Steffen Müller
2010-01-01
Full Text Available The activating immunoreceptor NKG2D promotes elimination of infected or malignant cells by cytotoxic lymphocytes through engagement of stress-induced MHC class I-related ligands. The human cytomegalovirus (HCMV-encoded immunoevasin UL16 subverts NKG2D-mediated immune responses by retaining a select group of diverse NKG2D ligands inside the cell. We report here the crystal structure of UL16 in complex with the NKG2D ligand MICB at 1.8 A resolution, revealing the molecular basis for the promiscuous, but highly selective, binding of UL16 to unrelated NKG2D ligands. The immunoglobulin-like UL16 protein utilizes a three-stranded beta-sheet to engage the alpha-helical surface of the MHC class I-like MICB platform domain. Intriguingly, residues at the center of this beta-sheet mimic a central binding motif employed by the structurally unrelated C-type lectin-like NKG2D to facilitate engagement of diverse NKG2D ligands. Using surface plasmon resonance, we find that UL16 binds MICB, ULBP1, and ULBP2 with similar affinities that lie in the nanomolar range (12-66 nM. The ability of UL16 to bind its ligands depends critically on the presence of a glutamine (MICB or closely related glutamate (ULBP1 and ULBP2 at position 169. An arginine residue at this position however, as found for example in MICA or ULBP3, would cause steric clashes with UL16 residues. The inability of UL16 to bind MICA and ULBP3 can therefore be attributed to single substitutions at key NKG2D ligand locations. This indicates that selective pressure exerted by viral immunoevasins such as UL16 contributed to the diversification of NKG2D ligands.
Ciferri, Claudio; Chandramouli, Sumana; Donnarumma, Danilo; Nikitin, Pavel A; Cianfrocco, Michael A; Gerrein, Rachel; Feire, Adam L; Barnett, Susan W; Lilja, Anders E; Rappuoli, Rino; Norais, Nathalie; Settembre, Ethan C; Carfi, Andrea
2015-02-10
Human cytomegalovirus (HCMV) is a major cause of morbidity and mortality in transplant patients and the leading viral cause of birth defects after congenital infection. The glycoprotein complexes gH/gL/gO and gH/gL/UL128/UL130/UL131A (Pentamer) are key targets of the human humoral response against HCMV and are required for HCMV entry into fibroblasts and endothelial/epithelial cells, respectively. We expressed and characterized soluble forms of gH/gL, gH/gL/gO, and Pentamer. Mass spectrometry and mutagenesis analysis revealed that gL-Cys144 forms disulfide bonds with gO-Cys351 in gH/gL/gO and with UL128-Cys162 in the Pentamer. Notably, Pentamer harboring the UL128-Cys162Ser/gL-Cys144Ser mutations had impaired syncytia formation and reduced interference of HCMV entry into epithelial cells. Electron microscopy analysis showed that HCMV gH/gL resembles HSV gH/gL and that gO and UL128/UL130/UL131A bind to the same site at the gH/gL N terminus. These data are consistent with gH/gL/gO and Pentamer forming mutually exclusive cell entry complexes and reveal the overall location of gH/gL-, gH/gL/gO-, and Pentamer-specific neutralizing antibody binding sites. Our results provide, to our knowledge, the first structural view of gH/gL/gO and Pentamer supporting the development of vaccines and antibody therapeutics against HCMV.
PKR-like endoplasmic reticulum kinase is necessary for lipogenic activation during HCMV infection.
Yongjun Yu
Full Text Available PKR-like endoplasmic reticulum (ER kinase (PERK is an ER-associated stress sensor protein which phosphorylates eukaryotic initiation factor 2α (eIF2α to induce translation attenuation in response to ER stress. PERK is also a regulator of lipogenesis during adipocyte differentiation through activation of the cleavage of sterol regulatory element binding protein 1 (SREBP1, resulting in the upregulation of lipogenic enzymes. Our recent studies have shown that human cytomegalovirus (HCMV infection in human fibroblasts (HF induces adipocyte-like lipogenesis through the activation of SREBP1. Here, we report that PERK expression is highly increased in HCMV-infected cells and is necessary for HCMV growth. Depletion of PERK, using short hairpin RNA (shRNA, resulted in attenuation of HCMV growth, inhibition of lipid synthesis and reduction of lipogenic gene expression. Examination of the cleavage of SREBP proteins showed PERK depletion inhibited the cleavage of SREBP1, but not SREBP2, in HCMV-infected cells, suggesting different cleavage regulatory mechanisms for SREBP1 and 2. Further studies showed that the depletion of SREBP1, but not SREBP2, reduced lipid synthesis in HCMV infection, suggesting that activation of SREBP1 is sufficient to induce lipogenesis in HCMV infection. The reduction of lipid synthesis by PERK depletion can be partially restored by expressing a Flag-tagged nuclear form of SREBP1a. Our studies also suggest that the induction of PERK in HCMV-infected cells stimulates SREBP1 cleavage by reducing levels of Insig1 (Insulin inducible gene 1 protein; this occurs independent of the phosphorylation of eIF2α. Introduction of an exogenous Insig1-Myc into HCMV infected cells significantly reduced HCMV growth and lipid synthesis. Our data demonstrate that the induction of PERK during HCMV infection is necessary for full activation of lipogenesis; this effect appears to be mediated by limiting the levels of Insig1 thus freeing SREBP1-SCAP
PKR-like endoplasmic reticulum kinase is necessary for lipogenic activation during HCMV infection.
Yu, Yongjun; Pierciey, Francis J; Maguire, Tobi G; Alwine, James C
2013-01-01
PKR-like endoplasmic reticulum (ER) kinase (PERK) is an ER-associated stress sensor protein which phosphorylates eukaryotic initiation factor 2α (eIF2α) to induce translation attenuation in response to ER stress. PERK is also a regulator of lipogenesis during adipocyte differentiation through activation of the cleavage of sterol regulatory element binding protein 1 (SREBP1), resulting in the upregulation of lipogenic enzymes. Our recent studies have shown that human cytomegalovirus (HCMV) infection in human fibroblasts (HF) induces adipocyte-like lipogenesis through the activation of SREBP1. Here, we report that PERK expression is highly increased in HCMV-infected cells and is necessary for HCMV growth. Depletion of PERK, using short hairpin RNA (shRNA), resulted in attenuation of HCMV growth, inhibition of lipid synthesis and reduction of lipogenic gene expression. Examination of the cleavage of SREBP proteins showed PERK depletion inhibited the cleavage of SREBP1, but not SREBP2, in HCMV-infected cells, suggesting different cleavage regulatory mechanisms for SREBP1 and 2. Further studies showed that the depletion of SREBP1, but not SREBP2, reduced lipid synthesis in HCMV infection, suggesting that activation of SREBP1 is sufficient to induce lipogenesis in HCMV infection. The reduction of lipid synthesis by PERK depletion can be partially restored by expressing a Flag-tagged nuclear form of SREBP1a. Our studies also suggest that the induction of PERK in HCMV-infected cells stimulates SREBP1 cleavage by reducing levels of Insig1 (Insulin inducible gene 1) protein; this occurs independent of the phosphorylation of eIF2α. Introduction of an exogenous Insig1-Myc into HCMV infected cells significantly reduced HCMV growth and lipid synthesis. Our data demonstrate that the induction of PERK during HCMV infection is necessary for full activation of lipogenesis; this effect appears to be mediated by limiting the levels of Insig1 thus freeing SREBP1-SCAP complexes for
Adam L Vanarsdall
2012-09-01
Full Text Available Epidermal growth factor receptor (EGFR and platelet-derived growth factor receptor-α (PDGFRα were reported to mediate entry of HCMV, including HCMV lab strain AD169. AD169 cannot assemble gH/gL/UL128-131, a glycoprotein complex that is essential for HCMV entry into biologically important epithelial cells, endothelial cells, and monocyte-macrophages. Given this, it appeared incongruous that EGFR and PDGFRα play widespread roles in HCMV entry. Thus, we investigated whether PDGFRα and EGFR could promote entry of wild type HCMV strain TR. EGFR did not promote HCMV entry into any cell type. PDGFRα-transduction of epithelial and endothelial cells and several non-permissive cells markedly enhanced HCMV TR entry and surprisingly, promoted entry of HCMV mutants lacking gH/gL/UL128-131 into epithelial and endothelial cells. Entry of HCMV was not blocked by a panel of PDGFRα antibodies or the PDGFR ligand in fibroblasts, epithelial, or endothelial cells or by shRNA silencing of PDGFRα in epithelial cells. Moreover, HCMV glycoprotein induced cell-cell fusion was not increased when PDGFRα was expressed in cells. Together these results suggested that HCMV does not interact directly with PDGFRα. Instead, the enhanced entry produced by PDGFRα resulted from a novel entry pathway involving clathrin-independent, dynamin-dependent endocytosis of HCMV followed by low pH-independent fusion. When PDGFRα was expressed in cells, an HCMV lab strain escaped endosomes and tegument proteins reached the nucleus, but without PDGFRα virions were degraded. By contrast, wild type HCMV uses another pathway to enter epithelial cells involving macropinocytosis and low pH-dependent fusion, a pathway that lab strains (lacking gH/gL/UL128-131 cannot follow. Thus, PDGFRα does not act as a receptor for HCMV but increased PDGFRα alters cells, facilitating virus entry by an abnormal pathway. Given that PDGFRα increased infection of some cells to 90%, PDGFRα may be very
Van Damme, Ellen; Thys, Kim; Tuefferd, Marianne; Van Hove, Carl; Aerssens, Jeroen; Van Loock, Marnix
2016-01-01
Human cytomegalovirus (HCMV) is a betaherpesvirus which rarely presents problems in healthy individuals, yet may result in severe morbidity in immunocompromised patients and in immune-naïve neonates. HCMV has a large 235 kb genome with a coding capacity of at least 165 open reading frames (ORFs). This large genome allows complex gene regulation resulting in different sets of transcripts during lytic and latent infection. While latent virus mainly resides within monocytes and CD34+ progenitor cells, reactivation to lytic infection is driven by differentiation towards terminally differentiated myeloid dendritic cells and macrophages. Consequently, it has been suggested that macrophages and dendritic cells contribute to viral spread in vivo. Thus far only limited knowledge is available on the expression of HCMV genes in terminally differentiated myeloid primary cells and whether or not the virus exhibits a different set of lytic genes in primary cells compared with lytic infection in NHDF fibroblasts. To address these questions, we used Illumina next generation sequencing to determine the HCMV transcriptome in macrophages and dendritic cells during lytic infection and compared it to the transcriptome in NHDF fibroblasts. Here, we demonstrate unique expression profiles in macrophages and dendritic cells which significantly differ from the transcriptome in fibroblasts mainly by modulating the expression of viral transcripts involved in immune modulation, cell tropism and viral spread. In a head to head comparison between macrophages and dendritic cells, we observed that factors involved in viral spread and virion composition are differentially regulated suggesting that the plasticity of the virion facilitates the infection of surrounding cells. Taken together, this study provides the full transcript expression analysis of lytic HCMV genes in monocyte-derived type 1 and type 2 macrophages as well as in monocyte-derived dendritic cells. Thereby underlining the potential
HCMV Infection Depress NGF Expression in Human Glioma Cells
Hai-tao WANG; Bin WANG; Zhi-jun LIU; Zhi-qiang BAI; Ling LI; Dong-meng QIAN; Zhi-yong YAN; Xu-xia SONG
2009-01-01
Human cytomegalovirus (HCMV) is the most common cause of congenital infection, resulting in birth defects such as microcephaly. In this study, RT-PCR and Western Blotting were performed to quantify the regulation of endogenic nerve growth factor expression in neuroglia cells by HCMV infection. The results showed that basal, endogenous NGF expression in U251 was unchanged during early HCMV infection. NGF expression is strongly down-regulated during the latent phase of infection. These results suggest that HCMV can depress the NGF expression in U251 cells.
Aziza Khodjaeva
2012-01-01
The research objective was to study frequency of antenatal infection and record probable clinical manifestations in 100 children with HCMV born from mother with HCMV in blood and mononuclear cells. The study identified poly-systemic internal organ damage in neonates due to prenatal HCMV. Research procedures involved study of 100 pairs of patients, Mother-Child tandem, using regular clinical assessment methods per algorithm and HCMV diagnostic methods: ELISA, affinity and avidity of HCMV antib...
Increased HCMV seroprevalence in patients with hepatocellular carcinoma
Lepiller Quentin
2011-10-01
Full Text Available Abstract Background Hepatocellular carcinoma (HCC is the most common primary liver cancer, usually arising after years of chronic liver inflammation that could result from viral infections such as hepatitis B virus (HBV and hepatitic C virus (HCV infections. Human cytomegalovirus (HCMV infects primary human hepatocytes and remains an important cause of morbidity in immunocompromised persons where it may manifest as symptomatic end-organ disease including hepatitis. The goal of the present study was to determine a potential correlation between HCMV infection and the appearance of HCC. Methods First, we analyzed the seroprevalence of HCMV in a cohort of 11,318 patients hospitalized between 2003 and 2009 in different departments of a French University Hospital. Second, we studied HCMV seroprevalence in a cohort of 190 subjects who were stratified on the basis of age, gender, HCC, cirrhosis (Cir, and the exposition to hepatotropic viruses (HCV, HBV. We further determined whether HCMV DNA was present specifically in tumour area in liver biopsies from HCC-positive patients by using nested PCR. Results We found that the HCMV seroprevalence was high in the Hepatology department. The HCMV seroprevalence was significantly higher in patients infected with HCV and/or HBV than in patients who were not infected by those later viruses (76.2% versus 56.5%, p Conclusions Our results indicate that HCMV seroprevalence in patients with HCC is significantly higher than in patients without HCC, is positively correlated with serum IL-6 levels in cirrhotic patients, and is positively associated with the presence of other hepatotropic viruses such as HCV and HBV.
Soraia Almeida Watanabe
2007-12-01
Full Text Available The purpose of the present investigation was to compare the presence of Epstein-Barr virus type 1 (EBV-1 and of Human Cytomegalovirus (HCMV in crevicular fluid samples from deep and shallow periodontal pocket sites of Brazilian patients with aggressive periodontitis. A total of 30 systemically healthy patients with aggressive periodontitis participated in the study. Paper points were inserted into 2 gingivitis sites ( 5 mm in each patient. PCR assay was used to identify genomic copies of HCMV and EBV-1. Twenty-three patients (77% were positive for EBV-1, while only 2 patients (6% were positive for HCMV. The McNemar test revealed a positive association between EBV-1 and periodontal lesions (p = 0.043. Thirty-four (57% out of 60 periodontitis sites were positive for EBV-1, whereas 18 (30% gingivitis sites were positive (p = 0.01. Only two sites (6.7% were positive for HCMV. No positive association was found between HCMV and periodontitis or gingivitis (p = 0.479. The elevated occurrence of EBV-1 DNA in periodontal pockets of patients with aggressive periodontitis supports a possible periodontopathic role of this virus.O objetivo do presente estudo foi comparar a presença do vírus Epstein-Barr tipo 1 (EBV-1 e do Citomegalovírus Humano (HCMV em amostras de fluido crevicular de bolsas periodontais rasas e profundas de pacientes brasileiros com periodontite agressiva. Trinta pacientes sistemicamente saudáveis com periodontite agressiva participaram deste estudo. Cones de papel foram inseridos em 2 sítios de gengivite ( 5 mm de cada paciente. Reações de PCR foram usadas para identificar cópias de DNA genômico de HCMV e EBV-1. Em 23 pacientes (77%, os testes foram positivos para EBV-1, enquanto apenas 2 pacientes (6% foram positivos para HCMV. O teste de McNemar apontou associação positiva entre EBV-1 e lesões periodontais (p = 0,043. Trinta e quatro (57% dos 60 sítios de periodontites foram positivos para o EBV-1, enquanto 18 (30% dos s
In vitro Study on Human Trophoblast Cells Infected with HCMV
肖娟; 张丹丹; 陈娟娟; 尹宗智; 刘涛; 艾继辉; 陈素华
2010-01-01
Human trophoblast cells were isolated and cultured in vitro in order to investigate possible pathogenesis of intrauterine infection caused by HCMV.Trophoblast cells were obtained by compound enzymes digestion and discontinuous percoll gradient.Cells and purity were identified by using immunocytochemistry assay with anti-CK7,Vim and β-hCG antibodies.HCMV AD169 strain replication in isolated trophoblast cells and cell apoptosis were detected at different time points post infection(p.i.).The results showed tha...
Gayoso, Inmaculada; Cantisán, Sara; Cerrato, Carolina; Sánchez-García, Joaquín; Martin, Carmen; Solana, Rafael; Torres-Gomez, Antonio; Torre-Cisneros, Julian
2013-01-01
Human cytomegalovirus (HCMV) infection causes significant morbidity and mortality after hematopoietic stem cell transplantation (HSCT). In this work, we characterized the phenotype and interferon-gamma (INF-γ) production of HCMV-specific T cells using QuantiFERON-HCMV assay in 26 patients 6 months after HSCT. We analysed whether these two parameters were associated with clinical variables. Our results showed that the patients receiving stem cells from donors ≥40 years old were 12 times more likely to have HCMV-specific CD8+ T cells with "differentiated phenotype" (CD45RA+CCR7+ ≤6.7% and CD28+ ≤30%) than patients grafted from donors <40 years old (OR = 12; P = 0.014). In addition, a detectable IFN-γ production in response to HCMV peptides (cutoff 0.2 IU/mL IFN-γ; "reactive" QuantiFERON-HCMV test) was statistically associated with HCMV replication after transplantation (OR = 11; P = 0.026), recipients ≥40 versus <40 years old (OR = 11; P = 0.026), and the use of peripheral blood versus bone marrow as stem cell source (OR = 17.5; P = 0.024). In conclusion, donor age is the only factor significantly associated with the presence of the "differentiated phenotype" in HCMV-specific CD8+ T cells, whereas HCMV replication after transplantation, recipient age, and stem cell source are the factors associated with the production of IFN-γ in response to HCMV epitopes.
Inmaculada Gayoso
2013-01-01
Full Text Available Human cytomegalovirus (HCMV infection causes significant morbidity and mortality after hematopoietic stem cell transplantation (HSCT. In this work, we characterized the phenotype and interferon-gamma (INF-γ production of HCMV-specific T cells using QuantiFERON-HCMV assay in 26 patients 6 months after HSCT. We analysed whether these two parameters were associated with clinical variables. Our results showed that the patients receiving stem cells from donors ≥40 years old were 12 times more likely to have HCMV-specific CD8+ T cells with “differentiated phenotype” (CD45RA+CCR7+ ≤6.7% and CD28+ ≤30% than patients grafted from donors <40 years old (OR=12; P=0.014. In addition, a detectable IFN-γ production in response to HCMV peptides (cutoff 0.2 IU/mL IFN-γ; “reactive” QuantiFERON-HCMV test was statistically associated with HCMV replication after transplantation (OR=11; P=0.026, recipients ≥40 versus <40 years old (OR=11; P=0.026, and the use of peripheral blood versus bone marrow as stem cell source (OR=17.5; P=0.024. In conclusion, donor age is the only factor significantly associated with the presence of the “differentiated phenotype” in HCMV-specific CD8+ T cells, whereas HCMV replication after transplantation, recipient age, and stem cell source are the factors associated with the production of IFN-γ in response to HCMV epitopes.
Hakki, Morgan; Goldman, Devorah C; Streblow, Daniel N; Hamlin, Kimberly L; Krekylwich, Craig N; Fleming, William H; Nelson, Jay A
2014-01-01
Human cytomegalovirus (HCMV) infection, including primary infection resulting from transmission from a seropositive donor to a seronegative recipient (D(+)/R(-)), remains a significant problem in the setting of peripheral blood stem cell transplantation (PBSCT). The lack of a suitable animal model for studying HCMV transmission after PBSCT is a major barrier to understanding this process and, consequently, developing novel interventions to prevent HCMV infection. Our previous work demonstrated that human CD34(+) progenitor cell-engrafted NOD-scid IL2Rγc(null) (NSG) mice support latent HCMV infection after direct inoculation and reactivation after treatment with granulocyte colony-stimulating factor. To more accurately recapitulate HCMV infection in the D(+)/R(-) PBSCT setting, granulocyte colony-stimulating factor-mobilized peripheral blood stem cells from seropositive donors were used to engraft NSG mice. All recipient mice demonstrated evidence of HCMV infection in liver, spleen, and bone marrow. These findings validate the NSG mouse model for studying HCMV transmission during PBSCT.
Aziza Khodjaeva
2012-10-01
Full Text Available The research objective was to study frequency of antenatal infection and record probable clinical manifestations in 100 children with HCMV born from mother with HCMV in blood and mononuclear cells. The study identified poly-systemic internal organ damage in neonates due to prenatal HCMV. Research procedures involved study of 100 pairs of patients, Mother-Child tandem, using regular clinical assessment methods per algorithm and HCMV diagnostic methods: ELISA, affinity and avidity of HCMV antibodies, and HCMV genome identification via PCR method in blood plasma and mononuclear cells. Initial clinical disease manifested in 71% of children during late neonatal period. Children who died of HCMV (5% were infected antenatal, and 39% were born prematurely. Embryonic stigma found in five cases. HCMV’s affinity to different tissues during the process of embryogenesis leads of poly-systemic damage and results in various clinical manifestations in the postnatal period. HCMV’s ability to invade mononuclear blood cells jeopardizes the antivirus defense system. The research is vital to deter the transmission of the virus and provide HCMV specific treatment to couples planning to have children.
Colombo Anna
2012-10-01
Full Text Available Abstract Background Human cytomegalovirus (HCMV infection of the central nervous system (CNS is a rare but life threatening condition which may follow hematopoietic stem cell transplantation. Diagnosis, monitoring and treatment approaches rely on anecdotal reports. Case presentations The different outcomes of HCMV CNS disease in an adult and a pediatric T-cell depleted hematopoietic stem cell transplant (HSCT recipient are reported. In the first case, HCMV encephalitis emerged in the context of simultaneous impairment of the T- and B-cell immunity. Antiviral treatment only reduced viral load in peripheral blood and the patient died. In the second case, an HCMV radiculopathy was observed and antiviral treatment was adjusted on the basis of intrathecal drug level. In addition, donor HCMV-specific cytotoxic T lymphocytes (CTLs were infused. Viral load in the CNS decreased and the patient recovered from the acute event. In neither case were drug-resistant HCMV variants observed in blood or CNS samples. Conclusions T-cell depleted HSCT appears a predisposing condition for CNS HCMV infection since never observed in other HSCT recipients at our center in the last 15 years. Intensive diagnostic approaches and timely aggressive combination treatments might improve clinical outcome in these patients.
Is HCMV vaccine an unmet need? The state of art of vaccine development.
Chiurchiu, S; Calo Carducci, F I; Rocchi, F; Simonetti, A; Bonatti, G; Salmaso, S; Melchiorri, D; Pani, L; Rossi, P
2013-01-01
Congenital HCMV infection is the most frequent congenital infection, with an incidence of 0.2- 2.5 percent among all live births. About 11 percent of infected newborns show symptoms at birth, including hepato-splenomegaly, thrombocytopenia, neurologic involvement, hearing impairment and visual deficit. Moreover, 5-25 percent of the asymptomatic congenital HCMV-infected neonates will develop sequelae over months or even years. The relevant social burden, the economic costs of pre-natal screening, post-natal diagnosis, follow-up and possible therapy, although still limited, are the major factors to be considered. Several types of vaccines have been explored in order to develop an effective and safe HCMV vaccine: live attenuated, subunit, vectored, peptide, DNA, and subviral ones, but none are available for use. This review illustrates the different vaccine types studied to date, focusing on the possible vaccination strategy to be implemented once the HCMV vaccine is available, in terms of target population.
ZHANG Xin-wen; LI Fen; SHENG Qiu; YU Xue-wen; REN Yong-hui; LI Xue-cheng
2007-01-01
Objective: To study the expression and its clinical significance of HLA-G in HCMV intrauterine infected placental villi at early pregnant stage. Methods: PCR (polymerase chain reaction) was used to screen the peripheral blood for HCMV-DNA in 462 women who had willingly undergone induced abortion.Then immunohistochemistry was also used to detect expressions of mouse anti-HCMV early antigen (HCMV-EA) and mouse anti-HLA-G in HCMV-DNA positive cases' placental villi. The difference of HLA-G expressions between the intrauterine infection group(HCMV EA positives), the intrauterine infection-free group (HCMV-EA negatives) and the normal control group (50 cases of healthy early placental villi) was compared. Results: Of the 78 cases,which were detected HCMV DNA positive, 11 (14.10％)were HCMV-EA positive. Compared with the other two groups, HLA-G expressions in the intrauterine infection group were both obviously decreased(both P＜0.001). HLA-G expression positions in all three groups were mainly located in the cytotrophoblast. Conclusion: Intrauterine HCMV infection at early pregnant stage is closely related to HLA-G expression at the maternal-fetal interface. The virogenetic products may affect the expression of HLA-G at the maternal-fetal interface and that of its immunological function,thus leading to different clinical outcomes.
HCMV seroprevalence and associated risk factors in pregnant women, Havana City, 2007 to 2008.
Correa, C B; Kourí, V; Verdasquera, D; Martínez, P A; Alvarez, A; Alemán, Y; Pérez, L; Viera, J; González, R; Pérez, E; Moro, I; Navarro, M A; Melin, P
2010-09-01
To prenatally identify pregnant women at risk of developing congenital infection due to human cytomegalovirus (HCMV). One thousand one hundred and thirty-one pregnant women from three municipalities from Havana City were serologically screened for HCMV infection (IgM/IgG, IgG avidity) from January 2007 to January 2008. Demographical, epidemiological, and clinical variables were correlated to serologic status to identify predictors of seroconversion in pregnancy. The majority of women were seropositive to HCMV (92.6%); 27 women (2.4%) developed HCMV active infection during pregnancy, defined by the detection of IgG+ and IgM+ (7 women), IgM+ and IgG- (2 women), and IgG seroconversion (18 women). Susceptibility of active HCMV infection during pregnancy was associated with maternal age < 20 years and nulligravidity. Primary infection was detected in 20 pregnant women (1.8%), whereas 7 patients (0.6%) had active non-primary infection. Although pregnant women in Cuba have high seroprevalence rates for HCMV, those younger than 20 years and nulligravidae are at risk of acquiring infection during pregnancy. (c) 2010 John Wiley & Sons, Ltd.
Host-viral effects of chromatin assembly factor 1 interaction with HCMV IE2
Sung-Bau Lee; Li-Jung Juan; Chung-Fan Lee; Derick S-C Ou; Kalpana Dulal; Liang-Hao Chang; Chen-Han Ma; Chien-Fu Huang; Hua Zhu; Young-Sun Lin
2011-01-01
Chromatin assembly factor 1 (CAF1) consisting of p150, p60 and p48 is known to assemble histones onto newly synthesized DNA and thus maintain the chromatin structure. Here, we show that CAF1 expression was induced in human cytomegalovirus (HCMV)-infected cells, concomitantly with global chromatin decondensation. This apparent conflict was thought to result, in part, from CAF1 mislocalization to compartments of HCMV DNA synthesis through binding of its largest subunit p150 to viral immediate-early protein 2 (IE2). p150 interaction with p60 and IE2 facilitated HCMV DNA synthesis. The IE2Q548R mutation, previously reported to result in impaired HCMV growth with unknown mechanism, disrupted IE2/p150 and IE2/histones association in our study. Moreover, IE2 interaction with histones partly depends on p150, and the HCMV-induced chromatin decondensation was reduced in cells ectopically expressing the p150 mutant defective in IE2 binding. These results not only indicate that CAF1 was hijacked by IE2 to facilitate the replication of the HCMV genome, suggesting chromatin assembly plays an important role in herpesviral DNA synthesis, but also provide a model of the virus-induced chromatin instability through CAF1.
HCMV Activates the IL-6-JAK-STAT3 Axis in HepG2 Cells and Primary Human Hepatocytes
Kumar, Amit; Tripathy, Manoj K.; Herbein, Georges
2013-01-01
Objectives There has been increased interest in the possible role of human cytomegalovirus (HCMV) in carcinogenesis during the last decade. HCMV seroprevalence was enhanced in patients with hepatocellular carcinoma (HCC) but a possible relationship between HCC and HCMV infection remained to be assessed. The aim of this work was to investigate the pro-tumor influence of HCMV on primary human hepatocytes (PHH) and HepG2 cells. Methods Following infection of PHH and HepG2 cells by two different strains of HCMV, we measured the production of IL-6 in culture supernatants by ELISA and the protein levels of STAT3, pSTAT3, JAK, cyclin D1, survivin, p53, p21, and Mdm2 by western Blotting in infected and uninfected cells. Cell proliferation and transformation were investigated using Ki67Ag expression measurement and soft-agar colony formation assay respectively. Results Infection of HepG2 cells and PHH by HCMV resulted in the production of IL-6 and the subsequent activation of the IL-6R-JAK-STAT3 pathway. HCMV increased the expression of cyclin D1 and survivin. Cell proliferation was enhanced in HepG2 and PHH infected with HCMV, despite a paradoxical overexpression of p53 and p21. More importantly, we observed the formation of colonies in soft agar seeded with PHH infected with HCMV and when we challenged the HepG2 cultures to form tumorspheres, we found that the HCMV-infected cultures formed 2.5-fold more tumorspheres than uninfected cultures. Conclusion HCMV activated the IL-6-JAK-STAT3 pathway in PHH and HepG2 cells, favored cellular proliferation, induced PHH transformation and enhanced HepG2 tumorsphere formation. Our observations raise the possibility that HCMV infection might be involved in the genesis of hepatocellular carcinoma. PMID:23555719
Yujing Huang; Ying Qi; Yanping Ma; Rong He; Yaohua Ji; Zhengrong Sun; Qiang Ruan
2013-09-01
MicroRNAs (miRNAs) are small RNAs, 19–23 nucleotides in length, which regulate a variety of cellular processes. Human cytomegalovirus (HCMV) encodes only one intronic miRNA: human cytomegalovirus microRNA UL36 (hcmv-miR-UL36). In this study, we found that over-expression of hcmv-miR-UL36 resulted in a more than threefold increase in HCMV DNA synthesis at 24 h post infection. Fifteen putative targets of hcmv-miR-UL36 were identified using hybrid PCR, one being the HCMV UL138 gene that has previously been identified as a novel latency-associated determinant of HCMV infection. Down-regulation of UL138 expression by hcmv-miR-UL36 was validated using luciferase reporter assays and Western blot analysis in HEK293 cells. In the presence of hcmv-miR-UL36, we observed a 74.6% decrease in luciferase activity and a 46.2% decrease in HCMV UL138 protein expression. Our results indicate that hcmv-miR-UL36 may be a viral miRNA contributing to HCMV replication.
Analysis of HSV-I ICP22 effects on HCMV major immediate-early promoter structure
2007-01-01
The human cytomegalovirus (HCMV) major immediate-early (MIE) promoter has strong transcriptional promoting capability. Its cis-acting regulatory elements form a special structure in this region that is repeated multiple times; the biological significance of these elements and their different compositions in the transcriptional promoting process remain unclear. Our results demonstrate that the HSV-I MIE protein ICP22 can generate strong repression of many viral and cellular promoters and enhancers. We further studied the transcriptional effects of ICP22 on structural elements and mutations in various HCMV MIE promoters by using a CAT assay. In spite of different transcriptional effects of all the ele- ments in the presence of ICP22, the transcriptional efficiencies exhibited by mutations generated by different compositions and an entire HCMV promoter, are not the simple sum of the functions of these elements. Furthermore, the transcriptional activities of specific sequences were not affected by the presence of ICP22. Therefore, it is assumed that the HCMV MIE promoter co-regulates expression of downstream genes by using viral and cellular specific factors via a specific pathway.
US28 actions in HCMV infection : lessons from a versatile hijacker
Boomker, JM; van Luyn, MJA; The, TH; de Leij, LFMH; Harmsen, MC
2005-01-01
Mimicking host proteins is a strategy adopted by several herpesviruses to exploit the host cell for their own benefit. In this respect the human cytomegalovirus (HCMV) chemokine receptor homologue US28, has been extensively studied. Molecular pirates such as US28 can teach us about crucial events in
Impact of HCMV infection on NK cell development and function after HSCT
Mariella eDella Chiesa
2013-12-01
Full Text Available Natural Killer (NK cell function is regulated by an array of inhibitory and activating surface receptors that during NK cell differentiation, at variance with T and B cells, do not require genetic rearrangement. Importantly, NK cells are the first lymphocyte population recovering after hematopoietic stem cell transplantation (HSCT. Thus, their role in early immunity after HSCT is considered crucial, as they can importantly contribute to protect the host from tumor recurrence and viral infections before T-cell immunity is fully recovered.In order to acquire effector functions and regulatory receptors, NK cell precursors undergo a maturation process that can be analysed during immune reconstitution after HSCT. In this context, the occurrence of human cytomegalovirus (HCMV infection/reactivation was shown to accelerate NK cell maturation by promoting the differentiation of high frequencies of NK cells characterized by a KIR+NKG2A− and NKG2C+ mature phenotype. Thus, it appears that the development of NK cells and the distribution of NK cell receptors can be deeply influenced by HCMV infection. Moreover, in HCMV-infected subjects the emergence of so called memory-like or long-lived NK cells has been documented. These cells could play an important role in protecting from infections and maybe from relapse in patients transplanted for leukemia.All the aspects regarding the influence of HCMV infection on NK cell development will be discussed.
Rössler Wolfgang
2007-07-01
Full Text Available Abstract Background The impact of infections with the human cytomegalovirus (HCMV for the development of atherosclerosis and restenosis is still unclear. Both a clear correlation and no correlation at all have been reported in clinical, mostly serological studies. In our study we employed a human non-injury ex vivo organ culture model to investigate the effect of an in vitro permissive HCMV-infection on cell proliferation and neointimal hyperplasia for a period of 56 days. Results During routine-nephrectomies parts of renal arteries from 71 patients were obtained and prepared as human organ cultures. Cell free HCMV infection was performed with the fibroblast adapted HCMV strain AD169, the endotheliotropic strain TB40E, and a clinical isolate (AN 365. After 3, 7, 14, 21, 28, 35, and 56 days in culture staining of HCMV-antigens was carried out and reactive cell proliferation and neointimal thickening were analysed. Successful HCMV-infection was accomplished with all three virus strains studied. During the first 21 days in organ culture no cell proliferation or neointimal hyperplasia was detected. At day 35 and day 56 moderate cell proliferation and neointimal hyperplasia was found both in HCMV-infected segments and mock infected controls. Neointimal hyperplasia in productively HCMV-infected segments was lower than in non infected at day 35 and day 56, but relatively higher after infection with the endotheliotropic TB40E in comparison with the two other strains. Conclusion The data do not support the hypothesis that HCMV-infection triggers restenosis via a stimulatory effect on cell proliferation and neointimal hyperplasia in comparison to non infected controls. Interestingly however, even after lytic infection, a virus strain specific difference was observed.
董玉琳
2012-01-01
Objective:This article through the study of HCMV-IgG avidity index (avidity the index,AI) and HCMV-DNA detection,maternal primary infection and secondary infection of a comprehensive evaluation. Designed to prevent and reduce perinatal infections,abortion and neonatal congenital malformations,hearing impairment and mental retardation to provide effective and accurate test data and clinical diagnosis is based on.Method:Using the German Virion/serion enzyme-linked immunosorbent assay (ELISA) quantitative reagent,detected in maternal serum of HCMV IgM and IgG antibodies and IgG avidity;Zhongshan Medical University,Tat RV nucleic acid amplification (PCR) fluorescence quantitative detection maternal serum levels in HCMV-DNA,and the results were analyzed.Result:341 cases of pregnant women,maternal history of poor pregnant women group of HCMV-IgG low affinity sample proportion was significantly higher than the initial pregnancy. The adverse pregnancy history of pregnant women HCMV-DNA positive proportion of the number of cases was significantly higher than the initial pregnancy.Conclusion:341 cases of pregnant women in a certain proportion of HCMV now disease infection,it is recommended that pregnant women especially those with history of adverse pregnancy by as much as possible HCMV-IgG avidity index and HCMV-DNA checks in order to take early measures to avoid due to HCMV infection causes the occurrence of birth defects.% 目的：本文通过研究HCMV-IgG亲和力指数(avidity index,AI)以及HCMV-DNA的检测,对孕产妇原发性感染及继发性感染进行综合评价。旨在为防止和减少围产期感染、流产及新生儿先天畸形、听力障碍和智力障碍提供有效而准确的检测数据及临床诊断依据。方法：采用德国Virion/serion公司酶联免疫吸附试验(ELISA)定量试剂,检测孕妇血清中HCMV的IgM和IgG抗体、IgG抗体亲和力；采用中山医科大学达安公司RV核酸扩增(PCR)荧光定量检测孕妇血清中HCMV
Indeterminate/moderate IgG avidity during HCMV infection: comparison of methods
Massimo De Paschale
2010-03-01
Full Text Available Background. The IgG avidity test is usually used for differentiating between primary and non-primary HCMV infection within 3 months. Weak avidity is highly suggestive of a primary infection, while high avidity tends to exclude it.An indeterminate or moderate avidity, however, does not allow a clear dating. Since there are several avidity tests with different performances, those tests that are able to minimize the results with indeterminate/moderate avidity are particularly useful. Objectives. The aim of our work was to evaluate the results obtained with two IgG avidity tests in IgG and IgM anti-HCMV positive patients. Study Design. 113 anti-HCMV IgG and IgM positive samples were tested with Enzime Linked Fluorescent Assay (ELFA and Chemiluminescence Immuno Assay (CLIA IgG avidity test. Results. 21 samples (18.6%, 50 (44.2% and 42 (37.2% with ELFA and 53 samples (46.9%, 10 (8.8% and 50 (44.2% with CLIA were found to have respectively low, indeterminate/moderate and high avidity. Of the 50 ELFA indeterminate avidity samples, 32 (64%, 10 (20% and 8 (16% were found to have respectively low, moderate and high CLIA.avidity. For 11 cases of the 32 ELFA indeterminate avidity and CLIA low avidity, there were previous data showing a seroconversion within three months. In a case of the 8 ELFA indeterminate avidity and CLIA high avidity, there were, instead, previous data of IgG and IgM positivity already four months earlier. Conclusions. It appears that the CLIA test for IgG avidity is more effective than ELFA for dating HCMV infection.
Szentgyörgyi, Ester
2006-01-01
In der Diagnostik der primären und reaktivierten Humanen Cytomegalievirus (HCMV)-Infektion hat sich die quantitative PCR als geeignete Methode erwiesen. Sie zeigt deutliche Vorteile bezüglich der Bestimmung der Schwere einer Infektion, der Vorhersage des Erkrankungsrisikos und eignet sich zum Monitoring der präemptiven antiviralen Therapie. Ziel dieser Arbeit war die Evaluation einer sensitiven, schnellen und kostengünstigen quantitativen PCR-Analyse mittels LightCycler (LC). Verglichen wu...
Transcriptional activation of endoplasmic reticulum chaperone GRP78 by HCMV IE1-72 protein
Derick Shi-Chen Ou; Sung-Bau Lee; Chi-Shuen Chu; Liang-Hao Chang; Bon-chu Chung; Li-Jung Juan
2011-01-01
Glucose-regulated protein 78 (GRP78), a key regulator of endoplasmic reticulum (ER) stress, facilitates cancer cell growth and viral replication. The mechanism leading to grp78 gene activation during viral infection is largely unknown, in this study, we show that the immediate-early 1 (IE1-72) protein of the human cytomegalovirus (HCMV) is essential for HCMV-mediated GRP78 activation. IE1-72 upregulated grp 78 gene expression depending on the ATPbinding site, the zinc-finger domain and the putative leucine-zipper motif of IE1-72, as well as the ER stress response elements (ERSEs) on the grp78 promoter. The purified IE1-72 protein bound to the CCAAT box within ERSE in vitro, whereas deletion mutants of IE1-72 deficient in grp78 promoter stimulation failed to do so. Moreover, IE1-72 binding to the grp78 promoter in infected cells accompanied the recruitment of TATA box-binding protein-associated factor 1 (TAF1), a histone acetyltransferase, and the increased level of acetylated histone H4, an indicator of activestate chromatin. These results provide evidence that HCMV IE1-72 activates grp78 gene expression through direct promoter binding and modulation of the local chromatin structure, indicating an active viral mechanism of cellular chaperone induction for viral growth.
Vieira Braga, Felipe A; Hertoghs, Kirsten M L; van Lier, René A W; van Gisbergen, Klaas P J M
2015-09-01
CD8(+) T cells are important for immunity against human cytomegalovirus (HCMV). The HCMV-specific CD8(+) T-cell response is characterized by the accumulation of terminally differentiated effector cells that have downregulated the costimulatory molecules CD27 and CD28. These HCMV-specific CD8(+) T cells maintain high levels of cytotoxic molecules such as granzyme B and rapidly produce the inflammatory cytokine IFN-γ upon activation. Remarkably, HCMV-specific CD8(+) T cells are able to persist long term as fully functional effector cells, suggesting a unique differentiation pathway that is distinct from the formation of memory CD8(+) T cells after infection with acute viruses. In this review, we aim to highlight the most recent developments in HCMV-specific CD8(+) T-cell differentiation, maintenance, tissue distribution, metabolism and function. HCMV also induces the differentiation of effector CD4(+) T cells and NK cells, which share characteristics with HCMV-specific CD8(+) T cells. We propose that the overlap in differentiation of NK cells, CD4(+) and CD8(+) T cells after HCMV infection may be regulated by a shared transcriptional machinery. A better understanding of the molecular framework of HCMV-specific CD8(+) T-cell responses may benefit vaccine design, as these cells uniquely combine the capacity to rapidly respond to infection with long-term survival. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
HCMV gB shares structural and functional properties with gB proteins from other herpesviruses
Sharma, Sapna [Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 (United States); Wisner, Todd W.; Johnson, David C. [Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR 97239 (United States); Heldwein, Ekaterina E., E-mail: katya.heldwein@tufts.edu [Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111 (United States)
2013-01-20
Glycoprotein B (gB) facilitates HCMV entry into cells by binding receptors and mediating membrane fusion. The crystal structures of gB ectodomains from HSV-1 and EBV are available, but little is known about the HCMV gB structure. Using multiangle light scattering and electron microscopy, we show here that HCMV gB ectodomain is a trimer with the overall shape similar to HSV-1 and EBV gB ectodomains. HCMV gB ectodomain forms rosettes similar to rosettes formed by EBV gB and the postfusion forms of other viral fusogens. Substitution of several bulky hydrophobic residues within the putative fusion loops with more hydrophilic residues reduced rosette formation and abolished cell fusion. We propose that like gB proteins from HSV-1 and EBV, HCMV gB has two internal hydrophobic fusion loops that likely interact with target membranes. Our work establishes structural and functional similarities between gB proteins from three subfamilies of herpesviruses.
Melpomeni Tseliou
2016-01-01
Full Text Available Background/Aims: Rho GTPases are crucial regulators of the actin cytoskeleton, membrane trafficking and cell signaling and their importance in cell migration and invasion is well- established. The human cytomegalovirus (HCMV is a widespread pathogen responsible for generally asymptomatic and persistent infections in healthy people. Recent evidence indicates that HCMV gene products are expressed in over 90% of malignant type glioblastomas (GBM. In addition, the HCMV Immediate Early-1 protein (IE1 is expressed in >90% of tumors analyzed. Methods: RhoA, RhoB and RhoC were individually depleted in U373MG glioblastoma cells as well as U373MG cells stably expressing the HCMV IE1 protein (named U373MG-IE1 cells shRNA lentivirus vectors. Cell proliferation assays, migration as well as wound-healing assays were performed in uninfected and HCMV-infected cells. Results: The depletion of RhoA, RhoB and RhoC protein resulted in significant alterations in the morphology of the uninfected cells, which were further enhanced by the cytopathic effect caused by HCMV. Furthermore, in the absence or presence of HCMV, the knockdown of RhoB and RhoC proteins decreased the proliferation rate of the parental and the IE1-expressing glioblastoma cells, whereas the knockdown of RhoA protein in the HCMV infected cell lines restored their proliferation rate. In addition, wound healing assays in U373MG cells revealed that depletion of RhoA, RhoB and RhoC differentially reduced their migration rate, even in the presence or the absence of HCMV. Conclusion: Collectively, these data show for the first time a differential implication of Rho GTPases in morphology, proliferation rate and motility of human glioblastoma cells during HCMV infection, further supporting an oncomodulatory role of HCMV depending on the Rho isoforms' state.
Einat Seidel
2015-02-01
Full Text Available Natural killer (NK cells mediate innate immune responses against hazardous cells and are particularly important for the control of human cytomegalovirus (HCMV. NKG2D is a key NK activating receptor that recognizes a family of stress-induced ligands, including MICA, MICB, and ULBP1-6. Notably, most of these ligands are targeted by HCMV proteins and a miRNA to prevent the killing of infected cells by NK cells. A particular highly prevalent MICA allele, MICA∗008, is considered to be an HCMV-resistant “escape variant” that confers advantage to human NK cells in recognizing infected cells. However, here we show that HCMV uses its viral glycoprotein US9 to specifically target MICA∗008 and thus escapes NKG2D attack. The finding that HCMV evolved a protein dedicated to countering a single host allele illustrates the dynamic co-evolution of host and pathogen.
Braendstrup, Peter; Mortensen, Bo Kok; Justesen, Sune Frederik Lamdahl
2014-01-01
tumor development. Both CD4(+) and CD8(+) T cell responses are important for long-term control of the virus, and adoptive transfer of HCMV-specific T cells has led to protection from reactivation and HCMV disease. Identification of HCMV-specific T cell epitopes has primarily focused on CD8(+) T cell......Human cytomegalovirus (HCMV) is an important human pathogen. It is a leading cause of congenital infection and a leading infectious threat to recipients of solid organ transplants as well as of allogeneic hematopoietic cell transplants. Moreover, it has recently been suggested that HCMV may promote...... responses against the pp65 phosphoprotein. In this study, we have focused on CD4(+) and CD8(+) T cell responses against the immediate early 1 and 2 proteins (IE1 and IE2). Using overlapping peptides spanning the entire IE1 and IE2 sequences, peripheral blood mononuclear cells from 16 healthy, HLA...
Cyclin-dependent kinase activity controls the onset of the HCMV lytic cycle.
Martin Zydek
Full Text Available The onset of human cytomegalovirus (HCMV lytic infection is strictly synchronized with the host cell cycle. Infected G0/G1 cells support viral immediate early (IE gene expression and proceed to the G1/S boundary where they finally arrest. In contrast, S/G2 cells can be infected but effectively block IE gene expression and this inhibition is not relieved until host cells have divided and reentered G1. During latent infection IE gene expression is also inhibited, and for reactivation to occur this block to IE gene expression must be overcome. It is only poorly understood which viral and/or cellular activities maintain the block to cell cycle or latency-associated viral IE gene repression and whether the two mechanisms may be linked. Here, we show that the block to IE gene expression during S and G2 phase can be overcome by both genotoxic stress and chemical inhibitors of cellular DNA replication, pointing to the involvement of checkpoint-dependent signaling pathways in controlling IE gene repression. Checkpoint-dependent rescue of IE expression strictly requires p53 and in the absence of checkpoint activation is mimicked by proteasomal inhibition in a p53 dependent manner. Requirement for the cyclin dependent kinase (CDK inhibitor p21 downstream of p53 suggests a pivotal role for CDKs in controlling IE gene repression in S/G2 and treatment of S/G2 cells with the CDK inhibitor roscovitine alleviates IE repression independently of p53. Importantly, CDK inhibiton also overcomes the block to IE expression during quiescent infection of NTera2 (NT2 cells. Thus, a timely block to CDK activity not only secures phase specificity of the cell cycle dependent HCMV IE gene expression program, but in addition plays a hitherto unrecognized role in preventing the establishment of a latent-like state.
