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Sample records for pinpoints cancer spread

  1. Brain cancer spreads.

    Science.gov (United States)

    Perryman, Lara; Erler, Janine T

    2014-07-30

    The discovery that ~20% of patients with brain cancer have circulating tumor cells breaks the dogma that these cells are confined to the brain and has important clinical implications (Müller et al., this issue).

  2. Brain cancer spreads

    DEFF Research Database (Denmark)

    Perryman, Lara; Erler, Janine Terra

    2014-01-01

    The discovery that ~20% of patients with brain cancer have circulating tumor cells breaks the dogma that these cells are confined to the brain and has important clinical implications (Müller et al., this issue).......The discovery that ~20% of patients with brain cancer have circulating tumor cells breaks the dogma that these cells are confined to the brain and has important clinical implications (Müller et al., this issue)....

  3. Pinpointing differences in cisplatin-induced apoptosis in adherent and non-adherent cancer cells

    DEFF Research Database (Denmark)

    Tastesen, Hanne Sørup; Holm, Jacob Bak; Poulsen, Kristian Arild

    2010-01-01

    Platinum compounds are used in the treatment of cancer. We demonstrate that cisplatin-induced (10 µM) apoptosis (caspase-3 activity) is pronounced within 18 hours in non-adherent Ehrlich ascites tumour cells (EATC), whereas there is no increase in caspase-3 activity in the adherent Ehrlich Lettré...... ascites tumour cells (ELA). Loss of KCl and cell shrinkage are hallmarks in apoptosis and has been shown in EATC. However, we find no reduction in cell volume and only a minor loss of K(+) which is accompanied by net uptake of Na(+) following 18 hours cisplatin exposure in ELA. Glutathione and taurine...... have previously been demonstrated to protect cells from apoptosis. We find, however, that increase or decrease in the cellular content of glutathione and taurine has no effect on cisplatin-induced cell death in EATC and ELA. Nevertheless, knock-down of the taurine transporter TauT leads...

  4. Breast Cancer Cells May Change When They Spread to Brain

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162415.html Breast Cancer Cells May Change When They Spread to Brain: ... 2016 WEDNESDAY, Dec. 7, 2016 (HealthDay News) -- When breast cancer spreads to the brain, important molecular changes may ...

  5. Atlas of prostate cancer heritability in European and African-American men pinpoints tissue-specific regulation

    DEFF Research Database (Denmark)

    Gusev, Alexander; Shi, Huwenbo; Kichaev, Gleb

    2016-01-01

    Although genome-wide association studies have identified over 100 risk loci that explain ∼33% of familial risk for prostate cancer (PrCa), their functional effects on risk remain largely unknown. Here we use genotype data from 59,089 men of European and African American ancestries combined with c...

  6. Atlas of prostate cancer heritability in European and African-American men pinpoints tissue-specific regulation.

    Science.gov (United States)

    Gusev, Alexander; Shi, Huwenbo; Kichaev, Gleb; Pomerantz, Mark; Li, Fugen; Long, Henry W; Ingles, Sue A; Kittles, Rick A; Strom, Sara S; Rybicki, Benjamin A; Nemesure, Barbara; Isaacs, William B; Zheng, Wei; Pettaway, Curtis A; Yeboah, Edward D; Tettey, Yao; Biritwum, Richard B; Adjei, Andrew A; Tay, Evelyn; Truelove, Ann; Niwa, Shelley; Chokkalingam, Anand P; John, Esther M; Murphy, Adam B; Signorello, Lisa B; Carpten, John; Leske, M Cristina; Wu, Suh-Yuh; Hennis, Anslem J M; Neslund-Dudas, Christine; Hsing, Ann W; Chu, Lisa; Goodman, Phyllis J; Klein, Eric A; Witte, John S; Casey, Graham; Kaggwa, Sam; Cook, Michael B; Stram, Daniel O; Blot, William J; Eeles, Rosalind A; Easton, Douglas; Kote-Jarai, Zsofia; Al Olama, Ali Amin; Benlloch, Sara; Muir, Kenneth; Giles, Graham G; Southey, Melissa C; Fitzgerald, Liesel M; Gronberg, Henrik; Wiklund, Fredrik; Aly, Markus; Henderson, Brian E; Schleutker, Johanna; Wahlfors, Tiina; Tammela, Teuvo L J; Nordestgaard, Børge G; Key, Tim J; Travis, Ruth C; Neal, David E; Donovan, Jenny L; Hamdy, Freddie C; Pharoah, Paul; Pashayan, Nora; Khaw, Kay-Tee; Stanford, Janet L; Thibodeau, Stephen N; McDonnell, Shannon K; Schaid, Daniel J; Maier, Christiane; Vogel, Walther; Luedeke, Manuel; Herkommer, Kathleen; Kibel, Adam S; Cybulski, Cezary; Wokolorczyk, Dominika; Kluzniak, Wojciech; Cannon-Albright, Lisa; Teerlink, Craig; Brenner, Hermann; Dieffenbach, Aida K; Arndt, Volker; Park, Jong Y; Sellers, Thomas A; Lin, Hui-Yi; Slavov, Chavdar; Kaneva, Radka; Mitev, Vanio; Batra, Jyotsna; Spurdle, Amanda; Clements, Judith A; Teixeira, Manuel R; Pandha, Hardev; Michael, Agnieszka; Paulo, Paula; Maia, Sofia; Kierzek, Andrzej; Conti, David V; Albanes, Demetrius; Berg, Christine; Berndt, Sonja I; Campa, Daniele; Crawford, E David; Diver, W Ryan; Gapstur, Susan M; Gaziano, J Michael; Giovannucci, Edward; Hoover, Robert; Hunter, David J; Johansson, Mattias; Kraft, Peter; Le Marchand, Loic; Lindström, Sara; Navarro, Carmen; Overvad, Kim; Riboli, Elio; Siddiq, Afshan; Stevens, Victoria L; Trichopoulos, Dimitrios; Vineis, Paolo; Yeager, Meredith; Trynka, Gosia; Raychaudhuri, Soumya; Schumacher, Frederick R; Price, Alkes L; Freedman, Matthew L; Haiman, Christopher A; Pasaniuc, Bogdan

    2016-04-07

    Although genome-wide association studies have identified over 100 risk loci that explain ∼33% of familial risk for prostate cancer (PrCa), their functional effects on risk remain largely unknown. Here we use genotype data from 59,089 men of European and African American ancestries combined with cell-type-specific epigenetic data to build a genomic atlas of single-nucleotide polymorphism (SNP) heritability in PrCa. We find significant differences in heritability between variants in prostate-relevant epigenetic marks defined in normal versus tumour tissue as well as between tissue and cell lines. The majority of SNP heritability lies in regions marked by H3k27 acetylation in prostate adenoc7arcinoma cell line (LNCaP) or by DNaseI hypersensitive sites in cancer cell lines. We find a high degree of similarity between European and African American ancestries suggesting a similar genetic architecture from common variation underlying PrCa risk. Our findings showcase the power of integrating functional annotation with genetic data to understand the genetic basis of PrCa.

  7. Atlas of prostate cancer heritability in European and African-American men pinpoints tissue-specific regulation

    Science.gov (United States)

    Gusev, Alexander; Shi, Huwenbo; Kichaev, Gleb; Pomerantz, Mark; Li, Fugen; Long, Henry W.; Ingles, Sue A.; Kittles, Rick A.; Strom, Sara S.; Rybicki, Benjamin A.; Nemesure, Barbara; Isaacs, William B.; Zheng, Wei; Pettaway, Curtis A.; Yeboah, Edward D.; Tettey, Yao; Biritwum, Richard B.; Adjei, Andrew A.; Tay, Evelyn; Truelove, Ann; Niwa, Shelley; Chokkalingam, Anand P.; John, Esther M.; Murphy, Adam B.; Signorello, Lisa B.; Carpten, John; Leske, M. Cristina; Wu, Suh-Yuh; Hennis, Anslem J. M.; Neslund-Dudas, Christine; Hsing, Ann W.; Chu, Lisa; Goodman, Phyllis J.; Klein, Eric A.; Witte, John S.; Casey, Graham; Kaggwa, Sam; Cook, Michael B.; Stram, Daniel O.; Blot, William J.; Eeles, Rosalind A.; Easton, Douglas; Kote-Jarai, ZSofia; Al Olama, Ali Amin; Benlloch, Sara; Muir, Kenneth; Giles, Graham G.; Southey, Melissa C.; Fitzgerald, Liesel M.; Gronberg, Henrik; Wiklund, Fredrik; Aly, Markus; Henderson, Brian E.; Schleutker, Johanna; Wahlfors, Tiina; Tammela, Teuvo L. J.; Nordestgaard, Børge G.; Key, Tim J.; Travis, Ruth C.; Neal, David E.; Donovan, Jenny L.; Hamdy, Freddie C.; Pharoah, Paul; Pashayan, Nora; Khaw, Kay-Tee; Stanford, Janet L.; Thibodeau, Stephen N.; McDonnell, Shannon K.; Schaid, Daniel J.; Maier, Christiane; Vogel, Walther; Luedeke, Manuel; Herkommer, Kathleen; Kibel, Adam S.; Cybulski, Cezary; Wokolorczyk, Dominika; Kluzniak, Wojciech; Cannon-Albright, Lisa; Teerlink, Craig; Brenner, Hermann; Dieffenbach, Aida K.; Arndt, Volker; Park, Jong Y.; Sellers, Thomas A.; Lin, Hui-Yi; Slavov, Chavdar; Kaneva, Radka; Mitev, Vanio; Batra, Jyotsna; Spurdle, Amanda; Clements, Judith A.; Teixeira, Manuel R.; Pandha, Hardev; Michael, Agnieszka; Paulo, Paula; Maia, Sofia; Kierzek, Andrzej; Cook, Margaret; Guy, Michelle; Govindasami, Koveela; Leongamornlert, Daniel; Sawyer, Emma J.; Wilkinson, Rosemary; Saunders, Edward J.; Tymrakiewicz, Malgorzata; Dadaev, Tokhir; Morgan, Angela; Fisher, Cyril; Hazel, Steve; Livni, Naomi; Lophatananon, Artitaya; Pedersen, John; Hopper, John L.; Adolfson, Jan; Stattin, Paer; Johansson, Jan-Erik; Cavalli-Bjoerkman, Carin; Karlsson, Ami; Broms, Michael; Auvinen, Anssi; Kujala, Paula; Maeaettaenen, Liisa; Murtola, Teemu; Taari, Kimmo; Weischer, Maren; Nielsen, Sune F.; Klarskov, Peter; Roder, Andreas; Iversen, Peter; Wallinder, Hans; Gustafsson, Sven; Cox, Angela; Brown, Paul; George, Anne; Marsden, Gemma; Lane, Athene; Davis, Michael; Zheng, Wei; Signorello, Lisa B.; Blot, William J.; Tillmans, Lori; Riska, Shaun; Wang, Liang; Rinckleb, Antje; Lubiski, Jan; Stegmaier, Christa; Pow-Sang, Julio; Park, Hyun; Radlein, Selina; Rincon, Maria; Haley, James; Zachariah, Babu; Kachakova, Darina; Popov, Elenko; Mitkova, Atanaska; Vlahova, Aleksandrina; Dikov, Tihomir; Christova, Svetlana; Heathcote, Peter; Wood, Glenn; Malone, Greg; Saunders, Pamela; Eckert, Allison; Yeadon, Trina; Kerr, Kris; Collins, Angus; Turner, Megan; Srinivasan, Srilakshmi; Kedda, Mary-Anne; Alexander, Kimberly; Omara, Tracy; Wu, Huihai; Henrique, Rui; Pinto, Pedro; Santos, Joana; Barros-Silva, Joao; Conti, David V.; Albanes, Demetrius; Berg, Christine; Berndt, Sonja I.; Campa, Daniele; Crawford, E. David; Diver, W. Ryan; Gapstur, Susan M.; Gaziano, J. Michael; Giovannucci, Edward; Hoover, Robert; Hunter, David J.; Johansson, Mattias; Kraft, Peter; Le Marchand, Loic; Lindström, Sara; Navarro, Carmen; Overvad, Kim; Riboli, Elio; Siddiq, Afshan; Stevens, Victoria L.; Trichopoulos, Dimitrios; Vineis, Paolo; Yeager, Meredith; Trynka, Gosia; Raychaudhuri, Soumya; Schumacher, Frederick R.; Price, Alkes L.; Freedman, Matthew L.; Haiman, Christopher A.; Pasaniuc, Bogdan

    2016-01-01

    Although genome-wide association studies have identified over 100 risk loci that explain ∼33% of familial risk for prostate cancer (PrCa), their functional effects on risk remain largely unknown. Here we use genotype data from 59,089 men of European and African American ancestries combined with cell-type-specific epigenetic data to build a genomic atlas of single-nucleotide polymorphism (SNP) heritability in PrCa. We find significant differences in heritability between variants in prostate-relevant epigenetic marks defined in normal versus tumour tissue as well as between tissue and cell lines. The majority of SNP heritability lies in regions marked by H3k27 acetylation in prostate adenoc7arcinoma cell line (LNCaP) or by DNaseI hypersensitive sites in cancer cell lines. We find a high degree of similarity between European and African American ancestries suggesting a similar genetic architecture from common variation underlying PrCa risk. Our findings showcase the power of integrating functional annotation with genetic data to understand the genetic basis of PrCa. PMID:27052111

  8. Mosquito vectors and the spread of cancer: an overlooked connection?

    Science.gov (United States)

    Benelli, Giovanni; Lo Iacono, Annalisa; Canale, Angelo; Mehlhorn, Heinz

    2016-06-01

    Mosquitoes (Diptera: Culicidae) represent a key threat for millions of humans and animals worldwide, vectoring important pathogens and parasites, including malaria, dengue, filariasis, and Zika virus. Besides mosquito-borne diseases, cancers figure among the leading causes of mortality worldwide. It is expected that annual cancer cases will rise from 14 million in 2012 to 22 million within the next two decades. Notably, there are few contrasting evidences of the relationship between cancer and mosquito-borne diseases, with special reference to malaria. However, analogies at the cellular level for the two diseases were reported. Recently, a significant association of malaria incidence with all cancer mortality in 50 USA states was highlighted and may be explained by the ability of Plasmodium to induce suppression of the immune system. However, it was hypothesized that Anopheles vectors may transmit obscure viruses linked with cancer development. The possible activation of cancer pathways by mosquito feeding events is not rare. For instance, the hamster reticulum cell sarcoma can be transmitted through the bites of Aedes aegypti by a transfer of tumor cells. Furthermore, mosquito bites may influence human metabolic pathways following different mechanisms, leading to other viral infections and/or oncogenesis. Hypersensitivity to mosquito bites is routed by a unique pathogenic mechanism linking Epstein-Barr virus infection, allergy, and oncogenesis. During dengue virus infection, high viral titers, macrophage infiltration, and tumor necrosis factor alpha production in the local tissues are the three key important events that lead to hemorrhage. Overall, basic epidemiological knowledge on the relationships occurring between mosquito vector activity and the spread of cancer is urgently needed, as well as detailed information about the ability of Culicidae to transfer viruses or tumor cells among hosts over time. Current evidences on nanodrugs with multipotency against

  9. Researchers Pinpoint More Genes Linked to Vitiligo

    Science.gov (United States)

    ... 161452.html Researchers Pinpoint More Genes Linked to Vitiligo Genetic clues to this autoimmune disease could lead ... identified more genes linked to the autoimmune disease vitiligo, which causes patches of white skin and hair. ...

  10. Clinico-pathological signiifcance of extra-nodal spread in special types of breast cancer

    Institute of Scientific and Technical Information of China (English)

    Ecmel Isik Kaygusuz; Handan Cetiner; Hulya Yavuz

    2014-01-01

    Objective: To investigate the signiifcance of extra-nodal spread in special histological sub-types of breast cancer and the relationship of such spread with prognostic parameters. Methods: A total of 303 breast cancer cases were classiifed according to tumor type, and each tumor group was subdivided according to age, tumor diameter, lymph node metastasis, extra-nodal spread, vein invasion in the adjacent soft tissue, distant metastasis, and immunohistochemical characteristics [estrogen receptor (ER), progesterone receptor (PR) existence, p53, c-erbB-2, and proliferative rate (Ki-67)]. hTe 122 cases with extra-nodal spread were clinically followed up. Results: An extra-nodal spread was observed in 40% (122 cases) of the 303 breast cancer cases. hTe spread most frequently presented in micro papillary carcinoma histological sub-type (40 cases, 75%), but least frequently presents in mucinous carcinoma (2 cases, 8%). Patients with extra-nodal spread had a high average number of metastatic lymph nodes (8.3) and a high distant metastasis rate (38 cases, 31%) compared with patients without extra-nodal spread. Conclusion: hTe existence of extra-nodal spread in the examined breast cancer sub-types has predictive value in forecasting the number of metastatic lymph nodes and the disease prognosis.

  11. HUMAN CANCER IS A PARASITE SPREAD VIA INTRUSION IN GENOME

    Directory of Open Access Journals (Sweden)

    Sergey N. Rumyantsev

    2013-03-01

    Full Text Available The present article is devoted to further development of new paradigm about the biology of human cancer: the hypothesis of parasitic nature, origin and evolution of the phenomenon. The study included integrative reconsidering, and reinterpretation of the make-ups, traits and processes existing both in human and animal cancers. It was demonstrated that human cancer possesses nearly analogous set of traits characteristic of transmissible animal cancer. Undoubted analogies are seen in the prevalence, clinical exposure, progression of disease, origin of causative agents, immune response against invasion and especially in the intrinsic deviations of the leading traits of cancerous cells. Both human and animal cancers are highly exceptional pathogens. But in contrast to contagious animal cancers the cells of of human cancer can not pass between individuals as usual infectious agents. Exhaustive evidence of the parasitic nature and evolutionary origin of human cancer was revealed and interpreted. In contrast to animal cancer formed of solitary cell lineage, human cancer consists of a couple of lineages constructed under different genetic regulations and performed different structural and physiological functions. The complex make-up of cancer composition remains stable over sequential propagation. The subsistence of human cancer regularly includes obligatory interchange of its successive forms. Human cancer possesses its own biological watch and the ability to gobble its victim, transmit via the intrusion of the genome, perform intercommunications within the tumor components and between the dispersed subunits of cancer. Such intrinsic traits characterize human cancer as a primitively structured parasite that can be classified in Class Mammalians, Species Genomeintruder malevolent (G.malevolent.

  12. Cell biomechanics and metastatic spreading: a study on human breast cancer cells

    OpenAIRE

    Tavano, Federica

    1982-01-01

    Despite the intensive research of the past decades in oncology, cancer invasion and metastasis still represent the most important problem for treatment and the most common cause of death in cancer patients. Metastasis refers to the spread of malignant cells from a primary tumour to distant sites of the body and the adaptation of these cancer cells to a new and different tissue microenvironment. Usually, millions of cells can be released by a tumour into the circulation every day, but only a t...

  13. Collective behavior and critical fluctuations in the spatial spreading of obesity, diabetes and cancer

    CERN Document Server

    Gallos, Lazaros K; Havlin, Shlomo; Sigman, Mariano; Makse, Hernán A

    2012-01-01

    Non-communicable diseases like diabetes, obesity and certain forms of cancer have been increasing in many countries at alarming levels. A difficulty in the conception of policies to reverse these trends is the identification of the drivers behind the global epidemics. Here, we implement a spatial spreading analysis to investigate whether diabetes, obesity and cancer show spatial correlations revealing the effect of collective and global factors acting above individual choices. We adapt a theoretical framework for critical physical systems displaying collective behavior to decipher the laws of spatial spreading of diseases. We find a regularity in the spatial fluctuations of their prevalence revealed by a pattern of scale-free long-range correlations. The fluctuations are anomalous, deviating in a fundamental way from the weaker correlations found in the underlying population distribution. This collective behavior indicates that the spreading dynamics of obesity, diabetes and some forms of cancer like lung can...

  14. Endoscopically observable white nodule caused by distal intramural lymphatic spread of rectal cancer: a case report

    Directory of Open Access Journals (Sweden)

    Tsumura Ayako

    2012-10-01

    Full Text Available Abstract This report describes a case of rectal cancer with endoscopically observable white nodules caused by distal intramural lymphatic spread. A 57-year-old female presented to our hospital with frequent diarrhea and hemorrhoids. Computed tomography showed bilateral ovarian masses and three hepatic tumors diagnosed as rectal cancer metastases, and also showed multiple lymph node involvement. The patient was preoperatively diagnosed with stage IV rectal cancer. Colonoscopy demonstrated that primary rectal cancer existed 15 cm from the anal verge and that there were multiple white small nodules on the anal side of the primary tumor extending to the dentate line. Biopsies of the white spots were performed, and they were identified as adenocarcinoma. The patient underwent Hartmann’s procedure because of the locally advanced primary tumor. The white nodules were ultimately diagnosed as being caused by intramural lymphatic spreading because lymphatic permeation was strongly positive at the surrounding area. Small white nodules near a primary rectal cancer should be suspected of being intramural spreading. Endoscopic detection of white nodules may be useful for the diagnosis of distal intramural spread.

  15. Bacterial proteins pinpoint a single eukaryotic root.

    Science.gov (United States)

    Derelle, Romain; Torruella, Guifré; Klimeš, Vladimír; Brinkmann, Henner; Kim, Eunsoo; Vlček, Čestmír; Lang, B Franz; Eliáš, Marek

    2015-02-17

    The large phylogenetic distance separating eukaryotic genes and their archaeal orthologs has prevented identification of the position of the eukaryotic root in phylogenomic studies. Recently, an innovative approach has been proposed to circumvent this issue: the use as phylogenetic markers of proteins that have been transferred from bacterial donor sources to eukaryotes, after their emergence from Archaea. Using this approach, two recent independent studies have built phylogenomic datasets based on bacterial sequences, leading to different predictions of the eukaryotic root. Taking advantage of additional genome sequences from the jakobid Andalucia godoyi and the two known malawimonad species (Malawimonas jakobiformis and Malawimonas californiana), we reanalyzed these two phylogenomic datasets. We show that both datasets pinpoint the same phylogenetic position of the eukaryotic root that is between "Unikonta" and "Bikonta," with malawimonad and collodictyonid lineages on the Unikonta side of the root. Our results firmly indicate that (i) the supergroup Excavata is not monophyletic and (ii) the last common ancestor of eukaryotes was a biflagellate organism. Based on our results, we propose to rename the two major eukaryotic groups Unikonta and Bikonta as Opimoda and Diphoda, respectively.

  16. CLINICALLY LOCALIZED PROSTATE CANCER: CAPACITIES OF MATRIX COIL MRI TO DETECT MINIMAL EXTRACAPSULAR TUMOR SPREAD

    Directory of Open Access Journals (Sweden)

    E. A. Petrova

    2012-01-01

    Full Text Available Retrospective assessment of preoperative magnetic resonance imaging (MRI data in 37 patients with prostate cancer, who had undergone radical prostatectomy, established the most diagnostically valuable MRI signs of minimal extracapsular spread (ECS: asymmetry of neurovascular fascicles (72 % accuracy, 93 % sensitivity, 77 % specificity, 73 % positive and 94% negative predictive values and iron outline deformity/irregularity (66/80/64/60/82 %, respectively; as well as their higher diagnostic efficiency versus the clinical and laboratory predictors of ECS: total Gleason scores (58/87/55/57/86 %, respectively and serum PSA levels (uninformative, which permits their consideration while choosing a more or less radical prostatectomy modality.

  17. CLINICALLY LOCALIZED PROSTATE CANCER: CAPACITIES OF MATRIX COIL MRI TO DETECT MINIMAL EXTRACAPSULAR TUMOR SPREAD

    Directory of Open Access Journals (Sweden)

    E. A. Petrova

    2014-08-01

    Full Text Available Retrospective assessment of preoperative magnetic resonance imaging (MRI data in 37 patients with prostate cancer, who had undergone radical prostatectomy, established the most diagnostically valuable MRI signs of minimal extracapsular spread (ECS: asymmetry of neurovascular fascicles (72 % accuracy, 93 % sensitivity, 77 % specificity, 73 % positive and 94% negative predictive values and iron outline deformity/irregularity (66/80/64/60/82 %, respectively; as well as their higher diagnostic efficiency versus the clinical and laboratory predictors of ECS: total Gleason scores (58/87/55/57/86 %, respectively and serum PSA levels (uninformative, which permits their consideration while choosing a more or less radical prostatectomy modality.

  18. Harnessing membrane trafficking to promote cancer spreading and invasion: The case of RAB2A.

    Science.gov (United States)

    Kajiho, Hiroaki; Kajiho, Yuko; Scita, Giorgio

    2017-01-06

    How cancer disseminates and metastasizes remains an outstanding open question. Emerging evidence indicates that membrane trafficking is frequently harnessed by tumors of epithelial origin to acquire a mesenchymal program of invasiveness. However, the critical molecular hubs used by cancer cells this context have only began to be elucidated. Here, we discussed the results of a recent phenotypic screening that led to the identification of the small GTPase RAB2A, not previously involved in cancer dissemination, as pivotal for the acquisition of pericellular proteolysis, cell dissemination and distant metastatic spreading of human breast cancer. At the cellular levels, RAB2A controls both canonical polarized Golgi-to-Plasma membrane trafficking of the junctional protein E-cadherin, and post-endocytic trafficking of the membrane-bound metalloprotease, MT1-MMP. This finding reveals an unexpected plasticity in the control of diverse trafficking routes exerted by RAB2A through canonical (Golgi stacking) and non-canonical (late endosome recycling) functional interactions, contributing to break established membrane trafficking dogma on the rigorous molecular distinction between polarized Golgi and post endocytic routes. Finally, they suggest that epithelial cancers may specifically select for those molecules that enable them to control multiple trafficking routes, in turn essential for the regulation of activities necessary for acquisition of mesenchymal traits.

  19. Lack of Methylene Blue Staining in Superficial Epithelia as a Possible Marker for Superficial Lateral Spread of Bile Duct Cancer

    Directory of Open Access Journals (Sweden)

    I. Maetani

    1996-01-01

    epithelia. The cancerous epithelia stained significantly less often than either the normal (p = 0.000005 or the metaplastic (p = 0.001 epithelia. Evaluation of methylene blue staining during PTCS revealed that this stain was absorbed by the cholangial epithelia, not superficially stuck to it. The difference in methylene blue staining properties between the cancerous and normal epithelia could be helpful to clarify the boundary of superficial lateral spread of bile duct cancer.

  20. Defining central themes in breast cancer biology by differential proteomics: conserved regulation of cell spreading and focal adhesion kinase.

    Science.gov (United States)

    Bateman, Nicholas W; Sun, Mai; Hood, Brian L; Flint, Melanie S; Conrads, Thomas P

    2010-10-01

    Breast cancer is a highly heterogeneous disease, an observation that underscores the importance of elucidating conserved molecular characteristics, such as gene and protein expression, across breast cancer cell types toward providing a greater understanding of context-specific features central to this disease. Motivated by the goal of defining central biological themes across breast cancer cell subtypes, we conducted a global proteomic analysis of three breast cancer cell lines, MCF7, SK-BR-3, and MDA-MB-231, and compared these to a model of nontransformed mammary cells (MCF10A). Our results demonstrate modulation of proteins localized to the extracellular matrix, plasma membrane, and nucleus, along with coordinate decreases in proteins that regulate "cell spreading," a cellular event previously shown to be dysregulated in transformed cells. Protein interaction network analysis revealed the clustering of focal adhesion kinase (FAK), a fundamental regulator of cell spreading, with several proteins identified as mutually, differentially abundant across breast cancer cell lines that impact expression and activity of FAK, such as neprilysin and keratin 19. These analyses provide insights into conservation of protein expression across breast cancer cell subtypes, a subset of which warrants further investigation for their roles in the regulation of cell spreading and FAK in breast cancer.

  1. New models of hematogenous ovarian cancer metastasis demonstrate preferential spread to the ovary and a requirement for the ovary for abdominal dissemination.

    Science.gov (United States)

    Coffman, Lan G; Burgos-Ojeda, Daniela; Wu, Rong; Cho, Kathleen; Bai, Shoumei; Buckanovich, Ronald J

    2016-09-01

    Emerging evidence suggest that many high-grade serous "ovarian" cancers (HGSOC) start in the fallopian tube. Cancer cells are then recruited to the ovary and then spread diffusely through the abdomen. The mechanism of ovarian cancer spread was thought to be largely due to direct shedding of tumor cells into the peritoneal cavity with vascular spread being of limited importance. Recent work challenges this dogma, suggesting hematogenous spread of ovarian cancer may play a larger role in ovarian cancer cell metastasis than previously thought. One reason the role of vascular spread of ovarian cancer has not been fully elucidated is the lack of easily accessible models of vascular ovarian cancer metastasis. Here, we present 3 metastatic models of ovarian cancer which confirm the ability of ovarian cancer to hematogenously spread. Strikingly, we observe a high rate of metastasis to the ovary with the development of ascites in these models. Interestingly, oophorectomy resulted in a complete loss of peritoneal metastases and ascites. Taken together, our data indicate that hematogenously disseminated HGSOC cells have a unique tropism for the ovary and that hematogenous spread in ovarian cancer may be more common than appreciated. Furthermore, our studies support a critical role for the ovary in promoting HGSOC cell metastasis to the abdomen. The models developed here represent important new tools to evaluate both the mechanism of cancer cell recruitment to the ovary and understand and target key steps in ovarian cancer metastasis.

  2. EXTRACAPSULAR SPREAD IN IPSILATERAL NECK METASTASIS: AN IMPORTANT PROGNOSTIC FACTOR IN LARYNGEAL CANCER

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To evaluate the impact of extracapsular spread (ECS) in ipsilateral neck metastasis on prognosis and its related factors in laryngeal cancer.Methods The study included 184 patients who underwent laryngectomy and simultaneous radical or modified radical neck dissection between January 1994 and December 1997 for laryngeal cancer. All of them had a complete 5-year follow-up. We used transparent lymph node detection and continuous slicing method on all neck dissection specimens.Kaplan-Meier model was used for survival analysis and the log-rank test was used to assess significance.Results We found pathological neck metastases in 80 patients. Among them, 26 cases (32.5%) had ECS in ipsilateral neck. ECS incidence increased with advanced pathological N (pN) stages (pN1 3.7%, pN2a 25.0%, pN2b 50. 0%, and pN2c 55.6%; P=0.001). ECS incidence also increased with number of positive nodes ( 1 positive node 8.6%, 2 positive nodes 33.3%, 3 and more positive nodes 66. 7%; P<0.001). Incidences of contralateral neck metastases and ipsilateral neck recurrence in patients with ECS were higher than those in patients without ECS (46.2%vs.24. 1%, P=0 046; 34. 6% vs. 7.4%, P =0. 002). The 5-year survival rate of patients with ECS was significantly lower than that of patients without ECS (23.1% vs. 57.4%,P=0.013).Conclusion ECS is an important prognostic factor in laryngeal cancer. Patients with ECS have a higher incidence of contralateral neck metastasis, so bilateral neck dissection should be selected.

  3. Utility of the dual-specificity protein kinase TTK as a therapeutic target for intrahepatic spread of liver cancer.

    Science.gov (United States)

    Miao, Ruoyu; Wu, Yan; Zhang, Haohai; Zhou, Huandi; Sun, Xiaofeng; Csizmadia, Eva; He, Lian; Zhao, Yi; Jiang, Chengyu; Miksad, Rebecca A; Ghaziani, Tahereh; Robson, Simon C; Zhao, Haitao

    2016-09-13

    Therapies for primary liver cancer, the third leading cause of cancer-related death worldwide, remain limited. Following multi-omics analysis (including whole genome and transcriptome sequencing), we were able to identify the dual-specific protein kinase TTK as a putative new prognostic biomarker for liver cancer. Herein, we show that levels of TTK protein are significantly elevated in neoplastic tissues from a cohort of liver cancer patients, when compared with adjacent hepatic tissues. We also tested the utility of TTK targeted inhibition and have demonstrated therapeutic potential in an experimental model of liver cancer in vivo. Following lentiviral shRNA knockdown in several human liver cancer cell lines, we demonstrated that TTK boosts cell growth and promotes cell spreading; as well as protects against senescence and decreases autophagy. In an experimental animal model, we show that in vitro knockdown of TTK effectively blocks intrahepatic growth of human HCC xenografts. Furthermore, we note that, in vivo silencing of TTK, by systemically delivering TTK siRNAs to already tumor-bearing liver, limits intrahepatic spread of liver cancer cells. This intervention is associated with decreased tumor aggressiveness, as well as increased senescence and autophagy. Taken together, our data suggest that targeted TTK inhibition might have clinical utility as an adjunct therapy in management of liver cancer.

  4. Estimation of the extent of local prostate cancer spread according to magnetic resonance imaging findings and clinical prognostic factors

    Directory of Open Access Journals (Sweden)

    A. T. Kazymov

    2015-01-01

    Full Text Available To estimate the extent of local tumor spread is a main goal in the diagnosis of prostate cancer (PC. The value of this criterion is that its clinical stage plays a key role in choosing a treatment policy. Overestimation of the clinical stage of cancer leads to the fact that specialists refuse radical and its underestimation gives rise to its recurrence. Our trial defined criteria for the diagnostic efficiency of magnetic resonance imaging (MRI in 150 PC patients who had undergone radical prostatectomy. The findings were as follows: the diagnostic sensitivity of the method in determining the spread of the cancer beyond the organ was 76.8 %; its diagnostic specificity and accuracy were 80.2 and 78.7 %, respectively. The positive predictive value in detecting the extra-organ spread of the tumor was equal to 76.8 %; the negative predictive value was 80.2 %. A prognostic classification of a risk for locally advanced PS has been developed using the independent clinical and MRI signs found.

  5. Clinical relevance of antigen spreading pattern induced by CHP-MAGE-A4 cancer vaccination.

    Science.gov (United States)

    Miyauchi, Kengo; Tsuchikawa, Takahiro; Wada, Masataka; Abiko, Takehiro; Kyogoku, Noriaki; Shichinohe, Toshiaki; Miyahara, Yoshihiro; Kageyama, Shinichi; Ikeda, Hiroaki; Shiku, Hiroshi; Hirano, Satoshi

    2016-05-01

    To investigate the antigen spreading pattern in the CHP-MAGE-A4-vaccinated patients and analyze the clinical relevance of antigen spreading pattern as a surrogate marker of patient survival. 12 patients who had been injected with 300 μg of CHP-MAGE-A4 and 0.5 Klinische Einheit of OK-432 in more than five vaccinations were analyzed. Increases in the anti-MAGE-A4-specific antibody response were observed in eight patients (66.7%), compared with six patients (50%) for anti-NY-ESO-1 and five patients (41.7%) for anti-MAGE-A3 after five vaccinations. We identified frequent antigen spreading following MAGE-A4 vaccinations without associations with the clinical response or patient prognosis. Antigen spreading pattern might reflect tumor shrinkage as a response to treatment and treatment history (clinical trial registration number: UMIN000001999).

  6. Implementation and spread of interventions into the multilevel context of routine practice and policy: implications for the cancer care continuum.

    Science.gov (United States)

    Yano, Elizabeth M; Green, Lawrence W; Glanz, Karen; Ayanian, John Z; Mittman, Brian S; Chollette, Veronica; Rubenstein, Lisa V

    2012-05-01

    The promise of widespread implementation of efficacious interventions across the cancer continuum into routine practice and policy has yet to be realized. Multilevel influences, such as communities and families surrounding patients or health-care policies and organizations surrounding provider teams, may determine whether effective interventions are successfully implemented. Greater recognition of the importance of these influences in advancing (or hindering) the impact of single-level interventions has motivated the design and testing of multilevel interventions designed to address them. However, implementing research evidence from single- or multilevel interventions into sustainable routine practice and policy presents substantive challenges. Furthermore, relatively few multilevel interventions have been conducted along the cancer care continuum, and fewer still have been implemented, disseminated, or sustained in practice. The purpose of this chapter is, therefore, to illustrate and examine the concepts underlying the implementation and spread of multilevel interventions into routine practice and policy. We accomplish this goal by using a series of cancer and noncancer examples that have been successfully implemented and, in some cases, spread widely. Key concepts across these examples include the importance of phased implementation, recognizing the need for pilot testing, explicit engagement of key stakeholders within and between each intervention level; visible and consistent leadership and organizational support, including financial and human resources; better understanding of the policy context, fiscal climate, and incentives underlying implementation; explication of handoffs from researchers to accountable individuals within and across levels; ample integration of multilevel theories guiding implementation and evaluation; and strategies for long-term monitoring and sustainability.

  7. The degree of extramural spread of T3 rectal cancer: a plea to the UICC and AJCC.

    Science.gov (United States)

    Zinicola, R; Pedrazzi, G; Haboubi, N; Nicholls, R J

    2017-03-01

    The above article, published online on 15 July 2016 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor-in-Chief, Neil Mortensen, and John Wiley & Sons Limited. After acceptance the authors were made aware of a contribution to a prior publication of the UICC, TNM Supplement: A commentary on uniform use, 4th Edition, ed. C. Wittekind (Wiley, 2012), p. 195, which renders the central argument of their article invalid. They have therefore asked for it to be withdrawn. A modified version of the paper was published in the January 2017 issue (volume 19; issue 1) with the title "The degree of extramural spread of T3 rectal cancer: an appeal to the American Joint Committee on Cancer".

  8. Landmark-based autonomous navigation for pinpoint planetary landing

    Science.gov (United States)

    Xu, Chao; Wang, Dayi; Huang, Xiangyu

    2016-12-01

    A landmark-based autonomous navigation scheme is presented for pinpoint planetary landing. The dynamic model is built on the basis of measurements from Inertial Measurement Unit. Measurement models of landmarks with known coordinates and landmarks with unknown coordinates extracted from sequential descent images are developed and used to calculated the state corrections in Extend Kalman Filter, respectively. Then, the corrections are fused by a covariance intersection fusion algorithm to perform state updates. The tight coupling of the two types of landmark observations yields accurate and robust state estimates. Extensive simulations are performed, which confirm the validity of the proposed navigation scheme and analyze the effects of factors, such as the horizonal position errors and the densities of landmarks with known coordinates and the roughness of the landing surface, on the navigation accuracy.

  9. The Role of Mesenchymal Stem Cells in Promoting Ovarian Cancer Growth and Spread

    Science.gov (United States)

    2014-12-01

    Coffelt  SB,  Ruth  S.  Waterman,  Luisa   Florez ,  Kerstin  Höner  zu  Bentrup,  Kevin  J.  Zwezdaryk,  Suzanne  L...cancer  cells.  Mol  Cancer  Res  2009,  7:907-­‐915.2755540 4. Coffelt  SB,  Waterman  RS,   Florez  L,  Honer  zu...66: 6807–6815. 49. Coffelt SB, Waterman RS, Florez L, Honer zu Bentrup K, Zwezdaryk KJ, et al. (2008) Ovarian cancers overexpress the antimicrobial

  10. Correlation of erythrocyte and plasma levels of zinc, copper, and iron with evidence of metastatic spread in cancer patients.

    Science.gov (United States)

    Gorodetsky, R; Fuks, Z; Sulkes, A; Ginsburg, H; Weshler, Z

    1985-02-15

    The level of plasma copper (Cu-Pl) and zinc (Zn-Pl) and the level of erythrocyte iron (Fe-RBC), copper (Cu-RBC), and zinc (Zn-RBC) were determined in the blood of 70 normal donors and 138 patients with various solid tumors by diagnostic x-ray spectrometry (DXS), a technique based on x-ray fluorescence spectrometry analysis. There were no significant changes in the mean values of Zn-Pl, Fe-RBC, and Cu-RBC in the patients when compared with those of normal donors. The mean level of Cu-Pl in the normal donors was 1.34 +/- 0.37 micrograms/ml; it was significantly increased in the patients, ranging between 1.47 +/- 0.34 micrograms/ml for patients without evidence of active cancer (NED) and 1.91 +/- 0.76 micrograms/ml for patients with hepatic metastases. The most significant change observed was an increase in the Zn-RBC found in the patients with clinical evidence of metastatic spread. Whereas the Zn-RBC level in the normal donors was 9.85 +/- 1.47 micrograms/g wet weight, and not significantly elevated in the NED patients, it was elevated to values of 11.37 +/- 1.55 micrograms/g (P less than 0.004) for patients with soft tissue and hepatic metastases and was 12.34 +/- 1.65 micrograms/g (P less than 0.001) for patients with bone metastases. The data suggest a clear correlation between Zn-RBC and metastatic spread in nonlymphomatous human cancer.

  11. Pinpointing disease genes through phenomic and genomic data fusion.

    Science.gov (United States)

    Jiang, Rui; Wu, Mengmeng; Li, Lianshuo

    2015-01-01

    Pinpointing genes involved in inherited human diseases remains a great challenge in the post-genomics era. Although approaches have been proposed either based on the guilt-by-association principle or making use of disease phenotype similarities, the low coverage of both diseases and genes in existing methods has been preventing the scan of causative genes for a significant proportion of diseases at the whole-genome level. To overcome this limitation, we proposed a rigorous statistical method called pgFusion to prioritize candidate genes by integrating one type of disease phenotype similarity derived from the Unified Medical Language System (UMLS) and seven types of gene functional similarities calculated from gene expression, gene ontology, pathway membership, protein sequence, protein domain, protein-protein interaction and regulation pattern, respectively. Our method covered a total of 7,719 diseases and 20,327 genes, achieving the highest coverage thus far for both diseases and genes. We performed leave-one-out cross-validation experiments to demonstrate the superior performance of our method and applied it to a real exome sequencing dataset of epileptic encephalopathies, showing the capability of this approach in finding causative genes for complex diseases. We further provided the standalone software and online services of pgFusion at http://bioinfo.au.tsinghua.edu.cn/jianglab/pgfusion. pgFusion not only provided an effective way for prioritizing candidate genes, but also demonstrated feasible solutions to two fundamental questions in the analysis of big genomic data: the comparability of heterogeneous data and the integration of multiple types of data. Applications of this method in exome or whole genome sequencing studies would accelerate the finding of causative genes for human diseases. Other research fields in genomics could also benefit from the incorporation of our data fusion methodology.

  12. The Host Microenvironment Influences Prostate Cancer Invasion, Systemic Spread, Bone Colonization, and Osteoblastic Metastasis

    Science.gov (United States)

    Ganguly, Sourik S.; Li, Xiaohong; Miranti, Cindy K.

    2014-01-01

    Prostate cancer (PCa) is the second leading cause of cancer death in men worldwide. Most PCa deaths are due to osteoblastic bone metastases. What triggers PCa metastasis to the bone and what causes osteoblastic lesions remain unanswered. A major contributor to PCa metastasis is the host microenvironment. Here, we address how the primary tumor microenvironment influences PCa metastasis via integrins, extracellular proteases, and transient epithelia-mesenchymal transition (EMT) to promote PCa progression, invasion, and metastasis. We discuss how the bone-microenvironment influences metastasis; where chemotactic cytokines favor bone homing, adhesion molecules promote colonization, and bone-derived signals induce osteoblastic lesions. Animal models that fully recapitulate human PCa progression from primary tumor to bone metastasis are needed to understand the PCa pathophysiology that leads to bone metastasis. Better delineation of the specific processes involved in PCa bone metastasize is needed to prevent or treat metastatic PCa. Therapeutic regimens that focus on the tumor microenvironment could add to the PCa pharmacopeia. PMID:25566502

  13. p53, cathepsin D, Bcl-2 are joint prognostic indicators of breast cancer metastatic spreading.

    Science.gov (United States)

    Guerra, Emanuela; Cimadamore, Alessia; Simeone, Pasquale; Vacca, Giovanna; Lattanzio, Rossano; Botti, Gerardo; Gatta, Valentina; D'Aurora, Marco; Simionati, Barbara; Piantelli, Mauro; Alberti, Saverio

    2016-08-18

    Traditional prognostic indicators of breast cancer, i.e. lymph node diffusion, tumor size, grading and estrogen receptor expression, are inadequate predictors of metastatic relapse. Thus, additional prognostic parameters appear urgently needed. Individual oncogenic determinants have largely failed in this endeavour. Only a few individual tumor growth drivers, e.g. mutated p53, Her-2, E-cadherin, Trops, did reach some prognostic/predictive power in clinical settings. As multiple factors are required to drive solid tumor progression, clusters of such determinants were expected to become stronger indicators of tumor aggressiveness and malignant progression than individual parameters. To identify such prognostic clusters, we went on to coordinately analyse molecular and histopathological determinants of tumor progression of post-menopausal breast cancers in the framework of a multi-institutional case series/case-control study. A multi-institutional series of 217 breast cancer cases was analyzed. Twenty six cases (12 %) showed disease relapse during follow-up. Relapsed cases were matched with a set of control patients by tumor diameter, pathological stage, tumor histotype, age, hormone receptors and grading. Histopathological and molecular determinants of tumor development and aggressiveness were then analyzed in relapsed versus non-relapsed cases. Stepwise analyses and model structure fitness assessments were carried out to identify clusters of molecular alterations with differential impact on metastatic relapse. p53, Bcl-2 and cathepsin D were shown to be coordinately associated with unique levels of relative risk for disease relapse. As many Ras downstream targets, among them matrix metalloproteases, are synergistically upregulated by mutated p53, whole-exon sequence analyses were performed for TP53, Ki-RAS and Ha-RAS, and findings were correlated with clinical phenotypes. Notably, TP53 insertion/deletion mutations were only detected in relapsed cases

  14. Reduced risk of axillary lymphatic spread in triple-negative breast cancer

    DEFF Research Database (Denmark)

    Holm-Rasmussen, Emil Villiam; Jensen, Maj-Britt; Balslev, Eva

    2015-01-01

    involvement at diagnosis compared to a HER2-negative status (OR 1.37; 95 % CI 1.24-1.50; P negative patients (P triple-negative...... of tumor subtypes in ALN involvement. The risk of ALN metastases at the time of diagnosis was significantly reduced in HR-negative patients compared to HR-positive patients [adjusted odds ratio (OR) 0.69; 95 % CI 0.63-0.76; P = 0.0009]. A HER2-positive status was associated with an increased risk of ALN...... breast cancer (TNBC) patients showed a significantly reduced risk of ALN involvement at the time of diagnosis compared to patients with HR-positive/HER2-negative tumors (OR 0.55; 95 % CI 0.49-0.62; P

  15. Magnetic resonance imaging for assessment of parametrial tumour spread and regression patterns in adaptive cervix cancer radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Maximilian P.; Fidarova, Elena [Dept. of Radiotherapy, Comprehensive Cancer Center, Medical Univ. of Vienna, Vienna (Austria)], e-mail: maximilian.schmid@akhwien.at; Poetter, Richard [Dept. of Radiotherapy, Comprehensive Cancer Center, Medical Univ. of Vienna, Vienna (Austria); Christian Doppler Lab. for Medical Radiation Research for Radiation Oncology, Medical Univ. of Vienna (Austria)] [and others

    2013-10-15

    Purpose: To investigate the impact of magnetic resonance imaging (MRI)-morphologic differences in parametrial infiltration on tumour response during primary radio chemotherapy in cervical cancer. Material and methods: Eighty-five consecutive cervical cancer patients with FIGO stages IIB (n = 59) and IIIB (n = 26), treated by external beam radiotherapy ({+-}chemotherapy) and image-guided adaptive brachytherapy, underwent T2-weighted MRI at the time of diagnosis and at the time of brachytherapy. MRI patterns of parametrial tumour infiltration at the time of diagnosis were assessed with regard to predominant morphology and maximum extent of parametrial tumour infiltration and were stratified into five tumour groups (TG): 1) expansive with spiculae; 2) expansive with spiculae and infiltrating parts; 3) infiltrative into the inner third of the parametrial space (PM); 4) infiltrative into the middle third of the PM; and 5) infiltrative into the outer third of the PM. MRI at the time of brachytherapy was used for identifying presence (residual vs. no residual disease) and signal intensity (high vs. intermediate) of residual disease within the PM. Left and right PM of each patient were evaluated separately at both time points. The impact of the TG on tumour remission status within the PM was analysed using {chi}2-test and logistic regression analysis. Results: In total, 170 PM were analysed. The TG 1, 2, 3, 4, 5 were present in 12%, 11%, 35%, 25% and 12% of the cases, respectively. Five percent of the PM were tumour-free. Residual tumour in the PM was identified in 19%, 68%, 88%, 90% and 85% of the PM for the TG 1, 2, 3, 4, and 5, respectively. The TG 3 - 5 had significantly higher rates of residual tumour in the PM in comparison to TG 1 + 2 (88% vs. 43%, p < 0.01). Conclusion: MRI-morphologic features of PM infiltration appear to allow for prediction of tumour response during external beam radiotherapy and chemotherapy. A predominantly infiltrative tumour spread at the

  16. Diagnostic Value of Multislice Computed Tomography and Magnetic Resonance Imaging in the Diagnosis of Retroperitoneal Spread of Testicular Cancer: A Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, J. (Dept. of Medical Physics, Aarhus Univ. Hospital, Aarhus Sygehus, Aarhus (Denmark)); Jurik, A.G. (Dept. of Radiology, Aarhus Univ. Hospital, Aarhus Sygehus, Aarhus (Denmark))

    2009-11-15

    Testicular cancer is the most frequent malignant disorder in men aged 15-35 years. Generally, diagnosing and follow-up include computer tomography (CT) examinations to detect possible retroperitoneal spread (abdomen and pelvis), resulting in at least eight CT examinations. This patient group is thereby exposed to a non-neglectable radiation dose, increasing the risk of future radiation-induced secondary cancer. This is especially problematic in potentially surgically cured patients with stage 1 testicular cancer. Thus, it can be beneficial to substitute CT with magnetic resonance imaging (MRI), provided there is valid evidence that the diagnostic value of MRI is at least comparable to current multislice CT (MSCT). The purpose of this study was to analyze whether there is evidence to recommend a substitution of MSCT with MRI in the diagnosis of retroperitoneal spread of testicular cancer. A literature search on the diagnostic accuracy, specificity, and sensitivity of MSCT and MRI in the diagnosis of retroperitoneal spread of testicular cancer was performed in the following databases: PubMed, EmBase, and ISI Web of Science. The search was limited to include the period from 2000 to September 2008, and to human and English-language publications. Forty-four publications were obtained for formal review (27 from PubMed, 15 from EmBase, two from ISI Web of Science). None of the publications reviewed encompassed diagnostic specificity and sensitivity of MSCT, and they lacked systematic comparison of MSCT and MRI. Only one study included sensitivity and specificity of MRI compared to single-slice CT. Both methods had a sensitivity and a specificity of approximately 70%. The literature review did not reveal valid data regarding diagnostic accuracy of MRI compared with MSCT for diagnosing retroperitoneal spread of testicular cancer. A prospective blinded comparative study is needed to provide valid evidence

  17. Cryotherapy in Treating Patients With Lung Cancer That Has Spread to the Other Lung or Parts of the Body

    Science.gov (United States)

    2017-01-17

    Advanced Malignant Mesothelioma; Extensive Stage Small Cell Lung Cancer; Lung Metastases; Recurrent Malignant Mesothelioma; Recurrent Non-small Cell Lung Cancer; Recurrent Small Cell Lung Cancer; Stage IV Non-small Cell Lung Cancer

  18. Irinotecan-Eluting Beads in Treating Patients With Refractory Metastatic Colon or Rectal Cancer That Has Spread to the Liver

    Science.gov (United States)

    2016-01-22

    Liver Metastases; Mucinous Adenocarcinoma of the Colon; Mucinous Adenocarcinoma of the Rectum; Recurrent Colon Cancer; Recurrent Rectal Cancer; Signet Ring Adenocarcinoma of the Colon; Signet Ring Adenocarcinoma of the Rectum; Stage IVA Colon Cancer; Stage IVA Rectal Cancer; Stage IVB Colon Cancer; Stage IVB Rectal Cancer

  19. Intramural and mesorectal distal spread detected by whole-mount sections in the determination of optimal distal resection margin in patients undergoing surgery for rectosigmoid or rectal cancer without preoperative therapy.

    Science.gov (United States)

    Shimada, Yoshifumi; Takii, Yasumasa; Maruyama, Satoshi; Ohta, Tamaki

    2011-12-01

    The current Japanese general rules for clinical and pathologic studies on cancer of the colon, rectum, and anus state that a 3-cm distal resection margin is needed in resecting rectosigmoid cancer and rectal cancer with a distal edge above the peritoneal reflection, and 2 cm is needed for rectal cancer with a distal edge below the peritoneal reflection. The appropriateness of these rules has not been proved. Our aim was to evaluate the appropriateness of the Japanese rules. We retrospectively analyzed surgical and pathology records of patients who underwent surgery at a tertiary care cancer center in Japan. The study included 381 consecutive patients with stage I to IV rectosigmoid or rectal cancer without preoperative chemotherapy or radiotherapy. We investigated both intramural and mesorectal distal spread, using whole-mount sections to measure the maximum length of distal spread. Long distal spread was defined as distal spread longer than the distal resection margin stated in the Japanese general rules. Risk factors for both distal spread and long distal spread were evaluated. Of 381 patients, 325 (85.3%) had no distal spread and a total of 56 (14.7%) had distal spread. Distal spread was within the limits specified by the Japanese general rules in 48 of the 381 patients (12.6%) and beyond the Japanese limits (long distal spread) in 8 patients (2.1%). The prevalence of distal spread increased with TNM stage (stage I, 2.7%; stage II, 5.3%; stage III, 17.4%; stage IV, 46.2%). Long distal spread was not observed in stage I or II, was found in only 1.4% of patients with stage III disease and in 11.5% of patients with stage IV. The maximum extent of distal spread in patients with rectosigmoid cancer or rectal cancer with the distal edge above the peritoneal reflection was 38 mm; in patients with rectal cancer with the distal edge below the peritoneal reflection, 35 mm. Multivariable analyses showed that nodal involvement and distant metastasis were independent risk

  20. Dose estimation outside radiation field using Pinpoint and Semiflex ionization chamber detectors

    Science.gov (United States)

    Abdelaal, Ahmed M.; Attalla, Ehab M.; Elshemey, Wael M.

    2017-10-01

    This work aims to provide a comparison between two important detectors (Pinpoint and Semiflex) that are frequently used in radiation dosimetery in radiotherapy. This is carried out through the employment of both detectors in a quantitative estimation of the change in out-of-field dose with important dosimetric parameters such as field size (from 5×5 cm2 to 30×30 cm2) and depth (from 1.5 cm to 30 cm) at two different energies (6 MV and 15 MV) and two different collimator angles (0-90°). The change in out-of-field dose with Source-Skin-Distance (SSD) from 80 to 115 cm is also studied using both detectors. Results show that, the Pinpoint and Semiflex detectors both reported an increase in out-of-field dose with field size, depth, energy and SSD. In almost all measurements, Pinpoint detector reported considerably higher out-of-field dose values compared to Semiflex. For 6 MV and 0° collimator angle, the out-of-field dose at field size of 30×30 cm2 and at a depth of 1.5 cm is 7.3% for Pinpoint detector compared to 4.3% for Semiflex. At collimator angle of 90°, the out-of-field dose is 6.5% for Pinpoint detector compared to 5.5% for semiflex. The out-of-field dose for a depth of 30 cm and field size of 10×10 cm is 7.9% for Pinpoint detector compared to 5.9% for Semiflex. For 15 MV and 0° collimator angle, the out-of-field dose at field size of 30×30 cm2 and at a depth of 1.5 cm is 7.5% for Pinpoint detector compared 5.1% for Semiflex. At 6 MV, field size of 10×10 cm2 and depth of 1.5 cm, the out-of-field dose at SSD 115 cm is 3.7% for Pinpoint detector compared to 3.4% for Semiflex. The considerably higher out-of-field dose values reported by Pinpoint detector compared to Semiflex may be attributed to the relatively higher sensitivity of Pinpoint detector for low doses (such as out-of-field doses). Therefore, for reliable out-of-field dose measurements a Pinpoint detector is highly recommended.

  1. LEAPS Vaccine Incorporating HER-2/neu Epitope Elicits Protection That Prevents and Limits Tumor Growth and Spread of Breast Cancer in a Mouse Model.

    Science.gov (United States)

    Rosenthal, Ken S; Stone, Sarah; Koski, Gary; Zimmerman, Daniel H

    2017-01-01

    The prototype J-LEAPS T cell vaccine for HER-2/neu breast cancer (J-HER) consists of the murine HER-2/neu66-74 H-2(d) CD8 T cell epitope covalently attached through a triglycine linker to the J-immune cell binding ligand (ICBL) (human β2 microglobulin38-50 peptide). The J-ICBL was chosen for its potential to promote Th1/Tc1 responses. In this proof-of-concept study, the ability of J-HER to prevent or treat cancer was tested in the TUBO cell-challenged BALB/c mouse model for HER-2/neu-expressing tumors. The J-HER vaccine was administered as an emulsion in Montanide ISA-51 without the need for a more potent adjuvant. When administered as a prophylactic vaccination before tumor challenge, J-HER protected against tumor development for at least 48 days. Despite eliciting protection, antibody production in J-HER-immunized, TUBO-challenged mice was less than that in unimmunized mice. More importantly, therapeutic administration of J-HER one week after challenge with TUBO breast cancer cells limited the spread of the tumors and the morbidity and the mortality in the challenged mice. The ability to elicit responses that prevent spread of the TUBO tumor by J-HER suggests its utility as a neoimmunoadjuvant therapy to surgery. Individual or mixtures of J-LEAPS vaccines can be readily prepared to include different CD8 T cell epitopes to optimize tumor therapy and customize treatment for individuals with different HLA types.

  2. Preliminary Investigation of the Role of Cellular Immunity in Estrous Cycle Modulation of Post-Resection Breast Cancer Spread

    Science.gov (United States)

    2004-08-01

    Research and Treatment, Dec 2004) 10 Breast Cancer Research and Treatment 00:1-14, 2004. ©Kluwer Academic Publishers. Printed in the Netherlands ...the s eries of tumor growth rates represents After euthanasia , tumor and liver tissues were dissected tumor growth over six different 12 hour

  3. Metastatic Small Bowel Tumor from Descending Colon Cancer with Extensive Hematogenous or Lymphogenous Spread: Survey of the Japanese Literature

    Directory of Open Access Journals (Sweden)

    Yutaka Kojima

    2010-09-01

    Full Text Available We present the case of a 68-year-old female patient who was diagnosed with cancer of the descending colon in July 1994 and underwent partial resection of the colon (type 2, moderately to well differentiated adenocarcinoma, se, ly1, v1, n(–. In April 1996, she was admitted to a nearby hospital for symptoms of ileus, which improved at the hospital. However, she was referred to our hospital for melena. In blood test, Hb was 8.7 g/dl, showing anemia, and carcinoembryonic antigen level was elevated to 50.7 ng/ml. Abdominal CT and small bowel series showed only mild expansion of the small bowel, suggesting no obvious occlusion. Abdominal surgery was performed in May 1995 for repeated development of ileus symptoms and suspicion of bleeding from the small bowel. Since the findings of the abdominal surgery showed a circular tumor in the lower ileum, partial resection of the small bowel was performed. Histopathological examination showed type 3, moderately to well differentiated adnocarcinoma, se, ly2, v0, n = 1/13. The principal tumor was located within the subserosa and grew up exclusively through the muscularis propria and the submucosa, into the mucous layer. The mucosa remained slightly on the surface layer. Based on these findings, the patient was diagnosed with metastasis of descending colon cancer to the small bowel. Her prognosis was good, and neither metastasis nor redevelopment of the cancer have been confirmed to date, 11 years and 7 months since the surgery.

