bluuebunny/crossref_metadata_2025 huggingface dataset:
Saxs Studies of Poly (3-Octylthiophene) and Poly (3,3″-Dioctyl-2, 2″,5′2″-Terithiophene) Polymer thin Films
Authors: Sivakumar K. , Kavitha B. , Wu C. , Narsimlu N.
Published: March 2012

Small angle X-ray scattering (SAXS) is familiar to the polymer community as a method for structural analysis. Here we applied the SAXS experimental technique to obtain the macromolecular parameters ( radius of gyration Rg, radius R, Specific surface area Ss and surface fractal dimension Ds) of two different polythiophene derivatives Poly (3-Octylthiophene) (POTH) and Poly (3,3”-dioctyl-2,2”, 5'2”-terthiophene) (POTTOT) thin films. Thin films of these two polymers were prepared on a glass substrate with thickness around 3.5 µm by spin coating. SAXS experiments are performed with an 18 kW rotating anode X-ray generator equipped with a Cu Target. A two-dimensional proportional counter is employed to detect the scattered X-rays intensity. Analysis of SAXS data using Guinier approximation the radius of gyration of POTH and POTTOT particles are determined as 10.73 Å and 9.99Å respectively. Porod approximation is used to find specific surface area of POTH and POTTOT polymeric thin films and they are determined as 3.6X108 cm-1 and 3.00×108 cm-1 respectively. The surface fractal dimension of POTH and POTTOT thin films are calculated as 2.85 and 2.65 respectively.
Short-term Exposure to Nanoparticle-rich Diesel Engine Exhaust Causes Changes in Brain Activity but not in Cognitive Performance in Human Volunteers.
Authors: Driessen Anique , Crüts Björn , van Etten Ludo , Crüts Anica , Fokkens Paul H.B. , Cassee Flemming R. , Borm. Paul J.A.
Published: March 2012

In previous studies we showed that short-term exposure to high (300 μg/m3) concentrations of diesel engine exhaust (DE) caused an increase in the high-frequency part of the brain spectrum (measured by electroencephalography, EEG). The purpose of this study was to investigate the same markers at lower, more commonly occurring concentrations of DE (100 μg/m3) and to investigate the effects of diesel exposure on cognitive performance. We exposed 12 healthy volunteers to dilute DE (particle concentration: 100 µg/m3) and filtered purified air for one hour using a double blind randomized crossover design. Brain activity of the frontal cortex was monitored before, during and 0, 1, 4 and 24 hours following exposure using quantitative electroencephalography (QEEG). Fast Fourier Transforms were used to calculate the amplitudes of pre-defined frequency bands in the spectrum of the QEEG. Cognitive performance was assessed at baseline and at 0 and 24 hrs by two tests focusing on acute memory and information processing. The data demonstrate a slow response to DE in the frontal cortex characterized by an increase in fast wave activity (beta 1, beta 2) which became significant between 1 and 4 hrs after exposure. Acute effects on cognitive function were not observed. Neither the memory task nor the attention task was affected during and after exposure to DE. Conclusion. This study confirms our earlier findings on effect of diesel exhaust on brain function with regard to the type of interaction (fast-wave activity in EEG) and shows that the effect continues up to 4 hours after exposure. A possible relationship between these EEG findings and cognitive functions could not be established.
La radioprotection en orthodontie : données
utiles
Authors: Foucart Jean-Michel , Felizardo Rufino , Pizelle Christophe
Published: March 2012

Depuis ces 30 dernières années, l’imagerie est au cœur des révolutions médicales. Elle
permet un diagnostic fiable et précis à l’origine d’une prise en charge individuelle, mais
aussi de suivre les évolutions liées au traitement. L’orthodontie a naturellement
bénéficié des innovations en imagerie médicale. Parallèlement, la connaissance des risques
liés à l’utilisation des rayonnements ionisants a progressé et l’utilisation de ces
derniers repose sur le principe « ALARA » : « Aussi bas qu’il est raisonnablement
possible » (« As Low As Reasonably Achievable »). Si ce principe est
inscrit dans les différentes législations nationales et européennes, la connaissance de
son origine scientifique permet une utilisation quotidienne des rayons X.
Les vertèbres cervicales : indicateurs du dynamisme de la
croissance mandibulaire ?
Authors: Raberin Monique , Cozor Ilinca , Gobert-Jacquart Stéphanie
Published: March 2012

Une étude de la maturation de la croissance mandibulaire a été réalisée sur une
population de 103 patients en cours de traitement (69 filles et 34 garçons) de 11 à 16 ans
présentant initialement une classe II squelettique. La relation entre les indices de
maturation du poignet et la classification de la maturation des vertèbres cervicales selon
Lamparski a été étudiée. Des corrélations significatives ont été trouvées entre les stades
de Björk, MP3=, MP3 cap et MP3 U et respectivement les stades de Lamparski CVS 2, CVS 3-4
et CVS 5-6. Cette étude longitudinale rétrospective a cerné trois variables mandibulaires
à trois stades de maturation différentes selon la classification de Björk et selon la
classification en six stades de Lamparski. Les relations entre ces différents stades de
maturation et la réponse quantitative de la croissance mandibulaire permettent de situer
la période optimale de stimulation thérapeutique. Les résultats indiquent une augmentation
significative des longueurs mandibulaires au stade CVS 4 et CVS 5, laissant présager de la
persistance d’une réponse condylienne à une stimulation thérapeutique après le stade CVS
3-CVS 4 (MP3 cap). Le dynamisme mandibulaire semble se poursuivre après le stade MP3 U
soit après le stade CVS 5.
Empreintes numériques : mythes et réalité
quotidienne
Authors: Coblentz Jean-François
Published: March 2012

