bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and optimization of a low voltage RF switch MEMS capacitance using genetic algorithm and Taguchi method
Authors: Ardehshiri Alireza , Karimi Gholamreza , Dehdasht-Heydari Ramin
Published: June 2019

Purpose

This paper aims to design, optimize and simulate the Radio Frequency (RF) micro electromechanical system (MEMS) Switch which is stimulated by electrostatically voltage.

Design/methodology/approach

The geometric structure of the switch was extracted based on the design of Taguchi-based experiment using the mathematical programming and obtaining objective function by the genetic meta-heuristic algorithm.

Findings

The RF parameters of the switch were calculated for the design of Taguchi-based S11 = −5.649 dB and S21 = −46.428 dB at the working frequency of 40 GHz. The pull-in voltage of the switch was 2.8 V and the axial residual stress of the proposed design was obtained 28 MPa and the design of Taguchi-based S11 = −4.422 dB and S21 = −48.705dB at the working frequency of 40 GHz. The pull-in voltage of the switch was 2.5 V and the axial residual stress of the proposed design was obtained 25 MPa.

Originality/value

A novel complex strategy in the design and optimization of capacitive RF switch MEMS modeling is proposed.
Numerical modeling of the simultaneous propagation of multiple hydraulic fractures with fluid lags
Authors: Zeng Qinglei , Liu Zhanli , Wang Tao , Gao Yue , Zhuang Zhuo
Published: June 2019

Purpose

The purpose of this paper is to develop a numerical method to model the simultaneous propagation of multiple hydraulic fractures (HFs) with fluid lags driven from a horizontal wellbore.

Design/methodology/approach

Fracture propagation in solid medium is modeled with the extended finite element method and fluid flow is modeled with finite volume method. Three iteration loops are introduced to solve the nonlinear system within each time increment, i.e. a Newtonian iteration to solve the solid-fluid coupling system, a Picard iteration to determine fluid front positions and a secant iteration to update fracture lengths.

Findings

The propagation of one single HF with a fluid lag is simulated and agrees well with semi-analytical solutions or other numerical results in the literature. The simultaneous propagation of two HFs are then investigated, which demonstrates the ability of the proposed method in capturing the hydraulic fracturing process with multiple fractures and fluid lags.

Originality/value

With the proposed method, one can simulate the simultaneous propagation of multiple HFs with fluid lags, which play a significant role during early-time propagation or when the confinement stress is relatively low (shallow HFs). Solid deformation and fracturing, fluid flow in fractures and in the wellbore are fully coupled, and three iteration loops are introduced to solve the nonlinear system.
Cooperation as a vehicle for innovation: a study of the effects of firm size and industry type
Authors: Cristo-Andrade Silveli , Franco Mário José
Published: June 2019

Purpose

Based on firms’ need to remain competitive and dynamic in a scenario of constant change, the purpose of this paper is to compare the actors involved in cooperation for innovation between Brazilian small- and medium-sized enterprises (SMEs) and large firms (LFs), and also in two industries/sectors, manufacturing and services.

Design/methodology/approach

To achieve this objective, the database chosen was PINTEC, with data available from 1998 to 2014. The statistical analyses performed were binary logistic regression, descriptive statistics of the variables, correlation matrix and the difference of means.

Findings

The empirical evidence show that the firm’s characteristics (SME or LF) favour the use of one type of cooperation for innovation or another, highlighting SMEs’ proximity to their clients and LFs’ structures, tending to belong to business groups and having links to training centres and technical assistance networks.

Research limitations/implications

The theoretical contribution of this study lies in the evidence that types of cooperation for innovation can vary according to firm size and the type of industry/sector, and the practical contribution lies in pointing out the importance of clients for SMEs, and for LFs the importance of business groups, technical assistance and professional training centres. The importance of suppliers in cooperation for innovation stands out in the service sector, and that of clients in the manufacturing sector.

Originality/value

This study shows that the types of cooperation to innovation can vary according to firm size and type of sector, in an emerging market and with low rates of innovation. It is emphasized that most research on the subject has been carried out in developed countries or emerging Asian ones. Therefore, this study is innovative because it shows particularities of the Brazilian market that can subsequently be observed in other emerging markets.
Identifying counterfeit brand logos: on the importance of the first and last letters of a logotype
Authors: Pathak Abhishek , Velasco Carlos , Calvert Gemma Anne
Published: June 2019

Purpose

Counterfeiting is a menace in the emerging markets and many successful brands are falling prey to it. Counterfeit brands not only deceive consumers but also fuel a demand for lower priced replicas, both of which can devalue the bona-fide brand. But can consumers accurately identify a counterfeit logo? This paper aims to explore this question and examines the accuracy and speed with which a consumer can identify a counterfeit (vs original) logo.