  4. BRCA1 loss pre-existing in small subpopulations of prostate cancer is associated with advanced disease and metastatic spread to lymph nodes and peripheral blood

    Energy Technology Data Exchange (ETDEWEB)

    Bednarz, Natalia; Eltze, Elke; Semjonow, Axel; Rink, Michael; Andreas, Antje; Mulder, Lennart; Hannemann, Juliane; Fisch, Margit; Pantel, Klaus; Weier, Heinz-Ulrich G.; Bielawski, Krzysztof P.; Brandt, Burkhard

    2010-03-19

    A recent study concluded that serum prostate specific antigen (PSA)-based screening is beneficial for reducing the lethality of PCa, but was also associated with a high risk of 'overdiagnosis'. Nevertheless, also PCa patients who suffered from organ confined tumors and had negative bone scans succumb to distant metastases after complete tumor resection. It is reasonable to assume that those tumors spread to other organs long before the overt manifestation of metastases. Our current results confirm that prostate tumors are highly heterogeneous. Even a small subpopulation of cells bearing BRCA1 losses can initiate PCa cell regional and distant dissemination indicating those patients which might be at high risk of metastasis. A preliminary study performed on a small cohort of multifocal prostate cancer (PCa) detected BRCA1 allelic imbalances (AI) among circulating tumor cells (CTCs). The present analysis was aimed to elucidate the biological and clinical role of BRCA1 losses on metastatic spread and tumor progression in prostate cancer patients. Experimental Design: To map molecular progression in PCa outgrowth we used FISH analysis of tissue microarrays (TMA), lymph node sections and CTC from peripheral blood. We found that 14% of 133 tested patients carried monoallelic BRCA1 loss in at least one tumor focus. Extended molecular analysis of chr17q revealed that this aberration was often a part of larger cytogenetic rearrangement involving chr17q21 accompanied by AI of the tumor suppressor gene PTEN and lack of the BRCA1 promoter methylation. The BRCA1 losses correlated with advanced T stage (p < 0.05), invasion to pelvic lymph nodes (LN, p < 0.05) as well as BR (p < 0.01). Their prevalence was twice as high within 62 LN metastases (LNMs) as in primary tumors (27%, p < 0.01). The analysis of 11 matched primary PCa-LNM pairs confirmed the suspected transmission of genetic abnormalities between those two sites. In 4 of 7 patients with metastatic disease, BRCA1

  5. Plant-Derived MINA-05 Inhibits Human Prostate Cancer Proliferation In Vitro and Lymph Node Spread In Vivo

    Directory of Open Access Journals (Sweden)

    Kate Vandyke

    2007-04-01

    Full Text Available Few treatment options exist for metastatic prostate cancer (PC that becomes hormone refractory (HRPC. In vitro, plant-derived MINA-05 caused dose-dependent decreases in cell numbers in HRPC cell lines LNCaPC4-2B and PC-3, and in androgen-sensitive LNCaP-FGC, DuCaP, and LAPC-4, by WST-1 assay. MINA-05 pretreatment significantly decreased clonogenic survival in agar and on plastic at 1 × and 2 × IC50 for PC-3 (P < .05 and P < .001, respectively, and at 1/2 ×, 1 ×, and 2 × IC50 for LNCaP-FGC cells (P < .001. MINA-05 also induced G2M arrest of LNCaP-FGC and PC-3 cells (by flow cytometry and caused some apoptosis in LNCaPFGC (sub-G1, peak on flow, expression of activated caspase-3 but not in PC-3 cells. Western blotting indicated that these cell cycle changes were associated with decreased levels of regulatory proteins cyclin B1 and cdc25C. MINA-05 given daily by gavage for 39 days did not diminish primary orthotopic PC-3 growth in nude mice, but decreased the extent of lymph node invasion at higher doses. We conclude that MINA-05 induces G2M arrest, inhibits cell growth, reduces PC cell re-growth in vitro, and reduces lymph node invasion after orthotopic PC-3 cell implantation in vivo. It has potential as an adjuvant treatment for patients with PC.

  6. What Is Colorectal Cancer?

    Science.gov (United States)

    ... Research? Colorectal Cancer About Colorectal Cancer What Is Colorectal Cancer? Colorectal cancer is a cancer that starts in ... and spread, see What Is Cancer? How does colorectal cancer start? Most colorectal cancers begin as a growth ...

  7. Chemokine axes in breast cancer: factors of the tumor microenvironment reshape the CCR7-driven metastatic spread of luminal-A breast tumors.

    Science.gov (United States)

    Weitzenfeld, Polina; Kossover, Olga; Körner, Cindy; Meshel, Tsipi; Wiemann, Stefan; Seliktar, Dror; Legler, Daniel F; Ben-Baruch, Adit

    2016-06-01

    Chemokine axes have been shown to mediate site-specific metastasis in breast cancer, but their relevance to different subtypes has been hardly addressed. Here, with the focus on the CCR7-CCL21 axis, patient datasets demonstrated that luminal-A tumors express relatively low CCR7 levels compared with more aggressive disease subtypes. Furthermore, lymph node metastasis was not associated with high CCR7 levels in luminal-A patients. The metastatic pattern of luminal-A breast tumors may be influenced by the way luminal-A tumor cells interpret signals provided by factors of the primary tumor microenvironment. Thus, CCR7-expressing human luminal-A cells were stimulated simultaneously by factors representing 3 tumor microenvironment arms typical of luminal-A tumors, hormonal, inflammatory, and growth stimulating: estrogen + TNF-α + epidermal growth factor. Such tumor microenvironment stimulation down-regulated the migration of CCR7-expressing tumor cells toward CCL21 and inhibited the formation of directional protrusions toward CCL21 in a novel 3-dimensional hydrogel system. CCL21-induced migration of CCR7-expressing tumor cells depended on PI3K and MAPK activation; however, when CCR7-expressing cancer cells were prestimulated by tumor microenvironment factors, CCL21 could not effectively activate these signaling pathways. In vivo, pre-exposure of the tumor cells to tumor microenvironment factors has put restraints on CCL21-mediated lymph node-homing cues and shifted the metastatic pattern of CCR7-expressing cells to the aggressive phenotype of dissemination to bones. Several of the aspects were also studied in the CXCR4-CXCL12 system, demonstrating similar patient and in vitro findings. Thus, we provide novel evidence to subtype-specific regulation of the CCR7-CCL21 axis, with more general implications to chemokine-dependent patterns of metastatic spread, revealing differential regulation in the luminal-A subtype.

  8. Monocytes conditioned media stimulate fibronectin expression and spreading of inflammatory breast cancer cells in three-dimensional culture: A mechanism mediated by IL-8 signaling pathway

    Directory of Open Access Journals (Sweden)

    Mohamed Mona M

    2012-02-01

    Full Text Available Abstract Background Inflammatory breast cancer (IBC is the most aggressive form of breast cancer characterized by invasion of carcinoma cells into dermal lymphatic vessels where they form tumor emboli over expressing adhesion molecule E-cadherin. Although invasion and metastasis are dynamic processes controlled by complex interaction between tumor cells and microenvironment the mechanisms by which soluble mediators may regulate motility and invasion of IBC cells are poorly understood. The present study investigated the effect of media conditioned by human monocytes U937 secreted cytokines, chemokines and growth factors on the expression of adhesion molecules E-cadherin and fibronectin of human IBC cell line SUM149. Furthermore, cytokines signaling pathway involved were also identified. Results U937 secreted cytokines, chemokines and growth factors were characterized by cytokine antibody array. The major U937 secreted cytokines/chemokines were interleukin-8 (IL-8 and monocyte chemotactic protein-1 (MCP-1/CCL2. When SUM149 cells were seeded in three dimensional (3D models with media conditioned by U937 secreted cytokines, chemokines and growth factors; results showed: 1 changes in the morphology of IBC cells from epithelial to migratory spindle shape branched like structures; 2 Over-expression of adhesion molecule fibronectin and not E-cadherin. Further analysis revealed that over-expression of fibronectin may be mediated by IL-8 via PI3K/Akt signaling pathway. Conclusion The present results suggested that cytokines secreted by human monocytes may promote chemotactic migration and spreading of IBC cell lines. Results also indicated that IL-8 the major secreted cytokine by U937 cells may play essential role in fibronectin expression by SUM149 cells via interaction with IL-8 specific receptors and stimulation of PI3K/Akt signaling pathway.

  9. MR-guided Neurolytic Celiac Plexus Ablation: An Evaluation of Effect and Injection Spread Pattern in Cancer Patients with Celiac Tumor Infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Akural, Etem [Helsinki University Central Hospital, Pain Clinic (Finland); Ojala, Risto O. [Oulu University Hospital, Department of Radiology (Finland); Jaervimaeki, Voitto [Oulu University Hospital, Department of Anesthesiology (Finland); Kariniemi, Juho; Tervonen, Osmo A.; Blanco Sequeiros, Roberto, E-mail: roberto.blanco@oulu.fi [Oulu University Hospital, Department of Radiology (Finland)

    2013-04-15

    ObjectiveThe purpose of this study was to evaluate the feasibility, the initial accuracy, and the effects of the MR-guided neurolytic celiac plexus ablation as a method to treat cancer-induced chronic abdominal pain. Thirteen celiac plexus ablations were performed for 12 patients. A 0.23-T open MRI scanner with optical navigation was used for procedural guidance. As an adjunct to the MR-guided needle positioning, the needle location was confirmed with saline injection and consequent MR imaging (STIR sequence). The spread of the ablative injection material (alcohol-lidocaine mix) was observed by repeating this sequence after the therapeutic injection. Pain scores from seven patients (eight ablations) were used to assess the therapy effect. MR guidance allowed adequate needle positioning and visualization of injection material in all cases. The rest pain scores significantly decreased from 4 (median) at baseline to 1 (median) at 2 weeks (p < 0.05). Average and worst pain experienced during the past week were significantly lower at the 2-week time point compared with the baseline (p < 0.05). However, the intervention did not result in reduction of opioid use at 2 weeks.MR guidance is an accurate and safe method for celiac plexus ablation with positive therapeutic effect.

  10. Navigated Pin-Point Approach to Osteoid Osteoma Adjacent to the Facet Joint of Spine

    Science.gov (United States)

    Neo, Masashi; Takemoto, Mitsuru; Nishizawa, Kazuya; Imai, Shinji

    2016-01-01

    Osteoid osteoma (OO) is a benign osteoblastic tumor. Its curative treatment is complete removal of the nidus, where intraoperative localization of the nidus governs clinical results. However, treatment can be difficult since the lesion is often invisible over the bony surface. Accordingly, establishment of an ideal less invasive surgical strategy for spinal OO remains yet unsettled. We illustrate the efficacy of a computed tomography (CT)-based navigation system in excising OO located adjacent to the facet joint of spine. In our 2 cases, complete and pin-point removal of the nidus located close to the facet joint was successfully achieved, without excessive removal of the bone potentially leading to spinal instability and possible damage of nearby neurovascular structures. We advocate a less invasive approach to spinal OO, particularly in an environment with an available CT-based navigation system. PMID:26949472

  11. Infrared-faint radio sources in the SERVS deep fields. Pinpointing AGNs at high redshift

    Science.gov (United States)

    Maini, A.; Prandoni, I.; Norris, R. P.; Spitler, L. R.; Mignano, A.; Lacy, M.; Morganti, R.

    2016-12-01

    Context. Infrared-faint radio sources (IFRS) represent an unexpected class of objects which are relatively bright at radio wavelength, but unusually faint at infrared (IR) and optical wavelengths. A recent and extensive campaign on the radio-brightest IFRSs (S1.4 GHz≳ 10 mJy) has provided evidence that most of them (if not all) contain an active galactic nuclei (AGN). Still uncertain is the nature of the radio-faintest IFRSs (S1.4 GHz≲ 1 mJy). Aims: The scope of this paper is to assess the nature of the radio-faintest IFRSs, testing their classification and improving the knowledge of their IR properties by making use of the most sensitive IR survey available so far: the Spitzer Extragalactic Representative Volume Survey (SERVS). We also explore how the criteria of IFRSs can be fine-tuned to pinpoint radio-loud AGNs at very high redshift (z > 4). Methods: We analysed a number of IFRS samples identified in SERVS fields, including a new sample (21 sources) extracted from the Lockman Hole. 3.6 and 4.5 μm IR counterparts of the 64 sources located in the SERVS fields were searched for and, when detected, their IR properties were studied. Results: We compared the radio/IR properties of the IR-detected IFRSs with those expected for a number of known classes of objects. We found that IR-detected IFRSs are mostly consistent with a mixture of high-redshift (z ≳ 3) radio-loud AGNs. The faintest ones (S1.4 GHz 100 μJy), however, could be also associated with nearer (z 2) dust-enshrouded star-burst galaxies. We also argue that, while IFRSs with radio-to-IR ratios >500 can very efficiently pinpoint radio-loud AGNs at redshift 2 < z < 4, lower radio-to-IR ratios ( 100-200) are expected for higher redshift radio-loud AGNs.

  12. Sodium Hydroxide Pinpoint Pressing Permeation Method for the Animal Modeling of Sick Sinus Syndrome.

    Science.gov (United States)

    Geng, Naizhi; Jiang, Ning; Peng, Cailiang; Wang, Huaiping; Zhang, Shuoxin; Chen, Tianyu; Liu, Lixia; Wu, Yaping; Liu, Dandan

    2015-01-01

    Sodium hydroxide pinpoint pressing permeation (SHPPP) was investigated in order to build a rat model of sick sinus syndrome (SSS), which is easy to operate and control the degree of damage, with fewer complications and applicable for large and small animals.Thirty healthy Wistar rats (15 males and 15 females, weighing 250-350 g) were randomly divided into 3 groups, namely a formaldehyde thoracotomy wet compressing group (FTWC), formaldehyde pinpoint pressing permeation group (FPPP) group, and SHPPP group. The number of surviving rats, heart rate (HR), sinoatrial node recovery time (SNRT), corrected SNRT (CSNRT), and sinoatrial conduction time (SACT) were recorded 3 days, one week, and two weeks after modeling.The achievement ratio of modeling was 10% in the FTWC group, 40% in the FPPP group, and 70% in the SHPPP group, and the differences were statistically significant (χ(2) = 7.250, P = 0.007). Meanwhile, the HR was reduced by about 37% in these 3 groups 3 days after modeling, while the reduction was maintained only in SHPPP (P > 0.05) and the HR was re-elevated in the FTWC and FPPP groups 2 weeks after modeling (P < 0.05). Additionally, the SNRT, cS-NRT, and SACT were significantly prolonged compared with pre-modeling in all 3 groups (P < 0.01).SHPPP was the best method with which to build an SSS model with stable and lasting low HR and high success rate of modeling, which might be helpful for further studies on the SSS mechanisms and drugs.

  13. Enhanced Fuel-Optimal Trajectory-Generation Algorithm for Planetary Pinpoint Landing

    Science.gov (United States)

    Acikmese, Behcet; Blackmore, James C.; Scharf, Daniel P.

    2011-01-01

    An enhanced algorithm is developed that builds on a previous innovation of fuel-optimal powered-descent guidance (PDG) for planetary pinpoint landing. The PDG problem is to compute constrained, fuel-optimal trajectories to land a craft at a prescribed target on a planetary surface, starting from a parachute cut-off point and using a throttleable descent engine. The previous innovation showed the minimal-fuel PDG problem can be posed as a convex optimization problem, in particular, as a Second-Order Cone Program, which can be solved to global optimality with deterministic convergence properties, and hence is a candidate for onboard implementation. To increase the speed and robustness of this convex PDG algorithm for possible onboard implementation, the following enhancements are incorporated: 1) Fast detection of infeasibility (i.e., control authority is not sufficient for soft-landing) for subsequent fault response. 2) The use of a piecewise-linear control parameterization, providing smooth solution trajectories and increasing computational efficiency. 3) An enhanced line-search algorithm for optimal time-of-flight, providing quicker convergence and bounding the number of path-planning iterations needed. 4) An additional constraint that analytically guarantees inter-sample satisfaction of glide-slope and non-sub-surface flight constraints, allowing larger discretizations and, hence, faster optimization. 5) Explicit incorporation of Mars rotation rate into the trajectory computation for improved targeting accuracy. These enhancements allow faster convergence to the fuel-optimal solution and, more importantly, remove the need for a "human-in-the-loop," as constraints will be satisfied over the entire path-planning interval independent of step-size (as opposed to just at the discrete time points) and infeasible initial conditions are immediately detected. Finally, while the PDG stage is typically only a few minutes, ignoring the rotation rate of Mars can introduce 10s

  14. What Is Breast Cancer?

    Science.gov (United States)

    ... Research? Breast Cancer About Breast Cancer What Is Breast Cancer? Breast cancer starts when cells in the breast ... spread, see our section on Cancer Basics . Where breast cancer starts Breast cancers can start from different parts ...

  15. Pinpointing changes in higher-order protein structure by hydrogen/deuterium exchange coupled to electron transfer dissociation mass spectrometry

    DEFF Research Database (Denmark)

    Rand, Kasper Dyrberg

    2013-01-01

    and new options for method optimization are discussed and exemplified. In addition, the real-world applicability of the HDX-ETD method to pinpoint conformational changes in a large 75 kDa protein complex of therapeutic interest is demonstrated. This feature highlights how the conformation and interactions...

  16. Pinpointing the base of the AGN jets through general relativistic X-ray reverberation studies

    CERN Document Server

    Emmanoulopoulos, D

    2014-01-01

    Many theoretical models of Active Galactic Nuclei (AGN) predict that the X-ray corona, lying above the black hole, constitutes the base of the X-ray jet. Thus, by studying the exact geometry of the close black hole environment, we can pinpoint the launching site of the jet. Detection of negative X-ray reverberation time delays (i.e. soft band X-ray variations lagging behind the corresponding hard band X-ray variations) can yield significant information about the geometrical properties of the AGN, such as the location of the X-ray source, as well as the physical properties of the the black hole, such as its mass and spin. In the frame-work of the lamp-post geometry, I present the first systematic X-ray time-lag modelling results of an ensemble of 12 AGN, using a fully general relativistic (GR) ray tracing approach for the estimation of the systems' response functions. By combing these state-of-the art GR response models with statistically innovative fitting routines, I derive the geometrical layout of the clos...

  17. Spread spectrum time domain reflectometry

    Science.gov (United States)

    Smith, Paul Samuel

    For many years, wiring has been treated as a system that could be installed and expected to work for the life of the aircraft. As aircraft age far beyond their original expected life span, this attitude is rapidly changing. Wiring problems have recently been identified as the cause of several tragic mishaps and hundreds of thousands of lost mission hours. Intermittent wiring faults have been and continue to be difficult to resolve. Test methods that pinpoint faults on the ground can miss intermittent failures. New test methods involving spread spectrum signals are investigated that could be used in flight to locate intermittent failures, including open circuits, short circuits, and arcs. Spread spectrum time domain reflectometry (SSTDR) and sequence time domain reflectometry (STDR) are analyzed in light of the signals commonly present on aircraft wiring. Pseudo noise codes used for the generation of STDR and SSTDR signals are analyzed for application in a STDR/SSTDR test system in the presence of noise. The effects of Mil-Std 1553 and white noise on the STDR and SSTDR signals are discussed analytically, through simulations, and with the use of test hardware. A test system using STDR and SSTDR is designed, built, and used to collect STDR and SSTDR test data. The data collected with the STDR/SSTDR test hardware is analyzed and compared to the theoretical results. Experimental data for open and short circuits collected using SSTDR and a curve fitting algorithm shows a maximum range estimation error of +/-0.2 ft for 75O coaxial cable up to 100ft, and +/-0.6ft for a sample 32.5ft non-controlled impedance aircraft cable. Mil-Std 1553 is specified to operate reliably with a signal-to-noise ratio of 17.5dB, and the SSTDR test system was able to locate an open circuit on a cable also carrying simulated Mil-Std 1553 data where the SSTDR signal was 50dB below the Mil-Std 1553 signal. STDR and SSTDR are shown to be effective in detecting and locating dry and wet arcs on wires.

  18. Different survival of Barcelona clinic liver cancer stage C hepatocellular carcinoma patients by the extent of portal vein invasion and the type of extrahepatic spread.

    Science.gov (United States)

    Sinn, Dong Hyun; Cho, Ju-Yeon; Gwak, Geum-Youn; Paik, Yong-Han; Choi, Moon Seok; Lee, Joon Hyeok; Koh, Kwang Cheol; Paik, Seung Woon; Yoo, Byung Chul

    2015-01-01

    Portal vein invasion (PVI) and extrahepatic spread (ES) are two tumor-related factors that define advanced stage in the Barcelona Clinic Liver Cancer (BCLC) staging system (BCLC stage C), and the recommended first line therapy in this stage is sorafenib. However, the extent of PVI and the type of ES may affect patient prognosis as well as treatment outcome. This study analyzed survival of BCLC stage C HCC patients in order to see whether sub-classification of BCLC stage C is necessary. A total of 582 treatment naïve, BCLC stage C HCC patients [age: 54.3 ± 10.8 years, males = 494 (84.9%), hepatitis B virus (458, 78.7%)], defined by PVI and/or ES, were analyzed. Extent of PVI was divided into none, type I-segmental/sectoral branches, type II-left and/or right portal vein, and type III-main portal vein trunk. Type of ES was divided into nodal and distant metastasis. The extent of PVI and type of ES were independent factors for survival. When patients were sub-classified according to the extent of PVI and type of ES, the median survival was significantly different [11.7 months, 5.7 months, 4.9 months and 2.3 months for C1 (PVI-O/I without distant ES), C2 (PVI-II/III without distant ES), C3 (PVI-0/I with distant ES), and C4 (PVI-II/III with distant ES), respectively, P = 0.01]. Patients' survival was different according to the treatment modality in each sub-stage. Sub-classification of BCLC stage C according to the extent of PVI and type of ES resulted in a better prediction of survival. Also, different outcome was observed by treatment modalities in each sub-stage. Sub-classification of BCLC stage C is required to minimize heterogeneity within the same tumor stage, that will help better predict survival and to select optimal treatment strategies.

  19. Different survival of Barcelona clinic liver cancer stage C hepatocellular carcinoma patients by the extent of portal vein invasion and the type of extrahepatic spread.

    Directory of Open Access Journals (Sweden)

    Dong Hyun Sinn

    Full Text Available Portal vein invasion (PVI and extrahepatic spread (ES are two tumor-related factors that define advanced stage in the Barcelona Clinic Liver Cancer (BCLC staging system (BCLC stage C, and the recommended first line therapy in this stage is sorafenib. However, the extent of PVI and the type of ES may affect patient prognosis as well as treatment outcome. This study analyzed survival of BCLC stage C HCC patients in order to see whether sub-classification of BCLC stage C is necessary. A total of 582 treatment naïve, BCLC stage C HCC patients [age: 54.3 ± 10.8 years, males = 494 (84.9%, hepatitis B virus (458, 78.7%], defined by PVI and/or ES, were analyzed. Extent of PVI was divided into none, type I-segmental/sectoral branches, type II-left and/or right portal vein, and type III-main portal vein trunk. Type of ES was divided into nodal and distant metastasis. The extent of PVI and type of ES were independent factors for survival. When patients were sub-classified according to the extent of PVI and type of ES, the median survival was significantly different [11.7 months, 5.7 months, 4.9 months and 2.3 months for C1 (PVI-O/I without distant ES, C2 (PVI-II/III without distant ES, C3 (PVI-0/I with distant ES, and C4 (PVI-II/III with distant ES, respectively, P = 0.01]. Patients' survival was different according to the treatment modality in each sub-stage. Sub-classification of BCLC stage C according to the extent of PVI and type of ES resulted in a better prediction of survival. Also, different outcome was observed by treatment modalities in each sub-stage. Sub-classification of BCLC stage C is required to minimize heterogeneity within the same tumor stage, that will help better predict survival and to select optimal treatment strategies.

  20. Spreading of Electrolyte Drops on Charged Surfaces: Electric Double Layer Effects on Drop Dynamics

    Science.gov (United States)

    Bae, Kyeong; Sinha, Shayandev; Chen, Guang; Das, Siddhartha

    2015-11-01

    Drop spreading is one of the most fundamental topics of wetting. Here we study the spreading of electrolyte drops on charged surfaces. The electrolyte solution in contact with the charged solid triggers the formation of an electric double layer (EDL). We develop a theory to analyze how the EDL affects the drop spreading. The drop dynamics is studied by probing the EDL effects on the temporal evolution of the contact angle and the base radius (r). The EDL effects are found to hasten the spreading behaviour - this is commensurate to the EDL effects causing a ``philic'' tendency in the drops (i.e., drops attaining a contact angle smaller than its equilibrium value), as revealed by some of our recent papers. We also develop scaling laws to illustrate the manner in which the EDL effects make the r versus time (t) variation deviate from the well known r ~tn variation, thereby pinpointing the attainment of different EDL-mediated spreading regimes.

  1. Correction of measured Gamma-Knife output factors for angular dependence of diode detectors and PinPoint ionization chamber.

    Science.gov (United States)

    Hršak, Hrvoje; Majer, Marija; Grego, Timor; Bibić, Juraj; Heinrich, Zdravko

    2014-12-01

    Dosimetry for Gamma-Knife requires detectors with high spatial resolution and minimal angular dependence of response. Angular dependence and end effect time for p-type silicon detectors (PTW Diode P and Diode E) and PTW PinPoint ionization chamber were measured with Gamma-Knife beams. Weighted angular dependence correction factors were calculated for each detector. The Gamma-Knife output factors were corrected for angular dependence and end effect time. For Gamma-Knife beams angle range of 84°-54°. Diode P shows considerable angular dependence of 9% and 8% for the 18 mm and 14, 8, 4 mm collimator, respectively. For Diode E this dependence is about 4% for all collimators. PinPoint ionization chamber shows angular dependence of less than 3% for 18, 14 and 8 mm helmet and 10% for 4 mm collimator due to volumetric averaging effect in a small photon beam. Corrected output factors for 14 mm helmet are in very good agreement (within ±0.3%) with published data and values recommended by vendor (Elekta AB, Stockholm, Sweden). For the 8 mm collimator diodes are still in good agreement with recommended values (within ±0.6%), while PinPoint gives 3% less value. For the 4 mm helmet Diodes P and E show over-response of 2.8% and 1.8%, respectively. For PinPoint chamber output factor of 4 mm collimator is 25% lower than Elekta value which is generally not consequence of angular dependence, but of volumetric averaging effect and lack of lateral electronic equilibrium. Diodes P and E represent good choice for Gamma-Knife dosimetry.

  2. Successful treatment of traumatic scars with combined nonablative fractional laser and pinpoint technique of standard CO2 laser.

    Science.gov (United States)

    Ibrahim, Shady M; Elsaie, Mohamed L; Kamel, Mohamed Ismail; Mohammed, Essam-Eldin

    2016-01-01

    To evaluate the use of a pinpoint irradiation technique followed by nonablative fractional technique in treatment of traumatic scars. Thirteen patients with traumatic sacrs were treated with pinpoint technique of CO2 laser using traditional headpiece activating laser at a frequency (50 Hz) to deliver pulsed mode with power of 1 W using the focusing technique followed by 3-5 passes of the nonablative 1540 nm fractional Er:glass laser. An independent physician evaluator assessed the treatment outcomes using Vancouver scar scale (VSS) and 5-point grading scale (grade 0, no improvement; grade 1, 1-25%; grade 2, 26-50%; grade 3, 51-75%; grade 4, 76-100% improvement). After the final treatment, average percentage changes of VSS were 41.5%. Improvement was evident in terms of vascularity, pigmentation, and height, while insignificant in terms of Pliability. Based on physician's global assessment, mean grade of 2.5 was achieved. Patient's subjective satisfaction scores paralleled the physician's objective evaluation. Pinpoint irradiation technique by CO2 laser followed by nonablative fractional laser is a safe and effective modality in treatment of scars.

  3. Information in CDS Spreads

    NARCIS (Netherlands)

    L. Norden (Lars)

    2014-01-01

    textabstractWe investigate how public and private information drives corporate CDS spreads before rating announcements. We find that CDS spreads of firms with higher news intensity move significantly earlier and stronger before rating announcements, which can be explained with public information fro

  4. The spreading of disorder.

    Science.gov (United States)

    Keizer, Kees; Lindenberg, Siegwart; Steg, Linda

    2008-12-12

    Imagine that the neighborhood you are living in is covered with graffiti, litter, and unreturned shopping carts. Would this reality cause you to litter more, trespass, or even steal? A thesis known as the broken windows theory suggests that signs of disorderly and petty criminal behavior trigger more disorderly and petty criminal behavior, thus causing the behavior to spread. This may cause neighborhoods to decay and the quality of life of its inhabitants to deteriorate. For a city government, this may be a vital policy issue. But does disorder really spread in neighborhoods? So far there has not been strong empirical support, and it is not clear what constitutes disorder and what may make it spread. We generated hypotheses about the spread of disorder and tested them in six field experiments. We found that, when people observe that others violated a certain social norm or legitimate rule, they are more likely to violate other norms or rules, which causes disorder to spread.

  5. Cancer

    Science.gov (United States)

    ... cancer Non-Hodgkin lymphoma Ovarian cancer Pancreatic cancer Testicular cancer Thyroid cancer Uterine cancer Symptoms Symptoms of cancer ... tumor Obesity Pancreatic cancer Prostate cancer Stomach cancer Testicular cancer Throat or larynx cancer Thyroid cancer Patient Instructions ...

  6. Higher Order Spreading Models

    CERN Document Server

    Argyros, S A; Tyros, K

    2012-01-01

    We introduce the higher order spreading models associated to a Banach space $X$. Their definition is based on $\\ff$-sequences $(x_s)_{s\\in\\ff}$ with $\\ff$ a regular thin family and the plegma families. We show that the higher order spreading models of a Banach space $X$ form an increasing transfinite hierarchy $(\\mathcal{SM}_\\xi(X))_{\\xi<\\omega_1}$. Each $\\mathcal{SM}_\\xi (X)$ contains all spreading models generated by $\\ff$-sequences $(x_s)_{s\\in\\ff}$ with order of $\\ff$ equal to $\\xi$. We also provide a study of the fundamental properties of the hierarchy.

  7. Effect of Ozone/Oxygen-Pneumoperitoneum on Tumour Growth and Metastatic Spread of the Rabbit VX2 Head and Neck Cancer Model

    OpenAIRE

    Häußler, Ulrich

    2009-01-01

    About 6% of all newly diagnosed malignancies worldwide are cancers of the head and neck. They account for nearly 5% of all cancer-related deaths. Surgery, radiation therapy and chemotherapy as well as combinations of these three are currently regarded as the standard treatment. While high cure rates can be achieved for the early stage disease, cure and survival rates for locoregionally advanced and distant metastatic disease are s...

  8. Research Advances. Image Pinpoints All 5 Million Atoms in Viral Coat; Bilirubin, "Animals-Only" Pigment, Found in Plants; New Evidence Shows Humans Make Salicylic Acid

    Science.gov (United States)

    King, Angela G.

    2009-08-01

    Recent "firsts" in chemical research: image of a viral capsid pinpointing 5 million atoms; isolation and identification of an "animal" pigment, bilirubin, from a plant source; evidence that humans make salicylic acid.

  9. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  10. Throat Cancer

    Science.gov (United States)

    ... food. Surgery to remove cancerous lymph nodes (neck dissection). If throat cancer has spread deep within your ... neck cancers. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015. Freedman ND, et al. Fruit ...

  11. SU-E-T-17: A Mathematical Model for PinPoint Chamber Correction in Measuring Small Fields

    Energy Technology Data Exchange (ETDEWEB)

    Li, T; Zhang, Y; Li, X; Heron, D.E.; Huq, M.Saiful [University of Pittsburgh Medical Center, Pittsburgh, PA (United States)

    2014-06-01

    Purpose: For small field dosimetry, such as measuring the cone output factor for stereotactic radiosurgery, ion chambers often result in underestimation of the dose, due to both the volume averaging effect and the lack of electron equilibrium. The purpose of this work is to develop a mathematical model, specifically for the pinpoint chamber, to calculate the correction factors corresponding to different type of small fields, including single cone-based circular field and non-standard composite fields. Methods: A PTW 0.015cc PinPoint chamber was used in the study. Its response in a certain field was modeled as the total contribution of many small beamlets, each with different response factor depending on the relative strength, radial distance to the chamber axis, and the beam angle. To get these factors, 12 cone-shaped circular fields (5mm,7.5mm, 10mm, 12.5mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 50mm, 60mm) were irradiated and measured with the PinPoint chamber. For each field size, hundreds of readings were recorded for every 2mm chamber shift in the horizontal plane. These readings were then compared with the theoretical doses as obtained with Monte Carlo calculation. A penalized-least-square optimization algorithm was developed to find out the beamlet response factors. After the parameter fitting, the established mathematical model was validated with the same MC code for other non-circular fields. Results: The optimization algorithm used for parameter fitting was stable and the resulted response factors were smooth in spatial domain. After correction with the mathematical model, the chamber reading matched with the Monte Carlo calculation for all the tested fields to within 2%. Conclusion: A novel mathematical model has been developed for the PinPoint chamber for dosimetric measurement of small fields. The current model is applicable only when the beam axis is perpendicular to the chamber axis. It can be applied to non-standard composite fields. Further

  12. Brain metastases from lung and breast cancer. Differences in patterns of spread and prognosis; Hirnmetastasen des Bronchial- und Mammakarzinoms. Unterschiede in Metastasierungsverhalten und Prognose

    Energy Technology Data Exchange (ETDEWEB)

    Nieder, C. [Abt. fuer Strahlentherapie, Radiologische Klinik der Univ. des Saarlandes, Homburg (Germany); Niewald, M. [Abt. fuer Strahlentherapie, Radiologische Klinik der Univ. des Saarlandes, Homburg (Germany); Hagen, T. [Inst. fuer Neuroradiologie der Univ. des Saarlandes, Homburg (Germany)

    1995-11-01

    Evaluation of 135 cases with brain metastases from non-small-cell lung cancer (group 1) compared with 51 cases from small-cell lung cancer (group 2) and 56 cases from breast cancer (group 3) showed that the frequency of solitary metastases was significantly higher in group 1 and 3. However, in group 2 lesions without surrounding edema occurred more frequently. The rate of patients with extracerebral metastases was significantly higher in groups 2 and 3. The longest median interval between primary tumor and brain metastases was observed in breast cancer patients. The highest local remission rate was seen in small-cell lung cancer if patients who received whole-brain irradiation of 30 Gy alone were compared (63% vs 45% in group 1 and 52% in group 3). However, with regard to clinical course no significant differences were recorded. Survival of lung cancer cases was similar, whereas breast cancer cases survived significantly longer, both after radiotherapy alone and after surgery plus radiotherapy. This might be caused by differences in the natural course of the two diseases as well as adjuvant treatment modalities like hormone and chemotherapy. In conclusion, because long-term survivors were observed only in the breast cancer group, these patients probably have the highest chance of profiting from a locally aggressive treatment approach. (orig.) [Deutsch] Eine Auswertung von 135 Faellen mit Hirnmetastasen eines nichtkleinzelligen Bronchialkarzinoms (Gruppe 1) verglichen mit 51 bzw. 56 Faellen, bei denen als Grunderkrankung ein kleinzelliges Bronchialkarzinom (Gruppe 2) bzw. ein Mammakarzinom (Gruppe 3) vorlag, zeigte, dass Solitaermetastasen beim kleinzelligen Bronchialkarzinom signifikant seltener auftraten. Metastasen ohne Perifokaloedem wurden am haeufigsten beim kleinzelligen Bronchialkarzinom gefunden. In Gruppe 2 und 3 lag der Anteil von Faellen mit extrazerebralen Metastasen signifikant hoeher. Das Intervall zwischen Primaertumor und Hirnmetastasen war beim

  13. The forced walking test: a novel test for pinpointing the anesthetic-induced transition in consciousness in mouse.

    Science.gov (United States)

    Hwang, Eunjin; Kim, Seunghwan; Shin, Hee-Sup; Choi, Jee Hyun

    2010-04-30

    In consciousness or anesthesia studies, pinpointing the precise moment of consciousness or anesthetic transition has been challenging because of the variable lag time between a treatment and its induced response. Here, we describe a novel behavioral method, a forced walking test, which pinpoints the moment of the anesthetic-induced loss of motion (LOM) without handling the animals manually. The mouse is forced to walk on a treadmill, and an anesthetic drug is administered into the peritoneum via a previously secured injection route. The physical activity and the angle of head posture are tracked using a motion sensor preinstalled on the animal's head. The moments of LOM and recovery of motion (ROM) are identified from the physical activity parameters obtained by the sensor. Comparison of our method with the conventional loss-of-righting-reflex assay showed that the time point of LOM was not significantly different between the two methods when examined with two different types of anesthetic agents, propofol and ketamine/xylazine cocktail. In addition, the electrophysiological signals simultaneously acquired in the cortex and the thalamus of the mouse during the forced walking test showed that the brain rhythms induced by ketamine/xylazine anesthesia were generated and terminated in a time-locked manner with respect to LOM and ROM, respectively. In conclusion, the forced walking test allows an objective and precise detection of anesthetic-induced LOM, as well as ROM during awakening from anesthesia, in test animals.

  14. Spread codes and spread decoding in network coding

    OpenAIRE

    Manganiello, F; Gorla, E.; Rosenthal, J.

    2008-01-01

    In this paper we introduce the class of spread codes for the use in random network coding. Spread codes are based on the construction of spreads in finite projective geometry. The major contribution of the paper is an efficient decoding algorithm of spread codes up to half the minimum distance.

  15. ENDOMETRIOSIS WITH LYMPHATIC SPREAD

    Directory of Open Access Journals (Sweden)

    Narmadha

    2014-10-01

    Full Text Available Pelvic endometriosis is a common gynaecologic problem. But the histogenesis of endometriosis was not so clear. Various theories have been proposed by Pathologist in the past. Here we present a case of endometriosis of fallopian tube by lymphatic spread which has been proved histopathologically

  16. Spreading of miscible liquids

    Science.gov (United States)

    Walls, Daniel J.; Haward, Simon J.; Shen, Amy Q.; Fuller, Gerald G.

    2016-05-01

    Miscible liquids commonly contact one another in natural and technological situations, often in the proximity of a solid substrate. In the scenario where a drop of one liquid finds itself on a solid surface and immersed within a second, miscible liquid, it will spread spontaneously across the surface. We show experimental findings of the spreading of sessile drops in miscible environments that have distinctly different shape evolution and power-law dynamics from sessile drops that spread in immiscible environments, which have been reported previously. We develop a characteristic time to scale radial data of the spreading sessile drops based on a drainage flow due to gravity. This time scale is effective for a homologous subset of the liquids studied. However, it has limitations when applied to significantly chemically different, yet miscible, liquid pairings; we postulate that the surface energies between each liquid and the solid surface becomes important for this other subset of the liquids studied. Initial experiments performed with pendant drops in miscible environments support the drainage flow observed in the sessile drop systems.

  17. Virus spread in networks

    NARCIS (Netherlands)

    Mieghem, P. van; Omic, J.; Kooij, R.E.

    2009-01-01

    The influence of the network characteristics on the virus spread is analyzed in a new-the N-intertwined Markov chain-model, whose only approximation lies in the application of mean field theory. The mean field approximation is quantified in detail. The N-intertwined model has been compared with the

  18. What Is Kidney Cancer (Renal Cell Carcinoma)?

    Science.gov (United States)

    ... Treatment? Kidney Cancer About Kidney Cancer What Is Kidney Cancer? Kidney cancer is a cancer that starts ... and spread, see What Is Cancer? About the kidneys To understand more about kidney cancer, it helps ...

  19. Prostate specific membrane antigen (PSM) is expressed in various human tissues: implication for the use of PSM reverse transcription polymerase chain reaction to detect hematogenous prostate cancer spread.

    Science.gov (United States)

    Renneberg, H; Friedetzky, A; Konrad, L; Kurek, R; Weingärtner, K; Wennemuth, G; Tunn, U W; Aumüller, G

    1999-01-01

    Detection of prostate-specific membrane antigen (PSM)-mRNA expression in blood samples using reverse transcription polymerase chain reaction (RT-PCR) is discussed as a new diagnostic marker of circulating micrometastases in prostate cancer patients. We applied the RT-PCR technique to different human tissues and obtained positive signals for PSM transcripts in human genital and multiple extra-genital tissue sites. The cDNAs were prepared from different human tissues and prostatic cell lines. RT-PCR and nested RT-PCR for PSM was performed with primers derived from the published PSM cDNA. The RT-PCR fragments obtained were cloned and showed 100% sequence homology to PSM. Southern blot hybridization with labeled probes was used to confirm the specificity of the amplicons. In addition to the known PSM expression in the human brain, PSM-mRNA was detected in cDNA isolated from human testis, epididymis and seminal vesicles and in the PC-3 prostatic cancer cell line. Furthermore, we found PSM-mRNA in heart, liver, lung, kidney, spleen, and thyroid gland. The results indicate that PSM expression is not restricted to the prostate gland, but represents a more general component of genital and extra-genital human tissues. This must be considered when RT-PCR and nested RT-PCR screening for PSM expression is performed as a diagnostic measure in blood from prostate cancer patients.

  20. A conditional piggyBac transposition system for genetic screening in mice identifies oncogenic networks in pancreatic cancer.

    Science.gov (United States)

    Rad, Roland; Rad, Lena; Wang, Wei; Strong, Alexander; Ponstingl, Hannes; Bronner, Iraad F; Mayho, Matthew; Steiger, Katja; Weber, Julia; Hieber, Maren; Veltkamp, Christian; Eser, Stefan; Geumann, Ulf; Öllinger, Rupert; Zukowska, Magdalena; Barenboim, Maxim; Maresch, Roman; Cadiñanos, Juan; Friedrich, Mathias; Varela, Ignacio; Constantino-Casas, Fernando; Sarver, Aaron; Ten Hoeve, Jelle; Prosser, Haydn; Seidler, Barbara; Bauer, Judith; Heikenwälder, Mathias; Metzakopian, Emmanouil; Krug, Anne; Ehmer, Ursula; Schneider, Günter; Knösel, Thomas; Rümmele, Petra; Aust, Daniela; Grützmann, Robert; Pilarsky, Christian; Ning, Zemin; Wessels, Lodewyk; Schmid, Roland M; Quail, Michael A; Vassiliou, George; Esposito, Irene; Liu, Pentao; Saur, Dieter; Bradley, Allan

    2015-01-01

    Here we describe a conditional piggyBac transposition system in mice and report the discovery of large sets of new cancer genes through a pancreatic insertional mutagenesis screen. We identify Foxp1 as an oncogenic transcription factor that drives pancreatic cancer invasion and spread in a mouse model and correlates with lymph node metastasis in human patients with pancreatic cancer. The propensity of piggyBac for open chromatin also enabled genome-wide screening for cancer-relevant noncoding DNA, which pinpointed a Cdkn2a cis-regulatory region. Histologically, we observed different tumor subentities and discovered associated genetic events, including Fign insertions in hepatoid pancreatic cancer. Our studies demonstrate the power of genetic screening to discover cancer drivers that are difficult to identify by other approaches to cancer genome analysis, such as downstream targets of commonly mutated human cancer genes. These piggyBac resources are universally applicable in any tissue context and provide unique experimental access to the genetic complexity of cancer.

  1. Pinpointing the molecular gas within an Lyα blob at z ∼ 2.7

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yujin; Bertoldi, Frank; Bădescu, Toma [Argelander Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); Walter, Fabian; Decarli, Roberto [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Weiss, Axel [Max-Planck-Insitut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Dey, Arjun [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Prescott, Moire K. M. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark)

    2014-04-01

    We present IRAM Plateau de Bure Interferometer observations of the CO(3-2) and CO(5-4) line transitions from an Lyα blob at z ∼ 2.7 in order to investigate the gas kinematics, determine the location of the dominant energy source, and study the physical conditions of the molecular gas. CO line and dust continuum emissions are detected at the location of a strong MIPS source that is offset by ∼1.''5 from the Lyα peak. Neither of these emission components is resolved with the 1.''7 beam, showing that the gas and dust are confined to within ∼7 kpc from this galaxy. No millimeter source is found at the location of the Lyα peak, ruling out a central compact source of star formation as the power source for the Lyα emission. Combined with a spatially resolved spectrum of Lyα and He II, we constrain the kinematics of the extended gas using the CO emission as a tracer of the systemic redshift. Near the MIPS source, the Lyα profile is symmetric, and its line center agrees with that of the CO line, implying that there are no significant bulk flows and that the photo-ionization from the MIPS source might be the dominant source of the Lyα emission. In the region near the Lyα peak, the gas is slowly receding (∼100 km s{sup –1}) with respect to the MIPS source, thus making the hyper-/superwind hypothesis unlikely. We find a sub-thermal line ratio between two CO transitions, I {sub CO(5-4)}/I {sub CO(3-2)} = 0.97 ± 0.21. This line ratio is lower than the average values found in high-z submillimeter galaxies and QSOs but is consistent with the value found in the Galactic center, suggesting that there is a large reservoir of low-density molecular gas that is spread over the MIPS source and its vicinity.

  2. Optimizing Hybrid Spreading in Metapopulations

    CERN Document Server

    Zhang, Changwang; Cox, Ingemar J; Chain, Benjamin M

    2014-01-01

    Epidemic spreading phenomena are ubiquitous in nature and society. Examples include the spreading of diseases, information, and computer viruses. Epidemics can spread by \\textit{local spreading}, where infected nodes can only infect a limited set of direct target nodes and \\textit{global spreading}, where an infected node can infect every other node. In reality, many epidemics spread using a hybrid mixture of both types of spreading. In this study we develop a theoretical framework for studying hybrid epidemics, and examine the optimum balance between spreading mechanisms in terms of achieving the maximum outbreak size. In a metapopulation, made up of many weakly connected subpopulations, we show that one can calculate an optimal tradeoff between local and global spreading which will maximise the extent of the epidemic. As an example we analyse the 2008 outbreak of the Internet worm Conficker, which uses hybrid spreading to propagate through the internet. Our results suggests that the worm would have been eve...

  3. Combinatorics of spreads and parallelisms

    CERN Document Server

    Johnson, Norman

    2010-01-01

    Partitions of Vector Spaces Quasi-Subgeometry Partitions Finite Focal-SpreadsGeneralizing André SpreadsThe Going Up Construction for Focal-SpreadsSubgeometry Partitions Subgeometry and Quasi-Subgeometry Partitions Subgeometries from Focal-SpreadsExtended André SubgeometriesKantor's Flag-Transitive DesignsMaximal Additive Partial SpreadsSubplane Covered Nets and Baer Groups Partial Desarguesian t-Parallelisms Direct Products of Affine PlanesJha-Johnson SL(2,

  4. Quasirandom Rumor Spreading

    CERN Document Server

    Doerr, Benjamin; Sauerwald, Thomas

    2010-01-01

    We propose and analyse a quasirandom analogue of the classical push model for disseminating information in networks ("randomized rumor spreading"). In the classical model, in each round each informed vertex chooses a neighbor at random and informs it, if it was not before. It is known that this simple protocol succeeds in spreading a rumor from one vertex to all others within O(log n) rounds on complete graphs, hypercubes, random regular graphs, Erdos-Renyi random graph and Ramanujan graphs with high probability. In the quasirandom model, we assume that each vertex has a (cyclic) list of its neighbors. Once informed, it starts at a random position of the list, but from then on informs its neighbors in the order of the list. Surprisingly, irrespective of the orders of the lists, the above mentioned bounds still hold. In some cases even better bounds than for the classical model can be shown.

  5. Spread spectrum image steganography.

    Science.gov (United States)

    Marvel, L M; Boncelet, C R; Retter, C T

    1999-01-01

    In this paper, we present a new method of digital steganography, entitled spread spectrum image steganography (SSIS). Steganography, which means "covered writing" in Greek, is the science of communicating in a hidden manner. Following a discussion of steganographic communication theory and review of existing techniques, the new method, SSIS, is introduced. This system hides and recovers a message of substantial length within digital imagery while maintaining the original image size and dynamic range. The hidden message can be recovered using appropriate keys without any knowledge of the original image. Image restoration, error-control coding, and techniques similar to spread spectrum are described, and the performance of the system is illustrated. A message embedded by this method can be in the form of text, imagery, or any other digital signal. Applications for such a data-hiding scheme include in-band captioning, covert communication, image tamperproofing, authentication, embedded control, and revision tracking.

  6. Single molecular force across single integrins dictates cell spreading.

    Science.gov (United States)

    Chowdhury, Farhan; Li, Isaac T S; Leslie, Benjamin J; Doğanay, Sultan; Singh, Rishi; Wang, Xuefeng; Seong, Jihye; Lee, Sang-Hak; Park, Seongjin; Wang, Ning; Ha, Taekjip

    2015-10-01

    Cells' ability to sense and interpret mechanical signals from the extracellular milieu modulates the degree of cell spreading. Yet how cells detect such signals and activate downstream signaling at the molecular level remain elusive. Herein, we utilize tension gauge tether (TGT) platform to investigate the underlying molecular mechanism of cell spreading. Our data from both differentiated cells of cancerous and non-cancerous origin show that for the same stiff underlying glass substrates and for same ligand density it is the molecular forces across single integrins that ultimately determine cell spreading responses. Furthermore, by decoupling molecular stiffness and molecular tension we demonstrate that molecular stiffness has little influence on cell spreading. Our data provide strong evidence that links molecular forces at the cell-substrate interface to the degree of cell spreading.

  7. Time-resolved dosimetry using a pinpoint ionization chamber as quality assurance for IMRT and VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Louwe, Robert J. W., E-mail: rob.louwe@ccdbh.org.nz; Satherley, Thomas; Day, Rebecca A.; Greig, Lynne [Department of Radiation Oncology, Wellington Blood and Cancer Centre, Wellington Hospital, Wellington 6242 (New Zealand); Wendling, Markus; Monshouwer, René [Department of Radiation Oncology, Radboud University Medical Center, Nijmegen 6500 HB (Netherlands)

    2015-04-15

    Purpose: To develop a method to verify the dose delivery in relation to the individual control points of intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) using an ionization chamber. In addition to more effective problem solving during patient-specific quality assurance (QA), the aim is to eventually map out the limitations in the treatment chain and enable a targeted improvement of the treatment technique in an efficient way. Methods: Pretreatment verification was carried out for 255 treatment plans that included a broad range of treatment indications in two departments using the equipment of different vendors. In-house developed software was used to enable calculation of the dose delivery for the individual beamlets in the treatment planning system (TPS), for data acquisition, and for analysis of the data. The observed deviations were related to various delivery and measurement parameters such as gantry angle, field size, and the position of the detector with respect to the field edge to distinguish between error sources. Results: The average deviation of the integral fraction dose during pretreatment verification of the planning target volume dose was −2.1% ± 2.2% (1 SD), −1.7% ± 1.7% (1 SD), and 0.0% ± 1.3% (1 SD) for IMRT at the Radboud University Medical Center (RUMC), VMAT (RUMC), and VMAT at the Wellington Blood and Cancer Centre, respectively. Verification of the dose to organs at risk gave very similar results but was generally subject to a larger measurement uncertainty due to the position of the detector at a high dose gradient. The observed deviations could be related to limitations of the TPS beam models, attenuation of the treatment couch, as well as measurement errors. The apparent systematic error of about −2% in the average deviation of the integral fraction dose in the RUMC results could be explained by the limitations of the TPS beam model in the calculation of the beam penumbra. Conclusions: This

  8. Evolution in a transmissible cancer: a study of the chromosomal changes in devil facial tumor (DFT) as it spreads through the wild Tasmanian devil population.

    Science.gov (United States)

    Pearse, Anne-Maree; Swift, Kate; Hodson, Pamela; Hua, Bobby; McCallum, Hamish; Pyecroft, Stephen; Taylor, Robyn; Eldridge, Mark D B; Belov, Katherine

    2012-03-01

    Tasmanian devils (Sarcophilus harrisii) are the largest extant marsupial carnivores. This species, now confined to Tasmania, is endangered from the emergence of a transmissible cancer, devil facial tumor disease (DFTD). In the present study, we use cytogenetic and molecular techniques to examine the stability of devil facial tumor (DFT) cell lines across time and space. This article describes disease progression from February 2004 to June 2011. We demonstrate evolutionary changes in the disease, which affects devils in different sites across Tasmania and over a period of several years, producing several chromosomal variants (strains) that are capable of transmission between devils. We describe the evolution of DFTs in the field and speculate on the possible impacts on the disease, including (1) development of less aggressive forms of the disease; (2) development of more aggressive forms of the disease; (3) development of forms capable of affecting closely related species of dasyurids (e.g., quolls); (4) extinction of the disease as it acquires additional deleterious mutations that affect either cell viability or transmissibility; and (5) co-evolution of the disease and the host. We also speculate about the future of the Tasmanian devil in the wild. We note that although DFTs are regarded as unstable by comparison with another much older transmissible cancer, canine transmissible venereal tumor (CTVT), the potential for development of less aggressive forms of DFTs or for development of resistance in devils is limited by devils' small numbers, low genetic diversity, and restricted geographical distribution. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Cervical cancer - screening and prevention

    Science.gov (United States)

    Cancer cervix - screening; HPV - cervical cancer screening; Dysplasia - cervical cancer screening; Cervical cancer - HPV vaccine ... Almost all cervical cancers are caused by HPV (human papilloma virus). HPV is a common virus that spreads through sexual contact. Certain ...

  10. Breast cancer metastasis suppressor 1 (BRMS1) suppresses attachment and spreading of breast cancer cells on 2D and 3D extracellular matrix components by altering focal adhesion-associated signaling

    Science.gov (United States)

    Metastatic dissemination of cancer cells from primary tumor to secondary sites is a multi-step process that depends heavily on the ability of cancer cells to respond to the microenvironmental cues, such as changes in composition of surrounding extracellular matrix (ECM), by adapting their adhesion a...

  11. Estimation of wave directional spreading

    Digital Repository Service at National Institute of Oceanography (India)

    Deo, M.C.; Gondane, D.S.; SanilKumar, V.

    One of the useful measures of waves directional spreading at a given location is the directional spreading parameter. This paper presents a new approach to arrive at its characteristic value using the computational technique of Artificial Neural...

  12. Metastatic spread in patients with non-small cell lung cancer is associated with a reduced density of tumor-infiltrating T cells.

    Science.gov (United States)

    Müller, Philipp; Rothschild, Sacha I; Arnold, Walter; Hirschmann, Petra; Horvath, Lukas; Bubendorf, Lukas; Savic, Spasenija; Zippelius, Alfred

    2016-01-01

    Tumor-infiltrating lymphocytes play an important role in cell-mediated immune destruction of cancer cells and tumor growth control. We investigated the heterogeneity of immune cell infiltrates between primary non-small cell lung carcinomas (NSCLC) and corresponding metastases. Formalin-fixed, paraffin-embedded primary tumors and corresponding metastases from 34 NSCLC patients were analyzed by immunohistochemistry for CD4, CD8, CD11c, CD68, CD163 and PD-L1. The percentage of positively stained cells within the stroma and tumor cell clusters was recorded and compared between primary tumors and metastases. We found significantly fewer CD4(+) and CD8(+) T cells within tumor cell clusters as compared with the stromal compartment, both in primary tumors and corresponding metastases. CD8(+) T cell counts were significantly lower in metastatic lesions than in the corresponding primary tumors, both in the stroma and the tumor cell islets. Of note, the CD8/CD4 ratio was significantly reduced in metastatic lesions compared with the corresponding primary tumors in tumor cell islets, but not in the stroma. We noted significantly fewer CD11c(+) cells and CD68(+) as well as CD163(+) macrophages in tumor cell islets compared with the tumor stroma, but no difference between primary and metastatic lesions. Furthermore, the CD8/CD68 ratio was higher in primary tumors than in the corresponding metastases. We demonstrate a differential pattern of immune cell infiltration in matched primary and metastatic NSCLC lesions, with a significantly lower density of CD8(+) T cells in metastatic lesions compared with the primary tumors. The lower CD8/CD4 and CD8/CD68 ratios observed in metastases indicate a rather tolerogenic and tumor-promoting microenvironment at the metastatic site.

  13. Hybrid spread spectrum radio system

    Science.gov (United States)

    Smith, Stephen F [London, TN; Dress, William B [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  14. Cancer Staging

    Science.gov (United States)

    ... the tumor is to grow and spread The TNM Staging System The TNM system is the most widely used cancer staging system. Most hospitals and medical centers use the TNM system as their main method for cancer reporting. ...

  15. Sites involved in intra- and interdomain allostery associated with the activation of factor VIIa pinpointed by hydrogen-deuterium exchange and electron transfer dissociation mass spectrometry

    DEFF Research Database (Denmark)

    Song, Hongjian; Olsen, Ole H; Persson, Egon;

    2014-01-01

    enhancement remain elusive. Here we have applied hydrogen/deuterium exchange mass spectrometry coupled to electron transfer dissociation to pinpoint individual residues in the heavy chain of FVIIa whose conformation and/or local interaction pattern changes when the enzyme transitions to the active form...

  16. Fundamentals of spread spectrum modulation

    CERN Document Server

    Ziemer, Rodger E

    2007-01-01

    This lecture covers the fundamentals of spread spectrum modulation, which can be defined as any modulation technique that requires a transmission bandwidth much greater than the modulating signal bandwidth, independently of the bandwidth of the modulating signal. After reviewing basic digital modulation techniques, the principal forms of spread spectrum modulation are described. One of the most important components of a spread spectrum system is the spreading code, and several types and their characteristics are described. The most essential operation required at the receiver in a spread spect

  17. Fugitive methane emission pinpointing and source attribution using ethane measurements in a portable cavity ring-down analyzer

    Science.gov (United States)

    Fleck, Derek; Hoffnagle, John; Yiu, John; Chong, Johnston; Tan, Sze

    2017-04-01

    Methane source pinpointing and attribution is ever more important because of the vast network of natural gas distribution which has led to a very large emission sources. Ethane can be used as a tracer to distinguish gas sources between biogenic and natural gas. Having this measurement sensitive enough can even distinguish between gas distributors, or maturity through gas wetness. Here we present data obtained using a portable cavity ring-down spectrometer weighing less than 11 kg and consuming less than 35W that simultaneously measures methane and ethane with a raw 1-σ precision of 50ppb and 4.5ppb, respectively at 2 Hz. These precisions allow for a C2:C1 ratio 1-σ measurement of right above the ground, correlations in the variations in C2H6 and CH4 are used to derive a source C2:C1. Additional hardware is needed for steady state concentration measurements to reliably measure the C2:C1 ratio instantaneously. Source discrimination data of local leaks and methane sources using this analysis method are presented. Additionally, two-dimensional plume snapshots are constructed using an integrated onboard GPS to visualize horizontal plane gas propagation.

