bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo analysis of human nucleoporin repeat domain interactions
Authors: Xu Songli , Powers Maureen A.
Published: February 2013

The nuclear pore complex (NPC), assembled from ∼30 proteins termed nucleoporins (Nups), mediates selective nucleocytoplasmic trafficking. A subset of nucleoporins bear a domain with multiple phenylalanine–glycine (FG) motifs. As binding sites for transport receptors, FG Nups are critical in translocation through the NPC. Certain FG Nups are believed to associate via low-affinity, cohesive interactions to form the permeability barrier of the pore, although the form and composition of this functional barrier are debated. We used green fluorescent protein–Nup98/HoxA9 constructs with various numbers of repeats and also substituted FG domains from other nucleoporins for the Nup98 domain to directly compare cohesive interactions in live cells by fluorescence recovery after photobleaching (FRAP). We find that cohesion is a function of both number and type of FG repeats. Glycine–leucine–FG (GLFG) repeat domains are the most cohesive. FG domains from several human nucleoporins showed no interactions in this assay; however, Nup214, with numerous VFG motifs, displayed measurable cohesion by FRAP. The cohesive nature of a human nucleoporin did not necessarily correlate with that of its yeast orthologue. The Nup98 GLFG domain also functions in pore targeting through binding to Nup93, positioning the GLFG domain in the center of the NPC and supporting a role for this nucleoporin in the permeability barrier.
Systematic parameter estimation in data-rich environments for cell signalling dynamics
Authors: Nim Tri Hieu , Luo Le , Clément Marie-Véronique , White Jacob K. , Tucker-Kellogg Lisa
Published: February 2013

Motivation: Computational models of biological signalling networks, based on ordinary differential equations (ODEs), have generated many insights into cellular dynamics, but the model-building process typically requires estimating rate parameters based on experimentally observed concentrations. New proteomic methods can measure concentrations for all molecular species in a pathway; this creates a new opportunity to decompose the optimization of rate parameters.

Results: In contrast with conventional parameter estimation methods that minimize the disagreement between simulated and observed concentrations, the SPEDRE method fits spline curves through observed concentration points, estimates derivatives and then matches the derivatives to the production and consumption of each species. This reformulation of the problem permits an extreme decomposition of the high-dimensional optimization into a product of low-dimensional factors, each factor enforcing the equality of one ODE at one time slice. Coarsely discretized solutions to the factors can be computed systematically. Then the discrete solutions are combined using loopy belief propagation, and refined using local optimization. SPEDRE has unique asymptotic behaviour with runtime polynomial in the number of molecules and timepoints, but exponential in the degree of the biochemical network. SPEDRE performance is comparatively evaluated on a novel model of Akt activation dynamics including redox-mediated inactivation of PTEN (phosphatase and tensin homologue).

Availability and implementation: Web service, software and supplementary information are available at www.LtkLab.org/SPEDRE

Supplementary information:  Supplementary data are available at Bioinformatics online.

Contact: LisaTK@nus.edu.sg
Heterogeneous and anisotropic integrative model of pulmonary veins: computational study of arrhythmogenic substrate for atrial fibrillation
Authors: Aslanidi Oleg V. , Colman Michael A. , Varela Marta , Zhao Jichao , Smaill Bruce H. , Hancox Jules C. , Boyett Mark R. , Zhang Henggui
Published: February 2013

Mechanisms underlying the genesis of re-entrant substrate for the most common cardiac arrhythmia, atrial fibrillation (AF), are not well understood. In this study, we develop a multi-scale three-dimensional computational model that integrates cellular electrophysiology of the left atrium (LA) and pulmonary veins (PVs) with the respective tissue geometry and fibre orientation. The latter is reconstructed in unique detail from high-resolution (approx. 70 μm) contrast micro-computed tomography data. The model is used to explore the mechanisms of re-entry initiation and sustenance in the PV region, regarded as the primary source of high-frequency electrical activity in AF. Simulations of the three-dimensional model demonstrate that an initial break-down of normal electrical excitation wave-fronts can be caused by the electrical heterogeneity between the PVs and LA. High tissue anisotropy is then responsible for the slow conduction and generation of a re-entrant circuit near the PVs. Evidence of such circuits has been seen clinically in AF patients. Our computational study suggests that primarily the combination of electrical heterogeneity and conduction anisotropy between the PVs and LA tissues leads to the generation of a high-frequency (approx. 10 Hz) re-entrant source near the PV sleeves, thus providing new insights into the arrhythmogenic mechanisms of excitation waves underlying AF.
On-lattice agent-based simulation of populations of cells within the open-source Chaste framework
Authors: Figueredo Grazziela P. , Joshi Tanvi V. , Osborne James M. , Byrne Helen M. , Owen Markus R.
Published: February 2013