Design/methodology/approach

Seven popular brand logos were altered by transposing and substituting the first and last letters of the logotypes. Consumers then classified the logos as counterfeit (vs original) across two experiments.

Findings

Participants were faster and more accurate in identifying a counterfeit logo when the first letter (vs last letter) of a logotype was manipulated, thus revealing last letter manipulations of a brand’s logotype to be more deceptive.

Research limitations/implications

This paper comments only on the manipulation of logotypes but not of logo symbols. Similarly, findings may not be generalizable across languages which are read from right to left.

Practical implications

Counterfeit trade is already a multibillion dollar industry. Understanding the key perceptual differentiators between a counterfeit (vs original) logo can be insightful for both consumers and firms alike.

Originality/value

Research available on objective measures of similarities (vs dissimilarities) between counterfeit (vs original) brand logos is limited. This paper contributes by examining the ability of consumers to discriminate between counterfeit (vs original) logos at different levels of visual similarity.
Brownian models effect on turbulent fluid flow and heat transfer and entropy generation of water/boehmite alumina nanofluid inside enclosure
Authors: Mozafari Behrouz , Abbasian Arani Ali Akbar , Sheikhzadeh Ghanbar Ali , Salimi Mahmoud
Published: June 2019

Purpose

The purpose of this paper is to study the effects of using different Brownian models on natural and mixed convection fluid flow and heat transfer inside the square enclosure filled with the AlOOH–water nanofluid.

Design/methodology/approach

Due to fulfill of this demand, five different models for the effective thermal conductivity and viscosity of the nanofluid are considered. The following results are presented for the
Ra=107 to 1010 and
Ri=0.01 to 100, whereas the volume fraction of the nanoparticles is varied from
φ = 0.01 to 0.04.

Findings

According to the obtained results, increasing of Rayleigh number and reduction of Richardson number leads to the higher values of the average Nusselt number and entropy generation. Also, it is realized that, variation trend of the average Nusselt number and entropy generation in all cases is increasing by growing the volume fraction. It is found that the obtained average Nusselt numbers and entropy generations with Koo and Kleinstreuer are the highest among all the studied cases, and it is followed by Patel, Vajjha and Das, Corcione and Maxwell–Brinkman models, respectively.

Originality/value

Based on the results of present investigation, the Nusselt number difference predicted between the Maxwell–Brinkman model (as constant-property model) and Koo and Kleinstreuer model is about 7.84 per cent at 0.01 per cent volume fraction and 5.47 per cent at 0.04 per cent volume fraction for the Rayleigh number equal to 107. The entropy generation difference predicted between the two above studied model is about 8.05 per cent at 0.01 per cent volume fraction and 5.86 per cent at 0.04 per cent volume fraction for the Rayleigh number equal to 107. It is observed that using constant-property model has a significant difference in the obtained results with the results of other variable-property models.
An efficient space-time operator-splitting method for high-dimensional vector-valued Allen–Cahn equations
Authors: Sun Yunxia , Xiao Xufeng , Gao Zhiming , Feng Xinlong
Published: June 2019

Purpose

The purpose of this paper is to propose an efficient space-time operator-splitting method for the high-dimensional vector-valued Allen–Cahn (AC) equations. The key of the space-time operator-splitting is to devide the complex partial differential equations into simple heat equations and nolinear ordinary differential equations.

Design/methodology/approach

Each component of high-dimensional heat equations is split into a series of one-dimensional heat equations in different spatial directions. The nonlinear ordinary differential equations are solved by a stabilized semi-implicit scheme to preserve the upper bound of the solution. The algorithm greatly reduces the computational complexity and storage requirement.

Findings

The theoretical analyses of stability in terms of upper bound preservation and mass conservation are shown. The numerical results of phase separation, evolution of the total free energy and total mass conservation show the effectiveness and accuracy of the space-time operator-splitting method.

Practical implications

Extensive 2D/3D numerical tests demonstrated the efficacy and accuracy of the proposed method.

Originality/value

The space-time operator-splitting method reduces the complexity of the problem and reduces the storage space by turning the high-dimensional problem into a series of 1D problems. We give the theoretical analyses of upper bound preservation and mass conservation for the proposed method.
Gender and business owner satisfaction
Authors: Li Wenxuan , Marshall Maria I.
Published: June 2019

Purpose

The purpose of this paper is to investigate how the factors associated with role satisfaction in farm and non-farm family businesses differ by gender of the business owner.

Design/methodology/approach

The data used are from a 30-minute telephone survey of owners of farm and non-farm family businesses in Indiana, Illinois, Michigan and Ohio. The sample consists of 627 small- and medium-size family businesses. Three ordered probit regressions are used to analyze role satisfaction.

Findings

Women’s participation in management and the number of family members in management are positively associated with women’s role satisfaction, while tension from resource competition is negatively associated with role satisfaction. In contrast, men’s role satisfaction is increased through high family business functioning and profit.

