bluuebunny/crossref_metadata_2025 huggingface dataset:
Competition for fluctuating resources reproduces statistics of species abundance over time across wide-ranging microbiotas
Authors: Ho Po-Yi , Good Benjamin , Huang Kerwyn Casey
Published: May 2021

Across diverse microbiotas, species abundances vary in time with distinctive statistical behaviors that appear to generalize across hosts, but the origins and implications of these patterns remain unclear. Here, we show that many of these patterns can be quantitatively recapitulated by a simple class of resource-competition models, in which the metabolic capabilities of different species are randomly drawn from a common statistical ensemble. Our coarse-grained model parametrizes the intrinsic consumer-resource properties of a community using a small number of macroscopic parameters, including the total number of resources, typical resource fluctuations over time, and the average overlap in resource-consumption profiles across species. We elucidate how variation in these parameters affects various time series statistics, enabling macroscopic parameter estimation and comparison across wide-ranging microbiotas, including the human gut, saliva, and vagina, as well as mouse gut and rice. The successful recapitulation of time series statistics across microbiotas suggests that resource competition generally acts as a dominant driver of community dynamics. Our work unifies numerous time series patterns under one model, clarifies their origins, and provides a framework to infer macroscopic parameters of resource competition from longitudinal studies of microbial communities.
Detection and characterization of folded-chain clusters in the structured melt of isotactic polypropylene
Authors: Li Xiangyang , Ding Jianjun , Chen Pujing , Zheng Kang , Zhang Xian , Tian Xingyou
Published: May 2021

Despite ceaseless efforts in past decades, the memory effect of semi-crystalline polymers has not been elucidated completely yet. An important reason why is that residual lamellar crystals in the structured melt are difficult to characterize. Recently, we developed a new small-angle X-ray scattering (SAXS) theory [Li et al. (2019). IUCrJ, 6, 968–983] and Fourier transform method [Li et al. (2020). CrystEngComm, 22, 3042–3058] for lamellar crystals that could derive structural information from SAXS readily. In this study, we tried to employ the new theory and method to characterize residual lamellar crystals in the structured melt. It was found that although scattering peaks cannot be observed in raw scattering profiles, they actually exist. Subtracting free-melt scattering and multiplying by q
4 benefit the observation of these weak scattering peaks. With the new Fourier transform method, it was found that indeed as proposed previously, thicker lamellar crystals exist in the structured melt. To determine the lateral size of residual lamellar crystal especially, a new method was developed under the guidance of the new theory. With the new method, it was found that although the crystallinity is very low (∼1% at 174°C), the lateral sizes in the structured melts are still large, e.g. 45.3 nm at 174°C, much greater than the critical nucleation size. This implies that these residual lamellar crystals can act as athermal nuclei after quenching to a lower temperature, as proposed by Ziabicki & Alfonso [(1994). Colloid Polym. Sci.
272, 1027–1042; (2002). Macromol. Symp.
185, 211–231] more than 20 years ago. The methodologies proposed here could also be applied to other polymer lamellar systems.
Crystal structure of the uranyl arsenate mineral hügelite, Pb2(UO2)3O2(AsO4)2(H2O)5, revisited: a correct unit cell, twinning and hydrogen bonding
Authors: Plášil Jakub , Petříček Václav , Škácha Pavel
Published: May 2021

Revisiting the structure of uranyl arsenate mineral hügelite provided some corrections to the available structural data. The previous twinning model (by reticular merohedry) in hügelite has been corrected. Twinning of the monoclinic unit cell [a = 7.0189 (7) Å,b = 17.1374 (10) Å,c = 8.1310 (10) Å and β = 108.904 (10)°], which can be expressed as a mirror in [100], leads to a pseudo-orthorhombic unit cell (a = 7.019 Å,b = 17.137 Å,c = 61.539 Å and β = 90.02°), which is eight times larger, with respect to the unit-cell volume, than a real cell. Moreover, the unit cell of chosen here and the unit cell given by the previous structure description both lead to the same supercell. A new structure refinement undertaken on an untwinned crystal of hügelite resulted inR = 4.82% for 12 864 reflections withIobs> 3σ(I) and GOF = 1.12. The hydrogen-bonding scheme has been proposed for hügelite for the first time.
Crystal structure of ethyl 2-(3-amino-5-oxo-2-tosyl-2,5-dihydro-1H-pyrazol-1-yl)acetate
Authors: Metwally Nadia H. , Elgemeie Galal H. , Jones Peter G.
Published: May 2021

In the title compound, C14H17N3O5S, the five-membered ring is essentially planar. The substituents at the nitrogen atoms subtend a C—N—N—S torsion angle of −95.52 (6)°. The amino group forms an intramolecular hydrogen bond to a sulfonyl oxygen atom; two intermolecular hydrogen bonds from the amino group, to the other S=O group and to the oxo substituent, form a layer structure parallel to theabplane. The structure determination confirms that the title compound isN- rather thanO-alkylated.
Synthesis and crystal structures of N-H, N-phenyl and N-benzyl-2-(4-hexyloxyphenyl)benzimidazoles
Authors: Smirnov Daniil E. , Tatarin Sergei V. , Bezzubov Stanislav I.
Published: May 2021

