. The peak maximum is as much as 1 eV larger, however, and the photoelectron intensity is only very weak at 1.38 eV. The PES does not lend support either to the valence anion of the canonical tautomer, which is the second most stable anion, and whose VDE is computed at about 0.60 eV. Agreement between the peak maximum and the computed VDE is only found for the third most stable tautomer, which shows an AEA of approximately -0.1 eV and a VDE of 2.58 eV. This tautomer results from a proton transfer from N3H to C5. The results illustrate that the characteristics of biomolecular anions are highly dependent on their tautomeric form. If indeed the third most stable anion is observed in the experiment, then it remains an open question why and how this species is formed under the given conditions.

The radiation stability of the RNA base uracil in H2O-ice and CO2-ice: in-situ laboratory measurements with applications to comets, Europa, and Mars

Science.gov (United States)

Gerakines, Perry A.; Frail, Sarah; Hudson, Reggie L.

2017-10-01

Planetary bodies of astrobiological interest, such as Mars, are often exposed to harsh incident radiation, which will influence the times that molecules can survive on them. Some or all of these bodies may well contain biologically-important organic molecules, some may even have supported life at some point in their history, and some may support life today. Future searches for organic molecules likely will include sampling the martian subsurface or a cometary surface sample return mission, where organics may be frozen in ices dominated by either H2O or CO2, which provide some protection from ionizing radiation.Recently, our research group has published studies of the radiation stability of amino acids, with a focus on glycine - in both undiluted form and in mixtures with H2O and CO2. Here, we present a similar study that focuses on the radiation-chemical kinetics of the RNA base uracil. We compare results for uracil decay for dilution in both H2O and CO2 ices. Moreover, we compare these new results with those for glycine. For each sample, we measured uracil’s destruction rate constant and half-life dose due to irradiation by 0.9-MeV protons. All measurements were made in situ at the temperature of irradiation using IR spectroscopy. Trends with dilution (up to ~300:1) and temperature (up to ~150 K) are considered, and results are discussed in the context of icy planetary surfaces.Acknowledgment: Our work is supported in part by the NASA Emerging Worlds Program and by the NASA Astrobiology Institute through the Goddard Center for Astrobiology.

Unravelling the potential of a new uracil phosphoribosyltransferase (UPRT) from Arabidopsis thaliana in sensitizing HeLa cells towards 5-fluorouracil.

Science.gov (United States)

Narayanan, Sharmila; Sanpui, Pallab; Sahoo, Lingaraj; Ghosh, Siddhartha Sankar

2016-10-01

In silico studies with uracil phosphoribosyltransferase from Arabidopsis thaliana (AtUPRT) revealed its lower binding energies for uracil and 5-fluorouracil (5-FU) as compared to those of bacterial UPRT indicating the prospective of AtUPRT in gene therapy implications. Hence, AtUPRT was cloned and stably expressed in cervical cancer cells (HeLa) to investigate the effect of prodrug 5-FU on these transfected cancer cells. The treatment of AtUPRT-expressing HeLa (HeLa-UPP) cells with 5-FU for 72h resulted in significant decrease in cell viability. Moreover, 5-FU was observed to induce apoptosis and perturb mitochondrial membrane potential in HeLa-UPP cells. While cell cycle analysis revealed significant S-phase arrest as a result of 5-FU treatment in HeLa-UPP cells, quantitative gene expression analysis demonstrated simultaneous upregulation of important cell cycle related genes, cyclin D1 and p21. The survival fractions of non-transfected, vector-transfected and AtUPRT-transfected HeLa cells, following 5-FU treatment, were calculated to be 0.425, 0.366 and 0.227, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Preparation of nucleoside-pyridine hybrids and pyridine attached acylureas from an unexpected uracil ring-opening and pyridine ring-forming sequence

Institute of Scientific and Technical Information of China (English)

Xue Sen Fan; Xia Wang; Xin Ying Zhang; Dong Feng; Ying Ying Qu

2009-01-01

Novel pyrimidine nucleoside-3,5-dicyanopyridine hybrids (4) or pyridine attached acylureas (5) were selectively and efficiently prepared from the reaction of 2'-deoxyuridin-5-yl-methylene malonortitrile (1), malononitrile (2) and thiophenol (3) or from an unexpected uracil ring-opening and pyridine ring-forming sequence via the reaction of 1 and 3. It is the first time such a sequence has ever been reported.

Sexual Violence Experienced in the Sport Context by a Representative Sample of Quebec Adolescents

Science.gov (United States)

Parent, Sylvie; Lavoie, Francine; Thibodeau, Marie-Ève; Hébert, Martine; Blais, Martin

2016-01-01

This is the first study to report the prevalence of sexual violence perpetrated by a sport coach within a representative sample of the general population of adolescents aged between 14 and 17 years (N = 6 450). The questionnaire administered in high schools includes self-reported measures on a variety of dimensions relevant to the study of victimization, including sexual abuse, sexual contacts perceived as consensual, sexual harassment and involvement in an organized sport context. Descriptive and chi-square analyses were performed. The results show that 0.5% of adolescents experienced sexual abuse involving a coach. When considering all adolescents who experienced sexual abuse in their lifetime (10.2%), it appears that 5.3% of them were victims of sexual abuse by a coach. Participants also reported experiencing sexual harassment from a coach (0.4%) and consensual sexual contacts (1.2%) with a coach in the 12 months preceeding the study. Questions are raised on the overrepresentation of boys in situations of sexual victimization experiences in an organized sport context. PMID:25873593

Investigation of aromatase inhibitory activity of metal complexes of 8-hydroxyquinoline and uracil derivatives

Directory of Open Access Journals (Sweden)

Prachayasittikul V

2014-08-01

Full Text Available Veda Prachayasittikul,1 Ratchanok Pingaew,2 Chanin Nantasenamat,3 Supaluk Prachayasittikul,3 Somsak Ruchirawat,4,5 Virapong Prachayasittikul1 1Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand; 2Department of Chemistry, Faculty of Science, Srinakharinwirot University, Bangkok, Thailand; 3Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand; 4Laboratory of Medicinal Chemistry, Chulabhorn Research Institute, 5Chulabhorn Graduate Institute, Bangkok, Thailand Purpose: Estrogens play important roles in the pathogenesis and progression of breast cancer as well as estrogen-related diseases. Aromatase is a key enzyme in the rate-limiting step of estrogen production, in which its inhibition is one strategy for controlling estrogen levels to improve prognosis of estrogen-related cancers and diseases. Herein, a series of metal (Mn, Cu, and Ni complexes of 8-hydroxyquinoline (8HQ and uracil derivatives (4–9 were investigated for their aromatase inhibitory and cytotoxic activities. Methods: The aromatase inhibition assay was performed according to a Gentest™ kit using CYP19 enzyme, wherein ketoconazole and letrozole were used as reference drugs. The cytotoxicity was tested on normal embryonic lung cells (MRC-5 using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Results: Only Cu complexes (6 and 9 exhibited aromatase inhibitory effect with IC50 0.30 and 1.7 µM, respectively. Cytotoxicity test against MRC-5 cells showed that Mn and Cu complexes (5 and 6, as well as free ligand 8HQ, exhibited activity with IC50 range 0.74–6.27 µM. Conclusion: Cu complexes (6 and 9 were found to act as a novel class of aromatase inhibitor. Our findings suggest that these 8HQ–Cu–uracil complexes are promising agents that could be potentially developed as a selective anticancer agent for breast cancer

Unique features of the structure and interactions of mycobacterial uracil-DNA glycosylase: structure of a complex of the Mycobacterium tuberculosis enzyme in comparison with those from other sources.

Science.gov (United States)

Kaushal, Prem Singh; Talawar, Ramappa K; Krishna, P D V; Varshney, Umesh; Vijayan, M

2008-05-01

Uracil-DNA glycosylase (UNG), a repair enzyme involved in the excision of uracil from DNA, from mycobacteria differs from UNGs from other sources, particularly in the sequence in the catalytically important loops. The structure of the enzyme from Mycobacterium tuberculosis (MtUng) in complex with a proteinaceous inhibitor (Ugi) has been determined by X-ray analysis of a crystal containing seven crystallographically independent copies of the complex. This structure provides the first geometric characterization of a mycobacterial UNG. A comparison of the structure with those of other UNG proteins of known structure shows that a central core region of the molecule is relatively invariant in structure and sequence, while the N- and C-terminal tails exhibit high variability. The tails are probably important in folding and stability. The mycobacterial enzyme exhibits differences in UNG-Ugi interactions compared with those involving UNG from other sources. The MtUng-DNA complex modelled on the basis of the known structure of the complex involving the human enzyme indicates a domain closure in the enzyme when binding to DNA. The binding involves a larger burial of surface area than is observed in binding by human UNG. The DNA-binding site of MtUng is characterized by the presence of a higher proportion of arginyl residues than is found in the binding site of any other UNG of known structure. In addition to the electrostatic effects produced by the arginyl residues, the hydrogen bonds in which they are involved compensate for the loss of some interactions arising from changes in amino-acid residues, particularly in the catalytic loops. The results arising from the present investigation represent unique features of the structure and interaction of mycobacterial Ungs.

The role of Duschinsky rotation in intersystem crossing: A case study of uracil

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Etinski Mihajlo

2011-01-01

Full Text Available The intersystem crossing rate for the transition between the lowest excited singlet and triplet electronic states of uracil was studied by means of ab initio methods. The rate was evaluated using the timedependent approach based on the correlation function and its two approximations: the second-order cumulant expansion and the short-time approximation. The normal modes of the singlet and triplet states are related by the Duschinsky transformation, i.e., by rotation and translation. It was found that for singlet-triplet adiabatic energy gaps below 6000 cm-1, the inclusion of the Duschinsky rotation is necessary for quantitative results. Above energy gaps of 6000 cm-1, the rates obtained with and without the Duschinsky rotation are similar. The cumulant expansion approximates well the correlation function. The short-time approximation, although crude, can be used as the first estimate of the rate.

Selectively improving nikkomycin Z production by blocking the imidazolone biosynthetic pathway of nikkomycin X and uracil feeding in Streptomyces ansochromogenes

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Yang Haihua

2009-11-01

Full Text Available Abstract Background Nikkomycins are a group of peptidyl nucleoside antibiotics and act as potent inhibitors of chitin synthases in fungi and insects. Nikkomycin X and Z are the main components produced by Streptomyces ansochromogenes. Of them, nikkomycin Z is a promising antifungal agent with clinical significance. Since highly structural similarities between nikkomycin Z and X, separation of nikkomycin Z from the culture medium of S. ansochromogenes is difficult. Thus, generating a nikkomycin Z selectively producing strain is vital to scale up the nikkomycin Z yields for clinical trials. Results A nikkomycin Z producing strain (sanPDM was constructed by blocking the imidazolone biosynthetic pathway of nikkomycin X via genetic manipulation and yielded 300 mg/L nikkomycin Z and abolished the nikkomycin X production. To further increase the yield of nikkomycin Z, the effects of different precursors on its production were investigated. Precursors of nucleoside moiety (uracil or uridine had a stimulatory effect on nikkomycin Z production while precursors of peptidyl moiety (L-lysine and L-glutamate had no effect. sanPDM produced the maximum yields of nikkomycin Z (800 mg/L in the presence of uracil at the concentration of 2 g/L and it was approximately 2.6-fold higher than that of the parent strain. Conclusion A high nikkomycin Z selectively producing was obtained by genetic manipulation combined with precursors feeding. The strategy presented here might be applicable in other bacteria to selectively produce targeted antibiotics.

Targeted cytosine deaminase-uracil phosphoribosyl transferase suicide gene therapy induces small cell lung cancer-specific cytotoxicity and tumor growth delay

DEFF Research Database (Denmark)

Christensen, Camilla L; Gjetting, Torben; Poulsen, Thomas Tuxen

2010-01-01

Small cell lung cancer (SCLC) is a highly malignant cancer for which there is no curable treatment. Novel therapies are therefore in great demand. In the present study we investigated the therapeutic effect of transcriptionally targeted suicide gene therapy for SCLC based on the yeast cytosine...... deaminase (YCD) gene alone or fused with the yeast uracil phosphoribosyl transferase (YUPRT) gene followed by administration of 5-fluorocytosine (5-FC) prodrug. Experimental design: The YCD gene or the YCD-YUPRT gene was placed under regulation of the SCLC-specific promoter insulinoma-associated 1 (INSM1...

Internet of Thing Context Awareness Model

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Derrick Ntalasha

2016-02-01

Full Text Available This paper aims to address key concept of context awareness in the Internet of Things (IoT domain by providing a model that proactively monitors behaviour of devices and services. This concept represents context into two types of information representation, namely set based and mark-up based ontology for the purpose of defining a context awareness model that accurately represent context in IoT. The context model is defined using Resources, Actors, Ambients and Policies. The model adds value to the next stage of IoT evolution by using context ambients to bring about predictive and proactive modelling in understanding context and context awareness. IoT context is represented using the hierarchical hybrid context model. This model provides a method of representing contexts based on context quality and availability in an entity relation hierarchy form. The model is exemplified using the context management application based on agents. Experimental results indicate that context awareness in the Internet of Things can be enhanced by the proposed model.

Tritiated uracil, tritiated thymidine, and bromodeoxyuridine induced mutations in eucaryotic cells

International Nuclear Information System (INIS)

Burki, H.J.; Moustacchi, E.; Cleaver, J.E.

1979-02-01

The induction of gene conversion at the ARG-4 locus in strain BZ34 of Saccharomyces cerevisiae was examined after the cells incorporated y- 3 H uracil under optimum growth conditions for 16 hours, and then received damage at 4 0 C from tritium decays at very low dose rates of 1.4 to 27.6 tritium decays per hour. The results were compared to the results of gene conversion induced by 60 Co. The induction of resistance to 6TG in Chinese hamster ovary (CHO) cells has been studied after incorporation of 3 H-methyl thymidine, 6- 3 H-thymidine, and bromodeoxyuridine under several experimental conditions. The induction of mutations by incorporated 6- 3 H-thymidine is about three times as effective as the induction of mutations by tritiated-methyl thymidine. These results suggest that the determination of the RBE for tritium decays in model eucaryotic systems like yeast and cultured Chinese hamster cells will be influenced by the precise experimental conditions employed. In particular, experiments with mammalian cells will be affected by hot times for mutagenesis in the cell cycle and hot positions within the DNA in the nucleus, and also by the position of tritium decay within the DNA-incorporated molecule

On the use of contexts for representing knowledge in defeasible argumentation

OpenAIRE

Chesñevar, Carlos Iván

1995-01-01

The notion of context and its importance in knowledge representation and nonmonotonic reasoning was first discussed in Artificial Intelligence by John McCarthy. Ever since, contexts have found many applications in developing knowledge-based reasoning systems. Defeasible argumentation has gained wide acceptance within the Al community in the last years. Different argument-based frameworks have been proposed. In this respect, MTDR (Simari & Loui, 1992) has come to be one of the most s...

Structural and biophysical analysis of interactions between cod and human uracil-DNA N-glycosylase (UNG) and UNG inhibitor (Ugi)

Energy Technology Data Exchange (ETDEWEB)

Assefa, Netsanet Gizaw [UiT The Arctic University of Norway, 9037 Tromsø (Norway); Niiranen, Laila [UiT The Arctic University of Norway, 9037 Tromsø (Norway); University of Turku, FIN-20014 Turku (Finland); Johnson, Kenneth A.; Leiros, Hanna-Kirsti Schrøder; Smalås, Arne Oskar; Willassen, Nils Peder [UiT The Arctic University of Norway, 9037 Tromsø (Norway); Moe, Elin, E-mail: elin.moe@uit.no [UiT The Arctic University of Norway, 9037 Tromsø (Norway); Universidade Nova de Lisboa, Avenida da Republica (EAN), 2780-157 Oeiras (Portugal)

2014-08-01

A structural and biophysical study of the interactions between cod and human uracil-DNA N-glycosylase (UNG) and their inhibitor Ugi is presented. The stronger interaction between cod UNG and Ugi can be explained by a greater positive electrostatic surface potential. Uracil-DNA N-glycosylase from Atlantic cod (cUNG) shows cold-adapted features such as high catalytic efficiency, a low temperature optimum for activity and reduced thermal stability compared with its mesophilic homologue human UNG (hUNG). In order to understand the role of the enzyme–substrate interaction related to the cold-adapted properties, the structure of cUNG in complex with a bacteriophage encoded natural UNG inhibitor (Ugi) has been determined. The interaction has also been analyzed by isothermal titration calorimetry (ITC). The crystal structure of cUNG–Ugi was determined to a resolution of 1.9 Å with eight complexes in the asymmetric unit related through noncrystallographic symmetry. A comparison of the cUNG–Ugi complex with previously determined structures of UNG–Ugi shows that they are very similar, and confirmed the nucleotide-mimicking properties of Ugi. Biophysically, the interaction between cUNG and Ugi is very strong and shows a binding constant (K{sub b}) which is one order of magnitude larger than that for hUNG–Ugi. The binding of both cUNG and hUNG to Ugi was shown to be favoured by both enthalpic and entropic forces; however, the binding of cUNG to Ugi is mainly dominated by enthalpy, while the entropic term is dominant for hUNG. The observed differences in the binding properties may be explained by an overall greater positive electrostatic surface potential in the protein–Ugi interface of cUNG and the slightly more hydrophobic surface of hUNG.

Targeted intra-arterial carboplatin chemoradiotherapy and tegafur/uracil for oral and oropharyngeal cancer

International Nuclear Information System (INIS)

Oya, Ryoichi; Takagi, Shinji; Inenaga, Ryuichiro; Nakamura, Shoichi; Ikemura, Kunio; Onari, Nobuhiro; Imada, Hajime; Korogi, Yukunori

2006-01-01

The aim of this study was to evaluate the usefulness of targeted intra-arterial carboplatin chemoradiotherapy in allowing less invasive surgery for patients with oral and oropharyngeal squamous cell carcinoma. Twenty patients with previously untreated squamous cell carcinoma of the oral cavity and oropharynx (T4; 8, T2; 12 patients) were treated with targeted transfemoral intra-arterial carboplatin infusion with concurrent hyperfractionated radiotherapy and the administration of tegafur/uracil (UFT). Of 20 patients, 15 underwent surgery after completion of one course of targeted chemoradiotherapy, and five were given another course or radiotherapy only. Eighteen (90%) of 20 patients had a clinically complete response at the primary site and two (10%) had a partial response. Of the 15 patients who underwent tumor resection, 11 (73%) showed histopathological disappearance of cancer cells at the primary site. Sixteen (80%) of 20 tumors were controlled at the primary site within a mean follow-up of 30 months. Adverse effects were relatively mild. Targeted intra-arterial chemoradiotherapy caused a down-staging of tumors and facilitated the use of less invasive surgery in patients with squamous cell carcinoma of the oral cavity and oropharynx as a result of its favorable anti-tumor effect. (author)

Differential role of base excision repair proteins in mediating cisplatin cytotoxicity.

Science.gov (United States)

Sawant, Akshada; Floyd, Ashley M; Dangeti, Mohan; Lei, Wen; Sobol, Robert W; Patrick, Steve M

2017-03-01

Interstrand crosslinks (ICLs) are covalent lesions formed by cisplatin. The mechanism for the processing and removal of ICLs by DNA repair proteins involves nucleotide excision repair (NER), homologous recombination (HR) and fanconi anemia (FA) pathways. In this report, we monitored the processing of a flanking uracil adjacent to a cisplatin ICL by the proteins involved in the base excision repair (BER) pathway. Using a combination of extracts, purified proteins, inhibitors, functional assays and cell culture studies, we determined the specific BER proteins required for processing a DNA substrate with a uracil adjacent to a cisplatin ICL. Uracil DNA glycosylase (UNG) is the primary glycosylase responsible for the removal of uracils adjacent to cisplatin ICLs, whereas other uracil glycosylases can process uracils in the context of undamaged DNA. Repair of the uracil adjacent to cisplatin ICLs proceeds through the classical BER pathway, highlighting the importance of specific proteins in this redundant pathway. Removal of uracil is followed by the generation of an abasic site and subsequent cleavage by AP endonuclease 1 (APE1). Inhibition of either the repair or redox domain of APE1 gives rise to cisplatin resistance. Inhibition of the lyase domain of Polymerase β (Polβ) does not influence cisplatin cytotoxicity. In addition, lack of XRCC1 leads to increased DNA damage and results in increased cisplatin cytotoxicity. Our results indicate that BER activation at cisplatin ICLs influences crosslink repair and modulates cisplatin cytotoxicity via specific UNG, APE1 and Polβ polymerase functions. Copyright © 2017 Elsevier B.V. All rights reserved.

The synthesis of no-carrier-added [11C]urea from [11C]carbon dioxide and application to [11C]uracil synthesis

International Nuclear Information System (INIS)

Chakraborty, P.K.; Mangner, T.J.; Chugani, H.T.

1997-01-01

No-carrier-added [ 11 C]urea has been synthesized by bubbling cyclotron-produced [ 11 C]-carbon dioxide directly into a tetrahydrofuran solution of lithium bis(trimethylsilyl)amide, followed by hydrolysis of the C-11 labeled adduct with aqueous ammonium chloride. Using this simple, one-pot method, [ 11 C]urea was produced in 55-70% radiochemical yield (decay-corrected) in 16 min following end-of-bombardment (or in 10 min following the introduction of the [ 11 C]carbon dioxide. The [ 11 C]urea thus produced was converted to [ 11 C]uracil (carrier-added) in 40-75% decay-corrected radiochemical yield by condensation with diethyl malate in presence of fuming sulfuric acid. (author)

Automated quantum chemistry based molecular dynamics simulations of electron ionization induced fragmentations of the nucleobases Uracil, Thymine, Cytosine, and Guanine.

Science.gov (United States)

Grimme, Stefan; Bauer, Christopher Alexander

2015-01-01

The gas-phase decomposition pathways of electron ionization (EI)-induced radical cations of the nucleobases uracil, thymine, cytosine, and guanine are investigated by means of mixed quantum-classical molecular dynamics. No preconceived fragmentation channels are used in the calculations. The results compare well to a plethora of experimental and theoretical data for these important biomolecules. With our combined stochastic and dynamic approach, one can access in an unbiased way the energetically available decomposition mechanisms. Additionally, we are able to separate the EI mass spectra of different tautomers of cytosine and guanine. Our method (previously termed quantum chemistry electron ionization mass spectra) reproduces free nucleobase experimental mass spectra well and provides detailed mechanistic in-sight into high-energy unimolecular decomposition processes.

Effects of 6-methyl-uracil upon the phagocytic activity in mice following whole-body X-irradiation or 2,4,6,-triethyleneimino-s-triazine treatment

International Nuclear Information System (INIS)

Raake, W.; Tempel, K.

1977-01-01

1. Phagocytic activity measured by means of the intravasal clearence of a soot dispersion in male NMRI-mice was increased six to ten days after whole-body X-irradiation (640 R) and decreased during the same period after i.v. administration of 2,4,6-triethyleneimino-s-triazine (TEM 2.0 mg/kg). 2. By means of 6-methyl-uracil food admixtures (200 to 400 ppm during 2 or 3 weeks) or by repeated intravenous injections of a N-methyl-D-glucosamine-6-methyluracil complex (62.5 to 250 mg/kg daily during five days), a significant augmentation of the phagocytic index being related to time and dosage was obtained in otherwise untreated mice. Comparable results were seen using cytidine and cytidine-5'-phosphate, whereas guanosine-5'-phosphate remained ineffective. 3. Whilst stimulating effects of 6-methyl-uracil or its N-methyl-D-glucosamine complex on X-irradiated mice were suspended, an increase up to supernormal values of the phagocytic index was produced by the pyrimidine base in animals treated with TEM. In accordance to this the survival rate of lethally X-irradiated mice (960 R) could not be increased; with animals given lethal TEM-doses, however, a significantly increased survival rate was obtained. 4. The present investigations as well as former biochemical analyses confirm the assumption that 6-methyluracil produces its regeneration effects, to some extent at least, by specific pathways influencing the reticuloendothelium. Different results from X-irradiated and TEM-treated mice are referring to the different points of attack of the two noxa. (orig.) [de

Secretion of Rhoptry and Dense Granule Effector Proteins by Nonreplicating Toxoplasma gondii Uracil Auxotrophs Controls the Development of Antitumor Immunity.

Directory of Open Access Journals (Sweden)

Barbara A Fox

2016-07-01

Full Text Available Nonreplicating type I uracil auxotrophic mutants of Toxoplasma gondii possess a potent ability to activate therapeutic immunity to established solid tumors by reversing immune suppression in the tumor microenvironment. Here we engineered targeted deletions of parasite secreted effector proteins using a genetically tractable Δku80 vaccine strain to show that the secretion of specific rhoptry (ROP and dense granule (GRA proteins by uracil auxotrophic mutants of T. gondii in conjunction with host cell invasion activates antitumor immunity through host responses involving CD8α+ dendritic cells, the IL-12/interferon-gamma (IFN-γ TH1 axis, as well as CD4+ and CD8+ T cells. Deletion of parasitophorous vacuole membrane (PVM associated proteins ROP5, ROP17, ROP18, ROP35 or ROP38, intravacuolar network associated dense granule proteins GRA2 or GRA12, and GRA24 which traffics past the PVM to the host cell nucleus severely abrogated the antitumor response. In contrast, deletion of other secreted effector molecules such as GRA15, GRA16, or ROP16 that manipulate host cell signaling and transcriptional pathways, or deletion of PVM associated ROP21 or GRA3 molecules did not affect the antitumor activity. Association of ROP18 with the PVM was found to be essential for the development of the antitumor responses. Surprisingly, the ROP18 kinase activity required for resistance to IFN-γ activated host innate immunity related GTPases and virulence was not essential for the antitumor response. These data show that PVM functions of parasite secreted effector molecules, including ROP18, manipulate host cell responses through ROP18 kinase virulence independent mechanisms to activate potent antitumor responses. Our results demonstrate that PVM associated rhoptry effector proteins secreted prior to host cell invasion and dense granule effector proteins localized to the intravacuolar network and host nucleus that are secreted after host cell invasion coordinately

Oral tegafur-uracil as metronomic therapy following intravenous FOLFOX for stage III colon cancer.

Directory of Open Access Journals (Sweden)

Wen-Yen Huang

Full Text Available The purpose of this study was to estimate the impact of metronomic therapy with oral tegafur-uracil (UFUR following an intravenous FOLFOX regimen as surgical adjuvant chemotherapy on the overall survival (OS and disease-free survival (DFS of stage III colon cancer patients. From the retrospective database of patients who underwent a surgical resection for colorectal cancer at the Tri-Service General Hospital from October 2008 through December 2014, stage III colon carcinomas treated with radical R0 resection were reviewed. One hundred thirty two patients were treated with a FOLFOX regimen (comparison group, and 113 patients were treated with the same regimen followed by additional oral UFUR (UFUR group. The clinical characteristics and mean age of the comparison and UFUR groups were similar. Furthermore, for all study patients, DFS was not significantly different between the two groups. However, 5-year OS rates were 86.8% and 68.5% in the UFUR and comparison groups, respectively (p = 0.0107. Adding UFUR to a FOLFOX regimen was found to significantly improve the OS in patients with stage III colon cancer. UFUR as a maintenance therapy following FOLFOX regimen as an alternative therapeutic option for the treatment of stage III colon cancer patients.

Oral tegafur-uracil as metronomic therapy following intravenous FOLFOX for stage III colon cancer.

Science.gov (United States)

Huang, Wen-Yen; Ho, Ching-Liang; Lee, Chia-Cheng; Hsiao, Cheng-Wen; Wu, Chang-Chieh; Jao, Shu-Wen; Yang, Jen-Fu; Lo, Cheng-Hsiang; Chen, Jia-Hong

2017-01-01

The purpose of this study was to estimate the impact of metronomic therapy with oral tegafur-uracil (UFUR) following an intravenous FOLFOX regimen as surgical adjuvant chemotherapy on the overall survival (OS) and disease-free survival (DFS) of stage III colon cancer patients. From the retrospective database of patients who underwent a surgical resection for colorectal cancer at the Tri-Service General Hospital from October 2008 through December 2014, stage III colon carcinomas treated with radical R0 resection were reviewed. One hundred thirty two patients were treated with a FOLFOX regimen (comparison group), and 113 patients were treated with the same regimen followed by additional oral UFUR (UFUR group). The clinical characteristics and mean age of the comparison and UFUR groups were similar. Furthermore, for all study patients, DFS was not significantly different between the two groups. However, 5-year OS rates were 86.8% and 68.5% in the UFUR and comparison groups, respectively (p = 0.0107). Adding UFUR to a FOLFOX regimen was found to significantly improve the OS in patients with stage III colon cancer. UFUR as a maintenance therapy following FOLFOX regimen as an alternative therapeutic option for the treatment of stage III colon cancer patients.

Accurate Dna Assembly And Direct Genome Integration With Optimized Uracil Excision Cloning To Facilitate Engineering Of Escherichia Coli As A Cell Factory

DEFF Research Database (Denmark)

Cavaleiro, Mafalda; Kim, Se Hyeuk; Nørholm, Morten

2015-01-01

Plants produce a vast diversity of valuable compounds with medical properties, but these are often difficult to purify from the natural source or produce by organic synthesis. An alternative is to transfer the biosynthetic pathways to an efficient production host like the bacterium Escherichia co......-excision-based cloning and combining it with a genome-engineering approach to allow direct integration of whole metabolic pathways into the genome of E. coli, to facilitate the advanced engineering of cell factories........ Cloning and heterologous gene expression are major bottlenecks in the metabolic engineering field. We are working on standardizing DNA vector design processes to promote automation and collaborations in early phase metabolic engineering projects. Here, we focus on optimizing the already established uracil...

Representing vision and blindness.

Science.gov (United States)

Ray, Patrick L; Cox, Alexander P; Jensen, Mark; Allen, Travis; Duncan, William; Diehl, Alexander D

2016-01-01

There have been relatively few attempts to represent vision or blindness ontologically. This is unsurprising as the related phenomena of sight and blindness are difficult to represent ontologically for a variety of reasons. Blindness has escaped ontological capture at least in part because: blindness or the employment of the term 'blindness' seems to vary from context to context, blindness can present in a myriad of types and degrees, and there is no precedent for representing complex phenomena such as blindness. We explore current attempts to represent vision or blindness, and show how these attempts fail at representing subtypes of blindness (viz., color blindness, flash blindness, and inattentional blindness). We examine the results found through a review of current attempts and identify where they have failed. By analyzing our test cases of different types of blindness along with the strengths and weaknesses of previous attempts, we have identified the general features of blindness and vision. We propose an ontological solution to represent vision and blindness, which capitalizes on resources afforded to one who utilizes the Basic Formal Ontology as an upper-level ontology. The solution we propose here involves specifying the trigger conditions of a disposition as well as the processes that realize that disposition. Once these are specified we can characterize vision as a function that is realized by certain (in this case) biological processes under a range of triggering conditions. When the range of conditions under which the processes can be realized are reduced beyond a certain threshold, we are able to say that blindness is present. We characterize vision as a function that is realized as a seeing process and blindness as a reduction in the conditions under which the sight function is realized. This solution is desirable because it leverages current features of a major upper-level ontology, accurately captures the phenomenon of blindness, and can be

Judgments of and by Representativeness

Science.gov (United States)

1981-05-15

p. 4i). This hy- pothesis was studied in several contexts, including intuitive statisti- cal judgments and the prediction of professional choice (Kahneman... professional choice . Here, X is representative of M either because it is frequently associated with M (e.g., high fever commonly accompanies pneumonia

Stabilization of very rare tautomers of uracil by an excess electron.

Science.gov (United States)

Bachorz, Rafał A; Rak, Janusz; Gutowski, Maciej

2005-05-21

We characterized valence-type and dipole-bound anionic states of uracil using various electronic structure methods. We found that the most stable anion is related to neither the canonical 2,4-dioxo nor a rare imino-hydroxy tautomer. Instead, it is related to an imino-oxo tautomer, in which the N1H proton is transferred to the C5 atom. This valence anion is characterized by an electron vertical detachment energy (VDE) of 1267 meV and it is adiabatically stable with respect to the canonical neutral by 3.93 kcal mol(-1). It is also more stable by 2.32 and 5.10 kcal mol(-1) than the dipole-bound and valence anion, respectively, of the canonical tautomer. The VDE values for the former and the latter are 73 and 506 meV, respectively. Another, anionic, low-lying imino-oxo tautomer with a VDE of 2499 meV has a proton transferred from N3H to C5. It is less stable than the neutral canonical tautomer by 1.38 kcal mol(-1). The mechanism of formation of anionic tautomers with the carbon C5 protonated may involve intermolecular proton transfer or dissociative electron attachment to the canonical neutral tautomer followed by a barrier-free attachment of a hydrogen atom to C5. The six-member ring structure of anionic tautomers with carbon atoms protonated might be unstable upon an excess electron detachment. Indeed, the neutral systems resulting from electron detachment from anionic tautomers with carbon atoms protonated evolve along barrier-free decomposition pathways to a linear or a bicyclo structure, which might be viewed as lesions to RNA. Within the PCM hydration model, the low-lying valence anions become adiabatically bound with respect to the canonical neutral and the two most stable tautomers have carbon atoms protonated.

Characterizing the context of sedentary lifestyles in a representative sample of adults: a cross-sectional study from the physical activity measurement study project.

Science.gov (United States)

Kim, Youngwon; Welk, Gregory J

2015-12-09

Research has clearly demonstrated that excess time spent on sedentary behavior (SB) increases health risks in the population. However, the lack of information on the context of SB in the population prevents a detailed understanding of sedentary lifestyles. The purpose of this study was to characterize the context of SB in a representative sample of adults and to examine differences across various socio-demographic indicators. A diverse sample of 1442 adults (ages 20-71 year) completed an interviewer-administered 24-h activity recall to provide detailed information about the time, type and location of the previous day's activities. All reported activities were matched with MET scores from the Compendium of Physical Activity but only SB (i.e., METS Work: 27.5%, Community: 24.8%, Home/Indoor: 20.5%, Home/Outdoor: 15.8%, and Transportation: 11.3%). Patterns of SB allocations varied considerably across different socio-demographic indicators indicating the extreme variability in SB in the population. The findings provide unique insights about the context of SB at the population level, and can serve as a guide for developing intervention/policy studies to reduce sedentary time and minimize disparities in SB.

Detrimental effects of hypoxia-specific expression of uracil DNA glycosylase (Ung) in Mycobacterium smegmatis.

Science.gov (United States)

Kurthkoti, Krishna; Varshney, Umesh

2010-12-01

Mycobacterium tuberculosis is known to reside latently in a significant fraction of the human population. Although the bacterium possesses an aerobic mode of metabolism, it adapts to persistence under hypoxic conditions such as those encountered in granulomas. While in mammalian systems hypoxia is a recognized DNA-damaging stress, aspects of DNA repair in mycobacteria under such conditions have not been studied. We subjected Mycobacterium smegmatis, a model organism, to the Wayne's protocol of hypoxia. Analysis of the mRNA of a key DNA repair enzyme, uracil DNA glycosylase (Ung), by real-time reverse transcriptase PCR (RT-PCR) revealed its downregulation during hypoxia. However, within an hour of recovery of the culture under normal oxygen levels, the Ung mRNA was restored. Analysis of Ung by immunoblotting and enzyme assays supported the RNA analysis results. To understand its physiological significance, we misexpressed Ung in M. smegmatis by using a hypoxia-responsive promoter of narK2 from M. tuberculosis. Although the misexpression of Ung during hypoxia decreased C-to-T mutations, it compromised bacterial survival upon recovery at normal oxygen levels. RT-PCR analysis of other base excision repair gene transcripts (UdgB and Fpg) suggested that these DNA repair functions also share with Ung the phenomenon of downregulation during hypoxia and recovery with return to normal oxygen conditions. We discuss the potential utility of this phenomenon in developing attenuated strains of mycobacteria.

The radiolysis of uracil in oxygenated aqueous solutions. A study by product analysis and pulse radiolysis

International Nuclear Information System (INIS)

Schuchnmann, M.N.; Sonntag, C. von

1983-01-01

Hydroxyl radicals are generated by the radiolysis of N 2 O-O 2 (4:1 v/v)-saturated aqueous solutions of uracil. They add to the 5,6-double bond of the substrate. These radicals are converted by oxygen into the corresponding peroxyl radicals (I) and (II), respectively. Peroxyl radical (I) undergoes a base-induced O 2 - elimination. As an intermediate 5-hydroxyisopyrimidine is formed which rearranges into isobarbituric acid and adds water forming 5,6-dihydro-5,6-dihydroxyuracil. Competing with this base-induced reaction of radical (I) there is a bimolecular decay of radicals (I) and (II). These processes become predominant at low pH. For this reason a strong pH dependence of G (products) is observed. The major products are (G values at pH 3 and 10 in parentheses) 5,6-dihydroxy-5,6-dihydrouracil (1.1; 2.4), isobarbituric acid (0; 1.2), N-formyl-5-hydroxyhydantoin (1.6; 0.2), 5-hydroxybarbituric acid (0.9; 0.2). 5-Hydroxybarbituric acid is formed in its keto form. Its deprotonation has been followed by pulse conductometry. Details of the reaction mechanism, e.g. the involvement of oxyl radicals in the bimolecular decay of (I) and (II), are discussed. (author)

Structure-wise discrimination of cytosine, thymine, and uracil by proteins in terms of their nonbonded interactions.

Science.gov (United States)

Usha, S; Selvaraj, S

2014-01-01

The molecular recognition and discrimination of very similar ligand moieties by proteins are important subjects in protein-ligand interaction studies. Specificity in the recognition of molecules is determined by the arrangement of protein and ligand atoms in space. The three pyrimidine bases, viz. cytosine, thymine, and uracil, are structurally similar, but the proteins that bind to them are able to discriminate them and form interactions. Since nonbonded interactions are responsible for molecular recognition processes in biological systems, our work attempts to understand some of the underlying principles of such recognition of pyrimidine molecular structures by proteins. The preferences of the amino acid residues to contact the pyrimidine bases in terms of nonbonded interactions; amino acid residue-ligand atom preferences; main chain and side chain atom contributions of amino acid residues; and solvent-accessible surface area of ligand atoms when forming complexes are analyzed. Our analysis shows that the amino acid residues, tyrosine and phenyl alanine, are highly involved in the pyrimidine interactions. Arginine prefers contacts with the cytosine base. The similarities and differences that exist between the interactions of the amino acid residues with each of the three pyrimidine base atoms in our analysis provide insights that can be exploited in designing specific inhibitors competitive to the ligands.

Overexpression of transcription factor AP-2 stimulates the PA promoter of the human uracil-DNA glycosylase (UNG) gene through a mechanism involving derepression

DEFF Research Database (Denmark)

Aas, Per Arne; Pena Diaz, Javier; Liabakk, Nina Beate

2009-01-01

within the region of DNA marked by PA. Footprinting analysis and electrophoretic mobility shift assays of PA and putative AP-2 binding regions with HeLa cell nuclear extract and recombinant AP-2alpha protein indicate that AP-2 transcription factors are central in the regulated expression of UNG2 m......The PA promoter in the human uracil-DNA glycosylase gene (UNG) directs expression of the nuclear form (UNG2) of UNG proteins. Using a combination of promoter deletion and mutation analyses, and transient transfection of HeLa cells, we show that repressor and derepressor activities are contained......alpha, lacking the activation domain but retaining the DNA binding and dimerization domains, stimulated PA to a level approaching that of full-length AP-2, suggesting that AP-2 overexpression stimulates PA activity by a mechanism involving derepression rather than activation, possibly by neutralizing...

Radiolysis of uracil in oxygenated aqueous solutions. A study by product analysis and pulse radiolysis. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Schuchnmann, M N; Sonntag, C von [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany, F.R.). Inst. fuer Strahlenchemie

1983-10-01

Hydroxyl radicals are generated by the radiolysis of N/sub 2/O-O/sub 2/ (4:1 v/v)-saturated aqueous solutions of uracil. They add to the 5,6-double bond of the substrate. These radicals are converted by oxygen into the corresponding peroxyl radicals (I) and (II), respectively. Peroxyl radical (I) undergoes a base-induced O/sub 2//sup -/ elimination. As an intermediate 5-hydroxyisopyrimidine is formed which rearranges into isobarbituric acid and adds water forming 5,6-dihydro-5,6-dihydroxyuracil. Competing with this base-induced reaction of radical (I) there is a bimolecular decay of radicals (I) and (II). These processes become predominant at low pH. For this reason a strong pH dependence of G (products) is observed. The major products are (G values at pH 3 and 10 in parentheses) 5,6-dihydroxy-5,6-dihydrouracil (1.1; 2.4), isobarbituric acid (0; 1.2), N-formyl-5-hydroxyhydantoin (1.6; 0.2), 5-hydroxybarbituric acid (0.9; 0.2). 5-Hydroxybarbituric acid is formed in its keto form. Its deprotonation has been followed by pulse conductometry. Details of the reaction mechanism, e.g. the involvement of oxyl radicals in the bimolecular decay of (I) and (II), are discussed.

Damage to uracil- and adenine-containing bases, nucleosides, nucleotides and polynucleotides: quantum yields on irradiation at 193 and 254 nm

International Nuclear Information System (INIS)

Gurzadyan, G.G.; Goerner, H.

1994-01-01

Photoreactions, such as base release and decomposition of the base moeity, induced by either 20 ns laser pulses at 193 nm or continuous 254 nm irradiation, were studied for a series of uracil and adenine derivatives in neutral aqueous solution. The quantum yield of chromophore loss (Φ cl ) depends significantly on the nature of the nucleic acid constituent and the saturating gas (Ar, N 2 O or O 2 ). In the case of polynucleotides the destruction of nucleotides was measured by high-performance liquid chromatography after hydrolysis; the quantum yields (Φ dn ) are comparable to those of chromophore loss or larger. The Φ cl and Φ dn of 0.04-0.1 for poly(U) and poly(dU), obtained for both wavelengths of irradiation, are due to processes originating from the lowest excited singlet state, i.e. formation of photohydrates and photodimers, and a second part from photoionization using λ irr = 193 nm. Irradiation at 193 nm effectively splits pyrimidine dimers and thus reverts them into monomers. (author)

Context management platform for tourism applications.

Science.gov (United States)

Buján, David; Martín, David; Torices, Ortzi; López-de-Ipiña, Diego; Lamsfus, Carlos; Abaitua, Joseba; Alzua-Sorzabal, Aurkene

2013-06-24

The notion of context has been widely studied and there are several authors that have proposed different definitions of context. However, context has not been widely studied in the framework of human mobility and the notion of context has been imported directly from other computing fields without specifically addressing the tourism domain requirements. In order to store and manage context information a context data model and a context management platform are needed. Ontologies have been widely used in context modelling, but many of them are designed to be applied in general ubiquitous computing environments, do not contain specific concepts related to the tourism domain or some approaches do not contain enough concepts to represent context information related to the visitor on the move. That is why we propose a new approach to provide a better solution to model context data in tourism environments, adding more value to our solution reusing data about tourist resources from an Open Data repository and publishing it as Linked Data. We also propose the architecture for a context information management platform based on this context data model.

A Two-Stage Composition Method for Danger-Aware Services Based on Context Similarity

Science.gov (United States)

Wang, Junbo; Cheng, Zixue; Jing, Lei; Ota, Kaoru; Kansen, Mizuo

Context-aware systems detect user's physical and social contexts based on sensor networks, and provide services that adapt to the user accordingly. Representing, detecting, and managing the contexts are important issues in context-aware systems. Composition of contexts is a useful method for these works, since it can detect a context by automatically composing small pieces of information to discover service. Danger-aware services are a kind of context-aware services which need description of relations between a user and his/her surrounding objects and between users. However when applying the existing composition methods to danger-aware services, they show the following shortcomings that (1) they have not provided an explicit method for representing composition of multi-user' contexts, (2) there is no flexible reasoning mechanism based on similarity of contexts, so that they can just provide services exactly following the predefined context reasoning rules. Therefore, in this paper, we propose a two-stage composition method based on context similarity to solve the above problems. The first stage is composition of the useful information to represent the context for a single user. The second stage is composition of multi-users' contexts to provide services by considering the relation of users. Finally the danger degree of the detected context is computed by using context similarity between the detected context and the predefined context. Context is dynamically represented based on two-stage composition rules and a Situation theory based Ontology, which combines the advantages of Ontology and Situation theory. We implement the system in an indoor ubiquitous environment, and evaluate the system through two experiments with the support of subjects. The experiment results show the method is effective, and the accuracy of danger detection is acceptable to a danger-aware system.

Structure-function relationship of a plant NCS1 member - Homology modeling and mutagenesis identified residues critical for substrate specificity of PLUTO, a nucleobase transporter from arabidopsis

KAUST Repository

Witz, Sandra

2014-03-12

Plastidic uracil salvage is essential for plant growth and development. So far, PLUTO, the plastidic nucleobase transporter from Arabidopsis thaliana is the only known uracil importer at the inner plastidic membrane which represents the permeability barrier of this organelle. We present the first homology model of PLUTO, the sole plant NCS1 member from Arabidopsis based on the crystal structure of the benzyl hydantoin transporter MHP1 from Microbacterium liquefaciens and validated by molecular dynamics simulations. Polar side chains of residues Glu-227 and backbones of Val-145, Gly-147 and Thr-425 are proposed to form the binding site for the three PLUTO substrates uracil, adenine and guanine. Mutational analysis and competition studies identified Glu-227 as an important residue for uracil and to a lesser extent for guanine transport. A differential response in substrate transport was apparent with PLUTO double mutants E227Q G147Q and E227Q T425A, both of which most strongly affected adenine transport, and in V145A G147Q, which markedly affected guanine transport. These differences could be explained by docking studies, showing that uracil and guanine exhibit a similar binding mode whereas adenine binds deep into the catalytic pocket of PLUTO. Furthermore, competition studies confirmed these results. The present study defines the molecular determinants for PLUTO substrate binding and demonstrates key differences in structure-function relations between PLUTO and other NCS1 family members. 2014 Witz et al.

Phase II trial of Uracil/Tegafur plus leucovorin and celecoxib combined with radiotherapy in locally advanced pancreatic cancer

International Nuclear Information System (INIS)

Morak, Marjolein J.M.; Richel, Dick J.; Eijck, Casper H.J. van; Nuyttens, Joost J.M.E.; Gaast, Ate van der; Vervenne, Walter L.; Padmos, Esther E.; Schaake, Eva E.; Busch, Olivier R.C.; Tienhoven, Geertjan van

2011-01-01

Background and purpose: To investigate the efficacy and toxicity of a short intensive Uracil/Tegafur (UFT) based chemoradiotherapy scheme combined with celecoxib in locally advanced pancreatic cancer. Material and methods: The Academic Medical Centre, Amsterdam and the Erasmus Medical Centre, Rotterdam enrolled 83 eligible patients with unresectable pancreatic cancer in a prospective multicentre phase II study. Median age was 62 years, median tumour size 40 mm and the majority of the patients (85%) had pancreatic head cancers. Treatment consisted of 20 x 2.5 Gy radiotherapy combined with UFT 300 mg/m 2 per day, leucovorin (folinic acid) 30 mg and celecoxib 800 mg for 28 days concomitant with radiotherapy. Four patients were lost to follow-up. Results: Full treatment compliance was achieved in 55% of patients, 80% received at least 3 weeks of treatment. No partial or complete response was observed. Median survival was 10.6 months and median time to progression 6.9 months. Toxicity was substantial with 28% grades III and IV gastro-intestinal toxicity and two early toxic deaths. Conclusions: Based on the lack of response, the substantial toxicity of mainly gastro-intestinal origin and the reported mediocre overall and progression free survival, we cannot advise our short intensive chemoradiotherapy schedule combined with celecoxib as the standard treatment.

