bluuebunny/crossref_metadata_2025 huggingface dataset:
Method for controlling vibration by exploiting piecewise-linear nonlinearity in energy harvesters
Authors: Tien Meng-Hsuan , D’Souza Kiran
Published: January 2020

Vibration energy is becoming a significant alternative solution for energy generation. Recently, a great deal of research has been conducted on how to harvest energy from vibration sources ranging from ocean waves to human motion to microsystems. In this paper, a theoretical model of a piecewise-linear (PWL) nonlinear vibration harvester that has potential applications in variety of fields is proposed and numerically investigated. This new technique enables automatic frequency tunability in the energy harvester by controlling the gap size in the PWL oscillator so that it is able to adapt to changes in excitations. To optimize the performance of the proposed system, a control method combining the response prediction, signal measurement and gap adjustment mechanism is proposed in this paper. This new energy harvester not only overcomes the limitation of traditional linear energy harvesters that can only provide the maximum power generation efficiency over a narrow frequency range but also improves the performance of current nonlinear energy harvesters that are not as efficient as linear energy harvesters at resonance. The proposed system is demonstrated in several case studies to illustrate its effectiveness for a number of different excitations.
Small deformation theory for two leaky dielectric drops in a uniform electric field
Authors: Zabarankin Michael
Published: January 2020

A small deformation theory for two non-identical spherical drops freely suspended in an ambient fluid and subjected to a uniform electric field is presented. The three phases are assumed to be leaky dielectric (slightly conducting) viscous incompressible fluids and the nonlinear effects of inertia and surface charge convection are neglected. The deformed shapes of the drops are linearized with respect to the electric capillary number that characterizes the balance between the electric stress and the surface tension. When the two drops are sufficiently far apart, their deformed shapes are predicted by Taylor’s small deformation theory—depending on Taylor’s discriminating function, the drops may become prolate, oblate or remain spherical. When the two drops get closer to each other, in addition to becoming prolate/oblate, they start translating and developing an egg shape. (Since there is no net charge, the centre of mass of the two drops remains stationary.) The extent of each of these ‘modes’ of deformation depends on the distance between the drops’ centres and on drop-to-ambient fluid ratios of electric conductivities, dielectric constants and viscosities. The predictions of the small deformation theory for two drops perfectly agree with the existing results of two-drop dynamics simulation based on a boundary-integral equation approach. Moreover, while previous works observed only three types of behaviour for two identical drops—the drops may either become prolate or oblate and move towards each other or become prolate and move away from each other—the small deformation theory predicts that non-identical drops may, in fact, become oblate and move away from each other when the drop-to-ambient fluid conductivity ratios are reciprocal and the drop-to-ambient fluid viscosity ratios are sufficiently large. The presented theory also readily yields an analytical insight into the interplay among different modes of drop deformation and can be used to guide the selection of the phases’ electromechanical properties for two-drop dynamics simulations.
The magnetorotational instability prefers three dimensions
Authors: Oishi Jeffrey S. , Vasil Geoffrey M. , Baxter Morgan , Swan Andrew , Burns Keaton J. , Lecoanet Daniel , Brown Benjamin P.
Published: January 2020

The magnetorotational instability (MRI) occurs when a weak magnetic field destabilizes a rotating, electrically conducting fluid with inwardly increasing angular velocity. The MRI is essential to astrophysical disc theory where the shear is typically Keplerian. Internal shear layers in stars may also be MRI-unstable, and they take a wide range of profiles, including near-critical. We show that the fastest growing modes of an ideal magnetofluid are three-dimensional provided the shear rate,
S
, is near the two-dimensional onset value,
S

c

. For a Keplerian shear, three-dimensional modes are unstable above
S
 ≈ 0.10
S

c

, and dominate the two-dimensional modes until
S
 ≈ 2.05
S

c

. These three-dimensional modes dominate for shear profiles relevant to stars and at magnetic Prandtl numbers relevant to liquid-metal laboratory experiments. Significant numbers of rapidly growing three-dimensional modes remainy well past 2.05
S

c

. These finding are significant in three ways. First, weakly nonlinear theory suggests that the MRI saturates by pushing the shear rate to its critical value. This can happen for systems, such as stars and laboratory experiments, that can rearrange their angular velocity profiles. Second, the non-normal character and large transient growth of MRI modes should be important whenever three-dimensionality exists. Finally, three-dimensional growth suggests direct dynamo action driven from the linear instability.
Steering eco-evolutionary game dynamics with manifold control
Authors: Wang Xin , Zheng Zhiming , Fu Feng
Published: January 2020

