bluuebunny/crossref_metadata_2025 huggingface dataset:
Review: The future of cell therapies and brain repair: Parkinson's disease leads the way
Authors: Petit G. H. , Olsson T. T. , Brundin P.
Published: December 2013

During the past 40 years brain tissue grafting techniques have been used both to study fundamental neurobiological questions and to treat neurological diseases. Motor symptoms of Parkinson's disease are largely due to degeneration of midbrain dopamine neurones. Because the nigrostriatal pathology is relatively focused anatomically, Parkinson's disease is considered the ideal candidate for brain repair by neural grafting and dopamine neurone transplantation for it has led the way in the neural transplantation research field. In this mini‐review, we briefly highlight four important areas of development. First, we describe marked functional benefits up to 18 years after transplantation surgery in patients with Parkinson's disease. This is proof‐of‐principle that, using optimal techniques and patient selection, grafted dopamine neurones can work in humans and the duration of the benefit exceeds placebo effects associated with surgery. Second, we describe that eventually protein aggregates containing α‐synuclein, identical to Lewy bodies, develop inside foetal dopamine neurones transplanted to patients with Parkinson's disease. This gives clues about pathogenetic mechanisms operating in Parkinson's disease, and also raises the question whether neural graft function will eventually decline as the result of the disease process. Third, we describe new emerging sources of transplantable dopamine neurones derived from pluripotent stem cells or reprogrammed adult somatic cells. Fourth, we highlight an important European Union‐funded multicentre clinical trial involving transplantation of foetal dopamine neurones in Parkinson's disease. We describe the design of this ongoing trial and how it can impact on the overall future of cell therapy in Parkinson's disease.
Impaired copper and iron metabolism in blood cells and muscles of patients affected by copper deficiency myeloneuropathy
Authors: Spinazzi Marco , Sghirlanzoni Angelo , Salviati Leonardo , Angelini Corrado
Published: December 2013

Aims

Severe copper deficiency leads in humans to a treatable multisystem disease characterized by anaemia and degeneration of spinal cord and nerves, but its mechanisms have not been investigated. We tested whether copper deficit leads to alterations in fundamental copper‐dependent proteins and in iron metabolism in blood and muscles of patients affected by copper deficiency myeloneuropathy, and if these metabolic abnormalities are associated with compensatory mechanisms for copper maintenance.

Methods

We evaluated the expression of critical copper enzymes, of iron‐related proteins, and copper chaperones and transporters in blood and muscles from five copper‐deficient patients presenting with subacute sensory ataxia, muscle paralysis, liver steatosis and variable anaemia. Severe copper deficiency was caused by chronic zinc intoxication in all of the patients, with an additional history of gastrectomy in two cases.

Results

The antioxidant enzyme SOD1 and subunit 2 of cytochrome c oxidase were significantly decreased in blood cells and in muscles of copper‐deficient patients compared with controls. In muscle, the iron storage protein ferritin was dramatically reduced despite normal serum ferritin, and the expression of the haem‐proteins cytochrome c and myoglobin was impaired. Muscle expression of the copper transporter CTR1 and of the copper chaperone CCS, was strikingly increased, while antioxidant protein 1 was diminished.

Conclusions

copper‐dependent enzymes with critical functions in antioxidant defences, in mitochondrial energy production, and in iron metabolism are affected in blood and muscles of patients with profound copper deficiency leading to myeloneuropathy. Homeostatic mechanisms are strongly activated to increase intracellular copper retention.
Synthetic TAL effectors for targeted enhancement of transgene expression in plants
Authors: Liu Wusheng , Rudis Mary R. , Peng Yanhui , Mazarei Mitra , Millwood Reginald J. , Yang Jian‐Ping , Xu Wenzhi , Chesnut Jonathan D. , Stewart Charles Neal
Published: December 2013

Transcription activator‐like effectors (TALEs), secreted by the pathogenic bacteria Xanthomonas, specifically activate expression of targeted genes in plants. Here, we designed synthetic TALEs that bind to the flanking regions of the TATA‐box motif on the CaMV 35S promoter for the purpose of understanding the engineerable ‘hot‐spots’ for increasing transgene expression. We demonstrated that transient expression of de novo‐engineered TALEs using agroinfiltration could significantly increase reporter gene expression in stable transgenic tobacco expressing the orange fluorescent protein reporter gene pporRFP under the control of synthetic inducible, minimal or full‐length 35S promoters. Moreover, the additive effects of a combination of two different synthetic TALEs could significantly enhance the activation effects of TALEs on reporter gene expression more than when each TALE was used individually. We also studied the effects of the C‐terminal domain and the activation domain of synthetic TALEs, as well as the best ‘hot‐spots’ on the 35S promoter on targeted transgene activation. Furthermore, TALE activation of the Arabidopsis MYB transcription factor AtPAP1 (PRODUCTION OF ANTHOCYANIN PIGMENT 1) in stable transgenic tobacco gave rise to a dark purple colour on infiltrated leaves when driven by four copies of cis‐regulatory elements of pathogenesis‐related gene (PR1) with enhancer motifs B and A1 from the 35S promoter. These results provide novel insights into the potential applications of synthetic TALEs for targeted gene activation of transgenes in plants.
Interactions between the jasmonic and salicylic acid pathway modulate the plant metabolome and affect herbivores of different feeding types
Authors: SCHWEIGER R. , HEISE A.‐M. , PERSICKE M. , MÜLLER C.
Published: December 2013

