bluuebunny/crossref_metadata_2025 huggingface dataset:
Exposure to Helicobacter pylori–positive Siblings and Persistence of Helicobacter pylori Infection in Early Childhood
Authors: Cervantes Diana T , Fischbach Lori A , Goodman Karen J , Phillips Carl V , Chen Shande , Broussard Cheryl S
Published: March 2010

Objectives:

Cross‐sectional studies suggest that Helicobacter pylori may be transmitted between siblings. The present study aimed to estimate the effect of an H pylori–infected sibling on the establishment of a persistent H pylori infection.

Materials and Methods:

The authors used data collected from a Texas–Mexico border population from 1998 to 2005 (the “Pasitos Cohort Study”). Starting at age 6 months, H pylori and factors thought to be associated with H pylori were ascertained every 6 months for participants and their younger siblings. Hazard ratios were estimated from proportional hazards regression models with household‐dependent modeling.

Results:

Persistent H pylori infection in older siblings always preceded persistent infection in younger siblings. After controlling for mother's H pylori status, breast‐feeding, antibiotic use, and socioeconomic factors, a strong effect was estimated for persistent H pylori infection in an older sibling on persistent infection in a younger sibling (hazard ratio 7.6, 95% confidence interval 1.6–37], especially when the difference in the age of the siblings was less than or equal to 3 years (hazard ratio 16, 95% confidence interval 2.5–112).

Conclusions:

These results suggest that when siblings are close in age, the older sibling may be an important source of H pylori transmission for younger siblings.
Individual specialists in a generalist population: results from a long-term stable isotope series
Authors: Vander Zanden Hannah B. , Bjorndal Karen A. , Reich Kimberly J. , Bolten Alan B.
Published: March 2010

Individual variation in resource use has often been ignored in ecological studies, but closer examination of individual patterns through time may reveal significant intrapopulation differences. Adult loggerhead sea turtles (
Caretta caretta
) are generalist carnivores with a wide geographical range, resulting in a broad isotopic niche. We microsampled scute, a persistent and continuously growing tissue, to examine long-term variation in resource use (up to 12 years) in 15 nesting loggerhead turtles. Using stable isotopes of nitrogen and carbon, we examined the resource use patterns (integration of diet, habitat and geographical location) and demonstrate that individual loggerheads are long-term specialists within a generalist population. We present our results in the context of a conceptual model comparing isotopic niches in specialist and generalist populations. Individual consistency may have important ecological, evolutionary and conservation consequences, such as the reduction of intraspecific competition.
Two explanations for the compliant running paradox: reduced work of bouncing viscera and increased stability in uneven terrain
Authors: Daley Monica A. , Usherwood James R.
Published: March 2010

Economy is a central principle for understanding animal locomotion. Yet, compared with theoretical predictions concerning economy, animals run with compliant legs that are energetically costly. Here, we address this apparent paradox, highlighting two factors that predict benefits for compliant gaits: (i) minimizing cost of work associated with bouncing viscera; and (ii) leg control for robust stability in uneven terrain. We show that consideration of the effects of bouncing viscera predicts an energetic optimum for relatively compliant legs. To compare stability in uneven terrain, we introduce the normalized maximum drop (NMD), a measure based on simple kinematics, which predicts that compliant legs allow negotiation of relatively larger terrain perturbations without failure. Our model also suggests an inherent trade-off in control of leg retraction velocity (ω) for stability: lowωallows higher NMD, reducing fall risk, whereas highωminimizes peak forces with terrain drops, reducing injury risk. Optimization for one of these factors explicitly limits the other; however, compliant legs relax this trade-off, allowing greater stability by both measures. Our models suggest compromises in leg control for economy and stability that might explain why animals run with compliant legs.
Synthesizing within-host and population-level selective pressures on viral populations: the impact of adaptive immunity on viral immune escape
Authors: Volkov Igor , Pepin Kim M. , Lloyd-Smith James O. , Banavar Jayanth R. , Grenfell Bryan T.
Published: March 2010

The evolution of viruses to escape prevailing host immunity involves selection at multiple integrative scales, from within-host viral and immune kinetics to the host population level. In order to understand how viral immune escape occurs, we develop an analytical framework that links the dynamical nature of immunity and viral variation across these scales. Our epidemiological model incorporates within-host viral evolutionary dynamics for a virus that causes acute infections (e.g. influenza and norovirus) with changes in host immunity in response to genetic changes in the virus population. We use a deterministic description of the within-host replication dynamics of the virus, the pool of susceptible host cells and the host adaptive immune response. We find that viral immune escape is most effective at intermediate values of immune strength. At very low levels of immunity, selection is too weak to drive immune escape in recovered hosts, while very high levels of immunity impose such strong selection that viral subpopulations go extinct before acquiring enough genetic diversity to escape host immunity. This result echoes the predictions of simpler models, but our formulation allows us to dissect the combination of within-host and transmission-level processes that drive immune escape.
A two-tiered model for simulating the ecological and evolutionary dynamics of rapidly evolving viruses, with an application to influenza
Authors: Koelle Katia , Khatri Priya , Kamradt Meredith , Kepler Thomas B.
Published: March 2010

