bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of guanylate cyclase-C, guanylin and uroguanylin is downregulated proportionally to the ulcerative colitis disease activity index
Authors: Lan Danfeng , Niu Junkun , Miao Jiarong , Dong Xiangqian , Wang Hong , Yang Gang , Wang Kunhua , Miao Yinglei
Published: April 2016

The transmembrane receptor guanylate cyclase-C (GC-C) signaling pathway has been implicated in several gastrointestinal disorders. Activation of GC-C via guanylin (Gn) and uroguanylin (Ugn) regulates intestinal fluid and electrolyte homeostasis. However, how it regulates the pathogenesis of inflammatory bowel disease (IBD) is still unclear. Here, we investigated the activation of GC-C signaling in ulcerative colitis (UC) of different clinical severities. A total of 60 UC patients and 20 normal controls were recruited. Evaluation of the UC disease activity index (DAI) was performed using a modified Mayo scoring system. The expression of GC-C, Gn and Ugn in the colonic mucosa was measured by quantitative real-time PCR and Western blot. We found that the UC patients had significantly lower expression of GC-C, Gn and Ugn than the controls. Furthermore, there were significant differences for GC-C, Gn and Ugn expression for the UC groups of Grade 1, 2 and 3 and their expression levels were reduced with increases in their DAI. Taken together, our results demonstrate that GC-C, Gn and Ugn are downregulated in UC and this downregulation is more significant with aggravation of the clinical condition. Therefore, the GC-C signaling pathway may be implicated in the progression of UC.
Erratum: Kallikrein-related peptidase 8 is expressed in myocardium and induces cardiac hypertrophy
Authors: Cao Buqing , Yu Qing , Zhao Wei , Tang Zhiping , Cong Binhai , Du Jiankui , Lu Jianqiang , Zhu Xiaoyan , Ni Xin
Published: April 2016

Scientific Reports 6: Article number: 20024; published online: 29 January 2016; updated: 29 April 2016. The original version of this Article contained a typographical error in the spelling of the author Binhai Cong, which was incorrectly given as Binghai Cong. This has now been corrected in the PDF and HTML versions of the Article, as well as the Supplementary Information file that now accompanies the Article.
Modulation of Staphylococcus aureus spreading by water
Authors: Lin Mei-Hui , Ke Wan-Ju , Liu Chao-Chin , Yang Meng-Wei
Published: April 2016

Staphylococcus aureus is known to spread rapidly and form giant colonies on the surface of soft agar and animal tissues by a process called colony spreading. So far, the mechanisms underlying spreading remain poorly understood. This study investigated the spreading phenomenon by culturing S. aureus and its mutant derivatives on Tryptic Soy Agarose (TSA) medium. We found that S. aureus extracts water from the medium and floats on water at 2.5 h after inoculation, which could be observed using phase contrast microscopy. The floating of the bacteria on water could be verified by confocal microscopy using an S. aureus strain that constitutively expresses green fluorescence protein. This study also found that as the density of bacterial colony increases, a quorum sensing response is triggered, resulting in the synthesis of the biosurfactants, phenolic-soluble modulins (PSMs), which weakens water surface tension, causing water to flood the medium surface to allow the bacteria to spread rapidly. This study reveals a mechanism that explains how an organism lacking a flagellar motor is capable of spreading rapidly on a medium surface, which is important to the understanding of how S. aureus spreads in human tissues to cause infections.
Gate-Tunable Spin Transport and Giant Electroresistance in Ferromagnetic Graphene Vertical Heterostructures
Authors: Myoung Nojoon , Park Hee Chul , Lee Seung Joo
Published: April 2016

Controlling tunneling properties through graphene vertical heterostructures provides advantages in achieving large conductance modulation which has been known as limitation in lateral graphene device structures. Despite of intensive research on graphene vertical heterosturctures for recent years, the potential of spintronics based on graphene vertical heterostructures remains relatively unexplored. Here, we present an analytical device model for graphene-based spintronics by using ferromagnetic graphene in vertical heterostructures. We consider a normal or ferroelectric insulator as a tunneling layer. The device concept yields a way of controlling spin transport through the vertical heterostructures, resulting in gate-tunable spin-switching phenomena. Also, we revealed that a ‘giant’ resistance emerges through a ferroelectric insulating layer owing to the anti-parallel configuration of ferromagnetic graphene layers by means of electric fields via gate and bias voltages. Our findings discover the prospect of manipulating the spin transport properties in vertical heterostructures without use of magnetic fields.
Contribution of dermal-derived mesenchymal cells during liver repair in two different experimental models
Authors: Tan Li , Dai Tingyu , Liu Dengqun , Chen Zelin , Wu Liao , Gao Li , Wang Yu , Shi Chunmeng
Published: April 2016