The phytohormones jasmonic acid (JA) and salicylic acid (SA) mediate induced plant defences and the corresponding pathways interact in a complex manner as has been shown on the transcript and proteine level. Downstream, metabolic changes are important for plant–herbivore interactions. This study investigated metabolic changes in leaf tissue and phloem exudates of Plantago lanceolata after single and combined JA and SA applications as well as consequences on chewing‐biting (Heliothis virescens) and piercing‐sucking (Myzus persicae) herbivores. Targeted metabolite profiling and untargeted metabolic fingerprinting uncovered different categories of plant metabolites, which were influenced in a specific manner, indicating points of divergence, convergence, positive crosstalk and pronounced mutual antagonism between the signaling pathways. Phytohormone‐specific decreases of primary metabolite pool sizes in the phloem exudates may indicate shifts in sink–source relations, resource allocation, nutrient uptake or photosynthesis. Survival of both herbivore species was significantly reduced by JA and SA treatments. However, the combined application of JA and SA attenuated the negative effects at least against H. virescens suggesting that mutual antagonism between the JA and SA pathway may be responsible. Pathway interactions provide a great regulatory potential for the plant that allows triggering of appropriate defences when attacked by different antagonist species.
Wood properties of Populus and Betula in long‐term exposure to elevated CO2 and O3
Authors: KOSTIAINEN KATRI , SARANPÄÄ PEKKA , LUNDQVIST SVEN‐OLOF , KUBISKE MARK E. , VAPAAVUORI ELINA
Published: December 2013

We studied the interactive effects of elevated concentrations of CO2 and O3 on radial growth and wood properties of four trembling aspen (Populus tremuloides Michx.) clones and paper birch (Betula papyrifera Marsh.) saplings. The material for the study was collected from the Aspen FACE (free‐air CO2 enrichment) experiment in Rhinelander (WI, USA). Trees had been exposed to four treatments [control, elevated CO2 (560 ppm), elevated O3 (1.5 times ambient) and combined CO2 + O3] during growing seasons 1998–2008. Most treatment responses were observed in the early phase of experiment. Our results show that the CO2‐ and O3‐exposed aspen trees displayed a differential balance between efficiency and safety of water transport. Under elevated CO2, radial growth was enhanced and the trees had fewer but hydraulically more efficient larger diameter vessels. In contrast, elevated O3 decreased radial growth and the diameters of vessels and fibres. Clone‐specific decrease in wood density and cell wall thickness was observed under elevated CO2. In birch, the treatments had no major impacts on wood anatomy or wood density. Our study indicates that short‐term impact studies conducted with young seedlings may not give a realistic view of long‐term ecosystem responses.
Carbon isotope discrimination during branch photosynthesis of Fagus sylvatica: a Bayesian modelling approach
Authors: GENTSCH LYDIA , HAMMERLE ALBIN , STURM PATRICK , OGÉE JÉRÔME , WINGATE LISA , SIEGWOLF ROLF , PLÜSS PETER , BAUR THOMAS , BUCHMANN NINA , KNOHL ALEXANDER
Published: December 2013

Field measurements of photosynthetic carbon isotope discrimination (13Δ) of Fagus sylvatica, conducted with branch bags and laser spectrometry, revealed a high variability of 13Δ, both on diurnal and day‐to‐day timescales. We tested the prediction capability of three versions of a commonly used model for 13Δ [called here comprehensive (13Δcomp), simplified (13Δsimple) and revised (13Δrevised) versions]. A Bayesian approach was used to calibrate major model parameters. Constrained estimates were found for the fractionation during CO2 fixation in 13Δcomp, but not in 13Δsimple, and partially for the mesophyll conductance for CO2 (gi). No constrained estimates were found for fractionations during mitochondrial and photorespiration, and for a diurnally variable apparent fractionation between current assimilates and mitochondrial respiration, specific to 13Δrevised. A quantification of parameter estimation uncertainties and interdependencies further helped explore model structure and behaviour. We found that 13Δcomp usually outperformed 13Δsimple because of the explicit consideration of gi and the photorespiratory fractionation in 13Δcomp that enabled a better description of the large observed diurnal variation (≈9‰) of 13Δ. Flux‐weighted daily means of 13Δ were also better predicted with 13Δcomp than with 13Δsimple.
Current growth status and metabolic parameters of Korean adolescents born small for gestational age: Results from the Korea National Health and Nutrition Examination Surveys (KNHANES) 2010–2011
Authors: Cho Won Kyoung , Jung In Ah , Suh Byung‐Kyu
Published: December 2013

Background

Currently, little information is available on current growth status and metabolic syndrome (MetS) components according to birthweight at gestational age (BWGA) on Korean adolescents. Herein, the current height and weight and MetS components of Korean adolescents who were born as small for gestational age (SGA) were compared to those of the appropriate for GA (AGA) or large for GA (LGA) groups.

Methods

Data for 2018 adolescents (aged 10–18 years) recorded in the Fifth Korean National Health and Nutrition Examination Survey 2010–2011 conducted by the Korean Ministry of Health and Welfare were assessed in this cross‐sectional study. A total of 1750 subjects were assessed for current growth according to BWGA, and 792 were assessed for MetS components according to BWGA.

