64 research outputs found

    Unity in Restoring: a Study on Healing Attributes of Persian Garden

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    Spending time in a Persian garden gives one the impression of being away and a sense of connection with nature. These feelings alleviate mental fatigue, or stress and bring about mental restoration. Simply, one feels mentally refreshed after visiting and strolling in a Persian garden. The motivation for the research is to evaluate the theory that whether Persian traditional garden can be used as a restorative garden or even its design principles can be employed to create an environment of such kind. The main areas of investigation in this paper include understanding restorative attributes provided with the garden on visitors. Persian garden provides opportunities that intuitively engender restorative attributes which can fully be felt by being there, whether it was intended for such a purpose or not. The paper tries to imply that the aim of creation of such spaces (Persian garden) was so supreme that restoration can be considered as one of the subjects which arouses from a dominant interrelation between human and space (nature) in a common entire inherence

    Magic numbers in the Dow

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    There is a widespread belief in financial markets that trends in prices are arrested at support and resistance levels that are to some degree predictable from the past behaviour of the price series. Here we examine whether ratios of the length and duration of successive price trends in the Dow Jones Industrial Average cluster around round fractions or Fibonacci ratios. We identify turning points by heuristics similar to those used in business cycle analysis, and test for clustering using a block bootstrap procedure. A few significant ratios appear, but no more than would be expected by chance given the large number of tests we conduct

    Nuclear Retention of Multiply Spliced HIV-1 RNA in Resting CD4(+) T Cells

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    HIV-1 latency in resting CD4(+) T cells represents a major barrier to virus eradication in patients on highly active antiretroviral therapy (HAART). We describe here a novel post-transcriptional block in HIV-1 gene expression in resting CD4(+) T cells from patients on HAART. This block involves the aberrant localization of multiply spliced (MS) HIV-1 RNAs encoding the critical positive regulators Tat and Rev. Although these RNAs had no previously described export defect, we show that they exhibit strict nuclear localization in resting CD4(+) T cells from patients on HAART. Overexpression of the transcriptional activator Tat from non-HIV vectors allowed virus production in these cells. Thus, the nuclear retention of MS HIV-1 RNA interrupts a positive feedback loop and contributes to the non-productive nature of infection of resting CD4(+) T cells. To define the mechanism of nuclear retention, proteomic analysis was used to identify proteins that bind MS HIV-1 RNA. Polypyrimidine tract binding protein (PTB) was identified as an HIV-1 RNA-binding protein differentially expressed in resting and activated CD4(+) T cells. Overexpression of PTB in resting CD4(+) T cells from patients on HAART allowed cytoplasmic accumulation of HIV-1 RNAs. PTB overexpression also induced virus production by resting CD4(+) T cells. Virus culture experiments showed that overexpression of PTB in resting CD4(+) T cells from patients on HAART allowed release of replication-competent virus, while preserving a resting cellular phenotype. Whether through effects on RNA export or another mechanism, the ability of PTB to reverse latency without inducing cellular activation is a result with therapeutic implications

    NlpC/P60 domain-containing proteins of Mycobacterium avium subspecies paratuberculosis that differentially bind and hydrolyze peptidoglycan

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    A subset of proteins containing NlpC/P60 domains are bacterial peptidoglycan hydrolases that cleave noncanonical peptide linkages and contribute to cell wall remodeling as well as cell separation during late stages of division. Some of these proteins have been shown to cleave peptidoglycan in Mycobacterium tuberculosis and play a role in Mycobacterium marinum virulence of zebra fish; however, there are still significant knowledge gaps concerning the molecular function of these proteins in Mycobacterium avium subspecies paratuberculosis (MAP). The MAP genome sequence encodes five NlpC/P60 domain-containing proteins. We describe atomic resolution crystal structures of two such MAP proteins, MAP_1272c and MAP_1204. These crystal structures, combined with functional assays to measure peptidoglycan cleavage activity, led to the observation that MAP_1272c does not have a functional catalytic core for peptidoglycan hydrolysis. Furthermore, the structure and sequence of MAP_1272c demonstrate that the catalytic residues normally required for hydrolysis are absent, and the protein does not bind peptidoglycan as efficiently as MAP_1204. While the NlpC/P60 catalytic triad is present in MAP_1204, changing the catalytic cysteine-155 residue to a serine significantly diminished catalytic activity, but did not affect binding to peptidoglycan. Collectively, these findings suggest a broader functional repertoire for NlpC/P60 domain-containing proteins than simply hydrolases

    MAP1272c Encodes an NlpC/P60 Protein, an Antigen Detected in Cattle with Johne’s Disease

