bluuebunny/crossref_metadata_2025_split huggingface dataset:
Degradation and fermentation of fructo‐oligosaccharides by oral streptococci
Authors: Hartemink R. , Quataert M.C.J. , van Laere K.M.J. , Nout M.J.R. , Rombouts F.M. 
Published: March 2008

Fructo‐oligosaccharides (FOS) are claimed to have a positive effect on the intestinal flora. They are being used in functional foods in Japan and Europe. This group have tested the degradation of two commercial FOS preparations by oral streptococci in order to predict the cariogenicity of these products. Both preparations could be fermented to some extent by the species of oral streptococci tested.The enzymes necessary for the degradation of FOS were inducible. Each strain showed a specific degradation pattern. All strains, particularly Streptococcus mutans rapidly produced acid, mainly lactic acid. Streptococcus mitis also produced high concentrations of acetic acid. Plaque formation by Strep. mutans was similar to the sucrose control. It is concluded that FOS are cariogenic to a similar extent as sucrose.
Antibiotic activity of isoxazolylnaphthoquinone imines on mice infected with Staphylococcus aureus
Authors: Albesa I. , Bogdanov P. , Eraso A. , Sperandeo N.R. , de Bertorello M.M. 
Published: March 2008

I. ALBESA, P. BOGDANOV, A. ERASO, N.R. SPERANDEO AND M.M. DE BERTORELLO. 1995. The antibiotic activity of new synthetic isoxazolylnaphthoquinone imines was studied. Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922 were resistant to the four compounds studied (MIC > 128 µg ml−1), but Staphylococcus aureus ATCC 25923, ATCC 29213 and 30 clinical isolates of Staph. aureus were inhibited by 2‐hydroxy‐N‐(3,4‐dimethyl‐5‐isoxazolyl)‐1,4‐naphthoquinone‐4‐imine (I). This compound diminished bloodstream infection of mice injected i.m. with Staph. aureus; septicaemia decayed significantly when I was applied at the beginning of the infection while when I was given 3 d after bacterial challenge, a significant protection was afforded. Bactericidal activity in serum increased during the 5 h after I was administered i.p.The acetyl derivative of I had a high MIC but when inoculated orally in mice decreased the Staph. aureus counts in circulation. This protection occurred only when the schedule of administration started close to the bacterial challenge. Antibiotic activity in vivo may be associated with in vitro effects.
Development of a detection system for histidine decarboxylating lactic acid bacteria based on DNA probes, PCR and activity test
Authors: Le Jeune Christine , Lonvaud‐Funel Aline , ten Brink B. , Hofstra H. , van der Vossen J.M.B.M. 
Published: March 2008

On the basis of the comparison of the nucleotide sequences of the histidine decarboxylase genes (hdc A) of Lactobacillus 30A and Clostridium perfringens and the amino acid sequences of these histidine decarboxylases and those of Lactobacillus buchneri and Micrococcus, oligonucleotides unique to the hdc A genes were synthesized and used in PCR. All histidine‐decarboxylating lactic acid bacteria gave a signal with primer set JV16HC/JV17HC in PCR. In addition to this primer set, CL1/CL2 and CL1/JV17HC were also useful for the detection of histamine‐forming Leuconostoc œnos strains in PCR. The 150 base pair amplification product of the decarboxylating Leuc. œnos strain generated with primer set CL1/CL2 was sequenced. Alignment studies showed a high degree of relatedness among the hdc A gene products of Gram‐positive bacteria.The amplification products of the hdc A genes from Lact. buchneri and Leuc. œnos were used to serve as a DNA probe in hybridization studies. All histidine‐decarboxylating lactic acid bacteria gave a hybridization signal with the DNA probes. In hybridization only one false‐positive signal with a Lactobacillus lindneri strain was observed, which was anticipated to contain a truncated hdc A gene.In addition to these DNA probe tests, a simple and reliable activity test is presented, which can be used during starter selection to test strains for histidine decarboxylase activity.
Quantitative structure activity relationship for the effect of benzoic acids, cinnamic acids and benzaldehydes on Listeria monocytogenes
Authors: Ramos‐Nino M.E. , Clifford M.N. , Adams M.R. 
Published: March 2008

