bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role and Regulation of Fatty Acid Biosynthesis in the Response ofShewanella piezotoleransWP3 to Different Temperatures and Pressures
Authors: Wang Feng , Xiao Xiang , Ou Hong-Yu , Gai Yingbao , Wang Fengping 
Published: February 2009

ABSTRACTMembers of the genusShewanellainhabit various environments; they are capable of synthesizing various types of low-melting-point fatty acids, including monounsaturated fatty acids (MUFA) and branched-chain fatty acids (BCFA) with and without eicosapentanoic acid (EPA). The genes involved in fatty acid synthesis in 15 whole-genome-sequencedShewanellastrains were identified and compared. A typical type II fatty acid synthesis pathway inShewanellawas constructed. A complete EPA synthesis gene cluster was found in all of theShewanellagenomes, although only a few of them were found to produce EPA. The roles and regulation of fatty acids synthesis inShewanellawere further elucidated in theShewanella piezotoleransWP3 response to different temperatures and pressures. The EPA and BCFA contents of WP3 significantly increased when it was grown at low temperature and/or under high pressure. EPA, but not MUFA, was determined to be crucial for its growth at low temperature and high pressure. A gene cluster for a branched-chain amino acid ABC transporter (LIV-I) was found to be upregulated at low temperature. Combined approaches, including mutagenesis and an isotopic-tracer method, revealed that the LIV-I transporter played an important role in the regulation of BCFA synthesis in WP3. The LIV-I transporter was identified only in the cold-adaptedShewanellaspecies and was assumed to supply an important strategy forShewanellacold adaptation. This is the first time the molecular mechanism of BCFA regulation in bacteria has been elucidated.
Crystal Structure of Butyrate Kinase 2 from
Thermotoga maritima
, a Member of the ASKHA Superfamily of Phosphotransferases
Authors: Diao Jiasheng , Hasson Miriam S. 
Published: February 2009

ABSTRACT

The enzymatic transfer of phosphoryl groups is central to the control of many cellular processes. One of the phosphoryl transfer mechanisms, that of acetate kinase, is not completely understood. Besides better understanding of the mechanism of acetate kinase, knowledge of the structure of butyrate kinase 2 (Buk2) will aid in the interpretation of active-site structure and provide information on the structural basis of substrate specificity. The gene
buk2
from
Thermotoga maritima
encodes a member of the ASKHA (acetate and sugar kinases/heat shock cognate/actin) superfamily of phosphotransferases. The encoded protein Buk2 catalyzes the phosphorylation of butyrate and isobutyrate. We have determined the 2.5-Å crystal structure of Buk2 complexed with (β,γ-methylene) adenosine 5′-triphosphate. Buk2 folds like an open-shelled clam, with each of the two domains representing one of the two shells. In the open active-site cleft between the N- and C-terminal domains, the active-site residues consist of two histidines, two arginines, and a cluster of hydrophobic residues. The ATP binding region of Buk2 in the C-terminal domain consists of abundant glycines for nucleotide binding, and the ATP binding motif is similar to those of other members of the ASKHA superfamily. The enzyme exists as an octamer, in which four disulfide bonds form between intermolecular cysteines. Sequence alignment and structure superposition identify the simplicity of the monomeric Buk2 structure, a probable substrate binding site, the key residues in catalyzing phosphoryl transfer, and the substrate specificity differences among Buk2, acetate, and propionate kinases. The possible enzyme mechanisms are discussed.
The Core Oligosaccharide and Thioredoxin of
Vibrio cholerae
Are Necessary for Binding and Propagation of Its Typing Phage VP3
Authors: Zhang Jingyun , Li Wei , Zhang Qian , Wang Hongxia , Xu Xiao , Diao Baowei , Zhang Lijuan , Kan Biao 
Published: February 2009