  18. Rifts in spreading wax layers

    CERN Document Server

    Ragnarsson, R; Santangelo, C D; Bodenschatz, E; Ragnarsson, Rolf; Ford, J Lewis; Santangelo, Christian D; Bodenschatz, Eberhard

    1995-01-01

    We report experimental results on the rift formation between two freezing wax plates. The plates were pulled apart with constant velocity, while floating on the melt, in a way akin to the tectonic plates of the earth's crust. At slow spreading rates, a rift, initially perpendicular to the spreading direction, was found to be stable, while above a critical spreading rate a "spiky" rift with fracture zones almost parallel to the spreading direction developed. At yet higher spreading rates a second transition from the spiky rift to a zig-zag pattern occurred. In this regime the rift can be characterized by a single angle which was found to be dependent on the spreading rate. We show that the oblique spreading angles agree with a simple geometrical model. The coarsening of the zig-zag pattern over time and the three-dimensional structure of the solidified crust are also discussed.

  19. How Cancers Spread to the Brain

    Institute of Scientific and Technical Information of China (English)

    University of Oxford

    2009-01-01

    【编者按】各种癌症中,有20%最终会转移到大脑。这种转移性大脑肿瘤的发病率比原发性脑癌高10倍。长期以来,医学研究者对癌症细胞的大脑转移机制不甚了解。最近牛津大学的研究人员终于发现:转移肿瘤细胞是从大脑的血管壁上长出来的,其中帮助它们附着于细胞壁上的重要营养物质是整联蛋白。这一发现将为人类研究出对应的治疗方法铺平道路。

  20. Heat transfer and fire spread

    Science.gov (United States)

    Hal E. Anderson

    1969-01-01

    Experimental testing of a mathematical model showed that radiant heat transfer accounted for no more than 40% of total heat flux required to maintain rate of spread. A reasonable prediction of spread was possible by assuming a horizontal convective heat transfer coefficient when certain fuel and flame characteristics were known. Fuel particle size had a linear relation...

  1. Drop spreading with random viscosity

    CERN Document Server

    Xu, Feng

    2016-01-01

    We examine theoretically the spreading of a viscous liquid drop over a thin film of uniform thickness, assuming the liquid's viscosity is regulated by the concentration of a solute that is carried passively by the spreading flow. The solute is assumed to be initially heterogeneous, having a spatial distribution with prescribed statistical features. To examine how this variability influences the drop's motion, we investigate spreading in a planar geometry using lubrication theory, combining numerical simulations with asymptotic analysis. We assume diffusion is sufficient to suppress solute concentration gradients across but not along the film. The solute field beneath the bulk of the drop is stretched by the spreading flow, such that the initial solute concentration immediately behind the drop's effective contact lines has a long-lived influence on the spreading rate. Over long periods, solute swept up from the precursor film accumulates in a short region behind the contact line, allowing patches of elevated v...

  2. Sinking, wedging, spreading - viscous spreading on a layer of fluid

    Science.gov (United States)

    Bergemann, Nico; Juel, Anne; Heil, Matthias

    2016-11-01

    We study the axisymmetric spreading of a sessile drop on a pre-existing layer of the same fluid in a regime where the drop is sufficiently large so that the spreading is driven by gravity while capillary and inertial effects are negligible. Experiments performed with 5 ml drops and layer thicknesses in the range 0.1 mm drop evolves as R tn , where the spreading exponent n increases with the layer thickness h. Numerical simulations, based on the axisymmetric free-surface Navier-Stokes equations, reveal three distinct spreading regimes depending on the layer thickness. For thick layers the drop sinks into the layer, accompanied by significant flow in the layer. By contrast, for thin layers the layer ahead of the propagating front is at rest and the spreading behaviour resembles that of a gravity-driven drop spreading on a dry substrate. In the intermediate regime the spreading is characterised by an advancing wedge, which is sustained by fluid flow from the drop into the layer.

  3. Spreading convulsions, spreading depolarization and epileptogenesis in human cerebral cortex

    DEFF Research Database (Denmark)

    Dreier, Jens P; Major, Sebastian; Pannek, Heinz-Wolfgang

    2012-01-01

    Spreading depolarization of cells in cerebral grey matter is characterized by massive ion translocation, neuronal swelling and large changes in direct current-coupled voltage recording. The near-complete sustained depolarization above the inactivation threshold for action potential generating...

  4. Collective behavior in the spatial spreading of obesity

    OpenAIRE

    Gallos, Lazaros K.; Barttfeld, Pablo; Havlin, Shlomo; Sigman, Mariano; Makse, Hernán A.

    2012-01-01

    Non-communicable diseases like diabetes, obesity and certain forms of cancer have been increasing in many countries at alarming levels. A difficulty in the conception of policies to reverse these trends is the identification of the drivers behind the global epidemics. Here, we implement a spatial spreading analysis to investigate whether diabetes, obesity and cancer show spatial correlations revealing the effect of collective and global factors acting above individual choices. We adapt a theo...

  5. Spreading the Bible in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    According to records of the Bible Society in China, more than 300 million copies of the Bible in Chinese have been published and distributed since 1823. The spread of the Bible in China has gone through five stages.

  6. Spread effects - methodology; Spredningseffekter - metodegrunnlag

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Diffusion of technology, environmental effects and rebound effects are the principal effects from the funding of renewable energy and energy economising. It is difficult to estimate the impact of the spread effects both prior to the measures are implemented and after the measures are carried out. Statistical methods can be used to estimate the spread effects, but they are insecure and always need to be complemented with qualitative and subjective evaluations. It is more adequate to evaluate potential spread effects from market and market data surveillance for a selection of technologies and parties. Based on this information qualitative indicators for spread effects can be constructed and used both ex ante and ex post (ml)

  7. Roles of Ties in Spreading

    CERN Document Server

    Cui, Ai-Xiang; Zhou, Tao

    2012-01-01

    Background: Controlling global epidemics in the real world and accelerating information propagation in the artificial world are of great significance, which have activated an upsurge in the studies on networked spreading dynamics. Lots of efforts have been made to understand the impacts of macroscopic statistics (e.g., degree distribution and average distance) and mesoscopic structures (e.g., communities and rich clubs) on spreading processes while the microscopic elements are less concerned. In particular, roles of ties are not yet clear to the academic community. Methodology/Principle Findings: Every edges is stamped by its strength that is defined solely based on the local topology. According to a weighted susceptible-infected-susceptible model, the steady-state infected density and spreading speed are respectively optimized by adjusting the relationship between edge's strength and spreading ability. Experiments on six real networks show that the infected density is increased when strong ties are favored i...

  8. Epidemic spreading in complex networks

    Institute of Scientific and Technical Information of China (English)

    Jie ZHOU; Zong-hua LIU

    2008-01-01

    The study of epidemic spreading in complex networks is currently a hot topic and a large body of results have been achieved.In this paper,we briefly review our contributions to this field,which includes the underlying mechanism of rumor propagation,the epidemic spreading in community networks,the influence of varying topology,and the influence of mobility of agents.Also,some future directions are pointed out.

  9. Spreading dynamics in complex networks

    CERN Document Server

    Pei, Sen

    2013-01-01

    Searching for influential spreaders in complex networks is an issue of great significance for applications across various domains, ranging from the epidemic control, innovation diffusion, viral marketing, social movement to idea propagation. In this paper, we first display some of the most important theoretical models that describe spreading processes, and then discuss the problem of locating both the individual and multiple influential spreaders respectively. Recent approaches in these two topics are presented. For the identification of privileged single spreaders, we summarize several widely used centralities, such as degree, betweenness centrality, PageRank, k-shell, etc. We investigate the empirical diffusion data in a large scale online social community -- LiveJournal. With this extensive dataset, we find that various measures can convey very distinct information of nodes. Of all the users in LiveJournal social network, only a small fraction of them involve in spreading. For the spreading processes in Li...

  10. 9 CFR 319.762 - Ham spread, tongue spread, and similar products.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Ham spread, tongue spread, and similar products. 319.762 Section 319.762 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... Salads and Meat Spreads § 319.762 Ham spread, tongue spread, and similar products. “Ham Spread,” “Tongue...

  11. New simple image overlay system using a tablet PC for pinpoint identification of the appropriate site for anastomosis in peripheral arterial reconstruction.

    Science.gov (United States)

    Mochizuki, Yasuaki; Hosaka, Akihiro; Kamiuchi, Hiroki; Nie, Jun Xiao; Masamune, Ken; Hoshina, Katsuyuki; Miyata, Tetsuro; Watanabe, Toshiaki

    2016-12-01

    To evaluate the accuracy and utility of a new image overlay system using a tablet PC for patients undergoing peripheral arterial reconstruction. Eleven limbs treated with distal bypass surgery were studied. Three-dimensional images obtained by processing a preoperative contrast-enhanced computed tomography scan were superimposed onto the back-camera images of a tablet PC. We used this system to pinpoint a planned distal anastomotic site preoperatively and to make a precise incision directly above it during surgery. We used a branch artery near the distal anastomotic site as a reference point and the accuracy of the system was validated by comparing its results with the intraoperative findings. The precision of the system was also compared with that of a preoperative ultrasonographic examination. Both the image overlay system and ultrasonography (US) accurately identified the target branch artery in all except one limb. In that limb, which had a very small reference branch artery, preoperative US wrongly identified another branch, whereas the image overlay system located the target branch with an error of 10 mm. Our image overlay system was easy to use and allowed us to precisely identify a target artery preoperatively. Therefore, this system could be helpful for pinpointing the most accurate incision site during surgery.

  12. Formation of Tethers from Spreading Cellular Aggregates.

    Science.gov (United States)

    Beaune, Grégory; Winnik, Françoise M; Brochard-Wyart, Françoise

    2015-12-01

    Membrane tubes are commonly extruded from cells and vesicles when a point-like force is applied on the membrane. We report here the unexpected formation of membrane tubes from lymph node cancer prostate (LNCaP) cell aggregates in the absence of external applied forces. The spreading of LNCaP aggregates deposited on adhesive glass substrates coated with fibronectin is very limited because cell-cell adhesion is stronger than cell-substrate adhesion. Some cells on the aggregate periphery are very motile and try to escape from the aggregate, leading to the formation of membrane tubes. Tethered networks and exchange of cargos between cells were observed as well. Growth of the tubes is followed by either tube retraction or tube rupture. Hence, even very cohesive cells are successful in escaping aggregates, which may lead to epithelial mesenchymal transition and tumor metastasis. We interpret the dynamics of formation and retraction of tubes in the framework of membrane mechanics.

  13. Olive oil in food spreads

    National Research Council Canada - National Science Library

    Blanco Muñoz, Miguel A

    2004-01-01

    .... The use of olive oil to prepare fat spread opens new insights into the commercial development of healthy novel foods with a positive image in terms of consumer appeal.La hidrogenación química de los...

  14. Worldwide spreading of economic crisis

    CERN Document Server

    Garas, Antonios; Rozenblat, Celine; Tomassini, Marco; Havlin, Shlomo

    2010-01-01

    We model the spreading of a crisis by constructing a global economic network and applying the Susceptible-Infected-Recovered (SIR) epidemic model with a variable probability of infection. The probability of infection depends on the strength of economic relations between the pair of countries, and the strength of the target country. It is expected that a crisis which originates in a large country, such as the USA, has the potential to spread globally, like the recent crisis. Surprisingly we show that also countries with much lower GDP, such as Belgium, are able to initiate a global crisis. Using the {\\it k}-shell decomposition method to quantify the spreading power (of a node), we obtain a measure of ``centrality'' as a spreader of each country in the economic network. We thus rank the different countries according to the shell they belong to, and find the 12 most central countries. These countries are the most likely to spread a crisis globally. Of these 12 only six are large economies, while the other six ar...

  15. Spreading dynamics in complex networks

    Science.gov (United States)

    Pei, Sen; Makse, Hernán A.

    2013-12-01

    Searching for influential spreaders in complex networks is an issue of great significance for applications across various domains, ranging from epidemic control, innovation diffusion, viral marketing, and social movement to idea propagation. In this paper, we first display some of the most important theoretical models that describe spreading processes, and then discuss the problem of locating both the individual and multiple influential spreaders respectively. Recent approaches in these two topics are presented. For the identification of privileged single spreaders, we summarize several widely used centralities, such as degree, betweenness centrality, PageRank, k-shell, etc. We investigate the empirical diffusion data in a large scale online social community—LiveJournal. With this extensive dataset, we find that various measures can convey very distinct information of nodes. Of all the users in the LiveJournal social network, only a small fraction of them are involved in spreading. For the spreading processes in LiveJournal, while degree can locate nodes participating in information diffusion with higher probability, k-shell is more effective in finding nodes with a large influence. Our results should provide useful information for designing efficient spreading strategies in reality.

  16. Stages of Renal Cell Cancer

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  17. Discovery – Preventing Skin Cancer

    Science.gov (United States)

    Cancer research includes stopping cancer before it spreads. NCI funded the development of the Melanoma Risk Assessment Tool and the ABC method. Both help to diagnose high-risk patients and prevent melanoma earlier in the fight against skin cancer.

  18. Spreading lengths of Hermite polynomials

    CERN Document Server

    Sánchez-Moreno, P; Manzano, D; Yáñez, R; 10.1016/j.cam.2009.09.043

    2009-01-01

    The Renyi, Shannon and Fisher spreading lengths of the classical or hypergeometric orthogonal polynomials, which are quantifiers of their distribution all over the orthogonality interval, are defined and investigated. These information-theoretic measures of the associated Rakhmanov probability density, which are direct measures of the polynomial spreading in the sense of having the same units as the variable, share interesting properties: invariance under translations and reflections, linear scaling and vanishing in the limit that the variable tends towards a given definite value. The expressions of the Renyi and Fisher lengths for the Hermite polynomials are computed in terms of the polynomial degree. The combinatorial multivariable Bell polynomials, which are shown to characterize the finite power of an arbitrary polynomial, play a relevant role for the computation of these information-theoretic lengths. Indeed these polynomials allow us to design an error-free computing approach for the entropic moments (w...

  19. Epidemic spreading by objective traveling

    Science.gov (United States)

    Tang, Ming; Liu, Zonghua; Li, Baowen

    2009-07-01

    A fundamental feature of agent traveling in social networks is that traveling is usually not a random walk but with a specific destination and goes through the shortest path from starting to destination. A serious consequence of the objective traveling is that it may result in a fast epidemic spreading, such as SARS etc. In this letter we present a reaction-traveling model to study how the objective traveling influences the epidemic spreading. We consider a random scale-free meta-population network with sub-population at each node. Through a SIS model we theoretically prove that near the threshold of epidemic outbreak, the objective traveling can significantly enhance the final infected population and the infected fraction at a node is proportional to its betweenness for the traveling agents and approximately proportional to its degree for the non-traveling agents. Numerical simulations have confirmed the theoretical predictions.

  20. Equatorial Spread F Fossil Plumes

    Science.gov (United States)

    2010-11-01

    Satyanarayana , P., and Ossakow, S. L.: The morphology of a multi-bubble system in the ionosphere, J. Geophys. Res., 88, 5528–5536, 1983. de La Beaujardiere...Haerendel, G.: Theory of equatorial spread F , preprint, Max Planck Inst. Extraterr. Phys., Munich, Germany, 1974. Haerendel, G., Eccles, J. V ., and...weather issues, J. Atmos. Terr. Phys., 58, 1527–1574, 1996. Sekar, R., Chakrabarty, D., Sarkhel, S., Patra, A. K., Devasia, C. V ., and Kelley, M. C

  1. Technique of green mulch spreading

    OpenAIRE

    Schäfer, Winfried; Väisänen, Jaana; Pihala, Marjo

    2001-01-01

    Finland’s policy of subsidising the conversion to organic production precipitated the rapid growth of organic farming in the 1990’s. As a consequence, many stockless farms encountered the problems of nitrogen deficit, poor grain quality, and weed control. Since the spreading of green mulch on cash crops is very common especially in tropical agriculture, organic fertilisers like green mulch may be an alternative that would compensate for the prohibition on the use of mineral N-fertilisers. How...

  2. Quality Improvement of Cheese Spread

    Science.gov (United States)

    2008-02-25

    Annatto (2% bixin) 3.5 mL Use as needed to conform color Vitamin A 0.14 0.003 Not less than 800 retinol units Added to comply with product...for samples with citrates (CIT) and altered levels of phosphates (LP) (Table 7). Although the citrates and phosphates have similar ionic components...Effect of vitamins The guidelines for cheese spread fortification include the addition of retinol (vitamin A), thiamine (vitamin B1), pyridoxine

  3. Physically Protected Spread Spectrum Communications

    Science.gov (United States)

    2016-04-14

    for the FH system in those days was because of implementation issues, such as a frequency -ringing problem , which occurred whenever a frequency was...PS-TR-2016-0046 HAS BEEN REVIEWED AND IS APPROVED FOR PUBLICATION IN ACCORDANCE WITH ASSIGNED DISTRIBUTION STATEMENT. KHANH PHAM PAUL D. LEVAN...keying (MPSK) and M-ary quadrature amplitude-shift keying (MQAM) for a slow frequency hopping (FH) spread spectrum (SS) system because, recently

  4. Drop Spreading with Random Viscosity

    Science.gov (United States)

    Xu, Feng; Jensen, Oliver

    2016-11-01

    Airway mucus acts as a barrier to protect the lung. However as a biological material, its physical properties are known imperfectly and can be spatially heterogeneous. In this study we assess the impact of these uncertainties on the rate of spreading of a drop (representing an inhaled aerosol) over a mucus film. We model the film as Newtonian, having a viscosity that depends linearly on the concentration of a passive solute (a crude proxy for mucin proteins). Given an initial random solute (and hence viscosity) distribution, described as a Gaussian random field with a given correlation structure, we seek to quantify the uncertainties in outcomes as the drop spreads. Using lubrication theory, we describe the spreading of the drop in terms of a system of coupled nonlinear PDEs governing the evolution of film height and the vertically-averaged solute concentration. We perform Monte Carlo simulations to predict the variability in the drop centre location and width (1D) or area (2D). We show how simulation results are well described (at much lower computational cost) by a low-order model using a weak disorder expansion. Our results show for example how variability in the drop location is a non-monotonic function of the solute correlation length increases. Engineering and Physical Sciences Research Council.

  5. Epidemic Spread in Human Networks

    CERN Document Server

    Sahneh, Faryad Darabi

    2011-01-01

    One of the popular dynamics on complex networks is the epidemic spreading. An epidemic model describes how infections spread throughout a network. Among the compartmental models used to describe epidemics, the Susceptible-Infected-Susceptible (SIS) model has been widely used. In the SIS model, each node can be susceptible, become infected with a given infection rate, and become again susceptible with a given curing rate. In this paper, we add a new compartment to the classic SIS model to account for human response to epidemic spread. Each individual can be infected, susceptible, or alert. Susceptible individuals can become alert with an alerting rate if infected individuals exist in their neighborhood. An individual in the alert state is less probable to become infected than an individual in the susceptible state; due to a newly adopted cautious behavior. The problem is formulated as a continuous-time Markov process on a general static graph and then modeled into a set of ordinary differential equations using...

  6. Spread of entanglement and causality

    CERN Document Server

    Casini, Horacio; Mezei, Márk

    2015-01-01

    We investigate causality constraints on the time evolution of entanglement entropy after a global quench in relativistic theories. We first provide a general proof that the so-called tsunami velocity is bounded by the speed of light. We then generalize the free particle streaming model of arXiv:cond-mat/0503393 to general dimensions and to an arbitrary entanglement pattern of the initial state. In more than two spacetime dimensions the spread of entanglement in these models is highly sensitive to the initial entanglement pattern, but we are able to prove an upper bound on the normalized rate of growth of entanglement entropy, and hence the tsunami velocity. The bound is smaller than what one gets for quenches in holographic theories, which highlights the importance of interactions in the spread of entanglement in many-body systems. We propose an interacting model which we believe provides an upper bound on the spread of entanglement for interacting relativistic theories. In two spacetime dimensions with multi...

  7. Spread of entanglement and causality

    Science.gov (United States)

    Casini, Horacio; Liu, Hong; Mezei, Márk

    2016-07-01

    We investigate causality constraints on the time evolution of entanglement entropy after a global quench in relativistic theories. We first provide a general proof that the so-called tsunami velocity is bounded by the speed of light. We then generalize the free particle streaming model of [1] to general dimensions and to an arbitrary entanglement pattern of the initial state. In more than two spacetime dimensions the spread of entanglement in these models is highly sensitive to the initial entanglement pattern, but we are able to prove an upper bound on the normalized rate of growth of entanglement entropy, and hence the tsunami velocity. The bound is smaller than what one gets for quenches in holographic theories, which highlights the importance of interactions in the spread of entanglement in many-body systems. We propose an interacting model which we believe provides an upper bound on the spread of entanglement for interacting relativistic theories. In two spacetime dimensions with multiple intervals, this model and its variations are able to reproduce intricate results exhibited by holographic theories for a significant part of the parameter space. For higher dimensions, the model bounds the tsunami velocity at the speed of light. Finally, we construct a geometric model for entanglement propagation based on a tensor network construction for global quenches.

  8. Reverse preferential spread in complex networks

    Science.gov (United States)

    Toyoizumi, Hiroshi; Tani, Seiichi; Miyoshi, Naoto; Okamoto, Yoshio

    2012-08-01

    Large-degree nodes may have a larger influence on the network, but they can be bottlenecks for spreading information since spreading attempts tend to concentrate on these nodes and become redundant. We discuss that the reverse preferential spread (distributing information inversely proportional to the degree of the receiving node) has an advantage over other spread mechanisms. In large uncorrelated networks, we show that the mean number of nodes that receive information under the reverse preferential spread is an upper bound among any other weight-based spread mechanisms, and this upper bound is indeed a logistic growth independent of the degree distribution.

  9. Blood coagulation-(in)dependent protease activated receptor signaling in pancreatic cancer

    NARCIS (Netherlands)

    K. Shi

    2015-01-01

    There is no doubt that pancreatic cancer is one of the most lethal diseases in general and current treatment options are limited. The studies described in this thesis pinpoint Protease activated receptors (PARs) as key players in pancreatic cancer progression. Inhibition of PAR-1 may be clinical rel

  10. Geodynamic environments of ultra-slow spreading

    Science.gov (United States)

    Kokhan, Andrey; Dubinin, Evgeny

    2015-04-01

    Ultra-slow spreading is clearly distinguished as an outstanding type of crustal accretion by recent studies. Spreading ridges with ultra-slow velocities of extension are studied rather well. But ultra-slow spreading is characteristic feature of not only spreading ridges, it can be observed also on convergent and transform plate boundaries. Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on divergent plate boundaries: 1. On spreading ridges with ultra-slow spreading, both modern (f.e. Gakkel, South-West Indian, Aden spreading center) and ceased (Labrador spreading center, Aegir ridge); 2. During transition from continental rifting to early stages of oceanic spreading (all spreading ridges during incipient stages of their formation); 3. During incipient stages of formation of spreading ridges on oceanic crust as a result of ridge jumps and reorganization of plate boundaries (f.e. Mathematicians rise and East Pacific rise); 4. During propagation of spreading ridge into the continental crust under influence of hotspot (Aden spreading center and Afar triple junction), under presence of strike-slip faults preceding propagation (possibly, rift zone of California Bay). Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on transform plate boundaries: 1. In transit zones between two "typical" spreading ridges (f.e. Knipovich ridge); 2. In semi strike-slip/extension zones on the oceanic crust (f.e. American-Antarctic ridge); 3. In the zones of local extension in regional strike-slip areas in pull-apart basins along transform boundaries (Cayman trough, pull-apart basins of the southern border of Scotia plate). Ultra-slow spreading is observed now or could have been observed in the past in the following geodynamic environments on convergent plate boundaries: 1. During back-arc rifting on the stage of transition into back-arc spreading (central

  11. Facteurs de risque de cancer du poumon chez la femme

    OpenAIRE

    Papadopoulos, Alexandra

    2012-01-01

    The incidence of female lung cancer in developed countries has been increasing since 1950 and particularly in France where the cigarettes consumption has also increased. Since 1980, a growing number of epidemiological surveys have pinpointed the risk of female lung cancer related to smoking. Consecutively, a debate on gender differences in lung cancer risk has appeared, but still in progress nowadays. The reproductive factors could explain these differences. In order to have recent and reliab...

  12. Plume spread and atmospheric stability

    Energy Technology Data Exchange (ETDEWEB)

    Weber, R.O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The horizontal spread of a plume in atmospheric dispersion can be described by the standard deviation of horizontal direction. The widely used Pasquill-Gifford classes of atmospheric stability have assigned typical values of the standard deviation of horizontal wind direction and of the lapse rate. A measured lapse rate can thus be used to estimate the standard deviation of wind direction. It is examined by means of a large dataset of fast wind measurements how good these estimates are. (author) 1 fig., 2 refs.

  13. Liquid Spreading under Nanoscale Confinement

    Science.gov (United States)

    Checco, Antonio

    2009-03-01

    Dynamic atomic force microscopy in the noncontact regime is used to study the morphology of a nonvolatile liquid (squalane) as it spreads along wettable nanostripes embedded in a nonwettable surface. Results show that the liquid profile depends on the amount of lateral confinement imposed by the nanostripes, and it is truncated at the microscopic contact line in good qualitative agreement with classical mesoscale hydrodynamics. However, the width of the contact line is found to be significantly larger than expected theoretically. This behavior may originate from small chemical inhomogeneity of the patterned stripes as well as from thermal fluctuations of the contact line.

  14. Spreading widths of doorway states

    Energy Technology Data Exchange (ETDEWEB)

    De Pace, A., E-mail: depace@to.infn.i [Istituto Nazionale di Fisica Nucleare, Sezione di Torino, via P. Giuria 1, I-10125 Torino (Italy); Molinari, A. [Dipartimento di Fisica Teorica dell' Universita di Torino, via P. Giuria 1, I-10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Torino, via P. Giuria 1, I-10125 Torino (Italy); Weidenmueller, H.A. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany)

    2011-01-01

    As a function of energy E, the average doorway strength function S(E)-bar of a doorway state is commonly assumed to be Lorentzian in shape and characterized by two parameters, the peak energy E{sub 0} and the spreading width {Gamma}{sup {down_arrow}}. The simple picture is modified when the density of background states that couple to the doorway state changes significantly in an energy interval of size {Gamma}{sup {down_arrow}}. For that case we derive an approximate analytical expression for S(E)-bar. We test our result successfully against numerical simulations. Our result may have important implications for shell-model calculations.

  15. Migration Helps Spread Bird Flu Worldwide

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161473.html Migration Helps Spread Bird Flu Worldwide Scientists recommend keeping ... birds can spread bird flu worldwide and monitoring migration routes could provide early warning of outbreaks, researchers ...

  16. Lexical Ambiguity: Making a Case against Spread

    Science.gov (United States)

    Kaplan, Jennifer J.; Rogness, Neal T.; Fisher, Diane G.

    2012-01-01

    We argue for decreasing the use of the word "spread" when describing the statistical idea of dispersion or variability in introductory statistics courses. In addition, we argue for increasing the use of the word "variability" as a replacement for "spread."

  17. The spreading of misinformation online.

    Science.gov (United States)

    Del Vicario, Michela; Bessi, Alessandro; Zollo, Fabiana; Petroni, Fabio; Scala, Antonio; Caldarelli, Guido; Stanley, H Eugene; Quattrociocchi, Walter

    2016-01-19

    The wide availability of user-provided content in online social media facilitates the aggregation of people around common interests, worldviews, and narratives. However, the World Wide Web (WWW) also allows for the rapid dissemination of unsubstantiated rumors and conspiracy theories that often elicit rapid, large, but naive social responses such as the recent case of Jade Helm 15--where a simple military exercise turned out to be perceived as the beginning of a new civil war in the United States. In this work, we address the determinants governing misinformation spreading through a thorough quantitative analysis. In particular, we focus on how Facebook users consume information related to two distinct narratives: scientific and conspiracy news. We find that, although consumers of scientific and conspiracy stories present similar consumption patterns with respect to content, cascade dynamics differ. Selective exposure to content is the primary driver of content diffusion and generates the formation of homogeneous clusters, i.e., "echo chambers." Indeed, homogeneity appears to be the primary driver for the diffusion of contents and each echo chamber has its own cascade dynamics. Finally, we introduce a data-driven percolation model mimicking rumor spreading and we show that homogeneity and polarization are the main determinants for predicting cascades' size.

  18. Rumor spreading in gaming social networks

    CERN Document Server

    Zhang, Yichao; Guan, Jihong; Zhou, Shuigeng

    2011-01-01

    So far, the focus on rumor spreading are mainly on some simple backgrounds, in other words, only taking consideration of the overall topological influences on its dynamical behavior. However, in the prospect of the individuality, personal strategies in the social networks play a more non-trivial role in the real social networks. To fill this gap, we will investigate the rumor spreading in gaming social networks. Our analysis is supported by the results of numerical simulations. We observe that the original rumor is still the most well known edition in case that the content is modified by the defectors. However, the portion decays with the stimulus generally. For the case that defectors keep silence in the spreading process, the scale of spreading decays with stimulus generally, suggesting the rumor can hardly spread in a community of defectors. This highlights the key role that stimulus plays in rumor spreading and the necessity to study information spreading in competitive circumstances.

  19. Random Information Spread in Networks

    CERN Document Server

    Lapus, Raymond; Tittmann, Peter

    2010-01-01

    Let G=(V,E) be an undirected loopless graph with possible parallel edges and s and t be two vertices of G. Assume that vertex s is labelled at the initial time step and that every labelled vertex copies its labelling to neighbouring vertices along edges with one labelled endpoint independently with probability p in one time step. In this paper, we establish the equivalence between the expected s-t first arrival time of the above spread process and the notion of the stochastic shortest s-t path. Moreover, we give a short discussion of analytical results on special graphs including the complete graph and s-t series-parallel graphs. Finally, we propose some lower bounds for the expected s-t first arrival time.

  20. Bank Lending, Housing and Spreads

    DEFF Research Database (Denmark)

    Aslam, Aqib; Santoro, Emiliano

    The framework presented in this paper takes its cue from recent financial events and attempts to develop a tractable framework for policy analysis of macro-linkages, in particular a first attempt at the integration of an independent profit-maximising banking sector that lends to and borrows from...... agents in the economy, and through which changes in the monetary policy rate by the central bank are transmitted. The inter-linkages between housing and the role of the banking sector in the transmission of monetary policy is emphasized. Two competing effects are highlighted: (i) a financial accelerator...... channel, due to the presence of collateralized borrowers, and (ii) a banking attenuator effect, which crucially arises from the spread in interest rates caused by the introduction of monopolistically competitive financial intermediaries. We show how the classical amplification mechanism explored in models...

  1. Interpolating point spread function anisotropy

    CERN Document Server

    Gentile, M; Meylan, G

    2012-01-01

    Planned wide-field weak lensing surveys are expected to reduce the statistical errors on the shear field to unprecedented levels. In contrast, systematic errors like those induced by the convolution with the point spread function (PSF) will not benefit from that scaling effect and will require very accurate modeling and correction. While numerous methods have been devised to carry out the PSF correction itself, modeling of the PSF shape and its spatial variations across the instrument field of view has, so far, attracted much less attention. This step is nevertheless crucial because the PSF is only known at star positions while the correction has to be performed at any position on the sky. A reliable interpolation scheme is therefore mandatory and a popular approach has been to use low-order bivariate polynomials. In the present paper, we evaluate four other classical spatial interpolation methods based on splines (B-splines), inverse distance weighting (IDW), radial basis functions (RBF) and ordinary Kriging...

  2. Bank Lending, Housing and Spreads

    DEFF Research Database (Denmark)

    Aslam, Aqib; Santoro, Emiliano

    of private borrowing between collaterally-constrained 'impatient' households and unconstrained 'patient' households, such as those put forward by Kiyotaki and Moore (1997) and Iacoviello (2005), is counteracted by the banking attenuator effect, given an endogenous steady state spread between loan and savings......The framework presented in this paper takes its cue from recent financial events and attempts to develop a tractable framework for policy analysis of macro-linkages, in particular a first attempt at the integration of an independent profit-maximising banking sector that lends to and borrows from...... agents in the economy, and through which changes in the monetary policy rate by the central bank are transmitted. The inter-linkages between housing and the role of the banking sector in the transmission of monetary policy is emphasized. Two competing effects are highlighted: (i) a financial accelerator...

  3. Cancer

    Science.gov (United States)

    Cancer begins in your cells, which are the building blocks of your body. Normally, your body forms ... be benign or malignant. Benign tumors aren't cancer while malignant ones are. Cells from malignant tumors ...

  4. On the contribution of Angola to the initial spread of HIV-1.

    Science.gov (United States)

    Pineda-Peña, Andrea-Clemencia; Varanda, Jorge; Sousa, João Dinis; Theys, Kristof; Bártolo, Inês; Leitner, Thomas; Taveira, Nuno; Vandamme, Anne-Mieke; Abecasis, Ana B

    2016-12-01

    Angola borders and has long-term links with Democratic Republic of Congo (DRC) as well as high levels of Human Immunodeficiency Virus (HIV) genetic diversity, indicating a potential role in the initial spread of the HIV-1 pandemic. Herein, we analyze 564 C2V3 and 354 pol publicly available sequences from DRC, Republic of Congo (RC) and Angola to better understand the initial spread of the virus in this region. Phylogeographic analyses were performed with the BEAST software. While our results pinpoint the origin of the pandemic to Kinshasa (DRC) around 1906, the introduction of HIV-1 to Angola could have occurred early between the 1910s and 1940s. Furthermore, most of the HIV-1 migrations out of Kinshasa were directed not only to Lubumbashi and Mbuji-Mayi (DRC), but also to Luanda and Brazzaville. Kinshasa census records corroborate these findings, indicating that the early exportation of the virus to Angola might be related to the high number of Angolans in Kinshasa at that time, originated mostly from the North of Angola. In summary, our results place Angola at the epicenter of the early HIV dissemination, together with DRC and RC.

  5. General Information about Small Cell Lung Cancer

    Science.gov (United States)

    ... lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The ... diagnosed, tests are done to find out if cancer cells have spread within the chest or to other ...

  6. Treatment Options for Renal Cell Cancer

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  7. Treatment Option Overview (Small Cell Lung Cancer)

    Science.gov (United States)

    ... lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The ... diagnosed, tests are done to find out if cancer cells have spread within the chest or to other ...

  8. Stages of Small Cell Lung Cancer

    Science.gov (United States)

    ... lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The ... diagnosed, tests are done to find out if cancer cells have spread within the chest or to other ...

  9. General Information about Renal Cell Cancer

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  10. Treatment Option Overview (Renal Cell Cancer)

    Science.gov (United States)

    ... cell cancer is a disease in which malignant (cancer) cells form in tubules of the kidney. Renal cell ... diagnosed, tests are done to find out if cancer cells have spread within the kidney or to other ...

  11. When your cancer treatment stops working

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000851.htm When your cancer treatment stops working To use the sharing features on this page, please enable JavaScript. Cancer treatments can keep cancer from spreading and even cure ...

  12. Lab-on-a-Drone: Toward Pinpoint Deployment of Smartphone-Enabled Nucleic Acid-Based Diagnostics for Mobile Health Care

    Science.gov (United States)

    2016-01-01

    We introduce a portable biochemical analysis platform for rapid field deployment of nucleic acid-based diagnostics using consumer-class quadcopter drones. This approach exploits the ability to isothermally perform the polymerase chain reaction (PCR) with a single heater, enabling the system to be operated using standard 5 V USB sources that power mobile devices (via battery, solar, or hand crank action). Time-resolved fluorescence detection and quantification is achieved using a smartphone camera and integrated image analysis app. Standard sample preparation is enabled by leveraging the drone’s motors as centrifuges via 3D printed snap-on attachments. These advancements make it possible to build a complete DNA/RNA analysis system at a cost of ∼$50 ($US). Our instrument is rugged and versatile, enabling pinpoint deployment of sophisticated diagnostics to distributed field sites. This capability is demonstrated by successful in-flight replication of Staphylococcus aureus and λ-phage DNA targets in under 20 min. The ability to perform rapid in-flight assays with smartphone connectivity eliminates delays between sample collection and analysis so that test results can be delivered in minutes, suggesting new possibilities for drone-based systems to function in broader and more sophisticated roles beyond cargo transport and imaging. PMID:26898247

  13. Bio-chemostratigraphy of the Barremian-Aptian shallow-water carbonates of the southern Apennines (Italy): pinpointing the OAE1a in a Tethyan carbonate platform

    Science.gov (United States)

    di Lucia, M.; Mutti, M.; Parente, M.

    2011-09-01

    Low resolution and lack of chronostratigraphic calibration of carbonate platform biostratigraphy hinder precise correlation with coeval deep-water successions. This is the main obstacle when studying the record of Mesozoic oceanic anoxic events in carbonate platforms. In this paper we use carbon isotope stratigraphy to produce the first chronostratigraphic calibration of the Barremian-Aptian biostratigraphy of the Apenninic carbonate platform of southern Italy. According to our calibration, the "Selli level" black shales of epicontinental and oceanic basins corresponds in the southern Apenninic carbonate platform to the interval between the "Orbitolina level", characterized by the association of Mesorbitolina parva and Mesorbitolina texana, and the second acme of Salpingoporella dinarica. The biocalcification crisis of nannoconids corresponds to the interval going from the first acme of S. dinarica to just above the top of the "Orbitolina level". Since these bioevents have been widely recognized beyond the Apenninic platform, our calibration can be used to pinpoint the interval corresponding to the Early Aptian oceanic anoxic event in other carbonate platforms of central and southern Tethys.

  14. Bio-chemostratigraphy of the Barremian–Aptian shallow-water carbonates of the southern Apennines (Italy: pinpointing the OAE1a in a Tethyan carbonate platform

    Directory of Open Access Journals (Sweden)

    M. Di Lucia

    2011-09-01

    Full Text Available Low resolution and lack of chronostratigraphic calibration of carbonate platform biostratigraphy hinder precise correlation with coeval deep-water successions. This is the main obstacle when studying the record of Mesozoic oceanic anoxic events in carbonate platforms. In this paper we use carbon isotope stratigraphy to produce the first chronostratigraphic calibration of the Barremian–Aptian biostratigraphy of the Apenninic carbonate platform of southern Italy. According to our calibration, the "Selli level" black shales of epicontinental and oceanic basins corresponds in the southern Apenninic carbonate platform to the interval between the "Orbitolina level", characterized by the association of Mesorbitolina parva and Mesorbitolina texana, and the second acme of Salpingoporella dinarica. The biocalcification crisis of nannoconids corresponds to the interval going from the first acme of S. dinarica to just above the top of the "Orbitolina level". Since these bioevents have been widely recognized beyond the Apenninic platform, our calibration can be used to pinpoint the interval corresponding to the Early Aptian oceanic anoxic event in other carbonate platforms of central and southern Tethys.

  15. Lab-on-a-Drone: Toward Pinpoint Deployment of Smartphone-Enabled Nucleic Acid-Based Diagnostics for Mobile Health Care.

    Science.gov (United States)

    Priye, Aashish; Wong, Season; Bi, Yuanpeng; Carpio, Miguel; Chang, Jamison; Coen, Mauricio; Cope, Danielle; Harris, Jacob; Johnson, James; Keller, Alexandra; Lim, Richard; Lu, Stanley; Millard, Alex; Pangelinan, Adriano; Patel, Neal; Smith, Luke; Chan, Kamfai; Ugaz, Victor M

    2016-05-03

    We introduce a portable biochemical analysis platform for rapid field deployment of nucleic acid-based diagnostics using consumer-class quadcopter drones. This approach exploits the ability to isothermally perform the polymerase chain reaction (PCR) with a single heater, enabling the system to be operated using standard 5 V USB sources that power mobile devices (via battery, solar, or hand crank action). Time-resolved fluorescence detection and quantification is achieved using a smartphone camera and integrated image analysis app. Standard sample preparation is enabled by leveraging the drone's motors as centrifuges via 3D printed snap-on attachments. These advancements make it possible to build a complete DNA/RNA analysis system at a cost of ∼$50 ($US). Our instrument is rugged and versatile, enabling pinpoint deployment of sophisticated diagnostics to distributed field sites. This capability is demonstrated by successful in-flight replication of Staphylococcus aureus and λ-phage DNA targets in under 20 min. The ability to perform rapid in-flight assays with smartphone connectivity eliminates delays between sample collection and analysis so that test results can be delivered in minutes, suggesting new possibilities for drone-based systems to function in broader and more sophisticated roles beyond cargo transport and imaging.

  16. Sites involved in intra- and interdomain allostery associated with the activation of factor VIIa pinpointed by hydrogen-deuterium exchange and electron transfer dissociation mass spectrometry.

    Science.gov (United States)

    Song, Hongjian; Olsen, Ole H; Persson, Egon; Rand, Kasper D

    2014-12-19

    Factor VIIa (FVIIa) is a trypsin-like protease that plays an important role in initiating blood coagulation. Very limited structural information is available for the free, inactive form of FVIIa that circulates in the blood prior to vascular injury and the molecular details of its activity enhancement remain elusive. Here we have applied hydrogen/deuterium exchange mass spectrometry coupled to electron transfer dissociation to pinpoint individual residues in the heavy chain of FVIIa whose conformation and/or local interaction pattern changes when the enzyme transitions to the active form, as induced either by its cofactor tissue factor or a covalent active site inhibitor. Identified regulatory residues are situated at key sites across one continuous surface of the protease domain spanning the TF-binding helix across the activation pocket to the calcium binding site and are embedded in elements of secondary structure and at the base of flexible loops. Thus these residues are optimally positioned to mediate crosstalk between functional sites in FVIIa, particularly the cofactor binding site and the active site. Our results unambiguously show that the conformational allosteric activation signal extends to the EGF1 domain in the light chain of FVIIa, underscoring a remarkable intra- and interdomain allosteric regulation of this trypsin-like protease. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Imaging techniques: Nanoparticle atoms pinpointed

    Science.gov (United States)

    Farle, Michael

    2017-02-01

    The locations of atoms in a metallic alloy nanoparticle have been determined using a combination of electron microscopy and image simulation, revealing links between the particle's structure and magnetic properties. See Letter p.75

  18. Impacts of suppressing guide on information spreading

    CERN Document Server

    Xu, Jinghong; Ma, Baojun; Wu, Ye

    2015-01-01

    It is quite common that guides are introduced to suppress the information spreading in modern society for different purposes. In this paper, an agent-based model is established to quantitatively analyze the impacts of suppressing guides on information spreading. We find that the spreading threshold depends on the attractiveness of the information and the topology of the social network with no suppressing guides at all. Usually, one would expect that the existence of suppressing guides in the spreading procedure may result in less diffusion of information within the overall network. However, we find that sometimes the opposite is true: the manipulating nodes of suppressing guides may lead to more extensive information spreading when there are audiences with the reversal mind. These results can provide valuable theoretical references to public opinion guidance on various information, e.g., rumor or news spreading.

  19. Impacts of suppressing guide on information spreading

    Science.gov (United States)

    Xu, Jinghong; Zhang, Lin; Ma, Baojun; Wu, Ye

    2016-02-01

    It is quite common that guides are introduced to suppress the information spreading in modern society for different purposes. In this paper, an agent-based model is established to quantitatively analyze the impacts of suppressing guides on information spreading. We find that the spreading threshold depends on the attractiveness of the information and the topology of the social network with no suppressing guides at all. Usually, one would expect that the existence of suppressing guides in the spreading procedure may result in less diffusion of information within the overall network. However, we find that sometimes the opposite is true: the manipulating nodes of suppressing guides may lead to more extensive information spreading when there are audiences with the reversal mind. These results can provide valuable theoretical references to public opinion guidance on various information, e.g., rumor or news spreading.

  20. A general method for identifying node spreading influence via the adjacent matrix and spreading rate

    CERN Document Server

    Lin, Jian-Hong; Guo, Qiang

    2014-01-01

    With great theoretical and practical significance, identifying the node spreading influence of complex network is one of the most promising domains. So far, various topology-based centrality measures have been proposed to identify the node spreading influence in a network. However, the node spreading influence is a result of the interplay between the network topology structure and spreading dynamics. In this paper, we build up the systematic method by combining the network structure and spreading dynamics to identify the node spreading influence. By combining the adjacent matrix $A$ and spreading parameter $\\beta$, we theoretical give the node spreading influence with the eigenvector of the largest eigenvalue. Comparing with the Susceptible-Infected-Recovered (SIR) model epidemic results for four real networks, our method could identify the node spreading influence more accurately than the ones generated by the degree, K-shell and eigenvector centrality. This work may provide a systematic method for identifyi...

  1. Equatorial spread F fossil plumes

    Directory of Open Access Journals (Sweden)

    S. L. Ossakow

    2010-11-01

    Full Text Available Behaviour of equatorial spread F (ESF fossil plumes, i.e., ESF plumes that have stopped rising, is examined using the NRL SAMI3/ESF three-dimensional simulation code. We find that fossil bubbles, plasma density depletions associated with fossil plumes, can persist as high-altitude equatorial depletions even while being "blown" by zonal winds. Corresponding airglow-proxy images of fossil plumes, plots of electron density versus longitude and latitude at a constant altitude of 288 km, are shown to partially "fill in" in most cases, beginning with the highest altitude field lines within the plume. Specifically, field lines upon which the E field has fallen entirely to zero are affected and only the low altitude (≤600 km portion if each field line fills in. This suggests that it should be possible to observe a bubble at high altitude on a field line for which the corresponding airglow image no longer shows a depletion. In all cases ESF plumes stop rising when the flux-tube-integrated ion mass density inside the upper edge of the bubble is equal to that of the nearby background, further supporting the result of Krall et al. (2010b.

  2. Drops spreading on flexible fibers

    Science.gov (United States)

    Somszor, Katarzyna; Boulogne, François; Sauret, Alban; Dressaire, Emilie; Stone, Howard

    2015-11-01

    Fibrous media are encountered in many engineered systems such as textile, paper and insulating materials. In most of these materials, fibers are randomly oriented and form a complex network in which drops of wetting liquid tend to accumulate at the nodes of the network. Here we investigate the role of the fiber flexibility on the spreading of a small volume of liquid on a pair of crossed flexible fibers. A drop of silicone oil is dispensed at the point of contact of the fibers and we characterize the liquid morphologies as we vary the volume of liquid, the angle between the fibers, and the length and bending modulus of the fibers. Drop morphologies previously reported for rigid fibers, i.e. a drop, a column and a mixed morphology, are also observed on flexible fibers with modified domains of existence. Moreover, at small inclination angles of the fibers, a new behavior is observed: the fibers bend and collapse. Depending on the volume, the liquid can adopt a column or a mixed morphology on the collapsed fibers. We rationalize our observations with a model based on energetic considerations. Our study suggests that the fiber flexibility adds a rich variety of behaviors that can be crucial for industrial applications.

  3. Information Spreading in Dynamic Graphs

    CERN Document Server

    Clementi, Andrea; Trevisan, Luca

    2011-01-01

    We present a general approach to study the flooding time (a measure of how fast information spreads) in dynamic graphs (graphs whose topology changes with time according to a random process). We consider arbitrary converging Markovian dynamic graph process, that is, processes in which the topology of the graph at time $t$ depends only on its topology at time $t-1$ and which have a unique stationary distribution. The most well studied models of dynamic graphs are all Markovian and converging. Under general conditions, we bound the flooding time in terms of the mixing time of the dynamic graph process. We recover, as special cases of our result, bounds on the flooding time for the \\emph{random trip} model and the \\emph{random path} models; previous analysis techniques provided bounds only in restricted settings for such models. Our result also provides the first bound for the \\emph{random waypoint} model (which is tight for certain ranges of parameters) whose analysis had been an important open question.

  4. Dynamical model for virus spread

    CERN Document Server

    Camelo-Neto, G

    1995-01-01

    The steady state properties of the mean density population of infected cells in a viral spread is simulated by a general forest fire like cellular automaton model with two distinct populations of cells ( permissive and resistant ones) and studied in the framework of the mean field approximation. Stochastic dynamical ingredients are introduced in this model to mimic cells regeneration (with probability {\\it p}) and to consider infection processes by other means than contiguity (with probability {\\it f}). Simulations are carried on a L \\times L square lattice considering the eight first neighbors. The mean density population of infected cells (D_i) is measured as function of the regeneration probability {\\it p}, and analyzed for small values of the ratio {\\it f/p } and for distinct degrees of the cell resistance. The results obtained by a mean field like approach recovers the simulations results. The role of the resistant parameter R (R \\geq 2) on the steady state properties is investigated and discussed in com...

  5. What Drives the POLONIA Spread in Poland?

    OpenAIRE

    Yinqiu Lu

    2012-01-01

    Since the start of the 2008 - 09 financial crisis, the Polish Overnight Index Average (POLONIA) has persistently been below the policy rate, suggesting a limited influence of the NBP’s open market operations on the short-term interbank rate. In this regard, this paper analyzes the behavior of the POLONIA spread and explore several potential factors that could influence the spread. An empirical analysis confirms that the negative POLONIA spread is related to a few factors, which include the ...

  6. Information spreading and development of cultural centers

    CERN Document Server

    Dybiec, Bartlomiej; Sneppen, Kim

    2012-01-01

    The historical interplay between societies are governed by many factors, including in particular spreading of languages, religion and other symbolic traits. Cultural development, in turn, is coupled to emergence and maintenance of information spreading. Strong centralized cultures exist thanks to attention from their members, which faithfulness in turn relies on supply of information. Here, we discuss a culture evolution model on a planar geometry that takes into account aspects of the feedback between information spreading and its maintenance. Features of model are highlighted by comparing it to cultural spreading in ancient and medieval Europe, where it in particular suggests that long lived centers should be located in geographically remote regions.

  7. Credit Spreads Across the Business Cycle

    DEFF Research Database (Denmark)

    Nielsen, Mads Stenbo

    This paper studies how corporate bond spreads vary with the business cycle. I show that both level and slope of empirical credit spread curves are correlated with the state of the economy, and I link this to variation in idiosyncratic jump risk. I develop a structural credit risk model that accou......This paper studies how corporate bond spreads vary with the business cycle. I show that both level and slope of empirical credit spread curves are correlated with the state of the economy, and I link this to variation in idiosyncratic jump risk. I develop a structural credit risk model...... to firm fundamentals....

  8. Olive oil in food spreads

    Directory of Open Access Journals (Sweden)

    Blanco Muñoz, Miguel A.

    2004-03-01

    Full Text Available Chemical hydrogenation of unsaturated fatty acids is a commonly applied reaction to food industries. The process may imply the movement of double bonds in their positions on the fatty acid carbon chain, producing positional and geometrical isomers ( trans fatty acids. Through hydrogenation, unsaturated oils are converted to margarines and vegetable shortenings. The presence of trans fatty acids in foods is undesirable, as trans fatty acids raise the plasma levels of total and low-density lipoproteins (LDL, while decrease the plasma level of high-density lipoproteins (HDL, among other effects. The use of olive oil to prepare fat spread opens new insights into the commercial development of healthy novel foods with a positive image in terms of consumer appeal.La hidrogenación química de los ácidos grasos insaturados es una reacción que se utiliza con frecuencia en la industria alimentaria. El proceso implica el movimiento de los dobles enlaces en la cadena hidrocarbonada de los ácidos grasos, y la aparición de isómeros posicionales y geométricos (ácidos grasos trans . La ingesta inadecuada de alimentos que pueden contener cantidades significativas de ácidos grasos trans se asocia con el aumento en sangre de colesterol total y LDL, y la disminución de HDL, entre otros efectos. Por lo tanto, el uso de aceite de oliva en la preparación de grasas para untar constituye un importante avance en el desarrollo comercial de nuevos alimentos saludables con una imagen positiva para el consumidor.

  9. Bio-chemostratigraphy of the Barremian-Aptian shallow-water carbonates of the southern Apennines (Italy: pinpointing the OAE1a in a Tethyan carbonate platform

    Directory of Open Access Journals (Sweden)

    M. Di Lucia

    2012-01-01

    Full Text Available Low biostratigraphic resolution and lack of chronostratigraphic calibration hinder precise correlations between platform carbonates and coeval deep-water successions. These are the main obstacle when studying the record of Mesozoic oceanic anoxic events in carbonate platforms. In this paper carbon and strontium isotope stratigraphy are used to produce the first chronostratigraphic calibration of the Barremian-Aptian biostratigraphy of the Apenninic carbonate platform of southern Italy. According to this calibration, the segment of decreasing δ13C values, leading to the negative peak that is generally taken as the onset of the Selli event, starts a few metres above the last occurrence of Palorbitolina lenticularis and Voloshinoides murgensis. The following rise of δ13C values, corresponding to the interval of enhanced accumulation of organic matter in deep-water sections, ends just below the first acme of Salpingoporella dinarica, which roughly corresponds to the segment of peak δ13C values. The whole carbon isotope excursion associated with the oceanic anoxic event 1a is bracketed in the Apenninic carbonate platform between the last occurrence of Voloshinoides murgensis and the "Orbitolina level", characterized by the association of Mesorbitolina parva and Mesorbitolina texana. Since these bioevents have been widely recognized beyond the Apenninic platform, the calibration presented in this paper can be used to pinpoint the interval corresponding to the Early Aptian oceanic anoxic event in other carbonate platforms of central and southern Tethys. This calibration will be particularly useful to interpret the record of the Selli event in carbonate platform sections for which a reliable carbon isotope stratigraphy is not available.

  10. Age, spreading rates, and spreading asymmetry of the world's ocean crust

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The authors present four companion digital models of the age, age uncertainty, spreading rates and spreading asymmetries of the world's ocean basins as geographic...

  11. Modelling unidirectional liquid spreading on slanted microposts

    DEFF Research Database (Denmark)

    Cavalli, Andrea; Blow, Matthew L.; Yeomans, Julia M.

    2013-01-01

    A lattice Boltzmann algorithm is used to simulate the slow spreading of drops on a surface patterned with slanted micro-posts. Gibb's pinning of the interface on the sides or top of the posts leads to unidirectional spreading over a wide range of contact angles and inclination angles of the posts...

  12. Spreading to localized targets in complex networks

    Science.gov (United States)

    Sun, Ye; Ma, Long; Zeng, An; Wang, Wen-Xu

    2016-12-01

    As an important type of dynamics on complex networks, spreading is widely used to model many real processes such as the epidemic contagion and information propagation. One of the most significant research questions in spreading is to rank the spreading ability of nodes in the network. To this end, substantial effort has been made and a variety of effective methods have been proposed. These methods usually define the spreading ability of a node as the number of finally infected nodes given that the spreading is initialized from the node. However, in many real cases such as advertising and news propagation, the spreading only aims to cover a specific group of nodes. Therefore, it is necessary to study the spreading ability of nodes towards localized targets in complex networks. In this paper, we propose a reversed local path algorithm for this problem. Simulation results show that our method outperforms the existing methods in identifying the influential nodes with respect to these localized targets. Moreover, the influential spreaders identified by our method can effectively avoid infecting the non-target nodes in the spreading process.

  13. The Imaging of Large Nerve Perineural Spread.

    Science.gov (United States)

    Gandhi, Mitesh; Sommerville, Jennifer

    2016-04-01

    We present a review of the imaging findings of large nerve perineural spread within the skull base. The MRI techniques and reasons for performing different sequences are discussed. A series of imaging examples illustrates the appearance of perineural tumor spread with an emphasis on the zonal staging system.

  14. Fire spread characteristics determined in the laboratory

    Science.gov (United States)

    Richard C. Rothermel; Hal E. Anderson

    1966-01-01

    Fuel beds of ponderosa pine needles and white pine needles were burned under controlled environmental conditions to determine the effects of fuel moisture and windspeed upon the rate of fire spread. Empirical formulas are presented to show the effect of these parameters. A discussion of rate of spread and some simple experiments show how fuel may be preheated before...

  15. Spreading Modes on Copper and Steel Surfaces

    Directory of Open Access Journals (Sweden)

    Feoktistov Dmitry

    2016-01-01

    Full Text Available This work presents the experimental results of the studying the effect of surface roughness, microstructure and liquid flow rate on the dynamic contact angle during spreading of distilled nondeaerated water drop on a solid horizontal substrate. Copper and steel substrates with different roughness have been investigated. Three spreading modes were conventionally indicated. It was found that the spreading of drops on substrates made of different materials occurs in similar modes. However, the duration of each mode for substrates made of copper and steel are different. Spreading of a liquid above the asperities of a surface micro relief was observed to be dominant for large volumetric flow rates of drops (0.01 ml/s. Liquid was spreading inside the grooves of a rough substrate at low rates (0.005 ml/s.

  16. Information spreading on dynamic social networks

    CERN Document Server

    Liu, Chuang

    2012-01-01

    Nowadays, information spreading on social networks has triggered an explosive attention in various disciplines. Most of previous related works in this area mainly focus on discussing the effects of spreading probability or immunization strategy on static networks. However, in real systems, the peer-to-peer network structure changes constantly according to frequently social activities of users. In order to capture this dynamical property and study its impact on information spreading, in this Letter, a link rewiring strategy based on the Fermi function is introduced. In the present model, the informed individuals tend to break old links and reconnect to ones with more uninformed neighbors. Simulation results on the susceptible-infected (\\textit{SI}) model with non-redundancy contacts indicate that the information spread more faster and broader with the rewiring strategy. Extensive analyses of the information cascading show that the spreading process of the initial steps plays a very important role, that is to s...

  17. Enhanced droplet spreading due to thermal fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Willis, A M; Freund, J B, E-mail: jbfreund@illinois.ed [Department of Mechanical Science and Engineering, College of Engineering, University of Illinois at Urbana-Champaign, 1206 West Green Street, Urbana, IL 61801 (United States)

    2009-11-18

    The lubrication equation that governs the dynamics of thin liquid films can be augmented to account for stochastic stresses associated with the thermal fluctuations of the fluid. It has been suggested that under certain conditions the spreading rate of a liquid drop on a surface will be increased by these stochastic stresses. Here, an atomistic simulation of a spreading drop is designed to examine such a regime and provide a quantitative assessment of the stochastic lubrication equation for spreading. It is found that the atomistic drop does indeed spread faster than the standard lubrication equations would suggest and that the stochastic lubrication equation of Gruen et al (2006 J. Stat. Phys. 122 1261-91) predicts the spread rate.

  18. Interpolating point spread function anisotropy

    Science.gov (United States)

    Gentile, M.; Courbin, F.; Meylan, G.

