bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrafast carriers dynamics in filled-skutterudites
Authors: Guo Liang , Xu Xianfan , Salvador James R.
Published: June 2015

Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4–0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.
Terahertz plasmon-polariton modes in graphene driven by electric field inside a Fabry-Pérot cavity
Authors: Zhao C. X. , Xu W. , Li L. L. , Zhang C. , Peeters F. M.
Published: June 2015

We present a theoretical study on plasmon-polariton modes in graphene placed inside an optical cavity and driven by a source-to-drain electric field. The electron velocity and electron temperature are determined by solving self-consistently the momentum- and energy-balance equations in which electron interactions with impurities, acoustic-, and optic-phonons are included. Based on many-body self-consistent field theory, we develop a tractable approach to study plasmon-polariton in an electron gas system. We find that when graphene is placed inside a Fabry-Pérot cavity, two branches of the plasmon-polariton modes can be observed and these modes are very much optic- or plasmon-like. The frequencies of these modes depend markedly on driving electric field especially at higher resonant frequency regime. Moreover, the plasmon-polariton frequency in graphene is in terahertz (THz) bandwidth and can be tuned by changing the cavity length, gate voltage, and driving electric field. This work is pertinent to the application of graphene-based structures as tunable THz plasmonic devices.
Hole mobility in thermally evaporated pentacene: Morphological and directional dependence
Authors: Günther Alrun A. , Widmer Johannes , Kasemann Daniel , Leo Karl
Published: June 2015

Pentacene has been extensively studied as an active material for organic field-effect transistors as it shows very good charge carrier mobility along its preferred transport direction. In this contribution, we investigate the hole transport in pentacene thin films by measurement in conventional lateral organic field-effect transistors (OFETs), which yields the hole mobility along the a-b plane of pentacene, and by the recently published potential mapping (POEM) approach, which allows for direct extraction of the charge carrier mobility perpendicular to the substrate, in this case perpendicular to the a-b plane, without the assumption of a specific transport model. While the mobility along the a-b plane—determined from OFET measurements—is found to be in the region of 0.45 cm2/Vs, transport perpendicular to this plane shows an average mobility at least one order of magnitude lower. Investigating also how these effective mobility values depend on the deposition rate of the pentacene films, we find that the decrease in grain size for increasing deposition rate causes the mobility to decrease both parallel and perpendicular to the substrate due to the increased number of grain boundaries to be overcome. For the out-of-plane transport, this effect is found to saturate for deposition rates higher than 2.5 Å/s.
Electrostatic charge sensor based on a micromachined resonator with dual micro-levers
Authors: Zhao Jiuxuan , Ding Hong , Xie Jin
Published: June 2015

This paper describes an electrostatic charge sensor based on a microelectromechanical systems (MEMS) resonator with dual micro-levers to improve sensitivity. The device comprises a double-ended tuning fork resonant element working at out-of-phase mode with a quality factor (Q) of about 4900 under operating pressure of 40 mTorr. The resonant frequency shifts in proportion to an axial force induced by charge additions and then transformed by dual micro-levers with an amplification factor over 8. The measured responsivity is 1.3×10−3 Hz/fC2, which matches well with the results from analytical models and finite element method. The sensitivity of the charge sensor is 21 fC under 4 ppm frequency fluctuation. Additionally, electrostatic spring softening and nonlinear feature of the resonator are also investigated.
Is fire a threatening process for Liopholis kintorei, a nationally listed threatened skink?
Authors: Moore Danae , Kearney Michael Ray , Paltridge Rachel , McAlpin Steve , Stow Adam
Published: June 2015

Context Prescribed burning is widely adopted as a conservation-management tool, with priorities largely being the protection of fire-sensitive plant communities, threatened fauna habitat and minimising the risk and impacts of broad-scale wildfire. However, an improved understanding of the ecological mechanisms that underpin species responses to fire will assist the development and refinement of prescribed-burning practice. Aims To examine the effect of fire on burrow-system occupancy and breeding success at different spatial and temporal scales for a threatened skink, Liopholis kintorei. Methods Experimental burns simulating different fire types (clean burn, patchy burn and no burn) were conducted at 30 L. kintorei burrow systems that were selected from within a 75-ha focal study area. Burrow-system occupancy was monitored daily for 1 month, then monthly for an additional 3 months. Breeding success was assessed once at all 30 burrow systems. Eight additional 1-km2 sites within L. kintorei habitat that had experienced some degree of fire 2 years earlier were selected from across Newhaven Wildlife Sanctuary. Burrow-system occupancy and breeding success of L. kintorei at these sites was assessed once. Key results There was no significant effect of fire on burrow-system occupancy 1 month after experimental burns; however, burrow-system occupancy was significantly higher at unburnt sites 4 months after experimental burns and 2 years post-fire. Breeding success was significantly higher at unburnt sites than at clean-burnt and patchy-burnt sites. Conclusions Fire adversely affects L. kintorei, as demonstrated by a higher proportion of unoccupied burrow systems and fewer successful breeding events post-fire, particularly when all ground cover is lost. Implications Because fire is an inevitable and natural process within arid-zone spinifex grasslands, the primary habitat for L. kintorei, we recommend prescribed-burning practices that aim to maximise ground cover by reducing the frequency, intensity and size of fires. More specifically, we recommend fire exclusion from key sites within distinct localities where L. kintorei is known to be locally abundant. Depending on the size of these key sites, there may also be a need to construct strategic fire breaks within sites to ensure that any unwanted ignitions do not result in the loss of all vegetation cover.
Impaired mitochondrial fat oxidation induces adaptive remodeling of muscle metabolism
Authors: Wicks Shawna E. , Vandanmagsar Bolormaa , Haynie Kimberly R. , Fuller Scott E. , Warfel Jaycob D. , Stephens Jacqueline M. , Wang Miao , Han Xianlin , Zhang Jingying , Noland Robert C. , Mynatt Randall L.
Published: June 2015