Over the years, agent-based models have been developed that combine cell division and reinforced random walks of cells on a regular lattice, reaction–diffusion equations for nutrients and growth factors; and ordinary differential equations for the subcellular networks regulating the cell cycle. When linked to a vascular layer, this multiple scale model framework has been applied to tumour growth and therapy. Here, we report on the creation of an agent-based multi-scale environment amalgamating the characteristics of these models within a Virtual Physiological Human (VPH) Exemplar Project. This project enables reuse, integration, expansion and sharing of the model and relevant data. The agent-based and reaction–diffusion parts of the multi-scale model have been implemented and are available for download as part of the latest public release of Chaste (Cancer, Heart and Soft Tissue Environment; http://www.cs.ox.ac.uk/chaste/), part of the VPH Toolkit (http://toolkit.vph-noe.eu/). The environment functionalities are verified against the original models, in addition to extra validation of all aspects of the code. In this work, we present the details of the implementation of the agent-based environment, including the system description, the conceptual model, the development of the simulation model and the processes of verification and validation of the simulation results. We explore the potential use of the environment by presenting exemplar applications of the ‘what if’ scenarios that can easily be studied in the environment. These examples relate to tumour growth, cellular competition for resources and tumour responses to hypoxia (low oxygen levels). We conclude our work by summarizing the future steps for the expansion of the current system.
Quantifying the roles of cell motility and cell proliferation in a circular barrier assay
Authors: Simpson Matthew J. , Treloar Katrina K. , Binder Benjamin J. , Haridas Parvathi , Manton Kerry J. , Leavesley David I. , McElwain D. L. Sean , Baker Ruth E.
Published: February 2013

Moving fronts of cells are essential features of embryonic development, wound repair and cancer metastasis. This paper describes a set of experiments to investigate the roles of random motility and proliferation in driving the spread of an initially confined cell population. The experiments include an analysis of cell spreading when proliferation was inhibited. Our data have been analysed using two mathematical models: a lattice-based discrete model and a related continuum partial differential equation model. We obtain independent estimates of the random motility parameter,D, and the intrinsic proliferation rate,λ, and we confirm that these estimates lead to accurate modelling predictions of the position of the leading edge of the moving front as well as the evolution of the cell density profiles. Previous work suggests that systems with a highλ/Dratio will be characterized by steep fronts, whereas systems with a lowλ/Dratio will lead to shallow diffuse fronts and this is confirmed in the present study. Our results provide evidence that continuum models, based on the Fisher–Kolmogorov equation, are a reliable platform upon which we can interpret and predict such experimental observations.
A mathematical model of tumour self-seeding reveals secondary metastatic deposits as drivers of primary tumour growth
Authors: Scott Jacob G. , Basanta David , Anderson Alexander R. A. , Gerlee Philip
Published: February 2013

Two models of circulating tumour cell (CTC) dynamics have been proposed to explain the phenomenon of tumour ‘self-seeding’, whereby CTCs repopulate the primary tumour and accelerate growth: primary seeding, where cells from a primary tumour shed into the vasculature and return back to the primary themselves; and secondary seeding, where cells from the primary first metastasize into a secondary tissue and form microscopic secondary deposits, which then shed cells into the vasculature returning to the primary. These two models are difficult to distinguish experimentally, yet the differences between them is of great importance to both our understanding of the metastatic process and also for designing methods of intervention. Therefore, we developed a mathematical model to test the relative likelihood of these two phenomena in the subset of tumours whose shed CTCs first encounter the lung capillary bed, and show that secondary seeding is several orders of magnitude more likely than primary seeding. We suggest how this difference could affect tumour evolution, progression and therapy, and propose several possible methods of experimental validation.
Energy audit and prospective energy conservation
Authors: Ainurzaman Jamaludin Adi , Zalina Mahmood Noor , Keumala Nila , Rosemary Mohd Ariffin Ati , Hussein Hazreena
Published: February 2013

Purpose

The purpose of this paper is to present the efficiency of electricity use and potential of electricity reduction at 12 residential colleges located at University of Malaya Campus, Kuala Lumpur.

Design/methodology/approach

The work presented applies an energy audit when energy consumption data were collected and analysed for a five‐year period. The total savings of electricity used at residential colleges were identified through the difference between average total energy use in a year (kWh) and minimum electricity usage.

Findings

The study finds that residential colleges with special features of building layout and arrangement performed better with regard to electricity consumption due to the prior group's superior utilisation of day lighting and natural ventilation. The floor area of the rooms, volume, density, enclosure and facade design, including window design, window area, and window‐to‐wall ratio also influenced the total electricity usage of the residential college buildings. Also, through adaptation of the corridor area to include more natural ventilation and daylight, approximately 40 to 90 percent of average electricity usage could be conserved in a year.

Research limitations/implications

The methodology is limited to energy audit for a five‐year period of metered data and walk‐through analysis.

Practical implications

The findings raised some issues related to thermal comfort of the residents.

Originality/value

The study can be used as baseline data for a tropical region particularly on current electricity usage and potential of energy conservation in residential building.
Volatility and foreign equity flows: evidence from the Philippines
Authors: French Joseph J. , Vishwakarma Vijay Kumar
Published: February 2013

Purpose

The purpose of this paper is to dissect the dynamic linkages between foreign equity flows, exchange rates and equity returns in the Philippines.

