bluuebunny/crossref_metadata_2025_split huggingface dataset:
Erythromycin‐induced ribosome stalling and RNase J1‐mediated mRNA processing in Bacillus subtilis
Authors: Yao Shiyi , Blaustein Joshua B. , Bechhofer David H. 
Published: July 2008

SummaryAddition of erythromycin (Em) to a Bacillus subtilis strain carrying the ermC gene results in ribosome stalling in the ermC leader peptide coding sequence. Using ΔermC, a deletion derivative of ermC that specifies the 254 nucleotide ΔermC mRNA, we showed previously that ribosome stalling is concomitant with processing of ΔermC mRNA, generating a 209 nucleotide RNA whose 5′ end maps to codon 5 of the ΔermC coding sequence. Here we probed for peptidyl‐tRNA to show that ribosome stalling occurs after incorporation of the amino acid specified by codon 9. Thus, cleavage upstream of codon 5 is not an example of ‘A‐site cleavage’ that has been reported for Escherichia coli. Analysis of ΔermC mRNA processing in endoribonuclease mutant strains showed that this processing is RNase J1‐dependent. ΔermC mRNA processing was inhibited by the presence of stable secondary structure at the 5′ end, demonstrating 5′‐end dependence, and was shown to be a result of RNase J1 endonuclease activity, rather than 5′‐to‐3′ exonuclease activity. Examination of processing in derivatives of ΔermC that had codons inserted upstream of the ribosome stalling site revealed that Em‐induced ribosome stalling can occur considerably further from the start codon than would be expected based on previous studies.
Constitutive SOS expression and damage‐inducible AddAB‐mediated recombinational repair systems for Coxiella burnetii as potential adaptations for survival within macrophages
Authors: Mertens Katja , Lantsheer Letty , Ennis Don G. , Samuel James E. 
Published: July 2008

Summary Coxiella burnetii, a Gram‐negative obligate intracellular pathogen, replicates within an parasitophorous vacuole with lysosomal characteristics. To understand how C. burnetii maintains genomic integrity in this environment, a database search for genes involved in DNA repair was performed. Major components of repair, SOS response and recombination were identified, including recA and ruvABC, but lexA and recBCD were absent. Instead, C. burnetii possesses addAB orthologous genes, functional equivalents to recBCD. Survival after treatment with UV, mitomycin C (MC) or methyl methanesulfonate (MMS), as well as homologous recombination in Hfr mating was restored in Escherichia coli deletion strains by C. burnetii recA or addAB. Despite the absence of LexA, co‐protease activity for C. burnetii RecA was demonstrated. Dominant‐negative inhibition of C. burnetii RecA by recA mutant alleles, modelled after E. coli recA1 and recA56, was observed and more apparent with expression of C. burnetii RecAG159D mutant protein. Expression of a subset of repair genes in C. burnetii was monitored and, in contrast to the non‐inducible E. coli recBCD, addAB expression was strongly upregulated under oxidative stress. Constitutive SOS gene expression due to the lack of LexA and induction of AddAB likely reflect a unique repair adaptation of C. burnetii to its hostile niche.
Grain‐size information from the statistical properties of digital images of sediment
Authors: BUSCOMBE DANIEL , MASSELINK GERHARD 
Published: July 2008

AbstractThe autocorrelation technique for estimating grain‐size from digital images of sand beds has been extended and validated for use on coarse sand (0·7 mm) and gravel (up to ∼20 mm). A number of aspects of the technique have been explored and some potential improvements suggested. Autocorrelation is just one suitable statistical method sensitive to the grain‐size of sediment in digital images; four additional techniques are presented and their relative merits discussed. A collective suite of techniques applicable to the general problem of grain‐size estimation from digital images of sediment might broaden the applicability to more sedimentary environments, as well as improve its accuracy. These techniques are compared using a large data set from a gravel barrier beach in southern England. Based on over 180 samples, mean grain‐size of sieved and imaged sediments correspond to within between 8% and 16%. Some theoretical aspects of the spatial arrangement of image intensity in digital images of natural sediments are addressed, including the fractal nature of sediments in images, which has potential implications for derivation of grain‐size distributions from images of sand‐sized material through segmentation and thresholding. The methods outlined in this contribution may also find application in further uncovering the geometric structure of sediment beds, as well as in the simulation of sedimentation processes.
Tectonic implications of new U–Pb zircon ages of the Ladakh batholith, Indus suture zone, northwest Himalaya, India
Authors: Upadhyay Rajeev , Frisch Wolfgang , Siebel Wolfgang 
Published: July 2008

