bluuebunny/crossref_metadata_2025 huggingface dataset:
Indigenous participation in an informal national Indigenous health policy network
Authors: Lock Mark J. , Thomas David P. , Anderson Ian P. , Pattison Philippa
Published: August 2011

Objective.
To determine and describe the features of Indigenous participation in an informal national Indigenous health policy network.

Design.
A questionnaire was administered during 2003–04. Through a snowball nomination process a total of 227 influential persons were identified. Of these, 173 received surveys of which 44 were returned, a return rate of 25%.

Outcome measures.
These data were analysed to detect the existence of network groups; measure the degree of group interconnectivity; and measure the characteristics of bonds between influential persons. Demographic information was used to characterise the network and its groups.

Results.
Indigenous people were integral to the network due to their high representation, their distribution throughout the 16 groups, and the interconnections between the groups. The network was demographically diverse and multiple relational variables were needed to characterise it. Indigenous and non-Indigenous people had strong ties in this network.

Conclusion.
Social network methods made visible an informal network where Indigenous and non-Indigenous people relate in a complex socio-political environment to influence national Indigenous health policy.

What is known about the topic?
The participation of Indigenous people is acknowledged as important in health, but there is criticism of the lack of real opportunities for Indigenous people to participate in national Indigenous health policy processes.

What does this paper add?
This research reveals the presence of an informal network of influential persons. It demonstrates a way to investigate the concept of participation through social network analytic techniques. It reveals that Indigenous people are fundamental to an informal network that influences national health policy processes.

What are the implications for practitioners?
Practitioners can become more aware of their place in informal networks of influence and of their capacity to exercise personal influence in national policy decisions based on advice drawn from their informal networks.
Micromorphology of sepiolite occurrences in recent lacustrine deposits affected by soil development
Authors: Mees Florias , Van Ranst Eric
Published: August 2011

Deposits in dry lake basins of the Aminuis region, south-western Kalahari, Namibia, contain abundant sepiolite. Thin-section observations show that it occurs as part of the groundmass, for which an authigenic origin is implied by the lack of a source for detrital sepiolite. The deposits also contain common sepiolite coatings, which are nearly exclusively illuvial rather than the result of mineral authigenesis in pores. Other sepiolitic pedofeatures are: (i) carbonate depletion hypocoatings, locally disturbed by development of porostriation; (ii) surface crusts, formed by re-suspension and settling of fine material after flooding, occurring at sites where low salinity allows their preservation; and (iii) common fragments of coatings, produced by physical or biogenic disturbance, in deposits with an often strongly fragmented microstructure. This study illustrates the need to consider an illuvial or depletion-related nature of sepiolite and palygorskite occurrences along pores in soils, as an alternative for the possibility of clay neoformation.
Field-based measurements of sulfur gas emissions from an agricultural coastal acid sulfate soil, eastern Australia
Authors: Kinsela Andrew S. , Denmead O. Tom , Macdonald Bennett C. T. , Melville Michael D. , Reynolds Jason K. , White Ian
Published: August 2011

The emissions of biogenic hydrogen sulfide (H2S) and sulfur dioxide (SO2) play important roles in the global atmospheric sulfur (S) cycle. Field-based investigations using ultraviolet fluorescence spectroscopy show that drained acid sulfate soils (ASS) are a potentially unaccounted source of biogenic H2S and SO2. Significant diurnal variations were evident in SO2 fluxes, with average daytime measurements 9.3–16.5-fold greater than night-time emissions. Similar diurnal patterns in H2S fluxes were observed but proved statistically insignificant. The results from simultaneously collected micrometeorological measurements suggest that emissions of SO2 and H2S are most likely occurring via different processes. The SO2 fluxes are closely linked to surface soil temperature and moisture content, whereas H2S is constantly emitted from the land surface at the two study sites. Drained ASS are most likely mapped as agricultural lands rather than drained backswamps. Therefore, these areas are likely to be assigned H2S and SO2 flux values of zero in greenhouse gas species inventories. These findings suggest a need to expand these measurements to other drained ASS areas to refine regional (and possibly global) atmospheric S budgets. Further research is necessary to elucidate the sources of measured S compounds, and specifically whether they are limited to individual agricultural drainage patterns in ASS.
Relationship between phosphorus concentration in surface runoff and a novel soil phosphorus test procedure (DGT) under simulated rainfall
Authors: Dougherty W. J. , Mason S. D. , Burkitt L. L. , Milham P. J.
Published: August 2011

There is a need to be able to identify soils with the potential to generate high concentrations of phosphorus (P) in runoff, and a need to predict these concentrations for modelling and risk-assessment purposes. Attempts to use agronomic soil tests such as Colwell P for such purposes have met with limited success. In this research, we examined the relationships between a novel soil P test (diffuse gradients in thin films, DGT), Colwell P, P buffering index (PBI), and runoff P concentrations. Soils were collected from six sites with a diverse range of soil P buffering properties, incubated for 9 months with a wide range of P additions, and then subjected to rainfall simulation in repacked trays growing pasture. For all soil and P treatment combinations, the relationship between DGT (0–10 mm) and runoff P was highly significant (P < 0.001, r2 = 0.84). Although there were significant curvilinear relationships between Colwell P and runoff P for individual soils, there were large differences in these relationships between soils. However, the inclusion of a P buffering measure (PBI) as an explanatory variable resulted in a highly significant model (P < 0.001, R2 = 0.82) that explained between-soil variability. We conclude that either DGT, or Colwell P and PBI, can be used to provide a relative measure of runoff P concentration.
Performance improvement of annealing-free P3HT : PCBM-based polymer solar cells via 3-methylthiophene additive
Authors: Peng Bo , Guo Xia , Zou Yingping , Pan Chunyue , Li Yongfang
Published: August 2011

