bluuebunny/crossref_metadata_2025 huggingface dataset:
Macrocell–femtocell resource allocation via hybrid optimization algorithm
Authors: Mohite Shailaja Sanjay , Kolekar Uttam D.
Published: May 2021

Purpose

Femtocells are low-power, inexpensive base stations (BS) used in business enterprises or homes. They could offer higher SNR in a smaller coverage area to enhance the data rates and QoS. Deployment of femtocell is expected to the witness constant development in upcoming years. Despite of all these benefits, there are certain challenges to be resolved that includes management of overlaying MC, interference among femtocells and the resource allocation between 2 tiers.

Design/methodology/approach

This work analyses the issues on cross-tier interfering and resource allocation alleviation in “full-duplex (FD) Orthogonal Frequency Division Multiple Access (OFDMA) oriented Heterogeneous Networks (HetNets) that includes macrocell as well as underlying femtocells”. This work concerns on three foremost contributions: portraying a single objective issue including subcarrier allocation, price allocation and power allocation of macrocell–femtocell networks. Moreover, this work introduces a novel Cat Swarm Mated-Lion algorithm (CSM-LA) for solving the defined optimization problem in macrocell–femtocell networks. At last, the supremacy of adopted scheme is proved over traditional models regarding statistical and convergence analysis.

Findings

By concerning the cost function, the developed CSM-LA attained 87.5, 60, 93.75 and 93.75% better than LM, WOA, LA and CSO respectively. For utility analysis, it accomplished 70.58% better than LM, 88.23% superior to GWO, 85.88% superior to WOA and 88.23% better than CSO. For statistical analysis, the median performance of developed CSM-LA attained better results, which was 80.52% superior to LA, 80.74% better than GWO, 72% superior to WOA and 48.7% better than LA. Hence, the developed CSM-LA proved its performance in terms of improved results and revealed its betterment over the conventional models.

Originality/value

This paper adopts a latest optimization algorithm called CSM-LA for analyzing the issues on cross-tier interfering and resource allocation alleviation in full-duplex (FD) orthogonal frequency division multiple access (OFDMA) oriented heterogeneous networks (HetNets). This is the first work that utilizes CSM-LA framework that proposes a new CSM-LA model for power control and resource allocation by considering the multi-objectives like price, subcarrier and power as well.
Dynamics between ownership structure and dividend policy: evidence from Bangladesh
Authors: Hasan Md. Bokhtiar , Wahid Abu N. M. , Amin Md. Ruhul , Hossain Md. Delowar
Published: May 2021

Purpose

The purpose of this study is to examine the impact of ownership structure such as family, government, institutional, foreign and public on dividend payouts as a representative of dividend policy of nonfinancial firms in Bangladesh.

Design/methodology/approach

This study employs a dynamic panel data model, namely, differenced generalized method of moments (GMM), which follows a two-step process. The study uses annual data of a sample of 159 nonfinancial firms of Dhaka Stock Exchange for the period 2008–2017, which constitutes a panel data of 1,590 firm-year observations.

Findings

This study’s findings reveal that family and public ownerships have a significant and positive effect on dividend payouts, while government and institutional ownerships have a significant but negative effect. This study additionally incorporates some very important controlled variables and finds that except for size, all the selected controlled variables, i.e. lagged-one of dividend payout, returns on assets, debts to assets, price-earnings (PE) ratio, age and financial crisis have a significant effect on the dividend payouts. However, the findings support several dividend-related theories or hypotheses, i.e. agency cost theory, dividend stability theory and reputation hypothesis.

Research limitations/implications

This study could consider some other aspects of corporate governance, as well as other emerging markets and financial institutions to perceive whether the results differ. Also, investigation could be carried out on conventional and Islamic firms individually to observe if the findings are different. However, the researchers are suggested to incorporate these issues in their future studies.

Practical implications

This study offers an important insight into the relationship dynamics between dividend payouts and ownership structure in the context of an emerging market like Bangladesh. Moreover, it enhances the understanding of the ties of dividend payouts with the firm-specific factors as well as the financial crisis. The findings of the present study have also important implications for managers, policymakers and researchers, who are in quest of directions on the dividend policy of publicly listed nonfinancial firms.

Originality/value

Most of the previous studies consider one or two types of ownership to examine the impacts on dividend payouts, while this study uses five types of ownership accompanied by a different data set. Moreover, to the authors’ knowledge, no study in Bangladesh has yet addressed this issue in such a comprehensive manner as theirs.
Tribological performance evaluation on brake friction material by using multi-objective optimization methods
Authors: Öktem Hasan , Shinde Dinesh
Published: May 2021

Purpose

The purpose of this study is to present a novel approach for the evaluation of tribological properties of brake friction materials (BFM).

