bluuebunny/crossref_metadata_2025 huggingface dataset:
Isogonal weavings on the sphere: knots, links, polycatenanes
Authors: O'Keeffe Michael , Treacy Michael M. J.
Published: August 2020

Mathematical knots and links are described as piecewise linear – straight, non-intersecting sticks meeting at corners. Isogonal structures have all corners related by symmetry (`vertex'-transitive). Corner- and stick-transitive structures are termed regular. No regular knots are found. Regular links are cubic or icosahedral and a complete account of these (36 in number) is given, including optimal (thickest-stick) embeddings. Stick 2-transitive isogonal structures are again cubic and icosahedral and also encompass the infinite family of torus knots and links. The major types of these structures are identified and reported with optimal embeddings. The relevance of this work to materials chemistry and biochemistry is noted.
Formation of a nonanuclear copper(II) cluster with 3,5-dimethylpyrazolate starting from an NHC complex of copper(I) chloride
Authors: Dodds Christopher A. , Kennedy Alan R.
Published: August 2020

The complete nonanuclear cluster in bis[1,3-bis(2,6-dimethylphenyl)imidazolium] di-μ-chlorido-tetrachloridooctakis(μ-3,5-dimethylpyrazolato)hexa-μ3-hydroxido-nonacopper(II) chloroform disolvate, [HIXy]2[Cu9(μ-pz*)8(μ3-OH)6(μ2-Cl)2Cl4]·2CHCl3 or (C19H21N2)2[Cu9(C5H7N2)8Cl6(OH)6]·2CHCl3, where pz* is the 3,5-dimethylpyrazolyl anion, C5H7N2
−, and HIXy is the 1,3-bis(2,6-dimethylphenyl)imidazolium cation, C19H21N2
+, is generated by a crystallographic centre of symmetry with a square-planar CuII ion bound to four μ3-OH ions lying on the inversion centre. Of the four remaining unique CuII atoms, three adopt CuN2O2Cl square-pyramidal coordination geometries with the chloride ion in the apical position and one has a distorted CuN2OCl tetrahedral geometry. The dianionic nonanuclear core can be described as a 24-membered [CuNN]8 ring that contains a Cu9O6Cl6 core. The cluster features three intramolecular O—H...Cl hydrogen bonds. In the crystal, weak C—H...N and C—H...Cl interactions link the components. Polynuclear paramagnetic clusters of this type are of considerable interest due to their relevance to both the bioinorganic and single-molecule magnets research fields.
Antecedents of entrepreneurial intentions of electrical installation and maintenance work students’ in technical colleges
Authors: Shodipe Taiwo Olabanji , Ohanu Ifeanyi Benedict
Published: August 2020

Purpose

Extending the theory of planned behaviour and the perspective of available resources, the purpose of this study is to expatiate the influence behavioural antecedents of available resources on electrical installation and maintenance work students’ (EIMW) entrepreneurial intentions (EIs) in technical colleges.

Design/methodology/approach

The study adopted a multistage sampling technique to select samples for the study. Data collected were analyzed using structural equation models in the empirical analysis.

Findings

The study showed that attitude, subjective norms, perceived behavioural control and perceived efficacy are behavioural antecedents that can be manipulated by exogenous factors to enhance EIMW students’ EIs.

Originality/value

This study stirs the government and other education agencies on the need to strengthen the technical institutions through adequate funding, employment of skilled personnel and provision of up-to-date types of machinery and equipment to help the students to compete globally. Therefore, adequate application of available resources will foster positive behaviours of EIMW students towards establishing their business venture.
The implications of Political Party Funding Act, No. 6 of 2018 in South Africa on records management
Authors: Netshakhuma Nkholedzeni Sidney
Published: August 2020

Purpose

This paper aims to assess the Section 12 of the Political Party Funding Act No. 6 of 2018 of South Africa with a view of recommending good records management practice.

Design/methodology/approach

This paper is based on a literature review and an analysis of political funding access to information and records management literatures.

Findings

The study found that a lack of good records management practice is hindering transparency in government practice in South Africa. Furthermore, the enactment of the Political Party Funding Act No. 6 of 2018 has created the potential for South Africa political parties to start applying good records management practices.

Research limitations/implications

This research is limited to Section 12 of the political parties funding Act No 6 of 2018 to promote accountability transparency.

Practical implications

The effective implementation of the Political Party Funding Act, 2018 will contribute to the preservation of records with financial, historical and cultural values.

Social implications

The implementation of the Political Party Funding Act No. 6 of 2018 Section 12 is expected to lead an open, transparent and accountable South African society through the establishment of a a records management programme.

Originality/value

This paper raises important considerations around ensuring compliance and accountability in government recordkeeping within the context of recent legislation. While discussion around the importance and use of records management is not new, the legislation brings an opportunity for fresh discussion within a national political context.
Factors affecting level of unemployment in South Asia
Authors: Shabbir Aiza , kousar Shazia , Zubair Alam Muhammad
Published: August 2020

Purpose

This study aims to investigate the short-run and long-run relationship between economic variables and the unemployment rate in South Asian countries.

Design/methodology/approach

A panel Vector Error Correction (VECM) model is used to establish the long-run and the short-run relationship between unemployment rate and selected economic variables. Data were collected from WDI, WGI and FDSD for the year's 1994–2016.