In this work, we studied the effect of 3-methylthiophene (3MT) and 3-hexylthiophene (3HT) additives on the morphology and photovoltaic performance of the polymer solar cells (PSCs) based on P3HT : PCBM (1 : 1 w/w). The P3HT : PCBM blend films prepared from the solutions with 3MT or 3HT additive show enhanced absorption in the 500–650 nm wavelength range and higher hole mobility than that of the film without the additives. X-ray diffraction data indicate a smaller interlayer distance of the conjugated backbones in the 3MT- or 3HT-processed films. Atomic force microscopy images of the 3MT-processed films demonstrate a nanoscaled phase separation and interpenetrating network morphology between the donor and the accept phases. The power conversion efficiency of PSCs based on 3MT-processed blend films without thermal annealing reached 3.72% which is increased by 30% over that of the devices without the additive.
Influence of the energy dissipation rate in the discharge of a plasma synthetic jet actuator
Authors: Belinger A , Hardy P , Barricau P , Cambronne J P , Caruana D
Published: August 2011

A promising actuator for high-speed flow control, referred to as a plasma synthetic jet (PSJ), is being studied by the DMAE department of the ONERA, and the Laplace laboratory of the CNRS, in France. This actuator was inspired by the ‘sparkjet’ device developed by the Johns Hopkins University Applied Physics Laboratory. The PSJ, which produces a synthetic jet with high exhaust velocities, no active mechanical components and no mass flow admission, holds the promise of enabling high-speed flows to be manipulated. With this high-velocity jet it is possible to reduce fluid phenomena such as transition and turbulence, thus making it possible to increase an aircraft's performance whilst at the same time reducing its environmental impact. A thermal plasma discharge was created in a micro-cavity, causing the gas to be expelled. It is relevant that the velocity and momentum depend on the energy dispersed by the electric discharge. To control the frequency and energy dispersed in the plasma, the Laplace laboratory has developed two high-voltage power supply systems. These allow two different types of discharge to be produced, with energy being supplied to the discharge in two different manners. In this paper, we focus on the impact of the power supply on the plasma synthetic jet, and in particular on the role of the rate of energy dissipation in the discharge. In order to estimate the influence of the power supply on the machinery of the actuator, specific experimental techniques were used to investigate the electrical (voltage, current), thermal (Infra-red camera) and aerodynamic (jet duration, isentropic pressure, jet velocity) characteristics. These data sets were used to determine which of the two power supplies was more effective, thus allowing us to reach several conclusions concerning the importance of the energy dissipation rate on the PSJ actuator.
Integration of SNP genotyping confidence scores in IBD inference
Authors: Markus Barak , Birk Ohad S. , Geiger Dan
Published: August 2011

Motivation: High-throughput single nucleotide polymorphism (SNP) arrays have become the standard platform for linkage and association analyses. The high SNP density of these platforms allows high-resolution identification of ancestral recombination events even for distant relatives many generations apart. However, such inference is sensitive to marker mistyping and current error detection methods rely on the genotyping of additional close relatives. Genotyping algorithms provide a confidence score for each marker call that is currently not integrated in existing methods. There is a need for a model that incorporates this prior information within the standard identical by descent (IBD) and association analyses.

Results: We propose a novel model that incorporates marker confidence scores within IBD methods based on the Lander–Green Hidden Markov Model. The novel parameter of this model is the joint distribution of confidence scores and error status per array. We estimate this probability distribution by applying a modified expectation-maximization (EM) procedure on data from nuclear families genotyped with Affymetrix 250K SNP arrays. The converged tables from two different genotyping algorithms are shown for a wide range of error rates. We demonstrate the efficacy of our method in refining the detection of IBD signals using nuclear pedigrees and distant relatives.

Availability: Plinke, a new version of Plink with an extended pairwise IBD inference model allowing per marker error probabilities is freely available at: http://bioinfo.bgu.ac.il/bsu/software/plinke.

Contact:  obirk@bgu.ac.il; markusb@bgu.ac.il

Supplementary Information:  Supplementary data are available at Bioinformatics online.
Effect of Germination on Flavor Volatiles of Cooked Brown Rice
Authors: Wu Fengfeng , Yang Na , Chen Haiying , Jin Zhengyu , Xu Xueming
Published: August 2011

The effect of germination on flavor volatiles of cooked brown rice among three different rice cultivars was investigated using the headspace solid‐phase microextraction method combined with gas chromatography‐mass spectrometry. The results showed that some flavor compounds varied significantly throughout the germination process and others did not show distinct changes. The amount of total volatiles, most lipid‐oxidation products, and phenolic compounds decreased in the initial stage of germination but increased significantly at a later stage. The amounts of ethanol and ethyl acetate increased significantly in the initial stage of germination and maintained almost the same levels during further germination. The amount of dimethyl sulfide increased significantly during germination; it showed the most significant change among all volatile compounds.
The Arabidopsis thaliana DNA-Binding Protein AHL19 Mediates Verticillium Wilt Resistance
Authors: Yadeta Koste A. , Hanemian Mathieu , Smit Patrick , Hiemstra Jelle A. , Pereira Andy , Marco Yves , Thomma Bart P. H. J.
Published: August 2011

