bluuebunny/crossref_metadata_2025 huggingface dataset:
Business valuation strategy for new hydroponic farm development – a proposal towards sustainable agriculture development in United Arab Emirates
Authors: Sisodia Gyanendra Singh , Alshamsi Raweya , Sergi Bruno S.
Published: December 2020

Purpose

This study aims to evaluate a hydroponic farm (through nutrient film technique) while considering uncertainty, sustainability and the system's utility in the dominant desert geography. The idea of the hydroponic farm is to allow individuals/businesses to grow plants. Given the geographical condition, the hydroponic system may be useful in the Gulf context and may lead to food security and sustainability. Additionally, the UAE government has initiated several support schemes that can be availed for investing in such businesses that can contribute to the nation's food security.

Design/methodology/approach

The hydroponic farm is evaluated using the net present value and real options approach. The authors studied five scenarios: 1. business as usual, 2. 50% subsidy on initial investment through Khalifa funding, 3. 4% premium, 4. Subsidy plus premium and 5. solar panel installation with bore well.

Findings

As per the assumptions and data usage, all the scenarios shows a positive net present value (NPV); Nevertheless, scenarios 4 and 5 report the significant highest net present and delay value.

Research limitations/implications

This study has environmental, economic and social implications. Lower imports indirectly lead to lower carbon footprints. The local production of food ensures higher employability in the sector and increase in local consumption. Additionally, fresh food consumption is directly associated to good health.

Practical implications

Supportive policies such as subsidies through Khalifa funding may accelerate the expansion of such projects through domestic and foreign investments. One of the important takeaway from the study is to invest in the training of the workforce.

Social implications

Given the geographical condition, the UAE usually depends on food imports. If the hydroponic farms become popular, the residents will have access to fresh vegetables and fruits. Higher engagement in agriculture activities also ensures a significant increase in agriculture-related businesses and higher employability.

Originality/value

The study adds novelty to the literature because the effect of Khalifa funding and investment analysis on solar (wells) has not been evaluated in any hydroponic studies. We presented the results with tornado graphs using NPV risk and real options approach in the Gulf context. The study represents functional scenarios that were previously not found in the literature.
A computational analysis of heat transport irreversibility phenomenon in a magnetized porous channel
Authors: Marzougui Souad , Bouabid M. , Mebarek-Oudina Fateh , Abu-Hamdeh Nidal , Magherbi Mourad , Ramesh K.
Published: December 2020

Purpose

The purpose of this paper is to evaluate the temperature, the Dirichlet conditions have been considered to the parallel horizontal plates. The model of generalized Brinkman-extended Darcy with the Boussinesq approximation is considered and the governing equations are computed by COMSOL multiphysics.

Design/methodology/approach

In the current study, the thermodynamic irreversible principle is applied to study the unsteady Poiseuille–Rayleigh–Bénard (PRB) mixed convection in a channel (aspect ratio A = 5), with the effect of a uniform transverse magnetic field.

Findings

The effects of various flow parameters on the fluid flow, Hartmann number (Ha), Darcy number (Da), Brinkman number (Br) and porosity (ε), are presented graphically and discussed. Numerical results for temperature and velocity profiles, entropy generation variations and contour maps of streamlines, are presented as functions of the governing parameter mentioned above. Basing on the generalized Brinkman-extended Darcy formulation, which allows the satisfaction of the no-slip boundary condition on a solid wall, it is found that the flow field and then entropy generation is notably influenced by the considering control parameters. The results demonstrate that the flow tends toward the steady-state with four various regimes, which strongly depends on the Hartman and Darcy numbers variations. Local thermodynamic irreversibilities are more confined near the active top and bottom horizontal walls of the channel when increasing the Da and decreasing the Hartmann number. Entropy generation is also found to be considerably affected by Brinkman number variation.

Originality/value

In the present work, we are presenting our investigations on the influence of a transverse applied external magnetohydrodynamic on entropy generation at the unsteady laminar PRB flow of an incompressible, Newtonian, viscous electrically conducting binary gas mixture fluid in porous channel of two horizontal heated plates. The numerical solutions for the liquid velocity, the temperature distribution and the rates of heat transport and entropy generation are obtained and are plotted graphically.
Numerical analysis of jet airflow impact inclined flat plate under electrohydrodynamics force in a porous medium
Authors: Ayuttaya Suwimon Saneewong Na
Published: December 2020

Purpose

This study aims to present a numerical analysis of the behavior of the electric field and flow field characteristics under electrohydrodynamics (EHD) force. The influence of the jet airflow under the EHD force is investigated when it impacts the inclined flat plate.

Design/methodology/approach

The high electrical voltage and angle of an inclined flat plate are tested in a range of 0–30 kV and 0–90°, respectively. In this condition, the air is set in a porous medium and the inlet jet airflow is varied from 0–2 m/s.

Findings

The results of this study show that the electric field line patterns increase with increasing the electrical voltage and it affects the electric force increasing. The angle of inclined flat plate and the boundary of the computational model are influenced by the electric field line patterns and electrical voltage surface. The electric field pattern is the difference in the fluid flow pattern. The fluid flow is more expanded and more concentrated with increasing the angle of an inclined flat plate, the electrical voltage and the inlet jet airflow. The velocity field ratio is increased with increasing the electrical voltage but it is decreased with increasing the angle of the inclined flat plate and the inlet jet airflow.

