bluuebunny/crossref_metadata_2025 huggingface dataset:
AutoMorph: Automated Retinal Vascular Morphology Quantification via a Deep Learning Pipeline
Authors: Zhou Yukun , Wagner Siegfried K. , Chia Mark , Zhao An , Woodward-Court Peter , Xu Moucheng , Struyven Robbert , Alexander Daniel C. , Keane Pearse A.
Published: May 2022

Purpose

To externally validate a deep learning pipeline (AutoMorph) for automated analysis of retinal vascular morphology on fundus photographs. AutoMorph has been made publicly available (https://github.com/rmaphoh/AutoMorph), facilitating widespread research in ophthalmic and systemic diseases.

Methods

AutoMorph consists of four functional modules: image pre-processing, image quality grading, anatomical segmentation (including binary vessel, artery/vein, and optic disc/cup segmentation), and vascular morphology feature measurement. Image quality grading and anatomical segmentation use the most recent deep learning techniques. We employ a model ensemble strategy to achieve robust results and analyse the prediction confidence to rectify false gradable cases in image quality grading. We externally validate each module’s performance on several independent publicly available datasets.

Results

The EfficientNet-b4 architecture used in the image grading module achieves comparable performance to the state-of-the-art for EyePACS-Q, with an F1-score of 0.86. The confidence analysis reduces the number of images incorrectly assessed as gradable by 76%. Binary vessel segmentation achieves an F1-score of 0.73 on AV-WIDE and 0.78 on DR-HAGIS. Artery/vein scores 0.66 on IOSTAR-AV, and disc segmentation achieves 0.94 in IDRID. Vascular morphology features measured from AutoMorph segmentation map and expert annotation show good to excellent agreement.

Conclusions

AutoMorph modules perform well even when external validation data shows domain differences from training data, e.g., with different imaging devices. This fully automated pipeline can thus allow detailed, efficient and comprehensive analysis of retinal vascular morphology on colour fundus photographs.

Translational Relevance

By making AutoMorph publicly available and open source, we hope to facilitate ophthalmic and systemic disease research, particularly in the emerging field of ‘oculomics’.
Long Covid stigma: estimating burden and validating scale in a UK-based sample
Authors: Pantelic Marija , Ziauddeen Nida , Boyes Mark , O’Hara Margaret E , Hastie Claire , Alwan Nisreen A
Published: May 2022

Background

Stigma can be experienced as perceived or actual disqualification from social and institutional acceptance on the basis of one or more physical, behavioural or other attributes deemed to be undesirable. Long Covid is a predominantly multisystem condition that occurs in people with a history of SARSCoV2 infection, often resulting in functional disability.

Aim

To develop and validate a Long Covid Stigma Scale (LCSS); and to quantify the burden of Long Covid stigma.

Design and Setting

Follow-up of a co-produced community-based Long Covid online survey using convenience non-probability sampling.

Method

Thirteen questions on stigma were designed to develop the LCSS capturing three domains – enacted (overt experiences of discrimination), internalised (internalising negative associations with Long Covid and accepting them as self-applicable) and anticipated (expectation of bias/poor treatment by others) stigma. Confirmatory factor analysis tested whether LCSS consisted of the three hypothesised domains. Model fit was assessed and prevalence was calculated.

Results

966 UK-based participants responded (888 for stigma questions), with mean age 48 years (SD: 10.7) and 85% female. Factor loadings for enacted stigma were 0.70-0.86, internalised 0.75-0.84, anticipated 0.58-0.87, and model fit was good. The prevalence of experiencing stigma at least ‘sometimes’ and ‘often/always’ was 95% and 76% respectively. Anticipated and internalised stigma were more frequently experienced than enacted stigma. Those who reported having a clinical diagnosis of Long Covid had higher stigma prevalence than those without.

Conclusion

This study establishes a scale to measure Long Covid stigma and highlights common experiences of stigma in people living with Long Covid.
Effect of the INSR gene variants on the long-term response to a 31-month childhood obesity intervention
Authors: Chen Jing , Shan Rui , Xiao Wu-Cai , Liu Zheng
Published: May 2022

Objective

To explore effects of the INSR genotype on the waist circumference reduction after a lifestyle-based obesity intervention.

Methods

This was a nested study in a cluster-randomized controlled trial conducted from September 2018 to June 2019 in Beijing, China. Four schools (200 children) were randomized to the intervention group (diet and physical activity) and 4 schools (193 children) were randomized to the control group (usual practice without a focus on obesity prevention). We followed up children at 9 months (the end of the intervention) and 31 months (22 months after the intervention), and genotyped 7 independent SNPs in the INSR gene. We assessed genetic effects on changes in five waist-related indicators [waist circumference, waist-to-hip ratio (whr), waist-to-height ratio (WHtR), waist circumference adjusted by BMI (WCadjBMI), waist-to-hip ratio adjusted by BMI (WHRadjBMI)] from baseline to 9 months and from 9 months to 31 months in the intervention and control group, respectively, and compared whether genetic effects differed by group (i.e., gene-group interaction).