AbstractWe determined U–Pb ages on zircons from Ladakh granitoid samples of three previously undated plutons and deduced four distinct age groups between c. 67 and c. 45 Ma (66.6 ± 2.1, 57.6 ± 1.4, 53.4 ± 1.8, 52.50 ± 0.53 and 45.27 ± 0.56 Ma). This suggests that the Ladakh batholith grew by addition of at least four distinct subduction‐related magma pulses at c. 67, 58, 53 and 45 Ma, thus indicating that the belt was continuously active throughout the Palaeocene and the Middle Eocene (Lutetian). The 45.27 ± 0.56 Ma pluton at Daah‐Hanu is the last major calcalkaline arc magmatic pulse in the Ladakh batholith. Thereafter, the subduction‐related major plutonism gradually waned. The earlier estimate for the youngest pluton within the Ladakh batholith is 49.8 ± 0.8 Ma for the Leh pluton (J. Geol., 2000, 108, 303).
Multiple hydro‐fracturing by boron‐rich fluids in the Late Miocene contact aureole of eastern Elba Island (Tuscany, Italy)
Authors: Dini A. , Mazzarini F. , Musumeci G. , Rocchi S. 
Published: July 2008

AbstractIn eastern Elba Island (Tuscany, Italy), a shallow crustal level felsic, tourmaline‐bearing, dyke‐sill swarm of Late Miocene age is associated with abundant tourmaline‐quartz hydrothermal veins and metasomatic masses. Development of these veins and masses in the host rocks demonstrates multiple hydro‐fracturing by magmatic, boron‐rich saline fluid. Tourmalines in felsic dykes are schorl, whereas in veins and metasomatic masses, tourmaline composition ranges from schorl‐dravite through dravite to uvite. This compositional shift is evidence for an increasing contribution to the magmatic boron‐rich fluids by a Mg‐Ca‐Ti‐rich external component represented by biotite‐rich and amphibolite host rocks. This system can be envisaged as an exposed proxy of the high temperature hydrothermal system presently active in the deepest part of the Larderello‐Travale geothermal field (Tuscany).
Propagators and ridge jumps in a back‐arc basin, the West Philippine Basin
Authors: Deschamps Anne , Shinjo Ryuichi , Matsumoto Takeshi , Lee Chao‐Shing , Lallemand Serge E. , Wu Shiguo ,   Scientific party of KR03‐04 and KR04‐14 cruises
Published: July 2008

AbstractWe explore the tectono‐magmatic processes in the western West Philippine Basin, Philippine Sea Plate, using bathymetric data acquired in 2003 and 2004. The northwestern part of the basin formed through a series of northwestward propagating rifts. We identify at least five sequences of propagating rifts, probably triggered by mantle flow away from the mantle thermal anomaly that is responsible for the origin of the Benham and Urdenata plateaus. Gravitational forces caused by along‐axis topographic gradient and a ∼30° ridge reorientation appear to also be driving the rift propagations. The along‐axis mantle flow appears to be reduced and deflected along the Luzon‐Okinawa fracture zone, because the spreading system remained stable west of this major fault zone. North‐east of the Benham plateau, a left‐lateral fracture zone has turned into a NE–SW‐trending spreading axis. As a result, a microplate developed at the triple junction.
Hydroxyethyl starch 130/0.42/6:1 for perioperative plasma volume replacement in children: preliminary results of a European prospective multicenter observational postauthorization safety study (PASS)
Authors: SÜMPELMANN ROBERT , KRETZ FRANZ‐JOSEF , GÄBLER RALF , LUNTZER ROBERT , BARONCINI SIMONE , OSTERKORN DIRK , HAEGER MICHAELA CARINA , OSTHAUS WILHELM ALEXANDER 
Published: July 2008