Design/methodology/approach

Using a parsimonious SVARX‐GARCH model and unique daily equity flow data, this research models the relationship between net equity flows, conditional variance of stock returns and conditional variance of exchange rates.

Findings

The authors find several noteworthy results, which are unique to this study and several results that confirm existing literature. Much of existing literature on foreign equity flows into emerging economies find that foreign equity investors are trend chasers and equity flows are auto correlated. The authors confirm these finding in the Philippines and document two new and important findings. First, it was found that unexpected increases in foreign equity flows to the Philippines increases the conditional volatility of the Filipino stock market significantly over the next two weeks of trading. The second major finding is that unexpected shocks to foreign equity flows sharply increases the conditional variance of the USD/PHP exchange rate over the next two to three weeks of trading.

Practical implications

Taken together, the results indicate that foreign equity investment, while providing many benefits for small open economies such as the Philippines, does in the short run increase the conditional variance of both the equity market and exchange rates. Policy makers must weigh the benefits of increased risk sharing and the potential for lower costs of capital with the short‐run potential for increase swings in asset prices.

Originality/value

This paper is one of the only studies of its kind to test the impact of foreign equity flows on the conditional volatility of returns and exchange rates.
Health and well being boards – developing transformational relationships
Authors: Allen Simon , Rowse Janet
Published: February 2013

Purpose

This paper aims to contribute to the discourse on the role and efficacy of the newly emerging health and well being boards which are established within the Health and Social Care Act 2012. It also aims to propose the importance of high functioning relationships underpinning clear but flexible local design.

Design/methodology/approach

The paper is based on the reflections of the chair of the shadow Health and Well Being Board in Bath and North East Somerset and the chief executive of one of the local provider organisations. They share a commitment to effective joint working and see the workings of health and well being boards epitomising the functionality of local interagency working. This is explored through a case study of the development of the Health and Well Being Board in Bath and North East Somerset.

Findings

The paper proposes the importance of high functioning relationships that can transcend structures and suggests that health and well being boards be considered as system orchestrators creating space for the challenge and creativity that creates “good enough” solutions to complex issues.

Originality/value

The paper contributes to the active discourse on how best to establish and develop effective health and well being boards and aims to create value through shared learning and experience.
Profiting from poverty: ethics of microfinance in BOP
Authors: Sama Linda M. , Mitch Casselman R.
Published: February 2013

Purpose

This paper seeks to examine the ethical dilemmas that emerge when offering microfinance services in BOP markets.

Design/methodology/approach

Utilizing the ethical lenses of deontology, teleology, virtue ethics and moral relativism, the paper builds on prior research on ethical issues in BOP markets and the ethics of microfinance to highlight the specific stakeholder impacts facing MFIs. Relevant literature and examples from practice are utilized to illustrate the different ethical perspectives.

Findings

In general, many of the key dilemmas represent themselves in the extreme poverty segment of the BOP where commercial business models have the least traction.

Research limitations/implications

Propositions are developed for the corrective actions in the paper which might allow future research to uncover differences in intervention success in different BOP markets.

Practical implications

The discussion of potential interventions for the various stakeholders may ameliorate criticisms of MFIs, suggest opportunities for cross‐sectoral partnerships and improve outreach to the poorest of the poor.

Social implications

For each issue addressed, this paper looks at the types of corrections that are made or called for through markets, government actions and civil society to respond to the negative impacts uncovered through our analysis.

Originality/value

The analysis in this paper contributes to the theoretical ethical literature with a very specific application to an emerging concern in the field of microfinance. It also offers prescriptive scenarios for industry and public policy makers. It challenges the ethics underlying businesses that wish to target the full spectrum of Base of Pyramid participants.
Postural influences on the mechanical and neural components of the cardiovagal baroreflex
Authors: Taylor C. E. , Willie C. K. , Atkinson G. , Jones H. , Tzeng Y.‐C.
Published: February 2013

Aim

The ability to maintain arterial blood pressure when faced with a postural challenge has implications for the occurrence of syncope and falls. It has been suggested that posture‐induced declines in the mechanical component of the baroreflex response drive reductions in cardiovagal baroreflex sensitivity associated with postural stress. However, these conclusions are largely based upon spontaneous methods of baroreflex assessment, the accuracy of which has been questioned. Therefore, the aim was to engage a partially open‐loop approach to explore the influence of posture on the mechanical and neural components of the baroreflex.

Methods

In nine healthy participants, we measured continuous blood pressure, heart rate,RRinterval and carotid artery diameter during supine and standing postures. The modifiedOxford method was used to quantify baroreflex sensitivity.

Results

In response to falling pressures, baroreflex sensitivity was similar between postures (P = 0.798). In response to rising pressures, there was an attenuated (P = 0.042) baroreflex sensitivity (mean ± SE) in the standing position (−0.70 ± 0.11 beats min−1mmHg−1) compared with supine (−0.83 ± 0.06 beats min−1mmHg−1). This was explained by a diminished (P = 0.016) neural component whilst standing (−30.17 ± 4.16 beats min−1mm−1) compared with supine (−38.23 ± 3.31 beats min−1mm−1). These effects were consistent when baroreflex sensitivity was determined usingRRinterval.