Progressive liver disease is a major health issue for which no effective treatment is available, leading to cirrhosis and orthotopic liver transplantation. However, the lack of availability of donor organs and other adverse factors including rejection limit its extensive clinical application. Cell-based therapy using mesenchymal stem/stromal cells (MSCs) may represent an attractive therapeutic option. Dermal-derived mesenchymal cells (DMCs) are attractive as one of the abundant sources from which to isolate mesenchymal cells for therapeutic applications and can be easily accessed with minimal harm to the donor. In this study, we used two different animal models to investigate potential therapeutic effect of DMCs transplantation in liver injury. We found that DMCs administration alleviated liver fibrosis and restored the liver function in fibrotic mice induced by CCl4. Furthermore, in an acute irradiation induced damage model, a unique population of DMCs could engraft into the liver tissue for a long period, exhibiting the phenotype of both mesenchymal cells and macrophage cells and improve the survival of mice exposed to 8 Gy lethally total-body irradiation. These discoveries provide important evidence that DMCs therapy has a beneficial effect on liver injury and provide new insight into liver injury therapy depending on the alternative cells.
Ultrahigh pressure liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry for the determination of polyphenolic profiles in the characterization and classification of cranberry-based pharmaceutical preparations and natural extracts
Authors: Parets Lidia , Alechaga Élida , Núñez Oscar , Saurina Javier , Hernández-Cassou Santiago , Puignou Lluis
Published: April 2016

UHPLC-APPI-MS/MS was used for authentication of fruit-based products and pharmaceutical preparations.
Samarocene oxide: from an undesired decomposition product to a new reagent
Authors: Schoo Christoph , Klementyeva Svetlana V. , Gamer Michael T. , Konchenko Sergey N. , Roesky Peter W.
Published: April 2016

Samarocene oxide [Cp*2Sm-O-SmCp*2], which is mostly considered as an undesired decomposition product, may act as a mild oxide base and thus is a valuable synthetic equivalent for “O2−”.
Embroidered electrochemical sensors for biomolecular detection
Authors: Liu Xiyuan , Lillehoj Peter B.
Published: April 2016

We demonstrate a unique textile-based electrochemical sensor utilizing embroidered electrodes for rapid biomolecular detection.
Photooxygenation of alkanes by dioxygen with p-benzoquinone derivatives with high quantum yields
Authors: Ohkubo Kei , Hirose Kensaku , Fukuzumi Shunichi
Published: April 2016

Alkanes were oxygenated by dioxygen with p-benzoquinone derivatives such as p-xyloquinone in alkanes which are used as solvents to yield the corresponding alkyl hydroperoxides, alcohols and ketones under visible light irradiation with high quantum yields (Φ = 1000, 1600%). The photooxygenation is started by hydrogen atom abstraction from alkanes by the triplet excited states of p-benzoquinone derivatives as revealed by laser-induced transient absorption spectral measurements.
Hydrogenation of cinnamaldehyde to hydrocinnamaldehyde over Pd nanoparticles deposited on nitrogen-doped mesoporous carbon
Authors: Nagpure Atul S. , Gurrala Lakshmiprasad , Gogoi Pranjal , Chilukuri Satyanarayana V.
Published: April 2016

Nitrogen-doped mesoporous carbon (NMC) supported Pd nanoparticles catalyst exhibited an admirable catalytic activity in cinnamaldehyde hydrogenation to produce hydrocinnamaldehyde.
Theoretical design of highly energetic poly-nitro cage compounds
Authors: Tian Meng , Chi Wei-Jie , Li Quan-Song , Li Ze-Sheng
Published: April 2016

The designed energetic compound, TNOAP, has a superior detonation performance to CL-20 and RDX, as well as satisfactory sensitivity.
Defects and properties of cadmium oxide based transparent conductors
Authors: Yu Kin Man , Detert D. M. , Chen Guibin , Zhu Wei , Liu Chaoping , Grankowska S. , Hsu L. , Dubon O. D. , Walukiewicz Wladek
Published: April 2016

Transparent conductors play an increasingly important role in a number of semiconductor technologies. This paper reports on the defects and properties of Cadmium Oxide, a transparent conducting oxide which can be potentially used for full spectrum photovoltaics. We carried out a systematic investigation on the effects of defects in CdO thin films undoped and intentionally doped with In and Ga under different deposition and annealing conditions. We found that at low growth temperatures (<200 °C), sputter deposition tends to trap both oxygen vacancies and compensating defects in the CdO film resulting in materials with high electron concentration of ∼2 × 1020/cm3 and mobility in the range of 40–100 cm2/V s. Thermal annealing experiments in different ambients revealed that the dominating defects in sputtered CdO films are oxygen vacancies. Oxygen rich CdO films grown by sputtering with increasing O2 partial pressure in the sputter gas mixture results in films with resistivity from ∼4 × 10−4 to >1 Ω cm due to incorporation of excess O in the form of O-related acceptor defects, likely to be O interstitials. Intentional doping with In and Ga donors leads to an increase of both the electron concentration and the mobility. With proper doping CdO films with electron concentration of more than 1021 cm−3 and electron mobility higher than 120 cm2/V s can be achieved. Thermal annealing of doped CdO films in N2 ambient can further improve the electrical properties by removing native acceptors and improving film crystallinity. Furthermore, the unique doping behavior and electrical properties of CdO were explored via simulations based on the amphoteric defect model. A comparison of the calculations and experimental results show that the formation energy of native donors and acceptors at the Fermi stabilization energy is ∼1 eV and that the mobility of sputtered deposited CdO is limited by a background acceptor concentration of ∼5–6 × 1020/cm3. The calculations offer an insight into understanding of the effects of defects on electrical properties of undoped and doped CdO and offer a potential to use similar methods to analyze doping and defect properties of other semiconductor materials.
Donor defects and small polarons on the TiO2(110) surface
Authors: Moses P. G. , Janotti A. , Franchini C. , Kresse G. , Van de Walle C. G.
Published: April 2016

