bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethylene mediates brassinosteroid‐induced stomatal closure via Gα protein‐activated hydrogen peroxide and nitric oxide production in Arabidopsis
Authors: Shi Chenyu , Qi Cheng , Ren Hongyan , Huang Aixia , Hei Shumei , She Xiaoping
Published: March 2015

Brassinosteroids (BRs) are essential for plant growth and development; however, whether and how they promote stomatal closure is not fully clear. In this study, we report that 24‐epibrassinolide (EBR), a bioactive BR, induces stomatal closure in Arabidopsis (Arabidopsis thaliana) by triggering a signal transduction pathway including ethylene synthesis, the activation of Gα protein, and hydrogen peroxide (H2O2) and nitric oxide (NO) production. EBR initiated a marked rise in ethylene, H2O2 and NO levels, necessary for stomatal closure in the wild type. These effects were abolished in mutant bri1‐301, and EBR failed to close the stomata of gpa1 mutants. Next, we found that both ethylene and Gα mediate the inductive effects of EBR on H2O2 and NO production. EBR‐triggered H2O2 and NO accumulation were canceled in the etr1 and gpa1 mutants, but were strengthened in the eto1‐1 mutant and the cGα line (constitutively overexpressing the G protein α‐subunit AtGPA1). Exogenously applied H2O2 or sodium nitroprusside (SNP) rescued the defects of etr1‐3 and gpa1 or etr1 and gpa1 mutants in EBR‐induced stomatal closure, whereas the stomata of eto1‐1/AtrbohF and cGα/AtrbohF or eto1‐1/nia1‐2 and cGα/nia1‐2 constructs had an analogous response to H2O2 or SNP as those of AtrbohF or Nia1‐2 mutants. Moreover, we provided evidence that Gα plays an important role in the responses of guard cells to ethylene. Gα activator CTX largely restored the lesion of the etr1‐3 mutant, but ethylene precursor ACC failed to rescue the defects of gpa1 mutants in EBR‐induced stomatal closure. Lastly, we demonstrated that Gα‐activated H2O2 production is required for NO synthesis. EBR failed to induce NO synthesis in mutant AtrbohF, but it led to H2O2 production in mutant Nia1‐2. Exogenously applied SNP rescued the defect of AtrbohF in EBR‐induced stomatal closure, but H2O2 did not reverse the lesion of EBR‐induced stomatal closure in Nia1‐2. Together, our results strongly suggest a signaling pathway in which EBR induces ethylene synthesis, thereby activating Gα, and then promotes AtrbohF‐dependent H2O2 production and subsequent Nia1‐catalyzed NO accumulation, and finally closes stomata.
PRC1 is taking the lead in PcG repression
Authors: Merini Wiam , Calonje Myriam
Published: March 2015

Polycomb group (PcG) proteins constitute a major epigenetic mechanism for gene repression throughout the plant life. For a long time, the PcG mechanism has been proposed to follow a hierarchical recruitment of PcG repressive complexes (PRCs) to target genes in which the binding of PRC2 and the incorporation of H3 lysine 27 trimethyl marks led to recruitment of PRC1, which in turn mediated H2A monoubiquitination. However, recent studies have turned this model upside‐down by showing that PRC1 activity can be required for PRC2 recruitment and H3K27me3 marking. Here, we review the current knowledge on plant PRC1 composition and mechanisms of repression, as well as its role during plant development.
Release from Endoplasmic Reticulum Matrix Proteins Controls Cell Surface Transport of MHC Class I Molecules
Authors: Fritzsche Susanne , Abualrous Esam T. , Borchert Britta , Momburg Frank , Springer Sebastian
Published: March 2015

The anterograde transport of secretory proteins from the endoplasmic reticulum (ER) to the plasma membrane is a multi‐step process. Secretory proteins differ greatly in their transport rates to the cell surface, but the contribution of each individual step to this difference is poorly understood. Transport rates may be determined by protein folding, chaperone association in the ER, access to ER exit sites (ERES) and retrieval from the ER‐Golgi intermediate compartment or the cis‐Golgi to the ER. We have used a combination of folding and trafficking assays to identify the differential step in the cell surface transport of two natural allotypes of the murine major histocompatibility complex (MHC) class I peptide receptor, H‐2Db and H‐2Kb. We find that a novel pre‐ER exit process that acts on the folded lumenal part of MHC class I molecules and that drastically limits their access to ERES accounts for the transport difference of the two allotypes. Our observations support a model in which the cell surface transport of MHC class I molecules and other type I transmembrane proteins is governed by the affinity of all their folding and maturation states to the proteins of the ER matrix.
Evaluation of the potassium adsorption capacity of a potassium adsorption filter during rapid blood transfusion
Authors: Matsuura H. , Akatsuka Y. , Muramatsu C. , Isogai S. , Sugiura Y. , Arakawa S. , Murayama M. , Kurahashi M. , Takasuga H. , Oshige T. , Yuba T. , Mizuta S. , Emi N.
Published: March 2015