Understanding the epidemiological and evolutionary dynamics of rapidly evolving pathogens is one of the most challenging problems facing disease ecologists today. To date, many mathematical and individual-based models have provided key insights into the factors that may regulate these dynamics. However, in many of these models, abstractions have been made to the simulated sequences that limit an effective interface with empirical data. This is especially the case for rapidly evolving viruses in which de novo mutations result in antigenically novel variants. With this focus, we present a simple two-tiered ‘phylodynamic’ model whose purpose is to simulate, along with case data, sequence data that will allow for a more quantitative interface with observed sequence data. The model differs from previous approaches in that it separates the simulation of the epidemiological dynamics (tier 1) from the molecular evolution of the virus's dominant antigenic protein (tier 2). This separation of phenotypic dynamics from genetic dynamics results in a modular model that is computationally simpler and allows sequences to be simulated with specifications such as sequence length, nucleotide composition and molecular constraints. To illustrate its use, we apply the model to influenza A (H3N2) dynamics in humans, influenza B dynamics in humans and influenza A (H3N8) dynamics in equine hosts. In all three of these illustrative examples, we show that the model can simulate sequences that are quantitatively similar in pattern to those empirically observed. Future work should focus on statistical estimation of model parameters for these examples as well as the possibility of applying this model, or variants thereof, to other host–virus systems.
Conservation laws of inviscid non-isentropic compressible fluid flow in
n
> 1 spatial dimensions
Authors: Anco Stephen C. , Dar Amanullah
Published: March 2010

Recent work giving a classification of kinematic and vorticity conservation laws of compressible fluid flow with barotropic equations of state (where pressure is a function only of the fluid density) in
n
>1 spatial dimensions is extended to general non-isentropic equations of state in which the pressure is also a function of the dynamical entropy (per unit mass) of the fluid. Two main results are obtained. First, we find that, apart from the familiar conserved integrals for mass, momentum, energy, angular momentum, Galilean momentum and volumetric entropy, additional kinematic conserved integrals arise only for non-isentropic equations of state given by a generalized form of the well-known polytropic equation of state with dimension-dependent exponent
γ
=1+2/
n
, such that the proportionality coefficient is an arbitrary function of the entropy (per unit mass). Second, we show that the only vorticity conserved integrals consist of a circulatory entropy (which vanishes precisely when the fluid flow is irrotational) in all even dimensions. In particular, the vorticity integrals for helicity in odd dimensions and enstrophy in even dimensions are found to be no longer conserved for any non-isentropic equation of state.
Anelasticity and grain boundary sliding
Authors: Lee L. C. , Morris S. J. S.
Published: March 2010

We describe a theoretical and numerical analysis of an existing model of anelasticity owing to grain boundary sliding. Two linearly elastic layers having finite thickness and identical material constants are separated by a given fixed spatially periodic interface across which the normal componentof velocity is continuous, whereas the tangential componenthas a discontinuity determined by the shear stressσ*nsand the boundary sliding viscosityη*. We derive asymptotic forms giving the complex rigidity for the extremes of low-frequency forcing and of high-frequency forcing. Using those forms, we create master variables allowing results for different interface shapes, and arbitrary forcing frequency, to be collapsed (very nearly) into a single curve. We then analyse numerically, with finite interface slope, three proposed factors that may weaken and broaden the theoretical prediction of a single Debye peak in the loss spectrum. They are, namely, stress concentrations at interface corners, spatial variation in grain size and spatial variation in boundary sliding viscosityη*. Our results show that all these factors can, indeed, contribute to a moderate weakening of the loss peak. By contrast, the loss peak markedly broadens only when the boundary sliding viscosityη* differs by an order of magnitude across adjacent interface. The shape of the loss spectrum (self-similar to a single Debye peak) is insensitive to the other two factors.
Dispersal scales up the biodiversity–productivity relationship in an experimental source-sink metacommunity
Authors: Venail Patrick A. , Maclean R. Craig , Meynard Christine N. , Mouquet Nicolas
Published: March 2010

The influence of biodiversity on ecosystem functioning is a major concern of ecological research. However, the biodiversity–ecosystem functioning relationship has very often been studied independently from the mechanisms allowing coexistence. By considering the effects of dispersal and niche partitioning on diversity, the metacommunity perspective predicts a spatial scale-dependence of the shape of the relationship. Here, we present experimental evidence of such scale-dependent patterns. After approximately 500 generations of diversification in a spatially heterogeneous environment, we measured functional diversity (FD) and productivity at both local and regional scales in experimental source-sink metacommunities of the bacteriumPseudomonas fluorescensSBW25. At the regional scale, environmental heterogeneity yielded high levels of FD and we observed a positive correlation between diversity and productivity. At the local scale, intermediate dispersal increased local FD through a mass effect but there was no correlation between diversity and productivity. These experimental results underline the importance of considering the mechanisms maintaining biodiversity and the appropriate spatial scales in understanding its relationship with ecosystem functioning.
A strong quantitative trait locus for wing length on chromosome 2 in a wild population of great reed warblers
Authors: Tarka Maja , Åkesson Mikael , Beraldi Dario , Hernández-Sánchez Jules , Hasselquist Dennis , Bensch Staffan , Hansson Bengt
Published: March 2010

