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Zirconium diboride (ZrB2) and silicon carbide (SiC) composites have long been of interest since it was observed that ZrB2 improved the thermal shock resistance of SiC. However, processing of these materials can be difficult due to high and different sintering temperatures and differences in the thermodynamic stability of each material. ZrB2–SiC composites have been processed in a variety of ways including hot-pressing, spark-plasma sintering, reactive melt infiltration, pack cementation, chemical vapor deposition, chemical vapor infiltration, stereolithography, direct ink writing, selective laser sintering, electron beam melting, and binder jet additive manufacturing. Each manufacturing method has its own pros and cons. This review serves to summarize more than 60 years of research and provide a coherent resource for the variety of methods and advancements in development of ZrB2–SiC composites.

Cognitive and sensory abilities are vital in affecting survival under predation risk, leading to selection on brain anatomy. However, how exactly predation and brain evolution are linked has not yet been resolved, as current empirical evidence is inconclusive. This may be due to predation pressure having different effects across life stages and/or due to confounding factors in ecological comparisons of predation pressure. Here, we used adult guppies (Poecilia reticulata) to experimentally test how direct predation during adulthood would impact the relative brain size and brain anatomy of surviving individuals to examine if predators selectively remove individuals with specific brain morphology. To this end, we compared fish surviving predation to control fish, which were exposed to visual and olfactory predator cues but could not be predated on. We found that predation impacted the relative size of female brains. However, this effect was dependent on body size, as larger female survivors showed relatively larger brains, while smaller survivors showed relatively smaller brains when compared to control females. We found no differences in male relative brain size between survivors and controls, nor for any specific relative brain region sizes for either sex. Our results corroborate the important, yet complex, role of predation as an important driver of variation in brain size.

Materials capable of oxidizing in a protective manner at ultrahigh (>1700 °C) temperatures are needed to push beyond this barrier defined by SiC. Although possessing attractive mechanical properties and oxidation resistance, SiC-based materials are ultimately temperature limited by the melting point of SiO2. The vast array of ultra-high and high temperature ceramic literature indicates the majority of these materials, like borides, carbides, MAX-phases, and high-entropy ceramics, fall woefully short regarding oxidation resistance. However, for specific applications, like low-orbit aeropropulsion, high ballistics coefficient atmospheric re-entry, and hypersonic cruise, there are a few promising materials. In the present review, oxidation criteria are gathered to build application specific heuristics and are then applied to a multitude of ultra-high temperature ceramics to gauge material efficacy. Discussion of oxidation kinetics, mechanisms and reaction products is offered for each material, identifying strengths, weaknesses, and the remaining gaps in our knowledge.

Abstract In recent years, many studies have investigated the potential state dependence of individual differences in behaviour, with the aim to understand the proximate and ultimate causes and consequences of animal personality. Among the potential state variables that could affect behavioural expression is size and mass, but few studies have found associations at the among-individual levels. Insufficient sampling and incorrect analysis of data are cited as impediments to detecting correlations, if they exist. Here, we conducted a study using 100 pillbugs (Armadillidium vulgare) and assayed their defensive behaviour 24 times each over time and across familiarity contexts, to test the asset protection hypothesis that predicts a negative correlation between boldness and mass, and with increases in mass over time. Multivariate mixed models revealed that despite mostly consistent individual behavioural differences over time (modest slope variance) and across contexts (near-parallel reaction norms), and 18-fold range in starting mass, there was no correlation between individual mean mass and boldness. However, individuals that gained more mass over time may have been more ‘shy’ compared to those gaining less mass, but the correlation was weak and observed variation in mass gain was small. There was also a mean level trend of increasing shyness over time that was coincident with mean level mass increases over time. Together, our study provides weak evidence for the asset protection hypothesis, whereby individuals that accumulate more resources are thought to protect them through risk averse behaviour. Significance statement Individual variation in ‘state’, such as mass or energy reserves, is thought to be a predictor of individual differences in behaviour that are consistent over time. However, few studies reveal such links, and several studies suggest insufficient sampling may explain null results in most studies. We studied 100 animals sampled 24 times each in a controlled setting to reveal stable individual differences in mean behaviour over time and across contexts; however, individual behaviour was unrelated to large differences in individual mass but weakly related to increases in mass through time whereby individuals became more shy and those growing faster were somewhat more shy. Our results provide little evidence for the asset protection hypothesis.

An additive manufacturing process for fabricating ceramic matrix composites has been developed based on the C/C-SiC system. Automated fiber placement of the continuous carbon fibers in a polyether ether ketone matrix was performed to consolidate the carbon fibers into a printed preform. Pyrolysis was performed to convert the polymer matrix to porous carbon, and then Si was introduced by reactive melt infiltration to convert a portion of the carbon matrix to silicon carbide. The densities and microstructures were characterized after each step during the processing, and the mechanical properties were measured. The C/C-SiC composites exhibited a porosity of 10–20%, characteristic flexural strength of 234.91 MPa, and Weibull modulus of 3.21. The composites displayed toughness via a significant displacement to failure.

In the evolutionary transition from solitary to group living, it should be adaptive for animals to respond to the environment and choose when to socialize to reduce conflict and maximize access to resources. Due to the associated proximate mechanisms (e.g. neural network, endocrine system), it is likely that this behavior varies between individuals according to genetic and non-genetic factors. We used long-term behavioral and genetic data from a population of eastern water dragons (Intellagama lesueurii) to explore variation in plasticity of social behavior, in response to sex ratio and density. To do so, we modeled individual variation in social reaction norms, which describe individuals’ mean behavior and behavioral responses to changes in their environment, and partitioned variance into genetic and non-genetic components. We found that reaction norms were repeatable over multiple years, suggesting that individuals consistently differed in their behavioral responses to changes in the social environment. Despite high repeatability of reaction norm components, trait heritability was below our limit of detection based on power analyses (h < 0.12), leading to very little power to detect heritability of plasticity. This was in contrast to a relatively greater amount of variance associated with environmental effects. This could suggest that mechanisms such as social learning and frequency-dependence may shape variance in reaction norms, which will be testable as the dataset grows.

