WorldWideScience

Sample records for bubr1 kinetochore interactions

  1. Structure of a Blinkin-BUBR1 complex reveals an interaction crucial for kinetochore-mitotic checkpoint regulation via an unanticipated binding Site

    DEFF Research Database (Denmark)

    Bolanos-Garcia, Victor M; Lischetti, Tiziana; Matak-Vinković, Dijana;

    2011-01-01

    The maintenance of genomic stability relies on the spindle assembly checkpoint (SAC), which ensures accurate chromosome segregation by delaying the onset of anaphase until all chromosomes are properly bioriented and attached to the mitotic spindle. BUB1 and BUBR1 kinases are central for this proc...

  2. The internal Cdc20 binding site in BubR1 facilitates both spindle assembly checkpoint signalling and silencing

    DEFF Research Database (Denmark)

    Lischetti, Tiziana; Zhang, Gang; Sedgwick, Garry G; Bolanos-Garcia, Victor M; Nilsson, Jakob

    2014-01-01

    in the SAC, we delineate the molecular details of its interaction with kinetochores. We find that BubR1 recruits the bulk of Cdc20 to kinetochores through its internal Cdc20 binding domain (IC20BD). We show that preventing Cdc20 kinetochore localization by removal of the IC20BD has a limited effect...

  3. BUBR1 recruits PP2A via the B56 family of targeting subunits to promote chromosome congression

    Directory of Open Access Journals (Sweden)

    Peng Xu

    2013-03-01

    BUBR1 is a mitotic phosphoprotein essential for the maintenance of chromosome stability by promoting chromosome congression and proper kinetochore–microtubule (K-fiber attachment, but the underlying mechanism(s has remained elusive. Here we identify BUBR1 as a binding partner of the B56 family of Protein Phosphatase 2A regulatory subunits. The interaction between BUBR1 and the B56 family is required for chromosome congression, since point mutations in BUBR1 that block B56 binding abolish chromosome congression. The BUBR1:B56-PP2A complex opposes Aurora B kinase activity, since loss of the complex can be reverted by inhibiting Aurora B. Importantly, we show that the failure of BUBR1 to recruit B56-PP2A also contributes to the chromosome congression defects found in cells derived from patients with the Mosaic Variegated Aneuploidy (MVA syndrome. Together, we propose that B56-PP2A is a key mediator of BUBR1's role in chromosome congression and functions by antagonizing Aurora B activity at the kinetochore for establishing stable kinetochore–microtubule attachment at the metaphase plate.

  4. Direct binding between BubR1 and B56-PP2A phosphatase complexes regulate mitotic progression

    DEFF Research Database (Denmark)

    Kruse, Thomas; Zhang, Gang; Larsen, Marie Sofie Yoo;

    2013-01-01

    and mutation of these residues prevents the establishment of a proper metaphase plate and delays cells in mitosis. Furthermore, we show that phosphorylation of S670 and S676 stimulates the binding of B56 to BubR1 and that BubR1 targets a pool of B56 to kinetochores. Our data suggests that BubR1...

  5. Protein kinase TTK interacts and co-localizes with CENP-E to the kinetochore of human cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Spindle checkpoint is an important biochemical signaling cascade during mitosis which monitors the fidelity of chromosome segregation, and is mediated by protein kinases Mps1 and Bub1/BubR1. Our recent studies show that kinesin-related motor protein CENP-E interacts with BubR1 and participates in spindle checkpoint signaling. To elucidate the molecular mechanisms underlying spindle checkpoint signaling, we carried out proteomic dissection of human cell kinetochore and revealed protein kinase TTK, human homologue of yeast Mps1. Our studies show that TTK is localized to the kinetochore of human cells, and interacts with CENP-E, suggesting that TTK may play an important role in chromosome segregation during mitosis.

  6. The Kinetochore Interaction Network (KIN) of ascomycetes

    Science.gov (United States)

    Freitag, Michael

    2016-01-01

    Chromosome segregation relies on coordinated activity of a large assembly of proteins, the “Kinetochore Interaction Network” (KIN). How conserved the underlying mechanisms driving the epigenetic phenomenon of centromere and kinetochore assembly and maintenance are remains unclear, even though various eukaryotic models have been studied. More than 50 different proteins, many in multiple copies, comprise the KIN or are associated with fungal centromeres and kinetochores. Proteins isolated from immune sera recognized centromeric regions on chromosomes and were thus named centromere proteins (“CENPs”). CENP-A, sometimes called “centromere-specific H3” (CenH3), is incorporated into nucleosomes within or near centromeres. The “constitutive centromere-associated network” (CCAN) assembles on this specialized chromatin, likely based on specific interactions with and requiring presence of CENP-C. The outer kinetochore comprises the Knl1-Mis12-Ndc80 (“KMN”) protein complexes that connect the CCAN to spindles, accomplished by binding and stabilizing microtubules (MTs) and in the process generating load-bearing assemblies for chromatid segregation. In most fungi the Dam1/DASH complex connects the KMN complexes to MTs. Fungi present a rich resource to investigate mechanistic commonalities but also differences in kinetochore architecture. While ascomycetes have sets of CCAN and KMN proteins that are conserved with those of either budding yeast or metazoans, searching other major branches of the fungal kingdom revealed that CCAN proteins are poorly conserved at the primary sequence level. Several conserved binding motifs or domains within KMN complexes have been described recently, and these features of ascomycete KIN proteins are shared with most metazoan proteins. In addition, several ascomycete-specific domains have been identified here. PMID:26908646

  7. The kinetochore interaction network (KIN) of ascomycetes.

    Science.gov (United States)

    Freitag, Michael

    2016-05-01

    Chromosome segregation relies on coordinated activity of a large assembly of proteins, the kinetochore interaction network (KIN). How conserved the underlying mechanisms driving the epigenetic phenomenon of centromere and kinetochore assembly and maintenance are remains unclear, even though various eukaryotic models have been studied. More than 50 different proteins, many in multiple copies, comprise the KIN or are associated with fungal centromeres and kinetochores. Proteins isolated from immune sera recognized centromeric regions on chromosomes and thus were named centromere proteins (CENPs). CENP-A, sometimes called centromere-specific H3 (CenH3), is incorporated into nucleosomes within or near centromeres. The constitutive centromere-associated network (CCAN) assembles on this specialized chromatin, likely based on specific interactions with and requiring presence of CENP-C. The outer kinetochore comprises the Knl1-Mis12-Ndc80 (KMN) protein complexes that connect CCAN to spindles, accomplished by binding and stabilizing microtubules (MTs) and in the process generating load-bearing assemblies for chromatid segregation. In most fungi the Dam1/DASH complex connects the KMN complexes to MTs. Fungi present a rich resource to investigate mechanistic commonalities but also differences in kinetochore architecture. While ascomycetes have sets of CCAN and KMN proteins that are conserved with those of budding yeast or metazoans, searching other major branches of the fungal kingdom revealed that CCAN proteins are poorly conserved at the primary sequence level. Several conserved binding motifs or domains within KMN complexes have been described recently, and these features of ascomycete KIN proteins are shared with most metazoan proteins. In addition, several ascomycete-specific domains have been identified here. PMID:26908646

  8. Stranglehold on the spindle assembly checkpoint: the human papillomavirus E2 protein provokes BUBR1-dependent aneuploidy.

    Science.gov (United States)

    Tan, Chye Ling; Teissier, Sébastien; Gunaratne, Jayantha; Quek, Ling Shih; Bellanger, Sophie

    2015-01-01

    The Human Papillomavirus (HPV) E2 protein, which inhibits the E6 and E7 viral oncogenes, is believed to have anti-oncogenic properties. Here, we challenge this view and show that HPV-18 E2 over-activates the Spindle Assembly Checkpoint (SAC) and induces DNA breaks in mitosis followed by aneuploidy. This phenotype is associated with interaction of E2 with the Mitotic Checkpoint Complex (MCC) proteins Cdc20, MAD2 and BUBR1. While BUBR1 silencing rescues the mitotic phenotype induced by E2, p53 silencing or presence of E6/E7 (inactivating p53 and increasing BUBR1 levels respectively) both amplify it. This work pinpoints E2 as a key protein in the initiation of HPV-induced cervical cancer and identifies the SAC as a target for oncogenic pathogens. Moreover, our results suggest a role of p53 in regulating the mitotic process itself and highlight SAC over-activation in a p53-negative context as a highly pathogenic event. PMID:25789401

  9. p21 both attenuates and drives senescence and aging in BubR1 progeroid mice.

    NARCIS (Netherlands)

    Baker, D.J.; Weaver, R.L.; Deursen, J.M.A. van

    2013-01-01

    BubR1 insufficiency occurs with natural aging and induces progeroid phenotypes in both mice and children with mosaic variegated aneuploidy syndrome. In response to BubR1 insufficiency, skeletal muscle, fat, and lens tissue engage p19(Arf) to attenuate senescence and age-related deterioration. Here,

  10. Sds22 regulates aurora B activity and microtubule–kinetochore interactions at mitosis

    OpenAIRE

    Posch, Markus; Khoudoli, Guennadi A.; Swift, Sam; King, Emma M.; DeLuca, Jennifer G.; Swedlow, Jason R.

    2010-01-01

    We have studied Sds22, a conserved regulator of protein phosphatase 1 (PP1) activity, and determined its role in modulating the activity of aurora B kinase and kinetochore–microtubule interactions. Sds22 is required for proper progression through mitosis and localization of PP1 to mitotic kinetochores. Depletion of Sds22 increases aurora B T-loop phosphorylation and the rate of recovery from monastrol arrest. Phospho–aurora B accumulates at kinetochores in Sds22-depleted cells juxtaposed to c...

  11. Synthetic Physical Interactions Map Kinetochore-Checkpoint Activation Regions.

    Science.gov (United States)

    Ólafsson, Guðjón; Thorpe, Peter H

    2016-01-01

    The spindle assembly checkpoint (SAC) is a key mechanism to regulate the timing of mitosis and ensure that chromosomes are correctly segregated to daughter cells. The recruitment of the Mad1 and Mad2 proteins to the kinetochore is normally necessary for SAC activation. This recruitment is coordinated by the SAC kinase Mps1, which phosphorylates residues at the kinetochore to facilitate binding of Bub1, Bub3, Mad1, and Mad2. There is evidence that the essential function of Mps1 is to direct recruitment of Mad1/2. To test this model, we have systematically recruited Mad1, Mad2, and Mps1 to most proteins in the yeast kinetochore, and find that, while Mps1 is sufficient for checkpoint activation, recruitment of either Mad1 or Mad2 is not. These data indicate an important role for Mps1 phosphorylation in SAC activation, beyond the direct recruitment of Mad1 and Mad2. PMID:27280788

  12. Caspase-Mediated Specific Cleavage of BubR1 Is a Determinant of Mitotic Progression

    OpenAIRE

    Kim, Mijin; Murphy, Katie; Liu, Fang; Parker, Sharon E.; Dowling, Melissa L.; Baff, Wesley; Kao, Gary D.

    2007-01-01

    The fidelity of chromosomal duplication is monitored by cell cycle checkpoints operational during mitosis. One such cell cycle delay is invoked by microtubule-targeting agents such as nocodazole or paclitaxel (Taxol) and is mediated by mitotic checkpoint proteins that include BubR1. Relatively little is known about the regulation of expression and stability of BubR1 (or other checkpoint proteins) and how these factors dictate the durability of the cell cycle delay. We report here that treatme...

  13. Highly Transient Molecular Interactions Underlie the Stability of Kinetochore-Microtubule Attachment During Cell Division.

    Science.gov (United States)

    Zaytsev, Anatoly V; Ataullakhanov, Fazly I; Grishchuk, Ekaterina L

    2013-12-13

    Chromosome segregation during mitosis is mediated by spindle microtubules that attach to chromosomal kinetochores with strong yet labile links. The exact molecular composition of the kinetochore-microtubule interface is not known but microtubules are thought to bind to kinetochores via the specialized microtubule-binding sites, which contain multiple microtubule-binding proteins. During prometaphase the lifetime of microtubule attachments is short but in metaphase it increases 3-fold, presumably owing to dephosphorylation of the microtubule-binding proteins that increases their affinity. Here, we use mathematical modeling to examine in quantitative and systematic manner the general relationships between the molecular properties of microtubule-binding proteins and the resulting stability of microtubule attachment to the protein-containing kinetochore site. We show that when the protein connections are stochastic, the physiological rate of microtubule turnover is achieved only if these molecular interactions are very transient, each lasting fraction of a second. This "microscopic" time is almost four orders of magnitude shorter than the characteristic time of kinetochore-microtubule attachment. Cooperativity of the microtubule-binding events further increases the disparity of these time scales. Furthermore, for all values of kinetic parameters the microtubule stability is very sensitive to the minor changes in the molecular constants. Such sensitivity of the lifetime of microtubule attachment to the kinetics and cooperativity of molecular interactions at the microtubule-binding site may hinder the accurate regulation of kinetochore-microtubule stability during mitotic progression, and it necessitates detailed experimental examination of the microtubule-binding properties of kinetochore-localized proteins. PMID:24376473

  14. BubR1 Insufficiency Impairs Liver Regeneration in Aged Mice after Hepatectomy through Intercalated Disc Abnormality.

    Science.gov (United States)

    Ikawa-Yoshida, Ayae; Matsumoto, Takuya; Okano, Shinji; Aoyagi, Yukihiko; Matsubara, Yutaka; Furuyama, Tadashi; Nakatsu, Yoshimichi; Tsuzuki, Teruhisa; Onimaru, Mitsuho; Ohkusa, Tomoko; Nomura, Masatoshi; Maehara, Yoshihiko

    2016-01-01

    A delay in liver regeneration after partial hepatectomy (PHx) leads to acute liver injury, and such delays are frequently observed in aged patients. BubR1 (budding uninhibited by benzimidazole-related 1) controls chromosome mitotic segregation through the spindle assembly checkpoint, and BubR1 down-regulation promotes aging-associated phenotypes. In this study we investigated the effects of BubR1 insufficiency on liver regeneration in mice. Low-BubR1-expressing mutant (BubR1(L/L)) mice had a delayed recovery of the liver weight-to-body weight ratio and increased liver deviation enzyme levels after PHx. Microscopic observation of BubR1(L/L) mouse liver showed an increased number of necrotic hepatocytes and intercalated disc anomalies, resulting in widened inter-hepatocyte and perisinusoidal spaces, smaller hepatocytes and early-stage microvilli atrophy. Up-regulation of desmocollin-1 (DSC1) was observed in wild-type, but not BubR1(L/L), mice after PHx. In addition, knockdown of BubR1 expression caused down-regulation of DSC1 in a human keratinocyte cell line. BubR1 insufficiency results in the impaired liver regeneration through weakened microstructural adaptation against PHx, enhanced transient liver failure and delayed hepatocyte proliferation. Thus, our data suggest that a reduction in BubR1 levels causes failure of liver regeneration through the DSC1 abnormality. PMID:27561386

  15. Inner Kinetochore Protein Interactions with Regional Centromeres of Fission Yeast.

    Science.gov (United States)

    Thakur, Jitendra; Talbert, Paul B; Henikoff, Steven

    2015-10-01

    Centromeres of the fission yeast Schizosaccharomyces pombe lack the highly repetitive sequences that make most other "regional" centromeres refractory to analysis. To map fission yeast centromeres, we applied H4S47C-anchored cleavage mapping and native and cross-linked chromatin immunoprecipitation with paired-end sequencing. H3 nucleosomes are nearly absent from the central domain, which is occupied by centromere-specific H3 (cenH3 or CENP-A) nucleosomes with two H4s per particle that are mostly unpositioned and are more widely spaced than nucleosomes elsewhere. Inner kinetochore proteins CENP-A, CENP-C, CENP-T, CENP-I, and Scm3 are highly enriched throughout the central domain except at tRNA genes, with no evidence for preferred kinetochore assembly sites. These proteins are weakly enriched and less stably incorporated in H3-rich heterochromatin. CENP-A nucleosomes protect less DNA from nuclease digestion than H3 nucleosomes, while CENP-T protects a range of fragment sizes. Our results suggest that CENP-T particles occupy linkers between CENP-A nucleosomes and that classical regional centromeres differ from other centromeres by the absence of CENP-A nucleosome positioning. PMID:26275423

  16. Elevated BUBR1 Expression Is Associated with Poor Survival in Early Breast Cancer Patients: 15-Year Follow-up Analysis

    OpenAIRE

    Maciejczyk, Adam; Szelachowska, Jolanta; Czapiga, Bogdan; Matkowski, Rafał; Hałoń, Agnieszka; Györffy, Balázs; Surowiak, Paweł

    2013-01-01

    BUBR1 (budding uninhibited by benzimidazole-related 1) represents the component of a controlling complex in mitosis. Defects in mitotic control complex result in chromosomal instability and, as a result, disturb the mitotic process. This study was aimed at examining the prognostic value linked to the expression of BUBR1 in a group of patients with breast cancer. We analyzed the expression of BUBR1 in 98 stage II breast cancer patients with a median follow-up of 15 years. Immunohistochemical r...

  17. Ctf3p, the Mis6 budding yeast homolog, interacts with Mcm22p and Mcm16p at the yeast outer kinetochore

    OpenAIRE

    Measday, Vivien; Hailey, Dale W.; Pot, Isabelle; Givan, Scott A.; Hyland, Katherine M.; Cagney, Gerard; Fields, Stan; Davis, Trisha N.; Hieter, Philip

    2002-01-01

    The budding yeast kinetochore is composed of an inner and outer protein complex, which binds to centromere (CEN) DNA and attaches to microtubules. We performed a genetic synthetic dosage lethality screen to identify novel kinetochore proteins in a collection of chromosome transmission fidelity mutants. Our screen identified several new kinetochore-related proteins including YLR381Wp/Ctf3p, which is a member of a conserved family of centromere-binding proteins. Ctf3p interacts with Mcm22p, Mcm...

  18. BubR1 Acts as a Promoter in Cellular Motility of Human Oral Squamous Cancer Cells through Regulating MMP-2 and MMP-9

    Directory of Open Access Journals (Sweden)

    Chou-Kit Chou

    2015-07-01

    Full Text Available BubR1 is a critical component of spindle assembly checkpoint, ensuring proper chromatin segregation during mitosis. Recent studies showed that BubR1 was overexpressed in many cancer cells, including oral squamous cell carcinomas (OSCC. However, the effect of BubR1 on metastasis of OSCC remains unclear. This study aimed to unravel the role of BubR1 in the progression of OSCC and confirm the expression of BubR1 in a panel of malignant OSCC cell lines with different invasive abilities. The results of quantitative real-time PCR showed that the mRNA level of BubR1 was markedly increased in four OSCC cell lines, Ca9-22, HSC3, SCC9 and Cal-27 cells, compared to two normal cells, normal human oral keratinocytes (HOK and human gingival fibroblasts (HGF. Moreover, the expression of BubR1 in these four OSCC cell lines was positively correlated with their motility. Immunofluorescence revealed that BubR1 was mostly localized in the cytosol of human gingival carcinoma Ca9-22 cells. BubR1 knockdown significantly decreased cellular invasion but slightly affect cellular proliferation on both Ca9-22 and Cal-27 cells. Consistently, the activities of metastasis-associated metalloproteinases MMP-2 and MMP-9 were attenuated in BubR1 knockdown Ca9-22 cells, suggesting the role of BubR1 in promotion of OSCC migration. Our present study defines an alternative pathway in promoting metastasis of OSCC cells, and the expression of BubR1 could be a prognostic index in OSCC patients.

  19. How chromosome mis-segregation leads to cancer: lessons from BubR1 mouse models.

    Science.gov (United States)

    Lee, Hyunsook

    2014-10-31

    Alteration in chromosome numbers and structures instigate and foster massive genetic instability. As Boveri has seen a hundred years ago (Boveri, 1914; 2008), aneuploidy is hallmark of many cancers. However, whether aneuploidy is the cause or the result of cancer is still at debate. The molecular mechanism behind aneuploidy includes the chromo-some mis-segregation in mitosis by the compromise of spindle assembly checkpoint (SAC). SAC is an elaborate network of proteins, which monitor that all chromosomes are bipolarly attached with the spindles. Therefore, the weakening of the SAC is the major reason for chromosome number instability, while complete compromise of SAC results in detrimental death, exemplified in natural abortion in embryonic stage. Here, I will review on the recent progress on the understanding of chromosome mis-segregation and cancer, based on the comparison of different mouse models of BubR1, the core component of SAC. PMID:25256220

  20. Assessment of protein domain fusions in human protein interaction networks prediction: application to the human kinetochore model.

    Science.gov (United States)

    Morilla, Ian; Lees, Jon G; Reid, Adam J; Orengo, Christine; Ranea, Juan A G

    2010-12-31

    In order to understand how biological systems function it is necessary to determine the interactions and associations between proteins. Some proteins, involved in a common biological process and encoded by separate genes in one organism, can be found fused within a single protein chain in other organisms. By detecting these triplets, a functional relationship can be established between the unfused proteins. Here we use a domain fusion prediction method to predict these protein interactions for the human interactome. We observed that gene fusion events are more related to physical interaction between proteins than to other weaker functional relationships such as participation in a common biological pathway. These results suggest that domain fusion is an appropriate method for predicting protein complexes. The most reliable fused domain predictions were used to build protein-protein interaction (PPI) networks. These predicted PPI network models showed the same topological features as real biological networks and different features from random behaviour. We built the PPI domain fusion sub-network model of the human kinetochore and observed that the majority of the predicted interactions have not yet been experimentally characterised in the publicly available PPI repositories. The study of the human kinetochore domain fusion sub-network reveals undiscovered kinetochore proteins with presumably relevant functions, such as hubs with many connections in the kinetochore sub-network. These results suggest that experimentally hidden regions in the predicted PPI networks contain key functional elements, associated with important functional areas, still undiscovered in the human interactome. Until novel experiments shed light on these hidden regions; domain fusion predictions provide a valuable approach for exploring them. PMID:20851221

  1. A Conserved Arginine-Rich Motif within the Hypervariable N-Domain of Drosophila Centromeric Histone H3 (CenH3CID) Mediates BubR1 Recruitment

    OpenAIRE

    Torras-Llort, Mònica; Medina-Giró, Sònia; Moreno-Moreno, Olga; Azorín, Ferran

    2010-01-01

    [Background]: Centromere identity is determined epigenetically by deposition of CenH3, a centromere-specific histone H3 variant that dictates kinetochore assembly. The molecular basis of the contribution of CenH3 to centromere/kinetochore functions is, however, incompletely understood, as its interactions with the rest of centromere/kinetochore components remain largely uncharacterised at the molecular/structural level. [Principal Findings]: Here, we report on the contribution of Drosophil...

  2. Ctf3p, the Mis6 budding yeast homolog, interacts with Mcm22p and Mcm16p at the yeast outer kinetochore.

    Science.gov (United States)

    Measday, Vivien; Hailey, Dale W; Pot, Isabelle; Givan, Scott A; Hyland, Katherine M; Cagney, Gerard; Fields, Stan; Davis, Trisha N; Hieter, Philip

    2002-01-01

    The budding yeast kinetochore is composed of an inner and outer protein complex, which binds to centromere (CEN) DNA and attaches to microtubules. We performed a genetic synthetic dosage lethality screen to identify novel kinetochore proteins in a collection of chromosome transmission fidelity mutants. Our screen identified several new kinetochore-related proteins including YLR381Wp/Ctf3p, which is a member of a conserved family of centromere-binding proteins. Ctf3p interacts with Mcm22p, Mcm16p, and the outer kinetochore protein Ctf19p. We used chromatin immunoprecipitation to demonstrate that Ctf3p, Mcm22p, and Mcm16p bind to CEN DNA in a Ctf19p-dependent manner. In addition, Ctf3p, Mcm22p, and Mcm16p have a localization pattern similar to other kinetochore proteins. The fission yeast Ctf3p homolog, Mis6, is required for loading of a CENP-A centromere specific histone, Cnp1, onto centromere DNA. We find however that Ctf3p is not required for loading of the budding yeast CENP-A homolog, Cse4p, onto CEN DNA. In contrast, Ctf3p and Ctf19p fail to bind properly to the centromere in a cse4-1 mutant strain. We conclude that the requirements for CENP-A loading onto centromere DNA differ in fission versus budding yeast. PMID:11782448

  3. Complex regulation of sister kinetochore orientation in meiosis-I

    Indian Academy of Sciences (India)

    Amit Bardhan

    2010-09-01

    Kinetochores mediate chromosome movement during cell division by interacting with the spindle microtubules. Sexual reproduction necessitates the daunting task of reducing ploidy (number of chromosome sets) in the gametes, which depends upon the specialized properties of meiosis. Kinetochores have a central role in the reduction process. In this review, we discuss the complexity of this role of kinetochores in meiosis-I.

  4. The Mps1 Kinase Modulates the Recruitment and Activity of Cnn1CENP-T at Saccharomyces cerevisiae Kinetochores

    OpenAIRE

    Thapa, Kriti Shrestha; Oldani, Amanda; Pagliuca, Cinzia; De Wulf, Peter; Hazbun, Tony R.

    2015-01-01

    Kinetochores are conserved protein complexes that bind the replicated chromosomes to the mitotic spindle and then direct their segregation. To better comprehend Saccharomyces cerevisiae kinetochore function, we dissected the phospho-regulated dynamic interaction between conserved kinetochore protein Cnn1CENP-T, the centromere region, and the Ndc80 complex through the cell cycle. Cnn1 localizes to kinetochores at basal levels from G1 through metaphase but accumulates abruptly at anaphase onset...

  5. Conformational mechanism for the stability of microtubule-kinetochore attachments

    CERN Document Server

    Bertalan, Zsolt; Maiato, Helder; Zapperi, Stefano

    2014-01-01

    Regulating the stability of microtubule(MT)-kinetochore attachments is fundamental to avoiding mitotic errors and ensure proper chromosome segregation during cell division. While biochemical factors involved in this process have been identified, its mechanics still needs to be better understood. Here we introduce and simulate a mechanical model of MT-kinetochore interactions in which the stability of the attachment is ruled by the geometrical conformations of curling MT-protofilaments entangled in kinetochore fibrils. The model allows us to reproduce with good accuracy in vitro experimental measurements of the detachment times of yeast kinetochores from MTs under external pulling forces. Numerical simulations suggest that geometrical features of MT-protofilaments may play an important role in the switch between stable and unstable attachments.

  6. Looping in on Ndc80 - how does a protein loop at the kinetochore control chromosome segregation?

    DEFF Research Database (Denmark)

    Nilsson, Jakob

    2012-01-01

    Segregation of chromosomes during mitosis requires the interaction of dynamic microtubules with the kinetochore, a large protein structure established on the centromere region of sister chromatids. The core microtubule-binding activity of the kinetochore resides in the KMN network, an outer...

  7. Phospholipase C Is Involved in Kinetochore Function in Saccharomyces cerevisiae

    OpenAIRE

    Lin, Hongyu; Choi, Jae H.; Hasek, Jiri; DeLillo, Nicholas; Lou, Willard; Vancura, Ales

    2000-01-01

    The budding yeast PLC1 gene encodes a homolog of the δ isoform of mammalian phosphoinositide-specific phospholipase C. Here, we present evidence that Plc1p associates with the kinetochore complex CBF3. This association is mediated through interactions with two established kinetochore proteins, Ndc10p and Cep3p. We show by chromatin immunoprecipitation experiments that Plc1p resides at centromeric loci in vivo. Deletion of PLC1, as well as plc1 mutations which abrogate the interaction of Plc1p...

  8. Paired arrangement of kinetochores together with microtubule pivoting and dynamics drive kinetochore capture in meiosis I.

    Science.gov (United States)

    Cojoc, Gheorghe; Florescu, Ana-Maria; Krull, Alexander; Klemm, Anna H; Pavin, Nenad; Jülicher, Frank; Tolić, Iva M

    2016-01-01

    Kinetochores are protein complexes on the chromosomes, whose function as linkers between spindle microtubules and chromosomes is crucial for proper cell division. The mechanisms that facilitate kinetochore capture by microtubules are still unclear. In the present study, we combine experiments and theory to explore the mechanisms of kinetochore capture at the onset of meiosis I in fission yeast. We show that kinetochores on homologous chromosomes move together, microtubules are dynamic and pivot around the spindle pole, and the average capture time is 3-4 minutes. Our theory describes paired kinetochores on homologous chromosomes as a single object, as well as angular movement of microtubules and their dynamics. For the experimentally measured parameters, the model reproduces the measured capture kinetics and shows that the paired configuration of kinetochores accelerates capture, whereas microtubule pivoting and dynamics have a smaller contribution. Kinetochore pairing may be a general feature that increases capture efficiency in meiotic cells. PMID:27166749

  9. The ultrastructure of the kinetochore and kinetochore fiber in Drosophila somatic cells

    OpenAIRE

    Maiato, Helder; Hergert, Polla J.; Moutinho-Pereira, Sara; Dong, Yimin; VandenBeldt, Kristin J.; Rieder, Conly L.; McEwen, Bruce F.

    2006-01-01

    Drosophila melanogaster is a widely used model organism for the molecular dissection of mitosis in animals. However, despite the popularity of this system, no studies have been published on the ultrastructure of Drosophila kinetochores and kinetochore fibers (K-fibers) in somatic cells. To amend this situation, we used correlative light (LM) and electron microscopy (EM) to study kinetochores in cultured Drosophila S2 cells during metaphase, and after colchicine treatment to depolymerize all m...

  10. The Monopolin Complex Crosslinks Kinetochore Components to Regulate Chromosome-Microtubule Attachments

    Energy Technology Data Exchange (ETDEWEB)

    Corbett, Kevin D.; Yip, Calvin K.; Ee, Ly-Sha; Walz, Thomas; Amon, Angelika; Harrison, Stephen C. (Harvard-Med); (MIT)

    2010-09-27

    The monopolin complex regulates different types of kinetochore-microtubule attachments in fungi, ensuring sister chromatid co-orientation in Saccharomyces cerevisiae meiosis I and inhibiting merotelic attachment in Schizosaccharomyces pombe mitosis. In addition, the monopolin complex maintains the integrity and silencing of ribosomal DNA (rDNA) repeats in the nucleolus. We show here that the S. cerevisiae Csm1/Lrs4 monopolin subcomplex has a distinctive V-shaped structure, with two pairs of protein-protein interaction domains positioned {approx}10 nm apart. Csm1 presents a conserved hydrophobic surface patch that binds two kinetochore proteins: Dsn1, a subunit of the outer-kinetochore MIND/Mis12 complex, and Mif2/CENP-C. Csm1 point-mutations that disrupt kinetochore-subunit binding also disrupt sister chromatid co-orientation in S. cerevisiae meiosis I. We further show that the same Csm1 point-mutations affect rDNA silencing, probably by disrupting binding to the rDNA-associated protein Tof2. We propose that Csm1/Lrs4 functions as a molecular clamp, crosslinking kinetochore components to enforce sister chromatid co-orientation in S. cerevisiae meiosis I and to suppress merotelic attachment in S. pombe mitosis, and crosslinking rDNA repeats to aid rDNA silencing.

  11. Human Zwint-1 Specifies Localization of Zeste White 10 to Kinetochores and Is Essential for Mitotic Checkpoint Signaling

    Institute of Scientific and Technical Information of China (English)

    HongmeiWang; XiaoyuHu; XiaDing; ZhenDou; ZhihongYank; AndrewW.Shaw; MaikunTcng; DonW.Cleveland; MichaelL.Goldberg; LiwenNiu; XucbiaoYao

    2005-01-01

    Chromosome segregation in mitosis is orchestrated by dynamic interaction between spindle microtubules and the kinetochore, a multiprotein complex assembled onto centromeric DNA of the chromosome. Here we show that Zwint-1 is required and is sufficient for kinetochore localization of Zestc White 10 (ZW10) in HeLa cells. Zwint-1 specifies the kinetochore association of ZW10 by interacting with its N-terminal domain. Suppression of synthesis of Zwint-1 by small interfering RNA abolishes the localization of ZW10 to the kinetochore, demonstrating the requirement of Zwint-1 for ZWl0 kinetochore localization. In addition, dcplction of Zwint-1 affects no mitotic arrest but causes aberrant premature chromo. some segregation. These Zwint-l-suppressed cells dis. play chromosome bridge phenotype with sister chromatids inter-connected. Moreover, Zwint-1 is required for stable association of CENP.F and dynamitin but not BUB1 with the kinetochore. Finally, our studies showthat Zwint-1 is a new component of the mitotic check. point, as cells lacking Zwint-1 fail to arrest in mitosis when exposed to microtubule inhibitors, yielding inter. phase cells with multinuclei. As ZWl0 and Zwint.1 are absent from yeast, we reasoned that metazoans evolved an elaborate spindle checkpoint machinery to ensure faithful chromosome segregation in mitosis.

  12. Dissection of the essential steps for condensin accumulation at kinetochores and rDNAs during fission yeast mitosis.

    Science.gov (United States)

    Nakazawa, Norihiko; Nakamura, Takahiro; Kokubu, Aya; Ebe, Masahiro; Nagao, Koji; Yanagida, Mitsuhiro

    2008-03-24

    The condensin complex has a fundamental role in chromosome dynamics. In this study, we report that accumulation of Schizosaccharomyces pombe condensin at mitotic kinetochores and ribosomal DNAs (rDNAs) occurs in multiple steps and is necessary for normal segregation of the sister kinetochores and rDNAs. Nuclear entry of condensin at the onset of mitosis requires Cut15/importin alpha and Cdc2 phosphorylation. Ark1/aurora and Cut17/Bir1/survivin are needed to dock the condensin at both the kinetochores and rDNAs. Furthermore, proteins that are necessary to form the chromatin architecture of the kinetochores (Mis6, Cnp1, and Mis13) and rDNAs (Nuc1 and Acr1) are required for condensin to accumulate specifically at these sites. Acr1 (accumulation of condensin at rDNA 1) is an rDNA upstream sequence binding protein that physically interacts with Rrn5, Rrn11, Rrn7, and Spp27 and is required for the proper accumulation of Nuc1 at rDNAs. The mechanism of condensin accumulation at the kinetochores may be conserved, as human condensin II fails to accumulate at kinetochores in hMis6 RNA interference-treated cells. PMID:18362178

  13. Sister kinetochores are mechanically fused during meiosis I in yeast

    OpenAIRE

    Sarangapani, Krishna K.; Duro, Eris; Deng, Yi; de Lima Alves, Flavia; Ye, Qiaozhen; Opoku, Kwaku N.; Ceto, Steven; Rappsilber, Juri; Corbett, Kevin D.; Biggins, Sue; Marston, Adèle L.; Asbury, Charles L.

    2014-01-01

    Production of healthy gametes requires a reductional meiosis I division in which replicated sister chromatids co-migrate, rather than separating as in mitosis or meiosis II. Fusion of sister kinetochores during meiosis I may underlie sister chromatid co-migration in diverse organisms, but direct evidence for such fusion has been lacking. Here we studied native kinetochore particles isolated from yeast using laser trapping and quantitative fluorescence microscopy. Meiosis I kinetochores formed...

  14. Identification of novel mitosis regulators through data mining with human centromere/kinetochore proteins as group queries

    Directory of Open Access Journals (Sweden)

    Tipton Aaron R

    2012-06-01

    Full Text Available Abstract Background Proteins functioning in the same biological pathway tend to be transcriptionally co-regulated or form protein-protein interactions (PPI. Multiple spatially and temporally regulated events are coordinated during mitosis to achieve faithful chromosome segregation. The molecular players participating in mitosis regulation are still being unravelled experimentally or using in silico methods. Results An extensive literature review has led to a compilation of 196 human centromere/kinetochore proteins, all with experimental evidence supporting the subcellular localization. Sixty-four were designated as “core” centromere/kinetochore components based on peak expression and/or well-characterized functions during mitosis. By interrogating and integrating online resources, we have mined for genes/proteins that display transcriptional co-expression or PPI with the core centromere/kinetochore components. Top-ranked hubs in either co-expression or PPI network are not only enriched with known mitosis regulators, but also contain candidates whose mitotic functions are not yet established. Experimental validation found that KIAA1377 is a novel centrosomal protein that also associates with microtubules and midbody; while TRIP13 is a novel kinetochore protein and directly interacts with mitotic checkpoint silencing protein p31comet. Conclusions Transcriptional co-expression and PPI network analyses with known human centromere/kinetochore proteins as a query group help identify novel potential mitosis regulators.

  15. An ultrastructural and irradiation study of diffuse and localised kinetochore

    International Nuclear Information System (INIS)

    An electron microscope study of plant types Luzula nivea and Cyperus eragrostis with diffuse kinetochores and Crepis neglecta with localised kinetochore showed that Luzula has a rather different kinetochore organisation from Cyperus, with features approaching the localised type of Crepis. These studies included an examination of the ultrastructure of the kinetochore at metaphase at low magnification in control and irradiated material of Luzula; the chromosomal ultrastructure at high magnification at interphase and all stages of mitosis in Luzula, Cyperus and Crepis; and the ultrastructure of the nucleolus in Luzula, Cyperus and Crepis. Light microscopic studies were also performed showing the effects of irradiation on first mitotic division in Cyperus, Luzula and Crepis, mitotic aberrations in Cyperus and Crepis and meiosis in Cyperus. Finally, the survival with the diffuse as opposed to the localised kinetochore in M1 and M2 generations following seed irradiation was studied. (U.K.)

  16. The kinetochore proteins Pcs1 and Mde4 and heterochromatin are required to prevent merotelic orientation

    OpenAIRE

    Gregan, Juraj; Riedel, Christian G.; Pidoux, Alison L.; Katou, Yuki; Rumpf, Cornelia; Schleiffer, Alexander; Kearsey, Stephen E.; Shirahige, Katsuhiko; Allshire, Robin C.; Nasmyth, Kim

    2007-01-01

    Summary Background Accurate chromosome segregation depends on the establishment of correct—amphitelic—kinetochore orientation. Merotelic kinetochore orientation is an error that occurs when a single kinetochore attaches to microtubules emanating from opposite spindle poles, a condition that hinders segregation of the kinetochore to a spindle pole in anaphase. To avoid chromosome missegregation resulting from merotelic kinetochore orientation, cells have developed mechanisms to prevent or corr...

  17. Attachment issues: kinetochore transformations and spindle checkpoint silencing.

    Science.gov (United States)

    Etemad, Banafsheh; Kops, Geert J P L

    2016-04-01

    Cell division culminates in the segregation of duplicated chromosomes in opposite directions prior to cellular fission. This process is guarded by the spindle assembly checkpoint (SAC), which prevents the anaphase of cell division until stable connections between spindle microtubules and the kinetochores of all chromosomes are established. The anaphase inhibitor is generated at unattached kinetochores and inhibitor production is prevented when microtubules are captured. Understanding the molecular changes in the kinetochore that are evoked by microtubule attachments is crucial for understanding the mechanisms of SAC signaling and silencing. Here, we highlight the most recent findings on these events, pinpoint some remaining mysteries, and argue for incorporating holistic views of kinetochore dynamics in order to understand SAC silencing. PMID:26947988

  18. Insights from the reconstitution of the divergent outer kinetochore of Drosophila melanogaster

    Science.gov (United States)

    Liu, Yahui; Petrovic, Arsen; Rombaut, Pascaline; Mosalaganti, Shyamal; Keller, Jenny; Raunser, Stefan; Herzog, Franz; Musacchio, Andrea

    2016-01-01

    Accurate chromosome segregation during mitosis and meiosis is crucial for cellular and organismal viability. Kinetochores connect chromosomes with spindle microtubules and are essential for chromosome segregation. These large protein scaffolds emerge from the centromere, a specialized region of the chromosome enriched with the histone H3 variant CENP-A. In most eukaryotes, the kinetochore core consists of the centromere-proximal constitutive centromere-associated network (CCAN), which binds CENP-A and contains 16 subunits, and of the centromere-distal Knl1 complex, Mis12 complex, Ndc80 complex (KMN) network, which binds microtubules and contains 10 subunits. In the fruitfly, Drosophila melanogaster, the kinetochore underwent remarkable simplifications. All CCAN subunits, with the exception of centromeric protein C (CENP-C), and two KMN subunits, Dsn1 and Zwint, cannot be identified in this organism. In addition, two paralogues of the KMN subunit Nnf1 (Nnf1a and Nnf1b) are present. Finally, the Spc105R subunit, homologous to human Knl1/CASC5, underwent considerable sequence changes in comparison with other organisms. We combined biochemical reconstitution with biophysical and structural methods to investigate how these changes reflect on the organization of the Drosophila KMN network. We demonstrate that the Nnf1a and Nnf1b paralogues are subunits of distinct complexes, both of which interact directly with Spc105R and with CENP-C, for the latter of which we identify a binding site on the Mis12 subunit. Our studies shed light on the structural and functional organization of a highly divergent kinetochore particle. PMID:26911624

  19. Ndc10 is a platform for inner kinetochore assembly in budding yeast

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Uhn-Soo; Harrison, Stephen C. (Harvard-Med)

    2012-01-10

    Kinetochores link centromeric DNA to spindle microtubules and ensure faithful chromosome segregation during mitosis. In point-centromere yeasts, the CBF3 complex Skp1-Ctf13-(Cep3){sub 2}-(Ndc10){sub 2} recognizes a conserved centromeric DNA element through contacts made by Cep3 and Ndc10. We describe here the five-domain organization of Kluyveromyces lactis Ndc10 and the structure at 2.8 {angstrom} resolution of domains I-II (residues 1-402) bound to DNA. The structure resembles tyrosine DNA recombinases, although it lacks both endonuclease and ligase activities. Structural and biochemical data demonstrate that each subunit of the Ndc10 dimer binds a separate fragment of DNA, suggesting that Ndc10 stabilizes a DNA loop at the centromere. We describe in vitro association experiments showing that specific domains of Ndc10 interact with each of the known inner-kinetochore proteins or protein complexes in budding yeast. We propose that Ndc10 provides a central platform for inner-kinetochore assembly.

  20. Kinetochore and heterochromatin domains of the fission yeast centromere.

    Science.gov (United States)

    Pidoux, Alison L; Allshire, Robin C

    2004-01-01

    Fission yeast centromeres are composed of two distinctive chromatin domains. The central domain nucleosomes contain the histone H3-like protein CENP-A(Cnp1). In contrast, the flanking repeats are coated with silent chromatin in which Swi6 (HP1) binds histone H3 methylated on lysine 9 that is induced by the action of the RNA interference pathway on non-coding centromeric transcripts. The overall structure is similar to that of metazoan centromeres where the kinetochore is embedded in surrounding heterochromatin. Kinetochore specific proteins associate with the central domain and affect silencing in that region. The flanking heterochromatin is required to recruit cohesin and mediate tight physical cohesion between sister centromeres. The loss of silencing that accompanies defects in heterochromatin has been invaluable as a tool in the investigation of centromere function. Both the heterochromatin and kinetochore regions are required for the de novo assembly of a functional centromere on DNA constructs, suggesting that heterochromatin may provide an environment that promotes kinetochore assembly within the central domain. The process is clearly epigenetically regulated. Fission yeast kinetochores associate with 2-4 microtubules, and flanking heterochromatin may be required to promote the orientation of multiple microtubule binding sites on one kinetochore towards the same pole and thus prevent merotelic orientation. PMID:15289660

  1. Kinetochore assembly and heterochromatin formation occur autonomously in Schizosaccharomyces pombe.

    Science.gov (United States)

    Brown, William R A; Thomas, Geraint; Lee, Nicholas C O; Blythe, Martin; Liti, Gianni; Warringer, Jonas; Loose, Matthew W

    2014-02-01

    Kinetochores in multicellular eukaryotes are usually associated with heterochromatin. Whether this heterochromatin simply promotes the cohesion necessary for accurate chromosome segregation at cell division or whether it also has a role in kinetochore assembly is unclear. Schizosaccharomyces pombe is an important experimental system for investigating centromere function, but all of the previous work with this species has exploited a single strain or its derivatives. The laboratory strain and most other S. pombe strains contain three chromosomes, but one recently discovered strain, CBS 2777, contains four. We show that the genome of CBS 2777 is related to that of the laboratory strain by a complex chromosome rearrangement. As a result, two of the kinetochores in CBS 2777 contain the central core sequences present in the laboratory strain centromeres, but lack adjacent heterochromatin. The closest block of heterochromatin to these rearranged kinetochores is ∼100 kb away at new telomeres. Despite lacking large amounts of adjacent heterochromatin, the rearranged kinetochores bind CENP-A(Cnp1) and CENP-C(Cnp3) in similar quantities and with similar specificities as those of the laboratory strain. The simplest interpretation of this result is that constitutive kinetochore assembly and heterochromatin formation occur autonomously. PMID:24449889

  2. The Ndc80 internal loop is required for recruitment of the Ska complex to establish end-on microtubule attachment to kinetochores

    DEFF Research Database (Denmark)

    Zhang, Gang; Kelstrup, Christian D; Hu, Xiao-Wen; Hansen, Mathilde J Kaas; Singleton, Martin R; Olsen, Jesper V; Nilsson, Jakob

    The Ndc80 complex establishes end-on attachment of kinetochores to microtubules essential for chromosome segregation. The Ndc80 subunit is characterized by an N-terminal region, that binds directly to microtubules, and a long coiled-coil region that interacts with Nuf2. A loop region in Ndc80 tha...

