bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geochemical arguments for identifying second‐order sea‐level changes in hemipelagic carbonate ramp deposits
Authors: Rosales Idoia , Quesada Santiago , Robles Sergio 
Published: June 2006

AbstractSecond‐order transgressive–regressive (T–R) cycles, previously recognized using sedimentological criteria in Lower Jurassic hemipelagic deposits from northern Spain, are distinguishable based upon bulk‐rock organic geochemistry [total organic carbon (TOC) and hydrogen index (HI)] and the stable carbon isotope compositions from belemnite rostra. There is a coincidence between regressions and decreasing δ13Cbel, TOC and HI values, and between transgressions and increasing δ13Cbel, TOC and HI values. The δ18O and Mg/Ca records from the belemnite rostra are not always in phase with the T–R cycles. The δ18Obel record reveals, however, a prominent excursion towards higher values within the spinatum Zone that correlates, according to our results, with a regression and with negative shifts in Mg/Ca, δ13Cbel and TOC. On the other hand, an excursion in the δ18Obel towards lower values in the serpentinus Zone also correlates with a peak transgression and with positive shifts in Mg/Ca, δ13Cbel and TOC. These two excursions have been identified in other European regions as geochemical perturbations of the same characteristics. This suggests a link between second‐order relative sea‐level changes and variations in seawater geochemistry that may reflect local and regional palaeoceanographic perturbations in sea‐water temperature, salinity and water circulation during the Early Jurassic.Terra Nova, 18, 233–240, 2006
The lba1 mutation of UPF1 RNA helicase involved in nonsense‐mediated mRNA decay causes pleiotropic phenotypic changes and altered sugar signalling in Arabidopsis
Authors: Yoine Masato , Ohto Masa‐aki , Onai Kiyoshi , Mita Satoru , Nakamura Kenzo 
Published: June 2006

SummaryThe low‐beta‐amylase1 (lba1) mutant of Arabidopsis thaliana has reduced sugar‐induced expression of Atβ‐Amy and shows pleiotropic phenotypes such as early flowering; short day‐sensitive growth; and seed germination that is hypersensitive to glucose and abscisic acid and resistant to mannose. lba1 was a missense mutation of UPF1 RNA helicase involved in nonsense‐mediated mRNA decay (NMD), which eliminates mRNAs with premature termination codons (PTCs), and replaces highly conserved Gly851 of UPF1 with Glu. Expression of the wild‐type UPF1 in lba1 rescued not only the reduced sugar‐inducible gene expression, but also early flowering and altered seed‐germination phenotypes. Sugar‐inducible mRNAs were over‐represented among transcripts decreased in sucrose‐treated lba1 compared with Col plants, suggesting that UPF1 is involved in the expression of a subset of sugar‐inducible genes. On the other hand, transcripts increased in lba1, which are likely to contain direct targets of NMD, included mRNAs for many transcription factors and metabolic enzymes that play diverse functions. Among these, the level of an alternatively spliced transcript of AtTFIIIA containing PTC was 17‐fold higher in lba1 compared with Col plants, and it was reduced to the level in Col by expressing the wild‐type UPF1. The lba1 mutant provides a good tool for studying NMD in plants.
Adaptive evolution of the Bordetella autotransporter pertactin
Authors: Diavatopoulos D. A. , Hijnen M. , Mooi F. R. 
Published: June 2006

Abstract
The virulence factor pertactin is expressed by the closely related pathogens Bordetella pertussis, Bordetella parapertussis and Bordetella bronchiseptica. Pertactin is an autotransporter involved in adherence of Bordetella species to the lung epithelium of mammalian hosts, and it is an important component of most current acellular pertussis vaccines. These three species produce immunologically distinct pertactin molecules, resulting in a lack of cross-protection against B. parapertussis and probably also against B. bronchiseptica. Variation in pertactin is not only inter-specific, but also occurs between isolates from the same species. Knowledge about codons that are under positive selection could facilitate the development of more broadly protective vaccines. Using different nucleotide substitution models, pertactin genes from B. bronchiseptica, B. parapertussis and B. pertussis were compared, and positively selected codons were identified using an empirical Bayesian approach. This approach yielded 15 codons predicted to be under diversifying selection pressure. These results were interpreted in an immunological context and may help in improving future pertussis vaccines.
Potential causes of weight gain in type 1 diabetes mellitus
Authors: Jacob A. N. , Salinas K. , Adams‐Huet B. , Raskin P. 
Published: June 2006