Le numérique s’impose chaque jour un peu plus dans tous les métiers,
l’ODF n’en est pas exempte. Les solutions d’études de moulages
numériques deviennent des produits matures et laissent penser que
l’étude de cas se fera, de plus en plus, à l’écran. De la prise
d’empreintes au plan de traitement, de plus en plus d’étapes sont donc
numériques ou numérisables. Encore faut-il disposer des outils
logiciels qui permettent d’augmenter réellement la productivité du
praticien et du cabinet. Ces systèmes existent et sont désormais
pérennes, même si d’autres étapes jalonneront le passage au tout
numérique, inéluctablement.
Macroscopic thermal entanglement in a spin chain caused by the magnetic field: Inhomogeneity effect
Authors: Zvyagin A. A.
Published: March 2012

The influence of the inhomogeneity on the macroscopic thermal pairwise entanglement for the system of coupled spins 1/2 (qubits) has been studied. The most important effect of the inhomogeneity on the thermal entanglement is in the new role of the external potential (magnetic field), which can produce nonzero entanglement for qubits, situated not far from the inhomogeneity.
The effect of molecular impurities CO and CH4 on the structural characteristics of the C60 fullerene around the orientational phase transition
Authors: Aksenova N. A. , Galtsov N. N. , Prokhvatilov A. I.
Published: March 2012

X-ray studies of structural characteristics of С60(С)0.9 and С60(CH4)0.5 solid solutions were carried out in around the orientation phase transition in the C60 fullerene. It was established that the filling of octahedral cavities of the fullerene lattice by molecules of CO and CH4 results in a significant increase of the lattice parameter and the thermal expansion coefficients of the ordered phase and in a decrease in the volume change and phase transition temperature TC. In this case there also occurs a noticeable “smearing” of the phase transformation. Based on these results and on the data in the literature contradictions in the conclusions about the structural peculiarities of the formation of a glass state in the CO–C60 solutions were analyzed and discussed. Linear dependences of orientational transition temperature TC and glass transition temperature Tg on CO concentration in the octahedral cavities were obtained. Concentrations of CO in the previous study of specific heat of solid mixtures were calculated.
Theory of diffraction in disordered crystals formed by linear asymmetric molecules
Authors: Danchuk V. V. , Strzhemechny M. A.
Published: March 2012

Using the general principles of Krivoglaz’s theory of diffraction for irregular crystals as well as the expansion of scattering structure amplitudes in spherical harmonics, a kinematic theory of diffraction has been developed for crystals, which consist of asymmetric linear molecules characterized by a “head-tail” disorder. The random variables that determine the statistics of deviations of molecular centers of mass and orientations of molecular axes from their average values are supposed to be independent. Detailed analysis is carried out for the N2O and CO cryocrystals, the structure of which is described on average by space group symmetry Pa3. The final formulas for integrated intensities of Bragg lines allow reconstruction of all parameters, which characterize the statistics of deviations of the relevant geometric parameters from their crystal averages.
Influence of pore size distribution and soil water content on nitrous oxide emissions
Authors: van der Weerden Tony J. , Kelliher Francis M. , de Klein Cecile A. M.
Published: March 2012

Nitrous oxide (N2O) emissions from agricultural soils have been estimated to comprise about two-thirds of the biosphere’s contribution of this potent greenhouse gas. In pasture systems grazed by farmed animals, where substrate is generally available, spatial variation in emissions, in addition to that cause by the patchiness of urine deposition, has been attributed to soil aeration, as governed by gas diffusion. However, this parameter is not readily measured, and the soil’s water-filled pore space (WFPS) has often been used as a proxy, despite gas diffusion in soils depending on the volumetric fractions of water and air. With changing water content, these fractions will reflect the soil’s pore size distribution. The aims of this study were: (i) to determine if the pore size distribution of two pastoral soils explains previously observed differences in N2O emissions under field conditions, and (ii) to assess the most appropriate soil water/gas diffusion metric for estimating N2O emissions. The N2O emissions were measured from intact cores of two soils (one classified as well drained and one as poorly drained) that had been sampled to a depth of 50 mm beneath grazed pasture. Nitrogen (N, 500 kg N/ha) was applied to soil cores as aqueous nitrate solution, and the cores were drained under controlled conditions at a constant temperature. The poorly drained soil had a larger proportion of macropores (23.5 v. 18.7% in the well-drained soil), resulting in more rapid drainage and increased pore continuity, thereby reducing the duration of anaerobicity, and leading to lower N2O emissions. Emissions were related to three soil water proxies including WFPS, volumetric water content (VWC), and matric potential (MP), and to relative diffusion (RD). All parameters showed highly significant relationships with N2O emissions (P < 0.001), with RD, WFPS, VWC, and MP accounting for 59, 72, 88, and 93% of the variability, respectively. As VWC is more readily determined than MP, the former is potentially more suitable for estimating N2O emission from different soils across a range of time and space scales under field conditions.
Distinct mechanism for long-term contrast adaptation
Authors: Bao Min , Engel Stephen A.
Published: March 2012