Feedback loops between population dynamics of individuals and their ecological environment are ubiquitously found in nature and have shown profound effects on the resulting eco-evolutionary dynamics. By incorporating linear environmental feedback law into the replicator dynamics of two-player games, recent theoretical studies have shed light on understanding the oscillating dynamics of the social dilemma. However, the detailed effects of more general
nonlinear
feedback loops in multi-player games, which are more common especially in microbial systems, remain unclear. Here, we focus on ecological public goods games with environmental feedbacks driven by a nonlinear selection gradient. Unlike previous models, multiple segments of stable and unstable equilibrium
manifolds
can emerge from the population dynamical systems. We find that a larger relative asymmetrical feedback speed for group interactions centred on cooperators not only accelerates the convergence of stable manifolds but also increases the attraction basin of these stable manifolds. Furthermore, our work offers an innovative manifold control approach: by designing appropriate switching control laws, we are able to steer the eco-evolutionary dynamics to any desired population state. Our mathematical framework is an important generalization and complement to coevolutionary game dynamics, and also fills the theoretical gap in guiding the widespread problem of population state control in microbial experiments.
Optimal kinematic dynamos in a sphere
Authors: Luo Jiawen , Chen Long , Li Kuan , Jackson Andrew
Published: January 2020

A variational optimization approach is used to optimize kinematic dynamos in a unit sphere and locate the enstrophy-based critical magnetic Reynolds number for dynamo action. The magnetic boundary condition is chosen to be either pseudo-vacuum or perfectly conducting. Spectra of the optimal flows corresponding to these two magnetic boundary conditions are identical since theory shows that they are relatable by reversing the flow field (Favier & Proctor 2013
Phys. Rev. E
88
, 031001 (
doi:10.1103/physreve.88.031001
)). A no-slip boundary for the flow field gives a critical magnetic Reynolds number of 62.06, while a free-slip boundary reduces this number to 57.07. Optimal solutions are found to possess certain rotation symmetries (or anti-symmetries) and optimal flows share certain common features. The flows localize in a small region near the sphere’s centre and spiral upwards with very large velocity and vorticity, so that they are locally nearly Beltrami. We also derive a new lower bound on the magnetic Reynolds number for dynamo action, which, for the case of enstrophy normalization, is five times larger than the previous best bound.
Opinions 97, 98 and 99
Authors: Arahal David R.
Published: January 2020

The International Committee on Systematics of Prokaryotes has formally endorsed the conclusions of the Judicial Commission on three pending Requests for an Opinion, thereby allowing the corresponding Opinions to be issued. According to Opinion 97, the request for the conservation of the name

Streptomyces scabies

is denied, allowing the continued use of the correction

Streptomyces scabiei

. Opinions 98 and 99 conclude that in the absence of associated authentic type material, the names

Bacillus aeolius

and

Pectinatus portalensis

, respectively, are not validly published.
TCF-1 regulates the stem-like memory potential of HIV-specific CD8+ T cells in elite controllers
Authors: Rutishauser Rachel L. , Deguit Christian Deo T. , Hiatt Joseph , Blaeschke Franziska , Roth Theodore L. , Wang Lynn , Raymond Kyle , Starke Carly E. , Mudd Joseph C. , Chen Wenxuan , Smullin Carolyn , Matus-Nicodemos Rodrigo , Hoh Rebecca , Krone Melissa , Hecht Frederick M. , Pilcher Christopher D. , Martin Jeffrey N. , Koup Richard A. , Douek Daniel C. , Brenchley Jason M. , Sékaly Rafick-Pierre , Pillai Satish K. , Marson Alexander , Deeks Steven G. , McCune Joseph M. , Hunt Peter W.
Published: January 2020

Although many HIV cure strategies seek to expand HIV-specific CD8+ T cells to control the virus, all are likely to fail if cellular exhaustion is not prevented. A loss in stem-like memory properties (i.e., the ability to proliferate and generate secondary effector cells) is a key feature of exhaustion; little is known, however, about how these properties are regulated in human virus-specific CD8+ T cells. We found that virus-specific CD8+ T cells from humans and non-human primates naturally controlling HIV/SIV infection express more of the transcription factor, TCF-1, than non-controllers. HIV-specific CD8+ T cell TCF-1 expression correlated with memory marker expression and proliferative capacity and declined with antigenic stimulation. CRISPR-Cas9 editing of TCF-1 in human primary T cells demonstrated a direct role in regulating expansion capacity. Collectively, these data suggest that TCF-1 controls the stem-like memory properties of HIV-specific CD8+ T cells and provides a rationale for enhancing this pathway in T cell-based therapeutic strategies for HIV.

One Sentence Summary

TCF-1 is highly expressed in HIV-specific CD8+ T cells from elite controllers and directly regulates human CD8+ T cell expansion capacity in response to T cell receptor stimulation.
Undergraduate accounting students’ perception of a course in accounting research and theory
Authors: Baker Ron , Wick Sara
Published: January 2020

Purpose

This study aims to measure the response of undergraduate accounting students to a stand-alone course in accounting theory and research. The aim of the study was to gauge students’ perceptions of the usefulness of this course and to determine if exposure to this material would increase student interest in accounting research and in pursuing a career in academia.

Design/methodology/approach

Three cohorts of students enrolled in the course completed an in-class survey. The study was conducted from 2015 to 2017.

Findings

The results of the survey show that student interest in accounting research and theory increased substantially as a result of the course. Students felt that learning about accounting research and the theories used in accounting research enhanced their overall understanding of accounting and would be useful to them as accounting practitioners. This study also reports that students interested in pursuing a PhD and/or an academic career also increased.