Significance

Many theories regarding the causes of insulin resistance in skeletal muscle center on the ability of muscle to oxidize fat, with evidence supporting either decreased or increased fatty acid oxidation (FAO) as causal to insulin resistance. Inhibition of fatty acid transport into mitochondria specifically in mouse muscle results in a rather remarkable phenotype. Despite an accumulation of lipids in muscle, insulin sensitivity is maintained. The muscle responds to decreased FAO by adapting muscle metabolism to use other fuel sources, and by an increased reliance upon peroxisomal fat oxidation. There is also an increase in mitochondrial biogenesis. At the whole-body level, the mice seem to enter an energy conservation mode with reduced activity, energy expenditure, and resistance to diet-induced obesity.
Empirical inference of circuitry and plasticity in a kinase signaling network
Authors: Wilkes Edmund H. , Terfve Camille , Gribben John G. , Saez-Rodriguez Julio , Cutillas Pedro Rodriguez
Published: June 2015

Significance

Signaling pathways form complex networks of biochemical reactions, but inferring the topology of such networks and measuring how they are remodeled in disease is still challenging. Using MS, our study defined the circuitry and plasticity of a kinase signaling network de novo, with unprecedented depth and without prior assumptions of its topology. In addition, we observed a degree of stochasticity in how the network was remodeled upon chronic inhibition of phosphoinositide 3-kinase (PI3K) or mammalian target of rapamycin complexes 1/2 (mTORC1/2), suggesting that the initial condition of the system was not the only determinant of how cells become resistant to targeted therapies. These observations may have implications for our ability to predict the evolution of signaling networks during therapy to prevent the acquisition of resistance.
Late Oligocene–early Miocene birth of the Taklimakan Desert
Authors: Zheng Hongbo , Wei Xiaochun , Tada Ryuji , Clift Peter D. , Wang Bin , Jourdan Fred , Wang Ping , He Mengying
Published: June 2015

Significance

The formation of the Taklimakan Desert marked a major geological event in central Asia during the Cenozoic, with far-reaching impacts. Deposition of both eolian sand dunes in the basin center and the genetically equivalent loessite along the basin margins provide evidence for the birth of the Taklimakan Desert. This paper resolves a long-standing debate concerning the age of the Taklimakan Desert, specifically whether it dates to ∼3.4–7 Ma, currently the dominant view. Our result shows that the desert came into existence during late Oligocene–early Miocene, between ∼26.7 Ma and 22.6 Ma, as a result of widespread regional aridification and increased erosion in the surrounding mountain fronts, both of which are closely linked to the tectonic uplift of the Tibetan–Pamir Plateau and Tian Shan.
Molecular diffusion in the human nail measured by stimulated Raman scattering microscopy
Authors: Chiu Wing Sin , Belsey Natalie A. , Garrett Natalie L. , Moger Julian , Delgado-Charro M. Begoña , Guy Richard H.
Published: June 2015

Significance

Diseases of the nail are particularly hard to treat because drug penetration to the target (which lies below the tightly woven keratin network) is extremely limited. To shed greater light on the problem, the diffusion of three pharmaceutically relevant solvents across the human nail has been imaged and characterized by stimulated Raman scattering microscopy. Remarkably, the kinetics of water transport were more than 10-fold faster than those of dimethyl sulphoxide and propylene glycol. Furthermore, the uptake of all three solvents, the diffusion of which appeared to be concentration dependent, progressively undermined the integrity of the nail. These new insights may facilitate the improved formulation of drug products effective in the treatment of diseases such as fungal infections and nail psoriasis.
Long-circulating siRNA nanoparticles for validating Prohibitin1-targeted non-small cell lung cancer treatment
Authors: Zhu Xi , Xu Yingjie , Solis Luisa M. , Tao Wei , Wang Liangzhe , Behrens Carmen , Xu Xiaoyang , Zhao Lili , Liu Danny , Wu Jun , Zhang Ning , Wistuba Ignacio I. , Farokhzad Omid C. , Zetter Bruce R. , Shi Jinjun
Published: June 2015