Practical implications

There is no difference in the level of role satisfaction between men and women when one controls for the owner, family and business characteristics. However, there is a difference in the factors that drive role satisfaction between men and women. This may be driven, in part, by what their roles are vis-à-vis the financial aspects of the business. Male and female business owners seem to focus on different aspects of their family business to achieve role satisfaction.

Originality/value

This paper determines the impact of gender on the role satisfaction of business owners of farm and non-farm family businesses in four Midwestern states. It identifies the different factors associated with role satisfaction for female and male family business owners based on their actual roles.
Mobile business travel application usage
Authors: Douglas Anneli
Published: June 2019

Purpose

Research abounds highlighting the differences between males and females when they travel. Even in business travel, these differences have been acknowledged, with suppliers and marketers spending significant money to develop and market products to accommodate them. The purpose of this study is to ascertain whether differences exist in terms of mobile application usage between male and female business travellers.

Design/methodology/approach

A mixed method approach is followed. An internet-based survey is distributed and in-depth interviews conducted with South African business travellers. The Mann–Whitney U-test is used to test the differences between males and females and their mobile application usage. Content analysis is used to analyse the interviews.

Findings

The results show that mobile applications are perceived as more important by females than males in all the phases of the travel cycle, although most of these differences in perceived importance were not significant.

Research limitations/implications

Owing to the online data-collection method and the self-selective process, the findings cannot be generalised to the global population of business travellers who use mobile applications.

Practical implications

The results should caution corporate organisations, travel management companies and their application developers not to spend unnecessary technological and financial resources on developing applications to accommodate differences between males and females, which might not exist. Companies should rather spend money on developing applications that will enhance and add convenience to the business traveller’s experience.

Originality/value

The main contribution of this study lies in investigating the applications market, particularly in the context of business travel. Applications focussed on specific sectors of the tourism industry, such as business travel applications, serve business travellers differently from generic travel applications. This research examines business travel-specific applications and expands the scale and scope of the enquiry, concentrating on the travellers’ view.
Industry and leadership experiences of the heads of departments and their impact on the performance of public universities
Authors: Rybnicek Robert , Leitner Karl-Heinz , Baumgartner Lisa , Plakolm Julia
Published: June 2019

Purpose

The purpose of this paper is to identify whether the prior industry experience (IE) or industry leadership experience (ILE) of the head might influence the department’s publication output, the ability to acquire external research funds or its entrepreneurial activities (e.g. the commercialization of research results through patents).

Design/methodology/approach

The study is based on data from 208 Austrian university departments and combines data from different sources (CVs of the heads of departments, commercial register, funding data and publication data).

Findings

The results show a positive relationship between ILE and the patent output of the departments as one indicator for the commercialization of research activities. Low positive effects of IE on the extent of third-party funding were also found. Furthermore, the scientific experience of the head of department has a positive influence on the publication output of the whole department.

Practical implications

The findings suggest that the scientific ability of researchers should be key when selecting the head of a department, due to the fact that scientific performance is still essential for most of these units. However, when universities seek to focus more strongly on other, for example, entrepreneurial activities, then additional competencies come into play. As the actual focus of universities is currently subject to change, former IE and ILE will become increasingly more important and the heads of departments will play a decisive role in the transition toward becoming an entrepreneurial university. Therefore, universities are well advised to integrate these experiences in the job specifications and to establish processes that facilitate the change from an industrial to a university job or which allow “double lives” in university and industry.

Originality/value

Previous studies have mostly investigated the role of the scientific experience of academic leaders in the research performance of their institution in later decades. This study examines the actual relevance of previous entrepreneurial experiences of heads of departments to the departments’ research performance, the ability to acquire external research funds or their entrepreneurial activities.
Using a stakeholder developed case study to develop soft skills
Authors: Samkin Grant , Keevy Monique
Published: June 2019

Purpose

The purpose of this paper is to illustrate the extent to which a case study developed by a financial institution and completed within a collaborative learning environment can be used to develop soft skills.

Design/methodology/approach

A questionnaire research instrument comprising open and closed response questions was used to collect the data.

Findings

The case study developed by the external stakeholder was found to be useful in developing soft skills. The primary skills identified by respondents were decision-making, problem-solving, critical thinking, communication and research ability. However, the respondents believed that the collaborative learning element had the greatest impact on the development of skills, particularly ethical behaviour, professionalism and personal attributes.

Research limitations/implications

The results are not generalisable beyond the scope of the particular higher education institution in which the study was conducted and the country in which the study was situated. Additionally, this paper measured soft skills development through perceptions of participating students. An objective measurement of students’ immediate soft skills improvement is not considered. Nonetheless, the findings provide guidance to educators on how a case study developed by a financial institution and completed within a collaborative learning environment can be used to develop soft skills.