Verticillium spp. are destructive soilborne fungal pathogens that cause vascular wilt diseases in a wide range of plant species. Verticillium wilts are particularly notorious, and genetic resistance in crop plants is the most favorable means of disease control. In a gain-of-function screen using an activation-tagged Arabidopsis mutant collection, we identified four mutants, A1 to A4, which displayed enhanced resistance toward the vascular wilt species Verticillium dahliae, V. albo-atrum and V. longisporum but not to Fusarium oxysporum f. sp. raphani. Further testing revealed that mutant A2 displayed enhanced Ralstonia solanacearum resistance, while mutants A1 and A3 were more susceptible toward Pseudomonas syringae pv. tomato. Identification of the activation tag insertion site in the A1 mutant revealed an insertion in close proximity to the gene encoding AHL19, which was constitutively expressed in the mutant. AHL19 knock-out alleles were found to display enhanced Verticillium susceptibility whereas overexpression of AHL19 resulted in enhanced Verticillium resistance, showing that AHL19 acts as a positive regulator of plant defense.
On the role of DNA biomechanics in the regulation of gene expression
Authors: Milstein J. N. , Meiners J.-C.
Published: August 2011

DNA is traditionally seen as a linear sequence of instructions for cellular functions that are expressed through biochemical processes. Cellular DNA, however, is also organized as a complex hierarchical structure with a mosaic of mechanical features, and a growing body of evidence is now emerging to imply that these mechanical features are connected to genetic function. Mechanical tension, for instance, which must be felt by DNA within the heavily constrained and continually fluctuating cellular environment, can affect a number of regulatory processes implicating a role for biomechanics in gene expression complementary to that of biochemical regulation. In this article, we review evidence for such mechanical pathways of genetic regulation.
Reactive oxygen species production and discontinuous gas exchange in insects
Authors: Boardman Leigh , Terblanche John S. , Hetz Stefan K. , Marais Elrike , Chown Steven L.
Published: August 2011

While biochemical mechanisms are typically used by animals to reduce oxidative damage, insects are suspected to employ a higher organizational level, discontinuous gas exchange mechanism to do so. Using a combination of real-time, flow-through respirometry and live-cell fluorescence microscopy, we show that spiracular control associated with the discontinuous gas exchange cycle (DGC) inSamia cynthiapupae is related to reactive oxygen species (ROS). Hyperoxia fails to increase mean ROS production, although minima are elevated above normoxic levels. Furthermore, a negative relationship between meanand mean ROS production indicates that higher ROS production is generally associated with lower. Our results, therefore, suggest a possible signalling role for ROS in DGC, rather than supporting the idea that DGC acts to reduce oxidative damage by regulating ROS production.
DNA methylation profiles of human active and inactive X chromosomes
Authors: Sharp Andrew J. , Stathaki Elisavet , Migliavacca Eugenia , Brahmachary Manisha , Montgomery Stephen B. , Dupre Yann , Antonarakis Stylianos E.
Published: August 2011

X-chromosome inactivation (XCI) is a dosage compensation mechanism that silences the majority of genes on one X chromosome in each female cell. To characterize epigenetic changes that accompany this process, we measured DNA methylation levels in 45,X patients carrying a single active X chromosome (Xa), and in normal females, who carry one Xa and one inactive X (Xi). Methylated DNA was immunoprecipitated and hybridized to high-density oligonucleotide arrays covering the X chromosome, generating epigenetic profiles of active and inactive X chromosomes. We observed that XCI is accompanied by changes in DNA methylation specifically at CpG islands (CGIs). While the majority of CGIs show increased methylation levels on the Xi, XCI actually results in significant reductions in methylation at 7% of CGIs. Both intra- and inter-genic CGIs undergo epigenetic modification, with the biggest increase in methylation occurring at the promoters of genes silenced by XCI. In contrast, genes escaping XCI generally have low levels of promoter methylation, while genes that show inter-individual variation in silencing show intermediate increases in methylation. Thus, promoter methylation and susceptibility to XCI are correlated. We also observed a global correlation between CGI methylation and the evolutionary age of X-chromosome strata, and that genes escaping XCI show increased methylation within gene bodies. We used our epigenetic map to predict 26 novel genes escaping XCI, and searched for parent-of-origin-specific methylation differences, but found no evidence to support imprinting on the human X chromosome. Our study provides a detailed analysis of the epigenetic profile of active and inactive X chromosomes.
Keep an Eye on PPi: The Vacuolar-Type H+-Pyrophosphatase Regulates Postgerminative Development inArabidopsis
Authors: Ferjani Ali , Segami Shoji , Horiguchi Gorou , Muto Yukari , Maeshima Masayoshi , Tsukaya Hirokazu
Published: August 2011