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    The protein encoded by MAP1272c has been shown to be an antigen of Mycobacterium avium subsp. paratuberculosis that con- tains an NlpC/P60 superfamily domain found in lipoproteins or integral membrane proteins. Proteins containing this domain have diverse enzymatic functions that include peptidases, amidases, and acetyltransferases. The NlpC protein was examined in comparison to over 100 recombinant proteins and showed the strongest antigenicity when analyzed with sera from cattle with Johne’s disease. To further localize the immunogenicity of NlpC, recombinant proteins representing defined regions were ex- pressed and evaluated with sera from cattle with Johne’s disease. The region from amino acids 74 to 279 was shown to be the most immunogenic. This fragment was also evaluated against a commercially available enzyme-linked immunosorbent assay (ELISA). Two monoclonal antibodies were produced in mice immunized with the full-length protein, and each recognized a dis- tinct epitope. These antibodies cross-reacted with proteins from other mycobacterial species and demonstrated variable sizes of the proteins expressed from these subspecies. Both antibodies were further analyzed, and their interaction with MAP1272c and MAP1204 was characterized by a solution-based, luminescent binding assay. These tools provide additional means to study a strong antigen of M. avium subsp. paratuberculosis

    Time-dependent rheological characteristics of self-consolidating concrete containing various mineral admixtures

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    The study herein was intended to evaluate the influence of elapsing time on rheological properties and thixotropy of self-consolidating concrete (SCC) mixtures containing various mineral admixtures. For this purpose, variation of T50 flow time, torque plastic viscosity, apparent yield stress and thixotropy were investigated as a function of time in a standstill condition. Various amounts of silica fume (SF), metakaolin (MK), Class F fly ash (FAF), Class C fly ash (FAC) and granulated blast-furnace slag (BFS) were utilized in binary, ternary and quaternary cementitious blends in 17 different SCC mixtures having a constant slump flow value. The results showed that SCC mixtures containing various mineral admixtures were highly stable or moderately stable (VSI between 0 and 1) at 0 min according to ASTM C 1611. However, mixtures containing FAC, FAF and BFS exhibited some bleeding and segregation at 50 min. In a standstill condition, apparent yield stress and thixotropy increased significantly with time while torque plastic viscosity values changed only in a limited range. In addition, with elapsing time, MK and FAC were found to have more influence on torque plastic viscosity and yield stress values in comparison with the other admixtures. However, increase in the yield values were more pronounced in comparison with the torque plastic viscosity values. Increase in thixotropy with time for the SF and MK blended mixtures were higher when compared to the control mixtures and mixtures containing the other mineral admixtures. © 2015 Elsevier Ltd

    The effect of high temperature on mortars containing silica fume

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    In this research the effect of high temperature on the compressive strength of silica incorporated mortar specimens have been studied. For this purpose prismatic mortar specimens containing 0, 5 and 10% silica fume substituted for cement with different w/b ratios and cured at different ages were prepared. The compressive strength before and after exposure to high temperatures of 300 and 600°C were recorded. It was observed that silica fume incorporated mortars has no potential effects in the face of fire hazardous. © 2011 Asian Network for Scientific Information

    Langerhans cell histiocytosis: A case report of a three year old boy with primary oral manifestations

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    Langerhans cell histiocytosis (LCH) is a rare disease with formation of granulomatous infiltrations consisting of Langerhans cells, histiocytes, lymphocytes and eosinophilic granulocytes. The ethiopathogenesis of the disease has not been fully clarified yet. It can occur as focal or disseminated form - acute or chronic. Oral manifestations may be the first signs. This article reports a case of a 3 year old boy with LCH suffering from severe dental mobility and foul breathe. Radiographically, the lesions appeared as well-defined radiolucent defects in maxilla and mandible. The microscopic findings consisted of sheet like arrangements of histiocytes with a mixture of eosinophils and other inflammatory cells. Biochemical tests were within normal limits

    NlpC/P60 domain-containing proteins of Mycobacterium avium subspecies paratuberculosis that differentially bind and hydrolyze peptidoglycan

    Get PDF
    A subset of proteins containing NlpC/P60 domains are bacterial peptidoglycan hydrolases that cleave noncanonical peptide linkages and contribute to cell wall remodeling as well as cell separation during late stages of division. Some of these proteins have been shown to cleave peptidoglycan in Mycobacterium tuberculosis and play a role in Mycobacterium marinum virulence of zebra fish; however, there are still significant knowledge gaps concerning the molecular function of these proteins in Mycobacterium avium subspecies paratuberculosis (MAP). The MAP genome sequence encodes five NlpC/P60 domain-containing proteins. We describe atomic resolution crystal structures of two such MAP proteins, MAP_1272c and MAP_1204. These crystal structures, combined with functional assays to measure peptidoglycan cleavage activity, led to the observation that MAP_1272c does not have a functional catalytic core for peptidoglycan hydrolysis. Furthermore, the structure and sequence of MAP_1272c demonstrate that the catalytic residues normally required for hydrolysis are absent, and the protein does not bind peptidoglycan as efficiently as MAP_1204. While the NlpC/P60 catalytic triad is present in MAP_1204, changing the catalytic cysteine-155 residue to a serine significantly diminished catalytic activity, but did not affect binding to peptidoglycan. Collectively, these findings suggest a broader functional repertoire for NlpC/P60 domain-containing proteins than simply hydrolases
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