Results

From the birth history of 1750 adolescents, the prevalence of SGA, AGA, and LGA was 11.4% (n = 193), 77.7% (n = 1366), and 10.9% (n = 191), respectively. Current height‐standard deviation score (SDS) and weight‐SDS were significantly positively related to BWGA in all Korean adolescents (P < 0.0001). Of the 792 adolescents, the prevalence of MetS was 1.2% (n = 9). There were no differences in MetS components in Korean adolescents between SGA and AGA or LGA group.

Conclusion

BWGA is related to current height and weight in Korean adolescents but is not related to individual components of MetS.
Biochemical Composition and Antioxidant Properties of Lavandula angustifolia Miller Essential Oil are Shielded by Propolis Against UV Radiations
Authors: Angelo Gismondi , Lorena Canuti , Marta Grispo , Antonella Canini
Published: December 2013

UV radiations are principal causes of skin cancer and aging. Suntan creams were developed to protect epidermis and derma layers against photodegradation and photooxidation. The addition of antioxidant plant extracts (i.e. essential oil) to sunscreens is habitually performed, to increase their UV protective effects and to contrast pro‐radical and cytotoxic compounds present in these solutions. According to these observations, in the present work, the alteration of chemical composition and bioactive properties of Lavandula angustifolia Miller essential oil, exposed to UV light, was investigated. UV induced a significant deterioration of lavender oil biochemical profile. Moreover, the antioxidant activity of this solution, in in vitro tests and directly on B16‐F10 melanoma cells, greatly decreased after UV treatment. Our results also showed that essential oil was shielded from UV stress by propolis addition. Even after UV treatment, bee glue highly protected lavender oil secondary metabolites from degradation and also preserved their antiradical properties, both in in vitro antioxidant assays and in cell oxidative damage evaluations. This research proposed propolis as highly efficient UV protective and antiradical additive for sunscreens, cosmetics and alimentary or pharmaceutical products containing plant extracts.
Humoural immune response and pathological analysis in patients with false immune diagnosis of cystic echinococcosis
Authors: Chen X. , Zhang J. , Feng X. , Chen X. , Yin S. , Wen H. , Zheng S.
Published: December 2013

The patients with false immune diagnosis of hydatid disease were investigated for the humoural immune response to analyse the possible reasons and mechanism leading to false immune diagnosis. Two hundred and thirty‐nine patients with nature‐unknown cysts and 30 healthy controls were detected by immunological assays (four hydatid antigen‐based immunogold filtration assay and enzyme‐linked immune absorbent assay) and ultrasound. Sensitivity of and specificity of immunological assay and ultrasound were calculated, respectively. The serological diagnosis was compared with surgical pathology to screen the patients with false immune diagnosis for the immunoglobulin measurement and pathological analysis. The history and cyst characteristics were also reviewed. The results indicate the immunoglobulin has little influence on false immunodiagnosis. The false‐negative immunodiagnosis was caused by the cysts' inactive status while the false positive caused by previous rupture, antigen cross‐reaction. The clinical diagnosis of cystic echinococcosis requires a combination of immunodiagnosis and ultrasonography, which is the necessary complementary confirmation.
Localism in Practice: Investigating Citizen Participation and Good Governance in Local Government Standards of Conduct
Authors: Lawton Alan , Macaulay Michael
Published: December 2013

This article examines how, against a background of localism endorsed by the 2010 coalition government in the United Kingdom, a key component of local integrity and governance was fundamentally altered. The Localism Act 2011 abolished the English local integrity framework, which relied on the participation of local citizens in the policy making and implementation of local government standards of conduct. The article utilizes Henrik Bang's concepts of “expert citizen” and “everyday maker” to explore citizen participation in local standards committees. Using a case study approach, the article demonstrates how standards committees shaped processes and practices in the local governance of integrity. The authors argue that standards committees were crucial in promoting local participation and enhancing good governance.
Altered sputum granzyme B and granzyme B/proteinase inhibitor‐9 in patients with non‐eosinophilic asthma
Authors: Simpson Jodie L , Gibson Peter G , Yang Ian A , Upham John , James Alan , Reynolds Paul N , Hodge Sandra ,   AMAZES Study Research Group
Published: December 2013

Background and objective

The non‐eosinophilic phenotype of asthma (NEA) is associated with chronic airway inflammation and airway neutrophilia. An accumulation of apoptotic airway epithelial cells, if not efficiently cleared by efferocytosis, can undergo secondary necrosis, with the potential for inflammation of surrounding tissues. Apoptosis may occur via the T cell granzyme B pathway. The role of granzyme B in NEA is not known. The aim of this study was to investigate production of granzyme B and its inhibitor proteinase inhibitor (PI)‐9 by T cells from induced sputum and compare expression between eosinophilic, NEA and healthy controls.

Methods

We investigated T cell intracellular granzyme B and its inhibitor, PI‐9, in sputum from healthy control subjects (n = 10), and patients with NEA (n = 22) or eosinophilic asthma (EA) (n = 15) using flow cytometry.