  3. Mechanism of the mitotic kinesin CENP-E in tethering kinetochores to spindle microtubules

    OpenAIRE

    Kim, Yumi

    2009-01-01

    The mitotic kinesin CENP-E is an essential kinetochore motor that directly contributes to the capture and stabilization of spindle microtubules by kinetochores. Although it has been well established that CENP-E is essential for metaphase chromosome alignment and reduction of CENP-E leads to high rates of whole chromosome missegregation in cells, its properties as a microtubule- dependent motor, the mechanism by which CENP-E contributes to the dynamic linkage between kinetochores and spindle m...

  4. Ipl1-dependent phosphorylation of Dam1 is reduced by tension applied on kinetochores

    OpenAIRE

    Keating, Patrick; Rachidi, Najma; Tanaka, Tomoyuki U.; Stark, Michael J. R.

    2009-01-01

    The conserved Aurora B protein kinase (Ipl1 in Saccharomyces cerevisiae) is essential for ensuring that sister kinetochores become attached to microtubules from opposite spindle poles (bi-orientation) before anaphase onset. When sister chromatids become attached to microtubules from a single pole, Aurora B/Ipl1 facilitates turnover of kinetochore-microtubule attachments. This process requires phosphorylation by Aurora B/Ipl1 of kinetochore components such as Dam1 in ye...

  5. Bod1, a novel kinetochore protein required for chromosome biorientation

    OpenAIRE

    Porter, Iain M.; McClelland, Sarah E.; Khoudoli, Guennadi A; Hunter, Christopher J; Andersen, Jens S; McAinsh, Andrew D.; Blow, J Julian; Swedlow, Jason R

    2007-01-01

    We have combined the proteomic analysis of Xenopus laevis in vitro–assembled chromosomes with RNA interference and live cell imaging in HeLa cells to identify novel factors required for proper chromosome segregation. The first of these is Bod1, a protein conserved throughout metazoans that associates with a large macromolecular complex and localizes with kinetochores and spindle poles during mitosis. Small interfering RNA depletion of Bod1 in HeLa cells produces elongated mitotic spindles wit...

  6. Fin1-PP1 Helps Clear Spindle Assembly Checkpoint Protein Bub1 from Kinetochores in Anaphase.

    Science.gov (United States)

    Bokros, Michael; Gravenmier, Curtis; Jin, Fengzhi; Richmond, Daniel; Wang, Yanchang

    2016-02-01

    The spindle assembly checkpoint (SAC) monitors chromosome attachment defects, and the assembly of SAC proteins at kinetochores is essential for its activation, but the SAC disassembly process remains unknown. We found that deletion of a 14-3-3 protein, Bmh1, or hyperactivation of Cdc14 early anaphase release (FEAR) allows premature SAC silencing in budding yeast, which depends on a kinetochore protein Fin1 that forms a complex with protein phosphatase PP1. Previous works suggest that FEAR-dependent Fin1 dephosphorylation promotes Bmh1-Fin1 dissociation, which enables kinetochore recruitment of Fin1-PP1. We found persistent kinetochore association of SAC protein Bub1 in fin1Δ mutants after anaphase entry. Therefore, we revealed a mechanism that clears SAC proteins from kinetochores. After anaphase entry, FEAR activation promotes kinetochore enrichment of Fin1-PP1, resulting in SAC disassembly at kinetochores. This mechanism is required for efficient SAC silencing after SAC is challenged, and untimely Fin1-kinetochore association causes premature SAC silencing and chromosome missegregation. PMID:26832405

  7. Unattached kinetochores rather than intrakinetochore tension arrest mitosis in taxol-treated cells.

    Science.gov (United States)

    Magidson, Valentin; He, Jie; Ault, Jeffrey G; O'Connell, Christopher B; Yang, Nachen; Tikhonenko, Irina; McEwen, Bruce F; Sui, Haixin; Khodjakov, Alexey

    2016-02-01

    Kinetochores attach chromosomes to the spindle microtubules and signal the spindle assembly checkpoint to delay mitotic exit until all chromosomes are attached. Light microscopy approaches aimed to indirectly determine distances between various proteins within the kinetochore (termed Delta) suggest that kinetochores become stretched by spindle forces and compact elastically when the force is suppressed. Low Delta is believed to arrest mitotic progression in taxol-treated cells. However, the structural basis of Delta remains unknown. By integrating same-kinetochore light microscopy and electron microscopy, we demonstrate that the value of Delta is affected by the variability in the shape and size of outer kinetochore domains. The outer kinetochore compacts when spindle forces are maximal during metaphase. When the forces are weakened by taxol treatment, the outer kinetochore expands radially and some kinetochores completely lose microtubule attachment, a condition known to arrest mitotic progression. These observations offer an alternative interpretation of intrakinetochore tension and question whether Delta plays a direct role in the control of mitotic progression. PMID:26833787

  8. Unattached kinetochores rather than intrakinetochore tension arrest mitosis in taxol-treated cells

    Science.gov (United States)

    Magidson, Valentin; He, Jie; Ault, Jeffrey G.; O’Connell, Christopher B.; Yang, Nachen; Tikhonenko, Irina; McEwen, Bruce F.

    2016-01-01

    Kinetochores attach chromosomes to the spindle microtubules and signal the spindle assembly checkpoint to delay mitotic exit until all chromosomes are attached. Light microscopy approaches aimed to indirectly determine distances between various proteins within the kinetochore (termed Delta) suggest that kinetochores become stretched by spindle forces and compact elastically when the force is suppressed. Low Delta is believed to arrest mitotic progression in taxol-treated cells. However, the structural basis of Delta remains unknown. By integrating same-kinetochore light microscopy and electron microscopy, we demonstrate that the value of Delta is affected by the variability in the shape and size of outer kinetochore domains. The outer kinetochore compacts when spindle forces are maximal during metaphase. When the forces are weakened by taxol treatment, the outer kinetochore expands radially and some kinetochores completely lose microtubule attachment, a condition known to arrest mitotic progression. These observations offer an alternative interpretation of intrakinetochore tension and question whether Delta plays a direct role in the control of mitotic progression. PMID:26833787

  9. Analysis of Ipl1-Mediated Phosphorylation of the Ndc80 Kinetochore Protein in Saccharomyces cerevisiae

    OpenAIRE

    Akiyoshi, Bungo; Nelson, Christian R.; Ranish, Jeffrey A; Biggins, Sue

    2009-01-01

    Phosphorylation of the Ndc80 kinetochore protein by the Ipl1/Aurora B kinase reduces its microtubule binding activity in vitro. We found that kinetochore-bound Ndc80 is phosphorylated on Ipl1 sites in vivo, but this phosphorylation is not essential. Instead, we show that additional Ipl1 targets contribute to segregation and the spindle checkpoint.

  10. Inner Kinetochore Protein Interactions with Regional Centromeres of Fission Yeast

    OpenAIRE

    Thakur, Jitendra; Talbert, Paul B; Henikoff, Steven

    2015-01-01

    Centromeres of the fission yeast Schizosaccharomyces pombe lack the highly repetitive sequences that make most other "regional" centromeres refractory to analysis. To map fission yeast centromeres, we applied H4S47C-anchored cleavage mapping and native and cross-linked chromatin immunoprecipitation with paired-end sequencing. H3 nucleosomes are nearly absent from the central domain, which is occupied by centromere-specific H3 (cenH3 or CENP-A) nucleosomes with two H4s per particle that are mo...

  11. Chromatin Assembly at Kinetochores Is Uncoupled from DNA Replication

    Science.gov (United States)

    Shelby, Richard D.; Monier, Karine; Sullivan, Kevin F.

    2000-01-01

    The specification of metazoan centromeres does not depend strictly on centromeric DNA sequences, but also requires epigenetic factors. The mechanistic basis for establishing a centromeric “state” on the DNA remains unclear. In this work, we have directly examined replication timing of the prekinetochore domain of human chromosomes. Kinetochores were labeled by expression of epitope-tagged CENP-A, which stably marks prekinetochore domains in human cells. By immunoprecipitating CENP-A mononucleosomes from synchronized cells pulsed with [3H]thymidine we demonstrate that CENP-A–associated DNA is replicated in mid-to-late S phase. Cytological analysis of DNA replication further demonstrated that centromeres replicate asynchronously in parallel with numerous other genomic regions. In contrast, quantitative Western blot analysis demonstrates that CENP-A protein synthesis occurs later, in G2. Quantitative fluorescence microscopy and transient transfection in the presence of aphidicolin, an inhibitor of DNA replication, show that CENP-A can assemble into centromeres in the absence of DNA replication. Thus, unlike most genomic chromatin, histone synthesis and assembly are uncoupled from DNA replication at the kinetochore. Uncoupling DNA replication from CENP-A synthesis suggests that regulated chromatin assembly or remodeling could play a role in epigenetic centromere propagation. PMID:11086012

  12. Contributions of microtubule dynamic instability and rotational diffusion to kinetochore capture

    CERN Document Server

    Blackwell, Robert; Edelmaier, Christopher; Gergely, Zachary R; Flynn, Patrick J; Montes, Salvador; Crapo, Ammon; Doostan, Alireza; McIntosh, J Richard; Glaser, Matthew A; Betterton, Meredith D

    2016-01-01

    Microtubule dynamic instability allows search and capture of kinetochores during spindle formation, an important process for accurate chromosome segregation during cell division. Recent work has found that microtubule rotational diffusion about minus-end attachment points contributes to kinetochore capture in fission yeast, but the relative contributions of dynamic instability and rotational diffusion are not well understood. We have developed a biophysical model of kinetochore capture in small fission-yeast nuclei using hybrid Brownian dynamics/kinetic Monte Carlo simulation techniques. With this model, we have studied the importance of dynamic instability and microtubule rotational diffusion for kinetochore capture, both to the lateral surface of a microtubule and at or near its end. Over a range of biologically relevant parameters, microtubule rotational diffusion decreased capture time, but made a relatively small contribution compared to dynamic instability. At most, rotational diffusion reduced capture ...

  13. The SUMO protease SENP6 is essential for inner kinetochore assembly.

    Science.gov (United States)

    Mukhopadhyay, Debaditya; Arnaoutov, Alexei; Dasso, Mary

    2010-03-01

    We have analyzed the mitotic function of SENP6, a small ubiquitin-like modifier (SUMO) protease that disassembles conjugated SUMO-2/3 chains. Cells lacking SENP6 showed defects in spindle assembly and metaphase chromosome congression. Analysis of kinetochore composition in these cells revealed that a subset of proteins became undetectable on inner kinetochores after SENP6 depletion, particularly the CENP-H/I/K complex, whereas other changes in kinetochore composition mimicked defects previously reported to result from CENP-H/I/K depletion. We further found that CENP-I is degraded through the action of RNF4, a ubiquitin ligase which targets polysumoylated proteins for proteasomal degradation, and that SENP6 stabilizes CENP-I by antagonizing RNF4. Together, these findings reveal a novel mechanism whereby the finely balanced activities of SENP6 and RNF4 control vertebrate kinetochore assembly through SUMO-targeted destabilization of inner plate components. PMID:20212317

  14. Reconstruction of the Kinetochore during Meiosis in Fission Yeast Schizosaccharomyces pombe

    OpenAIRE

    Hayashi, Aki; Asakawa, Haruhiko; Haraguchi, Tokuko; Hiraoka, Yasushi

    2006-01-01

    During the transition from mitosis to meiosis, the kinetochore undergoes significant reorganization, switching from a bipolar to a monopolar orientation. To examine the centromere proteins that are involved in fundamental reorganization in meiosis, we observed the localization of 22 mitotic and 2 meiotic protein components of the kinetochore during meiosis in living cells of the fission yeast. We found that the 22 mitotic proteins can be classified into three groups: the Mis6-like group, the ...

  15. The conserved protein kinase Ipl1 regulates microtubule binding to kinetochores in budding yeast

    OpenAIRE

    Biggins, Sue; Fedor F. Severin; Bhalla, Needhi; Sassoon, Ingrid; Hyman, Anthony A.; Murray, Andrew W.

    1999-01-01

    Chromosome segregation depends on kinetochores, the structures that mediate chromosome attachment to the mitotic spindle. We isolated mutants in IPL1, which encodes a protein kinase, in a screen for budding yeast mutants that have defects in sister chromatid separation and segregation. Cytological tests show that ipl1 mutants can separate sister chromatids but are defective in chromosome segregation. Kinetochores assembled in extracts from ipl1 mutants show altered binding to microtubules. Ip...

  16. Methylation of CenH3 arginine 37 regulates kinetochore integrity and chromosome segregation

    OpenAIRE

    Samel, Anke; Cuomo, Alessandro; Bonaldi, Tiziana; Ehrenhofer-Murray, Ann E

    2012-01-01

    Centromeres of eukaryotic chromosomes mark the site for kinetochore formation and microtubule attachment and are essential for accurate chromosome segregation. Although centromere identity is defined by the presence of the histone H3 variant CenH3/centromere protein A (CENP-A), little is known about how epigenetic modifications on CenH3 might regulate kinetochore assembly and centromere function. Here we show that CENP-A from Saccharomyces cerevisiae, termed Cse4, is methylated on arginine 37...

  17. CENP-E combines a slow, processive motor and a flexible coiled coil to produce an essential motile kinetochore tether

    OpenAIRE

    Kim, Yumi; Heuser, John E.; Waterman, Clare M.; Cleveland, Don W.

    2008-01-01

    The mitotic kinesin centromere protein E (CENP-E) is an essential kinetochore component that directly contributes to the capture and stabilization of spindle microtubules by kinetochores. Although reduction in CENP-E leads to high rates of whole chromosome missegregation, neither its properties as a microtubule-dependent motor nor how it contributes to the dynamic linkage between kinetochores and microtubules is known. Using single-molecule assays, we demonstrate that CENP-E is a very slow, h...

  18. Spatial Rule-Based Modeling: A Method and Its Application to the Human Mitotic Kinetochore

    Directory of Open Access Journals (Sweden)

    Jan Huwald

    2013-07-01

    Full Text Available A common problem in the analysis of biological systems is the combinatorial explosion that emerges from the complexity of multi-protein assemblies. Conventional formalisms, like differential equations, Boolean networks and Bayesian networks, are unsuitable for dealing with the combinatorial explosion, because they are designed for a restricted state space with fixed dimensionality. To overcome this problem, the rule-based modeling language, BioNetGen, and the spatial extension, SRSim, have been developed. Here, we describe how to apply rule-based modeling to integrate experimental data from different sources into a single spatial simulation model and how to analyze the output of that model. The starting point for this approach can be a combination of molecular interaction data, reaction network data, proximities, binding and diffusion kinetics and molecular geometries at different levels of detail. We describe the technique and then use it to construct a model of the human mitotic inner and outer kinetochore, including the spindle assembly checkpoint signaling pathway. This allows us to demonstrate the utility of the procedure, show how a novel perspective for understanding such complex systems becomes accessible and elaborate on challenges that arise in the formulation, simulation and analysis of spatial rule-based models.

  19. Regulation of a Spindle Positioning Factor at Kinetochores by SUMO-Targeted Ubiquitin Ligases.

    Science.gov (United States)

    Schweiggert, Jörg; Stevermann, Lea; Panigada, Davide; Kammerer, Daniel; Liakopoulos, Dimitris

    2016-02-22

    Correct function of the mitotic spindle requires balanced interplay of kinetochore and astral microtubules that mediate chromosome segregation and spindle positioning, respectively. Errors therein can cause severe defects ranging from aneuploidy to developmental disorders. Here, we describe a protein degradation pathway that functionally links astral microtubules to kinetochores via regulation of a microtubule-associated factor. We show that the yeast spindle positioning protein Kar9 localizes not only to astral but also to kinetochore microtubules, where it becomes targeted for proteasomal degradation by the SUMO-targeted ubiquitin ligases (STUbLs) Slx5-Slx8. Intriguingly, this process does not depend on preceding sumoylation of Kar9 but rather requires SUMO-dependent recruitment of STUbLs to kinetochores. Failure to degrade Kar9 leads to defects in both chromosome segregation and spindle positioning. We propose that kinetochores serve as platforms to recruit STUbLs in a SUMO-dependent manner in order to ensure correct spindle function by regulating levels of microtubule-associated proteins. PMID:26906737

  20. CENP-K and CENP-H may form coiled-coils in the kinetochores

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Kinetochores are large proteinaceous structure on the surface of chromosomes’ primary constriction during mitosis. They link chromosomes to spindle microtubules and also regulate the spindle assem- bly checkpoint, which is crucial for correct chromosome segregation in all eukaryotes. The better known core networks of kinetochores include the KMN network (K, KNL1; M, Mis12 complex; N, Ndc80 complex)and CCAN (constitutive centromere-associated network). However, the detailed molecular mechanism of the kinetochore protein network remains unclear. This study demonstrates that CENP-H and CENP-K form quite stable subcomplex by TAP (tandem affinity purification) with HEK 293 cells which express TAP-CENP-K, with the ratio of purified CENP-H and CENP-K being close to 1︰1 even with high salt. Bioinformatic analysis suggests that CENP-H and CENP-K are enriched with coiled-coil regions. This implies that CENP-H and CENP-K form heterodimeric coiled-coils. Furthermore, the func- tional regions which form the complex are respectively located on their N- and C-terminals, but the association between the C-terminals is more complex. It is possible that this is the first identified het- erodimeric coiled-coils within the inner kinetochore, which is directly involved in the attachment be- tween kinetochores and the spindle microtubules.

  1. Kinetochore-Independent Chromosome Poleward Movement during Anaphase of Meiosis II in Mouse Eggs

    Science.gov (United States)

    Deng, Manqi; Gao, Juntao; Suraneni, Praveen; Li, Rong

    2009-01-01

    Kinetochores are considered to be the key structures that physically connect spindle microtubules to the chromosomes and play an important role in chromosome segregation during mitosis. Due to different mechanisms of spindle assembly between centrosome-containing mitotic cells and acentrosomal meiotic oocytes, it is unclear how a meiotic spindle generates the poleward forces to drive two rounds of meiotic chromosome segregation to achieve genome haploidization. We took advantage of the fact that DNA beads are able to induce bipolar spindle formation without kinetochores and studied the behavior of DNA beads in the induced spindle in mouse eggs during meiosis II. Interestingly, DNA beads underwent poleward movements that were similar in timing and speed to the meiotic chromosomes, although all the beads moved together to the same spindle pole. Disruption of dynein function abolished the poleward movements of DNA beads but not of the meiotic chromosomes, suggesting the existence of different dynein-dependent and dynein-independent force generation mechanisms for the chromosome poleward movement, and the latter may be dependent on the presence of kinetochores. Consistent with the observed DNA bead poleward movement, sperm haploid chromatin (which also induced bipolar spindle formation after injection to a metaphase egg without forming detectable kinetochore structures) also underwent similar poleward movement at anaphase as DNA beads. The results suggest that in the chromatin-induced meiotic spindles, kinetochore attachments to spindle microtubules are not absolutely required for chromatin poleward movements at anaphase. PMID:19365562

  2. Mislocalization of the Drosophila centromere-specific histone CIDpromotes formation of functional ectopic kinetochores

    Energy Technology Data Exchange (ETDEWEB)

    Heun, Patrick; Erhardt, Sylvia; Blower, Michael D.; Weiss,Samara; Skora, Andrew D.; Karpen, Gary H.

    2006-01-30

    The centromere-specific histone variant CENP-A (CID in Drosophila) is a structural and functional foundation for kinetochore formation and chromosome segregation. Here, we show that overexpressed CID is mislocalized into normally non-centromeric regions in Drosophila tissue culture cells and animals. Analysis of mitoses in living and fixed cells reveals that mitotic delays, anaphase bridges, chromosome fragmentation, and cell and organismal lethality are all direct consequences of CID mislocalization. In addition, proteins that are normally restricted to endogenous kinetochores assemble at a subset of ectopic CID incorporation regions. The presence of microtubule motors and binding proteins, spindle attachments, and aberrant chromosome morphologies demonstrate that these ectopic kinetochores are functional. We conclude that CID mislocalization promotes formation of ectopic centromeres and multicentric chromosomes, which causes chromosome missegregation, aneuploidy, and growth defects. Thus, CENP-A mislocalization is one possible mechanism for genome instability during cancer progression, as well as centromere plasticity during evolution.

  3. Cyclin B1 is localized to unattached kinetochores and contributes to efficient microtubule attachment and proper chromosome alignment during mitosis

    Institute of Scientific and Technical Information of China (English)

    Qiang Chen; Xiaoyan Zhang; Qing Jiang; Paul R Clarke; Chuanmao Zhang

    2008-01-01

    Cyclin Bl is a key regulatory protein controlling cell cycle progression in vertebrates. Cyclin Bl binds CDK1, a cyclin-dependent kinase catalytic subunit, forming a complex that orchestrates mitosis through phosphorylation of key proteins. Cyclin Bl regulates both the activation of CDK1 and its subcellular localization, which may be critical for substrate selection. Here, we demonstrate that cyclin Bl is concentrated on the outer plate of the kinetochore during prometaphase. This localization requires the cyclin box region of the protein. Cyclin Bl is displaced from individual kinetochores to the spindle poles by microtubule attachment to the kinetochores, and this displacement is dependent on the dynein/dynactin complex. Depletion of cyclin Bl by vector-based siRNA causes inefficient attachment between kinetochores and microtubules, and chromosome alignment defects, and delays the onset of anaphase. We conclude that cyclin Bl accumulates at kinetochores during prometaphase, where it contributes to the correct attachment of microtubules to kinetochores and efficient alignment of the chromosomes, most likely through localized phosphorylation of specific substrates by cyclin B1-CDK1. Cyclin Bl is then transported from each kinetochore as microtubule attachment is completed, and this relocalization may redirect the activity of cyclin B1-CDK1 and contribute to inactivation of the spindle assembly checkpoint.

  4. Timely anaphase onset requires a novel spindle and kinetochore complex comprising Ska1 and Ska2

    NARCIS (Netherlands)

    Hanisch, Anja; Silljé, Herman H W; Nigg, Erich A

    2006-01-01

    Chromosome segregation during mitosis requires chromosomes to undergo bipolar attachment on spindle microtubules (MTs) and subsequent silencing of the spindle checkpoint. Here, we describe the identification and characterisation of a novel spindle and kinetochore (KT)-associated complex that is requ

  5. Auxin/AID versus conventional knockouts: distinguishing the roles of CENP-T/W in mitotic kinetochore assembly and stability

    Science.gov (United States)

    Wood, Laura; Booth, Daniel G.; Vargiu, Giulia; Ohta, Shinya; deLima Alves, Flavia; Samejima, Kumiko; Fukagawa, Tatsuo; Rappsilber, Juri; Earnshaw, William C.

    2016-01-01

    Most studies using knockout technologies to examine protein function have relied either on shutting off transcription (conventional conditional knockouts with tetracycline-regulated gene expression or gene disruption) or destroying the mature mRNA (RNAi technology). In both cases, the target protein is lost at a rate determined by its intrinsic half-life. Thus, protein levels typically fall over at least 1–3 days, and cells continue to cycle while exposed to a decreasing concentration of the protein. Here we characterise the kinetochore proteome of mitotic chromosomes isolated from a cell line in which the essential kinetochore protein CENP-T is present as an auxin-inducible degron (AID) fusion protein that is fully functional and able to support the viability of the cells. Stripping of the protein from chromosomes in early mitosis via targeted proteasomal degradation reveals the dependency of other proteins on CENP-T for their maintenance in kinetochores. We compare these results with the kinetochore proteome of conventional CENP-T/W knockouts. As the cell cycle is mostly formed from G1, S and G2 phases a gradual loss of CENP-T/W levels is more likely to reflect dependencies associated with kinetochore assembly pre-mitosis and upon entry into mitosis. Interestingly, a putative super-complex involving Rod-Zw10-zwilch (RZZ complex), Spindly, Mad1/Mad2 and CENP-E requires the function of CENP-T/W during kinetochore assembly for its stable association with the outer kinetochore, but once assembled remains associated with chromosomes after stripping of CENP-T during mitosis. This study highlights the different roles core kinetochore components may play in the assembly of kinetochores (upon entry into mitosis) versus the maintenance of specific components (during mitosis). PMID:26791246

  6. N-terminus-modified Hec1 suppresses tumour growth by interfering with kinetochore-microtubule dynamics.

    Science.gov (United States)

    Orticello, M; Fiore, M; Totta, P; Desideri, M; Barisic, M; Passeri, D; Lenzi, J; Rosa, A; Orlandi, A; Maiato, H; Del Bufalo, D; Degrassi, F

    2015-06-01

    Mitotic proteins are attractive targets to develop molecular cancer therapeutics due to the intimate interdependence between cell proliferation and mitosis. In this work, we have explored the therapeutic potential of the kinetochore (KT) protein Hec1 (Highly Expressed in Cancer protein 1) as a molecular target to produce massive chromosome missegregation and cell death in cancer cells. Hec1 is a constituent of the Ndc80 complex, which mediates KT-microtubule (MT) attachments at mitosis and is upregulated in various cancer types. We expressed Hec1 fused with enhanced green fluorescent protein (EGFP) at its N-terminus MT-interaction domain in HeLa cells and showed that expression of this modified Hec1, which localized at KTs, blocked cell proliferation and promoted apoptosis in tumour cells. EGFP-Hec1 was extremely potent in tumour cell killing and more efficient than siRNA-induced Hec1 depletion. In striking contrast, normal cells showed no apparent cell proliferation defects or cell death following EGFP-Hec1 expression. Live-cell imaging demonstrated that cancer cell death was associated with massive chromosome missegregation within multipolar spindles after a prolonged mitotic arrest. Moreover, EGFP-Hec1 expression was found to increase KT-MT attachment stability, providing a molecular explanation for the abnormal spindle architecture and the cytotoxic activity of this modified protein. Consistent with cell culture data, EGFP-Hec1 expression was found to strongly inhibit tumour growth in a mouse xenograft model by disrupting mitosis and inducing multipolar spindles. Taken together, these findings demonstrate that stimulation of massive chromosome segregation defects can be used as an anti-cancer strategy through the activation of mitotic catastrophe after a multipolar mitosis. Importantly, this study represents a clear proof of concept that targeting KT proteins required for proper KT-MT attachment dynamics constitutes a powerful approach in cancer therapy. PMID

  7. Small kinetochore associated protein (SKAP promotes UV-induced cell apoptosis through negatively regulating pre-mRNA processing factor 19 (Prp19.

    Directory of Open Access Journals (Sweden)

    Shan Lu

    Full Text Available Apoptosis is a regulated cellular suicide program that is critical for the development and maintenance of healthy tissues. Previous studies have shown that small kinetochore associated protein (SKAP cooperates with kinetochore and mitotic spindle proteins to regulate mitosis. However, the role of SKAP in apoptosis has not been investigated. We have identified a new interaction involving SKAP, and we propose a mechanism through which SKAP regulates cell apoptosis. Our experiments demonstrate that both overexpression and knockdown of SKAP sensitize cells to UV-induced apoptosis. Further study has revealed that SKAP interacts with Pre-mRNA processing Factor 19 (Prp19. We find that UV-induced apoptosis can be inhibited by ectopic expression of Prp19, whereas silencing Prp19 has the opposite effect. Additionally, SKAP negatively regulates the protein levels of Prp19, whereas Prp19 does not alter SKAP expression. Finally, rescue experiments demonstrate that the pro-apoptotic role of SKAP is executed through Prp19. Taken together, these findings suggest that SKAP promotes UV-induced cell apoptosis by negatively regulating the anti-apoptotic protein Prp19.

  8. Unique geometry of sister kinetochores in human oocytes during meiosis I may explain maternal age-associated increases in chromosomal abnormalities

    Directory of Open Access Journals (Sweden)

    Jessica Patel

    2016-02-01

    Full Text Available The first meiotic division in human oocytes is highly error-prone and contributes to the uniquely high incidence of aneuploidy observed in human pregnancies. A successful meiosis I (MI division entails separation of homologous chromosome pairs and co-segregation of sister chromatids. For this to happen, sister kinetochores must form attachments to spindle kinetochore-fibres emanating from the same pole. In mouse and budding yeast, sister kinetochores remain closely associated with each other during MI, enabling them to act as a single unified structure. However, whether this arrangement also applies in human meiosis I oocytes was unclear. In this study, we perform high-resolution imaging of over 1900 kinetochores in human oocytes, to examine the geometry and architecture of the human meiotic kinetochore. We reveal that sister kinetochores in MI are not physically fused, and instead individual kinetochores within a pair are capable of forming independent attachments to spindle k-fibres. Notably, with increasing female age, the separation between kinetochores increases, suggesting a degradation of centromeric cohesion and/or changes in kinetochore architecture. Our data suggest that the differential arrangement of sister kinetochores and dual k-fibre attachments may explain the high proportion of unstable attachments that form in MI and thus indicate why human oocytes are prone to aneuploidy, particularly with increasing maternal age.

  9. The kinetochore protein Kis1/Eic1/Mis19 ensures the integrity of mitotic spindles through maintenance of kinetochore factors Mis6/CENP-I and CENP-A.

    Science.gov (United States)

    Hirai, Hayato; Arai, Kunio; Kariyazono, Ryo; Yamamoto, Masayuki; Sato, Masamitsu

    2014-01-01

    Microtubules play multiple roles in a wide range of cellular phenomena, including cell polarity establishment and chromosome segregation. A number of microtubule regulators have been identified, including microtubule-associated proteins and kinases, and knowledge of these factors has contributed to our molecular understanding of microtubule regulation of each relevant cellular process. The known regulators, however, are insufficient to explain how those processes are linked to one another, underscoring the need to identify additional regulators. To find such novel mechanisms and microtubule regulators, we performed a screen that combined genetics and microscopy for fission yeast mutants defective in microtubule organization. We isolated approximately 900 mutants showing defects in either microtubule organization or the nuclear envelope, and these mutants were classified into 12 categories. We particularly focused on one mutant, kis1, which displayed spindle defects in early mitosis. The kis1 mutant frequently failed to assemble a normal bipolar spindle. The responsible gene encoded a kinetochore protein, Mis19 (also known as Eic1), which localized to the interface of kinetochores and spindle poles. We also found that the inner kinetochore proteins Mis6/CENP-I and Cnp1/CENP-A were delocalized from kinetochores in the kis1 cells and that kinetochore-microtubule attachment was defective. Another mutant, mis6, also displayed similar spindle defects. We conclude that Kis1 is required for inner kinetochore organization, through which Kis1 ensures kinetochore-microtubule attachment and spindle integrity. Thus, we propose an unexpected relationship between inner kinetochore organization and spindle integrity. PMID:25375240

  10. The kinetochore protein Kis1/Eic1/Mis19 ensures the integrity of mitotic spindles through maintenance of kinetochore factors Mis6/CENP-I and CENP-A.

    Directory of Open Access Journals (Sweden)

    Hayato Hirai

    Full Text Available Microtubules play multiple roles in a wide range of cellular phenomena, including cell polarity establishment and chromosome segregation. A number of microtubule regulators have been identified, including microtubule-associated proteins and kinases, and knowledge of these factors has contributed to our molecular understanding of microtubule regulation of each relevant cellular process. The known regulators, however, are insufficient to explain how those processes are linked to one another, underscoring the need to identify additional regulators. To find such novel mechanisms and microtubule regulators, we performed a screen that combined genetics and microscopy for fission yeast mutants defective in microtubule organization. We isolated approximately 900 mutants showing defects in either microtubule organization or the nuclear envelope, and these mutants were classified into 12 categories. We particularly focused on one mutant, kis1, which displayed spindle defects in early mitosis. The kis1 mutant frequently failed to assemble a normal bipolar spindle. The responsible gene encoded a kinetochore protein, Mis19 (also known as Eic1, which localized to the interface of kinetochores and spindle poles. We also found that the inner kinetochore proteins Mis6/CENP-I and Cnp1/CENP-A were delocalized from kinetochores in the kis1 cells and that kinetochore-microtubule attachment was defective. Another mutant, mis6, also displayed similar spindle defects. We conclude that Kis1 is required for inner kinetochore organization, through which Kis1 ensures kinetochore-microtubule attachment and spindle integrity. Thus, we propose an unexpected relationship between inner kinetochore organization and spindle integrity.

  11. Role of Intrinsic and Extrinsic Factors in the Regulation of the Mitotic Checkpoint Kinase Bub1

    Science.gov (United States)

    Breit, Claudia; Bange, Tanja; Petrovic, Arsen; Weir, John R.; Müller, Franziska; Vogt, Doro; Musacchio, Andrea

    2015-01-01

    The spindle assembly checkpoint (SAC) monitors microtubule attachment to kinetochores to ensure accurate sister chromatid segregation during mitosis. The SAC members Bub1 and BubR1 are paralogs that underwent significant functional specializations during evolution. We report an in-depth characterization of the kinase domains of Bub1 and BubR1. BubR1 kinase domain binds nucleotides but is unable to deliver catalytic activity in vitro. Conversely, Bub1 is an active kinase regulated by intra-molecular phosphorylation at the P+1 loop. The crystal structure of the phosphorylated Bub1 kinase domain illustrates a hitherto unknown conformation of the P+1 loop docked into the active site of the Bub1 kinase. Both Bub1 and BubR1 bind Bub3 constitutively. A hydrodynamic characterization of Bub1:Bub3 and BubR1:Bub3 demonstrates both complexes to have 1:1 stoichiometry, with no additional oligomerization. Conversely, Bub1:Bub3 and BubR1:Bub3 combine to form a heterotetramer. Neither BubR1:Bub3 nor Knl1, the kinetochore receptor of Bub1:Bub3, modulate the kinase activity of Bub1 in vitro, suggesting autonomous regulation of the Bub1 kinase domain. We complement our study with an analysis of the Bub1 substrates. Our results contribute to the mechanistic characterization of a crucial cell cycle checkpoint. PMID:26658523

  12. The Overexpression of a Saccharomyces cerevisiae Centromeric Histone H3 Variant Mutant Protein Leads to a Defect in Kinetochore Biorientation

    OpenAIRE

    Collins, Kimberly A.; Camahort, Raymond; Seidel, Chris; Gerton, Jennifer L.; Biggins, Sue

    2007-01-01

    Chromosomes segregate using their kinetochores, the specialized protein structures that are assembled on centromeric DNA and mediate attachment to the mitotic spindle. Because centromeric sequences are not conserved, centromere identity is propagated by an epigenetic mechanism. All eukaryotes contain an essential histone H3 variant (CenH3) that localizes exclusively to centromeres. Because CenH3 is required for kinetochore assembly and is likely to be the epigenetic mark that specifies centro...

  13. Maloriented Bivalents Have Metaphase Positions at the Spindle Equator with More Kinetochore Microtubules to One Pole than to the OtherV⃞

    OpenAIRE

    LaFountain, James R.; Oldenbourg, Rudolf

    2004-01-01

    To test the “traction fiber” model for metaphase positioning of bivalents during meiosis, kinetochore fibers of maloriented bivalents, induced during recovery from cold arrest, were analyzed with a liquid crystal polarizing microscope. The measured birefringence retardation of kinetochore fibers is proportional to the number of microtubules in a fiber. Five of the 11 maloriented bivalents analyzed exhibited bipolar malorientations that had at least four times more kinetochore microtubules to ...

  14. Ipl1p-dependent phosphorylation of Mad3p is required for the spindle checkpoint response to lack of tension at kinetochores

    OpenAIRE

    King, Emma M J; Rachidi, Najma; Morrice, Nick; Hardwick, Kevin G.; Stark, Michael J. R.

    2007-01-01

    The spindle checkpoint delays anaphase onset until all chromosomes are correctly attached to microtubules. Ipl1 protein kinase (Aurora B) is required to correct inappropriate kinetochore-microtubule attachments and for the response to lack of tension between sister kinetochores. Here we identify residues in the checkpoint protein Mad3p that are phosphorylated by Ipl1p. When phosphorylation of Mad3p at two sites is prevented, the cell's response to reduced kinetochore tension is dramatically c...

  15. Regulation of mitotic progression : Focus on Plk1 function and the novel Ska complex at kinetochores

    OpenAIRE

    Hanisch, Anja

    2007-01-01

    During mitosis the duplicated chromosomes have to be faithfully segregated into the nascent daughter cells in order to maintain genomic stability. This critical process is dependent on the rearrangement of the interphase microtubule (MT) network, resulting in the formation of a bipolar mitotic spindle. For proper chromosome segregation all chromosomes have to become connected to MTs emanating from opposite spindle poles. The MT attachment sites on the chromosomes are the kinetochores (KTs), w...

  16. Inhibitor-3 ensures bipolar mitotic spindle attachment by limiting association of SDS22 with kinetochore-bound protein phosphatase-1

    OpenAIRE

    Eiteneuer, Annika; Seiler, Jonas; Weith, Matthias; Beullens, Monique; Lesage, Bart; Krenn, Veronica; Musacchio, Andrea; Bollen, Mathieu; Meyer, Hemmo

    2014-01-01

    Faithful chromosome segregation during mitosis is tightly regulated by opposing activities of Aurora B kinase and protein phosphatase-1 (PP1). PP1 function at kinetochores has been linked to SDS22, but the exact localization of SDS22 and how it affects PP1 are controversial. Here, we confirm that SDS22 is required for PP1 activity, but show that SDS22 does not normally localize to kinetochores. Instead, SDS22 is kept in solution by formation of a ternary complex with PP1 and inhibitor-3 (I3)....

  17. Dissection of the essential steps for condensin accumulation at kinetochores and rDNAs during fission yeast mitosis

    OpenAIRE

    Nakazawa, Norihiko; Nakamura, Takahiro; Kokubu, Aya; Ebe, Masahiro; Nagao, Koji; Yanagida, Mitsuhiro

    2008-01-01

    The condensin complex has a fundamental role in chromosome dynamics. In this study, we report that accumulation of Schizosaccharomyces pombe condensin at mitotic kinetochores and ribosomal DNAs (rDNAs) occurs in multiple steps and is necessary for normal segregation of the sister kinetochores and rDNAs. Nuclear entry of condensin at the onset of mitosis requires Cut15/importin α and Cdc2 phosphorylation. Ark1/aurora and Cut17/Bir1/survivin are needed to dock the condensin at both the kinetoch...

  18. Theory of dynamic force spectroscopy for kinetochore-microtubule attachments: rupture force distribution

    CERN Document Server

    Ghanti, Dipanwita

    2016-01-01

    Application of pulling force, under force-clamp conditions, to kinetochore-microtubule attachments {\\it in-vitro} revealed a catch-bond-like behavior. In an earlier paper ({\\it Sharma et al. Phys. Biol. (2014)} the physical origin of this apparently counter-intuitive phenomenon was traced to the nature of the force-dependence of the (de-)polymerization kinetics of the microtubules. In this brief communication that work is extended to situations where the external forced is ramped up till the attachment gets ruptured. In spite of the fundamental differences in the underlying mechanisms, the trend of variation of the rupture force distribution observed in our model kinetochore-microtubule attachment with the increasing loading rate is qualitatively similar to that displayed by the catch bonds formed in some other ligand-receptor systems. Our theoretical predictions can be tested experimentally by a straightforward modification of the protocol for controlling the force in the optical trap set up that was used in...

  19. Polar Ejection Forces Promote the Conversion from Lateral to End-on Kinetochore-Microtubule Attachments on Mono-oriented Chromosomes

    Directory of Open Access Journals (Sweden)

    Danica Drpic

    2015-10-01

    Full Text Available Chromosome bi-orientation occurs after conversion of initial lateral attachments between kinetochores and spindle microtubules into stable end-on attachments near the cell equator. After bi-orientation, chromosomes experience tension from spindle forces, which plays a key role in the stabilization of correct kinetochore-microtubule attachments. However, how end-on kinetochore-microtubule attachments are first stabilized in the absence of tension remains a key unanswered question. To address this, we generated Drosophila S2 cells undergoing mitosis with unreplicated genomes (SMUGs. SMUGs retained single condensed chromatids that attached laterally to spindle microtubules. Over time, laterally attached kinetochores converted into end-on attachments and experienced intra-kinetochore stretch/structural deformation, and SMUGs eventually exited a delayed mitosis with mono-oriented chromosomes after satisfying the spindle-assembly checkpoint (SAC. Polar ejection forces (PEFs generated by Chromokinesins promoted the conversion from lateral to end-on kinetochore-microtubule attachments that satisfied the SAC in SMUGs. Thus, PEFs convert lateral to stable end-on kinetochore-microtubule attachments, independently of chromosome bi-orientation.

  20. Novel subcellular localization of the DNA helicase Twinkle at the kinetochore complex during mitosis in neuronal-like progenitor cells.

    Science.gov (United States)

    Uittenbogaard, Martine; Chiaramello, Anne

    2016-03-01

    During mitosis, the kinetochore, a multi-protein structure located on the centromeric DNA, is responsible for proper segregation of the replicated genome. More specifically, the outer kinetochore complex component Ndc80/Hec1 plays a critical role in regulating microtubule attachment to the spindle for accurate sister chromatid segregation. In addition, DNA helicases play a key contribution for precise and complete disjunction of sister chromatids held together through double-stranded DNA catenations until anaphase. In this study, we focused our attention on the nuclear-encoded DNA helicase Twinkle, which functions as an essential helicase for replication of mitochondrial DNA. It regulates the copy number of the mitochondrial genome, while maintaining its integrity, two processes essential for mitochondrial biogenesis and bioenergetic functions. Although the majority of the Twinkle protein is imported into mitochondria, a small fraction remains cytosolic with an unknown function. In this study, we report a novel expression pattern of Twinkle during chromosomal segregation at distinct mitotic phases. By immunofluorescence microscopy, we found that Twinkle protein colocalizes with the outer kinetochore protein HEC1 as early as prophase until late anaphase in neuronal-like progenitor cells. Thus, our collective results have revealed an unexpected cell cycle-regulated expression pattern of the DNA helicase Twinkle, known for its role in mtDNA replication. Therefore, its recruitment to the kinetochore suggests an evolutionary conserved function for both mitochondrial and nuclear genomic inheritance. PMID:26678504

  1. Effects of sense and antisense centromere/kinetochore complex protein-B (CENP-B) in cell cycle regulation

    Institute of Scientific and Technical Information of China (English)

    LUO Song; LIN Haiyan; QI Jianguo; WANG Yongchao

    2005-01-01

    This paper investigates the effects of sense and antisense centromere/kinetochore complex protein-B (CENP-B) in cell cycle regulation. Full-length cenpb cDNA was subcloned into pBI-EGFP eukaryotic expression vector in both sense and antisense orientation. HeLa-Tet-Off cells were transfected with sense or antisense cenpb vectors. Sense transfection of HeLa-Tet-Off cells resulted in the formation of a large centromere/kinetochore complex, and apoptosis of cells following several times of cell division. A stable antisense cenpb transfected cell line, named HACPB, was obtained. The centromere/kinetochore complex of HACPB cells became smaller than control HeLa-Tet-Off cells and scattered, and the expression of CENP-B was down-regulated. In addition, delayed cell cycle progression, inhibited malignant phenotype, restrained ability of tumor formation in nude mice, and delayed entry from G2/M phase into next G1 phase were observed in HACPB cells. Furthermore, the expression of cyclin-dependent kinases (CDKs), cyclins, and CDK inhibitors (CKIs) were modulated during different phases of the cell cycle. CENP-B is an essential protein for the maintenance of the structure and function of centromere/kinetochore complex, and plays important roles in cell cycle regulation.

  2. Ipl1p-dependent phosphorylation of Mad3p is required for the spindle checkpoint response to lack of tension at kinetochores

    OpenAIRE

    King, Emma M J; Rachidi, Najma; Morrice, Nick; Hardwick, Kevin G.; Stark, Michael J. R.

    2007-01-01

    The spindle checkpoint delays anaphase onset until all chromosomes are correctly attached to microtubules. Ipl1 protein kinase (Aurora B) is required to correct inappropriate kinetochore–microtubule attachments and for the response to lack of tension between sister kinetochores. Here we identify residues in the checkpoint protein Mad3p that are phosphorylated by Ipl1p. When phosphorylation of Mad3p at two sites is prevented, the cell’s response to reduced kinetochore tension is dramatically c...

  3. A minimal number of MELT repeats supports all functions of KNL1 in chromosome segregation

    DEFF Research Database (Denmark)

    Zhang, Gang; Lischetti, Tiziana; Nilsson, Jakob

    2013-01-01

    The Bub1-Bub3 and BubR1-Bub3 checkpoint complexes, or the Bubs, contribute to the accurate segregation of chromosomes during mitosis by promoting chromosome bi-orientation and halting exit from mitosis if this fails. The complexes associate with kinetochores during mitosis, which is required for...