Design/methodology/approach

In this study, a BFM was newly formulated with 16 different ingredients and produced using an industrial hot compression molding process. Experimentation was carried out on the brake tester, which was developed for this purpose according to SAE J661 standards. The braking applications, sliding speed and braking pressure were considered as performance parameters, whereas coefficient of friction (CoF) and wear rate as output parameters. The influence of the performance parameters on the output was studied using response surface plots. Analysis of variance and regression analysis was accomplished for post-experimental evaluation of results. Multi-criteria decision-making (MCDM) and multi-objective genetic algorithm (MOGA) were applied for estimating the most critical performance parameter combination to evaluate the BFM.

Findings

The present experimental model was significant and effectively used to predict the performance. MCDM generates the optimal values for the parameters braking applications, braking pressure (Bar) and sliding speed (rpm) as 1000, 30 and 915, whereas MOGA as 1008, 10.503 and 462.8202, respectively.

Originality/value

An efficient model for performance evaluation of the BFM considering maximum CoF and minimum wear rate was experimentally presented and statistically verified. Also, the two multi-objective optimization methodologies were implemented and compared. A comparison between the results of MCDM and MOGA reveals that MOGA yields 30% better results than MCDM.
Digital self-harm: an empirical analysis of the effects of broadband adoption on suicide
Authors: Kyung Nakyung , Lim Sanghee , Lee Byungtae
Published: May 2021

Purpose

Past literature offered competing predictions of the effect of broadband Internet on suicide. The Internet facilitates suicide by providing suicide-related information and ruining mental health. In contrast, Internet prevents suicide by offering social interaction and online mental treatment. This study aims to solve this tension by empirically examining the effect of broadband Internet on suicide with large-scale panel set.

Design/methodology/approach

This study takes instrument approach with the US county-level panel set for the period 2013–17. This study uses the number of household broadband Internet subscriptions as the measure of broadband and leverages the number of telecommunication carriers as an instrument to address concern for endogenous relationship.

Findings

There exists a positive and significant association between broadband Internet adoption and suicide on average. This study provides empirical evidence that this association is attributable to the Internet's role in leading to a general decline in the mental well-being and in providing suicide-relevant information. This association is more evident in areas with high poverty and low social capital.

Originality/value

This study contributes to literatures that address the dark side of information systems in general and that address how Internet adoption can influence public health and well-being in particular. Results of underlying mechanisms why Internet affects suicide, and heterogeneous effect of Internet by poverty and social capital provide insight for governments to enact proactive regulations to address continuing rise of suicide.
Contagion between liquid and illiquid assets during the financial crisis: evidence from the US credit derivative market
Authors: Kim Jungmu , Park Yuen Jung
Published: May 2021

This study aims to investigate the existence of contagion between liquid and illiquid assets in the credit default swap (CDS) market around the recent financial crisis. The authors perform analyses based on vector autoregression model and the dynamic conditional correlation model. The estimation of vector autoregression models reveals that changes in liquid CDS (LCDS) spreads lead to changes in illiquid CDS spreads at least one week ahead during the financial crisis period, whereas the leading direction is reversed during the post-crisis period. Moreover, the results are robust after controlling for structural variables which are proven as determinants of CDS spreads and are empirically supported. This study interprets that information was incorporated first into the LCDSs because of the flight-to-liquidity during the recent crisis period but there is a default contagion effect by reflecting illiquidity-induced credit risk after the crisis. Finally, the dynamic conditional correlation analysis also confirms the main results.
The necessity to activate long-term ETD in Korea
Authors: Lee Hyoseob
Published: May 2021

Purpose

This paper aims to provide the necessity to activate long-term exchange-traded derivatives (ETD) in Korea. In the era of aging, low interest rates and low economic growth, the investment demand for long-term financial products, and its hedging demand have steadily increased. Unfortunately, long-term ETD do not trade in Korea, and this study presents political suggestions to invigorate long-term ETD based on overseas cases and empirical analysis. Specifically, this study suggests the necessity to activate exchange traded funds (ETFs) options, long-term Korea treasury bond futures and options and long-term Volatility Index of Korea Composite Stock Price Index future and options. The introduction of those long-term ETD not only contributes to providing long-term investment and hedging vehicles but also reduces market inefficiencies in the Korean industry of ETFs, bonds and structured products.
Extreme returns and idiosyncratic risks: evidence from an emerging market
Authors: Cho Eunyoung
Published: May 2021

In this paper, we show that there is a negative premium for MAX stocks in the Korean stock market. However, there is no evidence that the MAX effect overwhelms the effects of idiosyncratic risk. When we control for idiosyncratic risk, the negative relationship between extreme returns and future returns is less robust. Rather, the cross-effect of the extreme returns and the idiosyncratic risk factors explains the negative premium. Furthermore, our results are not fully explained by the exposure to the market timing and economic state. Overall, both the extreme return and idiosyncratic risk effects appear to coexist in the Korean stock market, but they are not independently.
Understanding the impact of well-being on entrepreneurship in the context of emerging economies
Authors: Henao García Edwin Alexander , Galia Fabrice , Velez-Ocampo Juan
Published: May 2021

Purpose

This paper aims to assess what happens to a willingness to take entrepreneurial action when people experience low or high subjective well-being (SWB) in 12 emerging economies.