Synchronization of tumor cells with 5-fluorouracil plus uracil and with vinblastine and irradiation of synchronized cultures

International Nuclear Information System (INIS)

Severin, E.; Hagenhoff, B.

1988-01-01

In this article, some arguments are put forward which support the conception of a combined radio-chemotherapy acting by a reversible inhibition of tumor cells with cytostatic drugs in a not cytocidal dose and the following selective killing by irradiation of the cells blocked in a radiosensitive phase. The two cytostatic drugs 5-fluorouracil (FU) and vinblastine (VLB), as inhibitors of DNA synthesis and mitosis, respectively, are tested in vitro both separately and combined in two tumor cell lines of the mouse, i.e. the Ehrlich ascites tumor and the sarcoma S 180. A cell-proliferative and, as far as possible, not cytocidal dose is used because of the inevitable side effects exerted by these drugs on normal tissues. A reversible synchronization of the ascites tumor is achieved even in the young mouse by FU in a dose of 15 ng to 500 ng (applied seven times every two hours), if the synchronization is controlled by applying the antimetabolite together with uracil in an equimolar concentration and then stimulating the growth of the cells inhibited during DNA synthesis by the administration of thymidine. The statistical analysis of dose-effect curves after X-ray irradiation shows an increased radiosensitivity of the synchronized cell population, provided that the optimum moment had been chosen for the irradiation. (orig.) [de

The Unusual Presentation of Gastric Adenocarcinoma as a Testicular Mass: A Favorable Response to Docetaxel and Cisplatin Plus Oral Tegafur/Uracil and Leucovorin

Directory of Open Access Journals (Sweden)

Kai-Chung Yang

2010-02-01

Full Text Available Gastric cancer is one of the most common malignancies in the world. The routes of metastasis include direct extension, lymphatics, and peritoneal or hematogenous spread. Testicular metastasis is rare. We present here a 23-year-old gastric cancer patient who first presented with right-side testis swelling and pain. Diagnosis of metastatic adenocarcinoma was made after right-side orchiectomy. Gastric adenocarcinoma with ascites and peritoneal seeding was found after esophagogastroscopy and abdominal computed tomography. The patient received chemotherapy consisting of docetaxel 36 mg/m2 and cisplatin 30 mg/m2 on day 1 and day 8, plus oral tegafur/uracil 300 mg/m2/day and leucovorin 90 mg/day on day 1 to day 14 in a 21-day cycle, and he had a partial response to the chemotherapy. Metastatic tumors, especially gastric adenocarcinoma, should be considered in the differential diagnosis of patients presenting with testicular mass and they may respond well to chemotherapy.

Phase II study of preoperative radiation plus concurrent daily tegafur-uracil (UFT) with leucovorin for locally advanced rectal cancer

International Nuclear Information System (INIS)

Cellier, Patrice; Burtin, Pascal; Campion, Loïc; Boisdron-Celle, Michèle; Morel, Alain; Berger, Virginie; Gamelin, Erick; Leduc, Bernard; Martin, Laurent; Vié, Brigitte; Chevelle, Christian; Vendrely, Véronique; Salemkour, Augustin; Carrie, Christian; Calais, Gilles

2011-01-01

Considerable variation in intravenous 5-fluorouracil (5-FU) metabolism can occur due to the wide range of dihydropyrimidine dehydrogenase (DPD) enzyme activity, which can affect both tolerability and efficacy. The oral fluoropyrimidine tegafur-uracil (UFT) is an effective, well-tolerated and convenient alternative to intravenous 5-FU. We undertook this study in patients with locally advanced rectal cancer to evaluate the efficacy and tolerability of UFT with leucovorin (LV) and preoperative radiotherapy and to evaluate the utility and limitations of multicenter staging using pre- and post-chemoradiotherapy ultrasound. We also performed a validated pretherapy assessment of DPD activity and assessed its potential influence on the tolerability of UFT treatment. This phase II study assessed preoperative UFT with LV and radiotherapy in 85 patients with locally advanced T3 rectal cancer. Patients with potentially resectable tumors received UFT (300 mg/m/ 2 /day), LV (75 mg/day), and pelvic radiotherapy (1.8 Gy/day, 45 Gy total) 5 days/week for 5 weeks then surgery 4-6 weeks later. The primary endpoints included tumor downstaging and the pathologic complete response (pCR) rate. Most adverse events were mild to moderate in nature. Preoperative grade 3/4 adverse events included diarrhea (n = 18, 21%) and nausea/vomiting (n = 5, 6%). Two patients heterozygous for dihydropyrimidine dehydrogenase gene (DPYD) experienced early grade 4 neutropenia (variant IVS14+1G > A) and diarrhea (variant 2846A > T). Pretreatment ultrasound TNM staging was compared with postchemoradiotherapy pathology TN staging and a significant shift towards earlier TNM stages was observed (p < 0.001). The overall downstaging rate was 42% for primary tumors and 44% for lymph nodes. The pCR rate was 8%. The sensitivity and specificity of ultrasound for staging was poor. Anal sphincter function was preserved in 55 patients (65%). Overall and recurrence-free survival at 3 years was 86.1% and 66

Context Management Platform for Tourism Applications

Science.gov (United States)

Buján, David; Martín, David; Torices, Ortzi; López-de-Ipiña, Diego; Lamsfus, Carlos; Abaitua, Joseba; Alzua-Sorzabal, Aurkene

2013-01-01

The notion of context has been widely studied and there are several authors that have proposed different definitions of context. However, context has not been widely studied in the framework of human mobility and the notion of context has been imported directly from other computing fields without specifically addressing the tourism domain requirements. In order to store and manage context information a context data model and a context management platform are needed. Ontologies have been widely used in context modelling, but many of them are designed to be applied in general ubiquitous computing environments, do not contain specific concepts related to the tourism domain or some approaches do not contain enough concepts to represent context information related to the visitor on the move. That is why we propose a new approach to provide a better solution to model context data in tourism environments, adding more value to our solution reusing data about tourist resources from an Open Data repository and publishing it as Linked Data. We also propose the architecture for a context information management platform based on this context data model. PMID:23797739

Toward Sensor-Based Context Aware Systems

Directory of Open Access Journals (Sweden)

Kouhei Takada

2012-01-01

Full Text Available This paper proposes a methodology for sensor data interpretation that can combine sensor outputs with contexts represented as sets of annotated business rules. Sensor readings are interpreted to generate events labeled with the appropriate type and level of uncertainty. Then, the appropriate context is selected. Reconciliation of different uncertainty types is achieved by a simple technique that moves uncertainty from events to business rules by generating combs of standard Boolean predicates. Finally, context rules are evaluated together with the events to take a decision. The feasibility of our idea is demonstrated via a case study where a context-reasoning engine has been connected to simulated heartbeat sensors using prerecorded experimental data. We use sensor outputs to identify the proper context of operation of a system and trigger decision-making based on context information.

Citizen's initiatives and the representative system

International Nuclear Information System (INIS)

Guggenberger, B.; Kempf, U.

1978-01-01

This anthology containing contributions of 19 sociologists is a systematic investigation of the locality, the possibilities and the effective radius of citizen's initiatives under the functional conditions of the parliamentary - representative system. The intellectual and political surroundings, the sociologic context, the institutional, political and judical overall conditions as well as the consequences of this movement for the whole political system of the Federal Republic of Germany. (orig.) [de

Medial temporal lobe contributions to cued retrieval of items and contexts.

Science.gov (United States)

Hannula, Deborah E; Libby, Laura A; Yonelinas, Andrew P; Ranganath, Charan

2013-10-01

Several models have proposed that different regions of the medial temporal lobes contribute to different aspects of episodic memory. For instance, according to one view, the perirhinal cortex represents specific items, parahippocampal cortex represents information regarding the context in which these items were encountered, and the hippocampus represents item-context bindings. Here, we used event-related functional magnetic resonance imaging (fMRI) to test a specific prediction of this model-namely, that successful retrieval of items from context cues will elicit perirhinal recruitment and that successful retrieval of contexts from item cues will elicit parahippocampal cortex recruitment. Retrieval of the bound representation in either case was expected to elicit hippocampal engagement. To test these predictions, we had participants study several item-context pairs (i.e., pictures of objects and scenes, respectively), and then had them attempt to recall items from associated context cues and contexts from associated item cues during a scanned retrieval session. Results based on both univariate and multivariate analyses confirmed a role for hippocampus in content-general relational memory retrieval, and a role for parahippocampal cortex in successful retrieval of contexts from item cues. However, we also found that activity differences in perirhinal cortex were correlated with successful cued recall for both items and contexts. These findings provide partial support for the above predictions and are discussed with respect to several models of medial temporal lobe function. Copyright © 2013 Elsevier Ltd. All rights reserved.

Medial Temporal Lobe Contributions to Cued Retrieval of Items and Contexts

Science.gov (United States)

Hannula, Deborah E.; Libby, Laura A.; Yonelinas, Andrew P.; Ranganath, Charan

2013-01-01

Several models have proposed that different regions of the medial temporal lobes contribute to different aspects of episodic memory. For instance, according to one view, the perirhinal cortex represents specific items, parahippocampal cortex represents information regarding the context in which these items were encountered, and the hippocampus represents item-context bindings. Here, we used event-related functional magnetic resonance imaging (fMRI) to test a specific prediction of this model – namely, that successful retrieval of items from context cues will elicit perirhinal recruitment and that successful retrieval of contexts from item cues will elicit parahippocampal cortex recruitment. Retrieval of the bound representation in either case was expected to elicit hippocampal engagement. To test these predictions, we had participants study several item-context pairs (i.e., pictures of objects and scenes, respectively), and then had them attempt to recall items from associated context cues and contexts from associated item cues during a scanned retrieval session. Results based on both univariate and multivariate analyses confirmed a role for hippocampus in content-general relational memory retrieval, and a role for parahippocampal cortex in successful retrieval of contexts from item cues. However, we also found that activity differences in perirhinal cortex were correlated with successful cued recall for both items and contexts. These findings provide partial support for the above predictions and are discussed with respect to several models of medial temporal lobe function. PMID:23466350

Representative voice in different organizational contexts : a study of 40 departments of a Dutch childcare organization

NARCIS (Netherlands)

Pauksztat, Birgit; Wittek, Rafael

2011-01-01

'Representative voice' can be defined as actions in which one or more speakers represent others when speaking up about a problem at the workplace or making a suggestion. The purpose of this paper is to introduce the concept of representative voice, assess the frequency of its occurrence and examine

Service-oriented Context-aware Framework

Directory of Open Access Journals (Sweden)

László Kovács

2009-06-01

Full Text Available Location- and context-aware services are emerging technologies in mobile and desktop environments, however, most of them are difficult to use and do not seem to be beneficial enough. Our research focuses on designing and creating a service-oriented framework that helps location- and context-aware, client-service type application development and use. Location information is combined with other contexts such as the users' history, preferences and disabilities. The framework also handles the spatial model of the environment (e.g. map of a room or a building as a context. The framework is built on a semantic backend where the ontologies are represented using the OWL description language. The use of ontologies enables the framework to run inference tasks and to easily adapt to new context types. The framework contains a compatibility layer for positioning devices, which hides the technical differences of positioning technologies and enables the combination of location data of various sources.

Probing the Watson-Crick, wobble, and sugar-edge hydrogen bond sites of uracil and thymine.

Science.gov (United States)

Müller, Andreas; Frey, Jann A; Leutwyler, Samuel

2005-06-16

The nucleobases uracil (U) and thymine (T) offer three hydrogen-bonding sites for double H-bond formation via neighboring N-H and C=O groups, giving rise to the Watson-Crick, wobble and sugar-edge hydrogen bond isomers. We probe the hydrogen bond properties of all three sites by forming hydrogen bonded dimers of U, 1-methyluracil (1MU), 3-methyluracil (3MU), and T with 2-pyridone (2PY). The mass- and isomer-specific S1 origins exhibit large spectral blue shifts relative to the 2PY monomer. Ab initio CIS calculations of the spectral shifts of the different hydrogen-bonded dimers show a linear correlation with experiment. This correlation allows us to identify the R2PI spectra of the weakly populated Watson-Crick and wobble isomers of both 2PY.U and 2PY.T. (3) PW91 density functional calculation of the ground-state binding and dissociation energies De and D0 are in agreement with the assignment of the dominant hydrogen bond isomers of 2PY.U, 2PY.3MU and 2PY.T as the sugar-edge form. For 2PY.U, 2PY.T and 2PY.1MU the measured wobble:Watson-Crick:sugar-edge isomer ratios are in good agreement with the calculated ratios, based on the ab initio dissociation energies and gas-phase statistical mechanics. The Watson-Crick and wobble isomers are thereby determined to be several kcal/mol less strongly bound than the sugar-edge isomers. The 36 observed intermolecular frequencies of the nine different H-bonded isomers give detailed insight into the intermolecular force field.

Dementia and representative democracy: Exploring challenges and implications for democratic citizenship.

Science.gov (United States)

Sonnicksen, Jared

2016-05-01

Despite growing recognition of the rights of people with dementia for full citizenship, issues related to democracy, whether from theoretical or practical perspectives, remain neglected. Especially since discourses on dementia have expanded to this rights-based approach, it is imperative to begin to examine the meanings and practices of democracy within a context of dementia. Accordingly, the purpose of this article is to assess implications of dementia in the context of democracy. Rather than surveying the variety of democratic concepts, it will focus the analytical framework on representative democracy and then outline several challenges to and for representative democracy and citizens with dementia. The intention is to begin to identify paths for ensuring representation, inclusion and participation for those who have dementia. © The Author(s) 2016.

Comparison of the redox chemistry of sulfur- and selenium-containing analogs of uracil.

Science.gov (United States)

Payne, N Connor; Geissler, Andrew; Button, Aileen; Sasuclark, Alexandru R; Schroll, Alayne L; Ruggles, Erik L; Gladyshev, Vadim N; Hondal, Robert J

2017-03-01

Selenium is present in proteins in the form of selenocysteine, where this amino acid serves catalytic oxidoreductase functions. The use of selenocysteine in nature is strongly associated with redox catalysis. However, selenium is also found in a 2-selenouridine moiety at the wobble position of tRNA Glu , tRNA Gln and tRNA Lys . It is thought that the modifications of the wobble position of the tRNA improves the selectivity of the codon-anticodon pair as a result of the physico-chemical changes that result from substitution of sulfur and selenium for oxygen. Both selenocysteine and 2-selenouridine have widespread analogs, cysteine and thiouridine, where sulfur is used instead. To examine the role of selenium in 2-selenouridine, we comparatively analyzed the oxidation reactions of sulfur-containing 2-thiouracil-5-carboxylic acid (s 2 c 5 Ura) and its selenium analog 2-selenouracil-5-carboxylic acid (se 2 c 5 Ura) using 1 H-NMR spectroscopy, 77 Se-NMR spectroscopy, and liquid chromatography-mass spectrometry. Treatment of s 2 c 5 Ura with hydrogen peroxide led to oxidized intermediates, followed by irreversible desulfurization to form uracil-5-carboxylic acid (c 5 Ura). In contrast, se 2 c 5 Ura oxidation resulted in a diselenide intermediate, followed by conversion to the seleninic acid, both of which could be readily reduced by ascorbate and glutathione. Glutathione and ascorbate only minimally prevented desulfurization of s 2 c 5 Ura, whereas very little deselenization of se 2 c 5 Ura occurred in the presence of the same antioxidants. In addition, se 2 c 5 Ura but not s 2 c 5 Ura showed glutathione peroxidase activity, further suggesting that oxidation of se 2 c 5 Ura is readily reversible, while oxidation of s 2 c 5 Ura is not. The results of the study of these model nucleobases suggest that the use of 2-selenouridine is related to resistance to oxidative inactivation that otherwise characterizes 2-thiouridine. As the use of selenocysteine in proteins also confers

The importance of context: When relative relief renders pain pleasant

Science.gov (United States)

Leknes, Siri; Berna, Chantal; Lee, Michael C.; Snyder, Gregory D.; Biele, Guido; Tracey, Irene

2013-01-01

Context can influence the experience of any event. For instance, the thought that “it could be worse” can improve feelings towards a present misfortune. In this study we measured hedonic feelings, skin conductance, and brain activation patterns in 16 healthy volunteers who experienced moderate pain in two different contexts. In the “relative relief context,” moderate pain represented the best outcome, since the alternative outcome was intense pain. However, in the control context, moderate pain represented the worst outcome and elicited negative hedonic feelings. The context manipulation resulted in a “hedonic flip,” such that moderate pain elicited positive hedonics in the relative relief context. Somewhat surprisingly, moderate pain was even rated as pleasant in this context, despite being reported as painful in the control context. This “hedonic flip” was corroborated by physiological and functional neuroimaging data. When moderate pain was perceived as pleasant, skin conductance and activity in insula and dorsal anterior cingulate were significantly attenuated relative to the control moderate stimulus. “Pleasant pain” also increased activity in reward and valuation circuitry, including the medial orbitofrontal and ventromedial prefrontal cortices. Furthermore, the change in outcome hedonics correlated with activity in the periacqueductal grey (PAG) of the descending pain modulatory system (DPMS). The context manipulation also significantly increased functional connectivity between reward circuitry and the PAG, consistent with a functional change of the DPMS due to the altered motivational state. The findings of this study point to a role for brainstem and reward circuitry in a context-induced “hedonic flip” of pain. PMID:23352758

Etoricoxib selective sensor based on uracil-5,6-diamino-2-thio hydrochloride as neutral carrier for potentiometric analysis in pharmaceutical preparations

Directory of Open Access Journals (Sweden)

Salwa Fares Rassi

2016-06-01

Full Text Available A construction and electrochemical behavior of novel potentiometric membrane sensor responsive to the etoricoxib was described. The sensor was based on the ion-pair complex of etoricoxib (ET with Uracil-5,6-diamino-2-thio hydrochloride UDTH (ET-UDTH as exchange sites in a PVC matrix with different plasticizers dibutylphthalate (DBP (electrode B tri-n-butylphosphate (TBP (electrode C, and dioctylphthalate (DOP (electrode A. The electrodes exhibited near-Nernstian response for ET-UDTH over the concentration range 0.051-40.042 mM. The electrode offered significant advantages including long lifetime (about 2 months, excellent stability and reproducibility, good response time (10-25 s, and wide pH working range (pH 5-12. Selectivity coefficients of ET related to a number of interfering cation and some organic compounds were investigated, and there were negligible interference caused by most of the investigated species. The direct determination of 0.5-10 mM of ET showed an average recovery of 99.03-101.75% and a mean relative standard deviation 0.40-1.88. The results were obtained by determination of ET in tablets using the proposed electrodes which were comparable favorably with those obtained by spectrophotometric method

Representing and Reasoning with the Internet of Things: a Modular Rule-Based Model for Ensembles of Context-Aware Smart Things

OpenAIRE

S. W. Loke

2016-01-01

Context-aware smart things are capable of computational behaviour based on sensing the physical world, inferring context from the sensed data, and acting on the sensed context. A collection of such things can form what we call a thing-ensemble, when they have the ability to communicate with one another (over a short range network such as Bluetooth, or the Internet, i.e. the Internet of Things (IoT) concept), sense each other, and when each of them might play certain roles with respect to each...

Refinement of Representation Theorems for Context-Free Languages

Science.gov (United States)

Fujioka, Kaoru

In this paper, we obtain some refinement of representation theorems for context-free languages by using Dyck languages, insertion systems, strictly locally testable languages, and morphisms. For instance, we improved the Chomsky-Schützenberger representation theorem and show that each context-free language L can be represented in the form L = h (D ∩ R), where D is a Dyck language, R is a strictly 3-testable language, and h is a morphism. A similar representation for context-free languages can be obtained, using insertion systems of weight (3, 0) and strictly 4-testable languages.

Representing and Reasoning with the Internet of Things: a Modular Rule-Based Model for Ensembles of Context-Aware Smart Things

Directory of Open Access Journals (Sweden)

S. W. Loke

2016-03-01

Full Text Available Context-aware smart things are capable of computational behaviour based on sensing the physical world, inferring context from the sensed data, and acting on the sensed context. A collection of such things can form what we call a thing-ensemble, when they have the ability to communicate with one another (over a short range network such as Bluetooth, or the Internet, i.e. the Internet of Things (IoT concept, sense each other, and when each of them might play certain roles with respect to each other. Each smart thing in a thing-ensemble might have its own context-aware behaviours which when integrated with other smart things yield behaviours that are not straightforward to reason with. We present Sigma, a language of operators, inspired from modular logic programming, for specifying and reasoning with combined behaviours among smart things in a thing-ensemble. We show numerous examples of the use of Sigma for describing a range of behaviours over a diverse range of thing-ensembles, from sensor networks to smart digital frames, demonstrating the versatility of our approach. We contend that our operator approach abstracts away low-level communication and protocol details, and allows systems of context-aware things to be designed and built in a compositional and incremental manner.

"So Happy I Could Shout!" and "So Happy I Could Cry!" Dimorphous expressions represent and communicate motivational aspects of positive emotions.

Science.gov (United States)

Aragón, Oriana R; Bargh, John A

2018-03-01

Happiness can be expressed through smiles. Happiness can also be expressed through physical displays that without context, would appear to be sadness (tears, downward turned mouths, and crumpled body postures) and anger (clenched jaws, snarled lips, furrowed brows, and pumped fists). These seemingly incongruent displays of happiness, termed dimorphous expressions, we propose, represent and communicate expressers' motivational orientations. When participants reported their own aggressive expressions in positive or negative contexts, their expressions represented positive or negative emotional experiences respectively, imbued with appetitive orientations (feelings of wanting to go). In contrast, reported sad expressions, in positive or negative contexts, represented positive and negative emotional experiences respectively, imbued with consummatory orientations (feelings of wanting to pause). In six additional experiments, participant observers interpreted that aggression displayed in positive contexts signalled happy-appetitive states, and sadness displayed in positive contexts signalled happy-consummatory states. Implications for the production and interpretation of emotion expressions are discussed.

Cultural context in medical ethics: lessons from Japan

Directory of Open Access Journals (Sweden)

Powell Tia

2006-04-01

Full Text Available Abstract This paper examines two topics in Japanese medical ethics: non-disclosure of medical information by Japanese physicians, and the history of human rights abuses by Japanese physicians during World War II. These contrasting issues show how culture shapes our view of ethically appropriate behavior in medicine. An understanding of cultural context reveals that certain practices, such as withholding diagnostic information from patients, may represent ethical behavior in that context. In contrast, nonconsensual human experimentation designed to harm the patient is inherently unethical irrespective of cultural context. Attempts to define moral consensus in bioethics, and to distinguish between acceptable and unacceptable variation across different cultural contexts, remain central challenges in articulating international, culturally sensitive norms in medical ethics.

Harnessing Context for Vandalism Detection in Wikipedia

Directory of Open Access Journals (Sweden)

Lakshmish Ramaswamy

2014-05-01

Full Text Available The importance of collaborative social media (CSM applications such as Wikipedia to modern free societies can hardly be overemphasized. By allowing end users to freely create and edit content, Wikipedia has greatly facilitated democratization of information. However, over the past several years, Wikipedia has also become susceptible to vandalism, which has adversely affected its information quality. Traditional vandalism detection techniques that rely upon simple textual features such as spammy or abusive words have not been very effective in combating sophisticated vandal attacks that do not contain common vandalism markers. In this paper, we propose a context-based vandalism detection framework for Wikipedia. We first propose a contextenhanced finite state model for representing the context evolution ofWikipedia articles. This paper identifies two distinct types of context that are potentially valuable for vandalism detection, namely content-context and contributor-context. The distinguishing powers of these contexts are discussed by providing empirical results. We design two novel metrics for measuring how well the content-context of an incoming edit fits into the topic and the existing content of a Wikipedia article. We outline machine learning-based vandalism identification schemes that utilize these metrics. Our experiments indicate that utilizing context can substantially improve vandalism detection accuracy.

CCSD(T) calculations of stabilities and properties of confined systems

Energy Technology Data Exchange (ETDEWEB)

Holka, F.; Urban, M. [Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, Bottova 25, SK-917 24 Trnava (Slovakia); Melicherčík, M.; Neogrády, P. [Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava (Slovakia); Paldus, J. [Department of Applied Mathematics, University of Waterloo, N2L 3G1, Ontario (Canada)

2015-01-22

We analyze energies, electron affinities and polarizabilities of small anions exposed to an external confinement. The second electron in free O{sup 2−} and S{sup 2−} anions is unbound. We investigate the stabilizing effect of the spherical harmonic-oscillator confining potential ω. on these anions employing the Hartree-Fock stability analysis as introduced by Čížek and Paldus. With increasing strength of the external harmonic-oscillator confinement potential ω the broken symmetry (BS) solutions are systematically eliminated. For ω larger than 0.1 all BS solutions for O{sup 2−} disappear. For ω larger than 0.13 the CCSD(T) energy of O{sup 2−} becomes more negative than the energy of the singly charged O{sup −} anion. We relate the harmonic-oscillator confining potential to a crystalline environment in which the O{sup 2−} and S{sup 2−} anions are stable. We also present a model allowing calculations of the in-crystal polarizabilities of anions. The model is based on CCSD(T) calculations of static polarizabilities of selected anions exposed to the spherical harmonic-oscillator confining potential ω This artificial confinement potential ω is then related to the ionic radii of the cation in representative crystal lattices. We investigate the polarizability of O{sup 2−} and S{sup 2−} anions in MgO, MgS, CaO, CaS, SrO, SrS, BaO and BaS crystals. We compare our results with alternative models for in-crystal polarizabilities. External confinement also stabilizes the uracil anion U{sup −}, as is shown by calculations with a stepwise micro-hydration of U{sup −}. Upon hydration is the CCSD(T) adiabatic electron affinity (AEA) of uracil enhanced by about 250 up to 570 meV in comparison with AEA of the isolated molecule, depending on the geometry of the hydrated uracil anion complex. We tried to find an analogy of the stabilization effect of the external confinement on the otherwise unstable anions. In uracil and its anion is the external

The social context of land management

DEFF Research Database (Denmark)

Richardt, Ann-Sofie

‘peri-urban areas’ have particularly been associated with two dimensions of change; change of social relations between landowners and changes of the landscape. Together these changes represent a changed social context locally. This thesis claims that people, including landowners, are not unaffected......-self communicate norms of the appropriate and acceptable land management in particular placed. On this background the aim of this thesis is to examine the role of the social context for landowners’ land management locally in a peri-urban area. Specifically, the role of landowners’ social identities and relations...... is examined with respect to land management decisions. The study thus contributes to the body of research aiming to supplement structural explanations of land-use and management change with socio psychological perspectives. That is, research focusing on landowners as individuals’ behaviour in a social context...

Adaptable Grammars for Non-Context-Free Languages

DEFF Research Database (Denmark)

Christiansen, Henning

2009-01-01

languages that are considered as prototype representatives of non-context-free phenomena in natural languages. We define a grammar formalism with these characteristics and show how it can be implemented in logic programming in a surprisingly straightforward way, compared with the expressive...

Context effects: the role of collectivism as a moderator.

Science.gov (United States)

Puente-Díaz, Rogelio

2011-02-01

Social cognition experts have shown that participants' answers to research questions can be influenced by previous questions, something known as context effects. It has been suggested that participants from collectivist cultures pay more attention to the context, resulting in larger context effects. The present investigation examined context effects in an experiment that involved manipulating the order in which two questions, one about satisfaction with life as a whole and one about satisfaction with romantic life, were answered by a representative sample of participants from Mexico City. The results were consistent with other investigations that used samples from collectivistic cultures. Participants' responses to questions about satisfaction are influenced by a previous question, and country of origin affects the amount of attention given to the context. The implications of these results are discussed.

Using Structured Knowledge Representation for Context-Sensitive Probabilistic Modeling

National Research Council Canada - National Science Library

Sakhanenko, Nikita A; Luger, George F

2008-01-01

We propose a context-sensitive probabilistic modeling system (COSMOS) that reasons about a complex, dynamic environment through a series of applications of smaller, knowledge-focused models representing contextually relevant information...

Generalized contexts and consistent histories in quantum mechanics

International Nuclear Information System (INIS)

Losada, Marcelo; Laura, Roberto

2014-01-01

We analyze a restriction of the theory of consistent histories by imposing that a valid description of a physical system must include quantum histories which satisfy the consistency conditions for all states. We prove that these conditions are equivalent to imposing the compatibility conditions of our formalism of generalized contexts. Moreover, we show that the theory of consistent histories with the consistency conditions for all states and the formalism of generalized context are equally useful representing expressions which involve properties at different times

Clinical relevance of retrieval cues for attenuating context renewal of fear.

Science.gov (United States)

Culver, Najwa C; Stoyanova, Milena; Craske, Michelle G

2011-03-01

The present studies investigated if retrieval cues (reminder objects) can attenuate context renewal of fear. In Study 1, 32 participants completed exposure in one of two contexts; 1-week follow-up testing occurred in a novel or the same context. Results indicated significant renewal of fear for those tested in a novel context. In Study 2, 40 participants completed exposure in one of these contexts; half were presented with cues. One week later, all were tested in a novel context with or without cues. Results indicated weak attenuation of context renewal for participants re-presented with cues. In Study 3, 18 participants completed exposure in one of two maximally distinct contexts; all with cues. One week later, participants were tested in a novel context with or without cues. Results indicated no group differences. These findings suggest that clinical relevance of this set of cues for attenuating context renewal may be limited. Copyright © 2010 Elsevier Ltd. All rights reserved.

The Mandate of the Collective: Apology Representativeness Determines Perceived Sincerity and Forgiveness in Intergroup Contexts.

Science.gov (United States)

Wenzel, Michael; Okimoto, Tyler G; Hornsey, Matthew J; Lawrence-Wood, Ellie; Coughlin, Anne-Marie

2017-06-01

The sincerity of an apology is often critical for it to be viewed positively by victims. For collective apologies, we argue that sincerity takes on a particular meaning: It is a function of the apology's perceived representativeness for the offender group's will or sentiment. Consistent with this notion, when an apologetic (vs. nonapologetic) message was democratically chosen (Study 1) or explicitly endorsed by the majority of the offending outgroup (Study 2), it was considered more sincere and, through this, led to more forgiveness. Furthermore, while disagreement about an apology within the offender group reduced its perceived representativeness and sincerity, this was less so when the dissenters could be subtyped: when disagreement was correlated with an existing subgroup within the offending outgroup (Study 3) and in line with expectations for that subgroup (Study 4). This research shows that victim group members consider intragroup processes within the offending outgroup for attributions of sincerity.

Context-free pragmatism in Danish campus architecture

DEFF Research Database (Denmark)

Knudsen, Lars Emmerik Damgaard

an educational ideal that also seem to lack a sense of context, and hence both the architecture and the educational structuring in Campus Roskilde can be understood as a context free pragmatism. I analyze this tendency with references to Dewey’s own work on the meaning of the educational environment.......The idea of new pragmatism has inspired a new Danish wave in architecture that since 2012 has had enormous influence on the design of campus buildings in the professional education sector in Denmark. In arguing for a no-nonsense approach to architecture representatives of new pragmatism refers...

UV laser photoactivation of hexachloroplatinate bound to individual nucleobases in vacuo as molecular level probes of a model photopharmaceutical.

Science.gov (United States)

Matthews, Edward; Sen, Ananya; Yoshikawa, Naruo; Bergström, Ed; Dessent, Caroline E H

2016-06-01

Isolated molecular clusters of adenine, cytosine, thymine and uracil bound to hexachloroplatinate, PtCl6(2-), have been studied using laser electronic photodissociation spectroscopy to investigate photoactivation of a platinum complex in the vicinity of a nucleobase. These metal complex-nucleobase clusters represent model systems for identifying the fundamental photochemical processes occurring in photodynamic platinum drug therapies that target DNA. This is the first study to explore the specific role of a strongly photoactive platinum compound in the aggregate complex. Each of the clusters studied displays a broadly similar absorption spectra, with a strong λmax ∼ 4.6 eV absorption band and a subsequent increase in the absorption intensity towards higher spectral-energy. The absorption bands are traced to ligand-to-metal-charge-transfer excitations on the PtCl6(2-) moiety within the cluster, and result in Cl(-)·nucleobase and PtCl5(-) as primary photofragments. These results demonstrate how selective photoexcitation can drive distinctive photodecay channels for a model photo-pharmaceutical. In addition, cluster absorption due to excitation of nucleobase-centred chromophores is observed in the region around 5 eV. For the uracil cluster, photofragments consistent with ultrafast decay of the excited state and vibrational predissociation on the ground-state surface are observed. However, this decay channel becomes successively weaker on going from thymine to cytosine to adenine, due to differential coupling of the excited states to the electron detachment continuum. These effects demonstrate the distinctive photophysical characteristics of the different nucleobases, and are discussed in the context of the recently recorded photoelectron spectra of theses clusters.

Explicit Context Matching in Content-Based Publish/Subscribe Systems

Directory of Open Access Journals (Sweden)

Miguel Jiménez

2013-03-01

Full Text Available Although context could be exploited to improve performance, elasticity and adaptation in most distributed systems that adopt the publish/subscribe (P/S communication model, only a few researchers have focused on the area of context-aware matching in P/S systems and have explored its implications in domains with highly dynamic context like wireless sensor networks (WSNs and IoT-enabled applications. Most adopted P/S models are context agnostic or do not differentiate context from the other application data. In this article, we present a novel context-aware P/S model. SilboPS manages context explicitly, focusing on the minimization of network overhead in domains with recurrent context changes related, for example, to mobile ad hoc networks (MANETs. Our approach represents a solution that helps to effciently share and use sensor data coming from ubiquitous WSNs across a plethora of applications intent on using these data to build context awareness. Specifically, we empirically demonstrate that decoupling a subscription from the changing context in which it is produced and leveraging contextual scoping in the filtering process notably reduces (unsubscription cost per node, while improving the global performance/throughput of the network of brokers without altering the cost of SIENA-like topology changes.

Context in a wider context

Directory of Open Access Journals (Sweden)

John Traxler

2011-07-01

Full Text Available This paper attempts to review and reconsider the role of context in mobile learning and starts by outlining definitions of context-aware mobile learning as the technologies have become more mature, more robust and more widely available and as the notion of context has become progressively richer. The future role of context-aware mobile learning is considered within the context of the future of mobile learning as it moves from the challenges and opportunities of pedagogy and technology to the challenges and opportunities of policy, scale, sustainability, equity and engagement with augmented reality, «blended learning», «learner devices», «user-generated contexts» and the «internet of things». This is essentially a perspective on mobile learning, and other forms of technology-enhanced learning (TEL, where educators and their institutions set the agenda and manage change. There are, however, other perspectives on context. The increasing availability and use of smart-phones and other personal mobile devices with similar powerful functionality means that the experience of context for many people, in the form of personalized or location-based services, is an increasingly social and informal experience, rather than a specialist or educational experience. This is part of the transformative impact of mobility and connectedness on our societies brought about by these universal, ubiquitous and pervasive technologies. This paper contributes a revised understanding of context in the wider context (sic of the transformations taking place in our societies. These are subtle but pervasive transformations of jobs, work and the economy, of our sense of time, space and place, of knowing and learning, and of community and identity. This leads to a radical reconsideration of context as the notions of ‹self› and ‹other› are transformed.

Knowledge Representation in the Context of E-business Applications

Directory of Open Access Journals (Sweden)

Simona Elena Varlan

2010-03-01

Full Text Available The article emphasizes the theoretical principles of knowledge representation. The paper also tries to show how to represent knowledge in the context of e-business applications creating atagging platform for economic knowledge using SKOS language.

Environmental context-dependent memory: a review and meta-analysis.

Science.gov (United States)

Smith, S M; Vela, E

2001-06-01

To address questions about human memory's dependence on the coincidental environmental contexts in which events occur, we review studies of incidental environmental context-dependent memory in humans and report a meta-analysis. Our theoretical approach to the issue stems from Glenberg's (1997) contention that introspective thought (e.g., remembering, conceptualizing) requires cognitive resources normally used to represent the immediate environment. We propose that if tasks encourage processing of noncontextual information (i.e., introspective thought) at input and/or at test, then both learning and memory will be less dependent on the ambient environmental contexts in which those activities occur. The meta-analysis showed that across all studies, environmental context effects were reliable, and furthermore, that the use of noncontextual cues during learning (overshadowing) and at test (outshining), as well as mental reinstatement of appropriate context cues at test, all reduce the effect of environmental manipulations. We conclude that environmental context-dependent memory effects are less likely to occur under conditions in which the immediate environment is likely to be suppressed.

Semantic Context Detection Using Audio Event Fusion

Directory of Open Access Journals (Sweden)

Cheng Wen-Huang

2006-01-01

Full Text Available Semantic-level content analysis is a crucial issue in achieving efficient content retrieval and management. We propose a hierarchical approach that models audio events over a time series in order to accomplish semantic context detection. Two levels of modeling, audio event and semantic context modeling, are devised to bridge the gap between physical audio features and semantic concepts. In this work, hidden Markov models (HMMs are used to model four representative audio events, that is, gunshot, explosion, engine, and car braking, in action movies. At the semantic context level, generative (ergodic hidden Markov model and discriminative (support vector machine (SVM approaches are investigated to fuse the characteristics and correlations among audio events, which provide cues for detecting gunplay and car-chasing scenes. The experimental results demonstrate the effectiveness of the proposed approaches and provide a preliminary framework for information mining by using audio characteristics.

DOES FAIR VALUE REPRESENT A CONCERN FOR ROMANIAN RESEARCHERS?

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Jurcau Anca-Sabina

2010-07-01

Full Text Available In the actual economic context, the fair value concept is of high interest .We tried to see if the concept is only talk about, or if research in Romania has been actually done on this theme. We have analyzed the Romanian Journals recognized by CNCSIS in order to see if this concept represents a concern for Romanian researchers. This article is a literature review of the economic Romanian journals recognize by CNCSIS in the field of “fair value”.

Context-Dependent Egr1 Expression in the Avian Hippocampus.

Science.gov (United States)

Grella, Stephanie L; Guigueno, Mélanie F; White, David J; Sherry, David F; Marrone, Diano F

2016-01-01

In mammals, episodic memory and spatial cognition involve context-specific recruitment of unique ensembles in the hippocampal formation (HF). Despite their capacity for sophisticated spatial (e.g., for migration) and episodic-like (e.g., for food-caching) memory, the mechanisms underlying contextual representation in birds is not well understood. Here we demonstrate environment-specific Egr1 expression as male brown-headed cowbirds (Molothrus ater) navigate environments for food reward, showing that the avian HF, like its mammalian counterpart, recruits distinct neuronal ensembles to represent different contexts.

Effects of achievement contexts on the meaning structure of emotion words.

Science.gov (United States)

Gentsch, Kornelia; Loderer, Kristina; Soriano, Cristina; Fontaine, Johnny R J; Eid, Michael; Pekrun, Reinhard; Scherer, Klaus R

2018-03-01

Little is known about the impact of context on the meaning of emotion words. In the present study, we used a semantic profiling instrument (GRID) to investigate features representing five emotion components (appraisal, bodily reaction, expression, action tendencies, and feeling) of 11 emotion words in situational contexts involving success or failure. We compared these to the data from an earlier study in which participants evaluated the typicality of features out of context. Profile analyses identified features for which typicality changed as a function of context for all emotion words, except contentment, with appraisal features being most frequently affected. Those context effects occurred for both hypothesised basic and non-basic emotion words. Moreover, both data sets revealed a four-dimensional structure. The four dimensions were largely similar (valence, power, arousal, and novelty). The results suggest that context may not change the underlying dimensionality but affects facets of the meaning of emotion words.

Structural and Energetic Impact of Non-Natural 7-Deaza-8-Azaadenine and its 7-Substituted Derivatives on H-Bonding Potential with Uracil in RNA Molecules

KAUST Repository

Chawla, Mohit; Credendino, Raffaele; Oliva, Romina; Cavallo, Luigi

2015-01-01

Non-natural (synthetic) nucleobases, including 7-ethynyl- and 7-triazolyl-8-aza-7-deazaadenosine, have been introduced in RNA molecules for targeted applications, and have been characterized experimentally. However, no theoretical characterization of the impact of these modifications on the structure and energetics of the corresponding H-bonded base pair is available. To fill this gap, we performed quantum mechanics calculations, starting with the analysis of the impact of the 8-aza-7-deaza modification of the adenosine skeleton, and we moved then to analyze the impact of the specific substituents on the modified 8-aza-7-deazaadenosine. Our analysis indicates that, despite of these severe structural modifications, the H-bonding properties of the modified base pair gratifyingly replicate those of the unmodified base pair. Similar behavior is predicted when the same skeleton modifications are applied to guanosine when paired to cytosine. To stress further the H-bonding pairing in the modified adenosine-uracil base pair, we explored the impact of strong electron donor and electron withdrawing substituents on the C7 position. Also in this case we found minimal impact on the base pair geometry and energy, confirming the validity of this modification strategy to functionalize RNAs without perturbing its stability and biological functionality.

Structural and Energetic Impact of Non-Natural 7-Deaza-8-Azaadenine and its 7-Substituted Derivatives on H-Bonding Potential with Uracil in RNA Molecules

KAUST Repository

Chawla, Mohit

2015-09-21

Non-natural (synthetic) nucleobases, including 7-ethynyl- and 7-triazolyl-8-aza-7-deazaadenosine, have been introduced in RNA molecules for targeted applications, and have been characterized experimentally. However, no theoretical characterization of the impact of these modifications on the structure and energetics of the corresponding H-bonded base pair is available. To fill this gap, we performed quantum mechanics calculations, starting with the analysis of the impact of the 8-aza-7-deaza modification of the adenosine skeleton, and we moved then to analyze the impact of the specific substituents on the modified 8-aza-7-deazaadenosine. Our analysis indicates that, despite of these severe structural modifications, the H-bonding properties of the modified base pair gratifyingly replicate those of the unmodified base pair. Similar behavior is predicted when the same skeleton modifications are applied to guanosine when paired to cytosine. To stress further the H-bonding pairing in the modified adenosine-uracil base pair, we explored the impact of strong electron donor and electron withdrawing substituents on the C7 position. Also in this case we found minimal impact on the base pair geometry and energy, confirming the validity of this modification strategy to functionalize RNAs without perturbing its stability and biological functionality.

Photo-Crosslinking of Pendent Uracil Units Provides Supramolecular Hole Injection/Transport Conducting Polymers for Highly Efficient Light-Emitting Diodes

Directory of Open Access Journals (Sweden)

Hsi-Kang Shih

2015-04-01

Full Text Available A new process for modifying a polymeric material for use as a hole injection transport layer in organic light-emitting diodes has been studied, which is through 2π + 2π photodimerization of a DNA-mimetic π-conjugated poly(triphenylamine-carbazole presenting pendent uracil groups (PTC-U under 1 h of UV irradiation. Multilayer florescence OLED (Organic light-emitting diodes device with the PTC-U-1hr as a hole injection/transport layer (ITO (Indium tin oxide/HITL (hole-injection/transport layer (15 nm/N,N'-di(1-naphthyl- N,N'-diphenyl-(1,1'-biphenyl-4,4'-diamine (NPB (15 nm/Tris-(8-hydroxyquinoline aluminum (Alq3 (60 nm/LiF (1 nm/Al (100 nm is fabricated, a remarkable improvement in performance (Qmax (external quantum efficiency = 2.65%, Bmax (maximum brightness = 56,704 cd/m2, and LE (luminance efficiencymax = 8.9 cd/A relative to the control PTC-U (Qmax = 2.40%, Bmax = 40,490 cd/m2, and LEmax = 8.0 cd/A. Multilayer phosphorescence OLED device with the PTC-U-1hr as a hole injection/transport layer (ITO/HITL (15 nm/Ir(ppy3:PVK (40 nm/BCP (10nm/Alq3 (40 nm/LiF (1 nm/Al (100 nm is fabricated by successive spin-coating processes, a remarkable improvement in performance (Qmax = 9.68%, Bmax = 41,466 cd/m2, and LEmax = 36.6 cd/A relative to the control PTC-U (Qmax = 8.35%, Bmax = 34,978 cd/m2, and LEmax = 30.8 cd/A and the commercial product (poly(3,4-ethylenedioxythiophene:polystyrenesulfonate PEDOT:PSS (Qmax = 4.29%, Bmax = 15,678 cd/m2, and LEmax = 16.2 cd/A has been achieved.

Ad-me: Intelligent Context-Sensitive Advertising within a Mobile Tourist Guide.

OpenAIRE

Hristova, Nataliya; O'Hare, G. M. P. (Greg M. P.)

2001-01-01

The mobile commerce sector is set to witness phenomenal growth. In particular context sensitive advertising will represent a high yield revenue stream. This paper introduces the Ad-me (Advertising for the mobile e-commerce user) system which proactively delivers advertisements to users. Within the context of a mobile tourist guide advertisements are presented relative to user location and perceived needs. It uses Global Positioning System (GPS) and embraces agent-oriented design p...

INVESTIGATION OF REPRESENTATIVE CHARACTERISTICS OF LUKIŠKIŲ SQUARE IN VILNIUS

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Gintautas TIŠKUS

2018-05-01

Full Text Available Representative squares are sites where ideological monuments or monuments are built, or squares to important state or municipal buildings. Representation square is a mark or sign system that is intended to provide some relevant information. This information may include events or actors that are important and desirable to commemorate, ideological - political motives that want to be given exclusive importance. In determining the structure of the area’s representative area, causal relationships with the represented object are identified. The original key information is the name. Subsequently, the type of object represented – an event or personality, a connection to the square, the importance of the mark on the square (dominant, noticeable or invisible, and the interaction between the label and the environment are determined. After examining the structure of the square of the square and writing the values in the matrix, we can determine the representation level of the square. In the representation square we can name the square, for which the context of the environment and the level of representational marks for the purpose of the square have a decisive or significant influence.

Determining the relative importance of figures in journal articles to find representative images

Science.gov (United States)

Müller, Henning; Foncubierta-Rodríguez, Antonio; Lin, Chang; Eggel, Ivan

2013-03-01

When physicians are searching for articles in the medical literature, images of the articles can help determining relevance of the article content for a specific information need. The visual image representation can be an advantage in effectiveness (quality of found articles) and also in efficiency (speed of determining relevance or irrelevance) as many articles can likely be excluded much quicker by looking at a few representative images. In domains such as medical information retrieval, allowing to determine relevance quickly and accurately is an important criterion. This becomes even more important when small interfaces are used as it is frequently the case on mobile phones and tablets to access scientific data whenever information needs arise. In scientific articles many figures are used and particularly in the biomedical literature only a subset may be relevant for determining the relevance of a specific article to an information need. In many cases clinical images can be seen as more important for visual appearance than graphs or histograms that require looking at the context for interpretation. To get a clearer idea of image relevance in articles, a user test with a physician was performed who classified images of biomedical research articles into categories of importance that can subsequently be used to evaluate algorithms that automatically select images as representative examples. The manual sorting of images of 50 journal articles of BioMedCentral with each containing more than 8 figures by importance also allows to derive several rules that determine how to choose images and how to develop algorithms for choosing the most representative images of specific texts. This article describes the user tests and can be a first important step to evaluate automatic tools to select representative images for representing articles and potentially also images in other contexts, for example when representing patient records or other medical concepts when selecting

Encountering energy strategies and plans with the social context of household practice

DEFF Research Database (Denmark)

Quitzau, Maj-Britt; Nyborg, Sophie; Røpke, Inge

Encountering energy strategies and plans with the social context of household practices Governments and utility companies have developed a great deal of strategies and plans on how to cope with energy saving in households, since this represents a major issue for climate change remediation. Many...... in households, and provides important clues about the potentiality to anchor energy strategies and plans in the social context of local households....