Postgerminative growth of seed plants requires specialized metabolism, such as gluconeogenesis, to support heterotrophic growth of seedlings until the functional photosynthetic apparatus is established. Here, we show that the Arabidopsis thaliana fugu5 mutant, which we show to be defective in AVP1 (vacuolar H+-pyrophosphatase), failed to support heterotrophic growth after germination. We found that exogenous supplementation of Suc or the specific removal of the cytosolic pyrophosphate (PPi) by the heterologous expression of the cytosolic inorganic pyrophosphatase1 (IPP1) gene from budding yeast (Saccharomyces cerevisiae) rescued fugu5 phenotypes. Furthermore, compared with the wild-type and AVP1Pro:IPP1 transgenic lines, hypocotyl elongation in the fugu5 mutant was severely compromised in the dark but recovered upon exogenous supply of Suc to the growth media. Measurements revealed that the peroxisomal β-oxidation activity, dry seed contents of storage lipids, and their mobilization were unaffected in fugu5. By contrast, fugu5 mutants contained ~2.5-fold higher PPi and ~50% less Suc than the wild type. Together, these results provide clear evidence that gluconeogenesis is inhibited due to the elevated levels of cytosolic PPi. This study demonstrates that the hydrolysis of cytosolic PPi, rather than vacuolar acidification, is the major function of AVP1/FUGU5 in planta. Plant cells optimize their metabolic function by eliminating PPi in the cytosol for efficient postembryonic heterotrophic growth.
Genetic diversity of the imperilled bath sponge Spongia officinalis Linnaeus, 1759 across the Mediterranean Sea: patterns of population differentiation and implications for taxonomy and conservation
Authors: DAILIANIS T. , TSIGENOPOULOS C. S. , DOUNAS C. , VOULTSIADOU E.
Published: August 2011

The Mediterranean bath sponge Spongia officinalis is an iconic species with high socio‐economic value and precarious future owing to unregulated harvesting, mortality incidents and lack of established knowledge regarding its ecology. This study aims to assess genetic diversity and population structure of the species at different geographical scales throughout its distribution. For this purpose, 11 locations in the Eastern Mediterranean (Aegean Sea), Western Mediterranean (Provence coast) and the Strait of Gibraltar were sampled; specimens were analysed using partial mitochondrial cytochrome oxidase subunit I (COI) sequences, along with a set of eight microsatellite loci. According to our results (i) no genetic differentiation exists among the acknowledged Mediterranean morphotypes, and hence, S. officinalis can be viewed as a single, morphologically variable species; (ii) a notable divergence was recorded in the Gibraltar region, indicating the possible existence of a cryptic species; (iii) restriction to gene flow was evidenced between the Aegean Sea and Provence giving two well‐defined regional clusters, thus suggesting the existence of a phylogeographic break between the two systems; (iv) low levels of genetic structure, not correlated to geographical distance, were observed inside geographical sectors, implying mechanisms (natural or anthropogenic) that enhance dispersal and gene flow have promoted population connectivity; (v) the genetic diversity of S. officinalis is maintained high in most studied locations despite pressure from harvesting and the influence of devastating epidemics. These findings provide a basis towards the effective conservation and management of the species.
50,000 years of genetic uniformity in the critically endangered Iberian lynx
Authors: RODRÍGUEZ RICARDO , RAMÍREZ OSCAR , VALDIOSERA CRISTINA E. , GARCÍA NURIA , ALDA FERNANDO , MADURELL‐MALAPEIRA JOAN , MARMI JOSEP , DOADRIO IGNACIO , WILLERSLEV ESKE , GÖTHERSTRÖM ANDERS , ARSUAGA JUAN LUIS , THOMAS MARK G. , LALUEZA‐FOX CARLES , DALÉN LOVE
Published: August 2011

Low genetic diversity in the endangered Iberian lynx, including lack of mitochondrial control region variation, is thought to result from historical or Pleistocene/Holocene population bottlenecks, and to indicate poor long‐term viability. We find no variability in control region sequences from 19 Iberian lynx remains from across the Iberian Peninsula and spanning the last 50 000 years. This is best explained by continuously small female effective population size through time. We conclude that low genetic variability in the Iberian lynx is not in itself a threat to long‐term viability, and so should not preclude conservation efforts.
Sensitivity of Barley Leaves and Roots to Fusaric Acid, but not to H2O2, Is Associated with Susceptibility to Fusarium Infections
Authors: Barna Balázs , Jansen Carin , Kogel Karl‐Heinz
Published: August 2011

Fusarium head blight and rot root are among the most devastating plant diseases in modern agriculture. The causal pathogen, Fusarium spp., reduces plant yield and food quality in part because of mycotoxins, suggesting that breeding for resistance to Fusarium is an important control strategy. A simple and low‐cost tactic in plant resistance breeding is testing the cultivars for their sensitivity to fungal metabolites and secretion products. We analysed barley cultivars with differential resistance to Fusarium culmorum KF350 for their sensitivity to 5‐butylpicolinic acid [syn. fusaric acid (FA)], a product synthesized by Fusarium isolates of the Liseola section of the Gibberella fujikuroi species complex. We found similar sensitivity of first and second leaves of the cultivars to KF350 and to FA, as well as to head blight in the literature. Upon FA treatment, more resistant cultivars, Jolante and Chevron, compared with susceptible cultivars, Carola and Uschi, showed less necrosis and ion leakage in primary leaves and roots, suggesting that FA can possibly be used in breeding programs as a screening compound for improved cultivars. Importantly, sensitivity to H2O2 was not correlated with resistance to KF350 although it accumulated at penetration sites and in lesions associated with Fusarium infection in all cultivars.
A novel cause for abnormal liver function tests in pregnancy and the puerperium: non‐alcoholic fatty liver disease
Authors: Page LM , Girling JC
Published: August 2011

Please cite this paper as: Page L, Girling J. A novel cause for abnormal liver function tests in pregnancy and the puerperium: non‐alcoholic fatty liver disease. BJOG 2011;118:1532–1535.