Significance

This study developed a new generation lipid–polymer hybrid nanoparticle platform for effective systemic delivery of small interfering RNA (siRNA) to tumors, which represents a challenging hurdle for the widespread application of RNA interference (RNAi) in cancer research and therapy. With promising in vivo features such as long blood circulation, high tumor accumulation, and effective gene silencing, the hybrid siRNA nanoparticles were successfully used to reveal and validate a putative therapeutic target, Prohibitin1 (PHB1), in non-small cell lung cancer treatment. In vivo antitumor efficacy results and human tissue microarray analysis further suggested the feasibility of utilizing PHB1 siRNA nanoparticles as a novel therapeutic agent. This hybrid RNAi nanoparticle platform may serve as a valuable tool for validating potential cancer targets and developing new cancer therapies.
Pathways for abiotic organic synthesis at submarine hydrothermal fields
Authors: McDermott Jill M. , Seewald Jeffrey S. , German Christopher R. , Sylva Sean P.
Published: June 2015

Significance

Arguments for an abiotic origin of organic compounds in deep-sea hot springs are compelling because of their potential role in the origin of life and sustaining microbial communities. Theory predicts that warm H
2
-rich fluids circulating through serpentinizing systems create a favorable thermodynamic drive for inorganic carbon reduction to organic compounds. We show that abiotic synthesis proceeds by two spatially and temporally distinct mechanisms. Abundant dissolved CH
4
and higher hydrocarbons are likely formed in H
2
-rich fluid inclusions over geologic timescales. Conversely, formate production by ΣCO
2
reduction occurs rapidly during subsurface mixing, which may support anaerobic methanogenesis. We confirm models for abiotic metastable organic compound formation and argue that alkanes in all ultramafic-influenced vents may form independently of actively circulating serpentinizing fluids.
Bioimage analysis of
Shigella
infection reveals targeting of colonic crypts
Authors: Arena Ellen T. , Campbell-Valois Francois-Xavier , Tinevez Jean-Yves , Nigro Giulia , Sachse Martin , Moya-Nilges Maryse , Nothelfer Katharina , Marteyn Benoit , Shorte Spencer L. , Sansonetti Philippe J.
Published: June 2015

Significance

Shigella
spp
.
are responsible for devastating diarrheal diseases, primarily in children, within underdeveloped countries.
Shigella
invades the mucosa of the large intestine, causing inflammation and damage to the epithelium. Here, we have measured the progression of
Shigella
infection in a small animal model of the disease to better understand the mechanism of invasion of the colonic mucosa. The novelty of our approach relies on the tracking of fluorescent bacteria inside the infected tissue at various time points using confocal microscopy and subsequent quantitative bioimage analyses. Our approach is readily applicable to other host–pathogen systems to quantify host–pathogen interactions.
Molecular transitions from papillomavirus infection to cervical precancer and cancer: Role of stromal estrogen receptor signaling
Authors: den Boon Johan A. , Pyeon Dohun , Wang Sophia S. , Horswill Mark , Schiffman Mark , Sherman Mark , Zuna Rosemary E. , Wang Zhishi , Hewitt Stephen M. , Pearson Rachel , Schott Meghan , Chung Lisa , He Qiuling , Lambert Paul , Walker Joan , Newton Michael A. , Wentzensen Nicolas , Ahlquist Paul
Published: June 2015

Significance

Cervical cancer (CxCa) is the second most frequent cancer in women and the third leading cause of cancer death in women worldwide. Our global analysis of gene expression in normal, precancerous, and cancerous cervical tissue shows increased DNA replication/repair and cell proliferation followed by substantial metabolic shifts. We observed a dramatic, progressive decrease in estrogen receptor alpha (ERα) in tumor progression, and ranking specimens by estrogen-responsive gene expression correlated remarkably with histopathology. Whereas ERα expression shuts off in tumor epithelium, stromal fibroblasts in the microenvironment retain ERα, and the data indicate estrogen-related alteration of several candidate stroma–tumor signaling pathways. Our findings strongly support a role of stromal estrogen signaling in CxCa development with implications for CxCa management and control.
Japanese Huperzia serrata extract and the constituent, huperzine A, ameliorate the scopolamine-induced cognitive impairment in mice
Authors: Ohba Takuya , Yoshino Yuta , Ishisaka Mitsue , Abe Naohito , Tsuruma Kazuhiro , Shimazawa Masamitsu , Oyama Masayoshi , Tabira Takeshi , Hara Hideaki
Published: June 2015

Huperzia serrata has been used as a Chinese folk medicine for many years. It contains huperzine A, which has a protective effect against memory deficits in animal models; however, it is unclear if H. serrata extract exerts any effects in Alzheimer’s disease (AD) models. We used H. serrata collected in Japan and determined its huperzine A content using HPLC. We determined its inhibitory effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity. H. serrata extract (30 mg/kg/day) and donepezil (10 mg/kg/day) were orally administrated for 7 days. After repeated administration, we performed the Y-maze and passive avoidance tests. H. serrata extract contained 0.5% huperzine A; H. serrata extract inhibited AChE, but not BuChE. H. serrata extract ameliorated cognitive function in mice. These results indicate that Japanese H. serrata extract ameliorates cognitive function deficits by inhibiting AChE. Therefore, H. serrata extract may be valuable for the prevention or treatment of dementia in AD.
Digoxin-Specific Antibody Fragment Dosing: A Case Series
Authors: Chhabra Neeraj , Valento Matthew , Bryant Sean M. , Aks Steven E.
Published: June 2015