  4. PP2A regulates kinetochore-microtubule attachment during meiosis I in oocyte.

    Science.gov (United States)

    Tang, An; Shi, Peiliang; Song, Anying; Zou, Dayuan; Zhou, Yue; Gu, Pengyu; Huang, Zan; Wang, Qinghua; Lin, Zhaoyu; Gao, Xiang

    2016-06-01

    Studies using in vitro cultured oocytes have indicated that the protein phosphatase 2A (PP2A), a major serine/threonine protein phosphatase, participates in multiple steps of meiosis. Details of oocyte maturation regulation by PP2A remain unclear and an in vivo model can provide more convincing information. Here, we inactivated PP2A by mutating genes encoding for its catalytic subunits (PP2Acs) in mouse oocytes. We found that eliminating both PP2Acs caused female infertility. Oocytes lacking PP2Acs failed to complete 1(st) meiotic division due to chromosome misalignment and abnormal spindle assembly. In mitosis, PP2A counteracts Aurora kinase B/C (AurkB/C) to facilitate correct kinetochore-microtubule (KT-MT) attachment. In meiosis I in oocyte, we found that PP2Ac deficiency destabilized KT-MT attachments. Chemical inhibition of AurkB/C in PP2Ac-null oocytes partly restored the formation of lateral/merotelic KT-MT attachments but not correct KT-MT attachments. Taken together, our findings demonstrate that PP2Acs are essential for chromosome alignments and regulate the formation of correct KT-MT attachments in meiosis I in oocytes. PMID:27096707

  5. Human papillomavirus type 16 E7 oncoprotein engages but does not abrogate the mitotic spindle assembly checkpoint

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yueyang [Division of Infectious Diseases, Brigham and Women' s Hospital and Biological and Biomedical Sciences Program, Harvard Medical School, Boston, MA 02115 (United States); Munger, Karl, E-mail: kmunger@rics.bwh.harvard.edu [Division of Infectious Diseases, Brigham and Women' s Hospital and Biological and Biomedical Sciences Program, Harvard Medical School, Boston, MA 02115 (United States)

    2012-10-10

    The mitotic spindle assembly checkpoint (SAC) ensures faithful chromosome segregation during mitosis by censoring kinetochore-microtubule interactions. It is frequently rendered dysfunctional during carcinogenesis causing chromosome missegregation and genomic instability. There are conflicting reports whether the HPV16 E7 oncoprotein drives chromosomal instability by abolishing the SAC. Here we report that degradation of mitotic cyclins is impaired in cells with HPV16 E7 expression. RNAi-mediated depletion of Mad2 or BubR1 indicated the involvement of the SAC, suggesting that HPV16 E7 expression causes sustained SAC engagement. Mutational analyses revealed that HPV16 E7 sequences that are necessary for retinoblastoma tumor suppressor protein binding as well as sequences previously implicated in binding the nuclear and mitotic apparatus (NuMA) protein and in delocalizing dynein from the mitotic spindle contribute to SAC engagement. Importantly, however, HPV16 E7 does not markedly compromise the SAC response to microtubule poisons.

  6. Heterogeneous nuclear ribonucleoprotein K upregulates the kinetochore complex component NUF2 and promotes the tumorigenicity of colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Sugimasa, Hironobu; Taniue, Kenzui [Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan); Kurimoto, Akiko [Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan); Oncology Research Laboratories, Daiichi Sankyo Co., Ltd, 1-2-58, Hiromachi, Shinagawa-ku, Tokyo, 140-8710 (Japan); Takeda, Yasuko; Kawasaki, Yoshihiro [Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan); Akiyama, Tetsu, E-mail: akiyama@iam.u-tokyo.ac.jp [Laboratory of Molecular and Genetic Information, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-0032 (Japan)

    2015-03-27

    Heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a multi-functional protein involved in transcription, mRNA splicing, mRNA stabilization and translation. Although hnRNP K has been suggested to play a role in the development of many cancers, its molecular function in colorectal cancer has remained elusive. Here we show that hnRNP K plays an important role in the mitotic process in HCT116 colon cancer cells. Furthermore, we demonstrate that hnRNP K directly transactivates the NUF2 gene, the product of which is a component of the NDC80 kinetochore complex and which is known to be critical for a stable spindle microtubule-kinetochore attachment. In addition, knockdown of both hnRNP K and NUF2 caused failure in metaphase chromosome alignment and drastic decrease in the growth of colon cancer cells. These results suggest that the hnRNP K-NUF2 axis is important for the mitotic process and proliferation of colon cancer cells and that this axis could be a target for the therapy of colon cancer. - Highlights: • hnRNP K is required for the tumorigenicity of colon cancer cells. • hnRNP K binds to the promoter region of NUF2 and activates its transcription. • NUF2 expression is correlated with hnRNP K expression in colorectal cancer tissue. • hnRNP K and NUF2 are required for metaphase chromosome alignment. • The hnRNP K-NUF2 axis is important for the proliferation of colon cancer cells.

  7. Heterogeneous nuclear ribonucleoprotein K upregulates the kinetochore complex component NUF2 and promotes the tumorigenicity of colon cancer cells

    International Nuclear Information System (INIS)

    Heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a multi-functional protein involved in transcription, mRNA splicing, mRNA stabilization and translation. Although hnRNP K has been suggested to play a role in the development of many cancers, its molecular function in colorectal cancer has remained elusive. Here we show that hnRNP K plays an important role in the mitotic process in HCT116 colon cancer cells. Furthermore, we demonstrate that hnRNP K directly transactivates the NUF2 gene, the product of which is a component of the NDC80 kinetochore complex and which is known to be critical for a stable spindle microtubule-kinetochore attachment. In addition, knockdown of both hnRNP K and NUF2 caused failure in metaphase chromosome alignment and drastic decrease in the growth of colon cancer cells. These results suggest that the hnRNP K-NUF2 axis is important for the mitotic process and proliferation of colon cancer cells and that this axis could be a target for the therapy of colon cancer. - Highlights: • hnRNP K is required for the tumorigenicity of colon cancer cells. • hnRNP K binds to the promoter region of NUF2 and activates its transcription. • NUF2 expression is correlated with hnRNP K expression in colorectal cancer tissue. • hnRNP K and NUF2 are required for metaphase chromosome alignment. • The hnRNP K-NUF2 axis is important for the proliferation of colon cancer cells

  8. In vivo FRET imaging revealed a regulatory role of RanGTP in kinetochore-microtubule attachments via Aurora B kinase.

    Directory of Open Access Journals (Sweden)

    Yoke-Peng Lee

    Full Text Available Under the fluctuating circumstances provided by the innate dynamics of microtubules and opposing tensions resulted from microtubule-associated motors, it is vital to ensure stable kinetochore-microtubule attachments for accurate segregation. However, a comprehensive understanding of how this regulation is mechanistically achieved remains elusive. Using our newly designed live cell FRET time-lapse imaging, we found that post-metaphase RanGTP is crucial in the maintenance of stable kinetochore-microtubule attachments by regulating Aurora B kinase via the NES-bearing Mst1. More importantly, our study demonstrates that by ensuring stable alignment of metaphase chromosomes prior to segregation, RanGTP is indispensible in governing the genomic integrity and the fidelity of cell cycle progression. Our findings suggest an additional role of RanGTP beyond its known function in mitotic spindle assembly during the prometaphase-metaphase transition.

  9. Suppressors of ipl1-2 in Components of a Glc7 Phosphatase Complex, Cdc48 AAA ATPase, TORC1, and the Kinetochore

    OpenAIRE

    Robinson, Lucy C.; Phillips, Joshua; Brou, Lina; Boswell, Evan P.; Tatchell, Kelly

    2012-01-01

    Ipl1/Aurora B is the catalytic subunit of a protein kinase complex required for chromosome segregation and nuclear division. Before anaphase, Ipl1 is required to establish proper kinetochore-microtubule associations and to regulate the spindle assembly checkpoint (SAC). The phosphatase Glc7/PP1 opposes Ipl1 for these activities. To investigate Ipl1 and Glc7 regulation in more detail, we isolated and characterized mutations in the yeast Saccharomyces cerevisiae that raise the restrictive tempe...

  10. Condensin HEAT subunits required for DNA repair, kinetochore/centromere function and ploidy maintenance in fission yeast.

    Directory of Open Access Journals (Sweden)

    Xingya Xu

    Full Text Available Condensin, a central player in eukaryotic chromosomal dynamics, contains five evolutionarily-conserved subunits. Two SMC (structural maintenance of chromosomes subunits contain ATPase, hinge, and coiled-coil domains. One non-SMC subunit is similar to bacterial kleisin, and two other non-SMC subunits contain HEAT (similar to armadillo repeats. Here we report isolation and characterization of 21 fission yeast (Schizosaccharomyces pombe mutants for three non-SMC subunits, created using error-prone mutagenesis that resulted in single-amino acid substitutions. Beside condensation, segregation, and DNA repair defects, similar to those observed in previously isolated SMC and cnd2 mutants, novel phenotypes were observed for mutants of HEAT-repeats containing Cnd1 and Cnd3 subunits. cnd3-L269P is hypersensitive to the microtubule poison, thiabendazole, revealing defects in kinetochore/centromere and spindle assembly checkpoints. Three cnd1 and three cnd3 mutants increased cell size and doubled DNA content, thereby eliminating the haploid state. Five of these mutations reside in helix B of HEAT repeats. Two non-SMC condensin subunits, Cnd1 and Cnd3, are thus implicated in ploidy maintenance.

  11. Distribution of lifetimes of kinetochore-microtubule attachments:interplay of energy landscape, molecular motors and microtubule (de-)polymerization

    CERN Document Server

    Sharma, Ajeet K; Chowdhury, Debashish

    2013-01-01

    Before a cell divides into two daughter cells, the chromosomes are replicated resulting in two sister chromosomes embracing each other. Each sister chromosome is bound to a separate proteinous structure, called kinetochore (kt), that captures the tip of a filamentous protein, called microtubule (MT). Two oppositely oriented MTs pull the two kts attached to two sister chromosomes thereby pulling the two sisters away from each other. Here we theoretically study an even simpler system, namely an isolated kt coupled to a single MT; this system mimics an {\\it in-vitro} experiment where a single kt-MT attachment is reconstituted using purified extracts from budding yeast. Our models not only account for the experimentally observed "catch-bond-like" behavior of the kt-MT coupling, but also make new predictions on the probability distribution of the lifetimes of the attachments. In principle, our new predictions can be tested by analyzing the data collected in the {\\it in-vitro} experiments provided the experiment is...

  12. HJURP is a CENP-A chromatin assembly factor sufficient to form a functional de novo kinetochore.

    Science.gov (United States)

    Barnhart, Meghan C; Kuich, P Henning J L; Stellfox, Madison E; Ward, Jared A; Bassett, Emily A; Black, Ben E; Foltz, Daniel R

    2011-07-25

    Centromeres of higher eukaryotes are epigenetically marked by the centromere-specific CENP-A nucleosome. New CENP-A recruitment requires the CENP-A histone chaperone HJURP. In this paper, we show that a LacI (Lac repressor) fusion of HJURP drove the stable recruitment of CENP-A to a LacO (Lac operon) array at a noncentromeric locus. Ectopically targeted CENP-A chromatin at the LacO array was sufficient to direct the assembly of a functional centromere as indicated by the recruitment of the constitutive centromere-associated network proteins, the microtubule-binding protein NDC80, and the formation of stable kinetochore-microtubule attachments. An amino-terminal fragment of HJURP was able to assemble CENP-A nucleosomes in vitro, demonstrating that HJURP is a chromatin assembly factor. Furthermore, HJURP recruitment to endogenous centromeres required the Mis18 complex. Together, these data suggest that the role of the Mis18 complex in CENP-A deposition is to recruit HJURP and that the CENP-A nucleosome assembly activity of HJURP is responsible for centromeric chromatin assembly to maintain the epigenetic mark. PMID:21768289

  13. The Drosophila histone variant H2A.V works in concert with HP1 to promote kinetochore-driven microtubule formation.

    Science.gov (United States)

    Vernì, Fiammetta; Cenci, Giovanni

    2015-01-01

    Unlike other organisms that have evolved distinct H2A variants for different functions, Drosophila melanogaster has just one variant which is capable of filling many roles. This protein, H2A.V, combines the features of the conserved variants H2A.Z and H2A.X in transcriptional control/heterochromatin assembly and DNA damage response, respectively. Here we show that mutations in the gene encoding H2A.V affect chromatin compaction and perturb chromosome segregation in Drosophila mitotic cells. A microtubule (MT) regrowth assay after cold exposure revealed that loss of H2A.V impairs the formation of kinetochore-driven (k) fibers, which can account for defects in chromosome segregation. All defects are rescued by a transgene encoding H2A.V that lacks the H2A.X function in the DNA damage response, suggesting that the H2A.Z (but not H2A.X) functionality of H2A.V is required for chromosome segregation. We also found that loss of H2A.V weakens HP1 localization, specifically at the pericentric heterochromatin of metaphase chromosomes. Interestingly, loss of HP1 yielded not only telomeric fusions but also mitotic defects similar to those seen in H2A.V null mutants, suggesting a role for HP1 in chromosome segregation. We also show that H2A.V precipitates HP1 from larval brain extracts indicating that both proteins are part of the same complex. Moreover, we found that the overexpression of HP1 rescues chromosome missegregation and defects in the kinetochore-driven k-fiber regrowth of H2A.V mutants indicating that both phenotypes are influenced by unbalanced levels of HP1. Collectively, our results suggest that H2A.V and HP1 work in concert to ensure kinetochore-driven MT growth. PMID:25591068

  14. Gamma-tubulin is required for bipolar spindle assembly and for proper kinetochore microtubule attachments during prometaphase I in Drosophila oocytes.

    Directory of Open Access Journals (Sweden)

    Stacie E Hughes

    2011-08-01

    Full Text Available In many animal species the meiosis I spindle in oocytes is anastral and lacks centrosomes. Previous studies of Drosophila oocytes failed to detect the native form of the germline-specific γ-tubulin (γTub37C in meiosis I spindles, and genetic studies have yielded conflicting data regarding the role of γTub37C in the formation of bipolar spindles at meiosis I. Our examination of living and fixed oocytes carrying either a null allele or strong missense mutation in the γtub37C gene demonstrates a role for γTub37C in the positioning of the oocyte nucleus during late prophase, as well as in the formation and maintenance of bipolar spindles in Drosophila oocytes. Prometaphase I spindles in γtub37C mutant oocytes showed wide, non-tapered spindle poles and disrupted positioning. Additionally, chromosomes failed to align properly on the spindle and showed morphological defects. The kinetochores failed to properly co-orient and often lacked proper attachments to the microtubule bundles, suggesting that γTub37C is required to stabilize kinetochore microtubule attachments in anastral spindles. Although spindle bipolarity was sometimes achieved by metaphase I in both γtub37C mutants, the resulting chromosome masses displayed highly disrupted chromosome alignment. Therefore, our data conclusively demonstrate a role for γTub37C in both the formation of the anastral meiosis I spindle and in the proper attachment of kinetochore microtubules. Finally, multispectral imaging demonstrates the presences of native γTub37C along the length of wild-type meiosis I spindles.

  15. Yeast Interacting Proteins Database: YNL189W, YDR201W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available plex), couples kinetochores to the force produced by MT depolymerization thereby aiding in chromosome segreg...), couples kinetochores to the force produced by MT depolymerization thereby aiding in chromosome segregatio

  16. Yeast Interacting Proteins Database: YGL061C, YER016W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YGL061C DUO1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force... complex (aka DASH complex), couples kinetochores to the force produced by MT depolymerization thereby aidin

  17. Yeast Interacting Proteins Database: YLR423C, YKR083C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available of the Dam1 complex (aka DASH complex), couples kinetochores to the force produce...lex), couples kinetochores to the force produced by MT depolymerization thereby aiding in chromosome segrega

  18. Yeast Interacting Proteins Database: YKR037C, YDR016C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YKR037C SPC34 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...016C DAD1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...Bait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...ion Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by

  19. Yeast Interacting Proteins Database: YKR037C, YDR201W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YKR037C SPC34 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...201W SPC19 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...34 Bait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...ription Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced

  20. Yeast Interacting Proteins Database: YKR083C, YDR201W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YKR083C DAD2 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...1W SPC19 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...ait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force ...on Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by M

  1. Yeast Interacting Proteins Database: YGL061C, YDR016C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YGL061C DUO1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...6C DAD1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...it description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force p... Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by MT

  2. Yeast Interacting Proteins Database: YGR113W, YDR016C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YGR113W DAM1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...DR016C DAD1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force... Bait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...ription Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced

  3. Yeast Interacting Proteins Database: YGR113W, YGL061C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YGR113W DAM1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...GL061C DUO1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...M1 Bait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...scription Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produc

  4. Yeast Interacting Proteins Database: YKR083C, YKL052C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YKR083C DAD2 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...2C ASK1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...e name DAD2 Bait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...ey description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force p

  5. Yeast Interacting Proteins Database: YGR113W, YKR037C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YGR113W DAM1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...KR037C SPC34 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...M1 Bait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...escription Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produ

  6. Yeast Interacting Proteins Database: YKR037C, YGL061C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YKR037C SPC34 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...061C DUO1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...Bait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...ion Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by

  7. Multipolar spindle pole coalescence is a major source of kinetochore mis-attachment and chromosome mis-segregation in cancer cells.

    Directory of Open Access Journals (Sweden)

    William T Silkworth

    Full Text Available Many cancer cells display a CIN (Chromosome Instability phenotype, by which they exhibit high rates of chromosome loss or gain at each cell cycle. Over the years, a number of different mechanisms, including mitotic spindle multipolarity, cytokinesis failure, and merotelic kinetochore orientation, have been proposed as causes of CIN. However, a comprehensive theory of how CIN is perpetuated is still lacking. We used CIN colorectal cancer cells as a model system to investigate the possible cellular mechanism(s underlying CIN. We found that CIN cells frequently assembled multipolar spindles in early mitosis. However, multipolar anaphase cells were very rare, and live-cell experiments showed that almost all CIN cells divided in a bipolar fashion. Moreover, fixed-cell analysis showed high frequencies of merotelically attached lagging chromosomes in bipolar anaphase CIN cells, and higher frequencies of merotelic attachments in multipolar vs. bipolar prometaphases. Finally, we found that multipolar CIN prometaphases typically possessed gamma-tubulin at all spindle poles, and that a significant fraction of bipolar metaphase/early anaphase CIN cells possessed more than one centrosome at a single spindle pole. Taken together, our data suggest a model by which merotelic kinetochore attachments can easily be established in multipolar prometaphases. Most of these multipolar prometaphase cells would then bi-polarize before anaphase onset, and the residual merotelic attachments would produce chromosome mis-segregation due to anaphase lagging chromosomes. We propose this spindle pole coalescence mechanism as a major contributor to chromosome instability in cancer cells.

  8. Yeast Interacting Proteins Database: YER081W, YPL233W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available oins kinetochore subunits contacting DNA to those contacting microtubules; requir...tacting DNA to those contacting microtubules; required for accurate chromosome segr...t of the MIND kinetochore complex (Mtw1p Including Nnf1p-Nsl1p-Dsn1p) which joins kinetochore subunits con

  9. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    , and demonstrated in public settings. We then describe INTERACT, a proposed research project that stages the robotic marionettes in a live performance. The interdisciplinary project brings humanities research to bear on scientific and technological inquiry, and culminates in the development a live......This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions...... interaction between a human operator and an artificial actor or agent. We can apply insights from puppetry to develop culturally-aware robots. Here we describe the development of a robotic marionette theatre wherein robotic controllers assume the role of human puppeteers. The system has been built, tested...

  10. Interactions

    DEFF Research Database (Denmark)

    The main theme of this anthology is the unique interaction between mathematics, physics and philosophy during the beginning of the 20th century. Seminal theories of modern physics and new fundamental mathematical structures were discovered or formed in this period. Significant physicists such as...

  11. Highly Transient Molecular Interactions Underlie the Stability of Kinetochore–Microtubule Attachment During Cell Division

    Science.gov (United States)

    Zaytsev, Anatoly V.; Ataullakhanov, Fazly I.; Grishchuk, Ekaterina L.

    2013-01-01

    Chromosome segregation during mitosis is mediated by spindle microtubules that attach to chromosomal kinetochores with strong yet labile links. The exact molecular composition of the kinetochore–microtubule interface is not known but microtubules are thought to bind to kinetochores via the specialized microtubule-binding sites, which contain multiple microtubule-binding proteins. During prometaphase the lifetime of microtubule attachments is short but in metaphase it increases 3-fold, presumably owing to dephosphorylation of the microtubule-binding proteins that increases their affinity. Here, we use mathematical modeling to examine in quantitative and systematic manner the general relationships between the molecular properties of microtubule-binding proteins and the resulting stability of microtubule attachment to the protein-containing kinetochore site. We show that when the protein connections are stochastic, the physiological rate of microtubule turnover is achieved only if these molecular interactions are very transient, each lasting fraction of a second. This “microscopic” time is almost four orders of magnitude shorter than the characteristic time of kinetochore–microtubule attachment. Cooperativity of the microtubule-binding events further increases the disparity of these time scales. Furthermore, for all values of kinetic parameters the microtubule stability is very sensitive to the minor changes in the molecular constants. Such sensitivity of the lifetime of microtubule attachment to the kinetics and cooperativity of molecular interactions at the microtubule-binding site may hinder the accurate regulation of kinetochore–microtubule stability during mitotic progression, and it necessitates detailed experimental examination of the microtubule-binding properties of kinetochore-localized proteins. PMID:24376473

  12. Yeast Interacting Proteins Database: YDR439W, YCR086W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available inetochores during meiosis I to mediate accurate homolog segregation; required for condensin recruitment to ...and then Mam1p at kinetochores during meiosis I to mediate accurate homolog segregation; required for condensin recruitment...p, and then Mam1p at kinetochores during meiosis I to mediate accurate homolog segregation; required for condensin recruitment...with Lrs4p and then Mam1p at kinetochores during meiosis I to mediate accurate homolog segregation; required for condensin recruitmen

  13. Molecular insights into DNA binding and anchoring by the Bacillus subtilis sporulation kinetochore-like RacA protein

    Science.gov (United States)

    Schumacher, Maria A.; Lee, Jeehyun; Zeng, Wenjie

    2016-01-01

    During Bacillus subtilis sporulation, segregating sister chromosomes are anchored to cell poles and the chromosome is remodeled into an elongated structure called the axial filament. Data indicate that a developmentally regulated protein called RacA is involved in these functions. To gain insight into how RacA performs these diverse processes we performed a battery of structural and biochemical analyses. These studies show that RacA contains an N-terminal winged-helix-turn-helix module connected by a disordered region to a predicted coiled-coil domain. Structures capture RacA binding the DNA using distinct protein–protein interfaces and employing adjustable DNA docking modes. This unique DNA binding mechanism indicates how RacA can both specifically recognize its GC-rich centromere and also non-specifically bind the DNA. Adjacent RacA molecules within the protein–DNA structure interact leading to DNA compaction, suggesting a mechanism for axial filament formation. We also show that the RacA C-domain coiled coil directly contacts the coiled coil region of the polar protein DivIVA, which anchors RacA and hence the chromosome to the pole. Thus, our combined data reveal unique DNA binding properties by RacA and provide insight into the DNA remodeling and polar anchorage functions of the protein. PMID:27085804

  14. Yeast Interacting Proteins Database: YDR034C, YGR113W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available complex (aka DASH complex), couples kinetochores to the force produced by MT depolymerization thereby aidin...Rows with this bait as prey (0) YGR113W DAM1 Essential subunit of the Dam1 complex (aka DASH complex), coupl...es kinetochores to the force produced by MT depolymerization thereby aiding in ch

  15. Yeast Interacting Proteins Database: YGR113W, YGL079W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YGR113W DAM1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...ntial subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by MT depol

  16. Yeast Interacting Proteins Database: YGR113W, YLR423C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YGR113W DAM1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...al subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by MT depolyme

  17. Yeast Interacting Proteins Database: YKR037C, YLR423C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YKR037C SPC34 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force... subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force produced by MT depolymeri

  18. Yeast Interacting Proteins Database: YGR113W, YLR424W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YGR113W DAM1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...13W Bait gene name DAM1 Bait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force

  19. Yeast Interacting Proteins Database: YGR113W, YIL144W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YGR113W DAM1 Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force...113W Bait gene name DAM1 Bait description Essential subunit of the Dam1 complex (aka DASH complex), couples kinetochores to the force

  20. Yeast Interacting Proteins Database: YNL189W, YDR318W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available ponent of the COMA complex (Ctf19p, Okp1p, Mcm21p, Ame1p) that bridges kinetochore subunits that are in contact...t of the COMA complex (Ctf19p, Okp1p, Mcm21p, Ame1p) that bridges kinetochore subunits that are in contact w

  1. Yeast Interacting Proteins Database: YCL029C, YER016W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available rotubules and kinetochore, involved in sister chromatid separation; essential in polyploid cells but not in ...hromatid separation; essential in polyploid cells but not in haploid or diploid cells; ortholog of mammalian

  2. An Arabidopsis tissue-specific RNAi method for studying genes essential to mitosis.

    Science.gov (United States)

    Burgos-Rivera, Brunilís; Dawe, R Kelly

    2012-01-01

    A large fraction of the genes in plants can be considered essential in the sense that when absent the plant fails to develop past the first few cell divisions. The fact that angiosperms pass through a haploid gametophyte stage can make it challenging to propagate such mutants even in the heterozygous condition. Here we describe a tissue-specific RNAi method that allows us to visualize cell division phenotypes in petals, which are large dispensable organs. Portions of the APETALA (AP3) and PISTILLATA (PI) promoters confer early petal-specific expression. We show that when either promoter is used to drive the expression of a beta-glucuronidase (GUS) RNAi transgene in plants uniformly expressing GUS, GUS expression is knocked down specifically in petals. We further tested the system by targeting the essential kinetochore protein CENPC and two different components of the Spindle Assembly Checkpoint (MAD2 and BUBR1). Plant lines expressing petal-specific RNAi hairpins targeting these genes exhibited an array of petal phenotypes. Cytological analyses of the affected flower buds confirmed that CENPC knockdown causes cell cycle arrest but provided no evidence that either MAD2 or BUBR1 are required for mitosis (although both genes are required for petal growth by this assay). A key benefit of the petal-specific RNAi method is that the phenotypes are not expressed in the lineages leading to germ cells, and the phenotypes are faithfully transmitted for at least four generations despite their pronounced effects on growth. PMID:23236491

  3. Yeast Interacting Proteins Database: YOL069W, YIL144W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YOL069W NUF2 Component of the evolutionarily conserved kinetochore-associated Ndc80...inetochore clustering Rows with this bait as bait (3) Rows with this bait as prey (0) YIL144W TID3 Component of the evolution...NUF2 Bait description Component of the evolutionarily conserved kinetochore-associated Ndc80 complex (Ndc80p...bait as prey Rows with this bait as prey (0) Prey ORF YIL144W Prey gene name TID3 Prey description Component of the evolution

  4. Mitotic spindle organization by dynein & kinetochores

    NARCIS (Netherlands)

    Raaijmakers, J.A.

    2014-01-01

    The human body contains an estimated 37 trillion cells. Although most cells in the body are non-dividing, approximately 300 billion new cells are produced every day. This is important for the maintenance of our tissues but also for the repair of tissues when they are damaged. To prepare for cell div

  5. Dendrite Development Regulated by the Schizophrenia-Associated Gene FEZ1 Involves the Ubiquitin Proteasome System

    Directory of Open Access Journals (Sweden)

    Yasuhito Watanabe

    2014-04-01

    Full Text Available Downregulation of the schizophrenia-associated gene DISC1 and its interacting protein FEZ1 positively regulates dendrite growth in young neurons. However, little is known about the mechanism that controls these molecules during neuronal development. Here, we identify several components of the ubiquitin proteasome system and the cell-cycle machinery that act upstream of FEZ1. We demonstrate that the ubiquitin ligase cell division cycle 20/anaphase-promoting complex (Cdc20/APC controls dendrite growth by regulating the degradation of FEZ1. Furthermore, dendrite growth is modulated by BubR1, whose known function so far has been restricted to control Cdc20/APC activity during the cell cycle. The modulatory function of BubR1 is dependent on its acetylation status. We show that BubR1 is deacetylated by Hdac11, thereby disinhibiting the Cdc20/APC complex. Because dendrite growth is affected both in hippocampal dentate granule cells and olfactory bulb neurons upon modifying expression of these genes, we conclude that the proposed mechanism governs neuronal development in a general fashion.

  6. Yeast Interacting Proteins Database: YOL069W, YNL086W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YOL069W NUF2 Component of the evolutionarily conserved kinetochore-associated Ndc80...0 0 6 - Show YOL069W Bait ORF YOL069W Bait gene name NUF2 Bait description Component of the evolutionarily c

  7. Cenp-meta is required for sustained spindle checkpoint

    Directory of Open Access Journals (Sweden)

    Thomas Rubin

    2014-05-01

    Full Text Available Cenp-E is a kinesin-like motor protein required for efficient end-on attachment of kinetochores to the spindle microtubules. Cenp-E immunodepletion in Xenopus mitotic extracts results in the loss of mitotic arrest and massive chromosome missegregation, whereas its depletion in mammalian cells leads to chromosome segregation defects despite the presence of a functional spindle assembly checkpoint (SAC. Cenp-meta has previously been reported to be the Drosophila homolog of vertebrate Cenp-E. In this study, we show that cenp-metaΔ mutant neuroblasts arrest in mitosis when treated with colchicine. cenp-metaΔ mutant cells display a mitotic delay. Yet, despite the persistence of the two checkpoint proteins Mad2 and BubR1 on unattached kinetochores, these cells eventually enter anaphase and give rise to highly aneuploid daughter cells. Indeed, we find that cenp-metaΔ mutant cells display a slow but continuous degradation of cyclin B, which eventually triggers the mitotic exit observed. Thus, our data provide evidence for a role of Cenp-meta in sustaining the SAC response.

  8. Yeast Interacting Proteins Database: YOL069W, YMR294W [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YOL069W NUF2 Component of the evolutionarily conserved kinetochore-associated Ndc80 complex (Ndc ... his bait as prey (0) YMR294W JNM1 Component of the yeast ... dynactin complex, consisting of Nip100p, Jnm1p, an ... y gene name JNM1 Prey description Component of the yeast ... dynactin complex, consisting of Nip100p, Jnm1p, an ...

  9. Embarrassing Interactions

    DEFF Research Database (Denmark)

    Deterding, Sebastian; Lucero, Andrés; Holopainen, Jussi; Min, Chulhong; Cheok, Adrian; Waern, Annika; Walz, Steffen

    Wherever the rapid evolution of interactive technologies disrupts standing situational norms, creates new, often unclear situational audiences, or crosses cultural boundaries, embarrassment is likely. This makes embarrassment a fundamental adoption and engagement hurdle, but also a creative design...... space for human-computer interaction. However, research on embarrassment in HCI has remained scattered and unsystematic so far. This workshop therefore convenes researchers and practitioners to assemble and advance the current state of research on embarrassing interactions....

  10. Explicit Interaction

    DEFF Research Database (Denmark)

    Löwgren, Jonas; Eriksen, Mette Agger; Linde, Per; Olofsson, Stefan; Sokoler, Tomas; Grønfeldt, Peter; Rasmussen, Jørgen; Kramp, Gunnar; Käfer, Gerald; Schmid, Reiner; Wuchner, Egon

    2006-01-01

    We report an ongoing study of palpable computing to support surgical rehabilitation, in the general field of interaction design for ubiquitous computing. Through explorative design, fieldwork and participatory design techniques, we explore the design principle of explicit interaction as an...... interpretation of palpability, comprising usability as well as patient empowerment and socially performative issues. We present a prototype environment for video recording during physiotherapeutical consultation which illustrates our current thoughts on explicit interaction and serves as material for further...

  11. Floor interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Krogh, Peter; Ludvigsen, Martin; Lykke-Olesen, Andreas

    Within architecture, there is a long tradition of careful design of floors. The design has been concerned with both decorating floors and designing floors to carry information. Ubiquitous computing technology offers new opportunities for designing interactive floors. This paper presents three...... different interactive floor concepts. Through an urban perspective it draws upon the experiences of floors in architecture, and provides a set of design issues for designing interactive floors....

  12. Playful Interaction

    DEFF Research Database (Denmark)

    2003-01-01

    The video Playful Interaction describes a future architectural office, and envisions ideas and concepts for playful interactions between people, materials and appliances in a pervasive and augmented working environment. The video both describes existing developments, technologies and designs as...... well as ideas not yet implemented such as playful modes of interaction with an augmented ball. Playful Interaction has been used as a hybrid of a vision video and a video prototype (1). Externally the video has been used to visualising our new ideas, and internally the video has also worked to inspire...

  13. Interactive benchmarking

    DEFF Research Database (Denmark)

    Lawson, Lartey; Nielsen, Kurt

    2005-01-01

    We discuss individual learning by interactive benchmarking using stochastic frontier models. The interactions allow the user to tailor the performance evaluation to preferences and explore alternative improvement strategies by selecting and searching the different frontiers using directional...... suggested benchmarking tool. The study investigates how different characteristics on dairy farms influences the technical efficiency....

  14. Simple Interactions

    DEFF Research Database (Denmark)

    a Danish and international public. The exhibition Simple Interactions. Sound Art from Japan presents works by 9 Japanese artists at the Museum of Contemporary Art Roskilde. The exhibition mixes installations, performances and documentations, all of which examine how simple interactions can create...

  15. Kinesthetic Interaction

    DEFF Research Database (Denmark)

    Fogtmann, Maiken Hillerup; Fritsch, Jonas; Kortbek, Karen Johanne

    2008-01-01

    Within the Human-Computer Interaction community there is a growing interest in designing for the whole body in interaction design. The attempts aimed at addressing the body have very different outcomes spanning from theoretical arguments for understanding the body in the design process, to more...... practical examples of designing for bodily potential. This paper presents Kinesthetic Interaction as a unifying concept for describing the body in motion as a foundation for designing interactive systems. Based on the theoretical foundation for Kinesthetic Interaction, a conceptual framework is introduced...... to reveal bodily potential in relation to three design themes – kinesthetic development, kinesthetic means and kinesthetic disorder; and seven design parameters – engagement, sociality, movability, explicit motivation, implicit motivation, expressive meaning and kinesthetic empathy. The framework is...

  16. Aesthetic interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Iversen, Ole Sejer; Krogh, Peter; Ludvigsen, Martin

    There is a growing interest in considering aesthetic aspects in the design of interactive systems. A set of approaches are emerging each representing different applications of the terminology as well as different inherent assumptions on the role of the user, designer and interaction ideals. In this...... paper, we use the concept of Pragmatist Aesthetics to provide a framework for distinguishing between different approaches to aesthetics. Moreover, we use our own design cases to illustrate how pragmatist aesthetics is a promising path to follow in the context of designing interactive systems, as it...... promotes aesthetics of use, rather than aesthetics of appearance. We coin this approach in the perspective of aesthetic interaction. Finally we make the point that aesthetics is not re-defining everything known about interactive systems. We provide a framework placing this perspective among other...

  17. Interacting parasites

    Science.gov (United States)

    Lafferty, Kevin D.

    2010-01-01

    Parasitism is the most popular life-style on Earth, and many vertebrates host more than one kind of parasite at a time. A common assumption is that parasite species rarely interact, because they often exploit different tissues in a host, and this use of discrete resources limits competition (1). On page 243 of this issue, however, Telfer et al. (2) provide a convincing case of a highly interactive parasite community in voles, and show how infection with one parasite can affect susceptibility to others. If some human parasites are equally interactive, our current, disease-by-disease approach to modeling and treating infectious diseases is inadequate (3).

  18. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2012-01-01

    Ready to create rich interactive experiences with your artwork, designs, or prototypes? This is the ideal place to start. With this hands-on guide, you'll explore several themes in interactive art and design-including 3D graphics, sound, physical interaction, computer vision, and geolocation-and learn the basic programming and electronics concepts you need to implement them. No previous experience is necessary. You'll get a complete introduction to three free tools created specifically for artists and designers: the Processing programming language, the Arduino microcontroller, and the openFr

  19. Interaction Widget

    DEFF Research Database (Denmark)

    Ingstrup, Mads

    2003-01-01

    This pattern describes the idea of making a user interface of discrete, reusable entities---here called interaction widgets. The idea behind widgets is described using two perspectives, that of the user and that of the developer. It is the forces from these two perspectives that are balanced in the...... pattern. The intended audience of the pattern is developers and researchers within the field of human computer interaction....

  20. Interactive governance

    DEFF Research Database (Denmark)

    Sørensen, Eva; Torfing, Jacob; Peters, B. Guy;

    Governance has become one of the most commonly used concepts in contemporary political science. It is, however, often used to mean a variety of different things. This book helps to clarify this conceptual muddle by concentrating on one variety of governance-interactive governance. The authors argue...... that although the state may remain important for many aspects of governing, interactions between state and society represent an important, and perhaps increasingly important, dimension of governance. These interactions may be with social actors such as networks, with market actors or with other...... governments, but all these forms represent means of governing involving mixtures of state action with the actions of other entities.This book explores thoroughly this meaning of governance, and links it to broader questions of governance. In the process of explicating this dimension of governance the authors...

  1. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2009-01-01

    Make cool stuff. If you're a designer or artist without a lot of programming experience, this book will teach you to work with 2D and 3D graphics, sound, physical interaction, and electronic circuitry to create all sorts of interesting and compelling experiences -- online and off. Programming Interactivity explains programming and electrical engineering basics, and introduces three freely available tools created specifically for artists and designers: Processing, a Java-based programming language and environment for building projects on the desktop, Web, or mobile phonesArduino, a system t

  2. Weak Interactions

    Science.gov (United States)

    Lee, T. D.

    1957-06-01

    Experimental results on the non-conservation of parity and charge conservation in weak interactions are reviewed. The two-component theory of the neutrino is discussed. Lepton reactions are examined under the assumption of the law of conservation of leptons and that the neutrino is described by a two- component theory. From the results of this examination, the universal Fermi interactions are analyzed. Although reactions involving the neutrino can be described, the same is not true of reactions which do not involve the lepton, as the discussion of the decay of K mesons and hyperons shows. The question of the invariance of time reversal is next examined. (J.S.R.)

  3. Hadron interactions

    International Nuclear Information System (INIS)

    The proceedings contain invited lectures and papers presente at the symposium. Attention was devoted to hadron interactions a high energy in QCD, to the structure and decay of hadrons, the production of hadrons and supersymmetric particles in e+e- and ep collisions, to perturbation theory in quantum field theory, and new supersymmetric extensions of relativistic algebra. (Z.J

  4. Audiovisual Interaction

    DEFF Research Database (Denmark)

    Karandreas, Theodoros-Alexandros

    importance of each modality with respect to the overall quality evaluation. The results show that this was not due to specific interactions between stimuli but rather because the auditory modality dominated over the visual modality. Furthermore, for all experiments where less than optimal stimuli...

  5. Interactive Storytelling

    DEFF Research Database (Denmark)

    2015-01-01

    This book constitutes the refereed proceedings of the 8th International Conference on Interactive Digital Storytelling, ICIDS 2015, held in Copenhagen, Denmark, in November/December 2015. The 18 revised full papers and 13 short papers presented together with 9 posters, 9 workshop descriptions, and...

  6. Electroweak interactions

    International Nuclear Information System (INIS)

    The central part of the book consists of a comprehensive discussion of many scattering and decay processes involving electromagnetic, weak and strong interactions. A list of topics includes electron-proton scattering, Compton scattering, muon decay, electron-positron annihilation, photon and hadron structure functions, neutrino-nucleus scattering, Cabibbo theory, tau-lepton decays, W and Z boson decays, mixing phenomena and many others. For most processes, the author presents the appropriate Feynman diagrams, first-order matrix elements and the resulting cross sections or decay rates. The last section of Electroweak Interactions discusses some of the open or unanswered questions in the standard model, including the undiscovered top quark, the Higgs mechanism of electroweak symmetry breaking and detailed tests involving radiative effects. The book concludes with a brief account of ideas that extend beyond the standard model, such as left-right symmetric models, grand unified theories, compositeness, supersymmetry and string theory

  7. Interactive Storytelling

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik; Reng, Lars

    2015-01-01

    This book constitutes the refereed proceedings of the 8th International Conference on Interactive Digital Storytelling, ICIDS 2015, held in Copenhagen, Denmark, in November/December 2015. The 18 revised full papers and 13 short papers presented together with 9 posters, 9 workshop descriptions, an...... 3 demonstration papers were carefully reviewed and selected from 80 submissions. The papers are organized in topical sections on theoretical and design foundations, technical advances, analyses and evaluation systems, and current and future usage scenarios and applications....

  8. Constructive Interactions

    OpenAIRE

    Lemoisson, Philippe; Cerri, Stefano A.; Mahe, Serge-André; Sallantin, Jean

    2003-01-01

    The new paradigm of "knowledge construction using experiential based and collaborative learning approaches" is an outstanding opportunity for interdisciplinary research. This document is an attempt to introduce and exemplify as much as possible using the lexicon of "social sciences", considerations and tools belonging to "artificial intelligence" (eg.:the machine learning tradition). In the paper we first draw a conceptual framework for rational agents in conversational interaction; then we u...

  9. Weak interactions

    International Nuclear Information System (INIS)

    These lectures are an introduction to the standard weak-electromagnetic gauge model and its experimental tests, followed by six-quark phenomenology and some Grand Unification schemes dealt with under the headings; charged-current fermi interaction, gauge theories, tests of the Salam-Weinberg model, natural flavour-conservation neutral current, triangle anomalies, more gauge fields, more quarks and leptons, grand unification, economy of parameters. 54 reference. (UK)

  10. Interactive Workspaces

    DEFF Research Database (Denmark)

    Mogensen, Preben Holst

    augmented reality, interactive building elements, and mobile devices to support new ways of working in a diversity of application domains with work situations ranging from individual work, through local collaboration, to distributed collaboration. The work situations may take place in offices/project rooms......Many application domains such as architecture, engineering, industrial design, city planning, environmental supervision, health care etc. share the properties of users working collaboratively with complex mixtures of physical and digital materials. Studies in such domains show that it is hard...

  11. Electroweak interactions

    CERN Document Server

    Maiani, Luciano

    2016-01-01

    Written by one of the world's leading experts on particle physics and the standard model―an award-winning former director general of CERN―this book provides an up-to-date account of electroweak interactions. Part of a series describing the formal, physical, and phenomenological aspects of the standard model of particle physics, the text introduces the mathematical concepts and applications of symmetry principles to particle physics, from the isotopic spin symmetry to the Eightfold Way and the Yang-Mills theories.

  12. Electromagnetic interactions

    CERN Document Server

    Bosanac, Slobodan Danko

    2016-01-01

    This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.

  13. Attachment issues : kinetochore transformations and spindle checkpoint silencing

    NARCIS (Netherlands)

    Etemad, Banafsheh; Kops, Geert Jpl

    2016-01-01

    Cell division culminates in the segregation of duplicated chromosomes in opposite directions prior to cellular fission. This process is guarded by the spindle assembly checkpoint (SAC), which prevents the anaphase of cell division until stable connections between spindle microtubules and the kinetoc

  14. Probing CENP-E function in chromosome dynamics using small molecule inhibitor syntelin

    Institute of Scientific and Technical Information of China (English)

    Xia Ding; Tongge Zhu; Jiancun Zhang; Zhen Dou; Xuebiao Yao; Feng Yan; Phil Yao; Zhihong Yang; Weihong Wan; Xiwei Wang; Jing Liu; Xinjiao Gao; Ariane Abrieu

    2010-01-01

    @@ Dear Editor, Chromosome movements during mitosis are orchestrated primarily by the interaction of spindle microtubules with the kinetochore [1], the site for attachment of spindle microtubules to the centromere. The kinetochore has an active function in chromosomal segregation through microtubule-based motors located at or near it [1-2].

  15. Unification of Electromagnetic Interactions and Gravitational Interactions

    Institute of Scientific and Technical Information of China (English)

    WU Ning

    2002-01-01

    Unified theory of gravitational interactions and electromagnetic interactions is discussed in this paper.Based on gauge principle, electromagnetic interactions and gravitational interactions are formulated in the same mannerand are unified in a semi-direct product group of U(1) Abelian gauge group and gravitational gauge group.

  16. Unification of Electromagnetic Interactions and Gravitational Interactions

    Institute of Scientific and Technical Information of China (English)

    WUNing

    2002-01-01

    Unified theory of gravitational interactions and electromagnetic interactions is discussed in this paper.Based on gauge principle,electromagnetic interactions and gravitational interactions are formulated in the same manner and are unified in a semi-direct product group of U(1) Abelian gauge group and gravitational gauge group.

  17. Unification of Electromagnetic Interactions and Gravitational Interactions

    OpenAIRE

    Wu, Ning

    2002-01-01

    Unified theory of gravitational interactions and electromagnetic interactions is discussed in this paper. Based on gauge principle, electromagnetic interactions and gravitational interactions are formulated in the same manner and are unified in a semi-direct product group of U(1) Abel gauge group and gravitational gauge group.