The role of defects in the chemical activity of the rutile TiO2(110) surface remains a rich topic of research, despite the rutile (110) being one of the most studied surfaces of transition-metal oxides. Here, we present results from hybrid functional calculations that reconcile apparently disparate views on the impact of donor defects, such as oxygen vacancies and hydrogen impurities, on the electronic structure of the (110) rutile surface. We find that the bridging oxygen vacancy and adsorbed or substitutional hydrogen are actually shallow donors, which do not induce gap states. The excess electrons from these donor centers tend to localize in the form of small polarons, which are the factual cause of the deep states ∼1 eV below the conduction band, often observed in photoelectron spectroscopy measurements. Our results offer a new framework for understanding the surface electronic structure of TiO2 and related oxides.
Eddy-current effects on ferromagnetic resonance: Spin wave excitations and microwave screening effects
Authors: Flovik Vegard , Pettersen Bjørn Holst , Wahlström Erik
Published: April 2016

We investigate how controlling induced eddy currents in thin film ferromagnet-normal metal (FM/NM) structures can be used to tailor the local microwave (MW) fields in ferromagnetic resonance (FMR) experiments. The MW fields produced by eddy currents will in general have a relative phase shift with respect to the applied MW field which depends on the sample geometry. The induced fields can thus partially compensate the applied MW field, effectively screening the FM in selected parts of the sample. The highly localized fields produced by eddy currents enable the excitation of spin wave modes with non-zero wave vectors (k≠0), in contrast to the uniform k = 0 mode normally excited in FMR experiments. We find that the orientation of the applied MW field is one of the key parameters controlling the eddy-current effects. The induced currents are maximized when the applied MW field is oriented perpendicular to the sample plane. Increasing the magnitude of the eddy currents results in a stronger induced MW field, enabling a more effective screening of the applied MW field as well as an enhanced excitation of spin wave modes. This investigation underlines that eddy currents can be used to control the magnitude and phase of the local MW fields in thin film structures.
Band gap engineering of MoS2 upon compression
Authors: López-Suárez Miquel , Neri Igor , Rurali Riccardo
Published: April 2016

Molybdenum disulfide (MoS2) is a promising candidate for 2D nanoelectronic devices, which shows a direct band-gap for monolayer structure. In this work we study the electronic structure of MoS2 upon both compressive and tensile strains with first-principles density-functional calculations for different number of layers. The results show that the band-gap can be engineered for experimentally attainable strains (i.e., ±0.15). However, compressive strain can result in bucking that can prevent the use of large compressive strain. We then studied the stability of the compression, calculating the critical strain that results in the on-set of buckling for free-standing nanoribbons of different lengths. The results demonstrate that short structures, or few-layer MoS2, show semi-conductor to metal transition upon compressive strain without bucking.
Through eurocentric logics
Authors: Abalo Ernesto
Published: April 2016

This study aims to explore the construction of difference in foreign news discourse on culturally similar but politically different non-Western subjects. Applying critical discourse analysis (CDA) together with a critique of Eurocentrism, the study examines difference in newspaper constructions of government supporters and oppositional groups in Venezuela. Discursive differences are evident in the strategies used for constructing the two groups with regard to political rationality and violence. Government supporters are associated with social justice, Venezuela’s poor, dogmatic behavior, and the use of political violence. The opposition, in contrast, is constructed as following a Western democratic rationale that stresses anti-authoritarianism. This group is primarily associated with victims of violence. While the opposition is conveyed as being compatible with Eurocentric values and practices, government supporters to great extent deviate from these norms. Such constructions serve to legitimize politico-ideological undercurrents of Eurocentrism, as the defense of liberalism.
No ‘small genome attraction’ artifact: A response to Harish et al. ‘Did viruses evolve as a distinct supergroup from common ancestors of cells?’
Authors: Nasir Arshan , Kim Kyung Mo , Caetano-Anollés Gustavo
Published: April 2016

In a recent eLetter and associated preprint, Harish, Abroi, Gough and Kurland criticized our structural phylogenomic methods, which support the early cellular origin of viruses. Their claims include the argument that the rooting of our trees is artifactual and distorted by small genome (proteome) size. Here we uncover their aprioristic reasoning, which mingles with misunderstandings and misinterpretations of cladistic methodology. To demonstrate, we labeled the phylogenetic positions of the smallest proteomes in our phylogenetic trees and confirm that the smallest genomes were neither attracted towards the root nor caused any distortions in the four-supergroup tree of life. Their results therefore stem from confusing outgroups with ancestors and handpicking problematic taxa to distort tree reconstruction. In doing so, they ignored the details of our rooting method, taxa sampling rationale, the plethora of evidence given in our study supporting the ancient origin of the viral supergroup and also recent literature on viral evolution. Indeed, our tree of life uncovered many viral monophyletic groups consistent with ICTV classifications and showed remarkable evolutionary tracings of virion morphotypes onto a revealing tree topology.
Innovation incentives in an integrated market with vertical product differentiation
Authors: Acharyya Rajat , Roy Chowdhury Prabal
Published: April 2016

Purpose

This paper aims to examine whether integration of national markets fosters innovation in the technologically inferior country.