Aim:  To investigate the potential causes of weight gain with insulin therapy and improved diabetic control in type 1 diabetes mellitus.Methods:  This was an open‐label prospective study of insulin therapy of 6 months duration in an academic medical centre. Twenty‐one subjects with type 1 diabetes were enrolled. The goal was to achieve an haemoglobin A1c (HbA1c) in the range of individuals without diabetes (<5.6%). At baseline, 3 and 6 months, weight, resting energy expenditure, appetite assessment, food intake, activity level, HbA1c and 24‐h glycosuria and urea nitrogen were measured. Plasma leptin, ghrelin and adiponectin levels and body fat were measured at baseline and 6 months.Results:  At baseline, average weight was 73.7 ± 17.4 kg and HbA1c was 10.0 ± 2.2%. Weight increased by 2.15 kg (2.69% of baseline) by 6 months whereas the HbA1c dropped by 1.71% (16.3%) to 7.9%. Energy intake differences between 3 and 6 months had a negative correlation with weight gain, but the changes in glycosuria, appetite scores and the frequency of hypoglycaemia did not correlate with weight gain. Glycaemic control did not correlate with weight change but tended to correlate with fat mass increase (p = 0.064; r = −0.51). An increase in the activity levels between 3 and 6 months correlated with decreasing fat mass (p = 0.037; r = −0.74). The changes in the appetite scores had a negative correlation with fat mass gain (p = 0.035; r = −0.61). The changes in lean body mass correlated with protein and total energy intake (p = 0.007, r = 0.85 and p = 0.003, r = 0.73 respectively). The changes in leptin levels correlated with weight gain.Conclusions:  The lipogenic effect of insulin with subsequent increase in fat mass may be the primary cause of this weight gain that can be attenuated by the increases in the activity levels. The negative correlation of energy intake and appetite scores with fat mass gain suggests that they do not play a significant role in fat mass gain whereas energy intake did correlate with lean body mass gain.
Acute regulation of plasma leptin by isoprenaline in lean and obese fasted subjects
Authors: Baynes K. C. R. , Nicholas M. D. , Shojaee‐Moradie F. , Umpleby A. M. , Giannoulis M. G. 
Published: June 2006

Aim:  In human obesity, there is some evidence for impaired adrenergic sensitivity with respect to catecholamine‐induced lipolysis. The β‐adrenoceptor agonist isoprenaline has been shown to suppress plasma leptin levels in lean humans in vivo. We hypothesized that a reduced adrenergic sensitivity in obese humans would result in impaired suppression of leptin secretion.Methods:  Eight obese [Ob, body mass index (BMI) = 33.3 kg/m2] and seven lean (Ln, BMI = 21.8 kg/m2) men were studied after an overnight fast. Intravenous isoprenaline infusion was initiated at a rate of 8 ng/kg/min, titrated up to 24 ng/kg/min over 30 min and continued at this rate for a further 120 min with continuous electrocardiogram monitoring.Results:  Baseline fasting plasma leptin was higher in obese compared with lean subjects (Ob 12.2 ± 1.8, Ln 2.6 ± 0.6 ng/ml, p < 0.05 unpaired t‐test). Baseline fasting glycerol as a measure of lipolysis was similar in both groups (Ob 62.9 ± 7.6, Ln 42.4 ± 8.9 µmol/l) and increased from baseline to 150 min by equivalent amounts (Ob +66.9%, Ln +81.2%, p = NS). Plasma leptin decreased from baseline to 150 min with similar relative changes in both groups (Ob −29.2%, Ln −27.8%).Conclusions:  Obese subjects show a similar lipolytic and leptin response to acute isoprenaline infusion compared with lean subjects. Impaired β‐adrenergic‐induced inhibition of leptin secretion does not appear to contribute to hyperleptinaemia in obese human subjects.
A metabolomic study of substantial equivalence of field‐grown genetically modified wheat
Authors: Baker John M. , Hawkins Nathaniel D. , Ward Jane L. , Lovegrove Alison , Napier Johnathan A. , Shewry Peter R. , Beale Michael H. 
Published: June 2006