    2013-01-01

    Planned wide-field weak lensing surveys are expected to reduce the statistical errors on the shear field to unprecedented levels. In contrast, systematic errors like those induced by the convolution with the point spread function (PSF) will not benefit from that scaling effect and will require very accurate modeling and correction. While numerous methods have been devised to carry out the PSF correction itself, modeling of the PSF shape and its spatial variations across the instrument field of view has, so far, attracted much less attention. This step is nevertheless crucial because the PSF is only known at star positions while the correction has to be performed at any position on the sky. A reliable interpolation scheme is therefore mandatory and a popular approach has been to use low-order bivariate polynomials. In the present paper, we evaluate four other classical spatial interpolation methods based on splines (B-splines), inverse distance weighting (IDW), radial basis functions (RBF) and ordinary Kriging (OK). These methods are tested on the Star-challenge part of the GRavitational lEnsing Accuracy Testing 2010 (GREAT10) simulated data and are compared with the classical polynomial fitting (Polyfit). In all our methods we model the PSF using a single Moffat profile and we interpolate the fitted parameters at a set of required positions. This allowed us to win the Star-challenge of GREAT10, with the B-splines method. However, we also test all our interpolation methods independently of the way the PSF is modeled, by interpolating the GREAT10 star fields themselves (i.e., the PSF parameters are known exactly at star positions). We find in that case RBF to be the clear winner, closely followed by the other local methods, IDW and OK. The global methods, Polyfit and B-splines, are largely behind, especially in fields with (ground-based) turbulent PSFs. In fields with non-turbulent PSFs, all interpolators reach a variance on PSF systematics σ2sys better than the 1

  19. Lung Cancer Indicators Recurrence

    Science.gov (United States)

    This study describes prognostic factors for lung cancer spread and recurrence, as well as subsequent risk of death from the disease. The investigators observed that regardless of cancer stage, grade, or type of lung cancer, patients in the study were more

  20. Development of Pistachio (Pistacia vera L.) spread.

    Science.gov (United States)

    Shakerardekani, Ahmad; Karim, Roselina; Ghazali, Hasanah Mohd; Chin, Nyuk Ling

    2013-03-01

    Pistachio nut (Pistacia vera L.) is one of the most delicious and nutritious nuts in the world. Pistachio spreads were developed using pistachio paste as the main component, icing sugar, soy protein isolate (SPI), and red palm oil (RPO), at different ratios. The highest mean scores of all the sensory attributes were depicted by spreads that were made without addition of SPI. It was found that the work of shear was 0 to 11.0 kg s for an acceptable spread. Sensory spreadability, overall texture, spreadability, and overall acceptability were negatively correlated (R > 0.83) with the work of shear of spreads. The findings indicated that the presence of RPO had a direct effect on the viscoelastic behavior of the pistachio spreads. The a values, which are related to the green color of the pistachio product ranged from 1.7 to 3.9 for spread without addition of RPO, and 4.0 to 5.3 in the presence of RPO. The development of pistachio spread would potentially increase the food uses of pistachio and introduce consumers with a healthier snack food. © 2013 Institute of Food Technologists®

  1. Vagus nerve stimulation inhibits cortical spreading depression.

    Science.gov (United States)

    Chen, Shih-Pin; Ay, Ilknur; de Morais, Andreia Lopes; Qin, Tao; Zheng, Yi; Sadeghian, Homa; Oka, Fumiaki; Simon, Bruce; Eikermann-Haerter, Katharina; Ayata, Cenk

    2016-04-01

    Vagus nerve stimulation has recently been reported to improve symptoms of migraine. Cortical spreading depression is the electrophysiological event underlying migraine aura and is a trigger for headache. We tested whether vagus nerve stimulation inhibits cortical spreading depression to explain its antimigraine effect. Unilateral vagus nerve stimulation was delivered either noninvasively through the skin or directly by electrodes placed around the nerve. Systemic physiology was monitored throughout the study. Both noninvasive transcutaneous and invasive direct vagus nerve stimulations significantly suppressed spreading depression susceptibility in the occipital cortex in rats. The electrical stimulation threshold to evoke a spreading depression was elevated by more than 2-fold, the frequency of spreading depressions during continuous topical 1 M KCl was reduced by ∼40%, and propagation speed of spreading depression was reduced by ∼15%. This effect developed within 30 minutes after vagus nerve stimulation and persisted for more than 3 hours. Noninvasive transcutaneous vagus nerve stimulation was as efficacious as direct invasive vagus nerve stimulation, and the efficacy did not differ between the ipsilateral and contralateral hemispheres. Our findings provide a potential mechanism by which vagus nerve stimulation may be efficacious in migraine and suggest that susceptibility to spreading depression is a suitable platform to optimize its efficacy.

  2. Spread polynomials, rotations and the butterfly effect

    CERN Document Server

    Goh, Shuxiang

    2009-01-01

    The spread between two lines in rational trigonometry replaces the concept of angle, allowing the complete specification of many geometrical and dynamical situations which have traditionally been viewed approximately. This paper investigates the case of powers of a rational spread rotation, and in particular, a curious periodicity in the prime power decomposition of the associated values of the spread polynomials, which are the analogs in rational trigonometry of the Chebyshev polynomials of the first kind. Rational trigonometry over finite fields plays a role, together with non-Euclidean geometries.

  3. Pulsations, interpulsations, and sea-floor spreading.

    Science.gov (United States)

    Pessagno, E. A., Jr.

    1973-01-01

    It is postulated that worldwide transgressions (pulsations) and regressions (interpulsations) through the course of geologic time are related to the elevation and subsidence of oceanic ridge systems and to sea-floor spreading. Two multiple working hypotheses are advanced to explain major transgressions and regressions and the elevation and subsidence of oceanic ridge systems. One hypothesis interrelates the sea-floor spreading hypothesis to the hypothesis of sub-Mohorovicic serpentinization. The second hypothesis relates the sea-floor spreading hypothesis to a hypothesis involving thermal expansion and contraction.

  4. Stochastic dynamic model of SARS spreading

    Institute of Scientific and Technical Information of China (English)

    SHI Yaolin

    2003-01-01

    Based upon the simulation of the stochastic process of infection, onset and spreading of each SARS patient, a system dynamic model of SRAS spreading is constructed. Data from Vietnam is taken as an example for Monte Carlo test. The preliminary results indicate that the time-dependent infection rate is the most important control factor for SARS spreading. The model can be applied to prediction of the course with fluctuations of the epidemics, if the previous history of the epidemics and the future infection rate under control measures are known.

  5. Spreading chromatin into chemical biology.

    Science.gov (United States)

    Allis, C David; Muir, Tom W

    2011-01-24

    Epigenetics, broadly defined as the inheritance of non-Mendelian phenotypic traits, can be more narrowly defined as heritable alterations in states of gene expression ("on" versus "off") that are not linked to changes in DNA sequence. Moreover, these alterations can persist in the absence of the signals that initiate them, thus suggesting some kind of "memory" to epigenetic forms of regulation. How, for example, during early female mammalian development, is one X chromosome selected to be kept in an active state, while the genetically identical sister X chromosome is "marked" to be inactive, even though they reside in the same nucleus, exposed to the same collection of shared trans-factors? Once X inactivation occurs, how are these contrasting chromatin states maintained and inherited faithfully through subsequent cell divisions? Chromatin states, whether active (euchromatic) or silent (heterochromatic) are established, maintained, and propagated with remarkable precision during normal development and differentiation. However, mistakes made in establishing and maintaining these chromatin states, often executed by a variety of chromatin-remodeling activities, can lead to mis-expression or mis-silencing of critical downstream gene targets with far-reaching implications for human biology and disease, notably cancer. Though chromatin biologists have identified many of the "inputs" that are important for controlling chromatin states, the detailed mechanisms by which these processes work remain largely opaque, in part due to the staggering complexity of the chromatin polymer, the physiologically relevant form of our genome. The primary objective of this article is to serve as a "call to arms" for chemists to contribute to the development of the precision tools needed to answer pressing molecular problems in this rapidly moving field.

  6. Cancer

    Science.gov (United States)

    ... uses a surgical tool to remove the tumor.Mohs' surgery. Layers of cancer cells are removed one ... usually have not been approved by the U.S. Food and Drug Administration (FDA). The medicine may have ...

  7. ICAM-1 and AMPK regulate cell detachment and apoptosis by N-methyl-N Prime -nitro-N-nitrosoguanidine, a widely spread environmental chemical, in human hormone-refractory prostate cancers

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yi-Cheng; Lu, Pin-Hsuan; Hsu, Jui-Ling; Yu, Chia-Chun; Guh, Jih-Hwa, E-mail: jhguh@ntu.edu.tw

    2011-12-15

    Poly(ADP-ribose) polymerase-1 (PARP-1), a sensor of DNA damage, plays a crucial role in the regulation of DNA repair. PARP-1 hyperactivation causes DNA damage and cell death. The underlying mechanism is complicated and is through diverse pathways. The understanding of responsible signaling pathways may offer implications for effective therapies. After concentration-response determination of N-Methyl-N Prime -Nitro-N-Nitrosoguanidine (MNNG, a PARP-1 activating agent and an environmental mutagen) in human hormone-refractory prostate cancers, the data showed that concentrations below 5 {mu}M did not change cell survival but cause a time-dependent up-regulation of intracellular adhesion molecule-1 (ICAM-1) in mRNA, total protein and cell surface levels. Detection of phosphorylation and degradation of I{kappa}B-{alpha} and nuclear translocation of NF-{kappa}B showed that MNNG induced the activation of NF-{kappa}B that was responsible for the ICAM-1 up-regulation since PDTC (a NF-{kappa}B inhibitor) significantly abolished this effect. However, higher concentrations (e.g., 10 {mu}M) of MNNG induced a 61% detachment of the cells which were apoptosis associated with the activation of AMP-activated protein kinase (AMPK), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Further identification showed that both AMPK and JNK other than p38 MAPK functionally contributed to cell death. The remaining 39% attached cells were survival associated with high ICAM-1 expression. In conclusion, the data suggest that NF-{kappa}B-dependent up-regulation of ICAM-1 plays a key role on cell attachment and survival; whereas, activation of AMPK and JNK participates in cytotoxic signaling pathways in detached cells caused by PARP-1 activation. Highlights: Black-Right-Pointing-Pointer Low level of DNA damage helps cell attachment and survival via ICAM-1 upregulation. Black-Right-Pointing-Pointer High level of DNA damage causes AMPK- and JNK-involved cell detachment

  8. Inflammatory Breast Cancer

    Science.gov (United States)

    ... Other Funding Find NCI funding for small business innovation, technology transfer, and contracts Training Cancer Training at ... means they developed from cells that line the milk ducts of the breast and then spread beyond ...

  9. Zika Probably Not Spread Through Saliva: Study

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_167531.html Zika Probably Not Spread Through Saliva: Study Research with ... HealthDay News) -- Scientists have some interesting news about Zika: You're unlikely to get the virus from ...

  10. Spreading paths in partially observed social networks

    CERN Document Server

    Onnela, Jukka-Pekka

    2011-01-01

    Understanding how far information, behaviors, or pathogens spread in social networks is an important problem, having implications for both predicting the size of epidemics, as well as for planning effective interventions. There are, however, two main challenges for inferring spreading path lengths in real-world networks. One is the practical difficulty of observing a dynamic process on a network, and the other is the typical constraint of only partially observing a network. Using a static, structurally realistic social network as a platform for simulations, we juxtapose three distinct paths: (1) the stochastic path taken by a simulated spreading process from source to target; (2) the topologically shortest path in the fully observed network, and hence the single most likely stochastic path, between the two nodes; and (3) the topologically shortest path in a partially observed network. In a sampled network, how closely does the partially observed shortest path (3) emulate the unobserved spreading path (1)? Alt...

  11. Reactive spreading: Adsorption, ridging and compound formation

    Energy Technology Data Exchange (ETDEWEB)

    Saiz, E.; Cannon, R.M.; Tomsia, A.P.

    2000-09-11

    Reactive spreading, in which a chemically active element is added to promote wetting of noble metals on nonmetallic materials, is evaluated. Theories for the energetics and kinetics of the necessary steps involved in spreading are outlined and compared to the steps in compound formation that typically accompany reactive wetting. These include: fluid flow, active metal adsorption, including nonequilibrium effects, and triple line ridging. All of these can be faster than compound nucleation under certain conditions. Analysis and assessment of recently reported experiments on metal/ceramic systems lead to a focus on those conditions under which spreading proceeds ahead of the actual formation of a new phase at the interface. This scenario may be more typical than believed, and perhaps the most effective situation leading to enhanced spreading. A rationale for the pervasive variability and hysteresis observed during high temperature wetting also emerges.

  12. Emergence of Blind Areas in Information Spreading

    CERN Document Server

    Zhang, Zi-Ke; Han, Xiao-Pu; Liu, Chuang

    2013-01-01

    Recently, contagion-based (disease, information, etc.) spreading on social networks has been extensively studied. In this paper, other than traditional full interaction, we propose a partial interaction based spreading model, considering that the informed individuals would transmit information to only a certain fraction of their neighbors due to the transmission ability in real-world social networks. Simulation results on three representative networks (BA, ER, WS) indicate that the spreading efficiency is highly correlated with the network heterogeneity. In addition, a special phenomenon, namely \\emph{Information Blind Areas} where the network is separated by several information-unreachable clusters, will emerge from the spreading process. Furthermore, we also find that the size distribution of such information blind areas obeys power-law-like distribution, which has very similar exponent with that of site percolation. Detailed analyses show that the critical value is decreasing along with the network heterog...

  13. Spreading of charged micro-droplets

    Directory of Open Access Journals (Sweden)

    Joseph Iaia

    2013-09-01

    Full Text Available We consider the spreading of a charged microdroplet on a flat dielectric surface whose spreading is driven by surface tension and electrostatic repulsion. This leads to a third order nonlinear partial differential equation that gives the evolution of the height profile. Assuming the droplets are circular we are able to prove existence of solutions with infinite contact angle and in many cases we are able to prove nonexistence of solutions with finite contact angle.

  14. Mapping the Spread of Mounted Warfare

    Directory of Open Access Journals (Sweden)

    Peter Turchin

    2016-12-01

    Full Text Available Military technology is one of the most important factors affecting the evolution of complex societies. In particular, mounted warfare, the use of horse-riders in military operations, revolutionized war as it spread to different parts of Eurasia and Africa during the Ancient and Medieval eras, and to the Americas during the Early Modern period. Here we use a variety of sources to map this spread.

  15. Biology of cancer and aging.

    Science.gov (United States)

    Holmes, F F; Wilson, J; Blesch, K S; Kaesberg, P R; Miller, R; Sprott, R

    1991-12-01

    The greatest risk factor for cancer is aging. Human cancer incidence increases exponentially with advancing age. Cancer growth rate and potential for metastatic spread may be influenced by age-specific change in host response. Because cancer and aging are, thus, inextricably linked, the American Cancer Society should encourage submission of research proposals that address the mechanisms of aging and how aging alters cancer development.

  16. Gossip spread in social network Models

    Science.gov (United States)

    Johansson, Tobias

    2017-04-01

    Gossip almost inevitably arises in real social networks. In this article we investigate the relationship between the number of friends of a person and limits on how far gossip about that person can spread in the network. How far gossip travels in a network depends on two sets of factors: (a) factors determining gossip transmission from one person to the next and (b) factors determining network topology. For a simple model where gossip is spread among people who know the victim it is known that a standard scale-free network model produces a non-monotonic relationship between number of friends and expected relative spread of gossip, a pattern that is also observed in real networks (Lind et al., 2007). Here, we study gossip spread in two social network models (Toivonen et al., 2006; Vázquez, 2003) by exploring the parameter space of both models and fitting them to a real Facebook data set. Both models can produce the non-monotonic relationship of real networks more accurately than a standard scale-free model while also exhibiting more realistic variability in gossip spread. Of the two models, the one given in Vázquez (2003) best captures both the expected values and variability of gossip spread.

  17. Wave directional spreading from point field measurements

    Science.gov (United States)

    McAllister, M. L.; Venugopal, V.; Borthwick, A. G. L.

    2017-04-01

    Ocean waves have multidirectional components. Most wave measurements are taken at a single point, and so fail to capture information about the relative directions of the wave components directly. Conventional means of directional estimation require a minimum of three concurrent time series of measurements at different spatial locations in order to derive information on local directional wave spreading. Here, the relationship between wave nonlinearity and directionality is utilized to estimate local spreading without the need for multiple concurrent measurements, following Adcock & Taylor (Adcock & Taylor 2009 Proc. R. Soc. A 465, 3361-3381. (doi:10.1098/rspa.2009.0031)), with the assumption that directional spreading is frequency independent. The method is applied to measurements recorded at the North Alwyn platform in the northern North Sea, and the results compared against estimates of wave spreading by conventional measurement methods and hindcast data. Records containing freak waves were excluded. It is found that the method provides accurate estimates of wave spreading over a range of conditions experienced at North Alwyn, despite the noisy chaotic signals that characterize such ocean wave data. The results provide further confirmation that Adcock and Taylor's method is applicable to metocean data and has considerable future promise as a technique to recover estimates of wave spreading from single point wave measurement devices.

  18. Pinpointing P450s Associated with Pyrethroid Metabolism in the Dengue Vector, Aedes aegypti: Developing New Tools to Combat Insecticide Resistance

    OpenAIRE

    2012-01-01

    BACKGROUND: Pyrethroids are increasingly used to block the transmission of diseases spread by Aedes aegypti such as dengue and yellow fever. However, insecticide resistance poses a serious threat, thus there is an urgent need to identify the genes and proteins associated with pyrethroid resistance in order to produce effective counter measures. In Ae. aegypti, overexpression of P450s such as the CYP9J32 gene have been linked with pyrethroid resistance. Our aim was to confirm the role of CYP9J...

  19. General Information about Non-Small Cell Lung Cancer

    Science.gov (United States)

    ... have spread to the nerve that controls the larynx (not shown). (3) Cancer has not spread to the lymph nodes and ... or the nerves that control the diaphragm and larynx (not shown). (1) Cancer has spread to lymph nodes above the collarbone ...

  20. Treatment Options by Stage (Small Cell Lung Cancer)

    Science.gov (United States)

    ... lung cancer is a disease in which malignant (cancer) cells form in the tissues of the lung. The ... diagnosed, tests are done to find out if cancer cells have spread within the chest or to other ...

  1. Deranged Wnt signaling is frequent in hereditary nonpolyposis colorectal cancer

    DEFF Research Database (Denmark)

    Isinger-Ekstrand, Anna; Therkildsen, Christina; Bernstein, Inge

    2011-01-01

    The Wnt signaling pathway is frequently deranged in colorectal cancer and is a key target for future preventive and therapeutic approaches. Colorectal cancers associated with the hereditary nonpolyposis colorectal cancer (HNPCC) syndrome are characterized by wide-spread microsatellite instability...

  2. Spreading of liquid drops over porous substrates.

    Science.gov (United States)

    Starov, V M; Zhdanov, S A; Kosvintsev, S R; Sobolev, V D; Velarde, M G

    2003-07-01

    The spreading of small liquid drops over thin and thick porous layers (dry or saturated with the same liquid) has been investigated in the case of both complete wetting (silicone oils of different viscosities) and partial wetting (aqueous SDS solutions of different concentrations). Nitrocellulose membranes of different porosity and different average pore size have been used as a model of thin porous layers, glass and metal filters have been used as a model of thick porous substrates. The first problem under investigation has been the spreading of small liquid drops over thin porous layers saturated with the same liquid. An evolution equation describing the drop spreading has been deduced, which showed that both an effective lubrication and the liquid exchange between the drop and the porous substrates are equally important. Spreading of silicone oils over different nitrocellulose microfiltration membranes was carried out. The experimental laws of the radius of spreading on time confirmed the theory predictions. The spreading of small liquid drops over thin dry porous layers has also been investigated from both theoretical and experimental points of view. The drop motion over a dry porous layer appears caused by the interplay of two processes: (a). the spreading of the drop over already saturated parts of the porous layer, which results in a growth of the drop base, and (b). the imbibition of the liquid from the drop into the porous substrate, which results in a shrinkage of the drop base and a growth of the wetted region inside the porous layer. As a result of these two competing processes the radius of the drop base goes through a maximum as time proceeds. A system of two differential equations has been derived to describe the time evolution of the radii of both the drop base and the wetted region inside the porous layer. This system includes two parameters, one accounts for the effective lubrication coefficient of the liquid over the wetted porous substrate, and

  3. Parallel Impurity Spreading During Massive Gas Injection

    Science.gov (United States)

    Izzo, V. A.

    2016-10-01

    Extended-MHD simulations of disruption mitigation in DIII-D demonstrate that both pre-existing islands (locked-modes) and plasma rotation can significantly influence toroidal spreading of impurities following massive gas injection (MGI). Given the importance of successful disruption mitigation in ITER and the large disparity in device parameters, empirical demonstrations of disruption mitigation strategies in present tokamaks are insufficient to inspire unreserved confidence for ITER. Here, MHD simulations elucidate how impurities injected as a localized jet spread toroidally and poloidally. Simulations with large pre-existing islands at the q = 2 surface reveal that the magnetic topology strongly influences the rate of impurity spreading parallel to the field lines. Parallel spreading is largely driven by rapid parallel heat conduction, and is much faster at low order rational surfaces, where a short parallel connection length leads to faster thermal equilibration. Consequently, the presence of large islands, which alter the connection length, can slow impurity transport; but the simulations also show that the appearance of a 4/2 harmonic of the 2/1 mode, which breaks up the large islands, can increase the rate of spreading. This effect is seen both for simulations with spontaneously growing and directly imposed 4/2 modes. Given the prevalence of locked-modes as a cause of disruptions, understanding the effect of large islands is of particular importance. Simulations with and without islands also show that rotation can alter impurity spreading, even reversing the predominant direction of spreading, which is toward the high-field-side in the absence of rotation. Given expected differences in rotation for ITER vs. DIII-D, rotation effects are another important consideration when extrapolating experimental results. Work supported by US DOE under DE-FG02-95ER54309.

  4. A network model for Ebola spreading.

    Science.gov (United States)

    Rizzo, Alessandro; Pedalino, Biagio; Porfiri, Maurizio

    2016-04-01

    The availability of accurate models for the spreading of infectious diseases has opened a new era in management and containment of epidemics. Models are extensively used to plan for and execute vaccination campaigns, to evaluate the risk of international spreadings and the feasibility of travel bans, and to inform prophylaxis campaigns. Even when no specific therapeutical protocol is available, as for the Ebola Virus Disease (EVD), models of epidemic spreading can provide useful insight to steer interventions in the field and to forecast the trend of the epidemic. Here, we propose a novel mathematical model to describe EVD spreading based on activity driven networks (ADNs). Our approach overcomes the simplifying assumption of homogeneous mixing, which is central to most of the mathematically tractable models of EVD spreading. In our ADN-based model, each individual is not bound to contact every other, and its network of contacts varies in time as a function of an activity potential. Our model contemplates the possibility of non-ideal and time-varying intervention policies, which are critical to accurately describe EVD spreading in afflicted countries. The model is calibrated from field data of the 2014 April-to-December spreading in Liberia. We use the model as a predictive tool, to emulate the dynamics of EVD in Liberia and offer a one-year projection, until December 2015. Our predictions agree with the current vision expressed by professionals in the field, who consider EVD in Liberia at its final stage. The model is also used to perform a what-if analysis to assess the efficacy of timely intervention policies. In particular, we show that an earlier application of the same intervention policy would have greatly reduced the number of EVD cases, the duration of the outbreak, and the infrastructures needed for the implementation of the intervention.

  5. High-temperature spreading kinetics of metals

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, N.

    2005-05-15

    In this PhD work a drop transfer setup combined with high speed photography has been used to analyze the spreading of Ag on polished polycrystalline Mo and single crystalline Mo (110) and (100) substrates. The objective of this work was to unveil the basic phenomena controlling spreading in metal-metal systems. The observed spreading kinetics were compared with current theories of low and high temperature spreading such as a molecular kinetic model and a fluid flow model. Analyses of the data reveal that the molecular model does describe the fastest velocity data well for all the investigated systems. Therefore, the energy which is dissipated during the spreading process is a dissipation at the triple line rather than dissipation due to the viscosity in the liquid. A comparison of the determined free activation energy for wetting of {delta}G95{approx}145kJ/mol with literature values allows the statement that the rate determining step seems to be a surface diffusion of the Ag atoms along the triple line. In order to investigate possible ridge formation, due to local atomic diffusion of atoms of the substrate at the triple during the spreading process, grooving experiments of the polycrystalline Mo were performed to calculate the surface diffusities that will control ridge evolution. The analyses of this work showed that a ridge formation at the fastest reported wetting velocities was not possible if there is no initial perturbation for a ridge. If there was an initial perturbation for a ridge the ridge had to be much smaller than 1 nm in order to be able to move with the liquid font. Therefore ridge formation does not influence the spreading kinetics for the studied system and the chosen conditions. SEM, AFM and TEM investigations of the triple line showed that ridge formation does also not occur at the end of the wetting experiment when the drop is close to equilibrium and the wetting velocity is slow. (orig.)

  6. Use of Lagrangian transport models and Sterilized High Volume Sampling to pinpoint the source region of Kawasaki disease and determine the etiologic agent

    Science.gov (United States)

    Curcoll Masanes, Roger; Rodó, Xavier; Anton, Jordi; Ballester, Joan; Jornet, Albert; Nofuentes, Manel; Sanchez-Manubens, Judith; Morguí, Josep-Anton

    2015-04-01

    Kawasaki disease (KD) is an acute, coronary artery vasculitis of young children, and still a medical mystery after more than 40 years. A former study [Rodó et al. 2011] demonstrated that certain patterns of winds in the troposphere above the earth's surface flowing from Asia were associated with the times of the annual peak in KD cases and with days having anomalously high numbers of KD patients. In a later study [Rodó et al. 2014], we used residence times from an Air Transport Model to pinpoint the source region for KD. Simulations were generated from locations spanning Japan from days with either high or low KD incidence. In order to cope with stationarity of synoptic situations, only trajectories for the winter months, when there is the maximum in KD cases, were considered. Trajectories traced back in time 10 days for each dataset and location were generated using the flexible particle Lagrangian dispersion model (FLEXPART Version 8.23 [Stohl et al. 2005]) run in backward mode. The particles modeled were air tracers, with 10,000 particles used on each model run. The model output used was residence time, with an output grid of 0.5° latitude × longitude and a time resolution of 3 h. The data input used for the FLEXPART model was gridded atmospheric wind velocity from the European Center for Medium-Range Weather Forecasts Re-Analysis (ERA-Interim at 1°). Aggregates of winter period back-trajectories were calculated for three different regions of Japan. A common source of wind air masses was located for periods with High Kawasaki disease. Knowing the trajectories of winds from the air transport models, a sampling methodology was developed in order to capture the possible etiological agent or other tracers that could have been released together. This methodology is based on the sterilized filtering of high volumes of the transported air at medium tropospheric levels by aircraft sampling and a later analyze these filters with adequate techniques. High purity

  7. Variation of wave directional spread parameters along the Indian coast

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.

    Directional spreading of wave energy is popularly modeled with the help of the Cosine Power model and it mainly depends on the spreading parameter. This paper describes the variation of the spreading parameter estimated based on the wave data...

  8. Spreading of Cholera through Surface Water

    Science.gov (United States)

    Bertuzzo, E.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2009-12-01

    Cholera epidemics are still a major public health concern to date in many areas of the world. In order to understand and forecast cholera outbreaks, one of the most important factors is the role played by the environmental matrix in which the disease spreads. We study how river networks, acting as environmental corridors for pathogens, affect the spreading of cholera epidemics. The environmental matrix in which the disease spreads is constituted by different human communities and their hydrologic interconnections. Each community is characterized by its spatial position, population size, water resources availability and hygiene conditions. By implementing a spatially explicit cholera model we seek the effects on epidemic dynamics of: i) the topology and metrics of the pathogens pathways that connect different communities; ii) the spatial distribution of the population size; and iii) the spatial distributions and quality of surface water resources and public health conditions, and how they vary with population size. The model has been applied to study the space-time evolution of a well documented cholera epidemic occurred in the KwaZulu-Natal province of South Africa. The epidemic lasted for two years and involved about 140,000 confirmed cholera cases. The model does well in reproducing the distribution of the cholera cases during the two outbreaks as well as their spatial spreading. We further extend the model by deriving the speed of propagation of traveling fronts in the case of uniformly distributed systems for different topologies: one and two dimensional lattices and river networks. The derivation of the spreading celerity proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. The conditions are sought by comparison between spreading and disease timescales. Consider a cholera epidemic that starts from a point and spreads throughout a finite size system, it is possible to identify two different timescales: i

  9. Free energy analysis of cell spreading.

    Science.gov (United States)

    McEvoy, Eóin; Deshpande, Vikram S; McGarry, Patrick

    2017-10-01

    In this study we present a steady-state adaptation of the thermodynamically motivated stress fiber (SF) model of Vigliotti et al. (2015). We implement this steady-state formulation in a non-local finite element setting where we also consider global conservation of the total number of cytoskeletal proteins within the cell, global conservation of the number of binding integrins on the cell membrane, and adhesion limiting ligand density on the substrate surface. We present a number of simulations of cell spreading in which we consider a limited subset of the possible deformed spread-states assumed by the cell in order to examine the hypothesis that free energy minimization drives the process of cell spreading. Simulations suggest that cell spreading can be viewed as a competition between (i) decreasing cytoskeletal free energy due to strain induced assembly of cytoskeletal proteins into contractile SFs, and (ii) increasing elastic free energy due to stretching of the mechanically passive components of the cell. The computed minimum free energy spread area is shown to be lower for a cell on a compliant substrate than on a rigid substrate. Furthermore, a low substrate ligand density is found to limit cell spreading. The predicted dependence of cell spread area on substrate stiffness and ligand density is in agreement with the experiments of Engler et al. (2003). We also simulate the experiments of Théry et al. (2006), whereby initially circular cells deform and adhere to "V-shaped" and "Y-shaped" ligand patches. Analysis of a number of different spread states reveals that deformed configurations with the lowest free energy exhibit a SF distribution that corresponds to experimental observations, i.e. a high concentration of highly aligned SFs occurs along free edges, with lower SF concentrations in the interior of the cell. In summary, the results of this study suggest that cell spreading is driven by free energy minimization based on a competition between decreasing

  10. Post-Tanner spreading of nematic droplets

    Energy Technology Data Exchange (ETDEWEB)

    Mechkov, S; Oshanin, G [Laboratoire de Physique Theorique de la Matiere Condensee, Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris Cedex 5 (France); Cazabat, A M, E-mail: mechkov@lptmc.jussieu.f, E-mail: anne-marie.cazabat@lps.ens.f, E-mail: oshanin@lptmc.jussieu.f [Laboratoire de Physique Statistique, Ecole Normale Superieure, 75252 Paris Cedex 5 (France)

    2009-11-18

    The quasistationary spreading of a circular liquid drop on a solid substrate typically obeys the so-called Tanner law, with the instantaneous base radius R(t) growing with time as Rapproxt{sup 1/10}-an effect of the dominant role of capillary forces for a small-sized droplet. However, for droplets of nematic liquid crystals, a faster spreading law sets in at long times, so that Rapproxt{sup a}lpha with alpha significantly larger than the Tanner exponent 1/10. In the framework of the thin film model (or lubrication approximation), we describe this 'acceleration' as a transition to a qualitatively different spreading regime driven by a strong substrate-liquid interaction specific to nematics (antagonistic anchoring at the interfaces). The numerical solution of the thin film equation agrees well with the available experimental data for nematics, even though the non-Newtonian rheology has yet to be taken into account. Thus we complement the theory of spreading with a post-Tanner stage, noting that the spreading process can be expected to cross over from the usual capillarity-dominated stage to a regime where the whole reservoir becomes a diffusive film in the sense of Derjaguin.

  11. Social distancing strategies against disease spreading

    CERN Document Server

    Valdez, L D; Macri, P A; Braunstein, L A

    2013-01-01

    The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, $i.e$, the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibil...

  12. Epidemic spreading on evolving signed networks

    CERN Document Server

    Saeedian, M; Jafari, G R; Kertesz, J

    2016-01-01

    Most studies of disease spreading consider the underlying social network as obtained without the contagion, though epidemic influences peoples willingness to contact others: A friendly contact may be turned to unfriendly to avoid infection. We study the susceptible-infected (SI) disease spreading model on signed networks, in which each edge is associated with a positive or negative sign representing the friendly or unfriendly relation between its end nodes. In a signed network, according to Heiders theory, edge signs evolve such that finally a state of structural balance is achieved, corresponding to no frustration in physics terms. However, the danger of infection affects the evolution of its edge signs. To describe the coupled problem of the sign evolution and disease spreading, we generalize the notion of structural balance by taking into account the state of the nodes. We introduce an energy function and carry out Monte-Carlo simulations on complete networks to test the energy landscape, where we find loc...

  13. Temporal network structures controlling disease spreading

    Science.gov (United States)

    Holme, Petter

    2016-08-01

    We investigate disease spreading on eight empirical data sets of human contacts (mostly proximity networks recording who is close to whom, at what time). We compare three levels of representations of these data sets: temporal networks, static networks, and a fully connected topology. We notice that the difference between the static and fully connected networks—with respect to time to extinction and average outbreak size—is smaller than between the temporal and static topologies. This suggests that, for these data sets, temporal structures influence disease spreading more than static-network structures. To explain the details in the differences between the representations, we use 32 network measures. This study concurs that long-time temporal structures, like the turnover of nodes and links, are the most important for the spreading dynamics.

  14. Substrate stress relaxation regulates cell spreading

    Science.gov (United States)

    Chaudhuri, Ovijit; Gu, Luo; Darnell, Max; Klumpers, Darinka; Bencherif, Sidi A.; Weaver, James C.; Huebsch, Nathaniel; Mooney, David J.

    2015-02-01

    Studies of cellular mechanotransduction have converged upon the idea that cells sense extracellular matrix (ECM) elasticity by gauging resistance to the traction forces they exert on the ECM. However, these studies typically utilize purely elastic materials as substrates, whereas physiological ECMs are viscoelastic, and exhibit stress relaxation, so that cellular traction forces exerted by cells remodel the ECM. Here we investigate the influence of ECM stress relaxation on cell behaviour through computational modelling and cellular experiments. Surprisingly, both our computational model and experiments find that spreading for cells cultured on soft substrates that exhibit stress relaxation is greater than cells spreading on elastic substrates of the same modulus, but similar to that of cells spreading on stiffer elastic substrates. These findings challenge the current view of how cells sense and respond to the ECM.

  15. Disordered contact process with asymmetric spreading.

    Science.gov (United States)

    Juhász, Róbert

    2013-02-01

    An asymmetric variant of the contact process where the activity spreads with different and independent random rates to the left and to the right is introduced. A real space renormalization scheme is formulated for the model by means of which it is shown that the local asymmetry of spreading is irrelevant on large scales if the model is globally (statistically) symmetric. Otherwise, in the presence of a global bias in either direction, the renormalization method predicts two distinct phase transitions, which are related to the spreading of activity in and against the direction of the bias. The latter is found to be described by an infinite randomness fixed point while the former is not.

  16. Extended oil spill spreading with Langmuir circulation.

    Science.gov (United States)

    Simecek-Beatty, Debra; Lehr, William J

    2017-09-15

    When spilled in the ocean, most crude oils quickly spread into a thin film that ruptures into smaller slicks distributed over a larger area. Observers have also reported the film tearing apart into streaks that eventually merge forming fewer but longer bands of floating oil. Understanding this process is important to model oil spill transport. First, slick area is calculated using a spreading model. Next, Langmuir circulation models are used to approximate the merging of oiled bands. Calculations are performed on Troll blended and Alaska North Slope crude oils and results compared with measurements from the 1990s North Sea field experiments. Langmuir circulation increases the oil area but decreases the surface coverage of oil. This work modifies existing oil spreading formulas by providing a surface area correction due to the effects of Langmuir circulation. The model's simplicity is advantageous in situations with limited data, such as emergency oil spill response. Published by Elsevier Ltd.

  17. Temporal network structures controlling disease spreading

    CERN Document Server

    Holme, Petter

    2016-01-01

    We investigate disease spreading on eight empirical data sets of human contacts (mostly proximity networks recording who is close to whom, at what time). We compare three levels of representations of these data sets: temporal networks, static networks and a fully connected topology. We notice that the difference between the static and fully-connected networks -- with respect to time to extinction and average outbreak size -- is smaller than between the temporal and static topologies. This suggests that, for these data sets, temporal structures influence disease spreading more than static network structures. To explain the details in the differences between the representations, we use 32 network measures. This study concur that long-time temporal structures, like the turnover of nodes and links, are the most important for the spreading dynamics.

  18. Analysis of BER Performance of the Spread Spectrum Communication System with Constrained Spreading Code

    OpenAIRE

    長谷川, 孝明; 羽渕, 裕真

    1996-01-01

    Copyright notice. c1996 IEICE All rights reserved. "Analysis of BER Performance of the Spread Spectrum Communication System with Constrained Spreading Code"Hiromasa HABUCHI, Toshio TAKEBAYASHI, Takaaki HASEGAWA. IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences ,1996 Vol.E79-A No.12 pp. 2078-2080 許諾No.07RB0055.

  19. Spreading of Ultrarelativistic Wave Packet and Redshift

    CERN Document Server

    Lev, Felix M

    2012-01-01

    The red shift of light coming to the Earth from distant objects is usually explained as a consequence of the fact that the Universe is expanding. Such an explanation implies that photons emitted by distant objects travel in the interstellar medium practically without interaction with interstellar matter and hence they can survive their long journey to the Earth. We analyze this assumption by considering wave-packet spreading for an ultrarelativistic particle. We derive a formula which shows that spreading in the direction perpendicular to the particle momentum is very important and cannot be neglected. The implications of the results are discussed.

  20. Origin and turbulence spreading of plasma blobs

    Energy Technology Data Exchange (ETDEWEB)

    Manz, P.; Birkenmeier, G.; Stroth, U. [Physik-Department E28, Technische Universität München, James-Franck. Str. 1, Garching (Germany); Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, Garching (Germany); Ribeiro, T. T.; Scott, B. D.; Carralero, D.; Müller, S. H.; Müller, H. W.; Wolfrum, E. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, Garching (Germany); Fuchert, G. [IJL, Université de Lorraine, CNRS (UMR 7198), BP 40239, Vandoeuvre-lès-Nancy (France)

    2015-02-15

    The formation of plasma blobs is studied by analyzing their trajectories in a gyrofluid simulation in the vicinity of the separatrix. Most blobs arise at the maximum radial electric field outside the separatrix. In general, blob generation is not bound to one particular radial position or instability. A simple model of turbulence spreading for the scrape-off layer is derived. The simulations show that the blob dynamics can be represented by turbulence spreading, which constitutes a substantial energy drive for far scrape-off layer turbulence and is a more suitable quantity to study blob generation compared to the skewness.

  1. Technique for Controlling Spread of Limnotic Oncomelania

    Institute of Scientific and Technical Information of China (English)

    Li Damei(李大美); WANG Xiangsan(王祥三); LAI Yonggen

    2003-01-01

    Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River of China. The disease is spread solely through an intermediary named oncomelania, so its spread of schistosomiasis can be controlled by properly designing water intakes which prevent oncomelania from entering fanning land or residential areas. This paper reports a successful design process and a new oncomelania-free intake device. The design of the new intake is based on a sound research program in which extensive experimental studies were carried out to gain knowledge of oncomelania eco-hydraulic behavior and detailed flow field information through CFD simulation.

  2. Burstiness and spreading on temporal networks

    CERN Document Server

    Lambiotte, Renaud; Delvenne, Jean-Charles

    2013-01-01

    We discuss how spreading processes on temporal networks are impacted by the shape of their inter-event time distributions. Through simple mathematical arguments and toy examples, we find that the key factor is the ordering in which events take place, a property that tends to be affected by the bulk of the distributions and not only by their tail, as usually considered in the literature. We show that a detailed modeling of the temporal patterns observed in complex networks can change dramatically the properties of a spreading process, such as the ergodicity of a random walk process or the persistence of an epidemic.

  3. Detection of architectural distortion in prior mammograms using fractal analysis and angular spread of power

    Science.gov (United States)

    Banik, Shantanu; Rangayyan, Rangaraj M.; Desautels, J. E. L.

    2010-03-01

    This paper presents methods for the detection of architectural distortion in mammograms of interval-cancer cases taken prior to the diagnosis of breast cancer, using Gabor filters, phase portrait analysis, fractal dimension (FD), and analysis of the angular spread of power in the Fourier spectrum. In the estimation of FD using the Fourier power spectrum, only the distribution of power over radial frequency is considered; the information regarding the angular spread of power is ignored. In this study, the angular spread of power in the Fourier spectrum is used to generate features for the detection of spiculated patterns related to architectural distortion. Using Gabor filters and phase portrait analysis, a total of 4224 regions of interest (ROIs) were automatically obtained from 106 prior mammograms of 56 interval-cancer cases, including 301 ROIs related to architectural distortion, and from 52 mammograms of 13 normal cases. For each ROI, the FD and measures of the angular spread of power were computed. Feature selection was performed using stepwise logistic regression. The best result achieved, in terms of the area under the receiver operating characteristic curve, is 0.75 +/- 0.02 with an artificial neural network including radial basis functions. Analysis of the performance of the methods with free-response receiver operating characteristics indicated a sensitivity of 0.82 at 7.7 false positives per image.

  4. CANCER

    Directory of Open Access Journals (Sweden)

    N. Kavoussi

    1973-09-01

    Full Text Available There are many carcinogenetic elements in industry and it is for this reason that study and research concerning the effect of these materials is carried out on a national and international level. The establishment and growth of cancer are affected by different factors in two main areas:-1 The nature of the human or animal including sex, age, point and method of entry, fat metabolism, place of agglomeration of carcinogenetic material, amount of material absorbed by the body and the immunity of the body.2 The different nature of the carcinogenetic material e.g. physical, chemical quality, degree of solvency in fat and purity of impurity of the element. As the development of cancer is dependent upon so many factors, it is extremely difficult to determine whether a causative element is principle or contributory. Some materials are not carcinogenetic when they are pure but become so when they combine with other elements. All of this creates an industrial health problem in that it is almost impossible to plan an adequate prevention and safety program. The body through its system of immunity protects itself against small amounts of carcinogens but when this amount increases and reaches a certain level the body is not longer able to defend itself. ILO advises an effective protection campaign against cancer based on the Well –equipped laboratories, Well-educated personnel, the establishment of industrial hygiene within factories, the regular control of safety systems, and the implementation of industrial health principles and research programs.

  5. Locating the source of spreading in complex networks

    CERN Document Server

    Shen, Zhesi; Fan, Ying; Di, Zengru; Wang, Wen-Xu; Stanley, H Eugene

    2015-01-01

    Locating the sources that trigger a dynamical process is a fundamental but challenging problem in complex networks, ranging from epidemic spreading in society and on the Internet to cancer metastasis in the human body. An accurate localization of the source is inherently limited by our ability to simultaneously access the information of all nodes in a large-scale complex network, such as the time at which each individual is infected in a large population. This thus raises two critical questions: how do we locate the source from incomplete information and can we achieve full localization of sources at any possible location from a given set of observers. Here we develop an efficient algorithm to locate the source of a diffusion-like process and propose a general locatability condition. We test the algorithm by employing epidemic spreading and consensus dynamics as typical dynamical processes and apply it to the H1N1 pandemic in China. We find that the sources can be precisely located in arbitrary networks insof...

  6. Perineural tumor spread - Interconnection between spinal and cranial nerves.

    Science.gov (United States)

    Kozić, Duško; Njagulj, Vesna; Gaćeša, Jelena Popadić; Semnic, Robert; Prvulović, Nataša

    2012-12-15

    The secondary neoplastic involvement of the cervical plexus in patients with head and neck malignancies is extremely rare. MR examination of the neck revealed the diffuse neoplastic infiltration of the right C2 root, in a 57-year-old patient with several months long pain in the right ear region and a history of the tongue squamous cell carcinoma. Associated perineural tumor spread and consequent distal involvement of great auricular nerve and vagus nerve were evident. Best of our knowledge, this is the first reported involvement of the cervical plexus in patients with head and neck cancers, associated with the clearly documented interconnection between the cervical plexus and cranial nerves via great auricular nerve.

  7. Relativistic suppression of wave packet spreading.

    Science.gov (United States)

    Su, Q; Smetanko, B; Grobe, R

    1998-03-30

    We investigate numerically the solution of Dirac equation and analytically the Klein-Gordon equation and discuss the relativistic motion of an electron wave packet in the presence of an intense static electric field. In contrast to the predictions of the (non-relativistic) Schroedinger theory, the spreading rate in the field's polarization direction as well as in the transverse directions is reduced.

  8. Hiding Single Photons With Spread Spectrum Technology

    CERN Document Server

    Belthangady, Chinmay; Yu, Ite A; Yin, G Y; Kahn, J M; Harris, S E

    2010-01-01

    We describe a proof-of-principal experiment demonstrating the use of spread spectrum technology at the single photon level. We show how single photons with a prescribed temporal shape, in the presence of interfering noise, may be hidden and recovered.

  9. Modeling and simulation of epidemic spread

    DEFF Research Database (Denmark)

    Shatnawi, Maad; Lazarova-Molnar, Sanja; Zaki, Nazar

    2013-01-01

    and control such epidemics. This paper presents an overview of the epidemic spread modeling and simulation, and summarizes the main technical challenges in this field. It further investigates the most relevant recent approaches carried out towards this perspective and provides a comparison and classification...

  10. Restricted spread of tomato spotted wilt virus

    NARCIS (Netherlands)

    Maris, P.C.; Joosten, N.N.; Goldbach, R.W.; Peters, D.

    2003-01-01

    Spread of Tomato spotted wilt virus (TSWV) and population development of its vector Frankliniella occidentalis were studied on the pepper accessions CPRO-1 and Pikante Reuzen, which are resistant and susceptible to thrips, respectively. Viruliferous thrips were released on plants of each accession (

  11. Damage spreading on networks: Clustering effects

    Indian Academy of Sciences (India)

    Z Z Guo; Xiao-Wei Wu; Chun-An Wang

    2007-04-01

    The damage spreading of the Ising model on three kinds of networks is studied with Glauber dynamics. One of the networks is generated by evolving the hexagonal lattice with the star-triangle transformation. Another kind of network is constructed by connecting the midpoints of the edges of the topological hexagonal lattice. With the evolution of these structures, damage spreading transition temperature increases and a general explanation for this phenomenon is presented from the view of the network. The relationship between the transition temperature and the network measure-clustering coefficient is set up and it is shown that the increase of damage spreading transition temperature is the result of more and more clustering of the network. We construct the third kind of network-random graphs with Poisson degree distributions by changing the average degree of the network. We show that the increase in the average degree is equivalent to the clustering of nodes and this leads to the increase in damage spreading transition temperature.

  12. Social distancing strategies against disease spreading

    Science.gov (United States)

    Valdez, L. D.; Buono, C.; Macri, P. A.; Braunstein, L. A.

    2014-03-01

    The recurrent infectious diseases and their increasing impact on the society has promoted the study of strategies to slow down the epidemic spreading. In this review we outline the applications of percolation theory to describe strategies against epidemic spreading on complex networks. We give a general outlook of the relation between link percolation and the susceptible-infected-recovered model, and introduce the node void percolation process to describe the dilution of the network composed by healthy individual, i.e, the network that sustain the functionality of a society. Then, we survey two strategies: the quenched disorder strategy where an heterogeneous distribution of contact intensities is induced in society, and the intermittent social distancing strategy where health individuals are persuaded to avoid contact with their neighbors for intermittent periods of time. Using percolation tools, we show that both strategies may halt the epidemic spreading. Finally, we discuss the role of the transmissibility, i.e, the effective probability to transmit a disease, on the performance of the strategies to slow down the epidemic spreading.

  13. Spread of Rare Fungus from Vancouver Island

    Centers for Disease Control (CDC) Podcasts

    2006-12-20

    Cryptococcus gattii, a rare fungus normally found in the tropics, has infected people and animals on Vancouver Island, Canada. Dr. David Warnock, Director, Division of Foodborne, Bacterial, and Mycotic Diseases, CDC, discusses public health concerns about further spread of this organism.  Created: 12/20/2006 by Emerging Infectious Diseases.   Date Released: 12/29/2006.

  14. Energy spread in plasma-based acceleration

    NARCIS (Netherlands)

    Reitsma, A.; Trines, R.; Goloviznin, V.

    2000-01-01

    Electron acceleration in a one-dimensional plasma wave has been simulated, with emphasis on minimizing the energy spread of an accelerated electron bunch, while keeping the mean energy gain at a reasonable level. Bunch length, beam loading, and the injection phase are tuned to reach this goal. The s

  15. Optimization of network protection against virus spread

    NARCIS (Netherlands)

    Gourdin, E.; Omic, J.; Van Mieghem, P.

    2011-01-01

    The effect of virus spreading in a telecommunication network, where a certain curing strategy is deployed, can be captured by epidemic models. In the N-intertwined model proposed and studied in [1], [2], the probability of each node to be infected depends on the curing and infection rate of its neig

  16. Experiments in water spreading at Newark, Delaware

    Science.gov (United States)

    Boggess, Durward Haye; Rima, Donald Robert

    1962-01-01

    Two experiments in water spreading were made at Newark, Del., to evaluate the prospects of using excess storm runoff to recharge the shallow water-table aquifer which serves the community. Water was diverted from 1 of the city's 3 production wells and released into an infiltration ditch near the municipal well field. Although slightly more than 65,000 cubic feet of water (nearly 500,000 gallons ) was spread in the infiltration ditch and allowed to seep into the subsurface, there was no indication that any appreciable amount of water reached the producing aquifer. Instead, a perched zone of saturation was created by the presence of an impermeable or slightly permeable bed above the water table. So effective is this barrier to the downward movement of water that within a period of less than 1 day, the apex of the perched zone rose about 10 feet to the level of the bottom of the infiltration ditch. As more water was added, the mound of saturation spread laterally. On the basis of these experiments, it appears that the principal aquifer at Newark, Del., would not be benefited by spreading water in shallow infiltration ditches or basins. However, the absorptive capacity of the unsaturated materials which occur at a shallow depth, is sufficient to permit the disposal of large volumes of storm runoff.

  17. Centerfolds: Your Newspaper's Most Exciting Spreads

    Science.gov (United States)

    Quevedo, Jose

    1977-01-01

    Gives guidelines for planning copy and design for the centerfold spread of a newspaper in order to use this natural display section to enhance the overall interest of the newspaper. Shows how college and professional papers have used centerfolds effectively. (GW)

  18. ParB spreading requires DNA bridging

    NARCIS (Netherlands)

    Graham, Thomas G. W.; Wang, Xindan; Song, Dan; Etson, Candice M.; van Oijen, Antoine M.; Rudner, David Z.; Loparo, Joseph J.

    2014-01-01

    The parABS system is a widely employed mechanism for plasmid partitioning and chromosome segregation in bacteria. ParB binds to parS sites on plasmids and chromosomes and associates with broad regions of adjacent DNA, a phenomenon known as spreading. Although essential for ParB function, the mechani

  19. DataSpread: Unifying Databases and Spreadsheets.

    Science.gov (United States)

    Bendre, Mangesh; Sun, Bofan; Zhang, Ding; Zhou, Xinyan; Chang, Kevin ChenChuan; Parameswaran, Aditya

    2015-08-01

    Spreadsheet software is often the tool of choice for ad-hoc tabular data management, processing, and visualization, especially on tiny data sets. On the other hand, relational database systems offer significant power, expressivity, and efficiency over spreadsheet software for data management, while lacking in the ease of use and ad-hoc analysis capabilities. We demonstrate DataSpread, a data exploration tool that holistically unifies databases and spreadsheets. It continues to offer a Microsoft Excel-based spreadsheet front-end, while in parallel managing all the data in a back-end database, specifically, PostgreSQL. DataSpread retains all the advantages of spreadsheets, including ease of use, ad-hoc analysis and visualization capabilities, and a schema-free nature, while also adding the advantages of traditional relational databases, such as scalability and the ability to use arbitrary SQL to import, filter, or join external or internal tables and have the results appear in the spreadsheet. DataSpread needs to reason about and reconcile differences in the notions of schema, addressing of cells and tuples, and the current "pane" (which exists in spreadsheets but not in traditional databases), and support data modifications at both the front-end and the back-end. Our demonstration will center on our first and early prototype of the DataSpread, and will give the attendees a sense for the enormous data exploration capabilities offered by unifying spreadsheets and databases.

  20. Spreading of Excellence in Serious Gaming

    NARCIS (Netherlands)

    Westera, Wim; Berta, Riccardo; Moreno-Ger, Pablo; Bellotti, Francesco; Nadolski, Rob; Padrón-Nápoles, Carmen Luisa; Boyle, Liz; Beligan, Daniel; Baalsrud Hauge, Jannicke

    2014-01-01

    Westera, W., Berta, R., Moreno-Ger, P., Bellotti, F., Nadolski, R., Padrón-Nápoles, C. L., Boyle, L., Beligan, D., & Baalsrud Hauge, J. (2013, December 12). Spreading of Excellence in Serious Gaming. Presentation on the GALA project review meeting. Luxembourg: European Commission.

  1. Natural Spread of Plant Viruses by Birds

    NARCIS (Netherlands)

    Peters, D.; Engels, C.; Sarra, S.

    2012-01-01

    Observations made in Mali strongly suggest that Rice yellow mottle virus (RYMV) is spread by weaverbirds (Quelea quelea) below and around baobab trees (Adansonia digitata) in which they nest. Rice leaves in bird nests appeared to be infected. In Spain, an infection of Southern bean mosaic virus (SBM

  2. Experiments and modelling on vertical flame spread

    Energy Technology Data Exchange (ETDEWEB)

    Keski-Rahkonen, O.; Mangs, J. [VTT Building and Transport, Espoo (Finland)

    2004-07-01

    he principle and some preliminary results are shown of a new vertical flame spread modelling effort. Quick experimental screenings on relevant phenomena are made, some models are evaluated, and a new set of needed measuring instruments is proposed. Finally a single example of FRNC cable is shown as application of the methods. (orig.)

  3. Turbulence spreading in gyro-kinetic theory

    Science.gov (United States)

    Migliano, P.; Buchholz, R.; Grosshauser, S. R.; Hornsby, W. A.; Peeters, A. G.; Stauffert, O.

    2016-01-01

    In this letter a new operative definition for the turbulence intensity in connection with magnetized plasmas is given. In contrast to previous definitions the new definition satisfies a Fisher-Kolmogorov-Petrovskii-Piskunov type equation. Furthermore, explicit expressions for the turbulence intensity and the turbulence intensity flux, that allow for the first time direct numerical evaluation, are derived. A carefully designed numerical experiment for the case of a tokamak is performed to study the impact of turbulence spreading. The effective turbulence diffusion coefficient is measured to be smaller than the heat conduction coefficient and the turbulence spreading length is found to be of the order of the turbulence correlation length. The results show that turbulence spreading can play a role in the non-local flux gradient relation, or in the scaling of transport coefficients with the normalized Larmor radius, only over lengths scale of the order of the turbulence correlation length. A new turbulence convection mechanism, due to the drift connected with the magnetic field inhomogeneities, is described. The convective flux integrates to zero under the flux surface average unless there is an up-down asymmetry in the tubulence intensity. The latter asymmetry can be generated through a radial inhomogeneity or plasma rotation. It is shown that the turbulence convection can lead to a spreading of the order of the correlation length.

  4. Spreading of water nanodroplets on graphene

    Science.gov (United States)

    Andrews, Joseph; Sinha, Shayandev; Chung, Peter; Das, Siddhartha

    Understanding the wetting of 2D materials is central to the successful application of these materials in a variety of disciplines that involve the interaction of a liquid with such layered substrates. Recent studies focusing on wetting statics and contact angle selection on graphene-coated solids indicate a wetting translucent behavior of graphene. However, little research has been done on the wetting dynamics of graphene-coated systems. Here, we simulate the wetting dynamics of water drops on free-standing graphene layers using a molecular dynamics framework. We employ the extended simple point charge (SPC/E) model to simulate the water drops. Our simulations are validated against the experimental results of water drop contact angles on graphite. Unlike many existing MD studies, we obtain the results starting from a physical consideration of spherical water drops. We observe the half power law for the spreading dynamics, i.e., r~t(1/2) (r is the spreading radius and t is the spreading time). Identical spreading laws have been identified for Lennard Jones (LJ) nanodroplets on non-layered surfaces; therefore, we establish that the change in the nature of the substrate (non-layered to 2D) and the liquid (LJ to water) does not alter the physics of wetting dynamics of nanodroplets.

  5. Spreading depolarization may link migraine and stroke.

    Science.gov (United States)

    Eikermann-Haerter, Katharina

    2014-01-01

    Migraine increases the risk of stroke, particularly in young and otherwise healthy adults. Being the most frequent neurological condition, migraine prevalence is on a par with that of other common stroke risk factors, such as diabetes or hypertension. Several patterns of association have emerged: (1) migraine and stroke share a common association (eg, vasculopathies, patent foramen ovale, or pulmonary A-V malformations); (2) injury to the arterial wall such as acute arterial dissections can present as migraine aura attacks or stroke; (3) strokes rarely develop during a migraine attack, as described for "migrainous stroke." Increasing experimental evidence suggests that cerebral hyperexcitability and enhanced susceptibility to spreading depolarization, the electrophysiologic event underlying migraine, may serve as a mechanism underlying the migraine-stroke association. Mice carrying human vascular or neuronal migraine mutations exhibit an enhanced susceptibility to spreading depolarization while being particularly vulnerable to cerebral ischemia. The severe stroke phenotype in migraine mutant mice can be prevented by suppressing spreading depolarization. If confirmed in the clinical setting, inhibiting spreading depolarization might protect migraineurs at stroke risk as well as decrease attacks of migraine. © 2014 American Headache Society.

  6. Spreading of Excellence in Serious Gaming

    NARCIS (Netherlands)

    Westera, Wim; Berta, Riccardo; Moreno-Ger, Pablo; Bellotti, Francesco; Nadolski, Rob; Padrón-Nápoles, Carmen Luisa; Boyle, Liz; Beligan, Daniel; Baalsrud Hauge, Jannicke

    2014-01-01

    Westera, W., Berta, R., Moreno-Ger, P., Bellotti, F., Nadolski, R., Padrón-Nápoles, C. L., Boyle, L., Beligan, D., & Baalsrud Hauge, J. (2013, December 12). Spreading of Excellence in Serious Gaming. Presentation on the GALA project review meeting. Luxembourg: European Commission.

  7. Modelling of fire spread in car parks

    NARCIS (Netherlands)

    Noordijk, L.M.; Lemaire, A.D.

    2005-01-01

    Currently, design codes assume that in a car park fire at most 3-4 vehicles are on fire at the same time. Recent incidents in car parks have drawn international attention to such assumptions and have raised questions as to the fire spreading mechanism and the resulting fire load on the structure.

  8. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... cancer’s grade, which refers to how abnormal the cancer cells look under a microscope. Grade provides clues about ... to grow and spread. Certain traits of the cancer cells Your age and how healthy you were before ...