Non‐alcoholic fatty liver disease (NAFLD) is the commonest liver disease in the western world, but has never been reported in pregnancy before. We suggest that NAFLD should also be considered as a cause for abnormal liver function tests during pregnancy. As NAFLD is driven by insulin resistance, it is biologically plausible that pregnancy may reveal previously subclinical disease. Obstetricians have a vital role in optimising maternal health during and after pregnancy and therefore we need to include NAFLD in the differential diagnosis for abnormal liver function tests and recommend lifestyle modifications that may prevent progression to cirrhosis and hepatocellular carcinoma.
Primary surgical repair of anterior vaginal prolapse: a randomised trial comparing anatomical and functional outcome between anterior colporrhaphy and trocar‐guided transobturator anterior mesh
Authors: Vollebregt A , Fischer K , Gietelink D , van der Vaart CH
Published: August 2011

Please cite this paper as: Vollebregt A, Fischer K, Gietelink D, van der Vaart C. Primary surgical repair of anterior vaginal prolapse: a randomised trial comparing anatomical and functional outcome between anterior colporrhaphy and trocar‐guided transobturator anterior mesh. BJOG 2011;118:1518–1527.

Objective  To compare anterior colporrhaphy with a trocar‐guided transobturator mesh procedure (Avaulta® anterior).

Design  Randomised, controlled trial.

Setting  Three teaching hospitals.

Population  Women with a symptomatic cystocele at least stage II requiring primary surgical correction.

Methods  A total of 125 women were assessed at baseline and 1‐year follow up. A sacrospinous hysteropexy or posterior colporrhaphy was performed when indicated.

Main outcome measures  The primary outcome was the difference in anatomical cure (defined as Pelvic Organ Prolapse‐Quantification <stage II cystocele). Secondary outcomes were complications, self‐reported urogenital symptom severity, and quality of life, as measured with validated questionnaires.

Results  In all, 64 women were allocated to the anterior colporrhaphy group and 61 to the mesh group; 58/64 women versus 56/61 completed 12 months of follow‐up analysis. Compared with the anterior colporrhaphy group, the mesh reduced the risk of anatomical failure at 12 months follow up from 59 to 9% (risk reduction 50.3%, 95% CI 35.5–65.1). Only three (5%) re‐operations for anatomical failure in the anterior colporrhaphy group were performed versus 0% in the mesh group. Functional outcome improved significantly at 12 months on almost all domains, with similar results between groups. Mesh exposure occurred in two (4%) women. Baseline dyspareunia disappeared significantly more often after an anterior colporrhaphy (80%) than in the mesh group (20%). There was a trend towards more de novo dyspareunia in the mesh group (15% versus 9%).

Conclusions  Primary cystocele repair with trocar‐guided transobturator mesh resulted in a statistically significant better anatomical outcome compared with the anterior colporrhaphy. However, functional outcome was similar between groups.
Splenic abscesses due to migrant metallic wires from small intestine in a horse
Authors: Rosso A. , Bullone M. , Gillono E. , Greppi M. C. , Bertuglia A.
Published: August 2011

This reports discusses a perforating metallic wire that was suspected of causing chronic weight loss, inappetance and pyrexia in a 15‐year‐old Standardbred gelding, due to the fact that during the previous 18 months, 6 horses coming from the same yard were referred for recurrent or acute colic related to the ingestion of metallic wires. Splenomegaly was detected ultrasonographically and confirmed during surgery. During necropsy, 2 metallic wires 0.2 mm in diameter and 3–4 cm long were found in a markedly enlarged spleen with several nonencapsulated abscesses. Metallic wire perforation and migration through the lower alimentary tract may involve different abdominal quadrants (intestine, abdominal wall, spleen, liver) and lead to different clinical syndromes as acute or recurrent colic and weight loss. A clinical diagnosis is challenging as the clinical signs are often nonspecific and prognosis is generally considered poor.
Formation Mechanism of the Eigen-line in Electrofusion Joints of Polyethylene Pipes
Authors: Shi Jianfeng , Zheng Jinyang , Guo Weican
Published: August 2011

Cold welding is the most dangerous defect in the electrofusion joint of polyethylene (PE) pipes. A proprietary method was developed to detect the degree of cold welding by using an Eigen-line, which was discovered in our previous study. To understand when, where, and how the Eigen-line would appear, the forming mechanism was investigated in this paper. Three factors, i.e., micro-air-bubbles, difference of acoustic impendence of PE in the melted and unmelted region, and small-crowded crystals in the region of the interface of melted and unmelted region, may cause the appearance of the Eigen-line. It was found that the number of Eigen-lines was the same as that of welding times when rewelded with decreasing welding time, and only one Eigen-line could be observed when rewelded with increasing welding time. The result showed that small-crowded crystals in the region of the interface of melted and unmelted region may be the dominating factor. This was then verified by the temperature analysis and differential DSC tests, and the forming process of the small-crowded crystals was discussed in detail.
Characterization of an x‐ray phase contrast imaging system based on the miniature synchrotron MIRRORCLE‐6X
Authors: van Heekeren Joop , Kostenko Alexander , Hanashima Takayasu , Yamada Hironari , Stallinga Sjoerd , Offerman S. Erik , van Vliet Lucas J.
Published: August 2011