Digoxin-specific antibody fragments (DSFab) are used for the treatment of poisoning by cardiac glycosides, such as pharmaceutical digoxin. Dosing of this therapy for chronic and acute poisonings is based on the steady-state serum concentrations of digoxin, historical data in acute ingestions, or empiric regimens purportedly based on the average requirements. Empiric dosing for adult patients involves utilization of 3–6 vials for chronic poisoning and 10–20 vials for acute poisoning. The aim of this study was to describe the average dosing requirements based on the steady-state serum concentration of digoxin or historical data and compare this with the empiric dosing regimens. We performed a retrospective analysis of cases over an 11-year period presented to the Illinois Poison Center where administration of DSFab was recommended. We identified 140 cases of chronic digoxin poisoning and 26 cases or acute digoxin poisoning for analysis. The average dose of DSFab recommended in the cases of chronic digoxin poisoning was 3.05 vials (SD ± 1.31). The average dose of DSFab recommended in the cases of acute digoxin poisoning was 6.33 vials (SD ± 5.26). These values suggest that empiric dosing regimens may overestimate the need for DSFab in cases of both chronic and acute poisonings of pharmaceutical digoxin.
Thresholds for impaired species recovery
Authors: Hutchings Jeffrey A.
Published: June 2015

Studies on small and declining populations dominate research in conservation biology. This emphasis reflects two overarching frameworks: the small-population paradigm focuses on correlates of increased extinction probability; the declining-population paradigm directs attention to the causes and consequences of depletion. Neither, however, particularly informs research on the determinants, rate or uncertainty of population increase. By contrast, Allee effects (positive associations between population size and realizedper capitapopulation growth rate,rrealized, a metric of average individual fitness) offer a theoretical and empirical basis for identifying numerical and temporal thresholds at which recovery is unlikely or uncertain. Following a critique of studies on Allee effects, I quantify population-size minima and subsequent trajectories of marine fishes that have and have not recovered following threat mitigation. The data suggest that threat amelioration, albeit necessary, can be insufficient to effect recovery for populations depleted to less than 10% of maximum abundance (Nmax), especially when they remain depleted for lengthy periods of time. Comparing terrestrial and aquatic vertebrates, life-history analyses suggest that population-size thresholds for impaired recovery are likely to be comparatively low for marine fishes but high for marine mammals. Articulation of a ‘recovering population paradigm’ would seem warranted. It might stimulate concerted efforts to identify generic impaired recovery thresholds across species. It might also serve to reduce the confusion of terminology, and the conflation of causes and consequences with patterns currently evident in the literature on Allee effects, thus strengthening communication among researchers and enhancing the practical utility of recovery-oriented research to conservation practitioners and resource managers.
“Dangerous conversations”: a case study involving language
Authors: Madoc-Jones Iolo , Jones Dawn , Parry Odette , Dubberley Sarah
Published: June 2015

Purpose

– Drawing on the approach of Bourdieu (1977, 1986), and using language as an exemplar, the purpose of this paper is to engage in a “dangerous conversation” to explore how and why issues of diversity were mobilised, ignored and leveraged in one particular service context.

Design/methodology/approach

– Qualitative research exploring the language choices of 25 service users who had been processed through the criminal Justice System in Wales in the last five years.

Findings

– The argument is made that in some service contexts, a habitus obtains that renders reflexivity about diversity issues problematic and predicates against the critical reflection necessary to promote anti-oppressive practice.

Research limitations/implications

– Small sample size, not generalisable.

Practical implications

– The authors intend the paper to encourage greater reflection on instances when diversity issues are raised and to render simplistic any attempt to invalidate claims of discrimination.

Social implications

– Encourage dialogue about claims of discrimination and greater reflection by service providers about the legitimacy of such claims.

Originality/value

– Anti-oppressive theorising has, for the most part, constructed minority group members as passive victims within hierarchical power relationships. While acknowledging how power is unequally distributed, the paper challenges hierarchical models which designate minority group members as bereft of power.
Investigating the work practices of network security professionals
Authors: Adnan Muhammad , Just Mike , Baillie Lynne , Kayacik Hilmi Gunes
Published: June 2015

Purpose

– The purpose of this paper is to investigate the work practices of network security professionals and to propose a new and robust work practices model of these professionals.

Design/methodology/approach

– The proposed work practices model is composed by combining the findings of ten notable empirical studies performed so far this century. The proposed model was then validated by an online survey of 125 network security professionals with a wide demographic spread.

Findings

– The empirical data collected from the survey of network security professionals strongly validate the proposed work practices model. The results also highlight interesting trends for different groups of network security professionals, with respect to performing different security-related activities.

Research limitations/implications

– Further studies could investigate more closely the links and dependencies between the different activities of the proposed work practices model and tools used by network security professionals to perform these activities.

Practical implications

– A robust work practices model of network security professionals could hugely assist tool developers in designing usable tools for network security management.