To optimize perception, neurons in the visual system adapt to the current environment. What determines the durability of this plasticity? Longer exposures to an environment produce longer-lasting effects, which could be due to either (
i
) a single mechanism controlling adaptation that gains strength over time, or (
ii
) long-term mechanisms that become active after long-term exposure. Using recently developed technology, we tested adaptation durations an order of magnitude greater that those tested previously, and used a “deadaptation” procedure to reveal effects of a unique long-term mechanism in the longest adaptation periods. After 4 h of contrast adaptation, human observers were exposed to natural images for 15 min, which completely cancelled perceptual aftereffects of adaptation. Strikingly, during continued testing this deadaptation faded, and the original adaptation effects reappeared. This pattern strongly suggests that adaptation was maintained in a distinct long-term mechanism, whereas deadaptation affected a short-term mechanism.
Edge-carboxylated graphene nanosheets via ball milling
Authors: Jeon In-Yup , Shin Yeon-Ran , Sohn Gyung-Joo , Choi Hyun-Jung , Bae Seo-Yoon , Mahmood Javeed , Jung Sun-Min , Seo Jeong-Min , Kim Min-Jung , Wook Chang Dong , Dai Liming , Baek Jong-Beom
Published: March 2012

Low-cost, high-yield production of graphene nanosheets (GNs) is essential for practical applications. We have achieved high yield of edge-selectively carboxylated graphite (ECG) by a simple ball milling of pristine graphite in the presence of dry ice. The resultant ECG is highly dispersable in various solvents to self-exfoliate into single- and few-layer (≤ 5 layers) GNs. These stable ECG (or GN) dispersions have been used for solution processing, coupled with thermal decarboxylation, to produce large-area GN films for many potential applications ranging from electronic materials to chemical catalysts. The electrical conductivity of a thermally decarboxylated ECG film was found to be as high as 1214 S/cm, which is superior to its GO counterparts. Ball milling can thus provide simple, but efficient and versatile, and eco-friendly (CO
2
-capturing) approaches to low-cost mass production of high-quality GNs for applications where GOs have been exploited and beyond.
Impact of the
Deepwater Horizon
oil spill on a deep-water coral community in the Gulf of Mexico
Authors: White Helen K. , Hsing Pen-Yuan , Cho Walter , Shank Timothy M. , Cordes Erik E. , Quattrini Andrea M. , Nelson Robert K. , Camilli Richard , Demopoulos Amanda W. J. , German Christopher R. , Brooks James M. , Roberts Harry H. , Shedd William , Reddy Christopher M. , Fisher Charles R.
Published: March 2012

To assess the potential impact of the
Deepwater Horizon
oil spill on offshore ecosystems, 11 sites hosting deep-water coral communities were examined 3 to 4 mo after the well was capped. Healthy coral communities were observed at all sites >20 km from the Macondo well, including seven sites previously visited in September 2009, where the corals and communities appeared unchanged. However, at one site 11 km southwest of the Macondo well, coral colonies presented widespread signs of stress, including varying degrees of tissue loss, sclerite enlargement, excess mucous production, bleached commensal ophiuroids, and covering by brown flocculent material (floc). On the basis of these criteria the level of impact to individual colonies was ranked from 0 (least impact) to 4 (greatest impact). Of the 43 corals imaged at that site, 46% exhibited evidence of impact on more than half of the colony, whereas nearly a quarter of all of the corals showed impact to >90% of the colony. Additionally, 53% of these corals’ ophiuroid associates displayed abnormal color and/or attachment posture. Analysis of hopanoid petroleum biomarkers isolated from the floc provides strong evidence that this material contained oil from the Macondo well. The presence of recently damaged and deceased corals beneath the path of a previously documented plume emanating from the Macondo well provides compelling evidence that the oil impacted deep-water ecosystems. Our findings underscore the unprecedented nature of the spill in terms of its magnitude, release at depth, and impact to deep-water ecosystems.
Genetic switchboard for synthetic biology applications
Authors: Callura Jarred M. , Cantor Charles R. , Collins James J.
Published: March 2012

A key next step in synthetic biology is to combine simple circuits into higher-order systems. In this work, we expanded our synthetic riboregulation platform into a genetic switchboard that independently controls the expression of multiple genes in parallel. First, we designed and characterized riboregulator variants to complete the foundation of the genetic switchboard; then we constructed the switchboard sensor, a testing platform that reported on quorum-signaling molecules, DNA damage, iron starvation, and extracellular magnesium concentration in single cells. As a demonstration of the biotechnological potential of our synthetic device, we built a metabolism switchboard that regulated four metabolic genes,
pgi
,
zwf
,
edd
, and
gnd
, to control carbon flow through three
Escherichia coli
glucose-utilization pathways: the Embden–Meyerhof, Entner–Doudoroff, and pentose phosphate pathways. We provide direct evidence for switchboard-mediated shunting of metabolic flux by measuring mRNA levels of the riboregulated genes, shifts in the activities of the relevant enzymes and pathways, and targeted changes to the
E. coli
metabolome. The design, testing, and implementation of the genetic switchboard illustrate the successful construction of a higher-order system that can be used for a broad range of practical applications in synthetic biology and biotechnology.
Temporal and Ontogenetic Variability in Trophic Role of Four Groundfish Species—Walleye Pollock, Pacific Cod, Arrowtooth Flounder, and Pacific Halibut—around Kodiak Island in the Gulf of Alaska
Authors: Marsh Jennifer M. , Hillgruber Nicola , Foy Robert J.
Published: March 2012