Preliminary results of phase I trial of oral uracil/tegafur (UFT, leucovorin plus irinotecan and radiation therapy for patients with locally recurrent rectal cancer

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Fukunaga Mutsumi

2006-11-01

Full Text Available Abstract Background Surgical attempts for locally recurrent rectal cancer often fail due to local re-recurrence and distant metastasis. Preoperative chemoradiation may enhance better local control and survival. The aim of this study was to assess the safety of oral uracil and tegafur (UFT plus leucovorin (LV, and irinotecan combined with radiation and determine the maximum-tolerated dose (MTD and dose limiting toxicity (DLT of the triple drug regimen. Patients and methods Patients with locally recurrent rectal cancer received escalating doses of irinotecan on days 1, 8, 15, and 22 (starting at 30 mg/m2, with 10 mg increments between consecutive cohorts and fixed doses of UFT (300 mg/m2 plus LV (75 mg/day on days 3 to 7, 10 to 14, 17 to 21, and 24 to 28. Radiation was given 5 days per week totaling 40 to 50 Gy (2Gy/day. Results Six patients were treated at the starting dose, and 2 received the full scheduled chemoradiotherapy. The other 4 patients had grade 3 diarrhea and diarrhea was the DLT. One patient had partial response and he had subsequently radical surgical resection. Median progression free survival for local recurrence was 320 days. Conclusion Irinotecan plus UFT/LV with concomitant radiotherapy in patients with locally recurrent rectal cancer was not feasible due to diarrhea in this setting. Modification of the treatment is needed.

Context-dependence of Aimed Arm Movements: A Transitory or A Stable Phenomenon?

Directory of Open Access Journals (Sweden)

Benjamin Baak

2014-10-01

Full Text Available Previous work documented that grasping movements in a typical laboratory context differ widely from those in a more natural context. We evaluate whether this context-dependence changes with experience. Data from 48 subjects (24 female; 24.9 ± 2.7 years of age were (reanalyzed. They had participated in experimental blocks with externally triggered, purposeless and repetitive movements (context L, laboratory-like, and a block with self-initiated, ecologically valid movements embedded in a complex task (context E, everyday-like. Mechanical constraints on grasping were identical in both blocks. A global metric, representing context-dependence across multiple kinematic parameters, did not change appreciably across the 20 trials of a block. Furthermore, the metric was not affected by prior participation in the other block. We conclude that context-dependence of grasping is robust, i.e., it shows little influence of prior experience. This opens the avenue for within-subject designs on context-dependence, e.g., for clinical investigations. Keywords: Motor control, Prehension, Context-dependence, Serial order, Attunement

Brain structural connectivity and context-dependent extinction memory.

Science.gov (United States)

Hermann, Andrea; Stark, Rudolf; Blecker, Carlo R; Milad, Mohammed R; Merz, Christian J

2017-08-01

Extinction of conditioned fear represents an important mechanism in the treatment of anxiety disorders. Return of fear after successful extinction or exposure therapy in patients with anxiety disorders might be linked to poor temporal or contextual generalization of extinction due to individual differences in brain structural connectivity. The goal of this magnetic resonance imaging study was therefore to investigate the association of context-dependent extinction recall with brain structural connectivity. Diffusion-tensor imaging was used to determine the fractional anisotropy as a measure of white matter structural integrity of fiber tracts connecting central brain regions of the fear and extinction circuit (uncinate fasciculus, cingulum). Forty-five healthy men participated in a two-day fear conditioning experiment with fear acquisition in context A and extinction learning in context B on the first day. Extinction recall in the extinction context as well as renewal in the acquisition context and a novel context C took place one day later. Renewal of conditioned fear (skin conductance responses) in the acquisition context was associated with higher structural integrity of the hippocampal part of the cingulum. Enhanced structural integrity of the cingulum might be related to stronger hippocampal modulation of the dorsal anterior cingulate cortex, a region important for modulating conditioned fear output by excitatory projections to the amygdala. This finding underpins the crucial role of individual differences in the structural integrity of relevant fiber tracts for context-dependent extinction recall and return of fear after exposure therapy in anxiety disorders. © 2017 Wiley Periodicals, Inc.

Supporting imagination in the context of work

DEFF Research Database (Denmark)

Kolbæk, Ditte

2018-01-01

This chapter explores imagination in the context of work. When we work, we meet challenges and problems that we are obliged to solve. Most often we utilize well-defined work processes for the problem-solving, but now and then we run into new problems that need something else. This “something else...... hierarchical levels in the organisation. The research question is: How may a workplace support imagination for problem solving?...... on the task as well as colleagues who are influenced by the problem and its solution. Imagination becomes crucial to problem solving, and the final solution is a new way of doing – it is an innovation. When imagination is required at work, the workplace represents the context of the imagination. This chapter...

Imagining Another Context during Encoding Offsets Context-Dependent Forgetting

Science.gov (United States)

Masicampo, E. J.; Sahakyan, Lili

2014-01-01

We tested whether imagining another context during encoding would offset context-dependent forgetting. All participants studied a list of words in Context A. Participants who remained in Context A during the test recalled more than participants who were tested in another context (Context B), demonstrating the standard context-dependent forgetting…

Models with Men and Women: Representing Gender in Dynamic Modeling of Social Systems.

Science.gov (United States)

Palmer, Erika; Wilson, Benedicte

2018-04-01

Dynamic engineering models have yet to be evaluated in the context of feminist engineering ethics. Decision-making concerning gender in dynamic modeling design is a gender and ethical issue that is important to address regardless of the system in which the dynamic modeling is applied. There are many dynamic modeling tools that operationally include the female population, however, there is an important distinction between females and women; it is the difference between biological sex and the social construct of gender, which is fluid and changes over time and geography. The ethical oversight in failing to represent or misrepresenting gender in model design when it is relevant to the model purpose can have implications for model validity and policy model development. This paper highlights this gender issue in the context of feminist engineering ethics using a dynamic population model. Women are often represented in this type of model only in their biological capacity, while lacking their gender identity. This illustrative example also highlights how language, including the naming of variables and communication with decision-makers, plays a role in this gender issue.

Category Rating Is Based on Prototypes and Not Instances: Evidence from Feedback-Dependent Context Effects

Science.gov (United States)

Petrov, Alexander A.

2011-01-01

Context effects in category rating on a 7-point scale are shown to reverse direction depending on feedback. Context (skewed stimulus frequencies) was manipulated between and feedback within subjects in two experiments. The diverging predictions of prototype- and exemplar-based scaling theories were tested using two representative models: ANCHOR…

Energy in Ireland: context, management and research

International Nuclear Information System (INIS)

Saintherant, N.; Lerouge, Ch.; Welcker, A.

2008-01-01

In the framework of the climatic change and the fossil fuels shortage, the Ireland defined a new energy policy. The priority is the energy supply security and the research programs present a great interest in the ocean energies, which represent an important source in Ireland. The report presents the context, the irish energy policy, the research programs on energy and the different actors of the domain. (A.L.B.)

Using resource graphs to represent conceptual change

Directory of Open Access Journals (Sweden)

Michael C. Wittmann

2006-08-01

Full Text Available We introduce resource graphs, a representation of linked ideas used when reasoning about specific contexts in physics. Our model is consistent with previous descriptions of coordination classes and resources. It represents mesoscopic scales that are neither knowledge-in-pieces nor large-scale concepts. We use resource graphs to describe several forms of conceptual change: incremental, cascade, wholesale, and dual construction. For each, we give evidence from the physics education research literature to show examples of each form of conceptual change. Where possible, we compare our representation to models used by other researchers. Building on our representation, we analyze another form of conceptual change, differentiation, and suggest several experimental studies that would help understand the differences between reform-based curricula.

ETHNOCULTURAL CONTEXT IN “SIBERIAN TALES” OF V.G. KOROLENKO

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Oxana Ivanova

2012-05-01

Full Text Available The special features of ethnocultural context in the “Siberian Tales” of V.G. Korolenko based on the stories “Makar’s Dream”, “Sokolinets”,“Marusya’s wood house” are analyzed in this paper. The representatives of such nationalities as Yakuts, Russians and Tatars are regarded. The specific peculiarities of the representatives of these nationalities are pointed out. The dependence of the main national character features from the environment, severe climate and Yakut conditions is underlined.

Representativeness, legitimacy and power in public involvement in health-service management.

Science.gov (United States)

Martin, Graham P

2008-12-01

Public participation in health-service management is an increasingly prominent policy internationally. Frequently, though, academic studies have found it marginalized by health professionals who, keen to retain control over decision-making, undermine the legitimacy of involved members of the public, in particular by questioning their representativeness. This paper examines this negotiation of representative legitimacy between staff and involved users by drawing on a qualitative study of service-user involvement in pilot cancer-genetics services recently introduced in England, using interviews, participant observation and documentary analysis. In contrast to the findings of much of the literature, health professionals identified some degree of representative legitimacy in the contributions made by users. However, the ways in which staff and users constructed representativeness diverged significantly. Where staff valued the identities of users as biomedical and lay subjects, users themselves described the legitimacy of their contribution in more expansive terms of knowledge and citizenship. My analysis seeks to show how disputes over representativeness relate not just to a struggle for power according to contrasting group interests, but also to a substantive divergence in understanding of the nature of representativeness in the context of state-orchestrated efforts to increase public participation. This divergence might suggest problems with the enactment of such aspirations in practice; alternatively, however, contestation of representative legitimacy might be understood as reflecting ambiguities in policy-level objectives for participation, which secure implementation by accommodating the divergent constructions of those charged with putting initiatives into practice.

Organisational socialisation in a crisis context.

Science.gov (United States)

Lalonde, Carole

2010-04-01

The objective of this paper is to highlight the dimensions characterising the socialisation process in a crisis context. Based on the definition of organisational socialisation advanced by Van Maanen and Schein (1979) and employed later by Jones (1986), a crisis is presented as a passage from a 'normal' situation to an 'exceptional' situation. A crisis represents a socialisation context in the sense that it is a novel state in which actors must develop a different way of mobilising their knowledge, utilising their skills, and practicing their trade or profession. The paper discusses certain findings that have emerged from the literature on organisational socialisation, as well as from the testimony of actors who participated in efforts to manage the Quebec ice-storm crisis of early 1998. It is hoped that this exploratory study's data will give rise to fruitful interaction between the field of organisational socialisation and that of crisis management.

Physicians' perceptions of medical representative visits in Yemen: a qualitative study.

Science.gov (United States)

Al-Areefi, Mahmoud Abdullah; Hassali, Mohamed Azmi; Ibrahim, Mohamed Izham b Mohamed

2013-08-20

The pharmaceutical industry invests heavily in promotion, and it uses a variety of promotional strategies to influence physicians' prescribing decisions. Within this context, medical representatives (MRs) are the key personnel employed in promoting their products. One significant consequence of the interactions between physicians and medical representatives is a conflict of interests which may contribute to the over prescribing of medications and thus negative effects on patients' health and economics. There is limited detailed information published on the reasons why physicians interact with pharmaceutical representatives. This study aims to qualitatively explore physicians' attitudes about interactions with medical representatives and their reasons for accepting the medical representatives' visits. In-depth interviews were used to gain a better understanding of physicians' perceptions of medical representative visits. A total of 32 physicians from both private and public hospitals were interviewed. The recordings of the interviews were transcribed verbatim and subject to thematic analysis using a framework analysis approach. The present qualitative study found that the majority of the physicians had positive interactions with medical representatives. The physicians' main reasons stated for allowing medical representatives' visits are the social contacts and mutual benefits they will gain from these representatives. They also emphasized that the meeting with representatives provides educational and scientific benefits. A few physicians stated that the main reasons behind refusing the meeting with medical representatives were lack of conviction about the product and obligation to prescribe medicine from the representative company. Most of the physicians believed that they were under marketing pressure to prescribe certain medicines. Although physicians are aware that the medical representatives could influence their prescribing decision, they welcome

DNA context represents transcription regulation of the gene in mouse embryonic stem cells

Science.gov (United States)

Ha, Misook; Hong, Soondo

2016-04-01

Understanding gene regulatory information in DNA remains a significant challenge in biomedical research. This study presents a computational approach to infer gene regulatory programs from primary DNA sequences. Using DNA around transcription start sites as attributes, our model predicts gene regulation in the gene. We find that H3K27ac around TSS is an informative descriptor of the transcription program in mouse embryonic stem cells. We build a computational model inferring the cell-type-specific H3K27ac signatures in the DNA around TSS. A comparison of embryonic stem cell and liver cell-specific H3K27ac signatures in DNA shows that the H3K27ac signatures in DNA around TSS efficiently distinguish the cell-type specific H3K27ac peaks and the gene regulation. The arrangement of the H3K27ac signatures inferred from the DNA represents the transcription regulation of the gene in mESC. We show that the DNA around transcription start sites is associated with the gene regulatory program by specific interaction with H3K27ac.

From Usability Testing to Clinical Simulations: Bringing Context into the Design and Evaluation of Usable and Safe Health Information Technologies

DEFF Research Database (Denmark)

Kushniruk, Andre; Nøhr, Christian; Jensen, Sanne

2013-01-01

of clinical context into stronger focus. This involves testing of systems with representative users doing representative tasks, in representative settings/environments. Results: Application of methods where realistic clinical scenarios are used to drive the study of users interacting with systems under...... such evaluation can be used to improve both the usability and safety of HIT. In addition, recent work has shown that clinical simulations, in particular those conducted in-situ, can lead to considerable benefits when compared to the costs of running such studies. Conclusion: In order to bring context of use...

Promises and Limits of Representative Bureaucracy in the Study of the EU’s Bureaucracy

DEFF Research Database (Denmark)

Gravier, Magali

with the normative dimension of this theory. In an attempt to map the promises and limitations of the theory of representative bureaucracy for the study of the EU’s bureaucracy, the paper will tackle the following issues: How can this theory be adapted to fit the EU context? Can it be used despite its normative...

Ensemble coding of context-dependent fear memory in the amygdala.

Science.gov (United States)

Orsini, Caitlin A; Yan, Chen; Maren, Stephen

2013-01-01

After fear conditioning, presenting the conditioned stimulus (CS) alone yields a context-specific extinction memory; fear is suppressed in the extinction context, but renews in any other context. The context-dependence of extinction is mediated by a brain circuit consisting of the hippocampus, prefrontal cortex (PFC) and amygdala. In the present work, we sought to determine at what level of this circuit context-dependent representations of the CS emerge. To explore this question, we used cellular compartment analysis of temporal activity by fluorescent in situ hybridization (catFISH). This method exploits the intracellular expression profile of the immediate early gene (IEG), Arc, to visualize neuronal activation patterns to two different behavioral experiences. Rats were fear conditioned in one context and extinguished in another; 24 h later, they were sequentially exposed to the CS in the extinction context and another context. Control rats were also tested in each context, but were never extinguished. We assessed Arc mRNA expression within the basal amygdala (BA), lateral amygdala (LA), ventral hippocampus (VH), prelimbic cortex (PL) and infralimbic cortex (IL). We observed that the sequential retention tests induced context-dependent patterns of Arc expression in the BA, LA, and IL of extinguished rats; this was not observed in non-extinguished controls. In general, non-extinguished animals had proportionately greater numbers of non-selective (double-labeled) neurons than extinguished animals. Collectively, these findings suggest that extinction learning results in pattern separation, particularly within the BA, in which unique neuronal ensembles represent fear memories after extinction.

Ensemble coding of context-dependent fear memory in the amygdala

Directory of Open Access Journals (Sweden)

Caitlin A Orsini

2013-12-01

Full Text Available After fear conditioning, presenting the conditioned stimulus (CS alone yields a context-specific extinction memory; fear is suppressed in the extinction context, but renews in any other context. The context-dependence of extinction is mediated by a brain circuit consisting of the hippocampus, prefrontal cortex and amygdala. In the present work, we sought to determine at what level of this circuit context-dependent representations of the CS emerge. To explore this question, we used cellular compartment analysis of temporal activity by fluorescent in situ hybridization (catFISH. This method exploits the intracellular expression profile of the immediate early gene, Arc, to visualize neuronal activation patterns to two different behavioral experiences. Rats were fear conditioned in one context and extinguished in another; twenty-four hours later, they were sequentially exposed to the CS in the extinction context and another context. Control rats were also tested in each context, but were never extinguished. We assessed Arc mRNA expression within the basal amygdala (BA, lateral amygdala (LA, ventral hippocampus (VH, prelimbic cortex (PL and infralimbic cortex (IL. We observed that the sequential retention tests induced context-dependent patterns of Arc expression in the BA, LA, and IL of extinguished rats; this was not observed in non-extinguished controls. In general, non-extinguished animals had proportionately greater numbers of non-selective (double-labeled neurons than extinguished animals. Collectively, these findings suggest that extinction learning results in pattern separation, particularly within the BA, in which unique neuronal ensembles represent fear memories after extinction.

Maintenance treatment of Uracil and Tegafur (UFT) in responders following first-line fluorouracil-based chemotherapy in metastatic gastric cancer: a randomized phase II study.

Science.gov (United States)

Li, Wenhua; Zhao, Xiaoying; Wang, Huijie; Liu, Xin; Zhao, Xinmin; Huang, Mingzhu; Qiu, Lixin; Zhang, Wen; Chen, Zhiyu; Guo, Weijian; Li, Jin; Zhu, Xiaodong

2017-06-06

Maintenance therapy proves to be effective in advanced lung and breast cancer after initial chemotherapy. The purpose of this phase II study was to evaluate the efficacy and safety of Uracil and Tegafur (UFT) maintenance in metastatic gastric cancer patients following the first-line fluorouracil-based chemotherapy. Metastatic gastric cancer patients with stable disease or a better response after the completion of first-line chemotherapy were randomized to oral UFT (360mg/m2 × 2 weeks) every 3 weeks until disease progression/intolerable toxicity or to observation (OBS). The primary endpoint was progression-free survival (PFS); the secondary endpoints were overall survival (OS) and safety. The trial was closed after the interim analysis of the 58 enrolled (120 planned) patients. Median PFS was not improved in the UFT group compared with the OBS group (3.2 months versus 3.6 months, P = 0.752), as well as the median OS (14.2 months for both, P = 0.983). However, subgroup analysis showed that low baseline hemoglobin (maintenance therapy (P = 0.032), while the normal hemoglobin patients benefit from the UFT treatment (P = 0.008). Grade 3 to 4 toxicities in the UFT group were anemia (3.4%), thrombocytopenia (3.4%) and diarrhea (6.9%). This trial did not show superiority of UFT maintenance in non-selected patients responding to fluorouracil-based first-line chemotherapy. The normal hemoglobin level at baseline is a predictive biomarker for favorable patient subsets from the maintenance treatment.

Sales Forecasting in the Context of Seasonal Activities and Company Sustainable Growth

Directory of Open Access Journals (Sweden)

Ion Stancu

2015-08-01

Full Text Available The paper presents the use of the “time series model” to forecast the quarterly and yearly sales for a company with business seasonality. These sales forecasts will represent the fundamental basis for estimating the external financing, using the percentage to sales method. Sales growth rates are afterwards analysed in the context of ensuring a sustainable and self-financed growth. We focus on establishing the forecasted financial structure of the external financial requirements both in the context of using the reinvested profit complemented with credit, maintaining the debt rate constant, and in the context of total internal funding of the company economic growth, from reinvested profit.

ContextProvider: Context awareness for medical monitoring applications.

Science.gov (United States)

Mitchell, Michael; Meyers, Christopher; Wang, An-I Andy; Tyson, Gary

2011-01-01

Smartphones are sensor-rich and Internet-enabled. With their on-board sensors, web services, social media, and external biosensors, smartphones can provide contextual information about the device, user, and environment, thereby enabling the creation of rich, biologically driven applications. We introduce ContextProvider, a framework that offers a unified, query-able interface to contextual data on the device. Unlike other context-based frameworks, ContextProvider offers interactive user feedback, self-adaptive sensor polling, and minimal reliance on third-party infrastructure. ContextProvider also allows for rapid development of new context and bio-aware applications. Evaluation of ContextProvider shows the incorporation of an additional monitoring sensor into the framework with fewer than 100 lines of Java code. With adaptive sensor monitoring, power consumption per sensor can be reduced down to 1% overhead. Finally, through the use of context, accuracy of data interpretation can be improved by up to 80%.

Collaborating with consumer and community representatives in health and medical research in Australia: results from an evaluation

Directory of Open Access Journals (Sweden)

Bartu Anne E

2011-05-01

Full Text Available Abstract Objective To collaborate with consumer and community representatives in the Alcohol and Pregnancy Project from 2006-2008 http://www.ichr.uwa.edu.au/alcoholandpregnancy and evaluate researchers' and consumer and community representatives' perceptions of the process, context and impact of consumer and community participation in the project. Methods We formed two reference groups and sought consumer and community representatives' perspectives on all aspects of the project over a three year period. We developed an evaluation framework and asked consumer and community representatives and researchers to complete a self-administered questionnaire at the end of the project. Results Fifteen researchers (93.8% and seven (53.8% consumer and community representatives completed a questionnaire. Most consumer and community representatives agreed that the process and context measures of their participation had been achieved. Both researchers and consumer and community representatives identified areas for improvement and offered suggestions how these could be improved for future research. Researchers thought consumer and community participation contributed to project outputs and outcomes by enhancing scientific and ethical standards, providing legitimacy and authority, and increasing the project's credibility and participation. They saw it was fundamental to the research process and acknowledged consumer and community representatives for their excellent contribution. Consumer and community representatives were able to directly influence decisions about the research. They thought that consumer and community participation had significant influence on the success of project outputs and outcomes. Conclusions Consumer and community participation is an essential component of good research practice and contributed to the Alcohol and Pregnancy Project by enhancing research processes, outputs and outcomes, and this participation was valued by community and

Collaborating with consumer and community representatives in health and medical research in Australia: results from an evaluation.

Science.gov (United States)

Payne, Janet M; D'Antoine, Heather A; France, Kathryn E; McKenzie, Anne E; Henley, Nadine; Bartu, Anne E; Elliott, Elizabeth J; Bower, Carol

2011-05-14

To collaborate with consumer and community representatives in the Alcohol and Pregnancy Project from 2006-2008 http://www.ichr.uwa.edu.au/alcoholandpregnancy and evaluate researchers' and consumer and community representatives' perceptions of the process, context and impact of consumer and community participation in the project. We formed two reference groups and sought consumer and community representatives' perspectives on all aspects of the project over a three year period. We developed an evaluation framework and asked consumer and community representatives and researchers to complete a self-administered questionnaire at the end of the project. Fifteen researchers (93.8%) and seven (53.8%) consumer and community representatives completed a questionnaire. Most consumer and community representatives agreed that the process and context measures of their participation had been achieved. Both researchers and consumer and community representatives identified areas for improvement and offered suggestions how these could be improved for future research. Researchers thought consumer and community participation contributed to project outputs and outcomes by enhancing scientific and ethical standards, providing legitimacy and authority, and increasing the project's credibility and participation. They saw it was fundamental to the research process and acknowledged consumer and community representatives for their excellent contribution. Consumer and community representatives were able to directly influence decisions about the research. They thought that consumer and community participation had significant influence on the success of project outputs and outcomes. Consumer and community participation is an essential component of good research practice and contributed to the Alcohol and Pregnancy Project by enhancing research processes, outputs and outcomes, and this participation was valued by community and consumer representatives and researchers. The National Health and

An Ontology-Based Context Model for Wireless Sensor Network (WSN Management in the Internet of Things

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Adnan Al-Anbuky

2013-09-01

Full Text Available Wireless sensor networks (WSNs are an enabling technology of context-aware systems. The Internet of Things (IoT, which has attracted much attention in recent years, is an emerging paradigm where everyday objects and spaces are made context-aware and interconnected through heterogeneous networks on a global scale. However, the IoT system can suffer from poor performances when its underlying networks are not optimized. In this paper, an ontology model for representing and facilitating context sharing between network entities in WSNs is proposed for the first time. The context model aims to enable optimal context-aware management of WSNs in IoT, which will also harness the rich context knowledge of IoT systems.

Ad-Me: A Context-Sensitive Advertising System

OpenAIRE

Hristova, Nataliya; O'Hare, G. M. P. (Greg M. P.)

2001-01-01

The mobile commerce sector and in particular the context sensitive advertising will represent a high yield revenue stream. This paper introduces the Ad-me (Advertising for the Mobile E-commerce user) system. The Ad-me is a mobile tourist guide that proactively delivers advertisements to users based upon perceived individual user needs together with their location. A Multi-Agent Systems (MAS) design philosophy is adopted. In order to achieve maximum content diffusion a range of presentation...

Class-Based Context Quality Optimization For Context Management Frameworks

DEFF Research Database (Denmark)

Shawky, Ahmed; Olsen, Rasmus Løvenstein; Pedersen, Jens Myrup

2012-01-01

Context-awareness is a key requirement in many of today's networks, services and applications. Context Management systems are in this respect used to provide access to distributed, dynamic context information. The reliability of remotely accessed dynamic context information is challenged by network...

Preoperative Chemoradiotherapy for Rectal Cancer: Randomized Trial Comparing Oral Uracil and Tegafur and Oral Leucovorin Vs. Intravenous 5-Fluorouracil and Leucovorin

International Nuclear Information System (INIS)

Torre, Alejandro de la; Garcia-Berrocal, Maria Isabel; Arias, Fernando; Marino, Alfonso; Valcarcel, Francisco; Magallon, Rosa; Regueiro, Carlos A.; Romero, Jesus; Zapata, Irma; Fuente, Cristina de la; Fernandez-Lizarbe, Eva; Vergara, Gloria; Belinchon, Belen; Veiras, Maria; Moleron, Rafael; Millan, Isabel

2008-01-01

Purpose: To compare, in a randomized trial, 5-fluorouracil (FU) plus leucovorin (LV) (FU+LV) vs. oral uracil and tegafur (UFT) plus LV (UFT+LV) given concomitantly with preoperative irradiation in patients with cT3-4 or N+ rectal cancer. Methods and Materials: A total of 155 patients were entered onto the trial. Patients received pelvic radiotherapy (4500-5,040 cGy in 5 to 6 weeks) and chemotherapy consisting of two 5-day courses of 20 mg/m 2 /d LV and 350 mg/m 2 /d FU in the first and fifth weeks of radiotherapy (77 patients) or one course of 25 mg/d oral LV and 300 mg/m 2 /d UFT for 4 weeks beginning in the second week of radiotherapy (78 patients). The primary endpoints were pathologic complete response (pCR) and resectability rate. Secondary endpoints included downstaging rate, toxicity, and survival. Results: Grade 3-5 acute hematologic toxicity occurred only with FU+LV (leukopenia 9%; p = 0.02). There were no differences in resectability rates (92.1% vs. 93.4%; p = 0.82). The pCR rate was 13.2% in both arms. Tumor downstaging was more frequent with UFT+LV (59.2% vs. 43.3%; p = 0.04). Three-year overall survival was 87% with FU+LV and 74% with UFT+LV (p = 0.37). The 3-year cumulative incidences of local recurrence were 7.5% and 8.9%, respectively (p = 0.619; relative risk, 1.46; 95% confidence interval 0.32-6.55). Conclusion: Although this study lacked statistical power to exclude clinically significant differences between both groups, the outcome of patients treated with UFT+LV did not differ significantly from that of patients treated with FU+LV, and hematologic toxicity was significantly lower in the experimental arm

The mainstream is not electable: when vision triumphs over representativeness in leader emergence and effectiveness.

Science.gov (United States)

Halevy, Nir; Berson, Yair; Galinsky, Adam D

2011-07-01

Theories of visionary leadership propose that groups bestow leadership on exceptional group members. In contrast, social identity perspectives claim that leadership arises, in part, from a person's ability to be seen as representative of the group. Integrating these perspectives, the authors propose that effective leaders often share group members' perspectives concerning the present, yet offer a unique and compelling vision for the group's future. In addition, although intergroup contexts may increase the value of representativeness, the authors predict that vision dominates representativeness in single-group situations characterized by high levels of collective stress (e.g., a natural disaster). Five studies demonstrated that visionary leaders (those who offer novel solutions to their group's predicament) attract more followers, promote group identification and intrinsic motivation, mobilize collective action, and effectively regulate group members' emotions and reactions to crises compared to representative leaders. The authors discuss when, why, and how vision triumphs over representativeness in leader emergence and effectiveness. © 2011 by the Society for Personality and Social Psychology, Inc

NCBI nr-aa BLAST: CBRC-CREM-01-1290 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-CREM-01-1290 ref|YP_001478049.1| uracil-xanthine permease [Serratia proteamacu...lans 568] gb|ABV40921.1| uracil-xanthine permease [Serratia proteamaculans 568] YP_001478049.1 3e-95 65% ...

REPRESENTATIVE OF LGBTT IN PRINTED LOCAL PRESS GAZIANTEP SAMPLE (2009-2014

Directory of Open Access Journals (Sweden)

Fatma Yeşil

2017-07-01

Full Text Available The basic aim of the paper is an attempt to find out how Van Dijk's critical discourse analysis of LGBTT (Lesbian, Gay, Bisexual, Transvestite, Transsexual individuals who are represented at the local press. Sabah, Hâkimiyet, Express, Gaziantep27, Olay and Telgraf newspapers were selected from Gaziantep Printed Local Press for the study and how these LGBTT people were represented in these newspapers. The articles reviewed for the study were published between 2009 and 2014 is a key criterion for LGBTT people to be involved directly or indirectly (with links to various topics under different headings. In the context of Van Dijk's critical discourse analysis based on the study, and in the light of the determined criteria, the existing news obtained were carefully scanned from newspapers, examined and analyzed in detail by the method of critical discourse analysis.

Consumption of 100% Pure Fruit Juice and Dietary Quality in French Adults: Analysis of a Nationally Representative Survey in the Context of the WHO Recommended Limitation of Free Sugars

Directory of Open Access Journals (Sweden)

France Bellisle

2018-04-01

Full Text Available Sugar-containing beverages are often seen as a negative influence on diet quality and body weight control. The present study examines the consumption of 100% fruit juice (FJ based on a seven-day dietary survey in a representative sample of French adults (n = 1607. About a half of the participants (44% consumed FJ, most often at breakfast time (60%. Average intake in FJ consumers was 115.6 ± 4.0 mL/day (46.3 ± 1.7 kcal/day. Prevalence of consumption increased with education and income and decreased with age, but no association was observed with body mass index (BMI, physical activity, or smoking. In consumers, FJ brought 2% daily energy and contributed larger proportions of vitamins (B1 7%, B2 3%, B5 5%, B6 6%, B9 10%, C 32%, E 9%, beta-carotene 5%, minerals (magnesium 4%, potassium 7%, and free sugars (19%. FJ consumers ingested more whole fruits, vegetables, and many other foods than non-consumers did. Free sugars represented 11.2% of the daily energy in FJ consumers versus 8.6% in non-consumers. This cross-sectional survey reveals that FJ contributes to diet quality without association with excess body weight. These observations should be confirmed in longitudinal studies. They support the view that contribution to diet quality should be specifically recognized in the context of the World Health Organization (WHO recommended decrease of free sugar intake.

Context-Aware Community Construction in Proximity-Based Mobile Networks

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Na Yu

2015-01-01

Full Text Available Sensor-equipped mobile devices have allowed users to participate in various social networking services. We focus on proximity-based mobile social networking environments where users can share information obtained from different places via their mobile devices when they are in proximity. Since people are more likely to share information if they can benefit from the sharing or if they think the information is of interest to others, there might exist community structures where users who share information more often are grouped together. Communities in proximity-based mobile networks represent social groups where connections are built when people are in proximity. We consider information influence (i.e., specify who shares information with whom as the connection and the space and time related to the shared information as the contexts. To model the potential information influences, we construct an influence graph by integrating the space and time contexts into the proximity-based contacts of mobile users. Further, we propose a two-phase strategy to detect and track context-aware communities based on the influence graph and show how the context-aware community structure improves the performance of two types of mobile social applications.

Role of social workers in a context of crisis: adaptation opportunities to change

Directory of Open Access Journals (Sweden)

Marta García-Domingo

2017-06-01

Full Text Available The current situation of socioeconomic crisis shows a scenario characterized by the increase of inequality, as well as situations of vulnerability and social exclusion. In addition to the growth in social needs and problems, there is a shortage of resources to support individuals and families. This produces an important change in the philosophy and functioning of social services system, being interventions increasingly marked by control and sanction. Social Work, as a discipline integrated into a process of constant transformation and adaptation, deals with a series of challenges in the current context of crisis. It conditions, and even determines, the role to be performed by Social Workers. From semi-structured interviews and participant observation, we analyze the perception of experts of that role in three key European contexts: Nordic countries (represented by Sweden and Finland, Central Europe (represented by Germany y Mediterranean countries (represented by Spain. Through discourse analysis, we identify both responsibilities and suggestions for improving social intervention. Based on this, we conclude a dual role reflected in the speeches of the social actors involved: proactive and supportive.

Reasoning Strategies in the Context of Engineering Design with Everyday Materials

Science.gov (United States)

Worsley, Marcelo; Blikstein, Paulo

2016-01-01

"Making" represents an increasingly popular label for describing a form of engineering design. While making is growing in popularity, there are still open questions about the strategies that students are using in these activities. Assessing and improving learning in making/ engineering design contexts require that we have a better…

NCBI nr-aa BLAST: CBRC-PABE-24-0030 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PABE-24-0030 ref|YP_927793.1| uracil-xanthine permease [Shewanella amazonensis... SB2B] gb|ABM00124.1| uracil-xanthine permease [Shewanella amazonensis SB2B] YP_927793.1 3.4 27% ...

'Information Seeking in Context' and the development of information systems

Directory of Open Access Journals (Sweden)

Irina Gaslikova

1999-01-01

Full Text Available This paper reports on some findings of the explorations represented at the conference "Information Seeking in Context" (ISIC’98. These findings are investigated with the aim to evaluate their practical usefulness for the design of information computer systems. The paper discusses some common problems connected with the conceptual approaches to the information system development.

Pokémon Battles as a Context for Mathematical Modeling

Science.gov (United States)

McGuffey, William

2017-01-01

In this article I explore some of the underlying mathematics of Poke´mon battles and describe ways that teachers at the secondary level could explore concepts of mathematical game theory in this context. I discuss various ways of representing and analyzing a Poke´mon battle using game theory and conclude with an example of applying concepts of…

Context effects in embodied lexical-semantic processing

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Wessel O Van Dam

2010-10-01

Full Text Available The embodied view of language comprehension proposes that the meaning of words is grounded in perception and action rather than represented in abstract amodal symbols. Support for embodied theories of language processing comes from behavioural studies showing that understanding a sentence about an action can modulate congruent and incongruent physical responses, suggesting motor involvement during comprehension of sentences referring to bodily movement. Additionally, several neuroimaging studies have provided evidence that comprehending single words denoting manipulable objects elicits specific responses in the neural motor system. An interesting question that remains is whether action semantic knowledge is directly activated as motor simulations in the brain, or rather modulated by the semantic context in which action words are encountered. In the current paper we investigated the nature of conceptual representations using a go/no-go lexical decision task. Specifically, target words were either presented in a semantic context that emphasized dominant action features (features related to the functional use of an object or non-dominant action features. The response latencies in a lexical decision task reveal that participants were faster to respond to words denoting objects for which the functional use was congruent with the prepared movement. This facilitation effect, however, was only apparent when the semantic context emphasized corresponding motor properties. These findings suggest that motor involvement during comprehension of sentences is not automatic. Rather, the results suggest that conceptual processing is a context-dependent process that incorporates motor-related knowledge in a flexible manner.

Linear Narratives, Arbitrary Relationships: Arbitrary Relationships: Mimesis and Direct Communication for Effectively Representing Engineering Realities Multimodally

Science.gov (United States)

Jeyaraj, Joseph

2017-01-01

Engineers communicate multimodally using written and visual communication, but there is not much theorizing on why they do so and how. This essay, therefore, examines why engineers communicate multimodally, what, in the context of representing engineering realities, are the strengths and weaknesses of written and visual communication, and how,…

Validation of the Mnemonic Similarity Task – Context Version

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Giulia A. Aldi

2018-02-01

Full Text Available Objective: Pattern separation (PS is the ability to represent similar experiences as separate, non-overlapping representations. It is usually assessed via the Mnemonic Similarity Task – Object Version (MST-O which, however, assesses PS performance without taking behavioral context discrimination into account, since it is based on pictures of everyday simple objects on a white background. We here present a validation study for a new task, the Mnemonic Similarity Task – Context Version (MST-C, which is designed to measure PS while taking behavioral context discrimination into account by using real-life context photographs. Methods: Fifty healthy subjects underwent the two MST tasks to assess convergent evidence. Instruments assessing memory and attention were also administered to study discriminant evidence. The test-retest reliability of MST-C was analyzed. Results: Weak evidence supports convergent validity between the MST-C task and the MST-O as measures of PS (rs = 0.464; p < 0.01; PS performance assessed via the MST-C did not correlate with memory or attention; a moderate test-retest reliability was found (rs = 0.595; p < 0.01. Conclusion: The MST-C seems useful for assessing PS performance conceptualized as the ability to discriminate complex and realistic spatial contexts. Future studies are welcome to evaluate the validity of the MST-C task as a measure of PS in clinical populations.

Community socioeconomic context and its influence on intermediary determinants of child health : evidence from Colombia

OpenAIRE

Osorio Mejía, Ana María; Bolancé, Catalina; Madise, Nyovani

2014-01-01

Intermediary determinants are the most immediate mechanisms through which socioeconomic position shapes health inequities. This study examines the effect of community socioeconomic context on different indicators representing intermediary determinants of child health. In the context of Colombia, a developing country with a clear economic expansion, but one of the most unequal countries in the world, two categories of intermediary determinants, namely behavioural and psychoso...

Semantic Data Integration and Knowledge Management to Represent Biological Network Associations.

Science.gov (United States)

Losko, Sascha; Heumann, Klaus

2017-01-01

The vast quantities of information generated by academic and industrial research groups are reflected in a rapidly growing body of scientific literature and exponentially expanding resources of formalized data, including experimental data, originating from a multitude of "-omics" platforms, phenotype information, and clinical data. For bioinformatics, the challenge remains to structure this information so that scientists can identify relevant information, to integrate this information as specific "knowledge bases," and to formalize this knowledge across multiple scientific domains to facilitate hypothesis generation and validation. Here we report on progress made in building a generic knowledge management environment capable of representing and mining both explicit and implicit knowledge and, thus, generating new knowledge. Risk management in drug discovery and clinical research is used as a typical example to illustrate this approach. In this chapter we introduce techniques and concepts (such as ontologies, semantic objects, typed relationships, contexts, graphs, and information layers) that are used to represent complex biomedical networks. The BioXM™ Knowledge Management Environment is used as an example to demonstrate how a domain such as oncology is represented and how this representation is utilized for research.

Violent Victimization in the Prison Context: An Examination of the Gendered Contexts of Prison.

Science.gov (United States)

Teasdale, Brent; Daigle, Leah E; Hawk, Shila R; Daquin, Jane C

2016-07-01

Currently there are few published, multilevel studies of physical assault victimization of prisoners. This study builds on the extant research by utilizing a nationally representative sample of correctional facilities (n = 326) and inmates (n = 17,640) to examine the impacts of a large set of theoretically and empirically derived individual- and contextual-level variables on prison victimization, including how the gendered context of prison impacts victimization. Results support the lifestyles/routine activities approach. Inmates who were charged with a violent offense, were previously victimized, were smaller in size, were not married, were without a work assignment, misbehaved, did not participate in programs, used alcohol or drugs, and those who had a depression or personality disorder were more likely to be victimized. In addition, the data suggest that 8% of the variance in victimization is due to the prison context. Prisons with high proportions of violent offenders, males, inmates from multiracial backgrounds, and inmates with major infractions had increased odds of victimization. Moreover, the sex-composition of the prison has significant main and interactive effects predicting victimization. Specifically, we find that the effects of being convicted of a drug crime, drug use, military service, major infractions, and diagnosed personality disorders are all gendered in their impacts on victimization. © The Author(s) 2015.

Emergence of Industrial Ecosystems in Post-Authoritarian Contexts

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Kristina Grumadaite

2016-09-01

Full Text Available Purpose of the article: This article analyses cluster emergence in post-authoritarian countries with immature socio-economic context by adapting the approach of industrial clusters as industrial ecosystems and analysing cluster emergence cases. Methodology/methods: Review of scientific literature, case analysis. Scientific aim: This article presents different scenarios of cluster emergence based on cases of industrial clusters in a Lithuanian context and provides solutions for cluster emergence in post-authoritarian countries. Findings: The analysis of scientific literature revealed the following solutions of cluster emergence in postauthoritarian contexts: 1 Large firm(s acting as anchors for attracting smaller companies into cluster; 2 Cluster emergence as a means to serve the needs of large customer outside the cluster; 3 Cluster emergence via local business entrepreneurs; 4 Cluster emergence via local science representatives; 5 Cluster emergence through adapting historically formed regional knowledge and networks; 6 Government as the main agent for change. The analysis of industrial clusters emergence in Lithuania revealed four different combinations of planned/ unplanned non-equilibrium phenomena and the first explicit/inexplicit initiatives toward the emergence of selforganising industrial systems by analysing the cases of cluster emergence in Lithuanian context. These cases highlighted the importance of leaders-initiators that were local large or simply very experienced enterprises, groups of managers of small and medium sized enterprises, mediators-communication facilitators from nonbusiness enterprises. These actors helped to cope with unplanned and planned non-equilibrium phenomena. Conclusions: Since the empirical analysis concentrated only in the first stage of cluster emergence of postauthoritarian context, a further research is needed to take a deeper look at the development of industrial clusters as industrial ecosystems in post

14 CFR 1274.906 - Designation of New Technology Representative and Patent Representative.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Designation of New Technology... Conditions § 1274.906 Designation of New Technology Representative and Patent Representative. Designation of New Technology Representative and Patent Representative July 2002 (a) For purposes of administration...

Context-specific control and context selection in conflict tasks.

Science.gov (United States)

Schouppe, Nathalie; Ridderinkhof, K Richard; Verguts, Tom; Notebaert, Wim

2014-02-01

This study investigated whether participants prefer contexts with relatively little cognitive conflict and whether this preference is related to context-specific control. A conflict selection task was administered in which participants had to choose between two categories that contained different levels of conflict. One category was associated with 80% congruent Stroop trials and 20% incongruent Stroop trials, while the other category was associated with only 20% congruent Stroop trials and 80% incongruent Stroop trials. As predicted, participants selected the low-conflict category more frequently, indicating that participants avoid contexts with high-conflict likelihood. Furthermore, we predicted a correlation between this preference for the low-conflict category and the control implementation associated with the categories (i.e., context-specific proportion congruency effect, CSPC effect). Results however did not show such a correlation, thereby failing to support a relationship between context control and context selection. Copyright © 2013 Elsevier B.V. All rights reserved.

Middleware Support for Quality of Context in Pervasive Context-Aware Systems

NARCIS (Netherlands)

Sheikh, K.; Wegdam, M.; van Sinderen, Marten J.

Middleware support for pervasive context-aware systems relieves context-aware applications from dealing with the complexity of context-specific operations such as context acquisition, aggregation, reasoning and distribution. The middleware decouples applications from the underlying heterogeneous

Conditionally Pathogenic Gut Microbes Promote Larval Growth by Increasing Redox-Dependent Fat Storage in High-Sugar Diet-Fed Drosophila.

Science.gov (United States)

Whon, Tae Woong; Shin, Na-Ri; Jung, Mi-Ja; Hyun, Dong-Wook; Kim, Hyun Sik; Kim, Pil Soo; Bae, Jin-Woo

2017-12-01

Changes in the composition of the gut microbiota contribute to the development of obesity and subsequent complications that are associated with metabolic syndrome. However, the role of increased numbers of certain bacterial species during the progress of obesity and factor(s) controlling the community structure of gut microbiota remain unclear. Here, we demonstrate the inter-relationship between Drosophila melanogaster and their resident gut microbiota under chronic high-sugar diet (HSD) conditions. Chronic feeding of an HSD to Drosophila resulted in a predominance of resident uracil-secreting bacteria in the gut. Axenic insects mono-associated with uracil-secreting bacteria or supplemented with uracil under HSD conditions promoted larval development. Redox signaling induced by bacterial uracil promoted larval growth by regulating sugar and lipid metabolism via activation of p38a mitogen-activated protein kinase. The present study identified a new redox-dependent mechanism by which uracil-secreting bacteria (previously regarded as opportunistic pathobionts) protect the host from metabolic perturbation under chronic HSD conditions. These results illustrate how Drosophila and gut microbes form a symbiotic relationship under stress conditions, and changes in the gut microbiota play an important role in alleviating deleterious diet-derived effects such as hyperglycemia. Antioxid. Redox Signal. 27, 1361-1380.

Prostitution Research in Context

DEFF Research Database (Denmark)

chapters again actively engage with the ethical dilemmas that research on the topic of sex for sale can entail. The authors represent different disciplines, but share an interest in engaging in reflexive research practices informed by feminism and feminist epistemologies. An authoritative contribution......The starting point for this book is the question of how we research sex for sale and the implications of the choices we make in terms of epistemology and ethics. Which dilemmas and ethical aspects need to be taken into account when producing qualitative data within a highly politicised and moral......-infected realm? These two questions are exactly what Spanger and Skilbrei aim to unpack in this unusual interdisciplinary methodology book, Prostitution Research in Context. The book offers contributions from a number of scholars who, based on their reflections on their own research practice and the existing...

Peculiarities of inflorescences morphogenesis in model representatives of the Celastraceae R.Br. in context of molecular phylogenetic data

Directory of Open Access Journals (Sweden)

Ivan A. Savinov

2014-04-01

Full Text Available Peculiarities of laying and forming of inflorescences for model representatives of the Celastraceae are studied. Specific characters in rhythm development of generative elements for different taxa are determined. Morphological markers, which are coincided completely with molecular characters, are determined. They are evidenced on closely relation between next taxa: Celastrus and Tripterygium, Salacia and Sarawakodendron, Salacia and Brexia.

A phase I study of concurrent chemoradiotherapy and cetuximab for locally advanced esophageal cancer

DEFF Research Database (Denmark)

Holländer, Cecilie; Baeksgaard, Lene; Sorensen, Morten

2012-01-01

AIM: To determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of concurrent chemoradiotherapy and cetuximab in patients with non-resectable locally advanced esophageal cancer. PATIENTS AND METHODS: Escalating doses of oxaliplatin every second week and daily tegafur....../uracil were given concurrently with radiotherapy, 59.4 Gy in 33 fractions. Cetuximab was given on day 15 (400 mg/m(2)) and weekly (250 mg/m(2)) during radiotherapy. Fixed doses of oxaliplatin (130 mg/m(2)) and tegafur/uracil (300 mg/m(2)) were administered before, and after radiotherapy. RESULTS: Eleven...... patients were included in the study; two were excluded due to allergic reactions to cetuximab. In DL2 (tegafur/uracil 300 mg/m(2), oxaliplatin 30 mg/m(2)) two grade 3/4 fistula and one grade 3 neuropathy were observed. Six patients were enrolled in DL1 (tegafur/uracil 150 mg/m(2)/, oxaliplatin 30 mg/m(2...