Wing length is a key character for essential behaviours related to bird flight such as migration and foraging. In the present study, we initiate the search for the genes underlying wing length in birds by studying a long-distance migrant, the great reed warbler (Acrocephalus arundinaceus). In this species wing length is an evolutionary interesting trait with pronounced latitudinal gradient and sex-specific selection regimes in local populations. We performed a quantitative trait locus (QTL) scan for wing length in great reed warblers using phenotypic, genotypic, pedigree and linkage map data from our long-term study population in Sweden. We applied the linkage analysis mapping method implemented in GridQTL (a new web-based software) and detected a genome-wide significant QTL for wing length on chromosome 2, to our knowledge, the first detected QTL in wild birds. The QTL extended over 25 cM and accounted for a substantial part (37%) of the phenotypic variance of the trait. A genome scan for tarsus length (a body-size-related trait) did not show any signal, implying that the wing-length QTL on chromosome 2 was not associated with body size. Our results provide a first important step into understanding the genetic architecture of avian wing length, and give opportunities to study the evolutionary dynamics of wing length at the locus level.
Antagonistic effects of floral scent in an insect–plant interaction
Authors: Reisenman Carolina E. , Riffell Jeffrey A. , Bernays Elizabeth A. , Hildebrand John G.
Published: March 2010

In southwestern USA, the jimsonweed
Datura wrightii
and the nocturnal moth
Manduca sexta
form a pollinator–plant and herbivore–plant association. Because the floral scent is probably important in mediating this interaction, we investigated the floral volatiles that might attract
M. sexta
for feeding and oviposition. We found that flower volatiles increase oviposition and include small amounts of both enantiomers of linalool, a common component of the scent of hawkmoth-pollinated flowers. Because (+)-linalool is processed in a female-specific glomerulus in the primary olfactory centre of
M. sexta
, we hypothesized that the enantiomers of linalool differentially modulate feeding and oviposition. Using a synthetic mixture that mimics the
D. wrightii
floral scent, we found that the presence of linalool was not necessary to evoke feeding and that mixtures containing (+)- and/or (−)-linalool were equally effective in mediating this behaviour. By contrast, females oviposited more on plants emitting (+)-linalool (alone or in mixtures) over control plants, while plants emitting (−)-linalool (alone or in mixtures) were less preferred than control plants. Together with our previous investigations, these results show that linalool has differential effects in feeding and oviposition through two neural pathways: one that is sexually isomorphic and non-enantioselective, and another that is female-specific and enantioselective.
Phylogeny, niche conservatism and the latitudinal diversity gradient in mammals
Authors: Buckley Lauren B. , Davies T. Jonathan , Ackerly David D. , Kraft Nathan J. B. , Harrison Susan P. , Anacker Brian L. , Cornell Howard V. , Damschen Ellen I. , Grytnes John-Avid , Hawkins Bradford A. , McCain Christy M. , Stephens Patrick R. , Wiens John J.
Published: March 2010

Biologists have long searched for mechanisms responsible for the increase in species richness with decreasing latitude. The strong correlation between species richness and climate is frequently interpreted as reflecting a causal link via processes linked to energy or evolutionary rates. Here, we investigate how the aggregation of clades, as dictated by phylogeny, can give rise to significant climate–richness gradients without gradients in diversification or environmental carrying capacity. The relationship between climate and species richness varies considerably between clades, regions and time periods in a global-scale phylogenetically informed analysis of all terrestrial mammal species. Many young clades show negative richness–temperature slopes (more species at cooler temperatures), with the ages of these clades coinciding with the expansion of temperate climate zones in the late Eocene. In carnivores, we find steeply positive richness–temperature slopes in clades with restricted distributions and tropical origins (e.g. cat clade), whereas widespread, temperate clades exhibit shallow, negative slopes (e.g. dog–bear clade). We show that the slope of the global climate–richness gradient in mammals is driven by aggregating Chiroptera (bats) with their Eutherian sister group. Our findings indicate that the evolutionary history should be accounted for as part of any search for causal links between environment and species richness.
The evolution of sex-specific immune defences
Authors: Restif Olivier , Amos William
Published: March 2010

Why do males and females often differ in their ability to cope with infection? Beyond physiological mechanisms, it has recently been proposed that life-history theory could explain immune differences from an adaptive point of view in relation to sex-specific reproductive strategies. However, a point often overlooked is that the benefits of immunity, and possibly the costs, depend not only on the host genotype but also on the presence and the phenotype of pathogens. To address this issue we developed an adaptive dynamic model that includes host–pathogen population dynamics and host sexual reproduction. Our model predicts that, although different reproductive strategies, following Bateman's principle, are not enough to select for different levels of immunity, males and females respond differently to further changes in the characteristics of either sex. For example, if males are more exposed to infection than females (e.g. for behavioural reasons), it is possible to see them evolve lower immunocompetence than females. This and other counterintuitive results highlight the importance of ecological feedbacks in the evolution of immune defences. While this study focuses on sex-specific natural selection, it could easily be extended to include sexual selection and thus help to understand the interplay between the two processes.
Phylogenetic isolation of host trees affects assembly of local Heteroptera communities
Authors: Vialatte A. , Bailey R. I. , Vasseur C. , Matocq A. , Gossner M. M. , Everhart D. , Vitrac X. , Belhadj A. , Ernoult A. , Prinzing A.
Published: March 2010