Findings

The finding of the study showed a negative and significant relationship at the 5% level of significance among governance, internet users, mobile cellular subscriptions, fixed broadband subscriptions and human capital with an unemployment rate of South Asian economies. On the other hand, financial activity (credit) and population growth have a positive and significant relationship with the unemployment rate.

Research limitations/implications

In the light of our findings clear that employment problems can only be created if the government does not put in place adequate measures to control the population and allocate resources equitably, giving a sense of belonging to all citizens. Therefore, to provide the controlled population with the necessary employment opportunities, it is necessary to allocate resources efficiently and to launch projects aimed at creating jobs.

Practical implications

Transparency or merit is the basis of good governance and the very first step to achieving the goal of good governance is to fight against corruption. It provides a complete justification for providing good quality management records, financial controlling and managerial systems.

Originality/value

The connections between governance and unemployment are complex and need to be studied in a detailed manner. There is the absence of literature that strongly interfaces good governance to unemployment; the fundamental work in this regard is Farid (2015). They locate a solid relationship between good governance and improving external debt situation by in Pakistan a time series analysis. But there is no research in the context of South Asian countries between governance and unemployment.
Exploring the effects of “excessive tourism growth” on public health and ecosystem
Authors: Sari Ferika Ozer , Nazli Murat
Published: August 2020

Purpose

The purpose of this research is to explore and understand the effects of excessive tourism growth on public health, local people and the ecosystem. The secondary purpose of the study is to link excessive tourism growth to social exchange theory, in terms of interchanging key resources of tourism destinations.

Design/methodology/approach

This is an exploratory study where qualitative research methods are employed. Telephone interview technique is used to obtain data from academicians who work at various universities in Turkey. Content analysis and thematic analysis with an inductive approach are made by use of MAXQDA software program.

Findings

Findings reveal that the satisfaction of local people is an important gain in terms of the economy, but the destruction of the ecosystem due to the excessive crowd, in a sense, overtourism, garbage and too much waste is striking disadvantage based on the responses. Risk of contagious disease, effects on the natural environment and wastes are stated to have huge impacts on the public health and ecosystem.

Practical implications

The study identifies some implications in terms of imbalance and unfairness among the locals who face with excessive crowds. Managing the effects of excessive tourism growth on vulnerable destinations and local people, controlling the carrying capacity in destinations with anxiety, fear, depression, health problems and low living standards should be taken under consideration. Additionally, finding ways to get rid of infectious diseases (such as increasing health checkpoints at borders, investigating the carrying capacity of destinations) is important for tourism spots.

Originality/value

As a major theoretical contribution, this study links excessive tourism growth to social exchange theory and reveals that the degree of exchanging valuable resources in the destination and the level of interaction between locals and tourists are the most critical points for the well-being of the local community and ecosystem.
Estimation of the knowledge management model for performance measurement in university libraries
Authors: Rafi Muhammad , Jian Ming Zheng , Ahmad Khurshid
Published: August 2020

Purpose

The study aims to expand the literature on evaluating the performance of professionals and academic libraries, rationalizing management and providing reliable services to the academic community. The performance assessment model covers the four components (management competence, professional experience, financial add/projects and library services) in the context of the knowledge management model.

Design/methodology/approach

Based on quantitative data, the study defines a set of assumptions for testing the four components of performance evaluation within a knowledge management framework to develop appropriate and robust models for improving employee performance and library services. The structural equation model has been applied to sample data from 339 administrative librarians at 190 universities in Pakistan.

Findings

Statistical evidence confirms that the applicability of the proposed performance-based model enhances management competence, makes accurate decisions, develops professional skills and strengthens human resource organization and knowledge management techniques in developing the efficiency of academic libraries.

Practical implications

In the long term, academic leaders and policymakers value investment in the professional development of top library management as they participate in the decision-making process. Organizing training for service employees, supporting innovative research projects and providing library technology infrastructures ultimately improve academic performance and research when integrated into the knowledge management model.

Originality/value

So far, comprehensive literature on performance and knowledge management has been published separately. However, based on the key data collected by senior library administrators using the structured research questionnaire, the comprehensive performance evaluation research based on a knowledge management model is innovative to improve academic library services and close the literature gap.
English language professors' experiences in using social media network Telegram in their classes: a critical hermeneutic study in the context of Iran
Authors: Kayzouri Amir Hossein , Mohebiamin Amineh , Saberi Reza , Bagheri-Nia Hassan
Published: August 2020

Purpose

This qualitative study sought to explore how Iranian English language professors used social media network Telegram in their classes and what possibilities and constraints they experienced with regard to classroom interactions and university education, and how they rethought the use of social media network Telegram.

Design/methodology/approach

Data were collected through written reflective exercises and semi-structured interviews. Furthermore, data were analyzed based on three moments of critical hermeneutics: a moment of social-historical analysis, a moment of formal analysis and a moment of interpretation-reinterpretation.

Findings

The analysis of the data led to four themes: a dialogic classroom, the critical awareness of power-relations, the critical reflection on the experiences of the classroom and digital inequality. In fact, the participants pointed out that using social media network Telegram could lead to the persuasive discourse and multiplicity of voices as opportunities for sharing knowledge and distributing powers.