  9. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... cancer’s grade, which refers to how abnormal the cancer cells look under a microscope. Grade provides clues about ... to grow and spread. Certain traits of the cancer cells Your age and how healthy you were before ...

  10. What Is Bladder Cancer?

    Science.gov (United States)

    ... of the bladder through a tube called the urethra . Start and spread of bladder cancer The wall of the bladder has several layers, ... called the renal pelvis ), the ureters, and the urethra. Patients with bladder cancer sometimes have other tumors in these places, so ...

  11. Phase diagram of epidemic spreading - unimodal vs. bimodal probability distributions

    CERN Document Server

    Lancic, Alen; Sikic, Mile; Stefancic, Hrvoje

    2009-01-01

    The disease spreading on complex networks is studied in SIR model. Simulations on empirical complex networks reveal two specific regimes of disease spreading: local containment and epidemic outbreak. The variables measuring the extent of disease spreading are in general characterized by a bimodal probability distribution. Phase diagrams of disease spreading for empirical complex networks are introduced. A theoretical model of disease spreading on m-ary tree is investigated both analytically and in simulations. It is shown that the model reproduces qualitative features of phase diagrams of disease spreading observed in empirical complex networks. The role of tree-like structure of complex networks in disease spreading is discussed.

  12. Pinpointing P450s associated with pyrethroid metabolism in the dengue vector, Aedes aegypti: developing new tools to combat insecticide resistance.

    Directory of Open Access Journals (Sweden)

    Bradley J Stevenson

    Full Text Available BACKGROUND: Pyrethroids are increasingly used to block the transmission of diseases spread by Aedes aegypti such as dengue and yellow fever. However, insecticide resistance poses a serious threat, thus there is an urgent need to identify the genes and proteins associated with pyrethroid resistance in order to produce effective counter measures. In Ae. aegypti, overexpression of P450s such as the CYP9J32 gene have been linked with pyrethroid resistance. Our aim was to confirm the role of CYP9J32 and other P450s in insecticide metabolism in order to identify potential diagnostic resistance markers. METHODOLOGY/PRINCIPAL FINDINGS: We have expressed CYP9J32 in Escherichia coli and show that the enzyme can metabolize the pyrethroids permethrin and deltamethrin. In addition, three other Ae. aegypti P450s (CYP9J24, CYP9J26, CYP9J28 were found capable of pyrethroid metabolism, albeit with lower activity. Both Ae. aegypti and Anopheles gambiae P450s (CYP's 6M2, 6Z2, 6P3 were screened against fluorogenic and luminescent substrates to identify potential diagnostic probes for P450 activity. Luciferin-PPXE was preferentially metabolised by the three major pyrethroid metabolisers (CYP9J32, CYP6M2 and CYP6P3, identifying a potential diagnostic substrate for these P450s. CONCLUSIONS/SIGNIFICANCE: P450s have been identified with the potential to confer pyrethroid resistance in Ae.aegypti. It is recommended that over expression of these enzymes should be monitored as indicators of resistance where pyrethroids are used.

  13. Connectivity disruption sparks explosive epidemic spreading

    CERN Document Server

    Böttcher, L; Goles, E; Helbing, D; Herrmann, H J

    2016-01-01

    We investigate the spread of an infection or other malfunction of cascading nature when a system component can recover only if it remains reachable from a functioning central component. We consider the susceptible-infected-susceptible model, typical of mathematical epidemiology, on a network. Infection spreads from infected to healthy nodes, with the addition that infected nodes can only recover when they remain connected to a predefined central node, through a path that contains only healthy nodes. In this system, clusters of infected nodes will absorb their noninfected interior because no path exists between the central node and encapsulated nodes. This gives rise to the simultaneous infection of multiple nodes. Interestingly, the system converges to only one of two stationary states: either the whole population is healthy or it becomes completely infected. This simultaneous cluster infection can give rise to discontinuous jumps of different sizes in the number of failed nodes. Larger jumps emerge at lower ...

  14. Epidemic spreading on weighted complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ye [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Liu, Chuang, E-mail: liuchuang@hznu.edu.cn [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Chu-Xu [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China); Zhang, Zi-Ke, E-mail: zhangzike@gmail.com [Institute of Information Economy, Hangzhou Normal University, Hangzhou 311121 (China); Alibaba Research Center of Complexity Science, Hangzhou Normal University, Hangzhou 311121 (China)

    2014-01-31

    Nowadays, the emergence of online services provides various multi-relation information to support the comprehensive understanding of the epidemic spreading process. In this Letter, we consider the edge weights to represent such multi-role relations. In addition, we perform detailed analysis of two representative metrics, outbreak threshold and epidemic prevalence, on SIS and SIR models. Both theoretical and simulation results find good agreements with each other. Furthermore, experiments show that, on fully mixed networks, the weight distribution on edges would not affect the epidemic results once the average weight of whole network is fixed. This work may shed some light on the in-depth understanding of epidemic spreading on multi-relation and weighted networks.

  15. Forces driving epithelial spreading in zebrafish gastrulation.

    Science.gov (United States)

    Behrndt, Martin; Salbreux, Guillaume; Campinho, Pedro; Hauschild, Robert; Oswald, Felix; Roensch, Julia; Grill, Stephan W; Heisenberg, Carl-Philipp

    2012-10-12

    Contractile actomyosin rings drive various fundamental morphogenetic processes ranging from cytokinesis to wound healing. Actomyosin rings are generally thought to function by circumferential contraction. Here, we show that the spreading of the enveloping cell layer (EVL) over the yolk cell during zebrafish gastrulation is driven by a contractile actomyosin ring. In contrast to previous suggestions, we find that this ring functions not only by circumferential contraction but also by a flow-friction mechanism. This generates a pulling force through resistance against retrograde actomyosin flow. EVL spreading proceeds normally in situations where circumferential contraction is unproductive, indicating that the flow-friction mechanism is sufficient. Thus, actomyosin rings can function in epithelial morphogenesis through a combination of cable-constriction and flow-friction mechanisms.

  16. Compressive Sensing for Spread Spectrum Receivers

    DEFF Research Database (Denmark)

    Fyhn, Karsten; Jensen, Tobias Lindstrøm; Larsen, Torben

    2013-01-01

    With the advent of ubiquitous computing there are two design parameters of wireless communication devices that become very important: power efficiency and production cost. Compressive sensing enables the receiver in such devices to sample below the Shannon-Nyquist sampling rate, which may lead...... to a decrease in the two design parameters. This paper investigates the use of Compressive Sensing (CS) in a general Code Division Multiple Access (CDMA) receiver. We show that when using spread spectrum codes in the signal domain, the CS measurement matrix may be simplified. This measurement scheme, named...... Compressive Spread Spectrum (CSS), allows for a simple, effective receiver design. Furthermore, we numerically evaluate the proposed receiver in terms of bit error rate under different signal to noise ratio conditions and compare it with other receiver structures. These numerical experiments show that though...

  17. Spatial spread of the Hantavirus infection

    Science.gov (United States)

    Reinoso, José A.; de la Rubia, F. Javier

    2015-03-01

    The spatial propagation of Hantavirus-infected mice is considered a serious threat for public health. We analyze the spatial spread of the infected mice by including diffusion in the stage-dependent model for Hantavirus infection recently proposed by Reinoso and de la Rubia [Phys. Rev. E 87, 042706 (2013), 10.1103/PhysRevE.87.042706]. We consider a general scenario in which mice propagate in fronts from their refugia to the surroundings and find an expression for the speed of the front of infected mice. We also introduce a depletion time that measures the time scale for an appreciable impoverishment of the environment conditions and show how this new situation may change the spreading of the infection significantly.

  18. Branching Dynamics of Viral Information Spreading

    CERN Document Server

    Iribarren, José Luis

    2011-01-01

    Despite its importance for rumors or innovations propagation, peer-to-peer collaboration, social networking or Marketing, the dynamics of information spreading is not well understood. Since the diffusion depends on the heterogeneous patterns of human behavior and is driven by the participants' decisions, its propagation dynamics shows surprising properties not explained by traditional epidemic or contagion models. Here we present a detailed analysis of our study of real Viral Marketing campaigns where tracking the propagation of a controlled message allowed us to analyze the structure and dynamics of a diffusion graph involving over 31,000 individuals. We found that information spreading displays a non-Markovian branching dynamics that can be modeled by a two-step Bellman-Harris Branching Process that generalizes the static models known in the literature and incorporates the high variability of human behavior. It explains accurately all the features of information propagation under the "tipping-point" and can...

  19. Directional spread parameter at intermediate water depth

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Deo, M.C.; Anand, N.M.; AshokKumar, K.

    formulations (Niedzwecki and Whatley, 1991). The cosine power ‘2s’ model, originally proposed by Longuet-Higgins et al. (1963), is very popular due to its proven generality. 1.1. The cosine power ‘2s’ model The cosine power ‘2s’ model is as follows; D(f,u) 5 G...(s)cos 2s [(u2u m )/2] (1) where G(s) 5 2 2s 2p G 2 (s 1 1) G(2s 1 1) 5 1 2 p G(s 1 1) G(s 1 0.5) (2) and D(f,u) is directional spreading function, f is wave frequency, u is wave direction, u m is mean wave direction, G is gamma function and s is spreading...

  20. Spreading Models in Banach Space Theory

    CERN Document Server

    Argyros, S A; Tyros, K

    2010-01-01

    We extend the classical Brunel-Sucheston definition of the spreading model by introducing the $\\mathcal{F}$-sequences $(x_s)_{s\\in\\mathcal{F}}$ in a Banach space and the plegma families in $\\mathcal{F}$ where $\\mathcal{F}$ is a regular thin family. The new concept yields a transfinite increasing hierarchy of classes of 1-subsymmetric sequences. We explore the corresponding theory and we present examples establishing this hierarchy and illustrating the limitation of the theory.

  1. Morphogenetic action through flux-limited spreading

    Science.gov (United States)

    Verbeni, M.; Sánchez, O.; Mollica, E.; Siegl-Cachedenier, I.; Carleton, A.; Guerrero, I.; Ruiz i Altaba, A.; Soler, J.

    2013-12-01

    A central question in biology is how secreted morphogens act to induce different cellular responses within a group of cells in a concentration-dependent manner. Modeling morphogenetic output in multicellular systems has so far employed linear diffusion, which is the normal type of diffusion associated with Brownian processes. However, there is evidence that at least some morphogens, such as Hedgehog (Hh) molecules, may not freely diffuse. Moreover, the mathematical analysis of such models necessarily implies unrealistic instantaneous spreading of morphogen molecules, which are derived from the assumptions of Brownian motion in its continuous formulation. A strict mathematical model considering Fick's diffusion law predicts morphogen exposure of the whole tissue at the same time. Such a strict model thus does not describe true biological patterns, even if similar and attractive patterns appear as results of applying such simple model. To eliminate non-biological behaviors from diffusion models we introduce flux-limited spreading (FLS), which implies a restricted velocity for morphogen propagation and a nonlinear mechanism of transport. Using FLS and focusing on intercellular Hh-Gli signaling, we model a morphogen gradient and highlight the propagation velocity of morphogen particles as a new key biological parameter. This model is then applied to the formation and action of the Sonic Hh (Shh) gradient in the vertebrate embryonic neural tube using our experimental data on Hh spreading in heterologous systems together with published data. Unlike linear diffusion models, FLS modeling predicts concentration fronts and the evolution of gradient dynamics and responses over time. In addition to spreading restrictions by extracellular binding partners, we suggest that the constraints imposed by direct bridges of information transfer such as nanotubes or cytonemes underlie FLS. Indeed, we detect and measure morphogen particle velocity in such cell extensions in different

  2. Directional Wave Spectra Using Normal Spreading Function

    Science.gov (United States)

    1985-03-01

    energy spectral density function U. g. Army Engineer Waternays Experiment Station. Coastal Engineering Research Center P. 0. lox 631, Vicksburg...Z39-18 D(f,e) = spreading function E (f,(3) = directional spectral density function f = frequency in cycles per second 8 = direction in radians...of this assumption depends on the narrow bandedness of the energy spectral density function . For fairly narrow spectra (e.g., a swell train), the

  3. Large Scale Flame Spread Environmental Characterization Testing

    Science.gov (United States)

    Clayman, Lauren K.; Olson, Sandra L.; Gokoghi, Suleyman A.; Brooker, John E.; Ferkul, Paul V.; Kacher, Henry F.

    2013-01-01

    Under the Advanced Exploration Systems (AES) Spacecraft Fire Safety Demonstration Project (SFSDP), as a risk mitigation activity in support of the development of a large-scale fire demonstration experiment in microgravity, flame-spread tests were conducted in normal gravity on thin, cellulose-based fuels in a sealed chamber. The primary objective of the tests was to measure pressure rise in a chamber as sample material, burning direction (upward/downward), total heat release, heat release rate, and heat loss mechanisms were varied between tests. A Design of Experiments (DOE) method was imposed to produce an array of tests from a fixed set of constraints and a coupled response model was developed. Supplementary tests were run without experimental design to additionally vary select parameters such as initial chamber pressure. The starting chamber pressure for each test was set below atmospheric to prevent chamber overpressure. Bottom ignition, or upward propagating burns, produced rapid acceleratory turbulent flame spread. Pressure rise in the chamber increases as the amount of fuel burned increases mainly because of the larger amount of heat generation and, to a much smaller extent, due to the increase in gaseous number of moles. Top ignition, or downward propagating burns, produced a steady flame spread with a very small flat flame across the burning edge. Steady-state pressure is achieved during downward flame spread as the pressure rises and plateaus. This indicates that the heat generation by the flame matches the heat loss to surroundings during the longer, slower downward burns. One heat loss mechanism included mounting a heat exchanger directly above the burning sample in the path of the plume to act as a heat sink and more efficiently dissipate the heat due to the combustion event. This proved an effective means for chamber overpressure mitigation for those tests producing the most total heat release and thusly was determined to be a feasible mitigation

  4. Lognormal Infection Times of Online Information Spread

    CERN Document Server

    Doerr, Christian; Van Mieghem, Piet

    2013-01-01

    The infection times of individuals in online information spread such as the inter-arrival time of Twitter messages or the propagation time of news stories on a social media site can be explained through a convolution of lognormally distributed observation and reaction times of the individual participants. Experimental measurements support the lognormal shape of the individual contributing processes, and have resemblance to previously reported lognormal distributions of human behavior and contagious processes.

  5. Spreading the word ... hospice information systems.

    Science.gov (United States)

    Jackson, Avril; Hodson, Melanie; Brady, Denise; Pahl, Nick

    The rapid spread of Saunders' thinking across the world has been facilitated by the Hospice Information service and library at St Christopher's Hospice which she helped to create and further enhanced by Help the Hospices. We have set this article in the context of the Web and other information systems as they are developing today. "Connecting people" and "collecting people's experiences" were terms often used by Cicely Saunders when she described the work of Hospice Information, a service that has in some measure contributed to the rapid spread of her thinking across the world and which is currently in close contact with palliative care workers in over 120 countries. Connecting--or networking--putting people and organizations in touch with each other for mutual benefit and collecting and disseminating people's experiences are central to our work as a U.K. and international resource on hospice and palliative care for professionals and the public. Add to these the crucial role of information provision and advocacy for patients, carers, and health professionals alike and we hope that you may begin to appreciate how our respective organizations have contributed to the spread of Cicely Saunders' vision.

  6. Geomagnetic storm and equatorial spread-F

    Directory of Open Access Journals (Sweden)

    F. Becker-Guedes

    2004-09-01

    Full Text Available In August 2000, a new ionospheric sounding station was established at Sao Jose dos Campos (23.2° S, 45.9° W; dip latitude 17.6° S, Brazil, by the University of Vale do Paraiba (UNIVAP. Another ionospheric sounding station was established at Palmas (10.2° S, 48.2° W; dip latitude 5.5° S, Brazil, in April 2002, by UNIVAP in collaboration with the Lutheran University Center of Palmas (CEULP, Lutheran University of Brazil (ULBRA. Both the stations are equipped with digital ionosonde of the type known as Canadian Advanced Digital Ionosonde (CADI. In order to study the effects of geomagnetic storms on equatorial spread-F, we present and discuss three case studies, two from the ionospheric sounding observations at Sao Jose dos Campos (September and November 2000 and one from the simultaneous ionospheric sounding observations at Sao Jose dos Campos and Palmas (July 2003. Salient features from these ionospheric observations are presented and discussed in this paper. It has been observed that sometimes (e.g. 4-5 November 2000 the geomagnetic storm acts as an inhibitor (high strong spread-F season, whereas at other times (e.g. 11-12 July 2003 they act as an initiator (low strong spread-F season, possibly due to corresponding changes in the quiet and disturbed drift patterns during different seasons.

  7. Epidemic spreading on evolving signed networks

    Science.gov (United States)

    Saeedian, M.; Azimi-Tafreshi, N.; Jafari, G. R.; Kertesz, J.

    2017-02-01

    Most studies of disease spreading consider the underlying social network as obtained without the contagion, though epidemic influences people's willingness to contact others: A "friendly" contact may be turned to "unfriendly" to avoid infection. We study the susceptible-infected disease-spreading model on signed networks, in which each edge is associated with a positive or negative sign representing the friendly or unfriendly relation between its end nodes. In a signed network, according to Heider's theory, edge signs evolve such that finally a state of structural balance is achieved, corresponding to no frustration in physics terms. However, the danger of infection affects the evolution of its edge signs. To describe the coupled problem of the sign evolution and disease spreading, we generalize the notion of structural balance by taking into account the state of the nodes. We introduce an energy function and carry out Monte Carlo simulations on complete networks to test the energy landscape, where we find local minima corresponding to the so-called jammed states. We study the effect of the ratio of initial friendly to unfriendly connections on the propagation of disease. The steady state can be balanced or a jammed state such that a coexistence occurs between susceptible and infected nodes in the system.

  8. Did ice-age bovids spread tuberculosis?

    Science.gov (United States)

    Rothschild, Bruce M.; Martin, Larry D.

    2006-11-01

    Pathognomonic metacarpal undermining is a skeletal pathology that has been associated with Mycobacterium tuberculosis in bovids. Postcranial artiodactyl, perissodactyl, and carnivore skeletons were examined in major university and museum collections of North America and Europe for evidence of this and other pathology potentially attributable to tuberculosis. Among nonproboscidean mammals from pre-Holocene North America, bone lesions indicative of tuberculosis were restricted to immigrant bovids from Eurasia. No bone lesions compatible with diagnosis of tuberculosis were found in large samples of other pre-Holocene (164 Oligocene, 397 Miocene, and 1,041 Plio Pleistocene) North American mammals, including 114 antilocaprids. Given the unchanged frequency of bovid tubercular disease during the Pleistocene, it appears that most did not die from the disease but actually reached an accommodation with it (as did the mastodon) (Rothschild and Laub 2006). Thus, they were sufficiently long-lived to assure greater spread of the disease. The relationships of the proboscidean examples need further study, but present evidence suggests a Holarctic spread of tuberculosis during the Pleistocene, with bovids acting as vectors. While the role of other animals in the transmission of tuberculosis could be considered, the unique accommodation achieved by bovids and mastodons makes them the likely “culprits” in its spread.

  9. Spread Across Liquids Continues to Fly

    Science.gov (United States)

    Miller, Fletcher J.

    2001-01-01

    The physics and behavior of a flame spreading across a flammable liquid is an active area of research at the NASA Glenn Research Center. Spills of fuels and other liquids often result in considerable fire hazards, and much remains unknown about the details of how a flame, once ignited, moves across a pool. The depth of the liquid or size of the spill, the temperature, and wind, if any, can all complicate the combustion processes. In addition, with the advent of the International Space Station there may be fire hazards associated with cleaning, laboratory, or other fluids in space, and it is essential to understand the role that gravity plays in such situations. The Spread Across Liquids (SAL) experiment is an experimental and computational effort dedicated to understanding the detailed mechanisms of flame spread across a flammable liquid initially below its flashpoint temperature. The experimental research is being carried out in-house by a team of researchers from Glenn, the National Center for Microgravity Combustion, and Zin Technologies, with computer modeling being provided via a grant with the University of California, Irvine. Glenn's Zero Gravity Facility is used to achieve short microgravity periods, and normal gravity testing is done in the Space Experiments Laboratory. To achieve longer periods of microgravity, the showcase SAL hardware flies aboard a sounding rocket launched from White Sands Missile Range, New Mexico, approximately once per year. In addition to extended microgravity, this carrier allows the use of detailed diagnostics that cannot be employed in a drop tower.

  10. Branching dynamics of viral information spreading

    Science.gov (United States)

    Iribarren, José Luis; Moro, Esteban

    2011-10-01

    Despite its importance for rumors or innovations propagation, peer-to-peer collaboration, social networking, or marketing, the dynamics of information spreading is not well understood. Since the diffusion depends on the heterogeneous patterns of human behavior and is driven by the participants’ decisions, its propagation dynamics shows surprising properties not explained by traditional epidemic or contagion models. Here we present a detailed analysis of our study of real viral marketing campaigns where tracking the propagation of a controlled message allowed us to analyze the structure and dynamics of a diffusion graph involving over 31 000 individuals. We found that information spreading displays a non-Markovian branching dynamics that can be modeled by a two-step Bellman-Harris branching process that generalizes the static models known in the literature and incorporates the high variability of human behavior. It explains accurately all the features of information propagation under the “tipping point” and can be used for prediction and management of viral information spreading processes.

  11. Cancer immunology

    Energy Technology Data Exchange (ETDEWEB)

    Herberman, R.B. (Univ. of Pittsburgh, Pittsburgh, PA (US))

    1986-01-01

    This book contains seven chapters. They are: Immunlogy of human T-cell leukemia/lymphonma (lymphotropic) viruses (the HTLV 'family'); Tumor specific antigens induced by mutagens and DNA hypomethylating agents: implications for the immunobiology of neoplasia; Destruction of tumor cells by macrophages: mechanisms of recognition and lysis and their regulation; Mechanisms of NK-cell mediated cytotoxicity; Role of natural killer (NK) cells in the control of tumor growth and metastatic spread; Monoclonal antibody therapy of cancer; preclinical models and investigations in humans; and Abnormalities in interleukin 2 production and response in cancer and possible therapeutic approaches.

  12. SU-E-T-225: Correction Matrix for PinPoint Ionization Chamber for Dosimetric Measurements in the Newly Released Incise™ Multileaf Collimator Shaped Small Field for CyberKnife M6™ Machine

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y; Li, T; Heron, D; Huq, M [University of Pittsburgh Cancer Institute and UPMC CancerCenter, Pittsburgh, PA (United States)

    2015-06-15

    Purpose: For small field dosimetry, such as measurements of output factors for cones or MLC-shaped irregular small fields, ion chambers often Result in an underestimation of the dose, due to both the volume averaging effect and the lack of lateral charged particle equilibrium. This work presents a mathematical model for correction matrix for a PTW PinPoint ionization chamber for dosimetric measurements made in the newly released Incise™ Multileaf collimator fields of the CyberKnife M6™ machine. Methods: A correction matrix for a PTW 0.015cc PinPoint ionization chamber was developed by modeling its 3D dose response in twelve cone-shaped circular fields created using the 5mm, 7.5mm, 10mm, 12.5mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 50mm, 60mm cones in a CyberKnife M6™ machine. For each field size, hundreds of readings were recorded for every 2mm chamber shift in the horizontal plane. The contribution of each dose pixel to a measurement point depended on the radial distance and the angle to the chamber axis. These readings were then compared with the theoretical dose as obtained with Monte Carlo calculation. A penalized least-square optimization algorithm was developed to generate the correction matrix. After the parameter fitting, the mathematical model was validated for MLC-shaped irregular fields. Results: The optimization algorithm used for parameter fitting was stable and the resulted response factors were smooth in spatial domain. After correction with the mathematical model, the chamber reading matched with the calculation for all the tested fields to within 2%. Conclusion: A novel mathematical model has been developed for PinPoint chamber for dosimetric measurements in small MLC-shaped irregular fields. The correction matrix is dependent on detector, treatment unit and the geometry of setup. The model can be applied to non-standard composite fields and provides an access to IMRT point dose validation.

  13. Ice Control with Brine Spread with Nozzles on Highways

    DEFF Research Database (Denmark)

    Bolet, Lars; Fonnesbech, Jens Kristian

    2010-01-01

    . The improvements gained by the county of Funen were mainly due to the use of technologies (brine spreading with nozzles) giving a more precise spread pattern than the traditional gritting of pre-wetted salt. The spread pattern for every spreader, tested in The County of Funen, has been meassured 3 hours after...... spreading on a highway with traffic. A total of 800 spots were measured for residual salt for every spreader. The measurements and the spread pattern for brine spreading with nozzles were so precisely, that we learned: “When there is moisture, water or ice on the road, we need to take into account...

  14. A laterally-spreading tumor in a colonic interposition treated by endoscopic submucosal dissection

    Institute of Scientific and Technical Information of China (English)

    Hideaki; Bando; Hiroaki; Ikematsu; Kuang-I; Fu; Yasuhiro; Oono; Takashi; Kojima; Keiko; Minashi; Tomonori; Yano; Takahisa; Matsuda; Yutaka; Saito; Kazuhiro; Kaneko; Atsushi; Ohtsu

    2010-01-01

    Herein we describe an early colonic carcinoma which developed in a colonic interposition 14 years after surgery for esophageal cancer, which was successfully treated by endoscopic submucosal dissection (ESD). An 80-year-old man underwent colonic interposition between the upper esophagus and stomach after surgery for an early esophageal squamous cell carcinoma in 1994. He received a surveillance endoscopy, and a laterally-spreading tumor of granular type, approximately 20 mm in size, was identified in the co...

  15. Persistent spread in seasonal albedo change radiative forcings linked to forest cover changes at northern latitudes

    Science.gov (United States)

    Bright, R. M.; Myhre, G.; Astrup, R. A.; Antón-Fernández, C.; Strømman, A. H.

    2014-12-01

    Large-scale land use and land cover change (LULCC) can significantly affect regional climates from changes in surface biogeophysics, and a substantial part of historical LULCC from forest to crop or pasture occurred in the mid- and high-latitudes of North America and Eurasia where the snow-masking effect of forests often leads to a negative radiative forcing from albedo changes linked to deforestation. Results from several recent historical LULCC modeling studies, however, reveal an order of magnitude spread in climate forcing from the snow-masking effect by forests. This is likely because, in months with snow cover, the interactions between vegetation and snow significantly complicate the relationship between the change in forest cover fraction and albedo, thus accurate characterizations of land surface-albedo dynamics are essential given the importance of albedo feedbacks when ground or canopy surfaces are covered in snow Here, we evaluate snow masking parameterization schemes of seven prominent climate models in greater detail in order to pinpoint major sources of the persistent variability in albedo predictions across models. Using a comprehensive dataset of forest structure, meteorology, and daily MODIS albedo observations spanning three winter-spring seasons in three regions of boreal Norway, we estimate radiative forcings connected to canopy snow masking and compare it to the observed forcings. We develop a physically-based regression model and compare its performance to existing modeling schemes, concluding with a discussion on the utility of purely empirical parameterizations relative to those rooted in radiative transfer theory and/or process-based modeling.

  16. Pancreatic Metastasis from Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Julian Jacob

    2010-01-01

    Full Text Available The pancreas is an unusual location for metastases from other primary cancers. Rarely, pancreatic metastases from kidney or colorectal cancers have been reported. However, a variety of other cancers may also spread to the pancreas. We report an exceptional case of pancreatic metastasis from prostate cancer. Differences in management between primary and secondary pancreatic tumors make recognition of metastases to the pancreas an objective of first importance. Knowledge of unusual locations for metastatic spread will reduce diagnostic delay and lead to a timely delivery of an appropriate treatment.

  17. Familial Hemiplegic Migraine and Spreading Depression

    Directory of Open Access Journals (Sweden)

    Hadi KAZEMI

    2014-07-01

    Full Text Available How to Cite This Article: Kazemi H, Speckmann EJ, Gorji A. Familial Hemiplegic Migraine and Spreading Depression. Iran J Child Neurol. 2014 Summer;8(3: 6-11. AbstractObjectiveFamilial hemiplegic migraine (FHM is an autosomal dominantly inherited subtype of migraine with aura, characterized by transient neurological signs and symptoms. Typical hemiplegic migraine attacks start in the first or second decade of life. Some patients with FHM suffer from daily recurrent attacks since childhood. Results from extensive studies of cellular and animal models have indicated that gene mutations in FHM increase neuronal excitability and reduce the threshold for spreading depression (SD. SD is a transient wave of profound neuronal and glial depolarization that slowly propagates throughout the brain tissue and is characterized by a high amplitude negative DC shift. After induction of SD, S218L mutant mice exhibited neurological signs highly reminiscent of clinical attacks in FHM type 1 patients carrying this mutation. FHM1 with ataxia is attributable to specific mutations that differ from mutations that cause pure FHM1 and have peculiar consequences on cerebellar Cav2.1 currents that lead to profound Purkinje cell dysfunction and neuronal loss with atrophy. SD in juvenile rats produced neuronal injury and death. Hormonal factors involved in FHM affect SD initiation and propagation. The data identify SD as a possible target of treatment of FHM. In addition, FHM is a useful model to explore the mechanisms of more common types of migraine. ReferencesRussell MB, Ducros A. Sporadic and familial hemiplegic migraine: pathophysiological mechanisms, clinical characteristics, diagnosis, and management. Lancet Neurol 2011 (5:457-70.The International Classification of Headache Disorders, 3rd edition (beta version.Headache Classification Committee of the International Headache Society (IHS. Cephalalgia2013;33(9:629-808.Thomsen LL, Eriksen MK, Roemer SF

  18. Default Spread dan Term Spread sebagai Variabel Proxy Siklus Bisnis pada Model Fama-French

    Directory of Open Access Journals (Sweden)

    Edwin Hendra

    2015-08-01

    Full Text Available This research aims to apply the Fama-French models and test the effect of alternative variable of bond yield spread, default spread (RBBB – RAAA and RAAA – RF, and the term spread (RSUN10-RSUN1, as proxy variables of the business cycle, in IDX stock data during 2005-2010. Four types of asset pricing models tested are Sharpe-Lintner CAPM, Fama-French models, Hwang et al.model, and hybrid model. The results showed that the size effect and value effect has an impact on excess stock returns. Slopes of market beta, SMB, and HML are more sensitive to stock big size and high B / M. Default spreads and term spreads in Hwang et al. model can explain the value effect, and weakly explain the size effect, meanwhile the power of explanation disappeared on Hybrid models. Based on the assessment adjusted R2 and the frequency of rejection of non-zero alpha, is found that the hybrid model is the most suitable model.  

  19. Lung Cancer, Questions to Ask Your Health Professional | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: Lung Cancer Questions to Ask Your Health Professional Past Issues / ... 2013 Table of Contents Tests What type of lung cancer do I have? Has the cancer spread from ...

  20. Vectorised Spreading Activation algorithm for centrality measurement

    Directory of Open Access Journals (Sweden)

    Alexander Troussov

    2011-01-01

    Full Text Available Spreading Activation is a family of graph-based algorithms widely used in areas such as information retrieval, epidemic models, and recommender systems. In this paper we introduce a novel Spreading Activation (SA method that we call Vectorised Spreading Activation (VSA. VSA algorithms, like “traditional” SA algorithms, iteratively propagate the activation from the initially activated set of nodes to the other nodes in a network through outward links. The level of the node’s activation could be used as a centrality measurement in accordance with dynamic model-based view of centrality that focuses on the outcomes for nodes in a network where something is flowing from node to node across the edges. Representing the activation by vectors allows the use of the information about various dimensionalities of the flow and the dynamic of the flow. In this capacity, VSA algorithms can model multitude of complex multidimensional network flows. We present the results of numerical simulations on small synthetic social networks and multi­dimensional network models of folksonomies which show that the results of VSA propagation are more sensitive to the positions of the initial seed and to the community structure of the network than the results produced by traditional SA algorithms. We tentatively conclude that the VSA methods could be instrumental to develop scalable and computationally efficient algorithms which could achieve synergy between computation of centrality indexes with detection of community structures in networks. Based on our preliminary results and on improvements made over previous studies, we foresee advances and applications in the current state of the art of this family of algorithms and their applications to centrality measurement.

  1. Species D human adenovirus type 9 exhibits better virus-spread ability for antitumor efficacy among alternative serotypes.

    Directory of Open Access Journals (Sweden)

    Junji Uchino

    Full Text Available Species C human adenovirus serotype 5 (HAdV-C5 is widely used as a vector for cancer gene therapy, because it efficiently transduces target cells. A variety of HAdV-C5 vectors have been developed and tested in vitro and in vivo for cancer gene therapy. While clinical trials with HAdV-C5 vectors resulted in effective responses in many cancer patients, administration of HAdV-C5 vectors to solid tumors showed responses in a limited area. A biological barrier in tumor mass is considered to hinder viral spread of HAdV-C5 vectors from infected cells. Therefore, efficient virus-spread from an infected tumor cell to surrounding tumor cells is required for successful cancer gene therapy. In this study, we compared HAdV-C5 to sixteen other HAdV serotypes selected from species A to G for virus-spread ability in vitro. HAdV-D9 showed better virus-spread ability than other serotypes, and its viral progeny were efficiently released from infected cells during viral replication. Although the HAdV-D9 fiber protein contains a binding site for coxsackie B virus and adenovirus receptor (CAR, HAdV-D9 showed expanded tropism for infection due to human CAR (hCAR-independent attachment to target cells. HAdV-D9 infection effectively killed hCAR-negative cancer cells as well as hCAR-positive cancer cells. These results suggest that HADV-D9, with its better virus-spread ability, could have improved therapeutic efficacy in solid tumors compared to HAdV-C5.

  2. Multiscale modeling of virus replication and spread.

    Science.gov (United States)

    Kumberger, Peter; Frey, Felix; Schwarz, Ulrich S; Graw, Frederik

    2016-07-01

    Replication and spread of human viruses is based on the simultaneous exploitation of many different host functions, bridging multiple scales in space and time. Mathematical modeling is essential to obtain a systems-level understanding of how human viruses manage to proceed through their life cycles. Here, we review corresponding advances for viral systems of large medical relevance, such as human immunodeficiency virus-1 (HIV-1) and hepatitis C virus (HCV). We will outline how the combination of mathematical models and experimental data has advanced our quantitative knowledge about various processes of these pathogens, and how novel quantitative approaches promise to fill remaining gaps.

  3. Epidemic spreading with immunization on bipartite networks

    CERN Document Server

    Tanimoto, Shinji

    2011-01-01

    Bipartite networks are composed of two types of nodes and there are no links between nodes of the same type. Thus the study of epidemic spread and control on such networks is relevant to sexually transmitted diseases (STDs). When entire populations of two types cannot be immunized and the effect of immunization is not perfect, we have to consider the targeted immunization with immunization rates. We derive the epidemic thresholds of SIR and SIS models with immunization and illustrate the results with STDs on heterosexual contact networks.

  4. Rumor spreading models with random denials

    Science.gov (United States)

    Giorno, Virginia; Spina, Serena

    2016-11-01

    The concept of denial is introduced on rumor spreading processes. The denials occur with a certain rate and they reset to start the initial situation. A population of N individuals is subdivided into ignorants, spreaders and stiflers; at the initial time there is only one spreader and the rest of the population is ignorant. The denials are introduced in the classic DK model and in its generalization, in which a spreader can transmit the rumor at most to k ignorants. The steady state densities are analyzed for these models. Finally, a numerical analysis is performed to study the rule of the involved parameters and to compare the proposed models.

  5. Spreading and collapse of big basaltic volcanoes

    Science.gov (United States)

    Puglisi, Giuseppe; Bonforte, Alessandro; Guglielmino, Francesco; Peltier, Aline; Poland, Michael

    2016-04-01

    Among the different types of volcanoes, basaltic ones usually form the most voluminous edifices. Because volcanoes are growing on a pre-existing landscape, the geologic and structural framework of the basement (and earlier volcanic landforms) influences the stress regime, seismicity, and volcanic activity. Conversely, the masses of these volcanoes introduce a morphological anomaly that affects neighboring areas. Growth of a volcano disturbs the tectonic framework of the region, clamps and unclamps existing faults (some of which may be reactivated by the new stress field), and deforms the substratum. A volcano's weight on its basement can trigger edifice spreading and collapse that can affect populated areas even at significant distance. Volcano instability can also be driven by slow tectonic deformation and magmatic intrusion. The manifestations of instability span a range of temporal and spatial scales, ranging from slow creep on individual faults to large earthquakes affecting a broad area. In the frame of MED-SVU project, our work aims to investigate the relation between basement setting and volcanic activity and stability at three Supersite volcanoes: Etna (Sicily, Italy), Kilauea (Island of Hawaii, USA) and Piton de la Fournaise (La Reunion Island, France). These volcanoes host frequent eruptive activity (effusive and explosive) and share common features indicating lateral spreading and collapse, yet they are characterized by different morphologies, dimensions, and tectonic frameworks. For instance, the basaltic ocean island volcanoes of Kilauea and Piton de la Fournaise are near the active ends of long hotspot chains while Mt. Etna has developed at junction along a convergent margin between the African and Eurasian plates and a passive margin separating the oceanic Ionian crust from the African continental crust. Magma supply and plate velocity also differ in the three settings, as to the sizes of the edifices and the extents of their rift zones. These

  6. Perceptual transparency in neon color spreading displays.

    Science.gov (United States)

    Ekroll, Vebjørn; Faul, Franz

    2002-08-01

    In neon color spreading displays, both a color illusion and perceptual transparency can be seen. In this study, we investigated the color conditions for the perception of transparency in such displays. It was found that the data are very well accounted for by a generalization of Metelli's (1970) episcotister model of balanced perceptual transparency to tristimulus values. This additive model correctly predicted which combinations of colors would lead to optimal impressions of transparency. Color combinations deviating slightly from the additive model also looked transparent, but less convincingly so.

  7. Forced versus Spontaneous Spreading of Liquids.

    Science.gov (United States)

    Mohammad Karim, A; Davis, S H; Kavehpour, H P

    2016-10-11

    Two sets of experiments are performed, one for the free spreading of a liquid drop on a glass substrate and the other for the forced motion of a glass plate through a gas-liquid interface. The measured macroscopic advancing contact angle, θA, versus the contact line speed, U, differ markedly between the two configurations. The hydrodynamic theory (HDT) and the molecular kinetic theory (MKT) are shown to apply separately to the two systems. This distinction has not been previously noted. Rules of thumb are given that for an experimentalist involve a priori knowledge of the expected behavior.

  8. Optimization of Axial Intensity Point Spread Function

    Institute of Scientific and Technical Information of China (English)

    WANG Haifeng; GAN Fuxi; CHEN Zhongyu

    2001-01-01

    It is known that for the converged laser beam, the axial intensity distribution corresponds to a Gaussian curve, that is, the intensity on the focal plane is the peak intensity. When it defocuses, the intensity would decrease rapidly. In optical data storage, for instance, we expect the intensity within a certain distance to be almost equal. In this paper, we propose to use a pure phase superresolution apodizer to optimize the axial intensity distribution of the converged laser beam and at the same time improve the resolution. The intensity point spread function remains almost identical in a wide range within the focal depth.

  9. Self-organized model of cascade spreading

    Science.gov (United States)

    Gualdi, S.; Medo, M.; Zhang, Y.-C.

    2011-01-01

    We study simultaneous price drops of real stocks and show that for high drop thresholds they follow a power-law distribution. To reproduce these collective downturns, we propose a minimal self-organized model of cascade spreading based on a probabilistic response of the system elements to stress conditions. This model is solvable using the theory of branching processes and the mean-field approximation. For a wide range of parameters, the system is in a critical state and displays a power-law cascade-size distribution similar to the empirically observed one. We further generalize the model to reproduce volatility clustering and other observed properties of real stocks.

  10. Self-organized model of cascade spreading

    CERN Document Server

    Gualdi, Stanislao; Zhang, Yi-Cheng

    2010-01-01

    We study simultaneous price drops of real stocks and show that for high drop thresholds they follow a power-law distribution. To reproduce these collective downturns, we propose a self-organized model of cascade spreading based on a probabilistic response of the system's elements to stress conditions. This model is solvable using the theory of branching processes and the mean-field approximation and displays a power-law cascade-size distribution-similar to the empirically observed one-over a wide range of parameters.

  11. Migrant workers spreading HIV in Southeast Asia.

    Science.gov (United States)

    1996-10-21

    Interruption of the spread of human immunodeficiency virus (HIV) across southeast Asian borders by legal and illegal migrant laborers is a major concern of the Association of Southeast Asian Nations (ASEAN). ASEAN intends to move immediately to implement regional projects focused on education, information sharing, and improved surveillance. HIV transmission from laborers from poorer countries in search of jobs in economically booming regions underscores the global nature of the AIDS problem. Malaysia, for example, has over 1 million illegal workers. Moreover, many legal guest workers who enter Malaysia with letters from a physician stating they are not HIV-infected have falsified documents.

  12. Simultaneous spreading and evaporation: recent developments.

    Science.gov (United States)

    Semenov, Sergey; Trybala, Anna; Rubio, Ramon G; Kovalchuk, Nina; Starov, Victor; Velarde, Manuel G

    2014-04-01

    The recent progress in theoretical and experimental studies of simultaneous spreading and evaporation of liquid droplets on solid substrates is discussed for pure liquids including nanodroplets, nanosuspensions of inorganic particles (nanofluids) and surfactant solutions. Evaporation of both complete wetting and partial wetting liquids into a nonsaturated vapour atmosphere are considered. However, the main attention is paid to the case of partial wetting when the hysteresis of static contact angle takes place. In the case of complete wetting the spreading/evaporation process proceeds in two stages. A theory was suggested for this case and a good agreement with available experimental data was achieved. In the case of partial wetting the spreading/evaporation of a sessile droplet of pure liquid goes through four subsequent stages: (i) the initial stage, spreading, is relatively short (1-2 min) and therefore evaporation can be neglected during this stage; during the initial stage the contact angle reaches the value of advancing contact angle and the radius of the droplet base reaches its maximum value, (ii) the first stage of evaporation is characterised by the constant value of the radius of the droplet base; the value of the contact angle during the first stage decreases from static advancing to static receding contact angle; (iii) during the second stage of evaporation the contact angle remains constant and equal to its receding value, while the radius of the droplet base decreases; and (iv) at the third stage of evaporation both the contact angle and the radius of the droplet base decrease until the drop completely disappears. It has been shown theoretically and confirmed experimentally that during the first and second stages of evaporation the volume of droplet to power 2/3 decreases linearly with time. The universal dependence of the contact angle during the first stage and of the radius of the droplet base during the second stage on the reduced time has been

  13. Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses

    Science.gov (United States)

    Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses B Z Z Z Z . Aside from ... or Aedes albopictus ) can spread dengue, chikungunya, or Zika viruses. People become infected with dengue, chikungunya, or ...

  14. Spreading depolarisations and outcome after traumatic brain injury

    DEFF Research Database (Denmark)

    Hartings, Jed A; Bullock, M Ross; Okonkwo, David O

    2011-01-01

    Pathological waves of spreading mass neuronal depolarisation arise repeatedly in injured, but potentially salvageable, grey matter in 50-60% of patients after traumatic brain injury (TBI). We aimed to ascertain whether spreading depolarisations are independently associated with unfavourable...

  15. Expanded HIV Screening Projected to Decrease Spread of the Virus

    Science.gov (United States)

    ... of the Virus Expanded HIV Screening Projected To Decrease Spread of the Virus Email Facebook Twitter April ... 2014, April 3). Expanded HIV Screening Projected To Decrease Spread of the Virus. Retrieved from https://www. ...

  16. IL-33 facilitates endocrine resistance of breast cancer by inducing cancer stem cell properties.

    Science.gov (United States)

    Hu, Haiyan; Sun, Jiaxing; Wang, Chunhong; Bu, Xiangmao; Liu, Xiangping; Mao, Yan; Wang, Haibo

    2017-02-16

    Breast cancers with estrogen receptor (ER) expressions account for the majority of all clinical cases. Due to hormone therapy with tamoxifen, prognoses of patients with ER-positive breast cancer are significantly improved. However, endocrine resistance to tamoxifen is common and inevitable, leading to compromised efficacy of hormone therapy. Herein, we identify a crucial role of IL-33 in inducing endocrine resistance of breast cancer. IL-33 overexpression in breast cancer cells results in resistance to tamoxifen-induced tumor growth inhibition, while IL-33 knockdown corrects this problem. Mechanistically, IL-33 induces breast cancer stem cell properties evidenced by mammosphere formation and xenograft tumorigenesis, as well as expression of cancer stem cell genes including ALDH1A3, OCT4, NANOG and SOX2. In breast cancer patients, higher serum IL-33 levels portend advanced clinical stages, poorly differentiated cancer cells and tumor recurrence. IL-33 expression levels in patients' freshly isolated breast cancer cells predicts tamoxifen resistance and cancer stem cell features in individual patient. Collectively, IL-33 induces endocrine resistance of breast cancer by promoting cancer stem cell properties. These findings provide novel mechanisms connecting IL-33 with cancer pathogenesis and pinpoint IL-33 as a promising target for optimizing hormone therapy in clinical practice.

  17. Recording, analysis, and interpretation of spreading depolarizations in neurointensive care

    DEFF Research Database (Denmark)

    Dreier, Jens P; Fabricius, Martin; Ayata, Cenk

    2016-01-01

    recorded during multimodal neuromonitoring in neurocritical care as a causal biomarker providing a diagnostic summary measure of metabolic failure and excitotoxic injury. Focal ischemia causes spreading depolarization within minutes. Further spreading depolarizations arise for hours to days due to energy...... electrocorticographic monitoring affords even remote detection of injury because spreading depolarizations propagate widely from ischemic or metabolically stressed zones; characteristic patterns, including temporal clusters of spreading depolarizations and persistent depression of spontaneous cortical activity, can...

  18. Analysis of Yield Spreads on Commercial Mortgage-Backed Securities

    OpenAIRE

    Brian A. Maris; William Segal

    2002-01-01

    Yield spreads on commercial mortgage-backed securities (CMBS) are defined as the difference between the yield on CMBS and the yield on comparable-maturity Treasuries. CMBS yield spreads declined dramatically from 1992 until 1997, then increased in 1998 and 1999. The relationship between CMBS yield spreads and other variables is estimated in an effort to explain recent trends. Results identify several variables that are related to yield spreads on both fixed-rate and variable-rate CMBS. Howeve...

  19. 21 CFR 133.175 - Pasteurized cheese spread.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Pasteurized cheese spread. 133.175 Section 133.175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD... Cheese and Related Products § 133.175 Pasteurized cheese spread. Pasteurized cheese spread is the food...

  20. Spreading the Experience of Preschool Educational Establishments

    Directory of Open Access Journals (Sweden)

    V. M. Dyukov

    2012-01-01

    Full Text Available The paper observes the issue of spreading the innovative experience of municipal preschool educational establishments (MPEE. The author outlines the ways of spreading the ideas of «Development Program of MPEE» and « Educational Program of MPEE» worked out according to the federal state requirements. Theoretical methodological basis of the research combines the fundamental studies of the last century’s Russian teachers and psychologists: L. S. Vygodsky, A. N. Leontyev, L. I. Bozhovitch, A. V. Zaporozhets, V. V. Davydov, etc. Based on their studies, a series of teaching methodical manuals was developed in the Institute of Reflexive Psychology of Creativity and Humanizing the Education at the International Academy of Humanizing the Education, Sotchi–Magdeburg: «Russian Education 2020 – the Model of Preschool Education» and «Pedagogic Innovations in MPEE of Innovative Type».In author’s opinion, the outcome of the research can promote the modernization efficiency in preschool education.

  1. Spreading the Experience of Preschool Educational Establishments

    Directory of Open Access Journals (Sweden)

    V. M. Dyukov

    2015-02-01

    Full Text Available The paper observes the issue of spreading the innovative experience of municipal preschool educational establishments (MPEE. The author outlines the ways of spreading the ideas of «Development Program of MPEE» and « Educational Program of MPEE» worked out according to the federal state requirements. Theoretical methodological basis of the research combines the fundamental studies of the last century’s Russian teachers and psychologists: L. S. Vygodsky, A. N. Leontyev, L. I. Bozhovitch, A. V. Zaporozhets, V. V. Davydov, etc. Based on their studies, a series of teaching methodical manuals was developed in the Institute of Reflexive Psychology of Creativity and Humanizing the Education at the International Academy of Humanizing the Education, Sotchi–Magdeburg: «Russian Education 2020 – the Model of Preschool Education» and «Pedagogic Innovations in MPEE of Innovative Type».In author’s opinion, the outcome of the research can promote the modernization efficiency in preschool education.

  2. Intramolecular epitope spreading in Heymann nephritis.

    Science.gov (United States)

    Shah, Pallavi; Tramontano, Alfonso; Makker, Sudesh P

    2007-12-01

    Immunization with megalin induces active Heymann nephritis, which reproduces features of human idiopathic membranous glomerulonephritis. Megalin is a complex immunological target with four discrete ligand-binding domains (LBDs) that may contain epitopes to which pathogenic autoantibodies are directed. Recently, a 236-residue N-terminal fragment, termed "L6," that spans the first LBD was shown to induce autoantibodies and severe disease. We used this model to examine epitope-specific contributions to pathogenesis. Sera obtained from rats 4 weeks after immunization with L6 demonstrated reactivity only with the L6 fragment on Western blot, whereas sera obtained after 8 weeks demonstrated reactivity with all four recombinant fragments of interest (L6 and LBDs II, III, and IV). We demonstrated that the L6 immunogen does not contain the epitopes responsible for the reactivity to the LBD fragments. Therefore, the appearance of antibodies directed at LBD fragments several weeks after the primary immune response suggests intramolecular epitope spreading. In vivo, we observed a temporal association between increased proteinuria and the appearance of antibodies to LBD fragments. These data implicate B cell epitope spreading in antibody-mediated pathogenesis of active Heymann nephritis, a model that should prove valuable for further study of autoimmune dysregulation.

  3. Principles of spread-spectrum communication systems

    CERN Document Server

    Torrieri, Don

    2015-01-01

    This book provides a concise but lucid explanation of the fundamentals of spread-spectrum systems with an emphasis on theoretical principles. The choice of specific topics is tempered by the author’s judgment of their practical significance and interest to both researchers and system designers. The book contains many improved derivations of the classical theory and presents the latest research results that bring the reader to the frontier of the field. This third edition includes new coverage of topics such as CDMA networks, acquisition and synchronization in DS-CDMA cellular networks, hopsets for FH-CDMA ad hoc networks, implications of information theory, the central limit theorem, the power spectral density of FH/CPM complex envelopes, adaptive filters, and adaptive arrays.   ·         Focuses on the fundamentals of spread-spectrum communication systems and provides current examples of their applications ·         Includes problem sets at the end of each chapter to assist readers in co...

  4. Asynchronous Rumor Spreading on Random Graphs

    CERN Document Server

    Panagiotou, Konstantinos

    2016-01-01

    We perform a thorough study of various characteristics of the asynchronous push-pull protocol for spreading a rumor on Erd\\H{o}s-R\\'enyi random graphs $G_{n,p}$, for any $p>c\\ln(n)/n$ with $c>1$. In particular, we provide a simple strategy for analyzing the asynchronous push-pull protocol on arbitrary graph topologies and apply this strategy to $G_{n,p}$. We prove tight bounds of logarithmic order for the total time that is needed until the information has spread to all nodes. Surprisingly, the time required by the asynchronous push-pull protocol is asymptotically almost unaffected by the average degree of the graph. Similarly tight bounds for Erd\\H{o}s-R\\'enyi random graphs have previously only been obtained for the synchronous push protocol, where it has been observed that the total running time increases significantly for sparse random graphs. Finally, we quantify the robustness of the protocol with respect to transmission and node failures. Our analysis suggests that the asynchronous protocols are particu...

  5. A lattice model for influenza spreading.

    Directory of Open Access Journals (Sweden)

    Antonella Liccardo

    Full Text Available We construct a stochastic SIR model for influenza spreading on a D-dimensional lattice, which represents the dynamic contact network of individuals. An age distributed population is placed on the lattice and moves on it. The displacement from a site to a nearest neighbor empty site, allows individuals to change the number and identities of their contacts. The dynamics on the lattice is governed by an attractive interaction between individuals belonging to the same age-class. The parameters, which regulate the pattern dynamics, are fixed fitting the data on the age-dependent daily contact numbers, furnished by the Polymod survey. A simple SIR transmission model with a nearest neighbors interaction and some very basic adaptive mobility restrictions complete the model. The model is validated against the age-distributed Italian epidemiological data for the influenza A(H1N1 during the [Formula: see text] season, with sensible predictions for the epidemiological parameters. For an appropriate topology of the lattice, we find that, whenever the accordance between the contact patterns of the model and the Polymod data is satisfactory, there is a good agreement between the numerical and the experimental epidemiological data. This result shows how rich is the information encoded in the average contact patterns of individuals, with respect to the analysis of the epidemic spreading of an infectious disease.

  6. Strong Robustness of Randomized Rumor Spreading Protocols

    CERN Document Server

    Doerr, Benjamin; Levavi, Ariel

    2010-01-01

    Randomized rumor spreading is a classical protocol to disseminate information across a network. At SODA 2008, a quasirandom version of this protocol was proposed and competitive bounds for its run-time were proven. This prompts the question: to what extent does the quasirandom protocol inherit the second principal advantage of randomized rumor spreading, namely robustness against transmission failures? In this paper, we present a result precise up to $(1 \\pm o(1))$ factors. We limit ourselves to the network in which every two vertices are connected by a direct link. Run-times accurate to their leading constants are unknown for all other non-trivial networks. We show that if each transmission reaches its destination with a probability of $p \\in (0,1]$, after $(1+\\e)(\\frac{1}{\\log_2(1+p)}\\log_2n+\\frac{1}{p}\\ln n)$ rounds the quasirandom protocol has informed all $n$ nodes in the network with probability at least $1-n^{-p\\e/40}$. Note that this is faster than the intuitively natural $1/p$ factor increase over th...

  7. SIS Epidemic Spreading with Heterogeneous Infection Rates

    CERN Document Server

    Qu, Bo

    2015-01-01

    In this work, we aim to understand the influence of the heterogeneity of infection rates on the Susceptible-Infected-Susceptible (SIS) epidemic spreading. Specifically, we keep the recovery rates the same for all nodes and study the influence of the moments of the independently identically distributed (i.i.d.) infection rates on the average fraction $y_\\infty$ of infected nodes in the meta-stable state, which indicates the severity of the overall infection. Motivated by real-world datasets, we consider the log-normal and gamma distributions for the infection rates and we design as well a symmetric distribution so that we have a systematic view of the influence of various distributions. By continuous-time simulations on several types of networks, theoretical proofs and physical interpretations, we conclude that: 1) the heterogeneity of infection rates on average retards the virus spread, and 2) a larger even-order moment of the infection rates leads to a smaller average fraction of infected nodes, but the odd-...

  8. Epidemics spreading in interconnected complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Institute of High Performance Computing, Agency for Science, Technology and Research (A-STAR), Singapore 138632 (Singapore); Xiao, G., E-mail: egxxiao@ntu.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2012-09-03

    We study epidemic spreading in two interconnected complex networks. It is found that in our model the epidemic threshold of the interconnected network is always lower than that in any of the two component networks. Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. Theoretical analysis and simulation results show that, generally speaking, the epidemic size is not significantly affected by the inter-network correlation. In interdependent networks which can be viewed as a special case of interconnected networks, however, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant. -- Highlights: ► We study epidemic spreading in two interconnected complex networks. ► The epidemic threshold is lower than that in any of the two networks. And Interconnection correlation has impacts on threshold and average outbreak size. ► Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. ► We demonstrated and proved that Interconnection correlation does not affect epidemic size significantly. ► In interdependent networks, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant.

  9. Modelling dengue epidemic spreading with human mobility

    Science.gov (United States)

    Barmak, D. H.; Dorso, C. O.; Otero, M.

    2016-04-01

    We explored the effect of human mobility on the spatio-temporal dynamics of Dengue with a stochastic model that takes into account the epidemiological dynamics of the infected mosquitoes and humans, with different mobility patterns of the human population. We observed that human mobility strongly affects the spread of infection by increasing the final size and by changing the morphology of the epidemic outbreaks. When the spreading of the disease is driven only by mosquito dispersal (flight), a main central focus expands diffusively. On the contrary, when human mobility is taken into account, multiple foci appear throughout the evolution of the outbreaks. These secondary foci generated throughout the outbreaks could be of little importance according to their mass or size compared with the largest main focus. However, the coalescence of these foci with the main one generates an effect, through which the latter develops a size greater than the one obtained in the case driven only by mosquito dispersal. This increase in growth rate due to human mobility and the coalescence of the foci are particularly relevant in temperate cities such as the city of Buenos Aires, since they give more possibilities to the outbreak to grow before the arrival of the low-temperature season. The findings of this work indicate that human mobility could be the main driving force in the dynamics of vector epidemics.

  10. Cultural Incubators and Spread of Innovation.

    Science.gov (United States)

    Crema, Enrico R; Lake, Mark W

    2015-07-01

    Several forms of social learning rely on the direct or indirect evaluation of the fitness of cultural traits. Here we argue, via a simple agent-based model, that payoff uncertainty, that is, the correlation between a trait and the signal used to evaluate its fitness, plays a pivotal role in the spread of beneficial innovation. More specifically, we examine how this correlation affects the evolutionary dynamics of different forms of social learning and how each form can generate divergent historical trajectories depending on the size of the sample pool. In particular, we demonstrate that social learning by copying the best model is particularly susceptible to a sampling effect caused by the interaction of payoff uncertainty, the number of models sampled (the sample pool), and the frequency with which a trait is present in the population. As a result, we identify circumstances in which smaller sample pools can act as "cultural incubators" that promote the spread of innovations, while more widespread sampling of the population actually retards the rate of cultural evolution.

  11. Wave-like spread of Ebola Zaire.

    Directory of Open Access Journals (Sweden)

    2005-11-01

    Full Text Available In the past decade the Zaire strain of Ebola virus (ZEBOV has emerged repeatedly into human populations in central Africa and caused massive die-offs of gorillas and chimpanzees. We tested the view that emergence events are independent and caused by ZEBOV variants that have been long resident at each locality. Phylogenetic analyses place the earliest known outbreak at Yambuku, Democratic Republic of Congo, very near to the root of the ZEBOV tree, suggesting that viruses causing all other known outbreaks evolved from a Yambuku-like virus after 1976. The tendency for earlier outbreaks to be directly ancestral to later outbreaks suggests that outbreaks are epidemiologically linked and may have occurred at the front of an advancing wave. While the ladder-like phylogenetic structure could also bear the signature of positive selection, our statistical power is too weak to reach a conclusion in this regard. Distances among outbreaks indicate a spread rate of about 50 km per year that remains consistent across spatial scales. Viral evolution is clocklike, and sequences show a high level of small-scale spatial structure. Genetic similarity decays with distance at roughly the same rate at all spatial scales. Our analyses suggest that ZEBOV has recently spread across the region rather than being long persistent at each outbreak locality. Controlling the impact of Ebola on wild apes and human populations may be more feasible than previously recognized.