Results

Granzyme B expression and the ratio of granzyme B to PI‐9 positive cells were highest in those with NEA for both CD3+ and CD4+ T cells. The expression of granzyme B was not statistically different between patients with NEA and EA; however, the ratio of granzyme B to PI‐9 positive cells for CD3+ T cells was significantly higher in those with NEA compared with EA.

Conclusions

Induced sputum provides a non‐invasive tool for investigating T cell cytotoxic mediators in the various asthma subtypes. Granzyme B expression is increased in NEA and the contribution of granzyme B to chronic inflammation requires further study.
Does pressure affect performance? Continuous positive airway pressure for sleep‐disordered breathing in heart failure
Authors: Hamilton Garun S. , Edwards Bradley A. , Sands Scott A.
Published: December 2013

See article, page 47
Introduction to multiple imputation for dealing with missing data
Authors: Lee Katherine J. , Simpson Julie A.
Published: December 2013

Missing data are common in both observational and experimental studies. Multiple imputation (MI) is a two‐stage approach where missing values are imputed a number of times using a statistical model based on the available data and then inference is combined across the completed datasets. This approach is becoming increasingly popular for handling missing data. In this paper, we introduce the method of MI, as well as a discussion surrounding when MI can be a useful method for handling missing data and the drawbacks of this approach. We illustrate MI when exploring the association between current asthma status and forced expiratory volume in 1 s after adjustment for potential confounders using data from a population‐based longitudinal cohort study.
Australian standards of care for cystic fibrosis‐related diabetes
Authors: Middleton Peter G. , Wagenaar Monica , Matson Angela G. , Craig Maria E. , Holmes‐Walker Deborah Jane , Katz Tamarah , Hameed Shihab
Published: December 2013

Multiple guidelines have been published over the last few years for the diagnosis and management of cystic fibrosis (CF) and cystic fibrosis related diabetes (CFRD), although some of the recommendations are based on extrapolation from other forms of diabetes and/or expert opinions. This document seeks to combine the guidelines to provide an Australian approach to the management of CFRD and establish the guidelines within the Australian CF Standards of Care.

It is intended that this document will provide assistance to doctors, nurses, dietitians, physiotherapists, diabetes educators and CF patients concerning the issues surrounding CFRD, and will be reviewed and updated in 2016.
Uneasy Settlements: Reparation Politics and the Meanings of Money in the Israeli Withdrawal from Gaza
Authors: Dromi Shai M.
Published: December 2013

Negotiations about reparations tend to take the language of interests and to deal primarily with monetary compensation for disadvantaged groups. In such proceedings, aggrieved claimants are likely to make a variety of claims about the use of money to represent their experience, ranging from demands for increased compensation to rejections of the entire process altogether. This article draws attention to the communicative functions of money in the reparation process. It claims that actors may grudgingly agree to attach a monetary value to what they hold sacred, but simultaneously strive to preserve their sense of self‐worth and to elicit identification by raising moral critiques about the use of fiscal logic. To exemplify, the article focuses on the 2005 removal of Jewish‐Israeli settlers from Israeli‐occupied territories. It shows that settlers indeed demanded to be compensated fiscally for their lost property. At the same time, it shows that they raised objections to the use of fiscal logic in representing their experience and offered alternate logics of evaluation. The settlers resisted shame and devaluation through such competing logics, demanding that the state reaffirm a positive and embracing relationship with them despite its decision to evict them.
A preliminary molecular phylogenetic assessment of the lichen moths (Lepidoptera: Erebidae: Arctiinae: Lithosiini) with comments on palatability and chemical sequestration
Authors: SCOTT CLARE H. , ZASPEL JENNIFER M. , CHIALVO PABLO , WELLER SUSAN J.
Published: December 2013

The lichen moth tribe Lithosiini is best known for its hypothesized larval feeding behaviour, lichenivory. The larvae of some species have been found to be capable of sequestering polyphenolics, and the adults of some species are unpalatable to vertebrate predators. However, the chemical basis for the defence is unknown. Here we reconstruct a phylogenetic hypothesis using likelihood methods (maximum likelihood, Bayesian inference) for 65 species of Lithosiini representing 37 genera and seven outgroup species using 2806 bp of sequence data obtained from two mitochondrial gene fragments (COI barcoding region, CytB), and two nuclear gene fragments (RpS5 and ribosomal gene region 28S). Lithosiine species representing four of the seven subtribes and unplaced taxa are included in the analysis. The deeper relationships within the tribe are not strongly supported, and the monophyly of three of the four subtribes is not supported. The placement of the fourth subtribe, Acsalina, is weakly supported. We also conduct a survey of the secondary metabolites present within adults of five species. The species are examined for the presence of lichen polyphenolics and plant secondary metabolites sequestered by arctiines. Seven lichen polyphenolics are identified in the taxa examined, but no plant secondary metabolites are found using either analytical method. The results of this study and prior reports in the literature of chemical sequestration and unpalatability are plotted onto the resulting Bayesian inference phylogeny to examine the evolution of chemical defence within Lithosiini. Species that sequester lichen polyphenolics and unpalatable species occur in each of the major clades recovered in the analysis.
The effect of cuff presence and cuff inflation on airway pressure in a canine tracheostomy tube model
Authors: Wignall Jamie R. , Baines Stephen J.
Published: December 2013

Objective

To evaluate the effect of cuff presence and cuff inflation on airway pressure in an inspiratory model of canine tracheostomy.