The concentration of extracellular potassium in red blood cell concentrates (RCCs) increases during storage, leading to risk of hyperkalemia. A potassium adsorption filter (PAF) can eliminate the potassium at normal blood transfusion. This study aimed to investigate the potassium adsorption capacity of a PAF during rapid blood transfusion. We tested several different potassium concentrations under a rapid transfusion condition using a pressure bag. The adsorption rates of the 70‐mEq/l model were 76·8%. The PAF showed good potassium adsorption capacity, suggesting that this filter may provide a convenient method to prevent hyperkalemia during rapid blood transfusion.
Tolerance of platelet concentrates treated with UVC‐light only for pathogen reduction – a phase I clinical trial
Authors: Thiele T. , Pohler P. , Kohlmann T. , Sümnig A. , Aurich K. , Selleng K. , Westphal A. , Bakchoul T. , Petersmann A. , Müller T. H. , Greinacher A. , Seltsam A.
Published: March 2015

Background

The THERAFLEX UV‐Platelets pathogen reduction system for platelet concentrates (PCs) operates with ultraviolet C light (UVC; 254 nm) only without addition of photosensitizers. This phase I study evaluated safety and tolerability of autologous UVC‐irradiated PCs in healthy volunteers.

Methods

Eleven volunteers underwent two single (series 1 and 2) and one double apheresis (series 3). PCs were treated with UVC, stored for 48 h and retransfused in a dose‐escalation scheme: 12·5, 25% and 50% of a PC (series 1); one complete PC (series 2); two PCs (series 3). Platelet counts, fibrinogen, activated partial thromboplastin time, prothrombin time, D‐dimer, standard haematology, temperature, heart rate, blood pressure and clinical chemistry parameters were measured. One‐ and 24‐h corrected count increments were determined in series 2 and 3. Platelet‐specific antibodies were assessed before and at the end of the study.

Results

Neither adverse reactions related to transfusions nor antibodies against UVC‐treated platelets were observed. Corrected count increments did not differ between series 2 and 3.

Conclusions

Repeated transfusions of autologous UVC‐treated PCs were well tolerated and did not induce antibody responses in all volunteers studied. EudraCT No. 2010‐023404‐26.
Cohomology jump loci of differential graded Lie algebras
Authors: Budur Nero , Wang Botong
Published: March 2015

To study infinitesimal deformation problems with cohomology constraints, we introduce and study cohomology jump functors for differential graded Lie algebra (DGLA) pairs. We apply this to local systems, vector bundles, Higgs bundles, and representations of fundamental groups. The results obtained describe the analytic germs of the cohomology jump loci inside the corresponding moduli space, extending previous results of Goldman–Millson, Green–Lazarsfeld, Nadel, Simpson, Dimca–Papadima, and of the second author.
Frequency and Stability Analysis Method of Asymmetric Anisotropic Rotor-Bearing System Based on Three-Dimensional Solid Finite Element Method
Authors: Meng Ma Wei , Jun Wang Jian , Zhi Wang
Published: March 2015

An efficient analysis method is suggested to investigate the frequency characteristics and stability of asymmetric anisotropic rotor-bearing systems. Modifications are made to incorporate the effect of stator asymmetry into an existing three-dimensional (3D) solid finite element procedure developed for rotors with symmetric supports. The reduced ordered linear differential equations with periodic coefficients of the asymmetric anisotropic rotor model are established in the rotating frame. The frequency characteristics and stability of the obtained periodic time-varying coefficient differential equations are investigated based on Floquet theory and Hill's method. Numerical examples and experimental studies are presented to validate the effectiveness of the presented method.
Robust Heat Transfer Enhancement During Melting and Solidification of a Phase Change Material Using a Combined Heat Pipe-Metal Foam or Foil Configuration
Authors: Allen Michael J. , Bergman Theodore L. , Faghri Amir , Sharifi Nourouddin
Published: March 2015

Experiments are performed to analyze melting and solidification of a phase change material (PCM) enclosed in a vertical cylinder by a concentrically located heat pipe (HP) surrounded by either aluminum foam or radial aluminum foils. The PCM liquid fraction, temperature distribution, melting (solidification) rates, and effectiveness are reported to quantify the improvement in thermal performance relative to a base case, a Rod-PCM configuration. Parameters of interest include the porosity of the PCM-metal composite, the foil thickness, the number of foils, and the foam pore density. The main contributor to enhanced performance is shown to be the porosity for both the HP-Foil-PCM and HP-Foam-PCM configurations. Both of these configurations improve heat transfer rates relative to either the HP-PCM or the Rod-PCM configuration. However, the HP-Foil-PCM configuration with one-third of the metal (foil) mass is shown to have approximately the same performance as the HP-Foam-PCM configuration, for the range of porosities studied here (0.870–0.987). This may be attributed to the metal morphology and resulting contact area between the metal enhancer and the HP. The HP-Foil-PCM configuration, with a porosity of 0.957 using 162 foils of thickness 0.024 mm, attained an overall rate of phase change that is about 15 times greater than that of the Rod-PCM configuration and about 10 times greater than that of the HP-PCM configuration. The greatest degree of enhancement was achieved with the HP-Foil-PCM configuration (with porosity 0.957) yielding an average effectiveness during melting (solidification) of 14.7 (8.4), which is an extraordinary improvement over the base case.
Distributed mimicry: Big Data and Predictive Analytics
Authors: Farnsworth John
Published: March 2015