  12. Urethral Cancer Treatment (PDQ®)—Patient Version

    Science.gov (United States)

    Urethral cancer occurs in men and women and can spread quickly to lymph nodes near the urethra. Find out about risk factors, symptoms, tests to diagnose, prognosis, staging, and treatment for urethral cancer.

  13. Quantification of cell edge velocities and traction forces reveals distinct motility modules during cell spreading.

    Directory of Open Access Journals (Sweden)

    Benjamin J Dubin-Thaler

    Full Text Available Actin-based cell motility and force generation are central to immune response, tissue development, and cancer metastasis, and understanding actin cytoskeleton regulation is a major goal of cell biologists. Cell spreading is a commonly used model system for motility experiments -- spreading fibroblasts exhibit stereotypic, spatially-isotropic edge dynamics during a reproducible sequence of functional phases: 1 During early spreading, cells form initial contacts with the surface. 2 The middle spreading phase exhibits rapidly increasing attachment area. 3 Late spreading is characterized by periodic contractions and stable adhesions formation. While differences in cytoskeletal regulation between phases are known, a global analysis of the spatial and temporal coordination of motility and force generation is missing. Implementing improved algorithms for analyzing edge dynamics over the entire cell periphery, we observed that a single domain of homogeneous cytoskeletal dynamics dominated each of the three phases of spreading. These domains exhibited a unique combination of biophysical and biochemical parameters -- a motility module. Biophysical characterization of the motility modules revealed that the early phase was dominated by periodic, rapid membrane blebbing; the middle phase exhibited continuous protrusion with very low traction force generation; and the late phase was characterized by global periodic contractions and high force generation. Biochemically, each motility module exhibited a different distribution of the actin-related protein VASP, while inhibition of actin polymerization revealed different dependencies on barbed-end polymerization. In addition, our whole-cell analysis revealed that many cells exhibited heterogeneous combinations of motility modules in neighboring regions of the cell edge. Together, these observations support a model of motility in which regions of the cell edge exhibit one of a limited number of motility modules

  14. Resource Allocation with Adaptive Spread Spectrum OFDM Using 2D Spreading for Power Line Communications

    Directory of Open Access Journals (Sweden)

    Baudais Jean-Yves

    2007-01-01

    Full Text Available Bit-loading techniques based on orthogonal frequency division mutiplexing (OFDM are frequently used over wireline channels. In the power line context, channel state information can reasonably be obtained at both transmitter and receiver sides, and adaptive loading can advantageously be carried out. In this paper, we propose to apply loading principles to an spread spectrum OFDM (SS-OFDM waveform which is a multicarrier system using 2D spreading in the time and frequency domains. The presented algorithm handles the subcarriers, spreading codes, bits and energies assignment in order to maximize the data rate and the range of the communication system. The optimization is realized at a target symbol error rate and under spectral mask constraint as usually imposed. The analytical study shows that the merging principle realized by the spreading code improves the rate and the range of the discrete multitone (DMT system in single and multiuser contexts. Simulations have been run over measured power line communication (PLC channel responses and highlight that the proposed system is all the more interesting than the received signal-to-noise ratio (SNR is low.

  15. Non-aqueous phase liquid spreading during soil vapor extraction

    Science.gov (United States)

    Kneafsey, Timothy J.; Hunt, James R.

    2004-02-01

    Many non-aqueous phase liquids (NAPLs) are expected to spread at the air-water interface, particularly under non-equilibrium conditions. In the vadose zone, this spreading should increase the surface area for mass transfer and the efficiency of volatile NAPL recovery by soil vapor extraction (SVE). Observations of spreading on water wet surfaces led to a conceptual model of oil spreading vertically above a NAPL pool in the vadose zone. Analysis of this model predicts that spreading can enhance the SVE contaminant recovery compared to conditions where the liquid does not spread. Experiments were conducted with spreading volatile oils hexane and heptane in wet porous media and capillary tubes, where spreading was observed at the scale of centimeters. Within porous medium columns up to a meter in height containing stagnant gas, spreading was less than ten centimeters and did not contribute significantly to hexane volatilization. Water film thinning and oil film pinning may have prevented significant oil film spreading, and thus did not enhance SVE at the scale of a meter. The experiments performed indicate that volatile oil spreading at the field scale is unlikely to contribute significantly to the efficiency of SVE.

  16. Mutual Feedback Between Epidemic Spreading and Information Diffusion

    CERN Document Server

    Zhan, Xiu-Xiu; Zhou, Ge; Zhang, Zi-Ke; Sun, Gui-Quan; Zhu, Jonathan J H

    2015-01-01

    The impact that information diffusion has on epidemic spreading has recently attracted much attention. As a disease begins to spread in the population, information about the disease is transmitted to others, which in turn has an effect on the spread of disease. In this paper, using empirical results of the propagation of H7N9 and information about the disease, we clearly show that the spreading dynamics of the two-types of processes influence each other. We build a mathematical model in which both types of spreading dynamics are described using the SIS process in order to illustrate the influence of information diffusion on epidemic spreading. Both the simulation results and the pairwise analysis reveal that information diffusion can increase the threshold of an epidemic outbreak, decrease the final fraction of infected individuals and significantly decrease the rate at which the epidemic propagates. Additionally, we find that the multi-outbreak phenomena of epidemic spreading, along with the impact of inform...

  17. Topology dependent epidemic spreading velocity in weighted networks

    Science.gov (United States)

    Duan, Wei; Quax, Rick; Lees, Michael; Qiu, Xiaogang; Sloot, Peter M. A.

    2014-12-01

    Many diffusive processes occur on structured networks with weighted links, such as disease spread by airplane transport or information diffusion in social networks or blogs. Understanding the impact of weight-connectivity correlations on epidemic spreading in weighted networks is crucial to support decision-making on disease control and other diffusive processes. However, a real understanding of epidemic spreading velocity in weighted networks is still lacking. Here we conduct a numerical study of the velocity of a Reed-Frost epidemic spreading process in various weighted network topologies as a function of the correlations between edge weights and node degrees. We find that a positive weight-connectivity correlation leads to a faster epidemic spreading compared to an unweighted network. In contrast, we find that both uncorrelated and negatively correlated weight distributions lead to slower spreading processes. In the case of positive weight-connectivity correlations, the acceleration of spreading velocity is weak when the heterogeneity of weight distribution increases.

  18. FACTORS INFLUENCING YIELD SPREADS OF THE MALAYSIAN BONDS

    Directory of Open Access Journals (Sweden)

    Norliza Ahmad

    2009-01-01

    Full Text Available Malaysian bond market is developing rapidly but not much is understood in terms of macroeconomic factors that could influence the yield spread of the Ringgit Malaysian denominated bonds. Based on a multifactor model, this paper examines the impact of four macroeconomic factors namely: Kuala Lumpur Composite Index (KLCI, Industry Production Index (IPI, Consumer Price Index (CPI and interest rates (IR on bond yield spread of the Malaysian Government Securities (MGS and Corporate Bonds (CBs for a period from January 2001 to December 2008. The findings support the expected hypotheses that CPI and IR are the major drivers that influence the changes in MGS yield spreads. However IPI and KLCI have weak and no influence on MGS yield spreads respectively Whilst IR, CPI and IPI have significant influence on the yield spreads of CB1, CB2 and CB3, KLCI has significant influence only on the CB1 yield spread but not on CB2 and CB3 yield spreads.

  19. DETERMINANTS OF INTEREST RATE SPREAD IN BANKING INDUSTRY

    Directory of Open Access Journals (Sweden)

    Arezoo GHASEMI

    2016-02-01

    Full Text Available This study is done to consider affecting factors on spread rate and define a suitable model of spread rate in banking industry. Spread rate is a difference between two related interest rates. In banking industry, spread rate is the difference between debts rate (especially for deposit and assets rate (Especially for loan. Interest rate spread has always been one of the most important and significant economic issues in different countries of the world. In this study, affecting factors on spread rate are considering in an Iranian bank during the last 19 month. Some variables such as NPL ratio, ratio of demand deposits on deposits, non interest income, and interest assets to assets, capital adequacy ratio, ROA ratio and inflation and exchange rate are analyzed on spread rate and a model is defined for bank according to prior studies and economical issues of Iran.  

  20. Effective information spreading based on local information in correlated networks

    Science.gov (United States)

    Gao, Lei; Wang, Wei; Pan, Liming; Tang, Ming; Zhang, Hai-Feng

    2016-12-01

    Using network-based information to facilitate information spreading is an essential task for spreading dynamics in complex networks. Focusing on degree correlated networks, we propose a preferential contact strategy based on the local network structure and local informed density to promote the information spreading. During the spreading process, an informed node will preferentially select a contact target among its neighbors, basing on their degrees or local informed densities. By extensively implementing numerical simulations in synthetic and empirical networks, we find that when only consider the local structure information, the convergence time of information spreading will be remarkably reduced if low-degree neighbors are favored as contact targets. Meanwhile, the minimum convergence time depends non-monotonically on degree-degree correlation, and a moderate correlation coefficient results in the most efficient information spreading. Incorporating the local informed density information into contact strategy, the convergence time of information spreading can be further reduced, and be minimized by an moderately preferential selection.

  1. Spreading of cooperative behaviour across interdependent groups

    CERN Document Server

    Jiang, Luo-Luo

    2013-01-01

    Recent empirical research has shown that links between groups reinforce individuals within groups to adopt cooperative behaviour. Moreover, links between networks may induce cascading failures, competitive percolation, or contribute to efficient transportation. Here we show that there in fact exists an intermediate fraction of links between groups that is optimal for the evolution of cooperation in the prisoner's dilemma game. We consider individual groups with regular, random, and scale-free topology, and study their different combinations to reveal that an intermediate interdependence optimally facilitates the spreading of cooperative behaviour between groups. Excessive between-group links simply unify the two groups and make them act as one, while too rare between-group links preclude a useful information flow between the two groups. Interestingly, we find that between-group links are more likely to connect two cooperators than in-group links, thus supporting the conclusion that they are of paramount impor...

  2. Emergence and spreading potential of Zika virus

    Directory of Open Access Journals (Sweden)

    Alvaro Fajardo

    2016-10-01

    Full Text Available Zika virus (ZIKV is an arthropod-borne Flavivirus (family Flaviviridae closely related to dengue, yellow fever and West Nile viruses. ZIKV remained neglected, confined to enzootic transmission cycles in Africa and Asia, until the first significant outbreak was reported in Micronesia in 2007. Subsequent epidemics of growing incidence occurred in French Polynesia and other South Pacific Islands, and recently, in the Americas. The latter and currently ongoing outbreak of unprecedented incidence revealed the association of ZIKV infection with the occurrence of severe congenital malformations and neurological diseases, leading to a widespread concern about its potential to pose a global public health threat. Serological and molecular data suggest that the genetic and geographic diversification of ZIKV may be greatly underestimated. Here we discuss several ecological and epidemiological aspects, together with the evolutionary processes that may have driven the emergence and abrupt spread of ZIKV in the Americas.

  3. Avian Influenza spread and transmission dynamics

    Science.gov (United States)

    Bourouiba, Lydia; Gourley, Stephen A.; Liu, Rongsong; Takekawa, John Y.; Wu, Jianhong; Chen, Dongmei; Moulin, Bernard; Wu, Jianhong

    2015-01-01

    The spread of highly pathogenic avian influenza (HPAI) viruses of type A of subtype H5N1 has been a serious threat to global public health. Understanding the roles of various (migratory, wild, poultry) bird species in the transmission of these viruses is critical for designing and implementing effective control and intervention measures. Developing appropriate models and mathematical techniques to understand these roles and to evaluate the effectiveness of mitigation strategies have been a challenge. Recent development of the global health surveillance (especially satellite tracking and GIS techniques) and the mathematical theory of dynamical systems combined have gradually shown the promise of some cutting-edge methodologies and techniques in mathematical biology to meet this challenge.

  4. Spread of Misinformation in Social Networks

    CERN Document Server

    Acemoglu, Daron; ParandehGheibi, Ali

    2009-01-01

    We provide a model to investigate the tension between information aggregation and spread of misinformation in large societies (conceptualized as networks of agents communicating with each other). Each individual holds a belief represented by a scalar. Individuals meet pairwise and exchange information, which is modeled as both individuals adopting the average of their pre-meeting beliefs. When all individuals engage in this type of information exchange, the society will be able to effectively aggregate the initial information held by all individuals. There is also the possibility of misinformation, however, because some of the individuals are "forceful," meaning that they influence the beliefs of (some) of the other individuals they meet, but do not change their own opinion. The paper characterizes how the presence of forceful agents interferes with information aggregation. Under the assumption that even forceful agents obtain some information (however infrequent) from some others (and additional weak regular...

  5. Spreading of Persistent Infections in Heterogeneous Populations

    CERN Document Server

    Sanz, J; Moreno, Y

    2010-01-01

    Up to now, the effects of having heterogeneous networks of contacts have been studied mostly for diseases which are not persistent in time, i.e., for diseases where the infectious period can be considered very small compared to the lifetime of an individual. Moreover, all these previous results have been obtained for closed populations, where the number of individuals does not change during the whole duration of the epidemics. Here, we go one step further and analyze, both analytically and numerically, a radically different kind of diseases: those that are persistent and can last for an individual's lifetime. To be more specific, we particularize to the case of Tuberculosis' (TB) infection dynamics, where the infection remains latent for a period of time before showing up and spreading to other individuals. We introduce an epidemiological model for TB-like persistent infections taking into account the heterogeneity inherent to the population structure. This sort of dynamics introduces new analytical and numer...

  6. Global Spread of Carbapenemase-producing Enterobacteriaceae

    Science.gov (United States)

    Naas, Thierry; Poirel, Laurent

    2011-01-01

    Carbapenemases increasingly have been reported in Enterobacteriaceae in the past 10 years. Klebsiella pneumoniae carbapenemases have been reported in the United States and then worldwide, with a marked endemicity at least in the United States and Greece. Metallo-enzymes (Verona integron–encoded metallo-β-lactamase, IMP) also have been reported worldwide, with a higher prevalence in southern Europe and Asia. Carbapenemases of the oxacillinase-48 type have been identified mostly in Mediterranean and European countries and in India. Recent identification of New Delhi metallo-β-lactamase-1 producers, originally in the United Kingdom, India, and Pakistan and now worldwide, is worrisome. Detection of infected patients and carriers with carbapenemase producers is necessary for prevention of their spread. Identification of the carbapenemase genes relies mostly on molecular techniques, whereas detection of carriers is possible by using screening culture media. This strategy may help prevent development of nosocomial outbreaks caused by carbapenemase producers, particularly K. pneumoniae. PMID:22000347

  7. Initial Distribution Spread: A density forecasting approach

    CERN Document Server

    Machete, Reason L

    2012-01-01

    Ensemble forecasting of nonlinear systems involves the use of a model to run forward a discrete ensemble (or set) of initial states. Data assimilation techniques tend to focus on estimating the true state of the system, even though model error limits the value of such efforts. This paper argues for choosing the initial ensemble in order to optimise forecasting performance rather than estimate the true state of the system. Density forecasting and choosing the initial ensemble are treated as one problem. Forecasting performance can be quantified by some scoring rule. In the case of the logarithmic scoring rule, theoretical arguments and empirical results are presented. It turns out that, if the underlying noise dominates model error, we can diagnose the noise spread.

  8. Density enhancements associated with equatorial spread F

    Directory of Open Access Journals (Sweden)

    G. Joyce

    2010-02-01

    Full Text Available Forces governing the three-dimensional structure of equatorial spread-F (ESF plumes are examined using the NRL SAMI3/ESF three-dimensional simulation code. As is the case with the equatorial ionization anomaly (IA, density crests within the plume occur where gravitational and diffusive forces are in balance. Large E×B drifts within the ESF plume place these crests on field lines with apex heights higher than those of the background IA crests. Large poleward field-aligned ion velocities within the plume result in large ion-neutral diffusive forces that support these ionization crests at altitudes higher than background IA crest altitudes. We show examples in which density enhancements associated with ESF, also called "plasma blobs," can occur within an ESF plume on density-crest field lines, at or above the density crests. Simulated ESF density enhancements reproduce all key features of those that have been observed in situ.

  9. Trigeminal perineural spread of renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Hornik, Alejandro; Rosenblum, Jordan; Biller, Jose [Stritch School of Medicine, Loyola University Medical Center, Chicago (United States)

    2012-07-01

    A 55-year-old man had a five-day history of 'pins and needles' sensation on the left chin. Examination showed decreased pinprick sensation on the territory of the left mandibular branch of the trigeminal nerve. Brain magnetic resonance imaging (MRI) with gadolinium showed enhancement involving the left mandibular branch. Computed tomography (CT) of the chest, abdomen, and pelvis showed a left kidney mass diagnosed as renal carcinoma following nephrectomy. The 'numb-chin' syndrome heralds or accompanies systemic malignancies. Trigeminal perineural spread has been well-documented in head and neck neoplasms, however, to our knowledge, it has not been reported in renal neoplasms. (author)

  10. Emergence and Spreading Potential of Zika Virus

    Science.gov (United States)

    Fajardo, Álvaro; Cristina, Juan; Moreno, Pilar

    2016-01-01

    Zika virus (ZIKV) is an arthropod-borne Flavivirus (family Flaviviridae) closely related to dengue, yellow fever and West Nile viruses. ZIKV remained neglected, confined to enzootic transmission cycles in Africa and Asia, until the first significant outbreak was reported in Micronesia in 2007. Subsequent epidemics of growing incidence occurred in French Polynesia and other South Pacific Islands, and recently, in the Americas. The latter and currently ongoing outbreak of unprecedented incidence revealed the association of ZIKV infection with the occurrence of severe congenital malformations and neurological diseases, leading to a widespread concern about its potential to pose a global public health threat. Serological and molecular data suggest that the genetic and geographic diversification of ZIKV may be greatly underestimated. Here we discuss several ecological and epidemiological aspects, together with the evolutionary processes that may have driven the emergence and abrupt spread of ZIKV in the Americas. PMID:27812357

  11. Wolbachia spread dynamics in stochastic environments.

    Science.gov (United States)

    Hu, Linchao; Huang, Mugen; Tang, Moxun; Yu, Jianshe; Zheng, Bo

    2015-12-01

    Dengue fever is a mosquito-borne viral disease with 100 million people infected annually. A novel strategy for dengue control uses the bacterium Wolbachia to invade dengue vector Aedes mosquitoes. As the impact of environmental heterogeneity on Wolbachia spread dynamics in natural areas has been rarely quantified, we develop a model of differential equations for which the environmental conditions switch randomly between two regimes. We find some striking phenomena that random regime transitions could drive Wolbachia to extinction from certain initial states confirmed Wolbachia fixation in homogeneous environments, and mosquito releasing facilitates Wolbachia invasion more effectively when the regimes transit frequently. By superimposing the phase spaces of the ODE systems defined in each regime, we identify the threshold curves below which Wolbachia invades the whole population, which extends the theory of threshold infection frequency to stochastic environments.

  12. Quantifier spreading: children misled by ostensive cues

    Directory of Open Access Journals (Sweden)

    Katalin É. Kiss

    2017-04-01

    Full Text Available This paper calls attention to a methodological problem of acquisition experiments. It shows that the economy of the stimulus employed in child language experiments may lend an increased ostensive effect to the message communicated to the child. Thus, when the visual stimulus in a sentence-picture matching task is a minimal model abstracting away from the details of the situation, children often regard all the elements of the stimulus as ostensive clues to be represented in the corresponding sentence. The use of such minimal stimuli is mistaken when the experiment aims to test whether or not a certain element of the stimulus is relevant for the linguistic representation or interpretation. The paper illustrates this point by an experiment involving quantifier spreading. It is claimed that children find a universally quantified sentence like 'Every girl is riding a bicycle 'to be a false description of a picture showing three girls riding bicycles and a solo bicycle because they are misled to believe that all the elements in the visual stimulus are relevant, hence all of them are to be represented by the corresponding linguistic description. When the iconic drawings were replaced by photos taken in a natural environment rich in accidental details, the occurrence of quantifier spreading was radically reduced. It is shown that an extra object in the visual stimulus can lead to the rejection of the sentence also in the case of sentences involving no quantification, which gives further support to the claim that the source of the problem is not (or not only the grammatical or cognitive difficulty of quantification but the unintended ostensive effect of the extra object.  This article is part of the special collection: Acquisition of Quantification

  13. Smallpox: emergence, global spread, and eradication.

    Science.gov (United States)

    Fenner, F

    1993-01-01

    Speculatively, it is suggested that variola virus, the cause of smallpox, evolved from an orthopoxvirus of animals of the central African rain forests (possibly now represented by Tatera poxvirus), some thousands of years ago, and first became established as a virus specific for human beings in the dense populations of the Nile valley perhaps five thousand years ago. By the end of the first millennium of the Christian era, it had spread to all the densely populated parts of the Eurasian continent and along the Mediterranean fringe of north Africa. It became established in Europe during the times of the Crusades. The great voyages of European colonization carried smallpox to the Americas and to Africa south of the Sahara. Transported across the Atlantic by Europeans and their African slaves, it played a major role in the conquest of Mexico and Peru and the European settlement of north America. Variolation, an effective preventive inoculation, was devised as early as the tenth century. In 1798 this practice was supplanted by Jenner's cowpox vaccine. In 1967, when the disease was still endemic in 31 countries and caused ten to fifteen million cases and about two million deaths annually, the World Health Organization embarked on a programme that was to see the disease eradicated globally just over ten years later, and the world was formally declared to be free of smallpox in May 1980. Smallpox is unique--a specifically human disease that emerged from some animal reservoir, spread to become a worldwide, severe and almost universal affliction, and finally underwent the reverse process to emergence, namely global eradication.

  14. Locating the source of diffusion in complex networks by time-reversal backward spreading

    Science.gov (United States)

    Shen, Zhesi; Cao, Shinan; Wang, Wen-Xu; Di, Zengru; Stanley, H. Eugene

    2016-03-01

    Locating the source that triggers a dynamical process is a fundamental but challenging problem in complex networks, ranging from epidemic spreading in society and on the Internet to cancer metastasis in the human body. An accurate localization of the source is inherently limited by our ability to simultaneously access the information of all nodes in a large-scale complex network. This thus raises two critical questions: how do we locate the source from incomplete information and can we achieve full localization of sources at any possible location from a given set of observable nodes. Here we develop a time-reversal backward spreading algorithm to locate the source of a diffusion-like process efficiently and propose a general locatability condition. We test the algorithm by employing epidemic spreading and consensus dynamics as typical dynamical processes and apply it to the H1N1 pandemic in China. We find that the sources can be precisely located in arbitrary networks insofar as the locatability condition is assured. Our tools greatly improve our ability to locate the source of diffusion in complex networks based on limited accessibility of nodal information. Moreover, they have implications for controlling a variety of dynamical processes taking place on complex networks, such as inhibiting epidemics, slowing the spread of rumors, pollution control, and environmental protection.

  15. Symmetrical ethmoidal metastases from ductal carcinoma of the breast, suggesting transcribrosal spread.

    Science.gov (United States)

    Monserez, D; Vlaminck, S; Kuhweide, R; Casselman, J

    2001-01-01

    Symmetrical ethmoidal metastases from ductal carcinoma of the breast, suggesting transcribrosal spread. While half of breast cancers develop metastases, the appearance of metastatic disease in paranasal sinuses from this origin is very rare. Eighteen other cases were found in the literature, dating from 1939 till now. A case of metastatic breastcancer presenting as a subacute therapy-resistant pansinusitis is described. The perfect symmetry was misleading. Bilateral ethmoidal biopsies were compatible with metastases from a ductal adenocarcinoma. Further investigation revealed meningeal carcinomatosis in the supra-orbital region and locoregional recurrence in the mastectomy scar and axilla. Comparing these 19 cases in chronological order, it was noticed that symptoms at time of diagnosis shift from those of space occupying lesions to those suggestive for sinusitis. This shift could be explained by earlier diagnosis. High index of suspicion is the key to diagnosis. Earlier diagnosis does not result in longer survival since in most cases patients have already widespread disease and die within one year. Most authors mention the role of the vertebral venous plexus in hematogeneous spreading of tumor cells. Another pathway of hematogenous spread is via (occult) lung metastases. This case prompts the hypothesis of transcribrosal spread from meningeal involvement.

  16. Direct Liver Invasion from a Gastric Adenocarcinoma as an Initial Presentation of Extranodal Tumor Spread

    Directory of Open Access Journals (Sweden)

    Mitanshu Shah

    2012-01-01

    Full Text Available Gastric cancer often carries a poor prognosis, with an estimated 740,000 deaths from the malignancy occurring yearly worldwide (Dicken et al., 2005. The mortality of disease is largely dependent on the extent of tumor spread, as gastric cancer has a predilection to metastasize to other visceral secondaries via hematogenous and lymphatic dissemination. Direct invasion of a gastric adenocarcinoma to adjacent organs secondary to gastric wall perforation does occur; however, it is often present in the setting of advanced disease. Rarely does direct tumor invasion to adjacent organs from a gastric adenocarcinoma present as the initial manifestation of extranodal tumor spread. We present a case of a 40-year-old male with direct tumor extension to the liver as an initial presentation of extranodal tumor spread from a gastric adenocarcinoma. Clinicians should be aware of such an occurrence, as treatment modalities in direct liver extension from a gastric adenocarcinoma vary and may be directed towards palliation rather than curative intent.

  17. PRLs Promote Spreading, Adhesion, and Proliferation of Human SW480 and SW620 Cells

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Recent studies suggest that PRL-3 is involved in the metastasis of colorectal cancer, but the mechanism concerning that has not been well defined. This article expresses PRL-1, PRL-2, and PRL-3 and the catalytically inactive mutant forms of those enzymes in SW620 and SW480 cells, two human cell lines derived from non-metastatic cancer and metastatic colorectal cancer, respectively. While the expression of the native forms of PRLs promotes the spreading, adhesion, and proliferation of these cells, the expression of their mutant forms inhibits the earlier-mentioned processes. These data thus provide a cellular mechanism for the role of PRL-3 in tumor metastasis and suggest that all the three PRLs have similar functions.

  18. Practical aspects of cervical cancer

    NARCIS (Netherlands)

    Tillaart, Sabrina Ada Hendrika Maria van den

    2013-01-01

    The thesis describes studies on practical aspects of cervical cancer, concering surgical considerations, and aspects of tumour behaviour and tumour spread. The thesis comprises studies on: the comparison of nerve-sparing and non-nerve-sparing radical hysterectomy for cervical cancer; a new surgical

  19. Toe spreading ability in men with chronic pelvic pain syndrome

    Science.gov (United States)

    Yilmaz, Ugur; Rothman, Ivan; Ciol, Marcia A; Yang, Claire C; Berger, Richard E

    2005-01-01

    Background We examined toe-spreading ability in subjects with chronic pelvic pain syndrome (CPPS) to test the hypothesis that subjects with CPPS could have deficiencies in lower extremity functions innervated by sacral spinal roots. Methods Seventy two subjects with CPPS and 98 volunteer controls were examined as part of a larger study on CPPS. All the subjects underwent a detailed urologic and neurological examination including a toe-spreading examination with a quantitative scoring system. We compared the groups in terms of ability of toe-spreading as either "complete" (all toes spreading) or "incomplete" (at least one interdigital space not spreading) and also by comparing the number of interdigital spaces. For CPPS subjects only, we also analyzed the variation of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) scales by toe-spreading categories. Results CPPS subjects were less often able to spread all toes than subjects without CPPS (p = 0.005). None of the NIH-CPSI sub-scales (pain, urinary symptoms, and quality of life), nor the total score showed an association with toe spreading ability. Conclusion We found toe spreading to be diminished in subjects with CPPS. We hypothesize that incomplete toe spreading in subjects with CPPS may be related to subtle deficits involving the most caudal part of the spinal segments. PMID:15949041

  20. Toe spreading ability in men with chronic pelvic pain syndrome

    Directory of Open Access Journals (Sweden)

    Yang Claire C

    2005-06-01

    Full Text Available Abstract Background We examined toe-spreading ability in subjects with chronic pelvic pain syndrome (CPPS to test the hypothesis that subjects with CPPS could have deficiencies in lower extremity functions innervated by sacral spinal roots. Methods Seventy two subjects with CPPS and 98 volunteer controls were examined as part of a larger study on CPPS. All the subjects underwent a detailed urologic and neurological examination including a toe-spreading examination with a quantitative scoring system. We compared the groups in terms of ability of toe-spreading as either "complete" (all toes spreading or "incomplete" (at least one interdigital space not spreading and also by comparing the number of interdigital spaces. For CPPS subjects only, we also analyzed the variation of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI scales by toe-spreading categories. Results CPPS subjects were less often able to spread all toes than subjects without CPPS (p = 0.005. None of the NIH-CPSI sub-scales (pain, urinary symptoms, and quality of life, nor the total score showed an association with toe spreading ability. Conclusion We found toe spreading to be diminished in subjects with CPPS. We hypothesize that incomplete toe spreading in subjects with CPPS may be related to subtle deficits involving the most caudal part of the spinal segments.

  1. Asymmetrically interacting spreading dynamics on complex layered networks

    CERN Document Server

    Wang, Wei; Yang, Hui; Do, Younghae; Lai, Ying-Cheng; Lee, GyuWon

    2014-01-01

    The spread of disease through a physical-contact network and the spread of information about the disease on a communication network are two intimately related dynamical processes. We investigate the asymmetrical interplay between the two types of spreading dynamics, each occurring on its own layer, by focusing on the two fundamental quantities underlying any spreading process: epidemic threshold and the final infection ratio. We find that an epidemic outbreak on the contact layer can induce an outbreak on the communication layer, and information spreading can effectively raise the epidemic threshold. When structural correlation exists between the two layers, the information threshold remains unchanged but the epidemic threshold can be enhanced, making the contact layer more resilient to epidemic outbreak. We develop a physical theory to understand the intricate interplay between the two types of spreading dynamics.

  2. Asymmetrically interacting spreading dynamics on complex layered networks

    Science.gov (United States)

    Wang, Wei; Tang, Ming; Yang, Hui; Younghae Do; Lai, Ying-Cheng; Lee, Gyuwon

    2014-05-01

    The spread of disease through a physical-contact network and the spread of information about the disease on a communication network are two intimately related dynamical processes. We investigate the asymmetrical interplay between the two types of spreading dynamics, each occurring on its own layer, by focusing on the two fundamental quantities underlying any spreading process: epidemic threshold and the final infection ratio. We find that an epidemic outbreak on the contact layer can induce an outbreak on the communication layer, and information spreading can effectively raise the epidemic threshold. When structural correlation exists between the two layers, the information threshold remains unchanged but the epidemic threshold can be enhanced, making the contact layer more resilient to epidemic outbreak. We develop a physical theory to understand the intricate interplay between the two types of spreading dynamics.

  3. Fire Spread Model for Old Towns Based on Cellular Automaton

    Institute of Scientific and Technical Information of China (English)

    GAO Nan; WENG Wenguo; MA Wei; NI Shunjiang; HUANG Quanyi; YUAN Hongyong

    2008-01-01

    Old towns like Lijiang have enormous historic,artistic,and architectural value.The buildings in such old towns are usually made of highly combustible materials,such as wood and grass.If a fire breaks out,it will spread to multiple buildings,so fire spreading and controlling in old towns need to be studied.This paper presents a fire spread model for old towns based on cellular automaton.The cellular automaton rules were set according to historical fire data in empirical formulas.The model also considered the effects of climate.The simulation results were visualized in a geography information system.An example of a fire spread in Lijiang was investigated with the results showing that this model provides a realistic tool for predicting fire spread in old towns.Fire brigades can use this tool to predict when and how a fire spreads to minimize the losses.

  4. Minimizing Energy Spread In The REX/HIE-ISOLDE Linac

    CERN Document Server

    Yucemoz, Mert

    2017-01-01

    This report tries to minimize the energy spread of the beam at the end of the REX-HIE-ISOLDE Linac using the last RF cavity as a buncher. Beams with very low energy spread are often required by the users of the facility In addition, one of the main reason to have minimum energy spread in longitudinal phase space is that higher beam energy spread translates in to a position spread after interacting with target. This causes an overlap in the position of different particles that makes it difficult to distinguish them. Hence, in order to find the operation settings for minimum energy spread at the end of the REX-HIE-ISOLDE linac and to inspect the ongoing physics, several functions on Matlab were created that runs beam dynamics program called “TRACKV39” that provides some graphs and values as a result for analysis.

  5. Suppressing disease spreading by using information diffusion on multiplex networks

    CERN Document Server

    Wang, Wei; Cai, Shi-Min; Tang, Ming; Braunstein, Lidia A; Stanley, H Eugene

    2016-01-01

    Although there is always an interplay between the dynamics of information diffusion and disease spreading, the empirical research on the systemic coevolution mechanisms connecting these two spreading dynamics is still lacking. Here we investigate the coevolution mechanisms and dynamics between information and disease spreading by utilizing real data and a proposed model on multiplex network. Our empirical analysis finds asymmetrical interactions between the information and disease spreading dynamics. Our results obtained from both the theoretical framework and intensive stochastic numerical simulations suggest that an information outbreak can be triggered on a communication network by its own spreading dynamics or the disease outbreak on a contact network, but that the disease threshold is not affected by information spreading. Our key finding is that there is an optimal information transmission rate that markedly suppresses the disease speading. We find that the time evolution of the dynamics in the proposed...

  6. Unification of theoretical approaches for epidemic spreading on complex networks

    Science.gov (United States)

    Wang, Wei; Tang, Ming; Stanley, H. Eugene; Braunstein, Lidia A.

    2017-03-01

    Models of epidemic spreading on complex networks have attracted great attention among researchers in physics, mathematics, and epidemiology due to their success in predicting and controlling scenarios of epidemic spreading in real-world scenarios. To understand the interplay between epidemic spreading and the topology of a contact network, several outstanding theoretical approaches have been developed. An accurate theoretical approach describing the spreading dynamics must take both the network topology and dynamical correlations into consideration at the expense of increasing the complexity of the equations. In this short survey we unify the most widely used theoretical approaches for epidemic spreading on complex networks in terms of increasing complexity, including the mean-field, the heterogeneous mean-field, the quench mean-field, dynamical message-passing, link percolation, and pairwise approximation. We build connections among these approaches to provide new insights into developing an accurate theoretical approach to spreading dynamics on complex networks.

  7. B cell epitope spreading: mechanisms and contribution to autoimmune diseases.

    Science.gov (United States)

    Cornaby, Caleb; Gibbons, Lauren; Mayhew, Vera; Sloan, Chad S; Welling, Andrew; Poole, Brian D

    2015-01-01

    While a variety of factors act to trigger or initiate autoimmune diseases, the process of epitope spreading is an important contributor in their development. Epitope spreading is a diversification of the epitopes recognized by the immune system. This process happens to both T and B cells, with this review focusing on B cells. Such spreading can progress among multiple epitopes on a single antigen, or from one antigenic molecule to another. Systemic lupus erythematosus, multiple sclerosis, pemphigus, bullous pemphigoid and other autoimmune diseases, are all influenced by intermolecular and intramolecular B cell epitope spreading. Endocytic processing, antigen presentation, and somatic hypermutation act as molecular mechanisms that assist in driving epitope spreading and broadening the immune response in autoimmune diseases. The purpose of this review is to summarize our current understanding of B cell epitope spreading with regard to autoimmunity, how it contributes during the progression of various autoimmune diseases, and treatment options available.

  8. Dynamic properties of epidemic spreading on finite size complex networks

    Institute of Scientific and Technical Information of China (English)

    Li Ying; Liu Yang; Shan Xiu-Ming; Ren Yong; Jiao Jian; Qiu Ben

    2005-01-01

    The Internet presents a complex topological structure, on which computer viruses can easily spread. By using theoretical analysis and computer simulation methods, the dynamic process of disease spreading on finite size networks with complex topological structure is investigated. On the finite size networks, the spreading process of SIS (susceptibleinfected-susceptible) model is a finite Markov chain with an absorbing state. Two parameters, the survival probability and the conditional infecting probability, are introduced to describe the dynamic properties of disease spreading on finite size networks. Our results can help understanding computer virus epidemics and other spreading phenomena on communication and social networks. Also, knowledge about the dynamic character of virus spreading is helpful for adopting immunity policy.

  9. On the spreading of impacting drops

    CERN Document Server

    Wildeman, Sander; Sun, Chao; Lohse, Detlef

    2016-01-01

    The energy budget and dissipation mechanisms during droplet impact on solid surfaces are studied numerically and theoretically. We find that for high impact velocities and negligible surface friction, about one half of the initial kinetic energy is transformed into surface energy, independent of the impact parameters and the detailed energy loss mechanism(s). We argue that this seemingly universal rule is related to the deformation mode of the droplet and is reminiscent of pipe flow undergoing a sudden expansion, for which the head loss can be calculated by multiplying the kinetic energy of the incoming flow by a geometrical factor. For impacts on a no-slip surface also dissipation in the shear boundary layer at the solid surface is important. In this case the head loss acts as a lower bound on the total dissipation for small viscosities. This new view on the impact problem allows for simple analytical estimates of the maximum spreading diameter of impacting drops as a function of the impact parameters and th...

  10. Is heartworm disease really spreading in Europe?

    Science.gov (United States)

    Genchi, Claudio; Rinaldi, L; Cascone, C; Mortarino, M; Cringoli, G

    2005-10-24

    Based on recently published surveys and newly acquired data, a study was conducted to verify the distribution of filarial worm (Filarioidea) infections in Europe, with particular emphasis on canine heartworm infection (Dirofilaria immitis). A Geographic Information System based on thermal regimen was constructed as a means to identify areas potentially suitable for heartworm transmission, taking into account that the development of D. immitis larvae in the mosquito does not occur below the threshold temperature of approximately 14 degrees C. Furthermore, a bionomic model of D. immitis in its mosquito vectors, which calculates the moving cumulative heartworm development unit parameter, was applied using the available temperature data to assess the theoretic transmission timing of heartworm in Europe. The results show that the earliest infection risk occurs in Spain on March 21 and the latest risk occurs in Spain on September 11. The longest risk period occurs in Spain (Murcia station: March 21-November 11), and the shortest risk period occurs in northeastern Europe. The study also provides the first risk assessment maps for Europe and suggests that if the actual climatic trend continues, filarial infection should spread into previously infection-free areas.

  11. Oriental bittersweet (Celastrus orbiculatus): Spreading by fire

    Science.gov (United States)

    Pavlovic, Noel B.; Leicht-Young, Stacey A.; Grundel, Ralph

    2016-01-01

    In many forest ecosystems, fire is critical in maintaining indigenous plant communities, but can either promote or arrest the spread of invasive species depending on their regeneration niche and resprouting ability. We examined the effects of cutting and burning treatments on the vegetative response (cover, stem density) and root resources of Oriental bittersweet (Celastrus orbiculatus), a liana invasive to North America that was introduced from East Asia. Treatments were control, spring cut, spring burn, spring cut & burn, summer cut, fall cut, fall burn, fall cut & burn, and fall herbicide. Cover was reduced the greatest by herbicide and summer cutting treatments, but increased more in the second year on moraine soils than on sandy soils. Burning and cutting & burning combined resulted in a resprout density four times greater than stem density prior to treatment for stems suckers, and survival increased with increasing stem size. While cutting of C. orbiculatus during the growing season (summer) reduced total nonstructural carbohydrates by 50% below early growing season levels and 75% below dormant season levels, burning did not significantly reduce total nonstructural carbohydrates. Thus, Oriental bittersweet is quite responsive to burning as a disturbance and resprouting and root-suckering creates additional opportunities for growth and attainment of the forest canopy. The positive response of Oriental bittersweet to burning has important implications for management of invasive lianas in fire-dependent forest landscapes.

  12. Spreading continents kick-started plate tectonics.

    Science.gov (United States)

    Rey, Patrice F; Coltice, Nicolas; Flament, Nicolas

    2014-09-18

    Stresses acting on cold, thick and negatively buoyant oceanic lithosphere are thought to be crucial to the initiation of subduction and the operation of plate tectonics, which characterizes the present-day geodynamics of the Earth. Because the Earth's interior was hotter in the Archaean eon, the oceanic crust may have been thicker, thereby making the oceanic lithosphere more buoyant than at present, and whether subduction and plate tectonics occurred during this time is ambiguous, both in the geological record and in geodynamic models. Here we show that because the oceanic crust was thick and buoyant, early continents may have produced intra-lithospheric gravitational stresses large enough to drive their gravitational spreading, to initiate subduction at their margins and to trigger episodes of subduction. Our model predicts the co-occurrence of deep to progressively shallower mafic volcanics and arc magmatism within continents in a self-consistent geodynamic framework, explaining the enigmatic multimodal volcanism and tectonic record of Archaean cratons. Moreover, our model predicts a petrological stratification and tectonic structure of the sub-continental lithospheric mantle, two predictions that are consistent with xenolith and seismic studies, respectively, and consistent with the existence of a mid-lithospheric seismic discontinuity. The slow gravitational collapse of early continents could have kick-started transient episodes of plate tectonics until, as the Earth's interior cooled and oceanic lithosphere became heavier, plate tectonics became self-sustaining.

  13. Spread Spectrum Communication with Chaotic Frequency Modulation

    Science.gov (United States)

    Volkovskii, Alexander R.; Tsimring, Lev S.; Rulkov, Nikolai F.; Langmore, Ian; Young, Stephen C.

    We describe two different approaches to employ chaotic signals in spread-spectrum (SS) communication systems with phase and frequency modulation. In the first one a chaotic signal is used as a carrier. We demonstrate that using a feedback loop controller, the local chaotic oscillator in the receiver can be synchronized to the transmitter. The information can be transmitted using phase or frequency modulation of the chaotic carrier signal. In the second system the chaotic signal is used for frequency modulation of a voltage controlled oscillator (VCO) to provide a SS signal similar to frequency hopping systems. We show that in a certain parameter range the receiver VCO can be synchronized to the transmitter VCO using a relatively simple phase lock loop (PLL) circuit. The same PLL is used for synchronization of the chaotic oscillators. The information signal can be transmitted using a binary phase shift key (BPSK) or frequency shift key (BFSK) modulation of the frequency modulated carrier signal. Using an experimental circuit operating at radio frequency band and a computer modeling we study the bit error rate (BER) performance in a noisy channel as well as multiuser capability of the system.

  14. Spreading Optics in the primary school

    Science.gov (United States)

    Gargallo, Ana; Gómez-Varela, Ana I.; Gónzalez-Nuñez, Héctor; Delgado, Tamara; Almaguer, Citlalli; Cambronero, Ferran; García-Sánchez, Ángel; Pallarés, David; Aymerich, María; Aragón, Ángel L.; Flores-Arias, Maria T.

    2015-04-01

    The USC-OSA is a student chapter located at the University of Santiago de Compostela (Spain) whose objective is to bring optics and photonics knowledge closer to general public. In order to arouse kids' interest in Optics we developed an activity called Funny Light. This activity consisted on a visit of some USC-OSA members to a several local primary schools where we organized several optics experiments. In this work we present the optics demonstrations and the reaction of the 6 years-old students. The activities with greater acceptance include an explanation of light properties as polarization, refraction or reflection, and the workshop where they learnt how to build their own kaleidoscope and made a chromatic disk. Besides, they also participated in a demonstration and explanation of color properties and some optical illusions. We think that this activity has several benefits including spreading Optics through children meanwhile they have fun and experiment science in real life, as well as helping teachers to explain some complex properties and Physics phenomena of light. Given the broad acceptance of this activity, we are intending to make it a routine event of our student chapter repeating it every year.

  15. Facing Two Rapidly Spreading Internet Worms

    CERN Multimedia

    IT Department

    2009-01-01

    The Internet is currently facing a growing number of computer infections due to two rapidly spreading worms. The "Conficker" and "Downadup" worms have infected an estimated 1.1 million PCs in a 24-hour period, bringing the total number of infected computers to 3.5 million [1]. Via a single USB stick, these worms were also responsible for the infection of about 40 laptops at the last EGEE conference in Istanbul. In order to reduce the impact of these worms on CERN Windows computers, the Computer Security Team has suggested several preventive measures described here. Disabling the Windows AutoRun and AutoPlay Features The Computer Security Team and the IT/IS group have decided to disable the "AutoRun" and "AutoPlay" functionality on all centrally-managed Windows computers at CERN. When inserting CDs, DVDs or USB sticks into a PC, "AutoRun" and "AutoPlay" are responsible for automatically playing music or films stored on these media, or ...

  16. Estimating spread of violent behaviour with children

    Directory of Open Access Journals (Sweden)

    Volkova E.N.

    2016-06-01

    Full Text Available The article is to problems of violence (physical, psychological, sexual to children in the region of Nyzhniy Novgorod in the Russian Federation. It was used international tool for questionnaire ICAST-C. В исследовании приняли участие 227 children par- ticipated in this study (131 girls, 96 boys in the age of 11 to 18 years old. The results show that 78,4% of children have some experience of violence and abuse. 3/4 — in family, and 2/3 — at school. High level of psychological abuse at home was shown (more than 2/3 , at home it is more often than at school (54% versus 30%. Children suffer from physical abuse at home (49% versus 33% at school. Though they suffer from sexual abuse at school (27%. All kinds of abuse take place among girls as well as among boys. Except physical abuse at school where it is more usual among boys (45%, versus (33% girls. Girls suffer more at home. Teenagers suffer less, than youngsters. Emotional abuse is not spread widely (40% versus 60—75% in other groups. In general they suffer from sexual abuse not often, though it is usually at home (8,5% cases.

  17. Information Spreading in Stationary Markovian Evolving Graphs

    CERN Document Server

    Clementi, Andrea; Pasquale, Francesco; Silvestri, Riccardo

    2011-01-01

    Markovian evolving graphs are dynamic-graph models where the links among a fixed set of nodes change during time according to an arbitrary Markovian rule. They are extremely general and they can well describe important dynamic-network scenarios. We study the speed of information spreading in the "stationary phase" by analyzing the completion time of the "flooding mechanism". We prove a general theorem that establishes an upper bound on flooding time in any stationary Markovian evolving graph in terms of its node-expansion properties. We apply our theorem in two natural and relevant cases of such dynamic graphs. "Geometric Markovian evolving graphs" where the Markovian behaviour is yielded by "n" mobile radio stations, with fixed transmission radius, that perform independent random walks over a square region of the plane. "Edge-Markovian evolving graphs" where the probability of existence of any edge at time "t" depends on the existence (or not) of the same edge at time "t-1". In both cases, the obtained upper...

  18. Order Optimal Information Spreading Using Algebraic Gossip

    CERN Document Server

    Avin, Chen; Censor-Hillel, Keren; Lotker, Zvi

    2011-01-01

    In this paper we study gossip based information spreading with bounded message sizes. We use algebraic gossip to disseminate $k$ distinct messages to all $n$ nodes in a network. For arbitrary networks we provide a new upper bound for uniform algebraic gossip of $O((k+\\log n + D)\\Delta)$ rounds with high probability, where $D$ and $\\Delta$ are the diameter and the maximum degree in the network, respectively. For many topologies and selections of $k$ this bound improves previous results, in particular, for graphs with a constant maximum degree it implies that uniform gossip is \\emph{order optimal} and the stopping time is $\\Theta(k + D)$. To eliminate the factor of $\\Delta$ from the upper bound we propose a non-uniform gossip protocol, TAG, which is based on algebraic gossip and an arbitrary spanning tree protocol $\\S$. The stopping time of TAG is $O(k+\\log n +d(\\S)+t(\\S))$, where $t(\\S)$ is the stopping time of the spanning tree protocol, and $d(\\S)$ is the diameter of the spanning tree. We provide two general...

  19. Potential for international spread of wild poliovirus via travelers

    OpenAIRE

    Wilder-Smith, Annelies; Leong, Wei-Yee; Lopez, Luis Fernandez; Amaku, Marcos; Quam, Mikkel; Khan, Kamran; MASSAD, Eduardo

    2015-01-01

    Background: The endgame of polio eradication is hampered by the international spread of poliovirus via travelers. In response to ongoing importations of poliovirus into polio-free countries, on 5 May 2014, WHO's Director-General declared the international spread of wild poliovirus a public health emergency of international concern. Our objective was to develop a mathematical model to estimate the international spread of polio infections. Methods: Our model took into account polio endemicity i...

  20. Exchange Rate Policy and Sovereign Bond Spreads in Developing Countries

    OpenAIRE

    2004-01-01

    We test the hypothesis of a link between exchange rate policy and sovereign bonds. We analyze the effect of exchange rate policies on supply and credit spreads of sovereign bonds issued by developing countries. An exchange rate policy is captured by the de facto exchange rate regime and the real exchange rate misalignment. The main findings are: (1) real exchange rate overvaluation significantly increases sovereign bond issue probability and raises bond spreads; (2) spreads and the likelihood...

  1. Discrete Modeling of the Worm Spread with Random Scanning

    Science.gov (United States)

    Uchida, Masato

    In this paper, we derive a set of discrete time difference equations that models the spreading process of computer worms such as Code-Red and Slammer, which uses a common strategy called “random scanning” to spread through the Internet. We show that the derived set of discrete time difference equations has an exact relationship with the Kermack and McKendrick susceptible-infectious-removed (SIR) model, which is known as a standard continuous time model for worm spreading.

  2. Blood microRNA profile associates with the levels of serum lipids and metabolites associated with glucose metabolism and insulin resistance and pinpoints pathways underlying metabolic syndrome: the cardiovascular risk in Young Finns Study.

    Science.gov (United States)

    Raitoharju, Emma; Seppälä, Ilkka; Oksala, Niku; Lyytikäinen, Leo-Pekka; Raitakari, Olli; Viikari, Jorma; Ala-Korpela, Mika; Soininen, Pasi; Kangas, Antti J; Waldenberger, Melanie; Klopp, Norman; Illig, Thomas; Leiviskä, Jaana; Loo, Britt-Marie; Hutri-Kähönen, Nina; Kähönen, Mika; Laaksonen, Reijo; Lehtimäki, Terho

    2014-06-25

    Since metabolic syndrome (MetS) is a collection of cardiovascular risk factors involving multiple signaling systems, we related the metabolic abnormalities associated with MetS with circulating microRNA profiles to pinpoint the affected signaling pathways. The blood microRNA profile, genome wide gene expression and serum NMR metabolomics were analyzed from 71 participants of the Young Finns Study. We found nine microRNAs that associated significantly with metabolites connected to MetS. MicroRNA-144-5p concentration correlated with glucose levels, hsa-1207-5p with glycosylated hemoglobin and hsa-miR-484 with metabolites related to insulin resistance. Hsa-miR-625-3p correlated with cholesterol levels, hsa-miR-1237-3p and hsa-miR-331-3p expression with certain fatty acids levels and hsa-miR-129-1-3p, -129-2-3p, and -1288-3p with glycerol levels. The down-regulated targets of miR-1207-5p and -129-2-3p were enriched in PI3K and MAPK pathways and 8 out of the 12 enriched pathways were down-regulated in individuals with MetS. In conclusion microRNAs associated with several aspects of MetS, possibly regulating glucose and lipid metabolism. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. Suppressing disease spreading by using information diffusion on multiplex networks

    Science.gov (United States)

    Wang, Wei; Liu, Quan-Hui; Cai, Shi-Min; Tang, Ming; Braunstein, Lidia A.; Stanley, H. Eugene

    2016-07-01

    Although there is always an interplay between the dynamics of information diffusion and disease spreading, the empirical research on the systemic coevolution mechanisms connecting these two spreading dynamics is still lacking. Here we investigate the coevolution mechanisms and dynamics between information and disease spreading by utilizing real data and a proposed spreading model on multiplex network. Our empirical analysis finds asymmetrical interactions between the information and disease spreading dynamics. Our results obtained from both the theoretical framework and extensive stochastic numerical simulations suggest that an information outbreak can be triggered in a communication network by its own spreading dynamics or by a disease outbreak on a contact network, but that the disease threshold is not affected by information spreading. Our key finding is that there is an optimal information transmission rate that markedly suppresses the disease spreading. We find that the time evolution of the dynamics in the proposed model qualitatively agrees with the real-world spreading processes at the optimal information transmission rate.

  4. Reducing influenza spreading over the airline network

    Science.gov (United States)

    Marcelino, Jose; Kaiser, Marcus

    2009-01-01

    Disease spreading through human travel networks has been a topic of great interest in recent years, such as with swine influenza or SARS pandemics. Most studies have proposed removing highly connected nodes (hubs) to control spreading. Here, we test alternative strategies using edge removal (flight cancellation) for spreading over the airline network. Flight cancellation was more efficient than shutting down whole airports: spreading took 81% longer if solely selected flights were removed, compared to a 52% reduction when entire airports were shutdown, affecting the same number of flights. PMID:20020673

  5. Probing models of information spreading in social networks

    CERN Document Server

    Zoller, J

    2014-01-01

    We apply signal processing analysis to the information spreading in scale-free network. To reproduce typical behaviors obtained from the analysis of information spreading in the world wide web we use a modified SIS model where synergy effects and influential nodes are taken into account. This model depends on a single free parameter that characterize the memory-time of the spreading process. We show that by means of fractal analysis it is possible -from aggregated easily accessible data- to gain information on the memory time of the underlying mechanism driving the information spreading process.

  6. A theoretical analysis of global characteristics of spread-F

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Spread-F is an important ionosphere pheonome non and it has much effect on radio wave propogation. Tak ing magnetic inclination and declination into consideration, a theoretical model is deduced for the linear growth-rate of spread-F. It is a generalization of the earlier equatorial model and a relatively complete description o f the spread-F pheonomenon. This theory shows that the magnetic configu ration, i.e. the magnetic strength, inclination and declination,affects the occurrence rate greatly, which forms some re gional distribution characteristics of the spread-F.

  7. Gall bladder carcinoma: Aggressive malignancy with protean loco-regional and distant spread.

    Science.gov (United States)

    Dwivedi, Amit Nandan Dhar; Jain, Shivi; Dixit, Ruhi

    2015-03-16

    The most common malignancy of biliary tract is gallbladder cancer (GBC) which is the third most common cancer in gastrointestinal tract. It is a lethal disease for most patients in spite of growing awareness and improved diagnostic techniques. GBC has a very poor prognosis and the 5 year survival rate is loco-regional rather than distant. It spreads by lymphatic, vascular, neural, intraperitoneal, and intraductal routes. Sonography is usually the most common imaging test to evaluate symptoms of biliary tract disease including suspected GC. With recent advances in imaging modalities like multi-detector computed tomography (CT) scanners, magnetic resonance imaging-positron emission tomography/CT diagnosis of gallbladder cancer has improved. Studies have also targeted molecular and genetic pathways. Treatment options have included extended and radical surgeries and adjuvant chemotherapy. This review article deals in detail with important aspects of carcinoma gallbladder and its manifestations and challenges. Role of various imaging modalities in characterization and accurate staging has been discussed. The loco-regional spread of this aggressive malignancy is dealt explicitly.

  8. Mitochondrial DNA Fails to Pinpoint African Ancestry

    Institute of Scientific and Technical Information of China (English)

    葛群燕

    2006-01-01

    最新的线粒体基因(Mitochondrial DNA)研究结果恐怕要让一些黑人失望了:他们想要确定自己究竟属于哪一个具体的非洲部族,然而在抽样研究中,只有不到10%的样本可以确定与之完全吻合的部落族群,有一半的基因样本与多种部族相吻合,另有40%的样本基因则根本找不到与其吻合的非洲部族。这项新的基因研究技术最终能否给黑人们带来满意的答案呢?有限的数据限制了目前的研究,我们只能拭目以待。

  9. Stages of Laryngeal Cancer

    Science.gov (United States)

    ... or the vocal cords cannot move normally. Subglottis: Cancer has spread to one or both vocal cords, which may not move normally. Enlarge Tumor sizes. The size of a tumor may be compared to the size of a pea (1 cm), peanut (2 cm), grape (3 cm), walnut (4 cm), lime (5 cm), ...

  10. Stages of Oropharyngeal Cancer

    Science.gov (United States)

    ... of the oropharynx . These abnormal cells may become cancer and spread into nearby normal tissue . Stage 0 is also called carcinoma in situ . Enlarge Tumor sizes. The size of a tumor may be compared to the size of a pea (1 cm), peanut (2 cm), grape (3 cm), walnut (4 cm), lime (5 cm), ...

  11. Stages of Hypopharyngeal Cancer

    Science.gov (United States)

    ... of the hypopharynx . These abnormal cells may become cancer and spread into nearby normal tissue . Stage 0 is also called carcinoma in situ . Enlarge Tumor sizes. The size of a tumor may be compared to the size of a pea (1 cm), peanut (2 cm), grape (3 cm), walnut (4 cm), lime (5 cm), ...

  12. Hypopharyngeal Cancer Treatment

    Science.gov (United States)

    ... of the hypopharynx . These abnormal cells may become cancer and spread into nearby normal tissue . Stage 0 is also called carcinoma in situ . Enlarge Tumor sizes. The size of a tumor may be compared to the size of a pea (1 cm), peanut (2 cm), grape (3 cm), walnut (4 cm), lime (5 cm), ...

  13. Spreading depression sends microglia on Levy flights.

    Directory of Open Access Journals (Sweden)

    Yelena Y Grinberg

    Full Text Available Spreading depression (SD is thought to cause migraine aura, and perhaps migraine, and includes a transient loss of synaptic activity preceded and followed by increased neuronal excitability. Activated microglia influence neuronal activity and play an important role in homeostatic synaptic scaling via release of cytokines. Furthermore, enhanced neuronal function activates microglia to not only secrete cytokines but also to increase the motility of their branches, with somata remaining stationary. While SD also increases the release of cytokines from microglia, the effects on microglial movement from its synaptic activity fluctuations are unknown. Accordingly, we used time-lapse imaging of rat hippocampal slice cultures to probe for microglial movement associated with SD. We observed that in uninjured brain whole microglial cells moved. The movements were well described by the type of Lévy flight known to be associated with an optimal search pattern. Hours after SD, when synaptic activity rose, microglial cell movement was significantly increased. To test how synaptic activity influenced microglial movement, we enhanced neuronal activity with chemical long-term potentiation or LPS and abolished it with TTX. We found that microglial movement was significantly decreased by enhanced neuronal activity and significantly increased by activity blockade. Finally, application of glutamate and ATP to mimic restoration of synaptic activity in the presence of TTX stopped microglial movement that was otherwise seen with TTX. Thus, synaptic activity retains microglial cells in place and an absence of synaptic activity sends them off to influence wider expanses of brain. Perhaps increased microglial movements after SD are a long-lasting, and thus maladaptive, response in which these cells increase neuronal activity via contact or paracrine signaling, which results in increased susceptibility of larger brain areas to SD. If true, then targeting mechanisms that

  14. Animal cancer models of skeletal metastasis

    National Research Council Canada - National Science Library

    Hibberd, Catherine; Cossigny, Davina A F; Quan, Gerald M Y

    2013-01-01

    ... ability, and poorer quality of life. Animal cancer models of skeletal metastases are essential for better understanding of the molecular pathways behind metastatic spread and local growth and invasion of bone, to enable analysis of host...