Originality/value

The paper makes three contributions. The first is to detail how a real-world case study with a substantial technical component can be used to develop soft skills. Second, the paper contributes to the real-world case study and collaborative learning elements literature and ascertains the effectiveness of both methods in developing various soft skills. Finally, the paper contributes to the limited literature on how external stakeholders can become involved in the development of accounting curriculum content.
Interaction between internal and external auditors – insights from a developing country
Authors: Mubako Grace , Muzorewa Susan Charowedza
Published: June 2019

Purpose

The purpose of this study is to examine the nature and extent of interaction and the relationship between internal auditors (IAs) and external auditors (EAs) from the perspective of the IAs in a developing country, Zimbabwe.

Design/methodology/approach

This study was carried out by soliciting the opinions of chief audit executives (CAEs) in Zimbabwe through an online survey that was distributed via e-mail.

Findings

The study finds that the interaction between the IAs and EAs is limited and that EAs may not be making full use of the internal audit function (IAF). Findings also suggest that the relationship between the auditors is, in some instances, strained and that the actions of management do not always facilitate the fostering of a good, productive relationship between the auditors.

Originality/value

Results of this study contribute to the understanding of the nature and extent of interaction between the IAF and EAs in an African setting. The study also solicits qualitative data about the relationship between IAs and EAs where previous research has largely focused on objective measures, failing to take into account factors such as attitudes and biases, which can affect this relationship. Finally, the results of this study bring to light important, previously under-explored issues, which provide opportunities for future research.
Okara flour: its physicochemical, microscopical and functional properties
Authors: Santos Daiane Costa dos , Oliveira Filho Josemar Gonçalves de , Silva Jhessika de Santana , Sousa Milena Figueiredo de , Vilela Marcio da Silva , Silva Marco Antonio Pereira da , Lemes Ailton Cesar , Egea Mariana Buranelo
Published: June 2019

Purpose

Okara, which is the residue of hydrosoluble extract from soybean obtained after soymilk andtofuproduction, has high nutritional value and can be used for ingredient in specific food products. This study aims to evaluate the production and properties (physicochemical, microscopical and functional ones) of okara flour (OF) obtained from okara as a by-product ofsoymilkandtofuproduction.

Design/methodology/approach

Wet okara resulted from the soymilk process underwent convective drying up to reach mass stability (60°C for 12 h). OF properties were analyzed by official methods by AOAC, i.e. mineral composition was evaluated by atomic absorption equipment; color; water absorption index (WAI); milk absorption index (MAI); oil absorption capacity (OAC); and foam capacity (FC) required mixtures with water, milk and oil, separation and gravimetry, respectively; and microstructure was determined by a scanning electron microscope.

Findings

Results showed the potential OF has as a source of protein (24.74 g/100 g) and dietary fiber (58.27 g/100 g). Regarding its color after the drying process, OF was markedly yellow (b* parameter 20.16). Its WAI was 3.62 g/g, MAI was 4.33 g/g, OAC was 3.68 g/g and FC was 1.32 per cent. The microscopic analysis of OF showed that both loose and agglomerated particles had irregular structures and indefinite forms.

Originality/value

Production of flour from wet okara can be an alternative use of this by-product. This study showed important characteristics of OF and its possible application to the food industry. Thus, OF was shown as a potential ingredient with high nutritional value.
Earnings informativeness in dual-class firms
Authors: Lobanova Olesya , Barua Abhijit , Mishra Suchismita , Prakash Arun J.
Published: June 2019

Purpose

The purpose of this study is to explain the poor informativeness of earnings in dual-class firms by examining the quality of earnings and the information environment.

Design/methodology/approach

The earnings informativeness, earnings quality and information environment of dual-class firms are compared with a matched sample of single-class firms. The authors have performed the returns-earnings association tests, examine the quality of earnings by using proxies for discretionary accruals, and examine the information environment by employing four empirical constructs: the analyst forecast dispersion, absolute forecast errors, Amihud’s (2002) illiquidity measure, and the bid-ask spread.

Findings

The results show that the quality of earnings is better while the quality of the information environment is worse in dual-class firms compared to single-class firms. Overall, the results suggest that an inferior information environment is a plausible explanation for the low informativeness of dual-class firms’ earnings.

Research limitations/implications

The results provide empirical support for Dechow et al. (2010) that the use of the earnings-returns association measure to draw conclusions about the quality of earnings is not appropriate in the presence of a poor information environment.

Originality/value

This is the first study to empirically show that low earnings informativeness in dual-class firms can be explained by the inferior quality of the information environment.
Managing critical services through hybrid arrangements
Authors: Cabral Sandro , Ménard Claude
Published: June 2019

Purpose

Building on the literature of hybrids in the context of public organizations, this paper aims to discuss under which conditions hybrids can adequately provide “critical services”, a subset of public services characterized by their simultaneous exposure to externalities, socio-economic cohesion and legitimacy concerns.