Results

From baseline to 9 months, we found that INSR rs7508679, rs10420008, rs11883325, and rs4804416 modified the intervention effects on changes in all waist-related indicators (all P < 0.05). In the control group, the effect allele was associated with greater increases in waist-related indicators, whereas opposite-directional associations were observed in the intervention group. Such interactions between SNPs and group assignment were almost not observed from 9 months to 31 months.

Conclusion

Our data suggested that children carrying effect alleles of rs7508679, rs10420008, rs11883325, or rs4804416 may benefit more from a lifestyle intervention for obesity prevention, but the effect appeared to be attenuated in the long term.
Risk factors for adolescent smoking uptake – analysis of prospective data from the UK Millennium Cohort Study
Authors: Vrinten Charlotte , Parnham Jennie C , Filippidis Filippos T , Hopkinson Nicholas S , Laverty Anthony A
Published: May 2022

Background

Most smokers take up their habit in adolescence. Risk factors for smoking are changing over time as demographics shift, and technologies such as social media create new avenues for the tobacco industry to recruit smokers. We assessed risk factors associated with smoking uptake among a representative cohort of UK adolescents.

Methods

Data come from 8,944 children followed prospectively as part of the UK Millennium Cohort Study. Smoking uptake was assessed as adolescents who had never smoked tobacco at age 14, but reported smoking ≥1 cigarette per week by age 17 (regular smoking). We used logistic regression to assess associations between smoking uptake and selected socio-demographic factors including household income, caregiver smoking, peer smoking, and social media use. Weighted percentages and Office for National Statistics Data were used to estimate numbers of regular smokers and new smokers in the UK.

Results

Among the whole sample, 10.6% of adolescents were regular smokers at age 17. Of these, 52% had started smoking between ages 14 and 17. Uptake was more common if caregivers (14.7% vs 5.7%, p<0.001) or friends smoked (13.0% vs. 5.1%, p<0.001), and among those reporting >5hours/day of social media use (10.0% vs 5.2%, p=0.006). Applying these percentages to population data, an estimated 160,000 adolescents in the UK were regular smokers by age 17, of whom more than 100,000 took up the habit between ages 14 and 17.

Discussion

Smoking behaviour remains highly transmissible within families and peer groups, reinforcing inequalities. Social media are highlighted as a potential vector.

What this paper adds

What is already known on this subject?

Cross sectional data suggest that certain population groups, such as those from more deprived backgrounds, are more likely to take up smoking earlier in life, a factor which is linked to greater health risks.

What important gaps in knowledge exist on this topic?

There are few prospective studies with nationally representative data that track smoking uptake in adolescence and how this is changing over time in the UK.

What this study adds

Around one in nine adolescents in the UK were regular smokers by age 17 and around half (52%) had taken up the habit since they were 14 years old.

Smoking among peers and caregivers was linked to adolescent smoking uptake and more time spent on social media was associated with greater likelihood of smoking uptake.
A dual role for the RNA helicase DHX34 in NMD and pre-mRNA splicing and its function in hematopoietic differentiation
Authors: Hug Nele , Aitken Stuart , Longman Dasa , Raab Michaela , Armes Hannah , Mann Abigail R. , Rio-Machin Ana , Fitzgibbon Jude , Rouault-Pierre Kevin , Cáceres Javier F.
Published: May 2022

The DExD/H-box RNA helicase DHX34 is a Nonsense-mediated decay (NMD) factor that together with core NMD factors co-regulates NMD targets in nematodes and in vertebrates. Here, we show that DHX34 is also associated with the human spliceosomal catalytic C complex. Mapping of DHX34 endogenous binding sites using Cross-Linking Immunoprecipitation (CLIP) revealed that DHX34 is preferentially associated with pre-mRNAs and locates at exon-intron boundaries. Accordingly, we observed that DHX34 regulates a large number of alternative splicing (AS) events in mammalian cells in culture, establishing a dual role for DHX34 in both NMD and pre-mRNA splicing. We previously showed that germline DHX34 mutations associated to familial Myelodysplasia (MDS)/Acute Myeloid Leukemia (AML) predisposition abrogate its activity in NMD. Interestingly, we observe now that DHX34 regulates the splicing of pre-mRNAs that have been linked to AML/MDS predisposition. This is consistent with silencing experiments in hematopoietic stem/progenitor cells (HSPCs) showing that loss of DHX34 results in differentiation blockade of both erythroid and myeloid lineages, which is a hallmark of AML development. Altogether, these data unveil new cellular functions of DHX34 and suggests that alterations in the levels and/or activity of DHX34 could contribute to human disease.
Spatial and lineage dependent processes underpin floristic assembly in the megadiverse Eastern South American mountains
Authors: Barros-Souza Yago , Borges Leonardo M.
Published: May 2022