Design/methodology/approach

The authors examine a simple game theoretic framework where a technologically backward home firm and a technologically advanced foreign firm compete in both qualities and prices in an integrated market. They formalize the speed of response to market integration of the two countries as a first mover advantage in the R&D stage.

Findings

The authors find that the outcome depends on the speed of response of the two firms and their initial technological distance. If the domestic firm is not too far behind the foreign firm to begin with, and if it responds faster, then the technological gap may get reversed. Further, the authors find that integration may be welfare improving for both the countries. There are, however, distributional implications. While the consumers always gain from such integration the firms may not.

Originality/value

This paper contributes to the debate on the implication of market integration. In contrast to the literature the authors use a model of vertical product differentiation which is relatively less explored in the literature and formalize the speed of response to market integration as a first mover advantage in R&D. This allows them to establish several interesting results with interesting policy implications.
MOONACS: a mobile on-/offline NFC-based physical access control system
Authors: Gruntz Dominik , Arnosti Christof , Hauri Marco
Published: April 2016

Purpose

The purpose of this paper is to present a smartphone-based physical access control system in which the access points are not directly connected to a central authorization server, but rather use the connectivity of the mobile phone to authorize a user access request online by a central access server. The access points ask the mobile phone whether a particular user has access or not. The mobile phone then relays such a request to the access server or presents an offline ticket. One of the basic requirements of our solution is the independence from third parties like mobile network operators, trusted service managers and handset manufacturers.

Design/methodology/approach

The authentication of the smartphone is based on public key cryptography. This requires that the private key is stored in a secure element or in a trusted execution environment to prevent identity theft. However, due to the intended independence from third parties, subscriber identity module (SIM)-based secure elements and embedded secure elements (i.e. separate hardware chips on the handset) were not an option and only one of the remaining secure element architectures could be used: host card emulation (HCE) or a microSD-based secure element.

Findings

This paper describes the implementation of such a physical access control system and discusses its security properties. In particular, it is shown that the HCE approach cannot solve the relay attack under conservative security assumptions and an implementation based on a microSD secure element is presented and discussed. Moreover, the paper also describes an offline solution which can be used if the smartphone is not connected to the access server. In this case, an access token is sent to the access point in response to an access request. These tokens are renewed regularly and automatically whenever the smartphone is connected.

Originality/value

In this paper, a physical access control system is presented which operates as fast as existing card-based solutions. By using a microSD-based secure element (SE), the authors were able to prevent the software relay attack. This solution is not restricted to microSD-based SEs, it could also be implemented with SIM-based or embedded secure elements (with the consequence that the solution depends on third parties).
In pursuit of blended value in social entrepreneurial ventures: an empirical investigation
Authors: Bacq Sophie , Janssen Frank , Kickul Jill R.
Published: April 2016

Purpose

– The purpose of this paper is to contribute to the understanding of the factors that influence social entrepreneurial ventures’ (SEVs) pursuit of a blended value approach. This paper predicts and examines that the mindset of SEV senior decision-makers leads them to perceive organisational goals differently.

Design/methodology/approach

– This paper tests the hypotheses on an original data set of 171 SEVs by means of discriminant analysis.

Findings

– The results suggest that social entrepreneurs who display an agency-oriented mindset tend to perceive organisational goals as being single: either social or financial. Conversely, social entrepreneurs who have a stewardship-oriented mindset tend to perceive organisational goals as blending both. The findings also underline that senior decision-makers’ mindsets in terms of governance are far from being uniform in SEVs.

Research limitations/implications

– The findings empirically contribute to the argument that agency principles do apply to broader contexts than profit-oriented organisations (Wisemanet al., 2012) and frame SEVs as a promising context that redefines principal-agent relationships. It follows that the expected association between non-economic goals and stewardship put forward in the literature needs to be nuanced: only a blended value approach of social and financial objectives is associated with stewardship, whereas single social goals are best perceived by agency-oriented senior decision-makers. The results are limited to a single survey, using cross-sectional data.

Practical implications

– The findings have a bearing on goal setting in social entrepreneurship. The results suggest that practitioners who display a stewardship mindset are more likely to perceive a double bottom line than those displaying an agency mindset.