A host may be physically isolated in space and then may correspond to a geographical island, but it may also be separated from its local neighbours by hundreds of millions of years of evolutionary history, and may form in this case an evolutionarily distinct island. We test how this affects the assembly processes of the host's colonizers, this question being until now only invoked at the scale of physically distinct islands or patches. We studied the assembly of true bugs in crowns of oaks surrounded by phylogenetically more or less closely related trees. Despite the short distances (less than 150 m) between phylogenetically isolated and non-isolated trees, we found major differences between their Heteroptera faunas. We show that phylogenetically isolated trees support smaller numbers and fewer species of Heteroptera, an increasing proportion of phytophages and a decreasing proportion of omnivores, and proportionally more non-host-specialists. These differences were not due to changes in the nutritional quality of the trees, i.e. species sorting, which we accounted for. Comparison with predictions from meta-community theories suggests that the assembly of local Heteroptera communities may be strongly driven by independent metapopulation processes at the level of the individual species. We conclude that the assembly of communities on hosts separated from their neighbours by long periods of evolutionary history is qualitatively and quantitatively different from that on hosts established surrounded by closely related trees. Potentially, the biotic selection pressure on a host might thus change with the evolutionary proximity of the surrounding hosts.
Deregulated Copper Transport Affects Arabidopsis Development Especially in the Absence of Environmental Cycles
Authors: Andrés-ColÁs Nuria , Perea-García Ana , Puig Sergi , Peñarrubia Lola
Published: March 2010

Copper is an essential cofactor for key processes in plants, but it exerts harmful effects when in excess. Previous work has shown that the Arabidopsis (Arabidopsis thaliana) COPT1 high-affinity copper transport protein participates in copper uptake through plant root tips. Here, we show that COPT1 protein localizes to the plasma membrane of Arabidopsis cells and the phenotypic effects of transgenic plants overexpressing either COPT1 or COPT3, the latter being another high-affinity copper transport protein family member. Both transgenic lines exhibit increased endogenous copper levels and are sensitive to the copper in the growth medium. Additional phenotypes include decreased hypocotyl growth in red light and differentially affected flowering times depending on the photoperiod. Furthermore, in the absence of environmental cycles, such as light and temperature, the survival of plants overexpressing COPT1 or COPT3 is compromised. Consistent with altered circadian rhythms, the expression of the nuclear circadian clock genes CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) is substantially reduced in either COPT1- or COPT3-overexpressing plants. Copper affects the amplitude and the phase, but not the period, of the CCA1 and LHY oscillations in wild-type plants. Copper also drives a reduction in the expression of circadian clock output genes. These results reveal that the spatiotemporal control of copper transport is a key aspect of metal homeostasis that is required for Arabidopsis fitness, especially in the absence of environmental cues.
Isolation and Characterization of the Z-ISO Gene Encoding a Missing Component of Carotenoid Biosynthesis in Plants
Authors: Chen Yu , Li Faqiang , Wurtzel Eleanore T.
Published: March 2010

Metabolic engineering of plant carotenoids in food crops has been a recent focus for improving human health. Pathway manipulation is predicated on comprehensive knowledge of this biosynthetic pathway, which has been extensively studied. However, there existed the possibility of an additional biosynthetic step thought to be dispensable because it could be compensated for by light. This step, mediated by a putative Z-ISO, was predicted to occur in the sequence of redox reactions that are coupled to an electron transport chain and convert the colorless 15-cis-phytoene to the red-colored all-trans-lycopene. The enigma of carotenogenesis in the absence of light (e.g. in endosperm, a target for improving nutritional content) argued for Z-ISO as a pathway requirement. Therefore, understanding of plant carotenoid biosynthesis was obviously incomplete. To prove the existence of Z-ISO, maize (Zea mays) and Arabidopsis (Arabidopsis thaliana) mutants were isolated and the gene identified. Functional testing of the gene product in Escherichia coli showed isomerization of the 15-cis double bond in 9,15,9′-tri-cis-ζ-carotene, proving that Z-ISO encoded the missing step. Z-ISO was found to be important for both light-exposed and “dark” tissues. Comparative genomics illuminated the origin of Z-ISO found throughout higher and lower plants, algae, diatoms, and cyanobacteria. Z-ISO evolved from an ancestor related to the NnrU (for nitrite and nitric oxide reductase U) gene required for bacterial denitrification, a pathway that produces nitrogen oxides as alternate electron acceptors for anaerobic growth. Therefore, plant carotenogenesis evolved by recruitment of genes from noncarotenogenic bacteria.
Root-Specific Expression of OsNAC10 Improves Drought Tolerance and Grain Yield in Rice under Field Drought Conditions
Authors: Jeong Jin Seo , Kim Youn Shic , Baek Kwang Hun , Jung Harin , Ha Sun-Hwa , Do Choi Yang , Kim Minkyun , Reuzeau Christophe , Kim Ju-Kon
Published: March 2010