Aim

The astonishing diversity of ancient mountains was likely shaped by multiple evolutionary processes. However, there is an ongoing debate on what were the main processes driving the assembly ofcampos rupestres, the mega-diverse flora of Eastern South American mountains. Although the ancient nature of these mountains suggests their flora should be composed by relatively older lineages, they harbour a number of recently diverged clades. To better understand the evolution of ancient mountains’ floras, we tested if thecampos rupestresare mainly composed by relatively old or recent communities and if angiosperm diversity is geographically structured using analyses of diversity and endemism.

Location

Eastern South America.

Time period

Oligocene/Miocene to the present.

Major taxa studied

Flowering plants.

Methods

We used analyses of diversity and endemism for 10% of thecampos rupestres flora. We obtained distribution data from online databases, and phylogenetic hypotheses from the literature. With these datasets, we estimated alpha and beta metrics of taxonomic and phylogenetic diversity, and conducted categorical analyses of neo- and paleo-endemism.

Results

Phylogenetic overdispersion predominates in thecampos rupestres. However, this general pattern is permeated by both lineage- and site-specific phylogenetic clustering, suggesting that recent diversification events depend on particular regional conditions and on the overall maintenance of old lineages. Although endemism patterns vary among differentcampos rupestressites, paleo-endemism is widespread and particularly prominent where phylogenetic overdispersion is evident. Moreover, phylogenetic composition indicates variable past spatial connections across different sites, taxonomic composition is highly geographically structured and seems to be influenced by the vegetation surrounding thecampos rupestresand/or by abiotic conditions.

Main conclusions

Our results reinforce the idiosyncratic nature of diversification patterns in ancient mountains and suggest that old, climatically buffered, infertile montane ecosystems not only include both relatively old and recent lineages, but that recent diversification is lineage and spatially dependent.
FcRγ−NK cell induction by specific CMV and expansion by subclinical viral infections in rhesus macaques
Authors: Lee Jaewon , Chang W. L. William , Scott Jeannine M. , Hong Suyeon , Lee Taehyung , Deere Jesse D. , Park Peter , Sparger Ellen E. , Dandekar Satya , Hartigan-O’Connor Dennis J. , Barry Peter A. , Kim Sungjin
Published: May 2022

Long-lived ‘memory-like’ NK cells, characterized by FcRγ-deficiency and enhanced responsiveness to antibody-bound virus-infected cells, have been found in certain human cytomegalovirus (HCMV)-seropositive individuals. Because humans are exposed to numerous microbes and environmental agents, specific relationships between HCMV and FcRγ-deficient NK cells (also known as g-NK cells) have been challenging to define. Here, we show that a subgroup of rhesus cytomegalovirus (RhCMV)-seropositive macaques possesses FcRγ-deficient NK cells that stably persist and display phenotype resembling human FcRγ-deficient NK cells. Moreover, these macaque NK cells resembled human FcRγ-deficient NK cells with respect to functional characteristics, including enhanced responsiveness to RhCMV-infected target in an antibody-dependent manner and hypo-responsiveness to tumor and cytokine stimulation. These cells were not detected in specific-pathogen-free (SPF) macaques free of RhCMV and six other viruses; however, experimental infection of SPF animals with RhCMV strain UCD59, but not RhCMV strain 68-1 or SIV, led to induction of FcRγ-deficient NK cells. In non-SPF macaques, co-infection by RhCMV with other common viruses was associated with higher frequencies of FcRγ-deficient NK cells. These results support a causal role for specific cytomegalovirus strain(s) in the induction of FcRγ-deficient NK cells, and suggest that co-infection by other viruses further expands this memory-like NK cell pool.
Antibody evasion by SARS-CoV-2 Omicron subvariants BA.2.12.1, BA.4, and BA.5
Authors: Wang Qian , Guo Yicheng , Iketani Sho , Nair Manoj S. , Li Zhiteng , Mohri Hiroshi , Wang Maple , Yu Jian , Bowen Anthony D. , Chang Jennifer Y. , Shah Jayesh G. , Nguyen Nadia , Chen Zhiwei , Meyers Kathrine , Yin Michael T. , Sobieszczyk Magdalena E. , Sheng Zizhang , Huang Yaoxing , Liu Lihong , Ho David D.
Published: May 2022