Predation risk during early ontogeny can impact developmental trajectories and permanently alter adult phenotypes. Such phenotypic plasticity often leads to adaptive changes in traits involved in anti-predator responses. While plastic changes in cognition may increase survival, it remains unclear whether early predation experience shapes cognitive investment and drives developmental plasticity in cognitive abilities. Here, we show that predation risk during early ontogeny induces developmental plasticity in two cognitive domains. We reared female guppies (Poecilia reticulata) with and without predator cues and tested their adult cognitive abilities. We found that females reared under simulated predation took longer to learn a simple association task, yet outperformed animals reared without predation threat in a reversal learning task testing cognitive flexibility. These results show that predation pressure during ontogeny shapes adult cognitive abilities, which we argue is likely to be adaptive. Our study highlights the important role of predator-mediated developmental plasticity on cognitive investment in natural populations and the general role of plasticity in cognitive performance.

Quantifying individual variation in labile physiological or behavioral traits often involves repeated measures through time, so as to test for consistency of individual differences (often using repeatability, “R”) and/or individual differences in trendlines over time. Another form of temporal change in behavior is temporal autocorrelation, which predicts observations taken closely together in time to be correlated, leading to nonrandom residuals about individual temporal trendlines. Temporal autocorrelation may result from slowly changing internal states (e.g., hormone or energy levels), leading to slowly changing behavior. Autocorrelation is a well-known phenomenon, but has been largely neglected by those studying individual variation in behavior. Here, we provide two worked examples which show substantial temporal autocorrelation (r > 0.4) is present in spontaneous activity rates of guppies (Poecilia reticulata) and house mice (Mus domesticus) in stable laboratory conditions, even after accounting for temporal plasticity of individuals. Second, we show that ignoring autocorrelation does bias estimates of R and temporal reaction norm variances upwards, both in our worked examples and in separate simulations. This bias occurs due to the misestimation of individual-specific means and slopes. Given the increasing use of technologies that generate behavioral and physiological data at high sampling rates, we can now study among- and within-individual changes in behavior in more detailed ways, including autocorrelation, which we discuss from biological and methodological perspectives and provide recommendations and annotated R code to help researchers implement these models on their data.

OBJECTIVES Stricturing duodenal Crohn disease (CD) is a rare but serious presentation of CD causing significant morbidity. We aim to provide the first robust incidence data and case studies on this severe presentation in children. METHODS A regional cohort of prospectively acquired incident cases of paediatric CD diagnosed

Interactions between genotypes and environments are central to evolutionary genetics, but such interactions are typically described, rather than predicted from theory. Recent Bayesian models of development generate specific predictions about genotypic differences in developmental plasticity (changes in the value of a given trait as a result of a given experience) based on genotypic differences in the value of the trait that is expressed by naive subjects. We used these models to make a priori predictions about the effects of an aversive olfactory conditioning regime on the response of Drosophila melanogaster larvae to the odor of ethyl acetate. As predicted, across 116 genotypes initial trait values were related to plasticity. Genotypes most strongly attracted to the odor of ethyl acetate when naive reduced their attraction scores more as a result of the aversive training regime than those less attracted to the same odor when naive. Thus, as predicted, the variance across genotypes in attraction scores was higher before than after the shared experience. These results support predictions generated by Bayesian models of development and indicate that such models can be successfully used to investigate how variation across genotypes in information derived from ancestors combines with personal experience to differentially affect developmental plasticity in response to specific types of experience.

Neurohistopathological changes in the brain were assessed in juvenile beagle dogs given vigabatrin at 30 or 100 mg/kg/day by oral gavage from postnatal day 22 (PND22) until 16 weeks of age (PND112), when brain myelination is considered to reach the adult stage in dogs. Separate subgroups were treated from PND22 to PND35 or PND36 to PND49 to assess early effects. In addition to extensive brain histopathology, there were assessments of toxicokinetics, clinical condition, body weight, organ weights, and macroscopic pathology. In animals treated for 14 days from PND22, minimal or slight vacuolation was seen in the neuropil of the septal nuclei, hippocampus, hypothalamus, thalamus, cerebellum, and globus pallidus at 100 mg/kg/day and minimal vacuolation in the thalamus, globus pallidus, and cerebellum at 30 mg/kg/day. In animals given 100 mg/kg/day for 91 days from PND22, minimal or slight vacuolation was observed only in the hippocampus, hypothalamus, and thalamus. No vigabatrin-related brain vacuolation was observed in animals given 30 or 100 mg/kg/day for 14 days from PND36. Clear evidence of recovery was observed after 14-day and 6-week off-dose periods that followed treatment from PND22 to PND35 or PND22 to PND112, respectively.

There is still a need to develop reliable and robust matrix deposition methods for matrix-assisted laser desorption/ionisation mass spectrometry that are applicable to a range of matrices, solvents and analyte types. This paper presents a robust methodology for the airbrush application of matrices along with the implications of varying the set-up and airbrush parameters. A small number of organic analytes and metal salts are analysed in both positive and negative ion modes to exemplify this methodology. In the analyses with the airbrush deposited matrices, performance was enhanced when compared to standard pipette deposition with the need for a search for sweat spots greatly diminished due to the increase homogeneity of the matrix surface and resultant analyte spots. As expected, the graphite matrices were shown to specifically outperformed the organic matrices in negative ion mode.