This paper argues that mimicry is a central issue in the development of new practices of predictive analytics and big data. The issue concerns the increasingly precise reproduction of human interactional dynamics and their translation to machine and code worlds. Mimicry, in this sense, allows for predictive analytics to simulate a huge range of individual and collective cross-species behaviours. This includes human practices, particularly at the non-conscious, non-verbal level sometimes with an uncanny appearance of intuitive anticipation. The paper takes up different perspectives on mimesis and simulation to discuss the exploitative and emancipatory tensions these articulate. It investigates these through developments in swarm robotics, text mining and recent advances in codifying human synchrony. All of these utilise mimicry as core elements in their development.
Surveillance and Privacy in the Snowden Era
Authors: Hager Nicky
Published: March 2015

Surveillance and Privacy in the Snowden Era
We Have Never Been Open: Activism and Cryptography in Surveillance Societies
Authors: Taffel Sy
Published: March 2015

Whilst there exist a range of contemporaneous discourses surrounding the end of the open Internet, claims that the Internet was until recently “open” are highly dubious. This paper challenges readings of open which derives from the open source movement, but largely ignore the historical specificity of the term’s emergence from the free software movement, and consequently equate open to signify better. Indeed, for numerous activist projects, the default position has long been that unencrypted telecommunications present a serious security breach. Recent developments such as the revelations regarding the NSA-run PRISM program, the imprisonment of social media users for making open calls for citizens to engage in direct action, and state-led attempts to curtail online communications during periods of civil unrest, highlight that security measures taken to preserve anonymity and encrypt telecommunications are a useful strategy for contesting the pervasive surveillance apparatus of the state and large corporations within societies of control.This paper explores a range of such anti-surveillance technologies including TOR, GPG, and FreedomBox. Additionally the paper will highlight the activity of Hacktionlab, a UK-based tech-activist collective in promoting the application of these platforms within wider activist communities. Following Bernard Stiegler’s prescriptions surrounding the economy of contribution as an alternative to prevalent pathologies of control, the paper contends that if we are to contribute towards a sense of care through digital literacy – whereby individuals better understand the footprints left by their digital activities – it is pivotal to not only delineate the increasingly pervasive forms of surveillance enacted by state and corporate actors, but to outline various methods by which control over communicative spaces can be contested.
The Threatened End Of Digital Sharing: A Dissociated Milieu?
Authors: Ryan Simon
Published: March 2015

Edward Snowden has revealed the obscene presence in the lives of everyone for whom the free use of the internet is an essential part of daily life, of an NSA-led global network of extreme mass surveillance. The state, corporate, and self-censorship that such extreme surveillance of public and private communications imposes, constitutes an additional and direct threat to the positive functioning of the libidinal economy in an age in which the desire of individuals and groups is already threatened with commodification through subjection to the demands of the market by those who exploit for profit the technologies of telecommunications, the media, culture and program industries. Through the activities and publications of Ars Industrialis – the Paris-based association internationale pour une politique industrielle des technologies de l’esprit – Bernard Stiegler and his co-researchers have analysed the destruction of desire through consumerist exploitation and its negative impact on processes of psychic individuation and social adaption. They argue that to consign ‘technologies of the human spirit’ such as digital telecommunications to a control function ‘systematically forbids and impedes the development of new and original social practices’. This article examines the ways in which the attack on the open internet by the corporate, military-industrial state undermines the building of an economy of contribution (Stiegler et al.) and the formation of an associated milieu (G. Simondon) which enables a productive economy of desire.
Spatial atomic layer deposition: Performance of low temperature H2O and O3 oxidant chemistry for flexible electronics encapsulation
Authors: Maydannik Philipp S. , Plyushch Alexander , Sillanpää Mika , Cameron David C.
Published: March 2015

Water and oxygen were compared as oxidizing agents for the Al2O3 atomic layer deposition process using spatial atomic layer deposition reactor. The influence of the precursor dose on the deposition rate and refractive index, which was used as a proxy for film density, was measured as a function of residence time, defined as the time which the moving substrate spent within one precursor gas zone. The effect of temperature on the growth characteristics was also measured. The water-based process gave faster deposition rates and higher refractive indices but the ozone process allowed deposition to take place at lower temperatures while still maintaining good film quality. In general, processes based on both oxidation chemistries were able to produce excellent moisture barrier films with water vapor transmission rate levels of 10−4 g/m2 day measured at 38 °C and 90% of relative humidity on polyethylene naphthalate substrates. However, the best result of <5 × 10−5 was obtained at 100 °C process temperature with water as precursor.
Strong water isotopic anomalies in the martian atmosphere: Probing current and ancient reservoirs
Authors: Villanueva G. L. , Mumma M. J. , Novak R. E. , Käufl H. U. , Hartogh P. , Encrenaz T. , Tokunaga A. , Khayat A. , Smith M. D.
Published: March 2015

Mapping Mars' water history

We know the water cycle on Earth is complex. Neither is it simple on Mars. Infrared maps of water isotopes made by Villanueva
et al.
show the distribution of H
2
O and “semiheavy” water (HDO: deuterated water containing a mixture of hydrogen isotopes) across Mars. HDO enrichment varies with time and location; for example, irregular isotopic signals associate with different terrain features. The measurements also allow seasonal sublimation levels of the northern ice cap to be estimated and thus could be used to reveal past climate behavior.

