bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterising the vegetation-rainfall relationship in the Northeast Himalaya, India
Authors: Sarania Bidyut , Guttal Vishwesha , Tamma Krishnapriya
Published: October 2021

Ecosystems are complex systems and are characterised by positive and negative feedbacks between the abiotic and biotic components. The response of an ecosystem to its environment can be determined by examining state diagrams, which are plots of the state variable as a function of the environmental driver. For instance, tree cover as a function of rainfall is widely used to characterise vegetation patterns. Previous studies have shown that tree cover shows bimodal distributions for intermediate rainfall regimes in Africa and South America. In this study, we construct a vegetation state diagram – by plotting vegetation cover as a function of mean annual rainfall – for Northeast India, which is part of the Eastern Himalaya and the Indo-Burma biodiversity hotspot. We use remotely sensed satellite data of Enhanced Vegetation Index (EVI) as a proxy for vegetation cover. We obtain Mean Annual Precipitation (MAP) from the CHIRPS data (Climate Hazards Group InfraRed Precipitation with Station data). We find that EVI increases monotonically as a function of MAP in the range 1000-2000 mm, after which it plateaus. The 1000 to 2000 mm MAP corresponds to the vegetation transitional zone (1200-3700 m), whereas >2000 MAP region covers the greater extent of the tropical forest (<1200 m) of NEI. In other words, we find no evidence for bimodality in tree cover or vegetation states at coarser scales in North Eastern India. Our characterisation of the state diagram for vegetation in northeast India is important to understand response to ongoing change in rainfall patterns.
Untwisted α-synuclein Filaments formed in the Presence of Lipid Vesicles
Authors: Dasari Anvesh K. R. , Dillard Lucas , Hojjatian Alimohammad , Sengupta Urmi , Kayed Rakez , Taylor Kenneth A. , Borgnia Mario J. , Lim Kwang Hun
Published: October 2021

Accumulation of filamentous aggregates of α-synuclein is a pathological hallmark of several neurodegenerative diseases including Parkinson’s disease (PD). Interaction between α-synuclein and lipids has been shown to play a critical role in aggregation of α-synuclein. Most structural studies have, however, been focused on α-synuclein filaments formed in the absence of lipids. Here, we report structural investigation of α-synuclein filaments assembled under the quiescent conditions in the presence of anionic lipid vesicles using electron microscopy (EM) including cryo-EM. Our transmission electron microscopy (TEM) analyses reveal that α-synuclein forms curly protofilaments at an early stage of aggregation. The flexible protofilaments were then converted to long filaments after a longer incubation of 30 days. More detailed structural analyses using cryo-EM reveal that the long filaments adopt untwisted structures with different diameters, which have not been observed in previous α-synuclein filaments formed in vitro. The untwisted filaments are rather similar to straight filaments with no observable twist that are extracted from patients with dementia with Lewy bodies. Our structural studies highlight the conformational diversity of α-synuclein filaments, requiring additional structural investigation of not only more ex vivo α-synuclein filaments, but also in vitro α-synuclein filaments formed in the presence of diverse co-factors to better understand the molecular basis of diverse molecular conformations of α-synuclein filaments.
Systematic Discovery of Antibacterial and Antifungal Bacterial Toxins
Authors: Nachmias Nimrod , Dotan Noam , Fraenkel Rina , Rocha Marina Campos , Kluzek Monika , Shalom Maor , Rivitz Arbel , Shamash-Halevy Naama , Cahana Inbar , Deouell Noam , Klein Jacob , Schlezinger Neta , Tzarum Netanel , Oppenheimer-Shaanan Yaara , Levy Asaf
Published: October 2021

Microbes employ toxins to kill competing microbes or eukaryotic host cells. Polymorphic toxins are proteins that encode C-terminal toxin domains. Here, we developed a computational approach to discover novel toxin domains of polymorphic toxins within 105,438 microbial genomes. We validated nine short novel toxins (“PTs”) that cause bacterial or yeast cell death. The novel PTs are encoded by ∼2.2% of the sequenced bacteria, including numerous pathogens. We also identified five cognate immunity genes (“PIMs”) that neutralize the toxins. Intriguingly, we observed an antifungal effect of the PTs against various pathogenic fungi. The toxins likely act as enzymes that cause severe damage to cell shape, membrane, and DNA. Finally, we solved the 3D structure of two PTs in complex with their PIMs, and showed that they function as novel DNAses. The new potent toxins likely play key roles in inter-microbial competition and can be utilized in various clinical and biotechnological applications.
Diverse chemical functionalization of nucleobases within long RNAs using sulfinate salts
Authors: Gomez Anastassia , Bassi Tiziano , Grayson Leah , Vantourout Julien , Toor Navtej
Published: October 2021