Originality/value

– This paper proposes a new work practices model of network security professionals, which is built by consolidating existing empirical evidence and validated by conducting a survey of network security professionals. The findings enhance the understanding of tool developers about the day-to-day activities of network security professionals, consequently assisting developers in designing better tools for network security management.
Impact of the cost of capital on the financing decisions of Brazilian companies
Authors: Albanez Tatiana
Published: June 2015

Purpose

– The purpose of this paper is to examine the market timing behavior of listed Brazilian companies to verify the effects of the cost of capital on their financing decisions, and hence on their capital structure.

Design/methodology/approach

– The relation between the cost of capital (debt and equity capital) and the leverage of firms in the period from 2000 to 2011 is analyzed by means of regression models with panel data. For this purpose, different proxies are used for the cost of equity and debt capital.

Findings

– The results provide strong evidence that Brazilian firms take advantage of windows of opportunity to obtain financing, and that when the cost of equity capital is high, firms appear to follow a pecking order, giving preference to debt financing. However, the decision is based on the cost of alternative sources of funding rather than just on the hierarchy established by the pecking order theory, due to the information asymmetry between market agents.

Originality/value

– Few studies of the Brazilian capital market have analyzed firms’ capital structure under the market timing approach, and none have addressed the same aspects analyzed here. Therefore, this paper will be useful to different users of accounting information by indicating the factors that influence the capital structure of Brazilian firms, allowing a better analysis of whether these firms act to maximize the generation of shareholder wealth.
Sustainability vs credibility of fiscal consolidation
Authors: Passamani Giuliana , Tamborini Roberto , Tomaselli Matteo
Published: June 2015

Purpose

– The purpose of this paper is to explain why some countries in the eurozone between 2010 and 2012 experienced a dramatic vicious circle between hard austerity plans and rising default risk premia. Were such plans too small, and hence non-credible, or too large, and hence non-sustainable? These questions have prompted theoretical and empirical investigations in the line of the so-called “self-fulfilling beliefs”, where beliefs of unsustainability of fiscal adjustments, and hence default on debt, feed higher risk premia which indeed make fiscal adjustments less sustainable.

Design/methodology/approach

– Detecting the sustainability factor in the evolution of spreads is uneasy because it is largely non-observable and may be proxied by different variables. In this paper, the authors present the results of a dynamic principal components factor analysis (PCFA) applied to a panel data set of the 11 major EZ countries from 2000 to 2013, consisting of each country’s spread of long-term interest rate over Germany as dependent variable, and an array of leading fiscal and macroeconomic indicators of solvency fiscal effort and its sustainability.

Findings

– The authors have been able to identify the role of these indicators that combine themselves as significant latent variables in boosting spreads. Moreover, the large joint deterioration of these variables is identifiably located between 2009 and 2012 and particularly for the group of countries under most severe default risk (with Italy and France as borderline cases). The authors also find evidence that the announcement of the European Central Bank Outright Monetary Transactions program has improved the sustainability assessment of sovereign debts.

Originality/value

– Dynamic PCFA is a rather unusual technique with respect to standard econometric tests of models, which is particularly well-suited to reduce the number of variables in a data set by extracting meaningful linear combinations from the observed variables that may concur to explain a given phenomenon (the dependent variable). These combinations, called “common factors”, can be interpreted as latent, non-observable variables.
Rating sovereign debt in a monetary union – original sin by transnational governance
Authors: Körner Finn Marten , Trautwein Hans-Michael
Published: June 2015

Purpose

– The purpose of this paper is to test the hypothesis that major credit rating agencies (CRAs) have been inconsistent in assessing the implications of monetary union membership for sovereign risks. It is frequently argued that CRAs have acted procyclically in their rating of sovereign debt in the European Monetary Union (EMU), underestimating sovereign risk in the early years and over-rating the lack of national monetary sovereignty since the onset of the Eurozone debt crisis. Yet, there is little direct evidence for this so far. While CRAs are quite explicit about their risk assessments concerning public debt that is denominated in foreign currency, the same cannot be said about their treatment of sovereign debt issued in the currency of a monetary union.

Design/methodology/approach

– While CRAs are quite explicit about their risk assessments concerning public debt that is denominated in foreign currency, the same cannot be said about their treatment of sovereign debt issued in the currency of a monetary union. This paper examines the major CRAs’ methodologies for rating sovereign debt and test their sovereign credit ratings for a monetary union bonus in good times and a malus, akin to the “original sin” problem of emerging market countries, in bad times.

Findings

– Using a newly compiled dataset of quarterly sovereign bond ratings from 1990 until 2012, the panel regression estimation results find strong evidence that EMU countries received a rating bonus on euro-denominated debt before the European debt crisis and a large penalty after 2010.

Practical implications

– The crisis has brought to light that EMU countries’ euro-denominated debt may not be considered as local currency debt from a rating perspective after all.

Originality/value

– In addition to quantifying the local currency bonus and malus, this paper shows the fundamental problem of rating sovereign debt of monetary union members and provide approaches to estimating it over time.
Does commitment to environmental self-regulation matter? An empirical examination from China
Authors: Lin Han , Zeng Saixing , Ma Hanyang , Chen Hongquan
Published: June 2015

Purpose

– The purpose of this paper is to develop a better understanding of the mechanisms by which symbolic commitment to self-regulation influences corporate environmental performance through the adoption of substantive actions.