The inhibition of a cocktail of 18 strains of Listeria monocytogenes by 24 mono‐, di‐ and tri‐substituted benzoic and cinamic acids and 16 benzaldehydes was evaluated using the concentration (C) required to give a 50% growth inhibition under anaerobic conditions at 35°C and pH 6·2 as a measure of biological activity (BAV). Using the method of least squares, multiple regression equations were obtained which described the contribution of some physicochemical and other structural properties of the compounds to their biological activity. The equation that best described the activity of benzoic and cinnamic acids waswhere K is a lipophilicity parameter determined by RP‐HPLC and the effect of ionization is represented by pKa. Benzaldehydes behaved differently, their activity being best described by the equationwhere the activity is controlled by a steric parameter, the van der Waals volume (Vw), and an electronic‐steric parameter for ortho substituents. Absence of a lipophilicity parameter indicates that partitioning into the cell membrane might not be required for antimicrobial activity. The models were tested in several food systems which showed that in food with a high protein or lipid content antilisterial activity was much lower than predicted, making the models unacceptable in such circumstances.
The Norwegian version of the American pain society patient outcome questionnaire: reliability and validity of three subscales
Authors: Dihle Alfhild , Helseth Sølvi , Christophersen Knut‐Andreas 
Published: March 2008

Aims and objectives.  To examine some psychometric properties of the Norwegian version of the American Pain Society's Patient Outcome Questionnaire (APS‐POQ‐N).Background.  This study is part of an investigation of Norwegian orthopaedic surgical patients, where the overall aim is to evaluate the quality of postoperative pain management. Therefore, an adequate questionnaire on the quality of postoperative pain management was needed.Methods.  The sample included 114 orthopaedic postoperative patients. The instrument consists of three main subscales, namely the modified Brief Pain Inventory (modified BPI subscale), the subscale on satisfaction with pain management (Satisfaction subscale) and the subscale on beliefs about pain management (Beliefs subscale), together with six single items about pain management. The reliability of these three main subscales was estimated using Cronbach's alpha coefficients and the construct validity was evaluated using principal‐axis factor analysis with oblimin rotation.Results.  Face and content validity of the APS‐POQ‐N were satisfactory, while the modified BPI and the Beliefs subscales showed acceptable internal consistency but the Satisfaction subscale did not. Factor analyses yielded a three‐factor solution for the modified BPI, a one‐factor solution for the Satisfaction subscale and a two‐factor solution for the Beliefs subscale.Conclusions.  The APS‐POQ‐N appears, in general, to be an acceptable method of evaluating postoperative pain management in orthopaedic postoperative patients. However, the alpha value of the Satisfaction subscale was low, and thus the subscale is not recommended for this purpose.Relevance to clinical practice.  Reliable and valid instruments are important when performing clinical research. This instrument is applicable as an indicator of quality of postoperative pain management in clinical practice and research.
A phylogeographical analysis of the range disjunction for foxtail pine (Pinus balfouriana, Pinaceae): the role of Pleistocene glaciation
Authors: ECKERT ANDREW J. , TEARSE BRANDON R. , HALL BENJAMIN D. 
Published: March 2008

AbstractBiogeographical patterns within the California Floristic Province have been greatly affected by geological and climatic events. Here, we investigate the phylogeography of foxtail pine (Pinus balfouriana) in an effort to date its range disjunction using molecular data and to further our understanding of phylogeographical patterns for plants within the California Floristic Province. The distribution of foxtail pine is characterized by a 500‐km disjunction separating populations located in the Klamath Mountains from those in the southern Sierra Nevada. Previous authors suggested that this disjunction occurred approximately 4000–8000 years ago during the Holocene Xerotherm when western North America became warmer and drier. Those dates, however, are inconsistent with the morphological differences that separate regional populations into formally recognized subspecies. Using the coalescent‐based isolation with migration model and DNA sequence data from the chloroplast, mitochondrial, and nuclear genomes, we evaluate several hypotheses addressing the timing of this range disjunction and its effects on subsequent patterns of gene flow. Results from all three genomes are largely consistent with Middle to Early Pleistocene divergence dates. Those dates correspond to the Sherwin glaciation, which was the largest Pleistocene glacial episode in the Sierra Nevada. Gene flow, moreover, was only documented using data from the chloroplast genome, suggesting that low levels of long‐distance pollen dispersal (Nem < 0.5) have occurred since this divergence event. These results are extended to a discussion of the biogeographical development of subalpine forests in California.
Differences in the mechanism of the allosteric l‐rhamnose responses of the AraC/XylS family transcription activators RhaS and RhaR
Authors: Kolin Ana , Balasubramaniam Vinitha , Skredenske Jeff M. , Wickstrum Jason R. , Egan Susan M. 
Published: March 2008

