bluuebunny/crossref_metadata_2025_split huggingface dataset:
2‐Oxoglutarate and the PII homologues NifI1 and NifI2 regulate nitrogenase activity in cell extracts of Methanococcus maripaludis
Authors: Dodsworth Jeremy A. , Cady Nathaniel C. , Leigh John A. 
Published: July 2010

SummaryPost‐translational regulation of nitrogen fixation, or switch‐off, in the methanogenic archaeon Methanococcus maripaludis does not involve detectable covalent modification of the dinitrogenase reductase as in some bacteria, and the genes encoding the PII homologues NifI1 and NifI2 are both required, indicating a novel mechanism. To further understand the mechanism of switch‐off, we assayed nitrogenase activity in cell extracts from wild‐type and nifI mutant strains in the absence or presence of potential signals of nitrogen status. Activity in extracts from a ΔnifI1nifI2 strain was sixfold higher than in extracts from wild‐type cells. Addition of 2‐oxoglutarate to wild‐type extracts enhanced activity up to fivefold, a level similar to that observed  in ΔnifI1nifI2  extracts.  2‐Oxoglutarate  did not affect activity in ΔnifI1nifI2 or single nifI mutant extracts. Furthermore, extracts from genetically complimented nifI mutants regained wild‐type characteristics, indicating an in vitro correlation with in vivo effects. Extraction and quantification of 2‐oxoglutarate indicated concentrations 10‐fold higher in nitrogen‐fixing cells than in switched‐off and ammonium‐grown cells. We propose a model for switch‐off where the NifI proteins have an inhibitory effect on nitrogenase activity  that  is  counteracted  by  high  levels  of 2‐oxoglutarate, which acts as a signal of nitrogen limitation.
Extent of the activity domain and possible roles of FtsK in the Escherichia coli chromosome terminus
Authors: Corre Jacqueline , Louarn Jean‐Michel 
Published: July 2010

SummaryEscherichia coli FtsK protein couples cell division and chromosome segregation. It is a component of the septum essential for cell division. It also acts during chromosome dimer resolution by XerCD‐specific recombination at the dif site, with two distinct activities: DNA translocation oriented by skewed sequence elements and direct activation of Xer recombination. Dimer resolution requires that the skewed elements polarize in opposite directions 30–50 kb on either side of dif. This constitutes the DIF domain, approximately coincident with the region where replication terminates. The observation that the ftsK1 mutation increases recombination near dif was exploited to determine whether the chromosome region on which FtsK acts is limited to the DIF domain. A monitoring of recombination activity at multiple loci in a 350 kb region to the left of dif revealed (i) zones of differing activities unconnected to dimer resolution and (ii) a constant 10‐fold increase of recombination in the 250 kb region adjacent to dif in the ftsK1 mutant. The latter effect allows definition of an FTSK domain whose total size is at least fourfold that of the DIF domain. Additional analyses revealed that FtsK activity responds to polarization in the whole FTSK domain and that displacement of the region where replication terminates preserves differences between recombination zones. Our interpretation is that translocation by FtsK occurs mostly on DNA belonging to a specifically organized domain of the chromosome, when physical links between either dimeric or still intercatenated chromosomes force this DNA to run across the septum at division.
Elaborate transcription regulation of the Bacillus subtilis ilv‐leu operon involved in the biosynthesis of branched‐chain amino acids through global regulators of CcpA, CodY and TnrA
Authors: Tojo Shigeo , Satomura Takenori , Morisaki Kaori , Deutscher Josef , Hirooka Kazutake , Fujita Yasutaro 
Published: July 2010

SummaryThe Bacillus subtilis ilv‐leu operon involved in the biosynthesis of branched‐chain amino acids is under negative regulation mediated by TnrA and CodY, which recognize and bind to their respective cis‐elements located upstream of the ilv‐leu promoter. This operon is known to be under CcpA‐dependent positive regulation. We have currently identified a catabolite‐responsive element (cre) for this positive regulation (bases −96 to −82; +1 is the ilv‐leu transcription initiation base) by means of DNase I‐footprinting in vitro, and deletion and base‐substitution analyses of cre. Under nitrogen‐rich growth conditions in glucose‐minimal medium supplemented with glutamine and amino acids, CcpA and CodY exerted positive and negative regulation of ilv‐leu, respectively, but TnrA did not function. Moreover, CcpA and CodY were able to function without their counteracting regulation of each other, although the CcpA‐dependent positive regulation did not overcome the CodY‐dependent negative regulation. Furthermore, under nitrogen‐limited conditions in glucose‐minimal medium with glutamate as the sole nitrogen source, CcpA and TnrA exerted positive and negative regulation, respectively, but CodY did not function. This CcpA‐dependent positive regulation occurred without the TnrA‐dependent negative regulation. However, the TnrA‐dependent negative regulation did not occur without the CcpA‐dependent positive regulation, raising the possibility that this negative regulation might decrease the CcpA‐dependent positive regulation. The physiological role of this elaborate transcription regulation of the B. subtilis ilv‐leu operon in overall metabolic regulation in this organism is discussed.
Aerobic benzoyl‐CoA catabolic pathway in Azoarcus evansii: studies on the non‐oxygenolytic ring cleavage enzyme
Authors: Gescher Johannes , Eisenreich Wolfgang , Wörth Jürgen , Bacher Adelbert , Fuchs Georg 
Published: July 2010