Yaozhong Shao; Ying Qi; Yujing Huang; Zhongyang Liu; Yanping Ma; Xin Guo; Shujuan Jiang; Zhengrong Sun; Qiang Ruan
2016-06-01
Human cytomegalovirus (HCMV) can cause congenital diseases and opportunistic infections in immunocompromised individuals. Its functional proteins and microRNAs (miRNAs) facilitate efficient viral propagation by altering host cell behaviour. Identification of functional target genes of miRNAs is an important step in studies on HCMV pathogenesis. In this study, Glutaminyl-tRNA Synthetase (QARS), which could regulate signal transduction pathways for cellular apoptosis, was identified as a direct target of hcmv-miR-US4-1. Apoptosis assay revealed that as silence of QARS by ectopic expression of hcmv-miR-US4-1 and specific small interference RNA of QARS can promote cell apoptosis in HCMV-infected HELF cells. Moreover, viral growth curve assays showed that hcmv-miR-US4-1 benefits the discharge of infectious virus particles. However, silence of hcmv-miR-US4-1 by its specific inhibitor overturned these effects. These results imply that hcmv-miR-US4-1 might have the same effects during HCMV nature infection. In general, hcmv-miR-US4-1 may involve in promoting cell apoptosis and benefiting discharge of infectious virus particles via down-regulation of QARS in HCMV-infected HELF cells.
Braendstrup, Peter; Mortensen, Bo Kok; Justesen, Sune Frederik Lamdahl;
2014-01-01
tumor development. Both CD4(+) and CD8(+) T cell responses are important for long-term control of the virus, and adoptive transfer of HCMV-specific T cells has led to protection from reactivation and HCMV disease. Identification of HCMV-specific T cell epitopes has primarily focused on CD8(+) T cell......-typed, donors were screened by ex vivo IFN-gamma ELISpot and in vitro intracellular cytokine secretion assays. The specificities of CD4(+) and CD8(+) T cell responses were identified and validated by HLA class II and I tetramers, respectively. Eighty-one CD4(+) and 44 CD8(+) T cell responses were identified...... in IE1 and IE2 were recognized in about half of the analyzed donors. These data may be used to design a versatile anti-HCMV vaccine and/or immunotherapy strategy....
Courtot Anne Marie; Pallier Coralie; Testart Jacques
2003-01-01
The possibility of infection of the human male genital tract by human herpes virus type 2 (HSV2) or human cytomegalovirus (HCMV) is well established and their sexual transmission has been the object of many studies. Moreover, medically assisted procreation, which helps in numerous fertility problems, raises the question of new viral risks linked to the application of these new technologies. In this review, we shall consider current knowledge in terms of the presence of HSV2 and HCMV in the different parts of the genital tract of immunocompetent or immunodepressed men. We shall also consider the possibility of viral transmission by the sexual act or by the various techniques used in medically assisted procreation. We shall describe studies in human beings and in animals.
Abdul-Aleem Mohammad
Full Text Available BACKGROUND: microRNAs (miRNA are 18-22 nucleotides long non-coding RNAs that regulate gene expression at a post-transcriptional level. Human cytomegalovirus (HCMV encodes at least 26 known mature miRNAs. hcmv-miR-UL112-3p (miR-UL112-3p is the most well characterized HCMV miRNA, which is suggested to play role in establishment and maintenance of viral latency. Elevated miR-UL112-3p levels have been reported to be present in plasma of patients with hypertension. OBJECTIVES: In this study, we aimed to quantify miR-UL112-3p levels in the plasma/serum of patients with Diabetes Mellitus (DM; from the DIGAMI-2 cohort, Glioblastoma multiforme (GBM, Rheumatoid Arthritis (RA and Healthy Controls (HC. STUDY DESIGN: Total RNA was isolated from plasma/serum samples of 87 patients and controls, a TaqMan miRNA assay was performed to detect miR-UL112-3p and the copy numbers were normalized to 10 ng of total RNA. HCMV IgG and IgM were analysed using ELISA. RESULTS: HCMV miR-UL112-3p was detected in 14/27 (52% of DM, 5/20 (25% of GBM, 1/20 (5% of RA patients and in 2/20 (10% of HC, respectively. Anti-HCMV IgG was detected in 85%, 65%, 75% of patients and 70% of HC, respectively. Anti-HCMV IgM was found only in one GBM patient of 87 examined patients and controls. CONCLUSIONS: A higher prevalence of miR-UL112-3p was detected in DM and GBM patients than in RA patients and HC. Elevated levels of miR-UL112-3p and higher prevalence of HCMV IgG were observed in DM patients. Whether the presence of circulating miR-UL112-3p denotes a biomarker of HCMV latency or active replication in patients warrants further investigation.
Hartleif, Steffen; Göhring, Katharina; Goelz, Rangmar; Jahn, Gerhard; Hamprecht, Klaus
2016-11-01
For cytomegalovirus screening of breastfeeding mothers of preterm infants under risk, we present a rapid, quantitative real-time PCR protocol using the hybridization format of the viral gB target region. For quantification, we used an external gB fragment cloned into a vector system. For standardization, we created an internal control-plasmid by site-directed mutagenesis with an exchange of 9 nucleotides. Spiked with internal control, patient wildtype amplicons could be discriminated from internal controls by hybridization probes using two-channel fluorescence detection. Potential bias of formerly reported false nucleotide sequence data of gB-hybridization probes was excluded. Using this approach, we could demonstrate excellent analytical performance and high reproducibility of HCMV detection during lactation. This assay shows very good correlation with a commercial quantitative HCMV DNA PCR and may help to identify rapidly HCMV shedding mothers of very low birth weight preterm infants to prevent HCMV transmission. On the other hand, negative DNA amplification results allow feeding of milk samples of seropositive mothers to their preterm infants under risk (<30 weeks of gestational age, <1000g birth weight) during the onset and late stage of HCMV shedding during lactation. Copyright © 2016 Elsevier B.V. All rights reserved.
Peter Braendstrup
Full Text Available Human cytomegalovirus (HCMV is an important human pathogen. It is a leading cause of congenital infection and a leading infectious threat to recipients of solid organ transplants as well as of allogeneic hematopoietic cell transplants. Moreover, it has recently been suggested that HCMV may promote tumor development. Both CD4+ and CD8+ T cell responses are important for long-term control of the virus, and adoptive transfer of HCMV-specific T cells has led to protection from reactivation and HCMV disease. Identification of HCMV-specific T cell epitopes has primarily focused on CD8+ T cell responses against the pp65 phosphoprotein. In this study, we have focused on CD4+ and CD8+ T cell responses against the immediate early 1 and 2 proteins (IE1 and IE2. Using overlapping peptides spanning the entire IE1 and IE2 sequences, peripheral blood mononuclear cells from 16 healthy, HLA-typed, donors were screened by ex vivo IFN-γ ELISpot and in vitro intracellular cytokine secretion assays. The specificities of CD4+ and CD8+ T cell responses were identified and validated by HLA class II and I tetramers, respectively. Eighty-one CD4+ and 44 CD8+ T cell responses were identified representing at least seven different CD4 epitopes and 14 CD8 epitopes restricted by seven and 11 different HLA class II and I molecules, respectively, in total covering 91 and 98% of the Caucasian population, respectively. Presented in the context of several different HLA class II molecules, two epitope areas in IE1 and IE2 were recognized in about half of the analyzed donors. These data may be used to design a versatile anti-HCMV vaccine and/or immunotherapy strategy.
Villinger, Clarissa; Schubert, Axel; Walther, Paul; Sinzger, Christian; Lieber, Diana
2017-01-01
Widely used methods for quantification of human cytomegalovirus (HCMV) infection in cell culture such as immunoblotting or plaque reduction assays are generally restricted to low throughput and require time-consuming evaluation. Up to now, only few HCMV reporter cell lines have been generated to overcome these restrictions and they are afflicted with other limitations because permanently expandable cell lines are normally not fully permissive to HCMV. In this work, a previously existing epithelial cell line hosting a luciferase gene under control of a Varicella-zoster virus promoter was adopted to investigate HCMV infection. The cells were susceptible to different HCMV strains at infection efficiencies that corresponded to their respective degree of epithelial cell tropism. Expression of early and late viral antigens, formation of nuclear inclusions, release of infectious virus progeny, and focal growth indicated productive viral replication. However, viral release and spread occurred at lower levels than in primary cell lines which appears to be due to a malfunction of virion morphogenesis during the nuclear stage. Expression of the luciferase reporter gene was specifically induced in HCMV infected cultures as a function of the virus dose and dependent on viral immediate early gene expression. The level of reporter activity accurately reflected infection efficiencies as determined by viral antigen immunostaining, and hence could discriminate the cell tropism of the tested virus strains. As proof-of-principle, we demonstrate that this cell line is applicable to evaluate drug resistance of clinical HCMV isolates and the neutralization capacity of human sera, and that it allows comparative and simultaneous analysis of HCMV and human herpes simplex virus type 1. In summary, the permanent epithelial reporter cell line allows robust, rapid and objective quantitation of HCMV infection and it will be particularly useful in higher throughput analyses as well as in
Andrews, P W; Gönczöl, E; Plotkin, S A; Dignazio, M; Oosterhuis, J W
1986-01-01
Retinoic acid induces the differentiation of NTERA-2 cl. D1 human embryonal carcinoma (EC) cells into neurons, cells permissive for the replication of human cytomegalovirus (HCMV), and other cell types that cannot as yet be classified but are distinguishable from the stem cells. We tested several additional agents for their ability to induce the differentiation of these EC cells. No differentiation was induced by butyrate, cyclic AMP, cytosine arabinoside, the tumor promoter 12-0-tetradecanoylphorbol 13-acetate (TPA), or the chemotherapeutic agent cis-diaminedichloroplatinum, although morphological changes were detected at the highest concentrations of these agents that permitted cell survival. However, retinal, retinol, 5-bromouracil 2'deoxyribose (BUdR), 5-iodouracil 2'deoxyribose (IUdR), hexamethylene bisacetamide (HMBA), dimethylacetamide (DMA), and dimethylsulfoxide (DMSO) all induced some neuronal differentiation, but to a lesser extent than retinoic acid. Also, BUdR, IUdR, HMBA, and DMA induced the appearance of many cells permissive for the replication of HCMV. Differentiation was, in all cases, accompanied by the loss of SSEA-3, a globoseries glycolipid antigen characteristically expressed by human EC cells. However, another glycolipid antigen, A2B5, which appears in 60%-80% of differentiated cells 7 days following retinoic acid induction, was detected in less than 20% of the cells induced by the other agents studied. This implies that the HCMV-permissive cells induced by retinoic acid are not identical to those induced by BUdR, IUdR, and DMA.
Morales-Sánchez, A.; Pompa-Mera, E. N.; Fajardo-Gutiérrez, A.; Alvarez-Rodríguez, F. J.; Bekker-Méndez, V. C.; Flores-Chapa, J. de Diego; Flores-Lujano, J.; Jiménez-Hernández, E.; Peñaloza-González, J. G.; Rodríguez-Zepeda, M. C.; Torres-Nava, J. R.; Velázquez-Aviña, M. M.; Amador-Sánchez, R.; Alvarado-Ibarra, M.; Reyes-Zepeda, N.; Espinosa-Elizondo, R. M.; Pérez-Saldivar, M. L.; Núñez-Enríquez, J. C.; Mejía-Aranguré, J. M.; Fuentes-Pananá, E. M.
2014-01-01
Acute lymphoblastic leukemia (ALL) is the most common cancer in childhood worldwide and Mexico has reported one of the highest incidence rates. An infectious etiology has been suggested and supported by epidemiological evidences; however, the identity of the involved agent(s) is not known. We considered that early transmitted lymphotropic herpes viruses were good candidates, since transforming mechanisms have been described for them and some are already associated with human cancers. In this study we interrogated the direct role of EBV, HCMV, HHV6, and HHV7 human herpes viruses in childhood ALL. Viral genomes were screened in 70 bone marrow samples from ALL patients through standard and a more sensitive nested PCR. Positive samples were detected only by nested PCR indicating a low level of infection. Our result argues that viral genomes were not present in all leukemic cells, and, hence, infection most likely was not part of the initial genetic lesions leading to ALL. The high statistical power of the study suggested that these agents are not involved in the genesis of ALL in Mexican children. Additional analysis showed that detected infections or coinfections were not associated with prognosis. PMID:25309913
A. Morales-Sánchez
2014-01-01
Full Text Available Acute lymphoblastic leukemia (ALL is the most common cancer in childhood worldwide and Mexico has reported one of the highest incidence rates. An infectious etiology has been suggested and supported by epidemiological evidences; however, the identity of the involved agent(s is not known. We considered that early transmitted lymphotropic herpes viruses were good candidates, since transforming mechanisms have been described for them and some are already associated with human cancers. In this study we interrogated the direct role of EBV, HCMV, HHV6, and HHV7 human herpes viruses in childhood ALL. Viral genomes were screened in 70 bone marrow samples from ALL patients through standard and a more sensitive nested PCR. Positive samples were detected only by nested PCR indicating a low level of infection. Our result argues that viral genomes were not present in all leukemic cells, and, hence, infection most likely was not part of the initial genetic lesions leading to ALL. The high statistical power of the study suggested that these agents are not involved in the genesis of ALL in Mexican children. Additional analysis showed that detected infections or coinfections were not associated with prognosis.
Giada Rossini
2012-01-01
Full Text Available The interaction between human cytomegalovirus (HCMV and its host is a complex process that begins with viral attachment and entry into host cells, culminating in the development of a specific adaptive response that clears the acute infection but fails to eradicate HCMV. We review the viral and cellular partners that mediate early host responses to HCMV with regard to the interaction between structural components of virions (viral glycoproteins and cellular receptors (attachment/entry receptors, toll-like receptors, and other nucleic acid sensors or intrinsic factors (PML, hDaxx, Sp100, viperin, interferon inducible protein 16, the reactions of innate immune cells (antigen presenting cells and natural killer cells, the numerous mechanisms of viral immunoevasion, and the potential exploitation of events that are associated with early phases of virus-host interplay as a therapeutic strategy.
秦巴山区孕产期 HCMV感染状况调查%Research on HCMV infection during pregnancy in Qinba mountain areas
许静; 李芬; 宋晖; HUANG Hui
2013-01-01
目的：研究贫困山区人巨细胞病毒（ HCMV）的感染状况以及导致HCMV感染的危险因素。方法选择陕南贫困地区4个县434名中、晚期妊娠妇女，对其进行一般情况及孕期情况的问卷调查，应用酶联免疫吸附试验（ ELISA）及PCR技术检测孕妇外周血抗HCMV-IgG、IgM抗体及HCMV DNA片段。随访至其生产后（所有随访者均为足月生产），分别于产后2周内、3～14周内对随访产妇采集其乳汁及所生婴儿的尿液，继续进行HCMV的相关检查，区分先天性感染和围生期感染，并结合问卷分析HCMV感染的危险因素。结果①贫困山区妊娠妇女HCMV感染率为85．48％（371/434），活动性感染率为8．06％（35/434）；总宫内传播率为4．58％（17/371），其中活动性感染者宫内感染率为31．43％（11/35），潜伏性感染者为1．79％（6/336），两组间宫内传播率有显著性差异（χ2＝63．704，P＜0．05）；②产妇乳汁HCMV阳性率11．86％（44/371），其中活动性感染者乳汁排毒率为85．71％（30/35），潜伏性感染者乳汁排毒率为4．17％（14/336），两组间有显著性差异（确切概率0．000，P＜0．05）。乳汁排毒组中继续母乳喂养者中有14．28％（1/7）发生围生期感染，乳汁无排毒组中无围产期感染，两组间围生期感染率有显著性差异（确切概率0．021，P＜0．05）；③年龄、文化程度、家庭经济状况在活动性、潜伏性感染与正常对照组间均无显著性差异（χ2值分别为4．088、5．610、5．380，均P＞0．05）。孕产次、分娩方式在活动性、潜伏性感染与正常对照组间均有显著性差异（χ2值分别为9．383、17．746，均P＜0．05）。结论秦巴山区妊娠妇女HCMV活动性感染率、宫内传播率较课题组之前的研究有所下降，但仍高于其他地区感染水平。妊娠期HCMV活动性感染是导致宫内传播和产
罗勤; 刘明; 程均; 黄永健
2009-01-01
Objective: To understand the clinical significance of HCMV combined testing of serum, urine, breast milk samples using fluorescent quantitative polymerase chain reaction (FQ-PCR) in children. Methods: HCMV-DNA in serum and urine was detected by using FQ-PCR in 182 suspect cases, as well as breast milk from mothers, whose children was feed by breast and its HCMV infection was confirmed. Results: The positive rate of HCMV-DNA of serum, urine and combined testing was 15.93%, 29. 12%, 39.01%, respectively. The HCMV-DNA positive rate of breast milk from confirmed case's mother was significant higher than that of control group (X2 = 5.54, P < 0.02). Conclusion: The results indicated that combined testing could increase the positive rate of HCMV-DNA, the HCMVDNA positive rate of urine was higher than serum, and breast milk infected with HCMV should be the main route of acquired infection.%目的 探讨用荧光定量聚合酶链反应(fluorescence quantitative PCR,FQ-PCR)法进行血、尿、母乳联合检测小儿人巨细胞病毒(HCMV)的临床意义.方法 采用FQ-PCR法联合检测182例疑诊HCMV感染的患儿,对母乳喂养的阳性患儿补测母乳HCMV-DNA.结果 血、尿及联合检测HCMV-DNA阳性率分别为15.93%、29.12%、39.01%.阳性患儿配对的母乳HCMV-DNA阳性率为45.00%,阴性患儿配对的母乳HCMV-DNA阳性率为18.60%,两组进行X2检验,X2=5.54,具有显著性差异(P<0.02).结论 联合检测能提高HCMV-DNA检测阳性率,尿HCMV-DNA检测阳性率高于血HCMV-DNA检测,HCMV感染母乳是婴儿获得性感染的主要途径之一.
张俊玲; 黄维; 刘倩; 王明丽
2014-01-01
Objective To investigate the effects of human cytomegalovirus ( HCMV) persistent in-fection on the central nervous system of BALB/c mice.Methods Thirty specific-pathogen-free mice of 6-8 weeks old were randomly divided into three groups including HCMV infected group , inactivated HCMV group and human embryo fibroblast ( HF) control group .Each mouse in the three groups was intraperitoneally inoc-ulated with 1.8 ×107 PFU of HCMV, 1.8 ×107 PFU inactivated HCMV and 1 ×105 HF cells, respectively. All mice were housed in microisolator cages for three months and their behavior and body weight were ob -served.Then three tests including autonomic activities test , Morris Water Maze and step-down passive avoid-ance task were performed on all mice to evaluate the changes of their behavior .Cerebral cortex tissues were collected from all mice to detect HCMV and to conduct polymerase chain reaction (PCR) analysis.Brain tis-sues were stained by HE method to evaluate the pathological damages .Transmission electron microscope was used to observe the ultrastructure of neuron cells and the existence of virus particles .Results (1) The body weight of mice showed no significant differences among the three groups ( P>0 .05 ) .( 2 ) The frequency of autonomic activities were decreases in HCMV infected group in comparison with other two groups , but there was no significant differences among the three groups (P>0.05).(3)The place navigation test demonstra-ted that the escape latency of mice from HCMV infected group as well as HF group showed significant differ -ence after training for different periods of time (P0.05).Compared with the mice in two control groups , the mice in HCMV infected group showed a lower frequency of crossing the quadrant where the platform had been located on pre -vious trials in the probe trial test (P<0.05).Moreover, the time of first crossings was also longer than that of mice from two control groups (P<0.05).(4)In the learning phase the mice from HCMV
常艳军; 樊卫平; 郭文杰; 薛慧芳
2012-01-01
Objective To investigate the active infections of HCMV and the hepatic impairment who had infected HCV. Methods 98 patients with hepatitis C and 100 health people were detected for anti-HCMV-IgM by ELISA and ALT, AST by Reitman-Frankel. Results Of 98 patients with hepatitis C, 5 cases were positive for anti-HCMV-IgM, of 100 health people, 3 cases were positive for anti-HCMV-IgM. There was no difference between hepatitis C group and the health people group (P > 0.05). The results of ALT, AST in the patients with hepatitis C positive for anti-HCMV-IgM significantly were higher than that in the patients with hepatitis C negtive for anti-HCMV-IgM and the health people (P 0.05),抗HCMV-IgM阳性的丙型肝炎病例组ALT、AST值显著高于抗HCMV-IgM阴性的病例组和对照组(P < 0.01).结论 丙型肝炎患者伴有HCMV活动性感染时,加重肝脏的损伤程度.
Neuber, Sebastian; Wagner, Karen; Goldner, Thomas; Lischka, Peter; Steinbrueck, Lars; Messerle, Martin; Borst, Eva Maria
2017-06-15
Human cytomegalovirus (HCMV) genome encapsidation requires several essential viral proteins, among them pUL56, pUL89, and the recently described pUL51, which constitute the viral terminase. To gain insight into terminase complex assembly, we investigated interactions between the individual subunits. For analysis in the viral context, HCMV bacterial artificial chromosomes carrying deletions in the open reading frames encoding the terminase proteins were used. These experiments were complemented by transient-transfection assays with plasmids expressing the terminase components. We found that if one terminase protein was missing, the levels of the other terminase proteins were markedly diminished, which could be overcome by proteasome inhibition or providing the missing subunit in trans These data imply that sequestration of the individual subunits within the terminase complex protects them from proteasomal turnover. The finding that efficient interactions among the terminase proteins occurred only when all three were present together is reminiscent of a folding-upon-binding principle leading to cooperative stability. Furthermore, whereas pUL56 was translocated into the nucleus on its own, correct nuclear localization of pUL51 and pUL89 again required all three terminase constituents. Altogether, these features point to a model of the HCMV terminase as a multiprotein complex in which the three players regulate each other concerning stability, subcellular localization, and assembly into the functional tripartite holoenzyme.IMPORTANCE HCMV is a major risk factor in immunocompromised individuals, and congenital CMV infection is the leading viral cause for long-term sequelae, including deafness and mental retardation. The current treatment of CMV disease is based on drugs sharing the same mechanism, namely, inhibiting viral DNA replication, and often results in adverse side effects and the appearance of resistant virus strains. Recently, the HCMV terminase has emerged as
HCMV感染对神经胶质瘤U251缝隙连接的影响%Effect of HCMV Infection on U251 Cell Connexin Expression
邢菲菲; 王志飞; 王心慧; 胡明; 钱冬萌
2017-01-01
This research aims at investigating the effects of human cytomegalovirus (HCMV) infection in human malignant U251 cells junctional communication.HCMV was infected to U251 and the morphological changes were observed with phase contract microscope.The cell migration was detected by Wound Healing Assay after HCMV infection.Expression of the gap junction genes and connexins after HCMV AD 169 infection U251 Cell were detected by RT-PCR and Western-blot.Morphological observations results showed that U251 cell became big and round and fused each other after HCMV infection.The cell migration results showed that the cell migration were enhanced after HCMV AD 169 infection.RT-PCR and Western-blot shown that the gap junction genes and connexins expression of quantity will be less and less with the increase of the time of HCMV infection(p<0.05).The results above indicated that the expression of gap junction genes and connexins were different after HCMV infection.Therefore, the gap junction gene may be involved in human glioma, which provides a new way for tumor treatment.%为探究人巨细胞病毒(HCMV)感染对恶性神经胶质瘤U251细胞通讯连接的影响.采用HCMV ADl69株(MOI=5)感染神经胶质瘤U251细胞,相差显微镜观察细胞的形态学变化;细胞划痕法检测HCMV感染对U251细胞的迁移能力的影响;Real-time PCR及Western-blot检测神经胶质瘤U251细胞经HCMV感染后缝隙连接基因及蛋白的表达.相差显微镜观察结果显示U251细胞经HCMV感染后逐渐变大变圆;细胞划痕法结果显示经HCMV感染的U251细胞的侵袭转移能力增强;Real-time PCR及Western-blot结果显示U251细胞经HCMV感染的时间越长,其缝隙连接基因及蛋白的表达量会越少(p<0.05).实验结果表明,神经胶质瘤U251细胞经HCMV感染后,缝隙连接蛋白表达有所差异.这些缝隙连接基因可能参与了人神经胶质瘤的发生,为肿瘤治疗方面提供了新的思路.
Loughney, John W; Rustandi, Richard R; Wang, Dai; Troutman, Matthew C; Dick, Lawrence W; Li, Guanghua; Liu, Zhong; Li, Fengsheng; Freed, Daniel C; Price, Colleen E; Hoang, Van M; Culp, Timothy D; DePhillips, Pete A; Fu, Tong-Ming; Ha, Sha
2015-06-26
Congenital infection of human cytomegalovirus (HCMV) is one of the leading causes of nongenetic birth defects, and development of a prophylactic vaccine against HCMV is of high priority for public health. The gH/gL/pUL128-131 pentameric complex mediates HCMV entry into endothelial and epithelial cells, and it is a major target for neutralizing antibody responses. To better understand the mechanism by which antibodies interact with the epitopes of the gH/gL/pUL128-131 pentameric complex resulting in viral neutralization, we expressed and purified soluble gH/gL/pUL128-131 pentameric complex and gH/gL from Chinese hamster ovary cells to >95% purity. The soluble gH/gL, which exists predominantly as (gH/gL)2 homodimer with a molecular mass of 220 kDa in solution, has a stoichiometry of 1:1 and a pI of 6.0-6.5. The pentameric complex has a molecular mass of 160 kDa, a stoichiometry of 1:1:1:1:1, and a pI of 7.4-8.1. The soluble pentameric complex, but not gH/gL, adsorbs 76% of neutralizing activities in HCMV human hyperimmune globulin, consistent with earlier reports that the most potent neutralizing epitopes for blocking epithelial infection are unique to the pentameric complex. Functionally, the soluble pentameric complex, but not gH/gL, blocks viral entry to epithelial cells in culture. Our results highlight the importance of the gH/gL/pUL128-131 pentameric complex in HCMV vaccine design and emphasize the necessity to monitor the integrity of the pentameric complex during the vaccine manufacturing process.
孟红; 孙德刚; 王健; 刘菊华; 孙广莲; 李焱; 张家驹; 张维东
2000-01-01
Objective To Study the sensitivity of rat to human cytomegalovirus (HCMV) infection and to es-tablish a stable animal model. Methods Two kinds of rat experiments were carried out: 1)30 SD rats were divided intothree groups randomly,they were virus inoculated group,inactivated virus inoculated group and the normal rat group re-spectively; 2)40 Wistar rats were randomly divided into two groups,they were the virus inoculated group and the inacti-vated virus inoculated group. All the rats were inoculated through tail vein.90 d later,the rat's tissue lesions were ob-served by pathological techniques,HCMV antigen was detected by immunohistochemical method and the HCMV DNA wasanalyzed by in situ hybridization. Results The extensive pathological damages in tissues of HCMV infected rats wereobserved. Meanwhile,the viral antigen and viral DNA were also demonstrated in many tissues of HCMV infected rats.Conchusion Rat is sensitive to iridectiion of HCMV AD1168 strain, hut, as an animal model study,we stoll have a lot of works to do.%目的 探讨人巨细胞病毒(Human Cytomegalovirus,HCMV)感染大鼠的敏感性和稳定性，探讨建立大鼠感染HCMV动物模型的可行性。方法 第一次动物试验：SD大鼠30只，随机均分为3组，分别为接种病毒组、灭活病毒组和正常对照组，病毒接种途径为尾静脉注射；第二次动物试验：Wistar大鼠40只，分别为接种病毒组(20只)、灭活病毒组(20只)，病毒接种途径同第一次动物试验。两次试验动物均于90d后分别以病理学方法 研究动物组织损伤特点，以免疫组化方法 检查病毒抗原，原位杂交方法 检测动物组织细胞中HCMV基因。结果 两次静脉途径接种HCMV AD169株90d的动物，组织发生广泛病理损害，免疫组化方法 和原位杂交方法 在多种组织细胞内查到HCMV抗原和基因表达。结论 HCMV AD169株可感染健康大鼠，可望作为HCMV动物慢性感染模型。
Gershenson, Carlos
2011-01-01
The term complexity derives etymologically from the Latin plexus, which means interwoven. Intuitively, this implies that something complex is composed by elements that are difficult to separate. This difficulty arises from the relevant interactions that take place between components. This lack of separability is at odds with the classical scientific method - which has been used since the times of Galileo, Newton, Descartes, and Laplace - and has also influenced philosophy and engineering. In recent decades, the scientific study of complexity and complex systems has proposed a paradigm shift in science and philosophy, proposing novel methods that take into account relevant interactions.
Goodwin, T. J.; McCarthy, M.; Albrecht, T.; Cohrs, R.
2009-01-01
The old adage we are our own worst enemies may perhaps be the most profound statement ever made when applied to man s desire for extraterrestrial exploration and habitation of Space. Consider the immune system protects the integrity of the entire human physiology and is comprised of two basic elements the adaptive or circulating and the innate immune system. Failure of the components of the adaptive system leads to venerability of the innate system from opportunistic microbes; viral, bacteria, and fungal, which surround us, are transported on our skin, and commonly inhabit the human physiology as normal and imunosuppressed parasites. The fine balance which is maintained for the preponderance of our normal lives, save immune disorders and disease, is deregulated in microgravity. Thus analogue systems to study these potential Risks are essential for our progress in conquering Space exploration and habitation. In this study we employed two known physiological target tissues in which the reactivation of hCMV and VZV occurs, human neural and lung systems created for the study and interaction of these herpes viruses independently and simultaneously on the innate immune system. Normal human neural and lung tissue analogues called tissue like assemblies (TLAs) were infected with low MOIs of approximately 2 x 10(exp -5) pfu hCMV or VZV and established active but prolonged low grade infections which spanned .7-1.5 months in length. These infections were characterized by the ability to continuously produce each of the viruses without expiration of the host cultures. Verification and quantification of viral replication was confirmed via RT_PCR, IHC, and confocal spectral analyses of the respective essential viral genomes. All host TLAs maintained the ability to actively proliferate throughout the entire duration of the experiments as is analogous to normal in vivo physiological conditions. These data represent a significant advance in the ability to study the triggering
Goodwin, T. J.; McCarthy, M.; Albrecht, T.; Cohrs, R.
2009-01-01
The old adage we are our own worst enemies may perhaps be the most profound statement ever made when applied to man s desire for extraterrestrial exploration and habitation of Space. Consider the immune system protects the integrity of the entire human physiology and is comprised of two basic elements the adaptive or circulating and the innate immune system. Failure of the components of the adaptive system leads to venerability of the innate system from opportunistic microbes; viral, bacteria, and fungal, which surround us, are transported on our skin, and commonly inhabit the human physiology as normal and imunosuppressed parasites. The fine balance which is maintained for the preponderance of our normal lives, save immune disorders and disease, is deregulated in microgravity. Thus analogue systems to study these potential Risks are essential for our progress in conquering Space exploration and habitation. In this study we employed two known physiological target tissues in which the reactivation of hCMV and VZV occurs, human neural and lung systems created for the study and interaction of these herpes viruses independently and simultaneously on the innate immune system. Normal human neural and lung tissue analogues called tissue like assemblies (TLAs) were infected with low MOIs of approximately 2 x 10(exp -5) pfu hCMV or VZV and established active but prolonged low grade infections which spanned .7-1.5 months in length. These infections were characterized by the ability to continuously produce each of the viruses without expiration of the host cultures. Verification and quantification of viral replication was confirmed via RT_PCR, IHC, and confocal spectral analyses of the respective essential viral genomes. All host TLAs maintained the ability to actively proliferate throughout the entire duration of the experiments as is analogous to normal in vivo physiological conditions. These data represent a significant advance in the ability to study the triggering
CLEMENT O BEWAJI
Schiff bases and their complex compounds have been studied for their .... establishing coordination of the N–(2 – hydroxybenzyl) - L - α - valine Schiff base ..... (1967); “Spectrophotometric Identification of Organic Compounds”, Willey, New.
Irvine Alistair
2005-06-01
Full Text Available Abstract Background The hCMV promoter is very commonly used for high level expression of transgenes in mammalian cells, but its utility is hindered by transcriptional silencing. Large genomic fragments incorporating the CpG island region of the HNRPA2B1 locus are resistant to transcriptional silencing. Results In this report we describe studies on the use of a novel series of vectors combining the HNRPA2B1 CpG island with the hCMV promoter for expression of transgenes in CHO-K1 cells. We show that the CpG island gives at least twenty-fold increases in the levels of EGFP and EPO observed in pools of transfectants, and that transgene expression levels remain high in such pools for more than 100 generations. These novel vectors also allow facile isolation of clonal CHO-K1 cell lines showing stable, high-level transgene expression. Conclusion Vectors incorporating the hnRPA2B1 CpG island give major benefits in transgene expression from the hCMV promoter, including substantial improvements in the level and stability of expression. The utility of these vectors for the improved production of recombinant proteins in CHO cells has been demonstrated.
Talkhabifard, Majid; Javid, Naeme; Moradi, Abdolvahab; Ghaemi, Amir; Tabarraei, Alijan
2017-01-01
Human cytomegalovirus (HCMV) is a common opportunistic pathogen that causes serious complications in immunosuppressed patients and infected newborns. In this study, PCR-ELISA was optimized for semi-quantitative detection of infection in clinical specimens and simultaneous genotyping of glycoprotein B for 4 major genotypes, due to its significance. During DIG-labeling PCR, a pair of primers amplifies a fragment of variable region of the glycoprotein B encoding sequence. Under optimized conditions, labeled Target amplicons hybridize to biotinated specific probes and are detected in an ELISA system. PCR-ELISA system showed specific performance with detection limit of approximately 100 copies of CMV DNA. The linear correlation was observed between the PCR-ELISA results (OD) and logarithmic scale of CMV (r=0.979). Repeatability of PCR-ELISA detection system for intra-assay and inter-assay was evaluated for negative and positive samples. In optimized conditions of hybridization, differentiation between genotypes of glycoprotein B was feasible using genotype-specific probes in PCR-ELISA genotyping system. In comparison with sequencing method, genotyping system was confirmed with kappa index of 1. PCR-ELISA is proposed as an applicable and reliable technique for semi-quantitative diagnosis and typing of the infection. This technique is flexible to apply in a variety of molecular fields.
Ha, Sha; Li, Fengsheng; Troutman, Matthew C.; Freed, Daniel C.; Tang, Aimin; Loughney, John W.; Wang, I-Ming; Vlasak, Josef; Nickle, David C.; Rustandi, Richard R.; Hamm, Melissa; DePhillips, Pete A.; Zhang, Ningyan; McLellan, Jason S.; Zhu, Hua; Adler, Stuart P.; McVoy, Michael A.; An, Zhiqiang
2017-01-01
ABSTRACT Human cytomegalovirus (HCMV) is the leading cause of congenital viral infection, and developing a prophylactic vaccine is of high priority to public health. We recently reported a replication-defective human cytomegalovirus with restored pentameric complex glycoprotein H (gH)/gL/pUL128-131 for prevention of congenital HCMV infection. While the quantity of vaccine-induced antibody responses can be measured in a viral neutralization assay, assessing the quality of such responses, including the ability of vaccine-induced antibodies to cross-neutralize the field strains of HCMV, remains a challenge. In this study, with a panel of neutralizing antibodies from three healthy human donors with natural HCMV infection or a vaccinated animal, we mapped eight sites on the dominant virus-neutralizing antigen—the pentameric complex of glycoprotein H (gH), gL, and pUL128, pUL130, and pUL131. By evaluating the site-specific antibodies in vaccine immune sera, we demonstrated that vaccination elicited functional antiviral antibodies to multiple neutralizing sites in rhesus macaques, with quality attributes comparable to those of CMV hyperimmune globulin. Furthermore, these immune sera showed antiviral activities against a panel of genetically distinct HCMV clinical isolates. These results highlighted the importance of understanding the quality of vaccine-induced antibody responses, which includes not only the neutralizing potency in key cell types but also the ability to protect against the genetically diverse field strains. IMPORTANCE HCMV is the leading cause of congenital viral infection, and development of a preventive vaccine is a high public health priority. To understand the strain coverage of vaccine-induced immune responses in comparison with natural immunity, we used a panel of broadly neutralizing antibodies to identify the immunogenic sites of a dominant viral antigen—the pentameric complex. We further demonstrated that following vaccination of a replication
赵宏; 范骏; 胡建华; 高海女; 杨美芳; 张旋; 周琳; 马伟杭
2010-01-01
Objective To study the correlation of HBV infection pretransplantation and posttrans-plantation and HCMV recurrence after liver transplantation (LT). Methods We reviewed historical patient medical records of LT patients in recent two years in our hospital. All the patients were divided into HBV in-fection group and a control group based on a peripheral blood HB antigen assay before LT. The HBV infec-tion group was divided into HBV reactive infection group and HBV non-relapse group. HCMV antigen pp~65 was detected by immunohistochemical methods. HB antigens and antibodies were detected by time-resolved fluorescence immunoassay, and liver enzyme levels were detected by conventional methods. Results Com-paring two groups of patients, pp65-positive rates of LT patients with HBV infection and control group pa-tients were 84.3% and 57.9% respectively (P=0.024). While in HBV recurrence infection group and non-recurrence infection group, the incidences of HCMV recurrence were 90.9% and 83.3% (P=0.843). The changes in the liver transaminases level in both groups have no statistical significance (P>0.05). Conclusion Pretransplantation HBV infection may increase the incidence of HCMV recurrence. Posttrans-plantation HBV reactive infection, however, may not increase the incidence of HCMV reactive infection. Meanwhile, compare with either HBV infection or HCMV infection alone, co-infection may not serious in liv-er enzymes levels.%目的 探讨肝移植患者移植术前后HBV感染对移植术后巨细胞病毒(CMV)感染及其肝功能的影响.方法 回顾性分析我院近两年来113例肝移植患者临床资料,排除术后1月内死亡、血型不符、失访和并发其他噬肝病毒感染患者,共有102例患者纳入.根据肝移植术前是否感染HBV将患者分为HBV感染组和对照组(非HBV感染);对于感染组患者,又根据移植术后HBV是否复发分为术后复发组和非复发组,采用免疫组化方法 检测CMV被膜抗原pp65水平,时间
李兵; 古宇; 易珂
2014-01-01
Objective To explore the association between levels of anti -human cytomegalovirus (anti-HC-MV) antibody and oxidized low density lipoprotein (ox-LDL) in patients with kidney transplantation .Methods Lev-els of ox-LDL ,anti-HCMV-IgM and anti-HCMV-IgG were detected in patients with kidney transplantation .All en-rolled subjects were divided into three groups according to levels of ox-LDL ,including high level group (n=15 ,with ox-LDL level more than 25μg/mL) ,low level group (n=25 ,with ox-LDL level less than 25μg/mL) ,and the control group .Levels of ox-LDL ,anti-HCMV-IgM ,anti-HCMV-IgG were compared between the three groups .Results The results indicated that levels of ox-LDL were significantly different between the three groups (P<0 .05) .Level of ox-LDL was positively correlated with anti-HCMV-IgM and anti-HCMV-IgG (P<0 .05) .Conclusion There might be association between HCMV infection and level of ox-LDL .%目的：研究肾移植患者体内的抗人巨细胞病毒（HCM V ）水平和抗氧化低密度脂蛋白质（ox-LDL ）抗体水平的相关性。方法用抗ox-LDL抗体检测试剂盒和 HCM V抗体检测试剂盒分别检测肾移植患者中抗 HC-MV-免疫球蛋白M（IgM）、抗HCMV-免疫球蛋白G（IgG）、抗ox-LDL抗体水平。根据抗ox-LDL抗体水平将患者分为抗ox-LDL抗体高水平组（n＝15）（抗ox-LDL抗体平均值大于或等于25μg/mL）和低水平组（n＝25）（抗ox-LDL抗体平均值小于25μg/mL），以及对照组。比较3个组的抗ox-LDL抗体、抗 HCMV-IgM、抗 HCMV-IgG水平差异。结果3个组抗ox-LDL抗体水平差异有统计学意义（P＜0．05），抗HCMV-IgM与抗 HCMV-IgG水平与抗ox-LDL抗体水平呈正相关性（P＜0．05）。结论 HCMV感染与抗ox-LDL抗体水平有关。
Liliana Cruz Spano
2007-09-01
Full Text Available Human cytomegalovirus (HCMV displays genetic variability in several regions, supposed to be related with strain-specific tissue tropism and immunopathogenesis. Based on sequence variation in the UL55 gene that encodes gB glycoprotein, HCMV strains can be assigned to one of four genotypes. Previous studies have addressed gB genotyping mostly by investigating strains derived from immunosuppressed patients, sometimes without previous knowledge about genotype distribution in a geographic area. The present study verified the distribution of HCMV gB genotypes of strains obtained from immunocompetent women at Vitória City, Espírito Santo State, Southeastern, Brazil. The HCMV genome was extracted from their cervical secretion, fetal and maternal placenta tissues (chorionic villous and decidua from abortion cases and from white blood cells (WBCs. HCMV genotyping was performed by restriction fragment length polymorphism analyses of amplified product from the high variability site of the UL55 gene. All four genotypes were observed in both cervical secretion and placenta, whereas in WBCs a single gB1 genotype was detected. HCMV gB1 and gB2 genotypes were detected, respectively, in nine and in six of the 23 studied samples, while gB3 and gB4 were each found in four separate samples of the total. The differences in genotype frequency were not considered statistically significant. No mixed genotype infection was observed. The results indicated that the four gB HCMV genotypes had no particular tropism for placenta tissues and that all genotypes circulated within immunocompetent women at the time and in the region of study.O citomegalovírus humano (HCMV apresenta variabilidade em diversas regiões do genoma, supostamente relacionada ao tropismo tecidual e imunopatogênese viral. Baseando-se na variação de seqüência do gene UL55 que codifica a glicoproteína gB, o HCMV pode ser classificado em um dos quatro genótipos. Estudos prévios têm investigado a
HCMV pp65和gB联合核酸疫苗表达载体的构建及其体内生物学活性研究
马道新; 于修平; 张晓梅; 周亚滨; 李勇; 贾继辉; 赵蔚明
2005-01-01
人巨细胞病毒(HCMV)主要被膜磷蛋白pp65(phosphoprotein 65)及糖蛋白gB(glycoprotein B)在病毒感染及诱发机体免疫反应中起重要作用，近年来有不少学者对HCMV pp65和gB这两种抗原进行动物和临床试验研究，虽取得了一定效果，但仍存在免疫原性弱、免疫范围局限等缺点。本研究利用分子生物学方法将HCMV两种保护性免疫原性基因pp65和gB构建在一起，制备HCMV核酸疫苗，并研究其在小鼠体内的免疫活性。
Human Cytomegalovirus gH/gL Forms a Stable Complex with the Fusion Protein gB in Virions.
Adam L Vanarsdall
2016-04-01
Full Text Available Human cytomegalovirus (HCMV is a ubiquitous virus that is a major pathogen in newborns and immunocompromised or immunosuppressed patients. HCMV infects a wide variety of cell types using distinct entry pathways that involve different forms of the gH/gL glycoprotein: gH/gL/gO and gH/gL/UL128-131 as well as the viral fusion glycoprotein, gB. However, the minimal or core fusion machinery (sufficient for cell-cell fusion is just gH/gL and gB. Here, we demonstrate that HCMV gB and gH/gL form a stable complex early after their synthesis and in the absence of other viral proteins. gH/gL can interact with gB mutants that are unable to mediate cell-cell fusion. gB-gH/gL complexes included as much as 16-50% of the total gH/gL in HCMV virus particles. In contrast, only small amounts of gH/gL/gO and gH/gL/UL128-131 complexes were found associated with gB. All herpesviruses express gB and gH/gL molecules and most models describing herpesvirus entry suggest that gH/gL interacts with gB to mediate membrane fusion, although there is no direct evidence for this. For herpes simplex virus (HSV-1 it has been suggested that after receptor binding gH/gL binds to gB either just before, or coincident with membrane fusion. Therefore, our results have major implications for these models, demonstrating that HCMV gB and gH/gL forms stable gB-gH/gL complexes that are incorporated virions without receptor binding or membrane fusion. Moreover, our data is the best support to date for the proposal that gH/gL interacts with gB.
Human Cytomegalovirus gH/gL Forms a Stable Complex with the Fusion Protein gB in Virions.
Vanarsdall, Adam L; Howard, Paul W; Wisner, Todd W; Johnson, David C
2016-04-01
Human cytomegalovirus (HCMV) is a ubiquitous virus that is a major pathogen in newborns and immunocompromised or immunosuppressed patients. HCMV infects a wide variety of cell types using distinct entry pathways that involve different forms of the gH/gL glycoprotein: gH/gL/gO and gH/gL/UL128-131 as well as the viral fusion glycoprotein, gB. However, the minimal or core fusion machinery (sufficient for cell-cell fusion) is just gH/gL and gB. Here, we demonstrate that HCMV gB and gH/gL form a stable complex early after their synthesis and in the absence of other viral proteins. gH/gL can interact with gB mutants that are unable to mediate cell-cell fusion. gB-gH/gL complexes included as much as 16-50% of the total gH/gL in HCMV virus particles. In contrast, only small amounts of gH/gL/gO and gH/gL/UL128-131 complexes were found associated with gB. All herpesviruses express gB and gH/gL molecules and most models describing herpesvirus entry suggest that gH/gL interacts with gB to mediate membrane fusion, although there is no direct evidence for this. For herpes simplex virus (HSV-1) it has been suggested that after receptor binding gH/gL binds to gB either just before, or coincident with membrane fusion. Therefore, our results have major implications for these models, demonstrating that HCMV gB and gH/gL forms stable gB-gH/gL complexes that are incorporated virions without receptor binding or membrane fusion. Moreover, our data is the best support to date for the proposal that gH/gL interacts with gB.
Coleman, Stewart; Choi, K Yeon; Root, Matthew; McGregor, Alistair
2016-07-01
In human cytomegalovirus (HCMV), tropism to epithelial and endothelial cells is dependent upon a pentameric complex (PC). Given the structure of the placenta, the PC is potentially an important neutralizing antibody target antigen against congenital infection. The guinea pig is the only small animal model for congenital CMV. Guinea pig cytomegalovirus (GPCMV) potentially encodes a UL128-131 HCMV PC homolog locus (GP128-GP133). In transient expression studies, GPCMV gH and gL glycoproteins interacted with UL128, UL130 and UL131 homolog proteins (designated GP129 and GP131 and GP133 respectively) to form PC or subcomplexes which were determined by immunoprecipitation reactions directed to gH or gL. A natural GP129 C-terminal deletion mutant (aa 107-179) and a chimeric HCMV UL128 C-terminal domain swap GP129 mutant failed to form PC with other components. GPCMV infection of a newly established guinea pig epithelial cell line required a complete PC and a GP129 mutant virus lacked epithelial tropism and was attenuated in the guinea pig for pathogenicity and had a low congenital transmission rate. Individual knockout of GP131 or 133 genes resulted in loss of viral epithelial tropism. A GP128 mutant virus retained epithelial tropism and GP128 was determined not to be a PC component. A series of GPCMV mutants demonstrated that gO was not strictly essential for epithelial infection whereas gB and the PC were essential. Ectopic expression of a GP129 cDNA in a GP129 mutant virus restored epithelial tropism, pathogenicity and congenital infection. Overall, GPCMV forms a PC similar to HCMV which enables evaluation of PC based vaccine strategies in the guinea pig model.