SummaryThe ‘substantial equivalence’ of three transgenic wheats expressing additional high‐molecular‐weight subunit genes and the corresponding parental lines (two lines plus a null transformant) was examined using metabolite profiling of samples grown in replicate field trials on two UK sites (Rothamsted, Hertfordshire and Long Ashton, near Bristol) for 3 years. Multivariate comparison of the proton nuclear magnetic resonance spectra of polar metabolites extracted with deuterated methanol–water showed a stronger influence of site and year than of genotype. Nevertheless, some separation between the transgenic and parental lines was observed, notably between the transgenic line B73‐6‐1 (which had the highest level of transgene expression) and its parental line L88‐6. Comparison of the spectra showed that this separation resulted from increased levels of maltose and/or sucrose in this transgenic line, and that differences in free amino acids were also apparent. More detailed studies of the amino acid composition of material grown in 2000 were carried out using gas chromatography‐mass spectrometry. The most noticeable difference was that the samples grown at Rothamsted consistently contained larger amounts of acidic amino acids (glutamic, aspartic) and their amides (glutamine, asparagine). In addition, the related lines, L88‐6 and B73‐6‐1, both contained larger amounts of proline and γ‐aminobutyric acid when grown at Long Ashton than at Rothamsted. The results clearly demonstrate that the environment affects the metabolome and that any differences between the control and transgenic lines are generally within the same range as the differences observed between the control lines grown on different sites and in different years.
TECHNOLOGICAL CHANGE, INEQUALITY AND WORK SHARING
Authors: Moutos Thomas 
Published: June 2006

ABSTRACTThe effects of technological change on wage inequality are usually studied under the assumption of exogenous supplies of skilled and unskilled workers. Moreover, in these studies there is no distinction between the stock (number of workers) and the flow (hours of work) dimension of labour services. In the present paper, we construct a model in which hours of work and technological change affect both the (relative) demand and supply of unskilled workers. The labour supply of unskilled workers (numbers of persons) is derived from a model of household labour supply in which households differ regarding the disutility suffered when both household members work. Combining together the (relative) supply and demand parts of the model we are able to establish technological change (either biased or neutral) as a plausible explanation of recent trends in wage inequality.
BANK INTEREST MARGINS AND BUSINESS START‐UP COLLATERAL: TESTING FOR CONVEXITY
Authors: Burke Andrew , Hanley Aoife 
Published: June 2006

ABSTRACTThe paper investigates the relationship between bank interest rate margins and collateral for loans issued to new ventures. The analysis finds a convex U‐shaped relationship. The results indicate that while provision of collateral initially reduces bank exposure to risk (through security, more optimal levels of capital and lower moral hazard among entrepreneurs) that beyond a point, the positive risk‐wealth association gives rise to greater risk taking propensity among entrepreneurs and ultimately higher interest rates. This indicates that a lender's pricing policy may even somewhat help to level the competitive playing field between ventures launched by higher and moderately wealthy entrepreneurs.
COMPETITION, PARALLEL IMPORTS AND COST‐REDUCING INNOVATION
Authors: Li Changying 
Published: June 2006

ABSTRACTIncorporating parallel imports (PI), we develop a two‐country two‐firm model which relates to the incentives for cost‐reducing innovation. We show that PI may facilitate or inhibit the manufacturers' incentives to innovate. In particular, PI could encourage both firms' innovations. The difference between the manufacturer's profits under successful innovation and failed innovation is either a U‐shaped curve or an inverted U‐shaped curve in terms of the cost of engaging in PI. As these differences reflect the manufacturers' incentive to innovate, the variations in R&D investment depend on transportation cost, and firms' marginal costs before and after successful innovations.
OPTIMUM‐WELFARE AND MAXIMUM‐REVENUE TARIFFS UNDER BERTRAND DUOPOLY
Authors: Clarke Roger , Collie David R. 
Published: June 2006