Predation is a near ubiquitous factor of nature and a powerful selective force on prey. Moreover, it has recently emerged as an important driver in the evolution of brain anatomy, though population comparisons show ambiguous results with considerable unexplained variation. Here, we test the reproducibility of reduced predation on evolutionary trajectories of brain evolution. We make use of an introduction experiment, whereby guppies ( Poecilia reticulata ) from a single high predation stream were introduced to four low predation streams. After 8–9 years of natural selection in the wild and two generations of common garden conditions in the laboratory, we quantified brain anatomy. Relative brain region sizes did not differ between populations. However, we found a general increase and striking variation in relative brain size of introduced populations, which varied from no change to a 12.5% increase in relative brain weight, relative to the ancestral high predation population. We interpret this as evidence for non-parallel evolution, which implies a weak or inconsistent association of relative brain size with fitness in low predation sites. The evolution of brain anatomy appears sensitive to unknown environmental factors, or contingent on either chance events or historical legacies of environmental change.

Cytoplasmic dynein is a multisubunit motor protein responsible for intracellular cargo transport toward microtubule minus ends. There are multiple isoforms of the dynein intermediate chain (DYNC1I, IC), which is encoded by two genes. One way to regulate cytoplasmic dynein is by IC phosphorylation. The IC-2C isoform is expressed in all cells, and the functional significance of phosphorylation on IC-2C serine 84 was investigated by using live cell imaging of fluorescent protein-tagged IC-2C wild type (WT) and phospho- and dephosphomimic mutant isoforms in axonal transport model systems. Both mutations modulated dynein functional properties. The dephosphomimic mutant IC-2C S84A had greater colocalization with mitochondria than the IC-2C WT or the phosphomimic mutant IC-2C S84D. The dephosphomimic mutant IC-2C S84A was also more likely to be motile than the phosphomimic mutant IC-2C S84D or the IC-2C WT. In contrast, the phosphomimic mutant IC-2C S84D mutant was more likely to move in the retrograde direction than was the IC-2C S84A mutant. The phosphomimic IC-2C S84D was also as likely as the IC-2C WT to colocalize with mitochondria. Both the S84D phospho- and the S84A dephosphomimic mutants were found to be capable of microtubule minus-end-directed (retrograde) movement in axons. They were also observed to be passively transported in the anterograde direction. These data suggest that the IC-2C S84 has a role in modulating dynein properties.

There is a long-standing interest in behavioural ecology, exploring the causes and correlates of consistent individual differences in mean behavioural traits (‘personality’) and the response to the environment (‘plasticity’). Recently, it has been observed that individuals also consistently differ in their residual intraindividual variability (rIIV). This variation will probably have broad biological and methodological implications to the study of trait variation in labile traits, such as behaviour and physiology, though we currently need studies to quantify variation in rIIV, using more standardized and powerful methodology. Focusing on activity rates in guppies ( Poecilia reticulata ), we provide a model example, from sampling design to data analysis, in how to quantify rIIV in labile traits. Building on the doubly hierarchical generalized linear model recently used to quantify individual differences in rIIV, we extend the model to evaluate the covariance between individual mean values and their rIIV. After accounting for time-related change in behaviour, our guppies substantially differed in rIIV, and it was the active individuals that tended to be more consistent (lower rIIV). We provide annotated data analysis code to implement these complex models, and discuss how to further generalize the model to evaluate covariances with other aspects of phenotypic variation.

The retrograde transport of Trk-containing endosomes from the axon to the cell body by cytoplasmic dynein is necessary for axonal and neuronal survival. We investigated the recruitment of dynein to signaling endosomes in rat embryonic neurons and PC12 cells. We identified a novel phosphoserine on the dynein intermediate chains (ICs), and we observed a time-dependent neurotrophin-stimulated increase in intermediate chain phosphorylation on this site in both cell types. Pharmacological studies, overexpression of constitutively active MAP kinase kinase, and anin vitroassay with recombinant proteins demonstrated that the intermediate chains are phosphorylated by the MAP kinase ERK1/2, extracellular signal-regulated kinase, a major downstream effector of Trk. Live cell imaging with fluorescently tagged IC mutants demonstrated that the dephosphomimic mutants had significantly reduced colocalization with Trk and Rab7, but not a mitochondrial marker. The phosphorylated intermediate chains were enriched on immunoaffinity-purified Trk-containing organelles. Inhibition of ERK reduced the amount of phospho-IC and the total amount of dynein that copurified with the signaling endosomes. In addition, inhibition of ERK1/2 reduced the motility of Rab7- and TrkB-containing endosomes and the extent of their colocalization with dynein in axons. NGF-dependent survival of sympathetic neurons was significantly reduced by the overexpression of the dephosphomimic mutant IC-1B-S80A, but not WT IC-1B, further demonstrating the functional significance of phosphorylation on this site. These results demonstrate that neurotrophin binding to Trk initiates the recruitment of cytoplasmic dynein to signaling endosomes through ERK1/2 phosphorylation of intermediate chains for their subsequent retrograde transport in axons.