SummaryA novel aerobic benzoate pathway has recently been discovered in various bacteria in which benzoate is first converted to benzoyl‐CoA. The further downstream steps are associated with the gene products of the benzoate oxidation gene cluster (box) on the Azoarcus evansii chromosome. Benzoyl‐CoA is oxidized to 2,3‐dihydro‐2,3‐dihydroxybenzoyl‐CoA (benzoyl‐CoA dihydrodiol) by benzoyl‐CoA oxygenase/reductase BoxBA in the presence of molecular oxygen. This study identified the next, ring cleaving step catalysed by BoxC. The boxC gene was expressed in a recombinant Escherichia coli strain as a fusion protein with maltose binding protein (BoxCmal) and the wild type as well as the recombinant proteins were purified and studied. BoxC catalyses the reaction 2,3‐dihydro‐2,3‐dihydroxybenzoyl‐CoA + H2O → 3,4‐dehydroadipyl‐CoA semialdehyde + HCOOH. This is supported by the following results. Assays containing [ring‐13C6]benzoyl‐CoA, benzoyl‐CoA oxygenase/reductase, BoxCmal protein, NADPH and semicarbazide were analysed directly by NMR spectroscopy and mass spectrometry. The products were identified as the semicarbazone of [2,3,4,5,6‐13C5]3,4‐dehydroadipyl‐CoA semialdehyde; the missing one‐carbon unit being formate. The same reaction mixture without semicarbazide yielded a mixture of the hydrate of [2,3,4,5,6‐13C5]3,4‐dehydroadipyl‐CoA semialdehyde and [2,3,4,5,6‐13C5]4,5‐dehydroadipyl‐CoA semialdehyde. BoxC, a 122 kDa homodimeric enzyme (61 kDa subunits), is termed benzoyl‐CoA‐dihydrodiol lyase. It contains domains characteristic for enoyl‐CoA hydratases/isomerases, besides a large central domain with no significant similarity to sequences in the database. The purified protein did not require divalent metals, molecular oxygen or any cosubstrates or coenzymes for activity. The complex reaction is part of a widely distributed new principle of aerobic aromatic metabolism in which all intermediates are coenzyme A thioesters and the actual ring‐cleavage reaction does not require molecular oxygen.
Host factors that promote transpososome disassembly and the PriA‐PriC pathway for restart primosome assembly
Authors: North Stella H. , Nakai Hiroshi 
Published: July 2010

SummaryInitiation of bacteriophage Mu DNA replication by transposition requires the disassembly of the transpososome that catalyses strand exchange and the assembly of a replisome promoted by PriA, PriB, PriC and DnaT proteins, which function in the host to restart stalled replication forks. Once the molecular chaperone ClpX weakens the very tight binding of the transpososome to the Mu ends, host disassembly factors (MRFα‐DF) promote the dissociation of the transpososome from the DNA template and the assembly of a new nucleoprotein complex. Prereplisome factors (MRFα‐PR) further alter the complex, allowing PriA binding and loading of major replicative helicase DnaB onto the template promoted by the restart proteins. MRFα‐PR is essential for DnaB loading by restart proteins even on the deproteinized Mu fork whereas MRFα‐DF is not required on the deproteinized template. When the transition from transpososome to replisome was reconstituted using MRFα‐DF and MRFα‐PR, initiation of Mu DNA replication was strictly dependent upon added PriC and PriA helicase. In contrast, initiation on the deproteinized template was predominantly dependent upon PriB and did not require PriA's helicase activity. The results indicate that transition mechanisms beginning with the transpososome disassembly can determine the pathway of replisome assembly by restart proteins.
Partition‐associated incompatibility caused by random assortment of pure plasmid clusters
Authors: Ebersbach Gitte , Sherratt David J. , Gerdes Kenn 
Published: July 2010