The title compounds, 2-(4-hexyloxyphenyl)-1H-benzimidazole (C19H22N2O; 1), 2-(4-hexyloxyphenyl)-1-phenyl-1H-benzimidazole (C25H26N2O; 2) and 1-benzyl-2-(4-hexyloxyphenyl)-1H-benzimidazole (C26H28N2O; 3) were synthesized and their structures were determined by single-crystal X-ray analysis. The N-substituent at the imidazole moiety slightly affects the interplanar angle between the 4-hexyloxyphenyl ring and the benzimidazole system. The unsubstituted benzimidazole (1) forms intermolecular N—H...N bonds while in the crystal structures of 2 and 3, the molecules are assembled only through π–π and C—H...π interactions.
Synthesis and crystal structures of 3,6-dihydroxypicolinic acid and its labile intermediate dipotassium 3-hydroxy-6-(sulfonatooxy)pyridine-2-carboxylate monohydrate
Authors: Behrman Edward J. , Parkin Sean
Published: May 2021

A simplified two-step synthesis of 3,6-dihydroxypicolinic acid (3-hydroxy-6-oxo-1,6-dihydropyridine-2-carboxylic acid), C6H5NO4(II), an intermediate in the metabolism of picolinic acid, is described. The crystal structure ofII, along with that of a labile intermediate, dipotassium 3-hydroxy-6-(sulfonatooxy)pyridine-2-carboxylate monohydrate, 2K+·C6H3NO7S2−·H2O (I), is also described. CompoundIcomprises a pyridine ring with carboxylate, hydroxyl (connected by an intramolecular O—H...O hydrogen bond), and sulfate groups at the 2-, 3-, and 6-positions, respectively, along with two potassium cations for charge balance and one water molecule of crystallization. These components are connected into a three-dimensional network by O—H...O hydrogen bonds arising from the water molecule, C—H...O interactions and π–π stacking of pyridine rings. InII, the ring nitrogen atom is protonated, with charge balance provided by the carboxylate group (i.e., a zwitterion). The intramolecular O—H...O hydrogen bond observed inIis preserved inII. Crystals ofIIhave unusual space-group symmetry of typeAbm2 in which extended planar networks of O—H...O and N—H...O hydrogen-bonded molecules form sheets lying parallel to theacplane, constrained tob= 0.25 (and 0.75). The structure was refined as a 50:50 inversion twin. A minor disorder component was modeled by reflection of the major component across a mirror plane perpendicular toc.
Crystallographic fragment screening-based study of a novel FAD-dependent oxidoreductase from Chaetomium thermophilum
Authors: Švecová Leona , Østergaard Lars Henrik , Skálová Tereza , Schnorr Kirk Matthew , Koval' Tomáš , Kolenko Petr , Stránský Jan , Sedlák David , Dušková Jarmila , Trundová Mária , Hašek Jindřich , Dohnálek Jan
Published: May 2021

The FAD-dependent oxidoreductase from Chaetomium thermophilum (CtFDO) is a novel thermostable glycoprotein from the glucose–methanol–choline (GMC) oxidoreductase superfamily. However, CtFDO shows no activity toward the typical substrates of the family and high-throughput screening with around 1000 compounds did not yield any strongly reacting substrate. Therefore, protein crystallography, including crystallographic fragment screening, with 42 fragments and 37 other compounds was used to describe the ligand-binding sites of CtFDO and to characterize the nature of its substrate. The structure of CtFDO reveals an unusually wide-open solvent-accessible active-site pocket with a unique His–Ser amino-acid pair putatively involved in enzyme catalysis. A series of six crystal structures of CtFDO complexes revealed five different subsites for the binding of aryl moieties inside the active-site pocket and conformational flexibility of the interacting amino acids when adapting to a particular ligand. The protein is capable of binding complex polyaromatic substrates of molecular weight greater than 500 Da.
FragMAXapp: crystallographic fragment-screening data-analysis and project-management system
Authors: Lima Gustavo M. A. , Jagudin Elmir , Talibov Vladimir O. , Benz Laila S. , Marullo Costantino , Barthel Tatjana , Wollenhaupt Jan , Weiss Manfred S. , Mueller Uwe
Published: May 2021

Crystallographic fragment screening (CFS) has become one of the major techniques for screening compounds in the early stages of drug-discovery projects. Following the advances in automation and throughput at modern macromolecular crystallography beamlines, the bottleneck for CFS has shifted from collecting data to organizing and handling the analysis of such projects. The complexity that emerges from the use of multiple methods for processing and refinement and to search for ligands requires an equally sophisticated solution to summarize the output, allowing researchers to focus on the scientific questions instead of on software technicalities. FragMAXapp is the fragment-screening project-management tool designed to handle CFS projects at MAX IV Laboratory. It benefits from the powerful computing infrastructure of large-scale facilities and, as a web application, it is accessible from everywhere.
Dual diagnosis in older drinkers during the COVID-19 pandemic
Authors: Rao Rahul , Mueller Christoph , Broadbent Matthew
Published: May 2021

Purpose

There is a dearth of literature examining the impact of the COVID-19 pandemic on older people with dual diagnosis referred to mental health services. The purpose of this study was to compare dual diagnosis before and after lockdown in people aged between 55 and 74 with alcohol use.