SummaryProteins in the largest subset of AraC/XylS family transcription activators, including RhaS and RhaR, have C‐terminal domains (CTDs) that mediate DNA‐binding and transcription activation, and N‐terminal domains (NTDs) that mediate dimerization and effector binding. The mechanism of the allosteric effector response in this family has been identified only for AraC. Here, we investigated the mechanism by which RhaS and RhaR respond to their effector, l‐rhamnose. Unlike AraC, N‐terminal truncations suggested that RhaS and RhaR do not use an N‐terminal arm to inhibit activity in the absence of effector. We used random mutagenesis to isolate RhaS and RhaR variants with enhanced activation in the absence of l‐rhamnose. NTD substitutions largely clustered around the predicted l‐rhamnose‐binding pockets, suggesting that they mimic the structural outcome of effector binding to the wild‐type proteins. RhaS‐CTD substitutions clustered in the first HTH motif, and suggested that l‐rhamnose induces improved DNA binding. In contrast, RhaR‐CTD substitutions clustered at a single residue in the second HTH motif, at a position consistent with improved RNAP contacts. We propose separate allosteric mechanisms for the two proteins: Without l‐rhamnose, RhaS does not effectively bind DNA while RhaR does not effectively contact RNAP. Upon l‐rhamnose binding, both proteins undergo structural changes that enable transcription activation.
Identification and functional analysis of the Rz/Rz1‐like accessory lysis genes in the membrane‐containing bacteriophage PRD1
Authors: Krupovič Mart , Cvirkaitė‐Krupovič Virginija , Bamford Dennis H. 
Published: March 2008

SummaryBacteriophage PRD1 is a tailless membrane‐containing double‐stranded (ds) DNA virus infecting a variety of Gram‐negative bacteria. In order to affect cell lysis, like most dsDNA phages, PRD1 uses the holin‐endolysin system. In this study, we identified two accessory lysis genes, XXXVI and XXXVII, coding for proteins P36 and P37, respectively. Using genetic complementation assays, we show that protein pair P36/P37 is a functional and interchangeable analogue of the Rz/Rz1 of bacteriophage λ. Utilizing molecular biology, electrochemical as well as various microscopic techniques, we characterized the lysis phenotypes of PRD1 host cells infected with mutant viruses. Our results indicate that proteins P36 and P37 confer a competitive advantage to the phage by securing the efficient disruption of the infected cell and consequent release of the phage progeny under less favourable growth conditions. In concordance with prior data and the results obtained in this study, we propose a model explaining the role of Rz/Rz1‐like proteins in the lysis process: Rz/Rz1 complexes transform the mechanical stress caused by the holin lesion at the CM to the OM leading to its disintegration. Finally, identification of the Rz/Rz1‐like genes in PRD1 suggests that tailless icosahedral phages are involved in genetic trade with tailed bacteriophages.
Radial velocity mapping of Paczyński's star AW UMa: not a contact binary
Authors: Pribulla T. , Rucinski S. M. 
Published: March 2008