ABSTRACT

VP3 is a T7-like phage and was used as one of the typing phages in a phage-biotyping scheme that has been used for the typing of
Vibrio cholerae
O1 biotype El Tor. Here, we studied the receptor and other host genes of
V. cholerae
necessary for the lytic propagation of VP3. Six mutants resistant to VP3 infection were obtained from the random transposon insertion mutant bank of the sensitive strain N16961. The genes VC0229 and VC0231, which belong to the
wav
gene cluster encoding the core oligosaccharide (OS) region of lipopolysaccharide, were found to be interrupted by the transposon in five mutants, and the sixth mutant had the transposon inserted between the genes
rhlB
and
trxA
, which encode the ATP-dependent RNA helicase RhlB and thioredoxin, respectively. Gene complementation, transcription analysis, and the loss of VP3 sensitivity by the gene deletion mutants confirmed the relationship between VP3 resistance and VC0229, VC0231, and
trxA
mutation. The product of VP3 gene 44 (gp44) was predicted to be a tail fiber protein. gp44 could bind to the sensitive wild-type strain and the
trxA
mutant, but not to VC0229 and VC0231 mutants. The results showed that OS is a VP3 receptor on the surface of N16961, thioredoxin of the host strain is involved in the propagation of the phage, and gp44 is the tail fiber protein of VP3. This revealed the first step in the infection mechanism of the T7-like phage VP3 in
V. cholerae
.
Identification of anrshGene from aNovosphingobiumsp. Necessary for Quorum-Sensing Signal Accumulation
Authors: Gan Han Ming , Buckley Larry , Szegedi Ernő , Hudson André O. , Savka Michael A. 
Published: February 2009

ABSTRACTThe stringent response is a mechanism by which bacteria adapt to environmental stresses and nutritional deficiencies through the synthesis and hydrolysis of (p)ppGpp by RelA/SpoT enzymes. Alphaproteobacteria and plants contain a single Rsh enzyme (named forRelA/SpoThomolog) that is bifunctional. Here we report the identification of a new species of bacteria belonging to the genusNovosphingobiumand characterization of anrshmutation in this plant tumor-associated isolate. Isolate Rr 2-17, from a grapevine crown gall tumor, is a member of theNovosphingobiumgenus that produces theN-acyl-homoserine lactone (AHL) quorum-sensing (QS) signals. A Tn5mutant, Hx 699, deficient in AHL production was found to have an insertion in anrshgene. The Rsh protein showed significant percent sequence identity to Rsh proteins of alphaproteobacteria. TheNovosphingobiumsp.rshgene (rshNsp) complemented the multiple amino acid requirements of theEscherichia coli relA spoTdouble mutant by restoring the growth on selection media. Besides QS signal production, thershmutation also affects soluble polysaccharide production and cell aggregation. Genetic complementation of the Hx 699 mutant with thershNspgene restored these phenotypes. This is the first discovery of a functionalrshgene in a member of theNovosphingobiumgenus.
BldG and SCO3548 Interact Antagonistically To Control Key Developmental Processes inStreptomyces coelicolor
Authors: Parashar Archana , Colvin Kimberley R. , Bignell Dawn R. D. , Leskiw Brenda K. 
Published: February 2009

ABSTRACTThe similarity of BldG and the downstream coexpressed protein SCO3548 to anti-anti-sigma and anti-sigma factors, respectively, together with the phenotype of abldGmutant, suggests that BldG and SCO3548 interact as part of a regulatory system to control both antibiotic production and morphological differentiation inStreptomyces coelicolor. A combination of bacterial two-hybrid, affinity purification, and far-Western analyses demonstrated that there was self-interaction of both BldG and SCO3548, as well as a direct interaction between the two proteins. Furthermore, a genetic complementation experiment demonstrated that SCO3548 antagonizes the function of BldG, similar to other anti-anti-sigma/anti-sigma factor pairs. It is therefore proposed that BldG and SCO3548 form a partner-switching pair that regulates the function of one or more sigma factors inS. coelicolor. The conservation ofbldGand sco3548 in other streptomycetes demonstrates that this system is likely a key regulatory switch controlling developmental processes throughout the genusStreptomyces.
A
Burkholderia cenocepacia
Orphan LuxR Homolog Is Involved in Quorum-Sensing Regulation
Authors: Malott Rebecca J. , O'Grady Eoin P. , Toller Jessica , Inhülsen Silja , Eberl Leo , Sokol Pamela A. 
Published: February 2009