We have devised a single pot, low-cost method to modify RNA with sulfinate salts that can directly add almost any desired functional group to nucleobases under mild aqueous conditions. This chemistry modifies the Hoogsteen edge of RNA and DNA nucleobases. It can be applied to RNA or DNA of any size, as well as to individual nucleotides. Existing methods of RNA modification have relatively limited applicability due to constraints on the size of the RNA and the lack of diversity of possible modifications. We have been able to add azide groups for click reactions directly onto the nucleobases of RNA utilizing sulfinate salts. C-H bonds on the nucleobase aromatic rings serve as the sites of attachment, with C-H being replaced with C-R, where R is the azide-containing linker. With the addition of azide functional groups, the modified RNA can easily be reacted with any alkyne-labeled compound of interest, including fluorescent dyes as shown in this work. This methodology enables the exploration of diverse chemical groups on RNA that can potentially confer protection from nucleases, allow for efficient delivery of nucleic acids into cells, or act as new tools for the investigation of nucleic acid structure and function.
Oral Lisinopril Raises Tissue Levels of ACE2, the SARS-CoV-2 Receptor, in Healthy Male and Female Mice
Authors: Brooks Steven D. , Smith Rachel L. , Moreira Aline da Silva , Ackerman Hans C.
Published: October 2021

Angiotensin-converting enzyme 2 (ACE2) is the established cellular receptor for SARS-CoV-2. However, it is unclear whether ACE1 inhibitors (e.g., lisinopril) or angiotensin receptor blockers (e.g., losartan) alter tissue ACE2 expression. This study sought to determine whether lisinopril or losartan, as monotherapies or in combination, change tissue levels of ACE2 in healthy male and female mice.

Mice received lisinopril (10 mg/kg/day), losartan (10 mg/kg/day), or both for 21 days via drinking water. A control group received water without drug. ACE2 protein index (ACE2 protein / total protein) was determined on small intestine, lung, kidney, and brain. Oral lisinopril increased ACE2 protein index across all tissues (p < 0.0001 vs control). In contrast, the combination of lisinopril plus losartan did not increase ACE2 levels in any tissue (p = 0.89 vs control) and even decreased tissue expression of the Ace2 gene (p < 0.001 vs control). Tissue ACE2 remained elevated in mice 21 days after cessation of lisinopril (p = 0.02). Across both cohorts, plasma ACE2 did not correlate with ACE2 protein index in any tissue. A sex difference was observed: kidney ACE2 levels were higher in males than females (p < 0.0001).

Oral lisinopril increases ACE2, the cellular receptor for SARS-CoV-2, in tissues that are relevant to the transmission and pathogenesis of COVID-19. Remarkably, the addition of losartan prevented lisinopril-induced increases in ACE2 across tissues. These results suggest that ACE inhibitors and angiotensin receptor blockers interact to determine tissue levels of ACE2.
Dynamic Brain Network States during Suspenseful Film Viewing
Authors: Bezdek Matthew A. , Keilholz Shella D. , Schumacher Eric H.
Published: October 2021

Studies of brain activity evoked by naturalistic stimuli have found narrative suspense produces reliable patterns of activation consistent with increased attention to the narrative and decreased processing of non-narrative stimuli (Bezdek et al., 2015). Yet the progression of brain states (i.e. patterns of activity levels across the whole brain) at suspense peaks and how they differ from suspense valleys or resting state scans has not previously been investigated. We used a fast fMRI acquisition sequence to measure sub-second brain states at peaks and valleys of narrative suspense and during rest. We found five brain states that occur during suspenseful film viewing, four of which differ in their frequency near suspense peaks compared to valleys. The pattern of results is consistent with the theoretical view that suspense captures and focuses attentional processing, triggering subsequent cognitive processing of narrative events.
Restoration of a pond: monitoring water quality and macroinvertebrate community succession
Authors: Kuranchie Abigail , Harmer Aaron , Evans Barbara , Brunton Dianne H.
Published: October 2021

To determine the success of restoration programmes, knowledge of the temporal dynamics in community structure and processes is vital. The water quality and macroinvertebrate community structures of a newly created and an established pond within the same ecosystem were sampled bi-monthly over a year to monitor the development of the new pond. The water quality measures of the ponds were significantly different. Conductivity, salinity, and total dissolved solids levels were also different between the ponds. The colonisation of a macroinvertebrate community in the new pond was rapid, resulting in a 75% resemblance to the established pond by the end of the first year. The pond was colonised by non-insect taxa like Crustacea and Gastropod and then by insects. There was a significant difference in the macroinvertebrate communities of the ponds due to temporal taxonomic composition differences. The high abundance of Diplacodes spp. (perchers), Physa spp. (left-handed pond snail), and Ostracod (seed shrimp) in the new pond contributed to the difference in the community between the two ponds. Cladocera (water fleas) dominated the macroinvertebrate community, and the highest abundance was recorded in August for both ponds. Our results suggest that a newly created pond can have a comparable macroinvertebrate community to nearby established ponds within a year.
Discovery of Potent Triple Inhibitors of Both SARS-CoV-2 Proteases and Human Cathepsin L
Authors: Meewan Ittipat , Kattoula Jacob , Kattoula Julius Y. , Skinner Danielle , Fajtová Pavla , Giardini Miriam A. , Woodworth Brendon , McKerrow James H. , de Siqueira-Neto Jair Lage , O’Donoghue Anthony J. , Abagyan Ruben
Published: October 2021