Abstract
We present 2D (radial velocity, orbital phase) spectroscopic results for the very low mass-ratio close binary AW UMa which strongly indicate that the spectroscopic mass ratio (qsp= 0.10) does not agree with the photometrically derived one and that the widely adopted contact binary model appears to experience serious inconsistencies and limitations for this object. AW UMa is compared with V566 Oph (qsp= 0.26) which we found to behave according to the contact model. Observed broadening functions of AW UMa can be interpreted by a very strong limb darkening and/or non-solid-body rotation of the dominant primary component; the former assumption is unphysical while the differential rotation is not supported by an apparent stability of localized, dark features on the outer side of the primary. There are indications of the existence of an equatorial belt encompassing the whole system. All deficiencies in the interpretation and the discrepancy between the photometric and spectroscopic mass ratio of AW UMa can be solved within a new model of AW UMa where both components are detached and the system is submerged in a stream of hot, optically thick matter which mimics the stellar contact. While the masses and their ratio are correctly given by spectroscopy, the photometric picture is heavily modified by the matter engulfing both stars in the equatorial plane.
Inactivation of the UGPase1 gene causes genic male sterility and endosperm chalkiness in rice (Oryza sativa L.)
Authors: Woo Mi‐Ok , Ham Tae‐Ho , Ji Hyeon‐So , Choi Min‐Seon , Jiang Wenzhu , Chu Sang‐Ho , Piao Rihua , Chin Joong‐Hyoun , Kim Jung‐A , Park Bong Soo , Seo Hak Soo , Jwa Nam‐Soo , McCouch Susan , Koh Hee‐Jong 
Published: March 2008

SummaryA rice genic male‐sterility gene ms‐h is recessive and has a pleiotropic effect on the chalky endosperm. After fine mapping, nucleotide sequencing analysis of the ms‐h gene revealed a single nucleotide substitution at the 3′‐splice junction of the 14th intron of the UDP‐glucose pyrophosphorylase 1 (UGPase1; EC2.7.7.9) gene, which causes the expression of two mature transcripts with abnormal sizes caused by the aberrant splicing. An in vitro functional assay showed that both proteins encoded by the two abnormal transcripts have no UGPase activity. The suppression of UGPase by the introduction of a UGPase1‐RNAi construct in wild‐type plants nearly eliminated seed set because of the male defect, with developmental retardation similar to the ms‐h mutant phenotype, whereas overexpression of UGPase1 in ms‐h mutant plants restored male fertility and the transformants produced T1 seeds that segregated into normal and chalky endosperms. In addition, both phenotypes were co‐segregated with the UGPase1 transgene in segregating T1 plants, which demonstrates that UGPase1 has functional roles in both male sterility and the development of a chalky endosperm. Our results suggest that UGPase1 plays a key role in pollen development as well as seed carbohydrate metabolism.
Identification of high levels of phytochelatins, glutathione and cadmium in the phloem sap of Brassica napus. A role for thiol‐peptides in the long‐distance transport of cadmium and the effect of cadmium on iron translocation
Authors: Mendoza‐Cózatl David G. , Butko Emerald , Springer Franziska , Torpey Justin W. , Komives Elizabeth A. , Kehr Julia , Schroeder Julian I. 
Published: March 2008

SummaryPhytochelatins (PCs) are glutathione‐derived peptides that function in heavy metal detoxification in plants and certain fungi. Recent research in Arabidopsis has shown that PCs undergo long‐distance transport between roots and shoots. However, it remains unknown which tissues or vascular systems, xylem or phloem, mediate PC translocation and whether PC transport contributes to physiologically relevant long‐distance transport of cadmium (Cd) between shoots and roots. To address these questions, xylem and phloem sap were obtained from Brassica napus to quantitatively analyze which thiol species are present in response to Cd exposure. High levels of PCs were identified in the phloem sap within 24 h of Cd exposure using combined mass spectrometry and fluorescence HPLC analyses. Unexpectedly, the concentration of Cd was more than four‐fold higher in phloem sap compared to xylem sap. Cadmium exposure dramatically decreased iron levels in xylem and phloem sap whereas other essential heavy metals such as zinc and manganese remained unchanged. Data suggest that Cd inhibits vascular loading of iron but not nicotianamine. The high ratios [PCs]/[Cd] and [glutathione]/[Cd] in the phloem sap suggest that PCs and glutathione (GSH) can function as long‐distance carriers of Cd. In contrast, only traces of PCs were detected in xylem sap. Our results suggest that, in addition to directional xylem Cd transport, the phloem is a major vascular system for long‐distance source to sink transport of Cd as PC–Cd and glutathione–Cd complexes.
Mutations of genes in synthesis of the carotenoid precursors of ABA lead to pre‐harvest sprouting and photo‐oxidation in rice
Authors: Fang Jun , Chai Chenglin , Qian Qian , Li Chunlai , Tang Jiuyou , Sun Lei , Huang Zejun , Guo Xiaoli , Sun Changhui , Liu Min , Zhang Yan , Lu Qingtao , Wang Yiqin , Lu Congming , Han Bin , Chen Fan , Cheng Zhukuan , Chu Chengcai 
Published: March 2008