Changes in trophic position estimates of commercial fishery catches are used as an ecosystem‐based indicator for sustainability, but often these estimates do not incorporate species‐specific seasonal feeding dynamics and ontogenetic diet changes. Using stable isotope analysis, we obtained a fine‐scale resolution of ontogenetic and temporal (interannual and seasonal) variations in the trophic roles of four commercially and ecologically important groundfish species in the Gulf of Alaska: walleye pollock Theragra chalcogramma, Pacific cod Gadus macrocephalus, arrowtooth flounder Atheresthes stomias, and Pacific halibut Hippoglossus stenolepis. For each groundfish taxon, the nitrogen stable isotope signature (δ15N) increased with total length. In contrast, the lipid‐normalized carbon stable isotope signature (δ13C′) significantly varied with size‐class only for walleye pollock. There were species‐specific differences in trophic position; adult Pacific cod fed at the highest trophic position, and walleye pollock fed at the lowest trophic position. Walleye pollock also had the lowest δ13C′, indicating a mainly pelagic diet, while Pacific halibut and Pacific cod had the highest δ13C′, indicating a mostly benthic diet. Interannual differences in trophic position were detected for each species. Pacific cod, arrowtooth flounder, and Pacific halibut fed at a significantly lower trophic position in 2003 than in 2001, 2002, or 2004. All species had a significantly lower average δ13C′ (i.e., a more benthic diet) in 2001 and a higher average δ13C′ (a more pelagic diet) in 2003. Pacific cod, Pacific halibut, and walleye pollock had a significantly more pelagic diet in the summer. Walleye pollock, arrowtooth flounder, and Pacific halibut showed a significantly more benthic diet in the fall, which probably corresponded with their seasonal migrations. Temporal variations in stable isotope signatures were observed but were relatively small (<1.25‰). Length‐based ontogenetic diet shifts, however, were much larger (up to 6‰) and must be considered when trophic position is used as an ecosystem indicator of sustainability.
Effects of Feeding Rate and Frequency on Production Characteristics of Pond-Raised Hybrid Catfish
Authors: Li Menghe H , Robinson Edwin H , Oberle Daniel F , Lucas Penelope M
Published: March 2012

The present study examined the effects of various daily feeding rates and feeding every other day on the growth, net yield, feed conversion ratio, and size distribution of hybrid catfish (female channel catfish Ictalurus punctatus × male blue catfish I. furcatus) in production ponds. Hybrid catfish fingerlings (average size, 45 g) were stocked into 0.04-ha ponds at a density of 14,826 fish/ha. Initially, all fish were fed to apparent satiation until feed consumption reached predetermined levels. Thereafter, the daily feeding rates for fish in the restricted feeding group were no more than 112, 135, or 168 kg·ha−1·d−1. Fish in the every-other-day feeding group were fed to apparent satiation daily until they reached about 0.23 kg and every other day to satiation thereafter. The results from the present study show that feeding every other day significantly reduces the weight gain and net yield of hybrid catfish but improves the feed conversion ratio. Partial budget analysis indicates that feeding hybrid catfish every other day is not economical at recent feed and fish prices. There were no significant differences in net yield, weight gain, and percentage of market-size fish among fish fed daily at various rates. Fish fed daily at no more than 112 and 135 kg/ha had significantly lower feed conversion ratios than fish fed daily to satiation. Simple regression analysis indicates that the weight gain, net yield, feed conversion ratio, and percentage of market-size fish increased linearly as the total amount of feed fed increased in fish fed daily. The results also show that the feed restriction used in the present study does not affect the size distribution of hybrid catfish.
Proliferation risks of magnetic fusion energy: clandestine production, covert production and breakout
Authors: Glaser A. , Goldston R.J.
Published: March 2012

Nuclear proliferation risks from magnetic fusion energy associated with access to weapon-usable materials can be divided into three main categories: (1) clandestine production of weapon-usable material in an undeclared facility, (2) covert production of such material in a declared facility and (3) use of a declared facility in a breakout scenario, in which a state begins production of fissile material without concealing the effort. In this paper, we address each of these categories of risks from fusion. For each case, we find that the proliferation risk from fusion systems can be much lower than the equivalent risk from fission systems, if the fusion system is designed to accommodate appropriate safeguards.
The directional flow of visual information transfer between pedestrians
Authors: Gallup Andrew C. , Chong Andrew , Couzin Iain D.
Published: March 2012

Close behavioural coupling of visual orientation may provide a range of adaptive benefits to social species. In order to investigate the natural properties of gaze-following between pedestrians, we displayed an attractive stimulus in a frequently trafficked corridor within which a hidden camera was placed to detect directed gaze from passers-by. The presence of visual cues towards the stimulus by nearby pedestrians increased the probability of passers-by looking as well. In contrast to cueing paradigms used for laboratory research, however, we found that individuals were more responsive to changes in the visual orientation of those walking in the same direction in front of them (i.e. viewing head direction from behind). In fact, visual attention towards the stimulus diminished when oncoming pedestrians had previously looked. Information was therefore transferred more effectively behind, rather than in front of, gaze cues. Further analyses show that neither crowding nor group interactions were driving these effects, suggesting that, within natural settings gaze-following is strongly mediated by social interaction and facilitates acquisition of environmentally relevant information.
Biomimetic modification of metallic cardiovascular biomaterials: from function mimicking to endothelialization
in vivo
Authors: Weng Yajun , Chen Junying , Tu Qiufen , Li Quanli , Maitz Manfred F. , Huang Nan
Published: March 2012