SARS-CoV-2 Omicron subvariants BA.2.12.1 and BA.4/5 have surged dramatically to become dominant in the United States and South Africa, respectively1,2. These novel subvariants carrying additional mutations in their spike proteins raise concerns that they may further evade neutralizing antibodies, thereby further compromising the efficacy of COVID-19 vaccines and therapeutic monoclonals. We now report findings from a systematic antigenic analysis of these surging Omicron subvariants. BA.2.12.1 is only modestly (1.8-fold) more resistant to sera from vaccinated and boosted individuals than BA.2. However, BA.4/5 is substantially (4.2-fold) more resistant and thus more likely to lead to vaccine breakthrough infections. Mutation at spike residue L452 found in both BA.2.12.1 and BA.4/5 facilitates escape from some antibodies directed to the so-called class 2 and 3 regions of the receptor-binding domain3. The F486V mutation found in BA.4/5 facilitates escape from certain class 1 and 2 antibodies but compromises the spike affinity for the viral receptor. The R493Q reversion mutation, however, restores receptor affinity and consequently the fitness of BA.4/5. Among therapeutic antibodies authorized for clinical use, only bebtelovimab retains full potency against both BA.2.12.1 and BA.4/5. The Omicron lineage of SARS-CoV-2 continues to evolve, successively yielding subvariants that are not only more transmissible but also more evasive to antibodies.
IMMUNE PROFILING UNCOVERS POTENT ADJUVANT CAPACITIES OF SARS-COV-2 INFECTION TO VACCINATION LEADING TO MEMORY T CELL RESPONSES WITH A TH17 SIGNATURE IN CANCER PATIENTS
Authors: Echaide Miriam , Labiano Ibone , Delgado Marina , Fernández de Lascoiti Angela , Ochoa Patricia , Garnica Maider , Ramos Pablo , Chocarro Luisa , Fernández Leticia , Arasanz Hugo , Bocanegra Ana , Blanco Ester , Piñeiro Sergio , Vera Ruth , Alsina Maria , Escors David , Kochan Grazyna
Published: May 2022

It is unclear whether cancer patients show impaired responses to COVID-19 and vaccination. Immune profiling was performed in three cohorts of healthy donors and oncologic patients: infected with SARS CoV-2, BNT162b2-vaccinated, and with previous COVID-19 and subsequently vaccinated. Vaccination was a poor inductor of T cell responses compared to infection, which significantly potentiated vaccination in antibody and T cell responses. T cell major targets in natural infection were the M and S protein, but not the N protein. T cell responses quickly decayed after 6 months post-vaccination, and T cell profiling showed that vaccination expanded effector T cells rather than memory T cell subsets unless the subjects had previous COVID-19. Cancer patients with previous COVID-19 and vaccinated exhibited potent IL-17+ CD4 and CD8 responses and increased neutrophils. Concluding, COVID-19 infection had potent adjuvant effects for vaccination leading to memory T cell differentiation, but with enhanced IL-17 inflammation signatures.

Teaser

Adjuvancy of SARS CoV-2 in cancer patients.
Competition for cysteine acylation by C16:0 and C18:0 derived lipids is a global phenomenon in the proteome
Authors: Nůsková Hana , Garcia-Cortizo Fabiola , Schwenker Lena Sophie , Tiebe Marcel , Schneider Martin , Helm Dominic , Reid Carissa , Kopp-Schneider Annette , Miller Aubry K. , Teleman Aurelio A.
Published: May 2022

S-acylation is a reversible posttranslational protein modification consisting of attachment of a fatty acid to a cysteine via a thioester bond. Research over the last few years has shown that a variety of different fatty acids, such as C16:0, C18:0 or C18:1, are used in cells to S-acylate proteins. We recently showed that GNAI proteins can be acylated on a single residue, Cys3, with either C16:0 or C18:1 and that the relative proportion of acylation with these fatty acids depends on the level of the respective fatty acid in the cell’s environment. This has functional consequences for GNAI proteins, with the identity of the acylating fatty acid affecting the subcellular localization of GNAIs. Unclear is whether this competitive acylation is specific to GNAI proteins or a more general phenomenon in the proteome. We perform here a proteome screen to identify proteins acylated with different fatty acids. We identify 218 proteins acylated with C16:0 and 308 proteins acylated with C18-lipids, thereby uncovering novel targets of acylation. We find that most proteins that can be acylated by palmitic acid (C16:0) can also be acylated with C18-fatty acids. For proteins with more than one acylation site, we find that this competitive acylation occurs on each individual cysteine residue. This raises the possibility that the function of many different proteins can be regulated by the lipid environment via differential S-acylation.
Regulation of odd chain fatty acid metabolism in the development of metabolic diseases in mice fed a low protein diet
Authors: Ampong Isaac
Published: May 2022