ABSTRACT

Burkholderia cenocepacia
utilizes quorum sensing to control gene expression, including the expression of genes involved in virulence. In addition to CepR and CciR, a third LuxR homolog, CepR2, was found to regulate gene expression and virulence factor production. All
B. cenocepacia
strains examined contained this orphan LuxR homolog, which was not associated with an adjacent
N
-acyl-homoserine lactone synthase gene. Expression of
cepR2
was negatively autoregulated and was negatively regulated by CciR in strain K56-2. Microarray analysis and quantitative reverse transcription-PCR determined that CepR2 did not influence expression of
cepIR
or
cciIR
. However, in strain K56-2, CepR2 negatively regulated expression of several known quorum-sensing-controlled genes, including genes encoding zinc metalloproteases. CepR2 exerted positive and negative regulation on genes on three chromosomes, including strong negative regulation of a gene cluster located adjacent to
cepR2
. In strain H111, which lacks the CciIR quorum-sensing system, CepR2 positively regulated pyochelin production by controlling transcription of one of the operons required for the biosynthesis of the siderophore in an
N
-acyl-homoserine lactone-independent manner. CepR2 activation of a
luxI
promoter was demonstrated in a heterologous
Escherichia coli
host, providing further evidence that CepR2 can function in the absence of signaling molecules. This study demonstrates that the orphan LuxR homolog CepR2 contributes to the quorum-sensing regulatory network in two distinct strains of
B. cenocepacia
.
Combinatorial Regulation by a Novel Arrangement of FruA and MrpC2 Transcription Factors during
Myxococcus xanthus
Development
Authors: Mittal Sheenu , Kroos Lee 
Published: February 2009

ABSTRACT

Myxococcus xanthus
is a gram-negative soil bacterium that undergoes multicellular development upon nutrient limitation. Intercellular signals control cell movements and regulate gene expression during the developmental process. C-signal is a short-range signal essential for aggregation and sporulation. C-signaling regulates the
fmgA
gene by a novel mechanism involving cooperative binding of the response regulator FruA and the transcription factor/antitoxin MrpC2. Here, we demonstrate that regulation of the C-signal-dependent
fmgBC
operon is under similar combinatorial control by FruA and MrpC2, but the arrangement of binding sites is different than in the
fmgA
promoter region. MrpC2 was shown to bind to a crucial
cis
-regulatory sequence in the
fmgBC
promoter region. FruA was required for MrpC and/or MrpC2 to associate with the
fmgBC
promoter region in vivo, and expression of an
fmgB-lacZ
fusion was abolished in a
fruA
mutant. Recombinant FruA was shown to bind to an essential regulatory sequence located slightly downstream of the MrpC2-binding site in the
fmgBC
promoter region. Full-length FruA, but not its C-terminal DNA-binding domain, enhanced the formation of complexes with
fmgBC
promoter region DNA, when combined with MrpC2. This effect was nearly abolished with
fmgBC
DNA fragments having a mutation in either the MrpC2- or FruA-binding site, indicating that binding of both proteins to DNA is important for enhancement of complex formation. These results are similar to those observed for
fmgA
, where FruA and MrpC2 bind cooperatively upstream of the promoter, except that in the
fmgA
promoter region the FruA-binding site is located slightly upstream of the MrpC2-binding site. Cooperative binding of FruA and MrpC2 appears to be a conserved mechanism of gene regulation that allows a flexible arrangement of binding sites and coordinates multiple signaling pathways.
Are asthma-like symptoms in elite athletes associated with classical features of asthma?
Authors: Lund T K , Pedersen L , Anderson S D , Sverrild A , Backer V 
Published: February 2009