Character Education in Taiwan: A Reflection of Historical Shifts in Sociocultural Contexts

Science.gov (United States)

Ho, Hsiu-Zu; Lam, Yeana W.; Yeh, Kuang-Hui

2013-01-01

Education systems across the world reflect the values of the cultures and societies they represent. Character education is often framed as a response to certain values emphasized in a given context, reflecting the commonly accepted traits of good character and responsible citizenship in which learners are engaged. This article describes the nature…

Early Reminiscing in Cultural Contexts: Cultural Models, Maternal Reminiscing Styles, and Children's Memories

Science.gov (United States)

Schroder, Lisa; Keller, Heidi; Kartner, Joscha; Kleis, Astrid; Abels, Monika; Yovsi, Relindis D.; Chaudhary, Nandita; Jensen, Henning; Papaligoura, Zaira

2013-01-01

The present study examined conversations of 164 mothers from seven different cultural contexts when reminiscing with their 3-year-old children. We chose samples based on their sociodemographic profiles, which represented three different cultural models: (1) autonomy (urban middle-class families from Western societies), (2) relatedness (rural…

Representing Evolution

DEFF Research Database (Denmark)

Hedin, Gry

2012-01-01

. This article discusses Willumsen's etching in the context of evolutionary theory, arguing that Willumsen is a rare example of an artist who not only let the theory of evolution fuel his artistic imagination, but also concerned himself with a core issue of the theory, namely to what extent it could be applied...

Does bioleaching represent a biotechnological strategy for remediation of contaminated sediments?

Energy Technology Data Exchange (ETDEWEB)

Fonti, Viviana, E-mail: v.fonti@univpm.it; Dell' Anno, Antonio; Beolchini, Francesca

2016-09-01

Bioleaching is a consolidated biotechnology in the mining industry and in bio-hydrometallurgy, where microorganisms mediate the solubilisation of metals and semi-metals from mineral ores and concentrates. Bioleaching also has the potential for ex-situ/on-site remediation of aquatic sediments that are contaminated with metals, which represent a key environmental issue of global concern. By eliminating or reducing (semi-)metal contamination of aquatic sediments, bioleaching may represent an environmentally friendly and low-cost strategy for management of contaminated dredged sediments. Nevertheless, the efficiency of bioleaching in this context is greatly influenced by several abiotic and biotic factors. These factors need to be carefully taken into account before selecting bioleaching as a suitable remediation strategy. Here we review the application of bioleaching for sediment bioremediation, and provide a critical view of the main factors that affect its performance. We also discuss future research needs to improve bioleaching strategies for contaminated aquatic sediments, in view of large-scale applications. - Highlights: • Bioleaching may represent a sustainable strategy for contaminated dredged sediments • The performance is greatly influenced by several abiotic and biotic factors • Geochemical characteristics and metal partitioning have a key role • Sulphide minerals in the sediment are a favorable element • Microorganisms other than Fe/S oxidisers may open new perspectives.

Does bioleaching represent a biotechnological strategy for remediation of contaminated sediments?

International Nuclear Information System (INIS)

Fonti, Viviana; Dell'Anno, Antonio; Beolchini, Francesca

2016-01-01

Bioleaching is a consolidated biotechnology in the mining industry and in bio-hydrometallurgy, where microorganisms mediate the solubilisation of metals and semi-metals from mineral ores and concentrates. Bioleaching also has the potential for ex-situ/on-site remediation of aquatic sediments that are contaminated with metals, which represent a key environmental issue of global concern. By eliminating or reducing (semi-)metal contamination of aquatic sediments, bioleaching may represent an environmentally friendly and low-cost strategy for management of contaminated dredged sediments. Nevertheless, the efficiency of bioleaching in this context is greatly influenced by several abiotic and biotic factors. These factors need to be carefully taken into account before selecting bioleaching as a suitable remediation strategy. Here we review the application of bioleaching for sediment bioremediation, and provide a critical view of the main factors that affect its performance. We also discuss future research needs to improve bioleaching strategies for contaminated aquatic sediments, in view of large-scale applications. - Highlights: • Bioleaching may represent a sustainable strategy for contaminated dredged sediments • The performance is greatly influenced by several abiotic and biotic factors • Geochemical characteristics and metal partitioning have a key role • Sulphide minerals in the sediment are a favorable element • Microorganisms other than Fe/S oxidisers may open new perspectives

Video context-dependent recall.

Science.gov (United States)

Smith, Steven M; Manzano, Isabel

2010-02-01

In two experiments, we used an effective new method for experimentally manipulating local and global contexts to examine context-dependent recall. The method included video-recorded scenes of real environments, with target words superimposed over the scenes. In Experiment 1, we used a within-subjects manipulation of video contexts and compared the effects of reinstatement of a global context (15 words per context) with effects of less overloaded context cues (1 and 3 words per context) on recall. The size of the reinstatement effects in Experiment 1 show how potently video contexts can cue recall. A strong effect of cue overload was also found; reinstatement effects were smaller, but still quite robust, in the 15 words per context condition. The powerful reinstatement effect was replicated for local contexts in Experiment 2, which included a no-contexts-reinstated group, a control condition used to determine whether reinstatement of half of the cues caused biased output interference for uncued targets. The video context method is a potent way to investigate context-dependent memory.

Global work contexts as sites of discursive sense making

DEFF Research Database (Denmark)

Petersen, Nils Braad

2014-01-01

Global work contexts represent highly complex working environments with simultaneous attachment to several projects and teams (Rosen, Furst & Blackburn, 2007). This complexity increases the for the sense-making capabilities of employees (Weick, 1995). MyPhD project examines this sense-making proc...... of knowledge communication networks in a global organisation. Interviews were fully transscribed analysed using a combination of James Gee’s approach to discourse analysis, and a novel adaptation of Auatin’s speech act theory....

The Dark Side of Context: Context Reinstatement Can Distort Memory.

Science.gov (United States)

Doss, Manoj K; Picart, Jamila K; Gallo, David A

2018-04-01

It is widely assumed that context reinstatement benefits memory, but our experiments revealed that context reinstatement can systematically distort memory. Participants viewed pictures of objects superimposed over scenes, and we later tested their ability to differentiate these old objects from similar new objects. Context reinstatement was manipulated by presenting objects on the reinstated or switched scene at test. Not only did context reinstatement increase correct recognition of old objects, but it also consistently increased incorrect recognition of similar objects as old ones. This false recognition effect was robust, as it was found in several experiments, occurred after both immediate and delayed testing, and persisted with high confidence even after participants were warned to avoid the distorting effects of context. To explain this memory illusion, we propose that context reinstatement increases the likelihood of confusing conceptual and perceptual information, potentially in medial temporal brain regions that integrate this information.

TrpA1 Regulates Defecation of Food-Borne Pathogens under the Control of the Duox Pathway.

Directory of Open Access Journals (Sweden)

Eun Jo Du

2016-01-01

Full Text Available Pathogen expulsion from the gut is an important defense strategy against infection, but little is known about how interaction between the intestinal microbiome and host immunity modulates defecation. In Drosophila melanogaster, dual oxidase (Duox kills pathogenic microbes by generating the microbicidal reactive oxygen species (ROS, hypochlorous acid (HOCl in response to bacterially excreted uracil. The physiological function of enzymatically generated HOCl in the gut is, however, unknown aside from its anti-microbial activity. Drosophila TRPA1 is an evolutionarily conserved receptor for reactive chemicals like HOCl, but a role for this molecule in mediating responses to gut microbial content has not been described. Here we identify a molecular mechanism through which bacteria-produced uracil facilitates pathogen-clearing defecation. Ingestion of uracil increases defecation frequency, requiring the Duox pathway and TrpA1. The TrpA1(A transcript spliced with exon10b (TrpA1(A10b that is present in a subset of midgut enteroendocrine cells (EECs is critical for uracil-dependent defecation. TRPA1(A10b heterologously expressed in Xenopus oocytes is an excellent HOCl receptor characterized with elevated sensitivity and fast activation kinetics of macroscopic HOCl-evoked currents compared to those of the alternative TRPA1(A10a isoform. Consistent with TrpA1's role in defecation, uracil-excreting Erwinia carotovora showed higher persistence in TrpA1-deficient guts. Taken together, our results propose that the uracil/Duox pathway promotes bacteria expulsion from the gut through the HOCl-sensitive receptor, TRPA1(A10b, thereby minimizing the chances that bacteria adapt to survive host defense systems.

Context-Aided Sensor Fusion for Enhanced Urban Navigation

Science.gov (United States)

Martí, Enrique David; Martín, David; García, Jesús; de la Escalera, Arturo; Molina, José Manuel; Armingol, José María

2012-01-01

The deployment of Intelligent Vehicles in urban environments requires reliable estimation of positioning for urban navigation. The inherent complexity of this kind of environments fosters the development of novel systems which should provide reliable and precise solutions to the vehicle. This article details an advanced GNSS/IMU fusion system based on a context-aided Unscented Kalman filter for navigation in urban conditions. The constrained non-linear filter is here conditioned by a contextual knowledge module which reasons about sensor quality and driving context in order to adapt it to the situation, while at the same time it carries out a continuous estimation and correction of INS drift errors. An exhaustive analysis has been carried out with available data in order to characterize the behavior of available sensors and take it into account in the developed solution. The performance is then analyzed with an extensive dataset containing representative situations. The proposed solution suits the use of fusion algorithms for deploying Intelligent Transport Systems in urban environments. PMID:23223080

14 CFR 1260.58 - Designation of new technology representative and patent representative.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Designation of new technology... of new technology representative and patent representative. Designation of New Technology... of this grant entitled “New Technology,” the following named representatives are hereby designated by...

Recent activities of the Seismology Division Early Career Representative(s)

Science.gov (United States)

Agius, Matthew; Van Noten, Koen; Ermert, Laura; Mai, P. Martin; Krawczyk, CharLotte

2016-04-01

The European Geosciences Union is a bottom-up-organisation, in which its members are represented by their respective scientific divisions, committees and council. In recent years, EGU has embarked on a mission to reach out for its numerous 'younger' members by giving awards to outstanding young scientists and the setting up of Early Career Scientists (ECS) representatives. The division representative's role is to engage in discussions that concern students and early career scientists. Several meetings between all the division representatives are held throughout the year to discuss ideas and Union-wide issues. One important impact ECS representatives have had on EGU is the increased number of short courses and workshops run by ECS during the annual General Assembly. Another important contribution of ECS representatives was redefining 'Young Scientist' to 'Early Career Scientist', which avoids discrimination due to age. Since 2014, the Seismology Division has its own ECS representative. In an effort to more effectively reach out for young seismologists, a blog and a social media page dedicated to seismology have been set up online. With this dedicated blog, we'd like to give more depth to the average browsing experience by enabling young researchers to explore various seismology topics in one place while making the field more exciting and accessible to the broader community. These pages are used to promote the latest research especially of young seismologists and to share interesting seismo-news. Over the months the pages proved to be popular, with hundreds of views every week and an increased number of followers. An online survey was conducted to learn more about the activities and needs of early career seismologists. We present the results from this survey, and the work that has been carried out over the last two years, including detail of what has been achieved so far, and what we would like the ECS representation for Seismology to achieve. Young seismologists are

Short-Run Contexts and Imperfect Testing for Continuous Sampling Plans

Directory of Open Access Journals (Sweden)

Mirella Rodriguez

2018-04-01

Full Text Available Continuous sampling plans are used to ensure a high level of quality for items produced in long-run contexts. The basic idea of these plans is to alternate between 100% inspection and a reduced rate of inspection frequency. Any inspected item that is found to be defective is replaced with a non-defective item. Because not all items are inspected, some defective items will escape to the customer. Analytical formulas have been developed that measure both the customer perceived quality and also the level of inspection effort. The analysis of continuous sampling plans does not apply to short-run contexts, where only a finite-size batch of items is to be produced. In this paper, a simulation algorithm is designed and implemented to analyze the customer perceived quality and the level of inspection effort for short-run contexts. A parameter representing the effectiveness of the test used during inspection is introduced to the analysis, and an analytical approximation is discussed. An application of the simulation algorithm that helped answer questions for the U.S. Navy is discussed.

From user context states to context-aware applications

NARCIS (Netherlands)

Shishkov, Boris; van Sinderen, Marten J.; Filipe, J.; Cordeiro, J.; Cardoso, J.

2008-01-01

In many cases, in order to be effective, software applications need to allow sensitivity to user context state changes. This implies however additional complexity associated with the need for applications’ adaptability (being capable of capturing context, interpreting it and reacting on it). Hence,

Methods for detection of methyl-CpG dinucleotides

Science.gov (United States)

Dunn, John J.

2012-09-11

The invention provides methods for enriching methyl-CpG sequences from a DNA sample. The method makes use of conversion of cytosine residues to uracil under conditions in which methyl-cytosine residues are preserved. Additional methods of the invention enable to preservation of the context of me-CpG dinucleotides. The invention also provides a recombinant, full length and substantially pure McrA protein (rMcrA) for binding and isolation of DNA fragments containing the sequence 5'-C.sup.MeCpGG-3'. Methods for making and using the rMcrA protein, and derivatives thereof are provided.

Tone of voice guides word learning in informative referential contexts.

Science.gov (United States)

Reinisch, Eva; Jesse, Alexandra; Nygaard, Lynne C

2013-06-01

Listeners infer which object in a visual scene a speaker refers to from the systematic variation of the speaker's tone of voice (ToV). We examined whether ToV also guides word learning. During exposure, participants heard novel adjectives (e.g., "daxen") spoken with a ToV representing hot, cold, strong, weak, big, or small while viewing picture pairs representing the meaning of the adjective and its antonym (e.g., elephant-ant for big-small). Eye fixations were recorded to monitor referent detection and learning. During test, participants heard the adjectives spoken with a neutral ToV, while selecting referents from familiar and unfamiliar picture pairs. Participants were able to learn the adjectives' meanings, and, even in the absence of informative ToV, generalize them to new referents. A second experiment addressed whether ToV provides sufficient information to infer the adjectival meaning or needs to operate within a referential context providing information about the relevant semantic dimension. Participants who saw printed versions of the novel words during exposure performed at chance during test. ToV, in conjunction with the referential context, thus serves as a cue to word meaning. ToV establishes relations between labels and referents for listeners to exploit in word learning.

Cultural Context and Translation

Institute of Scientific and Technical Information of China (English)

张敏

2009-01-01

cultural context plays an important role in translation. Because translation is a cross-culture activity, the culture context that influ-ences translating is consisted of both the culture contexts of source language and target language. This article firstly analyzes the concept of context and cultural context, then according to the procedure of translating classifies cultural context into two stages and talks about how they respectively influence translating.

Anthropomorphic Networks as Representatives of Global Consciousness

Directory of Open Access Journals (Sweden)

Sergii Yahodzinskyi

2018-02-01

Full Text Available There has been analyzed a phenomenon of global consciousness, and its cultural and historical, civilizational dimensions have been substantiated. There has been demonstrated that the concept of planetary consciousness, global thinking, noosphere was described for the first time in the philosophy of cosmism. However, in modern conditions ideas of representatives of the naturalistic philosophical direction of cosmism have not lost their heuristic potential. They can be reconsidered in a new fashion within the context of emerging anthropomorphic (human dimension networks. There has been proved that global consciousness is a component of the social and cultural potential of global information networks defining vectors to prospects of humanity progress in the 21st century. Relying on methodology of the structural and functional analysis, the author arrives at a conclusion about global networks obtaining the status of representatives of global consciousness. This is the area of networks where all relevant information is concentrated – from statistical data to scientific and technical information. Access to these data is limited by human abilities and is realized in the form of discrete requests with using heuristic algorithms of information procession. A suggestion is introduced considering the fact that modern society being a self-organized system seeks to gain stable condition. Anthropomorphic networks are means of decreasing social entropy, which is growing as a result of any kind of human intervention into social processes. Thus, for the first time a human is challenged by their intellect, ability to create, discover and control.

Psychometric analysis of export market orientation measurement scale in Croatian SME exporters’ context

Directory of Open Access Journals (Sweden)

Dario Miočević

2009-07-01

Full Text Available Market orientation is a vital construct of the marketing concept. Although different conceptualization approaches to market orientation have been discussed by literature so far, a common denominator is its interdependence with business performance. Increasing globalization trends affect both the markets’ convergence and competition. Consequently, focusing on market orientation within an international context is of utmost importance. Export market orientation (EMO is relatively new concept, which puts market orientation into the international context. Since export is a dominant international entry strategy in the Croatian economy which comprises mostly SMEs, it is crucial to investigate the importance of the EMO in the Croatian SME context. Determining an appropriate measurement scale of the EMO to be applied in various national research contexts leading to generalization represents a challenge for marketing academicians. The paper aims to find out whether the EMO construct and measurement scale can be applied within the Croatian SME context. The authors have used the exploratory and the confirmatory factor analysis to determine the psychometric properties of the EMO scale. The results of psychometric assessment of the EMO scale confirm its dimensionability, reliability, validity and applicability in the Croatian SME context. Results clearly indicate the necessity of pursuing EMO activities in order to achieve a high level of export performance.

Conceptualizing Context and Its Relationship to the Information Behavior in Disseertation Research Process

Directory of Open Access Journals (Sweden)

Shan-Ju L.Chang、Yu-Ya Lee

2000-10-01

Full Text Available

頁次：4-18

Context has been addressed as an influential factor of human information behavior. However, there is no consensus on what constitutes a context, or what the relationship between context and information behavior is. In this paper we explore the notions of context and describe the relationship between context and information behavior based on empirical findings, and reviews of current· literature. Our finding suggests that context is stratified and dynamic.

A context is consisted of several situations, and each situation is defined by a set of related contextual factors. In this way, we propose a new approach to represent the context and situation. At different levels of context, multiple relationships between context and information behavior are identified, including the association relationship, the interaction relationship, and the one-directional relationship. These findings substantiate the concept of situation in Dervin's Sense-making approach, the concept of information horizon proposed by Sonnenwald, and Ingwersen's cognitive model of IR interaction. The multiple relationships between context and information behavior imply that information behavior is related to, but not equal to the process of problem solving. In contrast, information behavior can be viewed as a response of certain situation in the context.

X-ray structures of uridine phosphorylase from Vibrio cholerae in complexes with uridine, thymidine, uracil, thymine, and phosphate anion: Substrate specificity of bacterial uridine phosphorylases

Energy Technology Data Exchange (ETDEWEB)

Prokofev, I. I.; Lashkov, A. A., E-mail: alashkov83@gmail.com; Gabdulkhakov, A. G.; Balaev, V. V.; Seregina, T. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation); Mironov, A. S. [State Research Institute of Genetics and Selection of Industrial Microorganisms (Russian Federation); Betzel, C. [University of Hamburg (Germany); Mikhailov, A. M. [Russian Academy of Sciences, Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics” (Russian Federation)

2016-11-15

In many types of human tumor cells and infectious agents, the demand for pyrimidine nitrogen bases increases during the development of the disease, thus increasing the role of the enzyme uridine phosphorylase in metabolic processes. The rational use of uridine phosphorylase and its ligands in pharmaceutical and biotechnology industries requires knowledge of the structural basis for the substrate specificity of the target enzyme. This paper summarizes the results of the systematic study of the three-dimensional structure of uridine phosphorylase from the pathogenic bacterium Vibrio cholerae in complexes with substrates of enzymatic reactions—uridine, phosphate anion, thymidine, uracil, and thymine. These data, supplemented with the results of molecular modeling, were used to consider in detail the structural basis for the substrate specificity of uridine phosphorylases. It was shown for the first time that the formation of a hydrogen-bond network between the 2′-hydroxy group of uridine and atoms of the active-site residues of uridine phosphorylase leads to conformational changes of the ribose moiety of uridine, resulting in an increase in the reactivity of uridine compared to thymidine. Since the binding of thymidine to residues of uridine phosphorylase causes a smaller local strain of the β-N1-glycosidic bond in this the substrate compared to the uridine molecule, the β-N1-glycosidic bond in thymidine is more stable and less reactive than that in uridine. It was shown for the first time that the phosphate anion, which is the second substrate bound at the active site, interacts simultaneously with the residues of the β5-strand and the β1-strand through hydrogen bonding, thus securing the gate loop in a conformation.

X-ray structures of uridine phosphorylase from Vibrio cholerae in complexes with uridine, thymidine, uracil, thymine, and phosphate anion: Substrate specificity of bacterial uridine phosphorylases

Science.gov (United States)

Prokofev, I. I.; Lashkov, A. A.; Gabdulkhakov, A. G.; Balaev, V. V.; Seregina, T. A.; Mironov, A. S.; Betzel, C.; Mikhailov, A. M.

2016-11-01

In many types of human tumor cells and infectious agents, the demand for pyrimidine nitrogen bases increases during the development of the disease, thus increasing the role of the enzyme uridine phosphorylase in metabolic processes. The rational use of uridine phosphorylase and its ligands in pharmaceutical and biotechnology industries requires knowledge of the structural basis for the substrate specificity of the target enzyme. This paper summarizes the results of the systematic study of the three-dimensional structure of uridine phosphorylase from the pathogenic bacterium Vibrio cholerae in complexes with substrates of enzymatic reactions—uridine, phosphate anion, thymidine, uracil, and thymine. These data, supplemented with the results of molecular modeling, were used to consider in detail the structural basis for the substrate specificity of uridine phosphorylases. It was shown for the first time that the formation of a hydrogen-bond network between the 2'-hydroxy group of uridine and atoms of the active-site residues of uridine phosphorylase leads to conformational changes of the ribose moiety of uridine, resulting in an increase in the reactivity of uridine compared to thymidine. Since the binding of thymidine to residues of uridine phosphorylase causes a smaller local strain of the β-N1-glycosidic bond in this the substrate compared to the uridine molecule, the β-N1-glycosidic bond in thymidine is more stable and less reactive than that in uridine. It was shown for the first time that the phosphate anion, which is the second substrate bound at the active site, interacts simultaneously with the residues of the β5-strand and the β1-strand through hydrogen bonding, thus securing the gate loop in a conformation

University and Entrepreneurship: An Empirical Investigation in the Tunisian Context

OpenAIRE

Ali, Tarek Ben

2017-01-01

Higher education in Tunisia is currently confronted with the explosion of students’ number. This significant growth represents an important challenge to take up: improving the quality of education and its relevance to the labour market and promote entrepreneurial culture and firm creation. In this context, we investigate the entrepreneurial intentions of final-year university students in the Tunisian economy by applying the theory of planned behavior (TPB). The objectives of the study were to...

The new architecture of economies' typology within the globalization context

OpenAIRE

Popa, Catalin C.

2009-01-01

Over viewing the most recently evolutions throughout global economy, we can easily conceive that the collateral effects of economical globalization and market integration, represents the main issues debated in specialized professional or political circles. The first step toward regain the global markets functionality is to review as a sine-qua-non condition, the institutional and functional structure of financial system and global economy system as well. In such context, this paperwork is mea...

Why are Industrial Relations in Spain Competitive? Trust in Management, Union Support and Conflict Behaviour in Worker Representatives

Directory of Open Access Journals (Sweden)

Patricia Elgoibar

2013-04-01

Full Text Available In the current context of limited resources and economic, social and labour changes, organizational conflicts are becoming more and more competitive. Two possible explanations for this approach to conflict in Spain are the low trust between unions and management and the long tradition of confrontation in industrial relations. In this study we analyse the conflict pattern from worker representatives and the relation to trust in management and union support. The hypotheses are tested in a quantitative study of 719 representatives. Results show that a representatives use a competitive conflict style; b trust is negatively related to this style; and c union support is positively related to the style. We explore how societal culture and historical industrial relations tradition explain these relations.

How Do Pre-Service Teachers' Reflective Processes Differ in Relation to Different Contexts?

Science.gov (United States)

Kaasila, Raimo; Lauriala, Anneli

2012-01-01

Reflective practice represents a central theme in teacher education. The focus of this study is to look at pre-service teachers' reflection processes and their breadth and depth in four different contexts. Our research data consist of 53 pre-service teachers' mathematics portfolios, from which three were selected for closer scrutiny. The chosen…

Te Reo Maori: Indigenous Language Acquisition in the Context of New Zealand English

Science.gov (United States)

Reese, Elaine; Keegan, Peter; McNaughton, Stuart; Kingi, Te Kani; Carr, Polly Atatoa; Schmidt, Johanna; Mohal, Jatender; Grant, Cameron; Morton, Susan

2018-01-01

This study assessed the status of te reo Maori, the indigenous language of New Zealand, in the context of New Zealand English. From a broadly representative sample of 6327 two-year-olds ("Growing Up in New Zealand"), 6090 mothers (96%) reported their children understood English, and 763 mothers (12%) reported their children understood…

Neurocircuits underlying cognition-emotion interaction in a social decision making context.

Science.gov (United States)

Ho, S Shaun; Gonzalez, Richard D; Abelson, James L; Liberzon, Israel

2012-11-01

Decision making (DM) in the context of others often entails complex cognition-emotion interaction. While the literature suggests that the ventromedial prefrontal cortex (vmPFC), striatum, and amygdala are involved in valuation-based DM and hippocampus in context processing, how these neural mechanisms subserve the integration of cognitive and emotional values in a social context remains unclear. In this study we addressed this gap by systematically manipulating cognition-emotion interaction in a social DM context, when the participants played a card game with a hypothetical opponent in a behavioral study (n=73) and a functional magnetic-resonance-imaging study (n=16). We observed that payoff-based behavioral choices were influenced by emotional values carried by face pictures and identified neurocircuits involved in cognitive valuation, emotional valuation, and concurrent cognition-emotion value integration. Specifically, while the vmPFC, amygdala, and ventral striatum were all involved in both cognitive and emotional domains of valuation, these regions played dissociable roles in social DM. The payoff-dependent responses in vmPFC and amygdala, but not ventral striatum, were moderated by the social context. Furthermore, the vmPFC, but not amygdala, not only encoded the opponent's gains as if self's losses, but also represented a "final common currency" during valuation-based decisions. The extent to which emotional input influenced choices was associated with the functional connectivity between the value-signaling amygdala and value integrating vmPFC, and also with the functional connectivity between the context-setting hippocampus and value-signaling amygdala and ventral striatum. These results identify brain pathways through which emotion shapes subjective values in a social DM context. Copyright © 2012 Elsevier Inc. All rights reserved.

Methods and Contexts in the Study of Muslim Minorities

DEFF Research Database (Denmark)

Research on Islam and Muslim minorities in Europe has generally been focused on the active representatives of these groups, in the form of research on the development of movements and organizations, their legal and political status, activities and relations with the wider political contexts both ...... in the fields of race relations and migration have increasingly mobilized ‘Muslims’ and ‘Islam’ as a common denominator. Initially, among social scientists the motivation seems often to have been the necessity of refining larger unmanageable ethnic groupings....

End-of-life decisions for people with intellectual disabilities, an interview study with patient representatives.

Science.gov (United States)

Wagemans, Annemieke M A; Van Schrojenstein Lantman-de Valk, Henny M J; Proot, Ireen M; Metsemakers, Job; Tuffrey-Wijne, Irene; Curfs, Leopold M G

2013-09-01

Not much is known about the process of end-of-life decision-making for people with intellectual disabilities. To clarify the process of end-of-life decision-making for people with intellectual disabilities from the perspective of patient representatives. A qualitative study based on semi-structured interviews, recorded digitally and transcribed verbatim. Data were analysed using Grounded Theory procedures. We interviewed 16 patient representatives after the deaths of 10 people with intellectual disabilities in the Netherlands. The core category 'Deciding for someone else' describes the context in which patient representatives took end-of-life decisions. The patient representatives felt highly responsible for the outcomes. They had not involved the patients in the end-of-life decision-making process, nor any professionals other than the doctor. The categories of 'Motives' and 'Support' were connected to the core category of 'Deciding for someone else'. 'Motives' refers to the patient representatives' ideas about quality of life, prevention from suffering, patients who cannot understand the burden of interventions and emotional reasons reported by patient representatives. 'Support' refers to the support that patient representatives wanted the doctors to give to them in the decision-making process. From the perspective of the patient representatives, the process of end-of-life decision-making can be improved by ensuring clear roles and an explicit description of the tasks and responsibilities of all participants. Regular discussion between everyone involved including people with intellectual disabilities themselves can improve knowledge about each other's motives for end-of-decisions and can clarify expectations towards each other.

Context incorporation using context-aware language features

OpenAIRE

Vlachostergiou, Aggeliki; Marandianos, George; Kollias, Stefanos

2017-01-01

This paper investigates the problem of context incorporation into human language systems and particular in Sentiment Analysis (SA) systems. So far, the analysis of how different features, when incorporated into such systems, improve their performance, has been discussed in a number of studies. However, a complete picture of their effectiveness remains unexplored. With this work, we attempt to extend the pool of the context - aware language features at the sentence level and to provide the ...

A Comparative Study of Uncertainty Reduction Theory in High- and Low-Context Cultures.

Science.gov (United States)

Kim, Myoung-Hye; Yoon, Tae-Jin

To test the cross-cultural validity of uncertainty reduction theory, a study was conducted using students from South Korea and the United States who were chosen to represent high- and low-context cultures respectively. Uncertainty reduction theory is based upon the assumption that the primary concern of strangers upon meeting is one of uncertainty…

Family Caregivers’ Social Representations of Death in a Palliative Care Context

OpenAIRE

Sabrina Lessard; Bernard-Simon Leclerc; Suzanne Mongeau

2016-01-01

The objective of this study was to consider the social representations of death of family caregivers in a palliative care context. The authors focused on the analysis of 23 interviews with family caregivers who cared for a terminally ill person at home and/or in a specialized palliative care unit, in Québec, Canada. The finding showed that family caregivers had different images that specifically represented death: (a) ...

Pregnant Teenager Involvement in Sexual Activity and the Social Context

OpenAIRE

Sant'Anna, Maria José Carvalho; Catunda, Júlia Kerr; Carvalho, Kepler Alencar Mendes; Coates, Veronica; Omar, Hatim A.

2006-01-01

Pregnancy during adolescence represents a challenge to society as a whole. Its incidence is increasing and brings about social and medical consequences to both the teen mothers and their children. The purpose of this study was to evaluate pregnant teenager involvement in sexual activity and the social context. The group studied comprised 152 pregnant teenagers attending the Department of Pediatrics, Santa Casa de Sao Paulo (SCSP) General Hospital. All information was analyzed. The age at firs...

Diffusion of Telecommunications Services in a Complex Socio-Economic Context

DEFF Research Database (Denmark)

Ismail, Abdullah

This research aims at creating a detailed account on the diffusion of telecommunications services in a complex socio-economic context, taking Pakistan as a case study. The core research question of this thesis is to investigate why the successful experience of the rapid and an effective diffusion...... of mobile communications services in case of Pakistan couldn’t be replicated in the cases of fixed telephony and internet services. The book investigates those major attributes which play a significant role in the diffusion of telecommunications services in a complex socio-economic and political context...... of telecom services within a complex unit of adoption. The empirical part of the research includes a significantly high number of interviews that were conducted from the key players of the local telecom market, and they essentially represented all the five major domains i.e. the supplier, policy, regulatory...

Unpacking religious affiliation: Exploring associations between Christian children's religious cultural context, God image, and self-esteem across development.

Science.gov (United States)

Smith, Erin I; Crosby, Robert G

2017-03-01

In developmental research, religiousness is typically measured with omnibus affiliation or attendance variables that underspecify how the religious cultural contexts and experiences that affiliation represents influence developmental outcomes. This study explores associations between five aspects of a religious cultural context (family religiosity, religious schooling, church-based relationships with peers and adults, and view of God) in 844 seven- to 12-year-old Christian children to examine how they differentially predict self-esteem. Results of a structural equation model (SEM) analysis indicated that God image and peer church relationships directly predicted self-esteem, whereas God image mediated the influence of adult church relationships and family religious practices on self-esteem. A multiple group SEM analysis met the criterion for weak, but not strong, evidence that self-esteem is more related to younger children's adult church relationships but older children's peer church relationships. God image tended to be more related to younger children's family religious practices but older children's adult church relationships. Implications for developmental researchers and practitioners are discussed. Statement of contribution What is already known on this subject? Religious affiliation is an omnibus variable representing multiple contexts of development. Self-esteem is an important outcome variable with different influences across development. Religious affiliation is associated with increased self-esteem. What does this study add? Children's experience in the contexts of religious affiliation influences development differently. It is not just affiliation, but specific religious contexts that influence children's self-esteem. The role of religious contexts in shaping children's self-esteem shifts across development. © 2016 The British Psychological Society.

Dynamic Context Bindings, Infrastructural Support for Context-aware Applications

NARCIS (Netherlands)

Broens, T.H.F.

2008-01-01

The world is increasingly equipped with high-capacity, interconnected, mobile and embedded computing devices. Context-awareness provides an attractive approach to personalize applications such that they better suit the user’s needs in this rich computing environment. Context-aware applications use

Environmental and nutritional factors that affect growth and metabolism of the pneumococcal serotype 2 strain D39 and its nonencapsulated derivative strain R6.

Directory of Open Access Journals (Sweden)

Sandra M Carvalho

Full Text Available Links between carbohydrate metabolism and virulence in Streptococcus pneumoniae have been recurrently established. To investigate these links further we developed a chemically defined medium (CDM and standardized growth conditions that allowed for high growth yields of the related pneumococcal strains D39 and R6. The utilization of the defined medium enabled the evaluation of different environmental and nutritional factors on growth and fermentation patterns under controlled conditions of pH, temperature and gas atmosphere. The same growth conditions impacted differently on the nonencapsulated R6, and its encapsulated progenitor D39. A semi-aerobic atmosphere and a raised concentration of uracil, a fundamental component of the D39 capsule, improved considerably D39 growth rate and biomass. In contrast, in strain R6, the growth rate was enhanced by strictly anaerobic conditions and uracil had no effect on biomass. In the presence of oxygen, the difference in the growth rates was mainly attributed to a lower activity of pyruvate oxidase in strain D39. Our data indicate an intricate connection between capsule production in strain D39 and uracil availability. In this study, we have also successfully applied the in vivo NMR technique to study sugar metabolism in S. pneumoniae R6. Glucose consumption, end-products formation and evolution of intracellular metabolite pools were monitored online by (13C-NMR. Additionally, the pools of NTP and inorganic phosphate were followed by (31P-NMR after a pulse of glucose. These results represent the first metabolic profiling data obtained non-invasively for S. pneumoniae, and pave the way to a better understanding of regulation of central metabolism.

Limbaj și context = Speech and Context , no.1, 2012

OpenAIRE

Angela Cosciug

2017-01-01

Speech and Context International Journal of Linguistics, Semiotics and Literary Science (SCIJLSLS) is an open access, peer reviewed (double blind reviewed) journal which is indexed in many prestigious international databases, directories, lists etc. (see Journal Indexing and Registration by databases types or Journal Indexing and Registration by countries). It appears there like Limbaj şi context or Speech and Context International Journal of Linguistics, Semiotics and Literary Science. The j...

Limbaj și context = Speech and Context, no.1, 2011

OpenAIRE

Angela Cosciug

2017-01-01

Speech and Context International Journal of Linguistics, Semiotics and Literary Science (SCIJLSLS) is an open access, peer reviewed (double blind reviewed) journal which is indexed in many prestigious international databases, directories, lists etc. (see Journal Indexing and Registration by databases types or Journal Indexing and Registration by countries). It appears there like Limbaj şi context or Speech and Context International Journal of Linguistics, Semiotics and Literary Science. The j...

Limbaj și context = Speech and Context, no.1, 2014

OpenAIRE

Cosciug Angela

2017-01-01

Speech and Context International Journal of Linguistics, Semiotics and Literary Science (SCIJLSLS) is an open access, peer reviewed (double blind reviewed) journal which is indexed in many prestigious international databases, directories, lists etc. (see Journal Indexing and Registration by databases types or Journal Indexing and Registration by countries). It appears there like Limbaj şi context or Speech and Context International Journal of Linguistics, Semiotics and Literary Science. The j...

Limbaj și context = Speech and Context, no.1, 2009

OpenAIRE

Angela Cosciug

2009-01-01

Speech and Context International Journal of Linguistics, Semiotics and Literary Science (SCIJLSLS) is an open access, peer reviewed (double blind reviewed) journal which is indexed in many prestigious international databases, directories, lists etc. (see Journal Indexing and Registration by databases types or Journal Indexing and Registration by countries). It appears there like Limbaj şi context or Speech and Context International Journal of Linguistics, Semiotics and Literary Science. The j...

Limbaj și context = Speech and Context. no. 2, 2013

OpenAIRE

Cosciug Angela

2017-01-01

Speech and Context International Journal of Linguistics, Semiotics and Literary Science (SCIJLSLS) is an open access, peer reviewed (double blind reviewed) journal which is indexed in many prestigious international databases, directories, lists etc. (see Journal Indexing and Registration by databases types or Journal Indexing and Registration by countries). It appears there like Limbaj şi context or Speech and Context International Journal of Linguistics, Semiotics and Literary Science. The j...

Limbaj și context = Speech and Context, no.2, 2009

OpenAIRE

Angela Cosciug

2009-01-01

Speech and Context International Journal of Linguistics, Semiotics and Literary Science (SCIJLSLS) is an open access, peer reviewed (double blind reviewed) journal which is indexed in many prestigious international databases, directories, lists etc. (see Journal Indexing and Registration by databases types or Journal Indexing and Registration by countries). It appears there like Limbaj şi context or Speech and Context International Journal of Linguistics, Semiotics and Literary Science. The j...

Limbaj și context = Speech and Context, no.2, 2015

OpenAIRE

Cosciug Angela

2017-01-01

Speech and Context International Journal of Linguistics, Semiotics and Literary Science (SCIJLSLS) is an open access, peer reviewed (double blind reviewed) journal which is indexed in many prestigious international databases, directories, lists etc. (see Journal Indexing and Registration by databases types or Journal Indexing and Registration by countries). It appears there like Limbaj şi context or Speech and Context International Journal of Linguistics, Semiotics and Literary Science. The j...

Limbaj și context = Speech and Context, no.2, 2011

OpenAIRE

Angela Cosciug

2017-01-01

Speech and Context International Journal of Linguistics, Semiotics and Literary Science (SCIJLSLS) is an open access, peer reviewed (double blind reviewed) journal which is indexed in many prestigious international databases, directories, lists etc. (see Journal Indexing and Registration by databases types or Journal Indexing and Registration by countries). It appears there like Limbaj şi context or Speech and Context International Journal of Linguistics, Semiotics and Literary Science. The j...

An Approach to Represent and Communicate Product or System Design Ideas at the Fuzzy-Front End of the Design Process

NARCIS (Netherlands)

Opiyo, E.Z.

2016-01-01

The primary challenge underscored and dealt with was how to represent the product’s or system’s use environment and processes and to communicate ideas and envisaged use contexts effectively at the fuzzy-front early stages of the design process. The work focused specifically on complex products or

Operation Context

DEFF Research Database (Denmark)

Stüben, Henning; Tietjen, Anne

2006-01-01

Abstract: This paper seeks to challenge the notion of context from an operational perspective. Can we grasp the forces that shape the complex conditions for an architectural or urban design within the notion of context? By shifting the gaze towards the agency of architecture, contextual analysis...

Model-based analysis of context-specific cognitive control

Directory of Open Access Journals (Sweden)

Joseph A. King

2012-09-01

Full Text Available Interference resolution is improved for stimuli presented in contexts (e.g. locations associated with frequent conflict. This phenomenon, the context-specific proportion congruent (CSPC effect, has challenged the traditional juxtaposition of automatic and controlled processing because it suggests that contextual cues can prime top-down control settings in a bottom-up manner. We recently obtained support for this priming of control hypothesis with fMRI by showing that CSPC effects are mediated by contextually-cued adjustments in processing selectivity. However, an equally plausible explanation is that CSPC effects reflect adjustments in response caution triggered by expectancy violations (i.e. prediction errors when encountering rare events as compared to common ones (e.g. high-conflict incongruent trials in a task context associated with infrequent conflict. Here, we applied a quantitative model of choice, the linear ballistic accumulator (LBA, to distil the reaction time and accuracy data from four independent samples that performed a modified flanker task into latent variables representing the psychological processes underlying task-related decision making. We contrasted models which differentially accounted for CSPC effects as arising either from contextually-cued shifts in the rate of sensory evidence accumulation (drift models or in the amount of evidence required to reach a decision (threshold models. For the majority of the participants, the LBA ascribed CSPC effects to increases in response threshold for contextually-infrequent trial types (e.g. low-conflict congruent trials in the frequent conflict context, suggesting that the phenomenon may reflect more a prediction error-triggered shift in decision criterion rather than enhanced sensory evidence accumulation under conditions of frequent conflict.

Enhanced attention to context: An intervention that increases perceived control in mild depression.

Science.gov (United States)

Msetfi, R M; Brosnan, L; Cavus, H A

2016-01-01

People perceive that they have control over events to the extent that the same events do not occur outside of their control, randomly, in the environment or context. Therefore, perceived control should be enhanced if there is a large contrast between one's own control and the control that the context itself seems to exert over events. Given that depression is associated with low perceived control, we tested the hypothesis that enhanced attentional focus to context will increase perceived control in people with and without depression. A total of 106 non-depressed and mildly depressed participants completed a no control zero-contingency task with low and high outcome probability conditions. In the experimental context-focus group, participants were instructed to attend to the context, whereas in the control group, participants were instructed to attend to their thoughts. Irrespective of attentional focus, non-depressed participants displayed illusory control. However, people with mild depression responded strongly to the attention focus manipulation. In the control group, they evidenced low perceived control with classic depressive realism effects. In the experimental group, when asked to focus on the context in which events took place, participants with mild depression displayed enhanced perceived control or illusory control, similar to non-depressed participants. Findings are discussed in relation to whether depression effects on perceived control represent tendencies towards realism or attentional aspects of depressive thoughts.

48 CFR 1852.227-72 - Designation of new technology representative and patent representative.

Science.gov (United States)

2010-10-01

... CONTRACT CLAUSES Texts of Provisions and Clauses 1852.227-72 Designation of new technology representative... of New Technology Representative and Patent Representative (JUL 1997) (a) For purposes of administration of the clause of this contract entitled “New Technology” or “Patent Rights—Retention by the...

Context-Aided Sensor Fusion for Enhanced Urban Navigation

Directory of Open Access Journals (Sweden)

Enrique David Martí

2012-12-01

Full Text Available  The deployment of Intelligent Vehicles in urban environments requires reliable estimation of positioning for urban navigation. The inherent complexity of this kind of environments fosters the development of novel systems which should provide reliable and precise solutions to the vehicle. This article details an advanced GNSS/IMU fusion system based on a context-aided Unscented Kalman filter for navigation in urban conditions. The constrained non-linear filter is here conditioned by a contextual knowledge module which reasons about sensor quality and driving context in order to adapt it to the situation, while at the same time it carries out a continuous estimation and correction of INS drift errors. An exhaustive analysis has been carried out with available data in order to characterize the behavior of available sensors and take it into account in the developed solution. The performance is then analyzed with an extensive dataset containing representative situations. The proposed solution suits the use of fusion algorithms for deploying Intelligent Transport Systems in urban environments.

THE ROMANIAN TOURISM IN THE CONTEXT OF SUSTAINABLE DEVELOPMENT

Directory of Open Access Journals (Sweden)

Claudia Elena Paicu

2013-04-01

Full Text Available Currently tourism represents one of the basic elements for the sustainable development, considering that it is properly understood and implemented. To perform an analysis of tourism in this context, we must consider the three coordinates, interedependente, that influence and equally are influenced by the tourism activity. It is about the particularly impact that tourism has on living standards in areas with high potential for exploitation of tourism activities, about the impact and the effects generated in the economy and, not least, we discuss about the effects that tourism generates on the environment.

An Approach to Represent and Communicate Product or System Design Ideas at the Fuzzy-Front End of the Design Process

Directory of Open Access Journals (Sweden)

Eliab Z. Opiyo

2016-01-01

Full Text Available The primary challenge underscored and dealt with was how to represent the product’s or system’s use environment and processes and to communicate ideas and envisaged use contexts effectively at the fuzzy-front early stages of the design process. The work focused specifically on complex products or systems with physical, software and/or cyber components, and the question was how to represent, e.g., the operations of the product or system and the interactions between the user and the product or system betimes in the period between when an opportunity for a new product or system is first considered, and when the idea is judged to be ready to enter formal development. Several approaches are currently being used to express and to communicate ideas at the conceptualization, embodiment, and detail design stages of the design process, but none of them address the challenge described above. We therefore adapted and extended the abstract prototyping concept to allow for total representation of ideas, as well as of use environments and processes early on. Extended abstract prototyping (Ext-AP entails using combinations of low and high-fidelity prototyping techniques to create cognitive virtual representations, which represent and help designers to express ideas and use contexts—namely, what complex product or system would be like, and how its users would interact with it. Real-world product development case studies have been used to demonstrate how the Ext-AP technique can be put into practice. One of the main observations from the application case studies is that the Ext-AP technique enabled the subjects to express ideas and use contexts more effectively early on. In addition, the extended abstract prototypes (Ext-APs offered a low cost, yet effective solution for expressing ideas, representing concepts and using contexts, and allowed the subjects to think divergently, make associations, easily and quickly construct, combine, and evaluate

Multicriteria analysis of ontologically represented information

Science.gov (United States)

Wasielewska, K.; Ganzha, M.; Paprzycki, M.; Bǎdicǎ, C.; Ivanovic, M.; Lirkov, I.

2014-11-01

Our current work concerns the development of a decision support system for the software selection problem. The main idea is to utilize expert knowledge to help the user in selecting the best software / method / computational resource to solve a computational problem. Obviously, this involves multicriterial decision making and the key open question is: which method to choose. The context of the work is provided by the Agents in Grid (AiG) project, where the software selection (and thus multicriterial analysis) is to be realized when all information concerning the problem, the hardware and the software is ontologically represented. Initially, we have considered the Analytical Hierarchy Process (AHP), which is well suited for the hierarchical data structures (e.g., such that have been formulated in terms of ontologies). However, due to its well-known shortcomings, we have decided to extend our search for the multicriterial analysis method best suited for the problem in question. In this paper we report results of our search, which involved: (i) TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), (ii) PROMETHEE, and (iii) GRIP (Generalized Regression with Intensities of Preference). We also briefly argue why other methods have not been considered as valuable candidates.

A Religious Experience? Personal, Parental, and Peer Religiosity and the Academic Success of Sexual-Minority Youth Using Nationally Representative Samples

Science.gov (United States)

Gottfried, Michael A.; Polikoff, Morgan S.

2012-01-01

Using nationally representative transcript data, this study is the first to include a discussion of religiosity in the context of sexual-minority students' academic achievement. This study examines the issue in three capacities: first, by comparing school success of sexual-minority youth to a non-sexual-minority reference group; second, by…

Dynamics of Context-Dependent Recall: An Examination of Internal and External Context Change

Science.gov (United States)

Unsworth, Nash; Spillers, Gregory J.; Brewer, Gene A.