Originality/value

Indeed, the present study addressed the learning processes resulted from using social media network Telegram rather than the product and outcome that were mainly addressed by the previous studies by considering three levels of descriptions, which included micro-level of the learner and teacher interaction, meso-level of the processes of educational institutions and macro-level of wider cultural and societal contexts.
Nonlinear and linearized gray box models of direct-write printing dynamics
Authors: Simeunović Andrej , Hoelzle David John
Published: August 2020

Purpose

The purpose of this study is to develop nonlinear and linearized models of DW printing dynamics that capture the complexity of DW while remaining integrable into control schemes. Control of material metering in extrusion-based additive manufacturing modalities, such as positive displacement direct-write (DW), is critical for manufacturing accuracy. However, in DW, transient flows are poorly controlled due to capacitive pressure dynamics – pressure is stored and slowly released over time from the build material and other compliant system elements, adversely impacting flow rate start-ups and stops. Thus far, modeling of these dynamics has ranged from simplistic, potentially omitting key contributors to the observed phenomena, to highly complex, making usage in control schemes difficult.

Design/methodology/approach

The authors present nonlinear and linearized models that seek to both capture the capacitive and nonlinear resistive fluid elements of DW systems and to pose them as ordinary differential equations for integration into control schemes. The authors validate the theoretical study with experimental flow rate and material measurements across a range of extrusion nozzle sizes and materials. The authors explore the contribution of the system and build material bulk modulus to these dynamics.

Findings

The authors show that all tested models accurately describe the measured dynamics, facilitating ease of integration into future control systems. Additionally, the authors show that system bulk modulus may be substantially reduced through appropriate system design. However, the remaining build material bulk modulus is sufficient to require feedback control for accurate material delivery.

Originality/value

This study presents new nonlinear and linear models for DW printing dynamics. The authors show that linear models are sufficient to describe the dynamics, with small errors between nonlinear and linear models. The authors demonstrate control is necessary for accurate material delivery in DW.
How do perceived CPA and political CSR interact in their relationships with citizens’ trust in companies?
Authors: Tortosa-Edo Vicent , López-Navarro Miguel Ángel
Published: August 2020

Purpose

In the context of an industrial complex where corporate political activity (CPA) and political corporate social responsibility (political CSR) are not related, this study aims to investigate the possible relationship between citizens’ perceptions of these two non-market strategies and residents’ trust in companies located in the industrial complex.

Design/methodology/approach

Data were collected from 740 citizens living near a petrochemical complex in Tarragona (Spain). The results were analysed using structural equation modelling.

Findings

Based on institutional theory, the key findings of the study are that CPA and political CSR are differently related to citizens’ trust in companies. The results also verify that the negative relationship (between CPA and trust) outweighs the positive one (between political CSR and trust).

Practical implications

The lack of fit between political CSR and CPA in the complex analysed suggests that firms are neglecting approaches shared by these non-market strategies, and thus wasting a huge opportunity to improve citizens’ trust in and acceptance of the complex firms. Moreover, the ethical dimension should always be present when these firms take on political responsibilities.

Originality/value

To date, CPA and political CSR have largely been dealt with separately in the literature. This study attempted to bridge this gap by examining a situation where there is no strategic relationship between CPA and political CSR to analyse, from the perspective of citizens’ perceptions, the relationship each strategy has with the important academic concept of citizens’ trust in companies.
Combining discrete cosine transform and convolutional neural networks to speed up the Hamiltonian Monte Carlo inversion of pre‐stack seismic data
Authors: Aleardi Mattia
Published: August 2020

Markov chain Monte Carlo algorithms are commonly employed for accurate uncertainty appraisals in non‐linear inverse problems. The downside of these algorithms is the considerable number of samples needed to achieve reliable posterior estimations, especially in high‐dimensional model spaces. To overcome this issue, the Hamiltonian Monte Carlo algorithm has recently been introduced to solve geophysical inversions. Different from classical Markov chain Monte Carlo algorithms, this approach exploits the derivative information of the target posterior probability density to guide the sampling of the model space. However, its main downside is the computational cost for the derivative computation (i.e. the computation of the Jacobian matrix around each sampled model). Possible strategies to mitigate this issue are the reduction of the dimensionality of the model space and/or the use of efficient methods to compute the gradient of the target density. Here we focus the attention to the estimation of elastic properties (P‐, S‐wave velocities and density) from pre‐stack data through a non‐linear amplitude versus angle inversion in which the Hamiltonian Monte Carlo algorithm is used to sample the posterior probability. To decrease the computational cost of the inversion procedure, we employ the discrete cosine transform to reparametrize the model space, and we train a convolutional neural network to predict the Jacobian matrix around each sampled model. The training data set for the network is also parametrized in the discrete cosine transform space, thus allowing for a reduction of the number of parameters to be optimized during the learning phase. Once trained the network can be used to compute the Jacobian matrix associated with each sampled model in real time. The outcomes of the proposed approach are compared and validated with the predictions of Hamiltonian Monte Carlo inversions in which a quite computationally expensive, but accurate finite‐difference scheme is used to compute the Jacobian matrix and with those obtained by replacing the Jacobian with a matrix operator derived from a linear approximation of the Zoeppritz equations. Synthetic and field inversion experiments demonstrate that the proposed approach dramatically reduces the cost of the Hamiltonian Monte Carlo inversion while preserving an accurate and efficient sampling of the posterior probability.
Monitoring of seagrass along southern Andaman coast of Thailand
Authors: Rattanachot Ekkalak , Stankovic Milica , Tuntiprapas Piyalap , Prempree Supaporn , Prathep Anchana
Published: August 2020

