bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Mechanical Stability of a Commercial Sn88 Silicon Nitride at Intermediate Temperatures
Authors: Lin Hua‐Tay , Ferber Mattison K. , Kirkland Timothy P.
Published: July 2009

Dynamic fatigue and stress rupture tests in four‐point bending were conducted on a commercially available SN88 silicon nitride ceramic at temperatures in the range 700°–1000°C in air. The objective of the present study was to elucidate the failure of SN88 silicon nitride ceramic nozzles arising from a critical crack initiated at the intermediate temperature airfoil region during an engine field test. Results of dynamic fatigue tests indicated that SN88 silicon nitride tested at a stressing rate of 30 MPa/s exhibited little change in characteristic strength at the various test temperatures. However, SN88 silicon nitride exhibited a significant degradation in mechanical strength when tested at 0.003 MPa/s at temperatures indicative of a great susceptibility to slow crack growth, especially at 850°C. SEM and XRD analyses indicated that the mechanical instability of SN88 silicon nitride at intermediate temperatures resulted from the transformation of secondary phase(s) from oxidation. These phase transformations were accompanied by a large volume change, which led to the generation of large local residual tensile stresses. As a result, extensive damage zones were formed, which led to a substantial degradation of mechanical strength and reliability. Microstructural examination of failed SN88 airfoils indicated that a similar damage zone was formed in the regions exposed to intermediate temperatures during engine testing. Consequently, the ultimate failure of these vanes was attributed to the loss in mechanical strength from the damage zone formation.
Green Fabrication of Porous Ceramics Using an Aqueous Electrophoretic Deposition Process
Authors: Nakahira Atsushi , Nishimura Fumihide , Kato Shinji , Iwata Misao , Takeda Shinichi
Published: July 2009

We prepared porous ceramic depositions using gas generation in an aqueous electrophoretic deposition (EPD) process. Especially, this aqueous EPD process in combination with a sintering step could advantageously result in unique porous deposition containing many unidirectionally aligned continuous pores. The aqueous EPD process has environmental and cost reduction advantages.
Phase Formation and Microstructure of Titanium Oxides and Composites Produced by Thermal Plasma Oxidation of Titanium Carbide
Authors: Ishigaki Takamasa , Li Ya‐Li , Kataoka Eiji
Published: July 2009

The phase formation and microstructure of titanium oxides and composites produced by Ar–O2 thermal plasma oxidation of titanium carbide powders were investigated in detail by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). Relationships between the phase compositions and microstructures of the oxides were established by combined structural and phase analyses, in correlation with synthesis conditions and phase formation mechanisms. It is revealed that vapor condensation favored the formation of anatase, which existed as smaller particles, while liquid/solid oxidation favored the formation of rutile, which appeared as larger particles or composites. A higher oxygen input in the plasma gases (Ar + O2) enhanced the formation of anatase due to impeded oxidation and evaporation. A small amount of Ti4O7 and Ti3O5 was detected in the larger particles coexisting with rutile or TiC. These suboxides were formed as intermediates in solid oxidation of TiC or precipitated from the Ti–C–O melt during cooling. Furthermore, extensive cracks, dislocations and stresses were observed in the monolithic rutile and composites, in association with the rapid quenching in this high‐temperature in‐flight oxidation process.
Synthesis of Bismuth Sodium Titanate Nanosized Powders by Solution/Sol–Gel Process
Authors: Kim Chang Yeoul , Sekino Tohru , Niihara Koichi
Published: July 2009

(Bi1/2Na1/2)TiO3 (BNT) is a prominent candidate for a lead‐free piezoelectric material. In this study, BNT was synthesized using the solution/sol–gel method, in which a solution of Bi2O3 and Na2CO3 was dissolved in HNO3 as starting materials. The solution then was mixed with ethylene glycol and titanium tetraisopropoxide. The obtained BNT powder was analyzed using FT‐IR, DTA‐TG, Raman spectroscopy, and high‐temperature XRD. Results showed that BNT crystallization occurred above 600°C. TEM investigation showed that 100–200 nm BNT particles were formed by heat‐treating the sol–gel‐derived BNT sol at 700°C for 6 h.
Wet‐Chemical Routes Leading to Scandia Nanopowders
Authors: Li Ji‐Guang , Ikegami Takayasu , Mori Toshiyuki , Yajima Yoshiyuki
Published: July 2009

Two wet‐chemical routes have been used to synthesize Sc2O3 nanopowders from nitrate solutions employing ammonia water (AW) and ammonium hydrogen carbonate (AHC) as the precipitants. The precursors and the resultant oxides are characterized by elemental analysis, X‐ray diffractometry, differential thermal analysis/thermogravimetry, high‐resolution scanning electron microscopy, and Brunauer‐Emmett‐Teller analysis. Crystalline γ‐ScOOH·nH2O (n≈ 0.5) is the only phase obtained by the AW method. This phase dehydrates to Sc2O3 at ∼400°C, yielding hard aggregated nanocrystalline Sc2O3 powders. Three types of precursors have been synthesized by the AHC method, depending on the AHC/Sc3+ molar ratio (R): amorphous basic carbonate [Sc(OH)CO3·H2O] at R≤ 3, crystalline double carbonate [(NH4)Sc(CO3)2·H2O] at R≥ 4, and a mixture of the two phases at 3 < R < 4. Among these precursors, only the basic carbonate shows spherical particle morphology, ultrafine particle size (∼50 nm), and weak agglomeration. Sc2O3 nanopowders (∼28 nm) with high surface area (∼49 m2/g) have been prepared by calcining the basic carbonate at 700°C for 2 h.
Zeolite Synthesized by Alkaline Hydrothermal Treatment of Bottom Ash from Combustion of Municipal Solid Wastes
Authors: Penilla R. Peña , Bustos A. Guerrero , Elizalde S. Goñi
Published: July 2009