Design

Ex vivo experimental study. Cadaver tracheas from Beagle dogs were attached aborally to a vacuum. Airway pressure and flow rate was measured before and after placement of tracheostomy tubes.

Animals

None.

Interventions

Adult uncuffed tubes and cuffed tracheostomy tubes (sizes 4, 6, 8, and 10) were placed within tracheas. Cuffs were investigated without inflation and at maximum cuff inflation. Airway pressure was measured at constant airflow rates at 30 and 60 L/min.

Measurements and Main Results

At set flow rates, airway pressures of tracheostomy tubes were compared to the intact trachea. A size 4 uncuffed tracheostomy tube showed the lowest airway pressure and a size 4 cuffed trachestomy tube with inflation showed the highest airway pressures. For sizes 6, 8, and 10 tubes, the presence of a cuff with and without inflation significantly increased airway pressure. Inflation of a cuff always significantly increased airway pressure. Similar pressure is seen between sizes 4 and 6 uncuffed tubes.

Conclusions

Cuffed tracheostomy tubes should not be used unless specifically indicated due to increased airway pressure.
Emerging categories of urban shared sanitation
Authors: Mazeau Adrien , Reed Brian , Sansom Kevin , Scott Rebecca
Published: December 2013

With 2.6 billion people without access to improved sanitation facilities and with a growing urban population globally, shared sanitation in the form of public or community latrines is a pragmatic way of increasing coverage, but it is currently not deemed ‘improved’. This paper explores the variety of facilities that currently exist in order to identify what would enable some of these latrines to be classed as acceptable and to ensure that future shared sanitation facilities meet minimum standards. The categories mostly relate to issues of ownership, management, location and finance rather than technological considerations. An extensive literature review reveals that the users' perspective of acceptability is largely absent from current discussions.
Large‐scale identification of microsatellites for a major invasive weed, Ageratina adenophora, using the Illumina sequencing technology
Authors: Nie X J , Liu P X , Deng P C , Lu Y Z , Biradar S S , Du X H , Wu A P , Wan F H , Weining S
Published: December 2013

Microsatellites were identified and characterised for a worldwide invasive weed, Ageratina adenophora, based on the Illumina sequencing technology. Using the assembled genomic sequences obtained from the Illumina GAII sequencing platform, a total of 3012 microsatellites were identified, of which mono‐, di‐, tri‐, tetra‐, penta‐, and hexa‐nucleotide repeats were 181 (6.0%), 1379 (45.8%), 1064 (35.3%), 220 (7.3%), 73 (2.4%) and 95 (3.2%) respectively. The AC/GT and GAT/ATC motifs were the most frequent motif types of di‐nucleotide and tri‐nucleotide repeats respectively. To validate the newly identified simple sequence repeat markers, 15 primer pairs were randomly selected to test in 24 individuals of A. adenophora, and all of these primer sets could amplify PCR products of expected size. Of them, eight loci displayed polymorphism with the number of alleles per locus ranging from two to four and values for observed and expected heterozygosities ranging from 0.042 to 1 and from 0.082 to 0.551, with the averages of 0.578 and 0.371 respectively. These novel microsatellites should be useful for investigation of the genetic structure and genetic diversity between the invasive and native populations of this species.
Development and Validation of an Adaptive Method to Generate High-Resolution Quadrature Encoder Signals
Authors: Ulu Erva , Gecer Ulu Nurcan , Cakmakci Melih
Published: December 2013

This paper presents a new method to increase the measurement resolution of quadrature encoders. The method contains an adaptive signal correction step and a signal interpolation step. Measured encoder signals contain imperfections including amplitude differences, mean offsets, and quadrature phase shift errors. With the proposed method, these errors are first corrected by using recursive least squares (RLS) estimation with exponential forgetting and resetting. Then, the corrected signals are interpolated to higher order sinusoids using a quick access look-up table generated offline. The position information can be obtained with the conversion of these high-order sinusoids to binary pulses and counting the zero crossings. Using the method presented here, a 10 nm measurement resolution is obtained using an encoder with 1 μm off-the-shelf resolution. Validation of the method and the practical limitations are also presented. Further increase in the resolution can be achieved by minimizing the effects of the electrical noise.
Flame Dynamics With Hydrogen Addition at Lean Blowout Limits
Authors: Zhu Shengrong , Acharya Sumanta
Published: December 2013

Lean premixed combustion is widely used in power generation due to low nitric oxide emissions. Recent interest in syngas requires a better understanding of the role of hydrogen addition on the combustion process. In the present study, the extinction process of hydrogen enriched premixed flames near lean blow out (LBO) in a swirl-stabilized combustor has been examined in both unconfined and confined configurations. High speed images of the flame chemiluminescence are recorded, and a proper orthogonal decomposition (POD) procedure is used to extract the dominant flame dynamics during the LBO process. By examining the POD modes, the spectral information and the statistical properties of POD coefficients, the effect of hydrogen addition on the LBO processes are analyzed and described in the paper. Results show that in unconfined flames, the shear layer mode along with flame rotation with local quenching and reignition is dominant in the methane-only case. For the open hydrogen enriched flames, the extinction times are longer and are linked to the lower minimum ignition energy for hydrogen that facilitates reignition events. In confined methane flames, a conical flame is observed and the POD mode representing the burning in the central recirculation zone appears to be dominant. For the 60% hydrogen enriched flame, a columnar burning pattern is observed and the fluctuation energies are evenly spread across several POD modes making this structure more prone to external disturbances and shorter extinction times.
Low-Flow-Coefficient Centrifugal Compressor Design for Supercritical CO2
Authors: Lettieri C. , Baltadjiev N. , Casey M. , Spakovszky Z.
Published: December 2013