Originality/value

– A novel feature of the model is the incorporation of senior decision-makers’ heterogeneous “governance mindsets” (agency and stewardship) and one of the first empirical tests of blended value in social entrepreneurship.
An organizational taxonomy of entrepreneurship policy delivery structures
Authors: Nielsen Pia Schou
Published: April 2016

Purpose

– Organizing entrepreneurship policy efforts is not an easy task. There are often several different actors involved, and their efforts towards improving conditions for entrepreneurs may be more or less organized. The purpose of this paper is to investigate the organizational archetypes of local entrepreneurship policy, across a number of factors relating to coordination mechanisms and outsourcing.

Design/methodology/approach

– The study is based on a survey of 77 Danish municipalities, covering 79 per cent of the total population, and their entrepreneurship policy structures. A two-step cluster analysis has been performed to identify taxonomies of entrepreneurship policy organizations.

Findings

– The findings reveal four different clusters: arm’s length coordination; arm’s length decoupling; internal centralization; and arm’s length centralization. Moreover the study reveals a link between these archetypes and the effectiveness of the local entrepreneurship policy delivery structure, suggesting that some structures may be more effective than other.

Originality/value

– The paper shifts the focus from policy formulation to organization, showing the importance of organizational structure for better performance. Specifically, the paper illustrates how lack of reaction to the environment leads to underperformance. Moreover, the paper draws the attention towards these new taxonomies, which are of value not only to academia but also to the political world.
Educating graduates for marketing in SMEs
Authors: Cheng Ranis , Lourenço Fernando , Resnick Sheilagh
Published: April 2016

Purpose

– Despite rising graduate unemployment in the UK, there are insufficient numbers of graduates employed in small and medium sized-enterprises (SMEs). The literature suggests that a teaching emphasis on large organisational business models in higher education institutions, particularly in the teaching of marketing theory, renders the SME sector unattractive to graduate employment and conversely, it is perceived that graduates lack additional “soft skills” vital for SME development and growth. The purpose of this paper is to provide an analysis of how SMEs define marketing and to compare student perspective on marketing within a SME context. This paper also examines the need to improve the conventional marketing curriculum with additional teaching solutions that consider the reality of UK SME ownership and student employment prospects.

Design/methodology/approach

– A qualitative research approach was adopted using in-depth interviews amongst ten SME owners and 20 undergraduate marketing students of a UK university.

Findings

– Findings revealed that the marketing practices used in SMEs were not present in the marketing curriculum in the case university. The employment of marketing graduates was not positively perceived by SME owners and equally, marketing undergraduates did not view SMEs as the career organisation of choice.

Originality/value

– The study re-evaluates the HE marketing curriculum and suggests an update of the curriculum in order to move the university-industry-government relationship away from the traditional knowledge transfer perspective.
Cyclical comovements of the world equity indexes
Authors: Zhou Haigang
Published: April 2016

Purpose

– The purpose of this paper is to study synchronization in stock index cycles across 82 countries and the linkage between macroeconomic and financial integration and stock market synchronization.

Design/methodology/approach

– The author document the synchronization structure of the world equity index cycles and its evolution over time. The author examine the explanatory power of various economic and financial variables on cycle comovements.

Findings

– Trade openness, capital openness, and an EU membership contribute to higher stock index cycle synchronization. Additionally, the macroeconomic and financial variables have asymmetric impacts on countries of different development levels.

Originality/value

– The author is the first to thoroughly chronicle the turning points, i.e., bear and bull regimes, of world equity indexes and empirically examine determinants of their cyclical comovement across nations.
Financial integration and diversification benefits: China and ASEAN4 countries
Authors: Nguyen Tung Dao , Elisabeta Pana
Published: April 2016

Purpose

– The strategic partnership between China and ASEAN has resulted in significant financial reforms at the country and regional level. The scale and pace of these changes call for systematic assessments of their bearing on the development and integration of financial markets in this region. The purpose of this paper is to investigate the level of financial integration of the equity markets in China and ASEAN4 countries (Indonesia, Malaysia, Philippines, and Thailand) for the period 2004-2014.

Design/methodology/approach

– The authors use theβandσconvergence, dynamic conditional correlation, and wavelet correlation to assess the degree, trend, and change across different time scales of the integration of China-ASEAN4 equity markets. Using two measures of change in return per unit risk and variance, we assess the difference in diversification benefits between an equity portfolio China-ASEAN4 and China-EU.

Findings

– The authors find that financial integration across China-ASEAN4 equity markets fluctuated between a moderate level before and after the recent crisis and a higher level during the crisis. The results indicate that investors achieve higher diversification benefits from a cross-industry than a cross-country investment strategy within this region.

Research limitations/implications

– Future research should investigate whether local factors and existing cultural and political differences explain the weak to moderate level of integration of China and emerging ASEAN equity markets.

Practical implications

– A good understanding of the degree and evolution of the regional financial integration may be used by investors to allocate capital efficiently when adding ASEAN4 equities to a portfolio of Chinese equities.

Social implications

– Systematic assessments of the regional financial integration contribute to the effort to mitigate the ensuing cross-border financial contagion during crises.

