728 research outputs found
Computing identity co-reference across drug discovery datasets
Get PDFThis paper presents the rules used within the Open PHACTS (http://www.openphacts.org) Identity Management Service to compute co-reference chains across multiple datasets. The web of (linked) data has encouraged a proliferation of identifiers for the concepts captured in datasets; with each dataset using their own identifier. A key data integration challenge is linking the co-referent identifiers, i.e. identifying and linking the equivalent concept in every dataset. Exacerbating this challenge, the datasets model the data difierently, so when is one representation truly the same as another? Finally, different users have their own task and domain specific notions of equivalence that are driven by their operational knowledge. Consumers of the data need to be able to choose the notion of operational equivalence to be applied for the context of their application. We highlight the challenges of automatically computing co-reference and the need for capturing the context of the equivalence. This context is then used to control the co-reference computation. Ultimately, the context will enable data consumers to decide which co-references to include in their applications.</p
C.T. Vivian, Joseph E. Lowery, and Tom Brown, circa 1980
No full textSouthern Christian Leadership Conference President Joseph E. Lowery is shown standing outside with C.T. Vivian (left) and Tom Brown (right) at Paschal's Motor Hotel.The Atlanta University Center Robert W. Woodruff Library acknowledges the generous support of the Joseph & Evelyn Lowery Institute for Justice and Human Rights, the Joseph Echols Lowery Irrevocable Trust, and other donors in supporting the processing and digitization of Morehouse College's Joseph Echols and Evelyn Gibson Lowery Collection
Erythrocyte antioxidant defense response against cigarette smoking in humans-the glutathione S-transferase vulnerability
Get PDFCigarette smoking leads to uptake of a multitude of reactive chemicals including many electrophiles and may also give rise to oxidative stress. Human red blood cells are important targets for electrophilic and oxidant foreign compounds. We investigated the oxidative stress in erythrocytes upon cigarette smoking, and the response of antioxidant defense system against it. With this aim, simultaneous determination of erythrocyte superoxide dismutase (SOD), selenium dependent glutathione peroxidase (Se-GPx), catalase (CAT), glutathione S-transferase (GST) activities and plasma levels of thiobarbituric acid reactive substances (TBARS), and the degree of erythrocyte membrane lipid peroxidation (EMLP) were carried out in blood samples of smokers and their controls. Plasma TBARS levels and EMLP in smokers were significantly higher than the control levels (p < 0.01 and p < 0.005, respectively). SOD activity was diminished in smokers compared to nonsmoker controls (p < 0.005). Erythrocyte Se-GPx activity was also found significantly diminished in smokers (p < 0.005), while plasma Se-GPx activity was not changed. We observed that erythrocyte CAT activity was not different in smokers compared to nonsmoker controls. We found that the erythrocyte GST activity is significantly lower in young adult smokers (3.03 +/- 0.18 U/mg protein; mean +/- SEM; n = 46) than in nonsmoking contemporaries (3.98 +/- 0.26 U/mg protein; mean +/- SEM; n = 41). Together with previously reported data, it can be concluded that the decrease in GST activity leads to extra GST synthesis during erythrocyte proliferation. The same data were also analyzed for the sex differences. The statistically significant differences remained the same between nonsmoker and smoker females. Only EMLP degree and SOD activity were significantly different between nonsmoker and smoker males; however, when compared the parameters between male and female nonsmokers, GST activity was found to be significantly higher in females than that of males. (c) 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:226-233, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20088
Pectin - Xyloglucan linkages in type I primary cell walls of plants
No full textEvidence for covalent pectin - xyloglucan linkages in the cell wall of growing cells and maturing tissues has been reported. In-vitro studies using isolated Golgi membranes, and pulse-labelling studies in vivo, indicate that pectin - xyloglucan linkages form in the Golgi apparatus. The structure and biological significance of these complexes are discussed. © 2005 Società Botanica Italiana.Abdel-Massih RM, 2003, PLANTA, V216, P502, DOI 10.1007-s00425-002-0861-y; Brett C.T., 1996, PHYSL BIOCH PLANT CE; BRETT CT, 2004, 10 CELL WALL M 2004, P66; Femenia A, 1999, CARBOHYD POLYM, V39, P151, DOI 10.1016-S0144-8617(99)00003-X; KEEGSTRA K, 1973, PLANT PHYSIOL, V51, P188, DOI 10.1104-pp.51.1.188; MCCANN MC, 1990, J CELL SCI, V96, P323; POPPER ZA, 2004, 10 CELL WALL M 2004, P85; Thompson JE, 2000, PLANTA, V211, P275, DOI 10.1007-s004250000287; Vincken JP, 2003, PLANT PHYSIOL, V132, P1781, DOI 10.1104-pp.103.022350; WALDRON KW, 1992, PHYTOCHEMISTRY, V31, P1931, DOI 10.1016-0031-9422(92)80336-D89
Contribuicao para o estudo da epidemiologia molecular e da patogenia das infeccoes causadas por Chlamydia trachomatis