Design/methodology/approach

The authors collect indications from two stylized examples, prisons and defense, to develop propositions as a step toward assessing the potential role of hybrids as alternatives to direct public provision or full privatization in the delivery of critical services.

Findings

This paper examines the conditions under which hybrid arrangements outperform the polar cases of public bureaus and full privatization in the delivery of a specific subset of public goods that the authors identify as “critical services”.

Originality/value

The authors suggest that there might be comparative advantages in relying on hybrid arrangements rather than the usual solutions of fully private or fully governmental provision. However, they also submit that these advantages are conditional to the capacity of hybrids to reconcile competing interests to achieve socio-economic cohesion, to combine capabilities dispersed among partners to benefit from positive externalities and to satisfy legitimacy concerns with respect to the role of government.
Monetary-fiscal policies interactions and optimal rules in Egypt
Authors: Al-shawarby Sherine , El Mossallamy Mai
Published: June 2019

Purpose

This paper aims to estimate a New Keynesian small open economy dynamic stochastic general equilibrium (DSGE) model for Egypt using Bayesian techniques and data for the period FY2004/2005:Q1-FY2015/2016:Q4 to assess monetary and fiscal policy interactions and their impact on economic stabilization. Outcomes of monetary and fiscal authority commitment to policy instruments, interest rate, government spending and taxes, are evaluated using Taylor-type and optimal simple rules.

Design/methodology/approach

The study extends the stylized micro-founded small open economy New Keynesian DSGE model, proposed by Lubik and Schorfheide (2007), by explicitly introducing fiscal policy behavior into the model (Fragetta and Kirsanova, 2010 and Çebi, 2011). The model is calibrated using quarterly data for Egypt on key macroeconomic variables during FY2004/2005:Q1-FY2015/2016:Q4; and Bayesian methods are used in estimation.

Findings

The results show that monetary and fiscal policy instruments in Egypt contribute to economic stability through their effects on inflation, output and debt stock. The monetary policy Taylor rule estimates reveal that the Central Bank of Egypt (CBE) attaches significant importance to anti-inflationary policy and (to a lesser extent) to output targeting but responds weakly to nominal exchange rate variations. CBE decisions are significantly influenced by interest rate smoothing. Egyptian fiscal policy has an important role in output and government debt stabilization. Additionally, the fiscal authority chooses pro-cyclical government spending and counter-cyclical tax policies for output stabilization. Again, past values of the fiscal instruments are influential in the evolution of the future fiscal policy-making process.

Originality/value

A few studies have examined the interaction between monetary and fiscal policy in Egypt within a unified framework. The presented paper integrates the monetary and fiscal policy analysis within a unified dynamic general equilibrium open economy rational expectations framework. Without such a framework, it would not be easy to jointly analyze monetary and fiscal transmission mechanisms for output, inflation and debt. Also, it would be neither possible to contrast the outcome of monetary and fiscal authorities commitment to a simple Taylor instrument rule vis-à-vis optimal policy outcomes nor to assess the behavior of monetary and fiscal agents in macroeconomic stability in context of an active/passive policy decisions framework.
Risk-adjusted pricing of project loans
Authors: Walter György
Published: June 2019

Purpose

The purpose of this paper is to assess whether project finance loans were properly priced based on their risk before the crisis of 2008-2009 and what lessons can be learned under different market circumstances.

Design/methodology/approach

A literature review presents the structure of project financing, how banks are inspired to apply risk-adjusted price calculations for loans to create value for shareholders and how risk measurement differs by project loans. The authors adapt a general model for risk-adjusted pricing to project loans. Based on empirical parameters, assuming different margins and leverages, the authors estimate the implied maximum probability of default of projects, where project loans could produce value added to lenders. The authors compare these maximum probabilities of default with reference points.

Findings

The authors conclude that by the years of 2006-2007 several projects were very unlikely to produce any value added for shareholders and did not reach the minimum margin. Market and regulatory circumstances of 2016-2017 have significantly increased required margin levels and must shift lenders to a more conservative pricing and leverage policy.

Research limitations/implications

Though the presented model is general, the simulation focusses on the European banking market.

Practical implications

In high market competition, banks tend to underestimate risk, underprice loans and loosen risk parameters. The crisis pushed banks back to a more conservative approach, however, the danger to return to a loosen project loan policy is real. The simulation shows how required prices are influenced by different market circumstances.

Originality/value

The paper adapts the risk-adjusted pricing methodology of standard loans to a new segment of project financing and gives an insight into the risk-pricing characteristics of project loans. The authors can draw down several valuable conclusions what how the market environment or project phases affect risk-adjusted pricing and the ability to produce value added to shareholders.
Mycorrhizal network assembly in a community context: The presence of neighbours matters
Authors: Chagnon Pierre‐Luc , Bradley Robert L. , Klironomos John N.
Published: June 2019

Understanding the factors and mechanisms driving the structure of ecological networks is a challenge for community ecologists. Notably, it remains unclear whether observed interaction patterns between two trophic groups are a result of (a) preferential partner selection between groups, or (b) species interactions within groups.