There are currently no FDA approved inhibitors of SARS-CoV-2 viral proteases with specific treatment for post-exposure of SARS-CoV-2. Here, we discovered inhibitors containing thiuram disulfide or dithiobis-(thioformate) tested against three key proteases in SARS CoV-2 replication including SARS CoV-2 Main Protease (Mpro), SARS CoV-2 Papain Like Protease (PLpro), and human cathepsin L. The use of thiuram disulfide and dithiobis-(thioformate) covalent inhibitor warheads was inspired by disulfiram, a currently prescribed drug commonly used to treat chronic alcoholism that at the present time is in Phase 2 clinical trials against SARS-CoV-2. At the maximal allowed dose, disulfiram is associated with adverse effects. Our goal was to find more potent inhibitors that target both viral proteases and one essential human protease to reduce the dosage and minimize the adverse effects associated with these agents. We found that compounds coded as RI175, JX 06, and RI172 are the most potent inhibitors from an enzymatic assay against SARS-CoV-2 Mpro, SARS-CoV-2 PLpro, and human cathepsin L with IC50s of 330, 250 nM, and 190 nM about 4.5, 17, and 11.5-fold more potent than disulfiram, respectively. The identified protease inhibitors in this series were also tested against SARS CoV-2 in a cell-based and toxicity assay and were shown to have similar or greater antiviral effect than disulfiram. The identified triple protease inhibitors and their derivatives are promising candidates for treatment of the Covid-19 virus and related variants.
Expert annotation and life-cycle transcriptomics of transcription factors in rust fungi (Pucciniales) highlight the role of cold shock proteins in dormancy exit
Authors: Louet Clémentine , Blot Carla , Shelest Ekaterina , Guerillot Pamela , Pétrowski Jérémy , Frey Pascal , Duplessis Sébastien
Published: October 2021

Fungi of the order Pucciniales are obligate plant biotrophs causing rust diseases. They exhibit a complex life cycle with the production of up to five spore types, infection of two unrelated hosts and an overwintering stage. Transcription factors (TFs) are key regulators of gene expression in eukaryote cells. In order to better understand genetic programs expressed during major transitions of the rust life cycle, we surveyed the complement of TFs in fungal genomes with an emphasis on Pucciniales. We found that despite their large gene numbers, rust genomes have a reduced repertoire of TFs compared to other fungi. The proportions of C2H2 and Zinc cluster - two of the most represented TF families in fungi-indicate differences in their evolutionary relationships in Pucciniales and other fungal taxa. The cold shock protein (CSP) family showed a striking expansion in Pucciniomycotina with specific duplications in the order Pucciniales. The survey of expression profiles collected by transcriptomics along the life cycle of the poplar rust fungus revealed TF genes related to major biological transitions, e.g. response to environmental cues and host infection. Particularly, poplar rust CSPs were strongly expressed in basidia produced after the overwintering stage suggesting a possible role in dormancy exit. Expression during transition from dormant telia to basidia confirmed the specific expression of the three poplar rust CSP genes. Their heterologous expression in yeast improved cell growth after cold stress exposure, strengthening their implication in dormancy exit. This study addresses for the first time TF involved in developmental transition in the rust life cycle opening perspectives to further explore molecular regulation in the biology of the Pucciniales.
Two type II phosphatidylinositol 4-kinases function sequentially in tubule-mediated cargo delivery from early endosomes to melanosomes
Authors: Zhu Yueyao , Li Shuixing , Jaume Alexa , Jani Riddhi Atul , Delevoye Cédric , Raposo Graça , Marks Michael S.
Published: October 2021

Melanosomes are pigment cell-specific lysosome-related organelles in which melanin pigments are synthesized and stored. Melanosome maturation requires delivery of melanogenic cargoes via tubular transport carriers that emanate from early endosomes and that require BLOC-1 for their formation. Here we show that phosphatidylinositol-4-phosphate (PtdIns4P) and the type II PtdIns-4-kinases (PI4KIIα and PI4KIIβ) support BLOC-1-dependent tubule formation to regulate melanosome biogenesis. Depletion of either PI4KIIα or PI4KIIβ with shRNAs in melanocytes reduced melanin content and misrouted BLOC-1-dependent cargoes to late endosomes/lysosomes. Genetic epistasis, cell fractionation, and quantitative live-cell imaging analyses show that PI4KIIα and PI4KIIβ function sequentially and non-redundantly downstream of BLOC-1 during tubule elongation towards melanosomes by generating local pools of PtdIns4P. The data show that both type II PtdIns-4-kinases are necessary for efficient BLOC-1-dependent tubule elongation and subsequent melanosome contact and content delivery during melanosome biogenesis. The independent functions of PtdIns-4-kinases in tubule extension are downstream of likely redundant functions in BLOC-1-dependent tubule initiation.