Nonalcoholic fatty liver disease (NAFLD) and Metabolic syndrome (MS) have become a global health concern as incidence of these metabolic disorders is growing rapidly in developing countries particularly in the Middle East, South America and Africa. Studies have shown that protein restriction is associated with increased risk of metabolic diseases, possibly through effects on fatty acid (FA) metabolism. In the present study, we investigated whether a low protein diet modulates FA metabolism and whether methyl donor supplementation can ameliorate these effects and improve metabolic health. Male C57BL/6 mice were fed either a low protein diet (LPD, 90 g/kg protein, n=8), a LPD supplemented with methyl donors (MD-LPD; choline chloride, betaine, methionine, folic acid, vitamin B12, n=8) or normal protein diet (NPD, 180 g/kg protein, n=8) for 7 weeks prior to analysis of serum fatty acid profiles by GC FID and MS and liver fatty acid synthesis and uptake gene expression by RT-qPCR. We observed significant depletion of serum C15:0 and C17:0 in LPD-fed males compared to NPD. Serum long chain saturated FAs C18:0 and C24:0 were increased in LPD male mice compared to NPD. Gene expression analysis revealed an upregulation of hepatic cluster of differentiation 36 (CD36) expression in LPD mice compared to NPD suggesting increased fat uptake in the liver. However, when LPD diet was supplemented with methyl donors, we observed either no change in serum C15: 0 and an increased serum C17:0 compared to LPD with no methyl donor supplementation. Again, methyl donor supplementation upregulated fatty acid desaturase 1 (FADS1), thioredoxin-1 (TRX1) and catalase (CAT) expression in the liver of MD-LPD fed mice compared to LPD mice. Altogether, our study revealed that odd chain fatty acids (OCFA)s are key early markers observed in a suboptimal diet-induced metabolic changes and may be potential targets to improve metabolic health outcomes.
Spike mutation resilient scFv76 antibody counteracts SARS-CoV-2 lung damage upon aerosol delivery
Authors: Milazzo Ferdinando M. , Chaves-Sanjuan Antonio , Minenkova Olga , Santapaola Daniela , Anastasi Anna M. , Battistuzzi Gianfranco , Chiapparino Caterina , Rosi Antonio , Pich Emilio Merlo , Albertoni Claudio , Marra Emanuele , Luberto Laura , Viollet Cécile , Spagnoli Luigi G. , Riccio Anna , Rossi Antonio , Santoro M. Gabriella , Ballabio Federico , Paissoni Cristina , Camilloni Carlo , Bolognesi Martino , De Santis Rita
Published: May 2022

Uneven worldwide vaccination coverage against SARS-CoV-2 and emergence of variants escaping immunity call for broadly-effective and easily-deployable therapeutics. We previously described the human single-chain scFv76 antibody, which recognizes SARS-CoV-2 Alfa, Beta, Gamma and Delta variants. We now show that scFv76 also neutralizes infectivity and fusogenic activity of Omicron BA.1 and BA.2 variants. Cryo-EM analysis reveals that scFv76 binds to a well-conserved SARS-CoV-2 spike epitope, providing the structural basis for its broad-spectrum activity. Moreover, we demonstrate that nebulized scFv76 exhibits therapeutic efficacy in a severe hACE2 transgenic mouse model of COVID-19 pneumonia, as shown by body weight and pulmonary viral load data. Counteraction of infection correlates with the inhibition of lung inflammation observed by histopathology and expression of inflammatory cytokines and chemokines. Biomarkers of pulmonary endothelial damage were also significantly reduced in scFv76-treated mice. Altogether the results support the use of nebulized scFv76 for COVID-19 induced by any SARS-CoV-2 variants emerged so far.
SuperFi-Cas9 exhibits extremely high fidelity but reduced activity in mammalian cells
Authors: Kulcsár Péter István , Tálas András , Ligeti Zoltán , Krausz Sarah Laura , Welker Ervin
Published: May 2022