  15. Avoidable cancers in the Nordic countries. Diet, obesity and low physical activity

    DEFF Research Database (Denmark)

    Winther, J F; Dreyer, L; Overvad, K

    1997-01-01

    In the early 1980s, Doll and Peto estimated that about 35% of all deaths from cancer in the United States were attributable to dietary factors, with a margin of uncertainty ranging from 10 to 70%. Since then, several dietary factors, e.g. fat and meat, have been suggested to increase the risk...... through well-described modifications of dietary habits. During the last 10 years, low physical activity has been pinpointed as a risk factor for cancers at various sites, especially the colon; however, the causal mechanism is still unknown. Obesity, defined as a body mass index of 30 or more......, is consistently associated with endometrial and gall-bladder cancers in women and renal-cell cancer in both men and women. As the prevalence of obesity was between 5 and almost 20% in the Nordic populations in 1995, 625 cancer cases (310 endometrial cancers, 270 renal-cell cancers in men and women and 45 gall...

  16. Multiple seafloor spreading modes in the Mid-Cayman Spreading Centre

    Science.gov (United States)

    Searle, R. C.

    2012-12-01

    Multibeam bathymetry and TOBI deep-towed sidescan sonar data have been used to produce a preliminary geological map of the ultra-slow (~16 km/Ma) Mid-Cayman Spreading Centre (MCSC, the world's deepest spreading centre. The MCSC consists of two spreading segments, the northern of which is offset some 10 km dextrally from the southern, separated by an oceanic core complex (OCC), Mt. Dent. Each segment contains an axial volcanic ridge (AVR) displaying typical young, hummocky volcanic terrain. The northern AVR runs the length of the segment and its southern end abuts the north flank of Mt. Dent, suggesting it is about to cut off and terminate slip on the OCC detachment. A prominent ridge to the east of the northern AVR is not, as appears from the bathymetry, a separate AVR, but a fault block in the eastern MV wall. Recent-looking lavas erupt from partway up this fault. The southern AVR occupies the southern part of the southern segment. Both AVRs, but most prominently the northern one, exhibit NE trending volcanic spurs on their eastern flanks, which may be attributed to the action of dextral shear stresses associated with the plate boundary. The world's deepest hydrothermal vents (Beebe Vent Field) is located at the foot of one of these spurs. Between the southern AVR and Mt. Dent is a linear ridge, displaying considerable evidence of faulting but little recognisable volcanic terrain. The most likely tectonic interpretation is that this is a peridotite ridge produced by direct exhumation of mantle material, similar to those seen in 'smooth' seafloor on the ultra-slow spreading Southwest Indian Ridge. Its NNW-SSE orientation is somewhat paradoxical in this N-S spreading centre. This tectonised ridge is flanked by two flat-floored basins characterised by fairly uniform, moderate backscatter terrain typical of relatively young flat-lying lava flows. There are several smaller areas of young, flat-lying lavas, including the one to the east of the northern AVR. Another

  17. The transition from rifting to spreading in the Red Sea: No sign of discrete spreading nodes?

    Science.gov (United States)

    Augustin, N.; Devey, C. W.; Feldens, P.; van der Zwan, F. M.; Bantan, R.; Kwasnitschka, T.

    2012-12-01

    The rifting of a continent and its eventual splitting by the formation of an ocean basin is one of the decisive processes in plate tectonics - it is responsible for the formation of continental margins (home to most of the world's submarine hydrocarbon reserves) and has repeatedly divided and re-distributed the continental plates. The Red Sea is one of the few places on Earth where this process is presently occurring, with continental rifting occurring in the northern Red Sea (north of 23°N) and ocean floor creation in the south (south of 19.5°N). In the central region it has been proposed that the extension is accommodated in a series of discrete seafloor spreading cells in the so called "transition-" or "multi-deeps region". This suggestion is mainly based on interpretations of bathymetric, magnetic, gravimetric and seismic observations made in the late 1970's and mid 1980's at resolutions far below those possible today. During two major expeditions with the German and Dutch research vessels Poseidon (cruise #408) and Pelagia (cruise #350/51) in 2011 and 2012 we collected a continuous multibeam bathymetric dataset over and between the Red Sea deeps from the Thetis Deep at 23°N to the Red Sea Rift at 16.5°N, with a spatial acoustic resolution of 15-30 m over a total N-S distance of about 700 km. This data enables us to view in detail the bathymetric structures formed during extension and to make a detailed interpretation of the structural, tectonic, magmatic and sedimentary evolution of the Red Sea rift. Based on an analysis of the bathymetric datasets, combined with acoustic backscatter, shallow seismics, ground truthing sampling, and magmatic geochemical information, we arrive at a much simplier and less exotic model of the transition from rifting to spreading than previously proposed. Geomorphological features strongly indicate a continuous oceanic rift valley at least from Nereus Deep at 23°N southwards to the Danakil triple junction at 17°N. We can

  18. Patterns of metastasis in colon and rectal cancer

    OpenAIRE

    Matias Riihimäki; Akseli Hemminki; Jan Sundquist; Kari Hemminki

    2016-01-01

    Investigating epidemiology of metastatic colon and rectal cancer is challenging, because cancer registries seldom record metastatic sites. We used a population based approach to assess metastatic spread in colon and rectal cancers. 49,096 patients with colorectal cancer were identified from the nationwide Swedish Cancer Registry. Metastatic sites were identified from the National Patient Register and Cause of Death Register. Rectal cancer more frequently metastasized into thoracic organs (OR ...

  19. 12 CFR 619.9180 - Fixed interest spread.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Fixed interest spread. 619.9180 Section 619.9180 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9180 Fixed interest spread. A percentage to be added to the cost of money to the bank or association as the means...

  20. Comparative study on spreading function for directional wave spectra

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.S.; Anand, N.M.; Nayak, B.U.

    -dimensional wave energy S(f) and the directional spreading function D(f, theta). This paper reviews various spreading functions proposed in the past for estimating the directional wave energy and presents their application to the Indian wave condition. It is found...

  1. Regime-dependent determinants of Euro area sovereign CDS spreads

    NARCIS (Netherlands)

    Blommestein, H.J.; Eijffinger, Sylvester; Qian, Zongxin

    2016-01-01

    We study the determinants of sovereign CDS spreads of five Euro area countries (Greece, Ireland, Italy, Portugal, and Spain) after the collapse of Lehman Brothers. We find that global and/or European Monetary Union (EMU)-wide factors are the main drivers of changes in the sovereign CDS spreads in ou

  2. Raman hyperspectral imaging and analysis of fat spreads

    NARCIS (Netherlands)

    Dalen, van G.; Velzen, van E.J.J.; Heussen, P.C.M.; Sovago, M.; Malssen, van K.F.; Duynhoven, van J.P.M.

    2017-01-01

    The microstructure of fat spreads is of fundamental importance to their sensorial properties such as texture, mouthfeel and spreadability. Fat spreads are water in oil emulsions,with a continuous phase supported by a fat crystal network. Confocal Raman microscopy offers the possibility for the

  3. Influence of livestock markets on the spread of FMD

    DEFF Research Database (Denmark)

    Boklund, Anette; Hisham Beshara Halasa, Tariq; Christiansen, Lasse Engbo

    2012-01-01

    The purpose of this study was to investigate, whether cattle markets would influence the duration, size and economic consequences of a potential FMD epidemic in Denmark. The spread of FMD was simulated using the InterSpread Plus. For movements of cattle to and from markets, we modeled the frequency...

  4. Spreading depression transiently disrupts myelin via interferon-gamma signaling.

    Science.gov (United States)

    Pusic, Aya D; Mitchell, Heidi M; Kunkler, Phillip E; Klauer, Neal; Kraig, Richard P

    2015-02-01

    Multiple sclerosis and migraine with aura are clinically correlated and both show imaging changes suggestive of myelin disruption. Furthermore, cortical myelin loss in the cuprizone animal model of multiple sclerosis enhances susceptibility to spreading depression, the likely underlying cause of migraine with aura. Since multiple sclerosis pathology involves inflammatory T cell lymphocyte production of interferon-gamma and a resulting increase in oxidative stress, we tested the hypothesis that spreading depression disrupts myelin through similar signaling pathways. Rat hippocampal slice cultures were initially used to explore myelin loss in spreading depression, since they contain T cells, and allow for controlled tissue microenvironment. These experiments were then translated to the in vivo condition in neocortex. Spreading depression in slice cultures induced significant loss of myelin integrity and myelin basic protein one day later, with gradual recovery by seven days. Myelin basic protein loss was abrogated by T cell depletion, neutralization of interferon-gamma, and pharmacological inhibition of neutral sphingomyelinase-2. Conversely, one day after exposure to interferon-gamma, significant reductions in spreading depression threshold, increases in oxidative stress, and reduced levels of glutathione, an endogenous neutral sphingomyelinase-2 inhibitor, emerged. Similarly, spreading depression triggered significant T cell accumulation, sphingomyelinase activation, increased oxidative stress, and reduction of gray and white matter myelin in vivo. Myelin disruption is involved in spreading depression, thereby providing pathophysiological links between multiple sclerosis and migraine with aura. Myelin disruption may promote spreading depression by enhancing aberrant excitability. Thus, preservation of myelin integrity may provide novel therapeutic targets for migraine with aura.

  5. A case study on fractal simulation of forest fire spread

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper relates to the semi-empirical model based on fire field energy balance and the physical model based on land temperature,aiming to provide a practical way of describing fire spread.Fire spread is determined by the characteristics of combustible materials and the agency of meteorological factors and terrains.Combustible materials,such as surface area,have no featured scale,yet the process of forest fire spread contains the self-replicating feature,both of which contribute to the self-similarity of fire spread.Consequently,fire behavior can be described by fractal geometry.In this research,we select Wuchagou forest in Da Hinggan Mountains as the experimental site where a forest fire took place three years ago.The forest fire was detected on low-resolution NOAA-AVHRR images,and fire spread was simulated on high-resolution TM images as another attempt to merge information.Based on remote sensing and GIS,we adopted the method of limited spreading lumping (DLA) to describe growing phenomenon to simulate the dynamic process of fire spread and adjusting shape of the result of fire simulation by the scale rule.As a result,the simulated fire and the actual fire manifest the self-similarity in their spreading shapes as well as the quantitative similarity in their areas.

  6. A Deadly Path: Bacterial Spread During Bubonic Plague.

    Science.gov (United States)

    Gonzalez, Rodrigo J; Miller, Virginia L

    2016-04-01

    Yersinia pestis causes bubonic plague, a fulminant disease where host immune responses are abrogated. Recently developed in vivo models of plague have resulted in new ideas regarding bacterial spread in the body. Deciphering bacterial spread is key to understanding Y. pestis and the immune responses it encounters during infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Dogwood Anthracnose and its Spread in the South

    Science.gov (United States)

    Robert L. Anderson; John L. Knighten; Mark Windham; Keith Langdon; Floyd Hedrix; Ron Roncadori

    In the 15 years since it was first reported in the United States, dogwood anthracnose (caused by Discula destructive sp. nov.) has spread rapidly and caused serious losses among flowering dogwoods (Cornus florida L.), particularly in the South. Infection begins in leaves and spreads to twigs and branches, which dieback. Main-stem infections cause cankers, which kill...

  8. Swimming propulsion forces are enhanced by a small finger spread.

    Science.gov (United States)

    Marinho, Daniel A; Barbosa, Tiago M; Reis, Victor M; Kjendlie, Per L; Alves, Francisco B; Vilas-Boas, João P; Machado, Leandro; Silva, António J; Rouboa, Abel I

    2010-02-01

    The main aim of this study was to investigate the effect of finger spread on the propulsive force production in swimming using computational fluid dynamics. Computer tomography scans of an Olympic swimmer hand were conducted. This procedure involved three models of the hand with differing finger spreads: fingers closed together (no spread), fingers with a small (0.32 cm) spread, and fingers with large (0.64 cm) spread. Steady-state computational fluid dynamics analyses were performed using the Fluent code. The measured forces on the hand models were decomposed into drag and lift coefficients. For hand models, angles of attack of 0 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees, and 90 degrees, with a sweep back angle of 0 degrees, were used for the calculations. The results showed that the model with a small spread between fingers presented higher values of drag coefficient than did the models with fingers closed and fingers with a large spread. One can note that the drag coefficient presented the highest values for an attack angle of 90 degrees in the three hand models. The lift coefficient resembled a sinusoidal curve across the attack angle. The values for the lift coefficient presented few differences among the three models, for a given attack angle. These results suggested that fingers slightly spread could allow the hand to create more propulsive force during swimming.

  9. Targeting ECM Disrupts Cancer Progression.

    Science.gov (United States)

    Venning, Freja A; Wullkopf, Lena; Erler, Janine T

    2015-01-01

    Metastatic complications are responsible for more than 90% of cancer-related deaths. The progression from an isolated tumor to disseminated metastatic disease is a multistep process, with each step involving intricate cross talk between the cancer cells and their non-cellular surroundings, the extracellular matrix (ECM). Many ECM proteins are significantly deregulated during the progression of cancer, causing both biochemical and biomechanical changes that together promote the metastatic cascade. In this review, the influence of several ECM proteins on these multiple steps of cancer spread is summarized. In addition, we highlight the promising (pre-)clinical data showing benefits of targeting these ECM macromolecules to prevent cancer progression.

  10. Targeting ECM Disrupts Cancer Progression

    Science.gov (United States)

    Venning, Freja A.; Wullkopf, Lena; Erler, Janine T.

    2015-01-01

    Metastatic complications are responsible for more than 90% of cancer-related deaths. The progression from an isolated tumor to disseminated metastatic disease is a multistep process, with each step involving intricate cross talk between the cancer cells and their non-cellular surroundings, the extracellular matrix (ECM). Many ECM proteins are significantly deregulated during the progression of cancer, causing both biochemical and biomechanical changes that together promote the metastatic cascade. In this review, the influence of several ECM proteins on these multiple steps of cancer spread is summarized. In addition, we highlight the promising (pre-)clinical data showing benefits of targeting these ECM macromolecules to prevent cancer progression. PMID:26539408

  11. Cancer Clusters

    Science.gov (United States)

    ... Kidney (Renal Cell) Cancer Leukemia Liver Cancer Lung Cancer Lymphoma Pancreatic Cancer Prostate Cancer Skin Cancer Thyroid Cancer Uterine Cancer ... Myths and Misconceptions Diet Hormones Immunosuppression Infectious Agents Obesity Radiation Sunlight Tobacco Genetics NCI Cancer Genetics Services ...

  12. Effective information spreading based on local information in correlated networks

    CERN Document Server

    Gao, Lei; Pan, Liming; Tang, Ming; Zhang, Hai-Feng

    2016-01-01

    Using network-based information to facilitate information spreading is an essential task for spreading dynamics in complex networks, which will benefit the promotion of technical innovations, healthy behaviors, new products, etc. Focusing on degree correlated networks, we propose a preferential contact strategy based on the local network structure and local informed density to promote the information spreading. During the spreading process, an informed node will preferentially select a contact target among its neighbors, basing on their degrees or local informed densities. By extensively implementing numerical simulations in synthetic and empirical networks, we find that when only consider the local structure information, the convergence time of information spreading will be remarkably reduced if low-degree neighbors are favored as contact targets. Meanwhile, the minimum convergence time depends non-monotonically on degree-degree correlation, and moderate correlation coefficients result in most efficient info...

  13. Rapid evolution accelerates plant population spread in fragmented experimental landscapes.

    Science.gov (United States)

    Williams, Jennifer L; Kendall, Bruce E; Levine, Jonathan M

    2016-07-29

    Predicting the speed of biological invasions and native species migrations requires an understanding of the ecological and evolutionary dynamics of spreading populations. Theory predicts that evolution can accelerate species' spread velocity, but how landscape patchiness--an important control over traits under selection--influences this process is unknown. We manipulated the response to selection in populations of a model plant species spreading through replicated experimental landscapes of varying patchiness. After six generations of change, evolving populations spread 11% farther than nonevolving populations in continuously favorable landscapes and 200% farther in the most fragmented landscapes. The greater effect of evolution on spread in patchier landscapes was consistent with the evolution of dispersal and competitive ability. Accounting for evolutionary change may be critical when predicting the velocity of range expansions.

  14. Stability of Spreading Processes with General Transmission and Recovery Times

    CERN Document Server

    Ogura, Masaki

    2016-01-01

    Although viral spreading processes taking place in networks are commonly analyzed using Markovian models in which both the transmission times and the recovery times follow exponential distributions, empirical studies show that, in most real scenarios, the distribution of these times are far from exponential. To overcome this limitation, we first introduce a generalized spreading model that allows for transmission and recovery times to follow arbitrary distributions within an arbitrary accuracy. In this context, we derive conditions for the generalized spreading process to converge towards the disease-free equilibrium (in other words, to eradicate the viral spread) without relying on mean-field approximations. Based on our results, we illustrate how the particular shape of the transmission/recovery distribution heavily influences the boundary of the stability region of the spread, as well as the decay rate inside this region. Therefore, modeling non-exponential transmission/recovery times observed in realistic...

  15. Spreading of Viscous Liquids at High Temperature: Silicate Glasseson Molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Esteban, Sonia; Saiz, Eduardo; Moya, Jose S.; Tomsia,Antoni P.

    2004-12-15

    The spreading of Si-Ca-Al-Ti-O glasses on molybdenum has been investigated. By controlling the oxygen activity in the furnace, spreading can take place under reactive or non-reactive conditions. As the nucleation of the reaction product under reactive conditions is slow in comparison to the spreading kinetics, in both cases the glass front moves on the metal surface with similar spreading velocities. Spreading can be described using a molecular dynamics model where the main contribution to the wetting activation energy comes from the viscous interactions in the liquid. Enhanced interfacial diffusions in low-oxygen activities (reactive cases) form triple-line ridges that can pin the wetting front and cause a stick-slip motion.

  16. Comments on Landau damping due to synchrotron frequency spread

    Energy Technology Data Exchange (ETDEWEB)

    Ng, K.Y.; /Fermilab

    2005-01-01

    An inductive/space-charge impedance shifts the synchrotron frequency downwards above/below transition, but it is often said that the coherent synchrotron frequency of the bunch is not shifted in the rigid-dipole mode. On the other hand, the incoherent synchrotron frequency due to the sinusoidal rf always spreads in the downward direction. This spread will therefore not be able to cover the coherent synchrotron frequency, implying that there will not be any Landau damping no matter how large the frequency spread is. By studying the dispersion relation, it is shown that the above argument is incorrect, and there will be Landau damping if there is sufficient frequency spread. The main reason is that the coherent frequency of the rigid-dipole mode will no longer remain unshifted in the presence of a synchrotron frequency spread.

  17. Statistical analysis and model of spread F occurrence in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The spread F data obtained over Lanzhou (36.1°N,103.9°E),Chongqing (29.5°N,106.4°E) and Haikou (20.0°N,110.3°E) of China during the period from 1978 to 1997 are used to analyze the occurrence characteristics.The statistical results show that the post midnight spread F occurrence is maximum during the summer solstice months of the lower solar activity period,while post sunset spread F is dominant in equinoxes of higher solar activity period over Haikou station.Over Chongqing and Lanzhou stations,spread F mostly occurs at post midnight and relates negatively with solar activity.Using regression method and Fourier expansion,the preliminary single-station model of spread F occurrence is established and the accuracy of the model is evaluated.

  18. Efficient allocation of heterogeneous response times in information spreading process

    CERN Document Server

    Cui, Ai-Xiang; Tang, Ming; Fu, Yan; Liang, Xiaoming; Do, Younghae

    2014-01-01

    Recently, the impacts of spatiotemporal heterogeneities of human activities on spreading dynamics have attracted extensive attention. In this paper, to study heterogeneous response times on information spreading, we focus on the susceptible-infected spreading dynamics with adjustable power-law response time distribution based on uncorrelated scale-free networks. We find that the stronger the heterogeneity of response times is, the faster the information spreading is in the early and middle stages. Following a given heterogeneity, the procedure of reducing the correlation between the response times and degrees of individuals can also accelerate the spreading dynamics in the early and middle stages. However, the dynamics in the late stage is slightly more complicated, and there is an optimal value of the full prevalence time changing with the heterogeneity of response times and the response time-degree correlation, respectively. The optimal phenomena results from the efficient allocation of heterogeneous respon...

  19. ANTIMICROBIAL RESISTANCE AND ITS GLOBAL SPREAD

    Directory of Open Access Journals (Sweden)

    R P Sharma

    2010-06-01

    Full Text Available Since their discovery during the 20th century, antimicrobial agents (antibiotics and related medicinal drugs have substantially reduced the threat posed by infectious diseases. The use of these “wonder drugs”, combined with improvements in sanitation, housing, and nutrition, and the advent of widespread immunization programmes, has led to a dramatic drop in deaths from diseases that were previously widespread, untreatable, and frequently fatal. Over the years, antimicrobials have saved the lives and eased the suffering of millions of people. By helping to bring many serious infectious diseases under control, these drugs hav also contributed to the major gains in life expectancy experienced during the latter part of the last century. These gains are now seriously jeopardized by another recent development: the emergence and spread of microbes that are resistant to cheap and effective first-choice, or “first- line” drugs. The bacterial infections which contribute most to human disease are also those in which emerging microbial resistance is most evident: diarrhoeal diseases, respiratory tract infections, meningitis, sexually transmitted infections, and hospital-acquired infections. Some important examples include penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, multi-resistant salmonellae, and multi-resistant Mycobacterium tuberculosis. The development of resistance to drugs commonly used to treat malaria is of particular concern, as is the emerging resistance to anti-HIV drugs. Treatment, resu.lting in prolonged illness and greater risk of death, Treatment failures also lead to longer periods of infectivity, which increase the numbers of infected people moving in the community and thus expose the general population to the risk of contracting a resistant strain of infection. When infections become resistant to first-line antimicrobials, treatment has to be switched

  20. Flame spread over inclined electrical wires with AC electric fields

    KAUST Repository

    Lim, Seung J.

    2017-07-21

    Flame spread over polyethylene-insulated electrical wires was studied experimentally with applied alternating current (AC) by varying the inclination angle (θ), applied voltage (VAC), and frequency (fAC). For the baseline case with no electric field applied, the flame spread rate and the flame width of downwardly spreading flames (DSFs) decreased from the horizontal case for −20° ≤ θ < 0° and maintained near constant values for −90° ≤ θ < −20°, while the flame spread rate increased appreciably as the inclination angle of upwardly spreading flames (USFs) increased. When an AC electric field was applied, the behavior of flame spread rate in DSFs (USFs) could be classified into two (three) sub-regimes characterized by various functional dependences on VAC, fAC, and θ. In nearly all cases of DSFs, a globular molten polyethylene formed ahead of the spreading flame edge, occasionally dripping onto the ground. In these cases, an effective flame spread rate was defined to represent the burning rate by measuring the mass loss due to dripping. This effective spread rate was independent of AC frequency, while it decreased linearly with voltage and was independent of the inclination angle. In DSFs, when excessively high voltage and frequency were applied, the dripping led to flame extinction during propagation and the extinction frequency correlated well with applied voltage. In USFs, when high voltage and frequency were applied, multiple globular molten PEs formed at several locations, leading to ejections of multiple small flame segments from the main flame, thereby reducing the flame spread rate, which could be attributed to the electrospray phenomenon.

  1. The CS1 segment of fibronectin is involved in human OSCC pathogenesis by mediating OSCC cell spreading, migration, and invasion

    Directory of Open Access Journals (Sweden)

    D'Silva Nisha J

    2010-06-01

    Full Text Available Abstract Background The alternatively spliced V region or type III connecting segment III (IIICS of fibronectin is important in early development, wound healing, and tumorigenesis, however, its role in oral cancer has not been fully investigated. Thus, we investigated the role of CS-1, a key site within the CSIII region of fibronectin, in human oral squamous cell carcinoma (OSCC. Methods To determine the expression of CS-1 in human normal and oral SCC tissue specimens immunohistochemical analyses were performed. The expression of CS1 was then associated with clinicopathological factors. To investigate the role of CS-1 in regulating OSCC cell spreading, migration and invasion, OSCC cells were assayed for spreading and migration in the presence of a CS-1 peptide or a CS-1 blocking peptide, and for invasion using Matrigel supplemented with these peptides. In addition, integrin α4siRNA or a focal adhesion kinase (FAK anti-sense oligonucleotide was transfected into OSCC cells to examine the mechanistic role of integrin α4 or FAK in CS1-mediated cell spreading and migration, respectively. Results CS-1 expression levels were significantly higher in OSCC tissues compared to normal tissues (p Conclusion These data indicate that the CS-1 site of fibronectin is involved in oral cancer pathogenesis and in regulating OSCC cell spreading, migration and invasion.

  2. 关节镜下前交叉韧带股骨止点定位新方法的研究%A novel method to pinpoint the femoral foot-print of the anterior cruciate ligament

    Institute of Scientific and Technical Information of China (English)

    韩先伟; 李光政; 徐虎; 王迎春; 孙芳菲; 李小建; 赵阳; 张春礼

    2013-01-01

    Objective To explore a new method to pinpoint the femoral foot-print of the anterior cruciate ligament (ACL).Methods Enrolled in this study were 69 volunteers,50 men and 19 women with an average age of 29.1 years.Three-dimensional (3D) models of the internal wall of the lateral femoral condyle were reconstructed using a dual-source CT scanner and its workstation.The femoral foot-print of ACL was outlined on the images and the Blumensaat line wasalso drawn.The turning point from the posterior cartilage of the lateral femoral condyle to the posterior femoral metaphysis was defined as point O.Single-or double-bundle reconstruction pattern was determined in the volunteers according to their foot-print shape.The distance from point O to the single-bundle center and the angle between the Blumensaat line and the line from point O to the foot-print center (∠ 1),the distance from point O to the anteromedia1 bundle center and the angle between the Blumensaat line and the line from point O to the foot-print center (∠2),the distance from point O to the posterolateral bundle center and the angle between the Blumensaat line and the line from point O to the foot-print center (∠ 3) were measured.The above method was used in the clinical ACL reconstruction of 10 cases of simple ACL injury to pinpoint the femoral foot-print of ACL.Results In the 37 knees suitable for single-bundle reconstruction,the distance from point O to the foot-print center was 1.24 cm and∠ 1 43.4° on average.In the 32 knees suitable for double-bundle reconstruction,the distance from point O to the anteromedia1 foot-print center was 0.90 cm and ∠ 2 44.5° on average,and the distance from point O to the posterolateral foot-print center was 1.48 cm and∠3 47.9° on average.Dual-source CT scan showed fine accuracy and repeatability of the measurements by this novel method used in the 10 cases of clinical ACL reconstruction.Conclusions Since this novel method can well pinpoint the femoral foot-print of

  3. Alternating electric fields (TTFields) inhibit metastatic spread of solid tumors to the lungs.

    Science.gov (United States)

    Kirson, Eilon D; Giladi, Moshe; Gurvich, Zoya; Itzhaki, Aviran; Mordechovich, Daniel; Schneiderman, Rosa S; Wasserman, Yoram; Ryffel, Bernhard; Goldsher, Dorit; Palti, Yoram

    2009-01-01

    Tumor treating fields (TTFields) are low intensity, intermediate frequency, alternating electric fields used to treat cancerous tumors. This novel treatment modality effectively inhibits the growth of solid tumors in vivo and has shown promise in pilot clinical trials in patients with advanced stage solid tumors. TTFields were tested for their potential to inhibit metastatic spread of solid tumors to the lungs in two animal models: (1) Mice injected with malignant melanoma cells (B16F10) into the tail vein, (2) New Zealand White rabbits implanted with VX-2 tumors within the kidney capsule. Mice and rabbits were treated using two-directional TTFields at 100-200 kHz. Animals were either monitored for survival, or sacrificed for pathological and histological analysis of the lungs. The total number of lung surface metastases and the absolute weight of the lungs were both significantly lower in TTFields treated mice then in sham control mice. TTFields treated rabbits survived longer than sham control animals. This extension in survival was found to be due to an inhibition of metastatic spread, seeding or growth in the lungs of TTFields treated rabbits compared to controls. Histologically, extensive peri- and intra-tumoral immune cell infiltration was seen in TTFields treated rabbits only. These results raise the possibility that in addition to their proven inhibitory effect on the growth of solid tumors, TTFields may also have clinical benefit in the prevention of metastatic spread from primary tumors.

  4. Agent-based modeling to simulate the dengue spread

    Science.gov (United States)

    Deng, Chengbin; Tao, Haiyan; Ye, Zhiwei

    2008-10-01

    In this paper, we introduce a novel method ABM in simulating the unique process for the dengue spread. Dengue is an acute infectious disease with a long history of over 200 years. Unlike the diseases that can be transmitted directly from person to person, dengue spreads through a must vector of mosquitoes. There is still no any special effective medicine and vaccine for dengue up till now. The best way to prevent dengue spread is to take precautions beforehand. Thus, it is crucial to detect and study the dynamic process of dengue spread that closely relates to human-environment interactions where Agent-Based Modeling (ABM) effectively works. The model attempts to simulate the dengue spread in a more realistic way in the bottom-up way, and to overcome the limitation of ABM, namely overlooking the influence of geographic and environmental factors. Considering the influence of environment, Aedes aegypti ecology and other epidemiological characteristics of dengue spread, ABM can be regarded as a useful way to simulate the whole process so as to disclose the essence of the evolution of dengue spread.

  5. Spreading of a Lidocaine Formulation on Microneedle-Treated Skin.

    Science.gov (United States)

    Nayak, Atul; Das, Diganta B; Chao, Tzu C; Starov, Victor M

    2015-12-01

    The spreadability of a liquid drug formulation on skin is an indication of it either remaining stationary or distributing (spreading) as a droplet. Factors determining droplet spreadability of the formulation are spreading area, diameter of the droplet base, viscosity of the liquid, contact angle, volume of droplet on skin and any others. The creation of microcavities from the application of microneedle (MN) has the potential to control droplet spreading, and hence, target specific areas of skin for drug delivery. However, there is little work that demonstrates spreading of liquid drug formulation on MN-treated skin. Below, spreading of a lidocaine hydrogel formulation and lidocaine solution (reference liquid) on porcine skin is investigated over MN-treated skin. Controlled spreadability was achieved with the lidocaine hydrogel on MN-treated skin as compared with lidocaine solution. It was observed that the droplet spreading parameters such as spreading radius, droplet height and dynamic contact angle were slightly lower for the lidocaine hydrogel than the lidocaine solution on skin. Also, the lidocaine hydrogel on MN-treated skin resulted in slower dynamic reduction of droplet height, contact angle and reduced time taken in attaining static advancing droplets because of the MN microcavities.

  6. Axisymmetric model of drop spreading on a horizontal surface

    Science.gov (United States)

    Mistry, Aashutosh; Muralidhar, K.

    2015-09-01

    Spreading of an initially spherical liquid drop over a textured surface is analyzed by solving an integral form of the governing equations. The mathematical model extends Navier-Stokes equations by including surface tension at the gas-liquid boundary and a force distribution at the three phase contact line. While interfacial tension scales with drop curvature, the motion of the contact line depends on the departure of instantaneous contact angle from its equilibrium value. The numerical solution is obtained by discretizing the spreading drop into disk elements. The Bond number range considered is 0.01-1. Results obtained for sessile drops are in conformity with limiting cases reported in the literature [J. C. Bird et al., "Short-time dynamics of partial wetting," Phys. Rev. Lett. 100, 234501 (2008)]. They further reveal multiple time scales that are reported in experiments [K. G. Winkels et al., "Initial spreading of low-viscosity drops on partially wetting surfaces," Phys. Rev. E 85, 055301 (2012) and A. Eddi et al., "Short time dynamics of viscous drop spreading," Phys. Fluids 25, 013102 (2013)]. Spreading of water and glycerin drops over fully and partially wetting surfaces is studied in terms of excess pressure, wall shear stress, and the dimensions of the footprint. Contact line motion is seen to be correctly captured in the simulations. Water drops show oscillations during spreading while glycerin spreads uniformly over the surface.

  7. [Cortical spreading depolarization: a new pathophysiological mechanism in neurological diseases].

    Science.gov (United States)

    Sánchez-Porras, Renán; Robles-Cabrera, Adriana; Santos, Edgar

    2014-05-20

    Cortical spreading depolarization is a wave of almost complete depolarization of the neuronal and glial cells that occurs in different neurological diseases such as migraine with aura, subarachnoid hemorrhage, intracerebral hemorrhage, head trauma and stroke. These depolarization waves are characterized by a change in the negative potential with an amplitude between -10 and -30mV, duration of ∼1min and changes in the ion homeostasis between the intra- and extracellular space. This results in neuronal edema and dendritic distortion. Under pathologic states of hypoperfusion, cortical spreading depolarization can produce oxidative stress, worsen hypoxia and induce neuronal death. This is due to intense arterial vasoconstriction produced by an inverse response called spreading ischemia. Only in the last years there has been an electrophysiological confirmation of cortical spreading depolarization in human brains. Occurrence of cortical spreading depolarization has been associated with worse outcome in patients. Currently, increased knowledge regarding the pathophysiologic mechanisms supports the hypothetical correlation of cortical spreading depolarization with brain damage in humans. There are diverse therapeutic alternatives that promise inhibition of cortical spreading depolarization and subsequent better outcomes. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  8. Influence of trust in the spreading of information

    Science.gov (United States)

    Wu, Hongrun; Arenas, Alex; Gómez, Sergio

    2017-01-01

    The understanding and prediction of information diffusion processes on networks is a major challenge in network theory with many implications in social sciences. Many theoretical advances occurred due to stochastic spreading models. Nevertheless, these stochastic models overlooked the influence of rational decisions on the outcome of the process. For instance, different levels of trust in acquaintances do play a role in information spreading, and actors may change their spreading decisions during the information diffusion process accordingly. Here, we study an information-spreading model in which the decision to transmit or not is based on trust. We explore the interplay between the propagation of information and the trust dynamics happening on a two-layer multiplex network. Actors' trustable or untrustable states are defined as accumulated cooperation or defection behaviors, respectively, in a Prisoner's Dilemma setup, and they are controlled by a memory span. The propagation of information is abstracted as a threshold model on the information-spreading layer, where the threshold depends on the trustability of agents. The analysis of the model is performed using a tree approximation and validated on homogeneous and heterogeneous networks. The results show that the memory of previous actions has a significant effect on the spreading of information. For example, the less memory that is considered, the higher is the diffusion. Information is highly promoted by the emergence of trustable acquaintances. These results provide insight into the effect of plausible biases on spreading dynamics in a multilevel networked system.

  9. Acceleration of Evolutionary Spread by Long-Range Dispersal

    Science.gov (United States)

    Hallatschek, Oskar

    2014-03-01

    The spreading of evolutionary novelties across populations is the central element of adaptation. Unless population are well-mixed (like bacteria in a shaken test tube), the spreading dynamics not only depends on fitness differences but also on the dispersal behavior of the species. Spreading at a constant speed is generally predicted when dispersal is sufficiently short-ranged. However, the case of long-range dispersal is unresolved: While it is clear that even rare long-range jumps can lead to a drastic speedup, it has been difficult to analyze the ensuing stochastic growth process. We present a simple self-consistent argument supported by simulations that accurately predicts evolutionary spread for broad distributions of long distance dispersal. In contrast to the exponential laws predicted by deterministic ``mean-field'' models, spread is either according to a super-linear power-law or a stretched exponential law, depending on the tails of the dispersal kernel. Fluctuations and the relation to supercritical long-range percolation are discussed. Due to the simplicity of our model, which lacks any complex interactions between individuals, we expect our results to be applicable to a wide range of spreading processes. Our results may be used, in particular, to estimate the spread of modern human epidemics, which are greatly accelerated by the human aviation. Based on joint work with Daniel S. Fisher, Stanford.

  10. Energy-Spread-Feedback System for the KEKB Injector Linac

    CERN Document Server

    Satoh, Masanori; Suwada, Tsuyoshi

    2005-01-01

    New energy-spread feedback system using nondestructive energy-spread monitors have been developed in order to control and stabilize the energy spreads of single-bunch electron and positron beams in the KEKB injector linac. The well-controlled feedback systems of the injector linac are successfully working in dairy operation not only for keeping the injection rate higher along with the beam-orbit and energy feedback systems but also for reducing a background level to the high-energy B-factory experiment. The energy spreads of the injection beams are well stabilized within 0.2%, 0.5% and 0.3% for the electron beam, the positron beam, and the high-current primary electron beam for positron production, respectively, through the energy-spread feedback system under the nominal operation condition. In this paper, we will report in detail the energy-spread feedback system using the nondestructive energy-spread monitors with multi-strip-line electrodes and their performance in the KEKB operation.

  11. Where are the undiscovered hydrothermal vents on oceanic spreading ridges?

    Science.gov (United States)

    Beaulieu, Stace E.; Baker, Edward T.; German, Christopher R.

    2015-11-01

    In nearly four decades since the discovery of deep-sea vents, one-third of the length of global oceanic spreading ridges has been surveyed for hydrothermal activity. Active submarine vent fields are now known along the boundaries of 46 out of 52 recognized tectonic plates. Hydrothermal survey efforts over the most recent decade were sparked by national and commercial interests in the mineral resource potential of seafloor hydrothermal deposits, as well as by academic research. Here we incorporate recent data for back-arc spreading centers and ultraslow- and slow-spreading mid-ocean ridges (MORs) to revise a linear equation relating the frequency of vent fields along oceanic spreading ridges to spreading rate. We apply this equation globally to predict a total number of vent fields on spreading ridges, which suggests that ~900 vent fields remain to be discovered. Almost half of these undiscovered vent fields (comparable to the total of all vent fields discovered during 35 years of research) are likely to occur at MORs with full spreading rates less than 60 mm/yr. We then apply the equation regionally to predict where these hydrothermal vents may be discovered with respect to plate boundaries and national jurisdiction, with the majority expected to occur outside of states' exclusive economic zones. We hope that these predictions will prove useful to the community in the future, in helping to shape continuing ridge-crest exploration.

  12. Neuronal networks provide rapid neuroprotection against spreading toxicity.

    Science.gov (United States)

    Samson, Andrew J; Robertson, Graham; Zagnoni, Michele; Connolly, Christopher N

    2016-09-21

    Acute secondary neuronal cell death, as seen in neurodegenerative disease, cerebral ischemia (stroke) and traumatic brain injury (TBI), drives spreading neurotoxicity into surrounding, undamaged, brain areas. This spreading toxicity occurs via two mechanisms, synaptic toxicity through hyperactivity, and excitotoxicity following the accumulation of extracellular glutamate. To date, there are no fast-acting therapeutic tools capable of terminating secondary spreading toxicity within a time frame relevant to the emergency treatment of stroke or TBI patients. Here, using hippocampal neurons (DIV 15-20) cultured in microfluidic devices in order to deliver a localized excitotoxic insult, we replicate secondary spreading toxicity and demonstrate that this process is driven by GluN2B receptors. In addition to the modeling of spreading toxicity, this approach has uncovered a previously unknown, fast acting, GluN2A-dependent neuroprotective signaling mechanism. This mechanism utilizes the innate capacity of surrounding neuronal networks to provide protection against both forms of spreading neuronal toxicity, synaptic hyperactivity and direct glutamate excitotoxicity. Importantly, network neuroprotection against spreading toxicity can be effectively stimulated after an excitotoxic insult has been delivered, and may identify a new therapeutic window to limit brain damage.

  13. Did vaccination slow the spread of bluetongue in France?

    Science.gov (United States)

    Pioz, Maryline; Guis, Hélène; Pleydell, David; Gay, Emilie; Calavas, Didier; Durand, Benoît; Ducrot, Christian; Lancelot, Renaud

    2014-01-01

    Vaccination is one of the most efficient ways to control the spread of infectious diseases. Simulations are now widely used to assess how vaccination can limit disease spread as well as mitigate morbidity or mortality in susceptible populations. However, field studies investigating how much vaccines decrease the velocity of epizootic wave-fronts during outbreaks are rare. This study aimed at investigating the effect of vaccination on the propagation of bluetongue, a vector-borne disease of ruminants. We used data from the 2008 bluetongue virus serotype 1 (BTV-1) epizootic of southwest France. As the virus was newly introduced in this area, natural immunity of livestock was absent. This allowed determination of the role of vaccination in changing the velocity of bluetongue spread while accounting for environmental factors that possibly influenced it. The average estimated velocity across the country despite restriction on animal movements was 5.4 km/day, which is very similar to the velocity of spread of the bluetongue virus serotype 8 epizootic in France also estimated in a context of restrictions on animal movements. Vaccination significantly reduced the propagation velocity of BTV-1. In comparison to municipalities with no vaccine coverage, the velocity of BTV-1 spread decreased by 1.7 km/day in municipalities with immunized animals. For the first time, the effect of vaccination has been quantified using data from a real epizootic whilst accounting for environmental factors known to modify the velocity of bluetongue spread. Our findings emphasize the importance of vaccination in limiting disease spread across natural landscape. Finally, environmental factors, specifically those related to vector abundance and activity, were found to be good predictors of the velocity of BTV-1 spread, indicating that these variables need to be adequately accounted for when evaluating the role of vaccination on bluetongue spread.

  14. Did vaccination slow the spread of bluetongue in France?

    Directory of Open Access Journals (Sweden)

    Maryline Pioz

    Full Text Available Vaccination is one of the most efficient ways to control the spread of infectious diseases. Simulations are now widely used to assess how vaccination can limit disease spread as well as mitigate morbidity or mortality in susceptible populations. However, field studies investigating how much vaccines decrease the velocity of epizootic wave-fronts during outbreaks are rare. This study aimed at investigating the effect of vaccination on the propagation of bluetongue, a vector-borne disease of ruminants. We used data from the 2008 bluetongue virus serotype 1 (BTV-1 epizootic of southwest France. As the virus was newly introduced in this area, natural immunity of livestock was absent. This allowed determination of the role of vaccination in changing the velocity of bluetongue spread while accounting for environmental factors that possibly influenced it. The average estimated velocity across the country despite restriction on animal movements was 5.4 km/day, which is very similar to the velocity of spread of the bluetongue virus serotype 8 epizootic in France also estimated in a context of restrictions on animal movements. Vaccination significantly reduced the propagation velocity of BTV-1. In comparison to municipalities with no vaccine coverage, the velocity of BTV-1 spread decreased by 1.7 km/day in municipalities with immunized animals. For the first time, the effect of vaccination has been quantified using data from a real epizootic whilst accounting for environmental factors known to modify the velocity of bluetongue spread. Our findings emphasize the importance of vaccination in limiting disease spread across natural landscape. Finally, environmental factors, specifically those related to vector abundance and activity, were found to be good predictors of the velocity of BTV-1 spread, indicating that these variables need to be adequately accounted for when evaluating the role of vaccination on bluetongue spread.

  15. Epidemic spreading with immunization rate on complex networks

    CERN Document Server

    Tanimoto, Shinji

    2011-01-01

    We investigate the spread of diseases, computer viruses or information on complex networks and also immunization strategies to prevent or control the spread. When an entire population cannot be immunized and the effect of immunization is not perfect, we need the targeted immunization with immunization rate. Under such a circumstance we calculate epidemic thresholds for the SIR and SIS epidemic models. It is shown that, in scale-free networks, the targeted immunization is effective only if the immunization rate is equal to one. We analyze here epidemic spreading on directed complex networks, but similar results are also valid for undirected ones.

  16. Production of low energy spread ion beams with multicusp sources

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. [Lawrence Berkeley National Lab., CA (United States); Perkins, L.T. [Lawrence Berkeley National Lab., CA (United States); Gough, R.A. [Lawrence Berkeley National Lab., CA (United States); Hoffmann, M. [Lawrence Berkeley National Lab., CA (United States); Kunkel, W.B. [Lawrence Berkeley National Lab., CA (United States); Leung, K.N. [Lawrence Berkeley National Lab., CA (United States); Sarstedt, M. [Lawrence Berkeley National Lab., CA (United States); Vujic, J. [Lawrence Berkeley National Lab., CA (United States); Weber, M. [Lawrence Berkeley National Lab., CA (United States); Williams, M.D. [Lawrence Berkeley National Lab., CA (United States)

    1996-05-11

    The use of multicusp sources to generate ion beams with narrow energy spread has been investigated. It is found that the presence of a magnetic filter can reduce the longitudinal energy spread significantly. This is achieved by creating a uniform plasma potential distribution in the discharge chamber region, eliminating ion production in the extraction chamber and in the sheath of the exit aperture and by minimizing the probability of charge exchange processes in the extraction chamber. An energy spread as low as 1 eV has been measured. (orig.).

  17. Production of low energy spread ion beams with multicusp sources

    Science.gov (United States)

    Y., Lee; Perkins, L. T.; Gough, R. A.; Hoffmann, M.; Kunkel, W. B.; N. Leung, K.; Sarstedt, M.; Vujic, J.; Weber, M.; Williams, M. D.

    1996-02-01

    The use of multicusp sources to generate ion beams with narrow energy spread has been investigated. It is found that the presence of a magnetic filter can reduce the longitudinal energy spread significantly. This is achieved by creating a uniform plasma potential distribution in the discharge chamber region, eliminating ion production in the extraction chamber and in the sheath of the exit aperture and by minimizing the probability of charge exchange processes in the extraction chamber. An energy spread as low as 1 eV has been measured.

  18. Spreading of Trisiloxanes on Thin Water Film: Dry Spot Profile

    OpenAIRE

    Derrick Ovunda NJOBUENWU

    2007-01-01

    This paper reports the results of an experimental investigation of the spreading of trisiloxanes EO6, EO7, EO8, EO9 and sodium dodecyl sulphate SDS on thin films which are 320 microns in thickness; the concentrations covered are above the CMC. The spreading of SDS is accompanied by the formation of a “dry spot” which advances in time roughly as t1/4. The trisiloxanes spreading gave rise to dry spot formation that was accompanied by “irregularities”, which corresponded to an abrupt jump in the...

  19. Numerical simulation of filler metal droplets spreading in laser brazing

    Science.gov (United States)

    Chen, Yanbin; Feng, Xiaosong; Li, Liqun

    2007-11-01

    A finite element model was constructed using a commercial software Fidap to analyze the Cu-base filler metal droplet spreading process in laser brazing, in which the temperature distribution, droplet geometry, and fluid flow velocity were calculated. Marangoni and buoyancy convection and gravity force were considered, and the effects of laser power and spot size on the spreading process were evaluated. Special attention was focused on the free surface of the droplet, which determines the profile of the brazing spot. The simulated results indicate that surface tension is the dominant flow driving force and laser spot size determines the droplet spreading domain.

  20. Dynamic wetting and spreading and the role of topography.

    Science.gov (United States)

    McHale, Glen; Newton, Michael I; Shirtcliffe, Neil J

    2009-11-18

    The spreading of a droplet of a liquid on a smooth solid surface is often described by the Hoffman-de Gennes law, which relates the edge speed, v(e), to the dynamic and equilibrium contact angles θ and θ(e) through [Formula: see text]. When the liquid wets the surface completely and the equilibrium contact angle vanishes, the edge speed is proportional to the cube of the dynamic contact angle. When the droplets are non-volatile this law gives rise to simple power laws with time for the contact angle and other parameters in both the capillary and gravity dominated regimes. On a textured surface, the equilibrium state of a droplet is strongly modified due to the amplification of the surface chemistry induced tendencies by the topography. The most common example is the conversion of hydrophobicity into superhydrophobicity. However, when the surface chemistry favors partial wetting, topography can result in a droplet spreading completely. A further, frequently overlooked consequence of topography is that the rate at which an out-of-equilibrium droplet spreads should also be modified. In this report, we review ideas related to the idea of topography induced wetting and consider how this may relate to dynamic wetting and the rate of droplet spreading. We consider the effect of the Wenzel and Cassie-Baxter equations on the driving forces and discuss how these may modify power laws for spreading. We relate the ideas to both the hydrodynamic viscous dissipation model and the molecular-kinetic theory of spreading. This suggests roughness and solid surface fraction modified Hoffman-de Gennes laws relating the edge speed to the dynamic and equilibrium contact angle. We also consider the spreading of small droplets and stripes of non-volatile liquids in the capillary regime and large droplets in the gravity regime. In the case of small non-volatile droplets spreading completely, a roughness modified Tanner's law giving the dependence of dynamic contact angle on time is

  1. Modelling spreading dynamics of liquid crystals in three spatial dimensions

    CERN Document Server

    Lin, Te-Sheng; Thiele, Uwe; Cummings, Linda J

    2013-01-01

    We study spreading dynamics of nematic liquid crystal droplets within the framework of the long-wave approximation. A fourth order nonlinear parabolic partial differential equation governing the free surface evolution is derived. The influence of elastic distortion energy and of imposed anchoring variations at the substrate are explored through linear stability analysis and scaling arguments, which yield useful insight and predictions for the behaviour of spreading droplets. This behaviour is captured by fully nonlinear time-dependent simulations of three dimensional droplets spreading in the presence of anchoring variations that model simple defects in the nematic orientation at the substrate.

  2. Spreads of bonds issued by sub-sovereign European governments

    Directory of Open Access Journals (Sweden)

    Nicolas Jannone Bellot

    2017-09-01

    Full Text Available This paper identifies the factors that affect the primary and secondary market spreads of fixed and variable rate bonds issued by sub-sovereign European governments. The two markets were analyzed separately to compare whether the factors for the primary market coincided with those for the secondary market. Data for the period between February 2008 and December 2013 were analyzed using panel data estimation. The two markets behaved almost identically, and the signs of the variables were as expected in nearly every case. The most important factor determining the spread of sub-sovereign bonds was the spread of the sovereign bond.

  3. Numerical simulation of filler metal droplets spreading in laser brazing

    Institute of Scientific and Technical Information of China (English)

    Yanbin Chen; Xiaosong Feng; Liqun Li

    2007-01-01

    A finite element model was constructed using a commercial software Fidap to analyze the Cu-base filler metal droplet spreading process in laser brazing, in which the temperature distribution, droplet geometry,and fluid flow velocity were calculated. Marangoni and buoyancy convection and gravity force were considered, and the effects of laser power and spot size on the spreading process were evaluated. Special attention was focused on the free surface of the droplet, which determines the profile of the brazing spot.The simulated results indicate that surface tension is the dominant flow driving force and laser spot size determines the droplet spreading domain.

  4. Spreading dynamics in heterogeneous graphs: Beyond the assortativity coefficient

    Science.gov (United States)

    Sugarelli, Michele; Vergni, Davide

    2017-02-01

    We study spreading dynamics of a reaction-diffusion process in a special class of heterogeneous graphs with Poissonian degree distribution and composed of both local and long range links. The behavior of the spreading dynamics on such networks are investigated by relating them to the topological features of graphs. We find that the degree of assortativity can give just some indication about the large scale behavior of the spreading dynamics while a detailed description of the process can be addressed by introducing new, more appropriate, topological quantities linked to the distance between nodes.

  5. Lung Cancer: Early Detection is the Key | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: Lung Cancer Early Detection is the Key Past Issues / Winter 2013 Table of Contents Lung cancer survivor Dusty Donaldson helps to spread the word ...

  6. Rumor Spreading Model with Trust Mechanism in Complex Social Networks

    Institute of Scientific and Technical Information of China (English)

    WANG Ya-Qi; YANG Xiao-Yuan; HAN Yi-Liang; WANG Xu-An

    2013-01-01

    In this paper,to study rumor spreading,we propose a novel susceptible-infected-removed (SIR) model by introducing the trust mechanism.We derive mean-field equations that describe the dynamics of the SIR model on homogeneous networks and inhomogeneous networks.Then a steady-state analysis is conducted to investigate the critical threshold and the final size of the rumor spreading.We show that the introduction of trust mechanism reduces the final rumor size and the velocity of rumor spreading,but increases the critical thresholds on both networks.Moreover,the trust mechanism not only greatly reduces the maximum rumor influence,but also postpones the rumor terminal time,which provides us with more time to take measures to control the rumor spreading.The theoretical results are confirmed by sufficient numerical simulations.

  7. Epidemic spreading on random surfer networks with infected avoidance strategy

    Science.gov (United States)

    Feng, Yun; Ding, Li; Huang, Yun-Han; Guan, Zhi-Hong

    2016-12-01

    In this paper, we study epidemic spreading on random surfer networks with infected avoidance (IA) strategy. In particular, we consider that susceptible individuals’ moving direction angles are affected by the current location information received from infected individuals through a directed information network. The model is mainly analyzed by discrete-time numerical simulations. The results indicate that the IA strategy can restrain epidemic spreading effectively. However, when long-distance jumps of individuals exist, the IA strategy’s effectiveness on restraining epidemic spreading is heavily reduced. Finally, it is found that the influence of the noises from information transferring process on epidemic spreading is indistinctive. Project supported in part by the National Natural Science Foundation of China (Grant Nos. 61403284, 61272114, 61673303, and 61672112) and the Marine Renewable Energy Special Fund Project of the State Oceanic Administration of China (Grant No. GHME2013JS01).

  8. The effect of the forget-remember mechanism on spreading

    CERN Document Server

    Gu, Jiao; Cai, Xu

    2010-01-01

    We introduce a new mechanism---the forget-remember mechanism into the spreading process. Equipped with such a mechanism an individual is prone to forget the "message" received and remember the one forgotten, namely switching his state between active (with message) and inactive (without message). The probability of state switch is governed by linear or exponential forget-remember functions of history time which is measured by the time elapsed since the most recent state change. Our extensive simulations reveal that the forget-remember mechanism has significant effects on the saturation of message spreading, and may even lead to a termination of spreading under certain conditions. This finding may shed some light on how to control the spreading of epidemics. It is found that percolation-like phase transitions can occur. By investigating the properties of clusters, formed by connected, active individuals, we may be able to justify the existence of such phase transitions.

  9. Competing spreading processes on multiplex networks: awareness and epidemics

    CERN Document Server

    Granell, Clara; Arenas, Alex

    2014-01-01

    Epidemic-like spreading processes on top of multilayered interconnected complex networks reveal a rich phase diagram of intertwined competition effects. A recent study by the authors [Granell et al. Phys. Rev. Lett. 111, 128701 (2013)] presented the analysis of the interrelation between two processes accounting for the spreading of an epidemics, and the spreading of information awareness to prevent its infection, on top of multiplex networks. The results in the case in which awareness implies total immunization to the disease, revealed the existence of a metacritical point at which the critical onset of the epidemics starts depending on the reaching of the awareness process. Here we present a full analysis of these critical properties in the more general scenario where the awareness spreading does not imply total immunization, and where infection does not imply immediate awareness of it. We find the critical relation between both competing processes for a wide spectrum of parameters representing the interacti...

  10. Animal Research Yields Clues to Sexual Spread of Zika

    Science.gov (United States)

    ... Animal Research Yields Clues to Sexual Spread of Zika Researchers think vaginal fluid may be ideal breeding ... in mice may offer insight into how the Zika virus is transmitted sexually and affects a fetus. ...

  11. Improvement of SNR with Chaotic Spreading Sequences for CDMA

    CERN Document Server

    Umeno, K; Umeno, Ken; Kitayama, Ken-ichi

    1999-01-01

    We show that chaotic spreading sequences generated by ergodic mappings of Chebyshev orthogonal polynomials have better correlation properties for CDMA(code division multiple access) than the optimal binary sequences (Gold sequences) in the sense of ensemble average.

  12. Epidemic spreading in time-varying community networks

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Guangming, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [School of Electronic and Information, Guangdong Polytechnic Normal University, Guangzhou 510665 (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Xingyuan, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024 (China)

    2014-06-15

    The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q{sub c}. The epidemic will survive when q > q{sub c} and die when q < q{sub c}. These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure.

  13. Aquatic invertebrates doubly suspect in spreading duck malady : 1958

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A 1958 news release providing a brief overview of the U.S. Fish and Wildlife Service's findings regarding the role aquatic invertebrates play in the spread of avian...

  14. Physical Proximity and Spreading in Dynamic Social Networks

    CERN Document Server

    Stopczynski, Arkadiusz; Lehmann, Sune

    2015-01-01

    Most infectious diseases spread on a dynamic network of human interactions. Recent studies of social dynamics have provided evidence that spreading patterns may depend strongly on detailed micro-dynamics of the social system. We have recorded every single interaction within a large population, mapping out---for the first time at scale---the complete proximity network for a densely-connected system. Here we show the striking impact of interaction-distance on the network structure and dynamics of spreading processes. We create networks supporting close (intimate network, up to ~1m) and longer distance (ambient network, up to ~10m) modes of transmission. The intimate network is fragmented, with weak ties bridging densely-connected neighborhoods, whereas the ambient network supports spread driven by random contacts between strangers. While there is no trivial mapping from the micro-dynamics of proximity networks to empirical epidemics, these networks provide a telling approximation of droplet and airborne modes o...

  15. On the influence of trust in the spreading of information

    CERN Document Server

    Wu, Hongrun; Gómez, Sergio

    2016-01-01

    The understanding and prediction of information diffusion processes on networks is a major challenge in network theory with many implications in social sciences. Many theoretical advances came at the hand of stochastic spreading models. Nevertheless, these stochastic models overlooked the influence of rational decision on the outcome of the process. For instance, different levels of trust on acquaintances do play a role in the information spreading, and actors may change their spreading decisions during the information diffusion process accordingly. Here, we study an information spreading model where the decision to transmit or not is based on trust. We explore the interplay between the propagation of information and the trust dynamics happening on a two layer multiplex network. Actors' trustable or untrustable states are assimilated as accumulated cooperation or defection behaviors, respectively, in a prisoners' dilemma set up, and controlled by a memory span. The propagation of the information is abstracted...

  16. Knowledge of and misconceptions about the spread and prevention ...

    African Journals Online (AJOL)

    2009-05-27

    May 27, 2009 ... and misconceptions regarding the spread and prevention of HIV in older women attending the Tshwane District ... in this group.10,11 In such relations, the woman's risk is nine ..... Public media education campaigns targeting.

  17. Traffic-driven epidemic spreading in correlated networks

    CERN Document Server

    Yang, Han-Xin; Lai, Ying-Cheng

    2015-01-01

    In spite of the extensive previous efforts on traffic dynamics and epidemic spreading in complex networks, the problem of traffic-driven epidemic spreading on {\\em correlated} networks has not been addressed. Interestingly, we find that the epidemic threshold, a fundamental quantity underlying the spreading dynamics, exhibits a non-monotonic behavior in that it can be minimized for some critical value of the assortativity coefficient, a parameter characterizing the network correlation. To understand this phenomenon, we use the degree-based mean-field theory to calculate the traffic-driven epidemic threshold for correlated networks. The theory predicts that the threshold is inversely proportional to the packet-generation rate and the largest eigenvalue of the betweenness matrix. We obtain consistency between theory and numerics. Our results may provide insights into the important problem of controlling/harnessing real-world epidemic spreading dynamics driven by traffic flows.