The conversion of bottom ash from fluidized‐bed combustion of municipal solid waste (MSW) to zeolite, by means of alkaline hydrothermal treatment (HT), in 1M NaOH solution, is presented in this work. The transformation of the bottom ash was characterized by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, surface area (BET‐N2), and scanning electron microscopy (SEM) analyses. As a result of the HT at 100°C, Na6[AlSiO4]6·4H2O, of the structural family of zeolites, together with Ca3AlFe(SiO4)(OH)8, of the structural family of hydrogarnets, began to appear; the surface area of the bottom ash increased 11 times. At 150°C, the amount of Na6[AlSiO4]6·4H2O increased and andradite, hydroxylian (Ca3Fe2(SiO4)3−x(OH)4−x), of the structural family of garnet, was formed. After 200°C of HT, Na6[AlSiO4]6·4H2O was massively formed together with aluminum tobermorite (Ca5Si5Al(OH)O17·5H2O); Ca3AlFe(SiO4)(OH)8 decreased. The surface area of the bottom ash increased 13 times. The conversion of bottom ash in zeolite is considered of great significance, opening new opportunities for stabilization and applications of this type of waste. Zeolite and also the other compounds—aluminum tobermorite, andradite, and Ca3AlFe(SiO4)(OH)8—can substitute a variety of ionic species, which allows the bottom ash to be useful for immobilizing toxic and radioactive wastes. An equivalent study was conducted in water instead of NaOH as a reference.
Influence of Residual Stresses on the Wear Behavior of Alumina/Alumina–Zirconia Laminated Composites
Authors: Toschi Francesco , Melandri Cesare , Pinasco Paola , Roncari Edoardo , Guicciardi Stefano , de Portu Goffredo
Published: July 2009

Symmetric structures of laminated ceramic composites were produced by superimposing alternating layers of Al2O3 and Al2O3/ZrO2 composite prepared by tape casting. The composites were designed to have an alumina surface layer on either side. This configuration caused residual compressive stresses to be induced on the surface due to the different thermal expansion coefficients of the various layers, leading to an increase in the apparent surface toughness. The amount of residual stress was determined using the indentation technique. The tribological behavior of these laminated structures was evaluated using the pin‐on‐disk method for different loads and sliding speeds. Comparison with the results obtained from stress‐free alumina showed that, within the range of these experimental conditions, the improvement in surface toughness leads to a reduced friction coefficient and increased wear resistance of the composites. Possible wear mechanisms are proposed.
Effect of PO2 on Bulk and Grain Boundary Resistance of n‐Type BaTiO3 at Cryogenic Temperatures
Authors: Kolodiazhnyi Taras , Petric Anthony
Published: July 2009

Complex impedance analysis at cryogenic temperatures has revealed that the bulk and grain boundary properties of BaTiO3 polycrystals are very sensitive to the oxygen partial pressure during sintering. Polycrystals sintered at PO2 as low as 10−15 atm were already electrically heterogeneous. The activation energy of the bulk conductivity in the rhombohedral phase was found to be close to that of the reduced undoped single crystal (i.e., 0.093 eV). The activation energy of the grain boundary conductivity increases with the temperature of the postsinter oxidation treatment from 0.064 to 0.113 eV. Analysis of polycrystalline BaTiO3 sintered in reducing atmosphere and then annealed at PO2= 0.2 atm has shown that the onset of the PTCR effect occurs at much higher temperatures than expected in the framework of the oxygen chemisorption model. The EPR intensity of barium and titanium vacancies increases after oxidation at T > 1000°C. A substantial PTCR effect is achieved only after prolonged annealing of the ceramic in air at temperatures as high as 1200–1250°C. This result suggests that the PTCR effect in polycrystalline BaTiO3 is associated with interfacial segregation of cation vacancies during oxidation of the grain boundaries.
Properties of Lead Zirconate Titanate Thin Films Prepared Using a Triol Sol–Gel Route
Authors: Naksata Manoch , Brydson Rik , Milne Steven John
Published: July 2009

Microstructure and phase development during the thermal decomposition of sol–gel precursor coatings of PbZr0.53Ti0.47O3 on platinized silicon substrates have been investigated for a triol sol–gel route. The single‐layer, 0.4 μm PZT films were heated from below the substrate, over the temperature range 350–600°C, using a calibrated hot plate. The first crystalline phase to appear was a PbPt3 intermetallic phase at the Pt/PZT interface. Although perovskite PZT formed at ca. 500°C, heating at higher temperatures, for example 550°C for 30 min, was required to develop ferroelectric hysteresis loops. However, the rather low value of remanent polarization, Pr= 11 μC·cm−2, was consistent with incomplete crystallization at 550°C. The values of remanent polarization increased with increasing processing temperatures, reaching 21 μC·cm−2 for samples heated at 600°C, with a corresponding Ec value of 57 kV·cm−1. Distinctive spherical precipitates up to ca. 50 nm in size have been identified by TEM in the lower portions of otherwise amorphous coatings, after heating at around 350–400°C. Although their precise composition could not be identified, they were mostly Pb‐rich, and it is speculated that they form due to reduction of some of the lead(II) acetate starting reagent, to atomic Pb during the early stages of thermal decomposition of the organic components of the gel; it is possible that subsequent reactions occur to form lead oxides or carbonates. High levels of porosity were present in many of the fully crystallized films. The possible reasons for this are discussed.
CeO2−CoO Phase Diagram
Authors: Chen Ming , Hallstedt Bengt , Grundy A. Nicholas , Gauckler Ludwig J.
Published: July 2009