  18. OSBP-related protein 8 (ORP8) interacts with Homo sapiens sperm associated antigen 5 (SPAG5) and mediates oxysterol interference of HepG2 cell cycle

    International Nuclear Information System (INIS)

    We earlier identified OSBP-related protein 8 (ORP8) as an endoplasmic reticulum/nuclear envelope oxysterol-binding protein implicated in cellular lipid homeostasis, migration, and organization of the microtubule cytoskeleton. Here, a yeast two-hybrid screen identified Homo sapiens sperm associated antigen 5 (SPAG5)/Astrin as interaction partner of ORP8. The putative interaction was further confirmed by pull-down and co-immunoprecipitation assays. ORP8 did not colocalize with kinetochore-associated SPAG5 in mitotic HepG2 or HuH7 cells, but overexpressed ORP8 was capable of recruiting SPAG5 onto endoplasmic reticulum membranes in interphase cells. In our experiments, 25-hydroxycholesterol (25OHC) retarded the HepG2 cell cycle, causing accumulation in G2/M phase; ORP8 overexpression resulted in the same phenotype. Importantly, ORP8 knock-down dramatically inhibited the oxysterol effect on HepG2 cell cycle, suggesting a mediating role of ORP8. Furthermore, knock-down of SPAG5 significantly reduced the effects of both ORP8 overexpression and 25OHC on the cell cycle, placing SPAG5 downstream of the two cell-cycle interfering factors. Taken together, the present results suggest that ORP8 may via SPAG5 mediate oxysterol interference of the HepG2 cell cycle. - Highlights: • The oxysterol-binding protein ORP8 was found to interact with the mitotic regulator SPAG5/Astrin. • Treatment of HepG2 cells with 25-hydroxycholesterol caused cell cycle retardation in G2/M. • ORP8 overexpression caused a similar G2/M accumulation, and ORP8 knock-down reversed the 25-hydroxycholesterol effect. • Reduction of cellular of SPAG5/Astrin reversed the cell cycle effects of both 25-hydroxycholesterol and ORP8 overexpression. • Our results suggest that ORP8 mediates via SPAG5/Astrin the oxysterol interference of HepG2 cell cycle

  19. OSBP-related protein 8 (ORP8) interacts with Homo sapiens sperm associated antigen 5 (SPAG5) and mediates oxysterol interference of HepG2 cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Wenbin [Department of Biotechnology, Jinan University, Guangzhou 510632 (China); Zhou, You [Minerva Foundation Institute for Medical Research, Helsinki (Finland); Li, Jiwei [Department of Biotechnology, Jinan University, Guangzhou 510632 (China); Mysore, Raghavendra [Minerva Foundation Institute for Medical Research, Helsinki (Finland); Luo, Wei; Li, Shiqian [Department of Biotechnology, Jinan University, Guangzhou 510632 (China); Chang, Mau-Sun [Institute of Biochemical Sciences, National Taiwan University, No. 1, Taipei, Taiwan (China); Olkkonen, Vesa M. [Minerva Foundation Institute for Medical Research, Helsinki (Finland); Yan, Daoguang, E-mail: tydg@jnu.edu.cn [Department of Biotechnology, Jinan University, Guangzhou 510632 (China)

    2014-04-01

    We earlier identified OSBP-related protein 8 (ORP8) as an endoplasmic reticulum/nuclear envelope oxysterol-binding protein implicated in cellular lipid homeostasis, migration, and organization of the microtubule cytoskeleton. Here, a yeast two-hybrid screen identified Homo sapiens sperm associated antigen 5 (SPAG5)/Astrin as interaction partner of ORP8. The putative interaction was further confirmed by pull-down and co-immunoprecipitation assays. ORP8 did not colocalize with kinetochore-associated SPAG5 in mitotic HepG2 or HuH7 cells, but overexpressed ORP8 was capable of recruiting SPAG5 onto endoplasmic reticulum membranes in interphase cells. In our experiments, 25-hydroxycholesterol (25OHC) retarded the HepG2 cell cycle, causing accumulation in G2/M phase; ORP8 overexpression resulted in the same phenotype. Importantly, ORP8 knock-down dramatically inhibited the oxysterol effect on HepG2 cell cycle, suggesting a mediating role of ORP8. Furthermore, knock-down of SPAG5 significantly reduced the effects of both ORP8 overexpression and 25OHC on the cell cycle, placing SPAG5 downstream of the two cell-cycle interfering factors. Taken together, the present results suggest that ORP8 may via SPAG5 mediate oxysterol interference of the HepG2 cell cycle. - Highlights: • The oxysterol-binding protein ORP8 was found to interact with the mitotic regulator SPAG5/Astrin. • Treatment of HepG2 cells with 25-hydroxycholesterol caused cell cycle retardation in G2/M. • ORP8 overexpression caused a similar G2/M accumulation, and ORP8 knock-down reversed the 25-hydroxycholesterol effect. • Reduction of cellular of SPAG5/Astrin reversed the cell cycle effects of both 25-hydroxycholesterol and ORP8 overexpression. • Our results suggest that ORP8 mediates via SPAG5/Astrin the oxysterol interference of HepG2 cell cycle.

  20. Drug Interaction API

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Interaction API is a web service for accessing drug-drug interactions. No license is needed to use the Interaction API. Currently, the API uses DrugBank for its...

  1. Dynamic distribution of TTK in HeLa cells: insights from an ultrastructural study

    Institute of Scientific and Technical Information of China (English)

    ZHEN DOU; AKIRA SAWAGECHI; JIE ZHANG; HONG LUO; LAWRENCE BRAKO; XUE BIAO YAO

    2003-01-01

    Entry into mitosis is driven by signaling cascades of mitotic kinases.Our recent studies show that TTK,a kinetochore-associated protein kinase,interacts with CENP-E,a mitotic kinesin located to corona fiber ofkinetochore.Using immunoelectron microscopy,here we show that TTK is present at the nuclear pore adjacent complex of interphase HeLa cells.Upon nuclear envelope fragmentation,TTK targets to the outermostregion of the developing kinetochores ofmonoorient chromosome as well as to spindle poles.After stable attachment,throughout chromosome congression,TTK is a constituent of the corona fibers,extending up to 90 nm away from the kinetochore outer plate.Upon metaphase alignment,TTK departs from the kinetochore and migrates toward the centrosomes.Taken together,this evidence strongly supports a model in which TTK functions in spindle checkpoint signaling cascades at both kinetochore and centrosome.

  2. Centromeric chromatin and its dynamics in plants.

    Science.gov (United States)

    Lermontova, Inna; Sandmann, Michael; Mascher, Martin; Schmit, Anne-Catherine; Chabouté, Marie-Edith

    2015-07-01

    Centromeres are chromatin structures that are required for proper separation of chromosomes during mitosis and meiosis. The centromere is composed of centromeric DNA, often enriched in satellite repeats, and kinetochore complex proteins. To date, over 100 kinetochore components have been identified in various eukaryotes. Kinetochore assembly begins with incorporation of centromeric histone H3 variant CENH3 into centromeric nucleosomes. Protein components of the kinetochore are either present at centromeres throughout the cell cycle or localize to centromeres transiently, prior to attachment of microtubules to each kinetochore in prometaphase of mitotic cells. This is the case for the spindle assembly checkpoint (SAC) proteins in animal cells. The SAC complex ensures equal separation of chromosomes between daughter nuclei by preventing anaphase onset before metaphase is complete, i.e. the sister kinetochores of all chromosomes are attached to spindle fibers from opposite poles. In this review, we focus on the organization of centromeric DNA and the kinetochore assembly in plants. We summarize recent advances regarding loading of CENH3 into the centromere, and the subcellular localization and protein-protein interactions of Arabidopsis thaliana proteins involved in kinetochore assembly and function. We describe the transcriptional activity of corresponding genes based on in silico analysis of their promoters and cell cycle-dependent expression. Additionally, barley homologs of all selected A. thaliana proteins have been identified in silico, and their sequences and domain structures are presented. PMID:25976696

  3. Strong interactions, Zweig's rule, and weaker interactions

    International Nuclear Information System (INIS)

    An attempt is made to connect five notions: Strong interaction scattering amplitudes do not involve the action of a Hamiltonian and are only Clebsch-Gordan coefficients. The four momentum vector P is an SU(something) operator. The four momentum of a quark does not change in a strong interaction scattering. Zweig's rule. Gluons should not be drawn in strong interaction scattering diagrams. Finally, a simple explanation will be offered for the weak interaction of leptons amongst themselves and with hadrons. (U.S.)

  4. Designing for mobile interaction

    DEFF Research Database (Denmark)

    Nazzi, Elena

    2009-01-01

    The theme of this PhD project is designing for mobile interaction with devices and services, for the accessing, making, and sharing of information, taking into account the dynamic physical and social settings that embrace this interaction. To narrow down this theme, the whole project focuses on the...... exploitation of social interaction --- in particular among senior citizens --- to enhance and support mobile interaction....

  5. Interaction for visualization

    CERN Document Server

    Tominski, Christian

    2015-01-01

    Visualization has become a valuable means for data exploration and analysis. Interactive visualization combines expressive graphical representations and effective user interaction. Although interaction is an important component of visualization approaches, much of the visualization literature tends to pay more attention to the graphical representation than to interaction.The goal of this work is to strengthen the interaction side of visualization. Based on a brief review of general aspects of interaction, we develop an interaction-oriented view on visualization. This view comprises five key as

  6. Interaction Design: Foundations, Experiments

    OpenAIRE

    Hallnäs, Lars; Redström, Johan

    2006-01-01

    Interaction Design: Foundations, Experiments is the result of a series of projects, experiments and curricula aimed at investigating the foundations of interaction design in particular and design research in general. The first part of the book - Foundations - deals with foundational theoretical issues in interaction design. An analysis of two categorical mistakes -the empirical and interactive fallacies- forms a background to a discussion of interaction design as act design and of computa...

  7. PIC: Protein Interactions Calculator

    OpenAIRE

    Tina, KG; Bhadra, R.; Srinivasan, N.

    2007-01-01

    Interactions within a protein structure and interactions between proteins in an assembly are essential considerations in understanding molecular basis of stability and functions of proteins and their complexes. There are several weak and strong interactions that render stability to a protein structure or an assembly. Protein Interactions Calculator (PIC) is a server which, given the coordinate set of 3D structure of a protein or an assembly, computes various interactions such as disulphide bo...

  8. Interactive Pinball Business

    DEFF Research Database (Denmark)

    Buur, Jacob; Gudiksen, Sune

    2012-01-01

    Interaction design expands into new fields. Interaction design and business model innovation is a promising meeting of disciplines: Many businesses see the need to rethink their ways of doing business, and, as business models pose highly dynamic and interactive problems, interaction design has much...... to offer. This paper compares ‘tangible business models’ in the form of pinball-like contraptions, designed by interaction design students with those developed by groups of professionals around concrete business issues. We will show how the interactive models encourage business people to play with...... hypotheses and experiment with scenarios as a way of innovating their business models, and why this is so....

  9. Interactive pinball business

    DEFF Research Database (Denmark)

    Buur, Jacob; Gudiksen, Sune Klok

    2012-01-01

    Interaction design expands into new fields. Interaction design and business model innovation is a promising meeting of disciplines: Many businesses see the need to rethink their ways of doing business, and, as business models pose highly dynamic and interactive problems, interaction design has much...... to offer. This paper compares 'tangible business models' in the form of pinball-like contraptions, designed by interaction design students with those developed by groups of professionals around concrete business issues. We will show how the interactive models encourage business people to play with...... hypotheses and experiment with scenarios as a way of innovating their business models, and why this is so...

  10. Interacting dark sector with transversal interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chimento, Luis P.; Richarte, Martín G. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Pabellón I, Buenos Aires 1428 (Argentina)

    2015-03-26

    We investigate the interacting dark sector composed of dark matter, dark energy, and dark radiation for a spatially flat Friedmann-Robertson-Walker (FRW) background by introducing a three-dimensional internal space spanned by the interaction vector Q and solve the source equation for a linear transversal interaction. Then, we explore a realistic model with dark matter coupled to a scalar field plus a decoupled radiation term, analyze the amount of dark energy in the radiation era and find that our model is consistent with the recent measurements of cosmic microwave background anisotropy coming from Planck along with the future constraints achievable by CMBPol experiment.

  11. Phosphorylation of human Sgo1 by NEK2A is essential for chromosome congression in mitosis

    Institute of Scientific and Technical Information of China (English)

    Guosheng Fu; Xia Ding; Kai Yuan; Felix Aikhionbare; Jianhui Yao; Xin Cai; Kai Jiang; Xuebiao Yao

    2007-01-01

    Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD1 at the kinetochore and possibly functions as a novel integrator of spindle checkpoint signaling. However, it is unclear how NEK2 A regulates kinetochore-microtubule attachment in mitosis. Here we show that NEK2A phosphorylates human Sgol and such phosphorylation is essential for faithful chromosome congression in mitosis. NEK2A binds directly to HsSgol in vitro and co-distributes with HsSgol to the kinetochore of mitotic cells. Our in vitro phosphorylation experiment demonstrated that HsSgol is a substrate of NEK2A and the phosphorylation sites were mapped to Ser14 and Ser507 as judged by the incorporation of 32P. Although such phosphorylation is not required for assembly of HsSgol to the kinetochore, expression of non-phosphorylatable mutant HsSgol perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. These findings reveal a key role for the NEK2A-mediated phosphorylation of HsSgol in orchestrating dynamic kinetochore-microtubule interaction. We propose that NEK2A-mediated phosphorylation of human Sgol provides a link between centromeric cohesion and spindle microtubule attachment at the kinetochores.

  12. Sea Turtle Interaction Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Turtle Interaction Report is a report sent out in pdf format to authorized individuals that summarizes sea turtle interactions in the longline fishery. The...

  13. Health Data Interactive (HDI)

    Data.gov (United States)

    U.S. Department of Health & Human Services — Health Data Interactive (HDI) presents a broad range of important public health indicators through an interactive web-based application that provides access to...

  14. Compton effect: interacting particles or interacting waves

    CERN Document Server

    Hernández, O F

    2005-01-01

    Traditional textbook explanations of the Compton effect treat the photon electron interaction as a particle collision. This explanation is a pedagogical disaster, implying that sometimes interactions are particle-like whereas quantum mechanics always demands that they be wave-like; a photon wavefunction evolves according to a wave equation until its collapse at measurement. If this is so why then does the classical radiation wave equation fail to predict the Compton effect? We address these issues and propose a clearer explanation.

  15. Plasma-wall interaction; Interaction plasma paroi

    Energy Technology Data Exchange (ETDEWEB)

    Reichle, R

    2004-07-01

    This document gathers the 43 slides presented in the framework of the week long lecture 'hot plasmas 2004' and dedicated to plasma-wall interaction in a tokamak. This document is divided into 4 parts: 1) thermal load on the wall, power extraction and particle recovery, 2) basic edge plasma physics, 3) processes that drive the plasma-solid interaction, and 4) material conditioning (surface treatment...) for ITER.

  16. Predictability of social interactions

    OpenAIRE

    Xu, Kevin S.

    2013-01-01

    The ability to predict social interactions between people has profound applications including targeted marketing and prediction of information diffusion and disease propagation. Previous work has shown that the location of an individual at any given time is highly predictable. This study examines the predictability of social interactions between people to determine whether interaction patterns are similarly predictable. I find that the locations and times of interactions for an individual are...

  17. Gaze Interactive Building Instructions

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Ahmed, Zaheer; Mardanbeigi, Diako

    We combine eye tracking technology and mobile tablets to support hands-free interaction with digital building instructions. As a proof-of-concept we have developed a small interactive 3D environment where one can interact with digital blocks by gaze, keystroke and head gestures. Blocks may be moved...

  18. Food-Drug Interactions

    OpenAIRE

    Arshad Yar Khan; Nousheen Aslam; Rabia Bushra

    2011-01-01

    The effect of drug on a person may be different than expected because that drug interacts with another drug the person is taking (drug-drug interaction), food, beverages, dietary supplements the person is consuming (drug-nutrient/food interaction) or another disease the person has (drug-disease interaction). A drug interaction is a situation in which a substance affects the activity of a drug, i.e. the effects are increased or decreased, or they produce a new effect that neither produces on i...

  19. Grasp interaction with tablets

    CERN Document Server

    Wolf, Katrin

    2015-01-01

    This book presents guidelines for a future device type: a tablet that allows ergonomic front- and back-of-device interaction. These guidelines help designers and developers of user interfaces to build ergonomic applications for tablet devices, in particular for devices that enable back-of-device interaction. In addition, manufacturers of tablet devices obtain arguments that back-of-device interaction is a promising extension of the interaction design space and results in increased input capabilities, enriched design possibilities, and proven usability. The guidelines are derived from empirical studies and developed to fit the users’ skills to the way the novel device type is held. Three particular research areas that are relevant to develop design guidelines for tablet interaction are investigated: ergonomic gestures, interaction areas, and pointing techniques.

  20. Patient - patient interaction

    DEFF Research Database (Denmark)

    Birkelund, Regner; Søndergaard Larsen, Lene

    2013-01-01

    occasionally, the opposite was experienced too. Less typically, the patients experienced interaction with fellow patients as a burden and referred to it in negative terms. Conclusions:  Patients’ interaction resembled care as well as self-care. Patient–patient interaction was an important part of the social...... subcategories representing significance of patients’ interaction with fellow patients. Results:  The qualitative analysis resulted in two main categories: (i) Caring for fellow patients and (ii) Sharing illness information with fellow patients. Each of the main categories was elucidated through several...... subcategories. Our findings clearly showed that interpersonal interaction with fellow patients was of utmost importance when it came to care and support and when they needed information about their illness. Typically, the interpersonal interaction was experienced as giving and referred to in positive terms, but...

  1. Quantum interaction. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Bruza, Peter [Queensland Univ. of Technology, Brisbane (Australia). Faculty of Science and Technology; Sofge, Donald [Navy Center for Applied Research in Artificial Intelligence, Washington, DC (United States). Naval Research Lab.; Lawless, William [Paine Coll., Augusta, GA (United States); Rijsbergen, Keith van [Glasgow Univ. (United Kingdom). Dept. of Computing Science; Klusch, Matthias (eds.) [German Research Center for Artificial Intelligence, Saarbruecken (Germany)

    2009-07-01

    This book constitutes the refereed proceedings of the Third International Symposium on Quantum Interaction, QI 2009, held in Saarbruecken, Germany, in March 2009. The 21 revised full papers presented together with the 3 position papers were carefully reviewed and selected from numerous submissions. The papers show the cross-disciplinary nature of quantum interaction covering topics such as computation, cognition, decision theory, information retrieval, information systems, social interaction, computational linguistics and finance. (orig.)

  2. Interactions in multispecies biofilms

    DEFF Research Database (Denmark)

    Burmølle, Mette; Ren, Dawei; Bjarnsholt, Thomas;

    2014-01-01

    The recent focus on complex bacterial communities has led to the recognition of interactions across species boundaries. This is particularly pronounced in multispecies biofilms, where synergistic interactions impact the bacterial distribution and overall biomass produced. Importantly, in a number...... of settings, the interactions in a multispecies biofilm affect its overall function, physiology, or surroundings, by resulting in enhanced resistance, virulence, or degradation of pollutants, which is of significant importance to human health and activities. The underlying mechanisms causing these...

  3. Interaction Before Agriculture

    DEFF Research Database (Denmark)

    Richter, Tobias; Garrard, Andrew; Allcock, Samantha;

    2011-01-01

    This article discusses social interaction in the Epipalaeolithic of southwest Asia. Discussions of contact, social relationships and social organization have primarily focused on the Pre-Pottery Neolithic and are often considered to represent typical hallmarks of emergent farming societies. The h...... for interaction. We argue that interaction between differently-constituted groups can be traced within the Early Epipalaeolithic of the southern Levant, suggesting that it is of far greater antiquity than previously considered....

  4. Electroweak interactions in nuclei

    Science.gov (United States)

    Henley, E. M.

    1984-06-01

    Nuclear and subnuclear degrees of freedom and lepton nucleus scattering were discussed. Electroweak interactions in nuclei were examined. Topics discussed include: introduction to electroweak theory; the Weinberg-Salam theory for leptons; the Weinberg-Salam theory for hadrons-the GIM mechanism; electron scattering as a probe of the electroweak interaction (observation of PV, the weak interaction for nucleons, and parity violation in atoms); and time reversed invariance and electric dipole moments of nucleons, nuclei, and atoms.

  5. ENTREPRENEURSHIP AS SOCIAL INTERACTION

    DEFF Research Database (Denmark)

    Larsen, Henry; Lima, Patricia; Olsen, Bente;

    2013-01-01

    This paper aims to explore how entrepreneurs work with innovation; to explore and develop attention points in understanding entrepreneurship as social processes of interaction between people. Through interviews and engagement with entrepreneurs and key stakeholders, their actual social practices...... entrepreneurship as socially constructed through local interactions between players and identify key themes in these interactions within the organisation, such as leadership, becoming part of the initiative and trust/mistrust. By doing so, this paper contributes to an understanding of entrepreneurship as social...

  6. Framing interactive methods

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2011-01-01

    Two paradigms of organization and leadership is outlined and compared. A theoretical model of interactive leadership is developed, combining learning, knowledge flow, leadership and organizational principles....

  7. Vision-based interaction

    CERN Document Server

    Turk, Matthew

    2013-01-01

    In its early years, the field of computer vision was largely motivated by researchers seeking computational models of biological vision and solutions to practical problems in manufacturing, defense, and medicine. For the past two decades or so, there has been an increasing interest in computer vision as an input modality in the context of human-computer interaction. Such vision-based interaction can endow interactive systems with visual capabilities similar to those important to human-human interaction, in order to perceive non-verbal cues and incorporate this information in applications such

  8. Philosophy of Interaction

    DEFF Research Database (Denmark)

    Svanæs, Dag

    2011-01-01

    This is an encyclopedia entry for the Interaction-Design.org free IxD encyclopedia. The topic of the entry is the application of the philosophy of Heidegger and Merleau-Ponty to a theory of interactivity. Comments by Don Norman and Eva Hornecker.......This is an encyclopedia entry for the Interaction-Design.org free IxD encyclopedia. The topic of the entry is the application of the philosophy of Heidegger and Merleau-Ponty to a theory of interactivity. Comments by Don Norman and Eva Hornecker....

  9. The Science of Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Pike, William A.; Stasko, John T.; Chang, Remco; O' Connell, Theresa

    2009-09-23

    There is a growing recognition with the visual analytics community that interaction and inquiry are inextricable. It is through the interactive manipulation of a visual interface – the analytic discourse – that knowledge is constructed, tested, refined, and shared. This paper reflects on the interaction challenges raised in the original visual analytics research and development agenda and further explores the relationship between interaction and cognition. It identifies recent exemplars of visual analytics research that have made substantive progress toward the goals of a true science of interaction, which must include theories and testable premises about the most appropriate mechanisms for human-information interaction. Six areas for further work are highlighted as those among the highest priorities for the next five years of visual analytics research: ubiquitous, embodied interaction; capturing user intentionality; knowledge-based interfaces; principles of design and perception; collaboration; and interoperability. Ultimately, the goal of a science of interaction is to support the visual analytics community through the recognition and implementation of best practices in the representation of and interaction with visual displays.

  10. Interaction Analysis and Supervision.

    Science.gov (United States)

    Amidon, Edmund

    This paper describes a model that uses interaction analysis as a tool to provide feedback to a teacher in a microteaching situation. The author explains how interaction analysis can be used for teacher improvement, describes the category system used in the model, the data collection methods used, and the feedback techniques found in the model. (JF)

  11. Child Computer Interaction SIG

    DEFF Research Database (Denmark)

    Read, Janet; Hourcade, Juan Pablo; Markopoulos, Panos;

    The discipline of Child Computer Interaction (CCI) has been steadily growing and it is now firmly established as a community in its own right, having the annual IDC (Interaction and Design for Children) conference and its own journal and also enjoying its role as a highly recognisable and vibrant...

  12. Electroweak interactions in nuclei

    International Nuclear Information System (INIS)

    Topics include: introduction to electroweak theory; the Weinberg-Salam theory for leptons; the Weinberg-Salam theory for hadrons-the GIM mechanism; electron scattering as a probe of the electroweak interaction (observation of PV, the weak interaction for nucleons, and parity violation in atoms); and time reversed invariance and electric dipole moments of nucleons, nuclei, and atoms. 52 references

  13. Moving into an interaction

    DEFF Research Database (Denmark)

    Mortensen, Kristian; Hazel, Spencer

    2014-01-01

    Opening an interaction is a crucial step in establishing and maintaining social relationships. In this paper we describe how participants in an institutional setting, a help desk counter for exchange students at an international university, literally move into interaction. This is accomplished th...

  14. Future Interaction Design II

    CERN Document Server

    Isomaki, Heikki M

    2009-01-01

    Argues that it is the human character rather than the technology that should determine the nature of interaction, and that the term 'interaction design' covers a range of issues relevant to enabling quality design. This book discusses a number of topics, such as psychological design processes, gerotechnology, modeling, and e-learning

  15. Let Social Interaction Flourish

    Science.gov (United States)

    Case, Anny Fritzen

    2016-01-01

    The author describes lessons learned--through a high school project that grouped English language learners with native speakers to create a video--about ways to foster respectful, productive interaction among English learners and peers who are native speakers. The potential benefits of students who are just learning English interacting socially…

  16. INTERACT Station Catalogue - 2015

    DEFF Research Database (Denmark)

    INTERACT stations are located in all major environmental envelopes of the Arctic providing an ideal platform for studying climate change and its impact on the environment and local communities. Since alpine environments face similar changes and challenges as the Arctic, the INTERACT network also...

  17. Visualizing Dispersion Interactions

    Science.gov (United States)

    Gottschalk, Elinor; Venkataraman, Bhawani

    2014-01-01

    An animation and accompanying activity has been developed to help students visualize how dispersion interactions arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion interactions play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…

  18. Human Work Interaction Design

    DEFF Research Database (Denmark)

    Lopes, Arminda; Ørngreen, Rikke

    This book constitutes the thoroughly refereed post-conference proceedings of the Third IFIP WG 13.6 Working Conference on Human Work Interaction Design, HWID 2012, held in Copenhagen, Denmark, in December 2012. The 16 revised papers presented were carefully selected for inclusion in this volume. ......, and mobile probing. They have been organized in the following topical sections: work analysis: dimensions and methods; interactions, models and approaches; and evaluations, interactions and applications.......This book constitutes the thoroughly refereed post-conference proceedings of the Third IFIP WG 13.6 Working Conference on Human Work Interaction Design, HWID 2012, held in Copenhagen, Denmark, in December 2012. The 16 revised papers presented were carefully selected for inclusion in this volume....... The papers reflect many different areas and address many complex and diverse work domains, ranging from medical user interfaces, work and speech interactions at elderly care facilities, greenhouse climate control, navigating through large oil industry engineering models, crisis management, library usability...

  19. Laser-surface interactions

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    This book is about the interaction of laser radiation with various surfaces at variable parameters of radiation. As a basic principle of classification we chose the energetic or intensity level of interaction of laser radiation with the surfaces. These two characteristics of laser radiation are the most important parameters defining entire spectrum of the processes occurring on the surfaces during interaction with electromagnetic waves. This is a first book containing a whole spectrum of the laser-surface interactions distinguished by the ranges of used laser intensity. It combines the surface response starting from extremely weak laser intensities (~1 W cm-2) up to the relativistic intensities (~1020 W cm-2 and higher). The book provides the basic information about lasers and acquaints the reader with both common applications of laser-surface interactions (laser-related printers, scanners, barcode readers, discs, material processing, military, holography, medicine, etc) and unusual uses of the processes on t...

  20. Fibronectin-cell interactions

    DEFF Research Database (Denmark)

    Couchman, J R; Austria, M R; Woods, A

    1990-01-01

    in vivo. Much data suggests that fibronectins may promote extracellular matrix assembly, and cell adhesion to those matrices. However, one outstanding enigma is that fibronectins may, under different circumstances, promote both cell migration and anchorage. An analysis of the interaction of fibroblasts...... with proteolytically derived and purified domains of plasma fibronectin revealed that the type of adhesion and the correlated cytoskeletal organization depended on multiple interactions of fibronectin domains with the cell surface. Human dermal fibroblasts were capable of interacting with the integrin-binding domain...... and both heparin-binding domains of the plasma fibronectin molecule and their interactions determined the type of adhesion. The same principle was seen in a study of the ability of plasma fibronectin to promote basement membrane assembly in an endodermal cell line, PF-HR9. There also, interactions of both...

  1. Magnetic interactions between nanoparticles

    Directory of Open Access Journals (Sweden)

    Steen Mørup

    2010-12-01

    Full Text Available We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state of nanoparticles. This collective state has many similarities to spin-glasses. In samples of aggregated magnetic nanoparticles, exchange interactions are often important and this can also lead to a strong suppression of superparamagnetic relaxation. The temperature dependence of the order parameter in samples of strongly interacting hematite nanoparticles or goethite grains is well described by a simple mean field model. Exchange interactions between nanoparticles with different orientations of the easy axes can also result in a rotation of the sub-lattice magnetization directions.

  2. User interaction widgets for interactive theorem proving

    OpenAIRE

    Zacchiroli, Stefano

    2007-01-01

    Matita (that means pencil in Italian) is a new interactive theorem prover under development at the University of Bologna. When compared with state-of-the-art proof assistants, Matita presents both traditional and innovative aspects. The underlying calculus of the system, namely the Calculus of (Co)Inductive Constructions (CIC for short), is well-known and is used as the basis of another mainstream proof assistant—Coq—with which Matita is to some extent compatible. In the sam...

  3. Interaction English Teaching Model

    Institute of Scientific and Technical Information of China (English)

    穆宇娜

    2013-01-01

      Malash—Thomas pointed out“Interaction is a process in which people and things act upon each other through their ac⁃tions.”According to different subjects, interaction can be divided into human-computer interaction, people-people interaction and learner-content interaction. According to different forms, interactions can be divided into one-one interaction, one-more interac⁃tion and more-more interaction.“Interaction Education”means that teachers are leading parts and students are the center of class. During teaching process, teachers must lead students to discover. Demands from students can encourage teachers to inspire con⁃versely.Thus it can form a close communication between teachers and students. Teaching and learning are realized in a happy and harmonious atmosphere. Successful English teaching must take new bilateral teaching as the first part, which should let the func⁃tion of the two most important elements develop fully. Teachers should grasp opportunities to guide. Teaching methods need to be flexible, and contents of teaching need to be vivid;students should be keen to think, to participate actively, and can break the tradi⁃tion to produce fresh ideas, and in that situation the capability of students can develop fully. The educational model refers to the simplified description of detailed teaching activities. Possessing dual functions of theory and practice, the educational model is the manifestation of theoretical teaching method. The combination of interaction and educational model which are mentioned above form the“interactive teaching”model. With the coming of economic globalization and integration of science and technology, now communications are increasing with each passing day. If you want to take part in or to get in touch with others, you must use lan⁃guage. English has been learnt for 10 years in Middle school and in college, but it can’t be spoken very fluently. That is a realistic picture as the result of an

  4. Magnetic interactions between nanoparticles

    DEFF Research Database (Denmark)

    Mørup, Steen; Hansen, Mikkel Fougt; Frandsen, Cathrine

    2010-01-01

    We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state of nanoparti......We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state...... of nanoparticles. This collective state has many similarities to spin-glasses. In samples of aggregated magnetic nanoparticles, exchange interactions are often important and this can also lead to a strong suppression of superparamagnetic relaxation. The temperature dependence of the order parameter in samples...... of strongly interacting hematite nanoparticles or goethite grains is well described by a simple mean field model. Exchange interactions between nanoparticles with different orientations of the easy axes can also result in a rotation of the sub-lattice magnetization directions....

  5. Plasma-wall interactions

    International Nuclear Information System (INIS)

    The plasma wall interactions for two extreme cases, the 'vacuum model' and the 'cold gas blanket' are outlined. As a first step for understanding the plasma wall interactions the elementary interaction processes at the first wall are identified. These are energetic ion and neutral particle trapping and release, ion and neutral backscattering, ion sputtering, desorption by ions, photons and electrons and evaporation. These processes have only recently been started to be investigated in the parameter range of interest for fusion research. The few measured data and their extrapolation into regions not yet investigated are reviewed

  6. Interacting with virtual worlds

    Science.gov (United States)

    Zeltzer, David

    1991-01-01

    What tools should we provide the user for defining and interacting with objects and agents in virtual environments at varying levels of complexity? Understanding the appropriate simplifications to make is critical for modeling nontrivial environments and agents with varying levels of autonomy. I describe a set of abstraction mechanisms appropriate for constructing and interacting with virtual worlds, and I discuss how programming, and direct manipulation of guiding techniques, can be used to afford users interactive access to graphical simulations at appropriate levels of abstraction.

  7. Media Facades beyond Interaction

    DEFF Research Database (Denmark)

    Fritsch, Jonas

    2008-01-01

    As part of a the research project Digital Urban Living [www.digitalurbanliving.dk], we have taken part in the design of two large-scale installations that employ interactive technologies to facilitate participation and foster social interactions in public, urban settings. We present the two cases......, Aarhus by Light and Projected Poetry, and discuss the future trajectory of our work in this field, as well as some of our findings regarding the challenges of designing large-scale public interactive installations. In doing so, we specifically highlight the possibilities in relation to designing for...

  8. Interactive Strategy-Making

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    2015-01-01

    This article outlines an interactive strategy-making model that combines central reasoning with ongoing learning from decentralised responses. The management literature often presents strategy as implementing an optimal plan identified through rational analysis and ascribes potential shortcomings...... to failed communication and execution of the planned actions. However, effective strategy-making comprises both central reasoning from forward-looking planning considerations and decentralised responses to emerging events as interacting elements in a dynamic adaptive system. The interaction between...... these central and decentralised processes explains how strategic adaptation can thrive under turbulent conditions in the interface between central reasoning and decentralised responses....

  9. The Aurora B kinase in chromosome biorientation and spindle checkpoint signalling

    Directory of Open Access Journals (Sweden)

    Veronica eKrenn

    2015-10-01

    Full Text Available Aurora B, a member of the Aurora family of serine/threonine protein kinases, is a key player in chromosome segregation. As part of a macromolecular complex known as the chromosome passenger complex, Aurora B concentrates early during mitosis in the proximity of centromeres and kinetochores, the sites of attachment of chromosomes to spindle microtubules. There, it contributes to a number of processes that impart fidelity to cell division, including kinetochore stabilization, kinetochore-microtubule attachment, and the regulation of a surveillance mechanism named the spindle assembly checkpoint. In the regulation of these processes, Aurora B is the fulcrum of a remarkably complex network of interactions that feed back on its localization and activation state. In this review we discuss the multiple roles of Aurora B during mitosis, focusing in particular on its role at centromeres and kinetochores. Many details of the network of interactions at these locations remain poorly understood, and we focus here on several crucial outstanding questions.

  10. Semi-leptonic interactions

    International Nuclear Information System (INIS)

    In spite of the presence of poorly understood strong interaction effects, the theory of hadronic currents leads to a considerable predictive power. This is shown in the discussion of the semi-leptonic decays

  11. Atomic and Molecular Interactions

    International Nuclear Information System (INIS)

    The Gordon Research Conference (GRC) on Atomic and Molecular Interactions was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field

  12. Space for Interaction

    DEFF Research Database (Denmark)

    Jørgensen, Mariane Ellen; Folmer, Mette Blicher; Mullins, Michael;

    SPACE FOR INTERACTION QUALIFYING GROUP TREATMENT FOR PATIENTS WITH CHRONIC PAIN THROUGH OPTIMIZATION(?) OF SPACE. A RANDOMIZED PILOT STUDY. In a Ph-D. Mariane Ellen Jørgensen / Nurse + psykoterapist / maej@rn.dk / Pain Center / Aalborg University Hospital / Denmark / Mette Blicher Folmer...... Building Research Institute / Aalborg University / Denmark AIM Research shows the hospital space has significance for human healing processes and the physical environment can have both positive and negative impact on the interaction between patients and staff. In order to qualify treatment for patients...... with chronic pain, the effect and experience of two different rooms for group therapy were compared. Three hypotheses were tested: 1) Room decor affects the interaction and thus the psychotherapeutic group therapy 2) The meaning of space for the interaction could be measured on the effect of treatment 3...

  13. Theory of gravitational interactions

    CERN Document Server

    Gasperini, Maurizio

    2013-01-01

    This reference textbook is an up-to-date and self-contained introduction to the theory of gravitational interactions. The first part of the book follows the traditional presentation of general relativity as a geometric theory of the macroscopic gravitational field. A second, advanced part then discusses the deep analogies (and differences) between a geometric theory of gravity and the gauge theories of the other fundamental interactions. This fills a gap which is present in the context of the traditional approach to general relativity, and which usually makes students puzzled about the role of gravity. The necessary notions of differential geometry are reduced to the minimum, leaving more room for those aspects of gravitational physics of current phenomenological and theoretical interest, such as the properties of gravitational waves, the gravitational interactions of spinors, and the supersymmetric and higher-dimensional generalization of the Einstein equations. Theory of Gravitational Interactions will be o...

  14. Neutrino self-interactions

    Science.gov (United States)

    Hasenkamp, Jasper

    2016-03-01

    We propose a theory that equips the active neutrinos with interactions among themselves that are at least 3 orders of magnitude stronger than the weak interaction. We introduce an Abelian gauge group U (1 )X with vacuum expectation value vx≲O (100 MeV ) . An asymmetric mass matrix implements the active neutrinos as massless mass eigenstates carrying "effective" charges. To stabilize vx, supersymmetry breaking is mediated via loops to the additional sector with the only exception of xHiggs terms. No Standard Model interaction eigenstate carries U (1 )X charge. Thus, the dark photon's kinetic mixing is two-loop suppressed. With only simple and generic values of dimensionless parameters, our theory might explain the high-energy neutrino spectrum observed by IceCube including the PeV neutrinos. We comment on the imposing opportunity to incorporate a self-interacting dark matter candidate.

  15. Elementary particle interactions

    International Nuclear Information System (INIS)

    Work continues on strange particle production in weak interactions using data from a high-energy neutrino exposure in a freon bubble chamber. Meson photoproduction has also consumed considerable effort. Detector research and development activities have been carried out

  16. Neutrino Self-Interactions

    CERN Document Server

    Hasenkamp, Jasper

    2016-01-01

    We propose a theory that equips the active neutrinos with interactions among themselves that are at least three orders of magnitude stronger than the weak interaction. We introduce an Abelian gauge group $U(1)_x$ with vacuum expectation value $v_x \\lesssim \\mathcal{O}(100 \\textrm{ MeV})$. An asymmetric mass matrix implements the active neutrinos as massless mass eigenstates carrying "effective" charges. To stabilize $v_x$, supersymmetry breaking is mediated via loops to the additional sector with the only exception of xHiggs terms. No Standard Model interaction eigenstate carries $U(1)_x$ charge. Thus the dark photon's kinetic mixing is two-loop suppressed.With only simple and generic values of dimensionless parameters, our theory might explain the high-energy neutrino spectrum observed by IceCube including the PeV neutrinos. We comment on the imposing opportunity to incorporate a self-interacting dark matter candidate.

  17. Multiactivity in Social Interaction

    DEFF Research Database (Denmark)

    Doing more than one thing at the same time – a phenomenon that is often called ‘multitasking’ – is characteristic to many situations in everyday and professional life. Although we all experience it, its real time features remain understudied. Multiactivity in Social Interaction: Beyond multitasking...... offers a fresh view to the phenomenon by presenting studies that explore how two or more activities can be related and made co-relevant as people interact with one another. The studies build on the basis that multiactivity is a social, verbal and embodied phenomenon. They investigate multiactivity by...... using video recordings of real-life interactions from a range of different contexts, such as medical settings, office workplaces and car driving. With the companion collection Interacting with Objects: Language, materiality, and social activity, the book advances understanding of the complex...

  18. Nucleon-nucleon interactions

    International Nuclear Information System (INIS)

    Nucleon-nucleon interactions are at the heart of nuclear physics, bridging the gap between QCD and the effective interactions appropriate for the shell model. We discuss the current status of NN data sets, partial-wave analyses, and some of the issues that go into the construction of potential models. Our remarks are illustrated by reference to the Argonne v18 potential, one of a number of new potentials that fit elastic nucleon-nucleon data up to 350 MeV with a Χ2 per datum near 1. We also discuss the related issues of three-nucleon potentials, two-nucleon charge and current operators, and relativistic effects. We give some examples of calculations that can be made using these realistic descriptions of NN interactions. We conclude with some remarks on how our empirical knowledge of NN interactions may help constrain models at the quark level, and hence models of nucleon structure

  19. Human-machine interactions

    Science.gov (United States)

    Forsythe, J. Chris; Xavier, Patrick G.; Abbott, Robert G.; Brannon, Nathan G.; Bernard, Michael L.; Speed, Ann E.

    2009-04-28

    Digital technology utilizing a cognitive model based on human naturalistic decision-making processes, including pattern recognition and episodic memory, can reduce the dependency of human-machine interactions on the abilities of a human user and can enable a machine to more closely emulate human-like responses. Such a cognitive model can enable digital technology to use cognitive capacities fundamental to human-like communication and cooperation to interact with humans.

  20. Modelling interactions in fungi

    OpenAIRE

    Falconer, Ruth E; Bown, James L; White, Nia A.; Crawford, John W.

    2007-01-01

    Indeterminate organisms have received comparatively little attention in theoretical ecology and still there is much to be understood about the origins and consequences of community structure. The fungi comprise an entire kingdom of life and epitomize the indeterminate growth form. While interactions play a significant role in shaping the community structure of indeterminate organisms, to date most of our knowledge relating to fungi comes from observing interaction outcomes between two species...

  1. Neutrino Self-Interactions

    OpenAIRE

    Hasenkamp, Jasper(Center for Cosmology and Particle Physics, New York University, 70 Washington Square S, New York, NY, 10003 U.S.A.)

    2016-01-01

    We propose a theory that equips the active neutrinos with interactions among themselves that are at least three orders of magnitude stronger than the weak interaction. We introduce an Abelian gauge group $U(1)_x$ with vacuum expectation value $v_x \\lesssim \\mathcal{O}(100 \\textrm{ MeV})$. An asymmetric mass matrix implements the active neutrinos as massless mass eigenstates carrying "effective" charges. To stabilize $v_x$, supersymmetry breaking is mediated via loops to the additional sector ...

  2. Interaction with geospatial data

    OpenAIRE

    SCHOENING, Johannes

    2015-01-01

    My research interest lies at the interaction between human-computer interaction (HCI) and geoinformatics. I am interested in developing new methods and novel user interfaces to navigate through spatial information. This article will give a brief overview on my past and current research topics and streams. Generally speaking, geography is playing an increasingly important role in computer science and also in the field of HCI ranging from social computing to natural user interfaces (NUIs). At t...

  3. Beam-Material Interaction

    CERN Document Server

    Mokhov, N V

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high- intensity energetic particle beam interactions with accelerator, generic target , and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and envir onment in challenging current and future application

  4. Interacting Holographic Phantom

    OpenAIRE

    Setare, M. R.

    2007-01-01

    In this paper we consider the holographic model of interacting dark energy in non-flat universe. With the choice of $c\\leq 0.84$, the interacting holographic dark energy can be described by a phantom scalar field. Then we show this phantomic description of the holographic dark energy with $c\\leq 0.84$ and reconstruct the potential of the phantom scalar field.

  5. Plasma-wall interaction

    International Nuclear Information System (INIS)

    This document gathers the 43 slides presented in the framework of the week long lecture 'hot plasmas 2004' and dedicated to plasma-wall interaction in a tokamak. This document is divided into 4 parts: 1) thermal load on the wall, power extraction and particle recovery, 2) basic edge plasma physics, 3) processes that drive the plasma-solid interaction, and 4) material conditioning (surface treatment...) for ITER

  6. CONCEPT OF DRUG INTERACTION

    OpenAIRE

    Singh Nidhi

    2012-01-01

    Drug interaction is an increasingly important cause of adverse reactions (ADR), and is the modification of the effect of one drug (object) by the prior or concomitant administration of another drug (precipitant drug). Drug interaction may either enhance or diminish the intended effect of one or both drugs. For example severe haemorrhage may occur if warfarin and salicylates (asprin) are combined. Precipitant drugs modify the object drug's absorption, distribution, metabolism, excretion or act...

  7. Strongly interacting new physics

    International Nuclear Information System (INIS)

    In this talk. I will describe two aspects of the breaking of electroweak symmetry by new, strong interactions. First I will review the model independent approach to the low energy form of such new interactions emdash the electroweak chiral Lagrangian. Next I will summarize some of the phenomenological challenges facing technicolor theories, in particular those associated with the generation of the top and bottom masses. copyright 1997 American Institute of Physics

  8. Interacting Agegraphic Dark Energy

    OpenAIRE

    Wei, Hao; Cai, Rong-Gen

    2007-01-01

    A new dark energy model, named "agegraphic dark energy", has been proposed recently, based on the so-called K\\'{a}rolyh\\'{a}zy uncertainty relation, which arises from quantum mechanics together with general relativity. In this note, we extend the original agegraphic dark energy model by including the interaction between agegraphic dark energy and pressureless (dark) matter. In the interacting agegraphic dark energy model, there are many interesting features different from the original agegrap...

