bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vascular endothelial growth factor in allergen‐induced nasal inflammation
Authors: Choi G‐S , Park H‐J , Hur G‐Y , Choi S‐J , Shin S‐Y , Ye Y‐M , Park H‐S 
Published: February 2009

SummaryBackground
Increased vessel number and permeability are important features of the nasal mucosa in allergic rhinitis (AR), and are mediated in part by the cytokine vascular endothelial growth factor (VEGF). Eosinophils are the major effector cells in the nasal secretions of patients with AR during the responses to allergen challenges. To evaluate the involvement of VEGF in nasal allergic inflammation, we monitored the levels of VEGF, eosinophil cationic protein (ECP), and specific antibodies in the nasal lavage fluids (NLFs) of patients with AR in response to Dermatophagoides pteronyssinus (Dpt).Methods
Sixty‐three subjects with sensitization to Dpt were enrolled: 29 patients with AR (group I) who showed positive responses in a nasal provocation test (NPT) with Dpt; and 34 asymptomatic controls (group II) who showed sensitization to Dpt but negative NPT results. NLF samples were collected at baseline, 10, 30, and 60 min, and at 3, 6, and 24 h during the NPT. The ECP levels in the NLF samples were measured using the ImmunoCAP system. VEGF and Dpt‐specific IgE, IgA, and IgG in the NLF samples were detected by ELISA.Results
The eosinophil counts and ECP levels in the samples were significantly increased in group I, but not in group II, during the early and late responses. Although the baseline VEGF level was not significantly different between groups I and II, increased VEGF production was noted in group I after the NPT, especially during the early response. The level of Dpt‐specific IgA was significantly increased in group I during the NPT. A relationship was found between the levels of VEGF and ECP or Dpt‐specific IgA in the NLF samples collected at 10 min and at 3–6 h (P<0.05, respectively).Conclusion
Nasal VEGF secretion in response to allergen exposure may augment eosinophilic inflammation in the nasal mucosa of patients with AR.
Aligned vertical fractures, HTI reservoir symmetry and Thomsen seismic anisotropy parameters for polar media
Authors: Berryman James G. 
Published: February 2009

ABSTRACTCertain crack‐influence parameters of Sayers and Kachanov are shown to be directly related to Thomsen's weak‐anisotropy seismic parameters for fractured reservoirs when the crack/fracture density is small enough. These results are then applied to the problem of seismic wave propagation in polar reservoirs, i.e., those anisotropic reservoirs having two axes that are equivalent but distinct from the third axis), especially for horizontal transversely isotropic seismic wave symmetry due to the presence of aligned vertical fractures and resulting in azimuthal seismic wave symmetry at the Earth's surface. The approach presented suggests one method of inverting for fracture density from wave speed data. A significant fraction of the technical effort in the paper is devoted to showing how to predict the angular location of the true peak (or trough) of the quasi‐SV‐wave for polar media and especially how this peak is related to another angle that is very easy to compute. The axis of symmetry is always treated here as the x3‐axis for either vertical transversely isotropic symmetry (due, for example, to horizontal cracks), or horizontal transversely isotropic symmetry (due to aligned vertical cracks). Then, the meaning of the stiffnesses is derived from the fracture analysis in the same way for vertical transversely isotropic and horizontal transversely isotropic media, but for horizontal transverse isotropy the wave speeds relative to the Earth's surface are shifted by 90o in the plane perpendicular to the aligned vertical fractures. Skempton's poroelastic coefficient B is used as a general means of quantifying the effects of fluids inside the fractures. Explicit Biot‐Gassmann‐consistent formulas for Thomsen's parameters are also obtained for either drained or undrained fractures resulting in either vertical transversely isotropic or horizontal transversely isotropic symmetry of the reservoir.
Vertically fractured transversely isotropic media: dimensionality and deconstruction
Authors: Schoenberg Michael A. 
Published: February 2009