Seagrass ecosystems provide various important ecosystem services in the marine environment. However, their global distribution has been declining since the 1800s. At the current rate of decline of almost 1.5% per year, almost half the meadows will be lost in the next 100 years. To prevent or minimize their loss, global monitoring programs have been established, such as SeagrassNet. The aim of the program is to introduce a global monitoring protocol and to preserve seagrass ecosystems by increasing scientific knowledge of them. The aim of this study was to gather data obtained by this protocol and to set a baseline for knowledge of the seagrass meadows in marine national parks in Southern Thailand. The data were collected from February 2006 until March 2009, three times a month at three national parks: Haad Chao Mai, Tarutao and Mu Ko Petra. At each site, the data were obtained along three transects parallel to the coast with 12 quadrats, in which species coverage and biomass above and below ground were recorded. These data sets can be used in future seagrass health assessments, in observation of the temporal changes of the meadows and as a baseline for restoration efforts.

The complete data set for this abstract published in the Data Paper section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2020-10.1/jalter-en.
Nanoliposomes coencapsulating curcumin and vitamin D3 produced by hydration of proliposomes: Effects of the phospholipid composition in the physicochemical characteristics of vesicles and after incorporation in yoghurts
Authors: A. Chaves Matheus , Franckin Vinicius , Sinigaglia‐Coimbra Rita , Pinho Samantha C.
Published: August 2020

Nanoliposomes coencapsulating curcumin and vitamin D3 (VD3) using different compositions of purified and unpurified lecithins were produced by hydration of proliposomes and characterised over 15 days of storage. The dispersions were incorporated to pineapple yoghurts produced in laboratory‐scale, which were also characterised. Results showed that curcumin and vitamin D3 were retained in the nanovesicles up to 86.1% and 94.1%, respectively. Most of the parameters assessed for the yoghurt samples were within the limits required by the Brazilian legislation and the Codex Alimentarius. Finally, the enriched product was well accepted by the panellists with the purchase intention ranging from 53 to 75%.
Locking up my generation: Cohort differences in prison spells over the life course
Authors: Shen Yinzhi , Bushway Shawn D. , Sorensen Lucy C. , Smith Herbert L.
Published: August 2020

Crime rates have dropped substantially in the United States, but incarceration rates have remained high. The standard explanation for the lasting trend in incarceration is that the policy choices from the 1980s and 1990s were part of a secular increase in punitiveness that has kept rates of incarceration high. Our study highlights a heretofore overlooked perspective: that the crime–punishment wave in the 1980s and 1990s created cohort differences in incarceration over the life course that changed the level of incarceration even decades after the wave. With individual‐level longitudinal sentencing data from 1972 to 2016 in North Carolina, we show that cohort effects—the lingering impacts of having reached young adulthood at particular times in the history of crime and punishment—are at least as large (and likely much larger) than annual variation in incarceration rates attributable to period‐specific events and proclivities. The birth cohorts that reach prime age of crime during the 1980s and 1990s crime–punishment wave have elevated rates of incarceration throughout their observed life course. The key mechanism for their elevated incarceration rates decades after the crime–punishment wave is the accumulation of extended criminal history under a sentencing structure that systematically escalates punishment for those with priors.
Storage characteristics of two‐spotted cricket (Gryllus bimaculatus De Geer) powder according to drying method and storage temperature
Authors: Lee Ha Eun , Bang Won Yeong , Kim Yeojin , Bae Sujin , Hahn Dongyup , Jung Young Hoon
Published: August 2020

In order to broaden the usability of the two‐spotted cricket (Gryllus bimaculatus De Geer) as a food ingredient, we investigated the effects of freeze‐drying and hot air‐drying, as well as the effects of storage at various temperatures (4–40°C), on the quality of cricket powder during short‐term storage. We found that the water absorption index values of freeze‐dried and hot air‐dried powder were 3.6 and 3.0 g/g, respectively, while the pH and color values of the powders were similar for the two drying methods. During storage at various temperatures over 14 days, water absorption and pH remained similar regardless of the drying method and storage temperature. However, freeze‐dried powder showed more color change compared to air‐dried powder according to their chroma values. In total bacteria and Escherichia coli detection tests, Escherichia coli was not detected under all storage conditions, whereas total bacteria were observed (~4 Log CFU/g) only in freeze‐dried powder stored for 14 days at 40°C. Therefore, our results suggest that the quality characteristics of two‐spotted cricket powder can be affected by the drying method applied, but these powders can be maintained for 14 days, largely without changes, at storage temperatures up to 40°C.
Adverse events in meditation practices and meditation‐based therapies: a systematic review
Authors: Farias M. , Maraldi E. , Wallenkampf K. C. , Lucchetti G.
Published: August 2020

Objective

Meditation techniques are widely used as therapy and wellbeing practices, but there are growing concerns about its potential for harm. The aim of the present study is to systematically review meditation adverse events (MAEs), investigating its major clinical categories and its prevalence.