We conducted an experiment in order to disentangle these two drivers, using the plant–mycorrhizal symbiosis as a model system. We followed mycorrhizal colonization of plant roots growing either with or without neighbours. This allowed us to assess the relative importance of interaction within trophic groups (here, plant‐to‐plant interactions) on ecological network assembly.

Results showed that plants were not equally affected by the presence of neighbours and that network nestedness was higher when plants grew without neighbours. We also found a poor correlation between the centrality (i.e., standardized number of interactions) of plant species grown in communities and those grown without neighbours, while the reverse was true for mycorrhizal fungi. This suggests that the optimum level of specificity or generalism in mycorrhizal selection is not a fixed plant trait, but a plastic, context‐dependent one.

Synthesis. Our results show that ecological networks are not only shaped by preferential partner selection, but also by interactions within a given trophic group. This finding should be considered in future modelling exercises on ecological network dynamics. Moreover, our nestedness results suggest that in the presence of multiple host plants, mycorrhizal fungi display preferences for specific interactions, suggesting that local plant diversity may shape mycorrhizal fungal community structure.
HIV pre‐exposure prophylaxis and the ‘problems’ of reduced condom use and sexually transmitted infections in Australia: a critical analysis from an evidence‐making intervention perspective
Authors: Holt Martin , Newman Christy E. , Lancaster Kari , Smith Anthony K. , Hughes Shana , Truong Hong‐Ha M.
Published: June 2019

HIV pre‐exposure prophylaxis (PrEP) has been embraced in Australia, making PrEP available with public funding to people at risk of HIV. Here, we consider the associated ‘problems’ of reduced condom use and sexually transmissible infections (STIs), as seen by HIV professionals. Twenty‐one interviews were conducted during May‐August 2017. All agreed that PrEP was a valuable addition to HIV prevention, but their views about reduced condom use and STIs were variable. Using poststructural policy analysis, three main stances were identified: (1) Concerned/alarmed. PrEP was seen as causing reduced condom use, STIs and antibiotic resistance, posing threats to the general population; (2) Neutral/normalising. Stakeholders emphasised that condom use was declining and STIs increasing independently of PrEP, and that PrEP was simply a new tool to be accommodated; (3) Optimistic/critical. PrEP was seen as diminishing fear of HIV and engaging users in more frequent testing and treatment that could lead to declining STI rates. What linked all three stances was the selective performance of evidence, deploying a mixture of personal experience, clinical observations, behavioural data and epidemiology. Anticipating possible futures through evidence‐making suggested practical, political and moral consequences for what PrEP could become. We encourage others to consider these consequences with care.
Variation in Output Shares and Endogenous Matching in Land Rental Contracts: Evidence from Ethiopia
Authors: Gebrehiwot Desta B. , Holden Stein T.
Published: June 2019

We investigate the extent of variation in output sharing in land rental contracts and alternative hypotheses to explain this variation. Close to half of the rental contracts in our study in northern Ethiopia have output shares that deviate from the dominant 50–50 equal sharing. Variation in land quality, the relative bargaining power of landlords and tenants, production risks and shocks are hypothesised to influence output shares. Matched data of landlords and tenants are used. The importance of endogenous matching of landlords and tenants is investigated by assessing how endogenous tenant characteristics are correlated with landlord characteristics. We find evidence of negative assortative matching for key resource characteristics. A control function approach is used to control for endogenous matching in the output share models. The results reveal that production risks, as well as relative bargaining power, affect output shares in the reverse tenancy setting where tenants are relatively wealthier and more influential than landlords.
Two‐step method for isolating Cryptococcus species complex from environmental material using a new selective medium
Authors: Lin Kuo‐Hsi , Lin Yi‐Pei , Chung Wen‐Hsin
Published: June 2019

Cryptococcosis is an opportunistic infection caused by the Cryptococcus species complex. An outbreak of cryptococcosis caused by Cryptococcus gattii (AFLP6/VGII) in North America has indicated the need for studies of this organism and its environmental niche. Difficulties in isolating the Cryptococcus spp. because of the overgrowth of filamentous fungi onto culture media and its low fungal population size under natural conditions limit studies of these pathogenic yeasts. We designed a selective medium that inhibits the growth of environmental filamentous fungi but does not inhibit that of Cryptococcus cells. After enrichment in acidified YPD media and inoculation onto selective media, Cryptococcus cells in brown‐coloured colonies were isolated from environmental materials. This two‐step method is useful for isolating environmental members of the Cryptococcus species complex, which is essential for further studies involving diversity and the microbe–environment relationship of this yeast.
Accuracy of five self‐report screening instruments for substance use in pregnancy
Authors: Ondersma Steven J. , Chang Grace , Blake‐Lamb Tiffany , Gilstad‐Hayden Kathryn , Orav John , Beatty Jessica R. , Goyert Gregory L. , Yonkers Kimberly A.
Published: June 2019

