bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ichthyoplankton‐based spawning dynamics of blue mackerel (Scomber australasicus) in south‐eastern Australia: links to the East Australian Current
Authors: NEIRA FRANCISCO J. , KEANE JOHN P. 
Published: July 2008

AbstractWe describe findings of three ichthyoplankton surveys undertaken along south‐eastern Australia during spring (October 2002, 2003) and winter (July 2004) to examine spawning habitat and dynamics of blue mackerel (Scomber australasicus). Surveys covered ∼860 nautical miles between southern Queensland (Qld; 24.6°S) and southern New South Wales (NSW; 41.7°S), and were mainly centred on the outer shelf including the shelf break. Egg identifications were verified applying mtDNA barcoding techniques. Eggs (n = 2971) and larvae (n = 727; 94% preflexion) occurred both in spring and winter, and were confined to 25.0–34.6°S. Greatest abundances (numbers per 10 m2) of eggs (1214–7390) and larvae (437–1172) occurred within 10 nm shoreward from the break in northern NSW. Quotient analyses on egg abundances revealed that spawning is closely linked to a combination of bathymetric and hydrographic factors, with the outer shelf as preferred spawning area, in waters 100–125 m deep with mean temperatures of 19–20°C. Eggs and larvae in spring occurred in waters of the East Australian Current (EAC; 20.6–22.3°C) and mixed (MIX; 18.5–19.8°C) waters, with none occurring further south in the Tasman Sea (TAS; 16.0–17.0°C). Results indicate that at least some of the south‐eastern Australian blue mackerel stock spawns during winter‐spring between southern Qld and northern NSW, and that no spawning takes place south of 34.6°S due to low temperatures (<17°C). Spawning is linked to the EAC intrusion, which also facilitates the southward transport of eggs and larvae. Since spring peak egg abundances came from where the EAC deflects offshore, eggs and larvae are possibly being advected eastwards along this deflection front. This proposition is discussed based on recent data on blue mackerel larvae found apparently entrained along the Tasman Front.
An elemental and stable isotope assessment of water strider feeding ecology and lipid dynamics: synthesis of laboratory and field studies
Authors: JARDINE TIMOTHY D. , KIDD KAREN A. , POLHEMUS JOHN T. , CUNJAK RICHARD A. 
Published: July 2008

Summary1. Despite the ubiquity and abundance of water striders (Hemiptera: Gerridae) in temperate streams and rivers and their potential usefulness as sentinels in contaminant studies, little is known about their feeding ecology and lipid dynamics.2. In this study we used stable isotopes of carbon (δ13C) and nitrogen (δ15N) and elemental carbon to nitrogen ratios (C/N) to assess dietary habits and lipid content, respectively, for water striders.3. To determine diet‐tissue fractionation factors, nymphs of the most common species in New Brunswick, Canada, Aquarius remigis were reared in the laboratory for 73 days and exhibited rapid isotopic turnover in response to a switch in diet (C half‐life = 1.5 days, N half‐life = 7.8 days). Their lipid content increased towards the end of the growing season and resulted in lower δ13C values. Diet‐tissue fractionation factors were established after correction of δ13C data for the confounding effect of de novo lipid synthesis (strider δ13Cadj– diet δ13Cadj = 0.1‰, strider δ15N – diet δ15N = 2.7‰).4. Water striders from the majority of 45 stream sites (83%) in New Brunswick had less than 50% contribution of aquatic carbon to their diets but showed a gradual increase in the contribution of this carbon source to their diet with increasing stream size.5. These data indicate that striders exhibit a strong connection to terrestrial carbon sources, making them important users of energy subsidies to streams from the surrounding catchment. However, this dependence on terrestrial organic matter may limit their utility as indicators of contamination of aquatic systems by heavy metals and other pollutants.
Modelling production caused changes in conductivity for a siliciclastic reservoir: a differential effective medium approach
Authors: Gelius Leiv‐J. , Wang Zhong 
Published: July 2008