Design/methodology/approach

Data were collected for people referred to mental health services using an anonymised database of de-identified records to identify people with both substance use disorder alone, or accompanied by co-existing mental disorders.

Findings

In total, 366 older people were assessed with the Alcohol Use Disorders Identification Test (AUDIT), 185 before and 181 after lockdown. People with dual diagnosis were more likely to be referred than those without, after compared to before lockdown (13 and 6%, respectively, p < 0.05). People with any substance use disorder with and without dual diagnosis showed an even greater likelihood of referral after, compared with before, lockdown (61 and 34%, respectively, p < 0.0001). Opioid use more than once a month was more likely to be reported after, compared with before, lockdown (66 and 36%, respectively, p < 0.005).

Research limitations/implications

The finding of a higher likelihood of opioid use after compared with before lockdown during the COVID-19 pandemic warrants further exploration. There is also further scope for further studies that involve older non-drinkers.

Originality/value

A greater likelihood of both dual diagnosis and substance use disorder alone after, compared with before lockdown has implications for both mental health and addiction service provision during a pandemic.
Relationship of individual social entrepreneurial orientations and intentions: role of social entrepreneurship education
Authors: Naveed Muhammad , Zia Muhammad Qamar , Younis Sobia , Shah Zubair A.
Published: May 2021

Purpose

The purpose of the study is to probe the influence of individual social entrepreneurship orientations (ISEO) and SE education (SEE) which could affect social entrepreneurial intentions (SEI) among students.

Design/methodology/approach

The data were gathered from 241 entrepreneurship discipline university students. The data were analyzed with structural equation modeling.

Findings

Findings suggest that ISEO plays a vital role in stimulating SEI; moreover, SEE further moderates ISEO and SEI's relationship among students.

Practical implications

Based on the results, academia should focus on SEE and the government should devise policies to encourage social entrepreneurial ventures to aid in social problems solution.

Originality/value

This study validates the relationship of different factors (orientations and intentions) of the theory of planned behavior in the SE domain and confirms the significance of SEE.
Influence of an individual’s unethical behaviour on peers’ vicarious learning in organisations: the role of moral anger
Authors: Zeng Kai , Wang Duanxu , Ye Qingyan , Li Zhengwei , Zheng Xianwei
Published: May 2021

Purpose

Because unethical behaviour pervades in organisations, how to inhibit the interpersonal influence of unethical behaviour has become increasingly important. This study aims to integrate the deontic justice theory and affective events theory to examine the relationship between an individual’s unethical behaviour and his or her peers’ vicarious learning by highlighting the mediating effect of peers’ moral anger and the moderating effect of task interdependence on this relationship.

Design/methodology/approach

Data were collected in two waves from 254 employees of a large manufacturing company in the People’s Republic of China.

Findings

The hypothesised moderated mediation model was supported. Specifically, as expected, peers’ moral anger mediated the negative relationship between an individual’s unethical behaviour and peers’ vicarious learning. Task interdependence moderated the direct relationship between the individual’s unethical behaviour and his or her peers’ moral anger and the indirect relationship between an individual’s unethical behaviour and his or her peers’ vicarious learning via the peers’ moral anger such that these relationships were stronger when the level of task interdependence was higher.

Originality/value

This study argues that the deontic justice theory is a supplement for the social learning theory in explaining the interpersonal influence of unethical behaviour. Drawing on the deontic justice theory, this study demonstrates that an individual’s unethical behaviours are unlikely to be rewarded or accepted, and by integrating the theories of deontic justice and affective events, offers a rationale for the emotional mechanism that underlies the interpersonal influence of unethical behaviour.
Novel coupled analysis methods of automotive alternators considering synchronous rectification circuit
Authors: Hidaka Yuki
Published: May 2021

Purpose

The purpose of this paper is to develop a novel coupled analysis method for synchronous rectification alternators.

Design/methodology/approach

An ideal diode module is embedded in a rectification circuit. The resistance of the diode module is set such that it is equal to the on-resistance of the MOS-FET modules in the generation mode. In a mode without power generation, the motor voltage is less than the bus voltage; a sufficiently large value is defined for simulating the infinite resistance.

Findings

Because there is no need to decide the switch timing in advance, only one round of coupled analysis is needed to evaluate the synchronous rectification alternators.

Research limitations/implications

As limited case study is denoted in this paper, much more case studies are needed to be discussed.

Practical implications

By using the proposed method, it can be fulfilled that generation characteristic of automotive alternators can be evaluated without using the control simulation or pre-conducted analysis to decide the switch timing.

Social implications

By using the proposed method, it can be fulfilled that generation characteristic of automotive alternators can be evaluated without using the control simulation or pre-conducted analysis to decide the switch timing.