SummaryBacterial plasmids and chromosomes encode centromere‐like partition loci that actively segregate DNA before cell division. The molecular mechanism behind DNA segregation in bacteria is largely unknown. Here we analyse the mechanism of partition‐associated incompatibility for plasmid pB171, a phenotype associated with all known plasmid‐encoded centromere loci. An R1 plasmid carrying par2 from plasmid pB171 was destabilized by the presence of an F plasmid carrying parC1, parC2 or the entire par2 locus of pB171. Strikingly, cytological double‐labelling experiments revealed no evidence of long‐lived pairing of plasmids. Instead, pure R1 and F foci were positioned along the length of the cell, and in a random order. Thus, our results raise the possibility that partition‐mediated plasmid incompatibility is not caused by pairing of heterologous plasmids but instead by random positioning of pure plasmid clusters along the long axis of the cell. The strength of the incompatibility was correlated with the capability of the plasmids to compete for the mid‐cell position.
Inhibitory effect of ACC deaminase‐producing bacteria on crown gall formation in tomato plants infected by Agrobacterium tumefaciens or A. vitis
Authors: Toklikishvili N. , Dandurishvili N. , Vainstein A. , Tediashvili M. , Giorgobiani N. , Lurie S. , Szegedi E. , Glick B. R. , Chernin L. 
Published: July 2010

This study showed that various rhizosphere bacteria producing the enzyme 1‐aminocyclopropane‐1‐carboxylate (ACC) deaminase (ACCD), which can degrade ACC, the immediate precursor of ethylene in plants, and thereby lower plant ethylene levels, can act as promising biocontrol agents of pathogenic strains of Agrobacterium tumefaciens and A. vitis. Soaking the roots of tomato (Solanum lycopersicum) seedlings in a suspension of the ACCD‐producing Pseudomonas putida UW4, Burkholderia phytofirmans PsJN or Azospirillum brasilense Cd1843 transformed by plasmid pRKTACC carrying the ACCD‐encoding gene acdS from UW4, significantly reduced the development of tumours on tomato plants injected 4–5 days later with pathogenic Agrobacterium strains via wounds on the plant stem. The fresh mass of tumours formed by plants pretreated with ACCD‐producing strains was typically four‐ to fivefold less than that of tumours formed on control plants inoculated only with a pathogenic Agrobacterium strain. Simultaneously, the level of ethylene evolution per amount of tumour mass on plants pretreated with ACCD‐producing bacteria decreased four to eight times compared with that from tumours formed on control plants or plants pretreated with bacteria deficient in ACCD production. Moreover, transgenic tomato plants expressing a bacterial ACCD were found to be highly resistant to crown gall formation relative to the parental, non‐transformed tomato plants. The results support the hypothesis that ethylene is a crucial factor in Agrobacterium tumour formation, and that ACCD‐produced rhizosphere bacteria may protect plants infected by pathogenic Agrobacteria from crown gall disease.
Alopecia areata in Eringer cows
Authors: Timm Katrin , Rüfenacht Silvia , Von Tscharner Claudia , Bornand Valérie F. , Doherr Marcus G. , Oevermann Anna , Flury Christine , Rieder Stefan , Hirsbrunner Gaby , Drögemüller Cord , Roosje Petra J. 
Published: July 2010

AbstractAlopecia areata is a hair loss disorder in humans, dogs and horses with a suspected autoimmune aetiology targeting anagen hair follicles. Alopecia areata is only sporadically reported in cows. Recently, we observed several cases of suspected alopecia areata in Eringer cows. The aim of this study was to confirm the presumptive diagnosis of alopecia areata and to define the clinical phenotype and histopathological patterns, including characterization of the infiltrating inflammatory cells. Twenty Eringer cows with alopecia and 11 Eringer cows without skin problems were included in this study. Affected cows had either generalized or multifocal alopecia or hypotrichosis. The tail, forehead and distal extremities were usually spared. Punch biopsies were obtained from the centre and margin of alopecic lesions and normal haired skin. Histological examination revealed several alterations in anagen hair bulbs. These included peri‐ and intrabulbar lymphocytic infiltration, peribulbar fibrosis, degenerate matrix cells with clumped melanosomes and pigmentary incontinence. Mild lymphocytic infiltrative mural folliculitis was seen in the inferior segment and isthmus of the hair follicles. Hair shafts were often unpigmented and dysplastic. The large majority of infiltrating lymphocytes were CD3+ T cells, whereas only occasional CD20+ lymphocytes were present in the peribulbar infiltrate. Our findings confirm the diagnosis of T‐cell‐mediated alopecia areata in these cows. Alopecia areata appears to occur with increased frequency in the Eringer breed, but distinct predisposing factors could not be identified.
Maze Learning and Recall in a Weakly Electric Fish, Mormyrus rume proboscirostris Boulenger (Mormyridae, Teleostei)1
Authors: Walton Alice G. , Moller Peter 
Published: July 2010