Research limitations/implications

Data were only collected at a single university and represent student perceptions only.

Practical implications

The results of this study and the description of the course design will inform academics seeking to answer the American Accounting Association Pathways Commission’s call to integrate accounting research and education. This study also suggests a pathway towards addressing the chronic academic accounting faculty shortage. Finally, the results will be of interest to those designing undergraduate accounting curriculum.

Originality/value

This study contributes to the literature on the “teaching-research nexus” in accounting by providing evidence, from the perspective of undergraduate accounting students, of the usefulness of integrating research into undergraduate accounting education. While many accounting researchers view accounting research and teaching accounting as separate activities, the response from students suggests that there is value in fostering a more complementary relationship between these two activities.
Weave coding into K-5 curricula as new literacies
Authors: Jin Yi , Zha Shenghua
Published: January 2020

Purpose

The purpose of this paper is to posit that coding should be considered as a critical part of new literacies. Teacher educators should first adopt the new literacies perspective, and then prepare pre-service teachers to teach both traditional literacy and new literacies skills, especially preparing them how to weave coding into K-5 literacy curricula to cultivate younger learners’ new ways of expressions and computational thinking skills. To facilitate this educational transformation, low-cost Web 2.0 tools and apps were introduced as one practical approach, along with some literacy lesson ideas to help teacher educators and pre-service teachers begin to integrate coding into the K-5 literacy curricula.

Design/methodology/approach

This paper is a viewpoint paper.

Findings

A table of low-cost Web 2.0 tools was presented with sample lesson ideas.

Originality/value

More than ever, coding breaks the traditional definition of literacy as paper-based reading and writing. It empowers students to read, write and create with multimodality on multiple platforms. Weaving coding into the literacy curricula offers the window to promote both computational thinking and new literacies skills. Teacher educators, among all other stakeholders, should begin the efforts to prepare pre-service teachers to weave coding into the literacy curricula and other content areas in the teacher educations programs now.
Lean Startup, Agile Methodologies and Customer Development for business model innovation
Authors: Silva Diego Souza , Ghezzi Antonio , Aguiar Rafael Barbosa de , Cortimiglia Marcelo Nogueira , ten Caten Carla Schwengber
Published: January 2020

Purpose

Startups have attracted increased attention over the past years. While entrepreneurs develop startups to capture new business opportunities, also large companies are turning to these fast-growing organizations in efforts to become more agile. However, managing business model innovation and validation is challenging. A number of methodologies, like the Lean Startup (LS), emerged to reduce uncertainties concerning innovation-based projects, and to contribute to business model validation. Despite its popularity, the literature on the LS and its key underpinnings (Agile Methodologies and Customer Development) is sparse, lacking an integrated and structured analysis of their impacts and potentialities. The paper aims to discuss this issue.

Design/methodology/approach

The authors conducted a comprehensive systematic literature review on the topic fully analyzing a final set of 71 papers.

Findings

There is a turning point in the research stream’s maturity with publications in conferences and major journals, with the predominance of empirical investigations in the European region. Articles on the topic are on the rise in several technology fields. However, the literature on the subject falls short on providing guidance to assist practitioners and scholars on the adoption and investigation of these methodologies.

Practical implications

The paper provides guidance for practice by presenting a staircase roadmap for the LS implementation drawing from the final set of papers reviewed.

Originality/value

The study categorizes the current literature through a concept map, and offers a structured research agenda beyond the categories from the thematic analysis.
The effects of accounting conservatism on executive compensation
Authors: Li Hui , Henry Darren , Wu Xiaohui
Published: January 2020

Purpose

The purpose of this paper is to identify means of better associating executive remuneration with managerial decision making and firm performance.

Design/methodology/approach

The authors evaluate the influence of conditional accounting conservatism on CEO compensation. The authors focus particularly on theex antepay-for-performance sensitivity (PPS) of CEO stock option grants. The empirical method used is panel data regression.

Findings

The authors find that accounting conservatism is positively related to the PPS of CEO option-based compensation. The effects of accounting conservatism on the PPS of options are more significant for firms with relatively weaker corporate governance and for the period before the introduction of FAS 123R. The findings suggest that directors reward CEOs for adopting accounting conservatism, both in general terms and incrementally, and that rewards are channelled through incentive-linked compensation. The results are also consistent with the view that accounting conservatism compliments other mechanisms, such as corporate governance, in reducing information asymmetry and agency problems between managers and shareholders and other stakeholders.

Originality/value

This paper provides a number of important contributions to the literature. It is the first to identify a relationship between accounting conservatism and option-based CEO compensation, which has important potential contracting and enforcement implications due to the incomplete nature of option contracts and the reward and risk attributes of CEOs. This paper is also the first to analyse the association between conditional accounting conservatism and CEO compensation at the firm–year level, by employing the firm–year conservatism score approach proposed by Khan and Watts (2009). This provides for greater insight regarding the interaction between accounting conservatism and other firm-specific elements than is otherwise obtainable from an overall firm or year interpretations derived from the traditional Basu (1997) asymmetric timeliness model approach. Furthermore, this paper also provides a comparison of the relative association of accounting conservatism on both explicit and implicit forms of CEO compensation for the same firm sample. This allows for the assessment of whether accounting conservatism relates differently to incentive-based CEO remuneration relative toex postCEO compensation outcomes.
Performance potential of gas foil journal bearings enhanced with micro taper-grooves on top foil
Authors: Feng Ming , Hu Hongyang , Ren Tianming
Published: January 2020

Purpose

To improve the load capacity and stability of gas foil journal bearings (GFJB), this paper aims to propose a novel GFJB with taper-grooved top foil.