ABSTRACTMarine controlled‐source electromagnetic sounding is a rapidly growing exploration technique that complements the seismic method in case of pore fluid discrimination between water and oil. Further development of the method is foreseen to be within reservoir monitoring involving permanent instrumentation on both seafloor and within wells. Such advanced applications demand a good understanding and description of the electric Earth model to ensure accurate modelling of possible Earth responses as well as successful inversion of measurement data. Based on earlier works carried out within petrophysics and resistivity‐logging, an extended effective‐medium scheme is derived that can be applied to model reservoir production effects. This rock‐physics model has the potential of taking into account the effect of important parameters like grain‐shape distribution, grain alignment, shaliness, salinity, saturation, temperature and stress, based on a uniform formulation. It has been calibrated by employing various core sample measurements. The effective‐medium scheme can easily be interfaced with an existing standard electromagnetic modelling program and several such examples are presented.
Forward modelling and inverse problem in the comprehensive interpretation of well logs
Authors: Woznicka U. , Jarzyna J. , Cichy A. 
Published: July 2008

ABSTRACTComprehensive interpretation of well logs often consists in solving a set of equations with complex boundary conditions. For each log, the equation combines geological parameters and a response by the device. Minimization is a way of obtaining the best solution that involves finding the minimum of the defined error function. In the case discussed here, an error is a measure of the difference between recorded and theoretical logs.The simplest and quickest way to determine a solution to the presented problem is to apply the conjugate gradient descent method to minimize the error function. This approach is not efficient in some cases when logging in regions with complex geology.We prove that a special algorithm using the Monte Carlo method combined with the conjugate gradient descent method gives considerably better results in comprehensive interpretation. A measure of the quality of the proposed method is the discrepancy between the standard solution obtained from commercial software used in the petroleum industry and the new algorithm result.We present examples of the application of the proposed algorithm for comprehensive interpretation in typical Zechstein dolomite beds and the Carboniferous sandstone layer in the Polish Lowland.
Application of the continuous wavelet transform on seismic data for mapping of channel deposits and gas detection at the CO2SINK site, Ketzin, Germany
Authors: Kazemeini Sayed Hesammoddin , Juhlin Christopher , Zinck‐Jørgensen Kim , Norden Ben 
Published: July 2008

ABSTRACTConventional seismic data are band limited and therefore, provide limited geological information. Every method that can push the limits is desirable for seismic data analysis. Recently, time‐frequency decomposition methods are being used to quickly extract geological information from seismic data and, especially, for revealing frequency‐dependent amplitude anomalies. Higher frequency resolution at lower frequencies and higher temporal resolution at higher frequencies are the objectives for different time‐frequency decomposition methods. Continuous wavelet transform techniques, which are the same as narrow‐band spectral analysis methods, provide frequency spectra with high temporal resolution without the windowing process associated with other techniques. Therefore, this technique can be used for analysing geological information associated with low and high frequencies that normally cannot be observed in conventional seismic data. In particular, the continuous wavelet transform is being used to detect thin sand bodies and also as a direct hydrocarbon indicator. This paper presents an application of the continuous wavelet transform method for the mapping of potential channel deposits, as well as remnant natural gas detection by mapping low‐frequency anomalies associated with the gas. The study was carried out at the experimental CO2 storage site at Ketzin, Germany (CO2SINK). Given that reservoir heterogeneity and faulting will have significant impact on the movement and storage of the injected CO2, our results are encouraging for monitoring the migration of CO2 at the site. Our study confirms the efficiency of the continuous wavelet transform decomposition method for the detection of frequency‐dependent anomalies that may be due to gas migration during and after the injection phase and in this way, it can be used for real‐time monitoring of the injected CO2 from both surface and borehole seismics.
First‐order error propagation formulae for the Gassmann relations
Authors: Broadhead Michael K. 
Published: July 2008