Design/methodology/approach

The research uses principal component analysis (PCA) and logistic regressions with a data sample from the global entrepreneurship monitor (GEM) for emerging economies.

Findings

The main results suggest that SWB, measured as satisfaction with life (SWL) and job satisfaction (JOBS), increases the probability of a person becoming an entrepreneur.

Social implications

The findings of this research suggest that designing and implementing public policies that seek to promote the well-being of individuals might foster their entrepreneurial activities in emerging economies.

Originality/value

The literature on entrepreneurship, which assesses its relationship with SWB is still scarce. Most of the academic work has been carried out for developed countries, mainly analysing how entrepreneurial activity affects SWB in self-employees or entrepreneurs. This manuscript analyses these elements in the opposite direction, contributing to an underdeveloped discussion on how well-being affects the decision to be an entrepreneur.
Leveraging customer-to-customer interactions to create immersive and memorable theme park experiences
Authors: Wei Wei , Zheng Yanyan , Zhang Lu , Line Nathaniel
Published: May 2021

Purpose

Theme park experiences ubiquitously unfold in the presence of others. In acknowledgement of this important part of theme park consumption, this research set out to examine if other visitors help create an immersive environment and, in turn, memorable experiences for theme park visitors.

Design/methodology/approach

An online survey was distributed to 561 theme park visitors. Structural equation modeling (AMOS 26) was used for testing the hypotheses in the proposed framework.

Findings

Results of SEM analyses reveal the positive impact of perceived similarity on visitors' sense of immersion at theme parks and the memorability of the experience. In turn, memorable experiences further drive behavioral intentions (i.e., return intention and willingness to pay premiums).

Practical implications

The findings provide suggestions for theme parks to leverage customer-to-customer interactions in order to create immersive and memorable visitor experiences.

Originality/value

This research marks one of the first attempts to approach customer-to-customer interactions (CCIs) at theme parks by empirically examining the impact of the perceived similarity of others on focal visitors' emotions and experiences.
An investigation of technology trust and habit in IT use continuance: a study of a social network
Authors: Ambalov Igor Alexander
Published: May 2021

Purpose

Social networking services/systems (SNSs) have grown in popularity in the past decade. However, while some have been abandoned by their once loyal users, others have grown in popularity. Literature provides diverse and often conflicting justifications for this phenomenon. Seeking a credible explanation, this study aims to examine the roles of system-like trust and habit in SNS use continuance.

Design/methodology/approach

This study conducted a comprehensive review of related literature to formulate an extended model of information technology (IT) continuance. A cross-sectional field survey was used to collect data from 401 university-student Facebook users. The research model was evaluated using structural equation modeling.

Findings

The results indicate that trust in technology and hedonic motivation are important direct influences on end-user continuance intention (CI), while habit is not. Interestingly, the most salient (indirect) predictor of CI is confirmation of (user) expectations.

Practical implications

The study suggests a set of practical steps that managers and practitioners can undertake to support users’ decisions to continue using the systems.

Originality/value

This paper advances IT continuance research by theorizing that trust in technology along with habit and hedonic motivation positively influence CI. In addition, the study enhances the concept of perceived usefulness by modeling this unitary measure as a multidimensional construct.
“The contribution of MOOCs to upskilling the labor force”
Authors: Goglio Valentina , Bertolini Sonia
Published: May 2021

Purpose

The study aims to investigate whether participation to massive open online courses (MOOCs) may lead to labor market returns and through which mechanisms such relative advantage may take place. Indeed, despite high figures of registered users, empirical studies on occupational returns are limited and MOOCs may represent a viable, cost-efficient example of lifelong learning practice to respond to the demand of a better skilled workforce for the fourth industrial revolution.

Design/methodology/approach

The study is based on qualitative empirical material constituted by a set of 21 qualitative semi-structured interviews conducted in 2019 among learners who registered in MOOCs provided by European higher education institutions.

Findings

Interviews return a situation in which MOOCs are beneficial for work: learners appreciate the new knowledge and skills they can access, with time flexibility and low entry cost. However, MOOCs positive contribution is not at everyone’s reach: self-selection issues tend to further advantage individuals with high levels of education and individual resources. Moreover, MOOCs can increase the risk of a shift of responsibility for training to the employees and qualify as a lower tier type of qualification, reinforcing social closure mechanisms based on educational credentials.

Originality/value

The study contributes to the empirical analysis of MOOCs economic returns empirically, by providing original qualitative material. Second, it contributes theoretically by bridging literature on economic and occupational returns to education on one side and literature on digital technologies in education on the other, providing new insights on the potentials and limits of MOOCs as a new form of lifelong learning.
Do Indian firms engage in classification shifting to report inflated core earnings?
Authors: Bansal Manish , Kumar Ashish , Badhani K. N.
Published: May 2021

Purpose

The authors aim at investigating different forms of classification shifting (CS). CS is a novel form of earnings management under which managers misclassify income statement line items and cash flow statement line items with an intent to report favorable operating performance of firms. In particular, the authors check the existence of revenue misclassification, expense misclassification and cash flows misclassification among Indian firms by taking the uniform sample of firms over a single period.