ABSTRACTThis article derives the maximum‐revenue tariff and the optimum‐welfare tariff under Bertrand duopoly with differentiated products. It is shown that both tariffs are lower under Bertrand duopoly than under Cournot duopoly. Also, the optimum‐welfare tariff may exceed the maximum‐revenue tariff under both Bertrand duopoly and Cournot duopoly. This result is more likely the lower the costs of the home firm relative to the costs of the foreign firm, and the greater the degree of product substitutability. Also, it is shown that the optimum‐welfare tariff is less likely to exceed the maximum‐revenue tariff under Bertrand duopoly than under Cournot duopoly.
Analysis of strain‐induced ground‐water fluctuations at Devils Hole, Nevada
Authors: CUTILLO P. A. , GE S. 
Published: June 2006

AbstractThe pool in Devils Hole is a sensitive indicator of crustal strain and fluctuates in response to changes in atmospheric pressure, earth tides, earthquakes, large‐scale tectonic activity and ground‐water development. Short‐term and cyclic water‐level fluctuations caused by atmospheric pressure and earth tides were found to be on the order of millimeters to centimeters. The 1992 Landers/Little Skull Mountain earthquake sequence and the 1999 Hector Mine earthquake induced water‐level offsets of greater than −12 and −3.6 cm, respectively. The results of a dislocation model used to compute volumetric strain for each earthquake indicates that the coseismic water‐level offsets are consistent in magnitude and sense with poroelastic responses to earthquake‐induced strain. Theoretical postseismic fluid‐flow modeling indicates that the diffusivity of the system is on the order of 0.03 m2 sec−1, and identified areas of anomalous water‐level fluctuations. Interpretation of model results suggests that while the persistent post‐Landers rise in water‐level can be attributed to deformation‐induced channeling of fluid to the Devils Hole fault zone, the cause of the pre‐Hector Mine water‐level rise may be related to postseismic excess fluid pressures or preseismic strain accumulation.
Physiological correlates of habitat association in East African sunbirds (Nectariniidae)
Authors: Seavy N. E. 
Published: June 2006

AbstractEast African sunbirds (Nectariniidae) vary in the degree to which they use open habitats and forest habitats. Species that use open habitats may experience more extreme temperatures and greater exposure to solar radiation than those in forest habitats. Basal rates of metabolism, body temperature and thermal conductance were compared for open habitat‐ and forest‐associated sunbirds from Kibale National Park, Uganda. Variation in basal rate of metabolism was associated with body mass, but there was no difference between forest and open habitat species. Variation in body temperature was not associated with body mass or habitat. Variation in thermal conductance was associated with body mass and habitat; open habitat species were characterized by significantly lower thermal conductances than forest species. Because reduced thermal conductance may decrease energy expenditure at low ambient temperatures and reduce exogenous heat gain at high ambient temperatures, this difference may optimize energy expenditure when temperatures are highly variable. This suggests a mechanism by which physiological characteristics may influence energetic consequences of habitat selection.
Microsatellite loci for Cherrie's tanager (Ramphocelus costaricensis)
Authors: KRUEGER TERRY R. , WILLIAMS DEAN A. 
Published: June 2006

AbstractCherrie's tanager (Ramphocelus costaricensis) is a common woodland bird of the Pacific lowlands of Costa Rica. Males and females have sexually dimorphic plumage and are socially monogamous. As part of a study of sexual selection in this species, we characterized six species‐specific polymorphic microsatellite loci and one cross‐species locus that works well in Cherrie's tanager to ascertain parentage.
Nine polymorphic microsatellite markers in Centaurea stoebe L. [subspecies C. s. stoebe and C. s. micranthos (S. G. Gmelin ex Gugler) Hayek] and C. diffusa Lam. (Asteraceae)
Authors: MARRS ROBIN A. , HUFBAUER RUTH A. , BOGDANOWICZ STEVEN M. , SFORZA RENÉ 
Published: June 2006

Abstract Centaurea stoebe (subspecies C. s. stoebe and C. s. micranthos[S. G. Gmelin ex Gugler) Hayek] and Centaurea diffusa are Eurasian plant species that have invaded much of North America. We isolated seven microsatellite loci from C. stoebe and two loci from C. diffusa. All loci described here amplify in both species and have between six and 25 alleles each. These markers will be useful in examining population structure and addressing questions regarding these invasions.
Albite vein formation during exhumation of high‐pressure terranes: a case study from alpine Corsica
Authors: MILLER J. A. , CARTWRIGHT I. 
Published: June 2006