Abstract Mormyrus rume proboscirostris, African weakly electric fish, were trained to seek shelter in a meander maze, and following path acquisition released into the empty arena with all maze cues removed, either from the original start box or from a novel site (recall). We demonstrate that fish use their active electrosense, sight, and lateral line synergistically in maze acquisition and recall. In the presence of an electric roadmap consisting of an array of aluminum and Plexiglas objects, fish employed landmark orientation. But fish ignored visual markers and relied on internalized motor routines, which was inconsistent with evidence for cognitive mapping.
Accurate phenotyping reveals better QTL for waterlogging tolerance in barley
Authors: Zhou M. 
Published: July 2010

With 5 figures and 2 tables AbstractTolerance to soil waterlogging stress is an important plant breeding objective in high rainfall or poorly drained areas across many countries in the world. Similar to other abiotic stresses, waterlogging tolerance is a complicated trait and the selection for tolerance has been a major obstacle in breeding programmes. Molecular marker‐assisted selection (MAS) can be very effective. However, the success of MAS depends on the development of reliable markers which requires accurate phenotyping when searching for the markers linked to the tolerance. In this experiment, a new screening facility, with the environment closer to field conditions, has been used to screen a double haploid population produced from a cross between waterlogging tolerant and susceptible varieties. A new scoring system of plant healthiness (0 = plant died from waterlogging; 10 = not affected by waterlogging) was also used in this experiment. The results were compared with a previous glasshouse pot experiment. Some quantitative trait loci (QTL) identified from the current experiment and previous pot experiment were quite different. From this experiment, two major QTL (QWL.YeFr.4H and QWL.YeFr.2H.2, accounting 24% and 17% of phenotypic variation) and two minor QTL (QWL.YeFr.2H.1 and QWL.YeFr.3H, accounting 8% and 7% of the variation) were found. These four markers can be very effectively used to select waterlogging tolerance. By selecting all four closely linked markers, all the lines will be quite tolerant with an average score of 7.6. In contrast, if none of above markers were selected all the lines would be susceptible with an average score of 1.4.
QTL mapping for resistance to strip virus disease in rice
Authors: Wang BaoXiang , Jiang Ling , Zhang YingXin , Zhang WenWei , Wang MaoQing , Cheng XiaNian , Liu Xi , Zhai HuQu , Wan JianMin 
Published: July 2010

With 2 figures and 5 tables AbstractTo discover new resistance genes to rice stripe virus disease (RSVD), quantitative trait loci (QTL) analysis was conducted by using 162 recombinant inbred lines, derived from a cross between ‘Guichao 2’ and ‘Koshihikari’, RSVD resistances were evaluated using both artificial inoculation and natural infection methods by scoring the ratio of the disease rating index. Three QTL‐controlling RSVD resistance were detected by the above two methods, which located on chromosomes 4(qStv4), 9(qStv9) and 12(qStv12), respectively. The qStv9 and qStv12 was repeatedly detected in artificial inoculation test in 2006 and 2008. In natural inoculation test, the qStv4 and qStv9 was detected in 2006, and the qStv12 was detected in 2008. As qStv9 and qStv12 explained 11.3–32.1% of the resistance effect from ‘Guichao 2’ across two environments, they should be a useful genetic resource in rice MAS breeding programme against RSVD. Further analysis revealed that the lines harbouring the alleles of qStv9 and qStv12 exhibited significantly increased resistance to RSVD, implying the possibility of breeding new resistant varieties by pyramiding resistant QTL through marker‐assisted selection.
Impact of previous mesh hernia repair on the performance of open radical prostatectomy – complications and functional outcome
Authors: Hocaoglu Yasemin , Bastian Patrick , Buchner Alexander , Bauer Ricarda , Bader Markus , Tritschler Stefan , Stanislaus Peter , Stief Christian , Karl Alexander 
Published: July 2010