  9. Quantum interaction. Selected papers

    International Nuclear Information System (INIS)

    This book constitutes the refereed proceedings of the 7th International Conference on Quantum Interaction, QI 2013, held in Leicester, UK, in July 2013. The 31 papers presented in this book were carefully selected from numerous submissions. The papers cover various topics on quantum interaction and revolve around four themes: information processing/retrieval/semantic representation and logic; cognition and decision making; finance/economics and social structures and biological systems.

  10. Smoking and Social Interaction

    OpenAIRE

    Poutvaara, Panu; Siemens, Lars-H. R.

    2007-01-01

    We study the social interaction of non-smokers and smokers as a sequential game, incorporating insights from social psychology and experimental economics into an economic model. Social norms a®ect human behavior such that non-smokers do not ask smokers to stop smoking and stay with them, even though disutility from smoking exceeds utility from social interaction. Overall, smoking is unduly often accepted when accommodating smoking is the social norm. The introduction of smoking and non-smokin...

  11. Soft interactions in Herwig++

    CERN Document Server

    Bahr, Manuel; Gieseke, Stefan; Seymour, Michael H

    2009-01-01

    We describe the recent developments to extend the multi-parton interaction model of underlying events in Herwig++ into the soft, non-perturbative, regime. This allows the program to describe also minimum bias collisions in which there is no hard interaction, for the first time. It is publicly available from versions 2.3 onwards and describes the Tevatron underlying event and minimum bias data. The extrapolations to the LHC nevertheless suffer considerable ambiguity, as we discuss.

  12. Quantum interaction. Selected papers

    Energy Technology Data Exchange (ETDEWEB)

    Atmanspacher, Harald [Eidgenoessische Technische Hochschule, Zurich (Switzerland); Haven, Emmanuel [Leicester Univ. (United Kingdom). School of Management; Kitto, Kirsty [Queensland Univ. of Technology, Brisbane, QLD (Australia); Raine, Derek (ed.) [Leicester Univ. (United Kingdom). Centre for Interdisciplinary Science

    2014-07-01

    This book constitutes the refereed proceedings of the 7th International Conference on Quantum Interaction, QI 2013, held in Leicester, UK, in July 2013. The 31 papers presented in this book were carefully selected from numerous submissions. The papers cover various topics on quantum interaction and revolve around four themes: information processing/retrieval/semantic representation and logic; cognition and decision making; finance/economics and social structures and biological systems.

  13. Grapefruit and drug interactions.

    Science.gov (United States)

    2012-12-01

    Since the late 1980s, grapefruit juice has been known to affect the metabolism of certain drugs. Several serious adverse effects involving drug interactions with grapefruit juice have been published in detail. The components of grapefruit juice vary considerably depending on the variety, maturity and origin of the fruit, local climatic conditions, and the manufacturing process. No single component accounts for all observed interactions. Other grapefruit products are also occasionally implicated, including preserves, lyophylised grapefruit juice, powdered whole grapefruit, grapefruit seed extract, and zest. Clinical reports of drug interactions with grapefruit juice are supported by pharmacokinetic studies, each usually involving about 10 healthy volunteers, in which the probable clinical consequences were extrapolated from the observed plasma concentrations. Grapefruit juice inhibits CYP3A4, the cytochrome P450 isoenzyme most often involved in drug metabolism. This increases plasma concentrations of the drugs concerned, creating a risk of overdose and dose-dependent adverse effects. Grapefruit juice also inhibits several other cytochrome P450 isoenzymes, but they are less frequently implicated in interactions with clinical consequences. Drugs interacting with grapefruit and inducing serious clinical consequences (confirmed or very probable) include: immunosuppressants, some statins, benzodiazepines, most calcium channel blockers, indinavir and carbamazepine. There are large inter-individual differences in enzyme efficiency. Along with the variable composition of grapefruit juice, this makes it difficult to predict the magnitude and clinical consequences of drug interactions with grapefruit juice in a given patient. There is increasing evidence that transporter proteins such as organic anion transporters and P-glycoprotein are involved in interactions between drugs and grapefruit juice. In practice, numerous drugs interact with grapefruit juice. Although only a few

  14. Drug interactions with grapefruit

    OpenAIRE

    Bojanić Vladmila V.; Bojanić Novica Z.; Bojanić Zoran Ž.

    2010-01-01

    Introduction. The concentration of many orally given medications may be affected by grapefruit or grapefruit juice consumption. It may result in numerous harmful effects. Interaction of grapefruit with drugs. Taking only one cup of juice may induce interactions with different drugs even during the period of a few days. The effect is induced by suppression of cytochrome P450 isoenzyme CYP3A4 in the intestinal wall. The Latin name of grapefruit, Citrus paradisi, is quite opposite to the e...

  15. Studies of Embodied Interaction

    OpenAIRE

    Stycke, Simon; Castillo Hansen, Frederikke; Debel, Niels; Heebøll, Lauge; Mohr, Markus

    2013-01-01

    The purpose of this project was to perform general studies on the phenomenon Embodied Interaction. Our motivation for doing this was the increasing interest, both creatively and commercially, in new ways to use our computer technologies in the tangible world, as well as in affecting the human perception. Embodied Interaction allows a person to use his body as an instrument in the world, and utilize his bodily presence and motions, to control software and hardware alike. By delv...

  16. Nonadditivity of nanoparticle interactions.

    Science.gov (United States)

    Batista, Carlos A Silvera; Larson, Ronald G; Kotov, Nicholas A

    2015-10-01

    Understanding interactions between inorganic nanoparticles (NPs) is central to comprehension of self-organization processes and a wide spectrum of physical, chemical, and biological phenomena. However, quantitative description of the interparticle forces is complicated by many obstacles that are not present, or not as severe, for microsize particles (μPs). Here we analyze the sources of these difficulties and chart a course for future research. Such difficulties can be traced to the increased importance of discreteness and fluctuations around NPs (relative to μPs) and to multiscale collective effects. Although these problems can be partially overcome by modifying classical theories for colloidal interactions, such an approach fails to manage the nonadditivity of electrostatic, van der Waals, hydrophobic, and other interactions at the nanoscale. Several heuristic rules identified here can be helpful for discriminating between additive and nonadditive nanoscale systems. Further work on NP interactions would benefit from embracing NPs as strongly correlated reconfigurable systems with diverse physical elements and multiscale coupling processes, which will require new experimental and theoretical tools. Meanwhile, the similarity between the size of medium constituents and NPs makes atomic simulations of their interactions increasingly practical. Evolving experimental tools can stimulate improvement of existing force fields. New scientific opportunities for a better understanding of the electronic origin of classical interactions are converging at the scale of NPs. PMID:26450215

  17. Strongly interacting Fermi gases

    Directory of Open Access Journals (Sweden)

    Bakr W.

    2013-08-01

    Full Text Available Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of 23Na 40K that will feature strong dipolar interactions in their absolute ground state.

  18. Interactions between photodegradation components

    Directory of Open Access Journals (Sweden)

    Abdollahi Yadollah

    2012-09-01

    Full Text Available Abstract Background The interactions of p-cresol photocatalytic degradation components were studied by response surface methodology. The study was designed by central composite design using the irradiation time, pH, the amount of photocatalyst and the p-cresol concentration as variables. The design was performed to obtain photodegradation % as actual responses. The actual responses were fitted with linear, two factor interactions, cubic and quadratic model to select an appropriate model. The selected model was validated by analysis of variance which provided evidences such as high F-value (845.09, very low P-value (2 = 0.999, adjusted R-squared (Radj2 = 0.998, predicted R-squared (Rpred2 = 0.994 and the adequate precision (95.94. Results From the validated model demonstrated that the component had interaction with irradiation time under 180 min of the time while the interaction with pH was above pH 9. Moreover, photocatalyst and p-cresol had interaction at minimal amount of photocatalyst (p-cresol. Conclusion These variables are interdependent and should be simultaneously considered during the photodegradation process, which is one of the advantages of the response surface methodology over the traditional laboratory method.

  19. The Demand for Social Interaction

    OpenAIRE

    Henry Saffer

    2005-01-01

    In this paper social interaction is modeled as a consumer good. Social interaction may provide an externality in the form of social capital, but the primary reason that individuals engage in social interaction is that these activities directly yield utility. It is important to note that some measures of social interaction show declines while many do not. A model of household production is employed to derive the demand for social interaction. The model shows that the demand for social interact...

  20. Dark Matter Gravitational Interactions

    CERN Document Server

    Tucker, R W

    1998-01-01

    We argue that the conjectured dark mater in the Universe may be endowed with a new kind of gravitational charge that couples to a short range gravitational interaction mediated by a massive vector field. A model is constructed that assimilates this concept into ideas of current inflationary cosmology. The model is also consistent with the observed behaviour of galactic rotation curves according to Newtonian dynamics. The essential idea is that stars composed of ordinary (as opposed to dark matter) experience Newtonian forces due to the presence of an all pervading background of massive gravitationally charged cold dark matter. The novel gravitational interactions are predicted to have a significant influence on pre-inflationary cosmology. The precise details depend on the nature of a gravitational Proca interaction and the description of matter. A gravitational Proca field configuration that gives rise to attractive forces between dark matter charges of like polarity exhibits homogeneous isotropic eternal cos...

  1. Electrocatalyst-support interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, K.

    1978-01-01

    The maximum utilization of noble metals as heterogeneous catalysts is achieved by dispersing the noble metals as small particles supported on a porous, high surface area powder. In some studies with supported noble metal catalysts, it has been reported that the metal particle interacts with the support material and that the interaction affects the catalytic properties of the metal. Experimental studies on metal-support interactions that are pertinent to electrocatalysis will be discussed. Platinum supported on carbon black is one of the most active electrocatalysts for oxygen reduction in phosphoric acid fuel cells. In the acid environment at 100 to 200/sup 0/C, the Pt surface area decreases with time due to the growth of the supported Pt particles. The effects of a liquid-phase environment on the particle growth mechanism of supported Pt catalysts is discussed. 60 references.

  2. History of Weak Interactions

    Science.gov (United States)

    Lee, T. D.

    1970-07-01

    While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.

  3. Dike/Drift Interactions

    International Nuclear Information System (INIS)

    This report presents and documents the model components and analyses that represent potential processes associated with propagation of a magma-filled crack (dike) migrating upward toward the surface, intersection of the dike with repository drifts, flow of magma in the drifts, and post-magma emplacement effects on repository performance. The processes that describe upward migration of a dike and magma flow down the drift are referred to as the dike intrusion submodel. The post-magma emplacement processes are referred to as the post-intrusion submodel. Collectively, these submodels are referred to as a conceptual model for dike/drift interaction. The model components and analyses of the dike/drift interaction conceptual model provide the technical basis for assessing the potential impacts of an igneous intrusion on repository performance, including those features, events, and processes (FEPs) related to dike/drift interaction (Section 6.1)

  4. "Interaction-Free" Imaging

    CERN Document Server

    White, A G; Nairz, O; Kwiat, P G; White, Andrew G.; Mitchell, Jay R.; Nairz, Olaf; Kwiat, Paul G.

    1998-01-01

    Using the complementary wave- and particle-like natures of photons, it is possible to make ``interaction-free'' measurements where the presence of an object can be determined with no photons being absorbed. We investigated several ``interaction-free'' imaging systems, i.e. systems that allow optical imaging of photosensitive objects with less than the classically expected amount of light being absorbed or scattered by the object. With the most promising system, we obtained high-resolution (10 \\mu m), one-dimensional profiles of a variety of objects (human hair, glass and metal wires, cloth fibers), by raster scanning each object through the system. We discuss possible applications and the present and future limits for interaction-free imaging.

  5. Dike/Drift Interactions

    Energy Technology Data Exchange (ETDEWEB)

    E. Gaffiney

    2004-11-23

    This report presents and documents the model components and analyses that represent potential processes associated with propagation of a magma-filled crack (dike) migrating upward toward the surface, intersection of the dike with repository drifts, flow of magma in the drifts, and post-magma emplacement effects on repository performance. The processes that describe upward migration of a dike and magma flow down the drift are referred to as the dike intrusion submodel. The post-magma emplacement processes are referred to as the post-intrusion submodel. Collectively, these submodels are referred to as a conceptual model for dike/drift interaction. The model components and analyses of the dike/drift interaction conceptual model provide the technical basis for assessing the potential impacts of an igneous intrusion on repository performance, including those features, events, and processes (FEPs) related to dike/drift interaction (Section 6.1).

  6. Star-Planet Interactions

    CERN Document Server

    Shkolnik, Evgenya; Cranmer, Steven; Fares, Rim; Fridlund, Malcolm; Pont, Frederic; Schmitt, Juergen; Smith, Alexis; Suzuki, Takeru

    2008-01-01

    Much effort has been invested in recent years, both observationally and theoretically, to understand the interacting processes taking place in planetary systems consisting of a hot Jupiter orbiting its star within 10 stellar radii. Several independent studies have converged on the same scenario: that a short-period planet can induce activity on the photosphere and upper atmosphere of its host star. The growing body of evidence for such magnetic star-planet interactions includes a diverse array of photometric, spectroscopic and spectropolarimetric studies. The nature of which is modeled to be strongly affected by both the stellar and planetary magnetic fields, possibly influencing the magnetic activity of both bodies, as well as affecting irradiation and non-thermal and dynamical processes. Tidal interactions are responsible for the circularization of the planet orbit, for the synchronization of the planet rotation with the orbital period, and may also synchronize the outer convective envelope of the star with...

  7. Sonic Interaction Design

    DEFF Research Database (Denmark)

    created for such contexts as mobile music, sensorimotor learning, rehabilitation, and gaming. The goal is not only to extend the existing research and pedagogical approaches to SID but also to foster domains of practice for sound designers, architects, interaction designers, media artists, product......) challenges these prevalent approaches by considering sound as an active medium that can enable novel sensory and social experiences through interactive technologies. This book offers an overview of the emerging SID research, discussing theories, methods, and practices, with a focus on the multisensory...... aspects of sonic experience. Sonic Interaction Design gathers contributions from scholars, artists, and designers working at the intersections of fields ranging from electronic music to cognitive science. They offer both theoretical considerations of key themes and case studies of products and systems...

  8. Interactive Topology Optimization

    DEFF Research Database (Denmark)

    Nobel-Jørgensen, Morten

    Interactivity is the continuous interaction between the user and the application to solve a task. Topology optimization is the optimization of structures in order to improve stiffness or other objectives. The goal of the thesis is to explore how topology optimization can be used in applications in...... an interactive and intuitive way. By creating such applications with an intuitive and simple user interface we allow non-engineers like designers and architects to easily experiment with boundary conditions, design domains and other optimization settings. This is in contrast to commercial topology...... optimization software where the users are assumed to be well-educated both in the finite element method and topology optimization. This dissertation describes how various topology optimization methods have been used for creating cross-platform applications with high performance. The user interface design is...

  9. Interactive Karyotyping Training

    Directory of Open Access Journals (Sweden)

    Ashwin Kotwaliwale

    2013-01-01

    Full Text Available Despite the wide use of newer techniques in genetic diagnostics, there remains a need for technologists to learn human chromosome morphology, identify abnormal metaphases and report clinical abnormalities. Global short age of cytogenetic trainers and a time consuming training process makes Karyotyping training difficult. We have developed a web based interactive Karyotyping training tool, KaryoTutor©, that allows technologists to learn karyotyping in an interactive environment and aids the trainer in the training process. KaryoTutor©provides visual clues for identifying abnormal chromosomes, provides instant test scores and includes a reference library of ideograms,sample chromosome images and reference materials. Trainees are able to recursively work on a case till a satisfactory result is achieved,with KaryoTutor providing interactive inputs.Additionally, trainers can assign cases and monitor trainee progress using audit trail management and other administrative features.

  10. Electron-positron interactions

    International Nuclear Information System (INIS)

    The experimental information available on e+e- interactions at the time of the Tbilisi Conference (Juli 1976) is reviewed. The topics of these lectures are: electron-positron storage rings, purely electromagnetic ee-interactions, phenomenology of hadron production, e+e- annihilation at low energies, nonresonant hadron production, the new particles psi-3105 and psi-3695, research for other vector states, radiative decays of psi-3105 and psi-3695, anti Q-Q model and predictions, the bound states of heavy quarks, data on new states with even charge conjugation, mesons with open charm, experimental evidence for charmed mesons and for a new lepton. (BJ)

  11. Thoughts on Interaction Design

    CERN Document Server

    Kolko, Jon

    2009-01-01

    Interaction Designers-whether practicing as Usability Engineers, Visual Interface Designers, or Information Architects-attempt to understand and shape human behavior in order to design products that are at once usable, useful, and desirable. Although the value of design is now recognized as essential to product development, the field is often misunderstood by managers and other team members, who don't understand a designer's role in a team. This can cause inefficient and ineffective products. Thoughts on Interaction Design gives individuals engaged in this profession the dialogue to justify t

  12. Gaze interaction from bed

    DEFF Research Database (Denmark)

    Hansen, John Paulin; San Agustin, Javier; Jensen, Henrik Tomra Skovsgaard Hegner

    2011-01-01

    This paper presents a low-cost gaze tracking solution for bedbound people composed of free-ware tracking software and commodity hardware. Gaze interaction is done on a large wall-projected image, visible to all people present in the room. The hardware equipment leaves physical space free to assist...... the person. Accuracy and precision of the tracking system was tested in an experiment with 12 subjects. We obtained a tracking quality that is sufficiently good to control applications designed for gaze interaction. The best tracking condition were achieved when people were sitting up compared to...

  13. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  14. Multiactivity in Social Interaction

    DEFF Research Database (Denmark)

    Haddington, Pentti; Keisanen, Tiina; Mondada, Lorenza;

    2014-01-01

    Doing more than one thing at the same time – a phenomenon that is often called ‘multitasking’ – is characteristic to many situations in everyday and professional life. Although we all experience it, its real time features remain understudied. Multiactivity in Social Interaction: Beyond multitaski......, communication studies and discourse analysis, but will be very valuable for scholars in cognitive sciences, psychology and sociology.......Doing more than one thing at the same time – a phenomenon that is often called ‘multitasking’ – is characteristic to many situations in everyday and professional life. Although we all experience it, its real time features remain understudied. Multiactivity in Social Interaction: Beyond multitasking...

  15. Cultivating objects in interaction

    DEFF Research Database (Denmark)

    Hazel, Spencer

    2014-01-01

    This paper demonstrates how an initial indexing of objects through gesture and talk provides a residual basis for later indexical development across a stretch of discourse. I show how participants are able to perform an initial mobilization of affordances (Hutchby, 2001) of objects in the immediate...... the interactional resources which mundane everyday objects provide interactants in the multimodal design of their turns-at-talk. Although the objects which feature in the data – for example notepads, tables, computer monitors – have practical functions within the social ecology of these institutional settings...

  16. Interactive Shape Design

    CERN Document Server

    Cani, Marie-Paule; Wyvill, Geoff

    2008-01-01

    Providing an intuitive modeling system, which would enable us to communicate about any free-form shape we have in mind at least as quickly as with real-world tools, is one of the main challenges of digital shape design. The user should ideally be able to create, deform, and progressively add details to a shape, without being aware of the underlying mathematical representation nor being tied by any constraint on the geometrical or topological nature of the model. This book presents the field of interactive shape design from this perspective. Since interactively creating a shape builds on the hu

  17. Interactive Collaborative Books

    OpenAIRE

    Al-Mutawa, Abdullah M.

    2007-01-01

    Books are one of the most important tools to convey knowledge, they survived to be a convenient and portable source of information. On the other side, Electronic books (e-books) are playing a big role in attracting a huge number of readers, but still paper books are preferable by many people due to some drawbacks in e-books. Yet, Interactive books combines all positive features in ordinary books as well as e-books, the author is introducing a new Interactive Collaborative book that might chan...

  18. Acting, interacting, enacting

    DEFF Research Database (Denmark)

    Hazel, Spencer

    2015-01-01

    notes – which forms a framework within which members reflect on their performances, and discuss possible modifications to be taken up on later occasions. This is argued to be a useful practice that may prove beneficial to other professional settings, such as in heathcare provision...... from professional medical treatment of the body, rather than of the person. I adopt an interaction analytic approach to investigate how theatre practitioners develop representations of interaction in clinical environments. The article introduces one practice from the theatre rehearsal setting – doing...

  19. Honesty through repeated interactions.

    Science.gov (United States)

    Rich, Patricia; Zollman, Kevin J S

    2016-04-21

    In the study of signaling, it is well known that the cost of deception is an essential element for stable honest signaling in nature. In this paper, we show how costs for deception can arise endogenously from repeated interactions between individuals. Utilizing the Sir Philip Sidney game as an illustrative case, we show that repeated interactions can sustain honesty with no observable signal costs, even when deception cannot be directly observed. We provide a number of potential experimental tests for this theory which distinguish it from the available alternatives. PMID:26869213

  20. Diachronic Perspective and Interaction

    DEFF Research Database (Denmark)

    Marchetti, Emanuela; Valente, Andrea

    . Although this interaction style may appeal to teachers, as it reminds of school teaching, it has several disadvantages: a dialogue never occurs between adults and children, who listen in silence, hence it becomes hard to evaluate what has being learnt and how deeply, and finally it is not very engaging. An...... ongoing participatory inquiry is being conducted, to explore deeper forms of learning and communication for historical museums. Our hypothesis is that the diachronic perspective on historical processes, defined as social interaction within the environment through time, is a key missing element...

  1. Interactive shape metamorphosis

    Science.gov (United States)

    Chen, David T.; State, Andrei; Banks, David

    1994-01-01

    A technique for controlled metamorphosis between surfaces in 3-space is described. Well-understood techniques to produce shape metamorphosis between models in a 2D parametric space is applied. The user selects morphable features interactively, and the morphing process executes in real time on a high-performance graphics multicomputer.

  2. Alkane dimers interaction

    DEFF Research Database (Denmark)

    Ferrighi, Lara; Madsen, Georg Kent Hellerup; Hammer, Bjørk

    The interaction energies of a series of n-alkane dimers, from methane to decane, have been investigated with Density Functional Theory (DFT), using the MGGA-M06-L density functional. The results are compared both to the available wavefunction-based values as well as to dispersion corrected DFT...

  3. Phonon-dislocation interaction

    International Nuclear Information System (INIS)

    Thermal conductivity measurements on LiF crystals in the temperature range 0.04 to 30 K have demonstrated that, throughout this range, thermal phonons interact with dislocations via a dynamic or resonant process which is highly frequency- and phonon-mode dependent. The results of earlier work are consistent with this interpretation

  4. Experiencing affective interactive art

    NARCIS (Netherlands)

    Bialoskorski, Leticia S.S.; Westerink, Joyce H.D.M.; Broek, van den Egon L.

    2010-01-01

    The progress in the field of affective computing enables the realization of affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on the integration of a framework for affective move

  5. Connectionist Interaction Information Retrieval.

    Science.gov (United States)

    Dominich, Sandor

    2003-01-01

    Discussion of connectionist views for adaptive clustering in information retrieval focuses on a connectionist clustering technique and activation spreading-based information retrieval model using the interaction information retrieval method. Presents theoretical as well as simulation results as regards computational complexity and includes…

  6. Interactions within wastewater systems

    NARCIS (Netherlands)

    Langeveld, J.G.

    2004-01-01

    Wastewater systems consist of sewer systems and wastewater treatment works. As the performance of a wastewater treatment plant is affected by the characteristics, i.e. operation and design, of the contributing sewer systems, knowledge of the interactions between sewers and wastewater treatment works

  7. Urban Interaction Design

    DEFF Research Database (Denmark)

    Brynskov, Martin; Bermúdez, Juan Carlos Carvajal; Fernández, Manu;

    table? What are the key concepts they are addressing in their work? In the second part of the book named 'Trends', we go into current developments in the networked city and how urban interaction design as a field addresses these. Taken together, these sections will not give the definite definition or...

  8. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Our theoretical research on dust-plasma interactions has concentrated on three main areas: (a)studies of grain charging and applications; (b) waves and instabilities in weakly correlated dusty plasma with applications to space and laboratory plasmas; (c) waves in strongly coupled dusty plasmas.

  9. Virtual Interactive Space (VIS)

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2015-01-01

    This paper shares code that enables the making of a Virtual Interactive Space (VIS) where the skin of the invisible active sensor area is dynamically responsive to the velocity of a limb e.g. hand. Used in proprioception training of movement the patch is at the core of the author’s Reafferentation...

  10. Proxemic Mobile Collocated Interactions

    DEFF Research Database (Denmark)

    Porcheron, Martin; Lucero, Andrés; Quigley, Aaron;

    2016-01-01

    Recent research on mobile collocated interactions has been looking at situations in which collocated users engage in collaborative activities using their mobile devices. However, existing practices fail to fully account for the culturally-dependent spatial relationships between people and their d...

  11. Empowered interaction through creativity

    DEFF Research Database (Denmark)

    Hasselblad, Stefan; Petersson, Eva; Brooks, Tony

    2007-01-01

    This paper reflects upon a case study where exploration, play and empowerment in interactive therapy sessions with audio and visual stimuli resulted in achievement, self-esteem and a shared pride between a young adult with profound and multiple learning disabilities (PMLD), his mother...... and family of similarly severe disabled users....

  12. Interaction and mindreading

    DEFF Research Database (Denmark)

    Michael, John

    2011-01-01

    In recent years, a number of theorists have developed approaches to social cognition that highlight the centrality of social interaction as opposed to mindreading (e.g. Gallagher and Zahavi 2008; Gallagher 2001, 2007, 2008; Hobson 2002; Reddy 2008; Hutto 2004; De Jaegher 2009; De Jaegher and Di...

  13. Tritium-surface interactions

    International Nuclear Information System (INIS)

    The report deals broadly with tritium-surface interactions as they relate to a fusion power reactor enterprise, viz., the vacuum chamber, first wall, peripherals, pumping, fuel recycling, isotope separation, repair and maintenance, decontamination and safety. The main emphasis is on plasma-surface interactions and the selection of materials for fusion chamber duty. A comprehensive review of the international (particularly U.S.) research and development is presented based upon a literature review (about 1 000 reports and papers) and upon visits to key laboratories, Sandia, Albuquerque, Sandia, Livermore and EGβG Idaho. An inventory of Canadian expertise and facilities for RβD on tritium-surface interactions is also presented. A number of proposals are made for the direction of an optimal Canadian RβD program, emphasizing the importance of building on strength in both the technological and fundamental areas. A compendium of specific projects and project areas is presented dealing primarily with plasma-wall interactions and permeation, anti-permeation materials and surfaces and health, safety and environmental considerations. Potential areas of industrial spinoff are identified

  14. Interactive Foresight Simulation

    DEFF Research Database (Denmark)

    Hansen, Mette Sanne; Rasmussen, Lauge Baungaard; Jacobsen, Peter

    2016-01-01

    The Combined Simulation Approach (CSA) is a way to evaluate risks and address potential unforeseen problems in a more interactive way than what is often observed in practice in companies or sectors. The approach is based on a combination of scenario analysis and discrete-event computer simulation...

  15. Critical ionization velocity interaction

    International Nuclear Information System (INIS)

    Different problems of current interest regarding the critical ionization velocity (CIV) phenomenon are discussed. The article is divided into five sections corresponding to different aspects of the interaction: velocity, magnetic field strength, geometry, neutral gas density, and time duration. In each section, experiments and theories - microscopic and macroscopic - are discussed

  16. Mobile Collocated Interactions

    DEFF Research Database (Denmark)

    Lucero, Andrés; Clawson, James; Lyons, Kent;

    2015-01-01

    Mobile devices such as smartphones and tablets were originally conceived and have traditionally been utilized for individual use. Research on mobile collocated interactions has been looking at situations in which collocated users engage in collaborative activities using their mobile devices, thus...

  17. Towards Directional Colloidal Interactions

    NARCIS (Netherlands)

    Kamp, M.

    2015-01-01

    Colloids are particles with a size on the scale of microns in at least one dimension. The central theme of this thesis is the synthesis of model colloids with anisotropic interactions - often called `patchy' colloids, as well as the search for new ways to assemble such colloids. Methods to build non

  18. Protein–DNA Interactions

    NARCIS (Netherlands)

    Kovacic, L.; Boelens, R.

    2012-01-01

    The recognition of specific DNA sequences by proteins and the coupling to signaling events are fundamental occurrences that lie at the root of many cellular processes. Many examples of tight control by protein–DNA interactions can be found in such dynamic processes as transcription, replication and

  19. Protein-protein interactions

    DEFF Research Database (Denmark)

    Byron, Olwyn; Vestergaard, Bente

    2015-01-01

    Responsive formation of protein:protein interaction (PPI) upon diverse stimuli is a fundament of cellular function. As a consequence, PPIs are complex, adaptive entities, and exist in structurally heterogeneous interplays defined by the energetic states of the free and complexed protomers. The...

  20. CONCEPT OF DRUG INTERACTION

    Directory of Open Access Journals (Sweden)

    Singh Nidhi

    2012-07-01

    Full Text Available Drug interaction is an increasingly important cause of adverse reactions (ADR, and is the modification of the effect of one drug (object by the prior or concomitant administration of another drug (precipitant drug. Drug interaction may either enhance or diminish the intended effect of one or both drugs. For example severe haemorrhage may occur if warfarin and salicylates (asprin are combined. Precipitant drugs modify the object drug's absorption, distribution, metabolism, excretion or actual clinical effect. Nonsteroidal anti-inflammatory drugs, antibiotics and, in particular, rifampin are common precipitant drugs prescribed in primary care practice. Drugs with a narrow therapeutic range or low therapeutic index are more likely to be the objects for serious drug interactions. Object drugs in common use include warfarin, fluoroquinolones, antiepileptic drugs, oral contraceptives, cisapride and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. Many other drugs, act as precipitants or objects, and a number of drugs act as both. The aim of present review is to throw light on the concept of drug interaction.

  1. Protein–protein interactions

    NARCIS (Netherlands)

    Janin, J.; Bonvin, A.M.J.J.

    2013-01-01

    We are proud to present the first edition of the Protein–protein interactions Section of Current Opinion in Structural Biology. The Section is new, but the topic has been present in the journal from the very start. Volume 1, Issue 1, dated February 1991, had a review by Janin entitled Protein–protei

  2. TIDE-TSUNAMI INTERACTIONS

    Directory of Open Access Journals (Sweden)

    Zygmunt Kowalik

    2006-01-01

    Full Text Available In this paper we investigate important dynamics defining tsunami enhancement in the coastal regions and related to interaction with tides. Observations and computations of the Indian Ocean Tsunami usually show amplifications of the tsunami in the near-shore regions due to water shoaling. Additionally, numerous observations depicted quite long ringing of tsunami oscillations in the coastal regions, suggesting either local resonance or the local trapping of the tsunami energy. In the real ocean, the short-period tsunami wave rides on the longer-period tides. The question is whether these two waves can be superposed linearly for the purpose of determining the resulting sea surface height (SSH or rather in the shallow water they interact nonlinearly, enhancing/reducing the total sea level and currents. Since the near–shore bathymetry is important for the run-up computation, Weisz and Winter (2005 demonstrated that the changes of depth caused by tides should not be neglected in tsunami run-up considerations. On the other hand, we hypothesize that much more significant effect of the tsunami-tide interaction should be observed through the tidal and tsunami currents. In order to test this hypothesis we apply a simple set of 1-D equations of motion and continuity to demonstrate the dynamics of tsunami and tide interaction in the vicinity of the shelf break for two coastal domains: shallow waters of an elongated inlet and narrow shelf typical for deep waters of the Gulf of Alaska.

  3. Relativistic Geometry and Weak Interactions

    CERN Document Server

    González-Martin, G R

    2000-01-01

    Geometric interactions in a new relativistic geometric unified theory include interactions other than gravitation and electromagnetism. In a low energy limit one of these interactions leads essentially to a Fermi type theory of weak interactions including the Hamiltonian and coupling constant.

  4. Interactions of tritium and materials

    Energy Technology Data Exchange (ETDEWEB)

    Yamawaki, Michio; Yamaguchi, Kenji; Tanaka, Satoru; Ono, Futaba (Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.); Yamamoto, Takuya

    1993-11-01

    In D-T burning fusion reactors, problems related to tritium-material interactions are vitally important. From this point of view, plasma-material interactions, blanket breeder material-tritium interactions, safety aspects of tritium-material interactions and tritium storage materials are reviewed with emphasis on the works going on in the authors' laboratories. (author) 83 refs.

  5. Interaction Design for Public Spaces

    DEFF Research Database (Denmark)

    Kortbek, Karen Johanne

    2008-01-01

    In this abstract I describe the doctorial research project "Interaction Design for Public Spaces". The objective of the project is to explore and design interaction contexts in culture related public spaces such as museums, experience centres and festivals. As a perspective on this domain, I will...... will help interaction designers when designing for bodily movement, and communicating and staging interactive content in public spaces....

  6. Serious drug interactions.

    Science.gov (United States)

    Aronson, J

    1993-10-01

    Of the many varieties of drug interactions, which occur when the disposition or actions of one drug are changed by another, only a few are serious or potentially fatal. A representative outline of some of these illustrates the problem. Precipitant drugs are those which produce the interaction, and object drugs are those whose effects are changed. The interactions which are usually significant are those which alter the metabolism, involve renal excretion, or change the effects of the object drug, especially when the object drug has a low therapeutic index (cardiovascular drugs, anticoagulants, drugs acting on the brain, hypoglycemic drugs, hormones, and cytotoxic drugs). Warfarin toxicity, for example, is produced by aspirin, phenylbutazone, and azapropazone. The dosage requirements of warfarin are reduced by chloramphenicol, ciprofloxacin and other quinolones, erythromycin and some of the other macrolides, metronidazole and other imidazoles, tetracyclines, amiodarone, cimetidine (but not ranitidine), and fibrates. Potassium-depleting drugs can potentiate the action of digoxin, and the elimination of digoxin can be reduced by amiodarone, propafenone, quinidine, and verapamil. Combined oral contraceptives can lose effectiveness through the interaction of carbamazepine, griseofulvin, phenytoin, or rifampicin, which increase estrogen metabolism. In addition, broad-spectrum antibiotics such as ampicillin or tetracyclines also reduce contraceptive effectiveness by altering gut absorption. Even a single drink of an alcoholic beverage may be dangerous to people taking antidepressants, antihistamines, antipsychotic drugs, benzodiazepines, or lithium. Antihistamines suffer inhibited metabolism in the liver if taken in conjunction with the antifungal imidazoles and some of the macrolide antibiotics. Cardiotoxicity of antihistamines is also enhanced by drugs with similar cardiotoxic effects. Lithium potentiation is enhanced by the new serotonin-reuptake inhibitors, and lithium

  7. Sustainable Buildings in Interaction

    DEFF Research Database (Denmark)

    Elle, Morten

    developments are going to consist of passive houses. The first sustainable buildings were built by their users, and the user – building interaction still play a decisive role for the performance of the present sustainable buildings. The users have to understand how the building functions. Urban design is...... essential for the possibilities of a sustainable building design: orientation and access to infrastructure are important factor. And the building design is decisive in making the city truly compact: dense in activities. In future, the interaction between the technical infrastructure, the buildings and their......The first attempts to build sustainable buildings in Denmark were typically located on the countryside. The basic idea was to create buildings that were independent of the technical infrastructure. District heating has, however, been the dominating solution to heating in buildings in Denmark, and...

  8. Dynamics of interacting diseases

    CERN Document Server

    Sanz, Joaquín; Meloni, Sandro; Moreno, Yamir

    2014-01-01

    Current modeling of infectious diseases allows for the study of complex and realistic scenarios that go from the population to the individual level of description. Most epidemic models however assume that the spreading process takes place on a single level (be it a single population, a meta-population system or a network of contacts). The latter is in part a consequence of our still limited knowledge about the interdependency of the many mechanisms and factors involved in disease spreading. In particular, interdependent contagion phenomena can only be addressed if we go beyond the scheme one pathogen-one network. In this paper, we study a model that allows describing the spreading dynamics of two concurrent diseases and apply it to a paradigmatic case of disease-disease interaction: the interaction between AIDS and Tuberculosis. Specifically, we characterize analytically the epidemic thresholds of the two diseases for different scenarios and also compute the temporal evolution characterizing the unfolding dyn...

  9. Ligand-Receptor Interactions

    CERN Document Server

    Bongrand, Pierre

    2008-01-01

    The formation and dissociation of specific noncovalent interactions between a variety of macromolecules play a crucial role in the function of biological systems. During the last few years, three main lines of research led to a dramatic improvement of our understanding of these important phenomena. First, combination of genetic engineering and X ray cristallography made available a simultaneous knowledg of the precise structure and affinity of series or related ligand-receptor systems differing by a few well-defined atoms. Second, improvement of computer power and simulation techniques allowed extended exploration of the interaction of realistic macromolecules. Third, simultaneous development of a variety of techniques based on atomic force microscopy, hydrodynamic flow, biomembrane probes, optical tweezers, magnetic fields or flexible transducers yielded direct experimental information of the behavior of single ligand receptor bonds. At the same time, investigation of well defined cellular models raised the ...

  10. Interactive Virtual Cinematography

    DEFF Research Database (Denmark)

    Burelli, Paolo

    A virtual camera represents the point-of-view of the player through which she perceives the game world and gets feedback on her actions. Thus, the virtual camera plays a vital role in 3D computer games and aects player experience and enjoyability in games. Interactive virtual cinematography is the...... process of visualising the content of a virtual environment by positioning and animating the virtual camera in the context of interactive applications such as a computer game. Camera placement and animation in games are usually directly controlled by the player or statically predened by designers. Direct....... The camera controller should dynamically and eciently translate these rules into camera positions and movements before (or while) the player plays the game. Automatically controlling the camera in virtual 3D dynamic environments is an open research problem and a challenging task. From an optimisation...

  11. Interactive White Board

    Directory of Open Access Journals (Sweden)

    Asadullah Khan Praveen Kumar Arun Nair Rishi R Hegde

    2012-02-01

    Full Text Available Visual Screen uses an inexpensive technique to transform an ordinary screen into a touch screen[1] using an ordinary camera[2]. The system can fullfill many tasks such as controlling a remote large display, and simulating a physical keyboard[4]. Users can naturally use their fingers or other tip pointers to issue commands and type texts. In many intelligent environments, instead of using conventional mice[3], keyboards[4] and joysticks[5], people are looking for an intuitive, immersive and cost-efficient interaction device. We describe two vision-based interface systems[10]. The first, Visual Screen, uses an inexpensive technique to transform an ordinary screen into a touch screen[1] using an ordinary camera[2], and a user can use his/her finger to interact with the computer. Touch screens[1] are very convenient because one can directly point to where it is interesting. No conventional mice[3] are needed.

  12. Interactive Energy Planning

    DEFF Research Database (Denmark)

    Blarke, Morten Boje

    2006-01-01

    anchoring along the shores of the land of communications and collaboration. Whether or not a particular typology is applicable, theory and praxis are establishing standpoints, which strengthens our understanding of the planning complex, and which should inspire improved energy planning methodologies and......Though it is being questioned whether planning theory should be fitted into neat typologies, some have described evolving planning theory as a journey away from ethnocentrism, through the lands of rationalism, pragmatism, socio-ecological idealism, political-economic mobilization, currently...... tools. This paper presents an “Interactive Energy Planning” framework, which is intended to support interactivity in planning, building on important theoretical and experimental advances in planning. In particular, the paper explores the potential significance of allowing a critical perspective on...

  13. Theory of fundamental interactions

    International Nuclear Information System (INIS)

    In the present article the theory of fundamental interactions is derived in a systematic way from the first principles. In the developed theory there is no separation between space-time and internal gauge space. Main equations for basic fields are derived. In is shown that the theory satisfies the correspondence principle and gives rise to new notions in the considered region. In particular, the conclusion is made about the existence of particles which are characterized not only by the mass, spin, charge but also by the moment of inertia. These are rotating particles, the particles which represent the notion of the rigid body on the microscopical level and give the key for understanding strong interactions. The main concepts and dynamical laws for these particles are formulated. The basic principles of the theory may be examined experimentally not in the distant future. 29 refs

  14. Interactive protein manipulation

    Energy Technology Data Exchange (ETDEWEB)

    SNCrivelli@lbl.gov

    2003-07-01

    We describe an interactive visualization and modeling program for the creation of protein structures ''from scratch''. The input to our program is an amino acid sequence -decoded from a gene- and a sequence of predicted secondary structure types for each amino acid-provided by external structure prediction programs. Our program can be used in the set-up phase of a protein structure prediction process; the structures created with it serve as input for a subsequent global internal energy minimization, or another method of protein structure prediction. Our program supports basic visualization methods for protein structures, interactive manipulation based on inverse kinematics, and visualization guides to aid a user in creating ''good'' initial structures.

  15. Plasmonic interaction between nanospheres

    CERN Document Server

    Yu, Sanghyeon

    2016-01-01

    When metallic nanospheres are nearly touching, strong nanofocusing of light can occur due to highly localized surface plasmons. It has potential applications in the design of nanophotonic devices, biosensing, and spectroscopy. Due to the singular behavior of electromagnetic fields in the narrow gap regions, its theoretical investigation is quite challenging in both analytical and numerical aspects. There are two approaches for studying the interaction between metallic spheres: transformation optics and the method of image charges. Here we clarify the connection between them. Based on the connection formula, we reveal the singular nature of plasmonic interaction between nanospheres in a completely analytical way. We also develop a hybrid numerical scheme for accurately and efficiently computing the field distribution produced by an arbitrary number of nearly touching plasmonic spheres.

  16. Interactive design center.

    Energy Technology Data Exchange (ETDEWEB)

    Pomplun, Alan R. (Sandia National Laboratories, Livermore, CA)

    2005-07-01

    Sandia's advanced computing resources provide researchers, engineers and analysts with the ability to develop and render highly detailed large-scale models and simulations. To take full advantage of these multi-million data point visualizations, display systems with comparable pixel counts are needed. The Interactive Design Center (IDC) is a second generation visualization theater designed to meet this need. The main display integrates twenty-seven projectors in a 9-wide by 3-high array with a total display resolution of more than 35 million pixels. Six individual SmartBoard displays offer interactive capabilities that include on-screen annotation and touch panel control of the facility's display systems. This report details the design, implementation and operation of this innovative facility.

  17. Intelligent Interactive Multimedia

    CERN Document Server

    Watanabe, Toyohide; Takahashi, Naohisa; 5th International Conference on Intelligent Interactive Multimedia Systems and Services

    2012-01-01

    This volume contains the Proceedings of the 5th International Conference on Intelligent Interactive Multimedia Systems and Services (KES-IIMSS-12).  The Conference was jointly organised by Nagoya University in Japan and the KES International organisation, and held in the attractive city of Gifu.   The KES-IIMSS conference series, (series chairs Prof. Maria Virvou and Prof. George Tsihrintzis), presents novel research in various areas of intelligent multimedia system relevant to the development of a new generation of interactive, user-centric devices and systems.  The aim of the conference is to provide an internationally respected forum for scientific research in the technologies and applications of this new and dynamic research area.

  18. Interactional Expertise and Embodiment

    CERN Document Server

    Collins, Harry

    2016-01-01

    In Part 1 of this paper, I introduce the idea of interactional expertise while in Part 2, I focus on its implications for philosophical theories of the importance of the body in forming our conceptual world. I argue that the way philosophers have dealt with the body turns attention away from the most important questions and that we cannot answer these questions without making the notion of socialisation, and therefore interactional expertise, a central concept in our thinking. This makes language at least as important, and often more important than bodily practice in our understanding of the world. The notion of a disembodied socialised agent leads in the direction of interesting questions while the notion of an embodied but unsocialised human actor is unimaginable.

  19. Interactive protein manipulation

    International Nuclear Information System (INIS)

    We describe an interactive visualization and modeling program for the creation of protein structures ''from scratch''. The input to our program is an amino acid sequence -decoded from a gene- and a sequence of predicted secondary structure types for each amino acid-provided by external structure prediction programs. Our program can be used in the set-up phase of a protein structure prediction process; the structures created with it serve as input for a subsequent global internal energy minimization, or another method of protein structure prediction. Our program supports basic visualization methods for protein structures, interactive manipulation based on inverse kinematics, and visualization guides to aid a user in creating ''good'' initial structures

  20. Embodying multilingual interaction

    DEFF Research Database (Denmark)

    Hazel, Spencer; Mortensen, Janus

    this linguistic diversity is managed in situ by participants engaged in dialogue with one another, and what it is used for in these transient multilingual communities. This paper presents CA-based micro-ethnographic analyses of language choice in an informal social setting – a kitchen – of an international study...... literature on language choice in interaction, our findings emphasize that analyses of language choice in multilingual settings need to take into account social actions beyond the words that are spoken. We show that facial, spatial and postural configurations, gaze orientation and gestures as well as prosodic...... in the particular community of practice that we are investigating. Reference Hazel, Spencer, and Janus Mortensen. forthcoming. Kitchen talk: Exploring linguistic practices in liminal institutional interactions in a multilingual university setting. in Language Alternation, Language Choice, and Language Encounter...