Originality/value

In the proposed methods, the definition of diode module differs from that of a conventional coupled analysis.
Known and anticipated medical geology issues in Ghana
Authors: Kazapoe Raymond Webrah , Arhin Emmanuel , Amuah Ebenezer Ebo Yahans
Published: May 2021

Purpose

This paper aims to review the known and anticipated medical geology problems in Ghana, to highlight the impact of some trace elements on human health and to reveal some essential aspects of medical geology on health.

Design/methodology/approach

Literature and empirical studies relating to medical geological issues in Ghana were reviewed. Secondary data were used in the present study such as case studies, reports, geological bulletins and published research studies.

Findings

High levels of heavy metals including arsenic, cadmium and mercury in gold extraction processes through artisanal small-scale mining have contributed to high concentrations of toxic elements in the environment. The distribution and availability of these elements in the environment are facilitated by the geological, chemical and local environmental activities that are irregularly spread exposing people mining areas to pollutions. Exposures to these elements in above and below baseline levels contributed to health implications including fluorosis, intellectual or developmental disability and death in some regions of Ghana. Cardiovascular and cerebrovascular diseases linked to mining activities were also presented in this study. Similarly, non-communicable diseases can affect many people if correct measures are not considered. Following the geometric increase in mining activities, it is anticipated that deleterious environmental and health impacts associated with mining may persist in mining areas in Ghana. Reported implications and continuous contamination of water bodies in mining areas could result in high pollution levels beyond treatment for human use or destroy aquatic habitats and aquatic lives through acid drainage. Above-threshold concentrations of heavy metals in soils could bio-accumulate in crops, and this could pose deleterious public health implications on consumers. Continuous effects posed on the environment and public health may prompt communities, regulatory institutions and government to reduce or ban mineral development.

Originality/value

This review has significantly revealed potential public health issues from the impact on the natural environment and recommends that medical geologists work together with medical workers to devise preventive and therapeutic techniques to address many geology-related-health issues in Ghana.
Twitter users’ coping behaviors during the COVID-19 lockdown: an analysis of tweets using mixed methods
Authors: Mittal Ruchi , Ahmed Wasim , Mittal Amit , Aggarwal Ishan
Published: May 2021

Purpose

Using data from Twitter, the purpose of this paper is to assess the coping behaviour and reactions of social media users in response to the initial days of the COVID-19-related lockdown in different parts of the world.

Design/methodology/approach

This study follows the quasi-inductive approach which allows the development of pre-categories from other theories before the sampling and coding processes begin, for use in those processes. Data was extracted using relevant keywords from Twitter, and a sample was drawn from the Twitter data set to ensure the data is more manageable from a qualitative research standpoint and that meaningful interpretations can be drawn from the data analysis results. The data analysis is discussed in two parts: extraction and classification of data from Twitter using automated sentiment analysis; and qualitative data analysis of a smaller Twitter data sample.

Findings

This study found that during the lockdown the majority of users on Twitter shared positive opinions towards the lockdown. The results also found that people are keeping themselves engaged and entertained. Governments around the world have also gained support from Twitter users. This is despite the hardships being faced by citizens. The authors also found a number of users expressing negative sentiments. The results also found that several users on Twitter were fence-sitters and their opinions and emotions could swing either way depending on how the pandemic progresses and what action is taken by governments around the world.

Research limitations/implications

The authors add to the body of literature that has examined Twitter discussions around H1N1 using in-depth qualitative methods and conspiracy theories around COVID-19. In the long run, the government can help citizens develop routines that help the community adapt to a new dangerous environment – this has very effectively been shown in the context of wildfires in the context of disaster management. In the context of this research, the dominance of the positive themes within tweets is promising for policymakers and governments around the world. However, sentiments may wish to be monitored going forward as large-spikes in negative sentiment may highlight lockdown-fatigue.

Social implications

The psychology of humans during a pandemic can have a profound impact on how COVID-19 shapes up, and this shall also include how people behave with other people and with the larger environment. Lockdowns are the opposite of what societies strive to achieve, i.e. socializing.

Originality/value

This study is based on original Twitter data collected during the initial days of the COVID-19-induced lockdown. The topic of “lockdowns” and the “COVID-19” pandemic have not been studied together thus far. This study is highly topical.
Triple grief cycle of cancelled events: the emotional crisis aftermath
Authors: Wong IpKin Anthony , Lin Shuyi , Lin Lixin , Liao Ruobing
Published: May 2021

Purpose

The coronavirus (COVID-19) pandemic response is not only devastating nations and economies across the globe but it is also severely disrupting the event industry, with government and health authorities forcing many events to be postponed or cancelled. The purpose of this study is to investigate the prospective attendees’ emotional responses to cancelled events. This study draws upon grief cycle theory to articulate different layers of the grief process in the event domain of inquiry.

Design/methodology/approach

The National Collegiate Athletic Association basketball tournament was selected as the research context. Taking user-generated messages from Twitter, this study first performed content analysis to organize lexical patterns into categories and higher-order themes based on the grief cycle. It also performed social network analyses using UCINET to illustrate how different grief phases are inter-related.