Phase equilibria in the CeO2−CoO system at temperatures above 1500°C were investigated. The microstructures and the phase compositions of the DTA (differential thermal analysis) samples and the quenched solid pellets were analyzed using SEM (scanning electron microscope), EDX (energy dispersive X‐ray), and WDX (wavelength dispersive X‐ray). A eutectic reaction was found at 1645 ± 5°C. The eutectic point was calculated to be at 82 ± 1.5 mol% CoO. The eutectic phases were the CeO2‐rich phase (containing <5 mol% CoO) and the CoO‐rich phase (containing ∼0.5 mol% CeO2). At 1580°C, the solubility of CoO in CeO2 was ∼3 mol%.
Anatase Sol Prepared from Peroxotitanium Complex Aqueous Solution Containing Niobium or Vanadium
Authors: Ichinose Hiromichi , Taira Masanori , Furuta Sachiko , Katsuki Hiroaki
Published: July 2009

Niobium‐ or vanadium‐doped anatase sols were prepared by hydrothermal treatment of 0.1 mol/dm3 peroxotitanium complex aqueous solutions dissolving 0–10 mol% niobium or vanadium at 100°C for 8 h. Niobium‐doping caused the increase of lattice constants of anatase and the shape change of anatase crystal from spindle‐like to cubic‐like structure, but no change of the optical absorbance. Vanadium‐doping caused the decrease of lattice constant of c‐axis, the miniaturization of anatase crystal and the increase of optical absorbance at the wavelength from 350–700 nm.
Combined Spectroscopic and Thermodynamic Investigation of Nextel‐720 Fiber/Alumina Ceramic‐Matrix Composite in Air and Water Vapor at 1100°C
Authors: Wannaparhun Surasak , Seal Sudipta
Published: July 2009

The high‐temperature performance of a Nextel‐720 fiber/Al2O3 composite in air and water vapor at 1100°C was investigated using X‐ray photoelectron spectroscopy (XPS) and thermodynamic calculations. In the presence of water vapor, the formation of volatile Si(OH)4 was responsible for the loss of mullite phase in the fiber of the ceramic‐matrix composite (CMC). XPS analysis revealed the formation of surface aluminosilicates for the water‐vapor‐exposed CMC for 1000 h.
Microwave Plasma Synthesis of Nanostructured γ‐Al2O3 Powders
Authors: Fu L. , Johnson D. Lynn , Zheng Jian G. , Dravid Vinayak P.
Published: July 2009

Nanostructured Al2O3 powders have been synthesized by combustion of aluminum powder in a microwave oxygen plasma, and characterized by X‐ray diffraction and electron microscopy. The main phase is γ‐Al2O3, with a small amount of δ‐Al2O3. The particles are truncated octahedral in shape, with mean particle sizes of 21–24 nm. The effect of reaction chamber pressure on the phase composition and the particle size was studied. The γ‐alumina content increases and the mean particle size decreases with decreasing pressure. No α‐Al2O3 appears in the final particles. Electron microscopy studies find that a particle may contain more than one phase.
Common genetic variants in candidate genes and risk of familial lymphoid malignancies
Authors: Liang Xueying (Sharon) , Caporaso Neil , McMaster Mary Lou , Ng David , Landgren Ola , Yeager Meredith , Chanock Stephen , Goldin Lynn R.
Published: July 2009

Familial aggregation, linkage and case–control studies support the role of germline genes in the aetiology of lymphoid malignancies. To further examine the role of genetic variation underlying susceptibility, we analysed 1536 single nucleotide polymorphisms in 152 genes involved in apoptosis, DNA repair, immune response and oxidative stress pathways among a unique sample of 165 unrelated familial cases including patients with chronic lymphocytic leukaemia (CLL), Waldenström macroglobulinaemia (WM) and Hodgkin lymphoma (HL), and 107 spouse controls. We confirmed previous studies showing a polymorphism in the IL10 promoter (rs1800890/‐3575T>A) to be associated with non‐Hodgkin lymphoma, as this allele was found to be associated with both CLL and WM. We also confirmed the role of IL6 variation to be associated with HL. Polymorphisms in TNFSF10 were associated with both CLL and WM. Future replication and functional studies are needed to clarify the role of these genetic variants. Finally, our data further support the close association of WM and CLL.
Simulation of physically mediated variability in prey resources of a larval fish: a three‐dimensional NPZ model
Authors: HINCKLEY S. , NAPP J. M. , HERMANN A. J. , PARADA C.
Published: July 2009

A three‐dimensional biophysical nutrient–phytoplankton–zooplankton model was used to investigate the spatial and temporal dynamics of food resources for young walleye pollock in the western Gulf of Alaska, to further understanding of recruitment processes for pollock. We modeled nitrogen, phytoplankton, a large herbivorous grazer parameterized as Neocalanus spp. (the biomass dominant copepod in the Gulf), and the 13 stages (egg, naupliar and copepodite) of Pseudocalanus spp. (a major constituent of the diet of pollock) so that the appropriate size class of food for each size of larval pollock was represented. Model results identified an area between the Semidi and Shumagin Islands that may not be suitable as a nursery area early in the year due to low prey abundance. Modeled mesoscale eddies, previously hypothesized to be important for larval pollock retention in Shelikof Strait, contained higher prey concentrations than the surrounding waters when they were cyclonic. This work also help to understand the consistency of pollock spawning in time and space in Shelikof Strait, by examining the timing and location of prey availability which, along with transport, narrows the window for optimal spawning.
Evaluating diel, ontogenetic and environmental effects on larval fish vertical distribution using Generalized Additive Models for Location, Scale and Shape
Authors: HERNANDEZ FRANK J. , HARE JONATHAN A. , FEY DARIUSZ P.
Published: July 2009