SummaryBackground:  Several clinical studies have shown that hydroxyethyl starch (HES) may be as effective and safe as, but less expensive than, albumin when used for perioperative plasma volume replacement (PVR) in children. The new third generation HES 130/0.42 solution was designed to reduce adverse drug reactions (ADRs) and improve safety while maintaining efficacy. Therefore, the objective of this prospective multicenter observational postauthorization safety study (PASS) was to evaluate the perioperative use of HES 130/0.42 in 1000 children with a particular focus on possible ADRs.Methods:  Approximately 300 of 1000 pediatric patients aged up to 12 years with ASA risk scores of I–III receiving perioperative HES 130/0.42 (Venofundin 6%; Braun, Melsungen, Germany) should be enrolled for interims analysis in the first year. The statistical sample size calculation showed that this number of patients would be sufficient to detect a 1% incidence of ADRs. Following approval by local ethics committee, patient demographics, data relating to HES 130/0.42 use, the procedures performed, anesthesia, and ADRs were documented with a particular focus on cardiovascular stability, hemodilution, acid–base balance, renal function, blood coagulation, and hypersensitivity.Results:  Three hundred and sixteen children (ASA I–III, age 3 ± 3.4 [range, day of birth–12 years], body weight 13 ± 10.5 [range, 1.1–60 kg]) were studied at five centers in Germany, Austria, and Italy from May 2006 until August 2007. Forty‐five percent of the patients underwent abdominal surgery, 12.4% urologic procedures, 11.4% thoracic surgery, 7.6% orthopedic procedures, and 7% cardiovascular surgery. The mean volume of infused HES 130/0.42 was 11 ± 4.8 ml·kg−1 (range, 5–42). Cardiovascular stability was maintained in all cases. After HES infusion, hemoglobin (11.5 vs 10.25 g·dl−1), base excess (−2 vs −2.7 mmol·l−1), anion gap (12.9 vs 11.2 mmol·l−1), and strong ion difference (34.3 vs 31.4 mmol·L−1) decreased, and chloride (105.7 vs 107.8 mmol·l−1) increased significantly (P < 0.05). No serious ADRs (i.e., anaphylactoid reaction, renal failure, clotting disorders) were observed.Conclusion:  Moderate doses of HES 130/0.42 help to maintain cardiovascular stability and lead to only moderate changes in hemoglobin concentration and acid–base balance in children. The probability of serious ADRs is lower than 1%. Therefore, HES 130/0.42 for PVR seems to be safe and effective even in neonates and small infants with normal renal function and coagulation.
Lower cuff pressures improve the seal of pediatric laryngeal mask airways
Authors: LICINA ANA , CHAMBERS NEIL A. , HULLETT BRUCE , ERB THOMAS O. , Von UNGERN‐STERNBERG BRITTA S. 
Published: July 2008

SummaryBackground:  Hyperinflation of laryngeal mask airway (LMA) cuffs may be harmful because of the exertion of high pressures on pharyngeal and laryngeal structures. Although cuff manometers may be used to monitor cuff pressure, their use is not routine in many institutions and clinical endpoints are used instead. Furthermore, it is common clinical practice to add air to the cuff in the presence of an air leak to obtain a better seal.Methods:  In a prospective audit, the authors assessed air leakage around pediatric sized LMAs (n = 200) following inflation guided by common clinical endpoints (slight outward movement of the LMA) and then following adjustment of the cuff pressure to the recommended pressure range (<60 cmH2O) according to institutional guidelines with the use of a calibrated cuff manometer, directly after induction of anesthesia. Following induction, all children were gently ventilated with pressure control ventilation with 10 cmH2O and a positive end‐expiratory pressure of 5 cmH2O.Results:  Following inflation of the cuff guided by clinical endpoints, the median initial cuff pressure (LMA size 1–3) was 92 (size 3) to >120 cmH2O (size 1) and the median leakage around the cuff ranged from 0.66 to 1.07 ml·kg−1. Following cuff pressure adjustment according to the recommended pressure range (<60 cmH2O), the leakage decreased significantly to 0.51–0.79 ml·kg−1 (P = 0.002 for size 1, P < 0.001 for size 1.5–3).Conclusion:  The use of clinical endpoints to inflate LMA cuffs is not only associated with significant hyperinflation in the majority of patients but also with an increased leakage around the LMA cuff when compared with adjusted LMA cuff pressures. Therefore, cuff manometers should routinely be used not only to avoid unnecessary hyperinflation but also to improve cuff sealing of LMA in children.
Spontaneous contractions of the pig urinary bladder: the effect of ATP‐sensitive potassium channels and the role of the mucosa
Authors: Akino Hironobu , Chapple Christopher R. , McKay Neil , Cross Rebecca L. , Murakami Shigetaka , Yokoyama Osamu , Chess‐Williams Russell , Sellers Donna J. 
Published: July 2008