Method

We searched PubMed, PsycINFO, Scopus, Embase and AMED up to October 2019. Eligible studies included original reports of meditation practices (excluding related physical practices such as Yoga postures) with adult samples across experimental, observational and case studies. We identified a total of 6742 citations, 83 of which met the inclusion criteria for MAEs with a total of 6703 participants who undertook meditation practice.

Results

Of the 83 studies analysed, 55 (65%) included reports of at least one type of MAE. The total prevalence of adverse events was 8.3% (95% CI 0.05–0.12), though this varied considerably across types of studies – 3.7% (95% CI 0.02–0.05) for experimental and 33.2% (95% CI 0.25–0.41) for observational studies. The most common AEs were anxiety (33%, 18), depression (27%, 15) and cognitive anomalies (25%, 14); gastrointestinal problems and suicidal behaviours (both 11%, 6) were the least frequent.

Conclusion

We found that the occurrence of AEs during or after meditation practices is not uncommon, and may occur in individuals with no previous history of mental health problems. These results are relevant both for practitioners and clinicians, and contribute to a balanced perspective of meditation as a practice that may lead to both positive and negative outcomes.
Efficacy of different irrigation activation systems on bacterial extrusion
Authors: Uğur Aydın Zeliha , Erdönmez Demet , Ateş Melis Oya , Doğan Tülin
Published: August 2020

The purpose of this study was to evaluate the quantity of extruded bacteria following with EndoVac, EDDY, EndoActivator (EA) and standard needle irrigation (SNI). Ninety teeth with a single root and canal were included in this study. Fifteen teeth were selected as the negative control group to confirm sterilization. Seventy‐five teeth were contaminated with Enterococcus faecalis (E. faecalis) for 4 weeks. Teeth were prepared and divided into five groups (n:15): EndoVac, EDDY, EA, SNI and positive control groups. The extruded bacteria were cultured for bacterial quantification. The counts of extruded bacteria were lower in the EndoVac group compared to the EDDY group (P˂ 0.05). The counts of extrusion bacteria were not different in EA and SNI groups compared to EDDY and EndoVac groups (P > 0.05). Within the limits of this study, EndoVac was found to be more reliable irrigation systems than EDDY in terms of the bacterial extrusion.
Trends in preterm birth in twin pregnancies in Victoria, Australia, 2007–2017
Authors: Burger Renée J. , Temmink Sofieke , Wertaschnigg Dagmar , Ganzevoort Wessel , Reddy Maya , Davey Mary‐Ann , Wallace Euan Morrison , Mol Ben‐Willem
Published: August 2020

Background

Preterm birth is a major cause of perinatal morbidity and mortality worldwide. In many countries, the preterm birth rate in women with a multiple pregnancy is increasing, mostly due to an increase in iatrogenic preterm birth.

Aims

To investigate trends in preterm birth in twin pregnancies in Victoria, Australia, in relation to maternal and perinatal complications.

Materials and methods

We conducted a retrospective population‐based cohort study in all women with a twin pregnancy who delivered at or after 20 weeks of gestation in the state of Victoria, Australia between 2007 and 2017. Annual spontaneous and iatrogenic preterm birth rates were calculated and trends analysed. Incidence of adverse pregnancy outcomes, maternal complications and risk factors for preterm birth were analysed.

Results

We studied 12 757 women with a twin pregnancy. Between 2007 and 2017 the preterm birth rate increased from 641/1231 (52%) to 803/1158 (69%), mainly due to an increase in iatrogenic preterm birth from 342/1231 (28%) to 567/1158 (49%). This was irrespective of the presence of pregnancy complications. Our study showed neither a decrease in perinatal mortality from 28 weeks of gestation nor in preterm average weekly prospective stillbirth risk.

Conclusion

Preterm birth rates in twins in Victoria are increasing, mainly driven by an increase in iatrogenic preterm birth. This occurred both in complicated and non‐complicated twin pregnancies, and has not been accompanied by reduction in perinatal mortality from 28 weeks.
A batch‐effect adjusted Simon's two‐stage design for cancer vaccine clinical studies
Authors: Wang Chenguang , Wang Zhixin , Rosner Gary L. , Huh Warner K. , Roden Richard B.S. , Bae Sejong
Published: August 2020

In the development of cancer treatment vaccines, phase II clinical studies are conducted to examine the efficacy of a vaccine in order to screen out vaccines with minimal activity. Immune responses are commonly used as the primary endpoint for assessing vaccine efficacy. With respect to study design, Simon's two‐stage design is a popular format for phase II cancer clinical studies because of its simplicity and ethical considerations. Nonetheless, it is not straightforward to apply Simon's two‐stage design to cancer vaccine studies when performing immune assays in batches, as outcomes from multiple patients may be correlated with each other in the presence of batch effects. This violates the independence assumption of Simon's two‐stage design. In this paper, we numerically explore the impact of batch effects on Simon's two‐stage design, propose a batch‐effect adjusted Simon's two‐stage design, demonstrate the proposed design by both a simulation study and a therapeutic human papillomavirus vaccine trial, and briefly introduce a software that implements the proposed design.
A Dynamic Quantitative Systems Pharmacology Model of Inflammatory Bowel Disease: Part 1 – Model Framework
Authors: Rogers Katharine V. , Martin Steven W. , Bhattacharya Indranil , Singh Ravi Shankar Prasad , Nayak Satyaprakash
Published: August 2020