2012-01-01

Retrieval dynamics in context-dependent recall were explored via manipulations of external and internal context in two experiments. Participants were tested in either the same or different context as the material was learned in and correct recalls, errors, and recall latency measures were examined. In both experiments changes in context resulted…

Comparing speech and nonspeech context effects across timescales in coarticulatory contexts.

Science.gov (United States)

Viswanathan, Navin; Kelty-Stephen, Damian G

2018-02-01

Context effects are ubiquitous in speech perception and reflect the ability of human listeners to successfully perceive highly variable speech signals. In the study of how listeners compensate for coarticulatory variability, past studies have used similar effects speech and tone analogues of speech as strong support for speech-neutral, general auditory mechanisms for compensation for coarticulation. In this manuscript, we revisit compensation for coarticulation by replacing standard button-press responses with mouse-tracking responses and examining both standard geometric measures of uncertainty as well as newer information-theoretic measures that separate fast from slow mouse movements. We found that when our analyses were restricted to end-state responses, tones and speech contexts appeared to produce similar effects. However, a more detailed time-course analysis revealed systematic differences between speech and tone contexts such that listeners' responses to speech contexts, but not to tone contexts, changed across the experimental session. Analyses of the time course of effects within trials using mouse tracking indicated that speech contexts elicited fewer x-position flips but more area under the curve (AUC) and maximum deviation (MD), and they did so in the slower portions of mouse-tracking movements. Our results indicate critical differences between the time course of speech and nonspeech context effects and that general auditory explanations, motivated by their apparent similarity, be reexamined.

Supporting Pervasive Computing Applications with Active Context Fusion and Semantic Context Delivery

DEFF Research Database (Denmark)

Roy, Nirmalya; Gu, Tao; Das, Sajal

2010-01-01

Future pervasive computing applications are envisioned to adapt the applications’ behaviors by utilizing various contexts of an environment and its users. Such context information may often be ambiguous and also heterogeneous, which make the delivery of unambiguous context information to real app...

Evaluation in Context

DEFF Research Database (Denmark)

Jaap, Kamps; Lalmas, Mounia; Larsen, Birger

All search happens in a particular context - such as the particular collection of a digital library, its associated search tasks, and its associated users. Information retrieval researchers usually agree on the importance of context, but they rarely address the issue. In particular, evaluation in......, e.g. those that suit a particular task scenario, and zoom in on the relative performance for such a group of topics.......All search happens in a particular context - such as the particular collection of a digital library, its associated search tasks, and its associated users. Information retrieval researchers usually agree on the importance of context, but they rarely address the issue. In particular, evaluation....../assessors - by designing targeted questionnaires. The questionnaire data becomes part of the evaluation test-suite as valuable data on the context of the search requests.We have experimented with this questionnaire approach during the evaluation campaign of the INitiative for the Evaluation of XML Retrieval (INEX...

Representing time

Directory of Open Access Journals (Sweden)

Luca Poncellini

2010-06-01

Full Text Available The analysis of natural phenomena applied to architectural planning and design is facing the most fascinating and elusive of the four dimensions through which man attempts to define life within the universe: time. We all know what time is, said St. Augustine, but nobody knows how to describe it. Within architectural projects and representations, time rarely appears in explicit form. This paper presents the results of a research conducted by students of NABA and of the Polytechnic of Milan with the purpose of representing time considered as a key element within architectural projects. Student investigated new approaches and methodologies to represent time using the two-dimensional support of a sheet of paper.

Putting retrieval-induced forgetting in context: an inhibition-free, context-based account.

Science.gov (United States)

Jonker, Tanya R; Seli, Paul; MacLeod, Colin M

2013-10-01

We present a new theoretical account of retrieval-induced forgetting (RIF) together with new experimental evidence that fits this account and challenges the dominant inhibition account. RIF occurs when the retrieval of some material from memory produces later forgetting of related material. The inhibition account asserts that RIF is the result of an inhibition mechanism that acts during retrieval to suppress the representations of interfering competitors. This inhibition is enduring, such that the suppressed material is difficult to access on a later test and is, therefore, recalled more poorly than baseline material. Although the inhibition account is widely accepted, a growing body of research challenges its fundamental assumptions. Our alternative account of RIF instead emphasizes the role of context in remembering. According to this context account, both of 2 tenets must be met for RIF to occur: (a) A context change must occur between study and subsequent retrieval practice, and (b) the retrieval practice context must be the active context during the final test when testing practiced categories. The results of 3 experiments, which directly test the divergent predictions of the 2 accounts, support the context account but cannot be explained by the inhibition account. In an extensive discussion, we survey the literature on RIF and apply our context account to the key findings, demonstrating the explanatory power of context. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Food-related lifestyles in a cross-cultural context: Comparing Australia with Singapore, Britain, France and Denmark

DEFF Research Database (Denmark)

Reid, Mike; Li, Elton; Bruwer, Johan

2001-01-01

, to compare lifestyles across a number of different cultural contexts including Australia, Singapore, Britain, France and Denmark. The research represents the first stage in an on-going process of mapping movements in Australian consumer food-related lifestyles and linking these to global trends and changes....

Spatio-Temporal Reasoning and Context Awareness

Science.gov (United States)

Guesgen, Hans W.; Marsland, Stephen

Smart homes provide many research challenges, but some of the most interesting ones are in dealing with data that monitors human behaviour and that is inherently both spatial and temporal in nature. This means that context becomes all important: a person lying down in front of the fireplace could be perfectly normal behaviour if it was cold and the fire was on, but otherwise it is unusual. In this example, the context can include temporal resolution on various scales (it is winter and therefore probably cold, it is not nighttime when the person would be expected to be in bed rather than the living room) as well as spatial (the person is lying in front of the fireplace) and extra information such as whether or not the fire is lit. It could also include information about how they reached their current situation: if they went from standing to lying very suddenly there would be rather more cause for concern than if they first knelt down and then lowered themselves onto the floor. Representing all of these different temporal and spatial aspects together is a major challenge for smart home research. In this chapter we will provide an overview of some of the methodologies that can be used to deal with these problems. We will also outline our own research agenda in the Massey University Smart Environments (MUSE) group.

VALUE ADDED TAX IN THE ECONOMIC CRISIS CONTEXT

Directory of Open Access Journals (Sweden)

Mara Cristian

2011-07-01

Full Text Available This article tries to present the major aspects concerning the value added tax in the context of economic crisis in European Union countries and Romania. The paper realizes an analysis of the impact of economic crises on VAT in the European space underlining the current situation when the revenues from VAT represent a valuable source of financing the public expenditures. In Romania the economic crises has led to increasing o f VAT rate from 19% to 24%. This measure is an important fiscal measure for the state budget and this study tries to reflect the impact of this VAT rate increase on the public revenues and consumption.

Limbaj și context = Speech and Context, no.1-2, 2016

OpenAIRE

Cosciug Angela

2017-01-01

Speech and Context International Journal of Linguistics, Semiotics and Literary Science (SCIJLSLS) is an open access, peer reviewed (double blind reviewed) journal which is indexed in many prestigious international databases, directories, lists etc. (see Journal Indexing and Registration by databases types or Journal Indexing and Registration by countries). It appears there like Limbaj şi context or Speech and Context International Journal of Linguistics, Semiotics and Literary Science. The j...

Effects of a Context Shift and Multiple Context Extinction on Reactivity to Alcohol Cues

Science.gov (United States)

MacKillop, James; Lisman, Stephen A.

2008-01-01

Cue exposure treatment (CET) attempts to reduce the influence of conditioned substance cues on addictive behavior via prolonged cue exposure with response prevention (i.e., extinction), but has received only modest empirical support in clinical trials. This may be because extinction learning appears to be context dependent and a change in context may result in a return of conditioned responding (i.e., renewal), although this has received only limited empirical examination. The current study used a four-session laboratory analogue of CET to examine whether a change in context following three sessions of alcohol cue exposure with response prevention would result in renewal of conditioned responding. In addition, this study examined whether conducting extinction in multiple contexts would attenuate renewal of conditioned responding. In a one-way between-subjects design, 73 heavy drinkers (71% male) were randomized to three conditions: 1) single context extinction (extinction to alcohol cues in the same context for three sessions followed by a context shift at the fourth session); 2) multiple context extinction (extinction to alcohol cues in different contexts each day for all four sessions); and 3) pseudo-extinction control condition (exposure to neutral cues in the same context for three sessions followed by exposure to alcohol cues at the fourth session). The results revealed the predicted cue reactivity and extinction effects, but the hypotheses that a context shift would generate renewed cue reactivity and that multiple contexts would enhance extinction were not supported. Methodological aspects of the study and the need for parametric data on the context dependency of extinction to alcohol cues are discussed. PMID:18729687

An Examination of the Moderating Effects of the High School Socioeconomic Context on College Enrollment

Science.gov (United States)

Engberg, Mark E.; Wolniak, Gregory C.

2014-01-01

Drawing on a nationally representative sample of high school seniors from the Educational Longitudinal Survey of 2002 (ELS), this study examines the influence of the high school socioeconomic context on students' decisions to attend two-and four-year postsecondary institutions. The results provide evidence of resource imbalances based on…

Reasoning Strategies in the Context of Engineering Design with Everyday Materials

OpenAIRE

Worsley, Marcelo; Blikstein, Paulo

2017-01-01

‘‘Making’’ represents an increasingly popular label for describing a form of engineering design. While making is growing in popularity, there are still open questions about the strategies that students are using in these activities. Assessing and improving learning in making/ engineering design contexts require that we have a better understanding of where students’ ideas are coming from and a better way to characterize student progress in open-ended learning environments. In this article, we ...

Generally representative is generally representative: comment on Shuttleworth-Edwards.

Science.gov (United States)

Taylor, Nicola

2016-10-01

The aim of this paper is to provide comment on Shuttleworth-Edwards' criticism of the general population norms created for the South African adaptation of the WAIS-IV. In her criticism, she states that the norms are not applicable for any groups in South Africa, based on the fact that the norms were not stratified according to quality of education. A discussion of some of the key issues that impact on the creation of general population norms in the South African context is provided. Demographic characteristics such as education level, quality of education, urban and rural demarcations, and home language are all considered. While the utility of within-group norms is not denied, the adoption of these without reference to the general population is not advised. To recommend that practitioners simply dispense with the general population norm without evidence that it creates misclassification or does not function effectively for the intended population lacks scientific merit at the current time. The need for clinical studies and further predictive validity research using the South African adaptation of the WAIS-IV is crucial to demonstrate the continued utility of the test in the South African context. Additional reference groups will improve the amount of comparative information available for clinicians to be able to make better informed decisions for diagnosis, but the general population norms will be an important starting point in this process.

Metabolism of tRNAs in growing cells of Escherichia coli illuminated with near-ultraviolet light

International Nuclear Information System (INIS)

Hajnsdorf, E.; Favre, A.

1986-01-01

The tRNA metabolism which accompanies illumination of growing E. coli cells has been examined in conditions that led to growth delay. The in vivo formation of the 8-13 link was followed by a fluorimetric procedure and revealed pseudo-first order kinetics very close to those obtained in vitro under the same illumination conditions. Comparison of these kinetics with published radiochromatographic data suggests the transient formation during illumination of a new RNase-T 2 -resistant dinucleotide in tRNA distinct from the 8-13 link. Under illumination some tRNA molecules lack one or more bases in a specific position in the sequence. During the growth lag, uracil incorporation into nucleic acids occurs at between 4-8% of the rate normally observed during exponential growth. However, the pyrimidine ribonucleoside triphosphate pools are strongly perturbed after illumination. Comparison of exogenous [ 3 H]uracil incorporation into two strains proficient or deficient in uracil biosynthesis suggests a derepression of the endogenous path after light treatment. In addition, the UTP-to-CTP conversion is inhibited. In spite of preferential incorporation of exogenously labelled uracil in tRNA after illumination, a possible pyrimidine base turnover cannot be proved. (author)

Contexts as Shared Commitments

Directory of Open Access Journals (Sweden)

Manuel eGarcía-Carpintero

2015-12-01

Full Text Available Contemporary semantics assumes two different notions of context: one coming from Kaplan (1989, on which contexts are sets of predetermined parameters, and another originated in Stalnaker (1978, on which contexts are sets of propositions that are common ground. The latter is deservedly more popular, given its flexibility to account for context-dependent aspects of language beyond manifest indexicals, such as epistemic modals, predicates of taste, and so on and so forth; in fact, properly dealing with demonstratives (perhaps ultimately all indexicals requires that further flexibility. Even if we acknowledge Lewis (1980 point that, in a sense, Kaplanian contexts already include common ground contexts, it is better to be clear and explicit about what contexts constitutively are. Now, Stalnaker (1978, 2002, 2014 defines context-as-common-ground as a set of propositions, but recent work shows that this is not an accurate conception. The paper explains why, and provides an alternative. The main reason is that several phenomena (presuppositional treatments of pejoratives and predicates of taste, forces other than assertion require that the common ground includes non-doxastic attitudes such as appraisals, emotions, etc. Hence the common ground should not be taken to include merely contents (propositions, but those together with attitudes concerning them: shared commitments, as I will defend.

Description logics of context

CSIR Research Space (South Africa)

Klarman, S

2013-05-01

Full Text Available We introduce Description Logics of Context (DLCs) - an extension of Description Logics (DLs) for context-based reasoning. Our approach descends from J. McCarthy's tradition of treating contexts as formal objects over which one can quantify...

Radiological Diagnoses in the Context of Emigration: Infectious diseases.

Science.gov (United States)

Stojkovic, Marija; Müller, Jan; Junghanss, Thomas; Weber, Tim Frederik

2018-02-01

 Globalization and emigration impact on the spectrum of diseases challenging health care systems. Medical practitioners have to particularly prepare for infectious diseases.  The database of a health care center specialized on tropical medicine was screened for patients with history of migration and one of the following diagnoses: Cystic echinococcosis, tuberculosis, schistosomiasis, visceral leishmaniosis, and neurocysticercosis. Representative casuistics were prepared from select case histories. Radiological pertinent knowledge was compiled based on literature search.  A small selection of frequently imported infectious diseases covers a considerable fraction of health care problems associated with migration. For cystic echinococcosis, schistosomiasis, and neurocysticercosis imaging is the most relevant diagnostic procedure defining also disease stages. Tuberculosis and visceral leishmaniosis are important differentials for malignant diseases.  Imaging plays a meaningful role in diagnosis, treatment stratification, and follow-up of imported infectious diseases. Radiological skills concerning these diseases are important for providing health care for patients in context of migration.   · Imaging plays a meaningful role in multidisciplinary care for imported infectious diseases.. · A small selection covers a considerable fraction of infectious diseases expected in context of migration.. · Stojkovic M, Müller J, Junghanss T et al. Radiological Diagnoses in the Context of Emigration: Infectious diseases. Fortschr Röntgenstr 2018; 190: 121 - 133. © Georg Thieme Verlag KG Stuttgart · New York.

a Context-Aware Tourism Recommender System Based on a Spreading Activation Method

Science.gov (United States)

Bahramian, Z.; Abbaspour, R. Ali; Claramunt, C.

2017-09-01

Users planning a trip to a given destination often search for the most appropriate points of interest location, this being a non-straightforward task as the range of information available is very large and not very well structured. The research presented by this paper introduces a context-aware tourism recommender system that overcomes the information overload problem by providing personalized recommendations based on the user's preferences. It also incorporates contextual information to improve the recommendation process. As previous context-aware tourism recommender systems suffer from a lack of formal definition to represent contextual information and user's preferences, the proposed system is enhanced using an ontology approach. We also apply a spreading activation technique to contextualize user preferences and learn the user profile dynamically according to the user's feedback. The proposed method assigns more effect in the spreading process for nodes which their preference values are assigned directly by the user. The results show the overall performance of the proposed context-aware tourism recommender systems by an experimental application to the city of Tehran.

A CONTEXT-AWARE TOURISM RECOMMENDER SYSTEM BASED ON A SPREADING ACTIVATION METHOD

Directory of Open Access Journals (Sweden)

Z. Bahramian

2017-09-01

Full Text Available Users planning a trip to a given destination often search for the most appropriate points of interest location, this being a non-straightforward task as the range of information available is very large and not very well structured. The research presented by this paper introduces a context-aware tourism recommender system that overcomes the information overload problem by providing personalized recommendations based on the user’s preferences. It also incorporates contextual information to improve the recommendation process. As previous context-aware tourism recommender systems suffer from a lack of formal definition to represent contextual information and user’s preferences, the proposed system is enhanced using an ontology approach. We also apply a spreading activation technique to contextualize user preferences and learn the user profile dynamically according to the user’s feedback. The proposed method assigns more effect in the spreading process for nodes which their preference values are assigned directly by the user. The results show the overall performance of the proposed context-aware tourism recommender systems by an experimental application to the city of Tehran.

Social Context as an Indirect Trigger in EFL Contexts: Issues and Solutions

Science.gov (United States)

Gholami, Reza; Rahman, Sharifah Zainab Abd; Mustapha, Ghazali

2012-01-01

This paper investigates the value of the social context and its role in learning a second language in different contexts. Social context is believed to be able to influence attitude and motivation. It also provides learning opportunities which give rise to learner's outcomes. In fact, students acquire a language by using it in social interaction…

Human resource configurations: investigating fit with the organizational context.

Science.gov (United States)

Toh, Soo Min; Morgeson, Frederick P; Campion, Michael A

2008-07-01

The present study investigated how key organizational contextual factors relate to bundles of human resource (HR) practices. In a two-phase study of a sample of 661 organizations representing a full range of industries and organizational size, the authors found that organizations use 1 of 5 HR bundles: cost minimizers, contingent motivators, competitive motivators, resource makers, and commitment maximizers. In addition, the authors showed that the organizations that use a given type of HR bundle may be distinguished by the organizational values they pursue and their organizational structure, thus suggesting that HR choices are related to the context within which organizations operate.

The approach of Hospital Pedagogy in the Venezuelan context

Directory of Open Access Journals (Sweden)

Marian SERRADAS FONSECA

2018-01-01

Full Text Available This document is intended to represent the reality of Hospital Pedagogy in Venezuela. Its purpose is to provide a historical view first, of the most significant events that allowed the emergence, development and consolidation of Hospital Pedagogy in Venezuela, as well as the implementation and commissioning of the first hospital wards. Then, addressing teacher training in Hospital Pedagogy, he continues to research in the advancement of this type of education in our context, as well as the description of programs and projects conducted in the country for the benefit of the hospitalized population and the presentation of some final considerations.

Synthesis of 2',3'-dideoxy-3'-C-(hydroxymethyl)-4'-thiopentofuranosyl nucleosides as potential antiviral agent.

Science.gov (United States)

Ichikawa, E; Yamamura, S; Kato, K

1999-04-19

1-O-Acetyl-2,3-dideoxy-3-C-(hydroxymethyl)-4-thiofuranose derivative was synthesized from (S,S)-1,4-bis(benzyloxy)-2,3-epoxybutane derived from (+)-diethyl L-tartrate and the enantiomerically pure (E)-5-(2-bromovinyl)-1-[2',3'-dideoxy-3'-C-(hydroxymethyl)-beta-D-4'- thiopentofuranosyl]uracil 4 was obtained via coupling of silylated uracil followed by palladium-mediated coupling of methyl acrylate.

How Two Differing Portraits of Newton Can Teach Us about the Cultural Context of Science

Science.gov (United States)

Tucci, Pasquale

2015-01-01

Like several scientists, Isaac Newton has been represented many times over many different periods, and portraits of Newton were often commissioned by the scientist himself. These portraits tell us a lot about the scientist, the artist and the cultural context. This article examines two very different portraits of Newton that were realized more…

Extinction produces context inhibition and multiple-context extinction reduces response recovery in human predictive learning.

Science.gov (United States)

Glautier, Steven; Elgueta, Tito; Nelson, James Byron

2013-12-01

Two experiments with human participants were used to investigate recovery of an extinguished learned response after a context change using ABC designs. In an ABC design, the context changes over the three successive stages of acquisition (context A), extinction (context B), and test (context C). In both experiments, we found reduced recovery in groups that had extinction in multiple contexts, and that the extinction contexts acquired inhibitory strength. These results confirm those of previous investigations, that multiple-context extinction can produce less response recovery than single-context extinction, and they also provide new evidence for the involvement of contextual inhibitory processes in extinction in humans. The foregoing results are broadly in line with a protection-from-extinction account of response recovery. Yet, despite the fact that we detected contextual inhibition, predictions based on protection-from-extinction were not fully reliable for the single- and multiple-context group differences that we observed in (1) rates of extinction and (2) the strength of context inhibition. Thus, although evidence was obtained for a protection-from-extinction account of response recovery, this account can not explain all of the data.

Efficacy and short-term outcomes of preoperative chemoradiotherapy with intermittent oral tegafur-uracil plus leucovorin in Japanese rectal cancer patients: a single center experience retrospective analysis.

Science.gov (United States)

Nakagawa, Ryosuke; Inoue, Yuji; Ohki, Takeshi; Kaneko, Yuka; Maeda, Fumi; Yamamoto, Masakazu

2017-05-31

Various types of preoperative chemoradiotherapy (CRT) have been established for rectal cancer; thus, Physicians will need to refine the selection of appropriate preoperative CRT for different patients since there are various treatment regimens. Oral tegafur-uracil (UFT) plus leucovorin (LV) is commonly used to treat rectal cancer in Japan. Oral chemotherapy offers patients many potential advantages. Since 2008, we have been performing preoperative CRT with intermittent oral UFT plus LV in locally advanced rectal cancer patients to prevent postoperative local recurrence. Here, in a retrospective analysis, we evaluated the efficacy and short-term outcomes of preoperative CRT with intermittent oral UFT plus LV. We analyzed data from 62 patients with locally advanced rectal cancer, including 31 patients who underwent preoperative CRT between 2009 and 2013 (the CRT group) and 31 patients who were treated with surgery alone between 2001 and 2008 (the non-CRT group). Clinicopathologically, both groups included patients with rectal cancer at clinical tumor stages III-IV or clinical node stages 0-III. In the CRT group, curative operations were performed ≥8 weeks after CRT. Patients were concomitantly treated with 2 cycles of oral UFT (300 mg/m 2 /day, days 1-14 and 29-42) plus LV (75 mg/day, days 1-14 and 29-42) and 45 Gy of radiotherapy. Chemotherapy was repeated every 28 days, followed by a 2-week break. The completion rate of CRT was high at 94% (n = 29/31). The downstaging rate of CRT was 61% (n = 19/31). The pathological complete response rate was 6.5% (n = 2/31). Significant differences were observed in the 3-year local recurrence rate between the two groups (P rectal cancer. A further investigation of a diversification of preoperative CRT for Japanese rectal cancer patients is required.

Context-awareness and Mobile HCI

DEFF Research Database (Denmark)

Qin, Xiangang; Tan, Chee Wee; Clemmensen, Torkil

2017-01-01

-awareness has been employed broadly in developing applications and services on mobile platform, has had a huge impact on mobile user experience, and has altered the interaction between humans and computers by giving the latter a more active role to play. The significance of context-awareness in the usage......Context-awareness endows mobile devices and services with the capability of interacting with users in an efficient, intelligent, natural and smart fashion. Consequently, context-awareness makes a significant difference to mobile HCI. However, the challenges brought by context-awareness to users...... of mobile devices are rarely examined in depth. In this paper, previous conceptions of context and their contribution to context-awareness in mobile HCI is scrutinized and a preliminary context-computer interaction (CCI) model is advanced to illustrate the interaction characterized by mobile context...

Vestibular nuclei and cerebellum put visual gravitational motion in context.

Science.gov (United States)

Miller, William L; Maffei, Vincenzo; Bosco, Gianfranco; Iosa, Marco; Zago, Myrka; Macaluso, Emiliano; Lacquaniti, Francesco

2008-04-01

Animal survival in the forest, and human success on the sports field, often depend on the ability to seize a target on the fly. All bodies fall at the same rate in the gravitational field, but the corresponding retinal motion varies with apparent viewing distance. How then does the brain predict time-to-collision under gravity? A perspective context from natural or pictorial settings might afford accurate predictions of gravity's effects via the recovery of an environmental reference from the scene structure. We report that embedding motion in a pictorial scene facilitates interception of gravitational acceleration over unnatural acceleration, whereas a blank scene eliminates such bias. Functional magnetic resonance imaging (fMRI) revealed blood-oxygen-level-dependent correlates of these visual context effects on gravitational motion processing in the vestibular nuclei and posterior cerebellar vermis. Our results suggest an early stage of integration of high-level visual analysis with gravity-related motion information, which may represent the substrate for perceptual constancy of ubiquitous gravitational motion.

An Emotion-Enriched Context Influences the Effect of Action Observation on Cortical Excitability

Directory of Open Access Journals (Sweden)

Giovanna Lagravinese

2017-10-01

Full Text Available Observing other people in action activates the “mirror neuron system” that serves for action comprehension and prediction. Recent evidence suggests that this function requires a high level codification triggered not only by components of motor behavior, but also by the environment where the action is embedded. An overlooked component of action perceiving is the one related to the emotional information provided by the context where the observed action takes place. Indeed, whether valence and arousal associated to an emotion might exert an influence on motor system activation during action observation has not been assessed so far. Here, cortico-spinal excitability of the left motor cortex was recorded in three groups of subjects. In the first condition, motor-evoked potential (MEPs were recorded from a muscle involved in the grasping movement (i.e., abductor pollicis brevis, APB while participants were watching the same reach-to-grasp movement embedded in contexts with negative emotional valence, but different levels of arousal: sadness (low arousal, and disgust (high arousal (“Context plus Movement-APB” condition. In the second condition, MEPs were recorded from APB muscle while participants were observing static images representing the contexts in which the movement observed by participants in “Context plus Movement-APB” condition took place (“Context Only-APB” condition. Finally, in the third condition, MEPS were recorded from a muscle not involved in the grasping action, i.e., abductor digiti minimi, ADM, while participants were watching the same videos shown during the “Context plus Movement-APB” condition (“Context plus Movement-ADM” condition. Results showed a greater increase of cortical excitability only during the observation of the hand moving in the context eliciting disgust, and these changes were specific for the muscle involved in the observed action. Our findings show that the emotional context in which a

Camera Motion and Surrounding Scene Appearance as Context for Action Recognition

KAUST Repository

Heilbron, Fabian Caba; Thabet, Ali Kassem; Niebles, Juan Carlos; Ghanem, Bernard

2015-01-01

This paper describes a framework for recognizing human actions in videos by incorporating a new set of visual cues that represent the context of the action. We develop a weak foreground-background segmentation approach in order to robustly extract not only foreground features that are focused on the actors, but also global camera motion and contextual scene information. Using dense point trajectories, our approach separates and describes the foreground motion from the background, represents the appearance of the extracted static background, and encodes the global camera motion that interestingly is shown to be discriminative for certain action classes. Our experiments on four challenging benchmarks (HMDB51, Hollywood2, Olympic Sports, and UCF50) show that our contextual features enable a significant performance improvement over state-of-the-art algorithms.

Camera Motion and Surrounding Scene Appearance as Context for Action Recognition

KAUST Repository

Heilbron, Fabian Caba

2015-04-17

This paper describes a framework for recognizing human actions in videos by incorporating a new set of visual cues that represent the context of the action. We develop a weak foreground-background segmentation approach in order to robustly extract not only foreground features that are focused on the actors, but also global camera motion and contextual scene information. Using dense point trajectories, our approach separates and describes the foreground motion from the background, represents the appearance of the extracted static background, and encodes the global camera motion that interestingly is shown to be discriminative for certain action classes. Our experiments on four challenging benchmarks (HMDB51, Hollywood2, Olympic Sports, and UCF50) show that our contextual features enable a significant performance improvement over state-of-the-art algorithms.

The UNG2 Arg88Cys variant abrogates RPA-mediated recruitment of UNG2 to single-stranded DNA.

Science.gov (United States)

Torseth, Kathrin; Doseth, Berit; Hagen, Lars; Olaisen, Camilla; Liabakk, Nina-Beate; Græsmann, Heidi; Durandy, Anne; Otterlei, Marit; Krokan, Hans E; Kavli, Bodil; Slupphaug, Geir

2012-06-01

In human cell nuclei, UNG2 is the major uracil-DNA glycosylase initiating DNA base excision repair of uracil. In activated B cells it has an additional role in facilitating mutagenic processing of AID-induced uracil at Ig loci and UNG-deficient patients develop hyper-IgM syndrome characterized by impaired class-switch recombination and disturbed somatic hypermutation. How UNG2 is recruited to either error-free or mutagenic uracil processing remains obscure, but likely involves regulated interactions with other proteins. The UNG2 N-terminal domain contains binding motifs for both proliferating cell nuclear antigen (PCNA) and replication protein A (RPA), but the relative contribution of these interactions to genomic uracil processing is not understood. Interestingly, a heterozygous germline single-nucleotide variant leading to Arg88Cys (R88C) substitution in the RPA-interaction motif of UNG2 has been observed in humans, but with unknown functional relevance. Here we demonstrate that UNG2-R88C protein is expressed from the variant allele in a lymphoblastoid cell line derived from a heterozygous germ line carrier. Enzyme activity as well as localization in replication foci of UNG2-R88C was similar to that of WT. However, binding to RPA was essentially abolished by the R88C substitution, whereas binding to PCNA was unaffected. Moreover, we show that disruption of the PCNA-binding motif impaired recruitment of UNG2 to S-phase replication foci, demonstrating that PCNA is a major factor for recruitment of UNG2 to unperturbed replication forks. Conversely, in cells treated with hydroxyurea, RPA mediated recruitment of UNG2 to stalled replication forks independently of functional PCNA binding. Modulation of PCNA- versus RPA-binding may thus constitute a functional switch for UNG2 in cells subsequent to genotoxic stress and potentially also during the processing of uracil at the immunoglobulin locus in antigen-stimulated B cells. Copyright © 2012 Elsevier B.V. All rights

Context-Enabled Business Intelligence

Energy Technology Data Exchange (ETDEWEB)

Troy Hiltbrand

2012-04-01

To truly understand context and apply it in business intelligence, it is vital to understand what context is and how it can be applied in addressing organizational needs. Context describes the facets of the environment that impact the way that end users interact with the system. Context includes aspects of location, chronology, access method, demographics, social influence/ relationships, end-user attitude/ emotional state, behavior/ past behavior, and presence. To be successful in making Business Intelligence content enabled, it is important to be able to capture the context of use user. With advances in technology, there are a number of ways in which this user based information can be gathered and exposed to enhance the overall end user experience.

How different contexts of social capital are associated with self-rated health among Lithuanian high-school students

Science.gov (United States)

Novak, Dario; Emeljanovas, Arunas; Mieziene, Brigita; Štefan, Lovro; Kawachi, Ichiro

2018-01-01

ABSTRACT Background. Adolescents’ self-rated health is related to a number of sociodemographic and socio-economic factors, health-related behaviors, and their social environment. The impact of the latter is still not well explored. An adolescent’s social environment is represented by the social capital, i.e. social resources that they can access. The relationships between various contexts of social capital (family, neighborhood, peers, and school) and self-rated health among adolescents are still unclear. Objective. This study aims to examine the relationships between various social capital contexts and self-rated health in Lithuanian adolescents. Methods. The current cross-sectional study includes a nationally representative sample of 1863 adolescents (51.4% were girls) aged 14–18 years. The indicators of self-rated health as well as indicators of social capital in family, neighborhood, and school contexts were assessed. The results of the relationships between self-rated health and contexts of social capital were calculated controlling for the following covariates: physical activity, psychological distress, gender, body mass index, and family socioeconomic status. Results. Results indicate that there are significant relationships between good self-rated health and a higher level of family support, neighborhood trust, and vertical school trust. In the final logistic regression model, while controlling for all covariates, a higher level of family support and neighborhood trust remain significant predictors of good self-rated health. Conclusions. Family support and neighborhood trust are important correlates of self-rated health in adolescents. PMID:29871556

How different contexts of social capital are associated with self-rated health among Lithuanian high-school students.

Science.gov (United States)

Novak, Dario; Emeljanovas, Arunas; Mieziene, Brigita; Štefan, Lovro; Kawachi, Ichiro

2018-01-01

Adolescents' self-rated health is related to a number of sociodemographic and socio-economic factors, health-related behaviors, and their social environment. The impact of the latter is still not well explored. An adolescent's social environment is represented by the social capital, i.e. social resources that they can access. The relationships between various contexts of social capital (family, neighborhood, peers, and school) and self-rated health among adolescents are still unclear. This study aims to examine the relationships between various social capital contexts and self-rated health in Lithuanian adolescents. The current cross-sectional study includes a nationally representative sample of 1863 adolescents (51.4% were girls) aged 14-18 years. The indicators of self-rated health as well as indicators of social capital in family, neighborhood, and school contexts were assessed. The results of the relationships between self-rated health and contexts of social capital were calculated controlling for the following covariates: physical activity, psychological distress, gender, body mass index, and family socioeconomic status. Results indicate that there are significant relationships between good self-rated health and a higher level of family support, neighborhood trust, and vertical school trust. In the final logistic regression model, while controlling for all covariates, a higher level of family support and neighborhood trust remain significant predictors of good self-rated health. Family support and neighborhood trust are important correlates of self-rated health in adolescents.

[Hearing loss in a cultural-historical context].

Science.gov (United States)

Brosch, S; Pirsig, W

2003-01-01

It is rare to find anything written about hearing loss or its treatment in either representative art or in a medicalhistorical context in ear, nose and throat journals. Examples dating back over the past 4000 years found in medical-historical, philosophical, and literary documents are presented and commented on. The ancient Egyptians and Greeks attempted to explain deafness and sought remedies,making use not only of empiric rational means but also magic and religion. Later, in the Middle Ages, examples from Christian iconography are found demonstrating miracle healing of deafness.Education of the deaf was not considered possible from the time of Aristotle to the sixteenth century, but from then on was organized on a large scale utilizing speech with gestures.

Retention performance of green roofs in representative climates worldwide

Science.gov (United States)

Viola, F.; Hellies, M.; Deidda, R.

2017-10-01

The ongoing process of global urbanization contributes to an increase in stormwater runoff from impervious surfaces, threatening also water quality. Green roofs have been proved to be innovative stormwater management measures to partially restore natural states, enhancing interception, infiltration and evapotranspiration fluxes. The amount of water that is retained within green roofs depends not only on their depth, but also on the climate, which drives the stochastic soil moisture dynamic. In this context, a simple tool for assessing performance of green roofs worldwide in terms of retained water is still missing and highly desirable for practical assessments. The aim of this work is to explore retention performance of green roofs as a function of their depth and in different climate regimes. Two soil depths are investigated, one representing the intensive configuration and another representing the extensive one. The role of the climate in driving water retention has been represented by rainfall and potential evapotranspiration dynamics. A simple conceptual weather generator has been implemented and used for stochastic simulation of daily rainfall and potential evapotranspiration. Stochastic forcing is used as an input of a simple conceptual hydrological model for estimating long-term water partitioning between rainfall, runoff and actual evapotranspiration. Coupling the stochastic weather generator with the conceptual hydrological model, we assessed the amount of rainfall diverted into evapotranspiration for different combinations of annual rainfall and potential evapotranspiration in five representative climatic regimes. Results quantified the capabilities of green roofs in retaining rainfall and consequently in reducing discharges into sewer systems at an annual time scale. The role of substrate depth has been recognized to be crucial in determining green roofs retention performance, which in general increase from extensive to intensive settings. Looking at the

Philosophy of Post-Modernism in Context of Modern Technogenic Problems

Directory of Open Access Journals (Sweden)

O. M. Khramtsova

2005-01-01

Full Text Available The purpose of the given paper is to analyse postmodernist philosophy in the context of modem technogenic problems. The author considers one of the main postmodernist philosophy problems that is the problem of «text» interpretation because narrative strategies are regarded as basic ones in modem technogenic culture. The author analyses some strategies concerning the relation to a text in postmodernist philosophy and reveals a general correlation. The conclusion has been made that postmodernist «text» represents a technogenic image of the world as a combination of non-linear processes.

Teacher Turnover in Organizational Context: Staffing Stability in Los Angeles Charter, Magnet, and Regular Public Schools

Science.gov (United States)

Newton, Xiaoxia A.; Rivero, Rosario; Fuller, Bruce; Dauter, Luke

2018-01-01

Background/Context: Studies that compare the achievement benefits of charter public schools versus traditional public schools (TPSs) yield quite uneven results. The quality and long-term commitment of teachers represent related mediators that may help to explain effective and ineffective charter schools. Early findings on the comparative rates of…

Decision theory, the context for risk and reliability analysis

International Nuclear Information System (INIS)

Kaplan, S.

1985-01-01

According to this model of the decision process then, the optimum decision is that option having the largest expected utility. This is the fundamental model of a decision situation. It is necessary to remark that in order for the model to represent a real-life decision situation, it must include all the options present in that situation, including, for example, the option of not deciding--which is itself a decision, although usually not the optimum one. Similarly, it should include the option of delaying the decision while the authors gather further information. Both of these options have probabilities, outcomes, impacts, and utilities like any option and should be included explicitly in the decision diagram. The reason for doing a quantitative risk or reliability analysis is always that, somewhere underlying there is a decision to be made. The decision analysis therefore always forms the context for the risk or reliability analysis, and this context shapes the form and language of that analysis. Therefore, they give in this section a brief review of the well-known decision theory diagram

Dating of a representative pottery sample from the basin of Sayula, Jalisco in Mexico using the thermoluminescence method

Energy Technology Data Exchange (ETDEWEB)

Mercado U, H. [CINVESTAV, Unidad Monterrey, Nuevo Leon (Mexico); Schaaf, P.; Ramirez, A. [Instituto de Geofisica, UNAM, 04510 Mexico D.F. (Mexico); Gonzalez, P.R. [ININ, 52750 Ocoyoacac, Estado de Mexico (Mexico); Brunet, J. [CUCSH, Universidad de Guadalajara, Jalisco (Mexico)

2006-07-01

In this work is presented a study of dating of the representative pottery sample from the west of Mexico, in a predominantly saline region. The study is carried out with the thermoluminescence method and the fine grain technique. The archaeological region was begun to study from 1990. This work also presents an historical and geographical context of the region and its relevance in the western culture of Mexico. (Author)

Dating of a representative pottery sample from the basin of Sayula, Jalisco in Mexico using the thermoluminescence method

International Nuclear Information System (INIS)

Mercado U, H.; Schaaf, P.; Ramirez, A.; Gonzalez, P.R.; Brunet, J.

2006-01-01

In this work is presented a study of dating of the representative pottery sample from the west of Mexico, in a predominantly saline region. The study is carried out with the thermoluminescence method and the fine grain technique. The archaeological region was begun to study from 1990. This work also presents an historical and geographical context of the region and its relevance in the western culture of Mexico. (Author)

Academic Success in Context-Based Chemistry: Demonstrating Fluid Transitions between Concepts and Context

Science.gov (United States)

King, Donna Therese; Ritchie, Stephen M.

2013-01-01

Curriculum developers and researchers have promoted context-based programmes to arrest waning student interest and participation in the enabling sciences at high school and university. Context-based programmes aim for student connections between scientific discourse and real-world contexts to elevate curricular relevance without diminishing…

Measuring School Contexts

Directory of Open Access Journals (Sweden)

Chandra L. Muller PhD

2015-11-01

Full Text Available This article describes issues in measuring school contexts with an eye toward understanding students’ experiences and outcomes. I begin with an overview of the conceptual underpinnings related to measuring contexts, briefly describe the initiatives at the National Center for Education Statistics to measure school contexts, and identify possible gaps in those initiatives that if filled could provide valuable new data for researchers. Next, I discuss new approaches and opportunities for measurement, and special considerations related to diverse populations and youth development. I conclude with recommendations for future priorities.

Knowledge Worker Mobility in Context

DEFF Research Database (Denmark)

Wright, Mike; Tartari, Valentina; Huang, Kenneth G.

2018-01-01

on advancing our understanding of KWM in context, pushing the boundaries of theory and methods by developing a framework focusing on five main contextual dimensions: organizational context and roles, geographical and spatial context, social context and teams, institutional and cultural norms, and temporal...

THE MOUNTAIN REGIONS IN CONTEXT OF STRATEGY 2020

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ANTONESCU Daniela

2014-07-01

Full Text Available The mountain regions in Romania and European Union represent a special territory of interest, with a huge economic, social, environmental and cultural potential. More, mountain area is considerate a natural-economic region and constitutes an important objective for regional development policy. The main sectors of mountain area are presented in agriculture and tourism fields that lead the key role in safeguarding the sensitive eco-system and thereby maintaining the general living and working space.Mountain areas should have a specific policy defined by the sustainable development principle, which meets the needs of the present without compromising the opportunities of future generations. The specific mountain policy aims to reduce the imbalance between favored and disadvantaged mountain regions, permanently marked by natural, economic, social, cultural and environmental constraints. In previous programming period, mountain regions among have profited from the intensive regional support, in specially, for constructing of and connecting them to fresh water and waste water networks, in particular for increasing of life quality. In context of 2020 Strategy, the Member States will concentrate investments on a small number of thematic objectives. In advanced regions, 60 % of funds will used for only two of these objectives (competitiveness of SME and research/innovation. The all less developed regions will received about 50% of Structural Funds In Romania, mountain representing 29.93% out of the total national surface and 20.14% from UAA (Utilised Agricultural Area of total national. The mountain territory has around 20% of the national population and is overlapping almost 100% with the Carpathian Mountains. Due to these conditions, Romania's regional development policy must take into account the specificities of mountain area, the problems they faced, and the requirements of 2020 Strategy.This paper presents the main aspects to be taken into account

Representing Development

DEFF Research Database (Denmark)

Representing Development presents the different social representations that have formed the idea of development in Western thinking over the past three centuries. Offering an acute perspective on the current state of developmental science and providing constructive insights into future pathways, ...

Representing dispositions

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Röhl Johannes

2011-08-01

Full Text Available Abstract Dispositions and tendencies feature significantly in the biomedical domain and therefore in representations of knowledge of that domain. They are not only important for specific applications like an infectious disease ontology, but also as part of a general strategy for modelling knowledge about molecular interactions. But the task of representing dispositions in some formal ontological systems is fraught with several problems, which are partly due to the fact that Description Logics can only deal well with binary relations. The paper will discuss some of the results of the philosophical debate about dispositions, in order to see whether the formal relations needed to represent dispositions can be broken down to binary relations. Finally, we will discuss problems arising from the possibility of the absence of realizations, of multi-track or multi-trigger dispositions and offer suggestions on how to deal with them.

Theory and context / Theory in context

DEFF Research Database (Denmark)

Glaveanu, Vlad Petre

2014-01-01

trans-disciplinary manner. Consideration needs to be given as well to connected scholarship focusing on imagination, innova-tion, and improvisation. Last but not least, an expanded the-ory of context cannot ignore the institutional context of doing research on creativity. Creativity scholars are facing......It is debatable whether the psychology of creativity is a field in crisis or not. There are clear signs of increased fragmenta-tion and a scarcity of integrative efforts, but is this necessari-ly bad? Do we need more comprehensive theories of creativ-ity and a return to old epistemological...... questions? This de-pends on how one understands theory. Against a view of theoretical work as aiming towards generality, universality, uniformity, completeness, and singularity, I advocate for a dynamic perspective in which theory is plural, multifaceted, and contextual. Far from ‘waiting for the Messiah...

Quantifying Heuristic Bias: Anchoring, Availability, and Representativeness.

Science.gov (United States)

Richie, Megan; Josephson, S Andrew

2018-01-01

significance for students (Version A, M = 7.28, SD = 3.46; Version B, M = 5.82, SD = 3.22), t(153) = 2.67, p = .008, and residents (Version A, M = 7.19, SD = 3.24; Version B, M = 5.56, SD = 2.72), t(77) = 2.32, p = .02, but not attendings. Authors developed an instrument to isolate and quantify bias produced by the availability and representativeness heuristics, and illustrated the utility of their instrument by demonstrating decreased heuristic bias within medical contexts at higher training levels.

Collaborative testing for key-term definitions under representative conditions: Efficiency costs and no learning benefits.

Science.gov (United States)

Wissman, Kathryn T; Rawson, Katherine A

2018-01-01

Students are expected to learn key-term definitions across many different grade levels and academic disciplines. Thus, investigating ways to promote understanding of key-term definitions is of critical importance for applied purposes. A recent survey showed that learners report engaging in collaborative practice testing when learning key-term definitions, with outcomes also shedding light on the way in which learners report engaging in collaborative testing in real-world contexts (Wissman & Rawson, 2016, Memory, 24, 223-239). However, no research has directly explored the effectiveness of engaging in collaborative testing under representative conditions. Accordingly, the current research evaluates the costs (with respect to efficiency) and the benefits (with respect to learning) of collaborative testing for key-term definitions under representative conditions. In three experiments (ns = 94, 74, 95), learners individually studied key-term definitions and then completed retrieval practice, which occurred either individually or collaboratively (in dyads). Two days later, all learners completed a final individual test. Results from Experiments 1-2 showed a cost (with respect to efficiency) and no benefit (with respect to learning) of engaging in collaborative testing for key-term definitions. Experiment 3 evaluated a theoretical explanation for why collaborative benefits do not emerge under representative conditions. Collectively, outcomes indicate that collaborative testing versus individual testing is less effective and less efficient when learning key-term definitions under representative conditions.

40 CFR 60.4112 - Changing Hg designated representative and alternate Hg designated representative; changes in...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Changing Hg designated representative and alternate Hg designated representative; changes in owners and operators. 60.4112 Section 60.4112... Generating Units Hg Designated Representative for Hg Budget Sources § 60.4112 Changing Hg designated...

Grammars with two-sided contexts

Directory of Open Access Journals (Sweden)

Mikhail Barash

2014-05-01

Full Text Available In a recent paper (M. Barash, A. Okhotin, "Defining contexts in context-free grammars", LATA 2012, the authors introduced an extension of the context-free grammars equipped with an operator for referring to the left context of the substring being defined. This paper proposes a more general model, in which context specifications may be two-sided, that is, both the left and the right contexts can be specified by the corresponding operators. The paper gives the definitions and establishes the basic theory of such grammars, leading to a normal form and a parsing algorithm working in time O(n^4, where n is the length of the input string.

Dictionary Networking in an LSP Learning Context

DEFF Research Database (Denmark)

Nielsen, Sandro

2007-01-01

text production, but discusses an individual dictionary for a particular function. It is shown that in a general context of learning accounting and its relevant LSP with a view to writing or translating financial reporting texts, the modern theory of dictionary functions provides a good theoretical...... and usage of a subject-field, particularly when they have to read, write or translate domain-specific texts. The modern theory of dictionary functions presented in Bergenholtz and Tarp (2002) opens up exciting new possibilities for theoretical and practical lexicography and encourages lexicographers......-lexicographic environment, i.e. what happens outside the dictionary when users write or translate texts, and relate these findings to the lexicographic environment represented by the theoretical basis and the dictionary itself. Nielsen (2006) gives a preliminary discussion of monolingual accounting dictionaries for EFL...

Guest editor's introduction: Energy homeostasis in context.