ABSTRACTThe Gassmann relations of poroelasticity provide a connection between the dry and the saturated elastic moduli of porous rock and are useful in a variety of petroleum geoscience applications. Because some uncertainty is usually associated with the input parameters, the propagation of error in the inputs into the final moduli estimates is immediately of interest. Two common approaches to error propagation include: a first‐order Taylor series expansion and Monte‐Carlo methods. The Taylor series approach requires derivatives, which are obtained either analytically or numerically and is usually limited to a first‐order analysis. The formulae for analytical derivatives were often prohibitively complicated before modern symbolic computation packages became prevalent but they are now more accessible. We apply this method and present formulae for uncertainty in the predicted bulk and shear moduli for two forms of the Gassmann relations. Numerical results obtained with these uncertainty formulae are compared with Monte‐Carlo calculations as a form of validation and to illustrate the relative characteristics of the two approaches. Particular emphasis is given to the problem of correlated variables, which are often ignored in naïve approaches to error analysis. Going out to the error level that the two methods were compared, the means agree and the variance of the Monte Carlo method for bulk modulus grows with input error.
Slowness surface approximations for qSV‐waves in transversely isotropic media
Authors: Stovas Alexey , Roganov Yuriy 
Published: July 2008

ABSTRACTThe vertical slowness approximations are widely used in phase‐shift migration methods for quasi P‐ and quasi SV‐waves in transversely isotropic medium. The description of the vertical slowness needed for the migration application for shear waves in transverse isotrophy media is generally complicated. The reason is that this type of approximations results in much simpler expressions for the vertical slowness and, which is most important, they contain fewer parameters than exact expressions.We derive slowness surface approximations valid for qSV‐wave propagation in transversely isotropic and tilted transversely isotropic media by applying an approximation extracted from acoustic approximation for qP‐wave propagation. One approximation has the same accuracy as a qP‐wave acoustic approximation for the same range of horizontal slowness, the other approximations are wide‐angle ones.
Activation‐induced deaminase heterozygous MRL/lpr mice are delayed in the production of high‐affinity pathogenic antibodies and in the development of lupus nephritis
Authors: Jiang Chuancang , Zhao Ming Lang , Diaz Marilyn 
Published: July 2008

SummaryWe previously reported that activation‐induced deaminase (AID) heterozygous MRL/lpr mice have substantially lower levels of serum anti‐dsDNA autoantibodies than AID wild‐type littermates. Given the known functions of AID, here we examined whether this decrease in pathogenic autoantibodies in the heterozygotes was the result of a defect in class switch recombination, somatic hypermutation, or both. We report significant impairment of switch recombination to most isotypes except immunoglobulin G3 (IgG3) in vitro. However, serum levels of IgG were similar to AID wild‐type levels even in very young mice. Mutation accumulation in the B cells from Peyer’s patches also revealed reduced somatic hypermutation in the heterozygotes. Unlike the switch defect, the hypermutation defect probably resulted in an in vivo effect because the serum IgG antibodies from the heterozygotes were of strikingly lower affinity to dsDNA than serum IgG antibodies from wild‐type littermates. This suggests that the somatic hypermutation defect resulted in impaired affinity maturation of autoantibodies in these mice and explains the low levels of specific anti‐dsDNA antibodies in the heterozygotes. This correlated with a delay in the development of kidney damage. These results imply that AID levels impact the class switch recombination and somatic hypermutation mechanisms and directly implicate affinity maturation of autoantibodies in autoimmunity.
Suppression of cell proliferation and cytokine expression by HL‐p36, a tick salivary gland‐derived protein of Haemaphysalis longicornis
Authors: Konnai Satoru , Nakajima Chie , Imamura Saiki , Yamada Shinji , Nishikado Hideto , Kodama Michi , Onuma Misao , Ohashi Kazuhiko 
Published: July 2008