A mechanistic, multistate, mathematical model of inflammatory bowel disease (IBD) was developed by including key biological mechanisms in blood and gut, including cell differentiation, cytokine production, and clinical biomarkers. The model structure is consistent between healthy volunteers and IBD disease phenotype, with 24 parameters changed between diseases. Modular nature of the model allows for easy incorporation of new mechanisms or modification of existing interactions. Model simulations for steady‐state levels of proteins and cells in the blood and gut using a population approach are consistent with published data. By simulating the response of two clinical biomarkers, C‐reactive protein and fecal calprotectin, to parameter perturbations, the model explores hypotheses for possible treatment mechanisms. With additional experimental validation and addition of drug treatments, the model provides a platform to test hypothesis on treatment effects in IBD.
COVID‐19 und Immunregulation – von grundlegenden und translationalen Aspekten zu klinischen Implikationen
Authors: Schön Michael P. , Berking Carola , Biedermann Tilo , Buhl Timo , Erpenbeck Luise , Eyerich Kilian , Eyerich Stefanie , Ghoreschi Kamran , Goebeler Matthias , Ludwig Ralf J. , Schäkel Knut , Schilling Bastian , Schlapbach Christoph , Stary Georg , von Stebut Esther , Steinbrink Kerstin
Published: August 2020

Die durch SARS‐CoV‐2 verursachte Pandemie COVID‐19 hat weitreichende direkte und indirekte medizinische Folgen. Dazu gehören sowohl der Verlauf als auch die Behandlung vieler Krankheiten. Es wird immer deutlicher, dass Infektionen mit SARS‐CoV‐2 erhebliche immunologische Veränderungen verursachen können, die insbesondere auch pathogenetisch und/oder therapeutisch relevante Faktoren betreffen.

Vor diesem Hintergrund fassen wir hier den aktuellen Wissensstand zur Interaktion von SARS‐CoV‐2/COVID‐19 mit Mediatoren der akuten Phase der Entzündung (TNF, IL‐1, IL‐6), der Typ‐1‐ und Typ‐17‐Immunantwort (IL‐12, IL‐23, IL‐17, IL‐36), Typ‐2‐Immunreaktionen (IL‐4, IL‐13, IL‐5, IL‐31, IgE), B‐Zell‐Immunität, Checkpoint‐Regulatoren (PD‐1, PD‐L1, CTLA4) und Signalwegen, die durch oral applizierte Medikamente moduliert werden (JAK, PDE4, Calcineurin), zusammen. Darüber hinaus diskutieren wir in diesem Zusammenhang die unspezifische Immunmodulation durch Glukokortikosteroide, Methotrexat, Malariamittel, Azathioprin, Dapson, Mycophenolsäure‐Derivate und Fumarsäureester sowie angeborene Immunmechanismen neutrophiler Granulozyten.

Aus diesen neueren Erkenntnissen leiten wir mögliche Implikationen für die therapeutische Modulation der genannten immunologischen Mechanismen im Zusammenhang mit SARS‐CoV‐2/COVID‐19 ab. Obwohl natürlich bei Patienten mit immunologisch vermittelten Krankheiten oder immunmodulierenden Therapien größte Vorsicht geboten ist, scheint es, dass viele Behandlungen auch während der COVID‐19‐Pandemie durchgeführt werden können; einige scheinen COVID‐19 sogar zu lindern.
Kontinuierliche medizinische Fortbildung in der Dermatologie für Ärzte und Studierende während der Coronavirus‐Pandemie – eine große Herausforderung
Authors: Martin Alice , Lang Estefanía , Ramsauer Babett , Gröning Thilo , Bedin Gustavo L. , Frank Jorge
Published: August 2020

Kontinuierliche medizinische Fortbildung (Continuing Medical Education, CME) ist die wesentliche Grundlage der studentischen Lehre sowie der Aus‐ und Weiterbildung von Ärzten. Eine moderne und adäquate Patientenversorgung ist ohne sie nicht denkbar. Vor kurzem zwang die durch das schwere akute respiratorische Syndrom‐Coronavirus 2 (SARS‐CoV‐2) verursachte Pandemie die gesamte medizinische Gemeinschaft, ihre Gewohnheiten bezüglich der medizinischen Fortbildung und Lehre sowie des Lernens in der Medizin zu ändern. Infolgedessen rückten über soziale Medien (Social Media) verbreitete digitale Aus‐, Fortbildungs‐ und Lehrformate, medizinische Online‐Enzyklopädien, webbasierte medizinische Lernportale und medizinische Podcasts in den Vordergrund. In diesem Beitrag geben wir einen Überblick zu aktuelle Konzepten in der medizinischen Online‐Fortbildung, unter besonderer Berücksichtigung der Dermatologie.
Klinische Merkmale und Behandlungen der transitorischen akantholytischen Dermatose (Morbus Grover): ein systematischer Review
Authors: Bellinato Francesco , Maurelli Martina , Gisondi Paolo , Girolomoni Giampiero
Published: August 2020