This paper presents a design strategy for very low flow coefficient multistage compressors operating with supercritical CO2 for carbon capture and sequestration (CCS) and enhanced oil recovery (EOR). At flow coefficients less than 0.01, the stage efficiency is much reduced due to dissipation in the gas-path and more prominent leakage and windage losses. Instead of using a vaneless diffuser as is standard design practice in such applications, the current design employs a vaned diffuser to decrease the meridional velocity and to widen the gas path. The aim is to achieve a step change in performance. The impeller exit width is increased in a systematic parameter study to explore the limitations of this design strategy and to define the upper limit in efficiency gain. The design strategy is applied to a full-scale reinjection compressor currently in service. Three-dimensional, steady, supercritical CO2 computational fluid dynamics (CFD) simulations of the full stage with leakage flows are carried out with the National Institute of Standards and Technology (NIST) real gas model. The design study suggests that a nondimensional impeller exit width parameter b2* = (b2/R)ϕ of six yields a 3.5 point increase in adiabatic efficiency relative to that of a conventional compressor design with vaneless diffuser. Furthermore, it is shown that in such stages the vaned diffuser limits the overall stability and that the onset of rotating stall is likely caused by vortex shedding near the diffuser leading edge. The inverse of the nondimensional impeller exit width parameter b2* can be interpreted as the Rossby number. The investigation shows that, for very low flow coefficient designs, the Coriolis accelerations dominate the relative flow accelerations, which leads to inverted swirl angle distributions at impeller exit. Combined with the two-orders-of-magnitude higher Reynolds number for supercritical CO2, the leading edge vortex shedding occurs at lower flow coefficients than in air suggesting an improved stall margin.
Development of a Novel Mixing Plane Interface Using a Fully Implicit Averaging for Stage Analysis
Authors: Hanimann Lucian , Mangani Luca , Casartelli Ernesto , Mokulys Thomas , Mauri Sebastiano
Published: December 2013

This paper describes the development and validation steps of a characteristics-based explicit along with a novel fully implicit mixing plane implementation for turbomachinery applications. The framework is an unstructured 3D RANS in-house modified solver, based on open-source libraries. Particular attention was paid to mass-conservation, accurate variables interpolation, and algorithm stability in order to improve robustness and convergence. By introducing a specific interface, allowing the use of algebraic multigrid solvers together with multiprocessor computation, a speed up of the numerical solution procedure was achieved. The validation of both mixing plane algorithms is carried out on an industrial radial compressor and a cold air 1.5 stages axial turbine.
Formation of Carbon Nanoscrolls During Wedge-Based Mechanical Exfoliation of HOPG
Authors: Jayasena B. , Subbiah S. , Reddy C. D.
Published: December 2013

Carbon nanoscrolls (CNS) of various forms are observed when highly ordered pyrolytic graphite (HOPG) is mechanically exfoliated using a wedge. We present two hypothesis of how such scrolls form. The first hypothesis is based on microscopy evidence of pre-existing folds in layer edges of the HOPG. The second hypothesis is based on the literature evidence that graphene sheets when subject to deformation can result in defects on the torn edges. The sample preparation process can induce such defects in the HOPG layers. We show using molecular simulations that the interaction of the moving wedge with certain fold geometries can trigger scroll formation, confirming the first hypothesis. To test the second hypothesis, we show using molecular simulations, that layers with edge defects, upon interacting with the moving wedge, can also form scrolls. In reality, both these factors could simultaneously cause scrolls to form. Opportunities exist in fine-tuning this wedge-based mechanical exfoliation process to synthesize CNS for use in potential applications.
Opportunities for Promoting Youth Physical Activity: An Examination of Youth Summer Camps
Authors: Hickerson Benjamin D. , Henderson Karla A.
Published: December 2013

Background:

Youth summer camp programs have the potential to provide opportunities for physical activity, but little to no research has been conducted to determine activity levels of campers. This study aimed to examine physical activity occurring in day and resident summer camps and how activity levels differed in these camps based upon demographic characteristics.

Methods:

Pedometer data were collected during hours of camp operation from 150 day campers and 114 resident campers between the ages of 8 and 12 years old. Independent t tests were used to compare physical activity by sex, race, and Body Mass Index.

Results:

Campers at day camps averaged 11,916 steps per camp day, while resident campers averaged 19,699 steps per camp day. Day campers averaged 1586 steps per hour over 7.5 hour days and resident campers averaged 1515 steps per hour over 13 hour days. Male sex, Caucasian race, and normal Body Mass Index were significant correlates of more physical activity.