Design/methodology/approach

Operating revenue model (Malikov et al., 2018), core earnings expectation model (McVay, 2006) and operating cash flows model (Roychowdhury, 2006) are employed for measuring revenue misclassification, expense misclassification and cash flows misclassification, respectively. The panel data regression models are used to analyze the data for this study.

Findings

Based on the sample of 12,870 Bombay Stock Exchange (BSE) listed firm-years observations between 2010 and 2018, we find that, on average, Indian firms are engaged in revenue misclassification rather than expense misclassification to report inflated core earnings. Firms are found to be engaged in cash flows misclassification too. Besides, we find that magnitude of shifting is greater among larger firms. Results also establish that adoption of Ind AS increases the scope of shifting practices. These results are based on several robustness checks.

Practical implications

The results suggest that investors conduct a comprehensive review of the items of financial statements before using them in their portfolio valuation. It suggests auditors check the basis of revenue classification and standard-setting authorities, like ICAI in India, to make more mandatory disclosure requirements for classification of revenues and cash flows. It suggests lenders not to make lending decisions by looking at the operating performance metrics, as CS is the most preferred tool to positively influence the perception of lenders toward operating performance.

Originality/value

It is the first study that investigates different forms of classification shifting jointly for a sample of firms. Most of the earlier studies have examined one kind of classification shifting at a time. This study adds to the existing literature on earnings management by documenting that some firm-specific factors pressurize firms to prefer one form of shifting over another to report inflated core earnings.
Warming of aquatic ecosystems disrupts aquatic–terrestrial linkages in the tropics
Authors: Nash Liam N. , Antiqueira Pablo A. P. , Romero Gustavo Q. , de Omena Paula M. , Kratina Pavel
Published: May 2021

Aquatic ecosystems are tightly linked to terrestrial ecosystems by exchanges of resources, which influence species interactions, community dynamics and functioning in both ecosystem types. However, our understanding of how this coupling responds to climate warming is restricted to temperate, boreal and arctic regions, with limited knowledge from tropical ecosystems.

We investigated how warming aquatic ecosystems impact cross‐ecosystem exchanges in the tropics, through the export of aquatic resources into the terrestrial environment and the breakdown of terrestrial resources within the aquatic environment. We experimentally heated 50 naturally assembled aquatic communities, contained within different‐sized tank‐bromeliads, to a 23.5–32°C gradient of mean water temperatures.

The biomass, abundance and richness of aquatic insects emerging into the terrestrial environment all declined with rising temperatures over a 45‐day experiment. Structural equation and linear mixed effects modelling suggested that these impacts were driven by deleterious effects of warming on insect development and survival, rather than being mediated by aquatic predation, nutrient availability or reduced body size. Decomposition was primarily driven by microbial activity. However, total decomposition by both microbes and macroinvertebrates increased with temperature in all but the largest ecosystems, where it decreased. Thus, warming decoupled aquatic and terrestrial ecosystems, by reducing the flux of aquatic resources to terrestrial ecosystems but variably enhancing or reducing terrestrial resource breakdown in aquatic ecosystems.

In contrast with increased emergence observed in warmed temperate ecosystems, future climate change is likely to reduce connectivity between tropical terrestrial and aquatic habitats, potentially impacting consumers in both ecosystem types. As tropical ectotherms live closer to their thermal tolerance limits compared to temperate species, warming can disrupt cross‐ecosystem dynamics in an interconnected tropical landscape and should be considered when investigating ecosystem‐level consequences of climate change.
Fast recovery of soil macrofauna in regenerating forests of the Amazon
Authors: Serra Raymony Tayllon , Santos Carlos David , Rousseau Guillaume Xavier , Triana Stefania Pinzón , Muñoz Gutiérrez Jhonatan Andrés , Burgos Guerrero Jesús Enrique
Published: May 2021

The emergence of secondary forests in deforested tropical regions represents an opportunity to mitigate biodiversity loss and climate change, but there is still debate on how fast and to which level these forests can recover biodiversity. Recent studies have shown that the recovery of plant and vertebrate species richness is relatively fast, but the pace of recovery for other groups remains unclear. Soil macroinvertebrates play critical roles on litter decomposition and seed dispersal, therefore the pace of their recovery has consequences for the entire forest ecosystem.

We investigated how fast broad taxonomic groups of soil macrofauna recover in the first 30 years of forest regeneration using forests older than 50 years as reference.

We surveyed the number, diversity and abundance of 19 broad taxonomic groups of soil macrofauna in 85 sites located in Brazilian Amazon, covering forests of different ages and clearing frequencies. Forest age and clearing frequency were obtained accurately from Landsat images in forests up to 30 years old. We used regression analysis to determine (a) the effects forest age and clearing frequency on macrofauna groups in secondary forests up to 30 years old; and (b) the changes in macrofauna groups between young forests (up to 10 years old), median age forests (between 10 and 30 years old) and forests older than 50 years.

