203,752 research outputs found
Note: Robert Chew to Ida M. Tarbell, April 3, 1901
No full textHandwritten response on back of letter April 1, 190
List of <i>M. xanthus</i> CheA, CheW and CheY.
No full text<p>List of <i>M. xanthus</i> CheA, CheW and CheY.</p
Optimizing Chew and Chen's Pitch-Spelling Algorithm
No full textPitch-spelling algorithms attempt to compute the
correct pitch names (e.g., C#4, Bb5) of the notes in a
passage of tonal music, when given only the onset
time, MIDI note number, and possibly the duration
and voice of each note. This article reports on a
study in which Chew and Chen’s (2003a, 2003b,
2005) pitch-spelling algorithm was re-implemented
and then optimized by running it with a range of
different parameter value combinations on a test
corpus containing 195,972 notes and consisting of
216 movements from works by eight Baroque and
Classical composers. The results of this evaluation
cast doubt upon some of the claims made by Chew
and Chen that were based on results obtained by
running their algorithm on a much smaller test corpus
containing only 4,462 notes and consisting of
just two movements from sonatas by Beethoven and
You-Di Huang’s Song of Ali-Shan. The results presented
here suggest that Chew and Chen’s algorithm
could be simplified in various ways without
compromising its performance
The Tsr chemoreceptor/CheW/CheA ternary complex as an allosteric enzyme
No full textThe transmembrane serine receptor Tsr associates with a coupling protein, CheW,
and a histidine kinase, CheA, to form a ternary complex that regulates the activity of
CheA. CheA activity is inhibited by binding of L-serine to Tsr. This work aims to
characterize the ligand-binding properties of Tsr and the inhibitory effect of L-serine on
CheA activity. The periplasmic domain of Tsr (pTsr) was purified and characterized.
Analytical gel filtration and analytical ultracentrifugation indicated that binding of Lserine
promotes dimerization. The binding stoichiometry and dissociation constant for
binding of L-serine to pTsr were determined by fluorescence spectroscopy. As protein
concentration decreased, the dissociation constant increased. A working model was
proposed to account for the interactions between L-serine and pTsr. The activity of
CheA in a ternary complex with full-length Tsr and CheW was analyzed by measuring
the production of [32P]-phospho-CheY. (Phospho-CheY is the product of CheA catalysis.)
The results revealed that binding of L-serine decreased CheA activity without changing
its affinity for ATP. These findings suggest that the allosteric effect of L-serine on CheA activity might occur through V-type inhibition. Optimization of an alternative,
continuous, non-radioactive assay for CheA is underway
Checklist of health promotion environments at worksites (CHEW): Development and measurement characteristics
No full textPurpose. Health promotion policy frameworks, recent theorizing, and research all emphasize understanding and mobilizing environmental influences to change particular health-related behaviors in specific settings. The workplace is a key environmental setting. The Checklist of Health Promotion Environments at Worksites (CHEW) was designed as a direct observation instrument to assess characteristics of worksite environments that are known to influence health-related behaviors. Methods. The CHEW is a 112-item checklist of workplace environment features hypothesized to be associated, both positively and negatively, with physical activity, healthy eating, alcohol consumption, and smoking. The three environmental domains assessed are (1) physical characteristics of the worksite, (2) features of the information environment, and (3) characteristics of the immediate neighborhood around the workplace. The conceptual rationale and development studies for the CHEW are described, and data from observational studies of 20 worksites are reported. Results. The data on CHEW-derived environmental attributes showed generally good reliability and identified meaningful sets of variables that plausibly may influence health-related behaviors. With the exception of one information environment attribute, intraclass correlation coefficients ranged from 0.80 to 1.00. Descriptive statistics on selected physical and information environment characteristics indicated that vending machines, showers, bulletin boards, and signs prohibiting smoking were common across worksites. Bicycle racks, visible stairways, and signs related to alcohol consumption, nutrition, and health. promotion were relatively uncommon. Conclusions. These findings illustrate the types of data on environmental attributes that can be derived, their relevance for program planning, and how they can characterize variability across worksites. The CHEW is a promising observational measure that has the potential to assess environmental influences on health behaviors and to evaluate workplace health promotion programs