Design/methodology/approach

A modified bump stiffness model is established considering rounding and friction. By considering the variation of clearance in the circumferential and axial direction, the static and dynamic characteristics of the novel bearing are calculated using the finite difference method, and perturbation method, respectively. The bearing performance under different groove parameters is studied and compared to the traditional bearings.

Findings

The results show that this novel GFJB can bring multi-extra local dynamic pressure and decrease the gas end leakage, which improves the static and dynamic properties. Moreover, as the increment of groove depth, the load capacity and direct stiffness are reinforced. There is an optimal groove width to maximize the load capacity, and the taper-groove is more beneficial to the improvement of bearing performance than other groove shapes. For the novel GFJB (Ng = 6, Hg = 10µm), the load capacity and direct stiffness increase by about 6.67 and 13.5 per cent, respectively. The stability threshold speed (STS) of a rotor supported by the novel bearings is also increased.

Originality/value

The performance of the presented novel GFJB is enhanced immensely compared to the traditional bearings, and the results are expected to be helpful to bearing designers, researchers and academicians concerned.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0307.
Algorithm applied: attracting MSEs to business associations
Authors: Moraes Jaqueline de , Schaefer Jones Luís , Schreiber Jacques Nelson Corleta , Thomas Johanna Dreher , Nara Elpidio Oscar Benitez
Published: January 2020

Purpose

This paper aims to propose a structured model based on a data mining algorithm that can calculate, based on business association (BA) attributes, the probability of micro and small enterprises (MSEs) becoming a new member of a BA. Another goal is the probability of a BA attracting new members.

Design/methodology/approach

As a methodological procedure, the authors used the Naive Bayes data mining algorithm. The collected data were analyzed both quantitatively and qualitatively and then used to define the model, which was tested randomly, while allowing for the possibility of future validation.

Findings

The findings suggest a structured model based on a data mining algorithm. The model can certainly be used as a management tool for BAs concentrating their efforts on those businesses that are certainly potential new recruits. Further, for an MSE, it serves as a means of evaluating a BA, indicating the possible advantages in becoming a member of a particular association.

Research limitations/implications

This paper is not intended to be generalized, considering that it only analyzes the BAs of Rio Grande do Sul, Brazil. In this way, when applying this model to other situations, the attributes listed here can be revised and even modified to adapt to the situation in focus.

Practical implications

The use of the proposed model will make it possible to optimize the time of BA managers. It also gives MSE greater reliability in choosing BA.

Social implications

Using this model will provide better decision-making and better targeting, thus benefiting both the BAs and the MSEs, which can improve their management and keep jobs.

Originality/value

This paper contributes to the literature because it is the first to connect BAs, MSEs and Naive Bayes. Also, this study helps in better management for BA managers in their daily activities and provides a better choice of BA for MSE managers. Also, this study contextualizes BAs, MSEs and data mining in an objective way.
Mathematical modelling of a shariah-compliant capital asset pricing model
Authors: Hazny Mohamad Hafiz , Mohamad Hasim Haslifah , Yusof Aida Yuzy
Published: January 2020

Purpose

The capital asset pricing model (CAPM) is the most widely used asset pricing model that measures risk–return relationship. The CAPM is based on Markowitz’s mean variance analysis. The advancement of Islamic finance leads to the question whether or not the practice of modern investment theories and analyses such as the Markowitz’s mean variance analysis and CAPM are in accordance to shariah and could be used in pricing Islamic financial assets. Therefore, this paper aims to present a review of the CAPM and to discourse the set of assumptions underlying the model in terms of shariah compliance.

Design/methodology/approach

Although most of the assumptions are not contradictory to shariah principles, there are Islamic variables such as prohibition of short selling, purification and zakat that should be taken into consideration when pricing Islamic financial assets. We then develop a mathematical model which is a modification of the traditional CAPM that incorporates principles of Islamic finance and integrating zakat, purification of return and exclusion of short sales.

Findings

As a proof-of-concept, this paper presents the results of an empirical study on the proposed shariah-compliant CAPM in comparison to the traditional CAPM. The results show that the proposed Islamic CAPM is appropriate and applicable in examining the relationship between risk and return in the Islamic stock market.