  1. Interactive Information Retrieval:

    DEFF Research Database (Denmark)

    Borlund, Pia

    This presentation addresses methodological issues of interactive information retrieval (IIR) evaluation in terms of what it entails to study users' use and interaction with IR systems, as well as their satisfaction with retrieved information. In particular, the presentation focuses on test design...... the habitat of the users to ensure a complete and realistic picture to enhance our understanding of IIR. The presentation also reflects on whether a re-thinking of the concept on an information need is necessary. One may ask whether it still makes sense to talk about types of information needs. Or...... should we rather study IIR from the perspective of search dedication and task load in order to also include everyday life information seeking? With this presentation, the IIR community is invited to an exchange of ideas and is encouraged to engage in collaborations with the solving of these (and other...

  2. Interactive Information Retrieval

    DEFF Research Database (Denmark)

    Borlund, Pia

    2013-01-01

    The paper introduces the research area of interactive information retrieval (IIR) from a historical point of view. Further, the focus here is on evaluation, because much research in IR deals with IR evaluation methodology due to the core research interest in IR performance, system interaction and...... satisfaction with retrieved information. In order to position IIR evaluation, the Cranfield model and the series of tests that led to the Cranfield model are outlined. Three iconic user-oriented studies and projects that all have contributed to how IIR is perceived and understood today are presented: The....... As a response to this call the ‘IIR evaluation model’ by Borlund (e.g., 2003a) is introduced. The objective of the IIR evaluation model is to facilitate IIR evaluation as close as possible to actual information searching and IR processes, though still in a relatively controlled evaluation environment...

  3. Interactive Chemical Reactivity Exploration

    CERN Document Server

    Haag, Moritz P; Bosson, Mael; Redon, Stephane; Reiher, Markus

    2014-01-01

    Elucidating chemical reactivity in complex molecular assemblies of a few hundred atoms is, despite the remarkable progress in quantum chemistry, still a major challenge. Black-box search methods to find intermediates and transition-state structures might fail in such situations because of the high-dimensionality of the potential energy surface. Here, we propose the concept of interactive chemical reactivity exploration to effectively introduce the chemist's intuition into the search process. We employ a haptic pointer device with force-feedback to allow the operator the direct manipulation of structures in three dimensions along with simultaneous perception of the quantum mechanical response upon structure modification as forces. We elaborate on the details of how such an interactive exploration should proceed and which technical difficulties need to be overcome. All reactivity-exploration concepts developed for this purpose have been implemented in the Samson programming environment.

  4. Wood–water interactions

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2011-01-01

    Predicting the performance of wood for decades ahead is important when using the material for structural purposes. The performance is closely related to the hierarchical material structure of wood and the dependent interaction with water in the structure. Accurately predicting wood performance...... therefore requires an understanding of material structure from molecular to macroscopic level as well as of the impact of water molecules. The objective of this work is to investigate the performance of wood in terms of mechanical response of the material and effect of water. To understand the latter, one...... must first know in which parts of the wood structure, water is located. If parts of the water in wood are held in capillaries in the wood structure, these water molecules interact with the material differently than those held within wood cell walls. In this study, the occurrence of capillary water in...

  5. Identification of social interactions

    OpenAIRE

    Blume, Lawrence E.; William A Brock; Durlauf, Steven N.; Ioannides, Yannis M.

    2010-01-01

    Abstract: While interest in social determinants of individual behavior has led to a rich theoretical literature and many efforts to measure these influences, a mature "social econometrics" has yet to emerge. This chapter provides a critical overviewof the identification of social interactions. We consider linear and discrete choice models as well as social networks structures. We also consider experimental and quasi-experimental methods. In addition to describing the state of the identificati...

  6. Interactive Submodular Set Cover

    OpenAIRE

    Guillory, Andrew; Bilmes, Jeff

    2010-01-01

    We introduce a natural generalization of submodular set cover and exact active learning with a finite hypothesis class (query learning). We call this new problem interactive submodular set cover. Applications include advertising in social networks with hidden information. We give an approximation guarantee for a novel greedy algorithm and give a hardness of approximation result which matches up to constant factors. We also discuss negative results for simpler approaches and present encouragin...

  7. Interactive Submodular Set Cover

    CERN Document Server

    Guillory, Andrew

    2010-01-01

    We introduce a natural generalization of submodular set cover and exact active learning with a finite hypothesis class (query learning). We call this new problem interactive submodular set cover. Applications include advertising in social networks with hidden information. We give an approximation guarantee for a greedy algorithm and give a hardness of approximation result which matches up to constant factors. We also discuss the adaptivity gap for the problem and present encouraging early experimental results.

  8. Moxifloxacin-warfarin interaction

    Directory of Open Access Journals (Sweden)

    Yan Ji

    2012-01-01

    Full Text Available Two case reports presented here show elevated prothrombin time/international normalized ratios (PT/INR following coadministration of warfarin and moxifloxacin. Although the underlying mechanism of this interaction still remains unclear, health care providers should be careful when prescribing moxifloxacin to patients on warfarin therapy, especially to patients with low albumin levels. More frequent monitoring of INR in these patients may be warranted.

  9. Moxifloxacin-warfarin interaction

    OpenAIRE

    Ji, Yan; Hokayem, Youssef

    2012-01-01

    Two case reports presented here show elevated prothrombin time/international normalized ratios (PT/INR) following coadministration of warfarin and moxifloxacin. Although the underlying mechanism of this interaction still remains unclear, health care providers should be careful when prescribing moxifloxacin to patients on warfarin therapy, especially to patients with low albumin levels. More frequent monitoring of INR in these patients may be warranted.Keywords: warfarin; moxifloxacin; PT/INR;...

  10. Structural control interaction

    Science.gov (United States)

    Ryan, R. S.; Mowery, D. K.; Winder, S. W.; Worley, H. E.

    1973-01-01

    The basic guidance and control concepts that lead to structural control interaction and structural dynamic loads are identified. Space vehicle ascent flight load sources and the load relieving mechanism are discussed, along with the the characteristics and special problems of both present and future space vehicles including launch vehicles, orbiting vehicles, and the Space Shuttle flyback vehicle. The special dynamics and control analyses and test problems apparent at this time are summarized.

  11. Interactions faibles en harmonie

    CERN Multimedia

    1978-01-01

    Des résultats de haute précision obtenus à Stanford ouvrent la voie vers une unification des interactions faible et électromagnétique ; Présentation à la Conférence neutrino d'Oxford de nouveaux résultats en accord avec la théorie de la synthèse des forces faible et électro- magnétique

  12. Electric hydraulic interaction

    OpenAIRE

    Helle, Ola Høydal

    2011-01-01

    The hydraulic models representing hydro turbines and conduit system found instandard model libraries of power system analysis tools are often simplied mod-els. Subsequently, important information about the dynamics of the hydraulicsystem may not be properly represented by such models, putatively resultingin insucient representation of the interaction between the electric system andhydraulic system.In this master thesis three dierent hydraulic models for hydro power plantsequipped with Francis...

  13. Question answering and interactions

    OpenAIRE

    Séjourné, Kévin

    2009-01-01

    The question answering systems monolingual or multilingual allow to look in a large collection of documents (of journalistic type for example), or on Web an answer specified to a question. However, there is no possible interaction after the answer: we cannot ask for a precision, modify the question. Now often the answer cannot be directly brought ( too indistinct question), or is not completely satisfactory for the user. The subject of the thesis consists in spreading these works so as to all...

  14. Wave-Ice interaction

    Institute of Scientific and Technical Information of China (English)

    沈奚海莉

    2001-01-01

    The growth and movement of sea ice cover are influenced by the presence of wave field. Inturn, the wave field is influenced by the presence of ice cover. Their interaction is not fully understood.In this paper, we discuss some current understanding on wave attenuation when it propagates through frag-mented ice cover, ice drift due to the wave motion, and the growth characteristics of ice cover in wave field.

  15. [Unexpected drug-interaction].

    Science.gov (United States)

    Tajima, Yutaka

    2002-02-01

    The case of a male patient suffering from chronic normal pressure hydrocephalus is outlined. Antidepressant and pravastatin were administered because of the patient's abulia and hypercholesterolemia, but neuroleptic malignant syndrome-like conditions developed. All physicians should suppose the occurrence of such an "unexpected drug-interaction" in any case. The author considered that a good sense of careful discernment and rapid reference system of medical information are "essential tools" for clinical management. PMID:11925849

  16. Antinucleon-nucleus interactions

    Energy Technology Data Exchange (ETDEWEB)

    Dover, C.B.

    1987-01-01

    Recent experimental and theoretical results on anti p-nucleus interactions are reviewed. We focus on determinations of the anti p optical potential from elastic scattering, the use of (anti p, anti p') inelastic scattering to reveal aspects of the spin-isospin dependence of N anti N amplitudes, and some puzzling features of (anti p, anti n) charge exchange reactions on nuclei. 47 refs., 7 figs.

  17. SEEPAGE/INVERT INTERACTIONS

    International Nuclear Information System (INIS)

    As directed by a written development plan (CRWMS M andO 1999a), a conceptual model for water entering the drift and reacting with the invert materials is to be developed. The purpose of this conceptual model is to assist Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift, thus allowing PAO to provide a more detailed and complete in-drift geochemical model abstraction, and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near-Field Environment (NFE), Revision 2 (NRC 1999). This AMR also seeks to: (1) Develop a logical conceptual model for physical/chemical interactions between seepage and the invert materials; (2) screen potential processes and reactions that may occur between seepage and invert to evaluate the potential consequences of the interactions; and (3) outline how seepage/invert processes may be quantified. This document provides the conceptual framework for screening out insignificant processes and for identifying and evaluating those seepage/invert interactions that have the potential to be important to subsequent PAO analyses including the Engineered Barrier System (EBS) physical and chemical model abstraction effort. This model has been developed to serve as a basis for the in-drift geochemical analyses performed by PAO. Additionally, the concepts discussed within this report may also apply to certain near and far-field geochemical processes and may have conceptual application within the unsaturated zone (UZ) and saturated zone (SZ) transport modeling efforts. The seepage/invert interactions will not directly affect any principal factors

  18. Interactive Video Search

    OpenAIRE

    Schoeffmann, Klaus; Hopfgartner, Frank

    2015-01-01

    With an increasing amount of video data in our daily life, the need for content-based search in videos increases as well. Though a lot of research has been spent on video retrieval tools and methods which allow for automatic search in videos through content-based queries, still the performance of automatic video retrieval is far from optimal. In this tutorial we discussed (i) proposed solutions for improved video content navigation, (ii) typical interaction of content-based querying features,...

  19. Protein-surfactant interactions

    OpenAIRE

    Valstar, Ank

    2000-01-01

    Protein-surfactant interactions in aqueous media have been investigated. The globular proteins lysozyme and bovine serum albumin (BSA) served as model proteins. Several ionic and non-ionic surfactants were used. Fluorescence probe measurements showed that at low sodium dodecyl sulfate (SDS) concentration (< 0.1 M) one micelle-like SDS cluster is bound to lysozyme. From dynamic light scattering (DLS) results it was observed that lysozyme in the complex does not correspond to the fully unfol...

  20. Hydrophobic interaction chromatography

    OpenAIRE

    O'Connor, Brendan; Cummins, Phil

    2011-01-01

    Most proteins and large polypeptides have hydrophobic regions at their surface. These hydrophobic ‘patches’ are due to the presence of the side chains of hydrophobic or non-polar amino acids such as phenylalanine, tryptophan, alanine and methionine. These surface hydrophobic regions are interspersed between more hydrophilic or polar regions and the number, size and distribution of them is a specific characteristic of each protein. Hydrophobic Interaction Chromatography (HIC) is a commonly use...

  1. Interactions within wastewater systems

    OpenAIRE

    Langeveld, J.G.

    2004-01-01

    Wastewater systems consist of sewer systems and wastewater treatment works. As the performance of a wastewater treatment plant is affected by the characteristics, i.e. operation and design, of the contributing sewer systems, knowledge of the interactions between sewers and wastewater treatment works is very important when trying to understand and improve wastewater systems. The thesis comprises three main topics: Firstly, the sensitivity of wastewater treatment plant performance to influent f...

  2. Interactive tabletops in education

    OpenAIRE

    Dillenbourg, Pierre; Evans, Michael

    2011-01-01

    Interactive tabletops are gaining increased attention from CSCL researchers. This paper analyses the relation between this technology and teaching and learning processes. At a global level, one could argue that tabletops convey a socio-constructivist flavor: they support small teams that solve problems by exploring multiple solutions. The development of tabletop applications also witnesses the growing importance of face-to-face collaboration in CSCL and acknowledges the physicality of learnin...

  3. Interaction, Relationships And Networks

    OpenAIRE

    Benson-Rea, M

    1999-01-01

    This paper presents four case studies which have been selected to represent different insights into the strategic evaluation of relationships within one industry. From an analysis of how each of the case study firms has formed its networks of relationships, within its overall approach to industry strategy, we discuss how the interactions are evaluated, with a particular emergent focus on social or actor bonds. The strategy literature models strategy formation processes and content. The networ...

  4. Interaction Graphs: Exponentials

    OpenAIRE

    Seiller, Thomas

    2013-01-01

    This paper is the fourth of a series exposing a systematic combinatorial approach to Girard's Geometry of Interaction program. This program aims at obtaining particular realizability models for linear logic that accounts for the dynamics of cut-elimination. This fourth paper tackles the complex issue of defining exponential connectives in this framework. In order to succeed in this, we use the notion of graphings, a generalization of graphs which was defined in earlier work. We explain how we...

  5. ELEMENTARY PARTICLE INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    EFREMENKO, YURI; HANDLER, THOMAS; KAMYSHKOV, YURI; SIOPSIS, GEORGE; SPANIER, STEFAN

    2013-07-30

    The High-Energy Elementary Particle Interactions group at UT during the last three years worked on the following directions and projects: Collider-based Particle Physics; Neutrino Physics, particularly participation in “NOνA”, “Double Chooz”, and “KamLAND” neutrino experiments; and Theory, including Scattering amplitudes, Quark-gluon plasma; Holographic cosmology; Holographic superconductors; Charge density waves; Striped superconductors; and Holographic FFLO states.

  6. Model of dynamic interactions

    OpenAIRE

    Klimchik, Alexandr; Pashkevich, Anatol; Caro, Stéphane

    2013-01-01

    In robotic-based machining, an interaction between the workpiece and technological tool causes essential deflections that significantly decrease the manufacturing accuracy. Relevant compliance errors highly depend on the manipulator configuration and essentially differ throughout the workspace. Their influence is especially important for heavy serial robots. To overcome this difficulty this report presents a new technique for compensation of the compliance errors caused by technological proce...

  7. Interactive Mediated Reality

    OpenAIRE

    Grasset, Raphaël; Boissieux, Laurence; Gascuel, Jean-Dominique; Schmalstieg, Dieter

    2005-01-01

    International audience Mediated reality describes the concept of filtering our vision of reality, typically using a head-mounted video mixing display. We can redefine this idea in a more constructive context, applying dynamic changes to the appearance and geometry of objects in a real scene using computer graphics. In this paper, we propose new tools for interactively mediated reality. After describing a new generic framework for achieving this goal, we present a prototype system for paint...

  8. Matrix string interactions

    OpenAIRE

    Periwal, Vipul; Tafjord, Oyvind

    1998-01-01

    String configurations have been identified in compactified Matrix theory at vanishing string coupling. We show how the interactions of these strings are determined by the Yang-Mills gauge field on the worldsheet. At finite string coupling, this suggests the underlying dynamics is not well-approximated as a theory of strings. This may explain why string perturbation theory diverges badly, while Matrix string perturbation theory presumably has a perturbative expansion with properties similar to...

  9. Between autonomy and interaction

    DEFF Research Database (Denmark)

    Verwohlt, Betina

    In 2007, a smoking law was implemented in Denmark, banning indoor tobacco smoke in public places such as pubs, restaurants, workplaces, public offices, hospitals and shopping malls. The law marks a paradigm shift in Danish tobacco policy manifesting a stronger structural focus than has been the c...... attitudes towards structural initiatives before and after the implementation and discusses what causes changes in the population’s attitudes and whether the attitudes are best described as autonomous or as interactive with societal changes....

  10. Interactive Mathematics Textbooks

    DEFF Research Database (Denmark)

    Sinclair, Robert

    1999-01-01

    We claim that important considerations have been overlooked in designinginteractive mathematics educational software in the past.In particular,most previous work has concentrated on how to make use ofpre-existing software in mathematics education, rather than firstasking the more...... fundamentalquestion of which requirements mathematics education puts on software, and thendesigning software to fulfil these requirements.We present a working prototype system which takes a script defining an interactivemathematicaldocument and then provides a reader with an interactive realization of thatdocument....

  11. Dynamics of interacting quintessence

    International Nuclear Information System (INIS)

    In this paper,we investigate coupled quintessence with scaling potential assuming specific forms of the coupling as A namely, αρm, βρφ and σ(ρm + ρφ), and present phase space analysis for three different interacting models. We focus on the attractor solutions that can give rise to late time acceleration with ΩDE/ΩDM of order unity in order to alleviate the coincidence problem. (orig.)

  12. Interactive Chemical Reactivity Exploration

    OpenAIRE

    Haag, Moritz P.; Vaucher, Alain C.; Bosson, Mael; Redon, Stephane; Reiher, Markus

    2014-01-01

    Elucidating chemical reactivity in complex molecular assemblies of a few hundred atoms is, despite the remarkable progress in quantum chemistry, still a major challenge. Black-box search methods to find intermediates and transition-state structures might fail in such situations because of the high-dimensionality of the potential energy surface. Here, we propose the concept of interactive chemical reactivity exploration to effectively introduce the chemist's intuition into the search process. ...

  13. Orbital interactions in chemistry

    CERN Document Server

    Albright, Thomas A; Whangbo, Myung-Hwan

    2013-01-01

    Explains the underlying structure that unites all disciplines in chemistry Now in its second edition, this book explores organic, organometallic, inorganic, solid state, and materials chemistry, demonstrating how common molecular orbital situations arise throughout the whole chemical spectrum. The authors explore the relationships that enable readers to grasp the theory that underlies and connects traditional fields of study within chemistry, thereby providing a conceptual framework with which to think about chemical structure and reactivity problems. Orbital Interactions

  14. Interacting Dark Energy

    OpenAIRE

    Zhang, Xinmin

    2004-01-01

    In this paper I discuss some of the phenomenologies of models of the dark energy interacting with the ordinary matter. After a very brief review about the current constraint on the equation of the state of the dark energy from the SN and a new scenario of dark energy {\\it the Quintom}, I present models of Quintessential Baryo(Lepto)genesis, Quintessino dark matter and mass varying neutrinos in details.

  15. Interacting Multiview Tracker.

    Science.gov (United States)

    Yoon, Ju Hong; Yang, Ming-Hsuan; Yoon, Kuk-Jin

    2016-05-01

    A robust algorithm is proposed for tracking a target object in dynamic conditions including motion blurs, illumination changes, pose variations, and occlusions. To cope with these challenging factors, multiple trackers based on different feature representations are integrated within a probabilistic framework. Each view of the proposed multiview (multi-channel) feature learning algorithm is concerned with one particular feature representation of a target object from which a tracker is developed with different levels of reliability. With the multiple trackers, the proposed algorithm exploits tracker interaction and selection for robust tracking performance. In the tracker interaction, a transition probability matrix is used to estimate dependencies between trackers. Multiple trackers communicate with each other by sharing information of sample distributions. The tracker selection process determines the most reliable tracker with the highest probability. To account for object appearance changes, the transition probability matrix and tracker probability are updated in a recursive Bayesian framework by reflecting the tracker reliability measured by a robust tracker likelihood function that learns to account for both transient and stable appearance changes. Experimental results on benchmark datasets demonstrate that the proposed interacting multiview algorithm performs robustly and favorably against state-of-the-art methods in terms of several quantitative metrics. PMID:26336117

  16. AGNs and galaxy interactions

    CERN Document Server

    Alonso, M S; Tissera, P; Coldwell, G; Lambas, Diego G.; Tissera, Patricia; Coldwell, Georgina

    2007-01-01

    We perform a statistical analysis of AGN host characteristics and nuclear activity for AGNs in pairs and without companions. Our study concerns a sample of AGNs derived from the SDSS-DR4 data by Kauffmann et al (2003) and pair galaxies obtained from the same data set by Alonso et al. (2006). An eye-ball classification of images of 1607 close pairs ($r_p<25$ kpc $h^{-1}$, $\\Delta V<350$ km $s^{-1}$) according to the evidence of interaction through distorted morphologies and tidal features provides us with a more confident assessment of galaxy interactions from this sample. We notice that, at a given luminosity or stellar mass content, the fraction of AGNs is larger for pair galaxies exhibiting evidence for strong interaction and tidal features which also show sings of strong star formation activity. Nevertheless, this process accounts only for a $\\sim 10%$ increase of the fraction of AGNs. As in previous works, we find AGN hosts to be redder and with a larger concentration morphological index than non-AG...

  17. Drug interactions with grapefruit

    Directory of Open Access Journals (Sweden)

    Bojanić Vladmila V.

    2010-01-01

    Full Text Available Introduction. The concentration of many orally given medications may be affected by grapefruit or grapefruit juice consumption. It may result in numerous harmful effects. Interaction of grapefruit with drugs. Taking only one cup of juice may induce interactions with different drugs even during the period of a few days. The effect is induced by suppression of cytochrome P450 isoenzyme CYP3A4 in the intestinal wall. The Latin name of grapefruit, Citrus paradisi, is quite opposite to the effects which could be induced by taking grapefruit and some medications at the same time. It is necessary to avoid taking grapefruit with the drugs whose pharmacokinetics could be altered by the active principles found in that fruit. Discussion. The coloured grapefruit contains less furanocoumarins, but there is no difference in induction and intensity of pharmacokinetic interaction with drugs related to its colour. Other citrus fruits (orange, lemon do not have such effects, but some other fruits (pomegranate, stella fruit, banpeiyu, hassaku, takaoka-buntan and kinkan exert inhibitory effects on the activity of cytochrome P450 isoenzyme.

  18. Web Interactive Campus Map

    Directory of Open Access Journals (Sweden)

    Marylene S. Eder

    2015-03-01

    Full Text Available Abstract Interactive campus map is a web based application that can be accessed through a web browser. With the Google Map Application Programming Interface availability of the overlay function has been taken advantage to create custom map functionalities. Collection of building points were gathered for routing and to create polygons which serves as a representation of each building. The previous campus map provides a static visual representation of the campus. It uses legends building name and its corresponding building number in providing information. Due to its limited capabilities it became a realization to the researchers to create an interactive campus map.Storing data about the building room and staff information and university events and campus guide are among the primary features that this study has to offer. Interactive Web-based Campus Information System is intended in providing a Campus Information System.It is open to constant updates user-friendly for both trained and untrained users and capable of responding to all needs of users and carrying out analyses. Based on the data gathered through questionnaires researchers analyzed the results of the test survey and proved that the system is user friendly deliver information to users and the important features that the students expect.

  19. Transactional interactive multimedia banner

    Science.gov (United States)

    Shae, Zon-Yin; Wang, Xiping; von Kaenel, Juerg

    2000-05-01

    Advertising in TV broadcasting has shown that multimedia is a very effective means to present merchandise and attract shoppers. This has been applied to the Web by including animated multimedia banner ads on web pages. However, the issues of coupling interactive browsing, shopping, and secure transactions e.g. from inside a multimedia banner, have only recently started to being explored. Currently there is an explosively growing amount of back-end services available (e.g., business to business commerce (B2B), business to consumer (B2C) commerce, and infomercial services) in the Internet. These services are mostly accessible through static HTML web pages at a few specific web portals. In this paper, we will investigate the feasibility of using interactive multimedia banners as pervasive access point for the B2C, B2B, and infomercial services. We present a system architecture that involves a layer of middleware agents functioning as the bridge between the interactive multimedia banners and back-end services.

  20. Intercultural Interaction and Handicrafts

    Directory of Open Access Journals (Sweden)

    Mine CAN

    2015-07-01

    Full Text Available Technological developments in the world since the mid - 20th century, has increased intercultural communication and the whole world today has been informed of the existence of societies even in the most remote corners of the world. With increase in globaliza tion in cultural context, the importance of local differences has emerged more today. As a result, a process has initiated in which the similarities with differences, localization with the universalization and modernization with the tradition experienced s imutaneously and intercultural interaction has become inevitable and a natural phenomenon. However, handicrafts has been affected by cultural interactions negatively and the mistakes done caused the national culture and identities to weaken. For this reaso n, the necessity of experience of changing and developing in the frame of development with identity, transformation and cultural heritage today is emphasized. To be protected from the negative effects of the global interaction, many government produce prot ection and sustenance contracts, laws and projects by engaging in various initiatives. In the study, subjects is discussed with the examples of successful countries that aim to promote their local cultures globally and provide income.

  1. Asynchronous interactive control systems

    Science.gov (United States)

    Vuskovic, M. I.; Heer, E.

    1980-01-01

    A class of interactive control systems is derived by generalizing interactive manipulator control systems. The general structural properties of such systems are discussed and an appropriate general software implementation is proposed. This is based on the fact that tasks of interactive control systems can be represented as a network of a finite set of actions which have specific operational characteristics and specific resource requirements, and which are of limited duration. This has enabled the decomposition of the overall control algorithm into a set of subalgorithms, called subcontrollers, which can operate simultaneously and asynchronously. Coordinate transformations of sensor feedback data and actuator set-points have enabled the further simplification of the subcontrollers and have reduced their conflicting resource requirements. The modules of the decomposed control system are implemented as parallel processes with disjoint memory space communicating only by I/O. The synchronization mechanisms for dynamic resource allocation among subcontrollers and other synchronization mechanisms are also discussed in this paper. Such a software organization is suitable for the general form of multiprocessing using computer networks with distributed storage.

  2. Designing an interactive multimedia instructional environment: The Civil War Interactive

    OpenAIRE

    Ward M. Cates; Fontana, Lynn A.; Charles S. White

    1993-01-01

    This article describes the rationales behind the design decisions made in creating The Civil War Interactive, an interactive multimedia instructional product based on Ken Burns''s film series The Civil War.DOI:10.1080/0968776930010202

  3. Michigan molecular interactions r2: from interacting proteins to pathways

    OpenAIRE

    Tarcea, V. Glenn; Weymouth, Terry; Ade, Alex; Bookvich, Aaron; Gao, Jing; Mahavisno, Vasudeva; Wright, Zach; Chapman, Adriane; Jayapandian, Magesh; Özgür, Arzucan; Tian, Yuanyuan; Cavalcoli, Jim; Mirel, Barbara; Patel, Jignesh; Radev, Dragomir

    2008-01-01

    Molecular interaction data exists in a number of repositories, each with its own data format, molecule identifier and information coverage. Michigan molecular interactions (MiMI) assists scientists searching through this profusion of molecular interaction data. The original release of MiMI gathered data from well-known protein interaction databases, and deep merged this information while keeping track of provenance. Based on the feedback received from users, MiMI has been completely redesigne...

  4. Scattering with absorptive interaction

    Science.gov (United States)

    Cassing, W.; Stingl, M.; Weiguny, A.

    1982-07-01

    The S matrix for a wide class of complex and nonlocal potentials is studied, with special attention given to the motion of singularities in the complex k plane as a function of the imaginary coupling strength. Modifications of Levinson's theorem are obtained and discussed. Analytic approximations to the S matrix in the vicinity of narrow resonances are exhibited and compared to numerical results of resonating-group calculations. The problem of defining resonances in the case of complex interactions is discussed, making contact with the usual analysis of scattering in terms of Argand diagrams. NUCLEAR REACTIONS Scattering theory, S matrix for absorptive potentials.

  5. Laser-matter interaction

    International Nuclear Information System (INIS)

    A brief summary is given of the physics of the problem of laser-mater interaction. In the limit of very low intensities, the absorption is dominated by inverse bremsstrahlung. At higher intensities and in a homogeneous medium, there are several parametric processes that may become significant. The threshold intensities for the onset of several parametric instabilities are listed. Results for threshold intensities and growth rates just above threshold are briefly discussed for an inhomogeneous plasma. A brief description of resonance absorption in an inhomogeneous plasma is included. (author)

  6. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    The objective of our theoretical research under this grant over the past 3 years was to develop new understanding in a range of topics in the physics of dust-plasma interactions, with application to space and the laboratory. We conducted studies related to the physical properties of dust, waves and instabilities in both weakly coupled and strongly coupled dusty plasmas, and innovative possible applications. A major consideration in our choice of topics was to compare theory with experiments or observations, and to motivate new experiments, which we believe is important for developing this relatively new field. Our research is summarized, with reference to our list of journal publications.

  7. Flavivirus-Mosquito Interactions

    Directory of Open Access Journals (Sweden)

    Yan-Jang S. Huang

    2014-11-01

    Full Text Available The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1–4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations.

  8. Anomalous gauge boson interactions

    International Nuclear Information System (INIS)

    We discuss the direct measurement of the trilinear vector boson couplings in present and future collider experiments. The major goals of such experiments will be the confirmation of the Standard Model (SM) predictions and the search for signals of new physics. We review our current theoretical understanding of anomalous trilinear gauge-boson self interactions. If the energy scale of the new physics is ∼ 1 TeV, these low energy anomalous couplings are expected to be no larger than Ο(10-2). Constraints from high precision measurements at LEP and low energy charged and neutral current processes are critically reviewed

  9. Interaction, transference, and subjectivity

    DEFF Research Database (Denmark)

    Lundgaard Andersen, Linda

    2012-01-01

    is also subjected to psychodynamic processes. In this article, I draw upon a number of research inquiries to illustrate how psychodynamic processes influence research processes: data production, research questions and methodology, relations to informants, as well as interpretation and analysis. I further...... are important filters for fieldwork. In general, fieldwork can be understood as processes where field reports and field analysis are determined by how the researcher interacts with and experiences the field, the events and informants in it, and how she subsequently develops an ethnography. However, fieldwork...

  10. Student interaction in workshops

    DEFF Research Database (Denmark)

    Evers, Winie

    2014-01-01

    A kind of teaching for active learning has been experimented with at SDU Sønderborg as part of the course Supply Chain Dynamics. In this course the students learn about complex systems, system dynamics as well as supply chain instability and oscillation, the course lecturer invited the author to...... experiment with novel workshop methods and techniques, where objects are used to illustrate and model business issues (Heinemann et al, 2011, Buur et al, 2013). The idea was to see how students could be engaged in a different and more interactive way to learn about these topics, by assigning the students a...

  11. Human Work Interaction Design

    DEFF Research Database (Denmark)

    Gonçalves, Frederica; Campos, Pedro; Clemmensen, Torkil

    2015-01-01

    In this paper, we review research in the emerging practice and research field of Human Work Interaction Design (HWID). We present a HWID framework, and a sample of 54 HWID related papers from workshops, conferences and journals from the period 2009–2014. We group the papers into six topical groups......, and then attempt to map these groups to the framework to find research gaps for future research. We find that the groups of papers cover all areas of the framework well for a variety of work and leisure domains. The area in strongest need for more research papers is the development of the holistic...... for research in prototyping and early organizational implementation...

  12. Alignment in hadronic interactions

    CERN Document Server

    Wibig, T

    2000-01-01

    The alignment of the products of very high energy interactions seen in mountain altitude experiments is one of the most puzzling phenomena in cosmic ray physics for quite a long time. The observations of the Pamir and Chacaltaya emulsion chamber groups and by the Tien-Shan extensive air shower experiment, together with a very clear event seen in the Concorde French-Japanese experiment in the stratosphere, makes the experimental basis very substantial. In the present paper a novel possible explanation is put forward.

  13. Drugging Membrane Protein Interactions.

    Science.gov (United States)

    Yin, Hang; Flynn, Aaron D

    2016-07-11

    The majority of therapeutics target membrane proteins, accessible on the surface of cells, to alter cellular signaling. Cells use membrane proteins to transduce signals into cells, transport ions and molecules, bind cells to a surface or substrate, and catalyze reactions. Newly devised technologies allow us to drug conventionally "undruggable" regions of membrane proteins, enabling modulation of protein-protein, protein-lipid, and protein-nucleic acid interactions. In this review, we survey the state of the art of high-throughput screening and rational design in drug discovery, and we evaluate the advances in biological understanding and technological capacity that will drive pharmacotherapy forward against unorthodox membrane protein targets. PMID:26863923

  14. Interacting Galaxies with MOND

    OpenAIRE

    Tiret, O; Combes, F

    2007-01-01

    We compare N-body simulations performed in MOND with analogs in Newtonian gravity with dark matter (DM). We have developed a code which solves the Poisson equation in both gravity models. It is a grid solver using adaptive mesh refinement techniques, allowing us to study isolated galaxies as well as interacting galaxies. Galaxies in MOND are found to form bars faster and stronger than in the DM model. In Newton dynamics, it is difficult to reproduce the observed high frequency of strong bars,...

  15. Human Computer Interaction

    Science.gov (United States)

    Bhagwani, Akhilesh; Sengar, Chitransh; Talwaniper, Jyotsna; Sharma, Shaan

    2012-08-01

    The paper basically deals with the study of HCI (Human computer interaction) or BCI(Brain-Computer-Interfaces) Technology that can be used for capturing brain signals and translating them into commands that allow humans to control (just by thinking) devices such as computers, robots, rehabilitation technology and virtual reality environments. The HCI is based as a direct communication pathway between the brain and an external device. BCIs are often aimed at assisting, augmenting, or repairing human cognitive or sensory-motor functions.The paper also deals with many advantages of BCI Technology along with some of its applications and some major drawbacks.

  16. Interactive Architecture #1

    OpenAIRE

    Oosterhuis, K.; X. Xia

    2007-01-01

    The iA bookzine series will consist of twelve issues, bi-annually published over a period of six years under the supervision of Prof. ir. Kas Oosterhuis, director of the Hperbody at the Delft University of Technology. Interactive Architecture - from here on abbreviated as iA - is NOT simply architecture that is responsive or adaptive to changing circumstances. On the contrary, iA is based on the concept of bi-directional communication, which requires two active parties. Naturally, communicati...

  17. Detection of molecular interactions

    Science.gov (United States)

    Groves, John T.; Baksh, Michael M.; Jaros, Michal

    2012-02-14

    A method and assay are described for measuring the interaction between a ligand and an analyte. The assay can include a suspension of colloidal particles that are associated with a ligand of interest. The colloidal particles are maintained in the suspension at or near a phase transition state from a condensed phase to a dispersed phase. An analyte to be tested is then added to the suspension. If the analyte binds to the ligand, a phase change occurs to indicate that the binding was successful.

  18. Interaction of open graphic dynamics

    OpenAIRE

    Dugowson, Stéphane

    2015-01-01

    The aim of this paper is to define what we shall call open graphic dynamics, their interactions and the dynamics produced by those interactions. It prepares the study of "open sub-categorical dynamics" and "open categorical dynamics".

  19. Hydrophobic interactions and chemical reactivity

    OpenAIRE

    Otto, Sijbren; Engberts, Jan B.F.N.

    2003-01-01

    This perspective describes how kinetic studies of organic reactions can be used to increase our understanding of hydrophobic interactions. In turn, our understanding of hydrophobic interactions can be used as a tool to influence chemical reactions.

  20. User producer interaction in context

    NARCIS (Netherlands)

    Nahuis, R.; Moors, E.H.M.; Smits, R.E.H.M.

    2012-01-01

    User producer interaction (UPI) increases chances for successful innovations. It is not always clear, however, what type of interaction is necessary in a particular context. This article identifies seven different types of UPI: constructing linkages, broadening, characterizing users, upstream involv

  1. Hadronic Interactions with Lattice QCD

    OpenAIRE

    Savage, Martin J.

    2008-01-01

    I discuss recent results of the NPLQCD Collaboration regarding the calculation of hadronic interactions with lattice QCD. A particular emphasis will be spent on pi-pi scattering and other meson interactions.

  2. Interaction in English Classroom Teaching

    Institute of Scientific and Technical Information of China (English)

    金晶

    2009-01-01

    This essay mainly elaborates on the interaction in English classroom teaching.It highlights the indispensable role interaction should play in teaching process.and give out a series of methods on how to promote the application of this strategy.

  3. Interactions in Dark Energy Models

    OpenAIRE

    Zhang, Yi; Hui LI; Gong, Yungui; Zhu, Zong-Hong

    2011-01-01

    We perform a full dynamical analysis by considering the interactions between dark energy and radiation, and dark energy and dark matter. We find that the interaction helps alleviate the coincidence problem for the quintessence model.

  4. Charged Dust Aggregate Interactions

    Science.gov (United States)

    Matthews, Lorin; Hyde, Truell

    2015-11-01

    A proper understanding of the behavior of dust particle aggregates immersed in a complex plasma first requires a knowledge of the basic properties of the system. Among the most important of these are the net electrostatic charge and higher multipole moments on the dust aggregate as well as the manner in which the aggregate interacts with the local electrostatic fields. The formation of elongated, fractal-like aggregates levitating in the sheath electric field of a weakly ionized RF generated plasma discharge has recently been observed experimentally. The resulting data has shown that as aggregates approach one another, they can both accelerate and rotate. At equilibrium, aggregates are observed to levitate with regular spacing, rotating about their long axis aligned parallel to the sheath electric field. Since gas drag tends to slow any such rotation, energy must be constantly fed into the system in order to sustain it. A numerical model designed to analyze this motion provides both the electrostatic charge and higher multipole moments of the aggregate while including the forces due to thermophoresis, neutral gas drag, and the ion wakefield. This model will be used to investigate the ambient conditions leading to the observed interactions. This research is funded by NSF Grant 1414523.

  5. XEphem: Interactive Astronomical Ephemeris

    Science.gov (United States)

    Downey, Elwood Charles

    2011-12-01

    XEphem is a scientific-grade interactive astronomical ephemeris package for UNIX-like systems. Written in C, X11 and Motif, it is easily ported to systems. Among other things, XEphem: computes heliocentric, geocentric and topocentric information for all objects; has built-in support for all planets; the moons of Mars, Jupiter, Saturn, Uranus and Earth; central meridian longitude of Mars and Jupiter; Saturn's rings; and Jupiter's Great Red Spot; allows user-defined objects including stars, deepsky objects, asteroids, comets and Earth satellites; provides special efficient handling of large catalogs including Tycho, Hipparcos, GSC; displays data in configurable tabular formats in conjunction with several interactive graphical views; displays a night-at-a-glance 24 hour graphic showing when any selected objects are up; displays 3-D stereo Solar System views that are particularly well suited for visualizing comet trajectories; quickly finds all close pairs of objects in the sky; and sorts and prints all catalogs with very flexible criteria for creating custom observing lists. Its capabilities are listed more fully in the user manual introduction.

  6. Electromagnetic Interactions of Muons

    CERN Multimedia

    2002-01-01

    This experiment was the first in a programme of physics experiments with high-energy muons using a large spectrometer facility. The aim of this experiment is to study the inelastic scattering of muons various targets to try to understand better the physics of virtual photon interactions over a wide of four-momentum transfer (q|2).\\\\ \\\\ The spectrometer includes a large aperture dipole magnet (2m x 1m) of bending power @C 5 T.m and a magnetized iron filter to distinguish the scattered muons from hadrons. Drift chambers and MWPC are used before and after the magnet to detect charged products of the interaction and to allow a momentum determination of the scattered muon to an accuracy of @C 1\\% at 100 GeV/c, and an angular definition of @+ 0.1 mrad. The triggering on scattered muons relies on three planes of scintillation counter hodoscopes before and after the magnetized iron, whose magnetic field serves to eliminate triggers from low momentum muons which are produced copiously by pion decay. \\\\ \\\\ The experime...

  7. Interactive fundamental physics

    International Nuclear Information System (INIS)

    THE REAL STUFF is an Expanded Media Physics Course aimed at students still in the formative early years of secondary school. Its consists of a working script for an interactive multimedia study unit in basic concepts of physics. The unit begins with a prologue on the Big Bang that sets the stage, and concludes with a lesson on Newton's first law of motion. The format is interactive, placing the individual student in control of a layered ''hypermedia'' structure that enables him or her to find a level of detail and difficulty that is comfortable and meaningful. The intent is to make physics relevant, intellectually accessible and fun. On-screen presenters and demonstrators will be females and males of various ages, ethnicities and backgrounds, and will include celebrities and physicists of note. A lean, layered design encourages repeated, cumulative study and makes the material useful for self-directed Teaming even by college students. THE REAL STUFF introduces a new science teaching paradigm, a way to teach science that will engage even students who have ''declined'' to be interested in science in the past. Increased participation in science by women, African-Americans and Spanish-speaking students is a particular goal

  8. JSPAM: Interacting galaxies modeller

    Science.gov (United States)

    Wallin, John F.; Holincheck, Anthony; Harvey, Allen

    2015-11-01

    JSPAM models galaxy collisions using a restricted n-body approach to speed up computation. Instead of using a softened point-mass potential, the software supports a modified version of the three component potential created by Hernquist (1994, ApJS 86, 389). Although spherically symmetric gravitationally potentials and a Gaussian model for the bulge are used to increase computational efficiency, the potential mimics that of a fully consistent n-body model of a galaxy. Dynamical friction has been implemented in the code to improve the accuracy of close approaches between galaxies. Simulations using this code using thousands of particles over the typical interaction times of a galaxy interaction take a few seconds on modern desktop workstations, making it ideal for rapidly prototyping the dynamics of colliding galaxies. Extensive testing of the code has shown that it produces nearly identical tidal features to those from hierarchical tree codes such as Gadget but using a fraction of the computational resources. This code was used in the Galaxy Zoo: Mergers project and is very well suited for automated fitting of galaxy mergers with automated pattern fitting approaches such as genetic algorithms. Java and Fortran versions of the code are available.

  9. Microbiome and immunological interactions.

    Science.gov (United States)

    Kelly, Denise; Mulder, Imke E

    2012-08-01

    The healthy human gut supports a complex and diverse microbiota, dominated by bacterial phylotypes belonging to Bacteroidetes and Firmicutes. In the inflamed gut, overall diversity decreases, coincident with a greater representation of Proteobacteria. There is growing evidence supporting an important role for human gut bacteria in mucosal immunity; interactions at the level of both intestinal and colonic epithelial cells, dendritic cells, and T and B immune cells have been documented. These interactions influence gut barrier and defense mechanisms that include antimicrobial peptide and secretory IgA synthesis. The functional effects of commensal bacteria on T helper cell differentiation have led to the emerging concept that microbiota composition determines T effector- and T regulatory-cell balance, immune responsiveness, and homeostasis. The importance of this biology in relation to immune homeostasis, inflammatory bowel disease, and the rising incidence of autoimmune diseases will be discussed. The detailed description of the human gut microbiota, integrated with evidence-based mechanisms of immune modulation, provides an exciting platform for the identification of next-generation probiotics and related pharmaceutical products. PMID:22861803

  10. Crack interaction with microstructure

    Directory of Open Access Journals (Sweden)

    Sharvan Kumar

    2007-09-01

    Full Text Available Designing microstructure for damage tolerance requires a detailed understanding of how an advancing crack interacts with the microstructure (and sometimes modifies it locally at multiple length scales. Advances in experimental techniques, such as the availability of well-controlled straining stages for optical and electron microscopes, the focused ion beam, electron backscattered diffraction, and nanoindentation, enable probing at these length scales in real time and through interrupted tests. Simultaneously, increasing computational power coupled with new computational methods, such as finite element analysis (FEA incorporating cohesive elements at the continuum level, discrete dislocation methodology at the mesoscopic level, and coupled atomistic/continuum methods that transitions atomic level information to the mesoscopic level, have made it possible to begin addressing these complex problems. By reviewing crack growth in a variety of multiphase alloys including steels, titanium aluminides, Mo alloys, and nanocrystalline metals, we demonstrate various aspects of crack interaction with microstructure, and how these problems are being addressed through experiments and computations.