Science
, this issue p.
218
Nonequilibrium clumped isotope signals in microbial methane
Authors: Wang David T. , Gruen Danielle S. , Lollar Barbara Sherwood , Hinrichs Kai-Uwe , Stewart Lucy C. , Holden James F. , Hristov Alexander N. , Pohlman John W. , Morrill Penny L. , Könneke Martin , Delwiche Kyle B. , Reeves Eoghan P. , Sutcliffe Chelsea N. , Ritter Daniel J. , Seewald Jeffrey S. , McIntosh Jennifer C. , Hemond Harold F. , Kubo Michael D. , Cardace Dawn , Hoehler Tori M. , Ono Shuhei
Published: March 2015

What controls clumped isotopes?

Stable isotopes of a molecule can clump together in several combinations, depending on their mass. Even for simple molecules such as O
2
, which can contain
16
O,
17
O, and
18
O in various combinations, clumped isotopes can potentially reveal the temperatures at which molecules form. Away from equilibrium, however, the pattern of clumped isotopes may reflect a complex array of processes. Using high-resolution gas-phase mass spectrometry, Yeung
et al.
found that biological factors influence the clumped isotope signature of oxygen produced during photosynthesis (see the Perspective by Passey). Similarly, Wang
et al.
showed that away from equilibrium, kinetic effects causing isotope clumping can lead to overestimation of the temperature at which microbially produced methane forms.

Science
, this issue p. 431; p. 428; see also p. 394
Draft Genome Sequences of Acinetobacter harbinensis Strain HITLi 7
T
, Isolated from River Water
Authors: Zhang Duoying , Li Weiguang , Qin Wen , Huang Xiaofei , Gong Xujin
Published: March 2015

Acinetobacter harbinensis
HITLi strain 7
T
, isolated from river water, has the ability to remove ammonium and organic chemicals at 2°C. The genome sequences might be useful for investigating the low-temperature adaptability and nitrogen or organic chemical metabolism.
Whole-Genome Sequences of Chlamydia psittaci Strain HJ, Isolated from Meat Pigeons with Severe Respiratory Distress and High Mortality
Authors: Zhang Qiang , Wu Zongxue , Sun Ruixue , Chu Jun , Han Er , Zhang Yinxin , Ling Yong , Gong Yanping , Li Dongfang , Wu Honglong , He Cheng , Ni Peixiang
Published: March 2015

The obligate intracellular Gram-negative bacterium
Chlamydia psittaci
causes systemic disease in psittacine birds, domestic poultry, and wild fowl. Importantly,
C. psittaci
may cause pneumonia, encephalitis, endocarditis, and even death in humans. The potential of pigeons as a source of human psittacosis is supported worldwide by relatively high seroconversion rates in the birds. This study reports the whole-genome sequencing of
C. psittaci
strain HJ, isolated from meat pigeons suffering from severe pneumonia and high mortality in 2013 in Hebei, China.
Whole-Genome Analysis of Quorum-Sensing Burkholderia sp. Strain A9
Authors: Chan Kok-Gan , Chen Jian Woon , Tee Kok Keng , Chang Chien-Yi , Yin Wai-Fong , Chan Xin-Yue
Published: March 2015

Burkholderia spp. rely on
N
-acyl homoserine lactone as quorum-sensing signal molecules which coordinate their phenotype at the population level. In this work, we present the whole genome of Burkholderia sp. strain A9, which enables the discovery of its
N
-acyl homoserine lactone synthase gene.
Draft Genome Sequence of “Candidatus Methylacidiphilum kamchatkense” Strain Kam1, a Thermoacidophilic Methanotrophic Verrucomicrobium
Authors: Erikstad Helge-André , Birkeland Nils-Kåre
Published: March 2015

“Candidatus Methylacidiphilum kamchatkense” strain Kam1 is an aerobic methane-oxidizing thermoacidophilic bacterium belonging to the
Verrucomicrobia
phylum. It was recovered from an acidic geothermal site in Uzon Caldera, Kamchatka, Russian Federation. Its genome possesses three complete
pmoCAB
gene clusters encoding particulate methane monooxygenase enzymes and a complete Calvin-Benson-Bassham cycle for carbon assimilation.
Genome Sequences of Serotype A6 Mannheimia haemolytica Isolates D174 and D38 Recovered from Bovine Pneumonia
Authors: Hauglund Melissa J. , Tatum Fred M. , Bayles Darrell O. , Maheswaran Samuel K. , Briggs Robert E.
Published: March 2015

Here, we report two genomes, one complete and one draft, from virulent bovine strains ofMannheimia haemolyticaserotype A6 recovered prior to the field usage of modern antimicrobial drugs.
Draft Genome Sequence of Methyloferula stellata AR4, an Obligate Methanotroph Possessing Only a Soluble Methane Monooxygenase
Authors: Dedysh Svetlana N. , Naumoff Daniil G. , Vorobev Alexey V. , Kyrpides Nikos , Woyke Tanja , Shapiro Nicole , Crombie Andrew T. , Murrell J. Colin , Kalyuzhnaya Marina G. , Smirnova Angela V. , Dunfield Peter F.
Published: March 2015

Methyloferula stellata
AR4 is an aerobic acidophilic methanotroph, which, in contrast to most known methanotrophs but similar to Methylocella spp., possesses only a soluble methane monooxygenase. However, it differs from Methylocella spp. by its inability to grow on multicarbon substrates. Here, we report the draft genome sequence of this bacterium.
Zinner syndrome: an uncommon cause of painful ejaculation
Authors: Sundar Raghav , Sundar Gaurav
Published: March 2015