Contents are delivered to maturing melanosomes from early endosomal intermediates through tubular transport carriers. Zhu et al show that two type II phosphatidylinositol kinases, PI4KIIα and PI4KIIβ, sequentially generate phosphatidylinositol-4-phosphate during tubule initiation and elongation for ultimate melanosome content delivery.
Contribution of rsaC, a small non-coding RNA, towards the pathogenicity of Staphylococcus aureus in a mouse systemic infection model
Authors: Panthee Suresh , Hamamoto Hiroshi , Paudel Atmika , Ohgi Suguru , Sekimizu Kazuhisa
Published: October 2021

Understanding how a pathogen responds to the host stimuli and succeeds in causing disease is crucial for developing a novel treatment approach against the pathogen. Transcriptomic analysis facilitated by RNA-Seq technologies is used to examine bacterial responses at the global level. However, the ability to understand pathogen behavior inside the host tissues is hindered by much lower pathogen biomass than host tissue. Recently, we succeeded in establishing a method to enrich Staphylococcus aureus cells from infected organs. In this research, we analyzed the small non-coding RNA (sRNA) transcriptome of S. aureus inside the host and found that rsaC was among the highly expressed sRNAs. Furthermore, by gene disruption and complementation, we demonstrated that rsaC was required for full pathogenicity of S. aureus in a murine model. Besides, we found that ΔrsaC showed a difference in gene expression depending on the oxygen and host stress. The findings of this study suggest rsaC acts as a novel virulence factor in S. aureus and might facilitate the adaptation of staphylococci within the host.

Importance

Drug-resistant Staphylococcus aureus is among the pathogen for which new treatment options are urgently needed. However, limited understanding of S. aureus pathogenesis in the host has hindered unearthing potential strategies to treat the infections. Here, based on the in vivo transcriptomic analysis, we present the identification of a small non-coding RNA (sRNA) rsaC as a novel virulence factor of S. aureus. Furthermore, we performed transcriptomic analysis of the rsaC disrupted mutant and identified different pathways, possibly controlled by rsaC, during aerobic, anaerobic, and in vivo conditions. These findings contribute to reveal the role of sRNA rsaC and broadens our understanding of the adaptation of S. aureus to host environments.
Comparative effectiveness of allocation strategies of COVID-19 vaccines and antivirals against emerging SARS-CoV-2 variants of concern in East Asia and Pacific region
Authors: Leung Kathy , Jit Mark , Leung Gabriel M , Wu Joseph T
Published: October 2021

Background

We aimed to evaluate the impact of various allocation strategies of COVID-19 vaccines and antiviral such that the pandemic exit strategy could be tailored to risks and preferences of jurisdictions in the East Asia and Pacific region (EAP) to improve its efficiency and effectiveness.

Methods

Vaccine efficacies were estimated from the titre distributions of 50% plaque reduction neutralization test (PRNT50), assuming that PRNT50 titres of primary vaccination decreased by 2-10 folds due to antibody waning and emergence of VOCs, and an additional dose of vaccine would increase PRNT50 titres by 3- or 9-fold. We then used an existing SARS-CoV-2 transmission model to assess the outcomes of vaccine allocation strategies with and without the use of antivirals for symptomatic patients in Japan, Hong Kong and Vietnam.

Findings

Increasing primary vaccination coverage was the most important contributing factor in reducing the total and peak number of COVID-19 hospitalizations, especially when population vaccine coverage or vaccine uptake among older adults was low. Providing antivirals to 50% of symptomatic infections only further reduced total and peak hospitalizations by 10-13%. The effectiveness of an additional dose of vaccine was highly dependent on the immune escape potential of VOCs and antibody waning, but less dependent on the boosting efficacy of the additional dose.

Interpretation

Increasing primary vaccination coverage should be prioritised in the design of allocation strategies of COVID-19 vaccines and antivirals in the EAP region. Heterologous vaccination with any available vaccine as the additional dose could be considered when planning pandemic exit strategies tailored to the circumstances of EAP jurisdictions.

Funding

Health and Medical Research Fund, General Research Fund, AIR@InnoHK
Factors affecting the mental health of pregnant women using UK maternity services during the COVID-19 pandemic: A qualitative interview study
Authors: McKinlay A R , Fancourt D , Burton A
Published: October 2021

Background

People using maternity services in the United Kingdom (UK) have faced significant changes brought on by the COVID-19 pandemic and social distancing regulations. We focused on the experiences of pregnant women using UK maternity services during the pandemic and the impact of social distancing rules on their mental health and wellbeing.

Methods

We conducted 23 qualitative semi-structured interviews from June 2020 to August 2021, with women from across the UK who experienced a pregnancy during the pandemic. Nineteen women in the study carried their pregnancy to term and four women experienced a miscarriage during the pandemic. Interviews took place remotely over video or telephone call, discussing topics such as mental health during pregnancy and use of UK maternity services. We used reflexive thematic analysis to analyse interview transcripts.

Results

We generated six higher order themes: (1) Some pregnancy discomforts alleviated by social distancing measures, (2) The importance of relationships that support coping and adjustment, (3) Missed pregnancy and parenthood experiences, (4) The mental health consequences of birth partner and visitor restrictions, (5) Maternity services under pressure, and (6) Lack of connection with staff. Many participants felt a sense of loss over a pregnancy experience that differed so remarkably to what they had expected because of the pandemic. Supportive relationships were important to help cope with pregnancy and pandemic-related changes; but feelings of isolation were compounded for some participants because opportunities to build social connections through face-to-face parent groups were unavailable. Participants also described feeling alone due to restrictions on partners being present when accessing UK maternity services.