Originality/value

The maximum Reynolds number, the maximum velocity field and the maximum cell Reynolds number are increased with increasing the electrical voltage, the inlet jet airflow and the angle of the inclined flat plate. In addition, the cell Reynolds number characteristics are more concentrated and more expanded with increasing the electrical voltage. The pattern of numerical results from the cell Reynolds number characteristics is similar to the pattern of the fluid flow characteristics. Finally, a similar trend of the maximum velocity field has appeared for experimental and numerical results so both techniques are in good agreement.
Understanding individuals' engagement and continuance intention of MOOCs: the effect of interactivity and the role of gender
Authors: Shao Zhen , Chen Kuanchin
Published: December 2020

Purpose

This study aims to examine how three perceived interactivity attributes of massive open online courses (MOOCs), namely, perceived active control, perceived synchronicity and perceived two-way communication, impact individuals' engagement and continuance intention of MOOCs through the stimulus-organism-response (S-O-R) lens and how that effect differs between male and female users.

Design/methodology/approach

Drawing upon S-O-R as an overarching theoretical framework, this study conducted an empirical study in China and collected 294 valid questionnaires from online learners. Structural equation modeling approach was used to examine the proposed research model.

Findings

Empirical results suggest that perceived active control, perceived synchronicity and perceived two-way communication are significant stimuli of individuals' continuance intention of MOOCs, and the influences of perceived active control and perceived synchronicity are partially or fully mediated by engagement on the platform. Multi-group analysis results further indicate that perceived synchronicity has a stronger influence on engagement on the platform for males, while perceived active control and perceived two-way communication are more salient in stimulating engagement on the platform for females.

Practical implications

Research findings from the present study can serve as the foundation to guide MOOCs’ administrators to respond to the needs of participants through interactivity designed into the platform and shed light on possible key solutions of high dropout rates in MOOCs.

Originality/value

This study uncovers the mediating mechanism of affective engagement between interactivity and continuance intention in the emerging context of the latest online learning platform MOOCs and reveals the behavioral differences between females and males regarding their affective reactions to the three interactivity attributes.
Linking supplier selection and management strategies with mass customization capability
Authors: Ullah Inayat , Narain Rakesh
Published: December 2020

Purpose

Owing to the paucity of literature, in the specific context of mass customization (MC), that explains what factors need to be considered while selecting suppliers and what strategies need to be implemented for effective management of suppliers, this paper aims to explore the effective supplier selection and management strategies and also investigate their impact on the development of mass customization capability (MCC).

Design/methodology/approach

Through an extensive review of literature, a total of 18 factors for supplier selection and management have been identified. Further, using multiple regression analysis, the linkages between these factors and MCCs have been examined based on the data set from the survey of Indian manufacturing organizations.

Findings

The results indicate that while concentrating on the responsive and reconfiguration capability, all the five measures of supplier selection and the four measures of supplier management have shown a significant influence. However, in the case of relational capability, only two of the supplier selection strategies and three of the supplier management strategies have shown a notable impact.

Practical implications

The study provides help to the firms in deciding whom to select and how to manage the suppliers in the course of improving their MCCs. The study has shown the possibility that different types of MCCs might require different approaches to both the supplier selection and management.

Originality/value

To the best of the authors’ knowledge, this study happens to be the first of its kind that investigates the interconnectedness among the supplier selection and management strategies and MCCs.
Ranking policing strategies as a function of criminal complaints: application of the PROMETHEE II method in the Brazilian context
Authors: Basilio Marcio Pereira , Pereira Valdecy , Oliveira Max William Coelho de , Costa Neto Antonio Fernandes da
Published: December 2020

Purpose

The purpose of this study is modelling of a problem of policing strategy order using a multicriteria method.

Design/methodology/approach

For the construction of the impact matrix strategies under the reduction of crime rates, considering a portfolio of crimes, a questionnaire applied to specialists was used. In a second moment, defined the criteria and strategies to be ordered, the multicriteria PROMETHEE II method was used, which with the help of the Visual PROMETHEE software, emulated the systematised data in the impact matrix and produced the final ordering of the most efficient strategies, in the fight against crime, in the perception of decision makers.

Findings

As a result, this research revealed that radio patrol, when used in a non-randomised manner, is the most effective policing strategy in reducing the 18 criminal demands studied in the perception of decision makers after data emulation with the PROMETHEE II method.

Research limitations/implications

As research implications, it can be inferred that the use of multicriteria methods in the modelling of problems in public security area can contribute to the rationalisation of use of the available means in the fight against crime in large cities. This research showed that it is possible to use customised policing strategies to absolute reality.

Practical implications

The practical impact of this research lies in optimising the resources available to law enforcement agencies in the fight against crime in general.

Social implications

It can be inferred that by choosing appropriate strategies to combat local crime, there is a direct implication in optimising the resources that the government makes available to police agencies. This optimisation allows pressure reduction under the public budget for more features. The model for choosing more effective strategies contributes to local crimes decrease, increasing the sense of the population security.