Changes in ichthyoplankton vertical distributions can have important consequences with respect to larval transport and survivorship, yet determining the relative importance of environmental influences on vertical migrations in a statistically meaningful framework remains challenging. Here we use Generalized Additive Models for Location, Scale and Shape (GAMLSS) and Akaike Information Criteria (AIC) to model the vertical distribution of larval Urophycis regia collected over a 108‐h time series on the Mid‐Atlantic Bight shelf. Depth was the response variable weighted by two measures of larval abundance: concentrations (number 100 m−3) and proportions at depth. Mean and variance of depth were modeled as a function of time, wind stress, current velocity, water column stratification and ontogeny. Model results indicated a large effect of stage for both concentration‐ and proportion‐based analyses. Subsequent and separate analyses on preflexion and postflexion U. regia indicated a differential response to the environmental parameters based on ontogeny. Model results suggested preflexion U. regia do not have a diel pattern in vertical distribution, but do avoid areas of high surface turbulence related to wind stress. In contrast, postflexion larvae have a significant diel pattern of vertical distribution mediated by surface turbulence (increased variance). The statistical approaches applied here offer the potential to evaluate the effect of multiple factors on vertical distribution and have provided significant insight into the factors that influence the vertical distribution of spotted hake larvae.
Distribution and migration of age‐0 jack mackerel (Trachurus japonicus) in the East China and Yellow Seas, based on seasonal bottom trawl surveys
Authors: SASSA CHIYUKI , YAMAMOTO KEISUKE , TSUKAMOTO YOUICHI , KONISHI YOSHINOBU , TOKIMURA MUNEHARU
Published: July 2009

We examined the distribution and migration of age‐0 jack mackerel in the East China Sea (ECS) and Yellow Sea, based on data from seasonal bottom trawl surveys. Sampling was conducted at 79–161 stations during five cruises in spring (April–June), early summer (May–July), late summer (August–October), autumn (October–December), and winter (January–February). During early summer, jack mackerel (mean 92 mm fork length), which were estimated to have hatched in the southern East China Sea (SECS) during winter, began to occur abundantly, especially along the shelf‐break region of the central East China Sea (CECS). In late summer, the distribution center of young fish (mean 126 mm) shifted northward into the shelf region of northern East China Sea (NECS), corresponding with the rise of bottom water temperature and high prey abundance. In winter when the bottom water temperature declined in the shelf region, the distribution center of jack mackerel (mean 144 mm) shifted southward, with high densities occurring in the SECS and CECS. In spring, overwintering jack mackerel that had become age‐1 (mean 175 mm) were distributed abundantly along the shelf‐break region of the ECS. On the other hand, jack mackerel were only sporadically found, generally at low densities, in the Yellow Sea during all seasons. High densities of jack mackerel were largely restricted to areas of >15°C bottom water temperature during all seasons. Our results indicate that the seasonal shifts of the 15°C isotherm of the bottom layer and the food conditions are significant environmental factors determining the migration of jack mackerel within the ECS.
Habitat preferences of selected demersal fish species in the Bay of Biscay and Celtic Sea, North‐East Atlantic
Authors: PERSOHN CECILE , LORANCE PASCAL , TRENKEL VERENA M.
Published: July 2009

According to the Ideal Free Distribution theory, individual fish are distributed where environmental conditions are optimal, and the occupied area may vary with population abundance. Thus, observed distributions are a combination of habitat suitability and density‐dependent effects. Data from an annual bottom trawl survey taking place in autumn were used to assess associations between the distributions of eight demersal fish species, separately for juveniles and adults, and habitat characteristics (depth, temperature and salinity) in the Bay of Biscay and Celtic Sea. Cumulative distribution functions were used to describe the general frequency distributions of environmental variables and their relationships with fish density. During the period 1992–2006, observed bottom temperatures fluctuated with no time trend (ΔT = 8°C in the first 80 m) and population abundances varied significantly. Juvenile hake, poor cod, blue whiting, adult red gurnard, adult megrim, and lesser‐spotted dogfish were found to be significantly associated with specific depth ranges. Associations with bottom temperature and salinity were weaker. For some species, preferred environmental conditions changed over time, independently of variations in environmental conditions. In general, most species seemed to be able to cope with the experienced range of conditions. Habitat associations were not influenced by abundance variations. Fluctuating abundances had an impact on spatial occupation only for red gurnard adults, lesser‐spotted dogfish and blue whiting juveniles, independent of absolute densities.
A new method to measure carbon isotope composition of CO2 respired by trees: stem CO2 equilibration
Authors: Ubierna Nerea , Marshall John D. , Cernusak Lucas A.
Published: July 2009

1. Applying Keeling plot techniques to derive δ13C of respiratory input in a closed non‐equilibrated chamber can lead to large errors because steady‐state diffusion rules are violated in a non‐steady‐state environment. To avoid these errors, respiratory δ13C can be derived using equilibrated closed chambers.