周午琼
2012-01-01
目的 观察EB病毒(EBV)与人类巨细胞病毒(HCMV)感染所致的传染性单核细胞增多症(IM)患儿超敏C-反应蛋白(hs-CRP)、白细胞(WBC)计数、嗜中性粒细胞比值(N)、异常淋巴细胞(异淋)、嗜异性抗体和血清酶的变化.方法 选择70例确诊有EBV病毒感染且具备传染性单核细胞增多症临床特点的患儿(A组)进行实验室检测指标分析及总结；并与37例HCMV相关传染性单核细胞增多症患儿(B组)进行比较.结果 与EB组(A组)比较,HCMV组(B组)感染患儿hs-CRP水平、肌酸激酶同功酶(CK-MB)、丙氨酸氨基转移酶(ALT)、外周血WBC计数、异型淋巴细胞增高程度较低(P＜0.05),嗜异性抗体常为阴性,两组N值差异无统计学意义(P＞0.05).结论 EBV与HCMV感染所致的传染性单核细胞增多症患儿的实验室指标变化不同,应重视IM患儿的实验室检查以辅助诊断.%Objective To observe the changes of the serum High-sensitivity C-reactive protein (hs-CRP), WBC count, the ratio of neutrophils (N) , abnormal lymphocytes, heterophilic antibody and serum enzyme in children with Epstein-barr virus (EBV) and HCMV infectious mononucleosis (IM) syndrome. Method Laboratory indicators of 70 cases of infectious mononucleosis syndrome related to EBV infection (group A) were retrospectively analyzed and compared with the laboratory indicators of 37 cases of infectious mononucleosis syndrome related to HCMV infection (group B). Result In group B, the incidences of hs-CRP, Creatine kinase isoenzyme (CK-MB), Alanine aminotransferase (ALT), WBC count and cervical lymphadenopathy were significantly lower than those in group A (P<0.05). Heterophilic antibody usually was negative. The N had no significant difference between group A and group B. Conclusion The changes of laboratory indicators in infectious mononucleosis syndrome related to EBV infection are different from that related to HCMV. Laboratory examination should be attached importance in
吴旗; 邹俊煊; 虞涛; 游上游; 张楚瑜
2006-01-01
目的比较常规PCR法与荧光定量PCR(FQ-PCR)法在人巨细胞病毒(HCMV)检测中的作用,寻找更适合于HCMV检测的方法.方法构建携带CMV-DNA的标准质粒,利用常规PCR技术及FQ-PCR技术分别对不同稀释度的标准质粒进行检测.结果RQ-PCR法对HCMV标准质粒检测的灵敏度及线性范围均显著高于常规PCR法.结论FQ-PCR法比常规PCR法更适合HCMV病毒的检测.
阿尼克孜·阿不都艾尼; 玛依努尔·尼牙孜
2012-01-01
宫颈癌是最常见的女性生殖道恶性肿瘤,人乳头状瘤病毒感染(HPV)是宫颈癌的主要致癌因素,此外其他病毒感染如单纯疱疹病毒2型( HSV-2)人类巨细胞病毒(HCMV)也引起了人们的重视.作者对HPV HSV-2 HCMV的感染途径,感染的人群,致癌机制与宫颈癌之间的相关性研究进展作一综述.%Cervical cancer (CC) is an important public health problem worldwide. HPV are the primary etiologic agents of cervical cancer. However, HPV can not be found in every patient with the disease and other factors have been associated with cervical cancer. In recent years, studies have revealed that other sexually transmitted factors such as HSV-2, HCMV may be cofactors in the malignancy of cervical uterus, In this review, research progress were summarized on the infection way and infected people of HPV, HSV-2 and HCMV, as well as the relationship between their mechanism and cervical cancer.
Complexity of Host Micro-RNA Response to Cytomegalovirus Reactivation After Organ Transplantation.
Egli, A; Lisboa, L F; O'Shea, D; Asberg, A; Mueller, T; Emery, V; Kumar, D; Humar, A
2016-02-01
Human (Homo sapiens) micro-RNAs (hsa-miRNAs) regulate virus and host-gene translation, but the biological impact in patients with human cytomegalovirus (hCMV) infection is not well defined in a clinically relevant model. First, we compared hsa-miRNA expression profiles in peripheral blood mononuclear cells from 35 transplant recipients with and without CMV viremia by using a microarray chip covering 847 hsa-miRNAs. This approach demonstrated a set of 142 differentially expressed hsa-miRNAs. Next, we examined the effect of each of these miRNAs on viral growth by using human fibroblasts (human foreskin fibroblast-1) infected with the hCMV Towne strain, identifying a subset of proviral and antiviral hsa-miRNAs. miRNA-target prediction software indicated potential binding sites within the hCMV genome (e.g., hCMV-UL52 and -UL100 [UL = unique long]) and host-genes (e.g., interleukin-1 receptor, IRF1). Luciferase-expressing plasmid constructs and immunoblotting confirmed several predicted miRNA targets. Finally, we determined the expression of selected proviral and antiviral hsa-miRNAs in 242 transplant recipients with hCMV-viremia. We measured hsa-miRNAs before and after antiviral therapy and correlated hsa-miRNA expression levels to hCMV-replication dynamics. One of six antiviral hsa-miRNAs showed a significant increase during treatment, concurrent with viral decline. In contrast, six of eight proviral hsa-miRNAs showed a decrease during viral decline. Our results indicate that a complex and multitargeted hsa-miRNA response occurs during CMV replication in immunosuppressed patients. This study provides mechanistic insight and potential novel biomarkers for CMV replication. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.
143例人巨细胞病毒感染婴幼儿血小板参数观察%Observation on platelet parameters of 143 HCMV-infected infants
吴起武
2014-01-01
目的:探讨人巨细胞病毒(HCMV)感染婴幼儿血小板参数的变化及意义.方法:采用全自动血细胞分析仪测定并比较143例HCMV感染婴幼儿(观察组)和36例正常婴幼儿(对照组)的血小板计数(PET)、血小板体积(MPV)、血小板分布宽度(PDW)和白细胞计数(WBC).结果:观察组血小板增多62例,发生率为43.36％ (62/143),血小板减少7例,发生率为4.90％ (7/143).观察组WBC明显高于对照组(t=3.551,P=0.001),PLT明显高于对照组(=2.468,P=0.019),MPV明显低于对照组(t=4.224,P=0.000),PDW明显高于对照组(t=6.179,P=0.000),差异均有统计学意义.结论:HCMV感染婴幼儿血小板增多发生率高,骨髓生成血小板功能紊乱,监测血小板参数变化可初步了解骨髓血小板增殖功能.
Kan, Chen-Chen
2002-03-01
Structure-based drug design is an organized, multidisciplinary endeavor undertaken by scientists from many different scientific fields. The success of structure-based drug design was only made possible by advances in structure biology that provides the three-dimensional structure of the drug design target with which small molecular chemical ligands interact. Visualization of the conformation and interactions of a small molecule ligand bound to the protein target in the co-crystal structure of the protein:ligand complex enables the design of new chemical compounds with improved binding affinity and specificity. With the advances in molecular biology, lab automation, and computational science, genomic data have now become available for the human genome, as well as various other organisms. The pharmaceutical industry is currently putting forth tremendous effort in the area of functional genomics and structural genomics in attempts to decipher functions and structures of protein encoded by genes, with the ultimate goal of identifying novel targets for drug discovery and development. This chapter discusses the significant impact made by recombinant DNA technology and protein engineering on structural biology and, more specifically, on structure-based drug design.
Lee, Jung-Bum; Yamagishi, Chihiro; Hayashi, Kyoko; Hayashi, Toshimitsu
2011-01-01
Three antiviral and immunostimulating substances (LC1, LC2 and LC3) were isolated from a hot water extract of seeds of Pimpinella anisum by combination of anion-exchange, gel filtration and hydrophobic interaction column chromatographies. Chemical and spectroscopic analyses revealed them to be lignin-carbohydrate-protein complexes. These lignin-carbohydrate complexes (LCs) showed antiviral activities against herpes simplex virus types 1 and 2 (HSV-1 and -2), human cytomegalovirus (HCMV) and measles virus. LCs were also found to interfere with virus adsorption to the host cell surface and directly inactivate viruses. Furthermore, they enhanced nitric oxide (NO) production by inducing iNOS mRNA and protein expression in RAW 264.7 murine macrophage cells. The induced mRNA expression of cytokines including IL-1β and IL-10 was also apparent. These results suggest that the lignin-carbohydrate-protein complexes from P. anisum possessed potency as functional food ingredients against infectious diseases.
陈文静; 黄崇安; 陈静; 郭刚强; 谢旺凯; 林刻智; 沈贤; 薛向阳
2015-01-01
目的：探讨基于人巨细胞病毒（HCMV）潜伏相关抗原UL138蛋白的ELISA方法用于HCMV感染血清学检测的意义。方法：生物信息学分析HCMVUL138蛋白的跨膜区结构，选择胞内区序列，经原核密码子优化后全基因合成，克隆至pET21a（+）原核载体，将成功构建的重组质粒转化至大肠杆菌BL21（DE3），诱导蛋白表达后，SDS-PAGE及Westernblot法鉴定目的蛋白表达，采用镍柱亲和层析法纯化目的蛋白。将纯化的UL138蛋白包被ELISA板，检测173例人血清UL138特异性抗体，并与临床上使用的罗氏公司cobas8000分析系统及配套试剂盒进行血清HCMVIgG抗体检测比较，评价UL138蛋白作为HCMV感染血清学检测工具的效能。结果：利用原核表达系统成功表达了UL138蛋白，经镍柱亲和纯化后获得高纯度的目的蛋白；健康成人血清UL138特异性抗体的ELISA法检测结果显示，几乎所有的健康成人都存在UL138特异性抗体，与罗氏公司的化学发光（CLIA）法IgG检测结果比较，灵敏性为100.0%，符合率为98.8%，差异无统计学意义（x2=0.5， P＞0.05），而且具有较好的一致性（Kappa=0.496，P＜0.001）。结论：潜伏相关抗原UL138是HCMV感染血清学检测重要候选抗原，可望为基于此蛋白的HCMV血清学检测试剂的研制提供依据。%Objective:To prepare latency-associated protein UL138 of human cytomegalovirus, determine its antigenicity and evaluate its preliminary use as an antigen in the serodiagnosis of HCMV infection. Methods:Bioinformatics methods were used to analyze the transmembrane domain of UL138 protein, and the complete coding region of pUL138’s cytoplasmic domain was optimized by the usage of the favorite codons in E.coli, am-pliifed by PCR and cloned into the expression vector pET21a(+). The constructed pET21a(+)/UL138 plasmid was transformed into E.coli BL21 cells and induced by IPTG. The recombinant protein p
Josephine S. Gnanandarajah
2014-02-01
Full Text Available Development of a vaccine against congenital infection with human cytomegalovirus (HCMV is a major public health priority. A potential vaccine target receiving considerable recent attention is the pentameric complex (PC of HCMV proteins consisting of gL, gH, UL128, UL130, and UL131, since some antibodies against these target proteins are capable of potently neutralizing virus at epithelial and endothelial cell surfaces. Recently, homologous proteins have been described for guinea pig cytomegalovirus (GPCMV, consisting of gH, gL, and the GPCMV proteins GP129, GP131, and GP133. To investigate these proteins as potential vaccine targets, expression of GP129-GP133 transcripts was confirmed by reverse-transcriptase PCR. Mass spectrometry combined with western blot assays demonstrated the presence of GP129, GP131, and GP133 proteins in virus particles. Recombinant proteins corresponding to these PC proteins were generated in baculovirus, and as GST fusion proteins. Recombinant proteins were noted to be immunoreactive with convalescent sera from infected animals, suggesting that these proteins are recognized in the humoral immune response to GPCMV infection. These analyses support the study of PC-based recombinant vaccines in the GPCMV congenital infection model.
Bock, Christina M; Parameshwarappa, Gangajji; Bönisch, Simon; Neiss, Christian; Bauer, Walter; Hampel, Frank; Görling, Andreas; Tsogoeva, Svetlana B
2016-04-04
Aza- and carbobicyclic compounds possess favorable pharmaceutical properties, but they are difficult to access. Herein, we demonstrate an unprecedented organocatalytic two component six-step chemodivergent domino reaction, which provides a straightforward, sustainable and atom economical route to difficult-to-access complex bicyclic architectures: azabicycles and carbobicycles, whose ratios can be controlled by the applied electrophiles and catalysts. Detailed NMR and X-ray studies on the structures and relative stereochemistry of selected compounds are presented. Mechanistic investigations of the chemoselective branching step have been carried out with DFT methods in conjunction with semiempirical van der Waals interactions. This new domino reaction opens up a new vista of generating, in a single operation, new bioactive compounds with strong antiviral properties (EC50 up to 0.071 μM for human cytomegalovirus (HCMV)) outperforming clinically used ganciclovir (EC50 2.6 μM). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
... Types of Cancer > Carney Complex Request Permissions Carney Complex Approved by the Cancer.Net Editorial Board , 11/2015 What is Carney complex? Carney complex is a hereditary condition associated with: ...
Franceschet, Massimo
2014-01-01
Complex systems and their underlying convoluted networks are ubiquitous, all we need is an eye for them. They pose problems of organized complexity which cannot be approached with a reductionist method. Complexity science and its emergent sister network science both come to grips with the inherent complexity of complex systems with an holistic strategy. The relevance of complexity, however, transcends the sciences. Complex systems and networks are the focal point of a philosophical, cultural ...
李丰耀; 查庆兵; 徐丽慧; 迟晓云; 贾仟涛; 何贤辉; 曾耀英
2006-01-01
为体外复性制备负载人巨细胞病毒(HCMV)pp65抗原肽的HLA-A*1101-GPI四聚体,研究优化HLA-A*1101重链与生物素化酶底物肽融合蛋白(HLA-A*1101-BSP)在大肠杆菌中的诱导表达的温度、时间和诱导剂IPTG浓度,并以抗HLA-A*0201抗血清进行免疫印迹鉴定HLA-A*1101-BSP的表达水平.将初步纯化的HLA-A*1101-BSP与β2-微球蛋白(β2m)和HCMV抗原肽pp6516-24(GPISGHVLK,简称GPI)一起利用稀释法进行重折叠复性,获得可溶性HLA-A*1101-GPI单体,经生物素化和纯化后,与Streptavidin-PE结合成四聚体.流式细胞仪分析显示HLA-A*1101-GPI四聚体具有与特异性细胞毒T细胞(CTL)的结合活性,表明成功获得可溶性HLA-A*1101-GPI四聚体,为研究HLA-A*1101限制性CTL的免疫应答打下基础.
Erdi, Peter
2008-01-01
This book explains why complex systems research is important in understanding the structure, function and dynamics of complex natural and social phenomena. Readers will learn the basic concepts and methods of complex system research.
Brešar, Bostjan; Chepoi, Victor; Gologranc, Tanja; Osajda, Damian
2012-01-01
In this article, we introduce and investigate bucolic complexes, a common generalization of systolic complexes and of CAT(0) cubical complexes. This class of complexes is closed under Cartesian products and amalgamations over some convex subcomplexes. We study various approaches to bucolic complexes: from graph-theoretic and topological viewpoints, as well as from the point of view of geometric group theory. Bucolic complexes can be defined as locally-finite simply connected prism complexes satisfying some local combinatorial conditions. We show that bucolic complexes are contractible, and satisfy some nonpositive-curvature-like properties. In particular, we prove a version of the Cartan-Hadamard theorem, the fixed point theorem for finite group actions, and establish some results on groups acting geometrically on such complexes. We also characterize the 1-skeletons (which we call bucolic graphs) and the 2-skeletons of bucolic complexes. In particular, we prove that bucolic graphs are precisely retracts of Ca...
Stegmann, Cora; Abdellatif, Mohamed E A; Laib Sampaio, Kerstin; Walther, Paul; Sinzger, Christian
2017-01-01
The glycoprotein O (gO) is betaherpesvirus specific. Together with the viral glycoproteins H and L, gO forms a covalent trimeric complex that is part of the viral envelope. This trimer is crucial for cell-free infectivity of human cytomegalovirus (HCMV) but dispensable for cell-associated spread. We hypothesized that the amino acids that are conserved among gOs of different cytomegaloviruses are important for the formation of the trimeric complex and hence for efficient virus spread. In a mutational approach, nine peptide sites, containing all 13 highly conserved amino acids, were analyzed in the context of HCMV strain TB40-BAC4 with regard to infection efficiency and formation of the gH/gL/gO complex. Mutation of amino acids (aa) 181 to 186 or aa 193 to 198 resulted in the loss of the trimer and a complete small-plaque phenotype, whereas mutation of aa 108 or aa 249 to 254 caused an intermediate phenotype. While individual mutations of the five conserved cysteines had little impact, their relevance was revealed in a combined mutation, which abrogated both complex formation and cell-free infectivity. C343 was unique, as it was sufficient and necessary for covalent binding of gO to gH/gL. Remarkably, however, C218 together with C167 rescued infectivity in the absence of detectable covalent complex formation. We conclude that all highly conserved amino acids contribute to the function of gO to some extent but that aa 181 to 198 and cysteines 343, 218, and 167 are particularly relevant. Surprisingly, covalent binding of gO to gH/gL is required neither for its incorporation into virions nor for proper function in cell-free infection. Like all herpesviruses, the widespread human pathogen HCMV depends on glycoproteins gB, gH, and gL for entry into target cells. Additionally, gH and gL have to bind gO in a trimeric complex for efficient cell-free infection. Homologs of gO are shared by all cytomegaloviruses, with 13 amino acids being highly conserved. In a mutational
Communication complexity and information complexity
Pankratov, Denis
Information complexity enables the use of information-theoretic tools in communication complexity theory. Prior to the results presented in this thesis, information complexity was mainly used for proving lower bounds and direct-sum theorems in the setting of communication complexity. We present three results that demonstrate new connections between information complexity and communication complexity. In the first contribution we thoroughly study the information complexity of the smallest nontrivial two-party function: the AND function. While computing the communication complexity of AND is trivial, computing its exact information complexity presents a major technical challenge. In overcoming this challenge, we reveal that information complexity gives rise to rich geometrical structures. Our analysis of information complexity relies on new analytic techniques and new characterizations of communication protocols. We also uncover a connection of information complexity to the theory of elliptic partial differential equations. Once we compute the exact information complexity of AND, we can compute exact communication complexity of several related functions on n-bit inputs with some additional technical work. Previous combinatorial and algebraic techniques could only prove bounds of the form theta( n). Interestingly, this level of precision is typical in the area of information theory, so our result demonstrates that this meta-property of precise bounds carries over to information complexity and in certain cases even to communication complexity. Our result does not only strengthen the lower bound on communication complexity of disjointness by making it more exact, but it also shows that information complexity provides the exact upper bound on communication complexity. In fact, this result is more general and applies to a whole class of communication problems. In the second contribution, we use self-reduction methods to prove strong lower bounds on the information
Thiyagalingam, Jeyarajan
2013-06-01
In this paper, we present a novel visualization technique for assisting the observation and analysis of algorithmic complexity. In comparison with conventional line graphs, this new technique is not sensitive to the units of measurement, allowing multivariate data series of different physical qualities (e.g., time, space and energy) to be juxtaposed together conveniently and consistently. It supports multivariate visualization as well as uncertainty visualization. It enables users to focus on algorithm categorization by complexity classes, while reducing visual impact caused by constants and algorithmic components that are insignificant to complexity analysis. It provides an effective means for observing the algorithmic complexity of programs with a mixture of algorithms and black-box software through visualization. Through two case studies, we demonstrate the effectiveness of complexity plots in complexity analysis in research, education and application. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.
Gys M. Loubser
2014-01-01
Full Text Available In this article, I discuss studies in complexity and its epistemological implications for systematic and practical theology. I argue that engagement with complexity does not necessarily assurea non-reductionist approach. However, if complexity is engaged transversally, it becomes possible to transcend reductionist approaches. Moreover, systematic and practical the ologians can draw on complexity in developing new ways of understanding and, therefore, new ways of describing the focus, epistemic scope and heuristic structures of systematic and practical theology. Firstly, Edgar Morin draws a distinction between restricted and general complexity based on the epistemology drawn upon in studies in complexity. Moving away from foundationalist approaches to epistemology, Morin argues for a paradigm of systems. Secondly,I discuss Kees van Kooten Niekerk�s distinction between epistemology, methodology andontology in studies in complexity and offer an example of a theological argument that drawson complexity. Thirdly, I argue for the importance of transversality in engaging complexity by drawing on the work of Wentzel van Huyssteen and Paul Cilliers. In conclusion, I argue that theologians have to be conscious of the epistemic foundations of each study in complexity, and these studies illuminate the heart of Reformed theology.Intradisciplinary and/or interdisciplinary implications: Therefore, this article has both intradisciplinary and interdisciplinary implications. When theologians engage studies incomplexity, the epistemological roots of these studies need to be considered seeing thatresearchers in complexity draw on different epistemologies. Drawing on transversality wouldenhance such considerations. Furthermore, Edgar Morin�s and Paul Cilliers� approach tocomplexity will inform practical and theoretical considerations in church polity and unity.
J. A. Tenreiro Machado
2017-02-01
Full Text Available Complex systems (CS involve many elements that interact at different scales in time and space. The challenges in modeling CS led to the development of novel computational tools with applications in a wide range of scientific areas. The computational problems posed by CS exhibit intrinsic difficulties that are a major concern in Computational Complexity Theory. [...
Simons, J.
2008-01-01
This paper brings together narratology, game theory, and complexity theory to untangle the intricate nature of complex narratives in contemporary cinema. It interrogates the different terms - forking-path narratives, mind-game films, modular narratives, multiple-draft films, database narratives, puz
Preetha, A; Balikai, Bharati S; Sujatha, D; Pai, Anuradha; Ganapathy, K S
2010-01-01
Odontomas are hamartomatous lesions or malformations composed of mature enamel, dentin, and pulp. They may be compound or complex, depending on the extent of morphodifferentiation or their resemblance to normal teeth. The etiology of odontoma is unknown, although several theories have been proposed. This article describes a case of a large infected complex odontoma in the residual mandibular ridge, resulting in considerable mandibular expansion.
Leemput, van de I.A.
2016-01-01
In this thesis I use mathematical models to explore the properties of complex systems ranging from microbial nitrogen pathways and coral reefs to the human state of mind. All are examples of complex systems, defined as systems composed of a number of interconnected parts, where the systemic behavior
Fisher, Stephen D
1999-01-01
The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic
Maylath, Bruce; Vandepitte, Sonia; Minacori, Patricia
2013-01-01
This article discusses the largest and most complex international learning-by-doing project to date- a project involving translation from Danish and Dutch into English and editing into American English alongside a project involving writing, usability testing, and translation from English into Dut...... and into French. The complexity of the undertaking proved to be a central element in the students' learning, as the collaboration closely resembles the complexity of international documentation workplaces of language service providers. © Association of Teachers of Technical Writing....
yellow power was collected as polydatin-lecithin complex. ... performed on an Agilent 1260 HPLC system. The injection volume .... rabbits. Biomed. Pharmacother 2009; 63: 457-462. 4. Liu B, Du J, Zeng J, Chen C, Niu S. Characterization and.
Freitag, Eberhard
2005-01-01
The guiding principle of this presentation of ``Classical Complex Analysis'' is to proceed as quickly as possible to the central results while using a small number of notions and concepts from other fields. Thus the prerequisites for understanding this book are minimal; only elementary facts of calculus and algebra are required. The first four chapters cover the essential core of complex analysis: - differentiation in C (including elementary facts about conformal mappings) - integration in C (including complex line integrals, Cauchy's Integral Theorem, and the Integral Formulas) - sequences and series of analytic functions, (isolated) singularities, Laurent series, calculus of residues - construction of analytic functions: the gamma function, Weierstrass' Factorization Theorem, Mittag-Leffler Partial Fraction Decomposition, and -as a particular highlight- the Riemann Mapping Theorem, which characterizes the simply connected domains in C. Further topics included are: - the theory of elliptic functions based on...
Evsukoff, Alexandre; González, Marta
2013-01-01
In the last decade we have seen the emergence of a new inter-disciplinary field focusing on the understanding of networks which are dynamic, large, open, and have a structure sometimes called random-biased. The field of Complex Networks is helping us better understand many complex phenomena such as the spread of deseases, protein interactions, social relationships, to name but a few. Studies in Complex Networks are gaining attention due to some major scientific breakthroughs proposed by network scientists helping us understand and model interactions contained in large datasets. In fact, if we could point to one event leading to the widespread use of complex network analysis is the availability of online databases. Theories of Random Graphs from Erdös and Rényi from the late 1950s led us to believe that most networks had random characteristics. The work on large online datasets told us otherwise. Starting with the work of Barabási and Albert as well as Watts and Strogatz in the late 1990s, we now know th...
Complex chemistry with complex compounds
Eichler Robert
2016-01-01
Full Text Available In recent years gas-phase chemical studies assisted by physical pre-separation allowed for the investigation of fragile single molecular species by gas-phase chromatography. The latest success with the heaviest group 6 transactinide seaborgium is highlighted. The formation of a very volatile hexacarbonyl compound Sg(CO6 was observed similarly to its lighter homologues molybdenum and tungsten. The interactions of these gaseous carbonyl complex compounds with quartz surfaces were investigated by thermochromatography. Second-generation experiments are under way to investigate the intramolecular bond between the central metal atom of the complexes and the ligands addressing the influence of relativistic effects in the heaviest compounds. Our contribution comprises some aspects of the ongoing challenging experiments as well as an outlook towards other interesting compounds related to volatile complex compounds in the gas phase.
Chassin, David P.; Posse, Christian; Malard, Joel M.
2004-08-01
Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today’s most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically-based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper explores the state of the art in the use physical analogs for understanding the behavior of some econophysical systems and to deriving stable and robust control strategies for them. In particular we review and discussion applications of some analytic methods based on the thermodynamic metaphor according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood.
Taylor, Joseph L
2011-01-01
The text covers a broad spectrum between basic and advanced complex variables on the one hand and between theoretical and applied or computational material on the other hand. With careful selection of the emphasis put on the various sections, examples, and exercises, the book can be used in a one- or two-semester course for undergraduate mathematics majors, a one-semester course for engineering or physics majors, or a one-semester course for first-year mathematics graduate students. It has been tested in all three settings at the University of Utah. The exposition is clear, concise, and lively
Flanigan, Francis J
2010-01-01
A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion
Carleson, Lennart
1993-01-01
Complex dynamics is today very much a focus of interest. Though several fine expository articles were available, by P. Blanchard and by M. Yu. Lyubich in particular, until recently there was no single source where students could find the material with proofs. For anyone in our position, gathering and organizing the material required a great deal of work going through preprints and papers and in some cases even finding a proof. We hope that the results of our efforts will be of help to others who plan to learn about complex dynamics and perhaps even lecture. Meanwhile books in the field a. re beginning to appear. The Stony Brook course notes of J. Milnor were particularly welcome and useful. Still we hope that our special emphasis on the analytic side will satisfy a need. This book is a revised and expanded version of notes based on lectures of the first author at UCLA over several \\Vinter Quarters, particularly 1986 and 1990. We owe Chris Bishop a great deal of gratitude for supervising the production of cour...
Mather, John C.
2012-01-01
What explains the extraordinary complexity of the observed universe, on all scales from quarks to the accelerating universe? My favorite explanation (which I certainty did not invent) ls that the fundamental laws of physics produce natural instability, energy flows, and chaos. Some call the result the Life Force, some note that the Earth is a living system itself (Gaia, a "tough bitch" according to Margulis), and some conclude that the observed complexity requires a supernatural explanation (of which we have many). But my dad was a statistician (of dairy cows) and he told me about cells and genes and evolution and chance when I was very small. So a scientist must look for me explanation of how nature's laws and statistics brought us into conscious existence. And how is that seemll"!gly Improbable events are actually happening a!1 the time? Well, the physicists have countless examples of natural instability, in which energy is released to power change from simplicity to complexity. One of the most common to see is that cooling water vapor below the freezing point produces snowflakes, no two alike, and all complex and beautiful. We see it often so we are not amazed. But physlc!sts have observed so many kinds of these changes from one structure to another (we call them phase transitions) that the Nobel Prize in 1992 could be awarded for understanding the mathematics of their common features. Now for a few examples of how the laws of nature produce the instabilities that lead to our own existence. First, the Big Bang (what an insufficient name!) apparently came from an instability, in which the "false vacuum" eventually decayed into the ordinary vacuum we have today, plus the most fundamental particles we know, the quarks and leptons. So the universe as a whole started with an instability. Then, a great expansion and cooling happened, and the loose quarks, finding themselves unstable too, bound themselves together into today's less elementary particles like protons and
Mather, John C.
2012-01-01
What explains the extraordinary complexity of the observed universe, on all scales from quarks to the accelerating universe? My favorite explanation (which I certainty did not invent) ls that the fundamental laws of physics produce natural instability, energy flows, and chaos. Some call the result the Life Force, some note that the Earth is a living system itself (Gaia, a "tough bitch" according to Margulis), and some conclude that the observed complexity requires a supernatural explanation (of which we have many). But my dad was a statistician (of dairy cows) and he told me about cells and genes and evolution and chance when I was very small. So a scientist must look for me explanation of how nature's laws and statistics brought us into conscious existence. And how is that seemll"!gly Improbable events are actually happening a!1 the time? Well, the physicists have countless examples of natural instability, in which energy is released to power change from simplicity to complexity. One of the most common to see is that cooling water vapor below the freezing point produces snowflakes, no two alike, and all complex and beautiful. We see it often so we are not amazed. But physlc!sts have observed so many kinds of these changes from one structure to another (we call them phase transitions) that the Nobel Prize in 1992 could be awarded for understanding the mathematics of their common features. Now for a few examples of how the laws of nature produce the instabilities that lead to our own existence. First, the Big Bang (what an insufficient name!) apparently came from an instability, in which the "false vacuum" eventually decayed into the ordinary vacuum we have today, plus the most fundamental particles we know, the quarks and leptons. So the universe as a whole started with an instability. Then, a great expansion and cooling happened, and the loose quarks, finding themselves unstable too, bound themselves together into today's less elementary particles like protons and
Roles of host and viral microRNAs in human cytomegalovirus biology
Dhuruvasan, Kavitha; Sivasubramanian, Geetha; Pellett, Philip E.
2011-01-01
Human cytomegalovirus (HCMV) has a relatively large and complex genome, a protracted lytic replication cycle, and employs a strategy of replicational latency as part of its lifelong persistence in the infected host. An important form of gene regulation in plants and animals revolves around a type of small RNA known as microRNA (miRNA). miRNAs can serve as major regulators of key developmental pathways, as well as provide subtle forms of regulatory control. The human genome encodes over 900 miRNAs, and miRNAs are also encoded by some viruses, including HCMV, which encodes at least 14 miRNAs. Some of the HCMV miRNAs are known to target both viral and cellular genes, including important immunomodulators. In addition to expressing their own miRNAs, infections with some viruses, including HCMV, can result in changes in the expression of cellular miRNAs that benefit virus replication. In this review, we summarize the connections between miRNAs and HCMV biology. We describe the nature of miRNA genes, miRNA biogenesis and modes of action, methods for studying miRNAs, HCMV-encoded miRNAs, effects of HCMV infection on cellular miRNA expression, roles of miRNAs in HCMV biology, and possible HCMV-related diagnostic and therapeutic applications of miRNAs. PMID:20969901
Human cytomegalovirus Fcγ binding proteins gp34 and gp68 antagonize Fcγ receptors I, II and III.
Eugenia Corrales-Aguilar
2014-05-01
Full Text Available Human cytomegalovirus (HCMV establishes lifelong infection with recurrent episodes of virus production and shedding despite the presence of adaptive immunological memory responses including HCMV immune immunoglobulin G (IgG. Very little is known how HCMV evades from humoral and cellular IgG-dependent immune responses, the latter being executed by cells expressing surface receptors for the Fc domain of IgG (FcγRs. Remarkably, HCMV expresses the RL11-encoded gp34 and UL119-118-encoded gp68 type I transmembrane glycoproteins which bind Fcγ with nanomolar affinity. Using a newly developed FcγR activation assay, we tested if the HCMV-encoded Fcγ binding proteins (HCMV FcγRs interfere with individual host FcγRs. In absence of gp34 or/and gp68, HCMV elicited a much stronger activation of FcγRIIIA/CD16, FcγRIIA/CD32A and FcγRI/CD64 by polyclonal HCMV-immune IgG as compared to wildtype HCMV. gp34 and gp68 co-expression culminates in the late phase of HCMV replication coinciding with the emergence of surface HCMV antigens triggering FcγRIII/CD16 responses by polyclonal HCMV-immune IgG. The gp34- and gp68-dependent inhibition of HCMV immune IgG was fully reproduced when testing the activation of primary human NK cells. Their broad antagonistic function towards FcγRIIIA, FcγRIIA and FcγRI activation was also recapitulated in a gain-of-function approach based on humanized monoclonal antibodies (trastuzumab, rituximab and isotypes of different IgG subclasses. Surface immune-precipitation showed that both HCMV-encoded Fcγ binding proteins have the capacity to bind trastuzumab antibody-HER2 antigen complexes demonstrating simultaneous linkage of immune IgG with antigen and the HCMV inhibitors on the plasma membrane. Our studies reveal a novel strategy by which viral FcγRs can compete for immune complexes against various Fc receptors on immune cells, dampening their activation and antiviral immunity.
Tan, Shanguang
2007-01-01
A new kind of numbers called Hyper Space Complex Numbers and its algebras are defined and proved. It is with good properties as the classic Complex Numbers, such as expressed in coordinates, triangular and exponent forms and following the associative and commutative laws of addition and multiplication. So the classic Complex Number is developed from in complex plane with two dimensions to in complex space with N dimensions and the number system is enlarged also.
Complex networks analysis of language complexity
Amancio, Diego R; Oliveira, Osvaldo N; Costa, Luciano da F; 10.1209/0295-5075/100/58002
2013-01-01
Methods from statistical physics, such as those involving complex networks, have been increasingly used in quantitative analysis of linguistic phenomena. In this paper, we represented pieces of text with different levels of simplification in co-occurrence networks and found that topological regularity correlated negatively with textual complexity. Furthermore, in less complex texts the distance between concepts, represented as nodes, tended to decrease. The complex networks metrics were treated with multivariate pattern recognition techniques, which allowed us to distinguish between original texts and their simplified versions. For each original text, two simplified versions were generated manually with increasing number of simplification operations. As expected, distinction was easier for the strongly simplified versions, where the most relevant metrics were node strength, shortest paths and diversity. Also, the discrimination of complex texts was improved with higher hierarchical network metrics, thus point...
Rebecca J. Aicheler
2013-12-01
Full Text Available Human cytomegalovirus (HCMV is an important pathogen that infects the majority of the population worldwide, yet, currently, there is no licensed vaccine. Despite HCMV encoding at least seven Natural Killer (NK cell evasion genes, NK cells remain critical for the control of infection in vivo. Classically Antibody-Dependent Cellular Cytotoxicity (ADCC is mediated by CD16, which is found on the surface of the NK cell in a complex with FcεRI-γ chains and/or CD3ζ chains. Ninety percent of NK cells express the Fc receptor CD16; thus, they have the potential to initiate ADCC. HCMV has a profound effect on the NK cell repertoire, such that up to 10-fold expansions of NKG2C+ cells can be seen in HCMV seropositive individuals. These NKG2C+ cells are reported to be FcεRI-γ deficient and possess variable levels of CD16+, yet have striking ADCC functions. A subset of HCMV cell surface proteins will induce robust antibody responses that could render cells susceptible to ADCC. We will consider how the strong anti-HCMV function of NKG2C+ FcεRI-γ-deficient NK cells could potentially be harnessed in the clinic to treat patients suffering from HCMV disease and in the development of an efficacious HCMV vaccine.
Zheng, Fangyang
2002-01-01
The theory of complex manifolds overlaps with several branches of mathematics, including differential geometry, algebraic geometry, several complex variables, global analysis, topology, algebraic number theory, and mathematical physics. Complex manifolds provide a rich class of geometric objects, for example the (common) zero locus of any generic set of complex polynomials is always a complex manifold. Yet complex manifolds behave differently than generic smooth manifolds; they are more coherent and fragile. The rich yet restrictive character of complex manifolds makes them a special and interesting object of study. This book is a self-contained graduate textbook that discusses the differential geometric aspects of complex manifolds. The first part contains standard materials from general topology, differentiable manifolds, and basic Riemannian geometry. The second part discusses complex manifolds and analytic varieties, sheaves and holomorphic vector bundles, and gives a brief account of the surface classifi...
Radioisotope trithiol complexes
Jurisson, Silvia S.; Cutler, Cathy S.; Degraffenreid, Anthony J.
2016-08-30
The present invention is directed to a series of stable radioisotope trithiol complexes that provide a simplified route for the direct complexation of radioisotopes present in low concentrations. In certain embodiments, the complex contains a linking domain configured to conjugate the radioisotope trithiol complex to a targeting vector. The invention is also directed to a novel method of linking the radioisotope to a trithiol compound to form the radioisotope trithiol complex. The inventive radioisotope trithiol complexes may be utilized for a variety of applications, including diagnostics and/or treatment in nuclear medicine.
Doxorubicin Lipid Complex Injection
Doxorubicin lipid complex is used to treat ovarian cancer that has not improved or that has worsened after treatment with other medications. Doxorubicin lipid complex is also used to treat Kaposi's ...
Irinotecan Lipid Complex Injection
Irinotecan lipid complex is used in combination with other medications to treat pancreatic cancer that has spread to other ... worsened after treatment with other chemotherapy medications. Irinotecan lipid complex is in a class of antineoplastic medications ...
Daunorubicin Lipid Complex Injection
Daunorubicin lipid complex is used to treat advanced Kaposi's sarcoma (a type of cancer that causes abnormal tissue to ... body) related to acquired immunodeficiency syndrome (AIDS). Daunorubicin lipid complex is in a class of medications called ...
Vincristine Lipid Complex Injection
Vincristine lipid complex is used to treat a certain type of acute lymphoblastic leukemia (ALL; a type of cancer ... least two different treatments with other medications. Vincristine lipid complex is in a class of medications called ...
Oligocyclopentadienyl transition metal complexes
de Azevedo, Cristina G.; Vollhardt, K. Peter C.
2002-01-18
Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.
Evolution of biological complexity
Adami, Christoph; Ofria, Charles; Travis C. Collier
2000-01-01
In order to make a case for or against a trend in the evolution of complexity in biological evolution, complexity needs to be both rigorously defined and measurable. A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment. We investigate the evolution of genomic complexity in populations of digital organisms and monitor in detail the evolutionary transitions that increase complexit...
Complexity, Systems, and Software
2014-08-14
complex ( Hidden issues; dumbs down operator) 11 Complexity, Systems, and Software Sarah Sheard August 14, 2014 © 2014 Carnegie...August 14, 2014 © 2014 Carnegie Mellon University Addressing Complexity in SoSs Source: SEBOK Wiki System Con truer Strateglc Context
Halyo, Edi
2015-01-01
We generalize the concept of complexity near horizons to all nondegenerate black holes. For Schwarzschild black holes, we show that Rindler observers see a complexity change of $S$ during proper time $1/\\kappa$ which corresponds to the creation of a causal patch with proper length $1/\\kappa$ inside the horizon. We attempt to describe complexity in the horizon CFT and the Euclidean picture.
Quaternionic versus complex maps
Asorey, M [Departamento de Fisica Teorica, Universidad de Zaragoza 50009 Zaragoza (Spain); Scolarici, G [Dipartimento di Fisica dell' Universita del Salento and INFN, Sezione di Lecce, I-73100 Lecce (Italy); Solombrino, L [Dipartimento di Fisica dell' Universita del Salento and INFN, Sezione di Lecce, I-73100 Lecce (Italy)
2007-11-15
We discuss the relation between completely positive quaternionic maps and the corresponding complex maps obtained via projection operation. In order to illustrate this formalism, we reobtain the (complex) qubit subdynamics of maximally entangled Bell states, as complex projection of unitary dynamics between quaternionic pure states.
WANG Chenghong; ZHANG Lijun
2004-01-01
Science of Complexity is a newly emerging branch of natural scienceAlthoughwe still haven't a precise definition, there are some principles for justifying whether a systemis a complex systemThe purpose of this article is to reveal some of such principlesOnthe basis of them, the concept of a system with complexity is proposedThey may helpus to distinguish a real complex system from complicated objects in common senseThenwe propose some fundamental problems faced by the study of systems with complexity.
Complex variables I essentials
Solomon, Alan D
2013-01-01
REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Complex Variables I includes functions of a complex variable, elementary complex functions, integrals of complex functions in the complex plane, sequences and series, and poles and r
Complexity Through Nonextensivity
Bialek, W; Tishby, N; Bialek, William; Nemenman, Ilya; Tishby, Naftali
2001-01-01
The problem of defining and studying complexity of a time series has interested people for years. In the context of dynamical systems, Grassberger has suggested that a slow approach of the entropy to its extensive asymptotic limit is a sign of complexity. We investigate this idea further by information theoretic and statistical mechanics techniques and show that these arguments can be made precise, and that they generalize many previous approaches to complexity, in particular unifying ideas from the physics literature with ideas from learning and coding theory; there are even connections of this statistical approach to algorithmic or Kolmogorov complexity. Moreover, a set of simple axioms similar to those used by Shannon in his development of information theory allows us to prove that the divergent part of the subextensive component of the entropy is a unique complexity measure. We classify time series by their complexities and demonstrate that beyond the `logarithmic' complexity classes widely anticipated in...
Photocytotoxic lanthanide complexes
Akhtar Hussain; Akhil R Chakravarty
2012-11-01
Lanthanide complexes have recently received considerable attention in the field of therapeutic and diagnostic medicines. Among many applications of lanthanides, gadolinium complexes are used as magnetic resonance imaging (MRI) contrast agents in clinical radiology and luminescent lanthanides for bioanalysis, imaging and sensing. The chemistry of photoactive lanthanide complexes showing biological applications is of recent origin. Photodynamic therapy (PDT) is a non-invasive treatment modality of cancer using a photosensitizer drug and light. This review primarily focuses on different aspects of the chemistry of lanthanide complexes showing photoactivated DNA cleavage activity and cytotoxicity in cancer cells. Macrocyclic texaphyrin-lanthanide complexes are known to show photocytotoxicity with the PDT effect in near-IR light. Very recently, non-macrocyclic lanthanide complexes are reported to show photocytotoxicity in cancer cells. Attempts have been made in this perspective article to review and highlight the photocytotoxic behaviour of various lanthanide complexes for their potential photochemotherapeutic applications.
[Gastrointestinal myoelectric complex].
Aeberhard, P
1977-03-01
Complexes of high amplitude action potentials have been shownn to occur in the stomach and duodenum of fasting dogs. These complexes recur at regular intervals as long as the animal is fasting, and they are propagated aborally over the whole lenght of the small bowel. The cyclical pattern is replaced by the digestive of "fed" pattern of activity upon feeding. Therefore the pattern has been known as the interdigestive myoelectrical complex. Studies in herbivorous species however, in which the flow of digesta is more or less continous have show that cyclically recurring migrating complexes can be demonstrated in these species as well. Thus, the term "migratory myoelectrical complex" may be more appropriate. Propagation of the complex is not dependent upon continuity of the bowel wall nor movement of luminal contents. Replacement of the complex by the digestive pattern of activity upon feeding and the restitution of the interdigestive pattern at the end of the digestive phase seem to be under nervous as well as hormonal control. The interdigestive complex in the dog has been looked upon as a "housekeeper" which sweeps the bowel clear of contents at the end of the digestive phase. Aspects of possible physiological significance of the complex are: periodic elimination of refluxed duodenal contents from the stomach and prevention of bacterial colonization of the small bowel by the colonic flora. The existence of propagated complexes has not been demonstrated in man, but there is increasing evidence for cyclical activity which fits the pattern.
Simplicial complexes of graphs
Jonsson, Jakob
2008-01-01
A graph complex is a finite family of graphs closed under deletion of edges. Graph complexes show up naturally in many different areas of mathematics, including commutative algebra, geometry, and knot theory. Identifying each graph with its edge set, one may view a graph complex as a simplicial complex and hence interpret it as a geometric object. This volume examines topological properties of graph complexes, focusing on homotopy type and homology. Many of the proofs are based on Robin Forman's discrete version of Morse theory. As a byproduct, this volume also provides a loosely defined toolbox for attacking problems in topological combinatorics via discrete Morse theory. In terms of simplicity and power, arguably the most efficient tool is Forman's divide and conquer approach via decision trees; it is successfully applied to a large number of graph and digraph complexes.
Ben Goertzel
1992-01-01
Full Text Available The concept of pattern is introduced, formally defined, and used to analyze various measures of the complexity of finite binary sequences and other objects. The standard Kolmogoroff-Chaitin-Solomonoff complexity measure is considered, along with Bennett's logical depth, Koppel's sophistication', and Chaitin's analysis of the complexity of geometric objects. The pattern-theoretic point of view illuminates the shortcomings of these measures and leads to specific improvements, it gives rise to two novel mathematical concepts--orders of complexity and levels of pattern, and it yields a new measure of complexity, the structural complexity, which measures the total amount of structure an entity possesses.
Anwer Khurshid
2012-07-01
Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In this paper, it is shown that a complex multivariate random variable is a complex multivariate normal random variable of dimensionality if and only if all nondegenerate complex linear combinations of have a complex univariate normal distribution. The characteristic function of has been derived, and simpler forms of some theorems have been given using this characterization theorem without assuming that the variance-covariance matrix of the vector is Hermitian positive definite. Marginal distributions of have been given. In addition, a complex multivariate t-distribution has been defined and the density derived. A characterization of the complex multivariate t-distribution is given. A few possible uses of this distribution have been suggested.
Complex networks and computing
Shuigeng ZHOU; Zhongzhi ZHANG
2009-01-01
@@ Nowadays complex networks are pervasive in various areas of science and technology. Popular examples of complex networks include the Internet, social networks of collaboration, citations and co-authoring, as well as biological networks such as gene and protein interactions and others. Complex networks research spans across mathematics, computer science, engineering, biology and the social sciences. Even in computer science area, increasing problems are either found to be related to complex networks or studied from the perspective of complex networks, such as searching on Web and P2P networks, routing in sensor networks, language processing, software engineering etc. The interaction and mergence of complex networks and computing is inspiring new chances and challenges in computer science.
Complex Systems and Dependability
Zamojski, Wojciech; Sugier, Jaroslaw
2012-01-01
Typical contemporary complex system is a multifaceted amalgamation of technical, information, organization, software and human (users, administrators and management) resources. Complexity of such a system comes not only from its involved technical and organizational structure but mainly from complexity of information processes that must be implemented in the operational environment (data processing, monitoring, management, etc.). In such case traditional methods of reliability analysis focused mainly on technical level are usually insufficient in performance evaluation and more innovative meth
Recognizing dualizing complexes
Jorgensen, Peter
2003-01-01
Let A be a noetherian local commutative ring and let M be a suitable complex of A-modules. This paper proves that M is a dualizing complex for A if and only if the trivial extension A \\ltimes M is a Gorenstein Differential Graded Algebra. As a corollary follows that A has a dualizing complex if and only if it is a quotient of a Gorenstein local Differential Graded Algebra.
Motulsky, Arno G
2006-02-01
Approaches to the study of the genetic basis of common complex diseases and their clinical applications are considered. Monogenic Mendelian inheritance in such conditions is infrequent but its elucidation may help to detect pathogenic mechanisms in the more common variety of complex diseases. Involvement by multiple genes in complex diseases usually occurs but the isolation and identification of specific genes so far has been exceptional. The role of common polymorphisms as indicators of disease risk in various studies is discussed.
Federal Laboratory Consortium — Description/History: Engineering laboratory The Berger Lab Complex is a multi-purpose building with professional office, 100 seat auditorium, general purpose labs,...
叶郁; 张璞
2003-01-01
In this paper we generalize the Koszul complexes and Koszul algebras, and introduce the higherKoszul (t-Koszul) complexes and higher Koszul algebras, where t ≥ 2 is an integer. We prove that an algebra ist-Koszul if and only if its t-Koszul complex is augmented, i.e. the higher degree (≥ 1) homologies vanish. Forarbitrary t-Koszul algebra , we also give a description of the structure of the cohomology algebra Ext ( 0, 0)by using the t-Koszul complexes, where the 0 is the direct sum of the simples.