Biosystem–surface interactions play an important role in various biological events and determine the ultimate functionality of implanted devices. Endothelialization or mimicking of endothelium on the surface of cardiovascular materials is a promising way to solve the problems of material-induced thrombosis and restenosis. Meanwhile, a multifunctional surface design is needed as antithrombotic properties should be considered in the period when the implants are not yet completely endothelialized. In this article, we summarize some successful approaches used in our laboratory for constructing multifunctional endothelium-like surfaces on metallic cardiovascular biomaterials through chemical modification of the surface or by the introduction of specific biological molecules to induce self-endothelialization
in vivo
. Some directions on future research in these areas are also presented.
Contributions of John Henry Poynting to the understanding of radiation pressure
Authors: Loudon R. , Baxter C.
Published: March 2012

The name of Poynting is universally recognized for his development of the well-known expression for the flow of electromagnetic energy. Not so well known is Poynting's series of papers on radiation pressure, with 2011 marking the centenary of the last of his 15 publications on this topic. This paper reviews and assesses his radiation-pressure work, with a level of coverage aimed at the reader familiar with the Maxwell electromagnetic theory and interested in the current understanding of radiation pressure. We begin with brief details of Poynting's life, followed by accounts of the relevant publications by others before and during his period of activity in the field from 1903 to 1911. His contributions to the understanding of radiation-pressure effects in the solar system, and the linear and angular momenta of light are discussed, with evaluations from a modern perspective.
Relationship between propagule pressure and colonization pressure in invasion ecology: a test with ships' ballast
Authors: Briski Elizabeta , Bailey Sarah A. , Casas-Monroy Oscar , DiBacco Claudio , Kaczmarska Irena , Levings Colin , MacGillivary Michael L. , McKindsey Christopher W. , Nasmith Leslie E. , Parenteau Marie , Piercey Grace E. , Rochon André , Roy Suzanne , Simard Nathalie , Villac Maria C. , Weise Andréa M. , MacIsaac Hugh J.
Published: March 2012

Increasing empirical evidence indicates the number of released individuals (i.e. propagule pressure) and number of released species (i.e. colonization pressure) are key determinants of the number of species that successfully invade new habitats. In view of these relationships, and the possibility that ships transport whole communities of organisms, we collected 333 ballast water and sediment samples to investigate the relationship between propagule and colonization pressure for a variety of diverse taxonomic groups (diatoms, dinoflagellates and invertebrates). We also reviewed the scientific literature to compare the number of species transported by ships to those reported in nature. Here, we show that even though ships transport nearly entire local communities, a strong relationship between propagule and colonization pressure exists only for dinoflagellates. Our study provides evidence that colonization pressure of invertebrates and diatoms may fluctuate widely irrespective of propagule pressure. We suggest that the lack of correspondence is explained by reduced uptake of invertebrates into the transport vector and the sensitivity of invertebrates and diatoms to selective pressures during transportation. Selection during transportation is initially evident through decreases in propagule pressure, followed by decreased colonization pressure in the most sensitive taxa.
Sex-biased terminal investment in offspring induced by maternal immune challenge in the house wren (
Troglodytes aedon
)
Authors: Bowers E. Keith , Smith Rebecca A. , Hodges Christine J. , Zimmerman Laura M. , Thompson Charles F. , Sakaluk Scott K.
Published: March 2012

The reproductive costs associated with the upregulation of immunity have been well-documented and constitute a fundamental trade-off between reproduction and self-maintenance. However, recent experimental work suggests that parents may increase their reproductive effort following immunostimulation as a form of terminal parental investment as prospects for future reproduction decline. We tested the trade-off and terminal investment hypotheses in a wild population of house wrens (
Troglodytes aedon
) by challenging the immune system of breeding females with lipopolysaccharide, a potent but non-lethal antigen. Immunized females showed no evidence of reproductive costs; instead, they produced offspring of higher phenotypic quality, but in a sex-specific manner. Relative to control offspring, sons of immunized females had increased body mass and their sisters exhibited higher cutaneous immune responsiveness to phytohaemagglutinin injection, constituting an adaptive strategy of sex-biased allocation by immune-challenged females to enhance the reproductive value of their offspring. Thus, our results are consistent with the terminal investment hypothesis, and suggest that maternal immunization can induce pronounced transgenerational effects on offspring phenotypes.
A systematic study of gene expression variation at single-nucleotide resolution reveals widespread regulatory roles for uAUGs
Authors: Yun Yue , Adesanya T.M. Ayodele , Mitra Robi D.
Published: March 2012