Purpose:

The implementation of in‐linex‐ray phase contrast imaging (PCI) for soft‐tissue patient imaging is hampered by the lack of a bright and spatially coherent x‐ray source that fits into the hospital environment. This article provides a quantitative characterization of the phase‐contrast enhancement of a PCI system based on the miniature synchrotron technology MIRRORCLE‐6X.

Methods:

The phase‐contrast effect was measured using an edge response of a plexiglass plate as a function of the incident angle of radiation. We have developed a comprehensive x‐ray propagation model based on the system's components, properties, and geometry in order to interpret the measurement data. Monte‐Carlo simulations are used to estimate the system's spectral properties and resolution.

Results:

The measured ratio of the detected phase‐contrast to the absorption contrast is currently in the range 100% to 200%. Experiments show that with the current implementation of the MIRRORCLE‐6X, a target smaller than 30–40 μm does not lead to a larger phase‐contrast. The reason for this is that the fraction of x‐rays produced by the material (carbon filament and glue) that is used for mounting the target in the electron beam is more than 25% of the total amount of x‐rays produced. This increases the apparent source size. The measured phase‐contrast is at maximum two times larger than the absorption contrast with the current set‐up.

Conclusions:

Calculations based on our model of the present imaging system predict that the phase‐contrast can be up to an order of magnitude larger than the absorption contrast in case the materials used for mounting the target in the electron beam do not (or hardly) produce x‐rays. The methods described in this paper provide vital feedback for guiding future modifications to the design of the x‐ray target of MIRRORCLE‐type system and configuration of the in‐line PCI systems in general.
USAYPT Holds Annual February Tournament
Authors: Oldaker Bruce
Published: August 2011

The United States Association for Young Physicists Tournaments (USAYPT) held its annual U.S. Invitational Young Physicists Tournament Feb. 4–5, 2011, at Oak Ridge Associated Universities Institute for Science Education, Oak Ridge, TN. Young physicists tournaments are theoretical and experimental research-based team competitions described more fully at the USAYPT website: www.usaypt.org. This year the problems were #1: Domino Wave, #2: Salt-Water Oscillator, #3: Magic Motor, and #4: Boiling Water.
An Improved Box Theater
Authors: Huster Michael E.
Published: August 2011

While designing an optics lab for a conceptual physics course, I came across a “box theater” activity.1 The box theater is a pinhole camera obscura made from a box that students put over their heads and shoulders. I use the activity as a capstone experience to explain optical systems. (Classroom demonstrations of the camera obscura have been described by others.2) First, the students build and experiment with a camera obscura made from a plastic cup and a convex lens with a focal length of 7.5 cm, and then “wear” the box theater. The difficulty with the box theater is the dimness of the image. A cloth drape has to be hung from the bottom of the box around the shoulders of the students to prevent light leakage, and the students have to wait a few minutes for their eyes to adjust to the darkness.
Building Dynamic Conceptual Physics Understanding
Authors: Trout Charlotte , Sinex Scott A. , Ragan Susan
Published: August 2011

Models are essential to the learning1 and doing of science, and systems thinking is key to appreciating many environmental issues. The National Science Education Standards2 include models and systems in their unifying concepts and processes standard, while the AAAS Benchmarks3 include them in their common themes chapter. Hyerle4 and Marzano5,6 argue for the importance of graphic organizers to student learning. In addition, there is a growing national interest in defining and implementing computational thinking for students.7 In the past 15 years, we have presented dozens of workshops to teachers who are interested in using the computational power of their computers in their classrooms.8–9 In addition to other programs, we use systems dynamics programs to encourage modeling in secondary science classrooms. The interface for these packages is a graphic organizer. In this article we will share some of our insights into the advantages of using such systems dynamics software with high school physics students.
Sub-$10 sound card photogate variants
Authors: Gingl Zoltan
Published: August 2011

Recently, a simple and very low-cost photogate has been shown by Horton1 as an efficient experimentation tool in physics education. The photogate connects to the microphone input of a personal computer, and free software can be used to visualize the light interruptions caused by a moving object such as a pendulum. Although the device works properly, there are further possibilities of improvement and similar alternatives also exist. The following brief review may help teachers to pick the one that best fits their needs and possibilities.
Potent Kinetic Stabilizers That Prevent Transthyretin-Mediated Cardiomyocyte Proteotoxicity
Authors: Alhamadsheh Mamoun M. , Connelly Stephen , Cho Ahryon , Reixach Natàlia , Powers Evan T. , Pan Dorothy W. , Wilson Ian A. , Kelly Jeffery W. , Graef Isabella A.
Published: August 2011