Findings

Results not only point to attendees’ self-expression manifested through a continuum of denial, anger, bargaining and acceptance but they also reveal a three-layer hierarchy of grief, namely, event-related, socio-politics-related and crisis-related. The network analysis further illustrates how grief phases are tied into a complex network of grief messages.

Originality/value

This study advances the event literature by improving knowledge about attendees’ emotional responses to cancelled events. It increases our understanding of the grieving process in the aftermath of COVID-19. The proposed triple grief cycle helps advance the literature by showcasing how voices from prospective attendees represent three pillars of grief hierarchy. The findings also underscore the emotional crisis of the COVID-19 aftermath.
COVID-19 and incarcerated older adults: a commentary on risk, care and early release in Australia
Authors: Hwang Ye In (Jane) , Ginnivan Natasha Ann , Simpson Paul Leslie , Baidawi Susan , Withall Adrienne , Williams Brie , Butler Tony
Published: May 2021

Purpose

The purpose of this commentary is to draw upon available literature and practices related to COVID-19 and management of older incarcerated adults in Australia to highlight key matters for better risk management and care of this population during this and future infectious disease pan/epidemics.

Design/methodology/approach

The present commentary draws on current policies, practices and literature regarding the health, needs and management of older incarcerated adults in Australia to discuss risk, care and early release for this population during the COVID-19 pandemic.

Findings

Incarcerated persons experience poorer health and accelerated age-related decline compared to those in the general community. The present situation offers the opportunity to fill knowledge and practice gaps, including policies for staff training, identification of dementia and cognitive decline, assessment of mobility issues, addressing barriers to health-seeking, possibilities of medical or compassionate release, risk assessment and release protocols and post-release needs.

Practical implications

While Australian prisons have acknowledged the vulnerability of older persons, more focused adaptation of COVID-19-related policies to consider adults as young as 45 years are needed. Appropriate ethical identification and management of cases in this population is needed, as is discussion on issues of decarceration and medical release. Re-conceptualisation of incarcerated adults as “citizens in need of care”, rather than as “offenders to be secured”, will be beneficial. Robust, local evidence is needed to assist decision-making.

Originality/value

This is a comprehensive, focused review of relevant evidence, policies and practices for a growing subpopulation of prisoners worldwide with complex needs and particular vulnerability to the COVID-19.
Islamic index market sentiment: evidence from the ASEAN market
Authors: Danila Nevi , Kamaludin Kamilah , Sundarasen Sheela , Bunyamin Bunyamin
Published: May 2021

Purpose

The purpose of this paper is to examine investor sentiment by measuring the impact of market sentiment shocks on the volatility of the Islamic stock index of five ASEAN countries, with noise traders as a proxy for market sentiment.

Design/methodology/approach

The GJR-GARCH model is used to capture the empirically observed fact that negative shocks in the past period have a stronger impact on variance than positive shocks in the present.

Findings

All five ASEAN Islamic stock indices show clustering volatility. However, only three countries, namely, Malaysia, Thailand and Singapore, demonstrate leverage effects. In addition, the effect of market sentiment on Islamic stock index returns is observed in the Indonesian and Malaysian markets, which are the two largest Islamic markets with a dominant Muslim population in the ASEAN. This finding implies that the trading behaviours of Muslim investors in the Shariah market are the same as their behaviours in the conventional market, that is, nonadherence to the Sunnah.

Practical implications

Whilst establishing investment strategies, creating portfolios and providing client-advisory services, investors and fund managers should factor in the presence of market sentiment and its impact on stock performance and volatility. In addition, a capital market system preventing rumour-based transactions is compelling.

Social implications

In some markets, the Islamic financial products awareness should be increased through education to attract increased domestic investors with the potential to boost growth in the Islamic stock market.

Originality/value

Investigation market sentiment impacts on the Islamic stock index using noise traders as a proxy.
Adaptive governance: learning from what organizations do and managing the role they play
Authors: van Assche Kristof , Valentinov Vladislav , Verschraegen Gert
Published: May 2021

Purpose

The purpose of this paper is to deepen the understanding of adaptive governance, which is advocated for as a manner to deal with dramatic changes in society and/or environment. To re-think the possible contributions of organizations and organization theory, to adaptive governance.

Design/methodology/approach

Based on social systems theory this study makes a distinction between “governance organizations” and “governance communities.” Organizations are conceptualized as the decision machines which organize and (co-)steer governance. Communities are seen as the social environments against which the governance system orients its operations. This study considers the adaptive mechanisms of organizations and reflect on the roles of organizations to enhance adaptive governance in communities and societies.

Findings

Diverse types of organizations can link or couple in different ways to communities in their social environment. Such links can enhance the coordinative capacity of the governance system and can also spur innovation to enable adaptation. Yet, linking with communities can also slow down responses to change and complexify the processes of deliberation in governance. Not all adaptive mechanisms available to organizations can be used in communicating with communities or can be institutionalized, but the continuous innovation in the field of organizations can inspire continuous testing of small-scale adaptive mechanisms at higher levels. Society can thus enhance its adaptive capacity by managing the role of organizations.