Originality/value

The originality lies in filling a gap in the literature with the elaboration of the impact matrix of policing strategies in reducing criminal indices and in their associated use in ordering strategies through a multicriteria method. This study contributed to applied police intelligence.
Assessment of employees’ attitudes toward ongoing organizational transformations
Authors: Heim Irina , Sardar-Drenda Nibedita
Published: December 2020

Purpose

Global companies in the digital service industry are experiencing a pressing urgency for ongoing transformations caused by external factors driven by the need to change business models. This study aims to evaluate the willingness and ability to change as constructs of employee attitude toward change, assess their predictors and develop an approach to analyzing willingness and ability to change.

Design/methodology/approach

This study uses an abductive approach, building on the refinement of existing theories. The authors conducted 306 employees' surveys and nine interviews to collect primary data.

Findings

The result of this study suggests that the employees are willing to change when they have a sense of perceived control based on collaboration with management. Factors that have an impact on the willingness and ability to change include job function, age, years of job experience, knowledge of values, company background, understanding the current challenges, understating the urgency for change, positive attitude toward past changes and trust in leadership.

Research limitations/implications

This is research is focused on one organization, and research in other industries or firms in the digital service industry would be beneficial.

Practical implications

This research contributes to the practice on the conduct of diagnostic investigation in an organization's readiness and risk for a planned change. The authors add to the existing literature the new dimensions related to the prior experience with change and understanding the need and urgency for change -specific factors that are relevant to individual ability to change. Managers can use findings in this study to learn how to plan and manage organizational change in the fast-paced business environment of digital service industries.

Social implications

This research will help to understand work attitudes, emotions and behaviors and therefore will improve the well-being in the organizations experiencing transformation.

Originality/value

Individual readiness as a stand-alone concept was not enough explored in the literature, thus creating an opportunity for this study to fill the research gap. The lessons learned from this study are the following: ongoing change initiatives require longer time with a need to extend the organizational restructuring to behavioral and mindset change. This research suggests a practical approach to the assessment of change readiness in organizations. A simple model explaining factors affecting employees' willingness and ability to change has been suggested.
Transforming the role of frontline service employees for cross-selling
Authors: Yen HsiuJu Rebecca , Hu Paul Jen-Hwa , Liao Yi-Chun
Published: December 2020

Purpose

This study aims to examine how a manager’s learning goal orientation (LGO) influences frontline service employees’ (FSEs’) engagement in cross-selling activities. Such engagements must exist before they can achieve service–sales ambidexterity. Drawing on achievement goal theory and the meaning-making perspective, this study predicts that learning-oriented managers encourage and foster FSEs’ cross-selling behaviors by facilitating their ability to derive positive meaning from the cross-selling initiative. They do so by conveying high-quality information about the initiative and related changes to individual employees, as well as by encouraging the formation of a collective perception of open communications within the work unit.

Design/methodology/approach

Hierarchical (nested) data from 39 managers and 357 FSEs of a major logistic service company are used to test the hypotheses.

Findings

As predicted, a manager’s LGO relates positively to FSEs’ cross-selling activities, through sequential mediations of the hypothesized communication mechanisms and employees’ benefits-finding.

Originality/value

A manager’s LGO is an important antecedent of FSEs’ cross-selling behaviors. This study establishes this influence and clarifies the processes by which it occurs. This study also extends previous research by specifying the important role of employees’ meaning-making, which prompts them to adopt cross-selling, as a mediator of the multilevel communication influences that result from their managers’ LGO.
Exploring the challenges in protecting the identity of small historic towns in Malaysia
Authors: Azmi Nur Farhana , Ali Azlan Shah , Ahmad Faizah
Published: December 2020

Purpose

Built heritage constitutes the uniqueness and identity of a place. While being overlooked in existing research, built heritage in small towns is increasingly threatened by dilapidation, exhaustion and disappearance. Therefore, this study aims to examine the challenges in protecting the unique features and identity of small towns with regard to building regulations, guidelines and policies.

Design/methodology/approach

A semi-structured interview was conducted amongst a purposive sample of nine stakeholders from different organizations involved in heritage matters in Malaysia to investigate the issues and challenges facing the protection of small towns’ identity with regard to existing protection mechanisms impacting development of the towns. The data were then analyzed using the qualitative software package NVivo 8.0. The summary models imported from NVivo were created to visualize the connections between various dimensions of constructs, concepts and categories identified in the interviews.

Findings

The study found that the current issues of built heritage protection at the local level can be classified into five emergent themes: legislative, institutional, economic, social and technical issues. While absence of specific guideline for identifying local cultural places has been identified as the most fundamental issues facing the protection of unique and distinct resources in small Malaysia towns, the paper concludes with a framework of measures that can then be used for identification and protection of small town identity.

Originality/value

This study is the first of many fruitful contributions that examine heritage identification and protection mechanisms at the local level.
Solar absorptive coating: a thermally stable spinel pigment based coating with inorganic binder for waterborne paint
Authors: Joglekar-Athavale Amruta , Shankarling Ganapati , Dubey Satishchandra , Deshpande Vinita , Jaiswal Bikashkumar , Nayak Arun
Published: December 2020

Purpose

The spectrally selective solar absorption paint is prepared from spinel-based mixed metal oxides with inorganic binder as a key component. Inorganic binder (furnace cement) is blended with mixed metal oxide pigment during synthesis. High temperature stability upto 1,100ºC is achieved by the use of this modified coating system. The purpose of this paper is to work on solar selective coating synthesis, and application of a coating as a water-borne paint is the additive key feature that helps in reduction of solvent use.