Design/methodology/approach

– Using a sample of Chinese listed private firms in manufacturing sectors, this paper empirically investigates whether and how corporate symbolic commitment to environmental self-regulation really improves the consequences of corporate activities with respect to environmental issues under the current Chinese context. A moderated mediation analysis is employed to test the hypotheses and examine the relationships proposed in the research framework.

Findings

– The authors argue that making a commitment to environmental self-regulation could motivate firms to implement effective means of being green. The intriguing and robust results show that firms with higher ranking environmental commitment are more likely to use political connections to obtain resources (green subsidies), and then improve environmental performance.

Practical implications

– The results of this study provide a snapshot of the mechanism between symbolic promises and real outcomes.

Originality/value

– The authors theorize about and test both direct and indirect effects of commitment to self-regulation on real outcomes which provide empirical evidence for the incipient but growing understanding of self-regulation.
The effect of cold-pressing and solvent extraction on some characteristics of kariya (Hildergadia barteri) seed oil
Authors: Adebayo Adewale Williams , Ogunsina Babatunde S , Gbadamosi Olasunkanmi Saka
Published: June 2015

Purpose

– This study aims to investigate some physicochemical characteristics of Hildegardia barteri seed oils obtained by cold-pressing and solvent extraction procedures.

Design/methodology/approach

– Crude oil samples were obtained from the kernels by cold pressing and solvent extraction. The physicochemical properties of the oil samples were investigated according to the standard procedures in published works of literature.

Findings

– The oil yield was 55.7 and 97 per cent for cold-pressed kariya seed oil (CPKSO) and solvent-extracted kariya seed oil (SEKSO), respectively. Specific gravities, refractive indices, viscosities, iodine value, saponification value, peroxide value and acid value were 0.8742 and 0.9036; 1.4629 and 1.4584; 75.93 and 74.90 mPa.s; 55.78 and 53.56 g of I2/100g of oil; 249.76 and 253.90 mg KOH/g; 4.86 and 5.02 meq KOH/g; 2.12 and 2.09 mg KOH/g of oil for CPKSO and SEKSO, respectively. The physicochemical characteristics of kariya seed oil were not significantly affected by extraction method. The fatty acid profiles of CPKSO and SEKSO showed that the two oil samples contain 24.2 and 23.7, 31.3 and 29.3, 23.2 and 23.7 and 19.6 and 21.3 per cent of myristic, palmitic, stearic and linolenic acids, respectively. Lauric and oleic acids were present in very little proportions of 0.3 and 0.41; and 0.01 and 0.03 per cent, respectively, whereas linoleic acid was 1.4 per cent for the two oil samples. Significant differences in fatty acid profiles were observed for lauric, palmitic and linolenic acids (p = 0.05). Saturated and unsaturated fatty acids were about 79.0 and 77.11 per cent and 21.01 and 22.73 per cent for CPKSO and SEKSO, respectively.

Practical implications

– This work promotes H. barteri tree beyond its use as a mere ornamental plant. The non-conventional seed oil it produces may find relevance in the food or biofuels industry subject to further investigation.

Originality/value

– This study is the first to document the extraction and physicochemical properties of kariya seed oils.
Accelerated maturation of processed yerba-mate under the controlled conditions of temperature and humidity
Authors: Gonçalves Itamar Luís , Dartora Nessana , Piovezan Borges Ana Cláudia , Picolo Ana Paula , Dallago Rogério Marcos , Mera de Souza Lauro , Valduga Alice Teresa
Published: June 2015

Purpose

– The purpose of this paper was to assess the changes in secondary metabolites and color during yerba-mate aging under controlled conditions. In Uruguay and Paraguay, the yerba-mate matured, in which chlorophyll degradation occurs, is preferred. For the matured product, the yerba-mate is stored for six months to one year.

Design/methodology/approach

– Processed yerba-mate was submitted to 35°C and 80 per cent humidity during 42 days in a climatic chamber. Samples were collected every seven days, and the phenolic compounds/methylxanthines were quantified by ultra-performance liquid chromatography – photodiode array and chlorophylls/phaeophytins by spectrophotometry. L*, a* and b* colorimetric coordinates were measured.

Findings

– The most expressive changes in the color occur in the first 14 days. At this time, 23.161 ± 2.984 per cent of total chlorophyll was degraded, considering that in 42 days, 37.458 ± 0.955 per cent is degraded, according to an exponential model. A positive correlation between theobromine amount and maturation time was found. This was verified by an increase in dicaffeoylquinic acid concentrations and small changes in chlorogenic acid isomers.

Practical implications

– The results indicate that this is a viable accelerated yerba-mate maturation process according to economics and nutraceutics.

Originality/value

– The paper has reported here a novel strategy to promote the yerba-mate maturation using controlled conditions.
Exploring optimism and pessimism in the Indian equity market
Authors: Prosad Jaya Mamta , Kapoor Sujata , Sengupta Jhumur
Published: June 2015

Purpose

– The purpose of this paper is to capture the presence and impact of optimism in the Indian equity market.

Design/methodology/approach

– The data set comprises the daily values of the Nifty 50 index, index options and Treasury-bill index for a period of five years (2006-2011). The focus of this paper is two pronged. It first investigates the presence of optimism (pessimism) using the pricing kernel technique suggested by Barone-Adesi et al. (2012). Second, it tries to analyze the relationship of this bias with stock market indicators like risk premium, market return and volatility using time series regression.