We found that the number and diversity of macrofauna groups recover rapidly in the first 10 years of forest regrowth, but show slower change among older forests. This rapid recovery was also observed in the abundance of several taxonomic groups and for predators and detritivores as functional groups. Forest clearing frequency had no effect on the number or the diversity of macrofauna groups, but the abundance of ants increased as forest was cleared more often.

Our results for soil macrofauna align with those in plant and vertebrate studies showing that secondary forests quickly recover a large part of their biodiversity and ecological functions. Therefore, global‐scale conservation strategies are needed to ensure the opportunity for secondary forests to grow.

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Mealtime behaviours of young children with sensory food aversions: An observational study
Authors: Caldwell Angela R. , Krause Elise K.
Published: May 2021

Introduction

Children with sensory food aversions (SFAs) are at risk for nutritional problems and occupational dysfunction during daily meals. To facilitate optimal occupational performance for children with SFAs, it is critical that clinicians understand child behaviour and caregiver strategy use to manage child behaviour during meals. The purpose of this paper is to examine the reliability of a novel coding scheme, the Behavioural Mealtime Coding System (BMCS) and identify associations among child acceptance of preferred and targeted foods, child food exploration and caregiver use of strategies to manage child behaviour.

Methods

Twenty‐one children (aged 18–60 months) with SFAs and their caregivers were recruited using a convenience sample. An observational video coding system was developed to code mealtime behaviour in 63 typical mealtime videos recorded by caregivers in the home environment. Inter‐rater reliability, descriptive statistics and bivariate correlations were calculated.

Results

The BMCS demonstrated excellent inter‐rater reliability (ICC = .95). Child bites of targeted foods were associated with mealtime duration (rs = .51, p = .02) and events of the child licking food (rs = .57, p = .007). Caregiver use of threats was positively associated with child age (rs = .48, p = .03) and negatively associated with caregiver education level (rs = −.49, p = .03).

Conclusion

For children with SFAs, increasing mealtime duration by embedding positive activities to encourage food exploration may improve acceptance of healthy targeted foods. Future research is needed to better understand the complex relationships among caregiver strategy use, mealtime duration and child mealtime behaviour.
Fungal transformation of natural and synthetic cobalt‐bearing manganese oxides and implications for cobalt biogeochemistry
Authors: Ferrier John , Csetenyi Laszlo , Gadd Geoffrey Michael
Published: May 2021

Manganese oxide minerals can become enriched in a variety of metals through adsorption and redox processes, and this forms the basis for a close geochemical relationship between Mn oxide phases and Co. Since oxalate‐producing fungi can effect geochemical transformation of Mn oxides, an understanding of the fate of Co during such processes could provide new insights on the geochemical behaviour of Co. In this work, the transformation of Mn oxides by Aspergillus niger was investigated using a Co‐bearing manganiferous laterite, and a synthetic Co‐doped birnessite. A. niger could transform laterite in both fragmented and powder forms, resulting in formation of biomineral crusts that were composed of Mn oxalates hosting Co, Ni and, in transformed laterite fragments, Mg. Total transformation of Co‐doped birnessite resulted in precipitation of Co‐bearing Mn oxalate. Fungal transformation of the Mn oxide phases included Mn(III,IV) reduction by oxalate, and may also have involved reduction of Co(III) to Co(II). These findings demonstrate that oxalate‐producing fungi can influence Co speciation in Mn oxides, with implications for other hosted metals including Al and Fe. This work also provides further understanding of the roles of fungi as geoactive agents which can inform potential applications in metal bioremediation, recycling and biorecovery.
Political Consumerism and Interpersonal Discussion Patterns
Authors: Zorell Carolin V. , Denk Thomas
Published: May 2021

The ecological impacts of consumption are well acknowledged, and most people worldwide are likely to have encountered proofs for or information about it. Likewise, online and offline media seem to be full of information on the issue. Even so, large numbers of people are ‘non‐political’ consumers, inconsiderate of the ethical and ecological implications of what they buy and consume. Using representative survey data from Sweden collected in 2019, this paper shows that a major reason for non‐political consumerism can be seen in the lack of interpersonal ‘recruitment’ efforts; that is, deliberate attempts by some to influence another's consumption. Moreover, the analyses show that for a person having faced such attempts by others to influence their consumption is distinct from them discussing political consumption issues. With this, the paper also provides one of the first large‐N studies confirming recent theoretical propositions of an extended definition of political consumerism: discussion, that is, discursive action, is a sub‐form of political consumerism next to boycotting, buycotting, and lifestyle change. Interpersonal influence, in turn, is a key predictor of political consumerism. Altogether, the results suggest that spreading information may feed discursive actions. Yet, to get more people change their consumption choices and engage in political consumerism, what is needed is that people influence each other to do so.
Variability of sense of place in Nigerian coastal communities
Authors: Dada Olanrewaju Timothy , Ojo Deborah Bunmi , Popoola Adewale Sheyi , Adebara Temitope Muyiwa , Oladele Boluwatife Grace
Published: May 2021