  11. Nucleon-antinucleon interaction

    International Nuclear Information System (INIS)

    The current status of our understanding of the low energy nucleon-antinucleon (N anti N) interaction is reviewed. We compare several phenomenological models which fit the available N anti N cross section data. The more realistic of these models employ an annihilation potential W(r) which is spin, isospin and energy dependent. The microscopic origins for these dependences are discussed in terms of quark rearrangement and annihilation processes. It is argued that the study of N anti N annihilation offers a powerful means of studying quark dynamics at short distances. We also discuss how one may try to isolate coherent meson exchange contributions to the medium and long range part of the N anti N potential. These pieces of the N anti N interaction are calculable via the G-parity transformation from a model for the NN potential; their effects are predicted to be seen in N anti N spin observables, to be measured at LEAR. The possible existence of quasi-stable bound states or resonances of the anti N plus one or more nucleons is discussed, with emphasis on few-body systems. 42 references

  12. The Interactive Zoooz Guide

    Directory of Open Access Journals (Sweden)

    Thang Nguyen

    2010-12-01

    Full Text Available GPS (Global Positioning System technology is widely known for its ability to track down devices in real time. Combined with mobile phones, it has become a very powerful tool with a great potential for future development of mobile GPS applications. The Interactive ZooOz Guide was a final year industry project carried out by seven students from three separate courses to tackle a project that involves upgrading the Melbourne Zoo’s mapping system through the use of GPS technology. The aim of the project is to explorethe potential capability of using GPS in the Zoo environment. The proposed system uses a PDA device with a GPS receiver that tracks users’ location in real time as they are touring around the Zoo. In this paper, an insight into GPS technology is briefly reviewed and the design and implementation of “Interactive ZooOZ Guide” is described. Then GUI (Graphical User Interface is presented in detail. Finally conclusion is drawn from the “proof of concept” prototype.

  13. Fuel-coolant interactions

    International Nuclear Information System (INIS)

    An important aspect of nuclear fuel behaviour that impacts on the fuel cycle is the interaction of the cladding with the coolant. In particular, the accumulation of deposited crud (corrosion products transported in the reactor coolant) on fuel element surfaces can severely hamper fuel performance by impeding heat transfer and promoting cladding corrosion, both of which may lead to fuel defects and the release of fission products and actinides to the primary coolant systems. Crud deposition is therefore an important consideration in reactor operation; it not only leads to poor performance and radiation field growth by exacerbating fuel defects but also serves as the source of radionuclides such as Co-60 which are major contaminants of out-reactor components. Furthermore, the sequestering of boron from the coolant by fuel deposits in PWRs can give rise to control problems as reactor flux characteristics are modified. As utilities apply the ALARA principle (As Low As Reasonably) to the management of occupational radiation doses and at the same time endeavour to optimise the fuel cycle, it becomes clear that an understanding of the mechanisms involved in coolant-cladding interactions is vital. There are several mechanisms of interest here. The source of crud is the fundamental corrosion process accruing on surfaces of the coolant system and the interaction of that process with local regimes of coolant flow. Accordingly, differences in the chemical and physical condition of the coolant across the reactor core and the steam generators are important factors in CANDUs and PWRs determining release of corrosion products from surfaces, while similar processes along the feedtrain influence crud levels in the reactor coolant in BWRs. The nature of suspended crud, which is determined by the materials of construction of the various components of the coolant system and the chemistry control of the coolant itself, determines the interaction with fuel cladding. Thus, crud in CANDUs

  14. MINT: the Molecular INTeraction database

    OpenAIRE

    Chatr-aryamontri, Andrew; Ceol, Arnaud; Palazzi, Luisa Montecchi; Nardelli, Giuliano; Schneider, Maria Victoria; Castagnoli, Luisa; Cesareni, Gianni

    2006-01-01

    The Molecular INTeraction database (MINT, ) aims at storing, in a structured format, information about molecular interactions (MIs) by extracting experimental details from work published in peer-reviewed journals. At present the MINT team focuses the curation work on physical interactions between proteins. Genetic or computationally inferred interactions are not included in the database. Over the past four years MINT has undergone extensive revision. The new version of MINT is based on a comp...

  15. The Discipline of Interactive Sonification

    OpenAIRE

    Hermann, Thomas; Hunt, Andy

    2004-01-01

    This paper argues for a special focus on the use of dynamic human interaction to explore datasets while they are being transformed into sound. We describe why this is a special case of both human computer interaction (HCI) techniques and sonification methods. Humans are adapted for interacting with their physical environment and making continuous use of all their senses. When this exploratory interaction is applied to a dataset (by continuously controlling its transformation into sound) new i...

  16. Phosphate Stabilization of Intermolecular Interactions

    OpenAIRE

    Jackson, Shelley N.; Wang, Hay-Yan J.; Yergey, Alfred; Woods, Amina S.

    2006-01-01

    Receptor heteromerization is an important phenomenon that results from the interaction of epitopes on two receptors. Previous studies have suggested the possibility of Dopamine D2- NMDA receptors’ interaction. We believe that the interaction is through an acidic epitope of the NMDA NR1 subunit (KVNSEEEEEDA) and a basic epitope of the D2 third intracellular loop (VLRRRRRKRVN), which was shown to also interact with the Adenosine A2A receptor. In previous work we highlighted the role of certain ...

  17. HUMAN INTERACTION WITH MOBILE APPLICATIONS

    OpenAIRE

    Alin Zamfiroiu; Emanuel Herteliu; Bogdan Vintila

    2012-01-01

    Computing - human interaction is a very important paradigm because informatics applications are created to be used by people via human interaction. Nowadays mobile applications are more used so is necessarily to talk about mobile - human interaction. In this paper types of mobile devices are presented. Citizen oriented character of mobile application and his utility are described. Different means of interactions with mobile devices are analyzed and in the end of the paper direction of mobile ...

  18. Design Principles for Interactive Software

    DEFF Research Database (Denmark)

    The book addresses the crucial intersection of human-computer interaction (HCI) and software engineering by asking both what users require from interactive systems and what developers need to produce well-engineered software. Needs are expressed as......The book addresses the crucial intersection of human-computer interaction (HCI) and software engineering by asking both what users require from interactive systems and what developers need to produce well-engineered software. Needs are expressed as...

  19. Household finances and social interaction

    OpenAIRE

    Brown, S; Taylor, K.

    2012-01-01

    In this paper, we investigate the relationship between social interaction and household finances using data from the British Household Panel Survey. We explore how social interaction influences the probability of holding different types of unsecured debt and assets, as well as how social interaction influences the levels of unsecured debt, financial assets and net worth held. Our findings suggest that social interaction has a positive influence upon the types of financial assets held, which i...

  20. Species interactions and plant polyploidy.

    Science.gov (United States)

    Segraves, Kari A; Anneberg, Thomas J

    2016-07-01

    Polyploidy is a common mode of speciation that can have far-reaching consequences for plant ecology and evolution. Because polyploidy can induce an array of phenotypic changes, there can be cascading effects on interactions with other species. These interactions, in turn, can have reciprocal effects on polyploid plants, potentially impacting their establishment and persistence. Although there is a wealth of information on the genetic and phenotypic effects of polyploidy, the study of species interactions in polyploid plants remains a comparatively young field. Here we reviewed the available evidence for how polyploidy may impact many types of species interactions that range from mutualism to antagonism. Specifically, we focused on three main questions: (1) Does polyploidy directly cause the formation of novel interactions not experienced by diploids, or does it create an opportunity for natural selection to then form novel interactions? (2) Does polyploidy cause consistent, predictable changes in species interactions vs. the evolution of idiosyncratic differences? (3) Does polyploidy lead to greater evolvability in species interactions? From the scarce evidence available, we found that novel interactions are rare but that polyploidy can induce changes in pollinator, herbivore, and pathogen interactions. Although further tests are needed, it is likely that selection following whole-genome duplication is important in all types of species interaction and that there are circumstances in which polyploidy can enhance the evolvability of interactions with other species. PMID:27370313

  1. Galaxy interactions : The HI signature

    NARCIS (Netherlands)

    Sancisi, R; Barnes, JE; Sanders, DB

    1999-01-01

    HI observations are an excellent tool for investigating tidal interactions. Ongoing major and minor interactions which can lead to traumatic mergers or to accretion and the triggering of star formation, show distinct HI signatures. Interactions and mergers in the recent past can also be recognized i

  2. Local Interaction on Random Graphs

    Directory of Open Access Journals (Sweden)

    Hans Haller

    2010-08-01

    Full Text Available We analyze dynamic local interaction in population games where the local interaction structure (modeled as a graph can change over time: A stochastic process generates a random sequence of graphs. This contrasts with models where the initial interaction structure (represented by a deterministic graph or the realization of a random graph cannot change over time.

  3. Quadratic spatial soliton interactions

    Science.gov (United States)

    Jankovic, Ladislav

    Quadratic spatial soliton interactions were investigated in this Dissertation. The first part deals with characterizing the principal features of multi-soliton generation and soliton self-reflection. The second deals with two beam processes leading to soliton interactions and collisions. These subjects were investigated both theoretically and experimentally. The experiments were performed by using potassium niobate (KNBO 3) and periodically poled potassium titanyl phosphate (KTP) crystals. These particular crystals were desirable for these experiments because of their large nonlinear coefficients and, more importantly, because the experiments could be performed under non-critical-phase-matching (NCPM) conditions. The single soliton generation measurements, performed on KNBO3 by launching the fundamental component only, showed a broad angular acceptance bandwidth which was important for the soliton collisions performed later. Furthermore, at high input intensities multi-soliton generation was observed for the first time. The influence on the multi-soliton patterns generated of the input intensity and beam symmetry was investigated. The combined experimental and theoretical efforts indicated that spatial and temporal noise on the input laser beam induced multi-soliton patterns. Another research direction pursued was intensity dependent soliton routing by using of a specially engineered quadratically nonlinear interface within a periodically poled KTP sample. This was the first time demonstration of the self-reflection phenomenon in a system with a quadratic nonlinearity. The feature investigated is believed to have a great potential for soliton routing and manipulation by engineered structures. A detailed investigation was conducted on two soliton interaction and collision processes. Birth of an additional soliton resulting from a two soliton collision was observed and characterized for the special case of a non-planar geometry. A small amount of spiraling, up to 30

  4. Human-Robot Interaction

    Science.gov (United States)

    Sandor, Aniko; Cross, E. Vincent, II; Chang, Mai Lee

    2015-01-01

    Human-robot interaction (HRI) is a discipline investigating the factors affecting the interactions between humans and robots. It is important to evaluate how the design of interfaces affect the human's ability to perform tasks effectively and efficiently when working with a robot. By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed to appropriately support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for the design of robotic systems. For efficient and effective remote navigation of a rover, a human operator needs to be aware of the robot's environment. However, during teleoperation, operators may get information about the environment only through a robot's front-mounted camera causing a keyhole effect. The keyhole effect reduces situation awareness which may manifest in navigation issues such as higher number of collisions, missing critical aspects of the environment, or reduced speed. One way to compensate for the keyhole effect and the ambiguities operators experience when they teleoperate a robot is adding multiple cameras and including the robot chassis in the camera view. Augmented reality, such as overlays, can also enhance the way a person sees objects in the environment or in camera views by making them more visible. Scenes can be augmented with integrated telemetry, procedures, or map information. Furthermore, the addition of an exocentric (i.e., third-person) field of view from a camera placed in the robot's environment may provide operators with the additional information needed to gain spatial awareness of the robot. Two research studies investigated possible mitigation approaches to address the keyhole effect: 1) combining the inclusion of the robot chassis in the camera view with augmented reality overlays, and 2) modifying the camera

  5. Cultivating objects in interaction

    DEFF Research Database (Denmark)

    Hazel, Spencer

    2014-01-01

    is chapter explores patterns of repeated orientations to physical objects in interactants’ visuo-spatial and haptic surround. A number of examples are presented from advice-giving activities in various institutional settings, where participants-in-interaction initially draw on material objects at...... hand while pursuing a particular line of explanation, and then return to these objects at later intervals. e analysis suggests that the objects are afforded representational properties through their being anchored to some referent in the talk, and that participants subsequently draw on these...... associations for describing, disambiguating or clarifying aspects of the relatively complex procedural frameworks discussed in the settings. is suggests that the temporal stability of material objects available to participants makes them an ideal resource to be developed as visual motifs....

  6. Interacting neural networks.

    Science.gov (United States)

    Metzler, R; Kinzel, W; Kanter, I

    2000-08-01

    Several scenarios of interacting neural networks which are trained either in an identical or in a competitive way are solved analytically. In the case of identical training each perceptron receives the output of its neighbor. The symmetry of the stationary state as well as the sensitivity to the used training algorithm are investigated. Two competitive perceptrons trained on mutually exclusive learning aims and a perceptron which is trained on the opposite of its own output are examined analytically. An ensemble of competitive perceptrons is used as decision-making algorithms in a model of a closed market (El Farol Bar problem or the Minority Game. In this game, a set of agents who have to make a binary decision is considered.); each network is trained on the history of minority decisions. This ensemble of perceptrons relaxes to a stationary state whose performance can be better than random. PMID:11088736

  7. Antigen antibody interactions

    CERN Document Server

    DeLisi, Charles

    1976-01-01

    1. 1 Organization of the Immune System One of the most important survival mechanisms of vertebrates is their ability to recognize and respond to the onslaught of pathogenic microbes to which they are conti- ously exposed. The collection of host cells and molecules involved in this recognition­ 12 response function constitutes its immune system. In man, it comprises about 10 cells 20 (lymphocytes) and 10 molecules (immunoglobulins). Its ontogenic development is c- strained by the requirement that it be capable of responding to an almost limitless variety of molecular configurations on foreign substances, while simultaneously remaining inert to those on self components. It has thus evolved to discriminate, with exquisite precision, between molecular patterns. The foreign substances which induce a response, called antigens, are typically large molecules such as proteins and polysaccharides. The portions of these with which immunoglobulins interact are called epitopes or determinants. A typical protein epitope m...

  8. Interactive molecular dynamics

    CERN Document Server

    Schroeder, Daniel V

    2015-01-01

    Physics students now have access to interactive molecular dynamics simulations that can model and animate the motions of hundreds of particles, such as noble gas atoms, that attract each other weakly at short distances but repel strongly when pressed together. Using these simulations, students can develop an understanding of forces and motions at the molecular scale, nonideal fluids, phases of matter, thermal equilibrium, nonequilibrium states, the Boltzmann distribution, the arrow of time, and much more. This article summarizes the basic features and capabilities of such a simulation, presents a variety of student exercises using it at the introductory and intermediate levels, and describes some enhancements that can further extend its uses. A working simulation code, in HTML5 and JavaScript for running within any modern Web browser, is provided as an online supplement.

  9. Interactive molecular dynamics

    Science.gov (United States)

    Schroeder, Daniel V.

    2015-03-01

    Physics students now have access to interactive molecular dynamics simulations that can model and animate the motions of hundreds of particles, such as noble gas atoms, that attract each other weakly at short distances but repel strongly when pressed together. Using these simulations, students can develop an understanding of forces and motions at the molecular scale, nonideal fluids, phases of matter, thermal equilibrium, nonequilibrium states, the Boltzmann distribution, the arrow of time, and much more. This article summarizes the basic features and capabilities of such a simulation, presents a variety of student exercises using it at the introductory and intermediate levels, and describes some enhancements that can further extend its uses. A working simulation code, in html5 and javascript for running within any modern Web browser, is provided as an online supplement.

  10. Human Work Interaction Design

    DEFF Research Database (Denmark)

    Gonçalves, Frederica; Campos, Pedro; Clemmensen, Torkil

    2015-01-01

    In this paper, we review research in the emerging practice and research field of Human Work Interaction Design (HWID). We present a HWID frame-work, and a sample of 54 papers from workshops, conferences and journals from the period 2009-2014. We group the papers into six topical groups, and then at......-tempt to map these groups to the framework to find research gaps for future re-search. We find that the groups of papers cover all areas of the framework well for a variety of work and leisure domains. The area in strongest need for more research papers is the development of the holistic framework itself....... Furthermore, much focus has been on studying design sketching or implemented systems-in-use, while little attention has been paid to mature design (prototypes) or early implementation (content templates). In conclusion, we recommend an update to the framework so that it can be also useful for research in...

  11. Interactive TV Narrativity

    Science.gov (United States)

    Ursu, Marian F.

    Looking back over the past 25 years, the impressive developments in information and communication technologies generated a booming popularity of the new forms of media consumption that allow for interactivity and mobility, such as Web information and entertainment and games. This was and still is particularly evident within the younger generation, who are the most avid adopters of both new technologies and new forms of media consumption (Schadler 2006; KPMG 2007). When asked, in 2006, which device they could not live without, 37% mentioned their PC, 26% their mobile phone, whereas only 17% mentioned their TVs (Schadler 2006); and all these were before the launch of products such as the iPhone, which offer increasing flexibility and mobility of the media experiences.

  12. Study of electroweak interactions

    International Nuclear Information System (INIS)

    The experimental study of electroweak interactions at Virginia Tech is multifaceted and consists of three parts. The first consists of analysis of the final states of matter produced in electron-positron annihilations at center-of-mass energies √s = 60 GeV at the TRISTAN collider in Japan (AMY). The second is a sensitive search for rare electroweak processes through a study of μ+ → e+γ at the LAMPF facility at Los Alamos (MEGA). It also includes a precise measurement of the Michel ρ parameter (RHO). The third activity is a R ampersand D detector development and is a precursor to anticipated experiments at proposed Bo meson factories in this country and/or abroad. The physics goals are the study of CP violation in the Bo system and the determination of the values for Kobayashi-Maskawa matrix

  13. Sustainable Buildings in Interaction

    DEFF Research Database (Denmark)

    Elle, Morten

    The first attempts to build sustainable buildings in Denmark were typically located on the countryside. The basic idea was to create buildings that were independent of the technical infrastructure. District heating has, however, been the dominating solution to heating in buildings in Denmark, and...... the focus on sustainable building have gradually turned from special houses on the countryside to normally looking houses in the urban fabric, integrated in the technical infrastructure. Some new built urban areas in Denmark will, however, not have to be supplied with district heating – these...... developments are going to consist of passive houses. The first sustainable buildings were built by their users, and the user – building interaction still play a decisive role for the performance of the present sustainable buildings. The users have to understand how the building functions. Urban design is...

  14. Universality in string interactions

    CERN Document Server

    Huang, Yu-tin; Wen, Congkao

    2016-01-01

    In this letter, we provide evidence for universality in the low-energy expansion of tree-level string interactions. More precisely, in the alpha'-expansion of tree-level scattering amplitudes, we conjecture that the leading transcendental coefficient at each order in alpha' is universal for all perturbative string theories. We have checked this universality up to seven points and trace its origin to the ability to restructure the disk integrals of open bosonic string into those of the superstring. The accompanying kinematic functions have the same low-energy limit and do not introduce any transcendental numbers in their alpha'-corrections. Universality in the closed-string sector then follows from the KLT-relations.

  15. Electroweak interactions at LEP

    International Nuclear Information System (INIS)

    Electroweak interaction at LEP are a subject based on a wealth of data, given the success of the CERN e+e- storage ring. The author will report on the results from the four experiments, ALEPH, DELPHI, L3 and OPAL after the analysis of about 1/2 of the data collected in 1989 and 1990. The review will cover the electroweak aspects of the process e+e- → Z* → f bar f where the fermions can be either quarks or leptons. The analysis of experimental data is based on the determination of the cross section integrated on the solid angle and on the asymmetry of forward-backward leptons in the final state. In this game the knowledge of the center mass energy is fundamental as the determination of the luminosity by which the event rate is normalized to compute the absolute cross section. Therefore a specific attention is given to these subjects

  16. The Interaction Programming Problem

    Institute of Scientific and Technical Information of China (English)

    LI Rong-sheng; CHENG Ying

    2001-01-01

    Based upon the research to the economic equilibrium problems, we present a kind of new mathematical programming problem-interaction programming problem (abbreviated by IPP). The IPP is composed of two or multiple parametric programming problems which is interrelated with each other. The IPP reflects the equality and mutual benefit relationship between two (or among multiple) economic planners in an economic system. In essence, the IPP is similar to the generalized Nash equilibria (GNE) game which has been given several names in the literature: social equilibria games, pseudo-Nash equilibria games, and equilibrium programming problems. In this paper, we establish the mathematical model and some basic concepts to the IPP. We investigate the structure and the properties of the IPP. We also give a necessary and sufficient conditions for the existence of the equilibrium points to a kind of linear IPP.

  17. Dark patterns in proxemic interactions

    DEFF Research Database (Denmark)

    Greenberg, Saul; Boring, Sebastian; Vermeulen, Jo; Dostal, Jakub

    2014-01-01

    easily exploited to the detriment of the user. In this paper, we offer a critical perspective on proxemic interactions in the form of dark patterns: ways proxemic interactions can be misused. We discuss a series of these patterns and describe how they apply to these types of interactions. In addition, we......Proxemics theory explains peoples' use of interpersonal distances to mediate their social interactions with others. Within Ubicomp, proxemic interaction researchers argue that people have a similar social understanding of their spatial relations with nearby digital devices, which can be exploited...

  18. Hadron nucleus interactions

    International Nuclear Information System (INIS)

    The elastic and inelastic scattering of intermediate energy (less than or equal to 1 GeV) protons by nuclei is considered first. The discussion focuses on the determination of the proton-nucleus optical potential in terms of the elementary nucleon-nucleon scattering amplitudes and the properties of the target and residual nucleus. The result is a series of terms for the optical potential. Then the interaction of pions with nuclei for energies in the neighborhood of the Δ-resonance is discussed. In this energy domain an incident pion will with high probability be absorbed by a nucleon to produce the Δ-resonance and thus form a Δ-particle hole state in the nucleus. Next, the subject of hypernuclei is taken up. The Λ hypernuclei and a recently observed Σ hypernuclei comprise situations in which the core nucleus can be probed by a baryon of roughly the same mass as a nucleon, with similar albeit not identical interactions with nucleons. But the Λ (or Σ) does not need to satisfy the Pauli exclusion principle with respect to the nucleons, and therefore can be in orbits forbidden to it if it were a nucleon. As the energy of the projectile increases, it becomes correspondingly more important to take relativistic effects into account. The importance of these effects is strikingly revealed by experiments involving the collision of ultrarelativistic hadrons, protons, pions, kaons (up to Fermilab energies) with nuclei. This phenomenon forms part of the final topic, which includes as well as the collision of relativistic heavy ion projectiles with nuclei. A nuclear Weiszaecker-Williams method developed for dealing with peripheral collisions is described. 32 figures, 10 tables

  19. HYDRODYNAMIC INTERACTIONS BETWEEN TWO BODIES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On the basis of model tests, potential flow theory, and viscous Computational Fluid Dynamics (CFD) method, the hydrodynamic interactions between two underwater bodies were investigated to determine the influencing factors, changing rule, interaction mechanism, and appropriate methods describing them. Some special phenomena were discovered in two series of near-wall interaction experiments. The mathematical model and predicting methods were presented for interacting forces near wall, and the calculation results agreed well with the experimental ones. From the comparisons among numerical results with respect to nonviscosity, numerical results with respect to viscosity, and measured results, data on the influence of viscosity on hydrodynamic interactions were obtained. For hydrodynamic interaction related to multi-body unsteady motions with six degrees of freedom that is difficult to simulate in tests, numerical predictions of unsteady interacting forces were given.

  20. Antiproton-nucleus interaction

    Science.gov (United States)

    Cugnon, J.; Vandermeulen, J.

    The antiproton-nucleus physics is reviewed. On the experimental side, the recent results obtained at the LEAR, BNL and KEK facilities are analyzed. A brief summary of the main pp and pn experimental data is also given. The antiproton-nucleus interaction can lead to elasic, inelastic and charge exchange scattering and to annihilation. The latter is very dominant. The scattering cross-sections are usually analyzed in terms of complex potential models. The relationship between potentials, charge conjugation and Dirac phenomenology is discussed. Much emphasis is put on the dynamics of the antiproton annihilation on nuclei. The energy transfer, pion absorption and target response are analyzed within the intranuclear cascade model. Special interest is devoted to strangeness production, hypernucleus formation and possible annihilation on two nucleons. Signatures for this new process are searched in experimental data. Finally, the highly debated question of quark-gluon formation is analyzed. Cet article constitue une revue de la physique antiproton-noyau. Du point de vue expérimental, cette revue porte particulièrement sur les récents résultats obtenus à LEAR, BNL et KEK. On y a aussi inclus une mise à jour des faits expérimentaux principaux pour pp et pn. L'interaction antiproton-noyau conduit à la diffusion élastique, inélastique et d'xA9change de charge et à des processus d'annihilation. Habituellement, les expériences de diffusion sont analysées en termes de potentiels complexes. La relation entre ces potentiels, la conjugaison de charge et la phénoménologie de Dirac est discutée. On s'est particulièrement intéressé à la dynamique de l'annihilation d'antiprotons sur des noyaux. Le transfert d'énergie, l'absorption de pions et la réponse de la cible sont analysés dans le cadre du modèle de cascade intranucléaire. Certains autres points sont discutés plus en détail: la production d'étrangeté, la formation d'hypernoyaux et l'annihilation sur

  1. Interactive Data Eyeslasses

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The data eyeglasses can read from the engineer’s eyes which details he needs to see on the building plans.A CMOS chip with an eyetracker in the microdisplay makes this possible.The eyeglasses are connected to a PDA,display information and respond to commands.For car designers,secret agents in the movies and jet fighter pilots,data eyeglasses-also called head-mounted displays,orHMDs for short-are everyday objects.They transport the wearer into virtual worlds or provide the user with data from the real environment.At present these devices can only display information."We want to make the eyeglasses bidirectional and interactive so thatnew areas of application can be opened up,"says Dr.Michael Scholles,business unit manager at the Fraunhofer Institute for PhotonicMicrosystems IPMS in Dresden.A group of scientists at IPMS is working on a device which incorporates eye tracking-users can influence the content presented by moving their eyes or fixing on certain points in the image.Without having to use any other devices to

  2. Wolbachia filarial interactions.

    Science.gov (United States)

    Taylor, Mark J; Voronin, Denis; Johnston, Kelly L; Ford, Louise

    2013-04-01

    Wolbachia pipientis is a widespread intracellular bacterial symbiont of arthropods and is common in insects. One of their more exotic and unexpected hosts is the filarial nematodes, notable for the parasites responsible for onchocerciasis (river blindness), lymphatic filariasis (elephantiasis) and dirofilariasis (heartworm). Wolbachia are only present in a subgroup of the filarial nematodes and do not extend to other groups of nematodes either parasitic or free-living. In the medically and veterinary important species that host Wolbachia, the symbiont has become an essential partner to key biological processes in the life of the nematode to the point where antibiotic elimination of the bacteria leads to a potent and effective anti-filarial drug treatment. We review the cellular and molecular basis of Wolbachia filarial interactions and highlight the key processes provided by the endosymbiont upon which the nematodes have become entirely dependent. This dependency is primarily restricted to periods of the lifecycle with heavy metabolic demands including growth and development of larval stages and embryogenesis in the adult female. Also, the longevity of filarial parasites is compromised following depletion of the symbiont, which for the first time has delivered a safe and effective treatment to kill adult parasites with antibiotics. PMID:23210448

  3. Dike/Drift Interactions

    International Nuclear Information System (INIS)

    This report documents the model of events associated with a potential intrusion of magma from a volcanic dike into a drift or drifts in the Yucca Mountain Nuclear Waste Repository. The following topics are included in this report: (1) A discussion of dike propagation, which provides the basis for describing the path that a representative dike, or swarm of dikes, would follow during an event. (2) A discussion of magma flow, which evaluates the interaction at the junction of the propagating dike with the drift and the movement of magmatic products into and down drifts and, potentially, through a drift to the surface by way of access drift or a secondary dike opened up along the drift. (3) A discussion of gas flow and conductive cooling of a magma-filled drift, describing how an adjacent drift that has not been intersected by a dike could be affected by post-intrusion phenomena. Note that a gas flow analysis is also addressed in ''Igneous Intrusion Impacts on Waste Form and Waste Packages'' (BSC 2003 [DIRS 161810]), and those results are consistent with the results presented in this report

  4. Copper/bentonite interaction

    International Nuclear Information System (INIS)

    The prediction of the processes and rate of corrosion of the KBS 2 copper canisters must be based on a proper scenario, which involves the physical state of the bentonite surrounding the canisters, and the chemical interaction between copper and bentonite. Literature data suggest slow Cu migration and Cu exchanging originally adsorbed cations. Two tests involving copper/bentonite contacts for 3 - 6 months in boreholes have yielded certain valuable information. Thus, Cu ion migration is indeed very slow and where it yields a sufficiently high concentration, it is associated with replacement of originally adsorbed Na ions, which should result in an increased permeability. In one of the tests the copper was separated from the bentonite by a partly air-filled slot. These conditions caused the formation of copper oxides and hydroxides which intermingled with the bentonite that expanded to fill the slot. Due to the low solubility of these copper compounds, the Cu ion concentration was too low to produce ion exchange during the time of observation. (Author)

  5. Influenza-Sediment Interactions

    Science.gov (United States)

    Trusiak, A.; Block, K. A.; Katz, A.; Gottlieb, P.; Alimova, A.; Galarza, J.; Wei, H.; Steiner, J. C.

    2013-12-01

    A typical water fowl can secrete 1012 influenza virions per day. Therefore it is not unexpected that influenza virions interact with sediments in the water column. The influence of sediments on avian influenza virions is not known. With the threat of avian influenza emerging into the human population, it is crucial to understand virus survivability and residence time in a body of water. Influenza and clay sediments are colloidal particles and thus aggregate as explained by DLVO (Derjaguin & Landau, Verwey & Overbeek) theory. Of great importance is an understanding of the types of particulate or macromolecular components that bind the virus particles, and whether the virus remains biologically active. We present results of hetero-aggregation and transmission electron microscopy experiments performed with influenza A/PR8/38. Influenza particles are suspended with sediment and minimal nutrients for several days, after which the components are evaluated to determine influenza concentration and survivability. Transmission electron microscopy results are reported on the influenza-sediment aggregates to elucidate structure and morphology of the components.

  6. Interacting boson approximation

    International Nuclear Information System (INIS)

    Lectures notes on the Interacting Boson Approximation are given. Topics include: angular momentum tensors; properties of T/sub i//sup (n)/ matrices; T/sub i//sup (n)/ matrices as Clebsch-Gordan coefficients; construction of higher rank tensors; normalization: trace of products of two s-rank tensors; completeness relation; algebra of U(N); eigenvalue of the quadratic Casimir operator for U(3); general result for U(N); angular momentum content of U(3) representation; p-Boson model; Hamiltonian; quadrupole transitions; S,P Boson model; expectation value of dipole operator; S-D model: U(6); quadratic Casimir operator; an O(5) subgroup; an O(6) subgroup; properties of O(5) representations; quadratic Casimir operator; quadratic Casimir operator for U(6); decomposition via SU(5) chain; a special O(3) decomposition of SU(3); useful identities; a useful property of D/sub αβγ/(α,β,γ = 4-8) as coupling coefficients; explicit construction of T/sub x//sup (2)/ and d/sub αβγ/; D-coefficients; eigenstates of T3; and summary of T = 2 states

  7. Strongly interacting ultracold polar molecules

    Science.gov (United States)

    Gadway, Bryce; Yan, Bo

    2016-08-01

    This paper reviews recent advances in the study of strongly interacting systems of dipolar molecules. Heteronuclear molecules feature large and tunable electric dipole moments, which give rise to long-range and anisotropic dipole–dipole interactions. Ultracold samples of dipolar molecules with long-range interactions offer a unique platform for quantum simulations and the study of correlated many-body physics. We provide an introduction to the physics of dipolar quantum gases, both electric and magnetic, and summarize the multipronged efforts to bring dipolar molecules into the quantum regime. We discuss in detail the recent experimental progress in realizing and studying strongly interacting systems of polar molecules trapped in optical lattices, with particular emphasis on the study of interacting spin systems and non-equilibrium quantum magnetism. Finally, we conclude with a brief discussion of the future prospects for studies of strongly interacting dipolar molecules.

  8. Strongly interacting ultracold polar molecules

    CERN Document Server

    Gadway, Bryce

    2016-01-01

    This paper reviews recent advances in the study of strongly interacting systems of dipolar molecules. Heteronuclear molecules feature large and tunable electric dipole moments, which give rise to long-range and anisotropic dipole-dipole interactions. Ultracold samples of dipolar molecules with long-range interactions offer a unique platform for quantum simulations and the study of correlated many-body physics. We provide an introduction to the physics of dipolar quantum gases, both electric and magnetic, and summarize the multipronged efforts to bring dipolar molecules into the quantum regime. We discuss in detail the recent experimental progress in realizing and studying strongly interacting systems of polar molecules trapped in optical lattices, with particular emphasis on the study of interacting spin systems and non-equilibrium quantum magnetism. Finally, we conclude with a brief discussion of the future prospects for studies of strongly interacting dipolar molecules.

  9. Animal-computer interaction SIG

    OpenAIRE

    Mancini, Clara; Lawson, Shaun; Van Der Linden, Janet; Häkkilä, Jonna; Noz, Frank; Juhlin, Oskar

    2012-01-01

    User-computer interaction research is demonstrating growing interest in the relation between animals and technology (e.g., computer-mediated interspecies interactions and animal-computer interfaces). However, as a research area, this topic is still underexplored and fragmented, and researchers lack opportunities to exchange ideas, identify resources, form collaborations and co-operatively develop a coherent research agenda. The Animal-Computer Interaction (ACI) SIG meeting aims to provide ...

  10. Interacting atoms in optical lattices

    OpenAIRE

    Mentink, Johan; Kokkelmans, Servaas

    2008-01-01

    We propose an easy to use model to solve for interacting atoms in an optical lattice. This model allows for the whole range of weakly to strongly interacting atoms, and it includes the coupling between relative and center-of-mass motion via anharmonic lattice terms. We apply this model to a high-precision spin dynamics experiment, and we discuss the corrections due to atomic interactions and the anharmonic coupling. Under suitable experimental conditions, energy can be transferred between the...

  11. Interaction themes in music therapy

    DEFF Research Database (Denmark)

    Holck, Ulla

    2004-01-01

    Based on a doctoral study, the author presents a type of music therapyinteraction called ?Interaction Themes.? These are developed fromsession to session and often appear in music therapy interventions withchildren with severe functional limitations, especially children withautism. Although...... whoseexpressions are often difficult to understand. The article describes thecharacteristics and functions of Interaction Themes, compares thephenomenon with music therapy case literature and delimits it in regardto other types of music therapy interaction with this client group. Theresults are described through...

  12. Pseudospin Conserving Shell Model Interactions

    OpenAIRE

    Ginocchio, Joseph N.

    2010-01-01

    Pseudospin symmetry is approximately conserved in nuclei. Normally shell model interactions are written in terms of spin an orbital angular momentum operators, not in terms of pseudospin and pseudo-orbital angular momentum operators. We determine the shell model interactions which conserve pseudospin symmetry and pseudo-orbital angular momentum symmetry and write them in terms of spin and orbital angular momentum operators including the tensor interaction. We show that, although the tensor in...

  13. Source Code Interaction on Touchscreens

    OpenAIRE

    Raab, Felix

    2016-01-01

    Direct interaction with touchscreens has become a primary way of using a device. This work seeks to devise interaction methods for editing textual source code on touch-enabled devices. With the advent of the “Post-PC Era”, touch-centric interaction has received considerable attention in both research and development. However, various limitations have impeded widespread adoption of programming environments on modern platforms. Previous attempts have mainly been successful by simplifying or con...

  14. Interaction between voriconazole and glimepiride

    OpenAIRE

    Shobha J; Muppidi M

    2010-01-01

    Voriconazole, a triazole antifungal, is gaining popularity in the treatment of invasive fungal infections, mostly in the immuno-compromised patients. Voriconazole, a CYP2C9 inhibitor, has many potential drug interactions. Its interactions are both due to its pharmacokinetic properties and the genetic polymorphism of CYP2C9 enzymes. Here is a case report of one such drug-drug interaction between voriconazole and glimepiride, an oral hypoglycemic agent, which led to prolonged and persistent hyp...

  15. Efficient Interaction in English Classroom

    Institute of Scientific and Technical Information of China (English)

    董红叶

    2013-01-01

    Lack of communicative competence will result in failure to efficiently interact with others and also weaken linguistic competence. This paper shows the importance of interaction through analyzing Klashen’s input hypothesis,emotional factors,lat⁃er Wittgenstein’s linguistic philosophy,selectivity and dynamics of languages. Different interaction activities are used in different teaching methods. A teacher needs to face all the challenges so as to find the most efficient way to teach in a language classroom.

  16. Weak interactions of elementary particles

    CERN Document Server

    Okun, Lev Borisovich

    1965-01-01

    International Series of Monographs in Natural Philosophy, Volume 5: Weak Interaction of Elementary Particles focuses on the composition, properties, and reactions of elementary particles and high energies. The book first discusses elementary particles. Concerns include isotopic invariance in the Sakata model; conservation of fundamental particles; scheme of isomultiplets in the Sakata model; universal, unitary-symmetric strong interaction; and universal weak interaction. The text also focuses on spinors, amplitudes, and currents. Wave function, calculation of traces, five bilinear covariants,

  17. Chemical interaction between undamaged plants

    OpenAIRE

    Glinwood, Robert; Ninkovic, Velemir; Pettersson, Jan

    2011-01-01

    Most research on plant–plant chemical interactions has focussed on events following herbivore or pathogen attack. However, undamaged plants also interact chemically as a natural facet of their behaviour, and this may have consequences for insects that use the plants as hosts. In this review, the links between allelopathy and insect behaviour are outlined. Findings on how chemical interactions between different plant species and genotypes affect aphid herbivores and their natural e...

  18. Nuclear interactions of heavy ions

    International Nuclear Information System (INIS)

    A possible source of preheat for heavy ion driven inertial fusion targets is the production of fast precursors by nuclear interactions between the incident heavy ions and the outer parts of the target. A model has been developed which roughly describes these interactions for all beam-target combinations for all incident energies. This interaction model has been applied to a specific capsule design. The resultant preheat is an order of magnitude below the level which could impair target performance

  19. Thermal imaging for interactive surfaces

    OpenAIRE

    Abdelrahman, Yomna

    2013-01-01

    Thermal camera operating in Far Infrared (FIR) is considered to be un- derexplored in elds other than security and law enforcement. Nevertheless, recently it drawn the attention of Human Computer Interaction (HCI) re- searchers as a new sensory system enabling novel interactive systems. They are robust to illumination changes and using it with well-known computer vi- sion techniques, the complexity of the interaction detection is highly reduced as compared to RGB and depth cameras. FIR radiat...

  20. Intergenerational Analysis of Social Interaction

    OpenAIRE

    Brown, Sarah; McHardy, Jolian; Taylor, Karl

    2011-01-01

    We explore the relationship between the social interaction of parents and their offspring from a theoretical and an empirical perspective. Our theoretical framework establishes possible explanations for the intergenerational transfer of social interaction whereby the social interaction of the parent may influence that of their offspring and vice versa. The empirical evidence, based on four data sets covering Great Britain and the U.S., is supportive of our theoretical priors. We find robust e...

  1. Social Interaction and Urban Sprawl

    OpenAIRE

    Brueckner, Jan Keith; Ann G. Largey

    2006-01-01

    Various authors, most notably Putnam (2000), have argued that low-density living reduces social capital and thus social interaction, and this argument has been used to buttress criticisms of urban sprawl. If low densities in fact reduce social interaction, then an externality arises, validating Putnam’s critique. In choosing their own lot sizes, consumers would fail to consider the loss of interaction benefits for their neighbors when lot size is increased. Lot sizes would then be inefficient...

  2. Studying kinetochore-fiber ultrastructure using correlative light-electron microscopy

    OpenAIRE

    Booth, Daniel G.; Cheeseman, Liam P.; Prior, Ian A.; Royle, Stephen J

    2013-01-01

    Electron microscopy (EM) has dominated high-resolution cellular imaging for over 50 years thanks to its ability to resolve on a nanometer-scale intracellular structures such as the microtubules of the mitotic spindle. It is advantageous to view the cell of interest prior to processing the sample for EM. Correlative light electron microscopy (CLEM) is a technique that allows one to visualize cells of interest by light microscopy (LM) before being transferred to EM for ultra-structural examinat...

  3. A meiotic mystery: How sister kinetochores avoid being pulled in opposite directions during the first division.

    Science.gov (United States)

    Nasmyth, Kim

    2015-06-01

    We now take for granted that despite the disproportionate contribution of females to initial growth of their progeny, there is little or no asymmetry in the contribution of males and females to the eventual character of their shared offspring. In fact, this key insight was only established towards the end of the eighteenth century by Joseph Koelreuter's pioneering plant breeding experiments. If males and females supply equal amounts of hereditary material, then the latter must double each time an embryo is conceived. How then does the amount of this mysterious stuff not multiply exponentially from generation to generation? A compensatory mechanism for diluting the hereditary material must exist, one that ensures that if each parent contributes one half, each grandparent contributes a quarter, and each great grandparent merely an eighth. An important piece of the puzzle of how hereditary material is diluted at each generation has been elucidated over the past ten years. PMID:25874377

  4. The kinetochore protein, CENPF, is mutated in human ciliopathy and microcephaly phenotypes

    DEFF Research Database (Denmark)

    Waters, Aoife M; Asfahani, Rowan; Carroll, Paula; Bicknell, Louise; Lescai, Francesco; Bright, Alison; Chanudet, Estelle; Brooks, Anthony; Christou-Savina, Sonja; Osman, Guled; Walsh, Patrick; Bacchelli, Chiara; Chapgier, Ariane; Vernay, Bertrand; Bader, David M; Deshpande, Charu; O' Sullivan, Mary; Ocaka, Louise; Stanescu, Horia; Stewart, Helen S; Hildebrandt, Friedhelm; Otto, Edgar; Johnson, Colin A; Szymanska, Katarzyna; Katsanis, Nicholas; Davis, Erica; Kleta, Robert; Hubank, Mike; Doxsey, Stephen; Jackson, Andrew; Stupka, Elia; Winey, Mark; Beales, Philip L

    2015-01-01

    BACKGROUND: Mutations in microtubule-regulating genes are associated with disorders of neuronal migration and microcephaly. Regulation of centriole length has been shown to underlie the pathogenesis of certain ciliopathy phenotypes. Using a next-generation sequencing approach, we identified...... mutations in a novel centriolar disease gene in a kindred with an embryonic lethal ciliopathy phenotype and in a patient with primary microcephaly. METHODS AND RESULTS: Whole exome sequencing data from a non-consanguineous Caucasian kindred exhibiting mid-gestation lethality and ciliopathic malformations...... microcephaly, we identified two CENPF mutations [c.1744G>T, p.E582X; c.8692 C>T, p.R2898X] by whole exome sequencing. We found that CENP-F colocalised with Ninein at the subdistal appendages of the mother centriole in mouse inner medullary collecting duct cells. Intraflagellar transport protein-88 (IFT-88...

  5. Structural interaction with control systems

    Science.gov (United States)

    Noll, R. B.; Zvara, J.

    1971-01-01

    A monograph which assesses the state of the art of space vehicle design and development is presented. The monograph presents criteria and recommended practices for determining the structural data and a mathematical structural model of the vehicle needed for accurate prediction of structure and control-system interaction; for design to minimize undesirable interactions between the structure and the control system; and for determining techniques to achieve the maximum desirable interactions and associated structural design benefits. All space vehicles are treated, including launch vehicles, spacecraft, and entry vehicles. Important structural characteristics which affect the structural model used for structural and control-system interaction analysis are given.

  6. Interaction Themes in Music Therapy

    DEFF Research Database (Denmark)

    Holck, Ulla

    2006-01-01

    Based on a doctoral study, the author presents a type of music therapy interaction called ‘Interaction Themes.’ These are developed from session to session and often appear in music therapy interventions with children with severe functional limitations, especially children with autism. Although...... whose expressions are often difficult to understand. The presented article describes the characteristics and functions of Interaction Themes, compares the phenomenon with music therapy case literature and delimits it in regard to other types of music therapy interaction with this client group....

  7. Interaction Themes in Music Therapy

    DEFF Research Database (Denmark)

    Holck, Ulla

    2006-01-01

    Based on a doctoral study, the author presents a type of music therapy interaction called ‘Interaction Themes.’ These are developed from session to session and often appear in music therapy interventions with children with severe functional limitations, especially children with autism. Although...... whose expressions are often difficult to understand. This presentation describes the characteristics and functions of Interaction Themes, compares the phenomenon with music therapy case literature and delimits it in regard to other types of music therapy interaction with this client group....

  8. RKKY interaction in bilayer graphene

    Science.gov (United States)

    Mohammadi, Yawar; Moradian, Rostam

    2015-12-01

    We study the RKKY interaction between two magnetic impurities located on the same layer (intralayer case) or on different layers (interlayer case) in undoped bilayer graphene (BLG) in the four-bands model, by directly calculating the Green functions in the eigenvalues and eigenvectors representation. Our results show that both intra- and interlayer RKKY interactions between two magnetic impurities located on the same (opposite) sublattice are always ferromagnetic (antiferromagnetic). Furthermore we find unusual long-distance decay of the RKKY interaction in BLG. The intralyer RKKY interactions between two magnetic impurities located on the same sublattice, J AnAn(R) and J BnBn(R), decay closely as 1 /R6 and 1 /R2 at large impurity distances respectively, but when they are located on opposite sublattices the RKKY interactions exhibit 1 /R4 decays approximately. In the interlayer case, the RKKY interactions between two magnetic impurities located on the same sublattice show a decay close to 1 /R4 at large impurity distances, but if two magnetic impurities be on opposite sublattices the RKKY interactions, J A1B2(R) and J B1A2(R), decay closely as 1 /R6 and 1 /R2 respectively. Both intra- and interlayer RKKY interactions have anisotropic oscillatory factors which for intralayer case is equal to that for single layer graphene (SLG). Our results at weak and strong interlayer coupling limits reduce to the RKKY interaction of SLG and that of BLG in the two-bands approximation respectively.