Background and aims

The accuracy of current screening instruments for identification of substance use in pregnancy is unclear, particularly given methodological shortcomings in existing research. This diagnostic accuracy study compared five existing instruments for ability to identify illicit drug, opioid and alcohol use, under privacy expectations consistent with applied practice and using a gold standard incorporating toxicological analysis.

Design

Prospective cross‐sectional screening accuracy study.

Setting

Three sites encompassing four prenatal care clinics in the United States.

Participants

Convenience sample of 1220 racially, ethnically and socio‐economically diverse pregnant women aged 18 years and over.

Measurements

In Phase I, participants completed the five screening instruments in counterbalanced order. Instruments included the Substance Use Risk Profile—Pregnancy (SURP‐P), CRAFFT (acronym for five‐item screener with items related to car, relax, alone, forget, friends and trouble), 5Ps (parents, peers, partner, pregnancy, past), Wayne Indirect Drug Use Screener (WIDUS) and the National Institute on Drug Abuse (NIDA) Quick Screen. In Phase II, participants provided a urine sample and completed a calendar recall‐based interview regarding substance use. These screeners were tested, using receiver operating characteristic (ROC) analysis and accuracy statistics, against a reference standard consisting of substance use in three classes (illicit drugs, opioids and alcohol), considered positive if use was evident via 30‐day calendar recall or urine analysis.

Findings

Three hundred and fifteen of 1220 participants (26.3%) met reference standard criteria for positivity. The single‐item screening questions from the NIDA Quick Screen showed high specificity (0.99) for all substances, but very poor sensitivity (0.10–0.27). The 5Ps showed high sensitivity (0.80–0.88) but low specificity (0.35–0.37). The CRAFFT, SURP‐P and 5Ps had the highest area under the curve (AUC) for alcohol (0.67, 0.66 and 0.62, respectively), and the WIDUS had the highest AUC for illicit drugs and opioids (0.70 and 0.69, respectively). Performance of all instruments varied significantly with race, site and economic status.

Conclusions

Of five screening instruments for substance use in pregnancy tested (Substance Use Risk Profile—Pregnancy (SURP‐P), CRAFFT, 5Ps, Wayne Indirect Drug Use Screener (WIDUS) and the National Institute on Drug Abuse (Quick Screen), none showed both high sensitivity and high specificity, and area under the curve was low for nearly all measures.
Cancer outcomes in patients requiring immunosuppression in addition to corticosteroids for immune‐related adverse events after immune checkpoint inhibitor therapy
Authors: Burdett Nikki , Hsu Kristin , Xiong Libo , Tapia‐Rico Gonzalo , Beckmann Kerri , Karapetis Christos , Brown Michael P.
Published: June 2019

Aim

To examine the cancer‐specific outcomes for patients who experience immune‐related adverse events requiring immunosuppression beyond corticosteroids.

Methods

We performed a retrospective case series of patients between January 1, 2009 and April 1, 2018, across three metropolitan hospitals in Adelaide, South Australia. Eligible patients were identified from pharmacy records. Patients with a solid organ malignancy had discontinued checkpoint inhibitor therapy due to toxicity, and required immunosuppression in addition to corticosteroids to treat any immune‐related adverse event.

Results

From 3860 patient dispensation records of immunosuppressive medications, 19 eligible patients were identified. Eight received a CTLA‐4 inhibitor, four a PD‐1 inhibitor, five combination immunotherapy, and two remained blinded. Sixteen patients had melanoma and three had non‐small cell lung cancer. Median time to treatment failure was 8.7 months, and median overall survival was 9.4 months. Of those evaluable, the objective response rate was 35%, while 53% had progressive disease. Four patients died due to complications of their irAE, while six died from progressive disease.

Conclusion

Patients who received immunosuppression for checkpoint inhibitor therapy toxicity had variable outcomes. This in part reflects a heterogeneous population, and the evolution of irAE management over time. Several patients continued to derive a benefit after cessation of therapy despite the use of immunosuppressive medications; conversely, four died as a direct consequence of their irAE. Physicians should promptly introduce immunosuppressive therapy in patients not responding to corticosteroids to mitigate the risk of life‐threatening adverse events, given that current evidence does not clearly demonstrate a detriment to cancer‐specific outcomes.
Who Uses Action Planning in a Web‐Based Computer‐Tailored Intervention to Reduce Workplace Sitting and What do Action Plans Look Like? Analyses of the Start to stand Intervention among Flemish Employees
Authors: De Cocker Katrien , Cardon Greet , Vergeer Ineke , Radtke Theda , Vandelanotte Corneel
Published: June 2019

Background

Action planning plays an important role in many web‐based behaviour change interventions. As such, it is important to identify who engages in action planning and what action plans look like. This study examines (1) attributes of users creating an action plan and (2) the content of action plans made during a web‐based intervention to reduce workplace sitting.