This study gathered residents' perceptual data to explore the variability of sense of place in coastal communities in Lagos, Nigeria. A questionnaire was administered to respondents from one in every 10 buildings using a systematic random sampling technique. Each respondent (preferably the oldest family member) was surveyed in the chosen residential buildings. In total, 265 questionnaires were completed and submitted for analysis. The findings revealed that residents' satisfaction levels with living in a coastal community were directly and positively proportional to the coastline's distance. In addition to this insight, the residents' satisfaction levels during the dry season differed significantly from that shown during the wet season. The results indicated a significant spatiotemporal relationship between satisfaction with safety, maintenance of streets, vehicular circulation, traffic density, and recreational facilities, altogether with a sense of place. It was established that sense of place was, at times, spatially heterogeneous and showed seasonal variability in coastal communities of Nigeria.
Management of patients with bilateral recurrent laryngeal nerve paralysis following esophagectomy
Authors: Jeon Yeong Jeong , Cho Jong Ho , Lee Hong Kyu , Kim Hong Kwan , Choi Yong Soo , Zo Jae Ill , Shim Young Mog
Published: May 2021

Background

Recurrent laryngeal nerve paralysis (RLNP) is a common complication after esophagectomy which can cause severe pulmonary complications. However, bilateral RLNP has been rarely reported in esophagectomy patients. The objective of our study is to investigate the clinical significance of patients who had bilateral RLNP following esophagectomy.

Methods

We retrospectively reviewed patients who underwent esophagectomy at a single center from 1994 to 2018. Among these, patients with bilateral vocal cord paralysis were included in this study.

Results

A total of 3217 patients were reviewed and 400 (12.4%) patients had RLNP, including 56 patients with bilateral RLNP identified by laryngoscopic examination. During the postoperative managements, 10 of the 56 patients (17.9%) required tracheostomy. Among them, two died of acute respiratory distress syndrome and the other eight patients were discharged after removing the tracheostomy tube. The median lengths of hospital and intensive care unit stay were 19.5 (range 8–157) and 2 (range 1–46) days, respectively. Forty‐six patients (83.6%) were discharged with oral feeding after swallowing therapy including tongue holding maneuver and head tilt exercise. The other five patients (8.9%) were discharged with alternative enteral feeding via jejunostomy, but they were able to achieve oral diet 2–3 months after surgery.

Conclusion

Bilateral RLNP following esophagectomy was rare, but it required great attention to prevent severe respiratory complications. However, only a few patients required tracheostomy and the majority achieved oral ingestion after intensive rehabilitation. Feeding education and respiratory rehabilitation are critical during the management of patients with bilateral RLNP.
Paraneoplastic neuromyelitis optica spectrum disorder associated with malignant melanoma: A case report
Authors: Morimoto Toshiki , Hayashida Shotaro , Yamasaki Kei , Sasahara Yosuke , Takaki Tsutomu , Yatera Kazuhiro
Published: May 2021

Neuromyelitis optica spectrum disorders (NMOSDs) are autoimmune demyelinating diseases involving the central nervous system, affecting the spinal cord and optic nerves. There are few reports of paraneoplastic NMOSD associated with malignant melanoma. Here, we report a rare case of anti‐aquaporin 4 (AQP4) antibody‐positive NMOSD associated with malignant melanoma. A 61‐year‐old Japanese woman was diagnosed with malignant melanoma and lung metastasis four years after a diagnosis of anti‐AQP4 antibody‐positive NMOSD. When diagnosing and treating patients with NMOSD, physicians should be aware of the development of malignancy for at least several years.
Small‐scale species distribution model identifies restricted breeding habitat for an endemic island bird
Authors: Segal R. D. , Massaro M. , Carlile N. , Whitsed R.
Published: May 2021

Mapped geographical distributions of many birds are an overestimation of their true range and this overestimation is particularly high for threatened species. Due to their restricted ranges, specialized habitats and inability to relocate to other areas, island birds are particularly vulnerable to anthropogenic effects on their habitats, but few studies have investigated the suitability of remaining habitat for species restricted to small oceanic islands. Here, we developed a fine‐scale species distribution model to investigate the breeding habitat of the Lord Howe currawong Strepera graculina crissalis. Using 73 nest locations as occurrence records, we found that currawongs nest preferentially near creek lines at lower elevations in the forested areas of the island (maximum elevation of 120 m). Habitat suitability decreased rapidly as the distance to creeks increased, indicating that many forested areas far from a creek line were unsuitable habitat for nesting currawongs. Using a combination of Thiessen polygons and suitable habitat to define territory boundaries, we estimated the average territory size to range between 2.48 ha and 5.23 ha. Using a conservative threshold, our model identified 195 ha of Lord Howe Island’s land area as highly suitable nesting habitat for the Lord Howe currawong, while using a less conservative threshold identified a further 246 ha as medium suitable habitat (441 ha total). Hence, we estimated that the island can support a maximum number of 84 breeding territories. This study shows that the Lord Howe currawong has a narrower ecological niche than was expected, lowering the carrying capacity for this species on the island. As birds on remote islands are often unable to relocate to other suitable areas, it is important to determine the remaining habitat to ensure the continued persistence and conservation of threatened island species.
Climbing for dummies: recommendation for multi‐specific fishways for the conservation of tropical eels and gobies
Authors: Lagarde R. , Courret D. , Grondin H. , Faivre L. , Ponton D.
Published: May 2021