Live cell imaging of the movement of various membrane-bounded organelle cargos has enhanced our understanding of their function. Eukaryotic cells utilize microtubules and two classes of microtubule-based motor proteins, cytoplasmic dynein and members of the kinesin family, to deliver a variety of membrane-bounded organelles and other cargos to their appropriate locations. In order to better understand the functions and regulation of cytoplasmic dynein, we developed a method to study its location and motility in living cells. The technique takes advantage of the long thin axons of cultured hippocampal neurons. We use calcium phosphate to transfect fluorescent-tagged dynein intermediate chain (IC) subunits (DYNC1I) into cultured neurons. When the ICs are expressed at low levels, they are effective probes for the location of the cytoplasmic dynein complex in axons when living cells are imaged with fluorescence microscopy. The fluorescent subunit probes can be used to identify specific cargos of dynein complexes with different IC isoforms as well as the kinetic properties of cytoplasmic dynein.

Live cell imaging of the movement of various membrane-bounded organelle cargos has enhanced our understanding of their function. Eukaryotic cells utilize microtubules and two classes of microtubule-based motor proteins, cytoplasmic dynein and members of the kinesin family, to deliver a variety of membrane-bounded organelles and other cargos to their appropriate locations. In order to better understand the functions and regulation of cytoplasmic dynein, we developed a method to study its location and motility in living cells. The technique takes advantage of the long thin axons of cultured hippocampal neurons. We use calcium phosphate to transfect fluorescent-tagged dynein intermediate chain (IC) subunits (DYNC1I) into cultured neurons. When the ICs are expressed at low levels, they are effective probes for the location of the cytoplasmic dynein complex in axons when living cells are imaged with fluorescence microscopy. The fluorescent subunit probes can be used to identify specific cargos of dynein complexes with different IC isoforms as well as the kinetic properties of cytoplasmic dynein.

This paper reports on the translocation of 5.6 ha of a 9.1 ha dry mesotrophic grassland in 1998. For 4 years before and 5 years after translocation, the vegetation was monitored annually by randomised quadrat sampling and compared with an area of the site which remained untranslocated. Associated soil and climatic variables were also monitored. The hypothesis to be tested was that changes in the vegetation ascribable to translocation were of a similar amplitude to those ascribable to other causes. Soil monitoring showed that it had been possible to reconstruct both vegetation and substrate with only minor changes in soil compaction and soil fertility. The frequencies of 28 species in the source meadow in the 4 years before translocation varied significantly. Three areas of the translocated vegetation monitored separately showed significant changes in frequency in a similar number of species, as did the untranslocated area. Species density gradually declined on the translocated turf for the first 4 years after translocation but recovered in the fifth year, although at least one species has so far failed to recover. Multivariate analysis showed that the translocated vegetation diverged from the untranslocated portion for the first 4 years but that this divergence ceased and partially reversed in the final year. The divergence involved an increase in the cover-abundances of several grasses and a parallel fall in a range of forbs. Weather records suggest that this pattern correlates with 4 years without water stress followed by a much drier growing season in the fifth year. It is concluded that there was a definite response to the 1998 translocation which appears to be comparable in severity with the pre-translocation changes in terms of the effects on species frequency. The untranslocated area also changed suggesting that the changes were not all the result of translocation, and the results for the last year of monitoring imply an element of recovery. The results support the use of turf translocation as a restoration technique where the alternative is the complete loss of the site and where the process of reconstructing the functioning of the ecosystem meets certain standards. Monitoring is continuing for 5 more years.

Due to reductions in domestic usage, legislation and changes in fuel use, coal derived particulates in the UK urban atmosphere have been significantly reduced. However, a large increase in road usage and an expansion in the use of diesel engines, has meant that the majority of particulates, now present in the urban atmosphere, originate from vehicle exhausts. Particulate matter, resulting from coal combustion, has been recorded as being present in black patinas observed on some historic stone buildings and monuments and has been associated with accelerated weathering of stone surfaces as a result of enhanced gypsum formation. In contrast, the effects of particulates resulting from vehicle exhaust on stone are much less understood. To investigate this, a comparative study was undertaken using the technique of microcatchments under ambient atmospheric conditions. This compared the elemental composition and volume of precipitation runoff from Portland Limestone coated with three different particulate treatments. Treatments consisted of coal and diesel particulates, both separately and in combination. Combining these treatments attempts to investigate any synergistic effects that may occur when coal derived particulates are overlain by layers formed by particulates from more contemporary sources. It was found that diesel-coated samples were much darker in appearance and showed a significant reduction (P

This study demonstrates significant correlations between the organic matter content of urban street dust and certain mineral magnetic properties, which accords with previous work that indicates magnetic parameters offer potential as a proxy for organic content. However, site-specific data demonstrate the relationship can be different for particular roads, even within the same area. This indicates the association may be more complex than previous work proposes and a cautionary note is required. It is recommended that the nature of the relationship between magnetic and organic properties should be fully explored for particular urban environments and individual field settings, before using magnetic measurements as a proxy for organic matter content. Furthermore, whilst soil is believed to significantly contribute to urban street dust, magnetic values in this study are much higher than those previously reported for top-soils and indicate the influence of other sources, such as anthropogenic pollutants. This suggests that using magnetic measurements to discriminate sources of urban particulates has considerable potential for development.