Conclusion

Cardiovagal baroreflex sensitivity in response to rising pressures is reduced in young individuals during postural stress. Our data suggest that the mechanical component is unaffected by standing, and the reduction in baroreflex sensitivity is driven by the neural component.
Population pharmacokinetics of rituximab with or without plasmapheresis in kidney patients with antibody‐mediated disease
Authors: Puisset Florent , White‐Koning Mélanie , Kamar Nassim , Huart Antoine , Haberer Frédérique , Blasco Hélène , Le Guellec Chantal , Lafont Thierry , Grand Anaïs , Rostaing Lionel , Chatelut Etienne , Pourrat Jacques
Published: February 2013

Aims

Both rituximab and plasmapheresis can be associated in the treatment of immune‐mediated kidney diseases. The real impact of plasmapheresis on rituximab pharmacokinetics is unknown. The aim of this study was to compare rituximab pharmacokinetics between patients requiring plasmapheresis and others without plasmapheresis.

Methods

The study included 20 patients receiving one or several infusions of rituximab. In 10 patients, plasmapheresis sessions were also performed (between two and six sessions per patient). Rituximab concentrations were measured in blood samples in all patients and in discarded plasma obtained by plasmapheresis using an enzyme‐linked immunosorbent assay method. Data were analysed according to a population pharmacokinetic approach.

Results

The mean percentage of rituximab removed during the first plasmapheresis session ranged between 47 and 54% when plasmapheresis was performed between 24 and 72 h after rituximab infusion. Rituximab pharmacokinetics was adequately described by a two‐compartment model with first‐order elimination. Plasmapheresis had a significant impact on rituximab pharmacokinetics, with an increase of rituximab clearance by a factor of 261 (95% confidence interval 146–376), i.e. from 6.64 to 1733 ml h−1. Plasmapheresis performed 24 h after rituximab infusion decreased the rituximab area under the curve by 26%.

Conclusions

Plasmapheresis removed an important amount of rituximab when performed less than 3 days after infusion. The removal of rituximab led to a significant decrease of the area under the curve. This pharmacokinetic observation should be taken into account for rituximab dosing, e.g. an additional third rituximab infusion may be recommended when three plasmapheresis sessions are performed after the first rituximab infusion.
Revisiting the concept of ‘style match’
Authors: Zhang Li‐fang , Sternberg Robert J. , Fan Jieqiong
Published: February 2013

Background

Intellectual style, an encompassing term for such constructs as learning style, teaching style, teaching approach, and thinking style, refers to one's preferred way of processing information. For the past several decades, whether or not there is a need for a match between teachers’ teaching styles and students’ learning styles has been the focal point for debate among researchers, educators, and the general public.

Aims

The preliminary objective of this research was to investigate the psychometric properties of the Preferred Teaching Approach Inventory (PTAI). The research's primary objective was to re‐examine the concept of ‘style match’ through testing the predictive power of students’ thinking styles for their preferred teaching approaches.

Samples

Data were collected from two samples of university students, one each from Shanghai, mainland China (N = 236), and Hong Kong (N = 123).

Methods

Participants provided the required demographic information and responded to two self‐report inventories: the Thinking Styles Inventory – Revised II and the PTAI.

Results

Acceptable reliability and good validity were found for the PTAI. All of the eight multiple regressions indicated that students’ thinking styles significantly contributed to their preferences for teachers’ teaching approaches. These contributions varied by gender among the Shanghai students and by academic discipline among the Hong Kong students.

Conclusions

Students, especially Shanghai female students and Hong Kong natural science students, are open to teaching approaches that do not precisely match their thinking styles. The concept of ‘style match’ requires new understanding. Findings have implications for research and education.
Making Sense of Neoliberal Securitization in Urban Policing and Surveillance
Authors: Deukmedjian John Edward
Published: February 2013

Grâce à une analyse historique des fonctions de surveillance de police civile, cet article examine comment la titrisation civile se déroule en traitant disciplinaire‐surveillance et de sécurité‐surveillance des pratiques distinctes et des appareils qui fonctionnent respectivement à des moyens “centripètes” et “centrifuge” et en reconfigurant triangulation de Foucault de la gouvernance d'une matrice à deux par deux: la souveraineté‐gouvernement et de la discipline‐sécurité. Cet article montre comment la titrisation de police civile s'aligne avec la transformation actuelle du gouvernement à partir d'un centripète (Keynésienne) d'une centrifuge (néolibéral) la rationalité politique. Cela revêt une importance plus large de recherche: où la rationalité politique favorise l’équilibre n'avons‐nous pas trouver une prépondérance de la discipline‐surveillance? Où déséquilibre est promu n'avons‐nous pas trouver une prépondérance de la sécurité‐surveillance?