Conclusions

Our findings highlight some of the changes that may have affected pregnant women’s mental health during the COVID-19 pandemic. Reduced social support and being unable to have a partner or support person present during maternity service use were the greatest concerns reported by women in this study, as this absence removed a protective buffer in times of uncertainty and distress. This suggests that the availability of a birth partner or support person must be prioritised wherever possible to protect the mental health of women experiencing pregnancy and miscarriage in times of pandemics.
Novel torin1-sensitive phosphorylation sites on the metabolic regulator AMPK revealed by label-free mass spectrometry
Authors: Smiles William J. , Ovens Ashley J. , Yu Dingyi , Ling Naomi X.Y. , Morrison Kaitlin R. , Hoque Ashfaqul , Scott John W. , Galic Sandra , Langendorf Christopher G. , Kemp Bruce E. , Peterson Janni , Oakhill Jonathan S.
Published: October 2021

AMPK and mTORC1 are nutrient-sensitive protein kinases that form a fundamental negative feedback loop that governs cell growth and proliferation. AMPK is an αβγ heterotrimer that is directly phosphorylated by mTORC1 on α2S345to suppress AMPK activity and promote cell proliferation under nutrient stress conditions. Using mass spectrometry, we generated precise phosphorylation profiles of all 12 AMPK complexes expressed in proliferating human cells. Of the 18 phosphorylation sites detected, seven were sensitive to pharmacological mTORC1 inhibition, including four in the AMPK γ2 isoform NH2-terminal domain and α2S377which is located in the nucleotide-sensing motif. In particular, β1S182and β2S184were found to be mTORC1 substratesin vitroand near-maximally or substantially phosphorylated under cellular growth conditions. βS182phosphorylation was elevated in α1-containing complexes, relative to α2, an effect partly attributable to the non-conserved α-subunit serine/threonine-rich loop. While mutation of β1S182to a non-phosphorylatable Ala had no effect on basal and ligand-stimulated AMPK activity, β2-S184A mutation increased nuclear AMPK activity and enhanced cell proliferation under nutrient stress. We conclude that mTORC1 governs the nuclear activity of AMPK to regulate transcription factors involved in metabolism and cell survival during nutrient shortage.
Driving singing behaviour in songbirds using multi-modal, multi-agent virtual reality
Authors: Larsen Leon Bonde , Adam Iris , Berman Gordon J. , Hallam John , Elemans Coen P.H.
Published: October 2021

Interactive biorobotics provides unique experimental potential to study the mechanisms underlying social communication but is limited by our ability to build expressive robots that exhibit the complex behaviours of birds and small mammals. An alternative to physical robots is to use virtual reality (VR). Here, we designed and built a modular, audio-visual virtual reality environment that allows online, multi-modal, multi-agent interaction for social communication. We tested this system in songbirds, which provide an exceptionally powerful and tractable model system to study social communication. We show that zebra finches (Taeniopygia guttata) communicating through the VR environment exhibit normal call timing behaviour, males sing female directed song and both males and females display high-intensity courtship behaviours to their mates. These results suggest that the VR system provides a sufficiently natural environment to elicit normal social communication behaviour. Furthermore, we developed a fully unsupervised online song motif detector and used it to manipulate the virtual social environment of male zebra finches based on the number of motifs sung. Our VR setup represents a first step in taking automatic behaviour annotation into the online domain and allows for animal-computer interaction using higher level behaviours such as song. Our unsupervised acoustic analysis eliminates the need for annotated training data thus reducing labour investment and experimenter bias.
Low-temperature phases of dicalcium barium hexakis(propanoate)
Authors: Fábry Jan , Dušek Michal
Published: October 2021

The structure determinations of phases (II) and (III) of barium dicalcium hexakis(propanoate) {or poly[hexa-μ4-propanoato-bariumdicalcium], [BaCa2(C3H5O2)6]
n
} are reported at 240 and 130 K, respectively [phase (I) was determined previously by Stadnicka & Glazer (1980). Acta Cryst. B36, 2977–2985; our structure determination of phase (I) at room temperature is included in the supporting information]. In the high-temperature phase, the Ba2+ cation is surrounded by six carboxylate groups in bidentate bridging modes. In the low-temperature phases, five carboxylate groups act in bidentate bridging modes and one acts in a monodentate bridging mode around Ba2+. The Ca2+ cations are surrounded by six carboxylate O atoms in a trigonal antiprism in all the structures. The Ba2+ and Ca2+ cations are underbonded and significantly overbonded, respectively, in all the phases. The bonding of the Ba2+ cation increases slightly at the cost of the bonding of Ca2+ cations during cooling to the low-temperature phases. The phase transitions during cooling are accompanied by ordering of the ethyl chains. In room-temperature phase (I), all six ethyl chains are positionally disordered over two positions in the crossed mode, with additional splitting of the ethyl α- and β-C atoms. In phase (II), on the other hand, there are three disordered ethyl chains, one with positionally disordered ethyl α- and β-C atoms, and the other two with positionally disordered ethyl β-C atoms only, and in the lowest-temperature phase (III) there are four ordered ethyl chains and two disordered ethyl chains with positionally disordered ethyl β-C atoms only.
APIs, the glue under the hood. Looking for the “API economy”
Authors: Simon Jean Paul
Published: October 2021

Purpose

Some specialized consultancies have been making the case of an “API economy”. This study aims to investigate the issue, marshalling data on the economic dimension, to better understand the environments of APIs. It offers an overview of the functions and definition of application programming interfaces (APIs) in the backdrop of the history of services computing. The paper attempt assessing the economic value (size of the market) of APIs and reviews some of the available metrics. The paper also takes a look some issues and challenges ahead for the deployment of all kind of APIs.