Respirable particulate matter was collected inside and outside of a building located in Wolverhampton city centre during the same time period between 19/9/00 and 1/5/01. A total of 103 pairs of indoor and outdoor mea surements were made using Casella personal dust moni tors. The building monitored was located in a small street canyon produced by 4- and 5-storey buildings on both sides of the road. The road is the main approach road to a major bus station and is used by large numbers of heavy-duty diesel vehicles each day. The mean con centration for outdoor samples was 27.6 and 9.8 μg.m-3 for indoor samples. The mean indoor/outdoor ratio for this period was 0.4 (±0.02 SE). Meteorological variables including wind speed, wind direction and precipitation were measured at a nearby urban monitoring station. A greater wind speed caused an increase in the quantity of outdoor generated particulates penetrating indoors. Wind direction affected both indoor and outdoor particu late concentrations, with lower concentrations being ob served when the wind direction was parallel to the street canyon. The indoor/outdoor ratio also showed a de crease during parallel wind conditions. During days with high amounts of precipitation, the concentration of par ticulates, both indoors and outdoors, decreased signifi cantly. The personal exposure of a building occupant was measured for 20 working days in conjunction with outdoor and indoor measurements. Personal exposure concentrations were well correlated with indoor concen trations (r2 = 0.98). Forty of the indoor and outdoor partic ulate samples of dust were chemically analysed for sul phate, nitrate, chloride, zinc, copper, manganese and aluminium to determine any indoor/outdoor relation ships of particulate chemistry and any interrelationships between the analytes.

Settled dust has been collected inside the main foyers ofthree University buildings in Wolverhampton City Centre,U.K. Two of the three buildings are located in a streetcanyon used almost exclusively by heavy duty dieselvehicles. The dust was collected on adhesive carbonspectro-tabs to be in a form suitable for analysis byscanning electron microscope and energy dispersive X-rayanalysis. Using these analytical techniques, individualparticle analysis was undertaken for morphology andchemistry. Seasonal variations and variations due tolocation were observed in both the morphologicalmeasurements and chemical analysis. Many of the differencesappear attributable to the influence of road traffic, inparticular, the heavy duty diesel vehicles, travellingalong the street canyon.

Despite accumulating evidence for individual variation in behavioural plasticity, there is currently little understanding of the causes and consequences of this variation. An outstanding question is whether individual reaction norm (RN) slopes are consistent across different environmental variables—that is, whether an individual that is highly responsive to one environmental variable will be equally responsive to a second variable. Another important and related question is whether RNs are themselves consistently expressed through time or whether they are simply state dependent. Here, we quantified individual activity rates of zebrafish in response to independent manipulations of temperature and food availability that were repeated in discrete ‘bursts’ of sampling through time. Individuals that were thermally responsive were not more responsive to food deprivation, but they did exhibit greater unexplained variation. Individual RN slopes were consistent (repeatable) over time for both temperature ( R slope = 0.92) and food deprivation responses ( R slope = 0.4), as were mean activity rates in the standard environment ( R intercept = 0.83). Despite the high potential lability of behaviour, we have demonstrated consistency of behavioural RN components and identified potential energetic constraints leading to high consistency of thermal RNs and low consistency of food deprivation RNs.

Ball-on-rod rolling contact fatigue experiments were performed using M50–M50 all-steel and Si 3 N 4 –M50 hybrid components, respectively. Experiments were performed using a jet turbine engine lubricant in the as-received condition or with particulate contaminants added. The added particulate contaminants were Arizona test dust or glycothermally synthesized α-Al 2 O 3 . Wear performance of the all-steel and hybrid rolling systems was evaluated with and without particulate contaminants in the lubricant. Wear surfaces were analyzed using optical microscopy, scanning electron microscopy, surface profilometry, and atomic force microscopy. Wear mechanisms, volume specific wear rates and modes of failure were determined for all systems. The primary wear mechanism produced in rolling contact fatigue experiments is shown to be contact stress fatigue, with secondary mechanisms of indenting, cutting, plowing and embedding occurring as particulate debris passes through the elastohydrodynamic lubricant layer between the ball and rod surfaces.

Climatically induced cycles of stone temperature and moisture content may result in physical rock weathering through various mechanisms. These mechanisms cause rock to oscillate between periods of expansion and contraction, resulting in compressive and tensile stresses. Cycles of compression and tension may cause fatigue of the stone and therefore the frequency of these cycles may be of critical importance. The temperature and moisture content of stones with four different aspects were monitored over one year and the frequency of heating-cooling, wetting-drying and freeze-thaw cycles calculated. Heating-cooling cycles were found to occur on all aspects, but the highest frequency of cycles occurred on south and west aspects during summer months. Heating and cooling of stone creates a thermal gradient within the stone, which is critical in causing insolation weathering. Differences in the rate of thermal expansion between minerals or superficially degraded parts of stone may also contribute to breakdown. Moisture availability may alter the mechanisms by which heating—cooling causes weathering. Cycles of wetting—drying are less frequent than heating—cooling cycles, but may cause weathering by five mechanisms, depending upon the hygrometric gradients. Freeze-thaw cycles show a much lower frequency than heating—cooling and wetting—drying cycles, but are active on all aspects.

Cytoplasmic dynein is a multi-subunit motor protein responsible for intracellular cargo transport toward microtubule minus ends. There are multiple isoforms of the dynein intermediate chain (DYNC1I, IC) which is encoded by two genes. One way to regulate cytoplasmic dynein is by IC phosphorylation. The IC-2C isoform is expressed in all cells and the functional significance of phosphorylation on IC-2C serine 84 was investigated using live cell imaging of fluorescent protein-tagged wild type IC-2C (WT) and phospho- and dephospho-mimic mutant isoforms in axonal transport model systems. Both mutations modulated dynein functional properties. The dephospho-mimic mutant IC-2C S84A had greater co-localization with mitochondria than IC-2C wild-type (WT) or the phospho-mimic mutant IC-2C S84D. The dephospho-mimic mutant IC-2C S84A was also more likely to be motile than the phospho-mimic mutant IC-2C S84D or IC-2C WT. In contrast, the phospho-mimic mutant IC-2C S84D mutant was more likely to move in the retrograde direction than was the IC-2C S84A mutant. The phospho-mimic IC-2C S84D was also as likely as IC-2C WT to co-localize with mitochondria. Both the S84D phospho- and S84A, dephospho-mimic mutants were found to be capable of microtubule minus end directed (retrograde) movement in axons. They were also observed to be passively transported in the anterograde direction. These data suggest that the IC-2C S84 has a role in modulating dynein properties.