Through a historic analysis of the surveillance functions of civil policing, this article considers how securitization is taking place by treating disciplinary surveillance and security surveillance as distinct practices and apparatuses that, respectively, function in “centripetal” and “centrifugal” ways and by reconfiguring Foucault's triangulation of governance to a two‐by‐two matrix: sovereignty government and discipline security. This article shows how the securitization of civil policing aligns with the current governmental transformation from a centripetal (Keynesian) to a centrifugal (neoliberal) governmentality. This has broader research significance: where governmentality promotes equilibrium do we not find a preponderance of disciplinary surveillance? Where disequilibrium is promoted do we not find a preponderance of security surveillance?
Twenty years of research shows UK child development team provision still varies widely for children with disability
Authors: Parr J. R. , Jolleff N. , Gray L. , Gibbs J. , Williams J. , McConachie H.
Published: February 2013

Objectives

To identify how services provided by child development teams (CDTs) have changed over 20 years. To what extent have major government initiatives aiming to improve the lives of children with disability and their families been implemented by teams?

Design

Survey sent to every UK CDT in 2009/2010; comparison with data gathered in 1988 and 1999.

Results

Ninety‐four per cent (225/240) of CDTs responded; data on 242 teams were available from 1999 and 125 teams from 1988. Despite policy recommendations advocating the value of interdisciplinary team working, there was a decline in numbers of professionals working within the CDT multidisciplinary team. One‐third of all teams reported a reduction in their funding over the last 5 years. However, specialist clinics provided increased. Teams reported patchy adoption of national initiatives designed to improve provision. Transition services were underdeveloped.

Conclusions

This comprehensive survey of UK CDT service provision, as well as national studies of the healthcare experience of families with a disabled child, shows that improvements in provision are required.
Dlx5 and Msx2 regulate mouse anterior neural tube closure through ephrinA5‐EphA7
Authors: Lee Jangwoo , Corcoran Amy , Han Manjong , Gardiner David M. , Muneoka Ken
Published: February 2013

Homeodomain‐containing transcription factors Dlx5 and Msx2 are able to form a heterodimer, and together can regulate embryonic development including skeletogenesis. Dlx5 functions as a transcriptional activator and Msx2 a transcriptional repressor, and they share common target genes. During mouse digit development, the expression domains of Dlx5 and Msx2 overlap at the distal region of the developing terminal phalange, although digit formation and regeneration are not altered in the Dlx5 and Msx2 null mutant embryos. Interestingly, we observed a high rate of defects in neural tube formation in Dlx5 and Msx2 double null mutants. In the absence of both Dlx5 and Msx2, a high occurrence of exencephaly and severe defects in craniofacial morphology are observed. Additionally, Dlx5 and Msx2 expression domain analysis showed overlap of the genes at the apex of the neural folds just prior to neural fold fusion. The expression patterns of ephrinA5 and two isoforms of EphA7 were tested as downstream targets of Dlx5 and Msx2. Results show that EphrinA5 and the truncated isoform of EphA7 are regulated by Dlx5 and Msx2 together, although the full length isoform of EphA7 expression is not altered. Overall, these data show that Dlx5 and Msx2 play a critical role in controlling cranial neural tube morphogenesis by regulating cell adhesion via the ephrinA5 and EphA7 pathway.
Association between duration and quality of sleep and the risk of pre‐diabetes: evidence from NHANES
Authors: Engeda J. , Mezuk B. , Ratliff S. , Ning Y.
Published: February 2013

Aims

To examine the association between duration and quality of sleep and the prevalence of undiagnosed and clinically identified diabetes mellitus and pre‐diabetes in a nationally representative sample.

Methods

Cross‐sectional study of 2285 participants ≥ 30 years old and without diagnosed sleep disorders from the National Health and Nutrition Examination Survey (2005–2008). The primary exposures were sleep duration and quality. Sleep quality was assessed by questionnaire using trouble initiating sleep, trouble maintaining sleep, and waking up too early. The primary outcomes were clinically identified and undiagnosed pre‐diabetes and diabetes as defined by the American Diabetes Association using fasting plasma glucose (5.6–6.9 mmol/l = pre‐diabetes; ≥ 7.0 mmol/l = diabetes). Multivariate logistic regression was used to test the association between sleep quality, sleep duration and glycaemic status.

Results

After adjustment for socio‐demographic characteristics and health behaviors, sleeping ≤ 5 h/night was associated with clinically identified pre‐diabetes (odds ratio 2.06, 95% CI 1.00–4.22 vs. 7 h). Both trouble maintaining sleep ≥ 5 times/month (odds ratio 3.50, 95% CI 1.30–9.45) and waking up too early ≥ 5 times/month (odds ratio 2.69, 95% CI 1.21–5.98) were also significantly associated with increased risk of clinically identified pre‐diabetes. Trouble initiating sleep and sleeping ≥ 9 h/night were not found to be associated with having diabetes.