Study Type – Therapy (case series) Level of Evidence 4OBJECTIVESTo determine the impact of previous inguinal mesh hernia repair (IMHR) on the performance of subsequent open radical retropubic prostatectomy (ORRP).PATIENTS AND METHODSA total of 1466 patients underwent ORRP for clinically localized prostate cancer from 2004 to 2008; 51 patients (3.5%) presented with a history of IMHR. Body‐mass index (BMI), perioperative blood loss (PBL), operating time (OT), performance of pelvic lymph node dissection (PLD), positive resection‐margins (R1), continence and potency between the groups were analysed using Mann–Whitney U and χ2 tests.RESULTSFifty‐one patients with previous IMHR were compared with 1466 patients without previous mesh implantation (nMI) who underwent ORRP. Mean age was 66.8 years and mean BMI 25.7. No statistically difference in the mean OT (68 vs 72 min, P= 0.112), mean PBL (167 vs 156 ml, P= 0.089) or R1 was observed in the pT2‐stage tumors (3% vs 9.7%, P= 0.197), or in the pT3‐stage tumors (16% vs 21%, P= 0.386). After 3 months 85% showed full continence in the nMI group vs 83.9% MI group (P= 0.864) and after 12 months 94.5% of the nMI patients vs 97.6% with mesh (P= 0.610). The IIEF‐5 score after 3 months showed a median of 9.0 in the MI group and 4.5 in the nMI group (P= 0.116) and after 12 months 12.0 in the MI group and 9.0 in the nMI group (P= 0.511). PLD was significantly more feasible in patients that underwent only unilateral IMHR compared with bilateral IMHR (96% vs 40%, P= 0.001) and significantly less feasible if previous IMHR was operated laparoscopically than with an open access (47% vs 88%, P= 0.014).CONCLUSIONNo impairment of perioperative variables or functional outcome during ORRP was observed in patients with IMHR. PLD could be performed in a significantly fewer patients who underwent bilateral IMHR or laparoscopic IMHR.
Body dissatisfaction assessed by the Photographic Figure Rating Scale is associated with sociocultural, personality, and media influences
Authors: SWAMI VIREN , TAYLOR ROSANNE , CARVALHO CHRISTINE 
Published: July 2010

Swami, V., Taylor, R. & Carvalho, C. (2011). Body dissatisfaction assessed by the Photographic Figure Rating Scale is associated with sociocultural, personality, and media influences. Scandinavian Journal of Psychology 52, 57–53.This study sought to investigate the convergent validity of a new measure of body dissatisfaction, namely the Photographic Figure Rating Scale (PFRS), in relation to media influence, celebrity worship, the Big Five personality factors, and respondent weight status. A total of 401 female undergraduates completed a battery of scales consisting of the PFRS, the third revision of the Sociocultural Attitudes Toward Appearance Scale (SATAQ‐3), a measure of celebrity worship, a measure of the Big Five personality factors, and provided their demographic details. Results of a multiple regression showed that body dissatisfaction was most strongly predicted by two of the SATAQ‐3 subscales and participant body mass index, although celebrity worship and Emotional Stability added incremental variance. Limitations of the current study are discussed in conclusion.
Thematic analysis of Antonovsky’s sense of coherence theory
Authors: GRIFFITHS CHRISTOPHER A. , RYAN PETER , FOSTER JOHN H. 
Published: July 2010

Griffiths, C.A., Ryan, P. & Foster, J.H. (2011). Thematic analysis of Antonovsky’s sense of coherence theory. Scandinavian Journal of Psychology 52, 168–173.Antonovsky’s sense of coherence (SOC) theory relates to the adaptive capacity of humans. In response to Antonovsky’s call to study the sense of coherence concept using methods other than his orientation to life questionnaire, and to further test the application of the concept, qualitative research methods were employed. Using thematic analysis this study investigated how sense of coherence theory applied when mapped onto descriptions by 20 mental health service users of how they deal with problems that they face in their lives. The thematic analysis revealed that sense of coherence theory mapped effectively onto the interview transcripts. The analysis identified various factors that can be considered to be general resistance resources in the sense of coherence model. It also revealed distinctions between concrete and relationship orientated problem solving that led to new insights into how mechanisms of sense of coherence theory may operate. The findings suggest that sense of coherence strength may be split into coping and adaptive capacity for concrete problems and coping and adaptive capacity for relationship oriented problems. This highlights the possibility that SOC strength is not an overall adaptive capacity measure which can be applied with equal effectiveness to all challenges/problems experienced in life.
Long‐term Care: A Suitable Case for Social Insurance
Authors: Barr Nicholas 
Published: July 2010

AbstractThere are potentially large welfare gains if people can buy insurance that covers the costs of long‐term care. However, technical problems – largely information problems – face both the providers of insurance and potential buyers. These problems on both the supply and demand sides of the market suggest that the actuarial mechanism is not well suited to addressing risks associated with long‐term care. This line of argument underpins the article's main conclusion – that social insurance is a better fit.