Background:Asthma is frequent in elite athletes and clinical studies in athletes have found increased airway inflammation.Objective:To investigate asthma-like symptoms, airway inflammation, airway reactivity (AR) to mannitol and use of asthma medication in Danish elite athletes.Methods:The study group consisted of 54 elite athletes (19 with doctor-diagnosed asthma), 22 non-athletes with doctor-diagnosed asthma (steroid naive for 4 weeks before the examination) and 35 non-athletes without asthma; all aged 18–35 years. Examinations (1 day): questionnaires, exhaled nitric oxide (eNO) in parts per billion, spirometry, skin prick test, AR to mannitol and blood samples. Induced sputum was done in subjects with asthma.Results:No significant difference was found in values for eNO, AR and atopy between 42 elite athletes with and 12 without asthma-like symptoms. Elite athletes with doctor-diagnosed asthma had less AR (response dose ratio 0.02 (0.004) vs 0.08 (0.018) p<0.01) and fewer sputum eosinophils (0.8% (0–4.8) vs 6.0% (0–18.5), p<0.01) than non-athletes with doctor-diagnosed asthma. Use of inhaled corticosteroids was similar in the two groups (not significant). In all, 42 elite athletes had asthma-like symptoms but only 12 had evidence of current asthma. Elite athletes without asthma had asthma-like symptoms more frequently than non-athletes without asthma (68.6% vs 25.7%, p<0.001).Conclusion:Asthma-like symptoms in elite athletes are not necessarily associated with classic features of asthma and alone should not give a diagnosis of asthma. More studies are needed to further investigate if and how the asthma phenotype of elite athletes differs from that of classical asthma.
Medical education on fitness to drive: a survey of all UK medical schools
Authors: Hawley C A , Galbraith N D , deSouza V A 
Published: February 2009

Abstract

Aim
To identify the extent to which medical aspects of fitness to drive (FTD) are taught within UK medical schools.

Methods
A survey of all 32 UK medical schools. In-depth interviews with a range of staff at two medical schools; telephone survey of 30 schools.

Results
Two thirds of schools reported specific teaching on medical aspects of FTD but few covered it in any depth or in relation to specific medical conditions. Only one school taught FTD in relation to elderly medicine. FTD was an examination topic at only 12 schools.

Conclusion
Teaching on FTD is inconsistent across UK medical schools. Many new doctors will graduate with limited knowledge of medical aspects of FTD.
From mountain to bedside: understanding the clinical relevance of human acclimatisation to high-altitude hypoxia
Authors: Martin D , Windsor J 
Published: February 2009

Abstract
For centuries man has strived to reach the greatest heights on earth. In order to explain the physiological changes that are needed to achieve this, physiologists have tended to focus on the improvements made in oxygen delivery to the body's tissues. Although this explains much of the acclimatisation process, it has not been able to address the large interindividual variations seen in human performance at altitude. In recent years, attention has shifted and now focuses on microvascular and cellular responses in an attempt to explain these differences. Investigating these processes not only helps to unravel the process of acclimatising to altitude, but it may also improve our understanding of the body's response to hypoxia in those with critical illness.
Climate Change and Well-Being
Authors: Heap Brian , Comim Flavio 
Published: February 2009

AbstractHuman well-being in industrialized and developing nations continues to be influenced by disparate components and there is growing evidence that climate change is a new and potentially damaging global threat. Context affects the prospect of finding solutions because socio-economic elements, ethical considerations, and moral norms all play their part. Of central concern is how to advance from the innumerable benefits of capitalism and industrialization based on economies driven by fossil fuels towards a predominantly low carbon economy faced with high population growth rates, consumerism in the North, poverty in the South, financial instability worldwide, and food insecurity. Cooperation among nations has become a pressing priority and it demands that value systems should be incorporated more strongly into international negotiations if we are to sustain a civil society that responds positively to the new politics of the global environment.
Auserwältes Volk und Staatsbürger Juden und Nichtjuden in der Lehre von Rabbi Elias Gutmacher
Authors: Hildesheimer Meir 
Published: February 2009

AbstractThe Jewish emancipation in Germany (1869-1871) brought about a fundamental change in the position of Jews in state and society, leading to a rapprochement between Jews and their non-Jewish surroundings. For religious Jews, this transition into neutral society brought up fundamental theological questions: How is emancipation to be evaluated from a religious perspective? What is the appropriate relationship with the state? How should Jews interact with Gentiles? How could Jews integrate into society without denying the singularity of Israel and without neglecting their religious obligations? Rabbi Elias Gutmacher (1796-1874) was one of the religious leaders of Judaism in Germany whose scholarship was deeply concerned with such questions. Gutmacher was from Grätz in the Posen region and became primarily known as a cabbalist. The following article summarizes his views on the topic, which can be found in his literary oeuvre and most of all in his sermons.
Das andere Zeremoniell Gottesdienst im Zeitalter der Aufklärung
Authors: Twellmann Marcus 
Published: February 2009