A high-throughput screen for transthyretin ligands that inhibit protein aggregation identifies agents that prevent amyloid formation and toxicity toward cardiomyocytes.
Hematopoietic Stem Cell Gene Therapy for Adenosine Deaminase–Deficient Severe Combined Immunodeficiency Leads to Long-Term Immunological Recovery and Metabolic Correction
Authors: Gaspar H. Bobby , Cooray Samantha , Gilmour Kimberly C. , Parsley Kathryn L. , Zhang Fang , Adams Stuart , Bjorkegren Emma , Bayford Jinhua , Brown Lucinda , Davies E. Graham , Veys Paul , Fairbanks Lynette , Bordon Victoria , Petropoulou Theoni , Kinnon Christine , Thrasher Adrian J.
Published: August 2011

Gene therapy can restore immune and metabolic function in patients with adenosine deaminase immunodeficiency.
Potential for Direct Interspecies Electron Transfer in Methanogenic Wastewater Digester Aggregates
Authors: Morita Masahiko , Malvankar Nikhil S. , Franks Ashley E. , Summers Zarath M. , Giloteaux Ludovic , Rotaru Amelia E. , Rotaru Camelia , Lovley Derek R.
Published: August 2011

Mechanisms for electron transfer within microbial aggregates derived from an upflow anaerobic sludge blanket reactor converting brewery waste to methane were investigated in order to better understand the function of methanogenic consortia. The aggregates were electrically conductive, with conductivities 3-fold higher than the conductivities previously reported for dual-species aggregates of
Geobacter
species in which the two species appeared to exchange electrons via interspecies electron transfer. The temperature dependence response of the aggregate conductance was characteristic of the organic metallic-like conductance previously described for the conductive pili of
Geobacter sulfurreducens
and was inconsistent with electron conduction through minerals. Studies in which aggregates were incubated with high concentrations of potential electron donors demonstrated that the aggregates had no significant capacity for conversion of hydrogen to methane. The aggregates converted formate to methane but at rates too low to account for the rates at which that the aggregates syntrophically metabolized ethanol, an important component of the reactor influent.
Geobacter
species comprised 25% of 16S rRNA gene sequences recovered from the aggregates, suggesting that
Geobacter
species may have contributed to some but probably not all of the aggregate conductivity. Microorganisms most closely related to the acetate-utilizing
Methanosaeta concilii
accounted for more than 90% of the sequences that could be assigned to methane producers, consistent with the poor capacity for hydrogen and formate utilization. These results demonstrate for the first time that methanogenic wastewater aggregates can be electrically conductive and suggest that direct interspecies electron transfer could be an important mechanism for electron exchange in some methanogenic systems.

IMPORTANCE
The conversion of waste organic matter to methane is an important bioenergy strategy, and a similar microbial metabolism of complex organic matter in anaerobic soils and sediments plays an important role in the global carbon cycle. Studies with laboratory cultures have demonstrated that hydrogen or formate can serve as an electron shuttle between the microorganisms degrading organic compounds and methanogens. However, the importance of hydrogen and formate as intermediates in the conversion of organic matter to methane in natural communities is less clear. The possibility that microorganisms within some natural methanogenic aggregates may directly exchange electrons, rather than producing hydrogen or formate as an intermediary electron carrier, is a significant paradigm shift with implications for the modeling and design of anaerobic wastewater reactors and for understanding how methanogenic communities will respond to environmental perturbations.
A qualitative approach to Bayes' theorem
Authors: Medow Mitchell A , Lucey Catherine R
Published: August 2011

While decisions made according to Bayes' theorem are the academic normative standard, the theorem is rarely used explicitly in clinical practice. Yet the principles can be followed without intimidating mathematics. To do so, one can first categorise the prior-probability of the disease being tested for as very unlikely (less likely than 10%), unlikely (10–33%), uncertain (34–66%), likely (67–90%) or very likely (more likely than 90%). Usually, for disorders that are very unlikely or very likely, no further testing is needed. If the prior probability is unlikely, uncertain or likely, a test and a Bayesian-inspired update process incorporating the result can help. A positive result of a good test increases the probability of the disorder by one likelihood category (eg, from uncertain to likely) and a negative test decreases the probability by one category. If testing is needed to escape the extremes of likelihood (eg, a very unlikely but particularly dangerous condition or in the circumstance of population screening, or a very likely condition with a particularly noxious treatment), two tests may be needed to achieve. Negative results of tests with sensitivity ≥99% are sufficient to rule-out a diagnosis; positive results of tests with specificity ≥99% are sufficient to rule-in a diagnosis. This method overcomes some common heuristic errors: ignoring the base rate, probability adjustment errors and order effects. The simplicity of the method, while still adhering to the basic principles of Bayes' theorem, has the potential to increase its application in clinical practice.
Clinical syndromes associated with the circulation of multiple serotypes of bluetongue virus in dairy cattle in Israel
Authors: Brenner J. , Batten C. , Yadin H. , Bumbarov V. , Friedgut O. , Rotenberg D. , Golender N. , Oura C. A. L.
Published: August 2011