Design/methodology/approach

The paint was formulated using water-based system, and the main component of colorant was made by mixed metal oxide–based spinel pigment and highly temperature stable inorganic binder.

Findings

The paint formed shows excellent absorptive power with low emittance even at high temperature. Optical and thermal properties were determined along with adhesion, abrasion and other properties. The solar absorptance for these samples were as = 0.93–0.95 with corresponding thermal emittance of eT = 0.096 (at room temperature) and 0.2–0.22 (at elevated temperature 100°C).

Originality/value

The paint formed shows excellent absorptive power with low emittance even at high temperature. The paint can be applied in solar absorptive tower system. The obtained results indicated excellent thermal stability of prepared paint coatings. As inorganic binder was used, the paint has reduction in solvent use, and being water as a base, it is environment friendly, easy to apply and durable at high temperatures, as the binder itself is stable up to 1,500ºC.
Influence of machine type and consecutive closed-loop recycling on macroscopic properties for fused filament fabrication of acrylonitrile-butadiene-styrene parts
Authors: Dal Fabbro Pierandrea , La Gala Andrea , Van De Steene Willem , D’hooge Dagmar R. , Lucchetta Giovanni , Cardon Ludwig , Fiorio Rudinei
Published: December 2020

Purpose

This study aims to evaluate and compare the macroscopic properties of commercial acrylonitrile-butadiene-styrene (ABS) processed by two different types of additive manufacturing (AM) machines. The focus is also on the effect of multiple closed-loop recycling of ABS.

Design/methodology/approach

A conventional direct-drive, Cartesian-type machine and a Bowden, Delta-type machine with an infrared radiant heating system are used to manufacture test specimens molded in ABS. Afterward, multiple closed-loop recycling cycles are conducted, involving consecutive AM (four times) and recycling (three times). The rheological, mechanical, morphological and physicochemical properties are investigated.

Findings

The type of machine affects the quality of the produced parts. The machine containing an infrared radiant system in a temperature-controlled chamber produces parts showing higher mechanical properties and filling fraction, although it increases the yellowing. Closed-loop recycling of ABS for AM is applicable for at least two cycles, inducing a slight increase in tensile modulus (ca. 5%) and in tensile strength (ca. 13%) and a decrease in the impact strength (ca. 14%) and melt viscosity. An increase in the filling fraction of the AM parts promotes an increase in tensile strength and tensile modulus, although it does not influence the impact strength. Furthermore, multiple closed-loop recycling does not affect the overall chemical structure of ABS.

Practical implications

Controlling the environmental temperature and using infrared radiant heating during AM of ABS improves the quality of the produced parts. Closed-loop recycling of ABS used in AM is feasible up to at least two recycling steps, supporting the implementation of a circular economy for polymer-based AM.

Originality/value

This study shows original results regarding the assessment of the effect of different types of AM machines on the main end-use properties of ABS parts and the influence of multiple closed-loop recycling on the characteristics of ABS fabricated by the most suited AM machine with an infrared radiant heating system and a temperature-controlled environment.
CEO network centrality and corporate social responsibility
Authors: Bouchet Adrien , Song Xuehu , Sun Li
Published: December 2020

Purpose

This study aims to examine the impact of a chief executive officer (CEO) social network centrality on corporate social responsibility (CSR) performance.

Design/methodology/approach

This study carries out a multivariate linear regression analysis on a panel data sample of 11,507 firm-year observations (representing 1,386 unique US firms) from 2004 to 2014.

Findings

This paper finds a significant negative relation between CEO network centrality and irresponsible CSR performance (measured as CSR concerns). The findings suggest that better-connected CEOs can better mitigate CSR concerns or weaknesses, leading to improved overall CSR performance of a firm.

Originality/value

This is the first study that directly examines the empirical link between CEO centrality and CSR performance.
Advances in study of the sequence of lung tumor biopsy and thermal ablation
Authors: Kong Fanlei , Wang Chengen , Li Yunfang , Li Xiaoguang
Published: December 2020

Percutaneous thermal ablation is an important treatment for lung cancer and is widely used in hospitals. Puncture biopsy is generally required for pathological diagnosis before or after thermal ablation. Pathological diagnosis provides both evidence of benign and malignant lesions for ablation therapy and is of important significance for the next step in disease management. Furthermore, the sequence of ablation and biopsy affects the accuracy of pathological diagnosis, the complete ablation rate of thermal ablation, and incidence of surgery‐related complications. Ultimately, it may affect the patient's benefit from local treatment. This article reviews the research progress of traditional asynchronous biopsy followed by ablation, the emerging methods of synchronous biopsy followed by ablation, and synchronous ablation followed by biopsy in the last decade.

Key points

The sequence of ablation and biopsy affects the accuracy of pathological diagnosis, the complete ablation rate of thermal ablation, and the incidence of surgical‐related complications.

This article reviewed the recent 10 years' literature on the surgical sequence of biopsy and ablation for lung tumors, the advantages, disadvantages and indications of different orders were analyzed.
Association of hOGG1‐Cys variants with occurrence of p53 and EGFR deletion mutations in non‐small cell lung cancer
Authors: Chen Ming‐Jenn , Shen Ching‐Ju , Wang Lee , Chen Po‐Ming , Chen Chih‐Yi , Lee Huei
Published: December 2020

Background

The human 8‐oxoguanine DNA glycosylase 1 (hOGG1) gene encodes a DNA glycosylase that removes 8‐hydroxy‐2‐deoxyguanine (8‐OH‐dG) DNA damage to protect against gene mutations. The association of hOGG1 Ser326Cys polymorphism with lung cancer risk has predicted that hOGG1‐Cys variants are less effective at removing 8‐OH‐dG damage from DNA; therefore, these variants might show an increased occurrence of tumor suppressor gene and oncogene mutations. However, no evidence has yet supported this hypothesis.