Der Morbus Grover (MG) ist eine juckende akantholytische Erkrankung, die bei Männern mittleren Alters am Rumpf auftritt. Ziel dieser Studie war es, eine Zusammenfassung der klinischen Charakteristika, des Krankheitsverlaufs und der Behandlungen des MG auf Grundlage der besten Evidenz zu erstellen. Entsprechend den PRISMA‐Leitlinien wurde ein systematischer Review von Originalarbeiten durchgeführt, die vom 01.01.1970 bis zum 15.08.2019 publiziert wurden. Dabei wurden die klinischen Merkmale und/oder jede Form von Intervention gegen MG bewertet. Insgesamt wurden 263 Artikel erfasst. Davon wurden 116 Originalberichte, welche als relevant erachtet wurden und die Einschlusskriterien erfüllten, in die Analyse eingeschlossen (88 Fallberichte, 26 Fallserien und zwei retrospektive Übersichtsarbeiten). Anhand dieser Artikel wurden 317 Patienten identifiziert. Das Verhältnis von Männern zu Frauen betrug 3,95 und das Durchschnittsalter lag bei 59 Jahren (Bereich 11–92). Typische Läsionen waren juckende Papeln und Papulovesikel, die im Allgemeinen am Rumpf lokalisiert waren, und in 42 % der Fälle innerhalb von einer Woche bis acht Monaten spontan abheilten. Topische Kortikosteroide (TCS) war die häufigste eingesetzte Therapieform (Ansprechrate 70 %), gefolgt von systemischen Retinoiden und Kortikosteroiden mit Ansprechraten von 86 % beziehungsweise 64 %. Den Ergebnissen dieser Untersuchung zufolge scheinen TCS die am häufigsten angewandte Therapiemodalität zu sein, und wir schlagen die TCS als Erstlinientherapie vor. Als Zweitlinienbehandlung kommen systemische Retinoide oder systemische Kortikosteroide in Frage.
Recreational angling demand in a mixed resource fishery
Authors: Grilli Gianluca , Mukhopadhyay Soumyadeep , Curtis John , Hynes Stephen
Published: August 2020

Several large Irish lake fisheries target both pike Esox lucius L. and brown trout Salmo trutta L. Due to predation on trout, pike stocks are actively managed in several locations with the objective of enhancing the trout fishery, which is a policy strongly supported by some trout anglers but intensely opposed by pike anglers. There is a dearth of economic knowledge to support management decisions concerning these mixed resource fisheries. This paper addresses some of that knowledge gap, investigating factors affecting angling recreational demand within these mixed resource fisheries and whether there are significant differences between pike and brown trout anglers. A travel cost model was used to estimate and test whether pike and trout anglers have different demand preferences. The substantive policy‐relevant finding relates not to differences associated with target species but to angling club membership. Angling club members are more price inelastic in their demand and particularly so in the case of trout anglers.
Sense of belonging to an industrial district and knowledge acquisition: The role of strong and trusting interorganizational relations
Authors: Córcoles‐Muñoz Mateo Manuel , Parra‐Requena Gloria , García‐Villaverde Pedro M. , Ruiz‐Ortega María José
Published: August 2020

Studying the level of sense of belonging in industrial districts is a key factor in understanding how firms acquire knowledge. This paper focuses on how the strength of ties and trust developed in interorganizational relationships drives the sense of belonging to the industrial district and leads firms to acquire knowledge. The proposed model was applied to a sample of 166 companies located in the industrial districts of the Spanish footwear industry. The findings suggest that the level of sense of belonging alone does not allow firms in industrial districts to directly acquire external knowledge. Only companies that are able to utilize their greater level of sense of belonging to industrial districts to generate strong and trusting relationships with other agents will acquire relevant knowledge. The study provides important empirical and theoretical contributions and several implications for managers.
Prevalence and characteristics of portopulmonary hypertension in cirrhotic patients who underwent both hepatic vein and pulmonary artery catheterization
Authors: Atsukawa Masanori , Tsubota Akihito , Hatano Masaru , Kondo Chisa , Shioda Kaori , Ohno Hiroki , Kawano Tadamichi , Hayama Korenobu , Arai Taeang , Nakagawa‐Iwashita Ai , Itokawa Norio , Kaneko Keiko , Yoshida Yuji , Koeda Mai , Okubo Tomomi , Yamamoto Teppei , Yamamoto Takeshi , Taniai Nobuhiko , Yoshida Hiroshi , Kanazawa Hidenori , Shimizu Wataru , Iwakiri Katsuhiko
Published: August 2020

Aim

Portopulmonary hypertension (PoPH) is a well‐known complication of liver cirrhosis. The aim of this study was to clarify the pulmonary hemodynamics and the prevalence and characteristics of PoPH in patients with portal hypertension.

Methods

The subjects were 335 patients with portal hypertension diagnosed by hepatic vein pressure gradient (HVPG). Among them, 186 patients received measurements of pulmonary artery pressure (PAP), pulmonary artery wedge pressure (PAWP) and pulmonary vascular resistance (PVR). PoPH was diagnosed by PAP >20 mmHg, PVR ≥3 Wood units (WU) and PAWP ≤15 mmHg.