2. We introduce a new method to obtain stem respired CO2δ13C (δst‐r) with closed equilibrated stem chambers (E‐SC). We present a theoretical model describing the equilibration process, test the model against field data and find excellent agreement. The method is further tested by comparing it with closed non‐equilibrated stem chambers (NE‐SC); we found no difference between these methods.

3. Our theoretical model to describe CO2 diffusion from the respiratory pool into the chamber and the equation to derive the δ13C of the efflux are general. They could be applied to other ecosystem components (e.g. soils).

4. Our method is easy to implement, cost effective, minimizes sources of error and allows for rigorous leak detection. One major limitation is its inability to detect rapid change; the equilibration process requires 15 ± 2 h. A second limitation is that it cannot be used for species that produce abundant pitch at sites of stem wounding (e.g. Pseudotsuga menziesii).

5. Investigating δ13C of CO2 respired by different ecosystem components is necessary to interpret δ13C of ecosystem respiration. This parameter has major implications with respect to global carbon cycle science.
Altitudinal and environmental variation in lifespan in the Copper butterfly Lycaena tityrus
Authors: Karl Isabell , Fischer Klaus
Published: July 2009

1. Variation in longevity within and between natural populations is widespread, and understanding the relative importance of environmental and genetic factors as well as their interactions in mediating such variation is crucial in longevity research.

2. In this study lifespan of adult copper butterflies was examined in relation to altitude, temperature (20 and 27 °C), sex and adult feeding.

3. As expected, longevity increased with decreasing temperature, and sucrose‐fed butterflies had longer lifespans compared to water‐fed and finally non‐fed individuals. The impact of feeding, especially of having access to water or not, was larger at the higher compared to the lower temperature.

4. Regarding altitudinal patterns, increased lifespan in high‐altitude populations was largely restricted to beneficial feeding conditions, while under carbohydrate deprivation low‐altitude animals lived longer, suggesting that low‐altitude butterflies do better under food stress.

5. Differences in longevity between sexes were small at 20 °C, while females lived substantially longer than males at the higher temperature. Consequently, females may be less susceptible to high temperature stress than males. Further, males suffered more from food stress than females, suggesting that females are generally more stress resistant than males.

6. Using a full factorial design, this study demonstrates that variation in longevity is caused by several factors, and additionally by substantial interactive effects. Consequently, patterns of variation in longevity are complex, and one needs to be cautious when neglecting this source of variation, by focussing on individual factors only.
When fathers make the difference: efficacy of male sexually selected antimicrobial glands in enhancing fish hatching success
Authors: Pizzolon Matteo , Giacomello Eva , Marri Laura , Marchini Daniela , Pascoli Francesco , Mazzoldi Carlotta , Rasotto Maria Berica
Published: July 2009

1. Egg and offspring resistance to pathogens is a major determinant of survival and has been mainly ascribed to maternal factors. However, paternal production of antimicrobials was recently suggested to increase offspring survival in species where males perform egg care.

2. In the peacock blenny, Salaria pavo, a demersal spawning species where males exhibit a pair of anal glands producing lysozyme‐like compounds, we tested the antimicrobial activity and the egg protection efficacy of these glands. The anal gland secretion (AGS) has an inhibitory effect on the growth of both Gram‐negative and Gram‐positive bacteria, including those causing the most severe fish diseases in marine culture. The egg clutches cared for by males deprived of anal glands have a significantly lower survival rate than those cared for by sham‐operated males and non‐viable eggs showed clear signs of bacterial infection.

3. Anal gland secretion production and its protein content are proportional to gland size. In species where male parental care plays a crucial role in offspring survival, females are expected to assess mates selecting those traits that are reliably associated with parental ability. Hence, we experimentally challenged females with dummy males differing in anal gland size. Females definitely preferred dummy males with larger anal glands, suggesting that their choice is driven by the pursuit of direct fecundity benefits.

4. These findings indicate that antimicrobial production is a crucial component of male parental care. The contribution of antimicrobials to male performance as fathers suggests that the development of traits devoted to this function may influence male attractiveness and be sexually selected.
Impact of altering the water table height of an acidic fen on N2O and NO fluxes and soil concentrations
Authors: GOLDBERG STEFANIE DANIELA , KNORR KLAUS‐HOLGER , BLODAU CHRISTIAN , LISCHEID GUNNAR , GEBAUER GERHARD
Published: July 2009

The impact of experimentally intensified summer drought and precipitation on N2O and NO turnover and fluxes was investigated in a minerotrophic fen over a 2‐year period. On three treatment plots, drought was induced for 6 and 10 weeks by means of roofs and drainage and decreased water table levels by 0.1–0.3 m compared with three nonmanipulated control plots. When averaged over the three treatment plots, both N2O and NO emission showed only little response to the drought. On the single plot scale, however, a clear impact of the treatment on N2O and NO fluxes could be identified. On the plot with the weakest water table reduction hardly any response could be observed, while on the plot with the greatest drainage effect, N2O and NO fluxes increased by 530% and 270%, respectively. Rewetting reduced NO emissions to background levels (0.05–0.15 μmol m−2 h−1), but heavily enhanced N2O emission (18–36 μmol m−2 h−1) for several days in the plots with largest water table reduction. These peaks contributed up to 40% to the cumulative N2O fluxes and were caused by rapid N2O production according to isotope abundance data. According to N2O concentrations and isotope abundance analysis N2O was mostly produced at depths between 0.3 and 0.5 m. During water table reduction net N2O production in 0.1 m depth steadily increased in the most effectively dried plot from 2 up to 44 pmol cm−3 day−1. Rewetting immediately increased net N2O production in the topsoil of the drought plots, showing rates of 18–174 pmol cm−3 day−1. This study demonstrates that drought and rewetting can temporarily increase N2O emission to levels that have to date only been reported from nutrient rich and degraded fens that have been drained for agricultural purposes.
Sustained predation effects of hatchery‐reared transgenic coho salmon Oncorhynchus kisutch in semi‐natural environments
Authors: Sundström L. Fredrik , Tymchuk Wendy E. , Lõhmus Mare , Devlin Robert H.
Published: July 2009