Conclusions

Only clinically identified pre‐diabetes was associated with trouble maintaining sleep, waking up too early, and short sleep. No other relations were found to be significant. Findings suggest that poor sleep quality and short sleep duration were more strongly associated with clinically identified pre‐diabetes than 7–8 hours per day.
No cumulative effect of 10 years of elevated [CO2] on perennial plant biomass components in the Mojave Desert
Authors: Newingham Beth A. , Vanier Cheryl H. , Charlet Therese N. , Ogle Kiona , Smith Stanley D. , Nowak Robert S.
Published: February 2013

Elevated atmosphericCO2concentrations ([CO2]) generally increase primary production of terrestrial ecosystems. Production responses to elevated [CO2] may be particularly large in deserts, but information on their long‐term response is unknown. We evaluated the cumulative effects of elevated [CO2] on primary production at the Nevada DesertFACE(free‐air carbon dioxide enrichment) Facility. Aboveground and belowground perennial plant biomass was harvested in an intact Mojave Desert ecosystem at the end of a 10‐year elevated [CO2] experiment. We measured community standing biomass, biomass allocation, canopy cover, leaf area index (LAI), carbon and nitrogen content, and isotopic composition of plant tissues for five to eight dominant species. We provide the first long‐term results of elevated [CO2] on biomass components of a desert ecosystem and offer information on understudied Mojave Desert species. In contrast to initial expectations, 10 years of elevated [CO2] had no significant effect on standing biomass, biomass allocation, canopy cover, and C : N ratios of above‐ and belowground components. However, elevated [CO2] increased short‐term responses, including leaf water‐use efficiency (WUE) as measured by carbon isotope discrimination and increased plot‐levelLAI. Standing biomass, biomass allocation, canopy cover, and C : N ratios of above‐ and belowground pools significantly differed among dominant species, but responses to elevated [CO2] did not vary among species, photosynthetic pathway (C3vs. C4), or growth form (drought‐deciduous shrub vs. evergreen shrub vs. grass). Thus, even though previous and current results occasionally show increased leaf‐level photosynthetic rates, WUE,LAI, and plant growth under elevated [CO2] during the 10‐year experiment, most responses were in wet years and did not lead to sustained increases in community biomass. We presume that the lack of sustained biomass responses to elevated [CO2] is explained by inter‐annual differences in water availability. Therefore, the high frequency of low precipitation years may constrain cumulative biomass responses to elevated [CO2] in desert environments.
Reducing Loss Tangent by Controlling Microstructure and Electrical Responses in CaCu3Ti4O12 Ceramics Prepared by a Simple Combustion Method
Authors: Thongbai Prasit , Pinitsoontorn Supree , Amornkitbamrung Vittaya , Yamwong Teerapon , Maensiri Santi , Chindaprasirt Prinya
Published: February 2013

The dielectric and electrical properties of CaCu3Ti4O12 ceramics prepared by a simple combustion method were investigated. Fine‐grained CaCu3Ti4O12 ceramics exhibited good dielectric properties and temperature stability. Very low loss tangents of 0.020–0.016 and high dielectric constant of 5776–6406 (at 1 kHz and 20°C) with temperature coefficient less than ±15% in the temperature range of −70 to 90°C were observed. Dielectric relaxation processes were observed in large‐grained CaCu3Ti4O12 ceramics. The dielectric relaxation in the temperature range of 60–150°C may be associated with sample–electrode contact. The relaxation in temperatures below −40°C is related to the electrical response at grain boundaries.
Languaging in Translation Tasks Used in a University Setting: Particular Potential for Student Agency?
Authors: Källkvist Marie
Published: February 2013

This article explores the value of judiciously used first language (L1)‐to‐second language (L2) translation in meaning‐focused, advanced‐level academic language education. It examines languaging in the teacher‐led discourse (TLD) that arises when translation tasks are used and compares it to languaging during the TLD engendered by 4 other grammar‐focused tasks. Data were collected in 3 different groups of students who were taught by the same teacher within a functioning university course in English at a Swedish university. Quantitative and qualitative analyses of audio‐recorded lessons revealed that translation tasks led to (a) particularly high levels of student‐initiated referential questions that break the initiation‐response‐feedback pattern and (b) a less‐frequent focus on targeted L2 grammar as student attention tended to be drawn to vocabulary. Qualitative analysis of teacher scaffolding suggests that the teacher used translation to create a forum for student‐centered discussion of various aspects of English language use in order to meet one of the course goals. The relatively strong presence of student‐initiated interaction suggests that translation may have particular potential to engender student activity. It is argued that translation, therefore, may have an important, yet limited, place in academic‐level language education where knowledge of the L1 is shared.
Sidestepping awkward encounters: avoidance as a response to outperformance‐related discomfort
Authors: Exline Julie Juola , Zell Anne L. , Lobel Marci
Published: February 2013

When people believe that their higher performance poses a threat to another person, they may experience discomfort or concern that has been termed Sensitivity to being the Target of a Threatening Upward Comparison (STTUC). One way to reduce STTUC discomfort might be to avoid contact with the outperformed person, a possibility examined in three studies of undergraduates. In laboratory contexts, STTUC discomfort predicted reluctance to meet an outperformed peer (Study 1) and preference for a different partner in future competitions (Study 2). In Study 3, which focused on naturalistic outperformance situations, STTUC distress again predicted avoidance. Additionally, avoidance of contact predicted less satisfaction with outcomes, especially in relationships where people knew each other well.
Paeonol inhibits hepatic fibrogenesis via disrupting nuclear factor‐κB pathway in activated stellate cells: In vivo and in vitro studies
Authors: Kong Desong , Zhang Feng , Wei Donghua , Zhu Xiaojing , Zhang Xiaoping , Chen Li , Lu Yin , Zheng Shizhong
Published: February 2013

Background and Aims

Hepatic fibrosis represents a major cause of morbidity and mortality worldwide. The present study was to evaluate the antifibrogenesis effect of paeonol and involved mechanisms.