Zinner syndrome refers to the triad of ipsilateral renal agenesis, seminal vesicle cysts and ejaculatory duct obstruction. Ipsilateral renal agenesis may be associated with seminal vesicle cysts in 70% of cases, but a remnant ureteral bud has been shown to coexist in only 27% of these cases. While some patients may remain asymptomatic and are discovered incidentally, others present with symptoms related to seminal vesicle cysts or ejaculatory duct obstruction: voiding or ejaculatory difficulty or pain. The diagnosis is made with imaging findings, and differentiation from other pelvic cysts requires a multimodality approach. In this report, we present typical imaging findings of a patient who presented with painful ejaculation where there was a congenital seminal vesicle cyst with ipsilateral renal agenesis associated with a remnant ureteral bud draining into the seminal vesicle cyst and also associated with a cyst of the prostatic utricle. We discuss the relevant embryological basis for this unusual combination of findings.
Out-of-hours palliative care: what are the educational needs and preferences of general practitioners?
Authors: Magee Claire , Koffman Jonathan
Published: March 2015

Objectives

Offering genuine choice to patients over place of care and death requires the provision of high-quality palliative care 24/7. This study examines the confidence of out-of-hours general practitioners (GPs) in symptom control and end of life prescribing, and identifies their educational needs and preferences in order to inform recommendations for future education.

Methods

A self-completion postal survey was designed and sent to 1005 GPs working for an independent provider of out-of-hours services across England. Quantitative data were analysed using descriptive statistics and non-parametric tests.

Results

203 (20.3%) GPs completed the survey questionnaire; 13.3% (n=27) worked exclusively out-of-hours. Confidence in assessing palliative care emergencies (42.8%, n=87: ‘not so confident’ or ‘not at all confident’), managing symptoms in non-cancer patients (39.4%, n=80) and prescribing a new syringe driver (39.0%, n=79) was lowest. Lower confidence was associated with infrequent exposure to palliative patients (p<0.05) and lack of training in palliative care (p<0.05); 12.8% (n=26) had never received formal training. Educational preferences were closely associated with confidence (p<0.0005); the topics above were most requested. E-learning was the preferred method (67.5%, n=137). 82.1% (n=165) believed training focused on out-of-hours work would be beneficial.

Conclusions

We identify that confidence in key palliative care competences is severely lacking. Educational strategies to address this concern must be targeted at GPs preferences for content and mode of delivery. Regular e-learning is favoured, but should be blended with other approaches that promote engagement including out-of-hours themed workshops and case discussion. Specialist palliative care services should engage with out-of-hours providers to support education.
Assessing the internal consistency and temporal stability of advance directives generated by an interactive, online computer program
Authors: Schubart Jane R , Camacho Fabian , Green Michael J , Rush Kimberly A , Levi Benjamin H
Published: March 2015

Objective

Evaluate the internal consistency and temporal stability of advance directives (ADs) generated by an interactive, online computer program.

Methods

33 participants completed the program at three visits, 2 weeks apart. Agreement rates were calculated for theGeneral Wishescomponent of the AD. The test–retest method was used to examine the temporal stability of theSpecific Wish for Treatmentcomponent which contains five clinical scenarios.

Results

General Wishesremained stable with 94% selecting the identical response at each visit. For theSpecific Wish for Treatmentscale,significant variations in test–retest correlations existed (ie, ρ=0.32–0.78, between time points 1 and 2); however within scenario, correlations did not significantly vary between time points. Temporal stability was lower in theSpecific Wish for Treatmentscale compared withGeneral Wishes (average ρ=0.59, between time points 1 and 2; and ρ=0.75, between time points 2 and 3).

Conclusions

ADs generated by an online decision aid demonstrate good temporal stability, with highest stability forGeneral Wishesand moderate stability forSpecific Wish for Treatmentregarding medical treatments in specific clinical scenarios. Internal consistency for wish for treatment across all time points and scenarios was high (Cronbach α>0.90).
Practical aspects of delivering a small bowel endoscopy service in the UK
Authors: Hale Melissa F , Davison Carolyn , Panter Simon , Drew Kaye , Sanders David S , Sidhu Reena , McAlindon Mark E
Published: March 2015

Capsule endoscopy remains at the forefront of small bowel investigation, offering the only non-invasive means of directly imaging the mucosa of the small bowel. Recommended for the investigation of obscure gastrointestinal bleeding, Crohn's disease, coeliac disease, small bowel tumours and hereditary polyposis syndromes, the uptake of small bowel capsule endoscopy has been widespread in the UK. However, despite a wealth of published literature supporting the utility of capsule endoscopy in clinical practice, there are limited data regarding the actual practical aspects of service delivery, training and quality assurance. In this article, we attempt to address this by considering specific factors that contribute to provision of a high-quality capsule service. The role of formal training, accreditation and quality assurance measures is also discussed.
A life of cycles
Authors: Pycock Jonathan
Published: March 2015

Jonathan Pycock is one of three equine claims consultants with the Veterinary Defence Society. His career in equine reproduction, and lecturing on the same topic, has given him the opportunity to work and travel widely, and ensure his work/life balance stays in sync
Food chain transfer and exposure effects of selenium in salmonid fish communities in two watersheds in the Canadian Rocky Mountains
Authors: Kuchapski Kathryn A. , Rasmussen Joseph B.
Published: March 2015