Methods

Direct sequencing was performed to examine the mutations of p53 and EGFR genes in lung tumors from patients with non‐small cell lung cancer (NSCLC). Polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) was used to examine hOGG1 Ser326Cys polymorphism in this study population.

Results

A total of 99 p53‐mutated and 99 EGFR‐mutated patients with NSCLC were selected to explore the possible associations of these mutations with hOGG1 Ser326Cys polymorphism. The p53‐mutated and EGFR‐mutated patients were divided into nondeletion and deletion subgroups. P53 deletion mutations were more commonly observed in male than in female patients (P = 0.030). However, EGFR exon 19 deletion mutations were more prevalent in female and adenocarcinoma patients than in male and squamous cell carcinoma patients (P = 0.028 for genders, P = 0.017 for tumor histology). Interestingly, p53 and EGFR exon 19 deletion mutations were more frequent in patients with hOGG1 Ser/Cys + Cys/Cys hOGG1‐Cys variants than with the hOGG1 Ser/Ser genotype (P = 0.010 for p53, P = 0.032 for EGFR).

Conclusions

We suggest that the association of hOGG1 Ser326Cys polymorphism with lung cancer risk could be partially explained by increases in p53 and EGFR deletion mutations.

Key points

Significant findings of the study

NSCLC patients with hOGG1‐Cys variants may have a higher risk of p53 and EGFR deletion mutations than with hOGG1 Ser/Ser genotype.

What this study adds

NSCLC patients with hOGG1‐Cys variants might be helpful to predict patients having higher risk of EGFR exon 19 deletion mutations and these patients who were treated with gefitinib or erlotinib could be a higher risk to occur EGFR T790M mutation.
Plasma miR‐1247‐5p, miR‐301b‐3p and miR‐105‐5p as potential biomarkers for early diagnosis of non‐small cell lung cancer
Authors: Dong Xiaohan , Chang Minghui , Song Xingguo , Ding Shanshan , Xie Li , Song Xianrang
Published: December 2020

Background

Accumulating evidence shows that microRNAs are aberrantly expressed and exert essential roles in the tumorigenesis and tumor progression of non‐small cell lung cancer (NSCLC).

Methods

The plasma miRNAs from five healthy donors and four NSCLC patients were profiled by miRNA microarray. The differentially expressed miRNAs from 154 primary NSCLC patients and 146 healthy donors were subjected to RNA isolation and verified by quantitative PCR (qPCR).

Results

The miRNA microarray analysis revealed that 40 differential miRNAs between NSCLC patients and healthy donors were selected. We found that the plasma miR‐1247‐5p, miR‐301b‐3p and miR‐105‐5p levels of patients were significantly higher than those of healthy controls. The receiver operating characteristic curve (ROC) analyses revealed higher area under the ROC curve (AUC) values and higher sensitivity/specificity of carcinoembryonic antigen (CEA) in combination with miR‐1247‐5p, miR‐301b‐3p, or miR‐105‐5p were superior to that of CEA alone.

Conclusions

High miR‐1247‐5p, miR‐301b‐3p and miR‐105‐5p expression have been demonstrated to accelerate tumorigenesis, and these three miRNAs in plasma act as novel biomarkers for the early diagnosis of NSCLC patients.

Key points

Plasma miR‐1247‐5p, miR‐301b‐3p and miR‐105‐5p act as novel biomarkers for early NSCLC and NSCLC.
The future of digital platforms: Conditions of platform overthrow
Authors: Thomas Maxime , Le Masson Pascal , Weil Benoit , Legrand Julien
Published: December 2020

Are the digital platforms that we know here to stay? Both empirical insights and theoretical works suggest digital platform stability. Digital platforms such as Airbnb, Netflix and Taobao have experienced tremendous success, and the theoretical works on modularity and multisided markets depict competitive platform landscapes as controlled by a hegemonic platform leader. However, platform history chronicles multiple cases of leadership shifts in platform ecosystems. In this paper, we coin these situations ‘platform overthrows’ and uncover the relevant strategies for both a challenger to conduct a platform overthrow and for a platform leader to resist it. To do so, we conducted an inductive protocol to reinterpret 27 already published cases of platform overthrow attempts. Our results suggest that, during a platform overthrow attempt, both players articulate functional expansion and technical genericity. Accordingly, we formulate propositions that account for the strategies at play during a platform overthrow attempt. We discuss these results regarding the digital platform literature on competition and conclude that the study of platform overthrow can yield useful insights on the future of digital platforms.
Evaluating tertiary adrenal insufficiency in rheumatology patients on long‐term systemic glucocorticoid treatment
Authors: Sagar Rebecca , Mackie Sarah , W. Morgan Ann , Stewart Paul , Abbas Afroze
Published: December 2020

Objective

Patients with rheumatic diseases are often treated with prolonged, high‐dose systemic glucocorticoids which can cause hypothalamic‐pituitary‐adrenal (HPA) axis suppression and development of tertiary adrenal insufficiency. Adrenal insufficiency carries the risk of serious, potentially life‐threatening adrenal crisis. Our study evaluated the prevalence, characteristics and recovery of patients with underlying rheumatology conditions who had received prolonged glucocorticoid treatment.