Dr. Clyde Chew Glascock, Modern Languages, Rice Institute
No full textDr. Clyde Chew Glascock, assistant professor of modern languages at the William M. Rice Institute. Glascock is wearing a dark suit, white shirt, and bow tie, and is standing to the side of the Administration Building. Original resource is a black and white photograph.Dr. Clyde Chew Glascock was the Assistant Professor of Modern Languages at Rice Institute from 1914-1923
Umweltbezogene Attribute der betrieblichen Gesundheitsförderung – CHEW – Checklist of Health Promotion Environments at Worksites
No full textBucksch J, Zinsmeister M, Brachmann H. Umweltbezogene Attribute der betrieblichen Gesundheitsförderung – CHEW – Checklist of Health Promotion Environments at Worksites. Präv Gesundheitsf. 2011;6(1):67-74
A divergent CheW confers plasticity to nucleoid-associated chemosensory arrays
No full textInternational audienceChemosensory systems are highly organized signaling pathways that allow bacteria to adapt to environmental changes. The Frz chemosensory system from M. xanthus possesses two CheW-like proteins, FrzA (the core CheW) and FrzB. We found that FrzB does not interact with FrzE (the cognate CheA) as it lacks the amino acid region responsible for this interaction. FrzB, instead, acts upstream of FrzCD in the regulation of M. xanthus chemotaxis behaviors and activates the Frz pathway by allowing the formation and distribution of multiple chemosensory clusters on the nucleoid. These results, together, show that the lack of the CheA-interacting region in FrzB confers new functions to this small protein
A proteomic investigation of Fusobacterium nucleatum alkaline-induced biofilms
No full textBackground: The Gram negative anaerobe Fusobacterium nucleatum has been implicated in the aetiology of periodontal diseases. Although frequently isolated from healthy dental plaque, its numbers and proportion increase in plaque associated with disease. One of the significant physico-chemical changes in the diseased gingival sulcus is increased environmental pH. When grown under controlled conditions in our laboratory, F. nucleatum subspecies polymorphum formed mono-culture biofilms when cultured at pH 8.2. Biofilm formation is a survival strategy for bacteria, often associated with altered physiology and increased virulence. A proteomic approach was used to understand the phenotypic changes in F. nucleatum cells associated with alkaline induced biofilms. The proteomic based identification of significantly altered proteins was verified where possible using additional methods including quantitative real-time PCR (qRT-PCR), enzyme assay, acidic end-product analysis, intracellular polyglucose assay and Western blotting. Results: Of 421 proteins detected on two-dimensional electrophoresis gels, spot densities of 54 proteins varied significantly (p < 0.05) in F. nucleatum cultured at pH 8.2 compared to growth at pH 7.4. Proteins that were differentially produced in biofilm cells were associated with the functional classes; metabolic enzymes, transport, stress response and hypothetical proteins. Our results suggest that biofilm cells were more metabolically efficient than planktonic cells as changes to amino acid and glucose metabolism generated additional energy needed for survival in a sub-optimal environment. The intracellular concentration of stress response proteins including heat shock protein GroEL and recombinational protein RecA increased markedly in the alkaline environment. A significant finding was the increased abundance of an adhesin, Fusobacterial outer membrane protein A (FomA). This surface protein is known for its capacity to bind to a vast number of bacterial species and human epithelial cells and its increased abundance was associated with biofilm formation. Conclusion: This investigation identified a number of proteins that were significantly altered by F. nucleatum in response to alkaline conditions similar to those reported in diseased periodontal pockets. The results provide insight into the adaptive mechanisms used by F. nucleatum biofilms in response to pH increase in the host environment.Jactty Chew, Peter S Zilm, Janet M Fuss and Neville J Gull
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