Selenium (Se) concentrations and fish biomass were examined in streams in two mined watersheds to determine if juvenile salmonids reflect local Se exposure concentrations downstream of surface coal mines and to investigate the relationship between Se exposure and toxicity effects at the fish community level. Se concentrations were measured in water, biofilm, macroinvertebrates, and muscle tissues from juvenile westslope cutthroat trout (Oncorhynchus clarkii lewisi), bull trout (Salvelinus confluentus), rainbow trout (Oncorhynchus mykiss), and brook trout (Salvelinus fontinalis) in mine-affected and reference streams. Significant positive Se transfer relationships were found at each measured level of the lotic food chain. Se accumulation from macroinvertebrates to juvenile fish muscle tissue was not significantly different among fish species, but indicated a significant positive relationship between juvenile fish muscle tissue and dietary Se at capture sites. Mean muscle Se concentrations in some stream reaches exceeded proposed individual-level toxic effective concentrations (EC10) in rainbow trout (3.14 ± 0.38 to 15.07 ± 2.24 mg·kg–1dry mass) and westslope cutthroat trout (3.31 ± 0.32 to 13.79 ± 1.27 mg·kg–1dry mass), but fish biomass at the reach scale was only significantly negatively related to mean fish muscle tissue Se concentrations for rainbow trout.
Orthogonal basis for the Shapovalov form on $U_q(\mathfrak{sl}(n + 1))$
Authors: Mudrov Andrey
Published: March 2015

Let U be either the classical or quantized universal enveloping algebra of the Lie algebra [Formula: see text] extended over the field of fractions of the Cartan subalgebra. We suggest a PBW basis in U over the extended Cartan subalgebra diagonalizing the contravariant Shapovalov form on generic Verma module. The matrix coefficients of the form are calculated and the inverse form is explicitly constructed.
LHCb detector performance
Authors:   The LHCb Collaboration
Published: March 2015

The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) at CERN. The experiment is designed for precision measurements of CP violation and rare decays of beauty and charm hadrons. In this paper the performance of the various LHCb sub-detectors and the trigger system are described, using data taken from 2010 to 2012. It is shown that the design criteria of the experiment have been met. The excellent performance of the detector has allowed the LHCb collaboration to publish a wide range of physics results, demonstrating LHCb's unique role, both as a heavy flavour experiment and as a general purpose detector in the forward region.
Elastic scattering and diffractive dissociation in the light of LHC data
Authors: Khoze V. A. , Martin A. D. , Ryskin M. G.
Published: March 2015

We study the behavior of elastic and diffractive proton dissociation cross sections at high energy. First, we describe what would be expected to be observed at the Large Hadron Collider (LHC) based on conventional Regge theory. We emphasize the tension between these expectations and the recent LHC measurements, and we discuss the possibilty to modify the classic Reggeon Field Theory (RFT) in a physically-motivated way so as to accommodate the tendencies observed at the LHC. As a result, we show that we are able to achieve a "global" description of the wide variety of high energy elastic and diffractive data that are presently available, particularly from the LHC experiments. The model is based on only one pomeron pole, but includes multi-pomeron interactions and, significantly, includes the transverse momentum dependence of intermediate partons as a function of their rapidity, which provides the rapidity dependence of the multi-pomeron vertices. We give predictions for diffractive observables at LHC, and higher, energies.
Exploring the Pomeron structure at the LHC
Authors: Royon Christophe , Saimpert Matthias
Published: March 2015

We present some physics topics that will allow us to constrain the Pomeron structure at the LHC in terms of gluon and quark densities using the dijet and γ+ jet events and tagged protons in AFP (ATLAS) and CMS-TOTEM. We also discuss the possibility to test the BFKL dynamics using jet-gap-jet events.
Summary of diffractive studies at ATLAS, CMS and TOTEM
Authors: Martin T. A. D.
Published: March 2015

A brief summary is reported on measurements of soft and hard diffractive processes by the ATLAS, CMS and TOTEM collaborations at a center of mass energy of 7 TeV.
New likelihoods for shape analysis
Authors: Fichet Sylvain
Published: March 2015

We introduce a new kind of likelihood function based on the sequence of moments of the data distribution. Both binned and unbinned data samples are discussed, and the multivariate case is also derived. Building on this approach we lay out the formalism of shape analysis for signal searches. In addition to moment-based likelihoods, standard likelihoods and approximate statistical tests are provided. Enough material is included to make the paper self-contained from the perspective of shape analysis. We argue that the moment-based likelihoods can advantageously replace unbinned standard likelihoods for the search of nonlocal signals, by avoiding the step of fitting Monte Carlo generated distributions. This benefit increases with the number of variables simultaneously analyzed. The moment-based signal search is exemplified and tested in various 1D toy models mimicking typical high-energy signal-background configurations. Moment-based techniques should be particularly appropriate for the searches for effective operators at the LHC.
Effect of electron correlation in proton–helium collisions
Authors: Ghavaminia H.
Published: March 2015

The four-body Born approximation is applied in post form to calculate the differential and total cross-sections for single electron capture from helium atoms by impact of the fast protons in the intermediate energy range. Theoretical results are obtained for hydrogen formation in ground state using full correlated accurate wave function for helium. The present results are compared with the results obtained from one parameter uncorrelated wave function to provide a clear visualization for the effect of electron correlation on the cross-sections. Comparison between the results for different wave functions shows the sensitivity of the processes on the electron–electron correlation especially at small scattering angles. The results are also compared with experimental data. The present calculated results show a general agreement with experimental finding for differential cross-sections and pursue the excellent trend with the measurement and other theoretical findings for total cross-sections.
Cohomology structure for a Poisson algebra: I
Authors: Bao Yan-Hong , Ye Yu
Published: March 2015