ABSTRACTA vertically fractured transversely isotropic (VFTI) elastic medium is one in which any number of sets of vertical aligned fractures (each set has its normal lying in the horizontal x1, x2‐plane) pervade the medium and the sets of aligned fractures are the only features of the medium disturbing the axi‐symmetry about the x3‐axis implying that in the absence of fractures, the background medium is transversely isotropic (TI). Under the assumptions of long wavelength equivalent medium theory, the compliance matrix of a fractured medium is the sum of the background medium's compliance matrix and a fracture compliance matrix. For sets of parallel rotationally symmetric fractures (on average), the fracture compliance matrix is dependent on 3 parameters − its normal and tangential compliance and its strike direction. When one fracture set is present, the medium is orthorhombic and the analysis is straightforward. When two (non‐orthogonal) or more sets are present, the overall medium is in general elastically monoclinic; its compliance tensor components are subject to two equalities yielding an 11 parameter monoclinic medium. Constructing a monoclinic VFTI medium with n embedded vertical fracture sets, requires 5 TI parameters plus 3×n fracture set parameters. A deconstruction of such an 11 parameter monoclinic medium involves using its compliance tensor to find a background transversely isotropic medium and several sets of vertical fractures which, in the long wavelength limit, will behave exactly as the original 11 parameter monoclinic medium. A minimal deconstruction, would be to determine, from the 11 independent components, the transversely isotropic background (5 parameters) and two fracture sets (specified by 2 × 3 = 6 parameters). Two of the background TI medium's compliance matrix components are known immediately by inspection, leaving nine monoclinic components to be used in the minimal deconstruction of the VFTI medium. The use of the properties of a TI medium, which are linear relations on its compliance components, allows the deconstruction to be reduced to solving a pair of non‐linear equations on the orientations of two fracture sets. A single root yielding a physically meaningful minimum deconstruction yields a unique minimal representation of the monoclinic medium as a VFTI medium. When no such root exists, deconstruction requires an additional fracture set and uniqueness is lost. The boundary between those monoclinic media that have a unique minimal representation and those that do not is yet to be determined.
P‐wave dispersion and attenuation in fractured and porous reservoirs – poroelasticity approach
Authors: Gurevich Boris , Brajanovski Miroslav , Galvin Robert J. , Müller Tobias M. , Toms‐Stewart Julianna 
Published: February 2009

ABSTRACTNatural fractures in hydrocarbon reservoirs can cause significant seismic attenuation and dispersion due to wave induced fluid flow between pores and fractures. We present two theoretical models explicitly based on the solution of Biot's equations of poroelasticity. The first model considers fractures as planes of weakness (or highly compliant and very thin layers) of infinite extent. In the second model fractures are modelled as thin penny‐shaped voids of finite radius. In both models attenuation is a result of conversion of the incident compressional wave energy into the diffusive Biot slow wave at the fracture surface and exhibits a typical relaxation peak around a normalized frequency of about 1. This corresponds to a frequency where the fluid diffusion length is of the order of crack spacing for the first model and the crack diameter for the second. This is consistent with an intuitive understanding of the nature of attenuation: when fractures are closely and regularly spaced, the Biot's slow waves produced by cracks interfere with each other, with the interference pattern controlled by the fracture spacing. Conversely, if fractures are of finite length, which is smaller than spacing, then fractures act as independent scatterers and the attenuation resembles the pattern of scattering by isolated cracks. An approximate mathematical approach based on the use of a branching function gives a unified analytical framework for both models.
Geomechanical simulation to predict open subsurface fractures
Authors: Lewis Helen , Hall Stephen A. , Couples Gary D. 
Published: February 2009