Drought poses a serious threat to the sustainability of rice (Oryza sativa) yields in rain-fed agriculture. Here, we report the results of a functional genomics approach that identified a rice NAC (an acronym for NAM [No Apical Meristem], ATAF1-2, and CUC2 [Cup-Shaped Cotyledon]) domain gene, OsNAC10, which improved performance of transgenic rice plants under field drought conditions. Of the 140 OsNAC genes predicted in rice, 18 were identified to be induced by stress conditions. Phylogenic analysis of the 18 OsNAC genes revealed the presence of three subgroups with distinct signature motifs. A group of OsNAC genes were prescreened for enhanced stress tolerance when overexpressed in rice. OsNAC10, one of the effective members selected from prescreening, is expressed predominantly in roots and panicles and induced by drought, high salinity, and abscisic acid. Overexpression of OsNAC10 in rice under the control of the constitutive promoter GOS2 and the root-specific promoter RCc3 increased the plant tolerance to drought, high salinity, and low temperature at the vegetative stage. More importantly, the RCc3:OsNAC10 plants showed significantly enhanced drought tolerance at the reproductive stage, increasing grain yield by 25% to 42% and by 5% to 14% over controls in the field under drought and normal conditions, respectively. Grain yield of GOS2:OsNAC10 plants in the field, in contrast, remained similar to that of controls under both normal and drought conditions. These differences in performance under field drought conditions reflect the differences in expression of OsNAC10-dependent target genes in roots as well as in leaves of the two transgenic plants, as revealed by microarray analyses. Root diameter of the RCc3:OsNAC10 plants was thicker by 1.25-fold than that of the GOS2:OsNAC10 and nontransgenic plants due to the enlarged stele, cortex, and epidermis. Overall, our results demonstrated that root-specific overexpression of OsNAC10 enlarges roots, enhancing drought tolerance of transgenic plants, which increases grain yield significantly under field drought conditions.
Parametric Rietveld refinement for the evaluation of powder diffraction patterns collected as a function of pressure
Authors: Halasz Ivan , Dinnebier Robert E. , Angel Ross
Published: March 2010

Under the assumption that the structural parameters of a crystalline phase change `smoothly' with increasing pressure, the evolution of the parameters can be parameterized as a function of pressure using continuous monotonic functions. Four different approaches to determine the structural evolution of As2O5with increasing pressure from a set of powder diffraction patterns collected over the pressure range from 2.5 to 19.5 GPa have been investigated. Approach (A) was the common sequential refinement of atomic coordinates with restraints on the geometry and was compared with three parameterization approaches. Approach (B) used direct parameterization by low-order polynomials of each crystallographically distinct atomic coordinate, (C) described the atoms of the asymmetric unit as a rigid body and allowed the internal degrees of freedom of the rigid body to vary with the change in pressure using rigid unit modes, and (D) described the crystal structure as a distortion of the higher-symmetry structure of As2O5(which is here also a high-temperature phase) by using symmetry-adapted distortion modes. Approach (D) offers the possibility to directly introduce an order parameter into Rietveld refinement through an empirical power law derived from Landau theory and thus to obtain the value of the critical exponent. In contrast, the rigid-body approach did not fit the data as well. All parameterizations greatly reduce the number of required parameters.
Powder diffraction by fixed incident angle reflection using a curved position-sensitive detector
Authors: Haggerty Ryan P. , Sarin Pankaj , Bérar Jean-Francois , Apostolov Zlatomir D. , Kriven Waltraud M.
Published: March 2010

As curved position-sensitive detectors improve in angular resolution, the effects that fixed incident angle reflection have on X-ray diffraction peaks become more apparent. In this study the effects of sample transparency, incident beam height, detector resolution and sample displacement on the intensity, location, width and shape of powder diffraction peaks were examined. The functions describing each of these phenomena are presented and were successfully used to quantitatively model the diffraction peaks collected in this geometry. Three distinct regimes of diffraction peak resolution were identified from the phenomena that limit the peak variance. Pertinent criteria based on experimental parameters have been outlined to classify fixed incident angle reflection experiments into each regime. Guidelines for improvement of experimental resolution and for conducting analysis of data acquired using fixed incident angle reflection geometry and curved position-sensitive detectors are also provided.
A thermosyphon-driven hydrothermal flow-through cell forin situand time-resolved neutron diffraction studies
Authors: Xia Fang , O'Neill Brian , Ngothai Yung , Peak Jason , Tenailleau Christophe , Etschmann Barbara , Qian Gujie , Brugger Joël , Studer Andrew , Olsen Scott , Pring Allan
Published: March 2010

A flow-through cell for hydrothermal phase transformation studies byin situand time-resolved neutron diffraction has been designed and constructed. The cell has a large internal volume of 320 ml and can operate at temperatures up to 573 K under autogenous vapor pressures (ca8.5 × 106 Pa). The fluid flow is driven by a thermosyphon, which is achieved by the proper design of temperature difference around the closed loop. The main body of the cell is made of stainless steel (316 type), but the sample compartment is constructed from non-scattering Ti–Zr alloy. The cell has been successfully commissioned on Australia's new high-intensity powder diffractometer WOMBAT at the Australian Nuclear Science and Technology Organization, using two simple phase transformation reactions from KAlSi2O6(leucite) to NaAlSi2O6·H2O (analcime) and then back from NaAlSi2O6·H2O to KAlSi2O6as examples. The demonstration proved that the cell is an excellent tool for probing hydrothermal crystallization. By collecting diffraction data every 5 min, it was clearly seen that KAlSi2O6was progressively transformed to NaAlSi2O6·H2O in a sodium chloride solution, and the produced NaAlSi2O6·H2O was progressively transformed back to KAlSi2O6in a potassium carbonate solution.
Whole-pattern profile fitting of powder diffraction data collected in parallel-beam flat-plate asymmetric reflection geometry
Authors: Rowles Matthew R. , Madsen Ian C.
Published: March 2010