Science.gov (United States)

Schneider, Jill E

2014-06-01

This article is part of a Special Issue "Energy Balance". Energy homeostasis is achieved through neuroendocrine and metabolic control of energy intake, storage, and expenditure. Traditionally, these controls have been studied in an unrealistic and narrow context. The appetite for food, for example, is most often assumed to be independent of other motivations, such as sexual desire, fearfulness, and competition. Furthermore, our understanding of all aspects of energy homeostasis is based on studying males of only a few species. The baseline control subjects are most often housed in enclosed spaces, with continuous, unlimited access to food. In the last century, this approach has generated useful information, but all the while, the global prevalence of obesity has increased and remains at unprecedented levels (Ogden et al., 2013, 2014). It is likely, however, that the mechanisms that control ingestive behavior were molded by evolutionary forces, and that few, if any vertebrate species evolved in the presence of a limitless food supply, in an enclosed 0.5 × 1 ft space, and exposed to a constant ambient temperature of 22+2 °C. This special issue of Hormones and Behavior therefore contains 9 review articles and 7 data articles that consider energy homeostasis within the context of other motivations and physiological processes, such as early development, sexual differentiation, sexual motivation, reproduction, seasonality, hibernation, and migration. Each article is focused on a different species or on a set of species, and most vertebrate classes are represented. Energy homeostasis is viewed in the context of the selection pressures that simultaneously molded multiple aspects of energy intake, storage, and expenditure. This approach yields surprising conclusions regarding the function of those traits and their underlying neuroendocrine mechanisms. Copyright © 2014. Published by Elsevier Inc.

SPP Toolbox: Supporting Sustainable Public Procurement in the Context of Socio-Technical Transitions

Directory of Open Access Journals (Sweden)

Paula Cayolla Trindade

2017-12-01

Full Text Available Public procurement can shape production and consumption trends and represents a stimulus for both innovation and diversification in products and services, through a direct increase in demand. In recent years, the interest in demand-side policies has grown and several approaches have emerged, such as Green Public Procurement (GPP, Sustainable Public Procurement (SPP and Public Procurement of Innovation (PPI, representing strategic goals to be achieved through public procurement. In this context, there is a need to guide and support public organizations in the uptake of GPP, SPP and PPI practices. To respond to the challenges raised by the operationalization of such strategies, this paper proposes a new tool—the SPP Toolbox—for guiding public organizations as they re-think the procurement process, raising their ambitions and broadening their vision, thus changing the organizational approach towards culture, strategies, structures and practices. This toolbox integrates insights from GPP, SPP and PPI objectives and practices, in the context of the emergence of socio-technical transitions. The toolbox coherently links GPP, SPP and PPI, allowing flexibility in terms of goals, yet promoting an increasing complexity of institutionalized practices and skills—from GPP to SPP and then from SPP to PPI, organized in a framework fully integrated into the organizational strategy.

5-Fluorouracil-resistant strain of Methanobacterium thermoautortrophicum

International Nuclear Information System (INIS)

Nagle, D.P. Jr.; Teal, R.; Eisenbraun, A.

1987-01-01

Growth of Methanobacterium thermoautotrophicum Marburg is inhibited by the pyrimidine, 5-fluorouracil (FU). It was shown previously that methanogenesis is not inhibited to the same extent as growth. A spontaneously occurring FU-resistant strain (RTAE-1) was isolated from a culture of strain Marburg. The growth of both strains was inhibited by 5-fluorodeoxyuridine but not 5-fluorocytosine, and the wild type was more susceptible to inhibition by 5-azauracil and 6-azauracil than was strain RTAE-1. The cellular targets for the pyrimidine analogs are not known. When the accumulation of 14 C-labeled uracil or FU by the two strains was compared, the wilt type took up 15-fold more radiolabel per cell than did the FU-resistant strain. In the wild type, radiolabel from uracil was incorporated into the soluble pool, RNA, and DNA. The metabolism of uracil appeared to involve a uracil phosphoribosyltransferase activity. Strain Marburg extracts contained this enzyme, whereas FU-resistant strain RTAE-1 extracts had less than 1/10 as much activity. Although it is possible that a change in permeability to the compounds plays a role in the stable resistance of strain RTAE-1, the fact that it lacks the ability to metabolize pyrimidines to nucleotides is sufficient to account for its phenotype

5-Fluorouracil-resistant strain of Methanobacterium thermoautotrophicum.

Science.gov (United States)

Nagle, D P; Teal, R; Eisenbraun, A

1987-09-01

Growth of Methanobacterium thermoautotrophicum Marburg is inhibited by the pyrimidine, 5-fluorouracil (FU). It was shown previously that methanogenesis is not inhibited to the same extent as growth. A spontaneously occurring FU-resistant strain (RTAE-1) was isolated from a culture of strain Marburg. The growth of both strains was inhibited by 5-fluorodeoxyuridine but not 5-fluorocytosine, and the wild type was more susceptible to inhibition by 5-azauracil and 6-azauracil than was strain RTAE-1. The cellular targets for the pyrimidine analogs are not known. When the accumulation of 14C-labeled uracil or FU by the two strains was compared, the wild type took up 15-fold more radiolabel per cell than did the FU-resistant strain. In the wild type, radiolabel from uracil was incorporated into the soluble pool, RNA, and DNA. The metabolism of uracil appeared to involve a uracil phosphoribosyltransferase activity. Strain Marburg extracts contained this enzyme, whereas FU-resistant strain RTAE-1 extracts had less than 1/10 as much activity. Although it is possible that a change in permeability to the compounds plays a role in the stable resistance of strain RTAE-1, the fact that it lacks the ability to metabolize pyrimidines to nucleotides is sufficient to account for its phenotype.

Context-dependent Generalization

Directory of Open Access Journals (Sweden)

Jordan A Taylor

2013-05-01

Full Text Available The pattern of generalization following motor learning can provide a probe on the neural mechanisms underlying learning. For example, the breadth of generalization to untrained regions of space after visuomotor adaptation to targets in a restricted region of space has been attributed to the directional tuning properties of neurons in the motor system. Building on this idea, the effect of different types of perturbations on generalization (e.g., rotation versus visual translation have been attributed to the selection of differentially tuned populations. Overlooked in this discussion is consideration of how the context of the training environment may constrain generalization. Here, we explore the role of context by having participants learn a visuomotor rotation or a translational shift in two different contexts, one in which the array of targets were presented in a circular arrangement and the other in which they were presented in a rectilinear arrangement. The perturbation and environments were either consistent (e.g., rotation with circular arrangement or inconsistent (e.g., rotation with rectilinear arrangement. The pattern of generalization across the workspace was much more dependent on the context of the environment than on the perturbation, with broad generalization for the rectilinear arrangement for both types of perturbations. Moreover, the generalization pattern for this context was evident, even when the perturbation was introduced in a gradual manner, precluding the use of an explicit strategy. We describe how current models of generalization might be modified to incorporate these results, building on the idea that context provides a strong bias for how the motor system infers the nature of the visuomotor perturbation and, in turn, how this information influences the pattern of generalization.

A complementary marriage of perspectives: understanding organizational social context using mixed methods.

Science.gov (United States)

Beidas, Rinad S; Wolk, Courtney L Benjamin; Walsh, Lucia M; Evans, Arthur C; Hurford, Matthew O; Barg, Frances K

2014-11-23

Organizational factors impact the delivery of mental health services in community settings. Mixed-methods analytic approaches have been recommended, though little research within implementation science has explicitly compared inductive and deductive perspectives to understand their relative value in understanding the same constructs. The purpose of our study is to use two different paradigmatic approaches to deepen our understanding of organizational social context. We accomplish this by using a mixed-methods approach in an investigation of organizational social context in community mental health clinics. Nineteen agencies, representing 23 sites, participated. Enrolled participants included 130 therapists, 36 supervisors, and 22 executive administrators. Quantitative data was obtained via the Organizational Social Context (OSC) measure. Qualitative data, comprised of direct observation with spot sampling generated from agency visits, was coded using content analysis and grounded theory. The present study examined elements of organizational social context that would have been missed if only quantitative data had been obtained and utilized mixed methods to investigate if stratifying observations based on quantitative ratings from the OSC resulted in the emergence of differential themes. Four of the six OSC constructs were commonly observed in field observations (i.e., proficiency, rigidity, functionality, stress), while the remaining two constructs were not frequently observed (i.e., resistance, engagement). Constructs emerged related to organizational social context that may have been missed if only quantitative measurement was employed, including those around the physical environment, commentary about evidence-based practice initiatives, leadership, cultural diversity, distrust, and affect. Stratifying agencies by "best," "average," and "worst" organizational social context impacted interpretation for three constructs (affect, stress, and leadership). Results

Context Sensitive Health Informatics

DEFF Research Database (Denmark)

Kuziemsky, Craig; Nøhr, Christian; Aarts, Jos

2013-01-01

Context is a key consideration when designing and evaluating health information technology (HIT) and cannot be overstated. Unintended consequences are common post HIT implementation and even well designed technology may not achieve desired outcomes because of contextual issues. While context should...... be considered in the design and evaluation of health information systems (HISs) there is a shortcoming of empirical research on contextual aspects of HIT. This conference integrates the sociotechnical and Human-Centered-Design (HCD) approaches and showcases current research on context sensitive health...... informatics. The papers and presentations outlines theories and models for studying contextual issues and insights on how we can better design HIT to accommodate different healthcare contexts....

Flow motifs reveal limitations of the static framework to represent human interactions

Science.gov (United States)

Rocha, Luis E. C.; Blondel, Vincent D.

2013-04-01

Networks are commonly used to define underlying interaction structures where infections, information, or other quantities may spread. Although the standard approach has been to aggregate all links into a static structure, some studies have shown that the time order in which the links are established may alter the dynamics of spreading. In this paper, we study the impact of the time ordering in the limits of flow on various empirical temporal networks. By using a random walk dynamics, we estimate the flow on links and convert the original undirected network (temporal and static) into a directed flow network. We then introduce the concept of flow motifs and quantify the divergence in the representativity of motifs when using the temporal and static frameworks. We find that the regularity of contacts and persistence of vertices (common in email communication and face-to-face interactions) result on little differences in the limits of flow for both frameworks. On the other hand, in the case of communication within a dating site and of a sexual network, the flow between vertices changes significantly in the temporal framework such that the static approximation poorly represents the structure of contacts. We have also observed that cliques with 3 and 4 vertices containing only low-flow links are more represented than the same cliques with all high-flow links. The representativity of these low-flow cliques is higher in the temporal framework. Our results suggest that the flow between vertices connected in cliques depend on the topological context in which they are placed and in the time sequence in which the links are established. The structure of the clique alone does not completely characterize the potential of flow between the vertices.

Context-aware system for pre-triggering irreversible vehicle safety actuators.

Science.gov (United States)

Böhmländer, Dennis; Dirndorfer, Tobias; Al-Bayatti, Ali H; Brandmeier, Thomas

2017-06-01

New vehicle safety systems have led to a steady improvement of road safety and a reduction in the risk of suffering a major injury in vehicle accidents. A huge leap forward in the development of new vehicle safety systems are actuators that have to be activated irreversibly shortly before a collision in order to mitigate accident consequences. The triggering decision has to be based on measurements of exteroceptive sensors currently used in driver assistance systems. This paper focuses on developing a novel context-aware system designed to detect potential collisions and to trigger safety actuators even before an accident occurs. In this context, the analysis examines the information that can be collected from exteroceptive sensors (pre-crash data) to predict a certain collision and its severity to decide whether a triggering is entitled or not. A five-layer context-aware architecture is presented, that is able to collect contextual information about the vehicle environment and the actual driving state using different sensors, to perform reasoning about potential collisions, and to trigger safety functions upon that information. Accident analysis is used in a data model to represent uncertain knowledge and to perform reasoning. A simulation concept based on real accident data is introduced to evaluate the presented system concept. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rich context information for just-in-time adaptive intervention promoting physical activity.

Science.gov (United States)

Cruciani, F; Nugent, C; Cleland, I; McCullagh, P

2017-07-01

Sedentary lifestyle and inadequate levels of physical activity represent two serious health risk factors. Nevertheless, within developed countries, 60% of people aged over 60 are deemed to be sedentary. Consequently, interest in behavior change to promote physical activity is increasing. In particular, the role of emerging mobile apps to facilitate behavior change has shown promising results. Smart technologies can help in providing rich context information including an objective assessment of the level of physical activity and information on the emotional and physiological state of the person. Collectively, this can be used to develop innovative persuasive solutions for adaptive behavior change. Such solutions offer potential in reducing levels of sedentary behavior. This work presents a study exploring new ways of employing smart technologies to facilitate behavior change. It is achieved by means of (i) developing a knowledge base on sedentary behaviors and recommended physical activity guidelines, and (ii) a context model able to combine information on physical activity, location, and a user's diary to develop a context-aware virtual coach with the ability to select the most appropriate behavior change strategy on a case by case basis.

Concepts of context in music therapy.

Science.gov (United States)

Rolvsjord, Randi; Stige, Brynjulf

2015-01-02

In contemporary music therapy as well as in related interdisciplinary fields, the importance of context in relation to theory, research, and practice has been emphasized. However, the word context seems to be used in several different ways and conceptualizations of contextual approaches vary too. The objective of this theoretical article is to clarify traditions of language use in relation to context in music therapy. In reviewing and discussing the literature, we focus on the field of mental health care. When discussing issues related to context, this literature partly focuses on the surroundings of music therapy practice, partly on the ecology of reciprocal influences within and between situations or systems. On this basis, three types of context awareness in music therapy are identified: music therapy in context; music therapy as context; and music therapy as interacting contexts. The identified types of context awareness are exemplified through references to music therapy literature and then discussed in relation to two very different metaphors, namely context as frame and context as link. Implications for practice, research, and theory development in music therapy are suggested.

Concepts of context in music therapy

Science.gov (United States)

Rolvsjord, Randi; Stige, Brynjulf

2015-01-01

In contemporary music therapy as well as in related interdisciplinary fields, the importance of context in relation to theory, research, and practice has been emphasized. However, the word context seems to be used in several different ways and conceptualizations of contextual approaches vary too. The objective of this theoretical article is to clarify traditions of language use in relation to context in music therapy. In reviewing and discussing the literature, we focus on the field of mental health care. When discussing issues related to context, this literature partly focuses on the surroundings of music therapy practice, partly on the ecology of reciprocal influences within and between situations or systems. On this basis, three types of context awareness in music therapy are identified: music therapy in context; music therapy as context; and music therapy as interacting contexts. The identified types of context awareness are exemplified through references to music therapy literature and then discussed in relation to two very different metaphors, namely context as frame and context as link. Implications for practice, research, and theory development in music therapy are suggested. PMID:26157199

Microglia in Alzheimer's Disease: It's All About Context

Directory of Open Access Journals (Sweden)

Tara M. Weitz

2012-01-01

Full Text Available Neuroinflammation is now regarded as both an early event and prime mover in the pathobiology of Alzheimer disease (AD, a neurodegenerative disease that represents a growing public health threat. As the resident innate immune cells within the central nervous system, microglia are centrally positioned as key orchestrators of brain inflammation. It is now accepted that numerous forms of activated microglia exist. Furthermore, while some types of reactive microglia are detrimental, others can actually be beneficial. In the context of AD etiopathology, much debate surrounds whether these enigmatic cells play “good” or “bad” roles. In this article, we distill a complex clinical and experimental literature focused on the contribution of microglia to AD pathology and progression. A synthesis of the literature only seems possible when considering context– the conditions under which microglia encounter and mount immunological responses to AD pathology. In order to carry out these diverse contextual responses, a number of key receptors and signaling pathways are variously activated. It will be critically important for future studies to address molecular mediators that lead to beneficial microglial responses and therefore represent important therapeutic targets for AD.

GPU-BSM: a GPU-based tool to map bisulfite-treated reads.

Directory of Open Access Journals (Sweden)

Andrea Manconi

Full Text Available Cytosine DNA methylation is an epigenetic mark implicated in several biological processes. Bisulfite treatment of DNA is acknowledged as the gold standard technique to study methylation. This technique introduces changes in the genomic DNA by converting cytosines to uracils while 5-methylcytosines remain nonreactive. During PCR amplification 5-methylcytosines are amplified as cytosine, whereas uracils and thymines as thymine. To detect the methylation levels, reads treated with the bisulfite must be aligned against a reference genome. Mapping these reads to a reference genome represents a significant computational challenge mainly due to the increased search space and the loss of information introduced by the treatment. To deal with this computational challenge we devised GPU-BSM, a tool based on modern Graphics Processing Units. Graphics Processing Units are hardware accelerators that are increasingly being used successfully to accelerate general-purpose scientific applications. GPU-BSM is a tool able to map bisulfite-treated reads from whole genome bisulfite sequencing and reduced representation bisulfite sequencing, and to estimate methylation levels, with the goal of detecting methylation. Due to the massive parallelization obtained by exploiting graphics cards, GPU-BSM aligns bisulfite-treated reads faster than other cutting-edge solutions, while outperforming most of them in terms of unique mapped reads.

Context reinstatement and memory for intrinsic versus extrinsic context: the role of item generation at encoding or retrieval.

Science.gov (United States)

Nieznański, Marek

2014-10-01

According to many theoretical accounts, reinstating study context at the time of test creates optimal circumstances for item retrieval. The role of context reinstatement was tested in reference to context memory in several experiments. On the encoding phase, participants were presented with words printed in two different font colors (intrinsic context) or two different sides of the computer screen (extrinsic context). At test, the context was reinstated or changed and participants were asked to recognize words and recollect their study context. Moreover, a read-generate manipulation was introduced at encoding and retrieval, which was intended to influence the relative salience of item and context information. The results showed that context reinstatement had no effect on memory for extrinsic context but affected memory for intrinsic context when the item was generated at encoding and read at test. These results supported the hypothesis that context information is reconstructed at retrieval only when context was poorly encoded at study. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Context matters!

DEFF Research Database (Denmark)

Bojesen, Anders

2004-01-01

for granted and unproblematic, although it is agreed to be of great importance. By crystallising three different modes of contextualised competence thinking (prescriptive, descriptive and analytical) the paper shows that the underlying assumptions about context - the interaction between the individual...... and the social - has major consequences for the specific enactment of competence. The paper argues in favour of a second order observation strategy for the context of competence. But in doing so it also shows that prevailing second-order competence theories so far, in criticising (counter) positions (and...

Context-specific metabolic networks are consistent with experiments.

Directory of Open Access Journals (Sweden)

Scott A Becker

2008-05-01

Full Text Available Reconstructions of cellular metabolism are publicly available for a variety of different microorganisms and some mammalian genomes. To date, these reconstructions are "genome-scale" and strive to include all reactions implied by the genome annotation, as well as those with direct experimental evidence. Clearly, many of the reactions in a genome-scale reconstruction will not be active under particular conditions or in a particular cell type. Methods to tailor these comprehensive genome-scale reconstructions into context-specific networks will aid predictive in silico modeling for a particular situation. We present a method called Gene Inactivity Moderated by Metabolism and Expression (GIMME to achieve this goal. The GIMME algorithm uses quantitative gene expression data and one or more presupposed metabolic objectives to produce the context-specific reconstruction that is most consistent with the available data. Furthermore, the algorithm provides a quantitative inconsistency score indicating how consistent a set of gene expression data is with a particular metabolic objective. We show that this algorithm produces results consistent with biological experiments and intuition for adaptive evolution of bacteria, rational design of metabolic engineering strains, and human skeletal muscle cells. This work represents progress towards producing constraint-based models of metabolism that are specific to the conditions where the expression profiling data is available.

Context factors in general practitioner - patient encounters and their impact on assessing communication skills - an exploratory study

Science.gov (United States)

2013-01-01

Background Assessment of medical communication performance usually focuses on rating generically applicable, well-defined communication skills. However, in daily practice, communication is determined by (specific) context factors, such as acquaintance with the patient, or the presented problem. Merely valuing the presence of generic skills may not do justice to the doctor’s proficiency. Our aim was to perform an exploratory study on how assessment of general practitioner (GP) communication performance changes if context factors are explicitly taken into account. Methods We used a mixed method design to explore how ratings would change. A random sample of 40 everyday GP consultations was used to see if previously identified context factors could be observed again. The sample was rated twice using a widely used assessment instrument (the MAAS-Global), first in the standard way and secondly after context factors were explicitly taken into account, by using a context-specific rating protocol to assess communication performance in the workplace. In between first and second rating, the presence of context factors was established. Item score differences were calculated using paired sample t-tests. Results In 38 out of 40 consultations, context factors prompted application of the context-specific rating protocol. Mean overall score on the 7-point MAAS-Global scale increased from 2.98 in standard to 3.66 in the context-specific rating (p communication was set at 3.17. Conclusions Applying the protocol, the mean overall score rose above the level set in an earlier study for the MAAS-Global scores to represent ‘adequate GP communication behaviour’. Our findings indicate that incorporating context factors in communication assessment thus makes a meaningful difference and shows that context factors should be considered as ‘signal’ instead of ‘noise’ in GP communication assessment. Explicating context factors leads to a more deliberate and transparent rating of

Context factors in general practitioner-patient encounters and their impact on assessing communication skills--an exploratory study.

Science.gov (United States)

Essers, Geurt; Kramer, Anneke; Andriesse, Boukje; van Weel, Chris; van der Vleuten, Cees; van Dulmen, Sandra

2013-05-22

Assessment of medical communication performance usually focuses on rating generically applicable, well-defined communication skills. However, in daily practice, communication is determined by (specific) context factors, such as acquaintance with the patient, or the presented problem. Merely valuing the presence of generic skills may not do justice to the doctor's proficiency.Our aim was to perform an exploratory study on how assessment of general practitioner (GP) communication performance changes if context factors are explicitly taken into account. We used a mixed method design to explore how ratings would change. A random sample of 40 everyday GP consultations was used to see if previously identified context factors could be observed again. The sample was rated twice using a widely used assessment instrument (the MAAS-Global), first in the standard way and secondly after context factors were explicitly taken into account, by using a context-specific rating protocol to assess communication performance in the workplace. In between first and second rating, the presence of context factors was established. Item score differences were calculated using paired sample t-tests. In 38 out of 40 consultations, context factors prompted application of the context-specific rating protocol. Mean overall score on the 7-point MAAS-Global scale increased from 2.98 in standard to 3.66 in the context-specific rating (pcommunication was set at 3.17. Applying the protocol, the mean overall score rose above the level set in an earlier study for the MAAS-Global scores to represent 'adequate GP communication behaviour'. Our findings indicate that incorporating context factors in communication assessment thus makes a meaningful difference and shows that context factors should be considered as 'signal' instead of 'noise' in GP communication assessment. Explicating context factors leads to a more deliberate and transparent rating of GP communication performance.

The pharmaceutical sales rep/physician relationship in Turkey: ethical issues in an international context.

Science.gov (United States)

Tengilimoglu, Dilaver; Kisa, Adnan; Ekiyor, Aykut

2004-01-01

In many developed countries, the physician/pharmaceutical sales representative relationship has increasingly become the focus of ethical questions. Given this context, the purpose of the present study was to determine the ethical dilemmas faced by pharmaceutical sales representatives in Turkey in their relations with physicians, and to identify possible solutions. Through an investigator-designed questionnaire, the ethical problems perceived by 215 pharmaceutical sales representatives were quantitatively analyzed. Nearly all of the participants (96.7%) reported that they had faced ethical dilemmas in marketing drugs to physicians. The most commonly reported problems included paramedical requests (for free lab test kits, etc.) and the necessity of bargaining with physicians over the use of their firm's drugs by offering gifts and sponsorships. The participants in the study felt that physicians were the primary source of ethical problems in the marketing of drugs, and the participants' most highly ranked potential solution to these ethical problems was a better understanding, on the part of physicians, of the role of pharmaceutical sales representatives. At the end of this study, suggestions are given with a view to helping health policy makers understand and address the current controversies involving drug company representatives and physicians.

Caliper Context Annotation Library

Energy Technology Data Exchange (ETDEWEB)

2015-09-30

To understand the performance of parallel programs, developers need to be able to relate performance measurement data with context information, such as the call path / line numbers or iteration numbers where measurements were taken. Caliper provides a generic way to specify and collect multi-dimensional context information across the software stack, and provide ti to third-party measurement tools or write it into a file or database in the form of context streams.

Political, religious and occupational identities in context: placing identity status paradigm in context.

Science.gov (United States)

Solomontos-Kountouri, Olga; Hurry, Jane

2008-04-01

This study critically contrasts global identity with domain-specific identities (political, religious and occupational) and considers context and gender as integral parts of identity. In a cross-sectional survey, 1038 Greek Cypriot adolescents (449 boys and 589 girls, mean age 16.8) from the three different types of secondary schools (state, state technical and private) and from different SES completed part of the Extended Objective Measure of Ego Identity Status-2 (EOMEIS-2). The macro-context of Greek Cypriot society is used to understand the role of context in adolescents' identities. Results showed that Greek Cypriot young people were not in the same statuses across their global, political, religious and occupational identities. This heterogeneity in the status of global identity and of each identity domain is partially explained by differences in gender, type of school and SES (socio-economic status). The fact that identity status is found to be reactive to context suggests that developmental stage models of identity status should place greater emphasis on context.

Context Sensitive Health Informatics

DEFF Research Database (Denmark)

involves careful consideration of both human and organizational factors. This book presents the proceedings of the Context Sensitive Health Informatics (CSHI) conference, held in Copenhagen, Denmark, in August 2013. The theme of this year’s conference is human and sociotechnical approaches. The Human...... different healthcare contexts. Healthcare organizations, health policy makers and regulatory bodies globally are starting to acknowledge this essential role of human and organizational factors for safe and effective health information technology. This book will be of interest to all those involved......Healthcare information technologies are now routinely deployed in a variety of healthcare contexts. These contexts differ widely, but the smooth integration of IT systems is crucial, so the design, implementation, and evaluation of safe, effective, efficient and easy to adopt health informatics...

Disrupting the memory of places induced by drugs of abuse weakens motivational withdrawal in a context-dependent manner.

Science.gov (United States)

Taubenfeld, Stephen M; Muravieva, Elizaveta V; Garcia-Osta, Ana; Alberini, Cristina M

2010-07-06

Addicts repeatedly relapse to drug seeking even after years of abstinence, and this behavior is frequently induced by the recall of memories of the rewarding effects of the drug. Established memories, including those induced by drugs of abuse, can become transiently fragile if reactivated, and during this labile phase, known as reconsolidation, can be persistently disrupted. Here we show that, in rats, a morphine-induced place preference (mCPP) memory is linked to context-dependent withdrawal as disrupting the reconsolidation of the memory leads to a significant reduction of withdrawal evoked in the same context. Moreover, the hippocampus plays a critical role in linking the place preference memory with the context-conditioned withdrawal, as disrupting hippocampal protein synthesis and cAMP-dependent-protein kinase A after the reactivation of mCPP significantly weakens the withdrawal. Hence, targeting memories induced by drugs may represent an important strategy for attenuating context-conditioned withdrawal and therefore subsequent relapse in opiate addicts.

INFORMATION AND KNOWLEDGE IN A GLOBAL CONTEXT

Directory of Open Access Journals (Sweden)

Florina BRAN

2015-12-01

Full Text Available Information and knowledge are two important entities, which make up present stage of globalization, based mostly on their dynamics. This paper is providing an overview of information and knowledge in global context, highlighting the importance of information society that turned into knowledge society in the beginning of the 21 century, being driven by Internet – the latter, as part of globalization process. Modern economic theories recognise the importance of information in economic process because its impact on globalization process in economy was essential, and change the way how markets and companies work and represent the key factor of new era of economic development. This paper presents main results from available literature about the relationship between information, knowledge and economic theory in a global conterxt and finally explained the benefits of the knowledge economy to all countries.

Color in context: psychological context moderates the influence of red on approach- and avoidance-motivated behavior.

Science.gov (United States)

Meier, Brian P; D'Agostino, Paul R; Elliot, Andrew J; Maier, Markus A; Wilkowski, Benjamin M

2012-01-01

A basic premise of the recently proffered color-in-context model is that the influence of color on psychological functioning varies as a function of the psychological context in which color is perceived. Some research has examined the appetitive and aversive implications of viewing the color red in romance- and achievement-relevant contexts, respectively, but in all existing empirical work approach and avoidance behavior has been studied in separate tasks and separate experiments. Research is needed to directly test whether red influences the same behavior differently depending entirely on psychological context. The present experiment was designed to put this premise to direct test in romance- and achievement-relevant contexts within the same experimental paradigm involving walking behavior. Our results revealed that exposure to red (but not blue) indeed has differential implications for walking behavior as a function of the context in which the color is perceived. Red increased the speed with which participants walked to an ostensible interview about dating (a romance-relevant context), but decreased the speed with which they walked to an ostensible interview about intelligence (an achievement-relevant context). These results are the first direct evidence that the influence of red on psychological functioning in humans varies by psychological context. Our findings contribute to both the literature on color psychology and the broader, emerging literature on the influence of context on basic psychological processes.

Radio Context Awareness and Applications

Directory of Open Access Journals (Sweden)

Luca Reggiani

2013-01-01

Full Text Available The context refers to “any information that can be used to characterize the situation of an entity, where an entity can be a person, place, or physical object.” Radio context awareness is defined as the ability of detecting and estimating a system state or parameter, either globally or concerning one of its components, in a radio system for enhancing performance at the physical, network, or application layers. In this paper, we review the fundamentals of context awareness and the recent advances in the main radio techniques that increase the context awareness and smartness, posing challenges and renewed opportunities to added-value applications in the context of the next generation of wireless networks.

High school dropouts: interactions between social context, self-perceptions, school engagement, and student dropout.

Science.gov (United States)

Fall, Anna-Mária; Roberts, Greg

2012-08-01

Research suggests that contextual, self-system, and school engagement variables influence dropping out from school. However, it is not clear how different types of contextual and self-system variables interact to affect students' engagement or contribute to decisions to dropout from high school. The self-system model of motivational development represents a promising theory for understanding this complex phenomenon. The self-system model acknowledges the interactive and iterative roles of social context, self-perceptions, school engagement, and academic achievement as antecedents to the decision to dropout of school. We analyzed data from the Education Longitudinal Study of 2002-2004 in the context of the self-system model, finding that perception of social context (teacher support and parent support) predicts students' self-perceptions (perception of control and identification with school), which in turn predict students' academic and behavioral engagement, and academic achievement. Further, students' academic and behavioral engagement and achievement in 10th grade were associated with decreased likelihood of dropping out of school in 12th grade. Published by Elsevier Ltd.

High school dropouts: Interactions between social context, self-perceptions, school engagement, and student dropout☆

Science.gov (United States)

Fall, Anna-Mária; Roberts, Greg

2012-01-01

Research suggests that contextual, self-system, and school engagement variables influence dropping out from school. However, it is not clear how different types of contextual and self-system variables interact to affect students’ engagement or contribute to decisions to dropout from high school. The self-system model of motivational development represents a promising theory for understanding this complex phenomenon. The self-system model acknowledges the interactive and iterative roles of social context, self-perceptions, school engagement, and academic achievement as antecedents to the decision to dropout of school. We analyzed data from the Education Longitudinal Study of 2002–2004 in the context of the self-system model, finding that perception of social context (teacher support and parent support) predicts students’ self-perceptions (perception of control and identification with school), which in turn predict students’ academic and behavioral engagement, and academic achievement. Further, students’ academic and behavioral engagement and achievement in 10th grade were associated with decreased likelihood of dropping out of school in 12th grade. PMID:22153483

Implementing the Health Promoting University approach in culturally different contexts: a systematic review.

Science.gov (United States)

Suárez-Reyes, Mónica; Van den Broucke, Stephan

2016-03-01

Universities represent a valuable opportunity to promote health and well-being. Based on the setting approach, the Health Promoting Universities concept has been developed in different countries and contexts. However, the implementation process remains poorly documented. This systematic review aims to describe how universities have implemented the Health Promoting University concept in different cultural contexts. Pubmed, Medline, Lilacs and Scielo were searched for articles on Health Promoting Universities, published between 1995 and 2015. Studies detailing the implementation of a Health Promoting University approach were included. Selected articles were content analysed paying attention to: (a) the definition of a Health Promoting University; (b) priority areas of action; (c) items of work; (d) coordination of the project; (e) evaluation; and (f) adaptation to the cultural context. Twelve studies were identified for in-depth analysis. Of those, three were theoretical papers, and nine were intervention studies. The programmes described in the selected studies are mostly based on the guidelines of the Edmonton Charter. They incorporated the main areas of action and items of works proposed by the Health Promoting University framework. The implementation of healthy policies and incorporation of health promotion in the curriculum are remaining challenges. Strategies to facilitate adaptation to context include: stakeholder participation in planning and implementation, adaptation of educational material and analysis of needs. The review suggests that most of the universities work towards similar goals, relying on the Health Promoting University framework, yet that the way in which initiatives are implemented depends on the context. © The Author(s) 2015.

Homeostasis between gut-associated microorganisms and the immune system in Drosophila.

Science.gov (United States)

You, Hyejin; Lee, Won Jun; Lee, Won-Jae

2014-10-01

The metabolic activities of a given gut bacterium or gut commensal community fluctuate in a manner largely depending on the physicochemical parameters within the gut niche. Recognition of the bacterial metabolic status in situ, by a sensing of the gut metabolites as a signature of a specific bacterial metabolic activity, has been suggested to be a highly beneficial means for the host to maintain gut-microbe homeostasis. Recently, analysis of Drosophila gut immunity revealed that bacterial-derived uracil and uracil-modulated intestinal reactive oxygen species (ROS) generation play a pivotal role in diverse aspects of host-microbe interactions, such as pathogen clearance, commensal protection, intestinal cell regeneration, colitogenesis, and possibly also interorgan immunological communication. A deeper understanding of the role of uracil in Drosophila immunity will provide additional insight into the molecular mechanisms underlying host-microbe symbiosis and dysbiosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Context-Aware Elevator Scheduling

OpenAIRE

Strang, Thomas; Bauer, Christian

2007-01-01

Research on context-aware systems is usually user-centric and thus focussed on the context of a specific user to serve his or her needs in an optimized way. In this paper, we want to apply core concepts developed in research on context-awareness in a system-centric way, namely to elevator systems. We show with three different examples that the performance of an elevator system can be significantly improved if the elevator control has access to contextual knowledge. The first example demons...

Synthesis and antiviral activity of 3'-deoxy-3'-C-hydroxymethyl nucleosides.

Science.gov (United States)

Bamford, M J; Coe, P L; Walker, R T

1990-09-01

A series of 3'-branched-chain sugar nucleosides, in particular 3'-deoxy-3'-C-hydroxmethyl nucleosides, have been synthesized and evaluated as antiviral agents. Reaction of 1-(2,3-epoxy-5-O-trityl-beta-D-lyxo-pentofuranosyl) derivatives 12 and 13, of uracil and thymine, respectively, with 5,6-dihydro-2-lithio-5-methyl-1,3,5-dithiazine 14 afforded the corresponding 3'-functionalized nucleosides 15 and 16, respectively. Replacement of the trityl group with tertbutyldiphenylsilyl allowed high yielding hydrolysis of the 3'-function to give the 3'-deoxy-3'-C-formyl-beta-D-arabino-pentofuranosyl nucleosides 21 and 22. Desilylation afforded the 1-(3-deoxy-3-C-formyl-beta- D-lyxo-pentofuranosyl) 3',5'-O-hemiacetal nucleosides 33 and 34, respectively. Reduction of the formyl group of 21 and 22, followed by desilylation, yielded the 3'-deoxy-3'-C-(hydroxymethyl)-beta-D-arabino- pentofuranosyl) analogues 7 and 8, respectively. The uracil base moiety of 7 was converted to 5-iodouracil and then to (E)-5-(2-bromovinyl)uracil to furnish an analogue 10 of BVaraU. The 1-(3-deoxy-3-C-(hydroxymethyl)-beta-D-lyxo-pentofuranosyl) and 1-(2,3-dideoxy-3-C-(hydroxymethyl)-beta-D-erythro-pentofuranosyl) derivatives of uracil (31 and 6, respectively) and 5-iodouracil (32 and 9, respectively) were also obtained. All novel, fully deprotected nucleoside analogues were evaluated for antiviral activity against human immunodeficiency virus type-1, herpes simplex virus types-1 and -2, varicella zoster virus, human cytomegalovirus and influenza A. Of the compounds tested only (E)-5-(2-bromovinyl)-1-[3-deoxy- 3-C-(hydroxymethyl)-beta-D-arabino-pentofuranosyl]uracil (10) inhibited VZV (alone), but did so at concentrations well below the cytotoxicity threshold.

Context-dependent memory and mood

OpenAIRE

Løhre, Erik

2011-01-01

This thesis examined the effects of affective state (mood) on context-dependent memory. In the so-called context-change paradigm, participants learn two lists of words, and their internal context is either changed or kept constant between the two lists. The usual finding in this paradigm is that participants remember fewer words from the first list, but more words from the second list when context is changed compared to when it is kept constant. To see whether these effects are influenced by ...

Context reinstatement in recognition: memory and beyond

OpenAIRE

Hanczakowski, M; Zawadzka, K; Coote, L

2014-01-01

Context effects in recognition tests are twofold. First, presenting familiar contexts at a test leads to an attribution of context familiarity to a recognition probe, which has been dubbed ‘context-dependent recognition’. Second, reinstating the exact study context for a particular target in a recognition test cues recollection of an item-context association, resulting in ‘context-dependent discrimination’. Here we investigated how these two context effects are expressed in metacognitive moni...

Mobile Context Toolbox - an extensible context framework for S60 mobile phones

DEFF Research Database (Denmark)

Larsen, Jakob Eg; Jensen, Kristian

2009-01-01

We describe an open framework utilizing sensors and application data on S60 mobile phones enabling rapid prototyping of context-aware mobile applications. The framework has an extensible layered architecture allowing new sensors and features to be added to the context framework as they become....... In the experiments 14 participants have been continuously using a Nokia N95 mobile phone with a context logger application for an average of 48 days per user and covering 70% of the time. The study has provided valuable insights into the performance issues of the system in real-life usage situations, including...

Represented Speech in Qualitative Health Research

DEFF Research Database (Denmark)

Musaeus, Peter

2017-01-01

Represented speech refers to speech where we reference somebody. Represented speech is an important phenomenon in everyday conversation, health care communication, and qualitative research. This case will draw first from a case study on physicians’ workplace learning and second from a case study...... on nurses’ apprenticeship learning. The aim of the case is to guide the qualitative researcher to use own and others’ voices in the interview and to be sensitive to represented speech in everyday conversation. Moreover, reported speech matters to health professionals who aim to represent the voice...... of their patients. Qualitative researchers and students might learn to encourage interviewees to elaborate different voices or perspectives. Qualitative researchers working with natural speech might pay attention to how people talk and use represented speech. Finally, represented speech might be relevant...

Color in context: psychological context moderates the influence of red on approach- and avoidance-motivated behavior.

Directory of Open Access Journals (Sweden)

Brian P Meier

Full Text Available BACKGROUND: A basic premise of the recently proffered color-in-context model is that the influence of color on psychological functioning varies as a function of the psychological context in which color is perceived. Some research has examined the appetitive and aversive implications of viewing the color red in romance- and achievement-relevant contexts, respectively, but in all existing empirical work approach and avoidance behavior has been studied in separate tasks and separate experiments. Research is needed to directly test whether red influences the same behavior differently depending entirely on psychological context. METHODOLOGY/PRINCIPAL FINDINGS: The present experiment was designed to put this premise to direct test in romance- and achievement-relevant contexts within the same experimental paradigm involving walking behavior. Our results revealed that exposure to red (but not blue indeed has differential implications for walking behavior as a function of the context in which the color is perceived. Red increased the speed with which participants walked to an ostensible interview about dating (a romance-relevant context, but decreased the speed with which they walked to an ostensible interview about intelligence (an achievement-relevant context. CONCLUSIONS/SIGNIFICANCE: These results are the first direct evidence that the influence of red on psychological functioning in humans varies by psychological context. Our findings contribute to both the literature on color psychology and the broader, emerging literature on the influence of context on basic psychological processes.

Color in Context: Psychological Context Moderates the Influence of Red on Approach- and Avoidance-Motivated Behavior

Science.gov (United States)

Meier, Brian P.; D’Agostino, Paul R.; Elliot, Andrew J.; Maier, Markus A.; Wilkowski, Benjamin M.

2012-01-01

Background A basic premise of the recently proffered color-in-context model is that the influence of color on psychological functioning varies as a function of the psychological context in which color is perceived. Some research has examined the appetitive and aversive implications of viewing the color red in romance- and achievement-relevant contexts, respectively, but in all existing empirical work approach and avoidance behavior has been studied in separate tasks and separate experiments. Research is needed to directly test whether red influences the same behavior differently depending entirely on psychological context. Methodology/Principal Findings The present experiment was designed to put this premise to direct test in romance- and achievement-relevant contexts within the same experimental paradigm involving walking behavior. Our results revealed that exposure to red (but not blue) indeed has differential implications for walking behavior as a function of the context in which the color is perceived. Red increased the speed with which participants walked to an ostensible interview about dating (a romance-relevant context), but decreased the speed with which they walked to an ostensible interview about intelligence (an achievement-relevant context). Conclusions/Significance These results are the first direct evidence that the influence of red on psychological functioning in humans varies by psychological context. Our findings contribute to both the literature on color psychology and the broader, emerging literature on the influence of context on basic psychological processes. PMID:22808136

Context Aware Middleware Architectures: Survey and Challenges

Directory of Open Access Journals (Sweden)

Xin Li

2015-08-01

Full Text Available Context aware applications, which can adapt their behaviors to changing environments, are attracting more and more attention. To simplify the complexity of developing applications, context aware middleware, which introduces context awareness into the traditional middleware, is highlighted to provide a homogeneous interface involving generic context management solutions. This paper provides a survey of state-of-the-art context aware middleware architectures proposed during the period from 2009 through 2015. First, a preliminary background, such as the principles of context, context awareness, context modelling, and context reasoning, is provided for a comprehensive understanding of context aware middleware. On this basis, an overview of eleven carefully selected middleware architectures is presented and their main features explained. Then, thorough comparisons and analysis of the presented middleware architectures are performed based on technical parameters including architectural style, context abstraction, context reasoning, scalability, fault tolerance, interoperability, service discovery, storage, security & privacy, context awareness level, and cloud-based big data analytics. The analysis shows that there is actually no context aware middleware architecture that complies with all requirements. Finally, challenges are pointed out as open issues for future work.

Simulation of nitrogen attenuation in a subterranean estuary, representative of the southern coast of Cape Cod, Massachusetts

Science.gov (United States)

Colman, John A.; Carlson, Carl S.; Robinson, C.

2015-01-01

A two-dimensional model was developed by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, to assess flow and chemical reaction associated with groundwater discharge through the subterranean estuary representative of coastal salt ponds of southern Cape Cod. The model simulated both the freshwater and saltwater flow systems and accounted for density-dependent flow, tidal fluctuation, and chemical reactivity among oxygen, dissolved organic carbon, nitrate, and ammonia. Not previously incorporated into one model, the interaction of these effects can now be simulated in the subterranean estuary context.

Stress Disrupts Context-Dependent Memory

Science.gov (United States)

Schwabe, Lars; Bohringer, Andreas; Wolf, Oliver T.

2009-01-01

Memory is facilitated when the retrieval context resembles the learning context. The brain structures underlying contextual influences on memory are susceptible to stress. Whether stress interferes with context-dependent memory is still unknown. We exposed healthy adults to stress or a control procedure before they learned an object-location task…

Photoelectron spectroscopy of the 6-azauracil anion.

Science.gov (United States)

Chen, Jing; Buonaugurio, Angela; Dolgounitcheva, Olga; Zakrzewski, V G; Bowen, Kit H; Ortiz, J V

2013-02-14

We report the photoelectron spectrum of the 6-azauracil anion. The spectrum is dominated by a broad band exhibiting a maximum at an electron binding energy (EBE) of 1.2 eV. This spectral pattern is indicative of a valence anion. Our calculations were carried out using ab initio electron propagator and other many-body methods. Comparison of the anion and corresponding neutral of 6-azauracil with those of uracil shows that substituting a nitrogen atom for C-H at the C6 position of uracil gives rise to significant changes in the electronic structure of 6-azauracil versus that of uracil. The adiabatic electron affinity (AEA) of the canonical 6-azauracil tautomer is substantially larger than that of canonical uracil. Among the five tautomeric, 6-azauracil anions studied computationally, the canonical structure was found to be the most stable. The vertical detachment energies (VDE) of the canonical, valence-bound anion of 6-azauracil and its closest "very-rare" tautomer have been calculated. Electron propagator calculations on the canonical anion yield a VDE value that is in close agreement with the experimentally determined VDE value of 1.2 eV. The AEA value of 6-azauracil, assessed at the CCSD(T) level of theory to be 0.5 eV, corresponds with the EBE value of the onset of the experimental spectrum.

Effect of the sulphur atom on geometry and spectra of the biomolecule 2-thiouracil and in the WC base pair 2-thiouridine-adenosine. Influence of water in the first hydration shell.

Science.gov (United States)

Alcolea Palafox, M; Rastogi, V K; Singh, S P

2018-04-01

The effect of the sulphur atom on 2-thiouracil (2TU) and 2-thiouridine molecules, as compared with uracil and uridine molecules, respectively, was carried out in several environments. The predicted IR spectrum of 2TU in the isolated state was compared with that obtained for uracil molecule and with those reported experimentally in matrix isolation. Its crystal unit cell in the solid state was simulated through a tetramer form using DFT methods for the first time. The calculated Raman spectrum was compared to the experimental ones in the solid state. A linear scaling procedure was used for this task. The first hydration shell was simulated by explicit number of water molecules surrounding 2TU up to 30 and was compared with that obtained in uracil molecule. Water molecules 'distributed' around 2TU was preferred over that 'clustering', because it can better reproduce the hydration and their effects on different parameters of the molecular structure of 2TU and uracil. The total atomic charges and several calculated thermodynamic parameters were discussed. The effect of the sulphur atom on the Watson-Crick (WC) and reverse WC base pair uridine-adenosine was estimated, and the CP corrected interaction energies were calculated. 2-thiouridine has a weaker WC pair than that with uridine, although its slight higher dipole moment (μ) facilitates the interaction with the water molecules. Several helical parameters were determined.

Teaching and nature: Middle school science teachers' relationship with nature in personal and classroom contexts

Science.gov (United States)

Ball, Nadine Butcher

2000-10-01

This qualitative study describes three middle-school science teachers' relationship-with-nature in personal and classroom contexts. Participating teachers had more than 7 years experience and were deemed exemplary practitioners by others. Interview data about personal context focused on photographs the teacher took representing her/his relationship-with-nature in daily life. Interview data for classroom context explored classroom events during three or more researcher observations. Transcripts were analyzed using a multiple-readings approach to data reduction (Gilligan, Brown & Rogers, 1990; Miles & Huberman, 1994, p. 14, 141). Readings generated categorical information focused on portrayals of: nature; self; and relationship-with-nature. Categorical data were synthesized into personal and teaching case portraits for each teacher, and cross case themes identified. Participants indicated the portraits accurately represented who they saw themselves to be. Additional readings identified sub-stories by plot and theme. Narrative data were clustered to highlight elements of practice with implications for the relationship-with-nature lived in the classroom. These individual-scale moments were compared with cultural-scale distinctions between anthropocentric and ecological world views. Cross case themes included dimensions of exemplary middle-school science teaching important to teacher education and development, including an expanded conception of knowing and skillful use of student experience. Categorical analysis revealed each teacher had a unique organizing theme influencing their interpretation of personal and classroom events, and that nature is experienced differently in personal as opposed to teaching contexts. Narrative analysis highlights teachers' stories of classroom pets, dissection, and student dissent, illustrating an interplay between conceptual distinctions and personal dimensions during moments of teacher decision making. Results suggest teachers

Do television food advertisements portray advertised foods in a 'healthy' food context?