Originality/value

The harnessing of insights in organization theory and systems theory for improving understanding of adaptive governance. The finding that both experiment and coordination at societal level are needed, toward adaptive governance, and that organizations can contribute to both.
An overview on joining/welding as post-processing technique to circumvent the build volume limitation of an FDM-3D printer
Authors: Tiwary Vivek Kumar , P. Arunkumar , Malik Vinayak R.
Published: May 2021

Purpose

Three-dimensional (3D) printing, one of the important technological pillars of Industry 4.0, is changing the landscape of future manufacturing. However, the limited build volume of a commercially available 3D printer is one inherent constraint, which holds its acceptability by the manufacturing business leaders. This paper aims to address the issue by presenting a novel classification of the possible ways by which 3D-printed parts can be joined or welded to achieve a bigger-sized component.

Design/methodology/approach

A two-step literature review is performed. The first section deals with the past and present research studies related to adhesive bonding, mechanical interlocking, fastening and big area additive manufacturing of 3D printed thermoplastics. In the second section, the literature searches were focused on retrieving details related to the welding of 3D printed parts, specifically related to friction stir welding, friction (spin) welding, microwave and ultrasonic welding.

Findings

The key findings of this review study comprise the present up-to-date research developments, pros, cons, critical challenges and the future research directions related to each of the joining/welding techniques. After reading this study, a better understanding of how and which joining/welding technique to be applied to obtain a bigger volume 3D printed component will be acquired.

Practical implications

The study provides a realistic approach for the joining of 3D printed parts made by the fused deposition modeling (FDM) technique.

Originality/value

This is the first literature review related to joining or welding of FDM-3D printed parts helping the 3D printing fraternity and researchers, thus increasing the acceptability of low-cost FDM printers by the manufacturing business leaders.
Corporate social responsibility, business group affiliation and shareholder wealth: evidence from an emerging market
Authors: Velayutham Eswaran , Ratnam Vijayakumaran
Published: May 2021

Purpose

This paper aims to examine the relationship between corporate social responsibility (CSR) and shareholder wealth arising from announcement returns of security issuance from a frontier market. It also explores the role of business group affiliation (BGA) on this relationship.

Design/methodology/approach

The study uses short-term scenarios to examine the link between CSR and shareholder wealth using the event study methodology which helps us mitigate the reverse causality problems related to studies of the relationship between CSR and firm value. Abnormal returns surrounding the security issue announcements were generated using the market model.

Findings

This paper finds that security issuers with high CSR scores are associated with higher shareholder value. However, this paper finds that CSR activities of security issuers with BGA are value-destroying which is consistent with the agency perspective of CSR.

Research limitations/implications

This study is limited to only one nascent market, namely the Colombo Stock Exchange.

Originality/value

This study documents that CSR and BGA are important determinants, among others, of stock price reactions to security offerings in emerging markets.
Modified brain storming optimization technique for transient stability improvement of SVC controller for a two machine system
Authors: Choudhury Subhashree , Dash Taraprasanna
Published: May 2021

Purpose

Static VAR compensators (SVC) have been recognized to be one of the most important flexible AC transmission systems devices used for mitigating the low-frequency electrochemical oscillations occurring in the system and for reactive power compensation, thereby improving the overall dynamic stability and efficiency of the system. The purpose of this paper is to optimize and dynamically tune the control parameters of the classical proportional integral and derivative (PID) controller of the SVC for a two-machine system by designing a new robust optimization technique.

Design/methodology/approach

The angular speed deviation between the two machines is used as an auxiliary signal to SVC for generation of the required damping output. To justify the efficacy of the system undertaken, a light load fault at time t = 1 s is projected to the system. The simulation is carried out in MATLAB/Simulink architecture.

Findings

The proposed technique helps in the enhancement of system efficiency, reliability and controllability and by effectively responding to the non-linearities taking place in a power grid network. The results obtained are indicative of the fact that the proposed modified brain storming optimization (MBSO) technique reduces system disturbances very quickly, increases the system response in terms of better rise time, settling time and peak overshoot and improves the efficiency of the system.

Originality/value

A detailed comparison of the MBSO technique is compared with the conventional brain storming optimization (BSO) and PID technique. Total harmonic distortion through fast Fourier transform is also compiled to prove that the values of the proposed MBSO method found out to be confined well within the prescribed IEEE-514 boundaries.
Potential of crocodile blood as a medication and dietary supplement: A systemic review
Authors: Chook Chui Yiu Bamboo , Chen Francis M. , Leung Fung Ping , Chen Zhen‐Yu , Wong Wing Tak
Published: May 2021

Crocodile blood has long been used as a traditional medicine in many Asian countries to treat diseases such as asthma, allergies, and many others. Yet, only recently has the safety and effectiveness of using crocodile blood as a medicine been examined using modern scientific methods; with both conserved and novel active components identified from crocodile blood. Further in vitro and in vivo investigations found that crocodile blood can have a wide range of beneficial effects, including antimicrobial, antiviral, anti‐oxidative, anti‐inflammatory, antitumour effects, anti‐anaemia, and enhancement of wound healing. A systematic research of literature published in English‐language journals up to April 2020 was conducted in PubMed, Google Scholar, and Web of Science. Based on the biological and chemical knowledge of crocodile immunity and crocodile blood, this article aims to: provide a critical review on the proposed properties of crocodile blood, identify the knowledge gap and offer some insights for future investigations regarding the use of crocodile blood as a medication or dietary supplement.
Genome‐informed approach to identify genetic determinants of Flavobacterium psychrophilum phage susceptibility
Authors: Daniel Castillo , Johanna Jørgensen , Krister Sundell , Lone Madsen , Inger Dalsgaard , Tom Wiklund , Mathias Middelboe
Published: May 2021