SummaryPreviously, a putative immunosuppressant‐coding gene was identified from a complementary DNA library derived from the salivary glands of partially‐fed Haemaphysalis longicornis. Using real‐time polymerase chain reaction, the gene was shown to be predominantly expressed during blood feeding with the site of expression being mainly in the salivary glands; this was confirmed by Western blotting analysis. To investigate the function of this novel protein, in this study, we examined the proliferative responses of bovine mononuclear cells and murine splenic cells as well as the expression of profiles of several cytokines in these cells in the presence of the recombinant protein (H. longicornis‐derived 36 000 molecular weight protein: rHL‐p36). The addition of rHL‐p36 at the beginning of the 72 hr cultivation period clearly inhibited proliferation of several mitogen‐stimulated cells in a dose‐dependent manner, with concomitantly significant down‐regulation of messenger RNA levels for interleukin‐2. The inhibitory response could be abrogated by blockage of HL‐p36 with antibody, suggesting the direct involvement of rHL‐p36 in the cell proliferation. Furthermore, the proliferative response of splenocytes isolated from rHL‐p36‐inoculated mice was significantly lower than for those from control mice, suggesting that rHL‐p36 could also directly suppress immune responses in vivo. Interestingly, microarray analysis of the splenocytes showed that the expression of several immunomodulating genes was down‐regulated by rHL‐p36 inoculation. In conclusion, these results suggest that HL‐p36 is an immunosuppressor that might play an important role in the modulation of host immune responses.
Transcriptomic profiles of Drosophila melanogaster third instar larval midgut and responses to oxidative stress
Authors: Li H.‐M. , Buczkowski G. , Mittapalli O. , Xie J. , Wu J. , Westerman R. , Schemerhorn B. J. , Murdock L. L. , Pittendrigh B. R. 
Published: July 2008

AbstractOligoarray analysis was used to determine the number and nature of genes expressed in third instar Drosophila melanogaster larval midguts. The majority of transcripts were associated with protein synthesis and metabolism. Serine proteases were the main proteolytic enzymes detected. Some 40% of the cytochrome P450 genes and 74% of the glutathione S transferases (GSTs) in the genome of D. melanogaster were observed to be expressed in the midgut by oligoarray analysis. We also identified potential transcription factor binding motifs (TFBMs) of P450s, GSTs and carboxylesterases. Many of the midgut‐expressed GST genes contained candidate TFBMs homologous to TFBMs in mammals that have been associated with responses to oxidative stress. We also investigated the response of GSTs in the midgut to dietary H2O2, which showed a dosage‐based differential response.
Diuretic hormone 44 receptor in Malpighian tubules of the mosquito Aedes aegypti: evidence for transcriptional regulation paralleling urination
Authors: Jagge C. L. , Pietrantonio P. V. 
Published: July 2008

AbstractIn the mosquito Aedes aegypti (L.), the molecular endocrine mechanisms underlying rapid water elimination upon eclosion and blood feeding are not fully understood. The genome contains a single predicted diuretic hormone 44 (DH44) gene, but two DH44 receptor genes. The identity of the DH44 receptor(s) in the Malpighian tubule is unknown in any mosquito species. We show that VectorBase gene ID AAEL008292 encodes the DH44 receptor (GPRDIH1) most highly expressed in Malpighian tubules. Sequence analysis and transcript localization indicate that AaegGPRDIH1 is the co‐orthologue of the Drosophila melanogaster DH44 receptor (CG12370‐PA). Time‐course quantitative PCR analysis of Malpighian tubule cDNA revealed AaegGPRDIH1 expression changes paralleling periods of excretion. This suggests that target tissue receptor biology is linked to the known periods of release of diuretic hormones from the nervous system pointing to a common up‐stream regulatory mechanism.
Spatial variation of wetland woods in the latitudinal transition to arid regions: a multiscale approach
Authors: Rodríguez‐González Patricia María , Ferreira Maria Teresa , Albuquerque António , Santo Dalila Espirito , Rego Pablo Ramil 
Published: July 2008