Originality/value

– The authors argue that that the increase in correlations of CHINA-ASEAN4 equity markets during the recent crisis does not reflect a permanent shift in the dynamic of the dominant markets in the region. While investors achieve higher diversification benefits from a cross-industry than a cross-country investment strategy within this region, the diversification benefits are lower for long-term than short-term investors.
Cointegration-based trading: evidence on index tracking & market-neutral strategies
Authors: Papantonis Ioannis
Published: April 2016

Purpose

– The purpose of this paper is to present an alternative approach to equity trading that is based on cointegration. If there are long-run equilibria among financial assets, a cointegration-based trading strategy can exploit profitable opportunities by capturing mean-reverting short-run deviations.

Design/methodology/approach

– First, the author introduces an equity indexing technique to form cointegration tracking portfolios that are able to replicate an index effectively. The author later enhances this tracking methodology in order to construct more complex portfolio-trading strategies that can be approximately market neutral. The author monitors the performance of a wide range of trading strategies under different specifications, and conducts an in-depth sensitivity analysis of the factors that affect the optimal portfolio construction. Several statistical-arbitrage tests are also carried out in order to examine whether the profitability of the cointegration-based trading strategies could indicate a market inefficiency.

Findings

– The author shows that under certain parameter specifications, an efficient tracking portfolio is able to produce similar patterns in terms of returns and volatility with the market. The author also finds that a successful long-short strategy of two cointegration portfolios can yield an annualized return of more than 8 percent, outperforming the benchmark and also demonstrating insignificant correlation with the market. Even though some cointegration-based pairs-trading strategies can consistently generate significant cumulative profits, yet they do not seem to converge to risk-less arbitrages, and thus the hypothesis of market efficiency cannot be rejected.

Originality/value

– The primary contribution of the research lies within the detailed analysis of the factors that affect the tracking-portfolio performance, thus revealing the optimal conditions that can lead to enhanced returns. Results indicate that cointegration can provide the means to successfully reproducing the risk-return profile of a benchmark and to implementing market-neutral strategies with consistent profitability. By testing for statistical arbitrage, the author also provides new evidence regarding the connection between the profit accumulation of cointegration-based pairs-trading strategies and market efficiency.
Patients’ use and views of real‐time feedback technology in general practice
Authors: Wright Christine , Davey Antoinette , Elmore Natasha , Carter Mary , Mounce Luke , Wilson Ed , Burt Jenni , Roland Martin , Campbell John
Published: April 2016

Background

There is growing interest in real‐time feedback (RTF), which involves collecting and summarizing information about patient experience at the point of care with the aim of informing service improvement.

Objective

To investigate the feasibility and acceptability of RTF in UK general practice.

Design

Exploratory randomized trial.

Setting/Participants

Ten general practices in south‐west England and Cambridgeshire. All patients attending surgeries were eligible to provide RTF.

Intervention

Touch screens were installed in waiting areas for 12 weeks with practice staff responsible for encouraging patients to provide RTF. All practices received fortnightly feedback summaries. Four teams attended a facilitated reflection session.

Outcomes

RTF ‘response rates’ among consulting patients were estimated, and the representativeness of touch screen users were assessed. The frequency of staff–patient interactions about RTF (direct observation) and patient views of RTF (exit survey) were summarized. Associated costs were collated.

Results

About 2.5% consulting patients provided RTF (range 0.7–8.0% across practices), representing a mean of 194 responses per practice. Patients aged above 65 were under‐represented among touch screen users. Receptionists rarely encouraged RTF but, when this did occur, 60% patients participated. Patients were largely positive about RTF but identified some barriers. Costs per practice for the twelve‐week period ranged from £1125 (unfacilitated team‐level feedback) to £1887 (facilitated team ± practitioner‐level feedback). The main cost was the provision of touch screens.

Conclusions

Response rates for RTF were lower than those of other survey modes, although the numbers of patients providing feedback to each practice were comparable to those achieved in the English national GP patient survey. More patients might engage with RTF if the opportunity were consistently highlighted to them.
Drift effects on the multivariate floral phenotype ofCalceolaria polyrhizaduring a post‐glacial expansion in Patagonia
Authors: Maubecin C. C. , Cosacov A. , Sérsic A. N. , Fornoni J. , Benitez‐Vieyra S.
Published: April 2016

Quaternary environmental changes substantially impacted the landscape and promoted rapid evolutionary changes in many species; however, analyses of adaptive phenotypic variation in plants have usually neglected the underlying historical context. Here, we associate phylogeography and phenotypic evolution by analysing the divergence ofCalceolaria polyrhizamultivariate floral phenotype after a Pleistocene post‐glacial expansion in Patagonia. Phenotypic matrix (P) properties (size, shape, orientation and phenotypic integration) of six refugium and six recent populations from two different phylogroups were compared following different approaches. We found thatP‐matrix shape and orientation remained stable despite the strong phylogeographic footprint of post‐glacial expansion. However, average proportional reductions in matrix size supported the expectation that drift had a significant effect on the floral phenotype in the northern phylogroup. When phylogeographic history was not included in the analyses, the results overestimated phenotypic differences, whereas under explicit phylogeographic control, drift appeared as the best explanation for matrix differences. In general, recent populations showed a larger phenotypic divergence among them, but a lower overall phenotypic variation than refugium populations. Random Skewers analyses indicated a lower potential response to selection in recently colonized populations than in refugium populations. We discuss that the combination of phylogeographic analyses with geographical distribution of functional phenotypic (genotypic) variation is critical not only to understand how historical effects influence adaptive evolution, but also to improve field comparisons in evolutionary ecology studies.
Effectiveness of Public Financial Support in an Electricity Transmission Project between Iceland and the UK
Authors: Sasaki Daisuke , Nakayama Mikiyasu
Published: April 2016