From 2008 to 2011, seven distinct bluetongue virus (BTV) serotypes (BTV‐2, BTV‐4, BTV‐5, BTV‐8, BTV‐15, BTV‐16 and BTV‐24) have been identified to be circulating in diseased sheep and cattle in Israel. This paper describes the array of clinical manifestations caused by BTV in cattle in Israel. Each set of clinical manifestations has been categorised as a syndrome and six distinct clinical syndromes have been observed in dairy cattle: ‘footrot‐like syndrome’, ‘sore nose syndrome’, ‘subcutaneous emphysema syndrome’, ‘red/rough udder syndrome’, ‘bluetongue/epizootic haemorrhagic disease systemic syndrome’ and ‘maladjustment syndrome’.
STRUCTURAL AND MAGNETOELASTIC PROPERTIES OF Y3Fe27.2Cr1.8 AND Ce3Fe25Cr4 FERROMAGNETIC COMPOUNDS
Authors: TAJABOR N. , GHOLIZADEH A. , BEHDANI M. , KHOSHNOUD D. SANAVI , SALAMATI H. , POURARIAN F.
Published: August 2011

The structural and magnetoelastic properties of polycrystalline samples of Y 3 Fe 27.2 Cr 1.8 and Ce 3 Fe 25 Cr 4 intermetallic compounds are investigated by means of X-ray diffraction, thermomagnetic, thermal expansion and magnetostriction measurements in the temperature range of 77–500 K under applied magnetic fields up to 1.5 T. The well defined anomalies observed in the linear thermal expansion coefficient curves are associated with the magnetic phase transitions and presence of small amounts of 1:12 phase in the Ce 3 Fe 25 Cr 4 sample; the latter is also confirmed by AC susceptibility measurements. For Y 3 Fe 27.2 Cr 1.8, saturation behavior is observed in the anisotropic magnetostriction isotherms near the magnetic ordering temperature (TC), whereas for Ce 3 Fe 25 Cr 4 compound, saturation starts well below TC. The additional anomalies observed in the volume magnetostriction isotherms of both compounds are explained based on the anisotropy field in the a–b plane and along the c-axis of the unit cell.
Language and Cognition Interaction Neural Mechanisms
Authors: Perlovsky Leonid
Published: August 2011

How language and cognition interact in thinking? Is language just used for communication of completed thoughts, or is it fundamental for thinking? Existing approaches have not led to a computational theory. We develop a hypothesis that language and cognition are two separate but closely interacting mechanisms. Language accumulates cultural wisdom; cognition develops mental representations modeling surrounding world and adapts cultural knowledge to concrete circumstances of life. Language is acquired from surrounding language “ready-made” and therefore can be acquired early in life. This early acquisition of language in childhood encompasses the entire hierarchy from sounds to words, to phrases, and to highest concepts existing in culture. Cognition is developed from experience. Yet cognition cannot be acquired from experience alone; language is a necessary intermediary, a “teacher.” A mathematical model is developed; it overcomes previous difficulties and leads to a computational theory. This model is consistent with Arbib's “language prewired brain” built on top of mirror neuron system. It models recent neuroimaging data about cognition, remaining unnoticed by other theories. A number of properties of language and cognition are explained, which previously seemed mysterious, including influence of language grammar on cultural evolution, which may explain specifics of English and Arabic cultures.
New Type Far IR and THz Schottky Barrier Detectors for Scientific and Civil Application
Authors: Ivanov V. G. , Ivanov G. V.
Published: August 2011

The results of an experimental investigation into a new type of VLWIR detector based on hot electron gas emission and architecture of the detector are presented and discussed. The detectors (further referred to as HEGED) take advantage of the thermionic emission current change effect in a semiconductor diode with a Schottky barrier (SB) as a result of the direct transfer of the absorbed radiation energy to the system of electronic gas in the quasimetallic layer of the barrier. The possibility of detecting radiation having the energy of quantums less than the height of the Schottky diode potential barrier and of obtaining a substantial improvement of a cutoff wavelength to VLWIR of the PtSi/Si detector has been demonstrated. The complementary contribution of two physical mechanisms of emanation detection—“quantum” and hot electrons gas emission—has allowed the creation of a superwideband IR detector using standard silicon technology.
Existence and Uniqueness of Limit Cycles in a Class of Planar Differential Systems
Authors: Al-Dosary Khalil I. T.
Published: August 2011

This paper is an extension to the recent results presented by M. Sabatini about the existence and uniqueness of limit cycles of a certain class of planar differential systems in order to include other new classes. A concrete example exhibiting the applicability of the result is introduced.
Two Cases ofHelicobacter pylori-Negative Gastric Outlet Obstruction in Children
Authors: Patel Raza A. , Baker Susan S. , Sayej Wael N. , Baker Robert D.
Published: August 2011

Gastric outlet obstruction (GOO) in children is most commonly caused by idiopathic hypertrophic pyloric stenosis. Prior to proton pump inhibitors and H2 blockers, peptic ulcer disease (PUD) secondary toH. pyloriwas a cause of GOO. Both patients presented with a history of weight loss, vomiting, and abdominal pain. Their diagnosis of PUD and GOO was made by EGD and UGI.H. pyloritesting was negative for both on multiple occasions but still receivedH. pylorieradication therapy. Patient 1 after failing pharmaceutical management underwent surgery for definitive treatment. Patient 2 underwent six therapeutic pyloric dilations before undergoing surgery as definitive treatment. These cases suggest that GOO secondary to PUD occurs in the absence ofH. pyloriinfection and surgical management can provide definitive therapy.