AbstractAim  In order to investigate the occurrence of wetland woods in the latitudinal transition to arid regions in south‐western Europe, we studied species patterns (richness and abundance), examined floristic differences between woods along the latitudinal gradient, and determined the relative influence of the underlying environmental drivers of plant variation at various scales.Location  The Atlantic coastal belt of the Iberian Peninsula along the entire latitudinal gradient (44–38° N).Methods  Large‐scale surveys were carried out in search of woods located in flats or depressions with prolonged waterlogging. Stands were selected for study when they displayed a continuous tree structure and little sign of human disturbance. Sampling included plant inventories in 114 plots, in which presence and abundance cover were recorded for all vascular and bryophyte species. Both diversity and composition were used to investigate plant species patterns. Gamma and alpha diversity (species richness) values were used to compare Ibero‐Atlantic wetland woods with other European woods. Species richness was modelled as a function of environmental variation at regional and finer scales (landscape and local scale), using linear mixed‐effects models and model selection based on the Akaike information criterion. Hierarchical clustering and ordination using perennial species were used to detect floristic differences between sites. Partial canonical correspondence analyses were performed to determine the relative importance of each set of environmental drivers in structuring the vegetation trends at regional and finer scales.Results  A significant proportion of wetland woods occurred in the transition to the Mediterranean region. Ibero‐Atlantic wetland woods displayed low gamma and alpha diversity compared with other woods. Species richness was strongly influenced by finer‐scale variables, in particular distance to rivers, whereas regional variables were less influential. Based on tree dominance, the classification revealed five vegetation types, but the majority of stands (86%) were included in woods dominated by Salix atrocinerea Brot. and Alnus glutinosa (L.) Gaertner. Species abundances were correlated with both regional and finer‐scale hydrological variables, which explained 37.5% of the variation, 11.9% of which corresponded to regional and 18.5% to finer‐scale environmental descriptors.Main conclusions  True wetland woods persist in the transition to arid regions of south‐western Europe. The latitudinal gradient influences the spatial variation of species, but local hydrological variables were found to play a significant role in both diversity and compositional patterns.
Cyclic habitat displacements during Pleistocene glaciations have induced independent evolution of Tasimia palpata populations (Trichoptera: Tasimiidae) in isolated subtropical rain forest patches
Authors: Múrria C. , Hughes J. M. 
Published: July 2008

AbstractAim  Mechanisms generating biodiversity and endemism are influenced by both historical and ecological patterns, and the relative roles of history vs. ecological interactions are still being debated. The phylogeography of one rain forest‐restricted caddisfly species, Tasimia palpata, thought to have good dispersal abilities, is used to address questions about shifts of highland rain forest habitat during Pleistocene glaciations and about their consequences for haplotype composition and distribution.Location  Tasimia palpata occurs in highland subtropical rain forest patches, which are separated from one another by lowland dry bush, in south‐eastern Queensland, Australia.Methods  We sequenced 375 base pairs of the mitochondrial cytochrome oxidase I gene from 169 individuals (20 populations) of T. palpata, mainly from three fragmented subtropical rain forest blocks, revealing 46 haplotypes. Analysis of molecular variance (amova), genetic divergence between populations, nested clade analyses and tests based on coalescent theory were used to analyse phylogeographical relationships among T. palpata populations.Results  amova indicates spatial genetic structure between isolated subtropical rain forest patches, with an isolation‐by‐distance effect. Tests based on coalescent theory suggest a repeated process of population reductions and divergence between isolated rain forests during Pleistocene glaciations as a consequence of habitat constrictions followed by population expansions during interglacial periods when subtropical rain forest expanded. In addition, these results suggest that, prior to the Pleistocene, rain forest and T. palpata had more widespread distributions in this region.Main conclusions  Historical rain forest expansion and contraction during the Pleistocene resulted in changes in demography and genetic diversity of T. palpata, as well as in an increase in genetic divergence between populations from different patches of subtropical rain forest. Despite the fact that this caddisfly species was isolated in separate highland rain forest patches at various times during the Pleistocene, there is no evidence of allopatric speciation during the Quaternary, which contrasts with other examples of endemism and high diversity in rain forest highlands.