Adaptive Leadership: Fighting Complexity with Complexity
2014-06-01
complex tasks.30 An astonishing level of sophistication arises out of the intricate combination of these simple insect minds. 23 Snowden and Boone, “A...system: individuals, with little or no central oversight, perform simple tasks: posting Web pages and linking to other Web pages…and the co- evolutionary ...existence today. 31 Bert Hölldobler and Edward Osborne Wilson, The Superorganism: The Beauty, Elegance, and Strangeness of Insect Societies (New York, NY
Complexity and valued landscapes
Michael M. McCarthy
1979-01-01
The variable "complexity," or "diversity," has received a great deal of attention in recent research efforts concerned with visual resource management, including the identification of complexity as one of the primary evaluation measures. This paper describes research efforts that support the hypothesis that the landscapes we value are those with...
Williams, R.M.; Verhoeven, J.M.
1994-01-01
In the recent paper by Atwood et al. (Nature 368, 229-231, 1994) on a purification procedure for C60 and C70 by selective complexation with calixarenes, it was implied that we had previously studied the complexation of C60 with cyclodextrins (Williams, R. M. & Verhoeven, J. W., Recl. Trav. Chim.
Complexity, Robustness, and Performance
B. Visser (Bauke)
2002-01-01
textabstractThis paper analyses the relationship between organizational complexity ( the degree of detail of information necessary to correctly assign agents to positions), robustness (the relative loss of performance due to mis-allocated agents), and performance. More complex structures are not
Silverman, Richard A
1984-01-01
A shorter version of A. I. Markushevich's masterly three-volume Theory of Functions of a Complex Variable, this edition is appropriate for advanced undergraduate and graduate courses in complex analysis. Numerous worked-out examples and more than 300 problems, some with hints and answers, make it suitable for independent study. 1967 edition.
Pocchiola, M; Vegter, G
1996-01-01
We introduce the visibility complex (rr 2-dimensional regular cell complex) of a collection of n pairwise disjoint convex obstacles in the plane. It can be considered as a subdivision of the set of free rays (i.e., rays whose origins lie in free space, the complement of the obstacles). Its cells cor
Trombly, Christopher E.
2014-01-01
As schools, districts, and the overall education system are complex entities, both the approaches taken to improve them and the methods used to study them must be similarly complex. Simple solutions imposed with no regard for schools' or districts' unique contexts hold little promise, while seemingly insignificant differences between those…
Lancaster, Jeanette Elizabeth
2013-01-01
A central feature of complexity is that it is based on non-linear, recursive relations. However, in most current accounts of complexity such relations, while non-linear, are based on the reductive relations of a Newtonian onto-epistemological framework. This means that the systems that are emergent from the workings of such relations are a…
Donderi, Don C.
2006-01-01
The idea of visual complexity, the history of its measurement, and its implications for behavior are reviewed, starting with structuralism and Gestalt psychology at the beginning of the 20th century and ending with visual complexity theory, perceptual learning theory, and neural circuit theory at the beginning of the 21st. Evidence is drawn from…
Complexity, Robustness, and Performance
B. Visser (Bauke)
2002-01-01
textabstractThis paper analyses the relationship between organizational complexity ( the degree of detail of information necessary to correctly assign agents to positions), robustness (the relative loss of performance due to mis-allocated agents), and performance. More complex structures are not nec
Conducting metal dithiolate complexes
Underhill, A. E.; Ahmad, M. M.; Turner, D. J.;
1985-01-01
Further work on the chemical composition of the one-dimensional metallic metal dithiolene complex Li-Pt(mnt) is reported. The electrical conduction and thermopower properties of the nickel and palladium complexes are reported and compared with those of the platinum compound...
Complexity dimensions and learnability
S-H. Nienhuys-Cheng (Shan-Hwei); M. Polman (Mark)
1992-01-01
textabstractA stochastic model of learning from examples has been introduced by Valiant [1984]. This PAC-learning model (PAC = probably approximately correct) reflects differences in complexity of concept classes, i.e. very complex classes are not efficiently PAC-learnable. Blumer et al. [1989
Leading healthcare in complexity.
Cohn, Jeffrey
2014-12-01
Healthcare institutions and providers are in complexity. Networks of interconnections from relationships and technology create conditions in which interdependencies and non-linear dynamics lead to surprising, unpredictable outcomes. Previous effective approaches to leadership, focusing on top-down bureaucratic methods, are no longer effective. Leading in complexity requires leaders to accept the complexity, create an adaptive space in which innovation and creativity can flourish and then integrate the successful practices that emerge into the formal organizational structure. Several methods for doing adaptive space work will be discussed. Readers will be able to contrast traditional leadership approaches with leading in complexity. They will learn new behaviours that are required of complexity leaders, along with challenges they will face, often from other leaders within the organization.
Supporting complex search tasks
Gäde, Maria; Hall, Mark; Huurdeman, Hugo
2015-01-01
There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks, is fragme......There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks......, and recommendations, and supporting exploratory search to sensemaking and analytics, UI and UX design pose an overconstrained challenge. How do we know that our approach is any good? Supporting complex search task requires new collaborations across the whole field of IR, and the proposed workshop will bring together...
Comments on Holographic Complexity
Carmi, Dean; Rath, Pratik
2016-01-01
We study two recent conjectures for holographic complexity: the complexity=action conjecture and the complexity=volume conjecture. In particular, we examine the structure of the UV divergences appearing in these quantities, and show that the coefficients can be written as local integrals of geometric quantities in the boundary. We also consider extending these conjectures to evaluate the complexity of the mixed state produced by reducing the pure global state to a specific subregion of the boundary time slice. The UV divergences in this subregion complexity have a similar geometric structure, but there are also new divergences associated with the geometry of the surface enclosing the boundary region of interest. We discuss possible implications arising from the geometric nature of these UV divergences.
Stable Spirocyclic Meisenheimer Complexes
Gonzalo Guirado
2008-06-01
Full Text Available Meisenheimer complexes are important intermediates in Nucleophilic Aromatic Substitution Reactions (SNAr. They are formed by the addition of electron rich species to polynitro aromatic compounds or aromatic compounds with strong electron withdrawing groups. It is possible to distinguish two types of Meisenheimer or ÃÂƒ-complexes, the ÃÂƒHcomplex or ÃÂƒX-complex (also named ipso, depending on the aromatic ring position attacked by the nucleophile (a non-substituted or substituted one, respectively. Special examples of ÃÂƒX- or ipso-complexes are formed through intermediate spiro adducts, via intramolecular SNAr. Some of these spirocyclic Meisenheimer complexes, a type of ÃÂƒXcomplex, are exceptionally stable in solution and/or as solids. They can be isolated and characterized using X-ray, and various spectroscopic techniques such as NMR, UV-Vis, IR, and fluorescence. A few of these stable spirocyclic Meisenheimer complexes are zwitterionic and exhibit interesting photophysical and redox properties. We will review recent advances, synthesis and potential applications of these stable spirocyclic Meisenheimer complexes.
Selenophene transition metal complexes
White, Carter James [Iowa State Univ., Ames, IA (United States)
1994-07-27
This research shows that selenophene transition metal complexes have a chemistry that is similar to their thiophene analogs. Selenophene coordination has been demonstrated and confirmed by molecular structure in both the η^{5}- and the η^{1}(Se)-coordination modes. The reaction chemistry of selenophene complexes closely resembles that of the analogous thiophene complexes. One major difference, however, is that selenophene is a better donor ligand than thiophene making the selenophene complexes more stable than the corresponding thiophene complexes. The ^{77}Se NMR chemical shift values for selenophene complexes fall within distinct regions primarily depending on the coordination mode of the selenophene ligand. In the final paper, the C-H bond activation of η^{1}(S)-bound thiophenes, η^{1}(S)-benzothiophene and η^{1}(Se)-bound selenophenes has been demonstrated. The deprotonation and rearrangement of the η^{1}(E)-bound ligand to the carbon bound L-yl complex readily occurs in the presence of base. Reprotonation with a strong acid gives a carbene complex that is unreactive towards nucleophilic attack at the carbene carbon and is stable towards exposure to air. The molecular structure of [Cp(NO)(PPh_{3})Re(2-benzothioenylcarbene)]O_{3}SCF_{3} was determined and contains a Re-C bond with substantial double bond character. Methyl substitution for the thienylcarbene or selenylcarbene gives a carbene that rearranges thermally to give back the η^{1}(E)-bound complex. Based on these model reactions, a new mechanism for the H/D exchange of thiophene over the hydrodesulfurization catalyst has been proposed.
Controllability of Complex Systems
Slotine, Jean-Jacques
2013-03-01
We review recent work on controllability of complex systems. We also discuss the interplay of our results with questions of synchronization, and point out key directions of future research. Work done in collaboration with Yang-Yu Liu, Center for Complex Network Research and Departments of Physics, Computer Science and Biology, Northeastern University and Center for Cancer Systems Biology, Dana-Farber Cancer Institute; and Albert-László Barabási, Center for Complex Network Research and Departments of Physics, Computer Science and Biology, Northeastern University; Center for Cancer Systems Biology, Dana-Farber Cancer Institute; and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School.
Svendsen, Idamarie Leth
2017-01-01
The article reports the findings of a qualitative study of Danish legal regulation of the public initial assessment of children and young persons and municipal practitioners’ decision-making under this regulation. The regulation mirrors new and complex relations between families and society...... in the form of 7 individual vignette interviews with municipal mid-level managers and professional consultants in five Danish municipalities. The study finds that the regulation is more complex than it looks, and that the complexity is handled through simplifying decision-making patterns that can be seen...
Localization of HCMV UL33 and US27 in endocytic compartments and viral membranes
Fraile-Ramos, Alberto; Pelchen-Matthews, Annegret; Kledal, Thomas N
2002-01-01
and undergoes constitutive endocytosis and recycling. Here we studied the cellular distributions and trafficking of two other human cytomegalovirus chemokine receptor-like proteins, UL33 and US27, in transfected and human cytomegalovirus-infected cells. Immunofluorescence staining indicated that UL33 and US27......The human cytomegalovirus genome encodes four putative seven transmembrane domain chemokine receptor-like proteins. Although important in viral pathogenesis, little is known about the properties or functions of these proteins. We previously reported that US28 is located in endocytic vesicles......27 undergoes endocytosis. By immunogold labeling of cryosections and electron microscopy, UL33 was seen to localize to multivesicular bodies (MVBs or multivesicular endosomes). Electron microscopy analysis of human cytomegalovirus-infected cells showed that most virus particles wrapped individually...
Immune Adaptation to Environmental Influence: The Case of NK Cells and HCMV.
Rölle, Alexander; Brodin, Petter
2016-03-01
The immune system of an individual human is determined by heritable traits and a continuous process of adaptation to a broad variety of extrinsic, non-heritable factors such as viruses, bacteria, dietary components and more. Cytomegalovirus (CMV) successfully infects the majority of the human population and establishes latency, thereby exerting a life-long influence on the immune system of its host. CMV has been shown to influence the majority of immune parameters in healthy individuals. Here we focus on adaptive changes induced by CMV in subsets of Natural Killer (NK) cells, changes that question our very definition of adaptive and innate immunity by suggesting that adaptations of immune cells to environmental influences occur across the entire human immune system and not restricted to the classical adaptive branch of the immune system.
Berthiaume, A; Laplante, S; Berthiaume, Andre; Dam, Wim van; Laplante, Sophie
2000-01-01
In this paper we give a definition for quantum Kolmogorov complexity. In the classical setting, the Kolmogorov complexity of a string is the length of the shortest program that can produce this string as its output. It is a measure of the amount of innate randomness (or information) contained in the string. We define the quantum Kolmogorov complexity of a qubit string as the length of the shortest quantum input to a universal quantum Turing machine that produces the initial qubit string with high fidelity. The definition of Vitanyi (Proceedings of the 15th IEEE Annual Conference on Computational Complexity, 2000) measures the amount of classical information, whereas we consider the amount of quantum information in a qubit string. We argue that our definition is natural and is an accurate representation of the amount of quantum information contained in a quantum state.
Complexity for Artificial Substrates (
Loke, L.H.L.; Jachowski, N.R.; Bouma, T.J.; Ladle, R.J.; Todd, P.A.
2014-01-01
Physical habitat complexity regulates the structure and function of biological communities, although the mechanisms underlying this relationship remain unclear. Urbanisation, pollution, unsustainable resource exploitation and climate change have resulted in the widespread simplification (and loss)
On scattered subword complexity
Kása, Zoltán
2011-01-01
Special scattered subwords, in which the gaps are of length from a given set, are defined. The scattered subword complexity, which is the number of such scattered subwords, is computed for rainbow words.
Complexity for Artificial Substrates (
Loke, L.H.L.; Jachowski, N.R.; Bouma, T.J.; Ladle, R.J.; Todd, P.A.
2014-01-01
Physical habitat complexity regulates the structure and function of biological communities, although the mechanisms underlying this relationship remain unclear. Urbanisation, pollution, unsustainable resource exploitation and climate change have resulted in the widespread simplification (and loss) o
Beyond complex Langevin equations
Wosiek, Jacek
2016-01-01
A simple integral relation between a complex weight and the corresponding positive distribution is derived by introducing a second complex variable. Together with the positivity and normalizability conditions, this sum rule allows to construct explicitly equivalent pairs of distributions in simple cases. In particular the well known solution for a complex gaussian distribution is generalized to an arbitrary complex slope. This opens a possibility of positive representation of Feynman path integrals directly in the Minkowski time. Such construction is then explicitly carried through in the second part of this presentation. The continuum limit of the new representation exists only if some of the additional couplings tend to infinity and are tuned in a specific way. The approach is then successfully applied to three quantum mechanical examples including a particle in a constant magnetic field -- a simplest prototype of a Wilson line. Further generalizations are shortly discussed and an amusing interpretation of ...
Management recommendations: Tewaukon Complex
US Fish and Wildlife Service, Department of the Interior — This document is a review of land management practices at the Tewaukon Complex, by a land use specialist. Recommendations, time frame and additional comments are...
Complex coacervate core micelles.
Voets, Ilja K; de Keizer, Arie; Cohen Stuart, Martien A
2009-01-01
In this review we present an overview of the literature on the co-assembly of neutral-ionic block, graft, and random copolymers with oppositely charged species in aqueous solution. Oppositely charged species include synthetic (co)polymers of various architectures, biopolymers - such as proteins, enzymes and DNA - multivalent ions, metallic nanoparticles, low molecular weight surfactants, polyelectrolyte block copolymer micelles, metallo-supramolecular polymers, equilibrium polymers, etcetera. The resultant structures are termed complex coacervate core/polyion complex/block ionomer complex/interpolyelectrolyte complex micelles (or vesicles); i.e., in short C3Ms (or C3Vs) and PIC, BIC or IPEC micelles (and vesicles). Formation, structure, dynamics, properties, and function will be discussed. We focus on experimental work; theory and modelling will not be discussed. Recent developments in applications and micelles with heterogeneous coronas are emphasized.
none,
2012-05-01
This report documents findings from a workshop on the impacts of complex wind flows in and out of wind turbine environments, the research needs, and the challenges of meteorological and engineering modeling at regional, wind plant, and wind turbine scales.
Moore, Cristopher
2011-11-01
In his tragically short life, Alan Turing helped define what computing machines are capable of, and where they reach inherent limits. His legacy is still felt every day, in areas ranging from computational complexity theory to cryptography and quantum computing.
DNA complexes: Durable binders
Urbach, Adam R.
2011-11-01
A tetra-intercalator compound that threads through a DNA double-helix to form a remarkably stable complex exhibits an unusual combination of sequence specificity and rapid association yet slow dissociation.
Federal Laboratory Consortium — This 88,000 square foot complex is used to investigate basic physical science in support of missile technology development. It incorporates office space, dedicated...
CLEMENT O BEWAJI
Key Words : Histidine, complex compound, acetylacetone, stability constant, ... of a class of chemical compounds called amino acids, which are organic .... Synthesis and techniques in inorganic chemistry W. B. Saunders campany, 2nd Edition.
Bai, Lin; Yu, Quan
2014-01-01
Multiple-input multiple-output (MIMO) systems can increase the spectral efficiency in wireless communications. However, the interference becomes the major drawback that leads to high computational complexity at both transmitter and receiver. In particular, the complexity of MIMO receivers can be prohibitively high. As an efficient mathematical tool to devise low complexity approaches that mitigate the interference in MIMO systems, lattice reduction (LR) has been widely studied and employed over the last decade. The co-authors of this book are world's leading experts on MIMO receivers, and here they share the key findings of their research over years. They detail a range of key techniques for receiver design as multiple transmitted and received signals are available. The authors first introduce the principle of signal detection and the LR in mathematical aspects. They then move on to discuss the use of LR in low complexity MIMO receiver design with respect to different aspects, including uncoded MIMO detection...
Leleur, Steen
. Complex Strategic Choices provides clear principles and methods which can guide and support strategic decision making to face the many current challenges. By considering ways in which planning practices can be renewed and exploring the possibilities for acquiring awareness and tools to add value...... and students in the field of planning and decision analysis as well as practitioners dealing with strategic analysis and decision making. More broadly, Complex Strategic Choices acts as guide for professionals and students involved in complex planning tasks across several fields such as business...... to strategic decision making, Complex Strategic Choices presents a methodology which is further illustrated by a number of case studies and example applications. Dr. Techn. Steen Leleur has adapted previously established research based on feedback and input from various conferences, journals and students...
Supporting complex search tasks
Gäde, Maria; Hall, Mark; Huurdeman, Hugo;
2015-01-01
There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks......, is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...... introductory to specialized, and from authoritative to speculative or opinionated, when to show what sources of information? How does the information seeking process evolve and what are relevant differences between different stages? With complex task and search process management, blending searching, browsing...
Complex Regional Pain Syndrome
Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. ... in skin temperature, color, or texture Intense burning pain Extreme skin sensitivity Swelling and stiffness in affected ...
Federal Laboratory Consortium — This 88,000 square foot complex is used to investigate basic physical science in support of missile technology development. It incorporates office space, dedicated...
complexes containing isocyanide and
MR. S. O. OWALUDE
Synthesis of new ruthenium(II) complexes containing isocyanide and labile nitrile ligands. Owalude,* S. O. ... both compounds has distorted octahedral coordination geometry. Key words: Nitrile ... commercial product from Acros Organics. All.
Complex and unpredictable Cardano
Ekert, Artur
2008-08-01
This purely recreational paper is about one of the most colorful characters of the Italian Renaissance, Girolamo Cardano, and the discovery of two basic ingredients of quantum theory, probability and complex numbers.
Network Complexity of Foodwebs
Standish, Russell K
2010-01-01
In previous work, I have developed an information theoretic complexity measure of networks. When applied to several real world food webs, there is a distinct difference in complexity between the real food web, and randomised control networks obtained by shuffling the network links. One hypothesis is that this complexity surplus represents information captured by the evolutionary process that generated the network. In this paper, I test this idea by applying the same complexity measure to several well-known artificial life models that exhibit ecological networks: Tierra, EcoLab and Webworld. Contrary to what was found in real networks, the artificial life generated foodwebs had little information difference between itself and randomly shuffled versions.
Microsolvation in molecular complexes
Pasquini, M; Schiccheri, N; Piani, G; Pietraperzia, G; Becucci, M; Castellucci, E [European Laboratory for Non-Linear Spectroscopy (LENS), Polo Scientifico e Tecnologico Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy)], E-mail: gianni.pietraperzia@unifi.it
2008-11-15
In this paper, we report the results of our study of the microsolvation process involving the anisole molecule. We are able to study bimolecular complexes of different compositions. Changing the second partner molecule bound to anisole, we observed complexes of different geometries, because of the large variety of interactions possible for the anisole. High-resolution electronic spectroscopy is the best tool to reveal the correct vibrationally (zero-point) averaged geometry of the complex. That is done by analysing the rovibronic structure of the electronic spectra, which are related to the equilibrium geometry of the complex as well as dynamical processes, both in the ground and in the excited state. The interpretation of the experimental results is supported by high-level quantum calculations.
Killingbeck, John P [Mathematics Department, University of Hull, Hull HU6 7RX (United Kingdom); Grosjean, Alain [Laboratoire d' Astrophysique de l' Observatoire de Besancon (CNRS, UPRES-A 6091), 41 bis Avenue de l' Observatoire, BP 1615, 25010 Besancon Cedex (France); Jolicard, Georges [Laboratoire d' Astrophysique de l' Observatoire de Besancon (CNRS, UPRES-A 6091), 41 bis Avenue de l' Observatoire, BP 1615, 25010 Besancon Cedex (France)
2004-08-13
Complex variable hypervirial perturbation theory is applied to the case of oscillator and Coulomb potentials perturbed by a single term potential of the form Vx{sup n} or Vr{sup n}, respectively. The trial calculations reported show that this approach can produce accurate complex energies for resonant states via a simple and speedy calculation and can also be useful in studies of PT symmetry and tunnelling resonance effects. (addendum)
Electrospun complexes - functionalised nanofibres
Meyer, T.; Wolf, M.; Dreyer, B.; Unruh, D.; Krüger, C.; Menze, M.; Sindelar, R.; Klingelhöfer, G.; Renz, F.
2016-12-01
Here we present a new approach of using iron-complexes in electro-spun fibres. We modify poly(methyl methacrylate) (PMMA) by replacing the methoxy group with Diaminopropane or Ethylenediamine. The complex is bound covalently via an imine-bridge or an amide. The resulting polymer can be used in the electrospinning process without any further modifications in method either as pure reagent or mixed with small amounts of not functionalised polymer resulting in fibres of different qualities (Fig. 1).
Electrospun complexes - functionalised nanofibres
Meyer, T.; Wolf, M.; Dreyer, B.; Unruh, D.; Krüger, C.; Menze, M. [Leibniz University Hannover, Institute of Inorganic Chemistry (Germany); Sindelar, R. [University of Applied Science Hannover, Faculty II (Germany); Klingelhöfer, G. [Gutenberg-University, Institute of Inorganic and Analytic Chemistry (Germany); Renz, F., E-mail: renz@acd.uni-hannover.de [Leibniz University Hannover, Institute of Inorganic Chemistry (Germany)
2016-12-15
Here we present a new approach of using iron-complexes in electro-spun fibres. We modify poly(methyl methacrylate) (PMMA) by replacing the methoxy group with Diaminopropane or Ethylenediamine. The complex is bound covalently via an imine-bridge or an amide. The resulting polymer can be used in the electrospinning process without any further modifications in method either as pure reagent or mixed with small amounts of not functionalised polymer resulting in fibres of different qualities (Fig. 1).
Chuang, W; Tomasiello, A; Chuang, Wu-yen; Kachru, Shamit; Tomasiello, Alessandro
2005-01-01
We construct a class of symplectic non--Kaehler and complex non--Kaehler string theory vacua, extending and providing evidence for an earlier suggestion by Polchinski and Strominger. The class admits a mirror pairing by construction. Comparing hints from a variety of sources, including ten--dimensional supergravity and KK reduction on SU(3)--structure manifolds, suggests a picture in which string theory extends Reid's fantasy to connect classes of both complex non-Kaehler and symplectic non-Kaehler manifolds.
Quantum Hamiltonian Complexity
2014-01-01
Constraint satisfaction problems are a central pillar of modern computational complexity theory. This survey provides an introduction to the rapidly growing field of Quantum Hamiltonian Complexity, which includes the study of quantum constraint satisfaction problems. Over the past decade and a half, this field has witnessed fundamental breakthroughs, ranging from the establishment of a "Quantum Cook-Levin Theorem" to deep insights into the structure of 1D low-temperature quantum systems via s...
Conversation, coupling and complexity
Fusaroli, Riccardo; Abney, Drew; Bahrami, Bahador;
We investigate the linguistic co-construction of interpersonal synergies. By applying a measure of coupling between complex systems to an experimentally elicited corpus of joint decision dialogues, we show that interlocutors’ linguistic behavior displays increasing signature of multi-scale coupling......, known as complexity matching, over the course of interaction. Furthermore, we show that stronger coupling corresponds with more effective interaction, as measured by collective task performance....
Provability, complexity, grammars
Beklemishev, Lev; Vereshchagin, Nikolai
1999-01-01
The book contains English translations of three outstanding dissertations in mathematical logic and complexity theory. L. Beklemishev proves that all provability logics must belong to one of the four previously known classes. The dissertation of M. Pentus proves the Chomsky conjecture about the equivalence of two approaches to formal languages: the Chomsky hierarchy and the Lambek calculus. The dissertation of N. Vereshchagin describes a general framework for criteria of reversability in complexity theory.
Tozoglu, Sinan; Yildirim, Umran; Buyukkurt, M Cemil
2010-01-01
Odontomas are benign tumors of odontogenic origin. The cause of the odontoma is unknown, but it is believed to be hereditary or due to a disturbance in tooth development triggered by trauma or infection. Odontomas may be either compound or complex. Although these tumors are seen frequently, erupted odontomas are rare. The purpose of this study is to present a rare case of complex odontoma that erupted into the oral cavity.
Advances in network complexity
Dehmer, Matthias; Emmert-Streib, Frank
2013-01-01
A well-balanced overview of mathematical approaches to describe complex systems, ranging from chemical reactions to gene regulation networks, from ecological systems to examples from social sciences. Matthias Dehmer and Abbe Mowshowitz, a well-known pioneer in the field, co-edit this volume and are careful to include not only classical but also non-classical approaches so as to ensure topicality. Overall, a valuable addition to the literature and a must-have for anyone dealing with complex systems.
Marian STAN
2015-07-01
Full Text Available The actuality of the investigated theme. Nowadays, human evolution, including his intellectual development, proves the fact that especially the creation manpower and the employment was the solution of all life’s ambitions in society. So, the fact is that in reality, man is the most important capital of the society. Also, in an individual’s life, the practice of sport plays a significant role and that’s why the initiation, the launch and the management of sports complexes activity reveal the existence of specific management features that we will identify and explain in the current study. The aim of the research refers to the elaboration of a theoretical base of the management of the sport complexes, to the pointing of the factors that influence the efficient existence and function of a sport complex in our country and to the determination of the responsibilities that have a manager who directs successfully the activity of the sport complexes. The investigation is based on theoretical methods, such as: scientific documentation, analysis, synthesis, comparison and on empirical research methods, like: study of researched literature and observation. The results of the research indicate the fact that the profitability of a sport complex must assure a particular structure to avoid the bankruptcy risk and also, that the administration of the sport complexes activity must keep in view the reliable functions of the contemporaneous management.
Modelling Complexity in Musical Rhythm
Liou, Cheng-Yuan; Wu, Tai-Hei; Lee, Chia-Ying
2007-01-01
This paper constructs a tree structure for the music rhythm using the L-system. It models the structure as an automata and derives its complexity. It also solves the complexity for the L-system. This complexity can resolve the similarity between trees. This complexity serves as a measure of psychological complexity for rhythms. It resolves the music complexity of various compositions including the Mozart effect K488. Keyword: music perception, psychological complexity, rhythm, L-system, autom...
Turbulent complex (dusty) plasma
Zhdanov, Sergey; Schwabe, Mierk
2017-04-01
As a paradigm of complex system dynamics, solid particles immersed into a weakly ionized plasma, so called complex (dusty) plasmas, were (and continue to be) a subject of many detailed studies. Special types of dynamical activity have been registered, in particular, spontaneous pairing, entanglement and cooperative action of a great number of particles resulting in formation of vortices, self-propelling, tunneling, and turbulent movements. In the size domain of 1-10 mkm normally used in experiments with complex plasmas, the characteristic dynamic time-scale is of the order of 0.01-0.1 s, and these particles can be visualized individually in real time, providing an atomistic (kinetic) level of investigations. The low-R turbulent flow induced either by the instability in a complex plasma cloud or formed behind a projectile passing through the cloud is a typical scenario. Our simulations showed formation of a fully developed system of vortices and demonstrated that the velocity structure functions scale very close to the theoretical predictions. As an important element of self-organization, cooperative and turbulent particle motions are present in many physical, astrophysical, and biological systems. Therefore, experiments with turbulent wakes and turbulent complex plasma oscillations are a promising mean to observe and study in detail the anomalous transport on the level of individual particles.
Complexity and Dynamical Depth
Terrence Deacon
2014-07-01
Full Text Available We argue that a critical difference distinguishing machines from organisms and computers from brains is not complexity in a structural sense, but a difference in dynamical organization that is not well accounted for by current complexity measures. We propose a measure of the complexity of a system that is largely orthogonal to computational, information theoretic, or thermodynamic conceptions of structural complexity. What we call a system’s dynamical depth is a separate dimension of system complexity that measures the degree to which it exhibits discrete levels of nonlinear dynamical organization in which successive levels are distinguished by local entropy reduction and constraint generation. A system with greater dynamical depth than another consists of a greater number of such nested dynamical levels. Thus, a mechanical or linear thermodynamic system has less dynamical depth than an inorganic self-organized system, which has less dynamical depth than a living system. Including an assessment of dynamical depth can provide a more precise and systematic account of the fundamental difference between inorganic systems (low dynamical depth and living systems (high dynamical depth, irrespective of the number of their parts and the causal relations between them.
Complexity: The bigger picture
Vicsek, Tamás
2010-01-01
If a concept is not well defined, there are grounds for its abuse. This is particularly true of complexity, an inherently interdisciplinary concept that has penetrated very different fields of intellectual activity from physics to linguistics, but with no underlying, unified theory. Complexity has become a popular buzzword used in the hope of gaining attention or funding -- institutes and research networks associated with complex systems grow like mushrooms. Why and how did it happen that this vague notion has become a central motif in modern science? Is it only a fashion, a kind of sociological phenomenon, or is it a sign of a changing paradigm of our perception of the laws of nature and of the approaches required to understand them? Because virtually every real system is inherently extremely complicated, to say that a system is complex is almost an empty statement - couldn't an Institute of Complex Systems just as well be called an Institute for Almost Everything? Despite these valid concerns, the world is ...
Algorithmic Relative Complexity
Daniele Cerra
2011-04-01
Full Text Available Information content and compression are tightly related concepts that can be addressed through both classical and algorithmic information theories, on the basis of Shannon entropy and Kolmogorov complexity, respectively. The definition of several entities in Kolmogorov’s framework relies upon ideas from classical information theory, and these two approaches share many common traits. In this work, we expand the relations between these two frameworks by introducing algorithmic cross-complexity and relative complexity, counterparts of the cross-entropy and relative entropy (or Kullback-Leibler divergence found in Shannon’s framework. We define the cross-complexity of an object x with respect to another object y as the amount of computational resources needed to specify x in terms of y, and the complexity of x related to y as the compression power which is lost when adopting such a description for x, compared to the shortest representation of x. Properties of analogous quantities in classical information theory hold for these new concepts. As these notions are incomputable, a suitable approximation based upon data compression is derived to enable the application to real data, yielding a divergence measure applicable to any pair of strings. Example applications are outlined, involving authorship attribution and satellite image classification, as well as a comparison to similar established techniques.
Complexity of Economical Systems
G. P. Pavlos
2015-01-01
Full Text Available In this study new theoretical concepts are described concerning the interpretation of economical complex dynamics. In addition a summary of an extended algorithm of nonlinear time series analysis is provided which is applied not only in economical time series but also in other physical complex systems (e.g. [22, 24]. In general, Economy is a vast and complicated set of arrangements and actions wherein agents—consumers, firms, banks, investors, government agencies—buy and sell, speculate, trade, oversee, bring products into being, offer services, invest in companies, strategize, explore, forecast, compete, learn, innovate, and adapt. As a result the economic and financial variables such as foreign exchange rates, gross domestic product, interest rates, production, stock market prices and unemployment exhibit large-amplitude and aperiodic fluctuations evident in complex systems. Thus, the Economics can be considered as spatially distributed non-equilibrium complex system, for which new theoretical concepts, such as Tsallis non extensive statistical mechanics and strange dynamics, percolation, nonGaussian, multifractal and multiscale dynamics related to fractional Langevin equations can be used for modeling and understanding of the economical complexity locally or globally.
Projectively related complex Finsler metrics
Aldea, Nicoleta
2011-01-01
In this paper we introduce in study the projectively related complex Finsler metrics. We prove the complex versions of the Rapcs\\'{a}k's theorem and characterize the weakly K\\"{a}hler and generalized Berwald projectively related complex Finsler metrics. The complex version of Hilbert's Fourth Problem is also pointed out. As an application, the projectiveness of a complex Randers metric is described.
Emergy and ecosystem complexity
Ulgiati, Sergio; Brown, Mark T.
2009-01-01
The question "What drives complexity?" is addressed in this paper. To answer this question, we explore the way energy and material resources of different quality flow through ecosystems and support, directly and indirectly, ecosystems growth and development. Processes of resource transformation throughout the ecosystem build order, cycle materials, generate and sustain information. Energy drives all these processes and energetic principles explain much of what is observed, including energy degradation according to the laws of thermodynamics. Emergy, a quantitative measure of the global environmental work supporting ecosystem dynamics, is used here in order to provide a deeper understanding of complexity growth and decline in ecosystems. Ecosystem complexity is discussed in this paper in relation to changes in structure, organization and functional capacity, as explained by changes in emergy, empower, and transformity.
Introduction to Complex Plasmas
Bonitz, Michael; Ludwig, Patrick
2010-01-01
Complex plasmas differ from traditional plasmas in many ways: these are low-temperature high pressure systems containing nanometer to micrometer size particles which may be highly charged and strongly interacting. The particles may be chemically reacting or be in contact with solid surfaces, and the electrons may show quantum behaviour. These interesting properties have led to many applications of complex plasmas in technology, medicine and science. Yet complex plasmas are extremely complicated, both experimentally and theoretically, and require a variety of new approaches which go beyond standard plasma physics courses. This book fills this gap presenting an introduction to theory, experiment and computer simulation in this field. Based on tutorial lectures at a very successful recent Summer Institute, the presentation is ideally suited for graduate students, plasma physicists and experienced undergraduates.
Emergent Complex Network Geometry
Wu, Zhihao; Rahmede, Christoph; Bianconi, Ginestra
2014-01-01
Networks are mathematical structures that are universally used to describe a large variety of complex systems such as the brain or the Internet. Characterizing the geometrical properties of these networks has become increasingly relevant for routing problems, inference and data mining. In real growing networks, topological, structural and geometrical properties emerge spontaneously from their dynamical rules. Nevertheless we still miss a model in which networks develop an emergent complex geometry. Here we show that a single two parameter network model, the growing geometrical network, can generate complex network geometries with non-trivial distribution of curvatures, combining exponential growth and small-world properties with finite spectral dimensionality. In one limit, the non-equilibrium dynamical rules of these networks can generate scale-free networks with clustering and communities, in another limit planar random geometries with non-trivial modularity. Finally we find that these properties of the geo...
Boccara, Nino
2010-01-01
Modeling Complex Systems, 2nd Edition, explores the process of modeling complex systems, providing examples from such diverse fields as ecology, epidemiology, sociology, seismology, and economics. It illustrates how models of complex systems are built and provides indispensable mathematical tools for studying their dynamics. This vital introductory text is useful for advanced undergraduate students in various scientific disciplines, and serves as an important reference book for graduate students and young researchers. This enhanced second edition includes: . -recent research results and bibliographic references -extra footnotes which provide biographical information on cited scientists who have made significant contributions to the field -new and improved worked-out examples to aid a student’s comprehension of the content -exercises to challenge the reader and complement the material Nino Boccara is also the author of Essentials of Mathematica: With Applications to Mathematics and Physics (Springer, 2007).
Bender, Carl M.
1999-07-01
This talk proposes a generalization of conventional quantum mechanics. In conventional quantum mechanics one imposes the condition H †=H , where † represents complex conjugation and matrix transpose, to ensure that the Hamiltonian has a real spectrum. By replacing this mathematical condition with the weaker and more physical requirement H ‡=H , where ‡= PT represents combined parity reflection and time reversal, one obtains new infinite classes of complex Hamiltonians whose spectra are also real and positive. These PT-symmetric theories may be viewed as analytic continuations of conventional theories from real to complex-phase space. This talk describes the unusual classical and quantum properties of PT-symmetric quantum-mechanical and quantum-field-theoretic models.
Complex Polynomial Vector Fields
The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields....
2011-01-01
The domain of nonlinear dynamical systems and its mathematical underpinnings has been developing exponentially for a century, the last 35 years seeing an outpouring of new ideas and applications and a concomitant confluence with ideas of complex systems and their applications from irreversible thermodynamics. A few examples are in meteorology, ecological dynamics, and social and economic dynamics. These new ideas have profound implications for our understanding and practice in domains involving complexity, predictability and determinism, equilibrium, control, planning, individuality, responsibility and so on. Our intention is to draw together in this volume, we believe for the first time, a comprehensive picture of the manifold philosophically interesting impacts of recent developments in understanding nonlinear systems and the unique aspects of their complexity. The book will focus specifically on the philosophical concepts, principles, judgments and problems distinctly raised by work in the domain of comple...
Viral quasispecies complexity measures.
Gregori, Josep; Perales, Celia; Rodriguez-Frias, Francisco; Esteban, Juan I; Quer, Josep; Domingo, Esteban
2016-06-01
Mutant spectrum dynamics (changes in the related mutants that compose viral populations) has a decisive impact on virus behavior. The several platforms of next generation sequencing (NGS) to study viral quasispecies offer a magnifying glass to study viral quasispecies complexity. Several parameters are available to quantify the complexity of mutant spectra, but they have limitations. Here we critically evaluate the information provided by several population diversity indices, and we propose the introduction of some new ones used in ecology. In particular we make a distinction between incidence, abundance and function measures of viral quasispecies composition. We suggest a multidimensional approach (complementary information contributed by adequately chosen indices), propose some guidelines, and illustrate the use of indices with a simple example. We apply the indices to three clinical samples of hepatitis C virus that display different population heterogeneity. Areas of virus biology in which population complexity plays a role are discussed.
Oleg Svatos
2013-01-01
Full Text Available In this paper we analyze complexity of time limits we can find especially in regulated processes of public administration. First we review the most popular process modeling languages. There is defined an example scenario based on the current Czech legislature which is then captured in discussed process modeling languages. Analysis shows that the contemporary process modeling languages support capturing of the time limit only partially. This causes troubles to analysts and unnecessary complexity of the models. Upon unsatisfying results of the contemporary process modeling languages we analyze the complexity of the time limits in greater detail and outline lifecycles of a time limit using the multiple dynamic generalizations pattern. As an alternative to the popular process modeling languages there is presented PSD process modeling language, which supports the defined lifecycles of a time limit natively and therefore allows keeping the models simple and easy to understand.
Nonergodic complexity management
Piccinini, Nicola; Lambert, David; West, Bruce J.; Bologna, Mauro; Grigolini, Paolo
2016-06-01
Linear response theory, the backbone of nonequilibrium statistical physics, has recently been extended to explain how and why nonergodic renewal processes are insensitive to simple perturbations, such as in habituation. It was established that a permanent correlation results between an external stimulus and the response of a complex system generating nonergodic renewal processes, when the stimulus is a similar nonergodic process. This is the principle of complexity management, whose proof relies on ensemble distribution functions. Herein we extend the proof to the nonergodic case using time averages and a single time series, hence making it usable in real life situations where ensemble averages cannot be performed because of the very nature of the complex systems being studied.
Synchronization in complex networks
Arenas, A.; Diaz-Guilera, A.; Moreno, Y.; Zhou, C.; Kurths, J.
2007-12-12
Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.
Management of complex fisheries
Frost, Hans Staby; Andersen, Peder; Hoff, Ayoe
2013-01-01
The purpose of this paper is to demonstrate how fisheries economics management issues or problems can be analyzed by using a complex model based on conventional bioeconomic theory. Complex simulation models contain a number of details that make them suitable for practical management advice......, including taking into account the response of the fishermen to implemented management measures. To demonstrate the use of complex management models this paper assesses a number of second best management schemes against a first rank optimum (FRO), an ideal individual transferable quotas (ITQ) system....... This is defined as the management scheme which produces the highest net present value over a 25 year period. The assessed management schemes (scenarios) are composed by several measures as used in the Common Fisheries Policy of the European Union for the cod fishery in the Baltic Sea. The scenarios are total...
Dettman, John W
1965-01-01
Analytic function theory is a traditional subject going back to Cauchy and Riemann in the 19th century. Once the exclusive province of advanced mathematics students, its applications have proven vital to today's physicists and engineers. In this highly regarded work, Professor John W. Dettman offers a clear, well-organized overview of the subject and various applications - making the often-perplexing study of analytic functions of complex variables more accessible to a wider audience. The first half of Applied Complex Variables, designed for sequential study, is a step-by-step treatment of fun
Complex HVPT and hyperasymptotics
Killingbeck, John P [Mathematics Department, University of Hull, Hull HU6 7RX (United Kingdom); Grosjean, Alain [Laboratoire d' Astrophysique de l' Observatoire de Besancon(CNRS, UMR 6091), 41 bis Avenue de l' Observatoire, BP 1615, 25010 Besancon Cedex (France); Jolicard, Georges [Laboratoire d' Astrophysique de l' Observatoire de Besancon(CNRS, UMR 6091), 41 bis Avenue de l' Observatoire, BP 1615, 25010 Besancon Cedex (France)
2006-08-25
Complex hypervirial perturbation theory (HVPT) is applied to the problem of a harmonic oscillator with a perturbation gx{sup 3}exp(i{psi}), for which the traditional Rayleigh-Schodinger perturbation theory has to be supplemented by hyperasymptotics for obtaining accurate resonance energies in the negative {psi} region. Complex HVPT gives accurate results for positive {psi} and for negative {psi} up to about vertical bar {phi} vertical bar = {pi}/24. The case of a quartic perturbed oscillator is also treated. (letter to the editor)
Introduction to complex analysis
Priestley, H A
2003-01-01
Complex analysis is a classic and central area of mathematics, which is studied and exploited in a range of important fields, from number theory to engineering. Introduction to Complex Analysis was first published in 1985, and for this much awaited second edition the text has been considerably expanded, while retaining the style of the original. More detailed presentation is given of elementary topics, to reflect the knowledge base of current students. Exercise sets have beensubstantially revised and enlarged, with carefully graded exercises at the end of each chapter.This is the latest additi
Dahlberg, Rasmus
2015-01-01
This paper explores two key concepts: resilience and complexity. The first is understood as an emergent property of the latter, and their inter-relatedness is discussed using a three tier approach. First, by exploring the discourse of each concept, next, by analyzing underlying relationships and...... robust. Robustness is a property of simple or complicated systems characterized by predictable behavior, enabling the system to bounce back to its normal state following a perturbation. Resilience, however, is an emergent property of complex adaptive systems. It is suggested that this distinction...
Chuang, Wu-yen; Kachru, Shamit; /Stanford U., ITP /SLAC; Tomasiello, Alessandro; /Stanford U., ITP
2005-10-28
We construct a class of symplectic non-Kaehler and complex non-Kaehler string theory vacua, extending and providing evidence for an earlier suggestion by Polchinski and Strominger. The class admits a mirror pairing by construction. Comparing hints from a variety of sources, including ten-dimensional supergravity and KK reduction on SU(3)-structure manifolds, suggests a picture in which string theory extends Reid's fantasy to connect classes of both complex non-Kaehler and symplectic non-Kaehler manifolds.
Sarason, Donald
2007-01-01
Complex Function Theory is a concise and rigorous introduction to the theory of functions of a complex variable. Written in a classical style, it is in the spirit of the books by Ahlfors and by Saks and Zygmund. Being designed for a one-semester course, it is much shorter than many of the standard texts. Sarason covers the basic material through Cauchy's theorem and applications, plus the Riemann mapping theorem. It is suitable for either an introductory graduate course or an undergraduate course for students with adequate preparation. The first edition was published with the title Notes on Co
Jacobians with complex multiplication
Carocca, Angel; Rodriguez, Rubi E
2009-01-01
We construct and study two series of curves whose Jacobians admit complex multiplication. The curves arise as quotients of Galois coverings of the projective line with Galois group metacyclic groups $G_{q,3}$ of order $3q$ with $q \\equiv 1 \\mod 3$ an odd prime, and $G_m$ of order $2^{m+1}$. The complex multiplications arise as quotients of double coset algebras of the Galois groups of these coverings. We work out the CM-types and show that the Jacobians are simple abelian varieties.
Brown, Adam R; Susskind, Leonard; Swingle, Brian; Zhao, Ying
2015-01-01
We conjecture that the quantum complexity of a holographic state is dual to the action of a certain spacetime region that we call a Wheeler-DeWitt patch. We illustrate and test the conjecture in the context of neutral, charged, and rotating black holes in AdS, as well as black holes perturbed with static shells and with shock waves. This conjecture evolved from a previous conjecture that complexity is dual to spatial volume, but appears to be a major improvement over the original. In light of our results, we discuss the hypothesis that black holes are the fastest computers in nature.
Complex variables II essentials
Solomon, Alan D
2013-01-01
REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Complex Variables II includes elementary mappings and Mobius transformation, mappings by general functions, conformal mappings and harmonic functions, applying complex functions to a
DiMario, Francis J; Sahin, Mustafa; Ebrahimi-Fakhari, Darius
2015-06-01
Tuberous sclerosis complex is an autosomal-dominant, neurocutaneous, multisystem disorder characterized by cellular hyperplasia and tissue dysplasia. The genetic cause is mutations in the TSC1 gene, found on chromosome 9q34, and TSC2 gene, found on chromosome 16p13. The clinical phenotypes resulting from mutations in either of the 2 genes are variable in each individual. Herein, advances in the understanding of molecular mechanisms in tuberous sclerosis complex are reviewed, and current guidelines for diagnosis, treatment, follow-up, and management are summarized.
Brown, T.W.
2010-11-15
The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)
Nonlinear dynamics and complexity
Luo, Albert; Fu, Xilin
2014-01-01
This important collection presents recent advances in nonlinear dynamics including analytical solutions, chaos in Hamiltonian systems, time-delay, uncertainty, and bio-network dynamics. Nonlinear Dynamics and Complexity equips readers to appreciate this increasingly main-stream approach to understanding complex phenomena in nonlinear systems as they are examined in a broad array of disciplines. The book facilitates a better understanding of the mechanisms and phenomena in nonlinear dynamics and develops the corresponding mathematical theory to apply nonlinear design to practical engineering.
Luminescent macrocyclic lanthanide complexes
Raymond, Kenneth N [Berkeley, CA; Corneillie, Todd M [Campbell, CA; Xu, Jide [Berkeley, CA
2012-05-08
The present invention provides a novel class of macrocyclic compounds as well as complexes formed between a metal (e.g., lanthanide) ion and the compounds of the invention. Preferred complexes exhibit high stability as well as high quantum yields of lanthanide ion luminescence in aqueous media without the need for secondary activating agents. Preferred compounds incorporate hydroxy-isophthalamide moieties within their macrocyclic structure and are characterized by surprisingly low, non-specific binding to a variety of polypeptides such as antibodies and proteins as well as high kinetic stability. These characteristics distinguish them from known, open-structured ligands.
Theories of computational complexity
Calude, C
1988-01-01
This volume presents four machine-independent theories of computational complexity, which have been chosen for their intrinsic importance and practical relevance. The book includes a wealth of results - classical, recent, and others which have not been published before.In developing the mathematics underlying the size, dynamic and structural complexity measures, various connections with mathematical logic, constructive topology, probability and programming theories are established. The facts are presented in detail. Extensive examples are provided, to help clarify notions and constructions. The lists of exercises and problems include routine exercises, interesting results, as well as some open problems.
Complex logistics audit system
Zuzana Marková
2010-02-01
Full Text Available Complex logistics audit system is a tool for realization of logistical audit in the company. The current methods for logistics auditare based on “ad hok” analysis of logisticsl system. This paper describes system for complex logistics audit. It is a global diagnosticsof logistics processes and functions of enterprise. The goal of logistics audit is to provide comparative documentation for managementabout state of logistics in company and to show the potential of logistics changes in order to achieve more effective companyperformance.