Design and patients

Retrospective, cross‐sectional study. We evaluated 238 patients seen in outpatient rheumatology clinic, managed in accordance with current nationally and internationally accepted clinical guidelines.

Measurements

Data collected included patient demographics, historical steroid data, 09.00 h cortisol/short synacthen test (SST) results and follow‐up data on those with repeat assessments.

Results

Overall, 65% of our cohort had a 09.00 h cortisol <350 nmol/L. On SST, 43% of patients demonstrated evidence of possible tertiary adrenal insufficiency.

Prednisolone equivalent dose at time of SST was significantly higher in the group who failed SST vs. those who passed; mean of 5.57 mg vs. 3.59mg (p = .005). 09.00 h cortisol result correlated with 30‐min cortisol on SST (R2 = .20, p = .002). 0‐min cortisol on SST correlated more strongly with 30‐min cortisol than 09.00 h cortisol (R2 = .59, p‐value < .001). Patients with 0‐min cortisol >350 nmol/L, all passed their SST.

Patients who remained on prednisolone were more likely to recover (71%) vs. those switched to hydrocortisone (27%), P = .02. Peak steroid dose was predictive of recovery; significantly lower in those who recovered (mean of 22.3 mg vs. 33.8 mg, P = .03). Steroid duration was not found to be a predictor of recovery [recovery (64.2 months) vs. non‐recovery (55.6 months), P = .58]. There was no correlation found to outcome on SST with age, sex, peak steroid dose, steroid duration, underlying rheumatological condition, additional exogenous steroid use or serum sodium.

Conclusions

Forty three percent of our patients demonstrated sub‐optimal adrenal function on SST. Steroid dose at the time of SST was the only significant predictive risk factor for tertiary adrenal insufficiency. 09.00 h cortisol demonstrated good correlation with outcome on SST and could represent a valid screening test to reduce need for SST if 09.00 h >350 nmol/L. Further prospective data are required to further characterize risk factors, predictive features of recovery and establish optimal management strategy of steroids (prednisolone vs hydrocortisone) to encourage adrenal recovery.
Postoperative Komplikationen bei dermatochirurgischen Patienten im Rahmen der stationären mikroskopisch‐kontrollierten Chirurgie: Eine monozentrische epidemiologische Studie
Authors: Artamonova Inga , Schmitt Laurenz , Yazdi Amir S. , Megahed Mosaad , von Felbert Verena , Balakirski Galina
Published: December 2020

Hintergrund

Postoperative Wundinfektionen (surgical site infections, SSI), Blutungen und Nekrosen sind mögliche Komplikationen im Rahmen dermatochirurgischer Eingriffe. Während für die Mohs‐Chirurgie (same‐day surgery) die Komplikationsraten gut beschrieben sind, ist für die in Deutschland etablierte stationäre mikroskopisch‐kontrollierte Chirurgie (next‐day surgery) die Datenlage begrenzt.

Patienten und Methodik

Wir führten eine retrospektive Analyse der Patientenakten durch und bezogen uns auf die Patienten, die im Jahr 2017 (12 Monate) im Rahmen einer mikroskopisch‐kontrollierten Hautchirurgie in der Klinik für Dermatologie und Allergologie des Universitätsklinikums der RWTH Aachen (Aachen, Deutschland) stationär behandelt wurden.

Ergebnisse

319 Patienten wurden in dem untersuchten Zeitraum 528 dermatochirurgischen Eingriffen unterzogen. Blutungen und Nekrosen traten bei 3,8 % (20/528) beziehungsweise 1,7 % (9/528) der Eingriffe auf. SSI traten in 5,1 % (27/528) der Fälle auf. Das Auftreten von Blutungen war ein statistisch signifikanter Risikofaktor für SSI (p  =  0,01). Darüber hinaus waren Blutungen, SSI und Wundverschluss mittels einer Vollhauttransplantation statistisch signifikante Risikofaktoren für die Entwicklung einer Nekrose (p < 0,05). Diabetes mellitus und Immunsuppression erwiesen sich nicht als statistisch signifikante Risikofaktoren für die Entwicklung einer SSI oder Nekrose nach dermatologischen Operationen (p > 0,05).

Schlussfolgerungen

Die Komplikationsraten bei stationären mikroskopisch‐kontrollierten dermatochirurgischen Eingriffen (next‐day surgery) sind relativ niedrig und vergleichbar mit den für die Mohs‐Chirurgie (same‐day surgery) beschriebenen Daten. Daher ist es wahrscheinlich möglich, einige evidenzbasierte, perioperative, für die Mohs‐Chirurgie entwickelte Empfehlungen auf die deutschen Standards für die stationäre Hautchirurgie zu übertragen. Dennoch sind prospektive Studien mit größeren Patientenzahlen erforderlich, um zuverlässige Empfehlungen speziell für die mikroskopisch‐kontrollierte Chirurgie der Haut (next‐day surgery) zu formulieren.
Diagnostischer Wert von Laborparametern zur Unterscheidung zwischen Erysipel und begrenzter Phlegmone
Authors: Drerup Christian , Eveslage Maria , Sunderkoetter Cord , Ehrchen Jan
Published: December 2020