A simple, physically based model that allows the whole-pattern profile fitting of diffraction data collected in parallel-beam flat-plate asymmetric reflection geometry is presented. In this arrangement, there is a fixed angle between the incident beam and the sample, resulting in a fixed-length beam footprint. The use of a wide-angle detector for the simultaneous detection of the data precludes the use of any diffracted beam optics. Therefore, the observed peak widths are a function of the length of the beam footprint on the sample. The model uses up to three refinable parameters, depending on the intensity profile of the beam, to calculate the effect of diffraction angle on the width of all diffracted peaks. The use of this model reduces the total number of parameters required to fit the observed peak widths and shapes, hence leading to increased stability in the profile analysis. Implementations of the model are provided for both fundamental parameters and empirical approaches.
Low-temperature phase transformation and phonon confinement in one-dimensional Ta2O5nanorods
Authors: Devan Rupesh S. , Ho Wei-Der , Wu Sheng Yun , Ma Yuan-Ron
Published: March 2010

The thermochromic phase transformations of one-dimensional Ta2O5nanorods have been analyzed at elevated temperatures ranging from 80 to 300 K. The nanorods, grown in a large-area high-density array, are 14–22 nm wide and approximately 500 nm long. The array contained ∼93.5% of the orthorhombic (β) phase and ∼6.5% of the tetragonal (α) phase. Low-temperature X-ray diffraction results showed complex and polymorphic thermochromic phase transformations of the β(001), α(101) and α(103) lattice planes of the nanorods, which incorporate (i) α-to-α (α–α), (ii) α–α–β and (iii) α–β phase transitions. In comparison with the Raman scattering of three-dimensional bulk powder and two-dimensional thin films of Ta2O5, there were concurrent Raman blue- and redshifts in the one-dimensional Ta2O5nanorods, indicating that the molecular vibrations of the nanorods were confined owing to the reduction of size and dimension.
A benchmark method for global optimization problems in structure determination from powder diffraction data
Authors: Shankland Kenneth , Markvardsen Anders J. , Rowlatt Christopher , Shankland Norman , David William I. F.
Published: March 2010

Quasi-Newton–Raphson minimization and conjugate gradient minimization have been used to solve the crystal structures of famotidine form B and capsaicin from X-ray powder diffraction data and characterize the χ2agreement surfaces. One million quasi-Newton–Raphson minimizations found the famotidine global minimum with a frequency ofca1 in 5000 and the capsaicin global minimum with a frequency ofca1 in 10 000. These results, which are corroborated by conjugate gradient minimization, demonstrate the existence of numerous pathways from some of the highest points on these χ2agreement surfaces to the respective global minima, which are passable using only downhill moves. This important observation has significant ramifications for the development of improved structure determination algorithms.
Aspects of maturation and reproduction in hexanchiform and squaliform sharks
Authors: White W. T. , Dharmadi
Published: March 2010

Three species of hexanchiform sharks belonging to two families and 12 species of squaliform sharks belonging to three families were recorded in fish landing site surveys in eastern Indonesia. Of these, the Squalidae were the most abundant species landed, with Squalus hemipinnis, Squalus edmundsi and Squalus montalbani contributing 0·4, 0·4 and 0·5% to the total number of sharks recorded in a 5 year survey of Indonesian fish landing sites. In comparison, the hexanchid Hexanchus griseus contributed the largest percentage to the total shark biomass. For many species, the majority of the catch consisted of immature fishes, which had not yet been able to reproduce. The data presented in this article are the first biological data reported on most of these shark species and are thus vital for fisheries managers and conservation assessors.
Recent progress in studies of infantile hemangioma
Authors: JINNIN Masatoshi , ISHIHARA Tsuyoshi , BOYE Eileen , OLSEN Bjorn R.
Published: March 2010

A hallmark of infantile hemangioma, the most common tumor of infancy, is its dramatic growth after birth, by diffuse proliferation of immature endothelial cells, followed by spontaneous regression. The growth and involution of infantile hemangioma is quite different from other vascular anomalies, which do not regress and can occur at any time during life. Some hemangioma lesions can be extremely disfiguring and destructive to normal tissue and may even be life‐threatening. Unfortunately, existing therapeutic approaches have limited success and significant adverse effects of some treatment modalities limit their use. Better understanding of the pathogenesis of hemangioma will enable the development of better therapeutic strategies. Here, we review recent studies and new hypotheses on the pathogenesis of the tumor. Detailed mechanisms of activated vascular endothelial growth factor signaling in tumor cells, identification of their origin and characterization of multipotent stem cells that can give rise to infantile hemangioma are shedding new light on this intriguing vascular tumor.
Apocrine gland carcinoma of the mammary skin concomitant with pagetoid phenomenon
Authors: USUI Keiko , OCHIAI Toyoko , ABE Ikuko , NISHIO Haruko , TOGO Kana , YAMAGATA Motoo
Published: March 2010

We reported a 52‐year‐old woman with an apocrine gland carcinoma of the mammary skin concomitant with pagetoid phenomenon. She had a 23‐year history of a small nodular lesion on the lower left part of her right breast with a 1‐year history of the pigmented plaque spreading peripherally around the nodule. Our diagnosis revealed that the nodule was an apocrine gland carcinoma and the intraepidermal neoplastic cells with pagetoid spread in the pigmented plaque were derived from the apocrine gland carcinoma. No Paget’s cells were detected in the right nipple, and no tumor cells were observed in the sentinel lymph node and underlying mammary gland tissue. We also investigated the immunohistochemical changes in this case. They showed that both intraepidermal neoplastic cells with pagetoid spread and tumor cells of the apocrine gland carcinoma were positive with cytokeratin‐7 and human epidermal growth factor receptor‐2 (HER‐2)/neu overexpression. The results of the present study conclude that the intraepithelial spread of tumor cells in the mammary skin distant from the nipple occurred as a pagetoid phenomenon, and that HER‐2 may have a key role in pagetoid phenomenon of an underlying apocrine gland carcinoma, as well as in mammary Paget’s disease.
Temporal triangular alopecia and a review of 52 past cases
Authors: YAMAZAKI Masashi , IRISAWA Ryokichi , TSUBOI Ryoji
Published: March 2010