1. The potential risks of accidental or intentional introduction of transgenic organisms to nature are unknown. We have previously shown that, after being reared in the hatchery, growth hormone transgenic coho salmon Oncorhynchus kisutch can exert a stronger predation effect on natural prey under simulated natural conditions compared with hatchery‐reared genetically wild conspecifics. However, when reared in a simulated natural environment, the difference between the two genotypes was greatly reduced.

2. Here, we tested if the difference in predation rate between the two genotypes after being reared in the hatchery diminishes with time spent in a simulated natural environment. Genetically wild coho salmon reared in the hatchery were size matched to younger satiation‐fed (fast‐growing) and same age restricted‐fed (growth rates matched to wild‐type) transgenic fish. These three types of predators were released into simulated natural habitats and their effects on prey survival and growth were monitored over a 2‐month period.

3. Restricted‐fed, but not satiation‐fed, transgenic predators consumed significantly more prey (×2·7) relative to wild predators during the first month, with an increase to 3.8 times during the second period. Prey biomass decreased more in the presence of restricted‐fed predators during the first period, but a faster growth of these prey during the second period compensated for the higher predation rate resulting in no significant difference in prey biomass among predators after 2 months. Transgenic predators grew more in length than wild type, but all three types converged in weight and condition over time.

4. 
Synthesis and applications. Behavioural phenotypes developed in the hatchery showed little plasticity after release. Hence, development of policy on the use of transgenic organisms must incorporate knowledge of the effect of environmental conditions, experienced by the organism prior to escape or release, on phenotype. The risk posed by culture‐reared organisms may depend on the frequency of escapes, number of individuals escaping and age of escapees. Important to note is that wild‐reared organisms may be biologically different from culture‐reared and thus require separate evaluation. Our results will be important for science policy makers and regulators to consider when deciding whether to allow commercial application of transgenic species in aquaculture.
Contemporary ecological threats from historical pollution sources: impacts of large‐scale resuspension of contaminated sediments on sessile invertebrate recruitment
Authors: Knott Nathan A. , Aulbury Joel P. , Brown Trevor H. , Johnston Emma L.
Published: July 2009

Historical contamination continues to pose a serious ecological threat to many ecosystems across the world. Marine sediments have long acted as sinks for contaminants from surrounding industry and urbanization, and sediment‐bound contaminants are known to affect the ecology of sediment infauna. When sediments are disturbed, however, contaminants are resuspended and potentially released into the water‐column and dispersed to other environments. The threat posed by the resuspension of contaminated sediments has been a focus of substantial research in the geochemical and ecotoxicology fields, yet to date there has been no ecological assessment of the impacts of a real‐world resuspension event involving contaminated sediments.

 We assessed the ecological threat posed by the resuspension of contaminated sediments by testing for impacts of a major dredging operation in an estuary with highly contaminated sediments. We sampled the recruitment of sessile invertebrates in this estuary and two external reference estuaries, before and during dredging. These invertebrates are filter‐feeders that settle and live on hard substrata above the seafloor. Impacts of the dredging‐related resuspension were tested using a Beyond BACI analysis.

 Dredging activities resulted in the large‐scale resuspension of contaminated sediments. Concurrently, the recruitment of the dominant filter‐feeders (e.g. barnacles and polychaete worms) was virtually extinguished for 4 months, despite being abundant prior to dredging. This pattern contrasted with the recruitment of the same invertebrates in the reference estuaries, which showed little change over the same period.

 Synthesis and applications. The severe decrease in the recruitment of sessile invertebrates within an estuary exposed to dredging and the deposition of contaminated sediments indicates that the resuspension of these sediments pose a real ecological threat to organisms in contact with the contaminated water‐column. Containment measures (e.g. silt curtains) are, therefore, essential and further engineering innovations (e.g. dredging designs and operations) are necessary to reduce resuspension during the dredging and deposition of sediments. In addition, this study demonstrates that past pollution events can cause current ecological impacts that extend well beyond those habitats recognized as being contaminated.
Catecholamine and cortisol levels during sleep in women with irritable bowel syndrome
Authors: Burr R. L. , Jarrett M. E. , Cain K. C. , Jun S.‐e. , Heitkemper M. M.
Published: July 2009