ABSTRACTGeomechanical simulation of the evolution of a geological structure can play an important role in predicting open fracture development for all stages in that structure's development. In this work, three such geomechanical simulations are used to predict the evolving stress and strain fields, including dilational and compactional changes in the rock fabric in developing fault and fold systems. Their consequences for open fracture development and flow are addressed. These simulated stress and strain fields show considerable spatial and temporal heterogeneity that is consistent with deformation patterns observed in both natural examples and in laboratory‐deformed analogues. But the stress and strain states that develop are neither co‐axial nor do they bear a simple relationship to one another. The dilational and compactional strains, manifest as open fracturing or sealing, represent some significantly increased or significantly decreased flow rates. However, open‐fracture predictions based on such geomechanical simulations are extremely difficult to validate with any degree of confidence as there is little direct evidence of sub‐surface fracture distributions. In this context we also discuss possible integration of seismic anisotropy measurements, as an independent measure of open fracture alignment, to support the geomechanically derived fracture predictions. The focus of this work is on volumetric strains in fault zone evolution, though folding is also addressed.
Variable temperature sensitivity of soil organic carbon in North American forests
Authors: FISSORE CINZIA , GIARDINA CHRISTIAN P. , SWANSTON CHRISTOPHER W. , KING GARY M. , KOLKA RANDALL K. 
Published: February 2009

AbstractWe investigated mean residence time (MRT) for soil organic carbon (SOC) sampled from paired hardwood and pine forests located along a 22 °C mean annual temperature (MAT) gradient in North America. We used acid hydrolysis fractionation, radiocarbon analyses, long‐term laboratory incubations (525‐d), and a three‐pool model to describe the size and kinetics of the acid insoluble C (AIC), active and slow SOC fractions in soil. We found that active SOC was 2 ± 0.2% (mean ± SE) of total SOC, with an MRT of 33 ± 6 days that decreased strongly with increasing MAT. In contrast, MRT for slow SOC and AIC (70 ± 6% and 27 ± 6% of total SOC, respectively) ranged from decades to thousands of years, and neither was significantly related to MAT. The accumulation of AIC (as a percent of total SOC) was greater in hardwood than pine stands (36% and 21%, respectively) although the MRT for AIC was longer in pine stands. Based on these results, we suggest that the responsiveness of most SOC decomposition in upland forests to global warming will be less than currently modeled, but any shifts in vegetation from hardwood to pine may alter the size and MRT of SOC fractions.
Spatial modelling of nitrous oxide emissions at the national scale using soil, climate and land use information
Authors: LILLY A. , BALL B. C. , MCTAGGART I. P. , DEGROOTE J. 
Published: February 2009

AbstractNitrous oxide (N2O) is a powerful greenhouse gas. The UK government is committed to reducing all greenhouse gas emissions and is required to make an inventory of the sources and emissions of these gases. Here, we extend work from a pilot study at the catchment scale reported in an earlier paper. This paper reports on the upscaling measurements of emissions to derive annual emission rates for specific combinations of soil type, land management and fertiliser practices to the national scale. Digital soil, climate and land use maps were combined within Geographic Information Systems (GIS) software. Upscaling of field emissions measurements involves adjusting measured annual N2O emissions to fit combinations of crop growth cycles, soil wetness and the amount and timing of fertiliser applications. We have also taken account of the differences in emission rates from grazed pasture land due to differences in land management between land utilised for dairy production and land utilised for beef production. Calculated annual emission rates were then spatially scaled to derive national figures through the use of a GIS modelling framework, termed NitOx. The annual emission of N2O from Scotland was determined as approximately 6 000 000 kg N yr−1 (2.8 Mt carbon dioxide (CO2) equivalents) and compares favourably with other national scale estimates such as the IPCC (1997). The combination of animal grazing, high N inputs, climatic warmth and poorly drained soils means that the south west contributes significantly to the national total N2O emissions. Localised areas of high emission can also be identified, but identification could be improved by applying this modelling approach at a larger scale. It would be beneficial to target these areas with mitigation strategies.
Biogeographical patterns of marine larval trematode parasites in two intermediate snail hosts in Europe
Authors: Thieltges David W. , Ferguson MacNeill A. D. , Jones Cathy S. , Noble Leslie R. , Poulin Robert 
Published: February 2009