Dams and other man‐made barriers impair upstream fish migration and thus threaten fish populations that need access to upper river reaches to complete their life cycle. For many years, fishways have been used to mitigate this impact. Fishways around the globe are typically built based on recommendations made for northern hemisphere species, particularly salmonids. These recommendations do not consider the locomotor characteristics and skills of other species, especially those living in the tropics. Among tropical species, freshwater eels and gobies of the Sicydiinae subfamily are important cultural and economic species that are particularly sensitive to the impact of man‐made barriers. Our experimental study aimed to test different substrates and slopes for ramp‐like fishways adapted to tropical eels and sicydiines. Among the five substrates tested for 368 eels Anguilla marmorata, elastomer pins appeared to be the most efficient. Elastomer pins also appeared to be more efficient than the fine concrete which is currently used in fishways for sicydiines (Sicyopterus lagocephalus, N = 1797, and Cotylopus acutipinnis, N = 1303). The slope had a lesser effect on the climbing success of sicydiines compared to substrate type, except for gradients greater than 50° that induced a slight decrease in success. Our results indicated that ramp‐like fishways fitted with 1.0 cm diameter elastomer pins, positioned in staggered rows with a diagonal spacing of 1.3 cm, wetted with low‐flow and angled less than 50°, are well adapted to accommodate the different locomotor characteristics and skills of tropical eels and sicydiines.
Acute alcohol intoxication modulates the temporal dynamics of resting electroencephalography networks
Authors: Schiller Bastian , Heinrichs Markus , Beste Christian , Stock Ann‐Kathrin
Published: May 2021

This study aimed to provide a currently missing link between general intoxication‐induced changes in overall brain activity and the multiple cognitive control deficits typically observed during acute alcohol intoxication. For that purpose, we analyzed the effects of acute alcohol intoxication (1.1‰) on the four archetypal electroencephalography (EEG) resting networks (i.e., microstates A–D) and their temporal dynamics (e.g., coverage and transitions from one microstate to another), as well as on self‐reported resting‐state cognition inn = 22 healthy young males using a counterbalanced within‐subject design. Our microstate analyses indicated that alcohol increased the coverage of the visual processing‐related microstate B at the expense of the autonomic processing‐related microstate C. Add‐on exploratory analyses revealed that alcohol increased transitions from microstate C to microstate B and decreased bidirectional transitions between microstate C and the attention‐related microstate D. In line with the observed alcohol‐induced decrease of the autonomic processing‐related microstate C, participants reported decreases of their somatic awareness during intoxication, which were positively associated with more transitions from microstate C to microstate B. In sum, the observed effects provide mechanistic insights into how alcohol might hamper cognitive processing by generally prioritizing the bottom‐up processing of visual stimuli over top‐down internal information processing. The fact that this was found during the resting state further proves that alcohol‐induced changes in brain activity are continuously present and do not only emerge during demanding situations or tasks.
Cost‐effectiveness implications of increasing the efficiency of the extended‐release naltrexone induction process for the treatment of opioid use disorder: a secondary analysis
Authors: Murphy Sean M. , Jeng Philip J. , McCollister Kathryn E. , Leff Jared A. , Jalali Ali , Shulman Matisyahu , Lee Joshua D. , Nunes Edward V. , Novo Patricia , Rotrosen John , Schackman Bruce R.
Published: May 2021

Background and Aims

In a US randomized‐effectiveness trial comparing extended‐release naltrexone (XR‐NTX) with buprenorphine–naloxone (BUP‐NX) for the prevention of opioid relapse among participants recruited during inpatient detoxification (CTN‐0051), the requirement to complete opioid detoxification prior to initiating XR‐NTX resulted in lower rates of initiation of XR‐NTX (72% XR‐NTX versus 94% BUP‐NX).

Design

This was a retrospective secondary analysis of CTN‐0051 trial data, including follow‐up data over 24–36 weeks.

Setting

Eight community‐based, inpatient‐detoxification and follow‐up outpatient treatment facilities in the United States.

Participants

A total of 283 participants randomized to receive XR‐NTX.

Measurements

Efficiency was estimated using a multivariable generalized structural equation model to explore simultaneous determinants of XR‐NTX induction and induction duration (detoxification + residential days). Cost‐effectiveness was estimated from the health‐care sector perspective and included expected costs and quality‐adjusted life‐years (QALYs).

Findings

Treatment site was the only modifiable factor that simultaneously increased the likelihood of XR‐NTX induction and decreased induction duration. Incorporating the higher predicted probability of XR‐NTX induction, and fewer predicted days of detoxification and subsequent residential treatment into the cost‐effectiveness framework, reduced the incremental average 24‐week total cost of XR‐NTX treatment from $5317 more than that of BUP‐NX (P = 0.01) to a non‐statistically‐significant difference of $1016 (P = 0.63). QALYs gained remained similar across arms.