OBJECTIVETo investigate the influence of the mucosa on the inhibitory effects of the ATP‐sensitive potassium channel (KATP channel) opener, cromakalim, on the spontaneous contractions of pig bladder strips from the bladder dome and trigone. Little is known about the influence of the mucosa on spontaneous contractions and whether the nature of these contractions differs between the bladder dome and trigone.MATERIALS AND METHODSPaired longitudinal strips of female pig bladders were isolated from the dome and trigone. The mucosa was removed from one strip per pair and tissues were set up in organ baths. Spontaneous activity was allowed to develop and recorded, and then cumulative concentration–response curves to cromakalim were obtained. The time needed for spontaneous contractions to develop, the frequency and amplitude of spontaneous contractions, and the effect of cromakalim were analysed. The strips of mucosa removed from the dome to produce denuded strips were also analysed by immunofluorescence using antibodies specific for vimentin and α‐smooth muscle actin (α‐SMA).RESULTSIn the dome removal of the mucosa delayed the development of spontaneous contractions compared with mucosa‐intact strips, whilst the trigone strips developed spontaneous contractions soon after set up in the organ baths irrespective of the presence or absence of mucosa. In the dome, cromakalim was more potent in suppressing spontaneous contractions when the mucosa was absent; whilst in the trigone the effects of cromakalim were similar in mucosa‐intact and denuded strips. Upon examination of the strips of mucosa by immunofluorescence these strips were shown to contain cells positive for α‐SMA or vimentin and cells positive for both, suggesting the presence of not only urothelium but also suburothelium and some detrusor smooth muscle bundles.CONCLUSIONIn the dome, the urothelium and suburothelium reduce the inhibitory effect of cromakalim on spontaneous contractions, whilst in the trigone these structures appear to have little influence. The mechanism for generating spontaneous contractions in the intact strips seems to be linked to the urothelium and suburothelium in the dome but not in the trigone.
Perceived control over ejaculation is central to treatment benefit in men with premature ejaculation: results from phase III trials with dapoxetine
Authors: Shabsigh Ridwan , Patrick Donald L. , Rowland David L. , Bull Scott A. , Tesfaye Fisseha , Rothman Margaret 
Published: July 2008

OBJECTIVESTo assess the utility of perceived control over ejaculation (‘control’) in the evaluation of treatment benefit in men with premature ejaculation (PE), and to compare effects associated with a two‐category or greater increase in this variable between men receiving dapoxetine and placebo.PATIENTS AND METHODSThis subanalysis used combined data from all treatment groups in an integrated analysis of two identically designed, 12‐week, double‐blind, randomized, placebo‐controlled trials of dapoxetine. Men (2614) met the Diagnostic and Statistical Manual of Mental Disorders (fourth edition, text revision) criteria for PE, had a stopwatch‐measured intravaginal ejaculatory latency time (IELT) of ≤2 min in ≥75% of events in a 2‐week baseline period, and self‐reported moderate or severe PE. Men received placebo or dapoxetine 30 or 60 mg, 1–3 h before intercourse. The stopwatch‐measured IELT was recorded for each episode; the patient‐reported global impression of change (PGI; 7‐point scale, ‘much worse’ to ‘much better’), control and satisfaction with sexual intercourse (5‐point scales, ‘very poor’ to ‘very good’) were assessed monthly. The utility of a two‐category or greater increase in control was evaluated by examining the relationship of this variable with IELT and satisfaction with sexual intercourse.RESULTSOf 2341 men with baseline and endpoint assessments, 96.8% reported ‘very poor’ or ‘poor’ control at baseline, and 748 (32%) reported a two‐category or greater increase in control after treatment. More than 95% of those men rated their PE as ‘slightly better’, ‘better’, or ‘much better’ on the PGI; 67.1% gave ratings of ‘better’ or ‘much better.’ They also had greater improvements in IELT than men with less than a two‐category increase in control, with a mean (sd) change from baseline of 3.7 (4.3) vs 0.77 (1.8) min, respectively, and a greater percentage reported good or very good satisfaction with sexual intercourse than men with less than a two‐category increase in control (74% vs 19%, respectively). Nausea, headache and upper respiratory tract infection were the most common adverse events reported by men with a two‐category or greater increase in control (15.8%, 7.4% and 6.6%, respectively) and those without (8.5%, 5.5% and 6.5%, respectively). The proportions of men with a two‐category or greater increase in control with dapoxetine 30 and 60 mg were 36.3% and 44.5%, respectively (vs 15% with placebo).CONCLUSIONSA two‐category or greater increase in control (5‐point scale) is useful for assessing the treatment benefit in men with PE; it corresponds with improvements in the man’s perception of his condition, substantially greater prolongation of IELT, and higher levels of satisfaction with sexual intercourse.
Resources and Student Achievement—Evidence from a Swedish Policy Reform*
Authors: Fredriksson Peter , Öckert Björn 
Published: July 2008