Science.gov (United States)

Adams, Jean; Tyrrell, Rachel; White, Martin

2011-03-01

Exposure to food promotion influences food preferences and diet. As food advertisements tend to promote 'less healthy' products, food advertising probably plays some role in the 'obesity epidemic'. Amid calls for increased regulation, food manufacturers are beginning to engage in a variety of health-promoting marketing initiatives. Positioning products in the context of a 'healthy', balanced diet in television advertisements is one such initiative. We explored whether the wider food context in which foods are advertised on television are 'healthier' than the advertised foods themselves. All foods shown in food advertisements broadcast during 1 week on one commercial UK channel were identified and classified as 'primary' (i.e. the focus of advertisements) or 'incidental'. The nutritional content of all foods was determined and that of primary and incidental foods were compared. Almost two-thirds of food advertisements did not include any incidental foods. When a wider food context was present, this tended to be 'healthier' than the primary foods that were the focus of food advertisements - particularly in terms of the food groups represented. It is not yet clear what effect this may have on consumers' perceptions and behaviour, and whether or not this practice should be encouraged or discouraged from a public health perspective.

Context Representation and Fusion: Advancements and Opportunities

Directory of Open Access Journals (Sweden)

Asad Masood Khattak

2014-05-01

Full Text Available The acceptance and usability of context-aware systems have given them the edge of wide use in various domains and has also attracted the attention of researchers in the area of context-aware computing. Making user context information available to such systems is the center of attention. However, there is very little emphasis given to the process of context representation and context fusion which are integral parts of context-aware systems. Context representation and fusion facilitate in recognizing the dependency/relationship of one data source on another to extract a better understanding of user context. The problem is more critical when data is emerging from heterogeneous sources of diverse nature like sensors, user profiles, and social interactions and also at different timestamps. Both the processes of context representation and fusion are followed in one way or another; however, they are not discussed explicitly for the realization of context-aware systems. In other words most of the context-aware systems underestimate the importance context representation and fusion. This research has explicitly focused on the importance of both the processes of context representation and fusion and has streamlined their existence in the overall architecture of context-aware systems’ design and development. Various applications of context representation and fusion in context-aware systems are also highlighted in this research. A detailed review on both the processes is provided in this research with their applications. Future research directions (challenges are also highlighted which needs proper attention for the purpose of achieving the goal of realizing context-aware systems.

Child sexual abuse as a risk factor for teen dating violence: Findings from a representative sample of Quebec youth

OpenAIRE

Hébert, Martine; Moreau, Catherine; Blais, Martin; Lavoie, Francine; Guerrier, Mireille

2016-01-01

Child sexual abuse (CSA) is identified as a significant risk factor for later victimization in the context of adult intimate relationships, but less is known about the risk associated with CSA in early romantic relationships. This paper aims to document the association between CSA and teen dating victimization in a large representative sample of Quebec high-school students. As part of the Youths’ Romantic Relationships Project, 8,194 teens completed measures on CSA and psychological, physical...

Context updates are hierarchical

Directory of Open Access Journals (Sweden)

Anton Karl Ingason

2016-10-01

Full Text Available This squib studies the order in which elements are added to the shared context of interlocutors in a conversation. It focuses on context updates within one hierarchical structure and argues that structurally higher elements are entered into the context before lower elements, even if the structurally higher elements are pronounced after the lower elements. The crucial data are drawn from a comparison of relative clauses in two head-initial languages, English and Icelandic, and two head-final languages, Korean and Japanese. The findings have consequences for any theory of a dynamic semantics.

Context and Chemistry Going Dutch? The Development of a Context-Based Curriculum in the Netherlands

NARCIS (Netherlands)

Apotheker, J. H.; GuptaBhowon, M; JhaumeerLaulloo, S; Wah, HLK; Ramasami, P

2009-01-01

In the Netherlands a new context-based curriculum has been designed to cope with the problem of the diminishing attention for chemistry as a subject. The curriculum consists of a number of modules in which a context is introduced. Based on scientific questions related to the context chemical

Product Context Analysis with Twitter Data

OpenAIRE

Sun, Tao

2016-01-01

Context. For the product manager, the product context analysis, which aims to align their products to the market needs, is very important. By understanding the market needs, the product manager knows the product context information about the environment the products conceived and the business the products take place. The product context analysis using the product context information helps the product manager find the accurate position of his/her products and support the decision-making of the...

The Effects of Solo Status on Women's and Men's Success: The Moderating Role of the Performance Context

Science.gov (United States)

Viallon, Marie-Laure; Martinot, Delphine

2009-01-01

A considerable body of research has shown that being the only representative of one's gender group (solo status) when performing an activity affects women more than men. The aim of our two experiments was to show that the performance context can moderate the effects of numerical status (majority vs. solo) on performance and that men can also be…

Social Contexts of Substance Use among U.S. High School Seniors: A Multi-Cohort National Study

Science.gov (United States)

McCabe, Sean Esteban; West, Brady T.; Veliz, Philip; Frank, Kenneth A.; Boyd, Carol J.

2015-01-01

Purpose To determine the social contexts associated with past-year substance use (multiple substances, alcohol, marijuana, and nonmedical use of prescription opioids, stimulants and tranquilizers) among U.S. high school seniors. Methods A secondary analysis of nationally representative survey data from ten cohorts (2002-2011) of the Monitoring the Future study, including 24,809 high school seniors. Results The social contexts associated with past-year substance use varied considerably based on which substance was used. The most prevalent location for alcohol, marijuana, and polydrug use was at a party while nonmedical use of prescription stimulants, tranquilizers and opioids was most likely to occur at home. Most types of substance use occurred in the presence of other people with the exception of nonmedical use of prescription stimulants that was a more solitary behavior. Conclusions These exploratory findings indicate that prevention efforts may need to account for differences in social contexts between types of substances used. PMID:25156895

Hybrid context aware recommender systems

Science.gov (United States)

Jain, Rajshree; Tyagi, Jaya; Singh, Sandeep Kumar; Alam, Taj

2017-10-01

Recommender systems and context awareness is currently a vital field of research. Most hybrid recommendation systems implement content based and collaborative filtering techniques whereas this work combines context and collaborative filtering. The paper presents a hybrid context aware recommender system for books and movies that gives recommendations based on the user context as well as user or item similarity. It also addresses the issue of dimensionality reduction using weighted pre filtering based on dynamically entered user context and preference of context. This unique step helps to reduce the size of dataset for collaborative filtering. Bias subtracted collaborative filtering is used so as to consider the relative rating of a particular user and not the absolute values. Cosine similarity is used as a metric to determine the similarity between users or items. The unknown ratings are calculated and evaluated using MSE (Mean Squared Error) in test and train datasets. The overall process of recommendation has helped to personalize recommendations and give more accurate results with reduced complexity in collaborative filtering.

Haptically Induced Illusory Self-motion and the Influence of Context of Motion

DEFF Research Database (Denmark)

Nilsson, Niels Christian; Nordahl, Rolf; Sikström, Erik

2012-01-01

of the feet. The experiment was based on the a within-subjects design and included four conditions, each representing one context of motion: an elevator, a train compartment, a bathroom, and a completely dark environment. The audiohaptic stimuli was identical across all conditions. The participants’ sensation...... of movement was assessed by means of existing measures of illusory self-motion, namely, reported self-motion illusion per stimulus type, illusion compellingness, intensity and onset time. Finally the participants were also asked to estimate the experienced direction of movement. While the data obtained from...

Context, you need

DEFF Research Database (Denmark)

Kristensen, Line Burholt

Two clauses can contain the same information, yet display differences with respect to information structure. As an example, “He invited her” and “Her, he invited” contain the same information, but display syntactic differences. Previous language experiments, e.g. from German and English, have shown......, he invited” depends on the context – it is therefore relevant to take contextual factors into account when examining how language users process information structure. The dissertation is based on a psycholinguistic reading experiment and three neuroimaging experiments that all examine the interplay...... between context and information structure. The experimental results indicate that context plays a significant role when it comes to sentence comprehension and that the activity in Broca’s area is also affected by contextual factors. Based on the results of the four language experiments, it is also argued...

Assessing the Effects of Personal Characteristics and Context on U.S. House Speakers’ Leadership Styles, 1789-2006

Directory of Open Access Journals (Sweden)

John E. Owens

2016-04-01

Full Text Available Research on congressional leadership has been dominated in recent decades by contextual interpretations that see leaders’ behavior as best explained by the environment in which they seek to exercise leadership—particularly, the preference homogeneity and size of their party caucus. The role of agency is thus discounted, and leaders’ personal characteristics and leadership styles are underplayed. Focusing specifically on the speakers of the U.S. House of Representatives from the first to the 110th Congress, we construct measures of each speaker’s commitment to comity and leadership assertiveness. We find the scores reliable and then test the extent to which a speaker’s style is the product of both political context and personal characteristics. Regression estimates on speakers’ personal assertiveness scores provide robust support for a context-plus-personal characteristics explanation, whereas estimates of their comity scores show that speakers’ personal backgrounds trump context.

Attachment Representation Moderates the Influence of Emotional Context on Information Processing.

Science.gov (United States)

Leyh, Rainer; Heinisch, Christine; Kungl, Melanie T; Spangler, Gottfried

2016-01-01

The induction of emotional states has repeatedly been shown to affect cognitive processing capacities. At a neurophysiological level, P3 amplitude responses that are associated with attention allocation have been found to be reduced to task-relevant stimuli during emotional conditions as compared to neutral conditions suggesting a draining impact of emotion on cognitive resources. Attachment theory claims that how individuals regulate their emotions is guided by an internal working model (IWM) of attachment that has formed early in life. While securely attached individuals are capable of freely evaluating their emotions insecurely attached ones tend to either suppress or heighten the emotional experience in a regulatory effort. To explore how attachment quality moderates the impact of emotional contexts on information processing event-related potentials (ERPs) in 41 individuals were assessed. Subjects were instructed to detect neutral target letters within an oddball paradigm. Various images taken from the International Affective Picture System (IAPS) served as background pictures and represented negative, positive and neutral task-irrelevant contexts. Attachment representation was assessed using the Adult Attachment Interview (AAI) and individuals were assigned to one of three categories (secure, insecure-dismissing, insecure-preoccupied). At a behavioral level, the study revealed that negative emotionally conditions were associated with the detection of less target stimuli in insecure-dismissing subjects. Accordingly, ERPs yielded reduced P3 amplitudes in insecure-dismissing subjects when given a negative emotional context. We interpret these findings in terms of less sufficient emotion regulation strategies in insecure-dismissing subjects at the cost of accurate behavioral performance. The study suggests that attachment representation differentially moderates the relationship between emotional contexts and information processing most evident in insecure

Energy in Ireland: context, strategy and research; Energie en Irlande: contexte, strategie et recherche

Energy Technology Data Exchange (ETDEWEB)

Saintherant, N.; Lerouge, Ch.; Welcker, A

2008-01-15

In the present day situation of sudden awareness about climatic change and announced fossil fuels shortage, Ireland has defined a new strategy for its energy future. Context: Ireland is strongly dependent of oil and gas imports which increase regularly to meet the demand. A small part of the electricity consumed is imported from Ulster. The share of renewable energies remains weak but is increasing significantly. Therefore, from 1990 to 2006, the proportion of renewable energies increased from 1.9% (mainly of hydroelectric origin) to 4.5%. Wind power represents now the main renewable energy source. The transportation sector is the most energy consuming and the biggest source of greenhouse gases. Strategy: the Irish policy is driven by pluri-annual strategic plans which define the objectives and means. Priority is given to the security of supplies at affordable prices: 8.5 billion euros will be invested during the 2007-2013 era for the modernization of existing energy infrastructures and companies, and in a lesser extent for the development of renewable energy sources. During this period, 415 million euros more will be devoted to the research, development and demonstration (RD and D) of new energy solutions. Research: in 2005 the energy RD and D expenses reached 12.8 million euros shared between 54% for R and D and 46% for demonstration projects. Half of the financing is given to higher education schools and is devoted to energy saving purposes (33%) and to renewable energies (29%, mainly wind power and biomass). Academic research gives a particular attention to ocean energy which represents an important potential resource in Ireland and which has already led to the creation of innovative companies. The integration of renewable energy sources to the power grid and the stability of supplies are also the object of active researches. (J.S.)

Context-aware system design

Science.gov (United States)

Chan, Christine S.; Ostertag, Michael H.; Akyürek, Alper Sinan; Šimunić Rosing, Tajana

2017-05-01

The Internet of Things envisions a web-connected infrastructure of billions of sensors and actuation devices. However, the current state-of-the-art presents another reality: monolithic end-to-end applications tightly coupled to a limited set of sensors and actuators. Growing such applications with new devices or behaviors, or extending the existing infrastructure with new applications, involves redesign and redeployment. We instead propose a modular approach to these applications, breaking them into an equivalent set of functional units (context engines) whose input/output transformations are driven by general-purpose machine learning, demonstrating an improvement in compute redundancy and computational complexity with minimal impact on accuracy. In conjunction with formal data specifications, or ontologies, we can replace application-specific implementations with a composition of context engines that use common statistical learning to generate output, thus improving context reuse. We implement interconnected context-aware applications using our approach, extracting user context from sensors in both healthcare and grid applications. We compare our infrastructure to single-stage monolithic implementations with single-point communications between sensor nodes and the cloud servers, demonstrating a reduction in combined system energy by 22-45%, and multiplying the battery lifetime of power-constrained devices by at least 22x, with easy deployment across different architectures and devices.

An Insight into the Environmental Effects of the Pocket of the Active Site of the Enzyme. Ab initio ONIOM-Molecular Dynamics (MD) Study on Cytosine Deaminase

International Nuclear Information System (INIS)

Matsubara, Toshiaki; Dupuis, Michel; Aida, Misako

2008-01-01

We applied the ONIOM-molecular dynamics (MD) method to cytosine deaminase to examine the environmental effects of the amino acid residues in the pocket of the active site on the substrate taking account of their thermal motion. The ab initio ONIOM-MD simulations show that the substrate uracil is strongly perturbed by the amino acid residue Ile33, which sandwiches the uracil with His62, through the steric contact due to the thermal motion. As a result, the magnitude of the thermal oscillation of the potential energy and structure of the substrate uracil significantly increases. TM and MA were partly supported by grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan.MD was supported by the Division of Chemical Sciences, Office of Basic Energy Sciences, and by the Office of Biological and Environmental Research of the U.S. Department of Energy DOE. Battelle operates Pacific Northwest National Laboratory for DOE

A second pathway to degrade pyrimidine nucleic acid precursors in eukaryotes

DEFF Research Database (Denmark)

Andersen, Gorm; Bjornberg, Olof; Polakova, Silvia

2008-01-01

Pyrimidine bases are the central precursors for RNA and DNA, and their intracellular pools are determined by de novo, salvage and catabolic pathways. In eukaryotes, degradation of uracil has been believed to proceed only via the reduction to dihydrouracil. Using a yeast model, Saccharomyces kluyv...... of the eukaryotic or prokaryotic genes involved in pyrimidine degradation described to date.......Pyrimidine bases are the central precursors for RNA and DNA, and their intracellular pools are determined by de novo, salvage and catabolic pathways. In eukaryotes, degradation of uracil has been believed to proceed only via the reduction to dihydrouracil. Using a yeast model, Saccharomyces......, respectively. The gene products of URC1 and URC4 are highly conserved proteins with so far unknown functions and they are present in a variety of prokaryotes and fungi. In bacteria and in some fungi, URC1 and URC4 are linked on the genome together with the gene for uracil phosphoribosyltransferase (URC6). Urc1...

Representing the Earth's shape: the polemics surrounding Maupertuis's expedition to Lapland.

Science.gov (United States)

Terrall, M.

1992-06-01

Historical accounts of quantification in the physical sciences in the eighteenth century have often been described as a straightforward series of steps in a process of maturation, as instruments and standards advanced in precision. This paper calls into question the self-evidence nature of precision by investigating the production and uses of measurements. In the case of the dispute over the shape of the Earth, centered in Paris in the 1730s, the precision of measurements was a matter to be interpreted, attacked, defended, and represented. The whole messy business, undertaken by the participants to win consensus from their contemporaries, took place in the context of academic politics and the intellectual fashions of the salons and the court. All parties to the dispute claimed to be drawing on precision measurements; evaluating precision turned out to require the use of a range of intellectual, mathematical, instrumental, political, and textual resources. The alleged precision was then used to construct and defend rival scientific programs and practices.

Talking wearables exploit context

NARCIS (Netherlands)

Geldof, S.; Terken, J.M.B.

2001-01-01

This paper addresses the issue of how natural language generation technology can contribute to less intrusive wearable devices. Based on the investigation of how humans adapt the form of their utterances to the context of their hearer, we propose a strategy to relate (physical) context to the

METRIC context unit architecture

Energy Technology Data Exchange (ETDEWEB)

Simpson, R.O.

1988-01-01

METRIC is an architecture for a simple but powerful Reduced Instruction Set Computer (RISC). Its speed comes from the simultaneous processing of several instruction streams, with instructions from the various streams being dispatched into METRIC's execution pipeline as they become available for execution. The pipeline is thus kept full, with a mix of instructions for several contexts in execution at the same time. True parallel programming is supported within a single execution unit, the METRIC Context Unit. METRIC's architecture provides for expansion through the addition of multiple Context Units and of specialized Functional Units. The architecture thus spans a range of size and performance from a single-chip microcomputer up through large and powerful multiprocessors. This research concentrates on the specification of the METRIC Context Unit at the architectural level. Performance tradeoffs made during METRIC's design are discussed, and projections of METRIC's performance are made based on simulation studies.

Distributed context-aware systems

CERN Document Server

Ferreira, Paulo

2014-01-01

Context-aware systems aim to deliver a rich user experience by taking into?account the current user context (location, time, activity, etc.), possibly?captured without his intervention. For example, cell phones are now able to?continuously update a user's location while, at the same time, users execute?an increasing amount of activities online, where their actions may be easily?captured (e.g. login in a web application) without user consent. In the last decade, this topic has seen numerous developments that demonstrate its relevance and usefulness. The?trend was accelerated with the widespread?availability of powerful mobile devices (e.g. smartphones) that include a myriad of?sensors which enable applications to capture the user context. However, there are several challenges that must be addressed; we focus on scalability?(large number of context aware messages) and privacy (personal data that may be propagated).?This book is organized in five chapters starting with an introduction to?the theme raising the mo...

Representing Color Ensembles.

Science.gov (United States)

Chetverikov, Andrey; Campana, Gianluca; Kristjánsson, Árni

2017-10-01

Colors are rarely uniform, yet little is known about how people represent color distributions. We introduce a new method for studying color ensembles based on intertrial learning in visual search. Participants looked for an oddly colored diamond among diamonds with colors taken from either uniform or Gaussian color distributions. On test trials, the targets had various distances in feature space from the mean of the preceding distractor color distribution. Targets on test trials therefore served as probes into probabilistic representations of distractor colors. Test-trial response times revealed a striking similarity between the physical distribution of colors and their internal representations. The results demonstrate that the visual system represents color ensembles in a more detailed way than previously thought, coding not only mean and variance but, most surprisingly, the actual shape (uniform or Gaussian) of the distribution of colors in the environment.

Hierarchical Context Modeling for Video Event Recognition.

Science.gov (United States)

Wang, Xiaoyang; Ji, Qiang

2016-10-11

Current video event recognition research remains largely target-centered. For real-world surveillance videos, targetcentered event recognition faces great challenges due to large intra-class target variation, limited image resolution, and poor detection and tracking results. To mitigate these challenges, we introduced a context-augmented video event recognition approach. Specifically, we explicitly capture different types of contexts from three levels including image level, semantic level, and prior level. At the image level, we introduce two types of contextual features including the appearance context features and interaction context features to capture the appearance of context objects and their interactions with the target objects. At the semantic level, we propose a deep model based on deep Boltzmann machine to learn event object representations and their interactions. At the prior level, we utilize two types of prior-level contexts including scene priming and dynamic cueing. Finally, we introduce a hierarchical context model that systematically integrates the contextual information at different levels. Through the hierarchical context model, contexts at different levels jointly contribute to the event recognition. We evaluate the hierarchical context model for event recognition on benchmark surveillance video datasets. Results show that incorporating contexts in each level can improve event recognition performance, and jointly integrating three levels of contexts through our hierarchical model achieves the best performance.

False Context Fear Memory in Rats

Science.gov (United States)

Bae, Sarah; Holmes, Nathan M.; Westbrook, R. Frederick

2015-01-01

Four experiments used rats to study false context fear memories. In Experiment 1, rats were pre-exposed to a distinctive chamber (context A) or to a control environment (context C), shocked after a delay in a second chamber (context B) and tested either in B or A. Rats pre-exposed to A froze just as much as control rats in B but more than control…

Health Inequalities in Global Context

Science.gov (United States)

Beckfield, Jason; Olafsdottir, Sigrun

2017-01-01

The existence of social inequalities in health is well established. One strand of research focuses on inequalities in health within a single country. A separate and newer strand of research focuses on the relationship between inequality and average population health across countries. Despite the theorization of (presumably variable) social conditions as “fundamental causes” of disease and health, the cross-national literature has focused on average, aggregate population health as the central outcome. Controversies currently surround macro-structural determinants of overall population health such as income inequality. We advance and redirect these debates by conceptualizing inequalities in health as cross-national variables that are sensitive to social conditions. Using data from 48 World Values Survey countries, representing 74% of the world’s population, we examine cross-national variation in inequalities in health. The results reveal substantial variation in health inequalities according to income, education, sex, and migrant status. While higher socioeconomic position is associated with better self-rated health around the globe, the size of the association varies across institutional context, and across dimensions of stratification. There is some evidence that education and income are more strongly associated with self-rated health than sex or migrant status. PMID:29104292

Atypical biological motion kinematics are represented by complementary lower-level and top-down processes during imitation learning.

Science.gov (United States)

Hayes, Spencer J; Dutoy, Chris A; Elliott, Digby; Gowen, Emma; Bennett, Simon J

2016-01-01

Learning a novel movement requires a new set of kinematics to be represented by the sensorimotor system. This is often accomplished through imitation learning where lower-level sensorimotor processes are suggested to represent the biological motion kinematics associated with an observed movement. Top-down factors have the potential to influence this process based on the social context, attention and salience, and the goal of the movement. In order to further examine the potential interaction between lower-level and top-down processes in imitation learning, the aim of this study was to systematically control the mediating effects during an imitation of biological motion protocol. In this protocol, we used non-human agent models that displayed different novel atypical biological motion kinematics, as well as a control model that displayed constant velocity. Importantly the three models had the same movement amplitude and movement time. Also, the motion kinematics were displayed in the presence, or absence, of end-state-targets. Kinematic analyses showed atypical biological motion kinematics were imitated, and that this performance was different from the constant velocity control condition. Although the imitation of atypical biological motion kinematics was not modulated by the end-state-targets, movement time was more accurate in the absence, compared to the presence, of an end-state-target. The fact that end-state targets modulated movement time accuracy, but not biological motion kinematics, indicates imitation learning involves top-down attentional, and lower-level sensorimotor systems, which operate as complementary processes mediated by the environmental context. Copyright © 2015 Elsevier B.V. All rights reserved.

Representations for Supporting Students' Context Awareness

DEFF Research Database (Denmark)

Demetriadis, Stavros N.; Papadopoulos, Pantelis M.

2005-01-01

The context of the specific situation where knowledge is applied affects significantly the problem solving process by forcing people to negotiate and reconsider the priorities of their mental representations and problem solving operators, in relation to this process. In this work we argue...... that students’ context awareness can significantly be enhanced by the use of appropriate external representations which guide them to activate context inducing cognitive processes. By embedding such representations in a case based learning environment we expect to guide students’ processing of the rich...... in contextual information material, in a way that improves both their context awareness and metacontextual competence. After presenting a context model, we discuss the design of such representations based on this model and explain why we expect that their use in a learning situation would enhance context...

Service Degradation in Context Management Frameworks

DEFF Research Database (Denmark)

Shawky, Ahmed; Olsen, Rasmus Løvenstein; Pedersen, Jens Myrup

2011-01-01

information. The paper considers a developed framework from the ICT project, OPEN, and investigates the impact of applying Differentiated Services (DiffServ) Quality of Services (QoS). The paper finally provides insight in how the insight gained can be utilized to ensure reliable remote accessed context......Context aware network services are a new and inter-esting way to enhance network users experience. A context aware application/service enhances network performance in relation to dynamic context information, e.g. mobility, location and device information as it senses and reacts to environment...... changes. The reliability of the information accessed is a key factor in achieving reliable context aware application. This paper will review the service degradation in Context Management Frameworks (CMF) and the effect of high network utilization, with particular focus on the reliability of the accessed...

CONTEXT 2015 Doctorial Symposium

DEFF Research Database (Denmark)

Eklund, Peter; wegener, rebekah

2015-01-01

What is the CONTEXT 2015 Doctoral Symposium? The CONTEXT 2015 Doctoral Symposium is an opportunity for doctoral researchers to showcase their work and discuss problems, challenges, and ideas in an open and collegial environment with expert feedback. The Doctoral Symposium is a workshop for doctoral...... feedback and general advice in a constructive atmosphere. Doctoral researchers will present and discuss their research in a supportive atmosphere with other doctoral researchers and an international panel of established researchers that provide expert feedback. The workshop will take place on a single full...... day, Monday November 2, 2015, the day prior to the start of the main CONTEXT 2015 conference....

The use of iodotrimethylsilane in nucleosidation procedure.

OpenAIRE

Tocik, Z; Earl, R A; Beránek, J

1980-01-01

1-O-Acetyl-2,3,5-tri-O-benzoyl-beta-D-ribofuranose (I) was reacted with iodotrimethylsilane (II) and the product, the glycosyl iodide, was coupled with silylated uracil to afford 1-(2,3,5-tri-O-benzoyl-beta-D-ribofuranosyl)uracil (III; 89%), with silyated cytosine to afford, on subsequent acetylation, 1-(2,3,5-tri-O-benzoyl-beta-0D-ribofuranosyl)-4-acetamido-2-(1H)-pyrimidinone (IVb; 81%), and with chloromercuri-N-benzoyl-adenine to afford Va and on subsequent debenzoylation, adenosine (Vb; 4...

Representative volume size: A comparison of statistical continuum mechanics and statistical physics

Energy Technology Data Exchange (ETDEWEB)

AIDUN,JOHN B.; TRUCANO,TIMOTHY G.; LO,CHI S.; FYE,RICHARD M.

1999-05-01

In this combination background and position paper, the authors argue that careful work is needed to develop accurate methods for relating the results of fine-scale numerical simulations of material processes to meaningful values of macroscopic properties for use in constitutive models suitable for finite element solid mechanics simulations. To provide a definite context for this discussion, the problem is couched in terms of the lack of general objective criteria for identifying the size of the representative volume (RV) of a material. The objective of this report is to lay out at least the beginnings of an approach for applying results and methods from statistical physics to develop concepts and tools necessary for determining the RV size, as well as alternatives to RV volume-averaging for situations in which the RV is unmanageably large. The background necessary to understand the pertinent issues and statistical physics concepts is presented.

Use of Context in Video Processing

Science.gov (United States)

Wu, Chen; Aghajan, Hamid

Interpreting an event or a scene based on visual data often requires additional contextual information. Contextual information may be obtained from different sources. In this chapter, we discuss two broad categories of contextual sources: environmental context and user-centric context. Environmental context refers to information derived from domain knowledge or from concurrently sensed effects in the area of operation. User-centric context refers to information obtained and accumulated from the user. Both types of context can include static or dynamic contextual elements. Examples from a smart home environment are presented to illustrate how different types of contextual data can be applied to aid the decision-making process.

Testing a cue outside the training context increases attention to the contexts and impairs performance in human predictive learning.

Science.gov (United States)

Aristizabal, José A; Ramos-Álvarez, Manuel M; Callejas-Aguilera, José E; Rosas, Juan M

2017-12-01

One experiment in human predictive learning explored the impact of a context change on attention to contexts and predictive ratings controlled by the cue. In Context A: cue X was paired with an outcome four times, while cue Y was presented without an outcome four times in Context B:. In both contexts filler cues were presented without the outcome. During the test, target cues X and Y were presented either in the context where they were trained, or in the alternative context. With the context change expectation of the outcome X, expressed as predictive ratings, decreased in the presence of X and increased in the presence of Y. Looking at the contexts, expressed as a percentage of the overall gaze dwell time on a trial, was high across the four training trials, and increased with the context change. Results suggest that the presentation of unexpected information leads to increases in attention to contextual cues. Implications for contextual control of behavior are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

The Role of Attention for Context-Context Binding of Intrinsic and Extrinsic Features

Science.gov (United States)

Boywitt, C. Dennis; Meiser, Thorsten

2012-01-01

There is converging evidence that the feeling of conscious recollection is usually accompanied by the bound retrieval of context features of the encoding episode (e.g., Meiser, Sattler, & Weiber, 2008). Recently, however, important limiting conditions have been identified for the binding between context features in memory. For example, focusing on…

Emotion Ontology for Context Awareness

OpenAIRE

Berthelon , Franck; Sander , Peter

2013-01-01

International audience; We present an emotion ontology for describing and reasoning on emotion context in order to improve emotion detection based on bodily expression. We incorporate context into the two-factor theory of emotion (bodily reaction plus cognitive input) and demonstrate the importance of context in the emotion experience. In attempting to determine emotion felt by another person, the bodily expresson of their emotion is the only evidence directly available, eg, ''John looks angr...

Agency, Context and Meaning

DEFF Research Database (Denmark)

Folkmann, Mads Nygaard

2014-01-01

The paper is a meta-discursive contribution to the discussion of how design can be understood as a medium of meaning formation and questioning of meaning. Further, the paper builds on plea for the role of humanities in relation to formulate relevant questions in design through conceptualizing the...... of meaning formulation and cultural contexts and, by this, contest design. In reflecting the foundational ground of design in terms of its agency, contexts and meaning constituents, design and its questioning of meaning can be critically reframed.......The paper is a meta-discursive contribution to the discussion of how design can be understood as a medium of meaning formation and questioning of meaning. Further, the paper builds on plea for the role of humanities in relation to formulate relevant questions in design through conceptualizing...... history, 2) the question of context in and of design, i.e. which contexts give meaning to design; this question calls for interpretive models of cultural analysis of the circuit of design in acknowledging phases and aspects of production, mediation and consumption, and 3) the question of the meaning...

The metabolism of histamine in the Drosophila optic lobe involves an ommatidial pathway: β-alanine recycles through the retina

Science.gov (United States)

Borycz, Janusz; Borycz, Jolanta A.; Edwards, Tara N.; Boulianne, Gabrielle L.; Meinertzhagen, Ian A.

2012-01-01

SUMMARY Flies recycle the photoreceptor neurotransmitter histamine by conjugating it to β-alanine to form β-alanyl-histamine (carcinine). The conjugation is regulated by Ebony, while Tan hydrolyses carcinine, releasing histamine and β-alanine. In Drosophila, β-alanine synthesis occurs either from uracil or from the decarboxylation of aspartate but detailed roles for the enzymes responsible remain unclear. Immunohistochemically detected β-alanine is present throughout the fly’s entire brain, and is enhanced in the retina especially in the pseudocone, pigment and photoreceptor cells of the ommatidia. HPLC determinations reveal 10.7 ng of β-alanine in the wild-type head, roughly five times more than histamine. When wild-type flies drink uracil their head β-alanine increases more than after drinking l-aspartic acid, indicating the effectiveness of the uracil pathway. Mutants of black, which lack aspartate decarboxylase, cannot synthesize β-alanine from l-aspartate but can still synthesize it efficiently from uracil. Our findings demonstrate a novel function for pigment cells, which not only screen ommatidia from stray light but also store and transport β-alanine and carcinine. This role is consistent with a β-alanine-dependent histamine recycling pathway occurring not only in the photoreceptor terminals in the lamina neuropile, where carcinine occurs in marginal glia, but vertically via a long pathway that involves the retina. The lamina’s marginal glia are also a hub involved in the storage and/or disposal of carcinine and β-alanine. PMID:22442379

The Crystal Structure of Streptococcus pyogenes Uridine Phosphorylase Reveals a Distinct Subfamily of Nucleoside Phosphorylases

Energy Technology Data Exchange (ETDEWEB)

Tran, Timothy H.; Christoffersen, S.; Allan, Paula W.; Parker, William B.; Piskur, Jure; Serra, I.; Terreni, M.; Ealick, Steven E. (Cornell); (Pavia); (Lund); (Southern Research)

2011-09-20

Uridine phosphorylase (UP), a key enzyme in the pyrimidine salvage pathway, catalyzes the reversible phosphorolysis of uridine or 2'-deoxyuridine to uracil and ribose 1-phosphate or 2'-deoxyribose 1-phosphate. This enzyme belongs to the nucleoside phosphorylase I superfamily whose members show diverse specificity for nucleoside substrates. Phylogenetic analysis shows Streptococcus pyogenes uridine phosphorylase (SpUP) is found in a distinct branch of the pyrimidine subfamily of nucleoside phosphorylases. To further characterize SpUP, we determined the crystal structure in complex with the products, ribose 1-phosphate and uracil, at 1.8 {angstrom} resolution. Like Escherichia coli UP (EcUP), the biological unit of SpUP is a hexamer with an ?/? monomeric fold. A novel feature of the active site is the presence of His169, which structurally aligns with Arg168 of the EcUP structure. A second active site residue, Lys162, is not present in previously determined UP structures and interacts with O2 of uracil. Biochemical studies of wild-type SpUP showed that its substrate specificity is similar to that of EcUP, while EcUP is {approx}7-fold more efficient than SpUP. Biochemical studies of SpUP mutants showed that mutations of His169 reduced activity, while mutation of Lys162 abolished all activity, suggesting that the negative charge in the transition state resides mostly on uracil O2. This is in contrast to EcUP for which transition state stabilization occurs mostly at O4.

TEACHING GRAMMAR IN CONTEXT: WHY AND HOW?

Directory of Open Access Journals (Sweden)

Noor Maulidiyah

2017-04-01

Then the paper explains the concept of context in teaching grammar and describes the reasons for teaching grammar in context. The last part of the paper demonstrates how grammar is taught in context. These sample lessons are taken from different sources based on experts when teaching grammar in context.Teaching grammar in context is more useful and can help the students to master English better.

Context-dependent retrieval of information by neural-network dynamics with continuous attractors.

Science.gov (United States)

Tsuboshita, Yukihiro; Okamoto, Hiroshi

2007-08-01

Memory retrieval in neural networks has traditionally been described by dynamic systems with discrete attractors. However, recent neurophysiological findings of graded persistent activity suggest that memory retrieval in the brain is more likely to be described by dynamic systems with continuous attractors. To explore what sort of information processing is achieved by continuous-attractor dynamics, keyword extraction from documents by a network of bistable neurons, which gives robust continuous attractors, is examined. Given an associative network of terms, a continuous attractor led by propagation of neuronal activation in this network appears to represent keywords that express underlying meaning of a document encoded in the initial state of the network-activation pattern. A dominant hypothesis in cognitive psychology is that long-term memory is archived in the network structure, which resembles associative networks of terms. Our results suggest that keyword extraction by the neural-network dynamics with continuous attractors might symbolically represent context-dependent retrieval of short-term memory from long-term memory in the brain.

Average Revisited in Context

Science.gov (United States)

Watson, Jane; Chick, Helen

2012-01-01

This paper analyses the responses of 247 middle school students to items requiring the concept of average in three different contexts: a city's weather reported in maximum daily temperature, the number of children in a family, and the price of houses. The mixed but overall disappointing performance on the six items in the three contexts indicates…

Mobile Context Toolbox

DEFF Research Database (Denmark)

Stopczynski, Arkadiusz; Larsen, Jakob Eg; Skomail, Lukasz

2010-01-01

In this paper we describe an open framework utilizing sensors and application data on the Maemo mobile platform enabling rapid prototyping of context-aware mobile applications. The framework has an extensible layered architecture allowing new hardware and software sensors and features to be added...... to the context framework. We present initial results from in-the-wild experiments where contextual data was acquired using the tool. In the experiments 6 participants were using a Nokia N900 mobile phone continuously with a logger application for an average of 33 days. The study has provided valuable insights...

Context-dependent memory: colour versus odour.

Science.gov (United States)

Pointer, S C; Bond, N W

1998-06-01

An olfactory stimulus and a visual stimulus were employed in a context-dependent memory study using a prose passage as the to-be-remembered item. Ninety-five university students (aged 17-35 years) learned the passage of prose in the presence of one of the stimuli and were then asked to recall the passage with the original context either reinstated or not reinstated. The results revealed a significant context-dependent memory effect for the olfactory cue but not for the visual cue. They demonstrate support for the effectiveness of odours as context cues and it is suggested that context-dependent memory processes may underlie the formation and retrieval of odour-evoked autobiographical memories.

Context Management Framework for MAGNET Beyond

DEFF Research Database (Denmark)

Bauer, Martin; Olsen, Rasmus Løvenstein; Jacobsen, Martin

2006-01-01

In this paper we discuss architectural issues that are especially relevant in a context management system for Personal Networks. We identify the needs and requirements for a solution, based on a set of use cases, which can manage context information within one Personal Network (PN) or a federatio...... stack. We also address security and privacy issues that arise, if context information is to be shared between users in different PNs......In this paper we discuss architectural issues that are especially relevant in a context management system for Personal Networks. We identify the needs and requirements for a solution, based on a set of use cases, which can manage context information within one Personal Network (PN) or a federation...

Life context of pharmacological academic performance enhancement among university students--a qualitative approach.

Science.gov (United States)

Hildt, Elisabeth; Lieb, Klaus; Franke, Andreas Günter

2014-03-07

Academic performance enhancement or cognitive enhancement (CE) via stimulant drug use has received increasing attention. The question remains, however, whether CE solely represents the use of drugs for achieving better academic or workplace results or whether CE also serves various other purposes. The aim of this study was to put the phenomenon of pharmacological academic performance enhancement via prescription and illicit (psycho-) stimulant use (Amphetamines, Methylphenidate) among university students into a broader context. Specifically, we wanted to further understand students' experiences, the effects of use on students and other factors, such as pressure to perform in their academic and private lives. A sample of 18 healthy university students reporting the non-medical use of prescription and illicit stimulants for academic performance enhancement was interviewed in a face-to-face setting. The leading questions were related to the situations and context in which the students considered the non-medical use of stimulants. Based on the resultant transcript, two independent raters identified six categories relating to the life context of stimulant use for academic performance enhancement: Context of stimulant use beyond academic performance enhancement, Subjective experience of enhancement, Timing of consumption, Objective academic results, Side effects, Pressure to perform. The answers reveal that academic performance enhancement through the use of stimulants is not an isolated phenomenon that solely aims at enhancing cognition to achieve better academic results but that the multifaceted life context in which it is embedded is of crucial relevance. The participants not only considered the stimulants advantageous for enhancing academic performance, but also for leading an active life with a suitable balance between studying and time off. The most common reasons given for stimulant use were to maximize time, to increase motivation and to cope with memorizing

Human Amygdala Represents the Complete Spectrum of Subjective Valence

Science.gov (United States)

Jin, Jingwen; Zelano, Christina; Gottfried, Jay A.

2015-01-01

Although the amygdala is a major locus for hedonic processing, how it encodes valence information is poorly understood. Given the hedonic potency of odor stimuli and the amygdala's anatomical proximity to the peripheral olfactory system, we combined high-resolution fMRI with pattern-based multivariate techniques to examine how valence information is encoded in the amygdala. Ten human subjects underwent fMRI scanning while smelling 9 odorants that systematically varied in perceived valence. Representational similarity analyses showed that amygdala codes the entire dimension of valence, ranging from pleasantness to unpleasantness. This unidimensional representation significantly correlated with self-reported valence ratings but not with intensity ratings. Furthermore, within-trial valence representations evolved over time, prioritizing earlier differentiation of unpleasant stimuli. Together, these findings underscore the idea that both spatial and temporal features uniquely encode pleasant and unpleasant odor valence in the amygdala. The availability of a unidimensional valence code in the amygdala, distributed in both space and time, would create greater flexibility in determining the pleasantness or unpleasantness of stimuli, providing a mechanism by which expectation, context, attention, and learning could influence affective boundaries for guiding behavior. SIGNIFICANCE STATEMENT Our findings elucidate the mechanisms of affective processing in the amygdala by demonstrating that this brain region represents the entire valence dimension from pleasant to unpleasant. An important implication of this unidimensional valence code is that pleasant and unpleasant valence cannot coexist in the amygdale because overlap of fMRI ensemble patterns for these two valence extremes obscures their unique content. This functional architecture, whereby subjective valence maps onto a pattern continuum between pleasant and unpleasant poles, offers a robust mechanism by which context

A Cross-Context Analysis of Civic Engagement Linking CIVED and U.S: Census Data

Directory of Open Access Journals (Sweden)

Judith Torney-Purta

2012-04-01

Full Text Available This study investigates direct and indirect family, peer, school, and neighborhood effects on adolescents’ civic engagement utilizing data from the 1999 IEA Civic Education Study and the U.S. Census. The nationally representative sample consists of 2,729 students from 119 schools in the U.S. Multi-level regression techniques provide precise estimates of the separate and shared impact of each context on adolescents’ civic engagement. Individual students’ civic experiences and discourse in school and at home predict higher civic engagement, although the effects of these experiences vary based on the larger school and neighborhood contexts. Overall, interactive effects indicate that students who may traditionally be deemed at a disadvantage (either because of poor school or neighborhood conditions experience more benefits from increases in civic learning opportunities than do more advantaged students. Suggestions are made for secondary analyses of ICCS (the IEA civic education study of 2009.

PUBLIC RELATIONS IN PUBLIC ADMINISTRATION: ROLE AND MANAGEMENT, IN A SOCIO-POLITICAL MARKETING CONTEXT

Directory of Open Access Journals (Sweden)

Dorian Pocovnicu

2014-07-01

Full Text Available Many agree that PR and marketing are at their best when used together, when it comes to local public administration institutions there is the need for both an individual and symbiotic approach of the two. Taking into consideration that public interest organizations act within public space, PR represents a public communication strategy. Thus they present the role of generating a climate and state of social normality and, especially in democratic societies, PR plays the part of generator of communication flows between public institutions, citizens and stakeholders. In a social-political marketing context, envisaged as an aggregate of processes, with a multiple purpose, the generator which is PR must unfold coherently for each of the processes. It is our purpose in this paper to depict the PR role and management in the case of one local public administration institution (Bacau Prefect Institution, in a socio-political marketing context.

Repair of U/G and U/A in DNA by UNG2-associated repair complexes takes place predominantly by short-patch repair both in proliferating and growth-arrested cells

DEFF Research Database (Denmark)

Akbari, Mansour; Otterlei, Marit; Pena Diaz, Javier

2004-01-01

Nuclear uracil-DNA glycosylase UNG2 has an established role in repair of U/A pairs resulting from misincorporation of dUMP during replication. In antigen-stimulated B-lymphocytes UNG2 removes uracil from U/G mispairs as part of somatic hypermutation and class switch recombination processes. Using......, PCNA and DNA ligase, the latter detected as activity. Short-patch repair was the predominant mechanism both in extracts and UNG2-ARC from proliferating and less BER-proficient growth-arrested cells. Repair of U/G mispairs and U/A pairs was completely inhibited by neutralizing UNG...

Context quantization by minimum adaptive code length

DEFF Research Database (Denmark)

Forchhammer, Søren; Wu, Xiaolin

2007-01-01

Context quantization is a technique to deal with the issue of context dilution in high-order conditional entropy coding. We investigate the problem of context quantizer design under the criterion of minimum adaptive code length. A property of such context quantizers is derived for binary symbols....

Mobile Context Toolbox - An Extensible Context Framework for the Maemo Platform

DEFF Research Database (Denmark)

Stopczynski, Arkadiusz; Larsen, Jakob Eg; Skomial, Lukasz

2011-01-01

In this paper we describe an open framework utilizing sensors and application data on the Maemo mobile platform enabling rapid prototyping of context-aware mobile applications. The framework has an extensible layered architecture allowing new hardware and software sensors and features to be added...... to the context framework. We present initial results from in-the-wild experiments where contextual data was acquired using the tool. In the experiments 6 participants were using a Nokia N900 mobile phone continuously with a logger application for an average of 33 days. The study has provided valuable insights...

Goal-Driven Context-aware Service Composition

DEFF Research Database (Denmark)

Yu, Lian; Glenstrup, Arne John; Zhang, Yang

2011-01-01

context, user profile and computed results, are gathered by various services, and imported into an ontology based a context repository. A Goal Description Language, Context Condition/Effect are designed to describe the dynamic semantics of goal requirements and service capability. A planner is designed...... and implemented to dynamically compose services based on the current contexts, and a service runner is designed and implemented to invoke proper services based on the contexts and interactions with users.......Two important aspects are associated with service composition. One is to understand the needs and constraints for a new added-value composite service, and otherwise it would lead to an ad-hoc effort for service composition. The second is to reflect the changes of computing environment...

Estimating the response times of human operators working in the main control room of nuclear power plants based on the context of a seismic event – A case study

International Nuclear Information System (INIS)

Park, Jinkyun; Kim, Yochan; Kim, Jung Han; Jung, Wondea; Jang, Seung Cheol

2015-01-01

Highlights: • Response times under seismic events are necessary for human reliability analysis. • Conceptual framework to estimate response times under a seismic event is suggested. • Four kinds of representative contexts in seismic events are considered. • Rules for estimating response times on the representative contexts are extracted. - Abstract: After the Fukushima accident, a couple of novel issues have raised in terms of the safety assessment of nuclear power plants (NPPs). This means that the performance of human operators should be properly evaluated under an extreme event. However, it is unrealistic to collect a sufficient amount of human performance data from a real event, such as a great earthquake. As one of the promising solutions, a conceptual framework is suggested in this paper, which is helpful for estimating the response time data of human operators working in the main control room of NPPs under a seismic event. To this end, the four kinds of representative contexts that could be anticipated from seismic events are identified. Then the response times of human operators who are faced with similar contexts are reviewed from existing literatures and databases. As a result, a couple of rules that allow us to extrapolate the response times of human operators under seismic events are extracted. Although underlying rationales being used for determining these rules are still arguable, it is expected that response times under seismic events could be properly understood along with accumulating those of human operators against non-seismic conditions

CWRML: representing crop wild relative conservation and use data in XML.