AbstractAim  We used published inventories of trematodes in Littorina littorea (L.) and Hydrobia ulvae (Pennant) in European seas to search for two basic biogeographical patterns in the spatial occurrence of various trematode species: (1) do parasite distribution and richness patterns in the two host snails overlap with known ecoregions of free‐living organisms; and (2) does trematode species richness in the snails follow latitudinal or longitudinal gradients?Location  North East Atlantic.Methods  We used multidimensional scaling (MDS), analysis of similarity (ANOSIM) and analysis of variance (ANOVA) to test whether there were overlaps of parasite distribution and richness with known ecoregions of free‐living organisms. In addition, we used linear regression analyses to test whether trematode richness in snails (corrected for sampling effort) was correlated with the latitude or longitude of the sampling sites.Results  When corrected for sampling effort, mean trematode species richness per site did not differ among the different ecoregions in L. littorea. In contrast, in H. ulvae, mean species richness was much lower for sites from the Celtic Sea compared with sites from the Baltic Sea and the North Sea. Based on the results of MDS analyses, trematode species composition was distinct among ecoregions; in particular, communities from the Baltic Sea differed markedly from communities in the Celtic Sea, for both snail species. Latitude and longitude were not significantly correlated with parasite species richness in either snail species. Most trematode species had restricted distributions, and only three species in L. littorea and five species in H. ulvae occurred at more than 50% of the sites.Main conclusions  There is more structure in the large‐scale distribution of trematodes in gastropods than one would expect from the large‐scale dispersal capabilities of their bird and fish final hosts. We propose mechanisms based both on limited dispersal via fish and bird final hosts and on gradients in environmental factors to explain the observed patterns.
Prospects and challenges for parametric models in historical biogeographical inference
Authors: Ree Richard H. , Sanmartín Isabel 
Published: February 2009

AbstractIn historical biogeography, phylogenetic trees have long been used as tools for addressing a wide range of inference problems, from explaining common distribution patterns of species to reconstructing ancestral geographic ranges on branches of the tree of life. However, the potential utility of phylogenies for this purpose has yet to be fully realized, due in part to a lack of explicit conceptual links between processes underlying the evolution of geographic ranges and processes of phylogenetic tree growth. We suggest that statistical approaches that use parametric models to forge such links will stimulate integration and propel hypothesis‐driven biogeographical inquiry in new directions. We highlight here two such approaches and describe how they represent early steps towards a more general framework for model‐based historical biogeography that is based on likelihood as an optimality criterion, rather than having the traditional reliance on parsimony. The development of this framework will not be without significant challenges, particularly in balancing model complexity with statistical power, and these will be most apparent in studies of regions with many component areas and complex geological histories, such as the Mediterranean Basin.
Multi‐stemmed trees in montane rain forests: their frequency and demography in relation to elevation, soil nutrients and disturbance
Authors: Bellingham Peter J. , Sparrow Ashley D. 
Published: February 2009