Methods

The degree of liver injury was evaluated biochemically by measuring serum and fibrotic markers and pathological examination. Cell viability was evaluated by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay and trypan blue staining. Cytotoxic effects were determined using lactate dehydrogenase release assay. Cell cycle was determined using single dyeing methods of propidium iodide (PI) by flow cytometry. Apoptosis was confirmed using double‐staining of annexin V/PI and Hoechst. Western blot, immunofluorescence and real‐time polymerase chain reaction were used to explore the molecular mechanisms.

Results

Treatment with paeonol significantly protected the liver from injury by reducing the activities of serum aspartate aminotransferase, alanine aminotransferase, improving the histological architecture of the liver, and by inhibiting activation of hepatic stellate cells (HSCs) in vivo. Interestingly, paeonol had no apparent cytotoxic effects but could markedly inhibit primary HSC proliferation and induced HSC cell cycle arrest at the G2/M checkpoint. These effects were caused by paeonol suppression of phosphorylation of cycle protein cdc2 and of CDK2. Moreover, that paeonol triggered mitochondrial apoptosis pathway and led to activation of caspase cascades in HSCs was found. Mechanistic investigations revealed that the nuclear factor‐κB (NF‐κB) pathway inhibition resulted in the earlier events. Furthermore, paeonol altered the expression of some marker proteins relevant to HSCs activation.

Conclusion

Paeonol could inhibit HSC proliferation and induce mitochondrial apoptosis via disrupting NF‐κB pathway, which might be the mechanisms of paeonol reduction of liver fibrosis.
Utility of baseline positron emission tomography with computed tomography for predicting endoscopic resectability and survival outcomes in patients with early esophageal adenocarcinoma
Authors: Sun Gang , Tian Jianmin , Gorospe Emmanuel C , Johnson Geoffrey B , Hunt Christopher H , Lutzke Lori S , Leggett Cadman L , Iyer Prasad G , Wang Kenneth K
Published: February 2013

Background and Aims

Positron emission tomography with computed tomography (PET/CT) has been used to detect metastasis in the diagnosis of esophageal adenocarcinoma (EAC). However, the utility of PET/CT to assess primary tumor for endoscopic resectability and prognosis in early EAC remains unclear. We conducted a retrospective study to determine the association of PET/CT findings with histopathological tumor invasion depth and survival outcomes.

Methods

EAC patients who underwent PET/CT followed by endoscopic mucosal resection (EMR) were included. Pathology on EMR and survival outcomes from a prospectively maintained database was retrieved. Two radiologists independently reviewed the PET/CT using the following parameters: detection of malignancy, fluorodeoxyglucose (FDG) uptake intensity, FDG focality, FDG eccentricity, esophageal thickness, maximal standard uptake value (SUVmax), and SUVmax ratio (lesion/liver).

Results

There were 72 eligible patients: 42 (58.3%) had T1a lesions, and 30 (41.7%) had ≥ T1b. Only SUVmax ratio was associated with tumor invasion depth (odds ratio = 2.77, 95% confidence interval 1.26–7.73, P = 0.0075). Using a cut‐off of 1.48, the sensitivity and specificity of SUVmax ratio for identification of T1a lesions were 43.3% and 80.9%, respectively. Adjusting the SUVmax ratio to 2.14, 16.7% (5/30) of ≥ T1b patients were identified without any false‐positive cases. Multivariate analysis showed SUVmax ratio, Charlson comorbidity index, and esophagectomy were independent predictors for survival.

Conclusions

SUVmax ratio (lesion/liver) is more accurate in predicting endoscopic resectability and mortality for EAC than other PET/CT parameters and appears promising as a useful adjunct to the current diagnostic work‐up.
Relationships Between Health Behaviors and Weight Status in American Indian and White Rural Children
Authors: Holm Jeffrey E. , Lilienthal Kaitlin R. , Poltavski Dmitri V. , Vogeltanz‐Holm Nancy
Published: February 2013

Purpose

Preventing obesity in childhood is an increasingly important public health goal. Prevention efforts can be improved by better understanding relationships between health behaviors and overweight and obesity. This study examined such relationships in young American Indian and white children living in the rural United States.

Methods

Self‐report measures of diet, screen time (passive and active), and physical activity were combined with cardiovascular fitness in cross‐sectional analyses to predict weight categories based on body mass index percentiles in 306 American Indian and white children (aged 8‐9 years) from a rural area in the upper Midwestern United States.