Originality/value

This study contributes to existing body of knowledge by presenting an algorithm and mathematical derivation of the shariah-compliant CAPM which has been lacking in the literature of Islamic finance. The paper offers a novel approach in pricing Islamic financial assets in accordance to shariah, advocated by modern investment theories of Markowitz’s mean variance analysis and CAPM.
MurabahaandMusharakah Moutanaquissahpricing: an interest-free approach
Authors: Ahroum Rida , Touri Othmane , Achchab Boujemâa
Published: January 2020

Purpose

This study aims to provide an interest-free valuation methodology forMurabahaandMusharakah Moutanaquissahcontracts. Indeed, In Islamic finance, Murabaha contracts are widely negotiated. Their yield depends mainly on the contracted profit margin. In the current practices, this latter is based on a reference interest rate, which is highly criticized in Islamic literature, just likeMusharakah Moutanaquissahcontracts. In this perspective, authors suggest a new valuation methodology with parameters related to the real economy.

Design/methodology/approach

The authors apply an indirect method to determine a lower bound of the profit margin of aMurabahacontract. ConsideringMusharakah Moutanaquissahas an equivalent contract, the new valuation methodology is based on participation and focuses on parameters from the real economy: the market rent and the rate of return used for an equivalent project.

Findings

The results show that the pricing ofMusharakah Moutanaquissahcontracts could be based on several parameters linked to the real economy. Consequently, an implied value of the profit margin could be computed. Also, the interest rate is no longer implicated in the pricing of neitherMurabahanorMusharakah Moutanaquissahcontracts.

Research limitations/implications

The valuation methodology is applicable only if the underlying asset’s financing can be made withMurabahaandMusharakah Moutanaquissahcontracts.

Practical implications

This work will restore the link between Islamic contracts and the real economy. For Islamic banks in particular, the suggested model would reduce the exposure to reputational risk and enhance the compliance to theSharia(Islamic Law).

Originality/value

Several studies have analyzed the dependence between Islamic contracts and interest rates. In general, these studies confirm this dependence and few of them have suggested alternatives. Thus, the authors contribute to the literature by providing a practical and applicable model to detach the valuation ofMurabahaandMusharakah Moutanaquissahfrom the interest rate.
International capital movement towards the Spanish real estate sector
Authors: Zhenyu Su , Taltavull Paloma
Published: January 2020

Purpose

The purpose of this paper is to examine the determinants that affect international capital flows (ICF) toward the Spanish real estate market over the period 1995 first quarter to 2017 fourth quarter.

Design/methodology/approach

VECM methodology is used to analyze time series and panel methods using pooled EGLS regression.

Findings

VECM parameter results for construction and real estate activities sectors, quickly suggesting a stable performance of capital flows toward Spanish real estate sector that the short-term fluctuation of foreign investment results contributes to the long-term equilibrium relatively soon. By applying the Monetary theory of Johnson, the model identifies a relevant role of M3 explaining capital flows to real estate, together with the lagged variables of construction and real estate activities capital flows, Spanish real interest rate and Spain’s economic growth rate; they are the significant determinants on capital movement to Spanish real estate sector. Interestingly, Spanish housing prices as an exogenous variable, directly, significantly and negatively affect real estate capital flows in all cases as a way to capture the assets price bubble.

Practical implications

Findings highlight reasons affecting capital flows to real estate and construction activities to Spanish sectors which allow capital Funds to take into account those drivers in their investment decisions.

Originality/value

This paper is the first attempt to analyze the determinants of ICF to Spanish real estate market; it has a significant meaning for both Spanish economy and international investors.
Work engagement as a mediator between subjective well-being and work-and-health outcomes
Authors: Garg Neha , Singh Pankaj
Published: January 2020

Purpose

The purpose of this paper is to examine the role of work engagement as a mediator in the relationship of subjective well-being with work performance, work withdrawal behavior, physical and mental health.

Design/methodology/approach

A survey design was used to collect the data from 369 Indian software developers. Latent variable structural equation modeling was used to test the hypothesized relationships.

Findings

Subjective well-being was found to have a significant positive association with work engagement and this, in turn, had significantly enhanced employee’s work performance and reduced work withdrawal behavior, mental and physical ill-health. In addition, work engagement was found to fully mediate the association of subjective well-being with work performance and mental ill-health, while it partially mediated the association of subjective well-being with work withdrawal behaviors and physical ill-health.

Practical implications

This paper contributes to the development of self-sustaining approach toward increasing work engagement and provides a way to deal with work-and-health outcomes.

Originality/value

This study is one of the early attempts to examine direct and indirect associations of subjective well-being with work-and-health outcomes in an Indian setting.
Fruit resource provisioning for avian frugivores: The overlooked side of effectiveness in seed dispersal mutualisms
Authors: Quintero Elena , Pizo Marco A. , Jordano Pedro
Published: January 2020

Mutualistic interactions between frugivorous birds and fleshy‐fruited plants are key processes for both natural plant regeneration and the maintenance of birds relying on fruit resources. However, seed dispersal effectiveness (SDE) has been frequently studied only from the plant's perspective, that is the contribution of animals to plant fitness.

Using a sample of Atlantic rainforest avian frugivores, this study presents a first comparative, empirical study of fruit effectiveness as a nutritional food resource for seed‐dispersing birds through the use of resource‐provisioning effectiveness (RPE) models. RPE is the product of the amount of fruits a frugivore can consume (quantity component) and the quality of the ingesta in terms of energy and nutrients obtained (quality component).