Temporal triangular alopecia (TTA) is a circumscribed, non‐cicatricial form of alopecia confined to the frontotemporal region. The patient, a 15‐year‐old boy, was noticed at birth to have an alopecial area, sized 1.5 cm × 2.5 cm, in the right temporal region. Microscopic examination revealed miniaturized hair follicles accompanied by differentiated sebaceous glands. We have provided a synopsis of the past 52 cases. Of the 53 cases of TTA including our case, more than half (55.8%) were detected in childhood between the ages of 2 and 9 years, while 36.5% were detected at birth and only 3.8% (only two cases) in adulthood. There were three familial cases. Several congenital diseases were associated with the condition, for example, phakomatosis pigmentovascularis, Down syndrome and Dandy–Walker malformation. This information suggests that TTA can be recognized as a hamartomatous mosaic disease.
Drug‐induced hypersensitivity syndrome due to carbapenem antibiotics
Authors: GOTO Mizuki , SHIMIZU Fumiaki , TAKEO Naoko , OKAMOTO Osamu , KATAGIRI Kazumoto , IKEWAKI Junji , OGATA Masao , KADOTA Jun‐ichi , FUJIWARA Sakuhei
Published: March 2010

Drug‐induced hypersensitivity syndrome (DIHS) is characterized by a serious adverse systemic reaction that usually appears after a 3–6‐week exposure to certain drugs, for example, anticonvulsants. Many different precipitating factors have been reported, but the pathophysiology of DIHS remains unknown. However, reactivation of members of the human herpesvirus (HHV) family, and of HHV‐6 in particular, has been reported in patients with DIHS. We report the case of a 64‐year‐old man who developed a generalized erythematous rash, fever, hepatic failure, lymphadenopathy and an increased number of atypical lymphocytes. In addition, reactivation of HHV‐6 and cytomegalovirus (CMV) was demonstrated by real‐time quantitative amplification by polymerase chain reaction. The patient was given a diagnosis of DIHS due to carbapenem antibiotics based on his clinical course, laboratory data, and results of lymphocyte‐stimulation tests with various drugs. This is the first report, to our knowledge, of DIHS induced by carbapenem antibiotics.
Dermoscopic evaluation of vascular structures of various skin tumors in Japanese patients
Authors: SAKAKIBARA Akihiro , KAMIJIMA Michihiro , SHIBATA Shinichi , YASUE Satoshi , KONO Michihiro , TOMITA Yasushi
Published: March 2010

Dermoscopic analysis of skin tumor has been mainly focused on pigmented structures. Recently, several different morphological types of vessels were found to be well associated with pigmented or non‐pigmented skin tumors in white subjects. Therefore, the recognition of such vascular structures has been applied for diagnostic purposes. As little statistical information on the various pigmented skin tumor vessels of Japanese patients has been reported, we therefore tried to evaluate the association between various vascular structures and 741 tumor lesions of Japanese patients. Vascular structures were dermoscopically recognized in 41 of 102 cases of melanoma, 104 of 119 basal cell carcinoma (BCC), 86 of 257 seborrheic keratosis (SK), 35 of 210 dermal and compound nevus (DN/CN), six of 12 squamous cell carcinoma (SCC) and 16 of 41 Bowen disease (BD). The structures of arborizing and glomerular vessels statistically revealed diagnostic specificity for BCC and BD, respectively, and hairpin vessels were helpful for differentiating SK from other pigmented tumors, as already reported in white patients. The most common vascular pattern observed in melanoma was the linear–irregular structure, but this pattern in Japanese patients had less diagnostic value than in white patients, because its sensitivity was not significantly higher than in SCC. The most remarkable differences between our study and previous reports with white patients were low frequency and sensitivity of dotted, comma and polymorphous vessels in lesions of melanoma, BCC and DN/CN; these vessels had less diagnostic value for Japanese patients. Finally, the frequency of vascular structures observed in melanoma rose along with the increase of the Breslow’s tumor thickness, and 88% of melanomas with vascular vessels revealed tumor thicknesses of more than 2 mm.
Bmi‐1 is related to proliferation, survival and poor prognosis in pancreatic cancer
Authors: Song Wenjie , Tao Kaishan , Li Haimin , Jin Chen , Song Zhenshun , Li Jun , Shi Hai , Li Xiao , Dang Zheng , Dou Kefeng
Published: March 2010