Hintergrund und Ziele

Das Erysipel, hervorgerufen durch beta‐hämolysierende Streptokokken, und die begrenzte Phlegmone, häufig ausgelöst durch Staphylococcus aureus oder andere Bakterien, sind Infektionen der Haut und des Weichteilgewebes mit typischen klinischen Symptomen. Allerdings wird oft (etwa in klinischen Studien) nicht zwischen den beiden Krankheitsbildern differenziert, obwohl dies therapeutisch relevant sein könnte. Das Erysipel lässt sich mit Penicillin effektiv behandeln, während man für die begrenzte Phlegmone Antibiotika mit breiterem Spektrum benötigt. Diese Studie untersucht, inwieweit Parameter wie CRP, Blutbild oder neuere Parameter wie unreife Granulozyten als Biomarker dienen können, um zwischen den beiden Entitäten zu unterscheiden.

Patienten und Methoden

In diese retrospektive Analyse wurden 163 Patienten einbezogen. Wir verglichen Laborparameter von Patienten mit Erysipel (n  =  68) mit denen von Patienten mit begrenzter Phlegmone (n  =  41). In allen Fällen handelte es sich um Infektionen am Bein. Die Diagnose „Erysipel“ beziehungsweise „begrenzte Phlegmone“ wurde klinisch gestellt, mit dem zusätzlichen Aspekt, dass ein schnelles Ansprechen auf Penicillin für die Diagnose „Erysipel“ sprach.

Ergebnisse

Beim Erysipel war die Entzündungsreaktion stärker ausgeprägt. Als die besten Parameter zur Unterscheidung zwischen den beiden Formen der Infektion erwiesen sich CRP und Leukozytenzahl. Ein CRP‐Wert von ≥ 3,27 mg/dl sprach mit 75 % Sensitivität und 73,2 % Spezifität für die Diagnose „Erysipel“.

Schlussfolgerungen

Unsere Ergebnisse stützen die in den deutschen Leitlinien vertretene These, dass das Erysipel und die begrenzte Phlegmone unterschiedliche Formen der Entzündung sind. Die Bestimmung von CRP und Leukozyten hilft bei der Differenzialdiagnose.
Borrelia burgdorferi in primär kutanen Lymphomen: eine systematische Übersicht und Metaanalyse
Authors: Travaglino Antonio , Varricchio Silvia , Pace Mirella , Russo Daniela , Picardi Marco , Baldo Antonello , Staibano Stefania , Mascolo Massimo
Published: December 2020

Hintergrund

Der Zusammenhang zwischen Borrelia burgdorferi und primär kutanen Lymphomen ist nach wie vor ungeklärt. Diese systematische Übersicht und Metaanalyse hat das Ziel, den Zusammenhang zwischen Borrelia burgdorferi und den verschiedenen Entitäten primär kutaner Lymphome zu definieren.

Methoden

Elektronische Datenbanken wurden nach sämtlichen Studien durchsucht, in denen Borrelia‐burgdorferi‐DNA in Proben primär kutaner Lymphome untersucht wurde. Der Zusammenhang zwischen Borrelia und primär kutanen Lymphomen wurde mittels Odds‐Ratio (p < 0,05 signifikant) beurteilt; kutane Proben ohne lymphoproliferative Erkrankung dienten als Kontrollen. Eine sekundäre Analyse wurde zur Beurteilung der Prävalenz von Borrelia‐Infektionen bei verschiedenen Lymphom‐Entitäten durchgeführt.

Ergebnisse

Zehn Studien mit 506 primär kutanen Lymphomen und 201 Kontrollen wurden eingeschlossen. Die Prävalenz von Borrelia‐DNA war in Studien aus verschiedenen Regionen sehr heterogen. Ein positives Ergebnis für Borrelia‐DNA war signifikant mit primär kutanen Lymphomen assoziiert (Odds‐Ratio  = 10,88; p < 0,00001). Bei den verschiedenen Entitäten zeigte sich eine ähnliche Prävalenz von Borrelia‐DNA (Marginalzonenlymphom: 7,3 %; follikuläres Lymphom: 8,1 %; diffuses großzelliges B‐Zell‐Lymphom: 7,5 %; Mycosis fungoides: 8 %).

Schlussfolgerungen

Borrelia burgdorferi ist signifikant mit primär kutanen Lymphomen assoziiert. Dabei zeigten sich keine Unterschiede zwischen den verschiedenen Lymphom‐Entitäten (sowohl B‐Zell‐ als auch T‐Zell‐Lymphome), aber deutliche geografische Unterschiede. Molekulare Tests auf Borrelia wären bei Patienten mit primär kutanem Lymphom aus endemischen Gebieten gerechtfertigt.
Dissociable changes in spike and wave discharges following exposure to injected cannabinoids and smoked cannabis in Genetic Absence Epilepsy Rats from Strasbourg
Authors: Roebuck Andrew J. , Greba Quentin , Onofrychuk Timothy J. , McElroy Dan L. , Sandini Thaísa M. , Zagzoog Ayat , Simone Jonathan , Cain Stuart M. , Snutch Terrance P. , Laprairie Robert B. , Howland John G.
Published: December 2020