Summary

Multi‐stemmed trees are a common component of tropical and temperate montane rain forests, where they co‐occur with single‐stemmed trees. We hypothesized that multi‐stemmed architecture should predominate in less productive sites (such as at high elevation or with low soil nutrient availability) and that, because it frequently results from sprouting, it should prevail in sites that are frequently disturbed. We also hypothesized that where multi‐stemmed architecture predominates, there should be lower rates of mortality and recruitment of individuals.
We tested these hypotheses using data from permanent plots in tropical montane rain forests in Jamaica (14 years) and in temperate montane rain forests in New Zealand (19 years). The frequency of multi‐stemmed trees varied across plots in both forests (4–34% in Jamaica; 0–21% in New Zealand) along gradients of elevation and soil nutrients.
Analyses examined the direct and indirect effects of the various environmental variables that are likely to drive site productivity and disturbance. We showed contrasting predictors of the frequency of multi‐stemmed trees in the tropical and temperate forests. Multi‐stemmed trees in Jamaican forests were most frequent on sites of low soil nutrient status (especially available soil phosphorus, P) whereas in New Zealand they were most frequent at high elevation sites, especially towards tree line. In both forests there was no relationship between multi‐stemmed tree frequency and slope.
Turnover (the mean of mortality and recruitment rates) of multi‐stemmed trees in Jamaican forests was lowest on sites of low soil nutrient status (especially available P) but was unrelated to environmental predictors in New Zealand. In both forests, turnover rates of multi‐stemmed trees overall were 60% lower than those for co‐occurring single‐stemmed trees, offering support for the hypothesis that multi‐stemmed architecture favours persistence.
Synthesis. Our study demonstrates that multi‐stemmed trees can predominate in low productivity sites in montane rain forests. Their low turnover compared with co‐occurring single‐stemmed trees confirms the importance of evaluating the persistence niche as a mechanism promoting woody species coexistence in forests.
Streptococcosis on a red tilapia, Oreochromis sp., farm: a case study
Authors: Hernández E , Figueroa J , Iregui C 
Published: February 2009

AbstractA commercial red tilapia farm was diagnosed with Streptococcus agalactiae infection using histopathology, microbiology and immunohistochemistry. One hundred fish were randomly taken from different weight/age groups including broodstock, market fish (larger than 150 g), on‐growing fish between 20 and 150 g, juveniles and larvae. Fish were clinically examined, anaesthetised and necropsied. Samples were taken from brain, liver, spleen, eyes and kidney for microbiology. All organs were processed for histopathology and an indirect immunoperoxidase test (IIP). Organs from wild fish and birds found in close proximity to the farm were also sampled for microbiology and IIP. The prevalence of lesions or infection found by IIP, histopathology and microbiology was 16%, 29% and 7% respectively. Clinical disease, lesions or infection were not seen in larvae or juveniles. By contrast, infection and disease were found in fish larger than 20 g, suggesting that the condition was linked to the intensive culture conditions of broodstock, on‐growing and market fish. S. agalactiae was not found in wild fish, or in birds, by microbiology and IIP.
Delivering oxytetracycline to first‐feeding zebrafish, Danio rerio (Hamilton), and goby, Asterropteryx semipunctata Rüppell, larvae using lipid spray beads
Authors: Temple E , Langdon C 
Published: February 2009

AbstractLipid spray beads (LSB) were evaluated for delivery of the low‐molecular weight, water‐soluble antibiotic, oxytetracycline·HCl (OTC) to fish larvae. Various OTC core‐to‐lipid ratios and OTC core concentrations were evaluated to maximize OTC delivery efficiency by LSB. Acceptability and digestion of LSB containing OTC and riboflavin by larval zebrafish, Danio rerio (Hamilton), and larval gobies, Asterropteryx semipunctata Rüppell, were also evaluated. Increasing LSB core‐to‐lipid ratios from 1:3 to 1:1 v/v resulted in an increase in encapsulation efficiency (EE) from 2.33 to 3.68% w/w. Increasing OTC concentrations of core solutions from 0.1 to 0.5 g OTC mL−1 increased EE from 3.95 to 18.77% w/w, respectively. Although retention efficiency (RE) was unaffected by this increase, delivery efficiency was increased to 7.9 ± 0.7% w/w, after correcting for leakage losses because of the suspension of beads in water for 60 min. Consumption of LSB containing OTC by first‐feeding zebrafish and goby larvae was confirmed by analysis of feeding incidence and gut fullness. Visual observations of larvae fed on LSB containing riboflavin indicated that larvae of both species digested LSB. Zebrafish larvae fed on OTC LSB contained 39.3 ± 2.5 ng OTC after purging LSB from their guts. Use of LSB provides an effective means of delivering therapeutics to fish larvae and could greatly reduce required doses compared with current methods of immersing larvae in solutions of therapeutic agents.