We introduce quasi-Poisson cohomology groups for a Poisson algebra, which can be computed by its quasi-Poisson complex. Moreover, there exists a Grothendieck spectral sequence relating quasi-Poisson cohomology to Hochschild cohomology and Lie algebra cohomology.
Primitivity rank of elements of free algebras of Schreier varieties
Authors: Klimakov Andrey
Published: March 2015

D. Puder defined the primitivity rank of elements of free groups [Primitive words, free factors and measure preservation, Israel J. Math.201(1) (2014) 25–73], we give a similar definition for free algebras of Schreier varieties and prove properties of a primitivity rank using the properties of the almost primitive elements.
Electronic structures of hexane isomers studied using quantum mechanics and graph theory
Authors: Chatterjee Subhojyoti , Wang Feng
Published: March 2015

Electronic and topological properties of hexane ( C 6 H 14) and its five geometric isomers are systematically studied quantum mechanically using several techniques such as positron–electron annihilation gamma-ray spectra, C1s binding energy spectra and carbon nuclear magnetic resonance (NMR) spectra, as well as information derived from graph theory. It is revealed that the Doppler-shift in the gamma-ray spectra of the hexane isomers is in the vicinity of the n-hexane molecule with small structural dependency, in agreement with the fact that the measured Doppler-shifts of other linear alkanes are in the vicinity of hexane. The present study further reveals the electronic structures of hexane isomers, which are deeply rooted into the carbon core electrons, more than mere properties in the valence space. The calculations show that the highest occupied molecular orbitals (HOMOs) of the isomers exhibit less important roles in gamma-ray spectra; whereas the electron–positron annihilation is dominated by the electrons of the lowest occupied valence orbitals (LOVOs) and other valence electrons underneath the HOMO electrons, in agreement with previous findings. The present study further reveals that the C1s binding energies of the isomers exhibit association with the nodes of the isomers using graph theory. That is, more branched carbons likely engage with larger chemical shift, which is indicated by the largest eigenvalues (LEVs) of the adjacency matrix (AM) from graph theory. The chemical shift of the carbon NMR spectra is revealed by the LEVs of the Laplacian matrix (LM) obtained from chemical graph theory.
A model for massless higher spin field interacting with a geometrical background
Authors: Bandelloni Giuseppe
Published: March 2015

We study a very general four-dimensional field theory model describing the dynamics of a massless higher spin N symmetric tensor field particle interacting with a geometrical background. This model is invariant under the action of an extended linear diffeomorphism. We investigate the consistency of the equations of motion, and the highest spin degrees of freedom are extracted by means of a set of covariant constraints. Moreover, the highest spin equations of motions (and in general all the highest spin field 1-PI irreducible Green functions) are invariant under a chain of transformations induced by a set of N - 2 Ward operators, while the auxiliary fields equations of motion spoil this symmetry. The first steps to a quantum extension of the model are discussed on the basis of the algebraic field theory. Technical aspects are reported in Appendices, in particular, one of them is devoted to illustrate the spin-2 case.
Combined effects of rotation and thermal radiation on peristaltic transport of Jeffrey fluid
Authors: Hayat T. , Rafiq Maimona , Ahmad B.
Published: March 2015

The objective of this communication is to examine the effect of rotation on the peristaltic motion of non-Newtonian fluid. Constitutive relationship of Jeffrey fluid is employed in the mathematical formulation and related analysis. The thermal radiation and Joule heating effects are also considered. An electrically conducting fluid in a channel with compliant boundaries is taken. Solution expressions are established through assumptions of large wavelength and low Reynolds number. Impact of Taylor and Hartman numbers on the axial velocity is similar in a qualitative sense. There is reverse effect of Taylor number on the secondary velocity when compared with the axial velocity. Temperature and heat transfer coefficients are increasing functions of Taylor number.
Transport of Sugars
Authors: Chen Li-Qing , Cheung Lily S. , Feng Liang , Tanner Widmar , Frommer Wolf B.
Published: March 2015

Soluble sugars serve five main purposes in multicellular organisms: as sources of carbon skeletons, osmolytes, signals, and transient energy storage and as transport molecules. Most sugars are derived from photosynthetic organisms, particularly plants. In multicellular organisms, some cells specialize in providing sugars to other cells (e.g., intestinal and liver cells in animals, photosynthetic cells in plants), whereas others depend completely on an external supply (e.g., brain cells, roots and seeds). This cellular exchange of sugars requires transport proteins to mediate uptake or release from cells or subcellular compartments. Thus, not surprisingly, sugar transport is critical for plants, animals, and humans. At present, three classes of eukaryotic sugar transporters have been characterized, namely the glucose transporters (GLUTs), sodium-glucose symporters (SGLTs), and SWEETs. This review presents the history and state of the art of sugar transporter research, covering genetics, biochemistry, and physiology—from their identification and characterization to their structure, function, and physiology. In humans, understanding sugar transport has therapeutic importance (e.g., addressing diabetes or limiting access of cancer cells to sugars), and in plants, these transporters are critical for crop yield and pathogen susceptibility.
Nuclear ADP-Ribosylation and Its Role in Chromatin Plasticity, Cell Differentiation, and Epigenetics
Authors: Hottiger Michael O.
Published: March 2015