There is significant interest in the use of cannabinoids for the treatment of many epilepsies including absence epilepsy (AE). Genetic Absence Epilepsy Rats from Strasbourg (GAERS) model many aspects of AE including the presence of spike‐and‐wave discharges (SWDs) on electroencephalogram (EEG) and behavioral comorbidities, such as elevated anxiety. However, the effects of cannabis plant‐based phytocannabinoids have not been tested in GAERS. Therefore, we investigated how SWDs in GAERS are altered by the two most common phytocannabinoids, Δ9‐tetrahydrocannabinol (THC) and cannabidiol (CBD), and exposure to smoke from two different chemovars of cannabis. Animals were implanted with bipolar electrodes in the somatosensory cortex and EEGs were recorded for 2 hr. Injected THC (1–10 mg/kg, i.p.) dose‐dependently increased SWDs to over 200% of baseline. In contrast, CBD (30–100 mg/kg, i.p.) produced a ~50% reduction in SWDs. Exposure to smoke from a commercially available chemovar of high‐THC cannabis (Mohawk, Aphria Inc.) increased SWDs whereas a low‐THC/high‐CBD chemovar of cannabis (Treasure Island, Aphria Inc.) did not significantly affect SWDs in GAERS. Pre‐treatment with a CB1R antagonist (SR141716A) did not prevent the high‐THC cannabis smoke from increasing SWDs, suggesting that the THC‐mediated increase may not be CB1R‐dependent. Plasma concentrations of THC and CBD were similar to previously reported values following injection and smoke exposure. Compared to injected CBD, it appears Treasure Island did not increase plasma levels sufficiently to observe an anti‐epileptic effect. Together these experiments provide initial evidence that acute phytocannabinoid administration exerts the biphasic modulation of SWDs and may differentially impact patients with AE.
Multifractal analysis of soil particle size distribution to evaluate the effects of gypsum on the quality of sodic soils
Authors: Liao Renkuan , Yu Haoliang , Yang Peiling
Published: December 2020

Soil particle size distribution (PSD) essentially determines the soil's physical characteristics, including aggregate stability and porosity. Evaluating the PSD of sodic soils altered by reclamation is beneficial to the development of strategies for addressing land degradation. However, it remains unclear how to extract the features of PSD of sodic soils sensitively under gypsum reclamation. In this study, a total of 108 soil samples collected from a reclaimed sodic field were measured for PSD along with other soil properties, including hydraulic conductivity. Almost all the reclaimed sodic soil was measured to be silt loam, which was not obviously different from their original texture. The concentration, uniformity and symmetry of PSD of sodic soils have been quantified by fractal and multifractal geometry methods, in which the multifractal method provided more parameters than the fractal method to characterize the features of PSD more sensitively. The multifractal method offering predictive parameters (i.e., D1, D2, αmin and α0‐αmin) was able to significantly (p < 0.05) differentiate the features of PSD. The multifractal results indicated that the heterogeneity of PSD at 0–60‐cm depth was increased by reclamation, whereas the major particle size (silt) in these sodic soils decreased, and the combined treatment (i.e., using flue gas desulphurization [FGD] gypsum plus leaching water) created the most heterogeneous PSD. The redistribution of soil particle size caused by reclamation treatments resulted in the improvement of soil physical and chemical properties, showing increased soil aggregate diameter, raised total porosity, enhanced saturated hydraulic conductivity and decreased pH. The findings of this study bring a new opportunity to evaluate the effects of gypsum on the quality of sodic soils from the PSD perspective, which also provides a reference for evaluation of reclamation of other poor soils.

Highlights

The quantification of soil particle size distribution (PSD) of sodic soils remains unclear.

A field evaluation using the multifractal method to characterize the PSD of sodic soil.

With the reduction of silt particles, the heterogeneity of PSD was increased by reclamation.

This study provides a new perspective for evaluation of the effects of gypsum on quality of sodic soils.
AJUBA: A regulator of epidermal homeostasis and cancer
Authors: Schleicher Krista , Schramek Daniel
Published: December 2020

The epidermis, outermost layer of the skin, is constantly renewing itself through proliferative and differentiation processes. These processes are vital to maintain proper epidermal integrity during skin development and homeostasis and for preventing skin diseases and cancers. The biological mechanisms that permit this balancing act are vast, where individual pathway regulators are known, but the exact regulatory control and cross‐talk between simultaneously turning one biological pathway on and an opposing one off remain elusive. This review explores the diverse roles the scaffolding protein AJUBA plays during epidermal homeostasis and cancer. Initially identified for its role in promoting meiotic progression in oocytes through Grb2 and MAP kinase activity, AJUBA also maintains cytoskeletal tension permitting epidermal tissue development and responds to retinoic acid committing cells to initiate development of surface epidermal layer. AJUBA regulates proliferation of skin stem cells through Hippo and Wnt signalling and encourages mitotic commitment through Aurora‐A, Aurora‐B and CDK1. In addition, AJUBA also induces epidermal differentiation to maintain appropriate epidermal thickness and barrier function by activating Notch signalling and stabilizing catenins and actin during cellular remodelling. AJUBA also plays an imperative context‐dependent tumor‐promoting and tumor‐suppressive role within epithelial cancers. AJUBA’s abundant roles within the epidermis signify its importance as a molecular switchboard, vetting multiple signalling pathways to control epidermal biology.