Several advances have been made to SpCas9, the most widely used CRISPR/Cas genome editing tool, to reduce its unwanted off-target effects. The most promising approach is the development of increased fidelity nuclease (IFN) variants of SpCas9, however, their fidelity has increased at the cost of reduced activity. SuperFi-Cas9 has been developed recently, and it has been described as a next-generation high fidelity SpCas9 variant, free from the drawbacks of the first-generation IFNs. In this study, we characterized the on-target activity and the off-target propensity of SuperFi-Cas9 in mammalian cells comparing it to first-generation IFNs. SuperFi-Cas9 demonstrated strongly reduced activity but exceptionally high fidelity exhibiting features that are in many aspects similar to those of the first-generation variants, such as evo- and HeFSpCas9. When combined with ABE8e, SuperFi-Cas9 produced DNA editing with high activity rate as well as high specificity by reducing both bystander and SpCas9-dependent off-target base editing.
Whole exome-sequencing of vitiligo lesions indicate lower burden of somatic variations: implications in risk for non-melanoma skin cancers
Authors: Gupta Iti , Shankrit Shambhavi , Narta Kiran , Ghazi Madeeha , Grover Ritika , Pandey Rajesh , Kar Hemanta K , Menon Shruti M , Gupta Aayush , Yenamandra Vamsi K , Singh Archana , Mukerji Mitali , Mukhopadhyay Arijit , Rani Rajni , Gokhale Rajesh S , Dash Debasis , Natarajan Vivek T
Published: May 2022

Mapping of somatic variations has enabled understanding the progression of clonal variations from healthy skin to cutaneous malignancies. Highlighting, the adaptive nature of pigmentation, germline mutations in albinism amplify skin cancer susceptibility. However, lower incidence of non-melanoma skin cancer among subjects with acquired depigmenting skin disorder vitiligo is enigmatic and a matter of longstanding debate. To address this, we performed high-coverage exome sequencing of matched non-lesional and lesional vitiligo skin along with whole blood to account for germline variations. Our analysis suggests lower burden of somatic cancer-associated variations in exposed depigmented lesional skin compared to the non-lesional skin. A detailed investigation of vitiligo skin transcriptome reveals elevation of DNA repair and cell-proliferation pathways. Validation by comet-assay for DNA damage and cell cycle analysis of epidermal cells suggest undamaged DNA in vitiligo lesions that could be attributed to higher proliferation-coupled repair. Endorsing this, UV-signature variations are not prominent, instead SBS5 associated with endogenous mutational processes is conspicuous in both the vitiligo tissues. Our systematic pilot study indicates lower somatic mutation burden in vitiligo skin and supports the earlier demographic observation on lower risk of non-melanoma skin cancer in vitiligo subjects, providing an opportunity to learn strategies for cancer prevention from vitiligo.

Brief Summary

Vitiligo skin harbors decreased somatic variation burden in cancer-associated genes and a concomitant augmentation in DNA repair response, explaining the lower incidence of cutaneous malignancies.
Developmental evidence for parental conflict in driving Mimulus species barriers
Authors: Sandstedt Gabrielle D. , Sweigart Andrea L.
Published: May 2022

The endosperm, a tissue that nourishes the embryo in the seeds of flowering plants, is often disrupted in inviable hybrid seeds between species presumed to have divergent histories of parental conflict. Despite the potential importance of parental conflict in plant speciation, we lack direct evidence of its action in driving species barriers. Here, we performed reciprocal crosses between pairs of three monkeyflower species (Mimulus caespitosa, M. tilingii, and M. guttatus). The severity of hybrid seed inviability varies among these crosses, which we determined was due to species divergence in effective ploidy. By performing a time series of seed development, we assessed whether regions within the endosperm were potential targets of parental conflict. We found that the chalazal haustorium, a tissue within the endosperm that occurs at the maternal-filial boundary, develops abnormally in hybrid seeds when the paternal parent has the greater effective ploidy. Within these Mimulus species, parental conflict might target the chalazal haustorium to control sucrose movement from the maternal parent into the endosperm. Consequently, conflict may be exposed in crosses between species. Our study suggests that parental conflict in the endosperm may function as a driver of speciation by targeting regions and developmental stages critical for resource allocation.
Determining lattice parameters from two electron diffraction patterns
Authors: Shi Honglong
Published: May 2022

Lattice parameters are the fundamental quantities to describe a crystal structure, but the X-ray or neutron diffraction technique can determine only the averaged structure. Local lattice parameters can be determined from two zone-axis electron diffraction patterns (ZAPs) and the overall tilt angle, but the crystal needs to be oriented at the exact zone axis. This is a time-consuming transmission electron microscopy operation and largely limits structure determination of nanocrystallites. Here, a new method is proposed to reconstruct the 3D reciprocal cell and determine the lattice parameters from two ZAPs, one of which contains a high-order Laue zone (HOLZ) ring. The validity of the method was verified on both a low-symmetry monoclinic structure and a high-symmetry cubic crystal. The advantage of the method is that the accuracy of the lattice parameters measured is largely dependent on the HOLZ ring, which will considerably simplify the transmission electron microscopy operation. In this work, both the HOLZ-based method and the angle-based method were integrated into the DigitalMicrograph plugin UnitCell Tools—Two Patterns. With the help of this program, the lattice parameters of a crystal can be determined from two electron diffraction patterns efficiently and precisely.
A generalization of Ascoli–Arzelá theorem inCnwith application in the existence of a solution for a class of higher-order boundary value problem
Authors: Benhiouna Salah , Bellour Azzeddine , Amiar Rachida
Published: May 2022

Purpose

A generalization of Ascoli–Arzelá theorem in Banach spaces is established. Schauder's fixed point theorem is used to prove the existence of a solution for a boundary value problem of higher order. The authors’ results are obtained under, rather, general assumptions.