Design/methodology/approach

The paper is based on desk research and a scientific and grey literature review. However, it relies mostly on specialized consultancies although from a critical viewpoint. The paper provides an historical account of the notions of APIs and API economy.

Findings

The paper questions the idea of an “API economy” that still stands on the “hype” side and is not clearly substantiated. It reveals that the number of firms with mature API programs remains small and that there is an uneven development across industries (traditional firms are less active than digital natives) and countries (Silicon Valley is leading). It highlights that the domination of IT companies (leaders and pioneers of APIs) raises issue of competition and at some point, may prevent rather than foster innovation.

Research limitations/implications

There is no robust data about the size of the API market nor about its value. Sources are highly heterogeneous and delimitations not always precise. The standard metrics or indicators are hard to find. Further research would be needed to better document this area.

Practical implications

The paper reviews some of the expected benefits of the use of APIs as enablers of private or public ecosystems.

Social implications

The paper delineates some of the economic benefits of the public APIs based on open data. It shows some positive examples of public APIs in the EU.

Originality/value

There is hardly any mention of the API economy in research literature. Most of the academic literature still stems from engineering department or business-management departments, not department of economics. Consultants would usually focus on the potential of business growth, on how to design an effective API strategy but not on the very economic dimension. The paper attempts providing a synthesis of the available data.
Antecedents and consequences of chatbot initial trust
Authors: Mostafa Rania Badr , Kasamani Tamara
Published: October 2021

Purpose

Artificial intelligence chatbots are shifting the nature of online services by revolutionizing the interactions of service providers with consumers. Thus, this study aims to explore the antecedents (e.g. compatibility, perceived ease of use, performance expectancy and social influence) and consequences (e.g. chatbot usage intention and customer engagement) of chatbot initial trust.

Design/methodology/approach

A sample of 184 responses was collected in Lebanon using a questionnaire and analyzed using structural equation modeling (SEM) by AMOS 24.

Findings

The results revealed that except for performance expectancy, all the other three factors (compatibility, perceived ease of use and social influence) significantly boost customers’ initial trust toward chatbots. Further, initial trust in chatbots enhances the intention to use chatbots and encourages customer engagement.

Research limitations/implications

The study provides insights into some variables influencing initial chatbot trust. Future studies could extend the model by adding other variables (e.g. customer experience and attitude), in addition to exploring the dark side of artificial intelligence chatbots.

Practical implications

This study suggests key insights for marketing managers on how to build chatbot initial trust, which, in turn, will lead to an increase in customers’ interactions with the brand.

Originality/value

The current study marks substantial contributions to the artificial intelligence marketing literature by proposing and testing a novel conceptual model that examines for the first time the factors that impact chatbot initial trust and the key outcomes of the latter.
The digital habitus of the unwedded emerging adults: a sociological interpretation of male-female differences in Facebook behavior
Authors: Masoom Muhammad Rehan
Published: October 2021

Purpose

By considering Facebook as a social context of manifesting digital habitus, this paper aims to explore the differences between men and women in the compensatory use of Facebook, their engagement in crafting and exhibiting virtual self-representation, and addictive traits associated with it. It is argued that while Facebook compensates for the negative consequences of real-world experiences by allowing users, particularly women to display an ideal self or a true virtual self and so aid in socializing, users eventually develop an addiction, which results in various social difficulties.

Design/methodology/approach

The study surveyed 511 male and 413 female undergraduate students who were between 19 to 26 years of age and reported being unmarried. Psycho-Social Aspects of Facebook Use Scale was used to solicit the responses. The factors were quantified by the items selected from the scale, and confirmatory factor analysis was used to assess the construct validity and reliability of items to check the usability of the scale in cross-cultural contexts. The Independent Samples t-test was used to check whether statistical evidence exists that the related sample means of men and women vary significantly.

Findings

While there is no difference in virtualizing the self by gender; women perceive Facebook as more compensating than men. Likewise, compared with men, women are found to be more self-presenting, more addictive and highly involved in socializing. The item-wise differences show that Facebook comparatively enhances the self-esteem of the women and women are more adventurous than men in Facebook interaction.