SummaryPre‐harvest sprouting (PHS) or vivipary in cereals is an important agronomic trait that results in significant economic loss. A considerable number of mutations that cause PHS have been identified in several species. However, relatively few viviparous mutants in rice (Oryza sativa L.) have been reported. To explore the mechanism of PHS in rice, we carried out an extensive genetic screening and identified 12 PHS mutants (phs). Based on their phenotypes, these phs mutants were classified into three groups. Here we characterize in detail one of these groups, which contains mutations in genes encoding major enzymes of the carotenoid biosynthesis pathway, including phytoene desaturase (OsPDS), ζ‐carotene desaturase (OsZDS), carotenoid isomerase (OsCRTISO) and lycopene β‐cyclase (β‐OsLCY), which are essential for the biosynthesis of carotenoid precursors of ABA. As expected, the amount of ABA was reduced in all four phs mutants compared with that in the wild type. Chlorophyll fluorescence analysis revealed the occurrence of photoinhibition in the photosystem and decreased capacity for eliminating excess energy by thermal dissipation. The greatly increased activities of reactive oxygen species (ROS) scavenging enzymes, and reduced photosystem (PS) II core proteins CP43, CP47 and D1 in leaves of the Oscrtiso/phs3‐1mutant and OsLCY RNAi transgenic rice indicated that photo‐oxidative damage occurred in PS II, consistent with the accumulation of ROS in these plants. These results suggest that the impairment of carotenoid biosynthesis causes photo‐oxidation and ABA‐deficiency phenotypes, of which the latter is a major factor controlling the PHS trait in rice.
Modelling the population dynamics of Papaver rhoeas under various weed management systems in a Mediterranean climate
Authors: TORRA J , GONZALEZ‐ANDUJAR J L , RECASENS J 
Published: March 2008

SummaryThe demography of the annual dicotyledonous weed Papaver rhoeas and the efficacy of different management practices were studied during three consecutive years in winter cereals in the north‐east of Spain. These data were used to estimate the parameters of a weed life cycle model that was used to describe the population dynamics of this species and to predict the effect of various control strategies and integrated weed management (IWM) scenarios. Without control, the annual rate of increase was 40 (λt), and the minimum control level required to maintain the population stable was 99% of the emerged plants. The annual application of post‐emergence and/or pre‐emergence herbicides did not prevent the growth of the population. Using various cultural control tactics (delayed seeding, harrowing and fallow) resulted in different trends in the overall population depending on the techniques and combinations analysed. Simulations showed that delayed seeding, fallow and pre‐emergence herbicides are the best techniques to employ in IWM programmes, always using a combination of these and other more common practices (i.e. post‐emergence herbicides). Sensitivity analysis indicated interaction between the parameters and that the model was especially sensitive to seed losses and also to fecundity, seedling survivorship and emergence. The study shows that new strategies should be sought to control these parameters. To develop IWM programmes for P. rhoeas, the combination of two or more control strategies is required.
A molecular assay for the proactive detection of target site‐based resistance to herbicides inhibiting acetolactate synthase in Alopecurus myosuroides
Authors: DÉLYE C , BOUCANSAUD K 
Published: March 2008

SummaryAcetolactate synthase (ALS) inhibitors are the most resistance‐prone herbicide group. Rapid resistance diagnosis is thus of importance for their optimal use. We formulate rules to use the derived cleaved amplified polymorphic sequence method to develop molecular tools detecting a change at a given codon, the nature of which is unknown. We applied them to Alopecurus myosuroides (black grass) to develop assays targeting ALS codons A122, P197, A205, W574 and S653 that are crucial for herbicide sensitivity. These assays detected W574L or P197T, or both substitutions, in most plants analysed from a field where ALS inhibitors failed after 3 years of use. Similar assays can easily be set up for any species. Given the rapidity of selection for resistance to ALS inhibitors, these assays should be very useful in proactive herbicide resistance diagnosis.