4,005 research outputs found
The Consequences of Perfectionism Scale: Factorial structure and relationships with perfectionism, performance perfectionism, affect, and depressive symptoms
This study investigated the Consequences of Perfectionism Scale (COPS) and its relationships with perfectionism, performance perfectionism, affect, and depressive symptoms in 202 university students using confirmatory factor analysis, correlations, and regression analyses. Results suggest that the COPS is a reliable and valid measure of positive and negative consequences of perfectionism
Effects of inhaled acids on lung biochemistry.
Effects of respirable aerosols of sulfuric acid, ammonium sulfate, sodium sulfite, and ammonium persulfate on lungs of rats are reviewed. The literature regarding interactions between ozone or nitrogen dioxide and acidic aerosols (ammonium sulfate, sulfuric acid) is discussed. An unexpected interaction between nitrogen dioxide and sodium chloride aerosol is also discussed. An attempt is made to identify bases for prediction of how and when acid aerosols might potentiate effects of inhaled gases
Transcriptional Regulation of a Human H4 Histone Gene is Mediated by Multiple Elements Interacting with Similar Transcription Factors: A Dissertation
Synthesis of histone proteins occurs largely during the S phase of the cell cycle and coincides with DNA replication to provide adequate amounts of histones necessary to properly package newly replicated DNA. Controlling transcription from cell cycle dependent and proliferation specific genes, including histone H4, is an important level of regulation in the overall governance of the cell growth process. Coordination of histone gene transcription results from the cumulative effects of cell signaling pathways, dynamic chromatin structure and multiple transcription factor interactions. The research of this dissertation focused on the characterization and identification of transcription factors interacting on the human histone H4 gene FO108. I also focused on the elucidation of regulatory elements within the histone coding region. Our results suggest a possible mechanism by which a transcription factor facilitates reorganization of histone gene chromatin structure.
The histone promoter region between -418 nt and -215 nt, Site III, was previously identified as both a positive and negative cis-regulatory element for transcription. Results of in vitroanalyses presented in this dissertation identified multiple transcription factors interacting at Site III. These factors include H4UA-1/YY1, AP-2, AP-2 like factor and distal factor (NF-1 like factor). Transient transfection experiments show that Site III does not confer significant influence on transcription; however, there may exist a physiological role for Site III which would not be detected in these assay systems.
We analyzed the histone H4 gene sequences for additional transcription factor binding motifs and identified several putative YY1 binding sites. Using electrophoretic mobility shift assays (EMSA), we found that Site IV, Site I and two elements within the histone H4 coding region are capable of interacting with YY1. In transient transfection experiments using reporter constructs containing either Site III or one of the coding region elements as potential promoter regulatory elements, and an expression vector encoding YY1, we observed levels of expression up to 2.7 fold higher than from the reporters lacking these elements. Therefore, YY1 appears to interact at multiple regulatory sites of the histone gene and can influence transcription through these elements.
Prior to this study, the role of the coding region in histone gene expression was not known. To determine if the coding region is involved in regulating transcription, I constructed and tested a series of heterologous reporter constructs containing various sequences of the histone coding region. Results from these experiments demonstrated that the histone coding region contains three repressor elements. Extensive in vitro analysis indicated that the three repressor elements interact with the repressor CDP/cut. Further analysis showed that CDP/cut interactions with the repressor elements are cell cycle regulated and proliferation specific. CDP/cut interactions increase during the cell cycle when histone transcription decreases. These observations are consistent with the hypothesis that CDP/cutis a cell cycle regulated repressor factor which influences transcription of the histone H4 gene as such.
The proximal promoter region of the histone H4 gene between -70 nt and +190 nt is devoid of normal nucleosome structure. This same region contains multiple CDP/cut binding sites. We hypothesized that CDP/cut is involved with chromatin remodeling of the histone gene. DNase I footprinting and EMSA results show purified recombinant CDP/cut interacts specifically with the histone promoter reconstituted into nucleosome cores. Thus, CDP/cutmay facilitate the organization of chromatin of the histone gene.
In conclusion, the research presented in this dissertation supports the hypothesis that expression from the human histone H4 gene FO108 is regulated by multiple cis-regulatory elements which interact with several proteins. CDP/cut interacts with Site II, the three repressor elements in the histone coding region and at Distal Site I. YY1 interacts at Site IV, Site III, Site I, and twice in the coding region. ATF/CREB interacts with Site IV and Site I. Distal factor interacts with Site III and within the histone coding region. IRF 2 interacts with Site II and Distal Site I. Thus, histone gene expression is probably regulated by transcription factors CDP/cut, YY1, IRF 2 and ATF/CREB interacting with multiple regulatory elements dispersed throughout its promoter and the coding region. Cell cycle regulation of these transcription factors may contribute to cell cycle dependent expression of the histone gene
Palm pairs and the general mass-transport principle
We consider a lcsc group G acting properly on a Borel space S and measurably
on an underlying sigma-finite measure space. Our first main result is a
transport formula connecting the Palm pairs of jointly stationary random
measures on S. A key (and new) technical result is a measurable disintegration
of the Haar measure on G along the orbits. The second main result is an
intrinsic characterization of the Palm pairs of a G-invariant random measure.