Originality/value

The study argues that there is a strong connection between the digital habitus and the social world. Social values and conditioning constrain people’s intention of being in the digital world and reflect their intention and decisions. Overall, the study is the most elaborative quantitative examination of how men and women differ in their Facebook behavior.
Knowledge and cardiovascular disease risk perception from the perspectives of prisoners and staff in a Scottish prison: a qualitative study
Authors: Mohan Andrea R.M. , Thomson Patricia , Haw Sally , Leslie Stephen J. , McKay Janet
Published: October 2021

Purpose

Prisoners have an increased risk of cardiovascular disease (CVD) compared to the general population. Knowledge and risk perception of CVD can influence engagement in preventative behaviours that lower an individual’s CVD risk. This paper aims to explore prisoners’ knowledge of CVD, and prisoners and staff’s perceptions of prisoners’ CVD risk.

Design/methodology/approach

This was a qualitative study in which semi-structured interviews were conducted with 16 prisoners and 11 prison and National Health Services staff in a Scottish prison. Data were analysed thematically using the framework method.

Findings

Most prisoners had limited knowledge of CVD as they could not describe it or could only identify one or two risk factors or cardiovascular events. Both prisoners and staff viewed prisoners’ CVD risk as either pertaining to one individual, or pertaining to the general prisoner population. Unhealthy behaviours that were believed to increase CVD risk were linked to three perceived consequences of imprisonment: mental health problems, boredom and powerlessness.

Originality/value

To the best of the authors’ knowledge, this is the first study to explore the CVD knowledge of prisoners, and perceptions of CVD risk from the perspectives of prisoners and prison staff. Findings from this study indicate that CVD education needs to be a priority for prisoners, addressing knowledge of CVD, its risk and risk perceptions. Additionally, the findings indicate that individual and socio-environmental factors linked to prisoners’ CVD risk need to be targeted to reduce this risk. Future research should focus on socio-environmental interventions that can lead to reducing the CVD risk of prisoners.
Lubrication efficiency of crankpin bearing using square-cylindrical textures of partial textures optimized by genetic algorithm
Authors: Xu Shaoyong , Nguyen Vanliem , Guo Xiaoyan , Yuan Huan
Published: October 2021

Purpose

This paper aims to propose an optimal design of the partial textures in the mixed lubrication regime of the crankpin bearing (CB) to maximize the CB's lubrication efficiency.

Design/methodology/approach

Based on a hybrid model between the slider-crank-mechanism dynamic and CB lubrication, the square-cylindrical textures (SCT) of partial textures designed on the CB’s mixed lubrication regime are researched. The effect of the density distributions of partial textures on CB’s lubrication efficiency is then evaluated via two indices of increasing the oil film pressure (p) and decreasing the frictional force (Ff) of the CB. The SCT’s geometrical dimensions are then optimized by the genetic algorithm to further improve the CB’s lubrication efficiency.

Findings

The results show that the SCT of partial textures optimized by the genetic algorithm has an obvious effect on enhancing CB’s lubrication efficiency. Especially, with the CB using the optimal SCT of partial textures (4 × 6), the maximum p is significantly increased by 3.7% and 8.2%, concurrently, the maximum Ff is evidently reduced by 9.5% and 21.6% in comparison with the SCT of partial textures (4 × 6) without optimization and the SCT of full textures (12 × 6) designed throughout the CB’s bearing surface, respectively.

Originality/value

The application of the optimal SCT of partial textures on the bearing surface not only is simple for the design-manufacturing process and maximizes CB’s lubrication efficiency but also can reduce the machining time, save cost and ensure the durability of the bearing compared to use the full textures designed throughout the CB’s bearing surface.
Optimal investment with time-varying transition probabilities for regime switching
Authors: Lee Hyo-Chan , Park Seyoung , Yoon Jong Mun
Published: October 2021

This study aims to generalize the following result of McDonald and Siegel (1986) on optimal investment: it is optimal for an investor to invest when project cash flows exceed a certain threshold. This study presents other results that refine or extend this one by integrating timing flexibility and changes in cash flows with time-varying transition probabilities for regime switching. This study emphasizes that optimal thresholds are either overvalued or undervalued in the absence of time-varying transition probabilities. Accordingly, the stochastic nature of transition probabilities has important implications to the search for optimal timing of investment.
How and when do employees hide knowledge from co-workers?
Authors: Arain Ghulam Ali , Hameed Imran , Khan Abdul Karim , Strologo Alberto Dello , Dhir Amandeep
Published: October 2021

Purpose

Drawing on social learning and social cognitive theories, this study aims to examine a multi-level moderated mediation model that tests the mediating effect of moral disengagement (MD: Level 1) between perceived organisational politics (POP: Level 1) and employee knowledge hiding from coworkers (EKHC: Level 1). The authors further propose that supervisor knowledge hiding from employees (SKHE: Level 2) moderates this mediation effect.

Design/methodology/approach

The authors obtained multi-sourced, multi-timed and multi-level data regarding 294 employees, working under 80 supervisors, from multiple organisations operating in Pakistan. The authors analysed these data using multi-level structural equation modelling via Mplus.

Findings

The results show that employee MD significantly mediates the direct relationship between POP and EKHC. The mediation effect is further positively moderated by SKHE, which amplifies the mediation effect.