In order to gain a greater insight into the mechanisms responsible for the deterioration of sandstone buildings, chemical analysis of runoff water from sandstone and glass (control) surfaces has been carried out. Results indicate that the blocking of the stone's pores by atmospheric particulates, soluble salts and algae may be involved in this decay. Evidence is presented which indicates that pressures created by salts and trapped moisture may cause the detachment of surface layers of sandstone from buildings. Weakening by kaolinite formation is identified as a potential factor in sandstone weathering.

Current-voltage (I-V) curves have been measured, independent of the main discharge, for electricity passing through the steady state fast flowing 'afterglow' plasma of a low power dc glow discharge in Ar. Voltage profiles along the axial line of conduction have been mapped using fixed probes and potentiometry, and the mass spectra of cations emerging from the downstream sampling Cone, also acting as a probe anode, were recorded simultaneously. Floating double probe experiments were also carried out. The electrical behavior is consistent with the well established I-V characteristics of such discharges, but does not comply with classical plasma theory predictions. The plasma decays along the line of conduction, with a lifetime of approximately 1 ms, despite carrying a steady state current, and its potential is below that of the large surface area anode voltage; a situation which cannot exist in the presence of a conventional free ion-electron plasma, unless the electron temperature is super cold. Currents, large by comparison with the main discharge current, and independent of it, are induced to flow through the downstream plasma, from the Anode (acting as a cathode) to the anodic ion exit Cone, induced by electron impact ionisation at the anode, but without necessarily increasing the plasma density. It appears to be conducted by direct charge transfer between a part of the anode surface (acting as cathode to the auxiliary circuit) and the plasma, without secondary electron emission or heating, which suggests the direct involvement of Rydberg atom intermediates. The reaction energy defect (= the work function of the electrode surface) fits with the plasma potential threshold observed for the cathodic reaction to occur. A true free ion-electron plasma is readily detected by the observation of cations at the anode surface, when induced at the downstream anode, at high bias voltages, by the electron impact ionisation in the boundary region. In contrast to the classical model, the complex electrical (and mass spectrometric) behaviour fits qualitatively, but can be understood well, with the Rydberg gas model described in papers II and III (R. S. Mason, and R. S. Mason and P. Douglas, PCCP, 2010, DOI: 10.1039/b918081h and b918083d) over a wide range of probe bias voltages. The full cycle of behavior is then described for the development of a true secondary discharge within the downstream plasma.

Disease caused by Fusarium solani f.sp. phaseoli in mung bean grown in hydroponic solutions was influenced by temperature and hydrogen ion concentration but not by ambient humidity or light quality. Differences in fresh weights between inoculated and noninoculated plants were greatest at 20 °C; they decreased as temperature increased to 28 °C and they were not significant at 30–36 °C. At 20 °C, 52–97% of inoculated plants wilted by 14 days after inoculation and plant fresh weights were reduced an average of 60–75% compared with noninoculated plants. Disease was similar among inoculated plants maintained at 20 °C and pH 4, 5, 6, and 7. However, when plants were maintained at 25 °C, fresh weights of inoculated and noninoculated plants were different at pH 5, 6, and 7, but they were not different at pH 4. Mature conidiophores and macroconidia were produced between 10 and 14 days after inoculation at 20 °C and by 14 days at 24 and 28 °C when the pH of the nutrient solution was maintained at 5–7. However, when plants were maintained at 20 °C and pH 4, mature conidiophores and macroconidia of F. solani f.sp. phaseoli were not observed; sporodochia and branched monophialides were disorganized and poorly developed. Results of bioassays, based on root lengths of germinating seedlings of Lactuca sativa, did not support the hypothesis that plant growth-inhibiting or growth-promoting compounds accumulated in hydroponic solutions. Key words: controlled ecological life support systems, NASA, space agriculture.

The potential for savings provided to worldwide operators of industrial gas turbines, by transitioning from the current standard of interval-based maintenance to condition-based maintenance may be in the hundreds of millions of dollars. In addition, the operational flexibility that may be obtained by knowing the historical and current condition of life-limiting components will enable more efficient use of industrial gas turbine resources, with less risk of unplanned outages as a result of off-parameter operations. To date, it has been impossible to apply true condition-based maintenance to industrial gas turbines because the extremely harsh operating conditions in the heart of a gas turbine preclude using the necessary advanced sensor systems to monitor the machine’s condition continuously. Siemens, Rove Technical Services, and Arkansas Power Electronics International are working together to develop a potentially industry-changing technology to build smart, self-aware engine components that incorporate embedded, harsh-environment-capable sensors and high temperature capable wireless telemetry systems for continuously monitoring component condition in the hot gas path turbine sections. The approach involves embedding sensors on complex shapes, such as turbine blades, embedding wireless telemetry systems in regions with temperatures that preclude the use of conventional silicon-based electronics, and successfully transmitting the sensor information from an environment very hostile to wireless signals. The results presented will include those from advanced, harsh environment sensor and wireless telemetry component development activities. In addition, results from laboratory and high temperature rig and spin testing will be discussed.