Findings

– The findings indicate that the Indian equity market has been predominantly pessimistic from the period 2006 to 2011. The interaction of this bias with market indicators also unveils some interesting insights. The study shows that high past volatility can lead to pessimism in the Indian equity market and vice versa. It further explores that when the investors are rational, their risk and return relationship is positive while it tends to be negative when they are irrational. The impact of investors’ irrationalities on asset valuation has also been accounted by Brown and Cliff (2005).

Research limitations/implications

– The findings of the paper have significant implications for fund managers and asset management companies. It is recommended that they should try to identify behavioral biases in their clients before designing their portfolios.

Originality/value

– This study is one of the very few attempts to capture the presence and impact optimism (pessimism) in the Indian equity market.
Species‐specific diversity of novel bacterial lineages and differential abundance of predicted pathways for toxic compound degradation in scorpion gut microbiota
Authors: Bolaños Luis M. , Rosenblueth Mónica , Castillo‐Ramírez Santiago , Figuier‐Huttin Gilles , Martínez‐Romero Esperanza
Published: June 2015

Scorpions are considered ‘living fossils’ that have conserved ancestral anatomical features and have adapted to numerous habitats. However, their gut microbiota diversity has not been studied. Here, we characterized the gut microbiota of two scorpion species, Vaejovis smithi and Centruroides limpidus. Our results indicate that scorpion gut microbiota is species‐specific and that food deprivation reduces bacterial diversity. 16S rRNA gene phylogenetic analysis revealed novel bacterial lineages showing a low level of sequence identity to any known bacteria. Furthermore, these novel bacterial lineages were each restricted to a different scorpion species. Additionally, our results of the predicted metagenomic profiles revealed a core set of pathways that were highly abundant in both species, and mostly related to amino acid, carbohydrate, vitamin and cofactor metabolism. Notably, the food‐deprived V. smithi shotgun metagenome matched almost completely the metabolic features of the prediction. Finally, comparisons among predicted metagenomic profiles showed that toxic compound degradation pathways were more abundant in recently captured C. limpidus scorpions. This study gives a first insight into the scorpion gut microbiota and provides a reference for future studies on the gut microbiota from other arachnid species.
The language needs of residents from linguistically diverse backgrounds in Victorian aged care facilities
Authors: Runci Susannah J. , Eppingstall Barbara J. , van der Ploeg Eva S. , Graham Georgia , O'Connor Daniel W.
Published: June 2015

Objectives

To investigate the language needs of residents of aged care facilities within the State of Victoria, Australia, and determine what language resources were accessible to them.

Methods

Postal questionnaires were sent to 586 aged care facilities, enquiring about residents' and staff members' languages and language‐specific resources.

Results

The response rate was 38%. The majority of facilities had residents who spoke non‐English languages, and 55 different languages were represented. Three‐quarters of the facilities employed staff members who spoke to residents in non‐English languages and employed language‐specific resources. The metropolitan and ethnospecific facilities had a greater presence of non‐English‐speaking residents and staff and more commonly used language‐specific resources in comparison with regional and mainstream facilities.

Conclusion

We found a large number of languages used by many residents from non‐English‐speaking backgrounds, with evidence of a large unmet language resource need. Unmet need was greatest in rural areas.
Global population collapse in a superabundant migratory bird and illegal trapping in China
Authors: Kamp Johannes , Oppel Steffen , Ananin Alexandr A. , Durnev Yurii A. , Gashev Sergey N. , Hölzel Norbert , Mishchenko Alexandr L. , Pessa Jorma , Smirenski Sergey M. , Strelnikov Evgenii G. , Timonen Sami , Wolanska Kolja , Chan Simba
Published: June 2015

Persecution and overexploitation by humans are major causes of species extinctions. Rare species, often confined to small geographic ranges, are usually at highest risk, whereas extinctions of superabundant species with very large ranges are rare. The Yellow‐breasted Bunting (Emberiza aureola) used to be one of the most abundant songbirds of the Palearctic, with a very large breeding range stretching from Scandinavia to the Russian Far East. Anecdotal information about rapid population declines across the range caused concern about unsustainable trapping along the species’ migration routes. We conducted a literature review and used long‐term monitoring data from across the species’ range to model population trend and geographical patterns of extinction. The population declined by 84.3–94.7% between 1980 and 2013, and the species’ range contracted by 5000 km. Quantitative evidence from police raids suggested rampant illegal trapping of the species along its East Asian flyway in China. A population model simulating an initial harvest level of 2% of the population, and an annual increase of 0.2% during the monitoring period produced a population trajectory that matched the observed decline. We suggest that trapping strongly contributed to the decline because the consumption of Yellow‐breasted Bunting and other songbirds has increased as a result of economic growth and prosperity in East Asia. The magnitude and speed of the decline is unprecedented among birds with a comparable range size, with the exception of the Passenger Pigeon (Ectopistes migratorius), which went extinct in 1914 due to industrial‐scale hunting. Our results demonstrate the urgent need for an improved monitoring of common and widespread species’ populations, and consumption levels throughout East Asia.
Synthesis and summary of patient‐reported outcome measures to inform the development of a core outcome set in colorectal cancer surgery
Authors: McNair A. G. K. , Whistance R. N. , Forsythe R. O. , Rees J. , Jones J. E. , Pullyblank A. M. , Avery K. N. L. , Brookes S. T. , Thomas M. G. , Sylvester P. A. , Russell A. , Oliver A. , Morton D. , Kennedy R. , Jayne D. G. , Huxtable R. , Hackett R. , Dutton S. J. , Coleman M. G. , Card M. , Brown J. , Blazeby J. M.
Published: June 2015