Conclusion

Adopting an efficient model of extended‐release naltrexone initiation could result in extended‐release naltrexone and buprenorphine–naloxone being of comparable economic value from the health‐care sector perspective over 24–36 weeks for patients seeking treatment for opioid use disorder at an inpatient detoxification facility.
The relationship between cannabis and schizophrenia: a genetically informed perspective
Authors: Johnson Emma C. , Hatoum Alexander S. , Deak Joseph D. , Polimanti Renato , Murray Robin M. , Edenberg Howard J. , Gelernter Joel , Di Forti Marta , Agrawal Arpana
Published: May 2021

Background and Aims

While epidemiological studies support a role for heavy, high‐potency cannabis use on first‐episode psychosis, genetic models of causation suggest reverse causal effects of schizophrenia on cannabis use liability. We estimated the genetic relationship between cannabis use disorder (CUD) and schizophrenia (SCZ) and tested whether liability for CUD is causally associated with increased liability to SCZ while adjusting for tobacco smoking.

Design

This study used summary statistics from published genome‐wide association studies (GWAS). We used genomic structural equation modeling, latent causal variable analysis, and multivariable Mendelian randomization to examine genetic relationships between CUD, cannabis ever‐use, ever‐smoked tobacco regularly, nicotine dependence and SCZ, and to test for a causal relationship between liability to CUD and liability to SCZ.

Setting

Genome‐wide association studies were published previously as part of international consortia.

Participants

Sample sizes of the GWAS summary statistics used in this study ranged from 161 405 to 357 806 individuals of European ancestry.

Measurements

Genome‐wide summary statistics for CUD and SCZ were the primary measurements, while summary statistics for cannabis ever‐use, ever‐smoked tobacco regularly and nicotine dependence were included as additional variables in the genomic structural equation models and the multivariable Mendelian randomization analyses.

Findings

Genetic liability to CUD was significantly associated with SCZ [β = 0.29, 95% confidence interval (CI) = 0.11, 0.46, P = 0.001], even when accounting for cannabis ever‐use, ever‐smoked tobacco regularly and nicotine dependence as simultaneous predictors. We found mixed evidence of a causal relationship, with the latent causal variable analysis finding no evidence of causality (genetic causality proportion = −0.08, 95% CI = −0.40, 0.23, P = 0.87) but the multivariable Mendelian randomization analyses suggesting a significant, risk‐increasing effect of CUD on liability to SCZ (β = 0.10, 95% CI = 0.02, 0.18, P = 0.02), accounting for the additional risk factors (cannabis ever‐use, ever‐smoked tobacco regularly and nicotine dependence).

Conclusions

Genetic liability for cannabis use disorder appears to be robustly associated with schizophrenia, above and beyond tobacco smoking and cannabis ever‐use, with mixed evidence to support a causal relationship between cannabis use disorder and schizophrenia.
Impact of an Australian/New Zealand organisational position statement on extended‐release opioid prescribing among surgical inpatients: a dual centre before‐and‐after study
Authors: Awadalla R. , Liu S. , Kemp‐Casey A. , Gnjidic D. , Patanwala A. , Stevens J. , Begley D. , Bugeja B. , Penm J.
Published: May 2021

Extended‐release opioids are often prescribed to manage postoperative pain despite being difficult to titrate to analgesic requirements and their association with long‐term opioid use. An Australian/New Zealand organisational position statement released in March 2018 recommended avoiding extended‐release opioid prescribing for acute pain. This study aimed to evaluate the impact of this organisational position statement on extended‐release opioid prescribing among surgical inpatients. Secondary objectives included predictors and clinical outcomes of prescribing extended‐release opioids among surgical inpatients. We conducted a retrospective, dual centre, 11‐month before‐and‐after study and time‐series analysis by utilising electronic medical records from two teaching hospitals in Sydney, Australia. The primary outcome was the proportion of patients prescribed an extended‐release opioid. For surgical patients prescribed any opioid (n = 16,284), extended‐release opioid prescribing decreased after the release of the position statement (38.4% before vs. 26.6% after, p < 0.001), primarily driven by a reduction in extended‐release oxycodone (31.1% before vs. 14.1% after, p < 0.001). There was a 23% immediate decline in extended‐release opioid prescribing after the position statement release (p < 0.001), followed by an additional 0.2% decline per month in the following months. Multivariable regression showed that the release of the position statement was associated with a decrease in extended‐release opioid prescribing (OR 0.54, 95%CI 0.50–0.58). Extended‐release opioid prescribing was also associated with increased incidence of opioid‐related adverse events (OR 1.52, 95%CI 1.35–1.71); length of stay (RR 1.44, 95%CI 1.39–1.51); and 28‐day re‐admission (OR 1.26, 95%CI 1.12–1.41). Overall, a reduction in extended‐release opioid prescribing was observed in surgical inpatients following position statement release.