Salen complexes with dianionic counterions
Job, Gabriel E.; Farmer, Jay J.; Cherian, Anna E.
2016-08-02
The present invention describes metal salen complexes having dianionic counterions. Such complexes can be readily precipitated and provide an economical method for the purification and isolation of the complexes, and are useful to prepare novel polymer compositions.
Jackson, Kara J.; Shahan, Emily C.; Gibbons, Lynsey K.; Cobb, Paul A.
2012-01-01
Mathematics lessons can take a variety of formats. In this article, the authors discuss lessons organized around complex mathematical tasks. These lessons usually unfold in three phases. First, the task is introduced to students. Second, students work on solving the task. Third, the teacher "orchestrates" a concluding whole-class discussion in…
Prediction of Biomolecular Complexes
Vangone, Anna
2017-04-12
Almost all processes in living organisms occur through specific interactions between biomolecules. Any dysfunction of those interactions can lead to pathological events. Understanding such interactions is therefore a crucial step in the investigation of biological systems and a starting point for drug design. In recent years, experimental studies have been devoted to unravel the principles of biomolecular interactions; however, due to experimental difficulties in solving the three-dimensional (3D) structure of biomolecular complexes, the number of available, high-resolution experimental 3D structures does not fulfill the current needs. Therefore, complementary computational approaches to model such interactions are necessary to assist experimentalists since a full understanding of how biomolecules interact (and consequently how they perform their function) only comes from 3D structures which provide crucial atomic details about binding and recognition processes. In this chapter we review approaches to predict biomolecular complexesBiomolecular complexes, introducing the concept of molecular dockingDocking, a technique which uses a combination of geometric, steric and energetics considerations to predict the 3D structure of a biological complex starting from the individual structures of its constituent parts. We provide a mini-guide about docking concepts, its potential and challenges, along with post-docking analysis and a list of related software.
Debating complexity in modeling
Hunt, Randall J.; Zheng, Chunmiao
1999-01-01
Complexity in modeling would seem to be an issue of universal importance throughout the geosciences, perhaps throughout all science, if the debate last year among groundwater modelers is any indication. During the discussion the following questions and observations made up the heart of the debate.
Statistical electromagnetics: Complex cavities
Naus, H.W.L.
2008-01-01
A selection of the literature on the statistical description of electromagnetic fields and complex cavities is concisely reviewed. Some essential concepts, for example, the application of the central limit theorem and the maximum entropy principle, are scrutinized. Implicit assumptions, biased choic
Brun, Guillaume
The Optical Complex Systems are more and more in the heart of various systems that industrial applications bring to everyday life. From environment up to spatial applications, OCS is also relevant in monitoring, transportation, robotics, life sciences, sub-marine, and even for agricultural purposes.
贾燕梅
2007-01-01
Being as one figurative form of language, metaphor plays the most complicated role to make language colorful and vivid.Demonstrating the types and the features of metaphor, this article will focus on the point that metaphor is a complex language phenomenon heavily loaded with the factor of culture.
Christiane Lefèvre
2008-01-01
The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.
Rosendahl, Mads
1989-01-01
One way to analyse programs is to to derive expressions for their computational behaviour. A time bound function (or worst-case complexity) gives an upper bound for the computation time as a function of the size of input. We describe a system to derive such time bounds automatically using abstrac...
2012-01-01
fundamental challenge for the millennial genera- tion. Complexity, it appears, is all the rage. We challenge these declarations and assumptions—not...arrested as a Soviet spy. • On 14 February 1950, the Soviets signed a Treaty of Friendship , Alliance and Mutual Assistance with the Chinese government
Edna Lemes Martins Pereira
2013-12-01
Full Text Available Economic globalization affects different countries on the globe, has positive effects mainly related to access to communication, which promotes the exchange of ideas, information, products and quality of life. However, extends numerous negative aspects such as marginalization, economic dependencies, political, cultural, scientific, educational accentuate social inequalities and cultural conflicts and territorial. In this article it is a dialogue with authors (Cunha 2009; BARNETT 2005; MORIN 1999, 2006, among others, who understand these changes in society from the contemporary world as conceived as the "Complexity era" or "supercomplexity". To understand and cope with this reality, they propose a paradigm that is able to overcome the fragmentation and reductionism of knowledge and to relate the multiple approaches and visions to meet the complexity of reality. Although this paper presents proposals to the aforementioned authors point to education and the university found in this tangle of interconnected global transformations, given the need to be subject to act in a complex reality that requires critical and self-critical professionals, able to think about their own ability to think, understand and act within this complex context.
De Melis, Cinzia
2016-01-01
The LHC is the last ring (dark blue line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.
Fratalocchi, Andrea
2014-12-01
Disorder and chaos are ubiquitous phenomena that are mostly unwanted in applications. On the contrary, they can be exploited to create a new technology. In this talk I will summarize my research in this field, discussing chaotic energy harvesting, nonlinear stochastic resonance and complex nanolasers.
Complex Digital Visual Systems
Sweeny, Robert W.
2013-01-01
This article identifies possibilities for data visualization as art educational research practice. The author presents an analysis of the relationship between works of art and digital visual culture, employing aspects of network analysis drawn from the work of Barabási, Newman, and Watts (2006) and Castells (1994). Describing complex network…
Transformations, Dynamics and Complexity
Glazunov, Nikolaj
2011-01-01
We review and investigate some new problems and results in the field of dynamical systems generated by iteration of maps, {\\beta}-transformations, partitions, group actions, bundle dynamical systems, Hasse-Kloosterman maps, and some aspects of complexity of the systems.
of complex formation of Group(lV) metal halides with .... significant of these extra bands are a second (C1-N) stretching (17) and a second. (C-=8) band (6). However ... Lower electron density on the tin atom (and thus greater contribution of the ...
Whitby, R. L. D.; Hsu, W. K.; Lee, T. H.; Boothroyd, C. B.; Kroto, H. W.; Walton, D. R. M.
2002-06-01
A range of elegant tubular and conical nanostructures has been created by template growth of (WS 2) n layers on the surfaces of single-walled carbon nanotube bundles. The structures exhibit remarkably perfect straight segments together with interesting complexities at the intersections, which are discussed here in detail in order to enhance understanding of the structural features governing tube growth.
Haffner, Julie
2013-01-01
The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.
Psychopathology and complexity
Leonardo Y. Álvarez R
2010-08-01
Full Text Available The paradigm of complexity states that reality conveys a chaotic dynamics, ambiguous, blurred, and paradoxical, and that it does not fulfill the values of order, harmony nor perfection. However, such a chaos represents a specific way of organization and order. Human behavior explained by this paradigm vindicates on this way the outstanding role of contradiction and irregularity aside of what is linear and predictable. The purpose of this review has the primary aim to describe some concepts and assumptions that give support to the approach to complexity in behavior, especially concerning the psychopathological behavior of an individual. Some comparisons with concepts associated to complexity in scientific approaches to psychology (contextual and paradigmatical behaviorism and interbehaviorism from its own persepctive are stablished. All these elements are developed underlining the concepts of reciprocal multicausality, complex and hierarchical learning, historical and contextual factors in the comprehension of behavior, and trying to make some extrapolations on the psychopathological behavior. This approach is hence considered appropriate and necessary to understand gnosiological entities and to intervene them in their role of clinical challenges.
Hamann, S; Zeuthen, T; La Cour, M
1998-01-01
Multiple physiological fluid movements are involved in vision. Here we define the cellular and subcellular sites of aquaporin (AQP) water transport proteins in human and rat eyes by immunoblotting, high-resolution immunocytochemistry, and immunoelectron microscopy. AQP3 is abundant in bulbar conj......, predicting specific roles for each in the complex network through which water movements occur in the eye....
Complex Interfaces Under Change
Rosbjerg, Dan
and mechanical processes that develop within this structure. Water-related processes at the interfaces between the compartments are complex, depending both on the interface itself, and on the characteristics of the interfaced compartments. Various aspects of global change directly or indirectly impact...
Complex Digital Visual Systems
Sweeny, Robert W.
2013-01-01
This article identifies possibilities for data visualization as art educational research practice. The author presents an analysis of the relationship between works of art and digital visual culture, employing aspects of network analysis drawn from the work of Barabási, Newman, and Watts (2006) and Castells (1994). Describing complex network…
Mobs, Esma Anais
2016-01-01
The LHC is the last ring (dark blue line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.
1981-05-01
try todefine a complex planar spline by holomorphic elements like polynomials, then by the well known identity theorem (e.g. Diederich- Remmert [9, p...R. Remmert : Funktionentheorie I, Springer, Berlin, Heidelberg, New York, 1972, 246 p. 10 0. Lehto - K.I. Virtanen: Quasikonforme AbbildunQen, Springer
Nashed, Gamal G.L. [Ain Shams University, Cairo (Egypt). Faculty of Science. Mathematics Dept.
2010-09-15
We show that the definition of the energy-momentum complex given by Moeller using Weitzenboeck spacetime in the calculations of gravitational energy gives results which are different from those obtained from other definitions given in the framework of general relativity. (author)
Tevatron's complex collider cousins
Fischer, W
2004-01-01
Letter referring to Schwarzschild's story "Disappointing performance and tight budgets confront Fermilab with tough decisions" and contesting that the Tevatron is not the most complex accelerator operating. They use the examples of CERN's SPS collider, HERA at DESY and the RHIC at Brookhaven (1/4 page)
Schuurmans, F.J.P.
1999-01-01
In this thesis the properties of light in complex dielectrics are described, with the two general topics of "modification of spontaneous emission" and "Anderson localization of light". The first part focuses on the spontaneous emission rate of an excited atom in a dielectric host with variable refra
Electromeric rhodium radical complexes
Puschmann, F.F.; Harmer, J.; Stein, D.; Rüegger, H.; de Bruin, B.; Grützmacher, H.
2010-01-01
Radical changes: One single P-Rh-P angle determines whether the odd electron in the paramagnetic complex [Rh(trop2PPh)(PPh3)] is delocalized over the whole molecule (see picture, blue) or is localized on the P—Rh unit (red). The two energetically almost degenerate electromers exist in a fast equilib
Angel Garrido
2011-01-01
Full Text Available In this paper, we analyze a few interrelated concepts about graphs, such as their degree, entropy, or their symmetry/asymmetry levels. These concepts prove useful in the study of different types of Systems, and particularly, in the analysis of Complex Networks. A System can be defined as any set of components functioning together as a whole. A systemic point of view allows us to isolate a part of the world, and so, we can focus on those aspects that interact more closely than others. Network Science analyzes the interconnections among diverse networks from different domains: physics, engineering, biology, semantics, and so on. Current developments in the quantitative analysis of Complex Networks, based on graph theory, have been rapidly translated to studies of brain network organization. The brain's systems have complex network features—such as the small-world topology, highly connected hubs and modularity. These networks are not random. The topology of many different networks shows striking similarities, such as the scale-free structure, with the degree distribution following a Power Law. How can very different systems have the same underlying topological features? Modeling and characterizing these networks, looking for their governing laws, are the current lines of research. So, we will dedicate this Special Issue paper to show measures of symmetry in Complex Networks, and highlight their close relation with measures of information and entropy.
O. Yusupova
2015-10-01
Full Text Available Complex promotions used by retailers introduce to the consumers several rules that must be satisfied in order to get some benefits and usually refer to multiple products (e.g. “buy two, get one free”. Rules of complex promotions can be quite sophisticated and complicated themselves. Since diversity of complex promotions limited only by marketers’ imagination we can observe broad variety of promotions’ rules and representa¬tions of those rules in retailers’ commercials. Such diversification makes no good for fellow scientist who’s trying to sort all type of promotions into the neatly organized classification. Although we can simple add every single set of rules offered by retailers as a separate form of sales promotion it seems not to be the best way of dealing with such a problem. The better way is to realize that mechanisms underlying that variety of promotions are basically the same, namely changes in demand or quantity demanded. Those two concepts alone provide powerful insight into classification of complex promotions and allow us to comprehend the variety of promotions offered by marketers nowadays.
The Colletotrichum acutatum complex
Damm, U.; Cannon, P.F.; Woudenberg, J.H.C.; Crous, P.W.
2012-01-01
Colletotrichum acutatum is known as an important anthracnose pathogen of a wide range of host plants worldwide. Numerous studies have reported subgroups within the C. acutatum species complex. Multilocus molecular phylogenetic analysis (ITS, ACT, TUB2, CHS-1, GAPDH, HIS3) of 331 strains previously
Managing Complex Dynamical Systems
Cox, John C.; Webster, Robert L.; Curry, Jeanie A.; Hammond, Kevin L.
2011-01-01
Management commonly engages in a variety of research designed to provide insight into the motivation and relationships of individuals, departments, organizations, etc. This paper demonstrates how the application of concepts associated with the analysis of complex systems applied to such data sets can yield enhanced insights for managerial action.
Complexity in Managing Modularization
Hansen, Poul H. Kyvsgård; Sun, Hongyi
2011-01-01
In general, the phenomenon of managing modularization is not well known. The cause-effect relationships between modularization and realized benefits are complex and comprehensive. Though a number of research works have contributed to the study of the phenomenon of efficient and effective modulari......In general, the phenomenon of managing modularization is not well known. The cause-effect relationships between modularization and realized benefits are complex and comprehensive. Though a number of research works have contributed to the study of the phenomenon of efficient and effective...... modularization management it is far from clarified. Recognizing the need for further empirical research, we have studied 40 modularity cases in various companies. The studies have been designed as long-term studies leaving time for various types of modularization benefits to emerge. Based on these studies we...... have developed a framework to support the heuristic and iterative process of planning and realizing modularization benefits....
Sensitivity of Complex Networks
Angulo, Marco Tulio; Liu, Yang-Yu; Barabási, Albert-László
2016-01-01
The sensitivity (i.e. dynamic response) of complex networked systems has not been well understood, making difficult to predict whether new macroscopic dynamic behavior will emerge even if we know exactly how individual nodes behave and how they are coupled. Here we build a framework to quantify the sensitivity of complex networked system of coupled dynamic units. We characterize necessary and sufficient conditions for the emergence of new macroscopic dynamic behavior in the thermodynamic limit. We prove that these conditions are satisfied only for architectures with power-law degree distributions. Surprisingly, we find that highly connected nodes (i.e. hubs) only dominate the sensitivity of the network up to certain critical frequency.
Anna Miles PhD
2016-08-01
Full Text Available Objective: Where swallowing difficulties are chronic or progressive, or a patient is palliative, tube feeding is often not deemed appropriate. Instead, patients continue to eat and drink despite the risks of pneumonia and death. There is currently little evidence to guide clinical practice in this field often termed “risk feeding.” This qualitative study investigated staff, patient, and family member perceptions of risk feeding practices in one New Zealand hospital. Method: Twenty-nine staff members and six patients and/or their family were interviewed. Results: Thematic analysis revealed four global themes: supporting practice, communication, complexity of feeding decisions, and patient and family-centered care. Staff described limited education and organizational policy around risk feeding decisions. Communication was considered a major factor in the success. Conclusion: Feeding decisions are complex in the hospital environment. The themes identified in this study provide a foundation for hospital guideline development and implementation.
Complex Polynomial Vector Fields
Dias, Kealey
or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields....
Hazelett, Dennis J.; Conti, David V.; Han, Ying; Al Olama, Ali Amin; Easton, Doug; Eeles, Rosalind A.; Kote-Jarai, Zsofia; Haiman, Christopher A.; Coetzee, Gerhard A.
2016-01-01
ABSTRACT Genome-wide association studies (GWAS) have revealed numerous genomic 'hits' associated with complex phenotypes. In most cases these hits, along with surrogate genetic variation as measure by numerous single nucleotide polymorphisms (SNPs) that are in linkage disequilibrium, are not in coding genes making assignment of functionality or causality intractable. Here we propose that fine-mapping along with the matching of risk SNPs at chromatin biofeatures lessen this complexity by reducing the number of candidate functional/causal SNPs. For example, we show here that only on average 2 SNPs per prostate cancer risk locus are likely candidates for functionality/causality; we further propose that this manageable number should be taken forward in mechanistic studies. The candidate SNPs can be looked up for each prostate cancer risk region in 2 recent publications in 20151,2 from our groups. PMID:26771711
Polystochastic Models for Complexity
Iordache, Octavian
2010-01-01
This book is devoted to complexity understanding and management, considered as the main source of efficiency and prosperity for the next decades. Divided into six chapters, the book begins with a presentation of basic concepts as complexity, emergence and closure. The second chapter looks to methods and introduces polystochastic models, the wave equation, possibilities and entropy. The third chapter focusing on physical and chemical systems analyzes flow-sheet synthesis, cyclic operations of separation, drug delivery systems and entropy production. Biomimetic systems represent the main objective of the fourth chapter. Case studies refer to bio-inspired calculation methods, to the role of artificial genetic codes, neural networks and neural codes for evolutionary calculus and for evolvable circuits as biomimetic devices. The fifth chapter, taking its inspiration from systems sciences and cognitive sciences looks to engineering design, case base reasoning methods, failure analysis, and multi-agent manufacturing...
Stable generalized complex structures
Cavalcanti, Gil R
2015-01-01
A stable generalized complex structure is one that is generically symplectic but degenerates along a real codimension two submanifold, where it defines a generalized Calabi-Yau structure. We introduce a Lie algebroid which allows us to view such structures as symplectic forms. This allows us to construct new examples of stable structures, and also to define period maps for their deformations in which the background three-form flux is either fixed or not, proving the unobstructedness of both deformation problems. We then use the same tools to establish local normal forms for the degeneracy locus and for Lagrangian branes. Applying our normal forms to the four-dimensional case, we prove that any compact stable generalized complex 4-manifold has a symplectic completion, in the sense that it can be modified near its degeneracy locus to produce a compact symplectic 4-manifold.
Complexes Tickling the $ubject
Matthew Gildersleeve
2016-11-01
Full Text Available This article continues my earlier work of reading Jung with Lacan. This article will develop Zizek’s work on Lacan’s concept of objet petit a by relating it to a phenomenological interpretation of Jung. I use a number of different examples, including Zizek’s interpretation of Francis Bacon, Edvard Munch, Hans Holbein and Johann Gottlieb Fichte, to describe the objet petit a and its relationship to a phenomenological interpretation of complexes. By integrating other Lacanian concepts, such as subject, drive, fantasy, jouissance, gaze, desire, and ego as well as the imaginary, symbolic and Real, this work also highlights how Hegel and Heidegger can elucidate the relationship between objet petit a and complexes. Jung’s transcendent function and the Rosarium Philosophorum also elucidate the relationship between Jung and Lacan.
Dahlberg, Rasmus
2015-01-01
This paper explores two key concepts: resilience and complexity. The first is understood as an emergent property of the latter, and their inter-relatedness is discussed using a three tier approach. First, by exploring the discourse of each concept, next, by analyzing underlying relationships and......, finally, by presenting the Cynefin Framework for Sense-Making as a tool of explicatory potential that has already shown its usefulness in several contexts. I further emphasize linking the two concepts into a common and, hopefully, useful concept. Furthermore, I argue that a resilient system is not merely...... robust. Robustness is a property of simple or complicated systems characterized by predictable behavior, enabling the system to bounce back to its normal state following a perturbation. Resilience, however, is an emergent property of complex adaptive systems. It is suggested that this distinction...
Complex Polynomial Vector Fields
Dias, Kealey
The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...... or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...
Sporadic meteoroid complex: Modeling
Andreev, V.
2014-07-01
The distribution of the sporadic meteoroids flux density over the celestial sphere is the common form of representation of the meteoroids distribution in the vicinity of the Earth's orbit. The determination of the flux density of sporadic meteor bodies is Q(V,e,f) = Q_0 P_e(V) P(e,f) where V is the meteoroid velocity, e,f are the radiant coordinates, Q_0 is the meteoroid flux over whole celestial sphere, P_e(V) is the conditional velocity distributions and P(e,f) is the radiant distribution over the celestial sphere. The sporadic meteoroid complex model is analytical and based on heliocentric velocities and radiant distributions. The multi-mode character of the heliocentric velocity and radiant distributions follows from the analysis of meteor observational data. This fact points to a complicated structure of the sporadic meteoroid complex. It is the consequence of the plurality of the parent bodies and the origin mechanisms of the meteoroids. The meteoroid complex was divided into four groups for that reason and with a goal of more accurate modelling of velocities and radiant distributions. As the classifying parameter to determine the meteoroid membership in any group, we adopt the Tisserand invariant relative to Jupiter T_J = 1/a + 2 A_J^{-3/2} √{a (1 - e^2)} cos i and the meteoroid orbit inclination i. Two meteoroid groups relate to long-period and short-period comets. One meteoroid group is related to asteroids. The relationship to the last, fourth group is a problematic one. Then, we construct models of radiant and velocity distributions for each group. The analytical model for the whole sporadic meteoroid complex is the sum of the ones for each group.
Poenaru, D N; Greiner, W
2005-01-01
Complex fission phenomena can be studied in a unified way. Very general reflection asymmetrical equilibrium (saddle-point) nuclear shapes, may be obtained by solving an integro-differential equation without being necessary to specify a certain parametrization. The mass asymmetry in cold fission phenomena can be explained as the result of adding a phenomenological shell correction to the liquid drop model deformation energy. Applications to binary, ternary, and quaternary fission are outlined. Predictions of two alpha accompanied fission are experimentally confirmed.
Poenaru, D. N.; Gherghescu, R. A.; Greiner, W.
2005-01-01
Complex fission phenomena are studied in a unified way. Very general reflection asymmetrical equilibrium (saddle point) nuclear shapes are obtained by solving an integro-differential equation without being necessary to specify a certain parametrization. The mass asymmetry in binary cold fission of Th and U isotopes is explained as the result of adding a phenomenological shell correction to the liquid drop model deformation energy. Applications to binary, ternary, and quaternary fission are outlined.
Complex and Fractional Dynamics
J. A. Tenreiro Machado
2017-02-01
Full Text Available Complex systems (CS are pervasive in many areas, namely financial markets; highway transportation; telecommunication networks; world and country economies; social networks; immunological systems; living organisms; computational systems; and electrical and mechanical structures. CS are often composed of a large number of interconnected and interacting entities exhibiting much richer global scale dynamics than could be inferred from the properties and behavior of individual elements. [...
2016-01-01
We propose an entropy function for simplicial complices. Its value gives the expected cost of the optimal encoding of sequences of vertices of the complex, when any two vertices belonging to the same simplex are indistinguishable. We show that the proposed entropy function can be computed efficiently. By computing the entropy of several complices consisting of hundreds of simplices, we show that the proposed entropy function can be used in the analysis of the large sequences of simplicial com...
Nakatoh, Tetsuya; Omori, Keisuke; Yamada, Yasuhiro; Hirokawa, Sachio
2003-01-01
We are developing a search system DAISEn which integrates multiple search engines and generates a metasearch engine automatically. The target search engines of DAISEn are not general search engines, but are search engines specialized in some area. Integration of such engines yields efficiency and quality. There are search engines of new type which accept complex query and return structured data. Integration of such search engines is much harder than that of simple search engines which accept ...
Arithmetic of Complex Manifolds
Lange, Herbert
1989-01-01
It was the aim of the Erlangen meeting in May 1988 to bring together number theoretists and algebraic geometers to discuss problems of common interest, such as moduli problems, complex tori, integral points, rationality questions, automorphic forms. In recent years such problems, which are simultaneously of arithmetic and geometric interest, have become increasingly important. This proceedings volume contains 12 original research papers. Its main topics are theta functions, modular forms, abelian varieties and algebraic three-folds.
Ekman, Ulrik
2015-01-01
This brief article presents the everyday cultural use of the Snapchat instant messaging application for video chats as an exemplary case of the challenges confronting studies of cinematics in an epoch marked by the rise in network societies of ubiquitous mobile and social media and technics....... It proffers and begins to detail the argument that snap video chats cannot be denigrated as mere ‘shorts’ but must be approached as spatiotemporally and experientally complex....
Complexity in Dynamical Systems
Moore, Cristopher David
The study of chaos has shown us that deterministic systems can have a kind of unpredictability, based on a limited knowledge of their initial conditions; after a finite time, the motion appears essentially random. This observation has inspired a general interest in the subject of unpredictability, and more generally, complexity; how can we characterize how "complex" a dynamical system is?. In this thesis, we attempt to answer this question with a paradigm of complexity that comes from computer science, we extract sets of symbol sequences, or languages, from a dynamical system using standard methods of symbolic dynamics; we then ask what kinds of grammars or automata are needed a generate these languages. This places them in the Chomsky heirarchy, which in turn tells us something about how subtle and complex the dynamical system's behavior is. This gives us insight into the question of unpredictability, since these automata can also be thought of as computers attempting to predict the system. In the culmination of the thesis, we find a class of smooth, two-dimensional maps which are equivalent to the highest class in the Chomsky heirarchy, the turning machine; they are capable of universal computation. Therefore, these systems possess a kind of unpredictability qualitatively different from the usual "chaos": even if the initial conditions are known exactly, questions about the system's long-term dynamics are undecidable. No algorithm exists to answer them. Although this kind of unpredictability has been discussed in the context of distributed, many-degree-of -freedom systems (for instance, cellular automata) we believe this is the first example of such phenomena in a smooth, finite-degree-of-freedom system.
The Complex Information Process
Edwina Taborsky
2000-07-01
Full Text Available Abstract: This paper examines the semiosic development of energy to information within a dyadic reality that operates within the contradictions of both classical and quantum physics. These two realities are examined within the three Peircean modal categories of Firstness, Secondness and Thirdness. The paper concludes that our world cannot operate within either of the two physical realities but instead filiates the two to permit a semiosis or information-generation of complex systems.
The Complex Information Process
Taborsky, Edwina
2000-09-01
This paper examines the semiosic development of energy to information within a dyadic reality that operates within the contradictions of both classical and quantum physics. These two realities are examined within the three Peircean modal categories of Firstness, Secondness and Thirdness. The paper concludes that our world cannot operate within either of the two physical realities but instead filiates the two to permit a semiosis or information-generation of complex systems.
Mangiarotti, G; Cesano, G; Thea, A; Hamido, D; Pacitti, A; Segoloni, G P
1998-03-01
Availability of a proper vascular access is a basic condition for a proper extracorporeal replacement in end-stage chronic renal failure. However, biological factors, management and other problems, may variously condition their middle-long term survival. Therefore, personal experience of over 25 years has been critically reviewed in order to obtain useful information. In particular "hard" situations necessitating complex procedures have been examined but, if possible, preserving the peripherical vascular features.
Carnevale, Mario
2013-04-01
Non-destructive testing of structures composed of various types of materials is performed using a variety of methods. Most commonly, electromagnetic and acoustic methods are used to perform this task. Advances in computer software and electro-mechanical hardware have resulted in semi-automated systems for performing simple low-cost in-situ concrete testing. These systems are designed to be operated by anyone who can read a manual and push the right buttons. Although useful in many circumstances, we ask: "What happens when concrete structures are not simple and are too complex to be analyzed by these semi-automated systems and, most importantly, by minimally trained operators?" Many infrastructure projects are boldly pushing the limit of traditional engineering design. As structures become more complex, the methods and techniques used to evaluate these structures must also evolve. A first step towards adapting geophysical methods to evaluate complex structures is to develop pre-investigation conceptual models of possible responses that structures will have to available geophysical methods. This approach is important for designing the geometry and data acquisition parameters necessary for achieving the desired results. Examples of case by case assessments of the application of GPR to concrete investigations are examined. These include complex concrete wall structures, soil tunnel structures, and airport runways. HGI's adaption of ground penetrating radar (GPR) and seismic methods for assessing the substrate of a heavily reinforced concrete structure up to seven feet thick is reviewed. A range of GPR antenna frequencies were used to image the concrete and the underlying material. Time and frequency domain GPR analyses where used in the assessment. A multi-channel seismic survey using a roll-along data collection technique was used to assess the resonant frequency of the concrete structure, the nature of the underlying medium, and behavior of the structural system.
Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob
2009-01-01
The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust parame...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....
Xu, Lei; Bergés, Alexis; Lu, Peter J.; Studart, André R.; Schofield, Andrew B.; Oki, Hidekazu; Davies, Simon; Weitz, David A.
2010-01-01
We investigate the 3D structure and drying dynamics of complex mixtures of emulsion droplets and colloidal particles, using confocal microscopy. Air invades and rapidly collapses large emulsion droplets, forcing their contents into the surrounding porous particle pack at a rate proportional to the square of the droplet radius. By contrast, small droplets do not collapse, but remain intact and are merely deformed. A simple model coupling the Laplace pressure to Darcy's law correctly estimates ...
Tirshu M.
2008-12-01
Full Text Available It is presented the technological scheme of complex biopower installation for manufacture of the electric power, hot water and gas at use as raw material of manure, birds dung and firm organic waste products. The suggested technical solution provides practically 100 % use of energy of burnt gas due to the introduced feedback between power station and a bioreactor. Recommendations for the best use of installation in Republics Moldova are developed as well.
Complexity Leadership: A Theoretical Perspective
Baltaci, Ali; Balci, Ali
2017-01-01
Complex systems are social networks composed of interactive employees interconnected through collaborative, dynamic ties such as shared goals, perspectives and needs. Complex systems are largely based on "the complex system theory". The complex system theory focuses mainly on finding out and developing strategies and behaviours that…
Classification of Software Projects' Complexity
Fitsilis, P.; Kameas, A.; Anthopoulos, L.
Software project complexity is a subject that has not received detailed attention. The purpose of this chapter is to present a systematic way for studying and modeling software project complexity. The proposed model is based on the widely known and accepted Project Management Body of Knowledge and it uses a typology for modeling complexity based on complexity of faith, fact, and interaction.
Predictive Surface Complexation Modeling
Sverjensky, Dimitri A. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Earth and Planetary Sciences
2016-11-29
Surface complexation plays an important role in the equilibria and kinetics of processes controlling the compositions of soilwaters and groundwaters, the fate of contaminants in groundwaters, and the subsurface storage of CO_{2} and nuclear waste. Over the last several decades, many dozens of individual experimental studies have addressed aspects of surface complexation that have contributed to an increased understanding of its role in natural systems. However, there has been no previous attempt to develop a model of surface complexation that can be used to link all the experimental studies in order to place them on a predictive basis. Overall, my research has successfully integrated the results of the work of many experimentalists published over several decades. For the first time in studies of the geochemistry of the mineral-water interface, a practical predictive capability for modeling has become available. The predictive correlations developed in my research now enable extrapolations of experimental studies to provide estimates of surface chemistry for systems not yet studied experimentally and for natural and anthropogenically perturbed systems.
Albertos, Pedro; Blanke, Mogens; Isidori, Alberto; Schaufelberger, Walter; Sanz, Ricardo
2001-01-01
The world of artificial systems is reaching complexity levels that es cape human understanding. Surface traffic, electricity distribution, air planes, mobile communications, etc. , are examples that demonstrate that we are running into problems that are beyond classical scientific or engi neering knowledge. There is an ongoing world-wide effort to understand these systems and develop models that can capture its behavior. The reason for this work is clear, if our lack of understanding deepens, we will lose our capability to control these systems and make they behave as we want. Researchers from many different fields are trying to understand and develop theories for complex man-made systems. This book presents re search from the perspective of control and systems theory. The book has grown out of activities in the research program Control of Complex Systems (COSY). The program has been sponsored by the Eu ropean Science Foundation (ESF) which for 25 years has been one of the leading players in stimula...
Watanabe, Osamu
2013-04-01
Various antibodies are associated with voltage-gated potassium channels (VGKCs). Representative antibodies to VGKCs were first identified by radioimmunoassays using radioisotope-labeled alpha-dendrotoxin-VGKCs solubilized from rabbit brain. These antibodies were detected only in a proportion of patients with acquired neuromyotonia (Isaacs' syndrome). VGKC antibodies were also detected in patients with Morvan's syndrome and in those with a form of autoimmune limbic encephalitis. Recent studies indicated that the "VGKC" antibodies are mainly directed toward associated proteins (for example LGI-1 and CASPR-2) that complex with the VGKCs themselves. The "VGKC" antibodies are now commonly known as VGKC-complex antibodies. In general, LGI-1 antibodies are most commonly detected in patients with limbic encephalitis with syndrome of inappropriate secretion of antidiuretic hormone. CASPR-2 antibodies are present in the majority of patients with Morvan's syndrome. These patients develop combinations of CNS symptoms, autonomic dysfunction, and peripheral nerve hyperexcitability. Furthermore, VGKC-complex antibodies are tightly associated with chronic idiopathic pain. Hyperexcitability of nociceptive pathways has also been implicated. These antibodies may be detected in sera of some patients with neurodegenerative diseases (for example, amyotrophic lateral sclerosis and Creutzfeldt-Jakob disease).
Advanced complex trait analysis.
Gray, A; Stewart, I; Tenesa, A
2012-12-01
The Genome-wide Complex Trait Analysis (GCTA) software package can quantify the contribution of genetic variation to phenotypic variation for complex traits. However, as those datasets of interest continue to increase in size, GCTA becomes increasingly computationally prohibitive. We present an adapted version, Advanced Complex Trait Analysis (ACTA), demonstrating dramatically improved performance. We restructure the genetic relationship matrix (GRM) estimation phase of the code and introduce the highly optimized parallel Basic Linear Algebra Subprograms (BLAS) library combined with manual parallelization and optimization. We introduce the Linear Algebra PACKage (LAPACK) library into the restricted maximum likelihood (REML) analysis stage. For a test case with 8999 individuals and 279,435 single nucleotide polymorphisms (SNPs), we reduce the total runtime, using a compute node with two multi-core Intel Nehalem CPUs, from ∼17 h to ∼11 min. The source code is fully available under the GNU Public License, along with Linux binaries. For more information see http://www.epcc.ed.ac.uk/software-products/acta. a.gray@ed.ac.uk Supplementary data are available at Bioinformatics online.
Ormerod, Paul
In the spirit of the overall topic of the conference, in this paper I consider the extent to which economic theory includes elements of the complex systems approach. I am setting to one side here the developments over the past decade in applying complex systems analysis to economic problems. This is not because this recent work is not important. It most certainly is. But I want to argue that there is a very distinct tradition of what we would now describe as a complex systems approach in the works of two of the greatest economists of the 20th century. There is of course a dominant intellectual paradigm within economics, that known as `neo-classical'economics. This paradigm is by no means an empty box, and is undoubtedly useful in helping to understand how some aspects of the social and economic worlds work. But even in its heyday, neo-classical economics never succeeded by its empirical success in driving out completely other theoretical approaches, for its success was simply not sufficient to do so. Much more importantly, economics over the past twenty or thirty years has become in an increasing state of flux.
Transition Complexity of Incomplete DFAs
Yuan Gao
2010-08-01
Full Text Available In this paper, we consider the transition complexity of regular languages based on the incomplete deterministic finite automata. A number of results on Boolean operations have been obtained. It is shown that the transition complexity results for union and complementation are very different from the state complexity results for the same operations. However, for intersection, the transition complexity result is similar to that of state complexity.
Baldi, Pierre; Lu, Zhiqin
2012-09-01
Autoencoders are unsupervised machine learning circuits, with typically one hidden layer, whose learning goal is to minimize an average distortion measure between inputs and outputs. Linear autoencoders correspond to the special case where only linear transformations between visible and hidden variables are used. While linear autoencoders can be defined over any field, only real-valued linear autoencoders have been studied so far. Here we study complex-valued linear autoencoders where the components of the training vectors and adjustable matrices are defined over the complex field with the L(2) norm. We provide simpler and more general proofs that unify the real-valued and complex-valued cases, showing that in both cases the landscape of the error function is invariant under certain groups of transformations. The landscape has no local minima, a family of global minima associated with Principal Component Analysis, and many families of saddle points associated with orthogonal projections onto sub-space spanned by sub-optimal subsets of eigenvectors of the covariance matrix. The theory yields several iterative, convergent, learning algorithms, a clear understanding of the generalization properties of the trained autoencoders, and can equally be applied to the hetero-associative case when external targets are provided. Partial results on deep architecture as well as the differential geometry of autoencoders are also presented. The general framework described here is useful to classify autoencoders and identify general properties that ought to be investigated for each class, illuminating some of the connections between autoencoders, unsupervised learning, clustering, Hebbian learning, and information theory.
Complex adaptive systems ecology
Sommerlund, Julie
2003-01-01
In the following, I will analyze two articles called Complex Adaptive Systems EcologyI & II (Molin & Molin, 1997 & 2000). The CASE-articles are some of the more quirkyarticles that have come out of the Molecular Microbial Ecology Group - a groupwhere I am currently making observational studies....... They are the result of acooperation between Søren Molin, professor in the group, and his brother, JanMolin, professor at Department of Organization and Industrial Sociology atCopenhagen Business School. The cooperation arises from the recognition that bothmicrobial ecology and sociology/organization theory works...
Sodha, Mahendra Singh
2014-01-01
The presentation in the book is based on charge balance on the dust particles, number and energy balance of the constituents and atom-ion-electron interaction in the gaseous plasma. Size distribution of dust particles, statistical mechanics, Quantum effects in electron emission from and accretion on dust particles and nonlinear interaction of complex plasmas with electric and electromagnetic fields have been discussed in the book. The book introduces the reader to basic concepts and typical applications. The book should be of use to researchers, engineers and graduate students.
Mellerup, Erling; Møller, Gert Lykke; Koefoed, Pernille
2012-01-01
A complex disease with an inheritable component is polygenic, meaning that several different changes in DNA are the genetic basis for the disease. Such a disease may also be genetically heterogeneous, meaning that independent changes in DNA, i.e. various genotypes, can be the genetic basis...... for the disease. Each of these genotypes may be characterized by specific combinations of key genetic changes. It is suggested that even if all key changes are found in genes related to the biology of a certain disease, the number of combinations may be so large that the number of different genotypes may be close...
Computability, complexity, logic
Börger, Egon
1989-01-01
The theme of this book is formed by a pair of concepts: the concept of formal language as carrier of the precise expression of meaning, facts and problems, and the concept of algorithm or calculus, i.e. a formally operating procedure for the solution of precisely described questions and problems. The book is a unified introduction to the modern theory of these concepts, to the way in which they developed first in mathematical logic and computability theory and later in automata theory, and to the theory of formal languages and complexity theory. Apart from considering the fundamental themes an
Complexity in Managing Modularization
Hansen, Poul H. Kyvsgård; Sun, Hongyi
2011-01-01
modularization management it is far from clarified. Recognizing the need for further empirical research, we have studied 40 modularity cases in various companies. The studies have been designed as long-term studies leaving time for various types of modularization benefits to emerge. Based on these studies we......In general, the phenomenon of managing modularization is not well known. The cause-effect relationships between modularization and realized benefits are complex and comprehensive. Though a number of research works have contributed to the study of the phenomenon of efficient and effective...
Fluorido complexes of technetium
Mariappan Balasekaran, Samundeeswari
2013-07-04
Fluorine chemistry has received considerable interest during recent years due to its significant role in the life sciences, especially for drug development. Despite the great nuclear medicinal importance of the radioactive metal technetium in radiopharmaceuticals, its coordination chemistry with the fluorido ligand is by far less explored than that of other ligands. Up to now, only a few technetium fluorides are known. This thesis contains the synthesis, spectroscopic and structural characterization of novel technetium fluorides in the oxidation states ''+1'', ''+2'', ''+4'' and ''+6''. In the oxidation state ''+6'', the fluoridotechnetates were synthesized either from nitridotechnetic(VI) acid or from pertechnetate by using reducing agent and have been isolated as cesium or tetraethylammonium salts. The compounds were characterized spectroscopically and structurally. In the intermediate oxidation state ''+4'', hexafluoridotechnetate(IV) was known for long time and studied spectroscopically. This thesis reports novel and improved syntheses and solved the critical issues of early publications such as the color, some spectroscopic properties and the structure of this key compound. Single crystal analyses of alkali metal, ammonium and tetramethylammonium salts of hexafluoridotechnetate(IV) are presented. In aqueous alkaline solutions, the ammonium salt of hexafluoridotechnetate(IV) undergoes hydrolysis and forms an oxido-bridged dimeric complex. It is the first step hydrolysis product of hexafluoridotechnetate(IV) and was characterized by spectroscopic and crystallographic methods. Low-valent technetium fluorides with the metal in the oxidation states of ''+2'' or ''+1'' are almost unknown. A detailed description of the synthesis and characterization of pentafluoridonitrosyltechnetate(II) is presented. The
Complex fermion coherent states
Tyc, T; Sanders, B C; Oliver, W D; Tyc, Tomas; Hamilton, Brett; Sanders, Barry C.; Oliver, William D.
2005-01-01
Whereas boson coherent states provide an elegant, intuitive and useful representation, we show that the desirable features of boson coherent states do not carry over very well to fermion fields unless one is prepared to use exotic approaches such as Grassmann fields. Specifically, we identify four appealing properties of boson coherent states (eigenstate of annihilation operator, displaced vacuum state, preservation of product states under linear coupling, and factorization of correlators) and show that fermion coherent states, and approximations to fermion coherent states, defined over the complex field, do not behave well for any of these four criteria.
Complex Polynomial Vector Fields
Dias, Kealey
vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...
Macroevolution of complex retroviruses
Katzourakis, Aris; Gifford, Robert J; Tristem, Michael
2009-01-01
Retroviruses can leave a "fossil record" in their hosts' genomes in the form of endogenous retroviruses. Foamy viruses, complex retroviruses that infect mammals, have been notably absent from this record. We have found an endogenous foamy virus within the genomes of sloths and show that foamy vir...... are the products of macroevolutionary conflict played out over a geological time scale....... viruses were infecting mammals more than 100 million years ago and codiverged with their hosts across an entire geological era. Our analysis highlights the role of evolutionary constraint in maintaining viral genome structure and indicates that accessory genes and mammalian mechanisms of innate immunity...
Characterizing biomaterial complexity
L.A. Clifton
2009-07-01
Full Text Available Biomaterials research will always require a range of techniques to examine structure and function on a range of length scales and in a range of settings. Neutron scattering provides a unique way of disentangling the molecular and structural complexity of biomaterials through study of the constituent components. We examine how the technique has been used to study surface immobilized proteins and lipid films, floating lipid bilayers as mimics of in vitro planar membranes, and formation of fibres from solution by insects and spiders.
Complex and Unpredictable Cardano
Ekert, Artur
2008-01-01
This purely recreational paper is about one of the most colorful characters of the Italian Renaissance, Girolamo Cardano, and the discovery of two basic ingredients of quantum theory, probability and complex numbers. The paper is dedicated to Giuseppe Castagnoli on the occasion of his 65th birthday. Back in the early 1990s, Giuseppe instigated a series of meetings at Villa Gualino, in Torino, which brought together few scattered individuals interested in the physics of computation. By doing so he effectively created and consolidated a vibrant and friendly community of researchers devoted to quantum information science. Many thanks for that!
Rosendahl, Mads
1989-01-01
One way to analyse programs is to to derive expressions for their computational behaviour. A time bound function (or worst-case complexity) gives an upper bound for the computation time as a function of the size of input. We describe a system to derive such time bounds automatically using abstrac...... interpretation. The semantics-based setting makes it possible to prove the correctness of the time bound function. The system can analyse programs in a first-order subset of Lisp and we show how the system also can be used to analyse programs in other languages....
STUDYING COMPLEX ADAPTIVE SYSTEMS
John H. Holland
2006-01-01
Complex adaptive systems (cas) - systems that involve many components that adapt or learn as they interact - are at the heart of important contemporary problems. The study of cas poses unique challenges: Some of our most powerful mathematical tools, particularly methods involving fixed points, attractors, and the like, are of limited help in understanding the development of cas. This paper suggests ways to modify research methods and tools, with an emphasis on the role of computer-based models, to increase our understanding of cas.
Polyhydride complexes for hydrogen storage
Jensen, C.M. [Univ. of Hawaii, Honolulu, HI (United States)
1995-09-01
Polyhydride metal complexes are being developed for application in hydrogen storage. Efforts have focused on developing complexes with improved available hydrogen weight percentages. We have explored the possibility that complexes containing aromatic hydrocarbon ligands could store hydrogen at both the metal center and in the ligands. We have synthesized novel indenyl hydride complexes and explored their reactivity with hydrogen. The reversible hydrogenation of [IrH{sub 3}(PPh{sub 3})({eta}{sup 5}-C{sub 10}H{sub 7})]{sup +} has been achieved. While attempting to prepare {eta}{sup 6}-tetrahydronaphthalene complexes, we discovered that certain polyhydride complexes catalyze both the hydrogenation and dehydrogenation of tetrahydronaphthalene.
Canonical metrics on complex manifold
YAU Shing-Tung
2008-01-01
@@ Complex manifolds are topological spaces that are covered by coordinate charts where the Coordinate changes are given by holomorphic transformations. For example, Riemann surfaces are one dimensional complex manifolds. In order to understand complex manifolds, it is useful to introduce metrics that are compatible with the complex structure. In general, we should have a pair (M, ds2M) where ds2M is the metric. The metric is said to be canonical if any biholomorphisms of the complex manifolds are automatically isometries. Such metrics can naturally be used to describe invariants of the complex structures of the manifold.
Canonical metrics on complex manifold
YAU; Shing-Tung(Yau; S.-T.)
2008-01-01
Complex manifolds are topological spaces that are covered by coordinate charts where the coordinate changes are given by holomorphic transformations.For example,Riemann surfaces are one dimensional complex manifolds.In order to understand complex manifolds,it is useful to introduce metrics that are compatible with the complex structure.In general,we should have a pair(M,ds~2_M)where ds~2_M is the metric.The metric is said to be canonical if any biholomorphisms of the complex manifolds are automatically isometries.Such metrics can naturally be used to describe invariants of the complex structures of the manifold.
Shapes of interacting RNA complexes
Fu, Benjamin Mingming; Reidys, Christian
2014-01-01
Shapes of interacting RNA complexes are studied using a filtration via their topological genus. A shape of an RNA complex is obtained by (iteratively) collapsing stacks and eliminating hairpin loops.This shape-projection preserves the topological core of the RNA complex and for fixed topological...... genus there are only finitely many such shapes. Our main result is a new bijection that relates the shapes of RNA complexes with shapes of RNA structures. This allows to compute the shape polynomial of RNA complexes via the shape polynomial of RNA structures. We furthermore present a linear time uniform...... sampling algorithm for shapes of RNA complexes of fixed topological genus....
Dawson, T
2000-04-01
This paper examines the possible psychological implications of two adaptations of the myth of Orpheus and Eurydice, both of which were completed in 1997. The first is by a man: 'Deconstructing Harry', a film by Woody Allen. The second is by a woman: 'Eurydice in the Underworld', a short story written by Kathy Acker in the last year of her life. The paper argues that there are only four 'necessary events' in the myth of Orpheus and Eurydice. It defines the sequence of these events as a 'mythic pattern' that represents the experience of loss, unconscious yearning, depression, and psychological inflation. The film is examined as an expression of an 'Orpheus complex', the short story as an expression of an 'Eurydice complex'. The paper suggests a possible reason for the persistence of interest in the myth throughout the twentieth century. Although it notes that women appear to find it easier to free themselves from identification with the mythic pattern, it also provides reasons for thinking that men may be about to do the same.
Teixeira, G. M.; Aguiar, M. S. F.; Carvalho, C. F.; Dantas, D. R.; Cunha, M. V.; Morais, J. H. M.; Pereira, H. B. B.; Miranda, J. G. V.