Regulatory single-nucleotide polymorphisms (rSNPs) alter gene expression. Common approaches for identifying rSNPs focus on sequence variants in conserved regions; however, it is unknown what fraction of rSNPs is undetectable using this approach. We present a systematic analysis of gene expression variation at the single-nucleotide level in the Saccharomyces cerevisiae GAL1-10 regulatory region. We exhaustively mutated nearly every base and measured the expression of each variant with a sensitive dual reporter assay. We observed an expression change for 7% (43/582) of the bases in this region, most of which (35/43, 81%) reside in conserved positions. The most dramatic changes were caused by variants that produced AUGs upstream of the translation start (uAUGs), and we sought to understand the consequences and molecular mechanisms underlying this class of mutations. A genome-wide analysis showed that genes with uAUGs display significantly lower mRNA and protein levels than genes without uAUGs. To determine the generality of this mechanism, we introduced uAUGs into S. cerevisiae genes and observed significantly reduced expression in 17/21 instances (p < 0.01), suggesting that uAUGs are functional in a wide variety of sequence contexts. Quantification of mRNA and protein levels for uAUG mutants showed that uAUGs affect both transcription and translation. Expression of uAUG mutants under the upf1Δ strain demonstrated that uAUGs stimulate the nonsense-mediated decay pathway. Our results suggest that uAUGs are potent and widespread regulators of gene expression that act by attenuating both protein and RNA levels.
Reconstructing ancient mitochondrial DNA links between Africa and Europe
Authors: Cerezo María , Achilli Alessandro , Olivieri Anna , Perego Ugo A. , Gómez-Carballa Alberto , Brisighelli Francesca , Lancioni Hovirag , Woodward Scott R. , López-Soto Manuel , Carracedo Ángel , Capelli Cristian , Torroni Antonio , Salas Antonio
Published: March 2012

Mitochondrial DNA (mtDNA) lineages of macro-haplogroup L (excluding the derived L3 branches M and N) represent the majority of the typical sub-Saharan mtDNA variability. In Europe, these mtDNAs account for <1% of the total but, when analyzed at the level of control region, they show no signals of having evolved within the European continent, an observation that is compatible with a recent arrival from the African continent. To further evaluate this issue, we analyzed 69 mitochondrial genomes belonging to various L sublineages from a wide range of European populations. Phylogeographic analyses showed that ∼65% of the European L lineages most likely arrived in rather recent historical times, including the Romanization period, the Arab conquest of the Iberian Peninsula and Sicily, and during the period of the Atlantic slave trade. However, the remaining 35% of L mtDNAs form European-specific subclades, revealing that there was gene flow from sub-Saharan Africa toward Europe as early as 11,000 yr ago.
First observation of diffusion‐limited plant root phosphorus uptake from nutrient solution
Authors: SANTNER JAKOB , SMOLDERS ERIK , WENZEL WALTER W. , DEGRYSE FIEN
Published: March 2012

Diffusion towards the root surface has recently been shown to control the uptake of metal ions from solutions. The uptake flux of phosphorus (P) from solutions often approaches the maximal diffusion flux at low external concentrations, suggesting diffusion‐controlled uptake also for P. Potential diffusion limitation in P uptake from nutrient solutions was investigated by measuring P uptake of Brassica napus from solutions using P‐loaded Al2O3 nanoparticles as mobile P buffer. At constant, low free phosphate concentration, plant P uptake increased up to eightfold and that of passive, diffusion‐based samplers up to 40‐fold. This study represents the first experimental evidence of diffusion‐limited P uptake by plant roots from nutrient solution. The Michaelis constant of the free phosphate ion obtained in unbuffered solutions (Km = 10.4 µmol L−1) was 20‐fold larger than in the buffered system (Km∼0.5 µmol L−1), indicating that Kms determined in unbuffered solutions do not represent the transporter affinity. Increases in the P uptake efficiency of plants by increasing the carrier affinity are therefore unlikely, while increased root surface area or exudation of P‐solubilizing compounds are more likely to enhance P uptake. Furthermore, our results highlight the important role natural nanoparticles may have in plant P nutrition.
Understanding the effects of multiple sources of seasonality on the risk of pathogen spread to vineyards: vector pressure, natural infectivity, and host recovery
Authors: Gruber B. R. , Daugherty M. P.
Published: March 2012

Seasonality plays an important role in the dynamics of infectious disease. For vector‐borne pathogens, the effects of seasonality may be manifested in the variability in vector abundance, vector infectiousness, and host‐infection dynamics over the year. The relative importance of multiple sources of seasonality on the spread of a plant pathogen, Xylella fastidiosa, into vineyards was explored. Observed seasonal population densities of the primary leafhopper vector, Graphocephala atropunctata, from 8 years of surveys in northern California were incorporated into a model of primary spread to estimate the risk of pathogen infection under different scenarios regarding seasonality in vector natural infectivity (i.e. constant or increasing over the season) and grapevine recovery from infection (i.e. none or seasonal recovery). The extent to which local climatic conditions affect risk estimates via differences in vector abundance was investigated. Seasonal natural infectivity, seasonal recovery, and especially the combination, reduced (up to 8‐fold on average) within‐season and cumulative yearly estimates of pathogen spread. Estimated risk of infection also differed greatly among years due to large differences in vector abundance, with wet and moderate winter and spring conditions favouring higher G. atropunctata abundance. Seasonal variation of the pathogen–vector interaction may play an important role in the dynamics of disease in vineyards, reducing the potential prevalence from what it could be in their absence. Moreover, climate, by affecting sharpshooter leafhopper abundance or activity, may influence Pierce’s disease dynamics.
Soluble receptor for advanced glycation end products (sRAGE) is present at high concentrations in the lungs of children and varies with age and the pattern of lung inflammation
Authors: YERKOVICH STEPHANIE T. , CHANG ANNE B. , CARROLL MELANIE L. , PETSKY HELEN L. , SCRIVENER GRETA , UPHAM JOHN W.
Published: March 2012

Background and objective:  The soluble receptor for advanced glycation end products (sRAGE) plays an important role in inflammation. Few studies have looked at sRAGE levels in human lungs, and there is no information in children. Therefore, this study aimed to compare bronchoalveolar lavage fluid (BALF) and plasma sRAGE concentrations in children in relation to age and inflammation.