The fish pathogen Flavobacterium psychrophilum infects farmed salmonids worldwide, and application of bacteriophages has been suggested for controlling disease outbreaks in aquaculture. Successful application of phages requires detailed knowledge about the variability in phage susceptibility of the host communities. In this study, we analysed the genetic diversity of F. psychrophilum hosts and phages from the Baltic Sea area to identify genetic determinants of phage‐host interaction patterns. A host range analysis of 103 phages tested against 177 F. psychrophilum strains (18 231 phage–host interactions) identified nine phage clusters, infecting from 10% to 91% of the strain collection. The core genome‐based comparison of 35 F. psychrophilum isolates revealed an extremely low overall genomic diversity (>99.5% similarity). However, a small subset of 16 ORFs, including genes involved in the type IX secretion system (T9SS), gliding motility and hypothetical cell‐surface related proteins, exhibited a highly elevated genetic diversity. These specific genetic variations were linked to variability in phage infection patterns obtained from experimental studies, indicating that these genes are key determinants of phage susceptibility. These findings provide novel insights on the molecular mechanisms determining phage susceptibility in F. psychrophilum and emphasizes the importance of phages as drivers of core genomic diversity in this pathogen.
Formate metabolism in the acetogenic bacterium Acetobacterium woodii
Authors: Moon Jimyung , Dönig Judith , Kramer Sina , Poehlein Anja , Daniel Rolf , Müller Volker
Published: May 2021

Acetogenic bacteria are already established as biocatalysts for production of high‐value compounds from C1 substrates such as H2 + CO2 or CO. However, little is known about the physiology, biochemistry and bioenergetics of acetogenesis from formate, an interesting feedstock for biorefineries. Here, we analysed formate metabolism in the model acetogen Acetobacterium woodii. Cells grew optimally on 200 mM formate to an optical density of 0.6. Formate was exclusively converted to acetate (and CO2) with a ratio of 4.4:1. Transcriptome analyses revealed genes/enzymes involved in formate metabolism. Strikingly, A. woodii has two genes potentially encoding a formyl‐THF synthetase, fhs1 and fhs2. fhs2 forms an operon with a gene encoding a potential formate transporter, fdhC. Deletion of fhs2/fdhC led to a reduced growth rate, formate consumption and optical densities. Acetogenesis from H2 + CO2 was accompanied by transient formate production; strikingly, formate reutilization was completely abolished in the Δfhs2/fdhC mutant. Take together, our studies gave the first detailed insights into the formatotrophic lifestyle of A. woodii.
Conservative Party Statecraft and the Johnson Government
Authors: Hayton Richard
Published: May 2021

This article uses the statecraft framework outlined by Andrew Gamble to analyse the Conservative government of Boris Johnson. It argues that under Johnson, the Conservative Party is pursuing its most far‐reaching statecraft strategy since the Thatcher era, aimed at re‐establishing the conditions for Conservative hegemony. At the heart of Johnson's statecraft lies Brexit itself, which serves as a national cause around which to organise the politics of support. Leaving the EU demands a renewal of the national community which, for the Conservatives, is framed as a narrow Anglo‐Britishness, centred on an essentially English understanding of the Union of the United Kingdom and of Britishness itself. This assertive politics of national identity shapes the party's approach to territorial statecraft and its ideological struggle to ensure that the dominant narratives of British politics are once again Conservative ones.
The Large Uterus Classification System: a prospective observational study
Authors: Uccella S , Kho RM , Garzon S , Casarin J , Zorzato PC , Ghezzi F
Published: May 2021

Objective

To investigate the Large Uterus Classification System (LUCS) ability to predict surgical outcomes and complications in total laparoscopic hysterectomies (TLHs) for large uteri.

Design

Prospective observational study.

Setting

Two referral centres.

Population or sample

Three hundred and ninety‐two women who underwent TLH for a large uterus (uterine fundus at or over the transverse umbilical line).

Methods

Between 2004 and 2019, the intraoperative LUCS was estimated in all patients. The LUCS considers the uterine and adnexal vascular pedicles displacement. Type 1 is without vascular pedicles displacement. Type 2 has the cephalad displacement of adnexal vascular pedicles. The uterine vessels displacement regardless of adnexal pedicles defines Type 3.

Main outcome measures

Patients’ characteristics with perioperative outcomes were prospectively collected and compared between the three types of large uteri.