AbstractA policy change is used to estimate the effect of teacher density on student performance. We find that an increase in teacher density has a positive effect on student achievement. The baseline estimate—obtained by using the grade‐point average as the outcome variable—implies that resource increases corresponding to the class‐size reduction in the STAR experiment (a reduction of seven students) improves performance by 2.6 percentile ranks (or 0.08 standard deviations). When we used test‐score data for men, potentially a more objective measure of student performance, the effect of resources appears to be twice as large.
Trade Integration and Business Cycle Convergence: Is the Relation Robust across Time and Space?*
Authors: Abbott Andrew , Easaw Joshy , Xing Tao 
Published: July 2008

AbstractIn this paper we investigate the relationship between trade intensity and the business cycle correlation using a panel data set taken from 24 countries over the period 1959–2003. Most previous studies did not account for the possibility that the business cycle correlation may be influenced by unobservable country‐pair specific effects. Our estimates, using both fixed‐ and random‐effects methodologies, suggest that trade intensity and the business cycle correlation are positively related to one another. However, detailed investigation shows that this relationship exists mainly for the European countries.
Moral Hazard, Income Taxation and Prospect Theory*
Authors: Kanbur Ravi , Pirttilä Jukka , Tuomala Matti 
Published: July 2008

AbstractThe standard theory of optimal income taxation under uncertainty has been developed under the assumption that individuals maximise expected utility. However, prospect theory has now been established as an alternative model of individual behaviour, with empirical support. This paper explores the theory of optimal income taxation under uncertainty when individuals behave according to the tenets of prospect theory. It is seen that many of the standard results are modified in interesting ways. The first‐order approach for solving the optimisation problem is not valid over the domain of losses, and the marginal tax schedule offers full insurance around the reference consumption level. The implications of non‐welfarist objectives under income uncertainty are also examined.
Stress that Doesn't Pay: The Commuting Paradox*
Authors: Stutzer Alois , Frey Bruno S. 
Published: July 2008

AbstractPeople spend a lot of time commuting and often find it a burden. According to standard economics, the burden of commuting is chosen when compensated either on the labor or on the housing market so that individuals' utility is equalized. However, in a direct test of this strong notion of equilibrium with panel data, we find that people with longer commuting time report systematically lower subjective well‐being. This result is robust with regard to a number of alternative explanations. We mention several possibilities of an extended model of human behavior able to explain this “commuting paradox”.
Do Slotting Allowances Harm Retail Competition?*
Authors: Foros Øystein , Jarle Kind Hans 
Published: July 2008

AbstractSlotting allowances are fees paid by manufacturers to get access to retailers' shelf space. Both in the USA and Europe, the use of slotting allowances has attracted attention in the general press as well as among policy makers and economists. One school of thought claims that slotting allowances are efficiency enhancing, while another school of thought maintains that slotting allowances are used in an anti‐competitive manner. In this paper, we argue that this controversy is partially caused by inadequate assumptions of how the retail market is structured and organized. Using a formal model, we show that there are good reasons to expect anti‐competitive effects of slotting allowances. We further point out that competition authorities tend to use an unsatisfactory basis for comparison when analyzing welfare consequences of slotting allowances.
Relative Wage Variation and Industry Location in the United Kingdom*
Authors: Bernard Andrew B. , Redding Stephen J. , Schott Peter K. , Simpson Helen 
Published: July 2008

AbstractThis paper shows that both relative wages and industry structure vary considerably across regions of the United Kingdom. In accordance with the neoclassical model of trade, regions abundant in a factor (i) exhibit lower relative prices of that factor than regions scarce in the factor, and (ii) tend to specialize in a mix of industries intensive in the use of the factor. We show that this specialization leads UK regions to be asymmetrically exposed to external macroeconomic or international trade shocks.
Why Do Price Limits Exist in Stock Markets? A Manipulation‐Based Explanation
Authors: Kim Kenneth A. , Park Jungsoo 
Published: July 2008

Abstract Numerous stock market regulators around the world impose daily price limits on individual stock price movements. We derive a simple model that shows that price limits may deter stock market manipulators. Based on our model's implications, we predict that regulators impose price limit rules for markets where the likelihood of manipulation is high. We present empirical evidence consistent with this hypothesis. Our study is the first to formally propose a manipulation‐based rationale for the existence of price limits in stock markets.