Abstract  Evidence suggests that patients with irritable bowel syndrome (IBS) are hyper‐responsive to environmental, physical and visceral stimuli. IBS patients also frequently report poor sleep quality. This study compared serum cortisol and plasma catecholamine levels during sleep between women with IBS (n = 30) and healthy controls (n = 31), and among subgroups within the IBS sample based on predominant stool patterns, IBS‐diarrhoea (n = 14), IBS‐constipation (n = 7) and IBS‐alternators (n = 9). Cortisol was measured from serial blood samples drawn every 20 min, and catecholamines every hour, in a sleep laboratory from 8 pm until awakening. Because of the varied sleep schedules of the individual participants, each subject’s hormone series time base was referenced with respect to their onset of Stage 2 sleep. Overall, there were no significant differences in cortisol or catecholamine patterns between women with IBS and controls, nor were there any group by time interactions. However, women with constipation‐predominant IBS demonstrated significantly increased noradrenaline, adrenaline and cortisol levels throughout the sleep interval, and women with diarrhoea‐predominant IBS were significantly lower on noradrenaline and cortisol. These results suggest that differences in neuroendocrine levels during sleep among IBS predominant bowel pattern subgroups may be greater than differences between IBS women and controls. Neuroendocrine profiles during sleep may contribute to our understanding of symptom expression in IBS.
The dorsal raphe nucleus shows phospho‐tau neurofibrillary changes before the transentorhinal region in Alzheimer's disease. A precocious onset?
Authors: Grinberg L. T. , Rüb U. , Ferretti R. E. L. , Nitrini R. , Farfel J. M. , Polichiso L. , Gierga K. , Jacob‐Filho W. , Heinsen H. ,   Brazilian Brain Bank Study Group
Published: July 2009

Aims: Alzheimer's disease (AD) is a progressive and irreversible disease. There is strong evidence that the progression of the phospho‐tau neurofibrillary cytoskeletal changes, rather than the β‐amyloid burden, is crucial in determining the severity of the dementia in AD. The Braak and Braak staging system (BB) focuses mainly on the cortical cytoskeletal pathology and classifies this progressive pathology into six stages, spreading from the transentorhinal region to primary cortices. Although it is reported elsewhere that the midbrain's dorsal raphe nucleus (DR), which is connected with those areas of the cerebral cortex undergoing early changes during BB I and II, exhibits AD‐related cytoskeletal pathology, this nucleus has not been considered by the BB. Methods: To determine during which BB stage and how frequently the DR is affected by AD‐related neurofibrillary changes, we studied the DR of 118 well‐characterized individuals of the Brain Bank of the Brazilian Aging Brain Study Group categorized according to the BB. Thirty‐eight of these individuals were staged as BB = 0, and 80 as BB ≥ 1. Results: In all of the BB ≥ 1 individuals (cortical neurofibrillary changes were present at least in the transentorhinal region) and in more than 1/5 of the BB = 0 individuals neurofibrillary changes were detected in the supratrochlear subnucleus of the DR. Conclusions: These observations: (i) support the hypothesis of transneuronal spread of neurofibrillary changes from the DR to its interconnected cortical brain areas; and (ii) indicate that the supratrochlear subnucleus of the DR is affected by neurofibrillary changes before the transentorhinal cortex during the disease process underlying AD.
Highly infiltrative brain tumours show reduced chemosensitivity associated with a stem cell‐like phenotype
Authors: Johannessen T.‐C. A. , Wang J. , Skaftnesmo K.‐O. , Sakariassen P. Ø. , Enger P. Ø. , Petersen K. , Øyan A. M. , Kalland K.‐H. , Bjerkvig R. , Tysnes B. B.
Published: July 2009

Aims: Cancer stem‐like cells might have important functions in chemoresistance. We have developed a model where highly infiltrative brain tumours with a stem‐like phenotype were established by orthotopic transplantation of human glioblastomas to immunodeficient rats. Serial passaging gradually transformed the tumours into a less invasive and more angiogenic phenotype (high‐generation tumours). The invasive phenotype (low‐generation tumours) was characterized by an increase in stem cell markers and increased phosphorylation of kinases in the phosphatidylinositol 3‐kinase (PI3K)/AKT pathway. These markers were reduced in the serially passaged vascular tumours. The present study was aimed at investigating how the two phenotypes responded in vitro to doxorubicin, a clinically potent cytotoxic drug for solid tumours. Methods: Biopsy spheroids were implanted and passaged intracranially in nude rats. Gene expression and protein analyses were performed, and drug sensitivity was assessed. Results: Microarray analysis revealed gene ontology categories connected to developmental aspects and negative regulators of differentiation, especially in the infiltrative stem cell‐like tumours. The highly invasive stem‐like phenotype was chemoresistant compared with the angiogenic phenotype. By interfering with the PI3K it was possible to sensitize tumour spheroids to chemotherapy. Real‐time quantitative polymerase chain reaction showed downregulation of the stem cell markers Nestin and Musashi‐1 in low‐generation biopsy spheroids following PI3K inhibition. Conclusions: Highly invasive tumours with a stem‐like phenotype are more chemoresistant than angiogenic tumours derived from the same patients. We suggest that treatment resistance in glioblastomas can be related to PI3K/AKT activity in stem‐like tumour cells, and that targeted interference with the PI3K/AKT pathway might differentiate and sensitize this subpopulation to chemotherapy.
Efficacy of tonsillectomy for patients with recurrence of IgA nephropathy after kidney transplantation
Authors: Ushigome Hidetaka , Suzuki Tomoyuki , Fujiki Masato , Nobori Syuji , Sakamoto Seisuke , Okamoto Masahiko , Urasaki Koji , Yoshimura Norio
Published: July 2009