Design/methodology/approach

First, a generalization of Ascoli–Arzelá theorem in Banach spaces inCnis established. Second, this new generalization with Schauder's fixed point theorem to prove the existence of a solution for a boundary value problem of higher order is used. Finally, an illustrated example is given.

Findings

There is no funding.

Originality/value

In this work, a new generalization of Ascoli–Arzelá theorem in Banach spaces inCnis established. To the best of the authors’ knowledge, Ascoli–Arzelá theorem is given only in Banach spaces of continuous functions. In the second part, this new generalization with Schauder's fixed point theorem is used to prove the existence of a solution for a boundary value problem of higher order, where the derivatives appear in the non-linear terms.
The Nest: post evaluation study on intentional learning space in public housing Malaysia
Authors: Kusumo Camelia May Li , Letchamanan Hema , Lee Sze-ee , Gooi Liang Jun
Published: May 2022

Purpose

Aligned with the United Nations 2030 agenda of leaving no one behind, a project called The Nest was initiated to create an in-house intentional learning space at two public housings in Klang Valley. In a small unit of public housing, most children in these houses sit on the floor in the living room to do their schoolwork or study with the TV switched on. Poor indoor environmental quality and lack of personal space are among the main reasons that lead to children not being able to study at home comfortably.

Design/methodology/approach

The research employed a quasi-experimental approach as the research field setting was not randomly assigned. Observation on the change in the quality of space and post-evaluation interviews with beneficiaries were conducted.

Findings

The findings show that besides the tangible space that the Nest project has created, it also has created in-tangible space. It has shown that even small spatial changes to existing spaces could improve children's active learning and the participation of parents in their children's learning.

Research limitations/implications

This study focuses on the home learning experience and parental involvement in their children's learning, so perhaps future research can be done to measure the impact of home learning space on academic achievement.

Practical implications

The research outcomes show that a good quality of learning space influences the children's learning experience at home and the parents' involvement. It will also contribute to the development of the building regulation for high-rise affordable housing in Malaysia. Particularly in improving the optimum requirement to achieve better comfort quality for the learning space at the residential unit.

Social implications

The Nest project will contribute to raising the awareness among all residents of public housing on the importance of in-house learning space and encourage them to build their own learning spaces through the Do-It-Yourself Guidelines.

Originality/value

The research outcomes show that both parental involvement and the quality of learning space influence the children's learning experience at home. It will contribute to the development of the building regulation for high-rise affordable housing in Malaysia. Particularly in improving the optimum requirement to achieve better comfort quality for the learning space at the residential unit.
New approach for imposing the nonlinear floating potential boundary condition in the Poisson-continuity coupled system
Authors: Cheng Qiwen , Zou Jun , Li Benliang , Lu Jun
Published: May 2022

Purpose

The purpose of this study is to develop a new approach for simulating the ion flow field with the floating conductors based on the existing inversion method.

Design/methodology/approach

The space charge keeps charging the floating conductors until the dynamic balance is reached. The corresponding floating potential boundary condition is linearized as the combination of the equipotential constraints and natural boundary condition, which can be directly imposed in the inversion process.

Findings

The numerical results demonstrate that the modified inversion algorithm performs well in the ion flow field with the floating conductors and the floating potential converges within five steps’ iterations. The proposed approach is applied to investigate the effect of the grounded line to the floating conductors in the practical high voltage direct current (HVDC) transmission lines.

Originality/value

The modified inverse algorithm provides a general way to deal with the Kapzov hypothesis and the floating boundary condition simultaneously within one loop, which can be applied to the multiphysics systems with different kinds of irregular boundary conditions.
Integrated numerical simulation of an electromagnetic transmission line galloping excitation test system
Authors: Zhang Li , Ruan Jiangjun , Huang Daochun
Published: May 2022

Purpose

This paper aims to establish the mathematical model and solve the complex calculation multi-field coupling problem for an electromagnetic overhead transmission line galloping excitation test system.

Design/methodology/approach

An electromagnetic excitation test system is introduced. To calculate the vibration response of the transmission line, a transient coupled finite element model containing electromagnetic repulsive mechanism and transmission line system was established. Considering the advantages of Newmark-ß algorithm and fourth-order Runge–Kutta algorithm, the two algorithms are combined to solve the model. Compared with the simulation results of existing commercial finite element software, the accuracy of the calculation model of electromagnetic force and wire vibration response are verified.