  18. Determinants of Commercial Banks' Interest Rate Spread in Namibia ...

    African Journals Online (AJOL)

    bank, commercial banks, development financial institutions and the non-banking sector which consists of .... its interest rate spread in order to shield itself against the risk. This suggests that the ..... PSG Wealth Management (Namibia). (2013).

  19. Predicted Spatial Spread of Canine Rabies in Australia

    National Research Council Canada - National Science Library

    Johnstone-Robertson, Simon P; Fleming, Peter J. S; Ward, Michael P; Davis, Stephen A

    2017-01-01

    ... for the spread of canine rabies in the currently rabies-free wild dog population of Australia. The introduction of a sub-clinically infected dog from Indonesia is a distinct possibility, as is t...

  20. Competing spreading processes and immunization in multiplex networks

    CERN Document Server

    Gao, Bo

    2016-01-01

    Epidemic spreading on physical contact network will naturally introduce the human awareness information diffusion on virtual contact network, and the awareness diffusion will in turn depress the epidemic spreading, thus forming the competing spreading processes of epidemic and awareness in a multiplex networks. In this paper, we study the competing dynamics of epidemic and awareness, both of which follow the SIR process, in a two-layer networks based on microscopic Markov chain approach and numerical simulations. We find that strong capacities of awareness diffusion and self-protection of individuals could lead to a much higher epidemic threshold and a smaller outbreak size. However, the self-awareness of individuals has no obvious effect on the epidemic threshold and outbreak size. In addition, the immunization of the physical contact network under the interplay between of epidemic and awareness spreading is also investigated. The targeted immunization is found performs much better than random immunization, ...

  1. Influence of periodic traffic congestion on epidemic spreading

    Science.gov (United States)

    Zheng, Muhua; Ruan, Zhongyuan; Tang, Ming; Do, Younghae; Liu, Zonghua

    2016-11-01

    In the metropolis, traffic congestion has become a very serious problem, especially in rush hours. This congestion causes people to have more chance to contact each other and thus will accelerate epidemic spreading. To explain this observation, we present a reaction-diffusion (RD) model with a periodic varying diffusion rate to represent the daily traveling behaviors of human beings and its influence to epidemic spreading. By extensive numerical simulations, we find that the epidemic spreading can be significantly influenced by traffic congestion where the amplitude, period and duration of diffusion rate are the three key parameters. Furthermore, a brief theory is presented to explain the effects of the three key parameters. These findings suggest that except the normal ways of controlling contagion in working places and long-distance traveling, controlling the contagion in daily traffic congestion may be another effective way to reduce epidemic spreading.

  2. Experimental Measurements of Spreading of Volatile Liquid Droplets

    Science.gov (United States)

    Zhang, Neng-Li; Chao, David F.

    2001-01-01

    Based on the laser shadowgraphic system used by the first author of the present paper, a simple optical system, which combined the laser shadowgraphy and the direct magnified-photography, has been developed to measure the contact angle, the spreading speed, and the evaporation rate. Additionally, the system can also visualize thermocapillary convection inside of a sessile drop simultaneously. The experimental results show that evaporation/condensation and thermocapillary convection in the sessile drop induced by the evaporation strongly affects the wetting and spreading of the drop. Condensation always promotes the wetting and spreading of the drop. Evaporation may increase or decrease the contact angle of the evaporating sessile drops, depending on the evaporation rate. The thermocapillary convection in the drop induced by the evaporation enhances the effects of evaporation to suppress the spreading.

  3. Little Threat of Zika Spread from Rio Olympics

    Science.gov (United States)

    ... html Little Threat of Zika Spread From Rio Olympics: Study Because it's winter in Brazil, mosquito activity ... HealthDay News) -- Travelers and competitors at the 2016 Olympic Games in Brazil are not likely to contract ...

  4. How to Prevent Spread of The Skin Infection Impetigo

    Science.gov (United States)

    ... How to Prevent Spread of the Skin Infection Impetigo It's a common childhood ailment, but adults can ... 27, 2016 SUNDAY, Nov. 27, 2016 (HealthDay News) -- Impetigo is a contagious skin infection that's preventable and ...

  5. Modelling of spreading process: effect from hydrogen bonds

    Institute of Scientific and Technical Information of China (English)

    Li Xin; Hu Yuan-Zhong; Jiang Lan

    2008-01-01

    Lubricant spreading on solid substrates has drawn considerable attention not only for the microscopic wetting theory but also for the dramatic application in head-disk interface of magnetic storage drive systems. Molecular dynamic simulation based on a coarse-grained bead-spring model has been used to study such a spreading process.The spreading profiles indicate that the hydrogen bonds among lubricant molecules and the hydrogen bonds between lubricant molecules and polar atoms of solid substrates will complicate the spreading process in a tremendous degree.The hydrogen bonds among lubricant molecules will strengthen the lubricant combination intensity, which may hinder most molecules from flowing down to the substrates and diffusing along the substrates. And the hydrogen bonds between lubricant molecules and polar atoms of solid substrates will confine the lubricant molecules around polar atoms, which may hinder the molecules from diffusing along the substrates and cause precursor film to vanish.

  6. Physical properties of fertilizer in relation to handling and spreading.

    NARCIS (Netherlands)

    Hofstee, J.W.

    1993-01-01

    The influence of physical properties of fertilizer on the handling and spreading is studied. The reviewed properties are particle size and particle size distribution, coefficient of friction, coefficient of restitution, particle strength and aerodynamic resistance. Further a measuring procedure base

  7. Epidemic spreading behavior in local-world evolving networks

    Institute of Scientific and Technical Information of China (English)

    Chengyi Xia; Zhongxin Liu; Zengqiang Chen; Shiwen Sun; Zhuzhi Yuan

    2008-01-01

    The susceptible-infected-susceptible (SIS) epidemic model is presented which can be used to study the epidemic spreading behavior in the local-world evolving network model. Local-world evolving model displays a transition from the exponential network to the scale-free network with respect to the connectivity distribution. From theoretical analyses and numerical simulations, we find that the epidemic spreading behavior on local-world networks also takes on some kind of transitional behaviors. The transitional behavior is further verified by comparing the spreading behavior of local-world network with that of random and scale-free networks. Some feasible control strategies are also proposed to keep from the epidemic spreading on networks.

  8. Temporal network sparsity and the slowing down of spreading

    CERN Document Server

    Perotti, Juan Ignacio; Holme, Petter; Saramäki, Jari

    2014-01-01

    Interactions in time-varying complex systems are often very heterogeneous at the topological level (who interacts with whom) and at the temporal level (when interactions occur and how often). While it is known that temporal heterogeneities often have strong effects on dynamical processes, e.g. the burstiness of contact sequences is associated with slower spreading dynamics, the picture is far from complete. In this paper, we show that temporal heterogeneities result in temporal sparsity} at the time scale of average inter-event times, and that temporal sparsity determines the amount of slowdown of Susceptible-Infectious (SI) spreading dynamics on temporal networks. This result is based on the analysis of several empirical temporal network data sets. An approximate solution for a simple network model confirms the association between temporal sparsity and slowdown of SI spreading dynamics. Since deterministic SI spreading always follows the fastest temporal paths, our results generalize -- paths are slower to t...

  9. Non-isothermal spreading dynamics of self-rewetting droplets

    Science.gov (United States)

    Mamalis, Dimitris; Sefiane, Khellil; Sahu, Kirti Chandra; Karapetsas, George; Matar, Omar K.

    2015-11-01

    We study the spreading dynamics of droplets on uniformly heated substrates. More specifically, we consider the case of binary alcohol mixtures which exhibit a non-monotonic dependence of the surface tension on temperature; these systems are often referred in the literature as self-rewetting fluids. We show through experiments that the early-stage spreading exponents depend non-monotonically on the substrate temperature in contrast to the monotonic dependence of pure liquids. In addition, we observe through the use of IR thermography visualization the formation of spontaneous travelling waves which develop along and across the free surface of the evaporating droplet and influence the spreading behaviour. Finally, we develop a theoretical model based on lubrication theory and derive an evolution equation for the interface accounting for capillarity and thermocapillarity. Using this model we investigate the effect of varying droplet wettability, which is linked to the temperature of the solid surface, on the spreading dynamics.

  10. Beat Noise Limitation in Coherent Time-Spreading OCDMA Network

    Institute of Scientific and Technical Information of China (English)

    Ken-ichi; Kitayama; Koji; Mutsushima

    2003-01-01

    The BER performance of the coherent time-spreading OCDMA network is analyzed by considering the MAI and beat noises as well as the other additive noises. The influence and solution for the beat noise issue are discussed.

  11. Water Droplet Spreading and Wicking on Nanostructured Surfaces.

    Science.gov (United States)

    Chen, Xue; Chen, Jiannan; Ouyang, Xiaolong; Song, Yu; Xu, Ruina; Jiang, Peixue

    2017-07-11

    Phase-change heat transfer on nanostructured surfaces is an efficient cooling method for high heat flux devices due to its superior wettability. Liquid droplet spreading and wicking effect then dominate the heat transfer. Therefore, this study investigates the flow behavior after a droplet touches a nanostructured surface focusing on the ZnO nanowire surface with three different nanowire sizes and two array types (regular and irregular). The spreading diameter and the wicking diameter are measured against time. The results show that the average spreading and wicking velocities on a regular nanostructured surface are both smaller than those on an irregular nanostructured surface and that the nanowire size affects the liquid spreading and capillary wicking.

  12. Infections Unlikely to be Spread Through Swimming Pools

    Science.gov (United States)

    ... lice, MRSA (methicillin-resistant Staphylococcus aureus ), and pin worm are unlikely to be spread through the use ... boils) that may be: Mistaken for spider bites Red, swollen, painful, warm to the touch, and have ...

  13. The SIRS Model of Epidemic Spreading in Virtual Society

    Science.gov (United States)

    Grabowski, A.; Kosiński, R.

    2008-09-01

    Dedicated to Professor Dietrich Stauffer on the occasion of his 65th birthday The phenomenon of epidemic spreading in a real social network is described and investigated numerically. On the basis of data concerning amount of time devoted daily to social interactions, the influence of human activity on spreading process is investigated in the frame of SIRS model. It was found that the activity of an individual is positively correlated with its connectivity and the relation has power law form. The influence of control measures on the spreading process is investigated as a function of initial conditions. The cost-effectiveness of mass immunizations campaigns and target vaccinations is compared. It was found that the form of activity distribution has significant influence on the spreading phenomena in the network.

  14. Epidemic spreading in interconnected networks: a continuous time approach

    CERN Document Server

    de Arruda, Guilherme Ferraz; Peixoto, Tiago P; Rodrigues, Francisco A; Moreno, Yamir

    2015-01-01

    We present a continuous formulation of epidemic spreading on interconnected networks using a tensorial notation, extending the models of monoplex networks to this context. We derive analytical expressions for the epidemic threshold on the SIS and SIR dynamics, as well as upper and lower bounds for the steady-state. Using the quasi-stationary state (QS) method we show the emergence of two or more phase transitions, and propose an analytical and numerical analysis based on the inverse participation ratio. Furthermore, when mapping the critical epidemic dynamics to the eigenvalue problem, we observe a characteristic transition in the eigenvalue spectra of the supra-contact tensor as a function of the ratio of spreading rates: If the spreading rate within each layer is comparable to the rate across layers, the individual spectra of each layer merge with the coupling between layers. Our formalism provides a mathematical approach to epidemic spreading in multiplex systems and our results reinforce the importance of...

  15. Emergence and spread of antibiotic resistance: setting a parameter space

    OpenAIRE

    Martínez, José Luis; Baquero, Fernando

    2014-01-01

    The emergence and spread of antibiotic resistance among human pathogens is a relevant problem for human health and one of the few evolution processes amenable to experimental studies. In the present review, we discuss some basic aspects of antibiotic resistance, including mechanisms of resistance, origin of resistance genes, and bottlenecks that modulate the acquisition and spread of antibiotic resistance among human pathogens. In addition, we analyse several parameters that modulate the evol...

  16. A Spread Spectrum Approach to Next Generation Intrusion Detection

    Science.gov (United States)

    2005-06-01

    14. SUBJECT TERMS Spread-Spectrum Message Embedding Capacity, Distortion, Spread Spectrum Steganography , Digital Watermarking 16. PRICE CODE 17...message) in another digital signal (image or audio ) called “cover” or “host.” Two applications of watermarking are a) image/ audio authentication and b... steganography , which is an attempt to establish covert communication between trusting parties. The first step in the design of a watermarking system

  17. Spreading of sediment due to underwater blasting and dredging

    DEFF Research Database (Denmark)

    Nielsen, Morten Holtegaard; Bach, Lis; Bollwerk, Sandra

    2015-01-01

    leads to a wider spreading of the organic part of the sediment. Almost all material less than 2 μm, including surficial clay minerals and much organic material, was transported away from the construction site and its vicinity, which could imply mobilization and export of pollutants. Environmental...... or maybe even increasing the spreading of sediment, depending on, e.g., the resilience of the flora and fauna and the surficial sediment and the pollution therein....

  18. Email networks and the spread of computer viruses

    Science.gov (United States)

    Newman, M. E.; Forrest, Stephanie; Balthrop, Justin

    2002-09-01

    Many computer viruses spread via electronic mail, making use of computer users' email address books as a source for email addresses of new victims. These address books form a directed social network of connections between individuals over which the virus spreads. Here we investigate empirically the structure of this network using data drawn from a large computer installation, and discuss the implications of this structure for the understanding and prevention of computer virus epidemics.

  19. Childhood atypical meningioma with perineural spread: MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Feng-Yu.; Wong, Alex Mun-Ching; Wong, Ho-Fai; Ng, Shu-Hang [Chang Gung Memorial Hospital, Department of Diagnostic Radiology, Kwei-Shan, Tao-Yuan (Taiwan); Wu, Chieh-Tsai [Chang Gung Memorial Hospital, Department of Neurosurgery, Kwei-Shan, Tao-Yuan (Taiwan); Lin, Kuang-Lin [Chang Gung Memorial Hospital, Division of Pediatric Neurology, Kwei-Shan, Tao-Yuan (Taiwan)

    2005-09-01

    Meningiomas are uncommon in children. When they occur, they are frequently associated with neurofibromatosis type 2. Childhood meningiomas are generally large and commonly associated with cyst formation and an unusual location. Perineural tumor spread, occasionally associated with head and neck malignancies, is very rare in meningiomas. We present the MR findings of an atypical meningioma with perineural spread in a 4.5-year-old girl. (orig.)

  20. A conceptual device for spreading (good) territorial governance in Europe

    OpenAIRE

    Cotella, Giancarlo; Janin Rivolin Yoccoz, Umberto

    2014-01-01

    Is it possible to spread good territorial governance in Europe and, if so, in which ways can such aim be achieved? This paper presents a conceptual device, developed within the ESPON project TANGO (Territorial Approaches for New Governance), usable to manage the spread of examples or "features" of good territorial governance in Europe. It is worth clarifying that this paper does not face the issues of defining what is "good" in territorial governance, nor of what can or should be transferred ...

  1. The Effect of Monetary Policy on Credit Spreads

    OpenAIRE

    Tolga Cenesizoglu; Badye Essid

    2010-01-01

    In this paper, we analyze the effect of monetary policy on credit spreads between yields on corporate bonds with different ratings over changing conditions in the economy. Using futures data on the fed funds rate, we distinguish between expected and unexpected changes in monetary policy. We find that unexpected changes in the fed funds rate do not have a significant effect on changes in credit spreads when we do not control for different conditions in the economy. We then distinguish between ...

  2. The Effect of Monetary Policy on Credit Spreads

    OpenAIRE

    Tolga Cenesizoglu; Badye Essid

    2010-01-01

    In this paper, we analyze the effect of monetary policy on credit spreads between yields on corporate bonds with different ratings over changing conditions in the economy. Using futures data on the fed funds rate, we distinguish between expected and unexpected changes in monetary policy. We find that unexpected changes in the fed funds rate do not have a significant effect on changes in credit spreads when we do not control for different conditions in the economy. We then distinguish between ...

  3. Spread of H1N1 within Households

    Centers for Disease Control (CDC) Podcasts

    2010-03-29

    This podcast describes an investigation into how H1N1 was spreading within households during the initial days of the pandemic in Texas. CDC's Dr. Oliver Morgan discusses what investigators learned about the role that children played in introducing the virus into households and spreading flu.  Created: 3/29/2010 by Emerging Infectious Diseases.   Date Released: 3/29/2010.

  4. A cellular automaton framework for infectious disease spread simulation.

    Science.gov (United States)

    Pfeifer, Bernhard; Kugler, Karl; Tejada, Maria M; Baumgartner, Christian; Seger, Michael; Osl, Melanie; Netzer, Michael; Handler, Michael; Dander, Andreas; Wurz, Manfred; Graber, Armin; Tilg, Bernhard

    2008-01-01

    In this paper, a cellular automaton framework for processing the spatiotemporal spread of infectious diseases is presented. The developed environment simulates and visualizes how infectious diseases might spread, and hence provides a powerful instrument for health care organizations to generate disease prevention and contingency plans. In this study, the outbreak of an avian flu like virus was modeled in the state of Tyrol, and various scenarios such as quarantine, effect of different medications on viral spread and changes of social behavior were simulated.The proposed framework is implemented using the programming language Java. The set up of the simulation environment requires specification of the disease parameters and the geographical information using a population density colored map, enriched with demographic data.The results of the numerical simulations and the analysis of the computed parameters will be used to get a deeper understanding of how the disease spreading mechanisms work, and how to protect the population from contracting the disease. Strategies for optimization of medical treatment and vaccination regimens will also be investigated using our cellular automaton framework.In this study, six different scenarios were simulated. It showed that geographical barriers may help to slow down the spread of an infectious disease, however, when an aggressive and deadly communicable disease spreads, only quarantine and controlled medical treatment are able to stop the outbreak, if at all.

  5. Directional spread of alphaherpesviruses in the nervous system.

    Science.gov (United States)

    Kramer, Tal; Enquist, Lynn W

    2013-02-11

    Alphaherpesviruses are pathogens that invade the nervous systems of their mammalian hosts. Directional spread of infection in the nervous system is a key component of the viral lifecycle and is critical for the onset of alphaherpesvirus-related diseases. Many alphaherpesvirus infections originate at peripheral sites, such as epithelial tissues, and then enter neurons of the peripheral nervous system (PNS), where lifelong latency is established. Following reactivation from latency and assembly of new viral particles, the infection typically spreads back out towards the periphery. These spread events result in the characteristic lesions (cold sores) commonly associated with herpes simplex virus (HSV) and herpes zoster (shingles) associated with varicella zoster virus (VZV). Occasionally, the infection spreads transsynaptically from the PNS into higher order neurons of the central nervous system (CNS). Spread of infection into the CNS, while rarer in natural hosts, often results in severe consequences, including death. In this review, we discuss the viral and cellular mechanisms that govern directional spread of infection in the nervous system. We focus on the molecular events that mediate long distance directional transport of viral particles in neurons during entry and egress.

  6. Cortical spreading depression impairs oxygen delivery and metabolism in mice.

    Science.gov (United States)

    Yuzawa, Izumi; Sakadžić, Sava; Srinivasan, Vivek J; Shin, Hwa Kyoung; Eikermann-Haerter, Katharina; Boas, David A; Ayata, Cenk

    2012-02-01

    Cortical spreading depression (CSD) is associated with severe hypoperfusion in mice. Using minimally invasive multimodal optical imaging, we show that severe flow reductions during and after spreading depression are associated with a steep decline in cerebral metabolic rate of oxygen. Concurrent severe hemoglobin desaturation suggests that the oxygen metabolism becomes at least in part supply limited, and the decrease in cortical blood volume implicates vasoconstriction as the mechanism. In support of oxygen supply-demand mismatch, cortical nicotinamide adenine dinucleotide (NADH) fluorescence increases during spreading depression for at least 5 minutes, particularly away from parenchymal arterioles. However, modeling of tissue oxygen delivery shows that cerebral metabolic rate of oxygen drops more than predicted by a purely supply-limited model, raising the possibility of a concurrent reduction in oxygen demand during spreading depression. Importantly, a subsequent spreading depression triggered within 15 minutes evokes a monophasic flow increase superimposed on the oligemic baseline, which markedly differs from the response to the preceding spreading depression triggered in naive cortex. Altogether, these data suggest that CSD is associated with long-lasting oxygen supply-demand mismatch linked to severe vasoconstriction in mice.

  7. Electrically modulated dynamic spreading of drops on soft surfaces

    Science.gov (United States)

    Dey, Ranabir; Daga, Ashish; DasGupta, Sunando; Chakraborty, Suman

    2015-07-01

    The intricate interaction between the deformability of a substrate and the dynamic spreading of a liquid drop on the same, under the application of an electrical voltage, has remained far from being well understood. Here, we demonstrate that electrospreading dynamics on soft substrates is dictated by the combined interplay of electrocapillarity, the wetting line friction, and the viscoelastic energy dissipation at the contact line. Our results reveal that during such electro-elastocapillarity mediated spreading of a sessile drop, the contact radius evolution exhibits a universal power-law in a substrate elasticity based non-dimensional time, with an electrical voltage dependent spreading exponent. Simultaneously, the macroscopic dynamic contact angle variation follows a general power-law in the contact line velocity, normalized by elasticity dependent characteristic velocity scale. These findings will be beneficial for comprehending droplet spreading dynamics stemming from the combination of electrically modulated spreading and "soft wetting." Hence, our results are likely to provide the foundation for the development of a plethora of applications involving droplet manipulations by exploiting the interplay between electrically triggered spreading and substrate-compliance over interfacial scales.

  8. The spreading behaviour of perfluoropolyether droplets on solid surfaces

    Institute of Scientific and Technical Information of China (English)

    Guo Xiao-Yan; Li Xin; Hu Yuan-Zhong; Wang Hui

    2008-01-01

    The spread of perfluoropolyether (PFPE) droplets on solid surfaces has been measured from the top-down view through a microscope system. Effects of substrates, molecular weight and end-group functionality on spreading of the PFPE droplets have been studied experimentally and the results were compared with those by molecular dynamics (MD)simulations. Silicon wafer and diamond-like carbon (DLC) substrates were used to study the effect of substrates on spreading. Two types of PFPE, Z-dol and Z-tetraol, with the same chain structure and various molecular weights (2000 and 4000 g/mol) were employed in experiments. Effect of molecular weight has been investigated through comparing the spreading of Z-dol 2000 and Z-dol 4000, and it is found that the increase of molecular weight will decrease the mobility of PFPE. Comparison between spreading of Z-dol and Z-tetraol of the same molecular weight proved that functional end group plays a significant role on the spreading of PFPE, which confirmed the MD simulation results.

  9. Fire spread predictions: Sweeping uncertainty under the rug.

    Science.gov (United States)

    Benali, Akli; Sá, Ana C L; Ervilha, Ana R; Trigo, Ricardo M; Fernandes, Paulo M; Pereira, José M C

    2017-08-15

    Predicting fire spread and behavior correctly is crucial to minimize the dramatic consequences of wildfires. However, our capability of accurately predicting fire spread is still very limited, undermining the utility of such simulations to support decision-making. Improving fire spread predictions for fire management purposes, by using higher quality input data or enhanced models, can be expensive, unfeasible or even impossible. Fire managers would benefit from fast and inexpensive ways of improving their decision-making. In the present work, we focus on i) understanding if fire spread predictions can be improved through model parameter calibration based on information collected from a set of large historical wildfires in Portugal; and ii) understanding to what extent decreasing parametric uncertainty can counterbalance the impact of input data uncertainty. Our results obtained with the Fire Area Simulator (FARSITE) modeling system show that fire spread predictions can be continuously improved by 'learning' from past wildfires. The uncertainty contained in the major input variables (wind speed and direction, ignition location and fuel models) can be 'swept under the rug' through the use of more appropriate parameter sets. The proposed framework has a large potential to improve future fire spread predictions, increasing their reliability and usefulness to support fire management and decision making processes, thus potentially reducing the negative impacts of wildfires. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Understanding the spreading patterns of mobile phone viruses

    Science.gov (United States)

    Wang, Pu; Gonzalez, Marta; Hidalgo, Cesar; Barabasi, Albert-Laszlo

    2009-03-01

    Mobile viruses are little more than a nuisance today, but given our increased reliance on wireless communication, in the near future they could pose more risk than their PC based counterparts. Despite of the more than three hundred mobile viruses known so far, little is known about their spreading pattern, partly due to a lack of data on the communication and travel patterns of mobile phone users. Starting from the traffic and the communication pattern of six million mobile phone users, we model the vulnerability of mobile communications against potential virus outbreaks. We show that viruses exploiting Bluetooth and multimedia messaging services (MMS) follow markedly different spreading patterns. The Bluetooth virus can reach all susceptible handsets, but spreads relatively slowly, as its spread is driven by human mobility. In contrast, an MMS virus can spread rapidly, but because the underlying social network is fragmented, it can reach only a small fraction of all susceptible users. This difference affects both their spreading rate, the number of infected users, as well as the defense measures one needs to take to protect the system against potential viral outbreak.

  11. Ensemble data assimilation with an adjusted forecast spread

    Directory of Open Access Journals (Sweden)

    Sabrina Rainwater

    2013-04-01

    Full Text Available Ensemble data assimilation typically evolves an ensemble of model states whose spread is intended to represent the algorithm's uncertainty about the state of the physical system that produces the data. The analysis phase treats the forecast ensemble as a random sample from a background distribution, and it transforms the ensemble according to the background and observation error statistics to provide an appropriate sample for the next forecast phase. We find that in the presence of model nonlinearity and model error, it can be fruitful to rescale the ensemble spread prior to the forecast and then reverse this rescaling after the forecast. We call this approach forecast spread adjustment, which we discuss and test in this article using an ensemble Kalman filter and a 2005 model due to Lorenz. We argue that forecast spread adjustment provides a tunable parameter, that is, complementary to covariance inflation, which cumulatively increases ensemble spread to compensate for underestimation of uncertainty. We also show that as the adjustment parameter approaches zero, the filter approaches the extended Kalman filter if the ensemble size is sufficiently large. We find that varying the adjustment parameter can significantly reduce analysis and forecast errors in some cases. We evaluate how the improvement provided by forecast spread adjustment depends on ensemble size, observation error and model error. Our results indicate that the technique is most effective for small ensembles, small observation error and large model error, though the effectiveness depends significantly on the nature of the model error.

  12. New PN Even Balanced Sequences for Spread-Spectrum Systems

    Directory of Open Access Journals (Sweden)

    Inácio JAL

    2005-01-01

    Full Text Available A new class of pseudonoise even balanced (PN-EB binary spreading sequences is derived from existing classical odd-length families of maximum-length sequences, such as those proposed by Gold, by appending or inserting one extra-zero element (chip to the original sequences. The incentive to generate large families of PN-EB spreading sequences is motivated by analyzing the spreading effect of these sequences from a natural sampling point of view. From this analysis a new definition for PG is established, from which it becomes clear that very high processing gains (PGs can be achieved in band-limited direct-sequence spread-spectrum (DSSS applications by using spreading sequences with zero mean, given that certain conditions regarding spectral aliasing are met. To obtain large families of even balanced (i.e., equal number of ones and zeros sequences, two design criteria are proposed, namely the ranging criterion (RC and the generating ranging criterion (GRC. PN-EB sequences in the polynomial range are derived using these criteria, and it is shown that they exhibit secondary autocorrelation and cross-correlation peaks comparable to the sequences they are derived from. The methods proposed not only facilitate the generation of large numbers of new PN-EB spreading sequences required for CDMA applications, but simultaneously offer high processing gains and good despreading characteristics in multiuser SS scenarios with band-limited noise and interference spectra. Simulation results are presented to confirm the respective claims made.

  13. An Improved Adaptive model for Information Recommending and Spreading

    Institute of Scientific and Technical Information of China (English)

    CHEN Duan-Bing; GAO Hui

    2012-01-01

    People in the Internet era have to cope with information overload and expend great effort on finding what they need.Recent experiments indicate that recommendations based on users' past activities are usually less favored than those based on social relationships,and thus many researchers have proposed adaptive algorithms on social recommendation.However,in those methods,quite a number of users have little chance to recommend information,which might prevent valuable information from spreading.We present an improved algorithm that allows more users to have enough followers to spread information.Experimental results demonstrate that both recommendation precision and spreading effectiveness of our method can be improved significantly.%People in the Internet era have to cope with information overload and expend great effort on finding what they need. Recent experiments indicate that recommendations based on users' past activities are usually less favored than those based on social relationships, and thus many researchers have proposed adaptive algorithms on social recommendation. However, in those methods, quite a number of users have little chance to recommend information, which might prevent valuable information from spreading. We present an improved algorithm that allows more users to have enough followers to spread information. Experimental results demonstrate that both recommendation precision and spreading effectiveness of our method can be improved significantly.

  14. Modeling universal dynamics of cell spreading on elastic substrates.

    Science.gov (United States)

    Fan, Houfu; Li, Shaofan

    2015-11-01

    A three-dimensional (3D) multiscale moving contact line model is combined with a soft matter cell model to study the universal dynamics of cell spreading over elastic substrates. We have studied both the early stage and the late stage cell spreading by taking into account the actin tension effect. In this work, the cell is modeled as an active nematic droplet, and the substrate is modeled as a St. Venant Kirchhoff elastic medium. A complete 3D simulation of cell spreading has been carried out. The simulation results show that the spreading area versus spreading time at different stages obeys specific power laws, which is in good agreement with experimental data and theoretical prediction reported in the literature. Moreover, the simulation results show that the substrate elasticity may affect force dipole distribution inside the cell. The advantage of this approach is that it combines the hydrodynamics of actin retrograde flow with moving contact line model so that it can naturally include actin tension effect resulting from actin polymerization and actomyosin contraction, and thus it might be capable of simulating complex cellular scale phenomenon, such as cell spreading or even crawling.

  15. Asymmetric Spreading of a Drop upon Impact onto a Surface.

    Science.gov (United States)

    Almohammadi, H; Amirfazli, A

    2017-06-13

    Study of the spreading of an impacting drop onto a surface has gained importance recently due to applications in printing, coating, and icing. Limited studies are conducted to understand asymmetric spreading of a drop seen upon drop impact onto a moving surface; there is no relation to describe such spreading. Here, we experimentally studied the spreading of a drop over a moving surface; such study also provides insights for systems where a drop impacts at an angle relative to a surface, i.e., drop has both normal and tangential velocities relative to the surface. We developed a model that for the first time allows prediction of time evolution for the asymmetric shape of the lamella during spreading. The developed model is demonstrated to be valid for a range of liquids and surface wettabilities as well as drop and surface velocities, making this study a comprehensive examination of the topic. We also found out how surface wettability can affect the recoil of the drop after spreading and explained the role of contact angle hysteresis and receding contact angle in delaying the recoil process.

  16. Directional Spread of Alphaherpesviruses in the Nervous System

    Directory of Open Access Journals (Sweden)

    Lynn W. Enquist

    2013-02-01

    Full Text Available Alphaherpesviruses are pathogens that invade the nervous systems of their mammalian hosts. Directional spread of infection in the nervous system is a key component of the viral lifecycle and is critical for the onset of alphaherpesvirus-related diseases. Many alphaherpesvirus infections originate at peripheral sites, such as epithelial tissues, and then enter neurons of the peripheral nervous system (PNS, where lifelong latency is established. Following reactivation from latency and assembly of new viral particles, the infection typically spreads back out towards the periphery. These spread events result in the characteristic lesions (cold sores commonly associated with herpes simplex virus (HSV and herpes zoster (shingles associated with varicella zoster virus (VZV. Occasionally, the infection spreads transsynaptically from the PNS into higher order neurons of the central nervous system (CNS. Spread of infection into the CNS, while rarer in natural hosts, often results in severe consequences, including death. In this review, we discuss the viral and cellular mechanisms that govern directional spread of infection in the nervous system. We focus on the molecular events that mediate long distance directional transport of viral particles in neurons during entry and egress.

  17. A case study on fractal simulation of forest fire spread

    Institute of Scientific and Technical Information of China (English)

    朱启疆; 戎太宗; 孙睿

    2000-01-01

    This paper relates to the semi-empirical model based on fire field energy balance and the physical model based on land temperature, aiming to provide a practical way of describing fire spread. Fire spread is determined by the characteristics of combustible materials and the agency of meteorological factors and terrains. Combustible materials, such as surface area, have no featured scale, yet the process of forest fire spread contains the self-replicating feature, both of which contribute to the self-similarity of fire spread. Consequently, fire behavior can be described by fractal geometry. In this research, we select Wuchagou forest in Da Hinggan Mountains as the experimental site where a forest fire took place three years ago. The forest fire was detected on low-resolution NOAA-AVHRR images, and fire spread was simulated on high-resolution TM images as another attempt to merge information. Based on remote sensing and GIS, we adopted the method of limited spreading lumping (DLA) to describe growing phe

  18. Staging for vaginal cancer.

    Science.gov (United States)

    Rajaram, Shalini; Maheshwari, Amita; Srivastava, Astha

    2015-08-01

    Vaginal cancer is a rare cancer comprising about 3% of all gynecologic cancers. Primary vaginal cancer should be carefully assigned as spread from cervix, vulva, and other metastatic tumors to vagina can occur. Although vaginal cancer traditionally occurs in older postmenopausal women, the incidence of high-risk human papillomavirus (HPV)-induced cancers is increasing in younger women. Squamous cell carcinoma is still the most common histopathologic type followed by adenocarcinoma. With decreasing use of diethylstilbestrol in pregnancy, non-diethylstilbestrol-associated cancers are described. The Federation Internationale de Gynecologie et d'Obstetrique (FIGO) staging of vaginal cancer (2009) follows the same rules as cervical cancer; it is clinically staged and allows the use of routine investigative modalities for staging. Although FIGO encourages the use of advanced imaging modalities, such as computed tomography, magnetic resonance imaging (MRI), and positron emission tomography (PET), to guide therapy, the imaging findings may not be used to change or reassign the stage. TNM staging is the pathologic staging system proposed by the American Joint Committee on Cancer, and information available from examination of the resected specimen, including pelvic and inguinal lymph nodes, may be used for staging. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Dynamics of cancerous tissue correlates with invasiveness

    Science.gov (United States)

    West, Ann-Katrine Vransø; Wullkopf, Lena; Christensen, Amalie; Leijnse, Natascha; Tarp, Jens Magelund; Mathiesen, Joachim; Erler, Janine Terra; Oddershede, Lene Broeng

    2017-03-01

    Two of the classical hallmarks of cancer are uncontrolled cell division and tissue invasion, which turn the disease into a systemic, life-threatening condition. Although both processes are studied, a clear correlation between cell division and motility of cancer cells has not been described previously. Here, we experimentally characterize the dynamics of invasive and non-invasive breast cancer tissues using human and murine model systems. The intrinsic tissue velocities, as well as the divergence and vorticity around a dividing cell correlate strongly with the invasive potential of the tissue, thus showing a distinct correlation between tissue dynamics and aggressiveness. We formulate a model which treats the tissue as a visco-elastic continuum. This model provides a valid reproduction of the cancerous tissue dynamics, thus, biological signaling is not needed to explain the observed tissue dynamics. The model returns the characteristic force exerted by an invading cell and reveals a strong correlation between force and invasiveness of breast cancer cells, thus pinpointing the importance of mechanics for cancer invasion.

  20. Dynamics of cancerous tissue correlates with invasiveness

    Science.gov (United States)

    West, Ann-Katrine Vransø; Wullkopf, Lena; Christensen, Amalie; Leijnse, Natascha; Tarp, Jens Magelund; Mathiesen, Joachim; Erler, Janine Terra; Oddershede, Lene Broeng

    2017-01-01

    Two of the classical hallmarks of cancer are uncontrolled cell division and tissue invasion, which turn the disease into a systemic, life-threatening condition. Although both processes are studied, a clear correlation between cell division and motility of cancer cells has not been described previously. Here, we experimentally characterize the dynamics of invasive and non-invasive breast cancer tissues using human and murine model systems. The intrinsic tissue velocities, as well as the divergence and vorticity around a dividing cell correlate strongly with the invasive potential of the tissue, thus showing a distinct correlation between tissue dynamics and aggressiveness. We formulate a model which treats the tissue as a visco-elastic continuum. This model provides a valid reproduction of the cancerous tissue dynamics, thus, biological signaling is not needed to explain the observed tissue dynamics. The model returns the characteristic force exerted by an invading cell and reveals a strong correlation between force and invasiveness of breast cancer cells, thus pinpointing the importance of mechanics for cancer invasion. PMID:28262796

  1. Antiangiogenesis immunotherapy induces epitope spreading to Her-2/neu resulting in breast tumor immunoediting

    Directory of Open Access Journals (Sweden)

    Matthew M Seavey

    2009-10-01

    Full Text Available Matthew M Seavey, Yvonne PatersonDepartment of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, PA, USAAbstract: Targeting tumors using cancer vaccine therapeutics has several advantages including the induction of long-term immunity, prime boost strategies for additional treatments and reduced side effects compared to conventional chemotherapeutics. However, one problem in targeting tumor antigens directly is that this can lead to antigen loss or immunoediting. We hypothesized that directing the immune response to a normal cell type required for tumor growth and survival could provide a more stable immunotherapeutic target. We thus examined the ability of an antiangiogenesis, Listeria monocytogenes (Lm-based vector to deliver extracellular and intracellular fragments of the mouse vascular endothelial growth factor receptor-2/Flk-1 molecule, Lm-LLO-Flk-E1, and Lm-LLO-Flk-11 respectively, in an autochthonous model for Her-2/neu+ breast cancer. We found that these vaccines could cause epitope spreading to the endogenous tumor protein Her-2/neu and significantly delay tumor onset. However, tumors that grew out overtime accumulated mutations in the Her-2/neu molecule near or within cytotoxic T lymphocytes epitopes. We show here for the first time how an antiangiogenesis immunotherapy can be used to delay the onset of a spontaneous tumor through epitope spreading and determine a possible mechanism of how immunoediting of an endogenous tumor protein can allow for tumor escape and outgrowth in an autochthonous mouse model for Her-2/neu+ breast cancer.Keywords: Listeria, Her-2/neu, immunotherapy, antiangiogenesis, immunoediting

  2. An analytical study of the improved nonlinear tolerance of DFT-spread OFDM and its unitary-spread OFDM generalization.

    Science.gov (United States)

    Shulkind, Gal; Nazarathy, Moshe

    2012-11-05

    DFT-spread (DFT-S) coherent optical OFDM was numerically and experimentally shown to provide improved nonlinear tolerance over an optically amplified dispersion uncompensated fiber link, relative to both conventional coherent OFDM and single-carrier transmission. Here we provide an analytic model rigorously accounting for this numerical result and precisely predicting the optimal bandwidth per DFT-S sub-band (or equivalently the optimal number of sub-bands per optical channel) required in order to maximize the link non-linear tolerance (NLT). The NLT advantage of DFT-S OFDM is traced to the particular statistical dependency introduced among the OFDM sub-carriers by means of the DFT spreading operation. We further extend DFT-S to a unitary-spread generalized modulation format which includes as special cases the DFT-S scheme as well as a new format which we refer to as wavelet-spread (WAV-S) OFDM, replacing the spreading DFTs by Hadamard matrices which have elements +/-1 hence are multiplier-free. The extra complexity incurred in the spreading operation is almost negligible, however the performance improvement with WAV-S relative to plain OFDM is more modest than that achieved by DFT-S, which remains the preferred format for nonlinear tolerance improvement, outperforming both plain OFDM and single-carrier schemes.

  3. Understanding Cancer Prognosis

    Medline Plus

    Full Text Available ... Types Recurrent Cancer Common Cancer Types Bladder Cancer Breast Cancer Colorectal Cancer Kidney (Renal Cell) Cancer Leukemia Liver Cancer Lung Cancer Lymphoma Pancreatic Cancer Prostate Cancer Skin Cancer Thyroid Cancer Uterine Cancer All Cancer Types ...

  4. Epidemiological models for the spread of anti-malarial resistance

    Directory of Open Access Journals (Sweden)

    Antia R

    2003-02-01

    Full Text Available Abstract Background The spread of drug resistance is making malaria control increasingly difficult. Mathematical models for the transmission dynamics of drug sensitive and resistant strains can be a useful tool to help to understand the factors that influence the spread of drug resistance, and they can therefore help in the design of rational strategies for the control of drug resistance. Methods We present an epidemiological framework to investigate the spread of anti-malarial resistance. Several mathematical models, based on the familiar Macdonald-Ross model of malaria transmission, enable us to examine the processes and parameters that are critical in determining the spread of resistance. Results In our simplest model, resistance does not spread if the fraction of infected individuals treated is less than a threshold value; if drug treatment exceeds this threshold, resistance will eventually become fixed in the population. The threshold value is determined only by the rates of infection and the infectious periods of resistant and sensitive parasites in untreated and treated hosts, whereas the intensity of transmission has no influence on the threshold value. In more complex models, where hosts can be infected by multiple parasite strains or where treatment varies spatially, resistance is generally not fixed, but rather some level of sensitivity is often maintained in the population. Conclusions The models developed in this paper are a first step in understanding the epidemiology of anti-malarial resistance and evaluating strategies to reduce the spread of resistance. However, specific recommendations for the management of resistance need to wait until we have more data on the critical parameters underlying the spread of resistance: drug use, spatial variability of treatment and parasite migration among areas, and perhaps most importantly, cost of resistance.

  5. Characteristics of Hydrothermal Mineralization in Ultraslow Spreading Ridges

    Science.gov (United States)

    Zhou, H.; Yang, Q.; Ji, F.; Dick, H. J.

    2014-12-01

    Hydrothermal activity is a major component of the processes that shape the composition and structure of the ocean crust, providing a major pathway for the exchange of heat and elements between the Earth's crust and oceans, and a locus for intense biological activity on the seafloor and underlying crust. In other hand, the structure and composition of hydrothermal systems are the result of complex interactions between heat sources, fluids, wall rocks, tectonic controls and even biological processes. Ultraslow spreading ridges, including the Southwest Indian Ridge, the Gakkel Ridge, are most remarkable end member in plate-boundary structures (Dick et al., 2003), featured with extensive tectonic amagmatic spreading and frequent exposure of peridotite and gabbro. With intensive surveys in last decades, it is suggested that ultraslow ridges are several times more effective than faster-spreading ridges in sustaining hydrothermal activities. This increased efficiency could attributed to deep mining of heat and even exothermic serpentinisation (Baker et al., 2004). Distinct from in faster spreading ridges, one characteristics of hydrothermal mineralization on seafloor in ultraslow spreading ridges, including the active Dragon Flag hydrothermal field at 49.6 degree of the Southwest Indian Ridge, is abundant and pervasive distribution of lower temperature precipitated minerals ( such as Fe-silica or silica, Mn (Fe) oxides, sepiolite, pyrite, marcasite etc. ) in hydrothermal fields. Structures formed by lower temperature activities in active and dead hydrothermal fields are also obviously. High temperature precipitated minerals such as chalcopyrite etc. are rare or very limited in hydrothermal chimneys. Distribution of diverse low temperature hydrothermal activities is consistence with the deep heating mechanisms and hydrothermal circulations in the complex background of ultraslow spreading tectonics. Meanwhile, deeper and larger mineralization at certain locations along the

  6. Acceleration of evolutionary spread by long-range dispersal.

    Science.gov (United States)

    Hallatschek, Oskar; Fisher, Daniel S

    2014-11-18

    The spreading of evolutionary novelties across populations is the central element of adaptation. Unless populations are well mixed (like bacteria in a shaken test tube), the spreading dynamics depend not only on fitness differences but also on the dispersal behavior of the species. Spreading at a constant speed is generally predicted when dispersal is sufficiently short ranged, specifically when the dispersal kernel falls off exponentially or faster. However, the case of long-range dispersal is unresolved: Although it is clear that even rare long-range jumps can lead to a drastic speedup--as air-traffic-mediated epidemics show--it has been difficult to quantify the ensuing stochastic dynamical process. However, such knowledge is indispensable for a predictive understanding of many spreading processes in natural populations. We present a simple iterative scaling approximation supported by simulations and rigorous bounds that accurately predicts evolutionary spread, which is determined by a trade-off between frequency and potential effectiveness of long-distance jumps. In contrast to the exponential laws predicted by deterministic "mean-field" approximations, we show that the asymptotic spatial growth is according to either a power law or a stretched exponential, depending on the tails of the dispersal kernel. More importantly, we provide a full time-dependent description of the convergence to the asymptotic behavior, which can be anomalously slow and is relevant even for long times. Our results also apply to spreading dynamics on networks with a spectrum of long-range links under certain conditions on the probabilities of long-distance travel: These are relevant for the spread of epidemics.

  7. [Hormone therapy in prostate cancer; a pharmacotherapeutic challenge

    NARCIS (Netherlands)

    Westdorp, H.; Benoist, G.E.; Schers, H.J.; Erp, P.H. van; Gerritsen, W.R.; Mulders, P.F.A.; Kramers, C.

    2015-01-01

    Prostate cancer is the most common form of cancer in men in the Western world. One-third of the patients with localised prostate cancer will develop recurrent disease, localised disease spread or distant metastases. The presence of distant metastases is an indication for primary palliative hormone

  8. Breast Cancer Diagnosis Using Machine Learning Algorithms - A Survey

    Directory of Open Access Journals (Sweden)

    B.M.Gayathri

    2013-06-01

    Full Text Available Breast cancer has become a common factor now-a-days. Despite the fact, not all general hospitalshave the facilities to diagnose breast cancer through mammograms. Waiting for diagnosing a breastcancer for a long time may increase the possibility of the cancer spreading. Therefore a computerizedbreast cancer diagnosis has been developed to reduce the time taken to diagnose the breast cancer andreduce the death rate. This paper summarizes the survey on breast cancer diagnosis using various machinelearning algorithms and methods, which are used to improve the accuracy of predicting cancer. This surveycan also help us to know about number of papers that are implemented to diagnose the breast cancer.

  9. Pulmonary nodules and metastases in colorectal cancer

    DEFF Research Database (Denmark)

    Nordholm-Carstensen, Andreas

    2016-01-01

    Patients with newly diagnosed colorectal cancer (CRC) are subjected to a preoperative thoraco-abdominal CT scan to determine the cancer stage. This staging is of relevance with regard to treatment and prognosis. About 20% of the patients have distant metastatic spread at the time of diagnosis, i...... detected in 7.5% of the patients and in 37% of these cases the metastatic spread was confined to the lungs. The prevalence of SPCM increased with the implementation of thoracic CT in CRC staging. SPCM impaired survival significantly and was associated with increasing age and rectal cancer. Resection...

  10. Molecular Cancer Imaging with Polymeric Nanoassemblies: From Tumor Detection to Theranostics.

    Science.gov (United States)

    Mi, Peng; Wang, Fang; Nishiyama, Nobuhiro; Cabral, Horacio

    2017-01-01

    Several imaging modalities have been widely applied for the detection of cancer and its pathological activity in combination with probes capable of improving the contrast between healthy and cancerous tissues. Biocompatible polymeric nanoassemblies have been developed for precise detection of malignant tumors by enhancing the selectivity and sensitivity of the imaging. Exploiting the compartmentalized structure of the nanoassemblies advantageously allows delivering both imaging and therapeutic agents for cancer multifunctional imaging and theranostics, i.e., the combination of therapy and diagnosis tool on a single platform. Thus, nanoassemblies have high potential not only for cancer molecular imaging but also for tracing nanoparticles in biological systems, studying their biological pathways, gathering pathological information, monitoring therapeutic effects, and guiding pinpoint therapies. In this review, polymeric nanoassemblies for optical imaging, magnetic resonance imaging, multifunctional imaging, and image-guided therapy, emphasizing their role in cancer diagnosis and theranostics are highlighted.

  11. Hsp74, a Potential Bladder Cancer Marker, Has Direct Interaction with Keratin 1

    Directory of Open Access Journals (Sweden)

    Ling Chen

    2014-01-01

    Full Text Available Early diagnosis and prognosis monitoring are very important for the survival of patients with bladder cancer. To identify candidate biomarkers of bladder cancer, we used a combination of techniques including 2-DE, co-IP, western blot, LC-MS/MS, and immunohistochemistry. Hsp74 was identified with high expression in bladder cancer. The cellular location of expression products of gene Hsp74 showed that they were distributed into cytoplasm and keratin 1 was found to be associated with Hsp74. The results provide a new idea to understand the molecular basis of bladder cancer progression and pinpoint new potential molecular target for early diagnosis and therapeutic monitoring of bladder cancer.

  12. Angular spreading measurements using MeV ion microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Whitlow, Harry J., E-mail: harry.whitlow@he-arc.ch [Institut des Microtechnologies Appliquées, Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Department of Physics, P.O. Box 35 (YFL), FI-40014 University of Jyväskylä (Finland); Ren, Minqin; Chen, Xiao; Osipowicz, Thomas; Kan, Jeroen A. van; Watt, Frank [Centre for Ion Beam Applications, National University of Singapore (Singapore)

    2013-07-01

    The sharpness of MeV ion microscope images is governed by small-angle scattering and associated lateral spreading of the ion beam in the sample. We have investigated measurement of the half-angle of the angular spreading distribution by characterising the image blurring in direct-Scanning Transmission Ion Microscopy (direct-STIM). In these tests Mylar™ foils of 0.5–6 μm were used to induce angular spreading. Images were taken of an electron microscope grid using 2 MeV protons with, and without, the foils in the beam path. The blurring was measured by fitting the width of a circular Gaussian point spread function to the images with and without the foil in position. The results show the half-angle width of the spreading has a square root dependence on foil thickness that lies intermediate between SRIM predictions and the theoretical estimates (Bird and Williams fits to the Sigmund and Winterbon data and Amsel et al.)

  13. Textural and sensory properties of spreads with sucrose and maltitol

    Directory of Open Access Journals (Sweden)

    Šoronja-Simović Dragana M.

    2012-01-01

    Full Text Available Spreads are confectionery products based on sugar, vegetable fat, cocoa powder, milk powder and other ingredients. Basic properties of these products are good spreadability in wide temperature range (from ambience to fridge temperature, rich creamy chocolate taste, and homogenous smooth structure without oil phase migration. Undesirable attribute of these products is their relatively high energy value (2300 kJ/100 g. In recent years, cocoa cream products with reduced energy values have become very popular among consumers and today they are present in the assortment of many confectionery manufacturers. One way to produce spreads with reduced energy value is the replacement of sugar (sucrose with adequate sweetener. Maltitol is a low-energy poliol capable to qualitatively and quantitatively replace sucrose. Cocoa spreads with maltitol and with the combination of maltitol and sucrose (produced at different temperatures and mixer rotation speeds have similar texture and rheological properties compared to the spreads with sucrose. The spreads with maltitol have about 15% lower energy value in comparison to the same product with sucrose.

  14. Phosphorylation of actopaxin regulates cell spreading and migration

    Science.gov (United States)

    Clarke, Dominic M.; Brown, Michael C.; LaLonde, David P.; Turner, Christopher E.

    2004-01-01

    Actopaxin is an actin and paxillin binding protein that localizes to focal adhesions. It regulates cell spreading and is phosphorylated during mitosis. Herein, we identify a role for actopaxin phosphorylation in cell spreading and migration. Stable clones of U2OS cells expressing actopaxin wild-type (WT), nonphosphorylatable, and phosphomimetic mutants were developed to evaluate actopaxin function. All proteins targeted to focal adhesions, however the nonphosphorylatable mutant inhibited spreading whereas the phosphomimetic mutant cells spread more efficiently than WT cells. Endogenous and WT actopaxin, but not the nonphosphorylatable mutant, were phosphorylated in vivo during cell adhesion/spreading. Expression of the nonphosphorylatable actopaxin mutant significantly reduced cell migration, whereas expression of the phosphomimetic increased cell migration in scrape wound and Boyden chamber migration assays. In vitro kinase assays demonstrate that extracellular signal-regulated protein kinase phosphorylates actopaxin, and treatment of U2OS cells with the MEK1 inhibitor UO126 inhibited adhesion-induced phosphorylation of actopaxin and also inhibited cell migration. PMID:15353548

  15. Analysis of Finite Field Spreading for Multiple-Access Channel

    CERN Document Server

    Song, Guanghui; Cheng, Jun; Watanabe, Yoichiro

    2012-01-01

    Finite field spreading scheme is proposed for a synchronous multiple-access channel with Gaussian noise and equal-power users. For each user, $s$ information bits are spread \\emph{jointly} into a length-$sL$ vector by $L$ multiplications on GF($2^s$). Thus, each information bit is dispersed into $sL$ transmitted symbols, and the finite field despreading (FF-DES) of each bit can take advantage of $sL$ independent receiving observations. To show the performance gain of joint spreading quantitatively, an extrinsic information transfer (EXIT) function analysis of the FF-DES is given. It shows that the asymptotic slope of this EXIT function increases as $s$ increases and is in fact the absolute slope of the bit error rate (BER) curve at the low BER region. This means that by increasing the length $s$ of information bits for joint spreading, a larger absolute slope of the BER curve is achieved. For $s, L\\geq 2$, the BER curve of the finite field spreading has a larger absolute slope than that of the single-user tra...

  16. Numerical Simulation of Microgravity Flame Spread Over Solid Combustibles

    Institute of Scientific and Technical Information of China (English)

    JIANGXi; FANWeicheng

    1995-01-01

    A computational model of three-dimensional,time-dependent flame spread in microgravity environment is presented.THe solid is assumed to be a thermally-thin,pyrolysing cellulosic sheet.The gas phase model includes the full Navier-Stokes equations with density and pressure variations and six-flus model of radiation heat transfer,The solid phase model consists of continuity and energy equations whose solution provides boundary conditions for the gas phase equatons.In the numerical procedure,the gas-and solid -phase equations are solved separately and iteratively at each time step.Predictions have been made of flame spreas in slow forced flow under gravitational acceleration normal to fuel surface and flame spread in a quiescent environment in an enclosed chamber under gravitational acceleration parallel to fuel surface.Numerical simulations show that,under microgravity,slow-flow conditions,flame spread process is highly unsteady with the upstream flame spreads faster than the downstream flame after a period of ignition,It has also been shown that the level of microgravity has a significant effect on the flame spread process.

  17. Spreading dynamics of droplet on an inclined surface

    Science.gov (United States)

    Shen, Chaoqun; Yu, Cheng; Chen, Yongping

    2016-06-01

    A three-dimensional unsteady theoretical model of droplet spreading process on an inclined surface is developed and numerically analyzed to investigate the droplet spreading dynamics via the lattice Boltzmann simulation. The contact line motion and morphology evolution for the droplet spreading on an inclined surface, which are, respectively, represented by the advancing/receding spreading factor and droplet wetted length, are evaluated and analyzed. The effects of surface wettability and inclination on the droplet spreading behaviors are examined. The results indicate that, dominated by gravity and capillarity, the droplet experiences a complex asymmetric deformation and sliding motion after the droplet comes into contact with the inclined surfaces. The droplet firstly deforms near the solid surface and mainly exhibits a radial expansion flow in the start-up stage. An evident sliding-down motion along the inclination is observed in the middle stage. And the surface-tension-driven retraction occurs during the retract stage. Increases in inclination angle and equilibrium contact angle lead to a faster droplet motion and a smaller wetted area. In addition, increases in equilibrium contact angle lead to a shorter duration time of the middle stage and an earlier entry into the retract stage.

  18. Cortical spreading depression-induced preconditioning in the brain

    Institute of Scientific and Technical Information of China (English)

    Ping-ping Shen; Shuai Hou; Di Ma; Ming-ming Zhao; Ming-qin Zhu; Jing-dian Zhang; Liang-shu Feng; Li Cui; Jia-chun Feng

    2016-01-01

    Cortical spreading depression is a technique used to depolarize neurons. During focal or global ischemia, cortical spreading depression-induced preconditioning can enhance tolerance of further injury. Howev-er, the underlying mechanism for this phenomenon remains relatively unclear. To date, numerous issues exist regarding the experimental model used to precondition the brain with cortical spreading depression, such as the administration route, concentration of potassium chloride, induction time, duration of the protection provided by the treatment, the regional distribution of the protective effect, and the types of neurons responsible for the greater tolerance. In this review, we focus on the mechanisms underlying cor-tical spreading depression-induced tolerance in the brain, considering excitatory neurotransmission and metabolism, nitric oxide, genomic reprogramming, inlfammation, neurotropic factors, and cellular stress response. Speciifcally, we clarify the procedures and detailed information regarding cortical spreading de-pression-induced preconditioning and build a foundation for more comprehensive investigations in the ifeld of neural regeneration and clinical application in the future.

  19. Epidemic spreading on dual-structure networks with mobile agents

    Science.gov (United States)

    Yao, Yiyang; Zhou, Yinzuo

    2017-02-01

    The rapid development of modern society continually transforms the social structure which leads to an increasingly distinct dual structure of higher population density in urban areas and lower density in rural areas. Such structure may induce distinctive spreading behavior of epidemics which does not happen in a single type structure. In this paper, we study the epidemic spreading of mobile agents on dual structure networks based on SIRS model. First, beyond the well known epidemic threshold for generic epidemic model that when the infection rate is below the threshold a pertinent infectious disease will die out, we find the other epidemic threshold which appears when the infection rate of a disease is relatively high. This feature of two thresholds for the SIRS model may lead to the elimination of infectious disease when social network has either high population density or low population density. Interestingly, however, we find that when a high density area is connected to a low density may cause persistent spreading of the infectious disease, even though the same disease will die out when it spreads in each single area. This phenomenon indicates the critical role of the connection between the two areas which could radically change the behavior of spreading dynamics. Our findings, therefore, provide new understanding of epidemiology pertinent to the characteristic modern social structure and have potential to develop controlling strategies accordingly.

  20. [SPREADING OF NCTC CLONE 929 CELLS AFTER RESEEDING].

    Science.gov (United States)

    Petrov, Yu P; Negulyaev, Yu A; Tsupkina, N V

    2015-01-01

    The period (1 h after reseeding) of behaviour of mouse NCTC clone 929 cells to the conditions of artificial cultivation was studied. The time-lapse imaging followed the processing of the cells with ImageJ program was applied. To characterize the parametres cell status we used the cell area (projection of the cell on substrate) and Rp/Ra ratio introduced earlier as a spreading coefficient (Kuz'minykh, Petrov, 2004). After attaching a substratum, cells have a form of sphere (the phase "sphere") as the daughter cells after a mitosis. We revealed however that after this phase the reseeded cells do not start usual spreading and migration along substratum. They pass a phase of equally spreading in all directions and shaping their area as a circle (phase "circle"). This phase is absent of the daughter cells spreading after mitosis. We assume that the phase "circle" is a result of adaptation of the cells to reseedings at artificial cultivation. It is necessary for formation of a substrate composed of own extracellular matrix components (ECM) of the cells. Own ECM facilitates transition of the cells to their usual spreading and migration along substratum.