Methods

Users answered “what” (short standing breaks and/or longer periods of standing), “when” (working hours, work breaks, commuting), “where” (workplace, transport mode), and “how” (frequency, duration, implementation intentions) questions. MANOVA and chi‐squared tests were conducted to compare those creating an action plan with those who did not. Descriptive statistics were used to examine the content of the action plans.

Results

Those creating an action plan (n = 236/1,701) were significantly older, more sedentary at work, and more aware of health risks related to excessive sitting compared to those not planning (n = 1,465). The majority planned standing breaks (n = 212) every 30 minutes, and periods of standing (n = 173) for 1 to 2 hours.

Conclusions

Future interventions should promote action planning more, especially among younger employees and those with less health‐related knowledge about sitting. Action plans were compatible with current sitting messages used in health promotion.
The usefulness of intraoperative X‐ray fluoroscopy in avoiding urethral injury during transanal total mesorectal excision
Authors: Tokunaga Takuya , Higashijima Jun , Yoshikawa Kozo , Nishi Masaaki , Kashihara Hideya , Takasu Chie , Shimada Mitsuo
Published: June 2019

Introduction

Urethral injury is one of the most important complications that can occur during transanal total mesorectal excision in male patients with rectal cancer. This report shows the usefulness of intraoperative X‐ray fluoroscopy to avoid urethral injury associated with transanal total mesorectal excision.

Materials and Surgical Technique

Real‐time navigation using fluoroscopy was performed to check the distance between the urethra and the dissection line at the level of the exposed rectourethral muscle, the middle level of the divided rectourethral muscle, and the level at which the prostate was identified.

Discussion

The dissection was completed transanally up to the level of peritoneal reflection on the anterior side without urethral injury. Pathological examination confirmed that the circumferential resection margin was tumor free. This novel technique using intraoperative X‐ray fluoroscopy is an easy‐to‐use approach that helps prevent urethral injury in male patient who undergo transanal total mesorectal excision for rectal cancer.
Effects of nutrient limitation on sperm and seminal fluid: a systematic review and meta‐analysis
Authors: Macartney Erin L. , Crean Angela J. , Nakagawa Shinichi , Bonduriansky Russell
Published: June 2019

Theory predicts that costly sexual traits should be reduced when individuals are in poor condition (i.e. traits should exhibit condition‐dependent expression). It is therefore widely expected that male ejaculate traits, such as sperm and seminal fluid, will exhibit reduced quantity and quality when dietary nutrients are limited. However, reported patterns of ejaculate condition dependence are highly variable, and there has been no comprehensive synthesis of underlying sources of such variation in condition‐dependent responses. In particular, it remains unclear whether all ejaculate traits are equally sensitive to nutrient intake, and whether such traits are particularly sensitive to certain dietary nutrients, respond more strongly to nutrients during specific life stages, or respond more strongly in some taxonomic groups. We systematically reviewed these potential sources of variation through a meta‐analysis across 50 species of arthropods and vertebrates (from 71 papers and 348 effect sizes). We found that overall, ejaculate traits are moderately reduced when dietary nutrients are limited, but we also detected substantial variation in responses. Seminal fluid quantity was strongly and consistently condition dependent, while sperm quantity was moderately condition dependent. By contrast, aspects of sperm quality (particularly sperm viability and morphology) were less consistently reduced under nutrient limitation. Ejaculate traits tended to respond in a condition‐dependent manner to a wide range of dietary manipulations, especially to caloric and protein restriction. Finally, while all major taxa for which sufficient data exist (i.e. arthropods, mammals, fish) showed condition dependence of ejaculate traits, we detected some taxonomic differences in the life stage that is most sensitive to nutrient limitation, and in the degree of condition dependence of specific ejaculate traits. Together, these biologically relevant factors accounted for nearly 20% of the total variance in ejaculate responses to nutrient limitation. Interestingly, body size showed considerably stronger condition‐dependent responses compared to ejaculate traits, suggesting that ejaculate trait expression may be strongly canalised to protect important reproductive functions, or that the cost of producing an ejaculate is relatively low. Taken together, our findings show that condition‐dependence of ejaculate traits is taxonomically widespread, but there are also many interesting, biologically relevant sources of variation that require further investigation. In particular, further research is needed to understand the differences in selective pressures that result in differential patterns of ejaculate condition dependence across taxa and ejaculate traits.