Methods:  BAL was performed in 76 children, and BALF and plasma sRAGE levels were determined by enzyme‐linked immunosorbent assay.

Results:  sRAGE levels were fourfold higher in BALF than in plasma (P < 0.001). BALF sRAGE was inversely proportional to age (r = −0.333, P = 0.008) and serum immunoglobulin A (r = −0.283, P = 0.028). Plasma sRAGE showed a positive correlation to the percentage of BAL macrophages and negative correlation to the percentage of neutrophils and lymphocytes (P < 0.05). Multivariate linear regression analysis identified that the percentage of BAL lymphocytes and neutrophils were significant independent predictors of plasma sRAGE levels, while age and the percentage of BAL macrophages independently predicted BALF sRAGE levels.

Conclusions:  In children, sRAGE is present at higher concentrations in the lung compared with blood. It appears that sRAGE varies with age, and hence future studies of sRAGE in paediatric lung disease require age matching. The significant relationship between sRAGE and lung inflammation warrants further research.
How to write research papers and grants: 2011 Asian Pacific Society for Respirology Annual Scientific Meeting Postgraduate Session
Authors: EASTWOOD PETER R. , NAUGHTON MATTHEW T. , CALVERLEY PETER , ZENG GUANGQIAO , BEASLEY RICHARD , ROBINSON BRUCE , LEE Y.C. GARY
Published: March 2012

This review article summarizes the content of a series of interrelated workshop presentations from the Annual Scientific Meeting of the Asian Pacific Society of Respirology held in Shanghai in November, 2011. The article describes tips and strategies for writing research papers and research grant applications and includes discussion of: the role of pulmonologists in research; the debates around the use of the journal impact factor; tips for writing manuscripts and publishing research in high‐impact journals; how journals assess manuscripts and the most common reasons editors reject manuscripts; how to write grant applications and what grant panels look for in successful proposals; and how to undertake research in resource‐limited countries.
Camperdown Program for adults who stutter: a student training clinic Phase I trial
Authors: Cocomazzo Nadia , Block Susan , Carey Brenda , O’Brian Sue , Onslow Mark , Packman Ann , Iverach Lisa
Published: March 2012

Objectives: During speech pathology professional preparation there is a need for adequate student instruction with speech‐restructuring treatments for adults. An important part of that clinical educational experience is to participate in a clinical setting that produces outcomes equivalent to those attained during clinical trials. A previous report showed that this is possible with a traditional, intensive speech‐restructuring treatment. Considering the treatment process advantages and time efficiency of the Camperdown Program, it is arguably a compelling prospect for clinician education. Therefore, the present study is a Phase I trial of the treatment at a student university clinic, with a similar design to a previous report.

Background:  During speech pathology professional preparation there is a need for adequate student instruction with speech‐restructuring treatments for adults. An important part of that clinical educational experience is to participate in a clinical setting that produces outcomes equivalent to those attained during clinical trials. A previous report showed that this is possible with a traditional, intensive speech‐restructuring treatment. Considering the treatment process advantages and time efficiency of the Camperdown Program, it is arguably a compelling prospect for clinician education.

Aims:  The present study is a Phase I trial of the treatment at a student university clinic, with a similar design to a previous report.

Methods & Procedures:  The design was a non‐randomized Phase I clinical trial with 12 adult participants. Primary outcomes were per cent syllables stuttered (%SS) within and beyond the clinic, and speech naturalness scores from pre‐ and post‐treatment stutter‐free speech samples.

Outcomes & Results: Pooled  %SS scores pre‐treatment were 5.7, at immediate post‐treatment were 1.0, and at 12 months post‐treatment were 2.4. The group speech naturalness scores post‐treatment did not increase to a clinically significant extent.

Conclusion & Implications: Results essentially replicate the previous study by producing similar outcomes to those attained with clinical trials. The Camperdown Program is recommended as a clinical environment for speech‐restructuring speech pathology student training.
SCORTEN and impaired renal function related to mortality of toxic epidermal necrolysis syndrome patients in the Asian population
Authors: Hu C.‐H. , Chang N.‐J. , Liu E.K.‐W. , Chuang S.‐S. , Chung W.‐H. , Yang J.‐Y.
Published: March 2012

Background  Toxic epidermal necrolysis syndrome (TEN) is a rare, life‐threatening, drug‐related skin reaction with a high mortality rate. To date, only a few studies with insufficient sample sizes have been conducted to analyse SCORTEN in Asian populations with TEN.

Objective  To analyse SCORTEN and other related factors that affect TEN patients in Taiwan.

Methods  A retrospective review of medical records of 101 patients with TEN from 1992 to 2009.

Results  There were 62 cases of adverse reactions to a single medication and 39 cases of idiopathic reaction, from multiple medications, or infectious pathogens, of 101 TEN patients. Of the seven individual SCORTEN parameters, only associate malignancy, detached or compromised body surface area >10%, serum urea and bicarbonate were statistically significant in the multivariate analysis. Factors such as 1.5 times baseline serum creatinine levels, urine output of less than 0.5 mL/kg for 6 h and acute renal failure were connected with subsequent mortality.