B‐cell‐specific Moloney murine leukemia virus insertion site 1 (BMI1) is a member of the polycomb group of transcriptional repressors. Until now, its expression and functional significance in pancreatic carcinogenesis was unknown. In the present study, we demonstrated that expression of BMI1 was markedly up‐regulated in pancreatic cancer cell lines and surgically resected cancer specimens. In addition, BMI1 expression levels correlated positively with the presence of lymph node metastases and negatively with patient survival rates, suggesting a role for BMI1 in the progression of pancreatic cancer. Furthermore, stable down‐regulation of BMI1 suppressed cell growth, delayed the G1/S transition, and enhanced the susceptibility of different pancreatic cell lines to apoptosis following expression of a lentiviral‐mediated shRNA targeted for BMI1. Expression of the short‐hairpin RNA also correlated with the up‐regulation of p21 and Bax and the down‐regulation of cyclin D1, cyclin‐dependent kinase (CDK)‐2 and ‐4, Bcl‐2, and phospho‐Akt. Finally, growth suppression following BMI1 depletion was confirmed in a nude mouse model. In conclusion, our findings indicate that BMI1 plays an important role in the late progression of pancreatic cancer and may represent a novel therapeutic target for the treatment of pancreatic cancer. (Cancer Sci 2010)
Pitavastatin inhibits azoxymethane‐induced colonic preneoplastic lesions in C57BL/KsJ‐db/db obese mice
Authors: Yasuda Yoichi , Shimizu Masahito , Shirakami Yohei , Sakai Hiroyasu , Kubota Masaya , Hata Kazuya , Hirose Yoshinobu , Tsurumi Hisashi , Tanaka Takuji , Moriwaki Hisataka
Published: March 2010

Obesity and related metabolic abnormalities are risk factors for colorectal cancer. A state of chronic inflammation and adipocytokine imbalance may play a role in colorectal carcinogenesis. Statins, which are commonly used for the treatment of hyperlipidemia, are known to possess anti‐inflammatory effects. Statins also exert chemopreventive properties against various cancers. The present study examined the effects of pitavastatin, a recently developed lipophilic statin, on the development of azoxymethane (AOM)‐initiated colonic premalignant lesions in C57BL/KsJ‐db/db (db/db) obese mice. Male db/db mice were administrated weekly subcutaneous injections of AOM (15 mg/kg body weight) for 4 weeks and then were subsequently fed a diet containing 1 ppm or 10 ppm pitavastatin for 8 weeks. Feeding with either dose of pitavastatin significantly reduced the number of colonic premalignant lesions, β‐catenin accumulated crypts, by inhibiting proliferation and the surrounding inflammation. Pitavastatin increased the serum levels of adiponectin while conversely decreasing the serum levels of total cholesterol, tumor necrosis factor‐α (TNF‐α), interleukin (IL)‐6, IL‐18, and leptin. Pitavastatin also caused a significant increase in the expression of phosphorylated form of the AMP‐activated kinase (AMPK) protein on the colonic mucosa of AOM‐treated mice. In addition, the expression levels of TNF‐α, IL‐6, IL‐18, and COX‐2 mRNAs on the colonic mucosa of AOM‐treated mice were decreased by treatment with this agent. These findings suggest that pitavastatin attenuates chronic inflammation and improves the imbalance of adipocytokines, both of which are caused by the presence of excess adipose tissues, thereby preventing the development of colonic premalignancies in an obesity‐related colon cancer model. Therefore, some types of statins, including pitavastatin, may be a useful chemoprevention modality for colon cancer in obese individuals. (Cancer Sci 2010)
Spinal anaesthesia and caesarean section in a patient with hypofibrinogenaemia and factor XIII deficiency*
Authors: Hanke A. A. , Elsner O. , Görlinger K.
Published: March 2010

We report the peri‐operative management of a 32‐year‐old patient suffering from symptomatic hypofibrinogenaemia and factor XIII deficiency scheduled for caesarean section. Starting with an impaired fibrinogen (1.04 g.l−1) and factor XIII level (48%), fibrinogen and factor XIII administration was guided by point‐of‐care rotational thrombelastometry (ROTEM®) to achieve normal whole blood coagulation, which allowed uncomplicated spinal anaesthesia and an uneventful surgical procedure. We conclude that rotational thrombelastometry may be suitable to guide administration of coagulation factors in patients with hereditary bleeding disorders and allow otherwise contraindicated neuraxial anaesthesia and surgery to proceed without increased risk of blood loss.
Effect‐site concentration of remifentanil attenuating surgical stress index responses to intubation of the trachea
Authors: Mustola S. , Toivonen J.
Published: March 2010

Surgical Stress Index has been proposed for assessment of surgical stress and analgesia. It is a numeric index based on the normalised pulse beat interval and photoplethysmographic pulse wave amplitude. We determined the effect‐site concentration of remifentanil for attenuation of Surgical Stress Index responses to intubation of the trachea. Thirty ASA 1–2 patients received either deep or normal anaesthesia and then target‐controlled remifentanil. Burst suppression was maintained in the deep group and state entropy at 40–60 (scale 0–91) in the normal group. Mean (SD) effect‐site concentrations of remifentanil attenuating responses in 50% of patients were 2.13 (0.25) ng.ml−1 and 3.05 (0.27) ng.ml−1 in deep and normal groups, respectively (p = 0.034). From probit analysis, EC50 and EC95 of remifentanil (95% CI) were 2.34 (1.97–2.71) ng.ml−1 and 3.19 (2.69–3.69) ng.ml−1 in deep group and 3.17 (2.67–3.67) ng.ml−1 and 3.79 (3.21–4.37) ng.ml−1 in the normal group, respectively. The values from probit analysis and up‐and‐down method did not differ significantly.