Science.gov (United States)

Moore, Jonathan D; Kell, Shelagh P; Iriondo, Jose M; Ford-Lloyd, Brian V; Maxted, Nigel

2008-02-25

Crop wild relatives are wild species that are closely related to crops. They are valuable as potential gene donors for crop improvement and may help to ensure food security for the future. However, they are becoming increasingly threatened in the wild and are inadequately conserved, both in situ and ex situ. Information about the conservation status and utilisation potential of crop wild relatives is diverse and dispersed, and no single agreed standard exists for representing such information; yet, this information is vital to ensure these species are effectively conserved and utilised. The European Community-funded project, European Crop Wild Relative Diversity Assessment and Conservation Forum, determined the minimum information requirements for the conservation and utilisation of crop wild relatives and created the Crop Wild Relative Information System, incorporating an eXtensible Markup Language (XML) schema to aid data sharing and exchange. Crop Wild Relative Markup Language (CWRML) was developed to represent the data necessary for crop wild relative conservation and ensure that they can be effectively utilised for crop improvement. The schema partitions data into taxon-, site-, and population-specific elements, to allow for integration with other more general conservation biology schemata which may emerge as accepted standards in the future. These elements are composed of sub-elements, which are structured in order to facilitate the use of the schema in a variety of crop wild relative conservation and use contexts. Pre-existing standards for data representation in conservation biology were reviewed and incorporated into the schema as restrictions on element data contents, where appropriate. CWRML provides a flexible data communication format for representing in situ and ex situ conservation status of individual taxa as well as their utilisation potential. The development of the schema highlights a number of instances where additional standards-development may

Here's the Content--Where's the Context?

Science.gov (United States)

Crawford, Walt

2000-01-01

Considers whether libraries should replace bound print journals with full text online versions. Discusses costs; the inclusion of illustrations and tables; whether a journal article can stand alone or if it's part of a thematic cluster which adds important context; vertical context; evaluating context; and explaining compromises to users. (LRW)

Context and Crossmodal Interactions: An ERP Study

Directory of Open Access Journals (Sweden)

Beatriz R Sarmiento

2011-10-01

Full Text Available In a previous behavioural study, we reported that a particular context of stimulus congruency influenced audiovisual interactions. In particular, audiovisual interaction, measured in terms of congruency effect, was reduced when a high proportion of incongruent trials was presented. We argued that this modulation was due to changes in participants' control set as a function of the context of congruency, with greater control applied when most of the trials were incongruent. Since behavioural data do not allow to specify the level at which control was affecting audiovisual interaction, we conducted an event-related potentials (ERPs study to further investigate each context of audiovisual congruency. Participants performed an audiovisual congruency task, where the stimulus onset could be present on two different contexts mixed at random: a high proportion congruent context and a low proportion congruent context. The context manipulation was found to modulate brain ERPs related to perceptual and response selection processes, ie, the N2 and P3 components. The N2 amplitude was larger for the less common trials on both high and low congruent proportion contexts, while the P3 amplitude and latency were differentially modulated by incongruent trials on the two contexts.

OSMOSE experiment representativity studies.

Energy Technology Data Exchange (ETDEWEB)

Aliberti, G.; Klann, R.; Nuclear Engineering Division

2007-10-10

The OSMOSE program aims at improving the neutronic predictions of advanced nuclear fuels through measurements in the MINERVE facility at the CEA-Cadarache (France) on samples containing the following separated actinides: Th-232, U-233, U-234, U-235, U-236, U-238, Np-237, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-243, Cm-244 and Cm-245. The goal of the experimental measurements is to produce a database of reactivity-worth measurements in different neutron spectra for the separated heavy nuclides. This database can then be used as a benchmark for integral reactivity-worth measurements to verify and validate reactor analysis codes and integral cross-section values for the isotopes tested. In particular, the OSMOSE experimental program will produce very accurate sample reactivity-worth measurements for a series of actinides in various spectra, from very thermalized to very fast. The objective of the analytical program is to make use of the experimental data to establish deficiencies in the basic nuclear data libraries, identify their origins, and provide guidelines for nuclear data improvements in coordination with international programs. To achieve the proposed goals, seven different neutron spectra can be created in the MINERVE facility: UO2 dissolved in water (representative of over-moderated LWR systems), UO2 matrix in water (representative of LWRs), a mixed oxide fuel matrix, two thermal spectra containing large epithermal components (representative of under-moderated reactors), a moderated fast spectrum (representative of fast reactors which have some slowing down in moderators such as lead-bismuth or sodium), and a very hard spectrum (representative of fast reactors with little moderation from reactor coolant). The different spectra are achieved by changing the experimental lattice within the MINERVE reactor. The experimental lattice is the replaceable central part of MINERVE, which establishes the spectrum at the sample location. This configuration

Context-dependent competition in a model gut bacterial community.

Directory of Open Access Journals (Sweden)

Eric J de Muinck

Full Text Available Understanding the ecological processes that generate complex community structures may provide insight into the establishment and maintenance of a normal microbial community in the human gastrointestinal tract, yet very little is known about how biotic interactions influence community dynamics in this system. Here, we use natural strains of Escherichia coli and a simplified model microbiota to demonstrate that the colonization process on the strain level can be context dependent, in the sense that the outcome of intra-specific competition may be determined by the composition of the background community. These results are consistent with previous models for competition between organisms where one competitor has adapted to low resource environments whereas the other is optimized for rapid reproduction when resources are abundant. The genomic profiles of E. coli strains representing these differing ecological strategies provide clues for deciphering the genetic underpinnings of niche adaptation within a single species. Our findings extend the role of ecological theory in understanding microbial systems and the conceptual toolbox for describing microbial community dynamics. There are few, if any, concrete examples of context-dependent competition on a single trophic level. However, this phenomenon can have potentially dramatic effects on which bacteria will successfully establish and persist in the gastrointestinal system, and the principle should be equally applicable to other microbial ecosystems.

Music in context : Four case studies

NARCIS (Netherlands)

Randwijck, R.J.C. van

2008-01-01

In his thesis entitled “Music in Context. Four Case Studies”, R.J.C. van Randwijck investigates the context in which music has been created. It is a search in Four Case Studies, approaching four pieces of music from the context in which they were written in order to understand their meaning. The

Representing Uncertainty by Probability and Possibility

DEFF Research Database (Denmark)

of uncertain parameters. Monte Carlo simulation is readily used for practical calculations. However, an alternative approach is offered by possibility theory making use of possibility distributions such as intervals and fuzzy intervals. This approach is well suited to represent lack of knowledge or imprecision......Uncertain parameters in modeling are usually represented by probability distributions reflecting either the objective uncertainty of the parameters or the subjective belief held by the model builder. This approach is particularly suited for representing the statistical nature or variance...

From Usability Testing to Clinical Simulations: Bringing Context into the Design and Evaluation of Usable and Safe Health Information Technologies. Contribution of the IMIA Human Factors Engineering for Healthcare Informatics Working Group.

Science.gov (United States)

Kushniruk, A; Nohr, C; Jensen, S; Borycki, E M

2013-01-01

The objective of this paper is to explore human factors approaches to understanding the use of health information technology (HIT) by extending usability engineering approaches to include analysis of the impact of clinical context through use of clinical simulations. Methods discussed are considered on a continuum from traditional laboratory-based usability testing to clinical simulations. Clinical simulations can be conducted in a simulation laboratory and they can also be conducted in real-world settings. The clinical simulation approach attempts to bring the dimension of clinical context into stronger focus. This involves testing of systems with representative users doing representative tasks, in representative settings/environments. Application of methods where realistic clinical scenarios are used to drive the study of users interacting with systems under realistic conditions and settings can lead to identification of problems and issues with systems that may not be detected using traditional usability engineering methods. In conducting such studies, careful consideration is needed in creating ecologically valid test scenarios. The evidence obtained from such evaluation can be used to improve both the usability and safety of HIT. In addition, recent work has shown that clinical simulations, in particular those conducted in-situ, can lead to considerable benefits when compared to the costs of running such studies. In order to bring context of use into the testing of HIT, clinical simulation, involving observing representative users carrying out tasks in representative settings, holds considerable promise.

Entrepreneurs in transitional Serbia - the context of management and socially accepted type of private enterprise

Directory of Open Access Journals (Sweden)

Trifunović Vesna

2015-01-01

Full Text Available The process of post-socialist transformation in Serbia included, among other things, a boost of selfemployed entrepreneurship looking to place themselves within a society. This phenomenon occurred within the complex conditions that included the past socialist heritage and egalitarian ideology, representing thus a potential a priori negative social attitudes towards private enterprise and entrepreneurs, as well as specific overall transition path that can be divided into two distinct and disparate stages. This particular context has influenced the complexity of the problem of entrepreneurship in this society. Therefore, this paper will firstly focus on the context and conditions of entrepreneurial business from the perspective of the very entrepreneurs; additionally, the paper will try to discern the socially accepted types of entrepreneurs, favoring the assumption that this type of economy, in principle, has been accepted, i.e., there is no social resistance. The discussion is based on analysis of newspaper articles that provide detailed written accounts, while the context of entrepreneurial business in transitional Serbia is based on data provided by the Union of Employers of Serbia, the Agency of Business Registers and reports of the National Agency for Regional Development of the Republic of Serbia.

The strategy curve. A method for representing and interpreting generator bidding strategies

International Nuclear Information System (INIS)

Lucas, N.; Taylor, P.

1995-01-01

The pool is the novel trading arrangement at the heart of the privatized electricity market in England and Wales. This central role in the new system makes it crucial that it is seen to function efficiently. Unfortunately, it is governed by a set of complex rules, which leads to a lack of transparency, and this makes monitoring of its operation difficult. This paper seeks to provide a method for illuminating one aspect of the pool, that of generator bidding behaviour. We introduce the concept of a strategy curve, which is a concise device for representing generator bidding strategies. This curve has the appealing characteristic of directly revealing any deviation in the bid price of a genset from the costs of generating electricity. After a brief discussion about what constitutes price and cost in this context we present a number of strategy curves for different days and provide some interpretation of their form, based in part on our earlier work with game theory. (author)

Exclusivity structures and graph representatives of local complementation orbits

Science.gov (United States)

Cabello, Adán; Parker, Matthew G.; Scarpa, Giannicola; Severini, Simone

2013-07-01

We describe a construction that maps any connected graph G on three or more vertices into a larger graph, H(G), whose independence number is strictly smaller than its Lovász number which is equal to its fractional packing number. The vertices of H(G) represent all possible events consistent with the stabilizer group of the graph state associated with G, and exclusive events are adjacent. Mathematically, the graph H(G) corresponds to the orbit of G under local complementation. Physically, the construction translates into graph-theoretic terms the connection between a graph state and a Bell inequality maximally violated by quantum mechanics. In the context of zero-error information theory, the construction suggests a protocol achieving the maximum rate of entanglement-assisted capacity, a quantum mechanical analogue of the Shannon capacity, for each H(G). The violation of the Bell inequality is expressed by the one-shot version of this capacity being strictly larger than the independence number. Finally, given the correspondence between graphs and exclusivity structures, we are able to compute the independence number for certain infinite families of graphs with the use of quantum non-locality, therefore highlighting an application of quantum theory in the proof of a purely combinatorial statement.

Studio CONTEXT at Studio Mumbai

DEFF Research Database (Denmark)

Hilberth, Thomas Roger

2017-01-01

Studio CONTEXT @ STUDIO MUMBAI Studio CONTEXT deals with a sustainable architecture based on complexity on all scales of a specific context, that involves geographical, historical, anthropological and social reflections, a cross cultural involvement and mutual learning as well as investigations...... into the most basic elements to define the core qualities of architecture: space, light and material. During three semesters Studio CONTEXT engaged in collaboration with the renowned Indian architectural office STUDIO MUMBAI, at the time located under the palm trees of Nagaon near Ali Bagh in Maharashtra...... MUMBAI, which whom we worked side by side on their premises, we developed proposals for a new square and different typologies of social housing. The projects were then presented for the local council and the community and left with them with the possibility of implementation. After a thorough phase...

The risk of a safety-critical event associated with mobile device use in specific driving contexts.

Science.gov (United States)

Fitch, Gregory M; Hanowski, Richard J; Guo, Feng

2015-01-01

We explored drivers' mobile device use and its associated risk of a safety-critical event (SCE) in specific driving contexts. Our premise was that the SCE risk associated with mobile device use increases when the driving task becomes demanding. Data from naturalistic driving studies involving commercial motor vehicle drivers and light vehicle drivers were partitioned into subsets representative of specific driving contexts. The subsets were generated using data set attributes that included level of service and relation to junction. These attributes were selected based on exogenous factors known to alter driving task demands. The subsets were analyzed using a case-cohort approach, which was selected to complement previous investigations of mobile device SCE risk using naturalistic driving data. Both commercial motor vehicle and light vehicle drivers varied as to how much they conversed on a mobile device but did not vary their engagement in visual-manual subtasks. Furthermore, commercial motor vehicle drivers conversed less frequently as the driving task demands increased, whereas light vehicle drivers did not. The risk of an SCE associated with mobile device use was dependent on the subtask performed and the driving context. Only visual-manual subtasks were associated with an increased SCE risk, whereas conversing was associated with a decreased risk in some driving contexts. Drivers' engagement in mobile device subtasks varies by driving context. The SCE risk associated with mobile device use is dependent on the types of subtasks performed and the driving context. The findings of this exploratory study can be applied to the design of driver-vehicle interfaces that mitigate distraction by preventing visual-manual subtasks while driving.

Decisions in poverty contexts.

Science.gov (United States)

Shafir, Eldar

2017-12-01

The circumstances surrounding poverty-tight financial challenges, instability of income and expenses, low savings, no insurance, and several other stressors-translate into persistent and cognitively taxing hardship for people in poverty contexts. Thoughts about money and expenses loom large, shape mental associations, interfere with other experiences, and are difficult to suppress. The persistent juggling of insufficient resources affects attention, cognitive resources, and ensuing decisions. Despite the demanding struggle with challenging circumstances, people in poverty encounter disdain rather than admiration, and obstacles rather than support. Societal appreciation for the power of context, along with behaviorally informed programs designed to facilitate life under poverty, are essential for those in poverty contexts to be able to make the most of their challenging circumstances. Copyright © 2017 Elsevier Ltd. All rights reserved.

"Let's Be Honest Most People in the Sporting Industry Are Still Males": The Importance of Socio-Cultural Context for Female Graduates

Science.gov (United States)

Leberman, Sarah; Shaw, Sally

2015-01-01

The business case for diversity is increasingly being recognised. However, worldwide women are still under-represented at the executive level. The notions of employability and career adaptability are examined in the context of female sport management graduates, to better understand why they are not attaining leadership positions in New Zealand…

Accounting for representativeness errors in the inversion of atmospheric constituent emissions: application to the retrieval of regional carbon monoxide fluxes

Directory of Open Access Journals (Sweden)

Mohammad Reza Koohkan

2012-07-01

Full Text Available A four-dimensional variational data assimilation system (4D-Var is developed to retrieve carbon monoxide (CO fluxes at regional scale, using an air quality network. The air quality stations that monitor CO are proximity stations located close to industrial, urban or traffic sources. The mismatch between the coarsely discretised Eulerian transport model and the observations, inferred to be mainly due to representativeness errors in this context, lead to a bias (average simulated concentrations minus observed concentrations of the same order of magnitude as the concentrations. 4D-Var leads to a mild improvement in the bias because it does not adequately handle the representativeness issue. For this reason, a simple statistical subgrid model is introduced and is coupled to 4D-Var. In addition to CO fluxes, the optimisation seeks to jointly retrieve influence coefficients, which quantify each station's representativeness. The method leads to a much better representation of the CO concentration variability, with a significant improvement of statistical indicators. The resulting increase in the total inventory estimate is close to the one obtained from remote sensing data assimilation. This methodology and experiments suggest that information useful at coarse scales can be better extracted from atmospheric constituent observations strongly impacted by representativeness errors.

Formation of partnership between business and government in the context of business formation in Ukraine

Directory of Open Access Journals (Sweden)

Сергій Анатолійович Єфіменко

2015-10-01

Full Text Available The philosophical aspects of mutual coverage of business and government in the context of Ukrainian reality are revealed in the article. The basic models of interaction between business and the state are pluralistic and neo-corporative models. The pluralist model is characterized for activities of the state in the interests of the business class and neo-corporative model implies for the authorities an opportunity to support and strengthen individual businesses, making them authorized representatives of their interests

Blockage of the pyrimidine biosynthetic pathway affects riboflavin production in Ashbya gossypii.

Science.gov (United States)

Silva, Rui; Aguiar, Tatiana Q; Domingues, Lucília

2015-01-10

The Ashbya gossypii riboflavin biosynthetic pathway and its connection with the purine pathway have been well studied. However, the outcome of genetic alterations in the pyrimidine pathway on riboflavin production by A. gossypii had not yet been assessed. Here, we report that the blockage of the de novo pyrimidine biosynthetic pathway in the recently generated A. gossypii Agura3 uridine/uracil auxotrophic strain led to improved riboflavin production on standard agar-solidified complex medium. When extra uridine/uracil was supplied, the production of riboflavin by this auxotroph was repressed. High concentrations of uracil hampered this (and the parent) strain growth, whereas excess uridine favored the A. gossypii Agura3 growth. Considering that the riboflavin and the pyrimidine pathways share the same precursors and that riboflavin overproduction may be triggered by nutritional stress, we suggest that overproduction of riboflavin by the A. gossypii Agura3 may occur as an outcome of a nutritional stress response and/or of an increased availability in precursors for riboflavin biosynthesis, due to their reduced consumption by the pyrimidine pathway. Copyright © 2014 Elsevier B.V. All rights reserved.

Trust-Based and Context-Aware Authentication in a Software Architecture for Context and Proximity-Aware Services

Science.gov (United States)

Lenzini, Gabriele

We describe an existing software architecture for context and proximity aware services that enables trust-based and context-aware authentication. A service is proximity aware when it automatically detects the presence of entities in its proximity. Authentication is context-aware when it uses contextual information to discern among different identities and to evaluate to which extent they are authentic. The software architecture that we describe here is functioning in our Institute: It manages a sensor network to detect the presence and location of users and their devices. A context manager is responsible to merge the different sources of contextual information, to solve potential contradictions, and to determine the level of authentication of the identity of the person approaching one of the services offered in the coffee-break corners of our Institute. In our solution for context-aware authentication, sensors are managed as if they were recommenders having subjective belief, disbelief, and uncertainty (i.e., trust) on the position and identity of users. A sensor’s subjective trust depends on what it has been sensing in the environment. We discuss the results of an array of simulations that we conducted to validate our concept of trust-based and context-aware authentication. We use Subjective Logic to manage trust.

40 CFR 72.22 - Alternate designated representative.

Science.gov (United States)

2010-07-01

... designated representative is selected shall include a procedure for the owners and operators of the source and affected units at the source to authorize the alternate designated representative to act in lieu...) In the event of a conflict, any action taken by the designated representative shall take precedence...

Associative recognition and the hippocampus: differential effects of hippocampal lesions on object-place, object-context and object-place-context memory.

Science.gov (United States)

Langston, Rosamund F; Wood, Emma R

2010-10-01

The hippocampus is thought to be required for the associative recognition of objects together with the spatial or temporal contexts in which they occur. However, recent data showing that rats with fornix lesions perform as well as controls in an object-place task, while being impaired on an object-place-context task (Eacott and Norman (2004) J Neurosci 24:1948-1953), suggest that not all forms of context-dependent associative recognition depend on the integrity of the hippocampus. To examine the role of the hippocampus in context-dependent recognition directly, the present study tested the effects of large, selective, bilateral hippocampus lesions in rats on performance of a series of spontaneous recognition memory tasks: object recognition, object-place recognition, object-context recognition and object-place-context recognition. Consistent with the effects of fornix lesions, animals with hippocampus lesions were impaired only on the object-place-context task. These data confirm that not all forms of context-dependent associative recognition are mediated by the hippocampus. Subsequent experiments suggested that the object-place task does not require an allocentric representation of space, which could account for the lack of impairment following hippocampus lesions. Importantly, as the object-place-context task has similar spatial requirements, the selective deficit in object-place-context recognition suggests that this task requires hippocampus-dependent neural processes distinct from those required for allocentric spatial memory, or for object memory, object-place memory or object-context memory. Two possibilities are that object, place, and context information converge only in the hippocampus, or that recognition of integrated object-place-context information requires a hippocampus-dependent mode of retrieval, such as recollection. © 2009 Wiley-Liss, Inc.

Kismeth: Analyzer of plant methylation states through bisulfite sequencing

Directory of Open Access Journals (Sweden)

Martienssen Robert A

2008-09-01

Full Text Available Abstract Background There is great interest in probing the temporal and spatial patterns of cytosine methylation states in genomes of a variety of organisms. It is hoped that this will shed light on the biological roles of DNA methylation in the epigenetic control of gene expression. Bisulfite sequencing refers to the treatment of isolated DNA with sodium bisulfite to convert unmethylated cytosine to uracil, with PCR converting the uracil to thymidine followed by sequencing of the resultant DNA to detect DNA methylation. For the study of DNA methylation, plants provide an excellent model system, since they can tolerate major changes in their DNA methylation patterns and have long been studied for the effects of DNA methylation on transposons and epimutations. However, in contrast to the situation in animals, there aren't many tools that analyze bisulfite data in plants, which can exhibit methylation of cytosines in a variety of sequence contexts (CG, CHG, and CHH. Results Kismeth http://katahdin.mssm.edu/kismeth is a web-based tool for bisulfite sequencing analysis. Kismeth was designed to be used with plants, since it considers potential cytosine methylation in any sequence context (CG, CHG, and CHH. It provides a tool for the design of bisulfite primers as well as several tools for the analysis of the bisulfite sequencing results. Kismeth is not limited to data from plants, as it can be used with data from any species. Conclusion Kismeth simplifies bisulfite sequencing analysis. It is the only publicly available tool for the design of bisulfite primers for plants, and one of the few tools for the analysis of methylation patterns in plants. It facilitates analysis at both global and local scales, demonstrated in the examples cited in the text, allowing dissection of the genetic pathways involved in DNA methylation. Kismeth can also be used to study methylation states in different tissues and disease cells compared to a reference sequence.

Learning in context

DEFF Research Database (Denmark)

Keiding, Tina Bering

2007-01-01

This article offers a re-description of the concept of learning context. Drawing on Niklas Luhmann and Gregory Bateson it suggests an alternative to situated, social learning and activity theory. The conclusion is that learning context designates an individual's reconstruction of the environment...... through contingent handling of differences and that the individual emerge as learning through the actual construction. Selection of differences is influenced by the learner's actual knowledge, the nature of the environment and the current horizon of meaning in which the current adaptive perspective...... becomes a significant factor. The re-description contributes to didaktik  through renewed understandings of participants' background in teaching and learning....

Theorising context in psychology

DEFF Research Database (Denmark)

Glaveanu, Vlad Petre

2014-01-01

This article aims to address the issue of what context is and how it can be incorporated in psychological theory by using the case study of creativity research. It starts from a basic definition of context as the spatiotemporal continuum that, together with psychological phenomena, constitutes...... a totality and should be considered a single, integrated whole. As such, contexts are neither subjective, existing only in perception, nor are they a set of variables external to the person, but participate directly in the processes under study in psychology. We can therefore distinguish between “flat......” theorising, one-dimensional and overconcerned with intra-psychological factors, and “3-D” models trying to articulate the psychological, the spatial (sociomaterial), and the temporal. These categories are illustrated by different theoretical approaches to creativity. It is argued here that a cultural...

Generative Contexts

Science.gov (United States)

Lyles, Dan Allen

Educational research has identified how science, technology, engineering, and mathematics (STEM) practice and education have underperforming metrics in racial and gender diversity, despite decades of intervention. These disparities are part of the construction of a culture of science that is alienating to these populations. Recent studies in a social science framework described as "Generative Justice" have suggested that the context of social and scientific practice might be modified to bring about more just and equitable relations among the disenfranchised by circulating the value they and their non-human allies create back to them in unalienated forms. What is not known are the underlying principles of social and material space that makes a system more or less generative. I employ an autoethnographic method at four sites: a high school science class; a farm committed to "Black and Brown liberation"; a summer program geared towards youth environmental mapping; and a summer workshop for Harlem middle school students. My findings suggest that by identifying instances where material affinity, participatory voice, and creative solidarity are mutually reinforcing, it is possible to create educational contexts that generate unalienated value, and circulate it back to the producers themselves. This cycle of generation may help explain how to create systems of justice that strengthen and grow themselves through successive iterations. The problem of lack of diversity in STEM may be addressed not merely by recruiting the best and the brightest from underrepresented populations, but by changing the context of STEM education to provide tools for its own systematic restructuring.

Context Memory in Korsakoff's Syndrome

NARCIS (Netherlands)

Kessels, R.P.C.; Kopelman, M.D.

2012-01-01

Memory for contextual information and target-context integration are crucial for successful episodic memory formation and are impaired in patients with Korsakoff's syndrome. In this paper we review the evidence for the notion that a context memory deficit makes an important contribution to the

Context memory in Korsakoff's syndrome.

NARCIS (Netherlands)

Kessels, R.P.C.; Kopelman, M.D.

2012-01-01

Memory for contextual information and target-context integration are crucial for successful episodic memory formation and are impaired in patients with Korsakoff's syndrome. In this paper we review the evidence for the notion that a context memory deficit makes an important contribution to the

Big data and information management: modeling the context decisional supported by sistemography

Directory of Open Access Journals (Sweden)

William Barbosa Vianna

2016-04-01

Full Text Available Introduction: The study justified by the scarcity of studies in the field of information science that addressing the phenomenon of big data from the perspective of information management. that will allow further development of computer simulation. Objective: The objective is to identify and represent the general elements of the decision-making process in the context of big data. Methodology: It is an exploratory study and theoretical and deductive nature. Results: It resulted in the identification of the main elements involved in decision-making on big data environment and its sistemografic representation. Conclusions: It was possible to develop a representation which will allow further development of computer simulation.

Dynamical control of quantum systems in the context of mean ergodic theorems

International Nuclear Information System (INIS)

Bernád, J Z

2017-01-01

Equidistant and non-equidistant single pulse ‘bang–bang’ dynamical controls are investigated in the context of mean ergodic theorems. We show the requirements in which the limit of infinite pulse control for both the equidistant and the non-equidistant dynamical control converges to the same unitary evolution. It is demonstrated that the generator of this evolution can be obtained by projecting the generator of the free evolution onto the commutant of the unitary operator representing the pulse. Inequalities are derived to prove this statement and in the case of non-equidistant approach these inequalities are optimised as a function of the time intervals. (paper)

Representative Sampling for reliable data analysis

DEFF Research Database (Denmark)

Petersen, Lars; Esbensen, Kim Harry

2005-01-01

regime in order to secure the necessary reliability of: samples (which must be representative, from the primary sampling onwards), analysis (which will not mean anything outside the miniscule analytical volume without representativity ruling all mass reductions involved, also in the laboratory) and data...

OAS :: Authorities : Permanent Representatives to the OAS

Science.gov (United States)

Rights Actions against Corruption C Children Civil Registry Civil Society Contact Us Culture Cyber Representative of Belize Diego Pary Rodríguez Bolivia Diego Pary Rodríguez Ambassador, Permanent Representative of Bolivia José Luiz Machado Brazil José Luiz Machado e Costa Ambassador, Permanent Representative

List of Accredited Representatives

Data.gov (United States)

Department of Veterans Affairs — VA accreditation is for the sole purpose of providing representation services to claimants before VA and does not imply that a representative is qualified to provide...

Spectroscopic Studies of Molecular Systems relevant in Astrobiology

Science.gov (United States)

Fornaro, Teresa

2016-01-01

double-ζ quality such as N07D and SNSD. Such a protocol has been then applied to the dimers of nucleobases in order to study the perturbation on the vibrational frequencies and infrared intensities induced by the intermolecular hydrogen-bonding interactions. Efforts have been made to challenge the problems of simulating strongly anharmonic vibrations within hydrogen-bonded bridges, focusing on the requirement of a very accurate description of the underlying potential energy surface. Improvements for such vibrations have been achieved by means of hybrid models, where the harmonic part of the force-field is computed at a higher level of theory like B2PLYP, or by application of the less demanding ONIOM B2PLYP:B3LYP scheme, which is a focused model where only the part of the molecular system forming the hydrogen bonds is treated at B2PLYP level of theory. Moreover, for improving the vibrational frequencies of modes like the stretching of C=O and N-H functional groups, which are particularly sensitive to hydrogen-bonding, correction parameters for the B3LYP-D3/N07D frequencies have been determined. Afterwards, the treatment of the vibrational properties of nucleobases in condensed phases has been faced, focusing on uracil in the solid state. In particular, a heptamer cluster of uracil molecules has been considered as model to represent the properties in the solid state. The relative vibrational frequencies have been computed at anharmonic level within the VPT2 framework, combining two cost-effective approaches, namely the hybrid B3LYP-D3/N07D:DFTBA model, where the harmonic frequencies are computed with B3LYP-D3/N07D method and the anharmonic corrections are evaluated with the less expensive DFTBA method, and the reduced dimensionality VPT2 (RD-VPT2) approach, in which only selected vibrational modes are calculated anharmonically (including the couplings with the other modes) while the remaining modes are treated at the harmonic level, using the B3LYP-D3/N07D method only

Understanding social disparities in hypertension prevalence, awareness, treatment, and control: the role of neighborhood context.

Science.gov (United States)

Morenoff, Jeffrey D; House, James S; Hansen, Ben B; Williams, David R; Kaplan, George A; Hunte, Haslyn E

2007-11-01

The spatial segregation of the US population by socioeconomic position and especially race/ethnicity suggests that the social contexts or "neighborhoods" in which people live may substantially contribute to social disparities in hypertension. The Chicago Community Adult Health Study did face-to-face interviews, including direct measurement of blood pressure, with a representative probability sample of adults in Chicago. These data were used to estimate socioeconomic and racial-ethnic disparities in the prevalence, awareness, treatment, and control of hypertension, and to analyze how these disparities are related to the areas in which people live. Hypertension was significantly negatively associated with neighborhood affluence/gentrification, and adjustments for context eliminated the highly significant disparity between blacks/African-Americans and whites, and reduced the significant educational disparity by 10-15% to borderline statistical significance. Awareness of hypertension was significantly higher in more disadvantaged neighborhoods and in places with higher concentrations of blacks (and lower concentrations of Hispanics and immigrants). Adjustment for context completely eliminated blacks' greater awareness, but slightly accentuated the lesser awareness of Hispanics and the greater levels of awareness among the less educated. There was no consistent evidence of either social disparities in or contextual associations with treatment of hypertension, given awareness. Among those on medication, blacks were only 40-50% as likely as whites to have their hypertension controlled, but context played little or no role in either the level of or disparities in control of hypertension. In sum, residential contexts potentially play a large role in accounting for racial/ethnic and, to a lesser degree, socioeconomic disparities in hypertension prevalence and, in a different way, awareness, but not in treatment or control of diagnosed hypertension.

Putting tumours in context

Energy Technology Data Exchange (ETDEWEB)

Bissell, Mina J.; Radisky, Derek

2001-10-01

The interactions between cancer cells and their micro- and macroenvironment create a context that promotes tumor growth and protects it from immune attack. The functional association of cancer cells with their surrounding tissues forms a new 'organ' that changes as malignancy progresses. Investigation of this process might provide new insights into the mechanisms of tumorigenesis and could also lead to new therapeutic targets. Under normal conditions, ORGANS are made up of TISSUES that exchange information with other cell types via cell-cell contact, cytokines and the EXTRACELLULAR MATRIX (ECM). The ECM, which is produced by collaboration between STROMAL fibroblasts and EPITHELIAL cells, provides structural scaffolding for cells, as well as contextual information. The endothelial vasculature provides nutrients and oxygen, and cells of the immune system combat pathogens and remove apoptotic cells. Epithelial cells associate into intact, polarized sheets. These tissues communicate through a complex network of interactions: physically, through direct contact or through the intervening ECM, and biochemically, through both soluble and insoluble signalling molecules. In combination, these interactions provide the information that is necessary to maintain cellular differentiation and to create complex tissue structures. Occasionally, the intercellular signals that define the normal context become disrupted. Alterations in epithelial tissues can lead to movement of epithelial sheets and proliferation - for example, after activation of mesenchymal fibroblasts due to wounding.Normally, these conditions are temporary and reversible, but when inflammation is sustained, an escalating feedback loop ensues.Under persistent inflammatory conditions, continual upregulation of enzymes such as matrix metalloproteinases (MMPs) by stromal fibroblasts can disrupt the ECM, and invading immune cells can overproduce factors that promote abnormal proliferation. As this process

Context-aware Mobile Hypermedia: Concepts, Framework, and Applications

DEFF Research Database (Denmark)

Hansen, Frank Allan

the requirements for context aware mobile hypermedia, both theoretically and practically, and is realized by: • A conceptual model for context-aware hypermedia, • HyCon, a framework for context-aware mobile hypermedia, • A range of hypermedia applications utilizing context-awareness to support mobile fieldwork...... moves beyond the desktop and into the physical environments we live and work in, it may be worthwhile to support these digital-physical relationships. The thesis addresses the definition, design and requirements for context-aware mobile hypermedia systems. Context-aware hypermedia applies ubiquitous...... of a framework for context-aware hypermedia, HyCon, implementing general abstractions for acquiring context information and demonstrating how traditional anchor based hypermedia models can be extended to encompass both digital and physical entities. Several prototype applications built atop HyCon are also...

Context counts! Social anxiety modulates the processing of fearful faces in the context of chemosensory anxiety signals

Directory of Open Access Journals (Sweden)

Dirk eAdolph

2013-06-01

Full Text Available During emotion perception, context is an important source of information. Whether contextual cues from modalities other than vision or audition influence the perception of social emotional information has not been investigated.Thus, the present study aimed at testing emotion perception and regulation in response to fearful facial expressions presented in the context of chemosensory stimuli derived from sweat of anxious individuals. In groups of high (HSA and low socially anxious (LSA participants we recorded the startle reflex (Experiment I, and analysed event-related potentials (ERPs; Experiment II while they viewed anxious facial expressions in the context of chemosensory anxiety signals and chemosensory control stimuli. Results revealed that N1/P1 and N170 amplitudes were larger while Late Positive Potential (LPP activity was smaller for facial expressions presented in the context of the anxiety and the chemosensory control stimulus as compared to facial expressions without a chemosensory context. Furthermore, HSA participants were highly sensitive to the contextual anxiety signals. They showed enhanced motivated attention allocation (LPP, Study II, as well as larger startle responses towards faces in the context of chemosensory anxiety signals than did LSA participants (Study I. Chemosensory context had no effect on emotion regulation, and both LSA and HSA participants showed effective emotion regulation (Study I and II. In conclusion, both anxiety and chemosensory sport context stimuli enhanced early attention allocation and structural encoding, but diminished motivated attention allocation to the facial expressions. The current results show that visual and chemosensory information is integrated on virtually all levels of stimulus processing and that socially anxious individuals might be especially sensitive to chemosensory contextual social information.

Social context and perceived agency affects empathy for pain: an event-related fMRI investigation.

Science.gov (United States)

Akitsuki, Yuko; Decety, Jean

2009-08-15

Studying of the impact of social context on the perception of pain in others is important for understanding the role of intentionality in interpersonal sensitivity, empathy, and implicit moral reasoning. Here we used an event-related fMRI with pain and social context (i.e., the number of individuals in the stimuli) as the two factors to investigate how different social contexts and resulting perceived agency modulate the neural response to the perception of pain in others. Twenty-six healthy participants were scanned while presented with short dynamic visual stimuli depicting painful situations accidentally caused by or intentionally caused by another individual. The main effect of perception of pain was associated with signal increase in the aMCC, insula, somatosensory cortex, SMA and PAG. Importantly, perceiving the presence of another individual led to specific hemodynamic increase in regions involved in representing social interaction and emotion regulation including the temporoparietal junction, medial prefrontal cortex, inferior frontal gyrus, and orbitofrontal cortex. Furthermore, the functional connectivity pattern between the left amygdala and other brain areas was modulated by the perceived agency. Our study demonstrates that the social context in which pain occurs modulate the brain response to other's pain. This modulation may reflect successful adaptation to potential danger present in a social interaction. Our results contribute to a better understanding of the neural mechanisms underpinning implicit moral reasoning that concern actions that can harm other people.

GEOMETRIC CONTEXT AND ORIENTATION MAP COMBINATION FOR INDOOR CORRIDOR MODELING USING A SINGLE IMAGE

Directory of Open Access Journals (Sweden)

A. B. Jahromi

2016-06-01

Full Text Available Since people spend most of their time indoors, their indoor activities and related issues in health, security and energy consumption have to be understood. Hence, gathering and representing spatial information of indoor spaces in form of 3D models become very important. Considering the available data gathering techniques with respect to the sensors cost and data processing time, single images proved to be one of the reliable sources. Many of the current single image based indoor space modeling methods are defining the scene as a single box primitive. This domain-specific knowledge is usually not applicable in various cases where multiple corridors are joined at one scene. Here, we addressed this issue by hypothesizing-verifying multiple box primitives which represents the indoor corridor layout. Middle-level perceptual organization is the foundation of the proposed method, which relies on finding corridor layout boundaries using both detected line segments and virtual rays created by orthogonal vanishing points. Due to the presence of objects, shadows and occlusions, a comprehensive interpretation of the edge relations is often concealed. This necessitates the utilization of virtual rays to create a physically valid layout hypothesis. Many of the former methods used Orientation Map or Geometric Context to evaluate their proposed layout hypotheses. Orientation map is a map that reveals the local belief of region orientations computed from line segments, and in a segmented image geometric context uses color, texture, edge, and vanishing point cues to estimate the likelihood of each possible label for all super-pixels. Here, the created layout hypotheses are evaluated by an objective function which considers the fusion of orientation map and geometric context with respect to the horizontal viewing angle at each image pixel. Finally, the best indoor corridor layout hypothesis which gets the highest score from the scoring function will be selected

Exchanging the Context between OGC Geospatial Web clients and GIS applications using Atom

Science.gov (United States)

Maso, Joan; Díaz, Paula; Riverola, Anna; Pons, Xavier

2013-04-01

Currently, the discovery and sharing of geospatial information over the web still presents difficulties. News distribution through website content was simplified by the use of Really Simple Syndication (RSS) and Atom syndication formats. This communication exposes an extension of Atom to redistribute references to geospatial information in a Spatial Data Infrastructure distributed environment. A geospatial client can save the status of an application that involves several OGC services of different kind and direct data and share this status with other users that need the same information and use different client vendor products in an interoperable way. The extensibility of the Atom format was essential to define a format that could be used in RSS enabled web browser, Mass Market map viewers and emerging geospatial enable integrated clients that support Open Geospatial Consortium (OGC) services. Since OWS Context has been designed as an Atom extension, it is possible to see the document in common places where Atom documents are valid. Internet web browsers are able to present the document as a list of items with title, abstract, time, description and downloading features. OWS Context uses GeoRSS so that, the document can be to be interpreted by both Google maps and Bing Maps as items that have the extent represented in a dynamic map. Another way to explode a OWS Context is to develop an XSLT to transform the Atom feed into an HTML5 document that shows the exact status of the client view window that saved the context document. To accomplish so, we use the width and height of the client window, and the extent of the view in world (geographic) coordinates in order to calculate the scale of the map. Then, we can mix elements in world coordinates (such as CF-NetCDF files or GML) with elements in pixel coordinates (such as WMS maps, WMTS tiles and direct SVG content). A smarter map browser application called MiraMon Map Browser is able to write a context document and read

A Framework for Developing Context-aware Systems

Directory of Open Access Journals (Sweden)

Vangalur Alagar

2014-09-01

Full Text Available Context-aware computing refers to a general class of mobile real-time reactive systems that continuously sense their physical environment, and adapt their behavior accordingly. Context-awareness is an essential inherent property of ubiquitous computing or pervasive computing systems. Such systems are much richer and more complex than many software systems. The richness mainly comes from context-awareness, the heterogeneity of mobile devices and their service types, while complexity arises in the multitude of adaptations enforced by system policies. In order to provide the true intended effect on the application of services without compromising on the richness, the complexity must be tamed. Towards this goal, this paper proposes a component-based architecture for a Context-aware Framework in which context, awareness capabilities, reactions, and adaptations are formally dealt with. Two formal languages are designed to express context situations and express workflow policies, which respectively lead to a context reasoner and to enforce adaptations.With these formalisms and a component design that can be formalized, this work fulfills a formal approach to construct context-aware applications. Two case studies are explained, of which one is a proof-of-concept case study from service-oriented domain. It is fully implemented to illustrate the expressiveness of the framework design and robustness of its implementation.

Specific work-life issues of single and childless female expatriates: An exploratory study in the Swiss context

OpenAIRE

Salamin Xavier

2015-01-01

Work life balance has been identified as a key challenge in expatriation which impacts both private and professional spheres. Especially for women work and private life issues have been found to be particularly exacerbated abroad. Up until today research on work life interface in the expatriation context has focused on expatriates relocating with a family. However single expatriates represent a non negligible proportion of the expatriate population and their work life experiences remain large...

Awareness of Entities, Activities and Contexts in Ambient Systems

DEFF Research Database (Denmark)

Kristensen, Bent Bruun

2013-01-01

Ambient systems are modeled by entities, activities and contexts, where entities exist in contexts and engage in activities. A context supports a dynamic collection of entities by services and offers awareness information about the entities. Activities also exist in contexts and model ongoing...... collaborations between entities. Activities and local contexts also obtain awareness information from the context about the dynamic collection of entities. Similarly activities, local contexts and entities are offered awareness information about activities and local contexts....

Language Teaching and Its Contexts

Science.gov (United States)

Byram, Michael

2013-01-01

The title of this new journal provides opportunity to review the many contexts which need to be taken into account in reflecting upon foreign language teaching. These contexts include the educational, the fact that much language teaching takes place within general educational and often compulsory educational settings and institutions. Learners…

Verification of Representative Sampling in RI waste

International Nuclear Information System (INIS)

Ahn, Hong Joo; Song, Byung Cheul; Sohn, Se Cheul; Song, Kyu Seok; Jee, Kwang Yong; Choi, Kwang Seop

2009-01-01

For evaluating the radionuclide inventories for RI wastes, representative sampling is one of the most important parts in the process of radiochemical assay. Sampling to characterized RI waste conditions typically has been based on judgment or convenience sampling of individual or groups. However, it is difficult to get a sample representatively among the numerous drums. In addition, RI waste drums might be classified into heterogeneous wastes because they have a content of cotton, glass, vinyl, gloves, etc. In order to get the representative samples, the sample to be analyzed must be collected from selected every drum. Considering the expense and time of analysis, however, the number of sample has to be minimized. In this study, RI waste drums were classified by the various conditions of the half-life, surface dose, acceptance date, waste form, generator, etc. A sample for radiochemical assay was obtained through mixing samples of each drum. The sample has to be prepared for radiochemical assay and although the sample should be reasonably uniform, it is rare that a completely homogeneous material is received. Every sample is shredded by a 1 ∼ 2 cm 2 diameter and a representative aliquot taken for the required analysis. For verification of representative sampling, classified every group is tested for evaluation of 'selection of representative drum in a group' and 'representative sampling in a drum'

New Historicism: Text and Context

Directory of Open Access Journals (Sweden)

Violeta M. Vesić

2016-02-01

Full Text Available During most of the twentieth century history was seen as a phenomenon outside of literature that guaranteed the veracity of literary interpretation. History was unique and it functioned as a basis for reading literary works. During the seventies of the twentieth century there occurred a change of attitude towards history in American literary theory, and there appeared a new theoretical approach which soon became known as New Historicism. Since its inception, New Historicism has been identified with the study of Renaissance and Romanticism, but nowadays it has been increasingly involved in other literary trends. Although there are great differences in the arguments and practices at various representatives of this school, New Historicism has clearly recognizable features and many new historicists will agree with the statement of Walter Cohen that New Historicism, when it appeared in the eighties, represented something quite new in reference to the studies of theory, criticism and history (Cohen 1987, 33. Theoretical connection with Bakhtin, Foucault and Marx is clear, as well as a kind of uneasy tie with deconstruction and the work of Paul de Man. At the center of this approach is a renewed interest in the study of literary works in the light of historical and political circumstances in which they were created. Foucault encouraged readers to begin to move literary texts and to link them with discourses and representations that are not literary, as well as to examine the sociological aspects of the texts in order to take part in the social struggles of today. The study of literary works using New Historicism is the study of politics, history, culture and circumstances in which these works were created. With regard to one of the main fact which is located in the center of the criticism, that history cannot be viewed objectively and that reality can only be understood through a cultural context that reveals the work, re-reading and interpretation of

Explicit instructions increase cognitive costs of deception in predictable social context

Directory of Open Access Journals (Sweden)

Marcel eFalkiewicz

2015-12-01

Full Text Available Convincing participants to deceive remains one of the biggest and most important challenges of laboratory-based deception research. The simplest and most prevalent method involves explicitly instructing participants to lie or tell the truth before presenting each task item. The usual finding of such experiments is increased cognitive load associated with deceptive responses, explained by necessity to inhibit default and automatic honest responses. However, explicit instructions are usually coupled with the absence of social context in the experimental task. Context plays a key role in social cognition by activating prior knowledge, which facilitates behaviors consistent with the latter. We hypothesized that in the presence of social context, both honest and deceptive responses can be produced on the basis of prior knowledge, without reliance on truth and without additional cognitive load during deceptive responses. In order to test the hypothesis, we have developed Speed-Dating Task (SDT, which is based on a real-life social event. In SDT, participants respond both honestly and deceptively to questions in order to appear similar to each of the dates. The dates are predictable and represent well-known categories (i.e. atheist or conservative. In one condition participants rely on explicit instructions preceding each question (external cue. In the second condition no explicit instructions are present, so the participants need to adapt based on prior knowledge about the category the dates belong to (internal cue. With internal cues, reaction times are similar for both honest and deceptive responses. However, in the presence of external cues, reaction times are longer for deceptive than honest responses, suggesting that deceptive responses are associated with increased cognitive load. Compared to internal cues, deception costs were higher when external cues were present. However, the effect was limited to the first part of the experiment, only

Paleoclimatological context and reference level of the 2°C and 1.5°C Paris Agreement long-term temperature limits

Science.gov (United States)

Lüning, Sebastian; Vahrenholt, Fritz

2017-12-01

The Paris Agreement adopted in December 2015 during the COP21 conference stipulates that the increase in the global average temperature is to be kept well below 2°C above “pre-industrial levels” and that efforts are pursued to limit the temperature increase to 1.5°C above “pre-industrial levels”. In order to further increase public acceptance of these limits it is important to transparently place the target levels and their baselines in a paleoclimatic context of the past 150,000 years (Last Interglacial, LIG) and in particular of the last 10,000 years (Holocene; Present Interglacial, PIG). Intense paleoclimatological research of the past decade has firmed up that pre-industrial temperatures have been highly variable which needs to be reflected in the pre-industrial climate baseline definitions. The currently used reference level 1850-1900 represents the end of the Little Ice Age (LIA).The LIA represents the coldest phase of the last 10,000 years when mean temperatures deviated strongly negatively from the Holocene average and which therefore are hard to justify as a representative pre-industrial baseline. The temperature level reached during the interval 1940-1970 may serve as a better reference level as it appears to roughly correspond to the average pre-industrial temperature of the past two millennia. Placing the climate limits in an enlarged paleoclimatic context will help to demonstrate that the chosen climate targets are valid and represent dangerous extremes of the known natural range of Holocene temperature variability.

Incorporating Context Effects into a Choice Model

NARCIS (Netherlands)

Rooderkerk, Robert P.; Van Heerde, Harald J.; Bijmolt, Tammo H. A.

The behavioral literature provides ample evidence that consumer preferences are partly driven by the context provided by the set of alternatives. Three important context effects are the compromise, attraction, and similarity effects. Because these context effects affect choices in a systematic and