Verbal language is a dynamic mental process. Ideas emerge by means of the selection of words from subjective and individual characteristics throughout the oral discourse. The goal of this work is to characterize the complex network of word associations that emerge from an oral discourse from a discourse topic. Because of that, concepts of associative incidence and fidelity have been elaborated and represented the probability of occurrence of pairs of words in the same sentence in the whole oral discourse. Semantic network of words associations were constructed, where the words are represented as nodes and the edges are created when the incidence-fidelity index between pairs of words exceeds a numerical limit (0.001). Twelve oral discourses were studied. The networks generated from these oral discourses present a typical behavior of complex networks and their indices were calculated and their topologies characterized. The indices of these networks obtained from each incidence-fidelity limit exhibit a critical value in which the semantic network has maximum conceptual information and minimum residual associations. Semantic networks generated by this incidence-fidelity limit depict a pattern of hierarchical classes that represent the different contexts used in the oral discourse.
Organometallic Complexes of Graphene
Sarkar, Santanu; Bekyarova, Elena; Haddon, Robert C
2013-01-01
We demonstrate the organometallic hexahapto complexation of chromium with graphene, graphite and carbon nanotubes. All of these extended periodic pi-electron systems exhibit some degree of reactivity toward the reagents CrCO)6 and (eta6-benzene)Cr(CO)3, and we are able to demonstrate the formation of (eta6-rene)Cr(CO)3 or (eta6-arene)2Cr, where arene = single-walled carbon nanotubes (SWNT), exfoliated graphene (XG), epitaxial graphene (EG) and highly-oriented pyrolytic graphite (HOPG). We find that the SWNTs are the least reactive presumably as a result of the effect of curvature on the formation of the hexahapto bond; in the case of HOPG, (eta6-HOPG)Cr(CO)3 was isolated while the exfoliated graphene samples were found to give both (eta6-graphene)2Cr, and (eta6-graphene)Cr(CO)3 structures. We report simple and efficient routes for the mild decomplexation of the graphene-chromium complexes which appears to restore the original pristine graphene state. This study represents the first example of the use of graph...
Henske, Elizabeth P; Jóźwiak, Sergiusz; Kingswood, J Christopher; Sampson, Julian R; Thiele, Elizabeth A
2016-05-26
Tuberous sclerosis complex (TSC) is an autosomal dominant disorder that affects multiple organ systems and is caused by loss-of-function mutations in one of two genes: TSC1 or TSC2. The disorder can affect both adults and children. First described in depth by Bourneville in 1880, it is now estimated that nearly 2 million people are affected by the disease worldwide. The clinical features of TSC are distinctive and can vary widely between individuals, even within one family. Major features of the disease include tumours of the brain, skin, heart, lungs and kidneys, seizures and TSC-associated neuropsychiatric disorders, which can include autism spectrum disorder and cognitive disability. TSC1 (also known as hamartin) and TSC2 (also known as tuberin) form the TSC protein complex that acts as an inhibitor of the mechanistic target of rapamycin (mTOR) signalling pathway, which in turn plays a pivotal part in regulating cell growth, proliferation, autophagy and protein and lipid synthesis. Remarkable progress in basic and translational research, in addition to several randomized controlled trials worldwide, has led to regulatory approval of the use of mTOR inhibitors for the treatment of renal angiomyolipomas, brain subependymal giant cell astrocytomas and pulmonary lymphangioleiomyomatosis, but further research is needed to establish full indications of therapeutic treatment. In this Primer, we review the state-of-the-art knowledge in the TSC field, including the molecular and cellular basis of the disease, medical management, major knowledge gaps and ongoing research towards a cure.
Stehr, N; Grundmann, R
2001-06-01
The assertion about the unique 'complexity' or the peculiarly intricate character of social phenomena has, at least within sociology, a long, venerable and virtually uncontested tradition. At the turn of the last century, classical social theorists, for example, Georg Simmel and Emile Durkheim, made prominent and repeated reference to this attribute of the subject matter of sociology and the degree to which it complicates, even inhibits the develop and application of social scientific knowledge. Our paper explores the origins, the basis and the consequences of this assertion and asks in particular whether the classic complexity assertion still deserves to be invoked in analyses that ask about the production and the utilization of social scientific knowledge in modern society. We present John Maynard Keynes' economic theory and its practical applications as an illustration. We conclude that the practical value of social scientific knowledge is not dependent on a faithful, in the sense of complete, representation of social reality. Instead, social scientific knowledge that wants to optimize its practicality has to attend and attach itself to elements of social situations that can be altered or are actionable.
Complexity in language acquisition.
Clark, Alexander; Lappin, Shalom
2013-01-01
Learning theory has frequently been applied to language acquisition, but discussion has largely focused on information theoretic problems-in particular on the absence of direct negative evidence. Such arguments typically neglect the probabilistic nature of cognition and learning in general. We argue first that these arguments, and analyses based on them, suffer from a major flaw: they systematically conflate the hypothesis class and the learnable concept class. As a result, they do not allow one to draw significant conclusions about the learner. Second, we claim that the real problem for language learning is the computational complexity of constructing a hypothesis from input data. Studying this problem allows for a more direct approach to the object of study--the language acquisition device-rather than the learnable class of languages, which is epiphenomenal and possibly hard to characterize. The learnability results informed by complexity studies are much more insightful. They strongly suggest that target grammars need to be objective, in the sense that the primitive elements of these grammars are based on objectively definable properties of the language itself. These considerations support the view that language acquisition proceeds primarily through data-driven learning of some form.
Complex dynamical invariants for two-dimensional complex potentials
J S Virdi; F Chand; C N Kumar; S C Mishra
2012-08-01
Complex dynamical invariants are searched out for two-dimensional complex potentials using rationalization method within the framework of an extended complex phase space characterized by $x = x_{1} + ip_{3}. y = x_{2} + ip_{4}, p_{x} = p_{1} + ix_{3}, p_{y} = p_{2} + ix_{4}$. It is found that the cubic oscillator and shifted harmonic oscillator admit quadratic complex invariants. THe obtained invariants may be useful for studying non-Hermitian Hamiltonian systems.
Theoretical research progress in complexity of complex dynamical networks
Fang Jinqing
2007-01-01
This article reviews the main progress in dynamical complexity of theoretical models for nonlinear complex networks proposed by our Joint Complex Network Research Group (JCNRG). The topological and dynamical properties of these theoretical models are numerically and analytically studied. Several findings are useful for understanding and deeply studying complex networks from macroscopic to microscopic levels and have a potential of applications in real-world networks.
Not so Complex: Iteration in the Complex Plane
O'Dell, Robin S.
2014-01-01
The simple process of iteration can produce complex and beautiful figures. In this article, Robin O'Dell presents a set of tasks requiring students to use the geometric interpretation of complex number multiplication to construct linear iteration rules. When the outputs are plotted in the complex plane, the graphs trace pleasing designs…
From Complex Fractional Fourier Transform to Complex Fractional Radon Transform
FAN Hong-Yi; JIANG Nian-Quan
2004-01-01
We show that for n-dimensional complex fractional Fourier transform the corresponding complex fractional Radon transform can also be derived, however, it is different from the direct product of two n-dimensional real fractional Radon transforms. The complex fractional Radon transform of two-mode Wigner operator is calculated.
Amphotericin B Lipid Complex Injection
Amphotericin B lipid complex injection is used to treat serious, possibly life-threatening fungal infections in people who did not respond ... to tolerate conventional amphotericin B therapy. Amphotericin B lipid complex injection is in a class of medications ...
Deformable Simplicial Complexes
Misztal, Marek Krzysztof
In this dissertation we present a novel method for deformable interface tracking in 2D and 3D|deformable simplicial complexes (DSC). Deformable interfaces are used in several applications, such as fluid simulation, image analysis, reconstruction or structural optimization. In the DSC method......, the interface (curve in 2D; surface in 3D) is represented explicitly as a piecewise linear curve or surface. However, the domain is also subject to discretization: triangulation in 2D; tetrahedralization in 3D. This way, the interface can be alternatively represented as a set of edges/triangles separating...... demonstrate those strengths in several applications. In particular, a novel, DSC-based fluid dynamics solver has been developed during the PhD project. A special feature of this solver is that due to the fact that DSC maintains an explicit interface representation, surface tension is more easily dealt with...
Complexity Science for Simpletons
Feinstein C. A.
2006-07-01
Full Text Available In this article, we shall describe some of the most interesting topics in the subject of Complexity Science for a general audience. Anyone with a solid foundation in high school mathematics (with some calculus and an elementary understanding of computer programming will be able to follow this article. First, we shall explain the significance of the P versus NP problem and solve it. Next, we shall describe two other famous mathematics problems, the Collatz 3n+ 1 Conjecture and the Riemann Hypothesis, and show how both Chaitin’s incompleteness theorem and Wolfram’s notion of “computational irreducibility” are important for understanding why no one has, as of yet, solved these two problems.
Mann, Jakob [Risoe National Lab., Wind Energy and Atmosheric Physics Dept., Roskilde (Denmark)
1999-03-01
The purpose of this work is to develop a model of the spectral velocity-tensor in neutral flow over complex terrain. The resulting equations are implemented in a computer code using the mean flow generated by a linear mean flow model as input. It estimates turbulence structure over hills (except on the lee side if recirculation is present) in the so-called outer layer and also models the changes in turbulence statistics in the vicinity roughness changes. The generated turbulence fields are suitable as input for dynamic load calculations on wind turbines and other tall structures and is under implementation in the collection of programs called WA{sup s}P Engineering. (au) EFP-97; EU-JOULE-3. 15 refs.
Hendil, Klavs B; Hartmann-Petersen, Rasmus
2004-01-01
Protein degradation in eukaryotic cells is important for regulation of metabolism, progression through the division cycle, in cell signalling pathways, and in mammals also for generation of antigen fragments for presentation on the major histocompatibility complex (MHC) class I. Most cell proteins...... are degraded via the ubiquitin/proteasome pathway where an elaborate enzyme system recognises the protein substrates and marks them for destruction by attachment of a chain of ubiquitin. The substrates are then bound to 26S proteasomes, unfolded, and threaded into the cylindrical central part of the 26S...... the substrates or release ubiquitin and glycans from them during degradation, stabilise proteasomes, regulate their cellular localisation, and modify their activity. It therefore appears that proteasomes are centres in macromolecular clusters, which degrade cell proteins in a tightly regulated manner....
Shiffman, Bernard
2010-01-01
We introduce several notions of `random fewnomials', i.e. random polynomials with a fixed number f of monomials of degree N. The f exponents are chosen at random and then the coefficients are chosen to be Gaussian random, mainly from the SU(m + 1) ensemble. The results give limiting formulas as N goes to infinity for the expected distribution of complex zeros of a system of k random fewnomials in m variables. When k = m, for SU(m + 1) polynomials, the limit is the Monge-Ampere measure of a toric Kaehler potential on CP^m obtained by averaging a `discrete Legendre transform' of the Fubini-Study symplectic potential at f points of the unit simplex in R^m.
Complex dynamics in nanosystems.
Ni, Xuan; Ying, Lei; Lai, Ying-Cheng; Do, Younghae; Grebogi, Celso
2013-05-01
Complex dynamics associated with multistability have been studied extensively in the past but mostly for low-dimensional nonlinear dynamical systems. A question of fundamental interest is whether multistability can arise in high-dimensional physical systems. Motivated by the ever increasing widespread use of nanoscale systems, we investigate a prototypical class of nanoelectromechanical systems: electrostatically driven Si nanowires, mathematically described by a set of driven, nonlinear partial differential equations. We develop a computationally efficient algorithm to solve the equations. Our finding is that multistability and complicated structures of basins of attraction are common types of dynamics, and the latter can be attributed to extensive transient chaos. Implications of these phenomena to device operations are discussed.
Geometric Complexity Theory: Introduction
Sohoni, Ketan D Mulmuley Milind
2007-01-01
These are lectures notes for the introductory graduate courses on geometric complexity theory (GCT) in the computer science department, the university of Chicago. Part I consists of the lecture notes for the course given by the first author in the spring quarter, 2007. It gives introduction to the basic structure of GCT. Part II consists of the lecture notes for the course given by the second author in the spring quarter, 2003. It gives introduction to invariant theory with a view towards GCT. No background in algebraic geometry or representation theory is assumed. These lecture notes in conjunction with the article \\cite{GCTflip1}, which describes in detail the basic plan of GCT based on the principle called the flip, should provide a high level picture of GCT assuming familiarity with only basic notions of algebra, such as groups, rings, fields etc.
Dan Ophir
2011-12-01
Full Text Available The process of making complex and controversial decisions, that is, dealing with moral or ethical dilemmas, have intrigued people and inspired writers from time immemorial. Dilemmas give both color and depth to characters in good literary works. But beyond literary fiction, dilemmas occupy society in every day issues such as in introducing legislation or solving current political problems. One example of a current political dilemma is how to deal with Iran’s quest for nuclear weapons. If it were possible to assess and quantify each of the alternative solutions for a given problem, the process of decision making would be much easier. If a problem involves only two optional solutions, game theory techniques can be used. However, real life problems are usually multi-unit, multi-optional problems, as in Iran
Hartmann, A.; Roehrich, J.; Frederiksen, Lars
2014-01-01
Purpose – The paper analyses how public buyers transition from procuring single products and services to procuring complex performance (PCP). The aim is to examine the change in the interactions between buyer and supplier, the emergence of value co-creation and the capability development during...... the transition process. Design/methodology/approach – A multiple, longitudinal case study method is used to examine the transition towards PCP. The study deploys rich qualitative data sets by combining semi-structured interviews, focus group meetings and organisational reports and documents. Findings...... – The transition towards PCP can be best described as a learning process which cumulates the knowledge and experience in the client-supplier interaction accompanied by changing contractual and relational capabilities. In public infrastructure this process is not initially motivated by the benefits of value co...
Kollár, János
1997-01-01
This volume contains the lectures presented at the third Regional Geometry Institute at Park City in 1993. The lectures provide an introduction to the subject, complex algebraic geometry, making the book suitable as a text for second- and third-year graduate students. The book deals with topics in algebraic geometry where one can reach the level of current research while starting with the basics. Topics covered include the theory of surfaces from the viewpoint of recent higher-dimensional developments, providing an excellent introduction to more advanced topics such as the minimal model program. Also included is an introduction to Hodge theory and intersection homology based on the simple topological ideas of Lefschetz and an overview of the recent interactions between algebraic geometry and theoretical physics, which involve mirror symmetry and string theory.
Bountis, Tassos
2012-01-01
This book introduces and explores modern developments in the well established field of Hamiltonian dynamical systems. It focuses on high degree-of-freedom systems and the transitional regimes between regular and chaotic motion. The role of nonlinear normal modes is highlighted and the importance of low-dimensional tori in the resolution of the famous FPU paradox is emphasized. Novel powerful numerical methods are used to study localization phenomena and distinguish order from strongly and weakly chaotic regimes. The emerging hierarchy of complex structures in such regimes gives rise to particularly long-lived patterns and phenomena called quasi-stationary states, which are explored in particular in the concrete setting of one-dimensional Hamiltonian lattices and physical applications in condensed matter systems. The self-contained and pedagogical approach is blended with a unique balance between mathematical rigor, physics insights and concrete applications. End of chapter exercises and (more demanding) res...
Segmentation of complex document
Souad Oudjemia
2014-06-01
Full Text Available In this paper we present a method for segmentation of documents image with complex structure. This technique based on GLCM (Grey Level Co-occurrence Matrix used to segment this type of document in three regions namely, 'graphics', 'background' and 'text'. Very briefly, this method is to divide the document image, in block size chosen after a series of tests and then applying the co-occurrence matrix to each block in order to extract five textural parameters which are energy, entropy, the sum entropy, difference entropy and standard deviation. These parameters are then used to classify the image into three regions using the k-means algorithm; the last step of segmentation is obtained by grouping connected pixels. Two performance measurements are performed for both graphics and text zones; we have obtained a classification rate of 98.3% and a Misclassification rate of 1.79%.
A.I.Arbab
2013-01-01
A unified complex model of Maxwell's equations is presented.The wave nature of the electromagnetic field vector is related to the temporal and spatial distributions and the circulation of charge and current densities.A new vacuum solution is obtained,and a new transformation under which Maxwell's equations are invariant is proposed.This transformation extends ordinary gauge transformation to include charge-current as well as scalar-vector potential.An electric dipole moment is found to be related to the magnetic charges,and Dirac's quantization is found to determine an uncertainty relation expressing the indeterminacy of electric and magnetic charges.We generalize Maxwell's equations to include longitudinal waves.A formal analogy between this formulation and Dirac's equation is also discussed.
Complex singularities and PDEs
Caflisch, R E; Sammartino, M; Sciacca, V
2015-01-01
In this paper we give a review on the computational methods used to characterize the complex singularities developed by some relevant PDEs. We begin by reviewing the singularity tracking method based on the analysis of the Fourier spectrum. We then introduce other methods generally used to detect the hidden singularities. In particular we show some applications of the Pad\\'e approximation, of the Kida method, and of Borel-Polya method. We apply these techniques to the study of the singularity formation of some nonlinear dispersive and dissipative one dimensional PDE of the 2D Prandtl equation, of the 2D KP equation, and to Navier-Stokes equation for high Reynolds number incompressible flows in the case of interaction with rigid boundaries.
Kahle, Matthew
2009-01-01
We study the expected topological properties of Cech and Vietoris-Rips complexes built on randomly sampled points in R^d. These are, in some cases, analogues of known results for connectivity and component counts for random geometric graphs. However, an important difference in this setting is that homology is not monotone in the underlying parameter. In the sparse range, we compute the expectation and variance of the Betti numbers, and establish Central Limit Theorems and concentration of measure. In the dense range, we introduce Morse theoretic arguments to bound the expectation of the Betti numbers, which is the main technical contribution of this article. These results provide a detailed probabilistic picture to compare with the topological statistics of point cloud data.
Complex pendulum biomass sensor
Hoskinson, Reed L.; Kenney, Kevin L.; Perrenoud, Ben C.
2007-12-25
A complex pendulum system biomass sensor having a plurality of pendulums. The plurality of pendulums allow the system to detect a biomass height and density. Each pendulum has an angular deflection sensor and a deflector at a unique height. The pendulums are passed through the biomass and readings from the angular deflection sensors are fed into a control system. The control system determines whether adjustment of machine settings is appropriate and either displays an output to the operator, or adjusts automatically adjusts the machine settings, such as the speed, at which the pendulums are passed through the biomass. In an alternate embodiment, an entanglement sensor is also passed through the biomass to determine the amount of biomass entanglement. This measure of entanglement is also fed into the control system.
Invitation to complex analysis
Boas, Ralph P
2010-01-01
Ideal for a first course in complex analysis, this book can be used either as a classroom text or for independent study. Written at a level accessible to advanced undergraduates and beginning graduate students, the book is suitable for readers acquainted with advanced calculus or introductory real analysis. The treatment goes beyond the standard material of power series, Cauchy's theorem, residues, conformal mapping, and harmonic functions by including accessible discussions of intriguing topics that are uncommon in a book at this level. The flexibility afforded by the supplementary topics and applications makes the book adaptable either to a short, one-term course or to a comprehensive, full-year course. Detailed solutions of the exercises both serve as models for students and facilitate independent study. Supplementary exercises, not solved in the book, provide an additional teaching tool. This second edition has been painstakingly revised by the author's son, himself an award-winning mathematical expositor...
Westerhoff, Hans V.; Jensen, Peter Ruhdal; Snoep, Jacky L.
1998-01-01
Thermodynamics has always been a remarkable science in that it studies macroscopic properties that are only partially determined by the properties of individual molecules. Entropy and free energy only exist in constellations of more than a single molecule (degree of freedom). They are the so......-called emergent properties. Tendency towards increased entropy is an essential determinant for the behaviour of ideal gas mixtures, showing that even in the simplest physical/chemical systems, (dys)organisation of components is crucial for the behaviour of systems. This presentation aims at illustrating...... understanding of this BioComplexity, modem thermodynamic concepts and methods (nonequilibrium thermodynamics, metabolic and hierarchical control analysis) will be needed. We shall propose to redefine nonequilibrium thermodynamics as: The science that aims at understanding the behaviour of nonequilibrium systems...
Divergences in holographic complexity
Reynolds, Alan; Ross, Simon F.
2017-05-01
We study the UV divergences in the action of the ‘Wheeler-de Witt patch’ in asymptotically AdS spacetimes, which has been conjectured to be dual to the computational complexity of the state of the dual field theory on a spatial slice of the boundary. We show that including a surface term in the action on the null boundaries which ensures invariance under coordinate transformations has the additional virtue of removing a stronger than expected divergence, making the leading divergence proportional to the proper volume of the boundary spatial slice. We compare the divergences in the action to divergences in the volume of a maximal spatial slice in the bulk, finding that the qualitative structure is the same, but subleading divergences have different relative coefficients in the two cases.
Recent Advances in Complex Networks
无
2002-01-01
Dramatic advances in the field of complex networks have been witnessed in the past few years. This paper reviews some important results in this direction of rapidly evolving research, with emphasis on the relationship between the dynamics and the topology of complex networks. Basic quantities and typical examples of various complex networks are described. Robustness of connectivity and epidemic dynamics in complex networks are evaluated.
Complex wounds Feridas complexas
Marcus Castro Ferreira
2006-01-01
Full Text Available Complex wound is the term used more recently to group those well-known difficult wounds, either chronic or acute, that challenge medical and nursing teams. They defy cure using conventional and simple "dressings" therapy and currently have a major socioeconomic impact. The purpose of this review is to bring these wounds to the attention of the health-care community, suggesting that they should be treated by multidisciplinary teams in specialized hospital centers. In most cases, surgical treatment is unavoidable, because the extent of skin and subcutaneous tissue loss requires reconstruction with grafts and flaps. New technologies, such as the negative pressure device, should be introduced. A brief review is provided of the major groups of complex wounds-diabetic wounds, pressure sores, chronic venous ulcers, post-infection soft-tissue gangrenes, and ulcers resulting from vasculitis.Ferida complexa é uma nova definição para identificar aquelas feridas crônicas e algumas agudas já bem conhecidas e que desafiam equipes médicas e de enfermagem. São difíceis de serem resolvidas usando tratamentos convencionais e simples curativos. Têm atualmente grande impacto sócio-econômico. Esta revisão procura atrair atenção da comunidade de profissionais de saúde para estas feridas, sugerindo que devam ser tratadas por equipe multidisciplinar em centro hospitalar especializado. Na maioria dos casos o tratamento cirúrgico deve ser indicado, uma vez que a perda de pele e tecido subcutâneo é extensa, necessitando de reconstrução com enxertos e retalhos. Nova tecnologia, como uso da terapia por pressão negativa foi introduzido. Breves comentários sobre os principais grupos de feridas complexas: pé diabético, úlceras por pressão, úlceras venosas, síndrome de Fournier e vasculites.
Kolmogorov complexity as a language
Shen, Alexander
2011-01-01
The notion of Kolmogorov complexity (=the minimal length of a program that generates some object) is often useful as a kind of language that allows us to reformulate some notions and therefore provide new intuition. In this survey we provide (with minimal comments) many different examples where notions and statements that involve Kolmogorov complexity are compared with their counterparts not involving complexity.
Managing complexity of aerospace systems
Tamaskar, Shashank
Growing complexity of modern aerospace systems has exposed the limits of conventional systems engineering tools and challenged our ability to design them in a timely and cost effective manner. According to the US Government Accountability Office (GAO), in 2009 nearly half of the defense acquisition programs are expecting 25% or more increase in unit acquisition cost. Increase in technical complexity has been identified as one of the primary drivers behind cost-schedule overruns. Thus to assure the affordability of future aerospace systems, it is increasingly important to develop tools and capabilities for managing their complexity. We propose an approach for managing the complexity of aerospace systems to address this pertinent problem. To this end, we develop a measure that improves upon the state-of-the-art metrics and incorporates key aspects of system complexity. We address the problem of system decomposition by presenting an algorithm for module identification that generates modules to minimize integration complexity. We demonstrate the framework on diverse spacecraft and show the impact of design decisions on integration cost. The measure and the algorithm together help the designer track and manage complexity in different phases of system design. We next investigate how complexity can be used as a decision metric in the model-based design (MBD) paradigm. We propose a framework for complexity enabled design space exploration that introduces the idea of using complexity as a non-traditional design objective. We also incorporate complexity with the component based design paradigm (a sub-field of MBD) and demonstrate it on several case studies. The approach for managing complexity is a small but significant contribution to the vast field of complexity management. We envision our approach being used in concert with a suite of complexity metrics to provide an ability to measure and track complexity through different stages of design and development. This will not
Complexity, Information and Biological Organisation
Attila Grandpierre
2005-12-01
Full Text Available Regarding the widespread confusion about the concept and nature of complexity, information and biological organization, we look for some coordinated conceptual considerations corresponding to quantitative measures suitable to grasp the main characteristics of biological complexity. Quantitative measures of algorithmic complexity of supercomputers like Blue Gene/L are compared with the complexity of the brain. We show that both the computer and the brain have a more fundamental, dynamic complexity measure corresponding to the number of operations per second. Recent insights suggest that the origin of complexity may go back to simplicity at a deeper level, corresponding to algorithmic complexity. We point out that for physical systems Ashby’s Law, Kahre’s Law and causal closure of the physical exclude the generation of information, and since genetic information corresponds to instructions, we are faced with a controversy telling that the algorithmic complexity of physics is much lower than the instructions’ complexity of the human DNA: I_algorithmic(physics ~ 10^3 bit << I_instructions(DNA ~ 10^9 bit. Analyzing the genetic complexity we obtain that actually the genetic information corresponds to a deeper than algorithmic level of complexity, putting an even greater emphasis to the information paradox. We show that the resolution of the fundamental information paradox may lie either in the chemical evolution of inheritance in abiogenesis, or in the existence of an autonomous biological principle allowing the production of information beyond physics.
Complexity a very short introduction
Holland, John H
2014-01-01
The importance of complexity is well-captured by Hawking's comment: "Complexity is the science of the 21st century". From the movement of flocks of birds to the Internet, environmental sustainability, and market regulation, the study and understanding of complex non-linear systems has become highly influential over the last 30 years. In this Very Short Introduction, one of the leading figures in the field, John Holland, introduces the key elements and conceptual framework of complexity. From complex physical systems such as fluid flow and the difficulties of predicting weather, to complex adaptive systems such as the highly diverse and interdependent ecosystems of rainforests, he combines simple, well-known examples - Adam Smith's pin factory, Darwin's comet orchid, and Simon's 'watchmaker' - with an account of the approaches, involving agents and urn models, taken by complexity theory. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost eve...
Complexity of Formation in Holography
Chapman, Shira; Myers, Robert C
2016-01-01
It was recently conjectured that the quantum complexity of a holographic boundary state can be computed by evaluating the gravitational action on a bulk region known as the Wheeler-DeWitt patch. We apply this complexity=action duality to evaluate the `complexity of formation' (arXiv:1509.07876, arXiv:1512.04993), i.e., the additional complexity arising in preparing the entangled thermofield double state with two copies of the boundary CFT compared to preparing the individual vacuum states of the two copies. We find that for boundary dimensions $d>2$, the difference in the complexities grows linearly with the thermal entropy at high temperatures. For the special case $d=2$, the complexity of formation is a fixed constant, independent of the temperature. We compare these results to those found using the complexity=volume duality.
Complexity of formation in holography
Chapman, Shira; Marrochio, Hugo; Myers, Robert C.
2017-01-01
It was recently conjectured that the quantum complexity of a holographic boundary state can be computed by evaluating the gravitational action on a bulk region known as the Wheeler-DeWitt patch. We apply this complexity=action duality to evaluate the `complexity of formation' [1, 2], i.e. the additional complexity arising in preparing the entangled thermofield double state with two copies of the boundary CFT compared to preparing the individual vacuum states of the two copies. We find that for boundary dimensions d > 2, the difference in the complexities grows linearly with the thermal entropy at high temperatures. For the special case d = 2, the complexity of formation is a fixed constant, independent of the temperature. We compare these results to those found using the complexity=volume duality.
Smith, M Shane; Bivins-Smith, Elizabeth R; Tilley, A Michael; Bentz, Gretchen L; Chan, Gary; Minard, Jessica; Yurochko, Andrew D
2007-07-01
Infected peripheral blood monocytes are proposed to play a key role in the hematogenous dissemination of human cytomegalovirus (HCMV) to tissues, a critical step in the establishment of HCMV persistence and the development of HCMV-associated diseases. We recently provided evidence for a unique strategy involved in viral dissemination: HCMV infection of primary human monocytes promotes their transendothelial migration and differentiation into proinflammatory macrophages permissive for the replication of the original input virus. To decipher the mechanism of hematogenous spread, we focused on the viral dysregulation of early cellular processes involved in transendothelial migration. Here, we present evidence that both phosphatidylinositol 3-kinase [PI(3)K] and NF-kappaB activities were crucial for the HCMV induction of monocyte motility and firm adhesion to endothelial cells. We found that the beta(1) integrins, the beta(2) integrins, intracellular adhesion molecule 1 (ICAM-1), and ICAM-3 were upregulated following HCMV infection and that they played a key role in the firm adhesion of infected monocytes to the endothelium. The viral regulation of adhesion molecule expression is complex, with PI(3)K and NF-kappaB affecting the expression of each adhesion molecule at different stages of the expression cascade. Our data demonstrate key roles for PI(3)K and NF-kappaB signaling in the HCMV-induced cellular changes in monocytes and identify the biological rationale for the activation of these pathways in infected monocytes, which together suggest a mechanism for how HCMV promotes viral spread to and persistence within host organs.
Muhammad Talha Khan
2014-01-01
Full Text Available Complex sleep apnea is the term used to describe a form of sleep disordered breathing in which repeated central apneas (>5/hour persist or emerge when obstructive events are extinguished with positive airway pressure (PAP and for which there is not a clear cause for the central apneas such as narcotics or systolic heart failure. The driving forces in the pathophysiology are felt to be ventilator instability associated oscillation in PaCO2 arterial partial pressure of Carbon Dioxide, continuous cositive airway pressure (CPAP related increased CO2 carbon dioxide elimination, and activation of airway and pulmonary stretch receptors triggering these central apneas. The prevalence ranges from 0.56% to 18% with no clear predictive characteristics as compared to simple obstructive sleep apnea. Prognosis is similar to obstructive sleep apnea. The central apnea component in most patients on followup using CPAP therap, has resolved. For those with continued central apneas on simple CPAP therapy, other treatment options include bilevel PAP, adaptive servoventilation, permissive flow limitation and/or drugs.
Complex emergencies in Indonesia.
Bradt, D A; Drummond, C M; Richman, M
2001-01-01
Recently, Indonesia has experienced six major provincial, civil, armed conflicts. Underlying causes include the transmigration policy, sectarian disputes, the Asian economic crisis, fall of authoritarian rule, and a backlash against civil and military abuses. The public health impact involves the displacement nationwide of > 1.2 million persons. Violence in the Malukus, Timor, and Kalimantan has sparked the greatest population movements such that five provinces in Indonesia each now harbor > 100,000 internally displaced persons. With a background of government instability, hyperinflation, macroeconomic collapse, and elusive political solutions, these civil armed conflicts are ripe for persistence as complex emergencies. Indonesia has made substantial progress in domestic disaster management with the establishment of central administrative authority, strategic planning, and training programs. Nevertheless, the Indonesian experience reveals recurrent issues in international humanitarian health assistance. Clinical care remains complicated by absences of treatment protocols, inappropriate drug use, high procedural complication rates, and variable referral practices. Epidemiological surveillance remains complicated by unsettled clinical case definitions, non-standardized case management of diseases with epidemic potential, variable outbreak management protocols, and inadequate epidemiological analytic capacity. International donor support has been semi-selective, insufficient, and late. The militia murders of three UN staff in West Timor prompted the withdrawal of UN international staff from West Timor for nearly a year to date. Re-establishing rules of engagement for humanitarian health workers must address security, public health, and clinical threats.
Complexity of Ising Polynomials
Kotek, Tomer
2011-01-01
This paper deals with the partition function of the Ising model from statistical mechanics, which is used to study phase transitions in physical systems. A special case of interest is that of the Ising model with constant energies and external field. One may consider such an Ising system as a simple graph together with vertex and edge weight values. When these weights are considered indeterminates, the partition function for the constant case is a trivariate polynomial Z(G;x,y,z). This polynomial was studied with respect to its approximability by L. A. Goldberg, M. Jerrum and M. Patersonin 2003. Z(G;x,y,z) generalizes a bivariate polynomial Z(G;t,y), which was studied in by D. Andr\\'{e}n and K. Markstr\\"{o}m in 2009. We consider the complexity of Z(G;t,y) and Z(G;x,y,z) in comparison to that of the Tutte polynomial, which is well-known to be closely related to the Potts model in the absence of an external field. We show that Z(G;\\x,\\y,\\z) is #P-hard to evaluate at all points in $mathbb{Q}^3$, except those in ...
Information Complexity and Biology
Bagnoli, Franco; Bignone, Franco A.; Cecconi, Fabio; Politi, Antonio
Kolmogorov contributed directly to Biology in essentially three problems: the analysis of population dynamics (Lotka-Volterra equations), the reaction-diffusion formulation of gene spreading (FKPP equation), and some discussions about Mendel's laws. However, the widely recognized importance of his contribution arises from his work on algorithmic complexity. In fact, the limited direct intervention in Biology reflects the generally slow growth of interest of mathematicians towards biological issues. From the early work of Vito Volterra on species competition, to the slow growth of dynamical systems theory, contributions to the study of matter and the physiology of the nervous system, the first 50-60 years have witnessed important contributions, but as scattered pieces apparently uncorrelated, and in branches often far away from Biology. Up to the 40' it is hard to see the initial loose build up of a convergence, for those theories that will become mainstream research by the end of the century, and connected by the study of biological systems per-se.
It is complicated! - misunderstanding the complexities of 'complex'.
Sturmberg, Joachim P; Martin, Carmel M; Katerndahl, David A
2017-04-01
Terminology matters - as Lakoff emphasised, words and phrases evoke powerful images and frames of understanding. It is for that reason that we need to discern and use appropriately the term complex/complexity in the health science/professional/policy domain. Complex is the fashionable term used when in reality one means 'complicated', 'difficult to understand' or 'multiple simultaneous actions'. However, this is not what complex means. The Latin term means 'entwined/interwoven' - a structural characteristic describing systems. Complexity arises from the interactions between structurally connected entities - a functional characteristic of a system. The basis of scientific rigor is a clear understanding of a discipline's epistemology. Complexity refers to the emergence of outcomes from the interactions of a system's constituent components (and thus has nothing in common with the colloquial meaning of complicatedness). © 2016 John Wiley & Sons, Ltd.
Almost complex connections on almost complex manifolds with Norden metric
Teofilova, Marta
2011-01-01
A four-parametric family of linear connections preserving the almost complex structure is defined on an almost complex manifold with Norden metric. Necessary and sufficient conditions for these connections to be natural are obtained. A two-parametric family of complex connections is studied on a conformal K\\"{a}hler manifold with Norden metric. The curvature tensors of these connections are proved to coincide.
Complexity measurement based on information theory and kolmogorov complexity.
Lui, Leong Ting; Terrazas, Germán; Zenil, Hector; Alexander, Cameron; Krasnogor, Natalio
2015-01-01
In the past decades many definitions of complexity have been proposed. Most of these definitions are based either on Shannon's information theory or on Kolmogorov complexity; these two are often compared, but very few studies integrate the two ideas. In this article we introduce a new measure of complexity that builds on both of these theories. As a demonstration of the concept, the technique is applied to elementary cellular automata and simulations of the self-organization of porphyrin molecules.
Complexity management in projects between rational momentum and complex conditions
Mac, Anita; Schlamovitz, Jesper
This study takes its departure in a model of complexity, developed by Stacey (1993), to test and discuss its practical benefit as perceived by practicing project managers. Based on a survey, the study finds that complexity is a phenomenon recognized by project managers, and complexity management...... is associated with benefits in the development of tasks and managing stakeholders. It is also associated with some difficulty in terms of an increased need for dialogue and a risk of creating goal ambiguity. Based on the findings, we conclude that classical project management approaches can benefit from...... incorporating complexity management....
Complexity Management In Projects Between Rational Momentum And Complex Conditions
Mac, Anita; Schlamovitz, Jesper
2015-01-01
Abstract: This study takes its departure in a model of complexity, developed by Stacey (1993), to test and discuss its practical benefit as perceived by practicing project managers. Based on a survey, the study finds that complexity is a phenomenon recognized by project managers, and complexity...... management is associated with benefits in the development of tasks and managing stakeholders. It is also associated with some difficulty in terms of an increased need for dialogue and a risk of creating goal ambiguity. Based on the findings, we conclude that classical project management approaches can...... benefit from incorporating complexity management....
Bertherat, Jérôme
2006-06-06
The Carney complex (CNC) is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). PPNAD, a rare cause of Cushing's syndrome, is due to primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations or familial history of the disease. Myxomas can be observed in the heart, skin and breast. Cardiac myxomas can develop in any cardiac chamber and may be multiple. One of the putative CNC genes located on 17q22-24, (PRKAR1A), has been identified to encode the regulatory subunit (R1A) of protein kinase A. Heterozygous inactivating mutations of PRKAR1A were reported initially in 45 to 65% of CNC index cases, and may be present in about 80% of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cAMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Genetic analysis should be proposed to all CNC index cases. Patients with CNC or with a genetic predisposition to CNC should have regular screening for manifestations of the disease. Clinical work-up for all the manifestations of CNC should be performed at least once a year in all patients and should start in infancy. Cardiac myxomas require surgical removal. Treatment of the other manifestations of CNC should be discussed and may include follow-up, surgery, or medical treatment depending on the location of the tumor, its size, the existence of clinical signs of tumor mass or hormonal excess, and the suspicion of malignancy. Bilateral adrenalectomy is the most common treatment for Cushing's syndrome due to PPNAD.
Bertherat Jérôme
2006-06-01
Full Text Available Abstract The Carney complex (CNC is a dominantly inherited syndrome characterized by spotty skin pigmentation, endocrine overactivity and myxomas. Skin pigmentation anomalies include lentigines and blue naevi. The most common endocrine gland manifestations are acromegaly, thyroid and testicular tumors, and adrenocorticotropic hormone (ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD. PPNAD, a rare cause of Cushing's syndrome, is due to primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations or familial history of the disease. Myxomas can be observed in the heart, skin and breast. Cardiac myxomas can develop in any cardiac chamber and may be multiple. One of the putative CNC genes located on 17q22-24, (PRKAR1A, has been identified to encode the regulatory subunit (R1A of protein kinase A. Heterozygous inactivating mutations of PRKAR1A were reported initially in 45 to 65 % of CNC index cases, and may be present in about 80 % of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cAMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Genetic analysis should be proposed to all CNC index cases. Patients with CNC or with a genetic predisposition to CNC should have regular screening for manifestations of the disease. Clinical work-up for all the manifestations of CNC should be performed at least once a year in all patients and should start in infancy. Cardiac myxomas require surgical removal. Treatment of the other manifestations of CNC should be discussed and may include follow-up, surgery, or medical treatment depending on the location of the tumor, its size, the existence of clinical signs of tumor mass or hormonal excess, and the suspicion of malignancy. Bilateral adrenalectomy is the most common treatment for Cushing
Canine immune complex diseases.
Plechner, A J
1976-11-01
Though not conclusive, our primary findings indicate that a feature common to many of our tumor and ICD patients is depressed cortisol production. Additionally, the response to ACTH adrenal cortex stimulation tests, at 2-hour intervals between rest and stimulation, have ranged from negative to substantially less than would be expected in normal subjects. Peripheral plasma cortisol values for dogs, at rest and 2 hours after ACTH stimulation, respectively, have been reported as 2-10 and 25-30 mug/dl, 3-8 and 7.5-18 mug/dl, and 1-12.5 and 9.5-22 mug/dl. For representative patients, our resting values have been 1.2-5.2 mug/dl, vs 1.2-7.6 mug after ACTH stimulation (Table 2). Altogether we have studied 42 cases in detail, and we feel that a post-ACTH level of 8.0 mug/dl or less is a conservative indication of adrenocortical insufficiency; all levels have been between 1 and 8 mug/dl. We believe these low cortisol levels indicate either a genetically-induced adrenal cortical insufficiency (evident at 2 months to 1 year of age) or an immune complex adrenal cortical suppression (occurring after 1 year of age in association with other immunodeficiency disorders). Our studies demonstrate a need for biphasic therapy. We have found it necessary to not only initiate cortisone acetate therapy to support the deficient adrenal cortical secretion, but also use other immunosuppressive drugs to control the ICD. If the target organ has been suppressed or destroyed, the need for supplementation is obvious. However, other immune-injury moieties must be suppressed also, eg, ANA, anti-IgG antibodies, etc.
Spatiotemporal Imaging of Complexity
Stephen Ellis Robinson
2013-01-01
Full Text Available What are the functional neuroimaging measurements required for more fully characterizing the events and locations of neocortical activity? A prime assumption has been that modulation of cortical activity will inevitably be reflected in changes in energy utilization (for the most part changes of glucose and oxygen consumption. Are such a measures complete and sufficient? More direct measures of cortical electrophysiological activity show event or task-related modulation of amplitude or band-limited oscillatory power. Using magnetoencephalography (MEG, these measures have been shown to correlate well with energy utilization sensitive BOLD fMRI. In this paper, we explore the existence of state changes in electrophysiological cortical activity that can occur independently of changes in averaged amplitude, source power or indices of metabolic rates. In addition, we demonstrate that such state changes can be described by applying a new measure of complexity, rank vector entropy (RVE, to source waveform estimates from beamformer-processed MEG. RVE is a non-parametric symbolic dynamic informational entropy measure that accommodates the wide dynamic range of measured brain signals while resolving its temporal variations. By representing the measurements by their rank values, RVE overcomes the problem of defining embedding space partitions without resorting to signal compression. This renders RVE independent of absolute signal amplitude. In addition, this approach is robust, being relatively free of tunable parameters. We present examples of task-free and task dependent MEG demonstrating that RVE provides new information by uncovering hidden dynamical struc-ture in the apparent turbulent (or chaotic dynamics of spontaneous cortical activity.
van der Made, A D; Wieldraaijer, T; Kerkhoffs, G M; Kleipool, R P; Engebretsen, L; van Dijk, C N; Golanó, P
2015-07-01
The anatomical appearance of the hamstring muscle complex was studied to provide hypotheses for the hamstring injury pattern and to provide reference values of origin dimensions, muscle length, tendon length, musculotendinous junction (MTJ) length as well as width and length of a tendinous inscription in the semitendinosus muscle known as the raphe. Fifty-six hamstring muscle groups were dissected in prone position from 29 human cadaveric specimens with a median age of 71.5 (range 45-98). Data pertaining to origin dimensions, muscle length, tendon length, MTJ length and length as well as width of the raphe were collected. Besides these data, we also encountered interesting findings that might lead to a better understanding of the hamstring injury pattern. These include overlapping proximal and distal tendons of both the long head of the biceps femoris muscle and the semimembranosus muscle (SM), a twist in the proximal SM tendon and a tendinous inscription (raphe) in the semitendinosus muscle present in 96 % of specimens. No obvious hypothesis can be provided purely based on either muscle length, tendon length or MTJ length. However, it is possible that overlapping proximal and distal tendons as well as muscle architecture leading to a resultant force not in line with the tendon predispose to muscle injury, whereas the presence of a raphe might plays a role in protecting the muscle against gross injury. Apart from these architectural characteristics that may contribute to a better understanding of the hamstring injury pattern, the provided reference values complement current knowledge on surgically relevant hamstring anatomy. IV.
ON COMPLEX DYNAMIC CONTROL SYSTEMS
CHENG Daizhan
2003-01-01
This paper presents some recent works on the control of dynamic systems, which have certain complex properties caused by singularity of the nonlinear structures, structure-varyings, or evolution process etc. First, we consider the structure singularity of nonlinear control systems. It was revealed that the focus of researches on nonlinear control theory is shifting from regular systems to singular systems. The singularity of nonlinear systems causes certain complexity. Secondly, the switched systems are considered. For such systems the complexity is caused by the structure varying. We show that the switched systems have significant characteristics of complex systems. Finally, we investigate the evolution systems. The evolution structure makes complexity, and itself is a proper model for complex systems.
Increasing complexity with quantum physics.
Anders, Janet; Wiesner, Karoline
2011-09-01
We argue that complex systems science and the rules of quantum physics are intricately related. We discuss a range of quantum phenomena, such as cryptography, computation and quantum phases, and the rules responsible for their complexity. We identify correlations as a central concept connecting quantum information and complex systems science. We present two examples for the power of correlations: using quantum resources to simulate the correlations of a stochastic process and to implement a classically impossible computational task.
Ecological thinking, education and complexity
Karol Herian
2008-01-01
The article reflects contemporary discussions on formation of ecological thinking and educational theory and praxis, all of which is related to the development of complex sciences - from two points of view: The first deals with ecological thinking with regard to meta-scientific implications of the disciplines dealing with organized complexity; the second concentrates on the relevance and impact of complexity science for transformation processes in the field of education (paradigms and institu...
Report: Genetics of complex diseases
MOTULSKY Arno G.
2006-01-01
Approaches to the study of the genetic basis of common complex diseases and their clinical applications are considered. Monogenic Mendelian inheritance in such conditions is infrequent but its elucidation may help to detect pathogenic mechanisms in the more common variety of complex diseases. Involvement by multiple genes in complex diseases usually occurs but the isolation and identification of specific genes so far has been exceptional. The role of common polymorphisms as indicators of disease risk in various studies is discussed.
On the interaction meteor complex
Rajchl, J.
An approach to the problem of a meteoric complex called the interaction meteor complex (IMC) is applied and discussed, generalizing the idea of the interaction layer (Rajchl 1969). The role of an extended interaction of meteoroids is emphasized, both with planet surfaces and/or their satellites and with planet atmospheres, elastic or inelastic in form. The dissipation and related formative aspect are joined in one complex and compared with a topological compact. Examples of these types of interaction are presented.
Measuring Complexity through Average Symmetry
Alamino, Roberto C.
2015-01-01
This work introduces a complexity measure which addresses some conflicting issues between existing ones by using a new principle - measuring the average amount of symmetry broken by an object. It attributes low (although different) complexity to either deterministic or random homogeneous densities and higher complexity to the intermediate cases. This new measure is easily computable, breaks the coarse graining paradigm and can be straightforwardly generalised, including to continuous cases an...
SYNCHRONIZATION IN COMPLEX DYNAMICAL NETWORKS
WANG Xiaofan; CHEN Guanrong
2003-01-01
In the past few years, the discovery of small-world and scale-free properties of many natural and artificial complex networks has stimulated increasing interest in further studying the underlying organizing principles of various complex networks. This has led to significant advances in understanding the relationship between the topology and the dynamics of such complex networks. This paper reviews some recent research works on the synchronization phenomenon in various dynamical networks with small-world and scalefree connections.
Xie, Hang
The theme of this thesis is the study of wave phenomena in complex systems. In particular, the following three topics constitute the foci of my research. The first topic involves the generalization of an electronic transport mechanism commonly observed in disordered media, fluctuation induced tunneling conduction, by considering tunneling through not just insulating potential barriers, but also narrow conducting channels. Here the wave nature of the electron implies that a narrow conduction channel can act as an electronic waveguide, with a cutoff transverse dimension that is half the Fermi wavelength. My research involves the study of electronic transport through finite-length conducting channels with transverse dimensions below the cutoff. Such narrow conduction channel may be physically realized by chains of single conducting atoms, for example. At small voltage bias across the conduction channel, only tunneling transport is possible at zero temperature. But at finite temperatures some of the electrons with energies above the Fermi level can ballistically transport across the channel. By considering both tunneling and thermal activation mechanisms, with thermally-generated (random) voltage bias across the narrow channel, we obtained a temperature-dependent conductivity behavior that is in good agreement with the measured two-lead conductance of RuO2 and IrO2 nanowires. Furthermore, by considering high applied voltage across the nano conduction channels, our model predicts interesting electronic Fabry-Perot behavior whose experimental verification is presently underway. The second topic involves the study of the Hall effect in mesoscopic samples. In particular, we are interested in the possibility of enhancing the Hall effect by nano-patterning samples of 2D electron gas. Through numerical solution of the Schrodinger equation in the presence of a magnetic field, mesoscopic transport behavior is obtained for samples with given geometric patterns of the
Complexity leadership: a healthcare imperative.