Rolling contact fatigue experiments were performed on all-steel and hybrid Si{sub 3}N{sub 4}-M50 steel rolling bearing systems using particulate contaminated lubricants. The particulate contaminants used were glycothermally synthesized {alpha}-Al{sub 2}O{sub 3} platelets or Arizona test dust. The effects of contaminant composition and morphology on rolling contact fatigue and wear behavior were explored. The effects of bearing element material properties on fatigue and wear behavior were also examined. Rolling wear behavior is related to bearing component material configuration and the type of particulate contaminant present in the lubricant. Component and particulate material properties such as hardness and elastic modulus are observed to affect rolling wear behavior. Wear mechanisms such as contact stress fatigue, indenting, cutting and plowing are observed.

The potential for savings provided to worldwide operators of industrial gas turbines, by transitioning from the current standard of interval-based maintenance to condition-based maintenance may be in the tens of millions of dollars per year. Knowledge of the historical and current condition of life-limiting components will enable more efficient use of industrial gas turbine resources via increased operational flexibility, with less risk of unplanned outages as a result of off-parameter operations. To date, it has been impossible to apply true condition-based maintenance to industrial gas turbines because the extremely harsh operating conditions in the heart of a gas turbine preclude using the necessary advanced sensor systems to monitor the machine’s condition continuously. The U.S. Department of Commerce’s National Institute of Standards and Technology – Advanced Technology Program (NIST-ATP) awarded the Joint Venture team of Siemens Power Generation, Inc. and MesoScribe Technologies, Inc. a four-year, $5.4 million program in November, 2004, titled Conformal, Direct-Write-Technology-Enabled, Wireless, Smart Turbine Components. The target was to develop a potentially industry-changing technology to build smart, self-aware engine components that incorporate embedded, harsh-environment-capable sensors and high temperature capable wireless telemetry systems for continuously monitoring component condition in both the compressor and turbine sections. The approach involves several difficult engineering challenges, including the need to embed sensors on complex shapes, such as turbine blades, embedding wireless telemetry systems in regions with temperatures that preclude the use of conventional silicon-based electronics, protecting both sensors and wireless devices from the extreme temperatures and environments of an operating gas turbine, and successfully transmitting the sensor information from an environment very hostile to wireless signals. The program included full-scale, F-class industrial gas turbine engine test demonstrations with smart components in both the compressor and turbine sections. The results of the development program and engine testing to date will be discussed.Copyright © 2008 by ASME

Probiotics are characterized by their ability to interact with commensal microflora in the gastrointestinal tract to produce beneficial health effects. In vitro studies suggest that Lactobacillus species have the potential to suppress the growth of Helicobacter pylori. The goal of this study was to determine if pretreatment of mice with a commercial mixture of live probiotics (L. rhamnosus, strain R0011, and L. acidophilus, strain R0052) would suppress colonization of H. pylori, strain SS1. Thirty C57BL/6 female mice were divided into four groups: Group A was fed sterile water, group B received probiotics in sterile drinking water, group C was challenged orogastrically with H. pylori, and group D was pretreated with probiotics in drinking water prior to and following challenge with H. pylori. Rectal swabs, stomach homogenates, and luminal contents from ileum and colon were plated onto colistin nalidixic acid plates. Serial dilutions of stomach homogenates were plated onto H. pylori-sensitive agar plates and incubated under microaerophilic conditions. Tissue samples from the stomach were analyzed histologically to determine the degree of H. pylori colonization, mucosal inflammation, and epithelial cell apoptosis. Probiotics in drinking water did not affect the overall well-being of mice. Lactobacillus species were excreted in stools over the entire duration of treatment. Pretreatment with probiotics reduced the number of mice with H. pylori growth from stomach homgenates (100 to 50%; P = 0.02). The percentage of mice with moderate-severe H. pylori-induced inflammation in the gastric antrum was reduced with probiotic pretreatment (71 to 29%; P = 0.14). However, pretreatment with probiotics did not prevent H. pylori-induced apoptosis in the gastric mucosa. This preparation of probiotics provided a safe and novel approach for reducing H. pylori colonization and bacterial-induced inflammation of mice.

Background Citrobacter rodentium is a naturally occurring murine pathogen that causes colonic epithelial-cell hyperplasia, disrupts the colonic mucosa, and elicits a predominantly T helper 1 cellular immune response; it thereby serves as a model for the study of mechanisms of disease induced by human attaching-effacing pathogens. We sought to determine whether pretreatment of mice with a mixture of Lactobacillus rhamnosus and L. acidophilus probiotics would attenuate C. rodentium-induced colonic disease in mice. Methods Mice were administered sterile drinking water, probiotics (10(9) cfu/mL) in sterile drinking water, maltodextrin in sterile drinking water, orogastric C. rodentium (10(7) cfu in 0.1 mL), or maltodextrin in sterile drinking water for 1 week before C. rodentium infection, or they were pretreated with probiotics (10(9) cfu/mL) for 1 week before challenge with C. rodentium. Results Mice that received viable probiotics remained healthy. C. rodentium infection elicited mucosal inflammation, epithelial-cell hyperplasia, apoptosis in the colon, and interferon (IFN)- gamma production by splenocytes. Pretreatment with probiotics decreased levels of all but IFN- gamma production. Conclusions Pretreatment with probiotics attenuates the effects of C. rodentium infection in mice. Understanding the mechanism of these beneficial effects will aid in determining the efficacy of probiotics in preventing infection with related attaching-effacing enteric pathogens in humans.