AbstractThe formation of late‐stage veins can yield valuable information about the movement and composition of fluids during uplift and exhumation of high‐pressure terranes. Albite veins are especially suited to this purpose because they are ubiquitously associated with the greenschist facies overprint in high‐pressure rocks. Albite veins in retrogressed metabasic rocks from high‐pressure ophiolitic units of Alpine Corsica (France) are nearly monomineralic, and have distinct alteration haloes composed of actinolite + epidote + chlorite + albite. Estimated P–T conditions of albite vein formation are 478 ± 31 °C and 0.37 ± 0.14 GPa. The P–T estimates and petrographic constraints indicate that the albite veins formed after the regional greenschist facies retrogression, in response to continued decompression and exhumation of the terrane. Stable isotope geochemistry of the albite veins, their associated alteration haloes and unaltered hostrocks indicates that the vein‐forming fluid was derived from the ophiolite units and probably from the metabasalts within each ophiolite slice. That the vein‐forming fluid was locally derived means that a viable source of fluid to form the veins was retained in the rocks during high‐pressure metamorphism, indicating that the rocks did not completely dehydrate. This conclusion is supported by the observation of abundant lawsonite at the highest metamorphic grades. Fluids were liberated during retrogression via decompression dehydration reactions such as those that break down hydrous high‐pressure minerals like lawsonite. Albite precipitation into veins is sensitive to the solubility and speciation of Al, which is more pressure sensitive than other factors which might influence albite vein formation such as silica saturation or Na:K fluid ratios. Hydraulic fracturing in response to fluid generation during decompression was probably the main mechanism of vein formation. The associated pressure decrease with fracturing and fluid decompression may also have been sufficient to change the solubility of Al and drive albite precipitation in fracture systems.
Fatty Acid Ethyl Ester Effects on Interleukin‐2 Production, Cyclic AMP Synthesis, and Calcium Influx in Human Mononuclear Cells
Authors: Alhomsi Khaled , Laposata Michael 
Published: June 2006

Background: Fatty acid ethyl esters (FAEE), nonoxidative ethanol metabolites, are produced by the esterification of fatty acids and ethanol. Plasma and serum FAEE correlate linearly with blood ethanol levels and are present in organs most commonly damaged by ethanol abuse. Our previous studies have shown that there is significant synthesis of FAEE by human mononuclear cells within seconds of exposure to physiologic doses of ethanol.Objectives: We studied the effects of FAEE on selected early events of mononuclear cell activation that follow stimulation with phytohemagglutinin (PHA). Fatty acid ethyl esters induced changes in cytosolic free calcium ([Ca2+]) levels, the production and secretion of interleukin‐2 (IL‐2) by the cells, and intracellular cAMP concentrations.Methods: A mononuclear fraction of human white blood cells (WBC) was incubated with physiologic doses of FAEE. For experiments involving IL‐2 production and calcium influx, PHA‐stimulated cells were incubated with 10, 25, 50, or 100 μM ethyl oleate, a representative FAEE species, for 60 minutes. Interleukin‐2 was measured by enzyme immunometeric assay and maximum levels of Ca2+ were monitored by spectrofluorimetry. In other experiments, mononuclear cells were incubated with 10, 25, and 50 μM ethyl oleate for 0.08 to 120 minutes, and then the concentration of cAMP was determined by a cAMP competitive enzyme immunoassay system.Results: Fatty acid ethyl esters inhibited the PHA‐induced IL‐2 production and secretion in activated human mononuclear cells. Fatty acid ethyl esters also inhibited PHA‐induced [Ca2+] influx into cells in a dose‐dependent fashion. There was a rapid increase in the intracellular cAMP concentration of mononuclear cells induced by FAEE, with FAEE dose dependence. The cAMP concentration decreased as the incubation time with FAEE was increased.Conclusions: Fatty acid ethyl esters inhibited PHA‐stimulated IL‐2 production and Ca2+ influx into human mononuclear cells and elevated intracellular cAMP concentration. These changes in mononuclear cell signaling may be associated with the immunosuppression associated with alcohol abuse.