The feasibility of the project called IceLink is now being examined, which entails laying 800–1,200 MW high-voltage direct current (HVDC) submarine cables over 1,000 km and transmitting over 5 TWh per annum. This project will meet the growing demand in Europe for electricity derived from renewable energy sources, though there exists a relatively high degree of potential risks (e.g., financial risk due to the lingering affect of the financial crisis). This study aims to examine the effectiveness of public financial support for the project by using a quantitative analysis as well as discussing public financial support as a possible measure to fill the viability gap. The simulation results imply that the project is unfeasible unless there is public financial support. In the light of the public nature of the project and its promotion of green power, public financial support may be acceptable. It can thus be said that public financial support will be effective for this project. Also, the sensitivity analysis results show break-even points for three major parameters:—WACC, wholesale power price, and CAPEX—to NPV. Furthermore, the corresponding public financial supports—concessional loans provided by public financial institutions, applying for the feed-in tariff (FiT) system in the UK, and receiving a government subsidy for initial investment—are discussed as potential measures to fill the viability gap. In order to have a feasible project, it is essential to introduce one or more effective measures of public financial support.
Topoisomerase 1 inhibition suppresses inflammatory genes and protects from death by inflammation
Authors: Rialdi Alex , Campisi Laura , Zhao Nan , Lagda Arvin Cesar , Pietzsch Colette , Ho Jessica Sook Yuin , Martinez-Gil Luis , Fenouil Romain , Chen Xiaoting , Edwards Megan , Metreveli Giorgi , Jordan Stefan , Peralta Zuleyma , Munoz-Fontela Cesar , Bouvier Nicole , Merad Miriam , Jin Jian , Weirauch Matthew , Heinz Sven , Benner Chris , van Bakel Harm , Basler Christopher , García-Sastre Adolfo , Bukreyev Alexander , Marazzi Ivan
Published: April 2016

Unwinding DNA and unleasing inflammation

Fighting infections often comes with collateral damage, which sometimes can be deadly. For instance, in septic shock, the overwhelming release of inflammatory mediators drives multi-organ failure. Rialdi
et al.
now report a potential new therapeutic target for controlling excessive inflammation: the DNA unwinding enzyme topoisomerase I (Top1) (see the Perspective by Pope and Medzhitov). Upon infection, Top1 specifically localizes to the promoters of pathogen-induced genes and promotes their transcription by helping to recruit RNA polymerase II. Pharmacological inhibition of Top1 in a therapeutic setting increased survival in several mouse models of severe microbially induced inflammation.

Science
, this issue p.
10.1126/science.aad7993
; see also p.
1058
Complete Genome Sequence of UV-Resistant
Campylobacter jejuni
RM3194, Including an 81.08-Kilobase Plasmid
Authors: Gunther Nereus W. , Reichenberger Erin R. , Bono James L.
Published: April 2016

Campylobacter jejuni
strain RM3194 was originally isolated from a human with enteritis and contains a novel 81,079-bp plasmid. RM3194 has exhibited superior survival compared to other
Campylobacter jejuni
strains when challenged with UV light. The chromosome of RM3194 was determined to be 1,651,183 bp, with a G+C content of 30.5%.
Acute otitis externa: the successful first‐opinion ear consultation
Authors: Forsythe Peter J.
Published: April 2016

Acute otitis externa is defined as disease that has been present for up to one week (Bensignor and Forsythe 2012) and is a common presentation in small animal practice (Hill and others 2006). Otitis externa is a complex disease involving primary and secondary causes of inflammation and predisposing and perpetuating factors. It frequently recurs, despite apparently successful initial therapy. Repeated episodes of otitis externa along with failure to address the various causes and factors, may lead to progressively more severe disease and potentially irreversible chronic pathological changes within the ear canal. A careful, considered approach in a case of acute otitis externa is the first step to prevent such chronic disease. In this article, Peter Forsythe outlines an approach to acute otitis externa that should be practical within the confines of a 10 to 15 minute first‐opinion consultation. Cases of chronic disease require more in depth investigation beyond the scope of the typical first‐opinion consultation and additional time has to be set aside for these more complex cases or consideration given to referral to a dermatology specialist.
Upper Ordovician – Upper Silurian conodont biostratigraphy, Devon Island and southern Ellesmere Island, Canadian Arctic Islands, with implications for regional stratigraphy, eustasy, and thermal maturation
Authors: Zhang Shunxin , Mirza Khusro , Barnes Christopher R.
Published: April 2016