Our results show wide variation in RPE among fleshy‐fruited plant species. Energy‐rich fruits consistently show a smaller quantity component, while energetically poor fruits are consistently the most consumed, with fruit species spanning a gradient from these two extremes.

The specific RPEi resulting from a pairwise fruit–frugivore interaction is positively correlated with the total RPE (RPET) that a given fruit species has for the whole frugivore assemblage. RPE therefore appears to be a characteristic feature of the fruit species, rather than of the specific frugivore partner.

Only the fruit's specific energy content showed a significant phylogenetic signal, suggesting potential constraints for free covariation between RPE and SDE of fruits and frugivores.

Synthesis. We analyse variation in the effectiveness of fleshy‐fruit food provisioning to avian frugivores by explicitly redefining RPE within the SDE framework. We found ample variation in RPE among plant species, showing differences in both quantity and quality components of fruit resources rewards for the frugivores. Our findings help unravel how seed‐dispersing birds may discriminate among alternative fruit resources and to understand the configuration of mutual dependencies among mutualistic partners.
Back to the Future: The Pulling Apart of our Towns and Cities
Authors: Nandy Lisa
Published: January 2020

Growing divisions between Britain’s towns and cities have created a dilemma for the Labour Party in seeking to represent very different parts of the country. There are some who argue that Labour must choose the global networked youth—who largely reside in cities—in order to maximise its electoral chances. This is an argument that defies electoral gravity and fails to address the root causes of the gulf between towns and cities. As jobs and investment have gone into cities, many towns have seen the local population age and local economies become unsustainable. In both towns and cities there is a clamour for power to move closer to home and for the renewal of democratic institutions, offering Labour the chance to win power and end the divisions that have come to characterise British politics.
A Public Ethics of Care for Policy Implementation
Authors: Engster Daniel
Published: January 2020

Liberal and republican political theorists have not paid much attention to a theory of public administration or policy implementation. To the extent that they have, they have tended to endorse an ideal‐typical Weberian model of bureaucracy and impersonal ethics of rules to limit street‐level discretion. This article argues that the Weberian bureaucratic ethics is inconsistent with core liberal and republican values and, in fact, dominating at the street level. In order for laws and policies to be implemented in a manner consistent with liberal and republican principles, an alternative public ethics is proposed—a public ethics of care. Building on earlier research, this article argues that a public ethics of care represents an important supplement to liberal and republican ideals, as well as a better alternative to Weberian bureaucratic ethics, for implementing laws and policies at the street level in limited and responsive, nondominating ways.
Association of sex with the global burden of glaucoma: an analysis from the global burden of disease study 2017
Authors: Ye Xin , She Xiangjun , Shen Lijun
Published: January 2020

Purpose

To investigate the association of sex with the global burden of glaucoma by year, age and socio‐economic status using disability‐adjusted life years (DALYs).

Method

The global, regional and national sex‐specific DALY numbers, crude DALY rates and age‐standardized DALY rates caused by glaucoma, by year and age, were obtained from the Global Burden of Disease Study 2017. Human development index (HDI) in 2017 as a national socio‐economic indicator was obtained from the Human Development Report. t‐Test and linear regression were performed to explore the association between sex difference in age‐standardized DALY rates and HDI.

Results

Globally, changes in glaucoma DALY number and crude rates were similar of both sexes between 1990 and 2017. After controlling for population size and age structure, age‐standardized DALY rates decreased consistently from 10.7 in 1990 to 9.4 in 2017 among men and from 8.8 in 1990 to 8.0 in 2017 among women. In 2017, the global average age‐standardized DALY rates were 11.6 ± 8.6 (mean ± standard deviation) in women and 14.9 ± 12.1 in men. The sex difference in age‐standardized DALY of 195 countries was significant (t = 3.109; p < .01) in 2017. Men had higher rates than women of the same age, and sexual differences increased with age. t‐Test revealed that age‐standardized DALY rates among men were higher than those among women for low‐HDI countries (t = 3.102; p < .01) and high‐HDI countries (t = 2.110; p < .05). The difference (male minus female) in age‐standardized DALY rates (standardized β = −0.434, p < .001) and the female‐to‐male age‐standardized DALY rate ratios (standardized β = −0.315, p < .001) were inversely correlated with HDI.

Conclusion

Although global glaucoma health care is progressing, sexual differences in glaucoma burden showed little improvement in the past few decades. Worldwide, men have higher glaucoma burden than women. Older age and lower socio‐economic status are associated with greater sex differences in glaucoma burden. Our findings may enhance public awareness of sexual differences in global glaucoma burden and emphasize the importance of making sex‐sensitive health policy to manage global vision loss caused by glaucoma.
Vision‐related quality of life and visual function in a 70‐year‐old Swedish population
Authors: Havstam Johansson Lena , Škiljić Dragana , Falk Erhag Hanna , Ahlner Felicia , Pernheim Christina , Rydberg Sterner Therese , Wetterberg Hanna , Skoog Ingmar , Zetterberg Madeleine
Published: January 2020

Purpose

To investigate vision‐related quality of life (VRQoL), visual function and predictors of poor vision in a population of 70‐year‐olds.