Conclusion  The SCORTEN score is effective in predicting the outcome in Taiwanese TEN patients. A number of factors are predictors of mortality. In our study, we determine renal insufficiency and failure to be a marker for predicting a poor outcome.
High-resolution nanopatterning by achromatic spatial frequency multiplication with electroplated grating structures
Authors: Wang Li , Terhalle Bernd , Hojeij Mohamad , Guzenko Vitaliy A. , Ekinci Yasin
Published: March 2012

The authors demonstrate generation of high-resolution nanostructures using achromatic spatial frequency multiplication in the extreme ultraviolet wavelength region. The technique based on the achromatic Talbot effect is used for periodic transmission gratings under wideband illumination, enabling one- and two-dimensional nanopatterns with sub-20 nm feature sizes. The transmission masks with desired properties are fabricated with electron-beam lithography followed by electroplating of gold. Features sizes down to 12 nm are obtained. The presented technique provides high-throughput and large-area nanopatterning with great flexibility in tuning pattern parameters such as linewidth and dot size.
Quantification of cesium surface contamination on silicon resulting from SIMS analysis
Authors: Penley C. , Stevie F. A. , Griffis D. P.
Published: March 2012

In order to improve the understanding of unintended cesium (Cs) contamination that occurs during SIMS depth profiling, Cs concentrations on sample surfaces were measured before analysis and at various distances from a depth profile crater after analysis. Cs concentrations in excess of 1 at. % were found directly adjacent to the depth profile analysis site. Cs was also detected at significant concentrations hundreds of micrometers from the depth profile measurement location. This Cs contamination can originate from a number of sources including Cs beam tails, Cs neutral beam, and secondary sputtering from instrument optics and other structures. Since the presence of cesium significantly affects the secondary ion yield of electronegative elements (e.g., phosphorus) in silicon, the unintended presence of cesium on the surface of a previously analyzed sample can strongly affect the reproducibility and accuracy of low dose electronegative element measurements, especially at the surface.
Influence of chemical composition and deposition conditions on microstructure evolution during annealing of arc evaporated ZrAlN thin films
Authors: Rogström L. , Johansson M. P. , Ghafoor N. , Hultman L. , Odén M.
Published: March 2012

The influence of substrate bias and chemical composition on the formed microstructure and resulting hardness of arc evaporated Zr1−xAlxN films in the compositional span 0.12≤ x ≤0.74 is investigated. A cubic ZrAlN phase is formed at low aluminum contents (x ≤ 0.38) whereas for a high Al-content, above x = 0.70, a single-phase hexagonal structure is obtained. For intermediate Al-contents, a two-phase structure is formed. The cubic structured films exhibit higher hardness than the hexagonal structured ones. A low bias results in N-rich films with a partly defect-rich microstructure while a higher substrate bias decreases the grain size and increases the residual stress in the cubic ZrAlN films. Recrystallization and out-diffusion of nitrogen from the lattice in the cubic ZrAlN films takes place during annealing at 800 °C, which results in an increased hardness. The cubic ZrAlN phase is stable to annealing temperatures of 1000 °C while annealing at higher temperature results in nucleation and growth of hexagonal AlN. In the high Al-content ZrAlN films, formation of ZrN- and AlN-rich domains within the hexagonal lattice during annealing at 1000 °C improves the mechanical properties.
A method to evaluate dose errors introduced by dose mapping processes for mass conserving deformations
Authors: Yan C. , Hugo G. , Salguero F. J. , Saleh‐Sayah N. , Weiss E. , Sleeman W. C. , Siebers J. V.
Published: March 2012

Purpose:

To present a method to evaluate the dose mapping error introduced by the dose mapping process. In addition, apply the method to evaluate the dose mapping error introduced by the 4D dose calculation process implemented in a research version of commercial treatment planning system for a patient case.

Methods:

The average dose accumulated in a finite volume should be unchanged when the dose delivered to one anatomic instance of that volume is mapped to a different anatomic instance—provided that the tissue deformation between the anatomic instances is mass conserving. The average dose to a finite volume on imageS is defined as , where is the energy deposited in the mass contained in the volume. Since mass and energy should be conserved, when is mapped to an image , the mean dose mapping error is defined as , where the and are integral doses (energy deposited), and and are the masses within the region of interest (ROI) on image R and the corresponding ROI on image S, where R and S are the two anatomic instances from the same patient. Alternatively, application of simple differential propagation yields the differential dose mapping error, with . A 4D treatment plan on a ten‐phase 4D‐CT lung patient is used to demonstrate the dose mapping error evaluations for a patient case, in which the accumulated dose, , and associated error values ( and ) are calculated for a uniformly spaced set of ROIs.

Results:

For the single sample patient dose distribution, the average accumulated differential dose mapping error is 4.3%, the average absolute differential dose mapping error is 10.8%, and the average accumulated mean dose mapping error is 5.0%. Accumulated differential dose mapping errors within the gross tumor volume (GTV) and planning target volume (PTV) are lower, 0.73% and 2.33%, respectively.

Conclusions:

A method has been presented to evaluate the dose mapping error introduced by the dose mapping process. This method has been applied to evaluate the 4D dose calculation process implemented in a commercial treatment planning system. The method could potentially be developed as a fully‐automatic QA method in image guided adaptive radiation therapy (IGART).