Weberg, Dan
2012-01-01
The healthcare system is plagued with increasing cost and poor quality outcomes. A major contributing factor for these issues is that outdated leadership practices, such as leader-centricity, linear thinking, and poor readiness for innovation, are being used in healthcare organizations. Complexity leadership theory provides a new framework with which healthcare leaders may practice leadership. Complexity leadership theory conceptualizes leadership as a continual process that stems from collaboration, complex systems thinking, and innovation mindsets. Compared to transactional and transformational leadership concepts, complexity leadership practices hold promise to improve cost and quality in health care. © 2012 Wiley Periodicals, Inc.
Measuring Complexity of SAP Systems
Ilja Holub
2016-10-01
Full Text Available The paper discusses the reasons of complexity rise in ERP system SAP R/3. It proposes a method for measuring complexity of SAP. Based on this method, the computer program in ABAP for measuring complexity of particular SAP implementation is proposed as a tool for keeping ERP complexity under control. The main principle of the measurement method is counting the number of items or relations in the system. The proposed computer program is based on counting of records in organization tables in SAP.
Kolmogorov Complexity, Causality And Spin
Shayda, Dara O
2012-01-01
A novel topological and computational method for 'motion' is described. Motion is constrained by inequalities in terms of Kolmogorov Complexity. Causality is obtained as the output of a high-pass filter, passing through only high values of Kolmogorov Complexity. Motion under the electromagnetic field described with immediate relationship with Subscript[G, 2] Holonomy group and its corresponding dense free 2-subgroup. Similar to Causality, Spin emerges as an immediate and inevitable consequence of high values of Kolmogorov Complexity. Consequently, the physical laws are nothing but a low-pass filter for small values of Kolmogorov Complexity.
Structural complexity of quantum networks
Siomau, Michael [Physics Department, Jazan University, P.O.Box 114, 45142 Jazan (Saudi Arabia); Network Dynamics, Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen (Germany)
2016-06-10
Quantum network is a set of nodes connected with channels, through which the nodes communicate photons and classical information. Classical structural complexity of a quantum network may be defined through its physical structure, i.e. mutual position of nodes and channels connecting them. We show here that the classical structural complexity of a quantum network does not restrict the structural complexity of entanglement graphs, which may be created in the quantum network with local operations and classical communication. We show, in particular, that 1D quantum network can simulate both simple entanglement graphs such as lattices and random graphs and complex small-world graphs.
Cyclomatic Complexity: theme and variations
Brian Henderson-Sellers
1993-11-01
Full Text Available Focussing on the "McCabe family" of measures for the decision/logic structure of a program, leads to an evaluation of extensions to modularization, nesting and, potentially, to object-oriented program structures. A comparison of rated, operating and essential complexities of programs suggests two new metrics: "inessential complexity" as a measure of unstructuredness and "product complexity" as a potential objective measure of structural complexity. Finally, nesting and abstraction levels are considered, especially as to how metrics from the "McCabe family" might be applied in an object-oriented systems development environment.
Reynolds, Alan P.; Ross, Simon F.
2017-09-01
We consider the holographic complexity conjectures for de-Sitter invariant states in a quantum field theory on de Sitter space, dual to asymptotically anti-de Sitter geometries with de Sitter boundaries. The bulk holographic duals include solutions with or without a horizon. If we compute the complexity from the spatial volume, we find results consistent with general expectations, but the conjectured bound on the growth rate is not saturated. If we compute complexity from the action of the Wheeler–de Witt patch, we find qualitative differences from the volume calculation, with states of smaller energy having larger complexity than those of larger energy, even though the latter have bulk horizons.
Technetium-aspirin molecule complexes
El-Shahawy, A.S.; Mahfouz, R.M.; Aly, A.A.M.; El-Zohry, M. (Assiut Univ. (Egypt))
1993-01-01
Technetium-aspirin and technetium-aspirin-like molecule complexes were prepared. The structure of N-acetylanthranilic acid (NAA) has been decided through CNDO calculations. The ionization potential and electron affinity of the NAA molecule as well as the charge densities were calculated. The electronic absorption spectra of Tc(V)-Asp and Tc(V)-ATS complexes have two characteristic absorption bands at 450 and 600 nm, but the Tc(V)-NAA spectrum has one characteristic band at 450 nm. As a comparative study, Mo-ATS complex was prepared and its electronic absorption spectrum is comparable with the Tc-ATS complex spectrum. (author).
Complex Constructivism: A Theoretical Model of Complexity and Cognition
Doolittle, Peter E.
2014-01-01
Education has long been driven by its metaphors for teaching and learning. These metaphors have influenced both educational research and educational practice. Complexity and constructivism are two theories that provide functional and robust metaphors. Complexity provides a metaphor for the structure of myriad phenomena, while constructivism…
Complexity regularized hydrological model selection
Pande, S.; Arkesteijn, L.; Bastidas, L.A.
2014-01-01
This paper uses a recently proposed measure of hydrological model complexity in a model selection exercise. It demonstrates that a robust hydrological model is selected by penalizing model complexity while maximizing a model performance measure. This especially holds when limited data is available.
Complex multiplication of abelian surfaces
Streng, Theodorus Cornelis
2010-01-01
The theory of complex multiplication makes it possible to construct certain class fields and abelian varieties. The main theme of this thesis is making these constructions explicit for the case where the abelian varieties have dimension 2. Chapter I is an introduction to complex multiplication
Bauerlein, Mark
2011-01-01
High school students' lack of experience and practice with reading complex texts is a primary cause of their difficulties with college-level reading. Filling the syllabus with digital texts does little to address this deficiency. Complex texts demand three dispositions from readers: a willingness to probe works characterized by dense meanings, the…
Multi-Timescale Complex Adaptation
2006-03-01
interconnected gene and biochemical regulatory networks. Attempts at reverse engineering the gene regulatory networks from microarray data alone...are considered as potentially regulating all the other genes and the suboptimal and nonunique results are subsequently pruned either by setting...postulate that systems engineering techniques developed for complex chemical processes may be applicable to complex cell biological processes is very
Complexity and Education: Vital Simultaneities
Davis, Brent
2008-01-01
This article explores the place of complexity science within education and educational research. The discussion begins with the suggestion that educational research has a history of adopting interpretive frames from other domains with little adaptation. Complexity science is argued to compel a different sort of positioning, one that requires…
Teacher Knowledge: A Complex Tapestry
Adoniou, Misty
2015-01-01
Teachers need to know a great deal, in many areas and in multiple ways. Teacher knowledge is a complex tapestry, and teachers must successfully weave the multiple threads. In this article, I present a conceptualisation of teacher knowledge that provides a framework for describing the complexity of teacher knowledge. The framework describes three…
Electrochemical analysis of metal complexes.
Jong, de H.G.
1987-01-01
The present study is concerned with the electroanalytical chemistry of complexes of metals with large ligands. The main purpose was to develop quantitative descriptions of the voltammetric current-potential relation of metal complex systems with different diffusion coefficients of the species involv
Complexity Results in Epistemic Planning
Bolander, Thomas; Jensen, Martin Holm; Schwarzentruber, Francois
2015-01-01
Epistemic planning is a very expressive framework that extends automated planning by the incorporation of dynamic epistemic logic (DEL). We provide complexity results on the plan existence problem for multi-agent planning tasks, focusing on purely epistemic actions with propositional preconditions......-hardness of the plan verification problem, which strengthens previous results on the complexity of DEL model checking....
Holistic education and complexity thinking
Jörg, T.|info:eu-repo/dai/nl/069806365
2007-01-01
Paper proposal for the SIG Holistic Education at AERA 2007 Title: Holistic Education and Complexity Thinking Ton Jörg IVLOS Institute of Education University of Utrecht The Netherlands A.G.D.Jorg@ivlos.uu.nl ABSTRACT In this paper I link complexity thinking with Holistic Education (HE). It is a
Complexity regularized hydrological model selection
Pande, S.; Arkesteijn, L.; Bastidas, L.A.
2014-01-01
This paper uses a recently proposed measure of hydrological model complexity in a model selection exercise. It demonstrates that a robust hydrological model is selected by penalizing model complexity while maximizing a model performance measure. This especially holds when limited data is available.
Copper complexes as chemical nucleases
Akhil R Chakravarty; Pattubala A N Reddy; Bidyut K Santra; Anitha M Thomas
2002-08-01
Redox active mononuclear and binuclear copper(II) complexes have been prepared and structurally characterized. The complexes have planar N-donor heterocyclic bases like 1,10-phenanthroline (phen), dipyridoquinoxaline (dpq) and dipyridophenazine (dppz) ligands that are suitable for intercalation to B-DNA. Complexes studied for nuclease activity have the formulations [Cu(dpq)2(H2O)] (ClO4)2.H2O (1), [{CuL(H2O)}2(-ox)](ClO4)2 (L = bpy, 2; phen, 3; dpq, 4; and dppz, 5) and [Cu(L)(salgly)] (L = bpy, 6; phen, 7; dpq, 8; and dppz, 9), where salgly is a tridentate Schiff base obtained from the condensation of glycine and salicylaldehyde. The dpq complexes are efficient DNA binding and cleavage active species. The dppz complexes show good binding ability but poor nuclease activity. The cleavage activity of the bis-dpq complex is significantly higher than the bis-phen complex of copper(II). The nuclease activity is found to be dependent on the intercalating nature of the complex and on the redox potential of the copper(II)/copper(I) couple. The ancillary ligand plays a significant role in binding and cleavage activity.
How to lead complex situations
Hansen, Michael Pingel
2013-01-01
The military leader is experiencing increasingly more complex situations, whether it is as leader in a foreign combat environment or in the home-based public administration. Complex situations like these call for a special set of managerial responses and a special way of leading organisations...
Complex Variables in Secondary Schools
Dwyer, Jerry; Moskal, Barbara; Duke, Billy; Wilhelm, Jennifer
2007-01-01
This article describes the work of outreach mathematicians introducing the topic of complex variables to eighth and ninth grade students (13- to 15-year-olds) in the US. Complex variables is an area of mathematics that is not typically studied at secondary level. The authors developed seven lessons designed to stimulate students' interest in…
Holistic education and complexity thinking
Jörg, T.|info:eu-repo/dai/nl/069806365
2007-01-01
Paper proposal for the SIG Holistic Education at AERA 2007 Title: Holistic Education and Complexity Thinking Ton Jörg IVLOS Institute of Education University of Utrecht The Netherlands A.G.D.Jorg@ivlos.uu.nl ABSTRACT In this paper I link complexity thinking with Holistic Education (HE). It is a chal
The Algebra of Complex Numbers.
LePage, Wilbur R.
This programed text is an introduction to the algebra of complex numbers for engineering students, particularly because of its relevance to important problems of applications in electrical engineering. It is designed for a person who is well experienced with the algebra of real numbers and calculus, but who has no experience with complex number…
Holistic education and complexity thinking
Jörg, T.
2007-01-01
Paper proposal for the SIG Holistic Education at AERA 2007 Title: Holistic Education and Complexity Thinking Ton Jörg IVLOS Institute of Education University of Utrecht The Netherlands A.G.D.Jorg@ivlos.uu.nl ABSTRACT In this paper I link complexity thinking with Holistic Education (HE). It is a chal
Holographic complexity and spacetime singularities
Barbón, José L.F. [Instituto de Física Teórica IFT UAM/CSIC,C/ Nicolás Cabrera 13, Campus Universidad Autónoma de Madrid,Madrid 28049 (Spain); Rabinovici, Eliezer [Racah Institute of Physics, The Hebrew University,Jerusalem 91904 (Israel); Laboratoire de Physique Théorique et Hautes Energies, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France)
2016-01-15
We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.
Improve Reading with Complex Texts
Fisher, Douglas; Frey, Nancy
2015-01-01
The Common Core State Standards have cast a renewed light on reading instruction, presenting teachers with the new requirements to teach close reading of complex texts. Teachers and administrators should consider a number of essential features of close reading: They are short, complex texts; rich discussions based on worthy questions; revisiting…
Team dynamics in complex projects
Oeij, P.; Vroome, E.E.M. de; Dhondt, S.; Gaspersz, J.B.R.
2012-01-01
Complexity of projects is hotly debated and a factor which affects innovativeness of team performance. Much attention in the past is paid to technical complexity and many issues are related to natural and physical sciences. A growing awareness of the importance of socioorganisational issues is annou
Team dynamics in complex projects
Oeij, P.; Vroome, E.E.M. de; Dhondt, S.; Gaspersz, J.B.R.
2012-01-01
Complexity of projects is hotly debated and a factor which affects innovativeness of team performance. Much attention in the past is paid to technical complexity and many issues are related to natural and physical sciences. A growing awareness of the importance of socioorganisational issues is
Complex Data: Mining using Patterns
Siebes, A.P.J.M.; Struzik, Z.R.
2002-01-01
There is a growing need to analyse sets of complex data, i.e., data in which the individual data items are (semi-) structured collections of data themselves, such as sets of time-series. To perform such analysis, one has to redefine familiar notions such as similarity on such complex data types. One
Complexity Metrics for Workflow Nets
Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.
2009-01-01
, etc. It seems obvious that the complexity of the model contributes to design errors and a lack of understanding. It is not easy to measure complexity, however. This paper presents three complexity metrics that have been implemented in the process analysis tool ProM. The metrics are defined...... analysts have difficulties grasping the dynamics implied by a process model. Recent empirical studies show that people make numerous errors when modeling complex business processes, e.g., about 20 percent of the EPCs in the SAP reference model have design flaws resulting in potential deadlocks, livelocks...... for a subclass of Petri nets named Workflow nets, but the results can easily be applied to other languages. To demonstrate the applicability of these metrics, we have applied our approach and tool to 262 relatively complex Protos models made in the context of various student projects. This allows us to validate...
European Conference on Complex Systems
Pellegrini, Francesco; Caldarelli, Guido; Merelli, Emanuela
2016-01-01
This work contains a stringent selection of extended contributions presented at the meeting of 2014 and its satellite meetings, reflecting scope, diversity and richness of research areas in the field, both fundamental and applied. The ECCS meeting, held under the patronage of the Complex Systems Society, is an annual event that has become the leading European conference devoted to complexity science. It offers cutting edge research and unique opportunities to study novel scientific approaches in a multitude of application areas. ECCS'14, its eleventh occurrence, took place in Lucca, Italy. It gathered some 650 scholars representing a wide range of topics relating to complex systems research, with emphasis on interdisciplinary approaches. The editors are among the best specialists in the area. The book is of great interest to scientists, researchers and graduate students in complexity, complex systems and networks.
Game interpretation of Kolmogorov complexity
Muchnik, Andrej A; Shen, Alexander; Vereshchagin, Nikolay
2010-01-01
The Kolmogorov complexity function K can be relativized using any oracle A, and most properties of K remain true for relativized versions. In section 1 we provide an explanation for this observation by giving a game-theoretic interpretation and showing that all "natural" properties are either true for all sufficiently powerful oracles or false for all sufficiently powerful oracles. This result is a simple consequence of Martin's determinacy theorem, but its proof is instructive: it shows how one can prove statements about Kolmogorov complexity by constructing a special game and a winning strategy in this game. This technique is illustrated by several examples (total conditional complexity, bijection complexity, randomness extraction, contrasting plain and prefix complexities).
Managing complexity insights, concepts, applications
Helbing, Dirk
2007-01-01
Each chapter in Managing Complexity focuses on analyzing real-world complex systems and transferring knowledge from the complex-systems sciences to applications in business, industry and society. The interdisciplinary contributions range from markets and production through logistics, traffic control, and critical infrastructures, up to network design, information systems, social conflicts and building consensus. They serve to raise readers' awareness concerning the often counter-intuitive behavior of complex systems and to help them integrate insights gained in complexity research into everyday planning, decision making, strategic optimization, and policy. Intended for a broad readership, the contributions have been kept largely non-technical and address a general, scientifically literate audience involved in corporate, academic, and public institutions.
Innovation in a complex environment
René Pellissier
2012-02-01
Full Text Available Background: As our world becomes more global and competitive yet less predictable, the focus seems to be increasingly on looking to innovation activities to remain competitive. Although there is little doubt that a nation’s competitiveness is embedded in its innovativeness, the complex environment should not be ignored. Complexity is not accounted for in balance sheets or reported in reports; it becomes entrenched in every activity in the organisation. Innovation takes many forms and comes in different shapes.Objectives: The study objectives were, firstly, to establish the determinants for complexity and how these can be addressed from a design point of view in order to ensure innovation success and, secondly, to determine how this changes innovation forms and applications.Method: Two approaches were offered to deal with a complex environment – one allowing for complexity for organisational innovation and the other introducing reductionism to minimise complexity. These approaches were examined in a qualitative study involving case studies, open-ended interviews and content analysis between seven developing economy (South African organisations and seven developed economy (US organisations.Results: This study presented a proposed framework for (organisational innovation in a complex environment versus a framework that minimises complexity. The comparative organisational analysis demonstrated the importance of initiating organisational innovation to address internal and external complexity, with the focus being on the leadership actions, their selected operating models and resultant organisational innovations designs, rather than on technological innovations.Conclusion: This study cautioned the preference for technological innovation within organisations and suggested alternative innovation forms (such as organisational and management innovation be used to remain competitive in a complex environment.
Complex coacervation: A field theoretic simulation study of polyelectrolyte complexation
Lee, Jonghoon; Popov, Yuri O.; Fredrickson, Glenn H.
2008-06-01
Using the complex Langevin sampling strategy, field theoretic simulations are performed to study the equilibrium phase behavior and structure of symmetric polycation-polyanion mixtures without salt in good solvents. Static structure factors for the segment density and charge density are calculated and used to study the role of fluctuations in the electrostatic and chemical potential fields beyond the random phase approximation. We specifically focus on the role of charge density and molecular weight on the structure and complexation behavior of polycation-polyanion solutions. A demixing phase transition to form a ``complex coacervate'' is observed in strongly charged systems, and the corresponding spinodal and binodal boundaries of the phase diagram are investigated.
Intermittency in Complex Flows
Ben Mahjoub, Otman; Redondo, Jose M.
2017-04-01
Experimental results of the complex turbulent wake of a cilinder in 2D [1] and 3D flows [2] were used to investigate the scaling of structure functions, similar research was also performed on wave propagation and breaking in the Ocean [3], in the the stratified Atmosphere (ABL) [4] and in a 100large flume (UPC) for both regular and irregular waves, where long time series of waves propagating and generating breaking turbulence velocity rms and higher order measurements were taken in depth. [3,5] by means of a velocimeter SONTEK3-D. The probability distribution functions of the velocity differences and their non Gaussian distribution related to the energy spectrum indicate that irregularity is an important source of turbulence. From Kolmogorov's K41 and K61 intermittency correction: the p th-order longitudinal velocity structure function δul at scale l in the inertial range of three-dimensional fully developed turbulence is related by ⟨δup⟩ = ⟨(u(x+ l)- u(x))p⟩ ˜ ɛp0/3lp/3 l where ⟨...⟩ represents the spatial average over flow domain, with ɛ0 the mean energy dissipation per unit mass and l is the separation distance. The importance of the random nature of the energy dissipation led to the K62 theory of intermittency, but locality and non-homogeneity are key issues. p p/3 p/3 ξd ⟨δul⟩ ˜ ⟨ɛl ⟩l ˜ l and ξp = p 3 + τp/3 , where now ɛl is a fractal energy dissipation at scale l, τp/3 is the scaling of and ξp is the scaling exponent of the velocity structure function of order p. Both in K41 and K62, the structure functions of third order related to skewness is ξ3 = 1. But this is not true either. We show that scaling exponents ξp do deviate from early studies that only investigated homogeneous turbulence, where a large inertial range dominates. The use of multi-fractal analysis and improvements on Structure function calculations on standard Enhanced mixing is an essential property of turbulence and efforts to alter and to control
Akdim, Mohamed Reda
2003-09-01
Nowadays plasmas are used for various applications such as the fabrication of silicon solar cells, integrated circuits, coatings and dental cleaning. In the case of a processing plasma, e.g. for the fabrication of amorphous silicon solar cells, a mixture of silane and hydrogen gas is injected in a reactor. These gases are decomposed by making a plasma. A plasma with a low degree of ionization (typically 10_5) is usually made in a reactor containing two electrodes driven by a radio-frequency (RF) power source in the megahertz range. Under the right circumstances the radicals, neutrals and ions can react further to produce nanometer sized dust particles. The particles can stick to the surface and thereby contribute to a higher deposition rate. Another possibility is that the nanometer sized particles coagulate and form larger micron sized particles. These particles obtain a high negative charge, due to their large radius and are usually trapped in a radiofrequency plasma. The electric field present in the discharge sheaths causes the entrapment. Such plasmas are called dusty or complex plasmas. In this thesis numerical models are presented which describe dusty plasmas in reactive and nonreactive plasmas. We started first with the development of a simple one-dimensional silane fluid model where a dusty radio-frequency silane/hydrogen discharge is simulated. In the model, discharge quantities like the fluxes, densities and electric field are calculated self-consistently. A radius and an initial density profile for the spherical dust particles are given and the charge and the density of the dust are calculated with an iterative method. During the transport of the dust, its charge is kept constant in time. The dust influences the electric field distribution through its charge and the density of the plasma through recombination of positive ions and electrons at its surface. In the model this process gives an extra production of silane radicals, since the growth of dust is
Complex Convexity of Orlicz Modular Sequence Spaces
Lili Chen
2016-01-01
Full Text Available The concepts of complex extreme points, complex strongly extreme points, complex strict convexity, and complex midpoint locally uniform convexity in general modular spaces are introduced. Then we prove that, for any Orlicz modular sequence space lΦ,ρ, lΦ,ρ is complex midpoint locally uniformly convex. As a corollary, lΦ,ρ is also complex strictly convex.
Three Types of Network Complexity Pyramid
FANG; Jin-qing; LI; Yong; LIU; Qiang
2012-01-01
<正>Exploring the complexity and diversity of complex networks have been very challenging issues in network science and engineering. Among them exploring the network complexity pyramids (NCP) are one of important expressions in network complexity. So far as we have proposed the three types of the network complexity pyramid (NCP). The first type of NCP is the network model complexity pyramid with
Formulation of Complex Action Theory
Nagao, Keiichi
2011-01-01
We formulate the complex action theory from a fundamental level so that we can deal with a complex coordinate $q$ and a complex momentum $p$. We extend $| q >$ and $| p>$ to complex $q$ and $p$ by utilizing coherent states of harmonic oscillators. Introducing a philosophy to keep the analyticity in parameter variables of Feynman path integral, we define a modified set of complex conjugate, real and imaginary parts, hermitian conjugates and bras. They enable us to have both orthogonality and completeness relations for $|q >$ and $|p >$ with complex $q$ and $p$. We also pose a theorem on the relation between functions and operators to make it clear to some extent. Furthermore, extending our previous work \\cite{Nagao:2010xu} to the complex coordinate case, we study a system defined by a diagonalizable non-hermitian bounded Hamiltonian, and show that a hermitian Hamiltonian is effectively obtained after a long time development by introducing a proper inner product. If the hermitian Hamiltonian is given in a local...
3D complex: a structural classification of protein complexes.
Emmanuel D Levy
2006-11-01
Full Text Available Most of the proteins in a cell assemble into complexes to carry out their function. It is therefore crucial to understand the physicochemical properties as well as the evolution of interactions between proteins. The Protein Data Bank represents an important source of information for such studies, because more than half of the structures are homo- or heteromeric protein complexes. Here we propose the first hierarchical classification of whole protein complexes of known 3-D structure, based on representing their fundamental structural features as a graph. This classification provides the first overview of all the complexes in the Protein Data Bank and allows nonredundant sets to be derived at different levels of detail. This reveals that between one-half and two-thirds of known structures are multimeric, depending on the level of redundancy accepted. We also analyse the structures in terms of the topological arrangement of their subunits and find that they form a small number of arrangements compared with all theoretically possible ones. This is because most complexes contain four subunits or less, and the large majority are homomeric. In addition, there is a strong tendency for symmetry in complexes, even for heteromeric complexes. Finally, through comparison of Biological Units in the Protein Data Bank with the Protein Quaternary Structure database, we identified many possible errors in quaternary structure assignments. Our classification, available as a database and Web server at http://www.3Dcomplex.org, will be a starting point for future work aimed at understanding the structure and evolution of protein complexes.
Complexity in physics and technology
Garrido, Manuel S
1992-01-01
A system is loosely defined as complex if it is composed of a large number of elements, interacting with each other, and the emergent global dynamics is qualitatively different from the dynamics of each one of the parts. The global dynamics may be either ordered or chaotic and among the most interesting emergent global properties are those of learning and adaptation.Complex systems, in the above sense, appear in many fields ranging from physics and technology to life and social sciences. Research in complex systems involves therefore a wide range of topics, studied in seemingly disparate field
Quantum Tunneling and Complex Trajectories
Meynig, Max; Haggard, Hal
2017-01-01
In general, the semiclassical approximation of quantum mechanical tunneling fails to treat tunneling through barriers if real initial conditions and trajectories are used. By analytically continuing classical dynamics to the complex plane the problems encountered in the approximation can be resolved. While, the complex methods discussed here have been previously explored, no one has exhibited an analytically solvable case. The essential features of the complex method will be discussed in the context of a novel, analytically solvable problem. These methods could be useful in quantum gravity, with applications to the tunneling of spacetime geometries.
Advances in computational complexity theory
Cai, Jin-Yi
1993-01-01
This collection of recent papers on computational complexity theory grew out of activities during a special year at DIMACS. With contributions by some of the leading experts in the field, this book is of lasting value in this fast-moving field, providing expositions not found elsewhere. Although aimed primarily at researchers in complexity theory and graduate students in mathematics or computer science, the book is accessible to anyone with an undergraduate education in mathematics or computer science. By touching on some of the major topics in complexity theory, this book sheds light on this burgeoning area of research.
Complexity Metrics for Workflow Nets
Lassen, Kristian Bisgaard; van der Aalst, Wil M.P.
2009-01-01
Process modeling languages such as EPCs, BPMN, flow charts, UML activity diagrams, Petri nets, etc.\\ are used to model business processes and to configure process-aware information systems. It is known that users have problems understanding these diagrams. In fact, even process engineers and system......, etc. It seems obvious that the complexity of the model contributes to design errors and a lack of understanding. It is not easy to measure complexity, however. This paper presents three complexity metrics that have been implemented in the process analysis tool ProM. The metrics are defined...
Complexity and Shock Wave Geometries
Stanford, Douglas
2014-01-01
In this paper we refine a conjecture relating the time-dependent size of an Einstein-Rosen bridge to the computational complexity of the of the dual quantum state. Our refinement states that the complexity is proportional to the spatial volume of the ERB. More precisely, up to an ambiguous numerical coefficient, we propose that the complexity is the regularized volume of the largest codimension one surface crossing the bridge, divided by $G_N l_{AdS}$. We test this conjecture against a wide variety of spherically symmetric shock wave geometries in different dimensions. We find detailed agreement.
Epidemic Diffusion on Complex Networks
WU Xiao-Yan; LIU Zong-Hua
2007-01-01
Boyh diffusion and epidemic are well studied in the stochastic systems and complex networks,respetively.Here we combine these two fields and study epidemic diffusion in complex networks.Instead of studying the threshold of infection,which was focused on in previous works,we focus on the diffusion.behaviour.We find that the epidemic diffusion in a complex network is an anomalous superdiffusion with varyingg diffusion exponext γand that γ is influenced seriously by the network structure,such as the clustering coefficient and the degree distribution.Numerical simulations have confirmed the theoretical predictions.
Scattering methods in complex fluids
Chen, Sow-Hsin
2015-01-01
Summarising recent research on the physics of complex liquids, this in-depth analysis examines the topic of complex liquids from a modern perspective, addressing experimental, computational and theoretical aspects of the field. Selecting only the most interesting contemporary developments in this rich field of research, the authors present multiple examples including aggregation, gel formation and glass transition, in systems undergoing percolation, at criticality, or in supercooled states. Connecting experiments and simulation with key theoretical principles, and covering numerous systems including micelles, micro-emulsions, biological systems, and cement pastes, this unique text is an invaluable resource for graduate students and researchers looking to explore and understand the expanding field of complex fluids.
Hydrophysical laser-interference complex
Sergey V. Yakovenko
2016-12-01
Full Text Available A new hydrophysical measuring complex has been developed on the basis of a laser instrument for measuring hydrospheric pressure variations. The complex was previously engineered and experimentally verified. This equipment allows to investigate the amplitude-phase variations of hydrospheric vibrations and waves in the low-frequency range. All performance data of the complex was considerably improved by virtue of the operating experience obtained previously. Radically new opportunities of the equipment were provided since the apparatus was rigged with new sensors for accompanying measurements and a container which allowed working independently. The new hydrophysical measuring complex is easier to operate and maintain, ensures higher quality of the data obtained and new spheres of application.
Machining of Complex Sculptured Surfaces
2012-01-01
The machining of complex sculptured surfaces is a global technological topic in modern manufacturing with relevance in both industrialized and emerging in countries particularly within the moulds and dies sector whose applications include highly technological industries such as the automotive and aircraft industry. Machining of Complex Sculptured Surfaces considers new approaches to the manufacture of moulds and dies within these industries. The traditional technology employed in the manufacture of moulds and dies combined conventional milling and electro-discharge machining (EDM) but this has been replaced with high-speed milling (HSM) which has been applied in roughing, semi-finishing and finishing of moulds and dies with great success. Machining of Complex Sculptured Surfaces provides recent information on machining of complex sculptured surfaces including modern CAM systems and process planning for three and five axis machining as well as explanations of the advantages of HSM over traditional methods ra...
Challenges in Complex Systems Science
Miguel, Maxi San; Kertesz, Janos; Kaski, Kimmo; Díaz-Guilera, Albert; MacKay, Robert S; Loreto, Vittorio; Erdi, Peter; Helbing, Dirk
2012-01-01
FuturICT foundations are social science, complex systems science, and ICT. The main concerns and challenges in the science of complex systems in the context of FuturICT are laid out in this paper with special emphasis on the Complex Systems route to Social Sciences. This include complex systems having: many heterogeneous interacting parts; multiple scales; complicated transition laws; unexpected or unpredicted emergence; sensitive dependence on initial conditions; path-dependent dynamics; networked hierarchical connectivities; interaction of autonomous agents; self-organisation; non-equilibrium dynamics; combinatorial explosion; adaptivity to changing environments; co-evolving subsystems; ill-defined boundaries; and multilevel dynamics. In this context, science is seen as the process of abstracting the dynamics of systems from data. This presents many challenges including: data gathering by large-scale experiment, participatory sensing and social computation, managing huge distributed dynamic and heterogeneou...
Complex Topographic Feature Ontology Patterns
Varanka, Dalia E.; Jerris, Thomas J.
2015-01-01
Semantic ontologies are examined as effective data models for the representation of complex topographic feature types. Complex feature types are viewed as integrated relations between basic features for a basic purpose. In the context of topographic science, such component assemblages are supported by resource systems and found on the local landscape. Ontologies are organized within six thematic modules of a domain ontology called Topography that includes within its sphere basic feature types, resource systems, and landscape types. Context is constructed not only as a spatial and temporal setting, but a setting also based on environmental processes. Types of spatial relations that exist between components include location, generative processes, and description. An example is offered in a complex feature type ‘mine.’ The identification and extraction of complex feature types are an area for future research.
Making the Tent Function Complex
Sprows, David J.
2010-01-01
This note can be used to illustrate to the student such concepts as periodicity in the complex plane. The basic construction makes use of the Tent function which requires only that the student have some working knowledge of binary arithmetic.
Complex systems: physics beyond physics
Holovatch, Yurij; Thurner, Stefan
2016-01-01
Complex systems are characterized by specific time-dependent interactions among their many constituents. As a consequence they often manifest rich, non-trivial and unexpected behavior. Examples arise both in the physical and non-physical world. The study of complex systems forms a new interdisciplinary research area that cuts across physics, biology, ecology, economics, sociology, and the humanities. In this paper we review the essence of complex systems from a physicist's point of view, and try to clarify what makes them conceptually different from systems that are traditionally studied in physics. Our goal is to demonstrate how the dynamics of such systems may be conceptualized in quantitative and predictive terms by extending notions from statistical physics and how they can often be captured in a framework of co-evolving multiplex network structures. We mention three areas of complex-systems science that are currently studied extensively, the science of cities, dynamics of societies, and the representatio...
Project Dynamics and Emergent Complexity
Schlick, Christopher M
2011-01-01
The present paper presents theoretical and empirical analyses of project dynamics and emergent complexity in new product development (NPD) projects. A model-driven approach was taken and a vector autoregression (VAR) model of cooperative task processing was formulated. The model is explained and validated based on an empirical study carried out in a industrial company. Furthermore, concepts and measures of complex systems science were reviewed and applied to project management. To evaluate emergent complexity in NPD projects, an information-theory quantity -termed "effective measure complexity" (EMC)- was selected, because it can be derived from first principles and therefore has high construct validity. Furthermore, EMC can be calculated efficiently from generative models of task processing or purely from historical data, without intervening models. EMC measures the mutual information between the infinite past and future histories of a stochastic process. According to this principle, it is particularly inter...
Synchronization in uncertain complex networks
Chen, Maoyin; Zhou, Donghua
2006-03-01
We consider the problem of synchronization in uncertain generic complex networks. For generic complex networks with unknown dynamics of nodes and unknown coupling functions including uniform and nonuniform inner couplings, some simple linear feedback controllers with updated strengths are designed using the well-known LaSalle invariance principle. The state of an uncertain generic complex network can synchronize an arbitrary assigned state of an isolated node of the network. The famous Lorenz system is stimulated as the nodes of the complex networks with different topologies. We found that the star coupled and scale-free networks with nonuniform inner couplings can be in the state of synchronization if only a fraction of nodes are controlled.
Anomaly Detection for Complex Systems
National Aeronautics and Space Administration — In performance maintenance in large, complex systems, sensor information from sub-components tends to be readily available, and can be used to make predictions about...
Complex Terrain and Wind Lidars
Bingöl, Ferhat
This thesis includes the results of a PhD study about complex terrain and wind lidars. The study mostly focuses on hilly and forested areas. Lidars have been used in combination with cups, sonics and vanes, to reach the desired vertical measurement heights. Several experiments are performed...... in complex terrain sites and the measurements are compared with two different flow models; a linearised flow model LINCOM and specialised forest model SCADIS. In respect to the lidar performance in complex terrain, the results showed that horizontal wind speed errors measured by a conically scanning lidar....... The SCADIS model worked better than the LINCOM model at the forest edge but the model reported closer results to the measurements at upwind than the downwind and this should be noted as a limitation of the model. As the general conclusion of the study, it was stated that the lidars can be used in complex...
Goyal, Philip; Skilling, John
2009-01-01
Complex numbers are an intrinsic part of the mathematical formalism of quantum theory, and are perhaps its most mysterious feature. In this paper, we show that it is possible to derive the complex nature of the quantum formalism directly from the assumption that a pair of real numbers is associated to each sequence of measurement outcomes, and that the probability of this sequence is a real-valued function of this number pair. By making use of elementary symmetry and consistency conditions, and without assuming that these real number pairs have any other algebraic structure, we show that these pairs must be manipulated according to the rules of complex arithmetic. We demonstrate that these complex numbers combine according to Feynman's sum and product rules, with the modulus-squared yielding the probability of a sequence of outcomes.
Formulation of Complex Action Theory
Nagao, Keiichi; Nielsen, Holger Bech
2011-01-01
We formulate a complex action theory which includes operators of coordinate and momentum $\\hat{q}$ and $\\hat{p}$ being replaced with non-hermitian operators $\\hat{q}_{new}$ and $\\hat{p}_{new}$, and their eigenstates ${}_m
ZIRCONIUM (IV) COMPLEXES WITH SOME ...
DR. AMINU
infrared spectra, elemental analysis and other properties suggest that the complexes are six coordinate. The schiff ... paper reports the synthesis and partial characterization of ... filtered, dried in a desiccator over phosphorus(v) oxide and yield ...
Genetics Home Reference: Carney complex
... cortisol (hypercortisolism) can lead to the development of Cushing syndrome. This syndrome causes weight gain in the face ... Institute of Diabetes and Digestive and Kidney Diseases: Cushing's Syndrome Educational Resources (7 links) Disease InfoSearch: Carney Complex ...
Coarse-graining complex dynamics
Sibani, Paolo
2013-01-01
Continuous Time Random Walks (CTRW) are widely used to coarse-grain the evolution of systems jumping from a metastable sub-set of their configuration space, or trap, to another via rare intermittent events. The multi-scaled behavior typical of complex dynamics is provided by a fat-tailed distribu......Continuous Time Random Walks (CTRW) are widely used to coarse-grain the evolution of systems jumping from a metastable sub-set of their configuration space, or trap, to another via rare intermittent events. The multi-scaled behavior typical of complex dynamics is provided by a fat......-law and logarithmic relaxation behaviors ubiquitous in complex dynamics, together with the sub-diffusive time dependence of the Mean Square Displacement characteristic of single particles moving in a complex environment....
Immobile Complex Verbs in Germanic
Vikner, Sten
2005-01-01
Certain complex verbs in Dutch, German, and Swiss German do not undergo verb movement. The suggestion to be made in this article is that these ‘‘immobile'' verbs have to fulfill both the requirements imposed on complex verbs of the V° type (=verbs with non-separable prefixes) and the requirements...... are immobile, - why such verbs are not found in Germanic VO-languages such as English and Scandinavian.......Certain complex verbs in Dutch, German, and Swiss German do not undergo verb movement. The suggestion to be made in this article is that these ‘‘immobile'' verbs have to fulfill both the requirements imposed on complex verbs of the V° type (=verbs with non-separable prefixes) and the requirements...
Unitarity and Complex Mass Fields
Bollini, C. G.; Oxman, L. E.
We consider a field obeying a simple higher order equation with a real mass and two complex conjugate mass parameters. The evaluation of vacuum expectation values leads to the propagators, which are (resp.) a Feynman causal function and two complex conjugate Wheeler-Green functions (half retarded plus half advanced). By means of the computation of convolutions, we are able to show that the total self-energy has an absorptive part which is only due to the real mass. In this way it is shown that this diagram is compatible with unitarity and the elimination of free complex-mass asymptotic states from the set of external legs of the S-matrix. It is also shown that the complex masses act as regulators of ultraviolet divergences.
ON COMPLEXITY OF POWER SYSTEMS
MA Jin; CHENG Daizhan; HONG Yiguang; SUN Yuanzhang
2003-01-01
The power system is a classical example of complex systems. In this paper it is shown that the power industry in China is facing a tremendous challenge. The complexity in power systems is investigated as follows. First, the cascade failure in power systems is analyzed, and compared with sand-pile model. Next, we show that the agent-based modelling is a proper way for power network. Mathematically, the geometric dynamics and differential inclusion are useful tools for the stability analysis of large scale power systems. As for power market, the game theory and generalized control system model are proposed. For a complex power system, an evolutive model may be more accurate in description and analysis. Finally, certain newly developed numerical methods in the power system computation are introduced. Overall, we are convinced that the theorem of complexity, combined with modern control theory, may be the right way to answer the challenges faced by the power industry in China.
Mathematicians, Attributional Complexity, and Gender
Stalder, Daniel R.
Given indirect indications in sex role and soda! psychology research that mathematical-deductive reasoning may negatively relate to social acuity, Study 1 investigated whether mathematicians were less attributionally complex than nonmathematicians. Study 1 administered the Attributional Complexity Scale, a measure of social acuity, to female and male faculty members and graduate students in four Midwestern schools. Atlrihutional complexity (AC) is the ability and motivation to give complex explanations for behavior. Study 1 found a significant interaction between field and gender. Only among women did mathematicians score lower on AC. In addition, an established gender difference in AC (that women score higher than men) was present only among nonmathematicians. Studies 2 and 3 offered some preliminary support for the possibility that it is generally female students who score tow on AC who aspire to he mathematicians and for the underlying view that female students' perceived similarity to mathematicians can influence their vocational choices.
Liquid-crystalline lanthanide complexes
Binnemans, Koen
1999-01-01
The paper describes the recent developments in the field of liquid-crystalline lanthanide complexes. The role of trivalent lanthanide ions as the central metal ion in metallomesogens is considered. An outlook for the future is given.
Association theories for complex thermodynamics
Kontogeorgis, Georgios; Rafiqul Gani
2013-01-01
Thermodynamics of complex systems (e.g. with associating molecules, multicomponent mixtures, multiphase equilibria, wide ranges of conditions, estimation of many different properties simultaneously) is a topic of great importance in chemical engineering and for a wide range of industrial...... promising direction for a general and useful for engineering purposes modeling of complex thermodynamics is via the use of association theories e.g. those based on chemical theory (like APACT), or on the lattice theory (like NRHB) or those based on perturbation theory (like SAFT and CPA). The purpose...... applications. While specialized models can handle different cases, even complex ones, with the advent of powerful theories and computers there is the hope that a single or a few models could be suitable for a general modeling of complex thermodynamics. After more than 100 years with active use of thermodynamic...
Management recommendations: Benton Lake Complex
US Fish and Wildlife Service, Department of the Interior — This document is a review of land management practices at the Benton Lake Complex, by a land use specialist. Recommendations, time frame and additional comments are...
Baillie, J; Sahlender, D A; Sinclair, J H
2003-06-01
Infection with human cytomegalovirus (HCMV) results in complex interactions between viral and cellular factors which perturb many cellular functions. HCMV is known to target the cell cycle, cellular transcription, and immunoregulation, and it is believed that this optimizes the cellular environment for viral DNA replication during productive infection or during carriage in the latently infected host. Here, we show that HCMV infection also prevents external signaling to the cell by disrupting the function of TNFRI, the 55-kDa receptor for tumor necrosis factor alpha (TNF-alpha), one of the receptors for a potent cytokine involved in eliciting a wide spectrum of cellular responses, including antiviral responses. HCMV infection of fully permissive differentiated monocytic cell lines and U373 cells resulted in a reduction in cell surface expression of TNFRI. The reduction appeared to be due to relocalization of TNFRI from the cell surface and was reflected in the elimination of TNF-alpha-induced Jun kinase activity. Analysis of specific phases of infection suggested that viral early gene products were responsible for this relocalization. However, a mutant HCMV in which all viral gene products known to be involved in down-regulation of major histocompatibility complex (MHC) class I were deleted still resulted in relocalization of TNFRI. Consequently, TNFRI relocalization by HCMV appears to be mediated by a novel viral early function not involved in down-regulation of cell surface MHC class I expression. We suggest that upon infection, HCMV isolates the cell from host-mediated signals, forcing the cell to respond only to virus-specific signals which optimize the cell for virus production and effect proviral responses from bystander cells.
Strategic Complexity and Global Expansion
Oladottir, Asta Dis; Hobdari, Bersant; Papanastassiou, Marina
2012-01-01
The purpose of this paper is to analyse the determinants of global expansion strategies of newcomer Multinational Corporations (MNCs) by focusing on Iceland, Israel and Ireland. We argue that newcomer MNCs from small open economies pursue complex global expansion strategies (CGES). We distinguish....... The empirical evidence suggests that newcomer MNCs move away from simplistic dualities in the formulation of their strategic choices towards more complex options as a means of maintaining and enhancing their global competitiveness....
Statistical mechanics of complex networks
Rubi, Miguel; Diaz-Guilera, Albert
2003-01-01
Networks can provide a useful model and graphic image useful for the description of a wide variety of web-like structures in the physical and man-made realms, e.g. protein networks, food webs and the Internet. The contributions gathered in the present volume provide both an introduction to, and an overview of, the multifaceted phenomenology of complex networks. Statistical Mechanics of Complex Networks also provides a state-of-the-art picture of current theoretical methods and approaches.
Boolean complexes and boolean numbers
Tenner, Bridget Eileen
2017-01-01
International audience; The Bruhat order gives a poset structure to any Coxeter group. The ideal of elements in this poset having boolean principal order ideals forms a simplicial poset. This simplicial poset defines the boolean complex for the group. In a Coxeter system of rank n, we show that the boolean complex is homotopy equivalent to a wedge of (n-1)-dimensional spheres. The number of these spheres is the boolean number, which can be computed inductively from the unlabeled Coxeter syste...
Evolving Complexity, Cognition, and Consciousness
Liljenström, H.
2012-12-01
All through the history of the universe there is an apparent tendency for increasing complexity, with the organization of matter in evermore elaborate and interactive systems. The living world in general, and the human brain in particular, provides the highest complexity known. It seems obvious that all of this complexity must be the result of physical, chemical and biological evolution, but it was only with Darwin that we began to get a scientific understanding of biological evolution. Darwinian principles are guiding in our understanding of such complex systems as the nervous system, but also for the evolution of human society and technology. Living organisms have to survive in a complex and changing environment. This implies response and adaption to environmental events and changes at several time scales. The interaction with the environment depends on the present state of the organism, as well as on previous experiences stored in its molecular and cellular structures. At a longer time scale, organisms can adapt to slow environmental changes, by storing information in the genetic material carried over from generation to generation. This phylogenetic learning is complemented by ontogenetic learning, which is adaptation at a shorter time scale, occuring in non-genetic structures. The evolution of a nervous system is a major transition in biological evolution and allows for an increasing capacity for information storage and processing, increasing chances of survival. Such neural knowledge processing, cognition, shows the same principal features as nonneural adaptive processes. Similarly, consciousness might appear, to different degrees, at different stages in evolution. Both cognition and consciousness depends critically on the organization and complexity of the organism. In this presentation, I will briefly discuss general principles for evolution of complexity, focussing on the evolution of the nervous system, which provides organisms with ever increasing
Septin pairs, a complex choreography.
Ewers, Helge
2011-06-13
Septins form a filamentous collar at the mother-bud neck in budding yeast. In cytokinesis, this collar splits into two rings and the septin complexes undergo a dramatic reorientation. Using fluorescence polarization microscopy, DeMay et al. (2011. J. Cell Biol. doi:10.1083/jcb.201012143) now demonstrate that septin complexes assemble as paired filaments in vivo and reveal new insights into septin organization during cytokinesis.
Symbolic Dynamics and Grammatical Complexity
Hao, Bai-Lin; Zheng, Wei-Mou
The following sections are included: * Formal Languages and Their Complexity * Formal Language * Chomsky Hierarchy of Grammatical Complexity * The L-System * Regular Language and Finite Automaton * Finite Automaton * Regular Language * Stefan Matrix as Transfer Function for Automaton * Beyond Regular Languages * Feigenbaum and Generalized Feigenbaum Limiting Sets * Even and Odd Fibonacci Sequences * Odd Maximal Primitive Prefixes and Kneading Map * Even Maximal Primitive Prefixes and Distinct Excluded Blocks * Summary of Results
Complex numbers in quantum theory
Maynard, Glenn
In 1927, Nobel prize winning physicist, E. Schrodinger, in correspondence with Ehrenfest, wrote the following about the new theory: "What is unpleasant here, and indeed directly to be objected to, is the use of complex numbers. Psi is surely fundamentally a real function." This seemingly simple issue remains unexplained almost ninety years later. In this dissertation I elucidate the physical and theoretical origins of the complex requirement. (Abstract shortened by ProQuest.).
Progress in Computational Complexity Theory
Jin-Yi Cai; Hong Zhu
2005-01-01
We briefly survey a number of important recent achievements in Theoretical Computer Science (TCS), especially Computational Complexity Theory. We will discuss the PCP Theorem, its implications to inapproximability on combinatorial optimization problems; space bounded computations, especially deterministic logspace algorithm for undirected graph connectivity problem; deterministic polynomial-time primality test; lattice complexity, worst-case to average-case reductions;pseudorandomness and extractor constructions; and Valiant's new theory of holographic algorithms and reductions.