Methods

Self‐reported ocular morbidity and responses to the National Eye Institute Visual Functioning Questionnaire‐25 (NEI VFQ‐25) in a cross‐sectional population study (N = 1203) in Gothenburg, Sweden, were compared with results from ophthalmic examination (N = 560).

Results

The most common self‐reported ophthalmic morbidities were cataract (23.4%), age‐related macular degeneration (AMD; 4.7%), glaucoma (4.3%) and diabetic retinopathy (1.4%). Cataract was more prevalent in women (p = 0.001). The composite score from NEI VFQ‐25 for the entire cohort was 91.4 (standard deviation: 27.5). When comparing composite score for different eye diseases, persons with cataract or AMD exhibited lower scores (p = 0.029 and 0.018, respectively). Best‐corrected visual acuity (BCVA) was normal (≥0.5 decimal) in 98.9%; two individuals had low vision (<0.3). Men exhibited better BCVA (median: −0.08 logMAR) than women (−0.06; p = 0.005). Visual field defects were observed in 16.3% and uncorrected refractive errors in 61.5%. Poor vision was reported by 7.4% of participants with presenting visual acuity (PVA) ≥0.5 (decimal), while 66.7% with PVA <0.5 reported good vision. Of 27 individuals with PVA <0.5, 55.6% obtained a BCVA of ≥1.0 with the right correction. Low contrast sensitivity was a significant predictor of experiencing poor vision (p = 0.008), while PVA and visual field defects were not.

Conclusions

Low contrast sensitivity is a predictor of experiencing poor vision. There is a discrepancy between subjective/objective visual function and a high prevalence of uncorrected refractive errors. Women have more cataract, and men demonstrate slightly better visual acuity.
Bariatric surgery might aggravate proliferative diabetic retinopathy
Authors: Sever Ozkan , Horozoglu Fatih
Published: January 2020

Purpose

This study aimed to assess the changes experienced by patients with proliferative diabetic retinopathy (PDR) after bariatric surgery (BS).

Methods

This retrospective observational study includes 37 eyes of 21 patients with PDR who underwent BS at a tertiary university hospital over the period of 2014–2018. The control group (CG) comprised 37 eyes of 27 patients with PDR who attended the same research hospital for diabetes care without undergoing BS. Preoperative and postoperative glycated haemoglobin (HbA1c) levels, weight and diabetic retinopathy screening results were collected from the medical records of the patients. Patients who had undergone preoperative retinal screening and at least one postoperative retinal screening were included in the analysis.

Results

Both groups exhibited statistically significant visual acuity (VA) loss at 6 months and 1 year (p < 0.001). At postoperative 6 months the VA loss experienced by the control BS group was significantly more severe than that experienced by the CG (p = 0.03). The first‐year HbA1c levels of the BS group were significantly lower than those of the CG (p = 0.02). The BS group had significantly higher intraocular haemorrhage (p = 0.04), neovascular glaucoma (p = 0.04) and retinal vein occlusion (p = 0.04) rates than the CG group. All complications occurred at different patients.

Conclusion

Patients with PDR who received BS showed more severe retinopathy than patients who were matched for age, sex, HbA1c levels and follow‐up duration and who did not receive BS.
Early antituberculosis drug exposure in hospitalized patients with human immunodeficiency virus‐associated tuberculosis
Authors: Schutz Charlotte , Chirehwa Maxwell , Barr David , Ward Amy , Janssen Saskia , Burton Rosie , Wilkinson Robert J. , Shey Muki , Wiesner Lubbe , Denti Paolo , McIlleron Helen , Maartens Gary , Meintjes Graeme
Published: January 2020

Aims

Patients hospitalized at the time of human immunodeficiency virus‐associated tuberculosis (HIV‐TB) diagnosis have high early mortality. We hypothesized that compared to outpatients, there would be lower anti‐TB drug exposure in hospitalized HIV‐TB patients, and amongst hospitalized patients exposure would be lower in patients who die or have high lactate (a sepsis marker).

Methods

We performed pharmacokinetic sampling in hospitalized HIV‐TB patients and outpatients. Plasma rifampicin, isoniazid and pyrazinamide concentrations were measured in samples collected predose and at 1, 2.5, 4, 6 and 8 hours on the third day of standard anti‐TB therapy. Twelve‐week mortality was ascertained for inpatients. Noncompartmental pharmacokinetic analysis was performed.

Results

Pharmacokinetic data were collected in 59 hospitalized HIV‐TB patients and 48 outpatients. Inpatient 12‐week mortality was 11/59 (19%). Rifampicin, isoniazid and pyrazinamide exposure was similar between hospitalized and outpatients (maximum concentration [Cmax]: 7.4 vs 8.3 μg mL–1, P = .223; 3.6 vs 3.5 μg mL–1, P = .569; 50.1 vs 46.8 μg mL–1, P = .081; area under the concentration–time curve from 0 to 8 hours: 41.0 vs 43.8 mg h L–1, P = 0.290; 13.5 vs 12.4 mg h L–1, P = .630; 316.5 vs 292.2 mg h L–1, P = .164, respectively) and not lower in inpatients who died. Rifampicin and isoniazid Cmax were below recommended ranges in 61% and 39% of inpatients and 44% and 35% of outpatients. Rifampicin exposure was higher in patients with lactate >2.2 mmol L–1.