  9. The Ontogenesis of Telephone Interaction.

    Science.gov (United States)

    Mininni, Giuseppe

    1985-01-01

    A longitudinal study of the acquisition of telephone skills among five preschool children analyzed play telephone interactions and real telephone conversations for similarities and changes in performance. (MSE)

  10. Water-Mediated Hydrophobic Interactions.

    Science.gov (United States)

    Ben-Amotz, Dor

    2016-05-27

    Hydrophobic interactions are driven by the combined influence of the direct attraction between oily solutes and an additional water-mediated interaction whose magnitude (and sign) depends sensitively on both solute size and attraction. The resulting delicate balance can lead to a slightly repulsive water-mediated interaction that drives oily molecules apart rather than pushing them together and thus opposes their direct (van der Waals) attraction for each other. As a consequence, competing solute size-dependent crossovers weaken hydrophobic interactions sufficiently that they are only expected to significantly exceed random thermal energy fluctuations for processes that bury more than ∼1 nm(2) of water-exposed area. PMID:27215821

  11. Novicidin interactions with phospholipid membranes

    DEFF Research Database (Denmark)

    Balakrishnan, Vijay Shankar

    Antimicrobial peptides target bacterial cell membranes and are considered as potential antibiotics. Their interactions with cell membranes are studied using different approaches. This thesis comprises of the biophysical investigations on the antimicrobial peptide Novicidin, interacting with...... liposomes. The lipid-induced changes in the peptide due to membrane binding, and the peptide-induced changes in the membrane properties were investigated using various spectroscopic and calorimetric methods, and the structural and thermodynamic aspects of peptide-lipid interactions are discussed. This helps...... in understanding not only the antimicrobial nature of Novicidin, but also sheds light on the membrane-peptide interactions....

  12. Theoretical studies of molecular interactions

    Energy Technology Data Exchange (ETDEWEB)

    Lester, W.A. Jr. [Univ. of California, Berkeley (United States)

    1993-12-01

    This research program is directed at extending fundamental knowledge of atoms and molecules including their electronic structure, mutual interaction, collision dynamics, and interaction with radiation. The approach combines the use of ab initio methods--Hartree-Fock (HF) multiconfiguration HF, configuration interaction, and the recently developed quantum Monte Carlo (MC)--to describe electronic structure, intermolecular interactions, and other properties, with various methods of characterizing inelastic and reaction collision processes, and photodissociation dynamics. Present activity is focused on the development and application of the QMC method, surface catalyzed reactions, and reorientation cross sections.

  13. Functions of Interactive Visual Representations in Interactive Mathematical Textbooks

    Science.gov (United States)

    Yerushalmy, Michal

    2005-01-01

    The paper explores changes in technology that have implications for the teaching and learning of school mathematics. To this end, it examines aspects of interactive mathematical textbooks; specifically it analyzes functions authors may intend to be carried out by embedded interactive diagrams. The paper analyzes theoretical as well as practical…

  14. Seepage/Cement Interactions

    International Nuclear Information System (INIS)

    The Development Plan (CRWMS M andO 1999a) pertaining to this task defines the work scopes and objectives for development of various submodels for the Physical and Chemical Environment Abstraction Model for TSPA-LA. The Development Plan (CRWMS M andO 1999a) for this specific task establishes that an evaluation be performed of the chemical reactions between seepage that has entered the drift and concrete which might be used in the repository emplacement drifts. The Development Plan (CRWMS M andO 1999a) then states that the potential effects of these water/grout reactions on chemical conditions in the drift be assessed factoring in the influence of carbonation and the relatively small amount of grout. This task is also directed at: (1) developing a conceptualization of important cement/seepage interactions and potential impacts on EBS performance, (2) performing a screening analysis to assess the importance of cement/seepage interactions. As the work progresses and evolves on other studies, specifically the Engineered Barrier System: Physical and Chemical Environment (P andCE) Model (in progress), many of the issues associated with items 1 and 2, above, will be assessed. Such issues include: (1) Describing the mineralogy of the specified cementitious grout and its evolution over time. (2) Describing the composition of the water before contacting the grout. (3) Developing reasonable upper-bound estimates for the composition of water contacting grout, emphasizing pH and concentrations for anions such as sulfate. (4) Evaluating the equilibration of cement-influenced water with backfill and gas-phase CO2. (5) Developing reasonable-bound estimates for flow rate of affected water into the drift. The concept of estimating an ''upper-bound'' range for reaction between the grout and the seepage, particularly in terms of pH is based on equilibrium being established between the seepage and the grout. For example, this analysis can be based on equilibrium being established as

  15. INCA- INTERACTIVE CONTROLS ANALYSIS

    Science.gov (United States)

    Bauer, F. H.

    1994-01-01

    The Interactive Controls Analysis (INCA) program was developed to provide a user friendly environment for the design and analysis of linear control systems, primarily feedback control systems. INCA is designed for use with both small and large order systems. Using the interactive graphics capability, the INCA user can quickly plot a root locus, frequency response, or time response of either a continuous time system or a sampled data system. The system configuration and parameters can be easily changed, allowing the INCA user to design compensation networks and perform sensitivity analysis in a very convenient manner. A journal file capability is included. This stores an entire sequence of commands, generated during an INCA session into a file which can be accessed later. Also included in INCA are a context-sensitive help library, a screen editor, and plot windows. INCA is robust to VAX-specific overflow problems. The transfer function is the basic unit of INCA. Transfer functions are automatically saved and are available to the INCA user at any time. A powerful, user friendly transfer function manipulation and editing capability is built into the INCA program. The user can do all transfer function manipulations and plotting without leaving INCA, although provisions are made to input transfer functions from data files. By using a small set of commands, the user may compute and edit transfer functions, and then examine these functions by using the ROOT_LOCUS, FREQUENCY_RESPONSE, and TIME_RESPONSE capabilities. Basic input data, including gains, are handled as single-input single-output transfer functions. These functions can be developed using the function editor or by using FORTRAN- like arithmetic expressions. In addition to the arithmetic functions, special functions are available to 1) compute step, ramp, and sinusoid functions, 2) compute closed loop transfer functions, 3) convert from S plane to Z plane with optional advanced Z transform, and 4) convert from Z

  16. Interact - Access to the Arctic

    Science.gov (United States)

    Johansson, M.; Callaghan, T. V.

    2013-12-01

    INTERACT is currently a network of 50 terrestrial research stations from all Arctic countries, but is still growing. The network was inaugurated in January 2011 when it received an EU 7th Framework award. INTERACT's main objective is to build capacity for identifying, understanding, predicting and responding to diverse environmental changes throughout the wide environmental and land-use envelopes of the Arctic. Implicit in this objective is the task to build capacity for monitoring, research, education and outreach. INTERACT is increasing access to the Arctic: 20 INTERACT research stations in Europe and Russia are offering Transnational Access and so far, 5600 person-days of access have been granted from the total of 10,000 offered. An INTERACT Station Managers' Forum facilitates a dialogue among station managers on subjects such as best practice in station management and standardised monitoring. The Station Managers' Forum has produced a unique 'one-stop-shop' for information from 45 research stations in an informative and attractive Station Catalogue that is available in hard copy and on the INTERACT web site (www.eu-interact.org). INTERACT also includes three joint research activities that are improving monitoring in remote, harsh environments and are making data capture and dissemination more efficient. Already, new equipment for measuring feedbacks from the land surface to the climate system has been installed at several locations, while best practices for sensor networking have been established. INTERACT networks with most of the high-level Arctic organisations: it includes AMAP and WWF as partners, is endorsed by IASC and CBMP, has signed MoUs with ISAC and the University of the Arctic, is a task within SAON, and contributes to the Cold Region community within GEO/GEOSS. INTERACT welcomes other interactions.

  17. Strategic interaction and conventions

    Directory of Open Access Journals (Sweden)

    Espinosa, María Paz

    2012-03-01

    Full Text Available The scope of the paper is to review the literature that employs coordination games to study social norms and conventions from the viewpoint of game theory and cognitive psychology. We claim that those two alternative approaches are in fact complementary, as they provide different insights to explain how people converge to a unique system of self-fulfilling expectations in presence of multiple, equally viable, conventions. While game theory explains the emergence of conventions relying on efficiency and risk considerations, the psychological view is more concerned with frame and labeling effects. The interaction between these alternative (and, sometimes, competing effects leads to the result that coordination failures may well occur and, even when coordination takes place, there is no guarantee that the convention eventually established will be the most efficient.

    El objetivo de este artículo es presentar la literatura que emplea los juegos de coordinación para el estudio de normas y convenciones sociales, que se han analizado tanto desde el punto de vista de la teoría de juegos como de la psicología cognitiva. Argumentamos en este trabajo que estos dos enfoques alternativos son en realidad complementarios, dado que ambos contribuyen al entendimiento de los procesos mediante los cuales las personas llegan a coordinarse en un único sistema de expectativas autorrealizadas, en presencia de múltiples convenciones todas ellas igualmente viables. Mientras que la teoría de juegos explica la aparición de convenciones basándose en argumentos de eficiencia y comportamientos frente al riesgo, el enfoque de la psicología cognitiva utiliza en mayor medida consideraciones referidas al entorno y naturaleza de las decisiones. La interacción entre estos efectos diferentes (y en ocasiones, rivales desemboca con frecuencia en fallos de coordinación y, aun cuando la coordinación se produce, no hay garantía de que la convención en vigor sea la m

  18. Educational interactive multimedia software: The impact of interactivity on learning

    Science.gov (United States)

    Reamon, Derek Trent

    This dissertation discusses the design, development, deployment and testing of two versions of educational interactive multimedia software. Both versions of the software are focused on teaching mechanical engineering undergraduates about the fundamentals of direct-current (DC) motor physics and selection. The two versions of Motor Workshop software cover the same basic materials on motors, but differ in the level of interactivity between the students and the software. Here, the level of interactivity refers to the particular role of the computer in the interaction between the user and the software. In one version, the students navigate through information that is organized by topic, reading text, and viewing embedded video clips; this is referred to as "low-level interactivity" software because the computer simply presents the content. In the other version, the students are given a task to accomplish---they must design a small motor-driven 'virtual' vehicle that competes against computer-generated opponents. The interaction is guided by the software which offers advice from 'experts' and provides contextual information; we refer to this as "high-level interactivity" software because the computer is actively participating in the interaction. The software was used in two sets of experiments, where students using the low-level interactivity software served as the 'control group,' and students using the highly interactive software were the 'treatment group.' Data, including pre- and post-performance tests, questionnaire responses, learning style characterizations, activity tracking logs and videotapes were collected for analysis. Statistical and observational research methods were applied to the various data to test the hypothesis that the level of interactivity effects the learning situation, with higher levels of interactivity being more effective for learning. The results show that both the low-level and high-level interactive versions of the software were effective

  19. Results-Based Interaction Design

    Science.gov (United States)

    Weiss, Meredith

    2008-01-01

    Interaction design is a user-centered approach to development in which users and their goals are the driving force behind a project's design. Interaction design principles are fundamental to the design and implementation of effective websites, but they are not sufficient. This article argues that, to reach its full potential, a website should also…

  20. Temporal form in interaction design

    DEFF Research Database (Denmark)

    Vallgårda, Anna; Winther, Morten Trøstrup; Mørch, Nina;

    2015-01-01

    a nuanced account of what temporal form is in interaction design, and we look at related work synthesizing what we already know of the temporal concerns in interaction design and HCI. In the second part we present a design experiment through which we explore the experiential qualities of a set of 11...

  1. Protein-Protein Interaction Databases

    DEFF Research Database (Denmark)

    Szklarczyk, Damian; Jensen, Lars Juhl

    2015-01-01

    of research are explored. Here we present an overview of the most widely used protein-protein interaction databases and the methods they employ to gather, combine, and predict interactions. We also point out the trade-off between comprehensiveness and accuracy and the main pitfall scientists have to be aware...

  2. Interactive Information Visualization in Neuroimaging

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    1998-01-01

    We describe a virtual environment for interactive visualization of 3D neuroimages. The environment is implemented in VRML and we will discuss the viability and limitation of this platform......We describe a virtual environment for interactive visualization of 3D neuroimages. The environment is implemented in VRML and we will discuss the viability and limitation of this platform...

  3. Perceived Attractiveness and Classroom Interactions

    Science.gov (United States)

    Algozzine, Bob

    1977-01-01

    Adams and Cohen (1974) demonstrated that facial attractiveness was a salient factor in differential student-teacher interactions. This research investigates further the interaction between teachers and children perceived to be attractive or unattractive by those teachers. It was hypothesized that attractive children would exhibit more "positive,"…

  4. Interactive Information Visualization in Neuroimaging

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    We describe a virtual environment for interactive visualization of 3D neuroimages. The environment is implemented in VRML and we will discuss the viability and limitation of this platform......We describe a virtual environment for interactive visualization of 3D neuroimages. The environment is implemented in VRML and we will discuss the viability and limitation of this platform...

  5. Mobile Collocated Interactions With Wearables

    DEFF Research Database (Denmark)

    Lucero, Andrés; Wilde, Danielle; Robinson, Simon;

    2015-01-01

    powerful, and closer to our bodies. Therefore, mobile collocated interactions research, which originally looked at smartphones and tablets, will inevitably move towards fully integrated wearable technologies. The focus of this workshop is to bring together a community of researchers, designers and...... practitioners to explore the potential of extending mobile collocated interactions from, through and around the body using wearable technologies....

  6. Nitrogen interactions at metal surfaces

    NARCIS (Netherlands)

    Gleeson, M. A.; Kleyn, A. W.

    2013-01-01

    Molecular beam experiments with specially prepared beams allow the study of the interaction of very reactive species with surfaces. In the present case the interaction of N-atoms with Ag(1 1 1) is studied. The energy of the atoms is around 5 eV, precisely between the classical energy regimes of seed

  7. Designing Interactive Online Nursing Courses

    Science.gov (United States)

    Jain, Smita; Jain, Pawan

    2015-01-01

    This study empirically tests the relation between the instructional design elements and the overall meaningful interactions among online students. Eighteen online graduate nursing courses are analyzed using bivariate and multivariate analysis techniques. Findings suggest that the quantity of meaningful interaction among learners can be improved by…

  8. Interacting with a Virtual Conductor

    NARCIS (Netherlands)

    Bos, P.

    2007-01-01

    The task of conducting human musicians in a live performance by a computer has not yet been addressed extensively before. A few attempts exist at letting a computer perform this task, but there is no interactive virtual conductor who can conduct human musicians and can interact with these musicians.

  9. Stable interactions via proper deformations

    International Nuclear Information System (INIS)

    A new method is proposed for switching on interactions that are compatible with global symmetries and conservation laws of the original free theory. The method is applied to the control of stability in Lagrangian and non-Lagrangian theories with higher derivatives. By way of illustration, a wide class of stable interactions is constructed for the Pais–Uhlenbeck oscillator. (paper)

  10. Assessing Preference for Social Interactions

    Science.gov (United States)

    Clay, Casey J.; Samaha, Andrew L.; Bloom, Sarah E.; Bogoev, Bistra K.; Boyle, Megan A.

    2013-01-01

    We examined a procedure to assess preference for social interactions in individuals with intellectual and developmental disabilities. Preferences were identified in five individuals using a paired-choice procedure in which participants approached therapists who provided different forms of social interactions. A subsequent tracking test showed that…

  11. Eye Movements in Gaze Interaction

    DEFF Research Database (Denmark)

    Møllenbach, Emilie; Hansen, John Paulin; Lillholm, Martin

    2013-01-01

    Gaze as a sole input modality must support complex navigation and selection tasks. Gaze interaction combines specific eye movements and graphic display objects (GDOs). This paper suggests a unifying taxonomy of gaze interaction principles. The taxonomy deals with three types of eye movements...

  12. Interactive Flow in Exercise Pedagogy

    Science.gov (United States)

    Lloyd, Rebecca; Smith, Stephen

    2006-01-01

    A phenomenology of the bodily experience of interactive flow adds to Csikszentmihalyi's flow theory. Whereas Csikszentmihalyi attended to teachers' and students' experiences of flow separately, this inquiry explores flow through three water-inspired layers of physical interaction between fitness professionals and their clients. Teaching fitness is…

  13. Transient interactions between photosynthetic proteins

    NARCIS (Netherlands)

    Hulsker, Rinske

    2008-01-01

    The biological processes that are the basis of all life forms are mediated largely by protein-protein interactions. The protein complexes involved in these interactions can be categorised by their affinity, which results in a range from static to transient complexes. Electron transfer complexes, whi

  14. Family Interactions and Child Psychopathology.

    Science.gov (United States)

    Donenberg, Geri R.; Nelson, Dana

    Previous research has not correlated parent-child interaction patterns with different forms of child psychopathology. This study examined whether parent-child interaction corresponded with childhood depression/anxiety and childhood aggression. Forty-two clinically-referred children and adolescents, 8 to 16 years old, were classified into four…

  15. Pathway Interaction Database (PID) —

    Science.gov (United States)

    The National Cancer Institute (NCI) in collaboration with Nature Publishing Group has established the Pathway Interaction Database (PID) in order to provide a highly structured, curated collection of information about known biomolecular interactions and key cellular processes assembled into signaling pathways.

  16. Brownian motion of interacting particles

    Energy Technology Data Exchange (ETDEWEB)

    Ackerson, B.J.

    1976-01-01

    Guided by the descriptions which are used to describe noninteracting particles, it is argued that the generalized Smoluchowski equation, including the hydrodynamic interaction and corrections for ion cloud effects may be used to describe interacting particles for the temporal and spatial regimes probed by light beating spectroscopy. This equation is then used to find cumulants of decay of the intermediate scattering function. The generalized Smoluchowski equation is reduced to a simple diffusion equation. The resulting diffusion constant depends upon the interparticle forces and is reminiscent of some early descriptions for interacting systems. The generalized Smoluchowski equation is solved for the model system of a linear chain of colloidal particles interacting via nearest neighbor harmonic couplings. The results for the intermediate scattering function and the static structure factor are very reminiscent of corresponding measurements made for interacting colloidal systems. (GHT)

  17. Noncovalent interaction of carbon nanostructures.

    Science.gov (United States)

    Umadevi, Deivasigamani; Panigrahi, Swati; Sastry, Garikapati Narahari

    2014-08-19

    The potential application of carbon nanomaterials in biology and medicine increases the necessity to understand the nature of their interactions with living organisms and the environment. The primary forces of interaction at the nano-bio interface are mostly noncovalent in nature. Quantifying such interactions and identifying various factors that influence such interactions is a question of outstanding fundamental interest in academia and industry. In this Account, we have summarized our recent studies in understanding the noncovalent interactions of carbon nanostructures (CNSs), which were obtained by employing first-principles calculations on various model systems representing carbon nanotubes (CNTs) and graphene. Bestowed with an extended sp(2) carbon network, which is a common feature in all of these nanostructures, they exhibit π-π interactions with aromatic molecules (benzene, naphthalene, nucleobases, amino acids), cation-π type of interactions with metal ions, anion-π interactions with anions, and other XH···π type of interactions with various small molecules (H2O, NH3, CH4, H2, etc.). CNTs are wrapped-up forms of two-dimensional graphene, and hence, it is interesting to compare the binding abilities of these two allotropes that differ in their curvature. The chirality and curvature of CNSs appear to play a major role in determining the structural, energetic, and functional properties. Flat graphene shows stronger noncovalent interactions than the curved nanotubes toward various substrates. Understanding the interactions of CNSs with organic molecules and biomolecules has gained a great deal of research interest because of their potential applications in various fields. Aromatic hydrocarbons show a strong propensity to interact with CNSs via the π-π mode of interaction rather than CH···π interaction. As DNA sequencing appears to be one of the most important potential applications of carbon nanomaterials, the study of CNS

  18. Hyperfine interaction in hydrogenated graphene

    Science.gov (United States)

    Garcia, Noel; Melle, Manuel; Fernandez-Rossier, Joaquin

    We study the hyperfine interaction of Hydrogen chemisorbed in graphene nanostructures with a gap in their spectrum, such as islands and ribbons. Chemisorption of Hydrogen on graphene results in a bound in-gap state that hosts a single electron localized around the adatom. Using both density functional theory and a four-orbital tight-binding model we study the hyperfine interaction between the hydrogen nuclear spin and the conduction electrons in graphene. We find that the strength of the hyperfine interaction decreases for larger nanostructures for which the energy gap is smaller. We then compare the results of the hyperfine interaction for large nanostructures with those of graphene 2D crystal with a periodic arrangement of chemisorbed Hydrogen atoms, obtaining very similar results. The magnitude of the hyperfine interaction is about 150 MHz, in line with that of Si:P. We acknowledge financial support by Marie-Curie-ITN 607904-SPINOGRAPH.

  19. Dynamics of two interacting dipoles

    International Nuclear Information System (INIS)

    We study the deterministic spin dynamic of two interacting magnetic moments with anisotropy and dipolar interaction under the presence of an applied magnetic field, by using the Landau-Lifshitz equation with and without a damping term. Due to different kinds of interactions, different time scales appear: a long time scale associated with the dipolar interaction and a short time scale associated with the Zeeman interaction. We found that the total magnetization is not conserved; furthermore, for the non-dissipative case it is a fluctuating function of time, with a strong dependence on the strength of the dipolar term. In the dissipative case there is a transient time before the total magnetization reaches its constant value. We examine this critical time as a function of the distance between the magnetic moments and the phenomenological damping coefficient, and found that it strongly depends on these control parameters

  20. Expanding the Interaction Equivalency Theorem

    Directory of Open Access Journals (Sweden)

    Brenda Cecilia Padilla Rodriguez

    2015-06-01

    Full Text Available Although interaction is recognised as a key element for learning, its incorporation in online courses can be challenging. The interaction equivalency theorem provides guidelines: Meaningful learning can be supported as long as one of three types of interactions (learner-content, learner-teacher and learner-learner is present at a high level. This study sought to apply this theorem to the corporate sector, and to expand it to include other indicators of course effectiveness: satisfaction, knowledge transfer, business results and return on expectations. A large Mexican organisation participated in this research, with 146 learners, 30 teachers and 3 academic assistants. Three versions of an online course were designed, each emphasising a different type of interaction. Data were collected through surveys, exams, observations, activity logs, think aloud protocols and sales records. All course versions yielded high levels of effectiveness, in terms of satisfaction, learning and return on expectations. Yet, course design did not dictate the types of interactions in which students engaged within the courses. Findings suggest that the interaction equivalency theorem can be reformulated as follows: In corporate settings, an online course can be effective in terms of satisfaction, learning, knowledge transfer, business results and return on expectations, as long as (a at least one of three types of interaction (learner-content, learner-teacher or learner-learner features prominently in the design of the course, and (b course delivery is consistent with the chosen type of interaction. Focusing on only one type of interaction carries a high risk of confusion, disengagement or missed learning opportunities, which can be managed by incorporating other forms of interactions.

  1. Final State Interactions Effects in Neutrino-Nucleus Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Golan, Tomasz [Univ. of Wroctaw (Poland); Juszczak, Cezary [Univ. of Wroctaw (Poland); Sobczyk, Jan T. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

    2012-07-01

    Final State Interactions effects are discussed in the context of Monte Carlo simulations of neutrino-nucleus interactions. A role of Formation Time is explained and several models describing this effect are compared. Various observables which are sensitive to FSI effects are reviewed including pion-nucleus interaction and hadron yields in backward hemisphere. NuWro Monte Carlo neutrino event generator is described and its ability to understand neutral current $\\pi^0$ production data in $\\sim 1$ GeV neutrino flux experiments is demonstrated.

  2. Plant biotic interactions

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    occurring after infestation by olive fly larvae. The last research article by Niu et al.(2016) describes a growth-promoting rhizobacterium that primes induced systemic resistance by suppressing a host R gene-targeting micro RNA pairs and activating host immune responses. This finding further supports the important roles of plant endogenous small RNAs in plant-pathogen interactions. Hailing Jin, Professor Special Issue Editor UC President’s Chair Director of Genetics, Genomics and Bioinformatics Graduate Program, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, USA doi:10.1111/jipb.12476 ©2016 Institute of Botany, Chinese Academy of Sciences REFERENCES Alagna F, Kal enbach M, Pompa A, De Marchis F, Rao R, Baldwin IT, Bonaventure G, Baldoni L (2016) Olive fruits infested with olive fly larvae respond with an ethylene burst and the emission of specific volatiles. J Integr Plant Biol 58:413–425 Castiblanco LF, Sundin GW (2016) New insights on molecular regulation of biofilm formation in plant-associated bacteria. J Integr Plant Biol 58:362–372 da GraSca JV, Douhan GW, Halbert SE, Keremane ML, Lee RF, Vidalakis G, Zhao H (2016) Huanglongbing: An overview of a complex pathosystem ravaging the world’s citrus. J Integr Plant Biol 58:373–387 Giovino A, Martinel i F, Saia S (2016) Rhynchophorus ferrugineus attack affects a group of compounds rather than rearranging Phoenix canariensis metabolic pathways. J Integr Plant Biol 58:388–396 Huang J, Yang M, Zhang X (2016) The function of smal RNAs in plant biotic stress response. J Integr Plant Biol 58:312–327 Kaloshian I, Wal ing LL (2016) Hemipteran and dipteran pests: Effectors and plant host immune regulators. J Integr Plant Biol 58:350–361 Mermigka G, Verret F, Kalantidis K (2016) RNA silencing movement in plants. J Integr Plant Biol 58:328–342 Niu D, Xia J, Jiang C, Qi B, Ling X, Lin S, Zhang W, Guo J, Jin H, Zhao H (2016) Bacil us cereus AR156

  3. Interactive computer code for dynamic and soil structure interaction analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mulliken, J.S.

    1995-12-01

    A new interactive computer code is presented in this paper for dynamic and soil-structure interaction (SSI) analyses. The computer program FETA (Finite Element Transient Analysis) is a self contained interactive graphics environment for IBM-PC`s that is used for the development of structural and soil models as well as post-processing dynamic analysis output. Full 3-D isometric views of the soil-structure system, animation of displacements, frequency and time domain responses at nodes, and response spectra are all graphically available simply by pointing and clicking with a mouse. FETA`s finite element solver performs 2-D and 3-D frequency and time domain soil-structure interaction analyses. The solver can be directly accessed from the graphical interface on a PC, or run on a number of other computer platforms.

  4. Independent pair parton interactions-model of hadron interactions

    OpenAIRE

    Dremin, I. M.; Nechitailo, V. A.

    2004-01-01

    A model of independent pair parton interactions is proposed, according to which, hadron interactions are represented by a set of independent binary parton collisions. The final multiplicity distribution is described by a convolution of the negative binomial distributions in each of the partonic collisions. As a result, it is given by a weighted sum of negative binomial distributions with parameters multiplied by the number of active pairs. Its shape and moments are considered. Experimental da...

  5. Calculations on Noncovalent Interactions and Databases of Benchmark Interaction Energies

    Czech Academy of Sciences Publication Activity Database

    Hobza, Pavel

    2012-01-01

    Roč. 45, č. 4 (2012), s. 663-672. ISSN 0001-4842 R&D Projects: GA ČR GBP208/12/G016 Grant ostatní: European Social Fund(XE) CZ.1.05/2.1.00/03.0058 Institutional research plan: CEZ:AV0Z40550506 Keywords : non-covalent interaction s * covalent interaction s * quantum chemical approach Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 20.833, year: 2012

  6. Detecting mutually exclusive interactions in protein-protein interaction maps.

    KAUST Repository

    Sánchez Claros, Carmen

    2012-06-08

    Comprehensive protein interaction maps can complement genetic and biochemical experiments and allow the formulation of new hypotheses to be tested in the system of interest. The computational analysis of the maps may help to focus on interesting cases and thereby to appropriately prioritize the validation experiments. We show here that, by automatically comparing and analyzing structurally similar regions of proteins of known structure interacting with a common partner, it is possible to identify mutually exclusive interactions present in the maps with a sensitivity of 70% and a specificity higher than 85% and that, in about three fourth of the correctly identified complexes, we also correctly recognize at least one residue (five on average) belonging to the interaction interface. Given the present and continuously increasing number of proteins of known structure, the requirement of the knowledge of the structure of the interacting proteins does not substantially impact on the coverage of our strategy that can be estimated to be around 25%. We also introduce here the Estrella server that embodies this strategy, is designed for users interested in validating specific hypotheses about the functional role of a protein-protein interaction and it also allows access to pre-computed data for seven organisms.

  7. Interaction of radiation with matter

    CERN Document Server

    Nikjoo, Hooshang; Emfietzoglou, Dimitris

    2012-01-01

    Written for students approaching the subject for the first time, this text provides a solid grounding in the physics of the interactions of photons and particles with matter, which is the basis of radiological physics and radiation dosimetry. The authors first present the relevant atomic physics and then describe the interactions, emphasizing practical applications in health/medical physics and radiation biology. They cover such important topics as microdosimetry, interaction of photons with matter, electron energy loss, and dielectric response. Each chapter includes exercises and a summary.

  8. Interaction sheaves on continuous domains

    DEFF Research Database (Denmark)

    Abdou, Joseph; Keiding, Hans

    2009-01-01

    We introduce a description of the power structure which is inherent in a strategic game form using the concept of an interaction sheaf. The latter assigns to each open set of outcomes a set of interaction arrays, specifying the changes that coalitions can make if outcome belongs to this open set....... The interaction sheaf generalizes the notion of effectivity functions which has been widely used in implementation theory, taking into consideration that changes in outcome may be sustained not only by single coalitions but possibly by several coalitions, depending on the underlying strategy choices...

  9. Interaction Sheaves on Continuous Domains

    DEFF Research Database (Denmark)

    Abdou, J.; Keiding, Hans

    We introduce a description of the power structure which is inherent in a strategic game form using the concept of an interaction sheaf. The latter assigns to each open set of outcomes a set of interaction arrays, specifying the changes that coalitions can make if outcome belongs to this open set....... The interaction sheaf generalizes the notion of effectivity functions which has been widely used in implementation theory, taking into consideration that changes in outcome may be sustained not only by single coalitions but possibly by several coalitions, depending on the underlying strategy choices...

  10. Viscosity coefficient with pairing interaction

    International Nuclear Information System (INIS)

    In the study of dynamic process (for example, deep-inelastic scattering of heavy ion, nuclear fission), viscosity, which describes the coupling between the intrinsic degrees of freedom and the collective one, is a basic quantity. In this paper, under BCS approximation, we derive a microscopic expression of viscosity coefficient with pairing interaction by means of a linear response theory. Taking the fission process of 236U as an example, we discuss the effect of pairing interaction on the viscosity coefficient. The results show that pairing interaction must be taken into account at lower temperature and can be neglected at a high-temperature region

  11. Aligned interactions in cosmic rays

    Science.gov (United States)

    Kempa, J.

    2015-12-01

    The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.

  12. Aligned interactions in cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Kempa, J., E-mail: kempa@pw.plock.pl [Warsaw University of Technology Branch Plock (Poland)

    2015-12-15

    The first clean Centauro was found in cosmic rays years many ago at Mt Chacaltaya experiment. Since that time, many people have tried to find this type of interaction, both in cosmic rays and at accelerators. But no one has found a clean cases of this type of interaction.It happened finally in the last exposure of emulsion at Mt Chacaltaya where the second clean Centauro has been found. The experimental data for both the Centauros and STRANA will be presented and discussed in this paper. We also present our comments to the intriguing question of the existence of a type of nuclear interactions at high energy with alignment.

  13. Coulomb interactions in particle beams

    International Nuclear Information System (INIS)

    This book develops analytical and computer models for beams in which Coulomb interactions are important. The research into the different phenomena of Coulomb interactions in particle beams is stimulated by developments in the field of electron beam lithography for VLSI electronics. The standard theory of charged particle optics breaks down for intense beams in which interactions between particles are significant. This monograph is devoted to the theory of these intense beams, which are not only used in VLSI electronics but also in scanning electron microscopes. The theory is also applicable to focused ion beams, which are used in VLSI mask repair

  14. Interactive 3D multimedia content

    CERN Document Server

    Cellary, Wojciech

    2012-01-01

    The book describes recent research results in the areas of modelling, creation, management and presentation of interactive 3D multimedia content. The book describes the current state of the art in the field and identifies the most important research and design issues. Consecutive chapters address these issues. These are: database modelling of 3D content, security in 3D environments, describing interactivity of content, searching content, visualization of search results, modelling mixed reality content, and efficient creation of interactive 3D content. Each chapter is illustrated with example a

  15. Diatomic interaction potential theory applications

    CERN Document Server

    Goodisman, Jerry

    2013-01-01

    Diatomic Interaction Potential Theory, Volume 2: Applications discusses the variety of applicable theoretical material and approaches in the calculations for diatomic systems in their ground states. The volume covers the descriptions and illustrations of modern calculations. Chapter I discusses the calculation of the interaction potential for large and small values of the internuclear distance R (separated and united atom limits). Chapter II covers the methods used for intermediate values of R, which in principle means any values of R. The Hartree-Fock and configuration interaction schemes des

  16. Theory of relativistic direct interaction

    International Nuclear Information System (INIS)

    Report discusses the structure, the generality and the physical meaning of the relativistic Hamiltonian theory (RHT) as a whole, starting from its most general quantum-field version and finishing with its classical counterpart. It is shown, in particular, that in the absence of bound states any relativistic invariant S-matrix can be obtained in the framework of the RHT. The properties of causality and locality of RHT are discussed, and two mechanisms of interaction transfer are considered. The space-time interaction of the motion of particles inside the direct interaction range is formulated and shown to be non-unique

  17. Interaction of spatial photorefractive solitons

    DEFF Research Database (Denmark)

    Królikowski, W.; Denz, C.; Stepken, A.;

    1998-01-01

    We present a review of our recent theoretical and experimental results on the interaction of two-dimensional solitary beams in photorefractive SBN crystals. We show that the collision of coherent solitons may result in energy exchange, fusion of the interacting solitons, the birth of a new solitary...... beam or the complete annihilation of some of them, depending on the relative phase of the interacting beams. In the case of mutually incoherent solitons, we show that the photorefractive nonlinearity leads to an anomalous interaction between solitons. Theoretical and experimental results reveal that a...... soliton pair may experience both attractive and repulsive forces; depending on their mutual separation. We also show that strong attraction leads to periodic collision or helical motion of solitons depending on initial conditions....

  18. Multi-shell effective interactions

    CERN Document Server

    Tsunoda, Naofumi; Hjorth-Jensen, Morten; Otsuka, Takaharu

    2013-01-01

    Background: Effective interactions, either derived from microscopic theories or based on fitting selected properties of nuclei in specific mass regions, are widely used inputs to shell-model studies of nuclei. Until recently, most shell-model calculations have been confined to a single oscillator shell. Recent interest in nuclei away from the stability line, requires however larger shell-model spaces. Since the derivation of microscopic effective interactions has been limited to degenerate model spaces, there are both conceptual and practical limits to present shell-model calculations that utilize such interactions. Purpose: The aim of this work is to present a novel microscopic method to calculate effective interactions for the nuclear shell model. Its main difference from existing theories is that it can be applied not only to degenerate model spaces but also to non-degenerate model spaces. Methods: The formalism is presented in the form of many-body perturbation theory based on the recently developed Exten...

  19. Ultracold fermions with repulsive interactions

    Directory of Open Access Journals (Sweden)

    Ketterle W.

    2013-08-01

    Full Text Available An ultracold Fermi gas with repulsive interaction has been studied. For weak interactions, the atomic gas is metastable, and the interactions were characterized by obtaining the isothermal compressibility from atomic density profiles. For stronger interactions (kFa ≈ 1, rapid conversion into Feshbach molecules is observed. When the conversion rate becomes comparable to the Fermi energy divided by η, the atomic gas cannot reach equilibrium without forming pairs. This precludes the predicted transition to a ferromagnetic state (Stoner transition. The absence of spin fluctuations proves that the gas stays paramagnetic. In free space, a Fermi gas with strong short-range repulsion does not exist because of the rapid coupling to molecular states.

  20. Spacecraft Environmental Interactions Technology, 1983

    Science.gov (United States)

    1985-01-01

    State of the art of environment interactions dealing with low-Earth-orbit plasmas; high-voltage systems; spacecraft charging; materials effects; and direction of future programs are contained in over 50 papers.

  1. Creep-Fatigue Interaction Testing

    Science.gov (United States)

    Halford, Gary R.

    2001-01-01

    Fatigue fives in metals are nominally time independent below 0.5 T(sub Melt). At higher temperatures, fatigue lives are altered due to time-dependent, thermally activated creep. Conversely, creep rates are altered by super. imposed fatigue loading. Creep and fatigue generally interact synergistically to reduce material lifetime. Their interaction, therefore, is of importance to structural durability of high-temperature structures such as nuclear reactors, reusable rocket engines, gas turbine engines, terrestrial steam turbines, pressure vessel and piping components, casting dies, molds for plastics, and pollution control devices. Safety and lifecycle costs force designers to quantify these interactions. Analytical and experimental approaches to creep-fatigue began in the era following World War II. In this article experimental and life prediction approaches are reviewed for assessing creep-fatigue interactions of metallic materials. Mechanistic models are also discussed briefly.

  2. Quadruplet scheme of weak interactions

    International Nuclear Information System (INIS)

    A possibility to describe lepton and quark weak interactions on the basis of the gauge group SU(4)sub(L)xSU(4)sub(R)xUsup(Y)(1) is discussed. RH (right-handed) currents are included into weak interaction scheme. Possible ways to construct weak interaction theory in a symmetric way with respect to the LH (left-handed) (V-A) and RH(V+A) currents are searched for. Neutral nondiagonal transitions that might explain heavy neutral lepton production in neutrino beams on the basis of gauge theory are discussed. The problem on mixing leptons (quarks) with different quantum numbers is discussed. Applicability of the given model is discussed in connection with some problems of neutrino interaction physics, as well as production and decay of heavy charged and neutral leptons

  3. Developer's handbook of interactive multimedia

    CERN Document Server

    Phillips, Robin

    2014-01-01

    New technology is being used more and more in education and providers have to be aware of what is on offer and how it can be used. This practical handbook demonstrates how interactive multimedia can be developed for educational application.

  4. Weak interactions of heavy quarks

    International Nuclear Information System (INIS)

    The status of our knowledhe about weak interactions of heavy quarks is reviewed within the framework of the Standard Theory. Several approaches to connect the basic Lagrangian to experimental measurements are discussed. (Author)

  5. Chiral interaction and biomolecular evolution

    International Nuclear Information System (INIS)

    Recent developments in the concept of chiral interaction open now new options and dynamical possibilities for biomolecules which have so far been overlooked. A few of these possibilities are mentioned, such as the control mechanism of enzymatic activity and the role played by non-ergodicity in evolutionary processes. It is shown that chiral interaction, being a surface phenomenon, does not obey Barron's symmetry constraints, which are suitable for force fields present in bulk interactions. In particular, the situation at the ocean-air surface in the prebiotic era is described, as well as the possible role played by chiral interaction in conjunction with the terrestrial magnetic field normal to the ocean surface, which could have lead to a process of deracernization at the ocean-air interface. (author)

  6. Coulomb interactions within halo EFT

    International Nuclear Information System (INIS)

    Preliminary results of an effective field theory applied to nuclear cluster systems are presented, where Coulomb interactions play a significant role. Presented at the 20th Few-Body Conference, Pisa, Italy, 10-14 September 2007. (author)

  7. Fundamental particles and their interactions

    OpenAIRE

    Ananthanarayan, B.

    2005-01-01

    In this article the current understanding of fundamental particles and their interactions is presented for the interested non-specialist, by adopting a semi-historical path. A discussion on the unresolved problems is also presented.

  8. InterAction Database (IADB)

    Science.gov (United States)

    The InterAction Database includes demographic and prescription information for more than 500,000 patients in the northern and middle Netherlands and has been integrated with other systems to enhance data collection and analysis.

  9. Learning Axure RP interactive prototypes

    CERN Document Server

    Krahenbuhl, John Henry

    2015-01-01

    If you are a user experience professional, designer, information architect, or business analyst who wants to gain interactive prototyping skills with Axure, then this book is ideal for you. Some familiarity with Axure is preferred but not essential.

  10. Database of Interacting Proteins (DIP)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The DIP database catalogs experimentally determined interactions between proteins. It combines information from a variety of sources to create a single, consistent...

  11. Models of Interacting Dark Energy

    CERN Document Server

    Zimdahl, W

    2012-01-01

    Any non-gravitational coupling between dark matter and dark energy modifies the cosmological dynamics. Interactions in the dark sector are considered to be relevant to address the coincidence problem. Moreover, in various models the observed accelerated expansion of the Universe is a pure interaction phenomenon. Here we review recent approaches in which a coupling between both dark components is crucial for the evolution of the Universe.

  12. Nominal Price and Wage Interactions

    OpenAIRE

    Andersen, Torben M.

    1995-01-01

    The interaction between price and wage setting is considered in a model with monopolistically product markets and unionized labour markets. It is shown how differential information can cause nominal rigidities which are amplified by the wage-price interactions arising due to strategic complementarity in price and wage setting. Nominal wages may be less flexible than nominal product prices even when there are no informational asymmetries between price and wage decisions.

  13. Interactive Dynamic-System Simulation

    CERN Document Server

    Korn, Granino A

    2010-01-01

    Showing you how to use personal computers for modeling and simulation, Interactive Dynamic-System Simulation, Second Edition provides a practical tutorial on interactive dynamic-system modeling and simulation. It discusses how to effectively simulate dynamical systems, such as aerospace vehicles, power plants, chemical processes, control systems, and physiological systems. Written by a pioneer in simulation, the book introduces dynamic-system models and explains how software for solving differential equations works. After demonstrating real simulation programs with simple examples, the author

  14. Facilitative root interactions in intercrops

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, H.; Jensen, E.S.

    2005-01-01

    Facilitation takes place when plants ameliorate the environment of their neighbours, and increase their growth and survival. Facilitation occurs in natural ecosystems as well as in agroecosystems. We discuss examples of facilitative root interactions in intercropped agroecosystems; including...... root architecture, exudation of growth stimulating substances, and biofumigation. Facilitative root interactions are most likely to be of importance in nutrient poor soils and in low-input agroecosystems due to critical interspecific competition for plant growth factors. However, studies from more...

  15. Allelopathic Interactions Involving Phenolic Acids

    OpenAIRE

    Blum, U.

    1996-01-01

    A major concern regarding allelopathic interactions involving phenolic acids in no-till systems pertains to the fact that concentrations of individual phenolic acids recoverable from field soils are well below levels required for inhibition of germination and seedling growth in laboratory bioassays. Field soils contain a variety of phenolic acids as well as other toxic and nontoxic organic compounds that are available to interact with seeds and roots; whereas in laboratory bioassays, with few...

  16. Interactive Video in Medical Education

    OpenAIRE

    Chandrasekhar, Arcot J.; Price, Ronald N.

    1989-01-01

    A variety of attributes have to be taught to a medical student. Various formats of these skills are currently in vogue, namely lectures, small group sessions, preceptorships, etc. The objective of this project is to evaluate the utility of interactive video in medical education. Lessons using interactive video were developed to teach history taking skills, procedural skills, problem solving skills and to acquire knowledge base. Evaluation strategies are being developed to assess which format,...

  17. Interaction engineering for environmental probing

    OpenAIRE

    M. Paternostro; Bose, S; Kim, M. S.

    2007-01-01

    We study the conditions for the probing of an environment affecting one party of a bipartite system of interacting objects by measurements operated only on the other element. We show that entanglement plays no crucial role in such an environment-characterization. On the other hand, if an interaction is established between the two parties, information can be reliably gathered. This result holds for both discrete and continuous variables and helps in the interpretation of recent experiments add...

  18. Interactive Design of Accelerators (IDA)

    International Nuclear Information System (INIS)

    IDA is a beam transport line calculation program which runs interactively on an IBM PC computer. It can be used for a large fraction of the usual calculations done for beam transport systems or periods of accelerators or storage rings. Because of the interactive screen editor nature of the data input, this program permits one to rather quickly arrive at general properties of a beam line or an accelerator period

  19. Strongly Interacting Light Dark Matter

    OpenAIRE

    Bruggisser, Sebastian; Riva, Francesco; Urbano, Alfredo

    2016-01-01

    In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM) can appear weakly coupled at small energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their...

  20. Action Research and Interactive Research

    DEFF Research Database (Denmark)

    Svensson, lennart; Nielsen, Kurt Aagaard

    2006-01-01

    The authors present trends in Nordic action research. They ask critical questions in the development towards mode 2 and points out alternative roads for a scientific consolidation of action research and interactive research.......The authors present trends in Nordic action research. They ask critical questions in the development towards mode 2 and points out alternative roads for a scientific consolidation of action research and interactive research....