Complexity, Action, and Black Holes
Brown, Adam; Susskind, Leonard; Swingle, Brian; Zhao, Ying
2015-01-01
Our earlier paper "Complexity Equals Action" conjectured that the quantum computational complexity of a holographic state is given by the classical action of a region in the bulk (the `Wheeler-DeWitt' patch). We provide calculations for the results quoted in that paper, explain how it fits into a broader (tensor) network of ideas, and elaborate on the hypothesis that black holes are fastest computers in nature.
Complexity, action, and black holes
Brown, Adam R.; Roberts, Daniel A.; Susskind, Leonard; Swingle, Brian; Zhao, Ying
2016-04-01
Our earlier paper "Complexity Equals Action" conjectured that the quantum computational complexity of a holographic state is given by the classical action of a region in the bulk (the "Wheeler-DeWitt" patch). We provide calculations for the results quoted in that paper, explain how it fits into a broader (tensor) network of ideas, and elaborate on the hypothesis that black holes are the fastest computers in nature.
Servitization, Services and Managing Complexity
Harjo, Ieva; Frandsen, Thomas; Hsuan, Juliana
This paper explores how seemingly complex servitized solutions can become tradable in a customer–supplier relationship by objectification and abbreviation. The key argument is that the complexity of product-service solutions can be reduced by abbreviation of the reality in written form of contracts...... and agreements that allow for customization while making the offer more comprehensible for customers and more manageable for suppliers. Preliminary results from an exploratory case study are presented....
Complex hybrid inflation and baryogenesis.
Delepine, David; Martínez, Carlos; Ureña-López, L Arturo
2007-04-20
We propose a hybrid inflation model with a complex waterfall field which contains an interaction term that breaks the U(1) global symmetry associated with the waterfall field charge. We show that the asymmetric evolution of the real and imaginary parts of the complex field during the phase transition at the end of inflation translates into a charge asymmetry. The latter strongly depends on the vacuum expectation value of the waterfall field, which is well constrained by diverse cosmological observations.
Quantum Complexity and Negative Curvature
Brown, Adam R; Zhao, Ying
2016-01-01
As time passes, once simple quantum states tend to become more complex. For strongly coupled k-local Hamiltonians, this growth of computational complexity has been conjectured to follow a distinctive and universal pattern. In this paper we show that the same pattern is exhibited by a much simpler system: classical geodesics on a compact two-dimensional geometry of uniform negative curvature. This striking parallel persists whether the system is allowed to evolve naturally or is perturbed from the outside.
Conforming Morse-Smale Complexes.
Gyulassy, Attila; Günther, David; Levine, Joshua A; Tierny, Julien; Pascucci, Valerio
2014-12-01
Morse-Smale (MS) complexes have been gaining popularity as a tool for feature-driven data analysis and visualization. However, the quality of their geometric embedding and the sole dependence on the input scalar field data can limit their applicability when expressing application-dependent features. In this paper we introduce a new combinatorial technique to compute an MS complex that conforms to both an input scalar field and an additional, prior segmentation of the domain. The segmentation constrains the MS complex computation guaranteeing that boundaries in the segmentation are captured as separatrices of the MS complex. We demonstrate the utility and versatility of our approach with two applications. First, we use streamline integration to determine numerically computed basins/mountains and use the resulting segmentation as an input to our algorithm. This strategy enables the incorporation of prior flow path knowledge, effectively resulting in an MS complex that is as geometrically accurate as the employed numerical integration. Our second use case is motivated by the observation that often the data itself does not explicitly contain features known to be present by a domain expert. We introduce edit operations for MS complexes so that a user can directly modify their features while maintaining all the advantages of a robust topology-based representation.
Walzer, Sascha A; Egerer-Sieber, Claudia; Sticht, Heinrich; Sevvana, Madhumati; Hohl, Katharina; Milbradt, Jens; Muller, Yves A; Marschall, Manfred
2015-11-13
Nuclear replication of cytomegalovirus relies on elaborate mechanisms of nucleocytoplasmic egress of viral particles. Thus, the role of two essential and conserved viral nuclear egress proteins, pUL50 and pUL53, is pivotal. pUL50 and pUL53 heterodimerize and form a core nuclear egress complex (NEC), which is anchored to the inner nuclear membrane and provides a scaffold for the assembly of a multimeric viral-cellular NEC. Here, we report the crystal structure of the pUL50-pUL53 heterodimer (amino acids 1-175 and 50-292, respectively) at 2.44 Å resolution. Both proteins adopt a globular fold with mixed α and β secondary structure elements. pUL53-specific features include a zinc-binding site and a hook-like N-terminal extension, the latter representing a hallmark element of the pUL50-pUL53 interaction. The hook-like extension (amino acids 59-87) embraces pUL50 and contributes 1510 Å(2) to the total interface area (1880 Å(2)). The pUL50 structure overall resembles the recently published NMR structure of the murine cytomegalovirus homolog pM50 but reveals a considerable repositioning of the very C-terminal α-helix of pUL50 upon pUL53 binding. pUL53 shows structural resemblance with the GHKL domain of bacterial sensory histidine kinases. A close examination of the crystal structure indicates partial assembly of pUL50-pUL53 heterodimers to hexameric ring-like structures possibly providing additional scaffolding opportunities for NEC. In combination, the structural information on pUL50-pUL53 considerably improves our understanding of the mechanism of HCMV nuclear egress. It may also accelerate the validation of the NEC as a unique target for developing a novel type of antiviral drug and improved options of broad-spectrum antiherpesviral therapy.
Fluoroquinolone-Gyrase-DNA Complexes
Mustaev, Arkady; Malik, Muhammad; Zhao, Xilin; Kurepina, Natalia; Luan, Gan; Oppegard, Lisa M.; Hiasa, Hiroshi; Marks, Kevin R.; Kerns, Robert J.; Berger, James M.; Drlica, Karl
2014-01-01
DNA gyrase and topoisomerase IV control bacterial DNA topology by breaking DNA, passing duplex DNA through the break, and then resealing the break. This process is subject to reversible corruption by fluoroquinolones, antibacterials that form drug-enzyme-DNA complexes in which the DNA is broken. The complexes, called cleaved complexes because of the presence of DNA breaks, have been crystallized and found to have the fluoroquinolone C-7 ring system facing the GyrB/ParE subunits. As expected from x-ray crystallography, a thiol-reactive, C-7-modified chloroacetyl derivative of ciprofloxacin (Cip-AcCl) formed cross-linked cleaved complexes with mutant GyrB-Cys466 gyrase as evidenced by resistance to reversal by both EDTA and thermal treatments. Surprisingly, cross-linking was also readily seen with complexes formed by mutant GyrA-G81C gyrase, thereby revealing a novel drug-gyrase interaction not observed in crystal structures. The cross-link between fluoroquinolone and GyrA-G81C gyrase correlated with exceptional bacteriostatic activity for Cip-AcCl with a quinolone-resistant GyrA-G81C variant of Escherichia coli and its Mycobacterium smegmatis equivalent (GyrA-G89C). Cip-AcCl-mediated, irreversible inhibition of DNA replication provided further evidence for a GyrA-drug cross-link. Collectively these data establish the existence of interactions between the fluoroquinolone C-7 ring and both GyrA and GyrB. Because the GyrA-Gly81 and GyrB-Glu466 residues are far apart (17 Å) in the crystal structure of cleaved complexes, two modes of quinolone binding must exist. The presence of two binding modes raises the possibility that multiple quinolone-enzyme-DNA complexes can form, a discovery that opens new avenues for exploring and exploiting relationships between drug structure and activity with type II DNA topoisomerases. PMID:24497635
Complexity analysis of angiogenesis vasculature
Mahadevan, Vijay; Tyrell, James A.; Tong, Ricky T.; Brown, Edward B.; Jain, Rakesh K.; Roysam, Badrinath
2005-04-01
Tumor vasculature has a high degree of irregularity as compared to normal vasculature. The quantification of the morphometric complexity in tumor images can be useful in diagnosis. Also, it is desirable in several other medical applications to have an automated complexity analysis to aid in diagnosis and prognosis under treatment. e.g. in diabetic retinopathy and in arteriosclerosis. In addition, prior efforts at segmentation of the tumor vasculature using matched filtering, template matching and splines have been hampered by the irregularity of these vessels. We try to solve both problems by introducing a novel technique for vessel detection, followed by a tracing-independent complexity analysis based on a combination of ideas. First, the vessel cross-sectional profile is modeled using a continuous and everywhere differentiable family of super-Gaussian curves. This family generates rectangular profiles that can accurately localize the vessel boundaries in microvasculature images. Second, a robust non-linear regression algorithm based on M-estimators is used to estimate the parameters that optimally characterize the vessel"s shape. A framework for the quantitative analysis of the complexity of the vasculature based on the vessel detection is presented. A set of measures that quantify the complexity are proposed viz. Squared Error, Entropy-based and Minimum Description Length-based Shape Complexities. They are completely automatic and can deal with complexities of the entire vessel unlike existing tortuousity measures which deal only with vessel centerlines. The results are validated using carefully constructed phantom and real image data with ground truth information from an expert observer.
Simply complexity a clear guide to complexity theory
Johnson, Neil
2009-01-01
What do traffic jams, stock market crashes, and wars have in common? They are all explained using complexity, an unsolved puzzle that many researchers believe is the key to predicting and ultimately solvingeverything from terrorist attacks and pandemic viruses right down to rush hour traffic congestion.Complexity is considered by many to be the single most important scientific development since general relativity and it promises to make sense of no less than the very heart of the Universe. Using it, scientists can find order emerging from seemingly random interactions of all kinds, from som
Actinide cation-cation complexes
Stoyer, Nancy Jane [Univ. of California, Berkeley, CA (United States)
1994-12-01
The +5 oxidation state of U, Np, Pu, and Am is a linear dioxo cation (AnO_{2}^{+}) with a formal charge of +1. These cations form complexes with a variety of other cations, including actinide cations. Other oxidation states of actinides do not form these cation-cation complexes with any cation other than AnO_{2}^{+}; therefore, cation-cation complexes indicate something unique about AnO_{2}^{+} cations compared to actinide cations in general. The first cation-cation complex, NpO_{2}^{+}•UO_{2}^{2+}, was reported by Sullivan, Hindman, and Zielen in 1961. Of the four actinides that form AnO_{2}^{+} species, the cation-cation complexes of NpO_{2}^{+} have been studied most extensively while the other actinides have not. The only PuO_{2}^{+} cation-cation complexes that have been studied are with Fe^{3+} and Cr^{3+} and neither one has had its equilibrium constant measured. Actinides have small molar absorptivities and cation-cation complexes have small equilibrium constants; therefore, to overcome these obstacles a sensitive technique is required. Spectroscopic techniques are used most often to study cation-cation complexes. Laser-Induced Photacoustic Spectroscopy equilibrium constants for the complexes NpO_{2}^{+}•UO_{2}^{2+}, NpO_{2}^{+}•Th^{4+}, PuO_{2}^{+}•UO_{2}^{2+}, and PuO_{2}^{+}•Th^{4+} at an ionic strength of 6 M using LIPAS are 2.4 ± 0.2, 1.8 ± 0.9, 2.2 ± 1.5, and ~0.8 M^{-1}.
Entwicklung und Evaluierung von HCMV- und HHV6-Fusionsantigenen für den Einsatz im Mikroblotsystem
Thäder-Voigt, Andrea
2011-01-01
Die Durchseuchungsrate der Bevölkerung in Deutschland mit den humanen ß-Herpesviren liegt zwischen 40 und 90%. Nach der Primärinfektion verbleiben die ß-Herpesviren latent in den Körperzellen und haben die Fähigkeit, z.B. nach körperlichem Stress, bei Immunsuppression oder unter UV-Strahlung erneut in den lytischen Vermehrungszyklus einzutreten. Die kommerziell erhältlichen serologischen Methoden für die Diagnostik der humanen ß Herpesviren haben sich in den letzten Jahren wenig weiterentwick...
Stangherlin, Lucas M; de Paula, Felipe N; Icimoto, Marcelo Y; Ruiz, Leonardo G P; Nogueira, Maurício L; Braz, Antônio S K; Juliano, Luiz; da Silva, Maria C C
2017-01-01
Human cytomegalovirus is a ubiquitous infectious agent that affects mainly immunosuppressed, fetuses, and newborns. The virus has several polymorphic regions, in particular in the envelope glycoproteins. The UL55 gene encodes the glycoprotein B that has a variable region, containing a furin cleavage site and according to the variability different genotypes are characterized. Here we investigated variability and existence of selective pressure on the UL55 variable region containing the furin cleavage site in 213 clinical sequences from patients worldwide. We showed the occurrence of positive selective pressure on gB codons 461 and 462, near the furin cleavage site. Cleavage analysis of synthesized peptides demonstrated that most mutations confer better cleavage by furin, suggesting that evolution is acting in order to increase the efficiency cleavage and supporting the hypothesis that gB processing is important in the host. We also demonstrated that peptides containing sequences, that characterize genotypes gB2 and 3, are differentially cleaved by furin. Our data demonstrate for the first time that variability in the cleavage site is related to degree of gB processing by furin.
Lucas M. Stangherlin
2017-05-01
Full Text Available Human cytomegalovirus is a ubiquitous infectious agent that affects mainly immunosuppressed, fetuses, and newborns. The virus has several polymorphic regions, in particular in the envelope glycoproteins. The UL55 gene encodes the glycoprotein B that has a variable region, containing a furin cleavage site and according to the variability different genotypes are characterized. Here we investigated variability and existence of selective pressure on the UL55 variable region containing the furin cleavage site in 213 clinical sequences from patients worldwide. We showed the occurrence of positive selective pressure on gB codons 461 and 462, near the furin cleavage site. Cleavage analysis of synthesized peptides demonstrated that most mutations confer better cleavage by furin, suggesting that evolution is acting in order to increase the efficiency cleavage and supporting the hypothesis that gB processing is important in the host. We also demonstrated that peptides containing sequences, that characterize genotypes gB2 and 3, are differentially cleaved by furin. Our data demonstrate for the first time that variability in the cleavage site is related to degree of gB processing by furin.
Triangular Fibrocartilage Complex MR Imaging
Seyed Hassan Mostafavi
2010-05-01
Full Text Available Interpretation of MR imaging of the wrist may be difficult because of the small size of this joint, its complex anatomy, and its sometimes poorly unders-tood pathologic lesions. A recent study revealed that MR imaging of the wrist influences clinicians' diagnoses and management plans in most patients. "nWhich structures make up the triangular fibrocarti-lage complex (TFCC are not universally agreed upon. In most descriptions, however, the TFCC is composed of the triangular fibrocartilage (TFC, the meniscus homolog, the ulnar collateral ligament, the dorsal and volar radioulnar ligaments and the sheath of the extensor carpi ulnaris tendon. The ulnolunate and ulnotriquetral ligaments may also be considered as part of the TFCC. These structures are a complex unit that function as a stabilizing element in the pivot movement of the radius and ulna and limit the lateral deviation of the carpus. The distal radioulnar joint is primarily stabilized by the TFCC. The TFC functions as a cushion between the ulnar head and carpal bones. Many of the structures that make up the complex are connected by fibrous bands. "nThis presentation summarizes the current diagnostic criteria that can be useful in interpreting abnormalities of the triangular fibrocartilage complex (TFCC of the wrist in this difficult topic in joint MR imaging
Complex solitons with real energies
Cen, Julia; Fring, Andreas
2016-09-01
Using Hirota’s direct method and Bäcklund transformations we construct explicit complex one and two-soliton solutions to the complex Korteweg-de Vries (KdV) equation, the complex modified KdV (mKdV) equation and the complex sine-Gordon equation. The one-soliton solutions of trigonometric and elliptic type turn out to be { P }{ T }-symmetric when a constant of integration is chosen to be purely imaginary with one special choice corresponding to solutions recently found by Khare and Saxena. We show that alternatively complex { P }{ T }-symmetric solutions to the KdV equation may also be constructed alternatively from real solutions to the mKdV by means of Miura transformations. The multi-soliton solutions obtained from Hirota’s method break the { P }{ T }-symmetric, whereas those obtained from Bäcklund transformations are { P }{ T }-invariant under certain conditions. Despite the fact that some of the Hamiltonian densities are non-Hermitian, the total energy is found to be positive in all cases, that is irrespective of whether they are { P }{ T }-symmetric or not. The reason is that the symmetry can be restored by suitable shifts in space-time and the fact that any of our N-soliton solutions may be decomposed into N separate { P }{ T }-symmetrizable one-soliton solutions.
Quotient Complexity of Regular Languages
Janusz Brzozowski
2009-07-01
Full Text Available The past research on the state complexity of operations on regular languages is examined, and a new approach based on an old method (derivatives of regular expressions is presented. Since state complexity is a property of a language, it is appropriate to define it in formal-language terms as the number of distinct quotients of the language, and to call it "quotient complexity". The problem of finding the quotient complexity of a language f(K,L is considered, where K and L are regular languages and f is a regular operation, for example, union or concatenation. Since quotients can be represented by derivatives, one can find a formula for the typical quotient of f(K,L in terms of the quotients of K and L. To obtain an upper bound on the number of quotients of f(K,L all one has to do is count how many such quotients are possible, and this makes automaton constructions unnecessary. The advantages of this point of view are illustrated by many examples. Moreover, new general observations are presented to help in the estimation of the upper bounds on quotient complexity of regular operations.
Complex systems: physics beyond physics
Holovatch, Yurij; Kenna, Ralph; Thurner, Stefan
2017-03-01
Complex systems are characterised by specific time-dependent interactions among their many constituents. As a consequence they often manifest rich, non-trivial and unexpected behaviour. Examples arise both in the physical and non-physical worlds. The study of complex systems forms a new interdisciplinary research area that cuts across physics, biology, ecology, economics, sociology, and the humanities. In this paper we review the essence of complex systems from a physicists' point of view, and try to clarify what makes them conceptually different from systems that are traditionally studied in physics. Our goal is to demonstrate how the dynamics of such systems may be conceptualised in quantitative and predictive terms by extending notions from statistical physics and how they can often be captured in a framework of co-evolving multiplex network structures. We mention three areas of complex-systems science that are currently studied extensively, the science of cities, dynamics of societies, and the representation of texts as evolutionary objects. We discuss why these areas form complex systems in the above sense. We argue that there exists plenty of new ground for physicists to explore and that methodical and conceptual progress is needed most.
Cortical complexity in cetacean brains.
Hof, Patrick R; Chanis, Rebecca; Marino, Lori
2005-11-01
Cetaceans (dolphins, whales, and porpoises) have a long, dramatically divergent evolutionary history compared with terrestrial mammals. Throughout their 55-60 million years of evolution, cetaceans acquired a compelling set of characteristics that include echolocation ability (in odontocetes), complex auditory and communicative capacities, and complex social organization. Moreover, although cetaceans have not shared a common ancestor with primates for over 90 million years, they possess a set of cognitive attributes that are strikingly convergent with those of many primates, including great apes and humans. In contrast, cetaceans have evolved a highly unusual combination of neurobiological features different from that of primates. As such, cetacean brains offer a critical opportunity to address questions about how complex behavior can be based on very different neuroanatomical and neurobiological evolutionary products. Cetacean brains and primate brains are arguably most meaningfully conceived as alternative evolutionary routes to neurobiological and cognitive complexity. In this article, we summarize data on brain size and hemisphere surface configuration in several cetacean species and present an overview of the cytoarchitectural complexity of the cerebral cortex of the bottlenose dolphin.
Copper complexes as therapeutic agents.
Duncan, Clare; White, Anthony R
2012-02-01
The importance of transition metals in biological processes has been well established. Copper (Cu) is a transition metal that can exist in oxidised and reduced states. This allows it to participate in redox and catalytic chemistry, making it a suitable cofactor for a diverse range of enzymes and molecules. Cu deficiency or toxicity is implicated in a variety of pathological conditions; therefore inorganic complexes of Cu have been investigated for their therapeutic and diagnostic potential. These Cu complexes have been shown to be effective in cancer treatment due to their cytotoxic action on tumour cells. Alternatively, Cu complexes can also modulate Cu homeostasis in the brain, resulting in protective effects in several models of neurodegeneration. In other diseases such as coronary heart disease and skin disease, the success of Cu complexes as potential therapeutics will most likely be due to their ability to increase SOD activity, leading to relief of oxidative stress. This review seeks to provide a broad insight into some of the diverse actions of Cu complexes and demonstrate the strong future for these compounds as potential therapeutic agents.
Control principles of complex systems
Liu, Yang-Yu; Barabási, Albert-László
2016-07-01
A reflection of our ultimate understanding of a complex system is our ability to control its behavior. Typically, control has multiple prerequisites: it requires an accurate map of the network that governs the interactions between the system's components, a quantitative description of the dynamical laws that govern the temporal behavior of each component, and an ability to influence the state and temporal behavior of a selected subset of the components. With deep roots in dynamical systems and control theory, notions of control and controllability have taken a new life recently in the study of complex networks, inspiring several fundamental questions: What are the control principles of complex systems? How do networks organize themselves to balance control with functionality? To address these questions here recent advances on the controllability and the control of complex networks are reviewed, exploring the intricate interplay between the network topology and dynamical laws. The pertinent mathematical results are matched with empirical findings and applications. Uncovering the control principles of complex systems can help us explore and ultimately understand the fundamental laws that govern their behavior.
Chemical complexity in galactic nuclei
Martin-Pintado, Jesus
2007-12-01
In recent years our knowledge of the chemical complexity in the nuclei of galaxies has dramatically changed. Recent observations of the nucleus of the Milky Way, of the starburst galaxy NGC253 and of the ultraluminous infrared galaxy (ULIRG) Arp220 have shown large abundance of complex organic molecules believed to be formed on grains. The Galactic center appears to be the largest repository of complex organic molecule like aldehydes and alcohols in the galaxy. We also measure large abundance of methanol in starburst galaxies and in ULIRGs suggesting that complex organic molecules are also efficiently produced in the central region of galaxies with strong star formation activity. From the systematic observational studies of molecular abundance in regions dominated by different heating processes like shocks, UV radiation, X-rays and cosmic rays in the center of the Milky Way, we are opening the possibility of using chemistry as a diagnostic tool to study the highly obscured regions of galactic centers. The templates found in the nucleus of the Milky Way will be used to establish the main mechanisms driving the heating and the chemistry of the molecular clouds in galaxies with different type of activity. The role of grain chemistry in the chemical complexity observed in the center of galaxies will be also briefly discussed.
The fifth adaptor protein complex.
Jennifer Hirst
2011-10-01
Full Text Available Adaptor protein (AP complexes sort cargo into vesicles for transport from one membrane compartment of the cell to another. Four distinct AP complexes have been identified, which are present in most eukaryotes. We report the existence of a fifth AP complex, AP-5. Tagged AP-5 localises to a late endosomal compartment in HeLa cells. AP-5 does not associate with clathrin and is insensitive to brefeldin A. Knocking down AP-5 subunits interferes with the trafficking of the cation-independent mannose 6-phosphate receptor and causes the cell to form swollen endosomal structures with emanating tubules. AP-5 subunits can be found in all five eukaryotic supergroups, but they have been co-ordinately lost in many organisms. Concatenated phylogenetic analysis provides robust resolution, for the first time, into the evolutionary order of emergence of the adaptor subunit families, showing AP-3 as the basal complex, followed by AP-5, AP-4, and AP-1 and AP-2. Thus, AP-5 is an evolutionarily ancient complex, which is involved in endosomal sorting, and which has links with hereditary spastic paraplegia.
On the Complexity of Labeled Oriented Trees
Stephan Rosebrock
2010-02-01
We define a notion of complexity for labeled oriented trees (LOTs) related to the bridge number in knot theory and prove that LOTs of complexity 2 are aspherical. We also present a class of LOTs of higher complexity which is aspherical, give an upper bound for the complexity of labeled oriented intervals and study the complexity of torus knots.
Joseph L. McCauley
1997-01-01
Full Text Available Deterministic chaos, and even maximum computational complexity, have been discovered within Newtonian dynamics. Economists assume that prices and price changes can also obey abstract mathematical laws of motion. Sociologists and other postmodernists advertise that physics and chemistry have outgrown their former limitations, that chaos and complexity provide new holistic paradigms for science, and that the boundaries between the hard and the soft sciences, once impenetrable, have disappeared like the Berlin Wall. Three hundred years after the deaths of Galileo, Descartes, and Kepler, and the birth of Newton, reductionism appears to be on the decline, with holistic approaches to science on the upswing. We therefore examine the evidence that dynamical laws of motion may be discovered from empirical studies of chaotic or complex phenomena, and also review the foundation of reductionism in invariance principles.
Complexity, cognition and the city
Portugali, Juval
2011-01-01
Complexity, Cognition and the City aims at a deeper understanding of urbanism, while invoking, on an equal footing, the contributions both the hard and soft sciences have made, and are still making, when grappling with the many issues and facets of regional planning and dynamics. In this work, the author goes beyond merely seeing the city as a self-organized, emerging pattern of some collective interaction between many stylized urban "agents" – he makes the crucial step of attributing cognition to his agents and thus raises, for the first time, the question on how to deal with a complex system composed of many interacting complex agents in clearly defined settings. Accordingly, the author eventually addresses issues of practical relevance for urban planners and decision makers. The book unfolds its message in a largely nontechnical manner, so as to provide a broad interdisciplinary readership with insights, ideas, and other stimuli to encourage further research – with the twofold aim of further pushing ba...
THE COMPLEXITY OF LANGUAGE LEARNING
Charles Nelson
2011-07-01
Full Text Available This paper takes a complexity theory approach to looking at language learning, an approach that investigates how language learners adapt to and interact with people and their environment. Based on interviews with four graduate students, it shows how complexity theory can help us understand both the situatedness of language learning and also commonalities across contexts by examining language learning through the lenses of emergence, distribution, and embodiment. These lenses underscore the perspective that language learning emerges from unique interactions, is distributed across social networks, and is embodied in individuals. Consequently, this paper concludes that it is not sufficient to study cognitive processes, activities, and situated learning alone; in addition, research must consider how learners’ interactions and adaptations are embodied, distributed, and emergent in ecologies of complex systems.
Quantum coherence in photosynthetic complexes
Calhoun, Tessa R.; Fleming, Graham R. [Department of Chemistry, University of California, Berkeley, CA 94720 (United States); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)
2011-04-15
The initial steps of photosynthesis require the absorption and subsequent transfer of energy through an intricate network of pigment-protein complexes. Held within the protein scaffold of these complexes, chromophore molecules are densely packed and fixed in specific geometries relative to one another resulting in Coulombic coupling. Excitation energy transfer through these systems can be accomplished with near unity quantum efficiency [Wraight and Clayton, Biochim. Biophys. Acta 333, 246 (1974)]. While replication of this feat is desirable for artificial photosynthesis, the mechanism by which nature achieves this efficiency is unknown. Recent experiments have revealed the presence of long-lived quantum coherences in photosynthetic pigment-protein complexes spanning bacterial and plant species with a variety of functions and compositions. Its ubiquitous presence and wavelike energy transfer implicate quantum coherence as key to the high efficiency achieved by photosynthesis. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Articulation Points in Complex Networks
Tian, Liang; Shi, Da-Ning; Liu, Yang-Yu
2016-01-01
An articulation point in a network is a node whose removal disconnects the network. Those nodes play key roles in ensuring connectivity of many real-world networks, from infrastructure networks to protein interaction networks and terrorist communication networks. Despite their fundamental importance, a general framework of studying articulation points in complex networks is lacking. Here we develop analytical tools to study key issues pertinent to articulation points, e.g. the expected number of them and the network vulnerability against their removal, in an arbitrary complex network. We find that a greedy articulation point removal process provides us a novel perspective on the organizational principles of complex networks. Moreover, this process is associated with two fundamentally different types of percolation transitions with a rich phase diagram. Our results shed light on the design of more resilient infrastructure networks and the effective destruction of terrorist communication networks.
Articulation points in complex networks
Tian, Liang; Bashan, Amir; Shi, Da-Ning; Liu, Yang-Yu
2017-01-01
An articulation point in a network is a node whose removal disconnects the network. Those nodes play key roles in ensuring connectivity of many real-world networks, from infrastructure networks to protein interaction networks and terrorist communication networks. Despite their fundamental importance, a general framework of studying articulation points in complex networks is lacking. Here we develop analytical tools to study key issues pertinent to articulation points, such as the expected number of them and the network vulnerability against their removal, in an arbitrary complex network. We find that a greedy articulation point removal process provides us a different perspective on the organizational principles of complex networks. Moreover, this process results in a rich phase diagram with two fundamentally different types of percolation transitions. Our results shed light on the design of more resilient infrastructure networks and the effective destruction of terrorist communication networks.
Emergence: complexity pedagogy in action.
Jonas-Simpson, Christine; Mitchell, Gail; Cross, Nadine
2015-01-01
Many educators are looking for new ways to engage students and each other in order to enrich curriculum and the teaching-learning process. We describe an example of how we enacted teaching-learning approaches through the insights of complexity thinking, an approach that supports the emergence of new possibilities for teaching-learning in the classroom and online. Our story begins with an occasion to meet with 10 nursing colleagues in a three-hour workshop using four activities that engaged learning about complexity thinking and pedagogy. Guiding concepts for the collaborative workshop were nonlinearity, distributed decision-making, divergent thinking, self-organization, emergence, and creative exploration. The workshop approach considered critical questions to spark our collective inquiry. We asked, "What is emergent learning?" and "How do we, as educators and learners, engage a community so that new learning surfaces?" We integrated the arts, creative play, and perturbations within a complexity approach.
Manipulating complex light with metamaterials.
Zeng, Jinwei; Wang, Xi; Sun, Jingbo; Pandey, Apra; Cartwright, Alexander N; Litchinitser, Natalia M
2013-10-02
Recent developments in the field of metamaterials have revealed unparalleled opportunities for "engineering" space for light propagation; opening a new paradigm in spin- and quantum-related phenomena in optical physics. Here we show that unique optical properties of metamaterials (MMs) open unlimited prospects to "engineer" light itself. We propose and demonstrate for the first time a novel way of complex light manipulation in few-mode optical fibers using optical MMs. Most importantly, these studies highlight how unique properties of MMs, namely the ability to manipulate both electric and magnetic field components of electromagnetic (EM) waves, open new degrees of freedom in engineering complex polarization states of light at will, while preserving its orbital angular momentum (OAM) state. These results lay the first steps in manipulating complex light in optical fibers, likely providing new opportunities for high capacity communication systems, quantum information, and on-chip signal processing.
Characterization of complex renal cysts
Graumann, Ole; Osther, Susanne Sloth; Osther, Palle Jörn Sloth
2010-01-01
Abstract Objective. Complex renal cysts represent a major clinical problem, since it is often difficult to exclude malignancy. The Bosniak classification system, based on computed tomography (CT), is widely used to categorize cystic renal lesions. The aim of this study was to evaluate critically ...... of this "new" classification strategy is, however, still missing. Data on other imaging modalities are too limited for conclusions to be drawn.......Abstract Objective. Complex renal cysts represent a major clinical problem, since it is often difficult to exclude malignancy. The Bosniak classification system, based on computed tomography (CT), is widely used to categorize cystic renal lesions. The aim of this study was to evaluate critically...... available data on the Bosniak classification. Material and methods. All publications from an Entrez Pubmed search were reviewed, focusing on clinical applicability and the use of imaging modalities other than CT to categorize complex renal cysts. Results. Fifteen retrospective studies were found. Most...
Complexity hints for economic policy
Salzano, Massimo
2007-01-01
This volume extends the complexity approach to economics. This complexity approach is not a completely new way of doing economics, and that it is a replacement for existing economics, but rather the integration of some new analytic and computational techniques into economists’ bag of tools. It provides some alternative pattern generators, which can supplement existing approaches by providing an alternative way of finding patterns than be obtained by the traditional scientific approach. On this new kind of policy hints can be obtained. The reason why the complexity approach is taking hold now in economics is because the computing technology has advanced. This advance allows consideration of analytical systems that could not previously be considered by economists. Consideration of these systems suggested that the results of the "control-based" models might not extend easily to more complicated systems, and that we now have a method—piggybacking computer assisted analysis onto analytic methods—to start gen...
Complex Fluids and Hydraulic Fracturing.
Barbati, Alexander C; Desroches, Jean; Robisson, Agathe; McKinley, Gareth H
2016-06-07
Nearly 70 years old, hydraulic fracturing is a core technique for stimulating hydrocarbon production in a majority of oil and gas reservoirs. Complex fluids are implemented in nearly every step of the fracturing process, most significantly to generate and sustain fractures and transport and distribute proppant particles during and following fluid injection. An extremely wide range of complex fluids are used: naturally occurring polysaccharide and synthetic polymer solutions, aqueous physical and chemical gels, organic gels, micellar surfactant solutions, emulsions, and foams. These fluids are loaded over a wide range of concentrations with particles of varying sizes and aspect ratios and are subjected to extreme mechanical and environmental conditions. We describe the settings of hydraulic fracturing (framed by geology), fracturing mechanics and physics, and the critical role that non-Newtonian fluid dynamics and complex fluids play in the hydraulic fracturing process.
Complex Wavelet Based Modulation Analysis
Luneau, Jean-Marc; Lebrun, Jérôme; Jensen, Søren Holdt
2008-01-01
because only the magnitudes are taken into account and the phase data is often neglected. We remedy this problem with the use of a complex wavelet transform as a more appropriate envelope and phase processing tool. Complex wavelets carry both magnitude and phase explicitly with great sparsity and preserve well...... polynomial trends. Moreover an analytic Hilbert-like transform is possible with complex wavelets implemented as an orthogonal filter bank. By working in an alternative transform domain coined as “Modulation Subbands”, this transform shows very promising denoising capabilities and suggests new approaches for joint...
Hierarchy measure for complex networks
Mones, Enys; Vicsek, Tamás
2012-01-01
Nature, technology and society are full of complexity arising from the intricate web of the interactions among the units of the related systems (e.g., proteins, computers, people). Consequently, one of the most successful recent approaches to capturing the fundamental features of the structure and dynamics of complex systems has been the investigation of the networks associated with the above units (nodes) together with their relations (edges). Most complex systems have an inherently hierarchical organization and, correspondingly, the networks behind them also exhibit hierarchical features. Indeed, several papers have been devoted to describing this essential aspect of networks, however, without resulting in a widely accepted, converging concept concerning the quantitative characterization of the level of their hierarchy. Here we develop an approach and propose a quantity (measure) which is simple enough to be widely applicable, reveals a number of universal features of the organization of real-world networks...
Articulation points in complex networks
Tian, Liang; Bashan, Amir; Shi, Da-Ning; Liu, Yang-Yu
2017-01-01
An articulation point in a network is a node whose removal disconnects the network. Those nodes play key roles in ensuring connectivity of many real-world networks, from infrastructure networks to protein interaction networks and terrorist communication networks. Despite their fundamental importance, a general framework of studying articulation points in complex networks is lacking. Here we develop analytical tools to study key issues pertinent to articulation points, such as the expected number of them and the network vulnerability against their removal, in an arbitrary complex network. We find that a greedy articulation point removal process provides us a different perspective on the organizational principles of complex networks. Moreover, this process results in a rich phase diagram with two fundamentally different types of percolation transitions. Our results shed light on the design of more resilient infrastructure networks and the effective destruction of terrorist communication networks. PMID:28139697
Complex Autocatalysis in Simple Chemistries.
Virgo, Nathaniel; Ikegami, Takashi; McGregor, Simon
2016-01-01
Life on Earth must originally have arisen from abiotic chemistry. Since the details of this chemistry are unknown, we wish to understand, in general, which types of chemistry can lead to complex, lifelike behavior. Here we show that even very simple chemistries in the thermodynamically reversible regime can self-organize to form complex autocatalytic cycles, with the catalytic effects emerging from the network structure. We demonstrate this with a very simple but thermodynamically reasonable artificial chemistry model. By suppressing the direct reaction from reactants to products, we obtain the simplest kind of autocatalytic cycle, resulting in exponential growth. When these simple first-order cycles are prevented from forming, the system achieves superexponential growth through more complex, higher-order autocatalytic cycles. This leads to nonlinear phenomena such as oscillations and bistability, the latter of which is of particular interest regarding the origins of life.
McCauley, J L
1997-01-01
Deterministic chaos, and even maximum computational complexity, have been discovered within Newtonian dynamics. Economists assume that prices and price changes can also obey abstract mathematical laws of motion. Sociologists and other postmodernists advertise that physics and chemistry have outgrown their former limitations, that chaos and complexity provide new holistic paradigms for science, and that the boundaries between the hard and soft sciences, once impenetrable, have disappeared like the Berlin Wall. Three hundred years after the deaths of Galileo, Descartes, and Kepler, and the birth of Newton, reductionism appears to be on the decline, with holistic approaches to science on the upswing. We therefore examine the evidence that dynamical laws of motion may be discovered from empirical studies of chaotic or complex phenomena, and also review the foundation of reductionism in invariance principle.
Compulsory formation of solvento complexes
Kukushkin, Yu.N.; Kukushkin, V.Yu.
1986-01-01
The essence of the method of the compulsory formation of solvated complexes which are labile in substitution reactions has been described in this review. It is based on three techniques for eliminating ligands from the inner sphere of the original compounds: 1) binding of the ligands in sparingly soluble productions or their conversion into highly volatile compounds; 2) binding of the ligands in stronger compounds than the original products; 3) chemical conversion of coordinated ligands, which result in a loss of donor capacity by the reaction products and the departure of these products from the inner sphere of the complex compounds. If the solvent in which the reaction is carried out has a sufficient donor capability, the coordination capacity of the central ion is saturated by means of solvent molecules with the formation of a solvento complex. The method has been illustrated by a large number of concrete examples of reactions which result in the formation of compounds with an assigned composition.
Hilbert complexes of nonlinear elasticity
Angoshtari, Arzhang; Yavari, Arash
2016-12-01
We introduce some Hilbert complexes involving second-order tensors on flat compact manifolds with boundary that describe the kinematics and the kinetics of motion in nonlinear elasticity. We then use the general framework of Hilbert complexes to write Hodge-type and Helmholtz-type orthogonal decompositions for second-order tensors. As some applications of these decompositions in nonlinear elasticity, we study the strain compatibility equations of linear and nonlinear elasticity in the presence of Dirichlet boundary conditions and the existence of stress functions on non-contractible bodies. As an application of these Hilbert complexes in computational mechanics, we briefly discuss the derivation of a new class of mixed finite element methods for nonlinear elasticity.
Multi-stage complex contagions
Melnik, Sergey; Ward, Jonathan A.; Gleeson, James P.; Porter, Mason A.
2013-03-01
The spread of ideas across a social network can be studied using complex contagion models, in which agents are activated by contact with multiple activated neighbors. The investigation of complex contagions can provide crucial insights into social influence and behavior-adoption cascades on networks. In this paper, we introduce a model of a multi-stage complex contagion on networks. Agents at different stages—which could, for example, represent differing levels of support for a social movement or differing levels of commitment to a certain product or idea—exert different amounts of influence on their neighbors. We demonstrate that the presence of even one additional stage introduces novel dynamical behavior, including interplay between multiple cascades, which cannot occur in single-stage contagion models. We find that cascades—and hence collective action—can be driven not only by high-stage influencers but also by low-stage influencers.
Complexation thermodynamics of modified cyclodextrins
Schönbeck, Jens Christian Sidney; Westh, Peter; Holm, Rene
2014-01-01
Inclusion complexes between two bile salts and a range of differently methylated β-cyclodextrins were studied in an attempt to rationalize the complexation thermodynamics of modified cyclodextrins. Calorimetric titrations at a range of temperatures provided precise values of the enthalpies (ΔH......°), entropies (ΔS°), and heat capacities (ΔCp) of complexation, while molecular dynamics simulations assisted the interpretation of the obtained thermodynamic parameters. As previously observed for several types of modified cyclodextrins, the substituents at the rims of the cyclodextrin induced large changes......° and then a strong decrease when the degree of substitution exceeded some threshold. Exactly the same trend was observed for ΔCp. The dehydration of nonpolar surface, as quantified by the simulations, can to a large extent explain the variation in the thermodynamic parameters. The methyl substituents form additional...
Graph distance for complex networks
Shimada, Yutaka; Hirata, Yoshito; Ikeguchi, Tohru; Aihara, Kazuyuki
2016-10-01
Networks are widely used as a tool for describing diverse real complex systems and have been successfully applied to many fields. The distance between networks is one of the most fundamental concepts for properly classifying real networks, detecting temporal changes in network structures, and effectively predicting their temporal evolution. However, this distance has rarely been discussed in the theory of complex networks. Here, we propose a graph distance between networks based on a Laplacian matrix that reflects the structural and dynamical properties of networked dynamical systems. Our results indicate that the Laplacian-based graph distance effectively quantifies the structural difference between complex networks. We further show that our approach successfully elucidates the temporal properties underlying temporal networks observed in the context of face-to-face human interactions.
Simulating social complexity a handbook
Meyer, Ruth
2013-01-01
Social systems are among the most complex known. This poses particular problems for those who wish to understand them. The complexity often makes analytic approaches infeasible and natural language approaches inadequate for relating intricate cause and effect. However, individual- and agent-based computational approaches hold out the possibility of new and deeper understanding of such systems. Simulating Social Complexity examines all aspects of using agent- or individual-based simulation. This approach represents systems as individual elements having each their own set of differing states and internal processes. The interactions between elements in the simulation represent interactions in the target systems. What makes these elements "social" is that they are usefully interpretable as interacting elements of an observed society. In this, the focus is on human society, but can be extended to include social animals or artificial agents where such work enhances our understanding of human society. The phenom...
Complexity Results in Epistemic Planning
Bolander, Thomas; Jensen, Martin Holm; Schwarzentruber, Francois
2015-01-01
Epistemic planning is a very expressive framework that extends automated planning by the incorporation of dynamic epistemic logic (DEL). We provide complexity results on the plan existence problem for multi-agent planning tasks, focusing on purely epistemic actions with propositional preconditions....... We show that moving from epistemic preconditions to propositional preconditions makes it decidable, more precisely in EXPSPACE. The plan existence problem is PSPACE-complete when the underlying graphs are trees and NP-complete when they are chains (including singletons). We also show PSPACE......-hardness of the plan verification problem, which strengthens previous results on the complexity of DEL model checking....
Tutorials in complex photonic media
Noginov, Mikhail A; McCall, Martin W; Zheludev, Nikolay I
2010-01-01
The field of complex photonic media encompasses many leading-edge areas in physics, chemistry, nanotechnology, materials science, and engineering. In Tutorials in Complex Photonic Media , leading experts have brought together 19 tutorials on breakthroughs in modern optics, such as negative refraction, chiral media, plasmonics, photonic crystals, and organic photonics. This text will help students, engineers, and scientists entering the field to become familiar with the interrelated aspects of the subject. It also serves well as a supplemental text in introductory and advanced courses on optica
Communication Complexities of XOR functions
Shi, Yaoyun; Zhang,Zhiqiang
2008-01-01
We call $F:\\{0, 1\\}^n\\times \\{0, 1\\}^n\\to\\{0, 1\\}$ a symmetric XOR function if for a function $S:\\{0, 1, ..., n\\}\\to\\{0, 1\\}$, $F(x, y)=S(|x\\oplus y|)$, for any $x, y\\in\\{0, 1\\}^n$, where $|x\\oplus y|$ is the Hamming weight of the bit-wise XOR of $x$ and $y$. We show that for any such function, (a) the deterministic communication complexity is always $\\Theta(n)$ except for four simple functions that have a constant complexity, and (b) up to a polylog factor, the error-bounded randomized and q...
Dispersion scenarios over complex terrain
Thykier-Nielsen, S.; Mikkelsen, T.; Moreno, J.
1993-01-01
A presentation of preliminary results from a real-time simulation of full-scale dispersion experiments carried out over complex terrain in Northern Spain is given. Actual wind and turbulence measurements as observed during the experiments were analysed and used as input data for a series of simul......A presentation of preliminary results from a real-time simulation of full-scale dispersion experiments carried out over complex terrain in Northern Spain is given. Actual wind and turbulence measurements as observed during the experiments were analysed and used as input data for a series...... are suitable for subsequent comparison with observed mean dispersion data when they become available....
1998 Complex Systems Summer School
NONE
1998-12-15
For the past eleven years a group of institutes, centers, and universities throughout the country have sponsored a summer school in Santa Fe, New Mexico as part of an interdisciplinary effort to promote the understanding of complex systems. The goal of these summer schools is to provide graduate students, postdoctoral fellows and active research scientists with an introduction to the study of complex behavior in mathematical, physical, and living systems. The Center for Nonlinear Studies supported the eleventh in this series of highly successful schools in Santa Fe in June, 1998.
Complex deformations of Bjorken flow
Gubser, Steven S.
2013-01-01
Through a complex shift of the time coordinate, a modification of Bjorken flow is introduced which interpolates between a glasma-like stress tensor at forward rapidities and Bjorken-like hydrodynamics around mid-rapidity. A Landau-like full-stopping regime is found at early times and rapidities not too large. Approximate agreement with BRAHMS data on the rapidity distribution of produced particles at top Relativistic Heavy Ion Collider (RHIC) energies can be achieved if the complex shift of the time coordinate is comparable to the inverse of the saturation scale. The form of the stress tensor follows essentially from symmetry considerations, and it can be expressed in closed form.
Complex deformations of Bjorken flow
Gubser, Steven S
2012-01-01
Through a complex shift of the time coordinate, a modification of Bjorken flow is introduced which interpolates between a glasma-like stress tensor at forward rapidities and Bjorken-like hydrodynamics around mid-rapidity. A Landau-like full-stopping regime is found at early times and rapidities not too large. Approximate agreement with BRAHMS data on the rapidity distribution of produced particles at top RHIC energies can be achieved if the complex shift of the time coordinate is comparable to the inverse of the saturation scale. The form of the stress tensor follows essentially from symmetry considerations, and it can be expressed in closed form.
Multiscale simulation of complex coacervates
Hoffmann, Kyle Q.; Whitmer, Jonathan K.; Qin, Jian; Priftis, Dimitris; Perry, Sarah; Leon, Lorraine; Kade, Matthew; Tirrell, Matthew; de Pablo, Juan J.
2014-03-01
Aqueous solutions of polymers having opposite charge can separate into a coacervate phase and a supernatant water phase.The conditions leading to such behavior, including chain lenght, ionization fraction, ionic strength, molecular structure, and temperature are poorly understood. Though thermodynamic models of this phase separation exist, they offer little descriptive power for the mechanism of complex coacervation, and the internal structure of the coacervate and precipitate phases. Here we use atomic-level and coarse-grained representations of polypeptides to study features of the phase diagram, scaling relations, and microstructure of complex coacervates, comparing results to experimental data and model calculations.
Complex variable methods in elasticity
England, A H
2003-01-01
The plane strain and generalized plane stress boundary value problems of linear elasticity are the focus of this graduate-level text, which formulates and solves these problems by employing complex variable theory. The text presents detailed descriptions of the three basic methods that rely on series representation, Cauchy integral representation, and the solution via continuation. Its five-part treatment covers functions of a complex variable, the basic equations of two-dimensional elasticity, plane and half-plane problems, regions with circular boundaries, and regions with curvilinear bounda
Correlation dimension of complex networks
Lacasa, Lucas
2012-01-01
We propose a new measure to characterize the dimension of complex networks based on the ergodic theory of dynamical systems. This measure is derived from the correlation sum of a trajectory generated by a random walker navigating the network, and extends the classical Grassberger-Procaccia algorithm to the context of complex networks. The method is validated with reliable results for both synthetic networks and real-world networks such as the world air-transportation network or urban networks, and provides a computationally fast way for estimating the dimensionality of networks which only relies on the local information provided by the walkers.