Results

The Child–Pugh classification was class A in 53, B in 92 and C in 41 patients. Median (range) values of HVPG, PAP, PVR and PAWP were 18.4 (5.5–39.0) mmHg, 12.9 (6.6–40.8) mmHg, 0.8 (0.1–4.5) WU and 7.5 (2.2–15.4) mmHg, respectively. Of six patients with PAP >20 mmHg, four had autoimmune hepatitis or primary biliary cholangitis, with the prevalence being significantly higher than that in patients with PAP ≤20 mmHg. Meanwhile, no significant difference was noted in the hepatic functional reserve or HVPG between patients with PAP >20 mmHg and ≤20 mmHg. Only two patients met the diagnostic criteria of PoPH and both patients were Child–Pugh B. The Child–Pugh score and HVPG were not associated with PoPH.

Conclusions

Our study demonstrated that only two patients were complicated by PoPH. High PAP values were noted in patients with primary biliary cholangitis or autoimmune hepatitis. However, the presence of PoPH and high PAP were not associated with the degree of hepatic functional reserve or HVPG.
Competitive pricing and innovation investment strategies of green products considering firms' farsightedness and myopia
Authors: Liu Guowei , Cao Hui , Zhu Guowei
Published: August 2020

With the deterioration of ecological environment and the improvement of consumer environmental awareness, a number of firms are actively engaging in product innovation to enhance product greenness. In this paper, we develop a differential game involving two competing firms, each of which produces and sells one green product to end consumers. The two firms carry out innovation investments to improve customers' perceived product greenness and also determine their own retail prices. Each firm's demand is linearly dependent on its own retail price and innovation investment, the rival's retail price and innovation investment, and the customer perceived product greenness. The objective of our study is to examine the impacts of the competing firms' farsighted and myopic behaviors regarding the consumer perceived product greenness on their pricing and innovation investment strategies and profits. We find the following interesting results. First, when one firm is farsighted and the other is myopic, the latter obtains more profits than the former if one firm's innovation investment has a relatively small direct effect on the other's demand, that is, there is a free‐riding for the myopic firm. Second, when the intensity of competition regarding the two firms' innovation investments is not strong, competing with a farsighted rival can make a firm better off. Third, the scenario that the two firms adopt farsighted strategies can achieve an equilibrium, whereas acting myopic strategies can bring more profits for both of them under some conditions, which leads to a prisoner's dilemma. These results still hold under separable multiplicative demand between retail prices and innovation investments.
Multidrug‐resistant bacteria in diabetic foot infections: Experience from a portuguese tertiary centre
Authors: Pessoa e Costa Tomás , Duarte Bruno , João Ana Luísa , Coelho Miguel , Formiga Ana , Pinto Margarida , Neves José
Published: August 2020

In recent years, the emergence of antibiotic resistant pathogens made increasingly difficult to establish appropriate empiric antimicrobial therapy protocols for acute diabetic foot infection (DFI) treatment. Early recognition of the population at‐risk for multidrug‐resistant (MDR) bacterial infection is of paramount importance in order to decrease large‐spectrum antibiotic overuse. This study used retrospective cohort study in a multidisciplinary tertiary diabetic foot unit. Patients with severe DFI were included and divided according to their infection resistance profile (susceptible vs MDR bacteria). Data regarding their comorbidities and length of hospital stay were collected. The primary endpoint was to determine the risk factors for MDR infections and to evaluate if these were associated with an increased length of stay (LOS). A total of 112 microbial isolates were included. Predominance of Gram‐positive bacteria was observed and 22.3% of isolated bacteria were MDR. Previous hospitalisation was associated with a higher likelihood of MDR infection. MDR bacterial infection was also associated with an increased LOS (P = .0296). Our study showed a high incidence of MDR bacteria in patients with a DFI, especially in those who had a recent hospitalisation. MDR infections were associated with a prolonged LOS and represent a global public health issue for which emergent measures are needed.
Lyopreserved amniotic membrane is cellularly and clinically similar to cryopreserved construct for treating foot ulcers
Authors: Davis Kathryn E. , Killeen Amanda L. , Farrar David , Raspovic Katherine M. , Berriman‐Rozen Zachary D. , Malone Matthew , Lavery Lawrence A.
Published: August 2020

We compared cellular viability between cryopreserved and lyopreserved amniotic membranes and clinical outcomes of the lyopreserved construct in a prospective cohort study of 40 patients with neuropathic foot ulcers. Patients received weekly application of lyopreserved membrane for 12 weeks with standard weekly debridement and offloading. We evaluated the proportion of foot ulcers that closed, time to closure, closure trajectories, and infection during therapy. We used chi‐square tests for dichotomous variables and independent t‐tests for continuous variables with an alpha ofα= .10. Cellular viability was equivalent between cryo‐ and lyopreserved amniotic tissues. Clinically, 48% of subjects' wounds closed in an average of 40.0 days. Those that did not close were older (63 vs 59 years,P= .011) and larger ulcers at baseline (7.8 vs 1.6 cm2,P= .012). Significantly more patients who achieved closure reached a 50% wound area reduction in 4 weeks compared with non‐closed wounds (73.7% vs 47.6%,P= .093). There was no difference in the slope of the wound closure trajectories between closed and non‐closed wounds (0.124 and 0.159,P= .85), indicating the rate of closure was similar. The rate of closure was 0.60 mm/day (SD = 0.47) for wounds that closed and 0.50 mm/day (SD = 0.58) for wounds that did not close (P= .89).