Conclusions:

Youth summer camps demonstrate the potential to provide ample opportunities for physical activity during the summer months. Traditional demographic disparities persisted in camps, but the structure of camp programs should allow for changes to increase physical activity for all participants.
The Influence of Travel Attitudes, Commute Mode Choice, and Perceived Neighborhood Characteristics on Physical Activity
Authors: Morckel Victoria , Terzano Kathryn
Published: December 2013

Background:

This study examines the relationships between physical activity, travel attitudes, commute mode choice, and perceived neighborhood characteristics. A recent study found that people who walk or bike during their commute exercise more outside of the commute than do people who commute by mass transit or car. The current study seeks to explain what might account for this relationship, using ANOVA models (Method) conducted on survey data from 3 cities.

Results:

Perceived neighborhood characteristics and travel attitudes influence participants’ reported physical activity levels both during the commute and outside of the commute.

Conclusion:

While the study does not establish causality, the results provide some support for the notion that policy makers interested in increasing physical activity levels should consider changing not only the physical environment, but also perceived neighborhood characteristics and travel attitudes.
Feasibility of the Diabetes and Technology for Increased Activity (DaTA) Study: A Pilot Intervention in High-Risk Rural Adults
Authors: Read Emily
Published: December 2013

Background:

Rural Canadians are at increased risk of metabolic syndrome. Physical inactivity is a primary target for preventing and reversing metabolic syndrome. Adherence to lifestyle interventions may be enhanced using cell phones and self-monitoring technologies. This study investigated the feasibility of a physical activity and self-monitoring intervention targeting high-risk adults in rural Ontario.

Methods:

Rural adults (n = 25, mean = 57.0 ± 8.7 years) with ≥ 2 criteria for metabolic syndrome participated in an 8-week stage-matched physical activity and self-monitoring intervention. Participants monitored blood glucose, blood pressure, weight, and physical activity using self-monitoring devices and Blackberry Smart phones. VO2max, stage of change, waist circumference, weight, blood lipids, and HbA1c were measured at weeks 1, 4, and 8.

Results:

Adherence to self-monitoring was > 94%. Participants’ experiences and perceptions of the technology were positive. Mean stage of change increased 1 stage, physical activity increased 26%, and predicted VO2max increased 17% (P < .05). Significant changes in weight, waist circumference, diastolic blood pressure, LDL cholesterol, and total cholesterol were found.

Conclusions:

This stage-matched technology intervention for increased physical activity was feasible and effective.
Sedentary and Active: Self-Reported Sitting Time Among Marathon and Half-Marathon Participants
Authors: Whitfield Geoffrey , Gabriel Kelley K. Pettee , Kohl Harold W.
Published: December 2013

Background:

Emerging evidence suggests that combined physical activity (PA) and inactivity may be more important for chronic disease risk than PA alone. A highly active yet highly sedentary population is needed to study this interaction. The present purpose is to describe the sitting habits of a group of recreational runners and determine if sitting varies with reported training duration or anticipated running velocity.

Methods:

Marathon and half-marathon participants completed the Multicontext Sitting Time Questionnaire and reported peak training duration, anticipated finishing time, and demographic information. Sitting time was described across 5 contexts for workdays and nonworkdays. Total sitting time was analyzed by tertiles of training duration and anticipated event running velocity.

Results:

218 participants took part in this study. Median reported training time was 6.5 hours per week. Median total sitting time was higher on workdays than nonworkdays (645 and 480 minutes, respectively, P < .0001). Total sitting time was not associated with training duration or anticipated event running velocity.

Conclusions:

These results suggest that recreational distance runners are simultaneously highly sedentary and highly active, supporting independence of sedentary behaviors and moderate- to vigorous-intensity PA. This population may provide the characteristics needed to study the joint effects of active and sedentary behaviors on health outcomes.
Determination of deep trapping states of the hole blocking layer in multilayer amorphous selenium X-ray detectors using transient dark current analysis
Authors: Kabir M.Z. , Imam Safayat-Al
Published: December 2013

The density of defect states near the valence band of the hole blocking layer (commonly called the n-layer) is determined by analyzing the transient dark current behavior of multilayer amorphous selenium (a-Se) X-ray image detectors. The previous transient dark current model (Mahmood et al. Appl. Phys. Lett. 92, 223506 (2008)) is modified and compared with recently published experimental transient dark currents on commercial n-i-p and cold deposited n-i a-Se detector structures to determine the energy distributed deep defect densities in these two types of n-layer. The peak defect state exists at 0.75 and 0.78 eV from the valence band mobility edge in alkaline doped and cold deposited n-layers, respectively. The peak trap density in these n-layers varies in the range of 5 × 1016 – 5 × 1017 cm−3eV−1. The energy depths of the trap centers should be ∼(0.75–0.8) eV from the valence band mobility edge for a requirement of less transient time to reach a plateau. The shallower trap levels are unable to retain sufficient trapped charge to reduce the dark current, and the deeper trap centers create longer transient times to reach a steady level of dark current.
DETERMINANTS OF LOW FERTILITY IN SINGAPORE: EVIDENCE FROM A HOUSEHOLD SURVEY
Authors: HASHMI AAMIR RAFIQUE , MOK WEN JIE
Published: December 2013