Originality/value

To the best of the authors’ knowledge, this is the first empirical study that examines both EKHC and SKHE together in a single research model and provides a thorough understanding of why, how and when POP leads to EKHC.
Evaluation of the condition of a Mamluk-illuminated paper manuscript at Al-Azhar Library, Egypt
Authors: Abdel-Maksoud Gomaa , Abdel-Hamied Mostafa , Abdelhafez Ahmed A.M.
Published: October 2021

Purpose

This paper aims to present the components' characterization and condition assessment of an important deteriorated Mamluk-illuminated paper manuscript housed in Al-Azhar Library, Egypt.

Design/methodology/approach

Different analytical techniques used in this study were the portable digital optical microscope, stereomicroscope, scanning electron microscope with EDX (SEM.EDX), portable X-ray fluorescence (pXRF), X-ray diffraction (XRD), pH measurement and Fourier transform infrared spectroscopy (FTIR).

Findings

The results obtained by different microscopes showed that the gilding in the surface of illuminated paper sheets was performed with gold leaves. Additionally, these microscopes revealed that the illuminated paper manuscript has different aspects of deterioration such as adhered dirt, staining, some micro-cracks, cracks and detachment of some parts in some illuminated areas. The results of elemental analysis by EDX, portable XRF and XRD analysis showed that the orange red pigment is red lead (Pb3O4), blue pigment is azurite (2CuCo3.Cu (OH)2), and the gold layer is has consisted of brass alloy (Cu-Zn) with a small amount of gold element (Au). The pH measurement stated that the historical paper in the acidity level. The ATR-FTIR analysis also revealed the oxidation of cellulose. Moreover, it was found from ATR-FTIR that Arabic gum was used as a binder for the pigments.

Originality/value

This study presents the important results of analytical methods used for condition assessment and identification of the components of an important Mamluk-illuminated paper manuscript, where these results referred that the studied paper manuscript had different aspects of deterioration. The conservation steps either conservation treatment or preventive conservation are urgently needed in future studies.
Autoregressive conditional duration models for high frequency financial data: an empirical study on mid cap exchange traded funds
Authors: Nunkoo Houmera Bibi Sabera , Gonpot Preethee Nunkoo , Sookia Noor-Ul-Hacq , Ramanathan T.V.
Published: October 2021

Purpose

The purpose of this study is to identify appropriate autoregressive conditional duration (ACD) models that can capture the dynamics of tick-by-tick mid-cap exchange traded funds (ETFs) for the period July 2017 to December 2017 and accurately predict future trade duration values. The forecasted durations are then used to demonstrate the practical usefulness of the ACD models in quantifying an intraday time-based risk measure.

Design/methodology/approach

Through six functional forms and six error distributions, 36 ACD models are estimated for eight mid-cap ETFs. The Akaike information criterion and Bayesian information criterion and the Ljung-Box test are used to evaluate goodness-of-fit while root mean square error and the Superior predictive ability test are applied to assess forecast accuracy.

Findings

The Box-Cox ACD (BACD), augmented Box-Cox ACD (ABACD) and additive and multiplicative ACD (AMACD) extensions are among the best fits. The results obtained prove that higher degrees of flexibility do not necessarily enhance goodness of fit and forecast accuracy does not always depend on model adequacy. BACD and AMACD models based on the generalised-F distribution generate the best forecasts, irrespective of the trading frequencies of the ETFs.

Originality/value

To the best of the authors’ knowledge, this is the first study that analyses the empirical performance of ACD models for high-frequency ETF data. Additionally, in comparison to previous works, a wider range of ACD models is considered on a reasonably longer sample period. The paper will be of interest to researchers in the area of market microstructure and to practitioners engaged in high-frequency trading.
Percentage of residual B cells after 2 weeks of rituximab treatment predicts the improvement of systemic sclerosis‐associated interstitial lung disease
Authors: Ebata Satoshi , Yoshizaki Ayumi , Fukasawa Takemichi , Yoshizaki‐Ogawa Asako , Asano Yoshihide , Kashiwabara Kosuke , Oba Koji , Sato Shinichi
Published: October 2021

The benefit of rituximab (RTX) for systemic sclerosis‐associated interstitial lung disease (SSc‐ILD) has been shown in previous clinical trials. However, predictors of RTX efficacy have not been clarified. We investigated whether B‐cell responsiveness to RTX is related to therapeutic effect. Ten SSc‐ILD patients treated with RTX in an independent clinical trial (Japan Registry of Clinical Trials, jRCTs031180373) were included in this analysis. Peripheral B‐cell counts were examined retrospectively before RTX administration (baseline) and at 2, 4, 12, and 24 weeks after the first RTX administration, along with percent‐predicted forced vital capacity (%FVC) before and 24 weeks after RTX treatment. Relative to baseline, the percentage of residual peripheral blood B cells at 2 weeks after RTX was negatively correlated with the %FVC improvement at the 24‐week assessment (r = −0.41, p = 0.04). In the subgroup with less than 5% B‐cell persistence at week 2, %FVC at the 24‐week assessment was significantly improved compared to baseline (p = 0.02). In another subgroup with more than 5% residual B cells, %FVC was not significantly different after 24 weeks compared to baseline (p = 0.41). In conclusion, the removal rate of B cells after 2 weeks of RTX treatment may be a useful surrogate marker of subsequent SSc‐ILD improvement.