Results

Two hundred and fifty‐one (64%), 82 (20.9%) and 59 (15.1%) women had Type 1, Type 2 and Type 3 uteri, respectively. Women with Type 1 uteri had a lower uterine weight, shorter operative time, less blood loss and lower complication rates than women with Types 2 and 3. The conversion rate to laparotomy in Type 1 was similar to that in Type 2 (odds ratio [OR] 0.98; 95% CI 0.32–3.56) but lower than Type 3 (OR 0.35; 95% CI 0.14–0.97); in Type 2 it was lower than Type 3, although without the conventional statistical significance (OR 0.36; 95% CI 0.13–1.13; P = 0.07). Multivariable analysis showed that the uterine Type (1 versus 2–3) was independently associated with the total complications rate (OR 2.00; 95% CI 1.09–3.68; P = 0.02).

Conclusions

The LUCS appears associated with surgical outcomes and complications, potentially stratifying the surgical risk and guiding the surgical technique in TLHs for large uteri.

Tweetable abstract

The Large Uterus Classification System may predict outcomes in total laparoscopic hysterectomy of large uteri.
Microinvasive glaucoma surgery: a review and classification of implant‐dependent procedures and techniques
Authors: Jabłońska Joanna , Lewczuk Katarzyna , Konopińska Joanna , Mariak Zofia , Rękas Marek
Published: May 2021

The aim of this article is to discuss how physiology and anatomical background affect the effectiveness of implant‐dependent microinvasive glaucoma surgery (MIGS). First, we provide a micro view of aqueous outflow and tissue behaviour. Second, we review studies exploring the mechanisms of the pressure‐lowering effect of MIGS, as well as tissue behaviour during aqueous flow and tissue motion. We also describe and classify microinvasive surgical procedures and the most important types of implants, as well as their mechanisms of action, implantation techniques and efficacy. Further, we summarize the indications and surgical results presented in recent studies, providing an evidence‐based update on novel and emerging MIGS techniques for the treatment of open‐angle glaucoma. These data can help surgeons to personalize the management of glaucoma and to choose the best MIGS option for individual glaucoma patients.
Taking parent personality and child temperament into account in child language development
Authors: Kucker Sarah C. , Zimmerman Caileigh , Chmielewski Michael
Published: May 2021

Individual differences have become increasingly important in the study of child development and language. However, despite the important role parents play in children’s language, no work has examined how parent personality impacts language development. The current study examines the impact of parent personality as well as child temperament on language development in 460 16‐ to 30‐month‐old children and 328 31‐ to 42‐month‐old children. Findings from both groups suggest multiple aspects of children’s language abilities are correlated with their parent’s personality. Specifically, parent consciousness, openness, and agreeableness positively correlate with child vocabulary size and other language abilities. Results also replicate and expand research on child temperament and language – child effortful control and surgency were positively correlated, and negative affect negatively correlated with most language abilities even after controlling for parent personality. Critically, parent and child traits appear to impact a child’s language abilities above and beyond well‐known predictors of language, such as age.
Endogenous neurosteroids pregnanolone and pregnanolone sulfate potentiate presynaptic glutamate release through distinct mechanisms
Authors: Smejkalova Tereza , Korinek Miloslav , Krusek Jan , Hrcka Krausova Barbora , Candelas Serra Miriam , Hajdukovic Dragana , Kudova Eva , Chodounska Hana , Vyklicky Ladislav
Published: May 2021

Background and Purpose

Neurosteroids influence neuronal function and have multiple promising clinical applications. Direct modulation of postsynaptic neurotransmitter receptors by neurosteroids is well characterized, but presynaptic effects remain poorly understood. Here, we report presynaptic glutamate release potentiation by neurosteroids pregnanolone and pregnanolone sulfate and compare their mechanisms of action to phorbol 12,13‐dibutyrate (PDBu), a mimic of the second messenger DAG.

Experimental Approach

We use whole‐cell patch‐clamp electrophysiology and pharmacology in rat hippocampal microisland cultures and total internal reflection fluorescence (TIRF) microscopy in HEK293 cells expressing GFP‐tagged vesicle priming protein Munc13‐1, to explore the mechanisms of neurosteroid presynaptic modulation.

Key Results

Pregnanolone sulfate and pregnanolone potentiate glutamate release downstream of presynaptic Ca2+ influx, resembling the action of a phorbol ester PDBu. PDBu partially occludes the effect of pregnanolone, but not of pregnanolone sulfate. Calphostin C, an inhibitor that disrupts DAG binding to its targets, reduces the effect PDBu and pregnanolone, but not of pregnanolone sulfate, suggesting that pregnanolone might interact with a well‐known DAG/phorbol ester target Munc13‐1. However, TIRF microscopy experiments found no evidence of pregnanolone‐induced membrane translocation of GFP‐tagged Munc13‐1, suggesting that pregnanolone may regulate Munc13‐1 indirectly or interact with other DAG targets.

Conclusion and Implications

We describe a novel presynaptic effect of neurosteroids pregnanolone and pregnanolone sulfate to potentiate glutamate release downstream of presynaptic Ca2+ influx. The mechanism of action of pregnanolone, but not of pregnanolone sulfate, partly overlaps with that of PDBu. Presynaptic effects of neurosteroids may contribute to their therapeutic potential in the treatment of disorders of the glutamate system.