Below-replacement fertility is a common problem among the rich countries with far-reaching economic and social implications. The problem is more acute in some economically fast-growing Asian countries where the fertility decline has been more rapid and the current fertility rates have reached levels that are unprecedented in recent history. In this paper, data from a unique household survey have been used to understand the determinants of low fertility in one such country: Singapore. The total fertility rate in Singapore has dropped from 4.7 children per woman in 1965 to 1.2 in 2011. This is well below the replacement level of 2.1 and one of the lowest in the world. The authors identify three key determinants of fertility in Singapore: (1) age at marriage; (2) household income; and (3) number of siblings' children. They find that fertility is negatively related to age at marriage and positively related to the number of siblings' children. The relationship between fertility and household income is U-shaped: the relationship is negative for household incomes of up to S$21 000 (in 2010 Singapore dollars) and positive for higher incomes.
THE IMPACT OF TAXATION ON INCOME DISTRIBUTION: EVIDENCE FROM INDONESIA
Authors: NUGRAHA KUNTA , LEWIS PHIL
Published: December 2013

The Indonesian economy has grown significantly since 2000, but income inequality has increased since 2001. One of the possible government tools to improve income inequality is through taxation. This paper evaluates household income, income tax, taxes on production, and their impact on income distribution. The major data sources are the National Socioeconomic Survey and the Input–Output Table. The key finding is that income tax only slightly improves income distribution, but taxes on production worsen income distribution. The other important finding is that both forms of taxation are regressive, especially for lower and middle income household. The results suggest that Indonesian taxation worsens income inequality.
ANOMALOUS LOCAL CRITICALITY IN HEAVY FERMION METALS FROM HOLOGRAPHY
Authors: LUO M. J.
Published: December 2013

In this paper, we propose a holographic theory to explain a number of anomalous critical phenomena observed in certain heavy fermion metals, e.g. CeCu 5.9 Au 0.1 and YbRh 2( Si 0.95 Ge 0.05)2, which are incompatible with any conventional spin-density-wave quantum critical point theory. We show that the non-Gaussian nature of the fixed point from holography plays an essential role in the physics of these materials near a quantum critical point, which is not in the same universality class of the spin-density-wave type fixed point. The critical spin fluctuations at the non-Gaussian fixed point are strongly anisotropic, localized in spatial directions and critical in temporal direction with critical exponent 2/3 in frequency over temperature dependence at low temperature. The local critical exponent tends to unity which leads to a constant spin relaxation rate in the quantum critical regime at high temperature. The stability of the fixed point is also discussed.
RANGE AND STOPPING POWER ENERGY RELATIONSHIPS FOR 0.5–30 keV ELECTRON BEAMS SLOWING DOWN IN SOLIDS: ANALYTICAL MODEL
Authors: BENTABET A.
Published: December 2013

The development of an analytical model for calculating the electron stopping power (SP) converging with the experimental data at lower energies is still not completed. The purpose of this work is to suggest a mathematical expression of the range and the stopping power of electrons impinging in solid targets in the energy range up to 30 keV based on the spherical geometric model [A. Bentabet, Vacuum86 (2012) 1855]. The results are in good agreement with those of the literature. The slight discrepancy between the obtained and both the theoretical and experimental results regarding the stopping power at very low energy (E<0.5 keV) is discussed.
An angular formalism for spin one half
Authors: Koch Benjamin , Rojas Nicolás
Published: December 2013

The use of geometrical quantities and geometrical methods in the calculation and interpretation of physical systems have been very successful. Among others it has been shown how non-relativistic spin one half and massless relativistic spin one half with the corresponding Pauli matrices can be phrased geometrically. An analogous formulation for massive and relativistic spin one half was however missing. By the use of geometrical angular coordinates we construct a concrete realization of relativistic and massive spin one half. A Lagrange formulation is found, equations of motion are derived, and Lorentz invariance is discussed.
A NOTE ON THE TUTTE POLYNOMIAL AND THE AUTOMORPHISM GROUP OF A GRAPH
Authors: Chbili Nafaa
Published: December 2013

A graph G is said to be p-periodic if the automorphism group Aut(G) contains an element of order p which preserves no edges. In this short note, we investigate the behavior of graph polynomials (Negami and Tutte) with respect to graph periodicity. In particular, we prove that if p is a prime, then the coefficients of the Tutte polynomial of such a graph satisfy a certain necessary condition.
PERMANENCE AND UNIFORMLY ASYMPTOTICAL STABILITY OF ALMOST PERIODIC SOLUTIONS FOR A SINGLE-SPECIES MODEL WITH FEEDBACK CONTROL ON TIME SCALES
Authors: Li Yongkun , Yang Li , Zhang Hongtao
Published: December 2013

In this paper, using the time scale calculus theory, we first discuss the permanence of a single-species model with feedback control on time scales. Based on the permanence result, by the Lyapunov functional method, we establish sufficient conditions for the existence and uniformly asymptotical stability of almost periodic solutions of the considered model. Moreover, we present an illustrative example to show the effectiveness of obtained results.
REPRESENTATIONS OF ORDERED DIMONOIDS BY BINARY RELATIONS
Authors: Zhuchok Yuriy V.
Published: December 2013

We introduce the notion of an ordered dimonoid and prove that every ordered dimonoid can be exactly represented as an ordered dimonoid of binary relations. Also we find sufficient conditions under which an ordered dimonoid is isomorphic to some ordered dimonoid of reflexive (or transitive) binary relations.