No full textThe study determined Chlamydia trachomatis (C.t.) genotype E as predominant, in the biological products of Lisbon citizens infected by C.t.. The author developed an experimental model of chronic infection, using mice of different haplotypes, inoculated (once or more) in the uterus (through the vagina) with one E C.t. strain. C.t. was isolated, by culture, after the first inoculation, but C.t. DNA was detected during the six months period of experiments; C.t. remained in tubal tissues in a nonviable biological state. The humoral immune response of infected animals indicated a chronic C.t. infection. The evaluation of the genetic expression of different cytokines produced by Th1 or Th2 cells, couldn't determine a profile specifically related with the chronic C.t. infection; however, the IFN_#gamma# production by illiac node cells, only occured during the acute infection. The production of isotype IgG2a or IgG1 showed a Th1 profile in C3H/He mice and a Th2 profile in C57BL/6 mice. C3H/He mice produced antibodies to the C.t HSP60 (CHSP60) during both acute and chronic C.t. infection; C57BL/6 mice only reacted to CHSP60 when submitted to several C.t. infection episodes. Mice carrying a chronic C.t. infection didn't exhibit any histological changes suggesting episodes. Mice carrying a chronic C.t. infection didn't exhibit any histological changes suggesting the establishment of a chronic inflammatory processAvailable from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1200 Lisboa / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga
A systematic review of large scale and heterogeneous gene array data in heart failure
Get PDFMicroarray analysis has become a widely available tool for the generation of gene expression data on a genomic scale. Since the studies with similar protocols are growing, it has become necessary to systematically revise the large body of literature to decipher the gene expression data. In this review, we analyzed and critically discussed the database presented from 14 published studies that showed the gene expression profile in heart failure (HF) using microarray as a primary tool. After comparing the diverse database from these studies, we explain the protein translational, matri-cellular, immunological and fibrosis-related mechanisms in HF. In addition to previously annotated genes, we analyzed two differentially expressed expressed sequence tags (ESTs) (KIAA0152 and Suppressor of G(Two) allele of the suppressor of kinetochore protein-1, SGT1) in HF and showed how bio-informatic analysis of ESTs can lead to the identification of novel pathways active in HF. We have also discussed the new publicly accessible tools that link the gene expression data to gene ontogeny (GO) and functionality. Finally, we have systematically revised the chromosomal localization of the genes that are specifically up-regulated in HF. We have thus spotted chromosome 1, 2, 11 and 12 as the chromosomal hotspots of HF. This methodical approach will simplify the existing concepts on the evolution and progression of HF and lead us toward the development of newer diagnostic and therapeutic tools. Although modeled to HF, this approach should be of broader scientific interest to elaborate multiple genes and complex pathways
The role of bioinformatics in pathway curation
No full textDiagrams and models of biological pathways are useful tools in biology. Pathway diagrams are mainly used for illustrative purposes for instance in textbooks and in presentations. Pathway models are used in the analysis of genomic data. Bridging the gap between diagrams and models allows not only the analysis of genomics data and interactions but also the visualisation of the results in a variety of different ways. The knowledge needed for pathway creation and curation is available from three distinct sources: databases, literature and experts. We describe the role of bioinformatics in facilitating the creation and curation of pathway
An Auto-Zero Stabilized Voltage Buffer with a Trimmed Input Current of 0.2pA
No full textThis paper presents an input-current trimming scheme for auto-zero amplifiers. Since their input current is mainly due to charge injection,the scheme operates by trimming the clock swing,and hence the charge injection,of two dummy input switches. At room temperature,the trimming scheme reduces the maximum input current of an auto-zero stabilized voltage buffer from 1pA to 0.2pA (13 samples) over its full input voltage range (0 to 1.3V). This increases to 0.4pA over temperature (0 to 85°C),which is well below the leakage of typical ESD diodes,and is the lowest input current ever reported for an auto-zero amplifier.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
An Auto-Zero-Stabilized Voltage Buffer With a Quiet Chopping Scheme and Constant Sub-pA Input Current
No full textThis article describes an auto-zero stabilized voltage buffer that achieves low offset and low noise with sub-pA input current. A high gain stabilization loop is used to periodically cancel the buffer’s offset. The loop itself is periodically disconnected from the buffer and auto-zeroed, during which its bandwidth is reduced to reduce the associated noise folding. However, this also reduces its offset correction range, and so to avoid overloading, its initial offset is digitally trimmed. To break up the correlation between the residual low-frequency (LF) noise of the auto-zero and stabilization phases, the loop is periodically chopped, which significantly reduces the buffer’s LF noise. Finally, the duty-cycle of the two phases is optimized to bring the buffer’s LF noise density close to 2–√ times its white noise density (14 nV/ Hz−−−√ ), which is the fundamental limit of an AZ amplifier. The buffer also achieves a constant and low input current (0.8 pA), as well as a state-of-the-art offset (0.4 μV ).Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
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