The conodont biostratigraphy for the Upper Ordovician – Upper Silurian carbonate shelf (Irene Bay and Allen Bay formations) and interfingering basinal (Cape Phillips Formation) facies is established for parts of Devon and Ellesmere islands, central Canadian Arctic Islands. Revisions to the interpreted regional stratigraphic relationships and correlations are based on the stratigraphic distribution of the 51 conodont species representing 32 genera, identified from over 5000 well-preserved conodonts recovered from 101 productive samples in nine stratigraphic sections. The six zones recognized are, in ascending order, Amorphognathus ordovicicus Local-Range Zone, Aspelundia fluegeli Interval Zone, Pterospathodus celloni Local-Range Zone, Pt. pennatus procerus Local-Range Zone, Kockelella patula Local-Range Zone, and K. variabilis variabilis – Ozarkodina confluens Concurrent-Range Zone. These provided a more precise dating of the members and formations and, in particular, the range of hiatuses within this stratigraphic succession. The pattern of regional stratigraphy, facies changes, and hiatuses is interpreted as primarily related to the effects of glacioeustasy associated with the terminal Ordovician glaciation and smaller Early Silurian glacial phases, the backstepping of the Silurian shelf margin, and the geodynamic effects of the collision with Laurentia by Baltica to the east and Pearya to the north. Conodont colour alteration index values (CAI 1–6.5) from the nine sections complement earlier graptolite reflectance data in providing regional thermal maturation data of value in hydrocarbon exploration assessments.
Kantowski–Sachs cosmological solutions in the generalized teleparallel gravity via Noether symmetry
Authors: Motavalli H. , Akbarieh A. Rezaei , Nasiry M.
Published: April 2016

We study the f(T) theory as an extension of teleparallel gravity and consider the Noether symmetry of Kantowski–Sachs (KS) anisotropic model for this theory. We specify the explicit teleparallel form of f(T) and find the corresponding exact cosmological solutions under the assumption that the Lagrangian admits the Noether symmetry. It is found that the universe experiences a power law expansion for the scale factors in the context of f(T) theory. By deriving equation of state (EOS) parameter, we show that the universe passes through the phantom and [Formula: see text]CDM theoretical scenarios. In this way, we estimate a lower limit age for the universe in excellent agreement with the value reported from recent observations. When KS model reduces to the flat Friedmann–Robertson–Walker (FRW) metric, our results are properly transformed into the corresponding values.
Excess conductivity analysis for Y3−xNdxBa5−xCaxCu8O18−δ superconducting phase
Authors: Barakat M. ME. , Abou-Aly A. I. , Awad R. , Aly N. S. , Ibrahim S.
Published: April 2016

Superconducting samples of type [Formula: see text] substituted by both [Formula: see text] and [Formula: see text] ions were prepared by a solid-state reaction technique. These substitutions affect the phase formation, lattice parameters, grains formations and superconducting transition temperature [Formula: see text]. The change in these parameters is mainly due to the partial substitution of [Formula: see text] by [Formula: see text] ions rather than the partial substitution of [Formula: see text] by [Formula: see text] ions. The analysis of the electrical resistivity [Formula: see text] versus temperature above [Formula: see text] was carried out using Aslamazov–Larkin (AL) and Lawrence–Doniach (LD) models. Different fluctuation regions starting from high temperature up to [Formula: see text] were estimated, and denoted by short-wave (sw), two-dimensional (2D), three-dimensional (3D) and critical (cr) fluctuations. A distinct crossover temperature [Formula: see text] from 2D to 3D, in the mean field region (MFR), is shifted to lower temperature by increasing substitutions content. The superconducting parameters such as zero temperature coherence length along the [Formula: see text]-axis [Formula: see text], inter-layer coupling strength [Formula: see text], Fermi velocity [Formula: see text] of the carriers and Fermi energy [Formula: see text] were calculated as a function of substitution content.
Endocytosis and Endosomal Trafficking in Plants
Authors: Paez Valencia Julio , Goodman Kaija , Otegui Marisa S.
Published: April 2016

Endocytosis and endosomal trafficking are essential processes in cells that control the dynamics and turnover of plasma membrane proteins, such as receptors, transporters, and cell wall biosynthetic enzymes. Plasma membrane proteins (cargo) are internalized by endocytosis through clathrin-dependent or clathrin-independent mechanism and delivered to early endosomes. From the endosomes, cargo proteins are recycled back to the plasma membrane via different pathways, which rely on small GTPases and the retromer complex. Proteins that are targeted for degradation through ubiquitination are sorted into endosomal vesicles by the ESCRT (endosomal sorting complex required for transport) machinery for degradation in the vacuole. Endocytic and endosomal trafficking regulates many cellular, developmental, and physiological processes, including cellular polarization, hormone transport, metal ion homeostasis, cytokinesis, pathogen responses, and development. In this review, we discuss the mechanisms that mediate the recognition and sorting of endocytic and endosomal cargos, the vesiculation processes that mediate their trafficking, and their connection to cellular and physiological responses in plants.