Conclusion

Mortality in hospitalized HIV‐TB patients was high. Early anti‐TB drug exposure was similar to outpatients and not lower in inpatients who died. Rifampicin and isoniazid Cmax were suboptimal in 61% and 39% of inpatients and rifampicin exposure was higher in patients with high lactate. Treatment strategies need to be optimized to improve survival.
Receptors for pro‐resolving mediators are increased in Alzheimer's disease brain
Authors: Emre Ceren , Hjorth Erik , Bharani Krishna , Carroll Steven , Granholm Ann‐Charlotte , Schultzberg Marianne
Published: January 2020

Neuroinflammation is a key element of AD pathology and conceivably a result of a disturbed resolution. Resolution of inflammation is an active process which is strictly orchestrated following the acute inflammatory response after removal of the inflammatory stimuli. Acute inflammation is actively terminated by specialized pro‐resolving mediators (SPMs) thereby promoting healing and return to homeostasis. Failed resolution may contribute to persistent neuroinflammation and aggravate AD pathology. BLT1 (leukotriene B4 receptor) and ChemR23 (chemerin receptor 23) are receptors for the SPM resolvin (Rv) E1 and are important clinical targets for ending inflammation. In AD, the levels of SPMs are decreased, and pro‐inflammatory mediators are increased. In the current study, the distribution of BLT1 and ChemR23 receptors in control brains and in AD as well as correlations with AD pathology was examined for the first time. BLT1 and ChemR23 were analyzed in different regions of post‐mortem human brain from cases with AD, early‐onset AD and mild cognitive impairment (MCI) and healthy controls, using western blotting and immunohistochemistry. BLT1 and ChemR23 were detected in neurons and glial cells in all examined regions of the human brain, with markedly higher levels in AD than in controls. The receptor levels correlated with the density of staining for the inflammation markers HLA‐DR and YKL‐40 for microglia and astrocytes, respectively, and elevated staining coincided with high Braak stages in AD. The relative staining densities of these receptors were higher in the basal forebrain, cingulate gyrus and hippocampal regions compared to the cerebellum and frontal cortex (BA46).

In conclusion, alterations in the expression of the resolution receptor BLT1 in AD have not been reported previously and the changes in both BLT1 and ChemR23 suggest a disturbed resolution pathway in several regions of the AD brain that may play a role in disease pathology.
Residential Segregation, Neighborhood Health Care Organizations, and Children's Health Care Utilization in the Phoenix Urbanized Area
Authors: Anderson Kathryn Freeman
Published: January 2020

Research has demonstrated health care consequences of racial/ethnic residential segregation. Here, I test one possible mechanism—the distribution of community health care organizations and service providers across urban communities. Using data from a 2013 survey on children's health care utilization in the Phoenix urbanized area combined with data on a 2013 census of health care organizations, I estimate a series of statistical models in order to test this relationship. I find that Latino and Native American segregation is related to a lower density of health care organizations. Furthermore, the lack of these resources increases the odds of a family using a clinic, versus a physician's office, which is a more ideal source of care. Finally, a higher rate of racial/ethnic clustering is also related to greater utilization of a clinic, as opposed to a physician's office, and this association is partially mitigated by distribution of health care organizations.
Spatial working memory, not IQ or executive function, discriminates early psychosis and clinically vulnerable creative individuals
Authors: Crabtree Julie , Hudson Jennifer L. , Brockman Robert , Newton‐John Toby
Published: January 2020

Aim

While associations between creativity and psychopathology have been well researched, the specific cognitive processes that distinguish highly creative from those with psychopathology warrant further investigation. This study will examine whether IQ, executive function, cognitive inhibition or spatial working memory differentiate individuals with early psychosis, clinically vulnerable creative individuals, creative controls and non‐creative controls.

Methods

The study sample consisted of 110 participants: early psychosis (n = 21); clinically vulnerable creative controls (n = 25); creative controls (n = 30) and non‐creative control (n = 34). The Diagnostic Interview for Psychosis assessed early psychosis participants and the Mini Neuropsychiatric Interview was used to screen for psychopathology in the remaining groups. Several cognitive tests were administered: IQ, neurocognitive measures of executive function and spatial working memory. Creativity was assessed using the Torrance Test of Creativity and Creative Achievement Questionnaire. A measure of vividness of mental imagery was also given.

Results

Across all cognitive tests, spatial working memory differentiated the early psychosis group from both creative and non‐creative control groups. Spatial working memory predicted group membership but vivid imagery was a better predictor of creative achievement. The early psychosis, clinically vulnerable creative and creative groups all recorded significantly higher results on creative achievement and creative cognition compared to non‐creative controls.

Conclusions

Our results provide further support for spatial working memory as an early neuro‐cognitive marker for early psychosis. Spatial working memory, rather than IQ or executive function, may also be an early protective factor for clinically vulnerable young creative individuals.