We then proceed with deriving a general version of the mass-transport principle
for possibly non-transitive and non-unimodular group operations first in a
deterministic and then in its full probabilistic form.Comment: 26 page
Mucus glycoprotein secretion by tracheal explants: effects of pollutants.
Tracheal slices incubated with radioactive precursors in tissue culture medium secrete labeled mucus glycoproteins into the culture medium. We have used an in vivtro approach, a combined method utilizing exposure to pneumotoxins in vivo coupled with quantitation of mucus secretion rates in vitro, to study the effects of inhaled pollutants on mucus biosynthesis by rat airways. In addition, we have purified the mucus glycoproteins secreted by rat tracheal explants in order to determine putative structural changes that might by the basis for the observed augmented secretion rates after exposure of rats to H2SO4 aerosols in combination with high ambient levels of ozone. After digestion with papain, mucus glycoproteins secreted by tracheal explants may be separated into five fractions by ion-exchange chromatography, with recovery in high yield, on columns of DEAE-cellulose. Each of these five fractions, one neutral and four acidic, migrates as a single unique spot upon cellulose acetate electrophoresis at pH values of 8.6 and 1.2. The neutral fraction, which is labeled with [3H] glucosamine, does not contain radioactivity when Na2 35SO4 is used as the precursor. Acidic fractions I-IV are all labeled with either 3H-glucosamine or Na2 35SO4 as precursor. Acidic fraction II contains sialic acid as the terminal sugar on its oligosaccharide side chains, based upon its chromatographic behavior on columns of wheat-germ agglutinin-Agarose. Treatment of this fraction with neuraminidase shifts its elution position in the gradient to a lower salt concentration, coincident with acidic fraction I. After removal of terminal sialic acid residues with either neuraminidase or low pH treatment, the resultant terminal sugar on the oligosaccharide side chains is fucose. These results are identical with those observed with mucus glycoproteins secreted by cultured human tracheal explants and purified by these same techniques
Collagen biosynthesis.
Collagen is the major structural protein of the lung. At least five genetically distinct collagen types have been identified in lung tissue. However, the precise role of collagen in nonrespiratory lung function is not well understood, in part because of the difficulties inherent in studying lung collagen, regardless of the type of assay used. A major problem is the insolubility of lung collagen; generally less than 20% of total lung collagen can be solubilized as intact chains, even with harsh extraction procedures. Since such collagen may not be representative of total lung collagen, errors in quantitating collagen types, for example, may arise from using such material. Measurement of total lung collagen content may also pose problems, unless appropriate parameters of normalization are chosen. Biopsy dry weight, protein content, and DNA content, for example, may all change in certain disease states. Despite these difficulties, a number of changes in lung collagen have been documented in experimental pulmonary fibrosis, including increased collagen content, increased collagen synthesis rates, and changes in collagen type ratios. Many questions remain. For example, why do diverse toxic substances appear to cause essentially the same fibrotic response, even though initial sites of damage may vary? Conversely, why do similar toxic substances, such as ozone and NO2, cause diverse responses (fibrosis and emphysema, respectively)? Much work remains to be done to elucidate the mechanisms underlying the lung's choice of response
Bloch electron in a magnetic field and the Ising model
The spectral determinant det(H-\epsilon I) of the Azbel-Hofstadter
Hamiltonian H is related to Onsager's partition function of the 2D Ising model
for any value of magnetic flux \Phi=2\pi P/Q through an elementary cell, where
P and Q are coprime integers. The band edges of H correspond to the critical
temperature of the Ising model; the spectral determinant at these (and other
points defined in a certain similar way) is independent of P. A connection of
the mean of Lyapunov exponents to the asymptotic (large Q) bandwidth is
indicated.Comment: 4 pages, 1 figure, REVTE
The Roles of ‘Conventional’ and Demand-Responsive Bus Services
Purpose - The roles of ‘conventional’ (fixed-route and fixed-timetable) bus services is examined and compared to demand-responsive services, taking rural areas in England as the basis for comparison. It adopts a ‘rural’ definition of settlements under a population of 10,000.
Design/methodology/approach - Evidence from the National Travel Survey, technical press reports and academic work is brought together to examine the overall picture.
Findings - Inter-urban services between towns can provide a cost-effective way of serving rural areas where smaller settlements are suitably located. The cost structures of both fixed-route and demand-responsive services indicate that staff time and cost associated with vehicle provision are the main elements. Demand-responsive services may enable larger areas to be covered, to meet planning objectives of ensuring a minimum of level of service, but experience often shows high unit cost and public expenditure per passenger trip. Economic evaluation indicates user benefits per passenger trip of similar magnitude to existing average public expenditure per trip on fixed-route services. Considerable scope exists for improvements to conventional services through better marketing and service reliability.
Practical implications - The main issue in England is the level of funding for rural services in general, and the importance attached to serving those without access to cars in such areas.
Social implications - The boundary between fixed-route and demand-responsive operation may lie at relatively low population densities.
Originality/value - The chapter uses statistical data, academic research and operator experience of enhanced conventional bus services to provide a synthesis of outcomes in rural areas
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