An ion source is described for use in low power glow discharge mass spectrometry, using fast flowing argon as the discharge gas, and attached to a quadrupole analyser. The flow carries the plasma downstream onto an ion exit sampling cone which can be variably biased relative to the anode, enabling the physical and chemical properties of the plasma to be studied independently of the main ionisation region, the cathode fall. The parts of the plasma studied were characterised by fixed probe potential measurements. Cone bias effects are consistent with a plasma which contains large quantities of high n Rydberg atoms of both the discharge gas and the sputtered cathode. The ionisable atom flux passing through the sampling aperture was measured directly, giving densities inside the plasma of 1010–1011 cm−3. The densities of lower n Rydbergs are expected to be very much higher. H2 is shown to quench these states and promote excitation of the cathode atoms to their Rydberg states. Field-ionisation or Auger deexcitation of the Rydberg gas inside the cell gives a high intensity cathode ion beam, which is relatively uncontaminated by the higher ionisation potential species, such as are formed from the discharge gas.

Stone Weathering and Urban Particulate Pollution in the UK: David E. Searle and David J. Mitchell Urban Pollution and Stone Weathering in the Black Country: David E. Searle and David J. Mitchell Potential for Building Stone Soiling from Vehicle-related Pollutants Along-side a Busy Road: Paul Giess and Vaughan Shilton Weathering of Rocks by Lichens with Special Reference to Stonework: A Review: M.J. Wilson Experimental Studies of Rock Weathering by Plant Roots: Updating the Work of Julius Sachs (1832-1897): D.N. Mottershead and H.A. Viles Comparison of the Process of Decay of Two Limestones in a Polluted Urban Environment: A. T r k Initial Stages of Sandstone Decay in a Polluted Urban Environment: Alice V. Turkington Role of NO2 and SO2 on the Degradation of Limestone: G.C. Allen et al. Dry Deposition of SO2 on Carbonate Stone: An Overview of Laboratory Studies: Elizabeth A. Bede Development and Potential Uses of Computer Simulation Techniques in the Study of Rock Weathering: Sarah Antill an

A review of the climate of southern China combined with data from an experimental site in Yunnan Province reveals a number of climatic constraints to crop production in the area dominated by red soils. In addition to the well-known effects of late summer drought and high summer evaporation, other factors include variability of the onset date of the summer monsoon as well as the intensity and damaging effects of the monsoon. Other climatic constraints identified are the occurrence of cold conditions and frost during the winter monsoon and local microclimatic variability due to topographic factors.

Infection withHelicobacter pyloriis chronic despite a vigorous mucosal immune response characterized by gastric T-helper type 1 cell expansion and gamma interferon (IFN-γ) production. IFN-γ signals by activation and nuclear translocation of signal transducer and activator of transcription 1 (STAT1); however, the effect ofH. pyloriinfection on IFN-γ-STAT1 signaling is unknown. We infected human gastric (MKN45 and AGS) and laryngeal (HEp-2) epithelial cell lines with type 1 and type 2H. pyloristrains and then stimulated them with IFN-γ. Western blotting of whole-cell protein extracts revealed that infection with live, but not heat-killed,H. pyloritime-dependently decreased IFN-γ-induced STAT1 tyrosine phosphorylation. Electrophoretic mobility shift assay of nuclear protein extracts demonstrated thatH. pyloriinfection reduced IFN-γ-induced STAT1 DNA binding. STAT1 was unable to translocate from the cytoplasm to the nucleus inH. pylori-infected HEp-2 cells examined by immunofluorescence, and reverse transcription-PCR showed that IFN-γ-induced interferon regulatory factor 1 expression was inhibited. These effects were independent of thecagA,cagE, and VacA status of the infectingH. pyloristrain. Furthermore, neitherH. pyloriculture supernatants nor conditioned medium fromH. pylori-infected MKN45 cells inhibited IFN-γ-induced STAT1 tyrosine phosphorylation, suggesting that inhibition is independent of a soluble epithelial or bacterial factor but is dependent on bacterial contact with epithelial cells.H. pyloridisruption of IFN-γ-STAT1 signaling in epithelial cells may represent a mechanism by which the bacterium modifies mucosal immune responses to promote its survival in the human host.

The underlying causes of chronic diarrhea beginning early in life are increasingly well defined. Infectious and post-infectious enteropathies and food sensitive/allergic enteropathy account for the majority of cases. Recent attention has focused on characterizing defined entities, which cause protracted diarrhea in infants and young children. Disorders of intestinal ion transport usually present at birth following a pregnancy complicated by polyhydramnios. Intestinal mucosal biopsies show normal architect with intact villus-crypt axis. Neonatal enteropathies, by contrast, are characterized by blunting of the villi. These include microvillus inclusion disease, tufting enteropathy, autoimmune enteropathy and IPEX syndrome - and it is these conditions that are the subject of the current review.

Ions created from the fast-flowing positive column plasma of a glow discharge were monitored using a high voltage magnetic sector mass spectrometer. Since the field gradient and sheath potentials created by the plasma inside the source opposed cation transfer, it is inferred that the ions detected were the field-ionized Rydberg species. This is supported by the mass spectral changes which occurred when a negative bias was applied to the sampling aperture and by the contrasting behavior when attached to a quadrupole analyzer. Reaction with H2 (titrated into the flowing plasma) quenched not only the ionization of discharge gas Rydberg atoms but also the passage of electric current through the plasma, without significant changes to the field and sheath potentials. Few "free" ions were present and the lifetimes of the Rydberg atoms detected were much longer than seen in lower pressure experiments, indicating additional stabilization in the plasma environment. The observations support the model of the flowing plasma, given previously [R. S. Mason, P. D. Miller, and I. P. Mortimer, Phys. Rev. E 55, 7462 (1997)] as mainly a neutral Rydberg atom gas, rather than a conventional ion-electron plasma.