Aim

Patient‐reported outcome (PRO) measures (PROMs) are standard measures in the assessment of colorectal cancer (CRC) treatment, but the range and complexity of available PROMs may be hindering the synthesis of evidence. This systematic review aimed to: (i) summarize PROMs in studies of CRC surgery and (ii) categorize PRO content to inform the future development of an agreed minimum ‘core’ outcome set to be measured in all trials.

Method

All PROMs were identified from a systematic review of prospective CRC surgical studies. The type and frequency of PROMs in each study were summarized, and the number of items documented. All items were extracted and independently categorized by content by two researchers into ‘health domains’, and discrepancies were discussed with a patient and expert. Domain popularity and the distribution of items were summarized.

Results

Fifty‐eight different PROMs were identified from the 104 included studies. There were 23 generic, four cancer‐specific, 11 disease‐specific and 16 symptom‐specific questionnaires, and three ad hoc measures. The most frequently used PROM was the EORTC QLQ‐C30 (50 studies), and most PROMs (n = 40, 69%) were used in only one study. Detailed examination of the 50 available measures identified 917 items, which were categorized into 51 domains. The domains comprising the most items were ‘anxiety’ (n = 85, 9.2%), ‘fatigue’ (n = 67, 7.3%) and ‘physical function’ (n = 63, 6.9%). No domains were included in all PROMs.

Conclusion

There is major heterogeneity of PRO measurement and a wide variation in content assessed in the PROMs available for CRC. A core outcome set will improve PRO outcome measurement and reporting in CRC trials.
Motor performance and correlates of mental health in children who are deaf or hard of hearing
Authors: Fellinger Matthäus J , Holzinger Daniel , Aigner Martin , Beitel Christoph , Fellinger Johannes
Published: June 2015

Aim

This cross‐sectional study investigates the relationship between motor performance and mental health in a representative population of children with hearing impairment.

Method

Ninety‐three pupils (45 males, 48 females) aged 6 years to 16 years (mean 11y 3mo, SD 2y 9mo) with hearing impairment of at least 40dB and a Nonverbal IQ greater than 70 were assessed for motor performance with the Zürich Neuromotor Assessment (ZNA) and for mental health with the parent version of the Strengths and Difficulties Questionnaire (SDQ).

Results

Children with hearing impairment had lower motor performance scores in all four ZNA subscales compared with ZNA norms (z‐scores −1.42 to −2.67). After controlling for Nonverbal IQ, ZNA pure motor performance correlated negatively with the SDQ total difficulties score. Pure motor, pegboard, and dynamic balance subscales correlated negatively with peer‐relationship problems. Dynamic balance correlated negatively with emotional problems. Performance in pure motor and dynamic balance skills correlated negatively with age. Except for static balance, no correlation was found between motor performance and the degree of hearing impairment.

Interpretation

Results confirm that a high percentage of children with hearing impairment have poor motor performance. These problems are associated with difficulties in social relationships. Early recognition of these problems may lead to interventions to assist children with hearing impairment with their peer relationships.
Vitamin D status and health‐related quality of life in patients with Type 2 diabetes
Authors: Krul‐Poel Y. H. M. , Westra S. , van Wijland H. J. J. , Stam F. , Lips P. , Pouwer F. , Simsek S.
Published: June 2015

Aims

To test whether vitamin D status was associated with health‐related quality of life in people with Type 2 diabetes mellitus.

Methods

Demographic and clinical characteristics, including health‐related quality of life scores, were obtained from 241 adult patients with Type 2 diabetes managed with oral hypoglycaemic agents. Health‐related quality of life was assessed using the Short‐Form 36 Health Survey. Multiple logistic regression analysis was used to investigate the association between vitamin D status and health‐related quality of life, with adjustment for confounders.

Results

The mean age of the patients included in the study was 67 ± 8 years. Their mean HbA1c concentration was 52 ± 8 mmol/mol (6.9 ± 0.7%) and their mean serum 25‐hydroxyvitamin D concentration was 59 ± 23 nmol/l. Vitamin D deficiency (serum 25‐hydroxyvitamin D < 50 nmol/l) was present in 38% of patients. No significant associations were found between vitamin D status and health‐related quality of life.

Conclusions

Vitamin D status was not associated with health‐related quality of life in patients with Type 2 diabetes. This could be explained by the relatively high serum 25‐hydroxyvitamin D concentration, good glycaemic control and relatively good health‐related quality of life of all patients. A prospective study among patients with vitamin D deficiency and poor glycaemic control would be interesting for future research.