AbstractDuring the first half of the 18th century, court-orientated scholarship helped shape a concept of ,,ceremony“ that had a great impact on religious practices in a number of ways: First, this scholarship itself fostered a ,,politicization“ of church services by subjugating them to the criteria of decorum and political utility. Second, in analogy to courtly ceremonies, church service was understood as a sign of reverence aiming to win grace. A critical religious philosophy, blaming this understanding for superstitious cult practices, foreclosed the full development of an ethical understanding of ceremony that was already recognizable in the philosophical foundations of the older ceremonial sciences. At the end of the century such an understanding continued to be pursued only within the context of justifying Jewish ceremonial law.
A New Bruker IFS 125HR FTIR Spectrometer for the Polar Environment Atmospheric Research Laboratory at Eureka, Nunavut, Canada: Measurements and Comparison with the Existing Bomem DA8 Spectrometer
Authors: Batchelor Rebecca L. , Strong Kimberly , Lindenmaier Rodica , Mittermeier Richard L. , Fast Hans , Drummond James R. , Fogal Pierre F. 
Published: February 2009

Abstract
A new Bruker IFS 125HR Fourier transform spectrometer has been installed at the Polar Environment Atmospheric Research Laboratory at Eureka, Nunavut, Canada (80.05°N, 86.42°W). This instrument will become the Network for the Detection of Atmospheric Composition Change’s (NDACC’s) primary instrument at Eureka, replacing the existing Bomem DA8 Fourier transform spectrometer, and will operate throughout the sunlit parts of the year. This paper introduces the new instrument and describes the retrieval procedure, including a comprehensive error analysis. Total columns of O3, HCl, HF, HNO3, N2O, CH4, and CO are presented for the first full year of measurements (2007). Perturbations in the total column resulting from the presence of the Arctic polar vortex over Eureka and the chemical processes within it are visible, as are annual cycles driven by photochemistry and dynamics. Enhancements in the CO total column resulting from specific biomass burning smoke events can also be seen. An intercomparison between the existing Bomem DA8 and the new Bruker IFS 125HR was carried out in July 2007 and is presented here. The total columns derived from the two instruments are shown to be in excellent agreement, with mean differences for all gases of less than 2.3%.
The CALIPSO Lidar Cloud and Aerosol Discrimination: Version 2 Algorithm and Initial Assessment of Performance
Authors: Liu Zhaoyan , Vaughan Mark , Winker David , Kittaka Chieko , Getzewich Brian , Kuehn Ralph , Omar Ali , Powell Kathleen , Trepte Charles , Hostetler Chris 
Published: February 2009

Abstract
The Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite was launched in April 2006 to provide global vertically resolved measurements of clouds and aerosols. Correct discrimination between clouds and aerosols observed by the lidar aboard the CALIPSO satellite is critical for accurate retrievals of cloud and aerosol optical properties and the correct interpretation of measurements. This paper reviews the theoretical basis of the CALIPSO lidar cloud and aerosol discrimination (CAD) algorithm, and describes the enhancements made to the version 2 algorithm that is used in the current data release (release 2). The paper also presents a preliminary assessment of the CAD performance based on one full day (12 August 2006) of expert manual classification and on one full month (July 2006) of the CALIOP 5-km cloud and aerosol layer products. Overall, the CAD algorithm works well in most cases. The 1-day manual verification suggests that the success rate is in the neighborhood of 90% or better. Nevertheless, several specific layer types are still misclassified with some frequency. Among these, the most prevalent are dense dust and smoke close to the source regions. The analysis of the July 2006 data showed that the misclassification of dust as cloud occurs for &lt;1% of the total tropospheric cloud and aerosol features found. Smoke layers are misclassified less frequently than are dust layers. Optically thin clouds in the polar regions can be misclassified as aerosols. While the fraction of such misclassifications is small compared with the number of aerosol features found globally, caution should be taken when studies are performed on the aerosol in the polar regions. Modifications will be made to the CAD algorithm in future data releases, and the misclassifications encountered in the current data release are expected to be reduced greatly.