Protein ADP-ribosylation is an ancient posttranslational modification with high biochemical complexity. It alters the function of modified proteins or provides a scaffold for the recruitment of other proteins and thus regulates several cellular processes. ADP-ribosylation is governed by ADP-ribosyltransferases and a subclass of sirtuins (writers), is sensed by proteins that contain binding modules (readers) that recognize specific parts of the ADP-ribosyl posttranslational modification, and is removed by ADP-ribosylhydrolases (erasers). The large amount of experimental data generated and technical progress made in the last decade have significantly advanced our knowledge of the function of ADP-ribosylation at the molecular level. This review summarizes the current knowledge of nuclear ADP-ribosylation reactions and their role in chromatin plasticity, cell differentiation, and epigenetics and discusses current progress and future perspectives.
Structure and Energy Transfer in Photosystems of Oxygenic Photosynthesis
Authors: Nelson Nathan , Junge Wolfgang
Published: March 2015

Oxygenic photosynthesis is the principal converter of sunlight into chemical energy on Earth. Cyanobacteria and plants provide the oxygen, food, fuel, fibers, and platform chemicals for life on Earth. The conversion of solar energy into chemical energy is catalyzed by two multisubunit membrane protein complexes, photosystem I (PSI) and photosystem II (PSII). Light is absorbed by the pigment cofactors, and excitation energy is transferred among the antennae pigments and converted into chemical energy at very high efficiency. Oxygenic photosynthesis has existed for more than three billion years, during which its molecular machinery was perfected to minimize wasteful reactions. Light excitation transfer and singlet trapping won over fluorescence, radiation-less decay, and triplet formation. Photosynthetic reaction centers operate in organisms ranging from bacteria to higher plants. They are all evolutionarily linked. The crystal structure determination of photosynthetic protein complexes sheds light on the various partial reactions and explains how they are protected against wasteful pathways and why their function is robust. This review discusses the efficiency of photosynthetic solar energy conversion.
Biostructural Science Inspired by Next-Generation X-Ray Sources
Authors: Gruner Sol M. , Lattman Eaton E.
Published: March 2015

Next-generation synchrotron radiation sources, such as X-ray free-electron lasers, energy recovery linacs, and ultra-low-emittance storage rings, are catalyzing novel methods of biomolecular microcrystallography and solution scattering. These methods are described and future trends are predicted. Importantly, there is a growing realization that serial microcrystallography and certain cutting-edge solution scattering experiments can be performed at existing storage ring sources by utilizing new technology. In this sense, next-generation sources are serving two distinct functions, namely, provision of new capabilities that require the newer sources and inspiration of new methods that can be performed at existing sources.
Single-Cell Physiology
Authors: Taheri-Araghi Sattar , Brown Steven D. , Sauls John T. , McIntosh Dustin B. , Jun Suckjoon
Published: March 2015

Single-cell techniques have a long history of unveiling fundamental paradigms in biology. Recent improvements in the throughput, resolution, and availability of microfluidics, computational power, and genetically encoded fluorescence have led to a modern renaissance in microbial physiology. This resurgence in research activity has offered new perspectives on physiological processes such as growth, cell cycle, and cell size of model organisms such as Escherichia coli. We expect these single-cell techniques, coupled with the molecular revolution of biology's recent half-century, to continue illuminating unforeseen processes and patterns in microorganisms, the bedrock of biological science. In this article we review major open questions in single-cell physiology, provide a brief introduction to the techniques for scientists of diverse backgrounds, and highlight some pervasive issues and their solutions.
Roles for Synonymous Codon Usage in Protein Biogenesis
Authors: Chaney Julie L. , Clark Patricia L.
Published: March 2015

Owing to the degeneracy of the genetic code, a protein sequence can be encoded by many different synonymous mRNA coding sequences. Synonymous codon usage was once thought to be functionally neutral, but evidence now indicates it is shaped by evolutionary selection and affects other aspects of protein biogenesis beyond specifying the amino acid sequence of the protein. Synonymous rare codons, once thought to have only negative impacts on the speed and accuracy of translation, are now known to play an important role in diverse functions, including regulation of cotranslational folding, covalent modifications, secretion, and expression level. Mutations altering synonymous codon usage are linked to human diseases. However, much remains unknown about the molecular mechanisms connecting synonymous codon usage to efficient protein biogenesis and proper cell physiology. Here we review recent literature on the functional effects of codon usage, including bioinformatics approaches aimed at identifying general roles for synonymous codon usage.
Reconciling Micro and Macro Labor Supply Elasticities: A Structural Perspective
Authors: Keane Michael , Rogerson Richard
Published: March 2015

The response of aggregate labor supply to various changes in the economic environment is central to many economic issues, including the optimal design of tax policies. Whereas the earlier literature often concluded that aggregate labor supply elasticities were small, we argue that recent work using structural models and micro data credibly supports large aggregate elasticities. We focus on three issues. First, earlier analyses abstracted from several key features, including human capital accumulation, that severely negatively biased estimates of a key preference parameter. Second, failure to understand that aggregate labor supply adjustments can occur along both the hours per worker and employment margins has led economists to misinterpret the implications of preference parameters for aggregate labor supply. Third, structural estimation of models that feature choice along the extensive margin using micro data typically finds large responses.