Abstract:  From January 2007, we started to perform the tonsillectomy for every patient with recurrent IgA nephropathy (IgAN) after kidney transplantation. Up to September 2008, four recipients with primary IgAN had biopsy‐proven recurrent IgAN. They had also progressive hematuria or proteinuria from on the average 14.3 months after transplantation. Then their specimens diagnosed as recurrent IgAN were collected and they underwent tonsillectomies on the average 52.3 months after transplantation. Abnormal urinary findings of all patients favorably improved after tonsillectomy. All cases but one had mild renal injury, where the severity of glomerular lesions, glomerular hypercellularity, segmental lesions, and sclerosis was mild, and no deteriorated serum creatinine (SCr) before their tonsillectomies. Even the case with exacerbated SCr and severe renal injury, where the severity of glomerular lesions was severe, had her urinary findings ameliorated promptly after tonsillectomy likely as others. At present, they have almost no symptoms after tonsillectomy and no remarkable change of SCr level compared with before and after tonsillectomy and maintain ameliorated urinary findings continuously. Tonsillectomy had possibility to be a favorable treatment of hematuria or proteinuria in recurrent IgAN recipients.
The acquisition time of infection: a determinant of the severity of hepatitis C virus‐related liver disease in renal transplant patients
Authors: Töz H. , Nart D. , Turan I. , Ersöz G. , Seziş M. , Aşçı G. , Özkahya M. , Zeytinoğlu A. , Erensoy S. , Ok E.
Published: July 2009

Abstract:  Background:  The aim of this study was to compare the clinical and histopathological course of HCV infection acquired before and during or after renal transplantation.

Methods:  According to HCV status, 197 RT patients were divided into three groups. At the time of RT, anti‐HCV antibody was positive in 47 patients (pre‐RT HCV group). In 27 patients, in whom anti‐HCV negative at the time of RT, anti‐HCV and/or HCV RNA was found to be positive following an ALT elevation episode after RT (post‐RT HCV group). Both anti‐HCV and HCV RNA were negative at all times in remaining 123 patients (control group).

Results:  Liver biopsy was performed in 31 of 47 patients in pre‐RT and 24 of 27 in post‐RT HCV group after RT. Duration of follow‐up was similar in all groups with a mean of 7.1 ± 4.0 yr. Ascites and encephalopathy were seen in only post‐RT HCV group (22%). Histological grade (6.5 ± 2.7 vs. 4.1 ± 1.4) and stage (2.0 ± 1.5 vs. 0.8 ± 0.8) was significantly severe in post‐RT HCV group (p < 0.01). Three patients died due to liver failure in post‐RT HCV group.

Conclusions:  HCV infection acquired during or after RT shows a severe and rapidly progressive clinicopathological course, which is significantly different from pre‐transplant anti‐HCV positive patients.
Use of enteric‐coated mycophenolate sodium in liver transplant patients with intestinal intolerance caused by mycophenolate mofetil
Authors: Doria Cataldo , Ramirez Carlo B. , Frank Adam M. , Vaccino Silvia , Fraser Natalie , Marino Ignazio R.
Published: July 2009

Abstract: Background: Post‐transplant gastrointestinal (GI) side effects can impair a patient’s quality of life (QoL). This study investigates the improvement in GI side effects and related QoL changes in recipients of liver transplantation (OLT) after converting patients from mycophenolate mofetil (MMF) to enteric‐coated mycophenolate sodium (EC‐MPS).

Methods: Thirty‐four patients who underwent OLT and suffered from GI intolerability were included in this study. Infectious causes of GI intolerability were excluded. QoL assessed by the Gastrointestinal Quality of Life Index was evaluated before conversion and at months 3, 6 and 12 post‐conversion. All patients received baseline immunosuppression of one calcineurin inhibitor, MMF, with or without steroids. Patients were converted from MMF to EC‐MPS on an equimolar basis. Pairedt‐test was used to assess differences in mean score changes over time.

Results: Conversion from MMF to EC‐MPS for GI intolerability post‐OLT shows statistically significant improvement in GI‐related QoL at 3, 6, and 12 months when compared to baseline assessments (p < 0.05 for total mean score); nonetheless, one‐third of patients discontinued EC‐MPS. No rejection episodes, deaths or graft loss were seen during the study period.

Conclusion: OLT recipients who develop GI side effects caused by MMF can be safely converted to EC‐MPS with improvement to their QoL.
ENDOPLASMIC RETICULUM STRESS INVOLVED IN HEART AND LIVER INJURY IN IRON‐LOADED RATS
Authors: Lou Li‐Xia , Geng Bin , Chen Yu , Yu Fang , Zhao Jing , Tang Chao‐Shu
Published: July 2009

Iron overload contributes to the pathogenesis of various diseases and directly induces tissue injury. In the present study, we investigated the relationship between heart and liver injury induced by iron overload and cellular endoplasmic reticulum (ER) stress to explore the molecular mechanism of iron overload‐induced cellular injury.

Iron overload in rats was generated by intraperitoneal injection of iron–dextran chronically (30 mg/kg per day for 9 weeks) or acutely (300 mg/kg once). Tissue injury was assessed by determining serum lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, as well as malondialdehyde (MDA) content in the heart and liver. The ER stress response was analysed by expression of glucose‐response protein 78 (GRP78) and activation of caspase 12.

In chronic iron‐loaded rats, iron levels in the heart and liver were higher, by approximately 2‐and 7.8‐fold, respectively (P < 0.01), compared with control. Serum LDH, ALT and AST activity, as well as MDA content, GRP78 expression and caspase 12 activity in the heart and liver, were upregulated in chronically iron‐loaded rats. In acute iron‐loaded rats, iron content in the heart and liver was 51% and 63% higher than in controls (both P < 0.01). Serum LDH, ALT and AST activity, MDA content in the heart and liver and levels of ER stress markers were all increased in acute iron‐loaded rats. N‐Acetylcysteine (150 mg/kg, s.c.) lowered the levels of these parameters in acute iron‐loaded rats.

The results of the present study indicate that ER stress may play an important role in iron‐induced tissue injury and that reactive oxygen species may mediate the ER stress response in the pathogenesis of iron‐overload cellular injury.