Findings

Multinomial logistic regression models were statistically significant for girls (χ2[20] = 42.73, P < .01), boys (χ2[20] = 50.44, P < .001), American Indian (χ2[20] = 36.67, P < .05), and white children (χ2[20] = 55.99, P < .001). Obesity was associated with poorer cardiovascular fitness in girls (OR = 0.82), boys (OR = 0.83), American Indian (OR = 0.79), and white children (OR = 0.85), and with passive screen time in girls (OR = 1.69), boys (OR = 2.1), and white children (OR = 1.81). Overweight was associated with passive screen time (OR = 2.24) and inversely with active screen time (OR = 0.54), but only in boys.

Conclusions

Logistic regression models were more successful at predicting obesity than overweight in all groups of participants. Poorer cardiovascular fitness showed the strongest and most consistent association with obesity, but passive screen time was also a significant and important contributor to the prediction of obesity in most prediction models. Prediction models were similar in girls, boys, American Indian, and white children.
Symbol and Substance: Effects of California's Three Strikes Law on Felony Sentencing
Authors: Sutton John R.
Published: February 2013

California's “three strikes and you're out” law is the most notorious example of the wave of mandatory sentencing policies that many states enacted beginning in the late 1970s. While advocates and critics predicted the law would have profound effects on aggregate punishment trends and individual case outcomes, Feeley and Kamin's analysis of previous sentencing reforms suggested the law's impact would be mainly symbolic because local officials would ignore, subvert, or nullify its major provisions. While aggregate analyses have tended to confirm this argument, so far there has been no systematic test of the law's effect on individual cases. This analysis uses multilevel models applied to case-level data from 12 urban California counties to test hypotheses about shifts in average punitiveness, the relative influence of legal and extralegal factors on sentencing, and the uncertainty of sentencing outcomes. Results mostly support Feeley and Kamin's symbolic interpretation, but also reveal important substantive impacts: since Three Strikes, sentences have become harsher, particularly in politically conservative counties, and black felons receive longer prison sentences.
Incidence and Characteristics of Acute Referred Orofacial Pain Caused by a Posterior Single Tooth Pulpitis in an Iranian Population
Authors: Hashemipour Maryam Alsadat , Borna Roya
Published: February 2013

Introduction

This study was designed to evaluate incidence and characteristics of acute referred orofacial pain caused by a posterior single tooth pulpitis in an Iranian population.

Methods

In this cross‐sectional study, 3,150 patients (1,400 males and 1,750 females) with pain in the orofacial region were evaluated via clinical and radiographic examination to determine their pain source. Patients completed a standardized clinical questionnaire consisting of a numerical rating scale for pain intensity and chose verbal descriptors from short form McGill questionnaire to describe the quality of their pain. Visual analog scale (VAS) was used to score pain intensity. In addition, patients indicated sites to which pain referred by drawing on an illustration of the head and neck. Data were analyzed using chi‐square, fisher exact, and Mann–Whitney tests.

Results

Two thousand and hundred twenty patients (67/3%) reported pain in sites that diagnostically differed from the pain source. According to statistical analysis, sex (P = 0.02), intensity of pain (0.04), and quality (P = 0.001) of pain influenced its referral nature, while age of patients and kind of stimulus had no considerable effect on pain referral (P > 0.05).

Conclusion

The results of the present study show the prevalence of referred pain in the head, face, and neck region is moderately high. Therefore, in patients with orofacial pain, it is essential to carefully examination before carrying out treatment that could be inappropriate.
Genetically engineered maize plants reveal distinct costs and benefits of constitutive volatile emissions in the field
Authors: Robert Christelle Aurélie Maud , Erb Matthias , Hiltpold Ivan , Hibbard Bruce Elliott , Gaillard Mickaël David Philippe , Bilat Julia , Degenhardt Jörg , Cambet‐Petit‐Jean Xavier , Turlings Ted Christiaan Joannes , Zwahlen Claudia
Published: February 2013

Genetic manipulation of plant volatile emissions is a promising tool to enhance plant defences against herbivores. However, the potential costs associated with the manipulation of specific volatile synthase genes are unknown. Therefore, we investigated the physiological and ecological effects of transforming a maize line with a terpene synthase gene in field and laboratory assays, both above‐ and below ground. The transformation, which resulted in the constitutive emission of (E)‐β‐caryophyllene and α‐humulene, was found to compromise seed germination, plant growth and yield. These physiological costs provide a possible explanation for the inducibility of an (E)‐β‐caryophyllene‐synthase gene in wild and cultivated maize. The overexpression of the terpene synthase gene did not impair plant resistance nor volatile emission. However, constitutive terpenoid emission increased plant apparency to herbivores, including adults and larvae of the above ground pest Spodoptera frugiperda, resulting in an increase in leaf damage. Although terpenoid overproducing lines were also attractive to the specialist root herbivore Diabrotica virgifera virgifera below ground, they did not suffer more root damage in the field, possibly because of the enhanced attraction of entomopathogenic nematodes. Furthermore, fewer adults of the root herbivore Diabrotica undecimpunctata howardii were found to emerge near plants that emitted (E)‐β‐caryophyllene and α‐humulene. Yet, overall, under the given field conditions, the costs of constitutive volatile production overshadowed its benefits. This study highlights the need for a thorough assessment of the physiological and ecological consequences of genetically engineering plant signals in the field to determine the potential of this approach for sustainable pest management strategies.