Findings

Comparison results show that the proposed calculation model can accurately obtain the force of electromagnetic mechanism and the vibration response of the overhead power lines, and improve the calculation efficiency. The calculation results show that vibration under electromagnetic excitation presents a double half-wave mode, and the galloping amplitude varies according to the charging voltage.

Originality/value

This paper built the transient simulation model for a galloping test system. The Newmark-ß algorithm and the fourth-order Runge–Kutta algorithm are used to solve the model. The research results are of great significance for the actual galloping test system design.
On the interaction between the design and operation under uncertainties of a simple distributed energy system
Authors: Radet Hugo , Sareni Bruno , Roboam Xavier
Published: May 2022

Purpose

The purpose of this study is toward a better understanding of the interplay between the design and the operation under uncertainties of a simple distributed energy system (DES), by analyzing the sensitivity of the operation strategy over the size of the assets.

Design/methodology/approach

A two-step framework is developed in this work: first, the equipment sizes are obtained solving an integrated design approach where an operation strategy Fd is embedded in a design loop; then, once the sizes have been fixed, the DES is evaluated with an operation strategy Fa (which can be the same as Fd). The operation strategies Fd and Fa are not necessarily the same, so the objective of the paper is to study the interplay between the design and the operation by varying the optimality level of the operation strategies in both phases.

Findings

The results show that the design of DES cannot be approached without considering its close relationship with the operation strategy. Indeed, the design method needs to be chosen according to the performance of the operation policy finally used in real life: no matter if the operation strategies are the same in both phases but they must lead to a similar level of optimality in terms of operating performance.

Originality/value

The originality of this work is to shed light on the importance of the operation strategy in the design procedure as it seems rarely addressed, to the best of the authors’ knowledge, in the literature. Indeed, most of the paper dealing with stochastic design of DES solves single large two-stage problems without discussing the way power flows are finally controlled in real life. The optimal design and operation of DES is rarely addressed conjointly, this study aims at bridging the gap between these two isolated scientific communities.
Organisational justice mechanisms’ mediating leadership style, cognition- and affect-based trust during COVID-19 in South Africa
Authors: Visser Schalk Willem Jacobus , Scheepers Caren Brenda
Published: May 2022

Purpose

This study aims to investigate how different kinds of leadership styles (transformational and transactional leadership) influence different components of trust (affect-based and cognition-based trust), mediated by organisational justice mechanisms (distributive, procedural and interactional justice) during COVID-19 conditions in South Africa.

Design/methodology/approach

This study conducted a quantitative study by collecting survey data from 366 leaders in three organisations in South Africa, using valid and reliable scales. Given the number of latent constructs, the statistical technique used for this research was partial least squares-structural equation modelling, which enabled the authors to evaluate the strength and significance of the mediating relationships.

Findings

Findings show unexpectedly that neither distributive nor procedural justice has any significant mediating effect between transformational and transactional leadership and between the components of trust (affect-based and cognition-based trust). However, interactional justice was found to have a significant positive mediating effect between transactional leadership and affect-based trust as well as cognition-based trust. The same did not apply to transformational leadership.

Originality/value

Given the context of this study, which was conducted during the COVID-19 pandemic, these findings support the notion that it is the responsibility of leaders in organisations to communicate effectively, clearly and transparently to their followers at all times but particularly during times of extreme uncertainty. These increased levels of perceived fairness result in the development of trust within the organisation.
Examining the concurrent impact of teaching and assessment format on undergraduate students' academic performance in marketing
Authors: Livas Christos , Karali Nansy
Published: May 2022

Purpose

By focusing on a Greek traditional learning university, during and post Covid-19 restrictions, the study aims at examining the concurrent effects of teaching and assessment format on students' academic performance. The inclusion of case studies in course assessment post Covid-19 restrictions is also expected to give a rough insight into students' employability skills and workplace readiness.

Design/methodology/approach

The academic performance of 489 undergraduate students, as determined by the grades they earned, was measured in the final exams of business-to-business marketing and integrated marketing communication courses, held in January 2021 and 2022 at a Greek public university. The primary predictor variable or interest was “teaching and assessment format”, and took two values: (1) online teaching with multiple-choice assessment format (during Covid-19 restrictions) and (2) traditional classroom teaching with in-person case study and open-ended assessment format (post Covid-19 restrictions).

Findings

Grades were found to be affected by the participants' year of study, the type of marketing course, in which they were examined, and the teaching and assessment format employed. Either in whole or by gender, students appear to perform significantly worse in the traditional teaching with in-person case study and open-ended questions assessment format.

Practical implications

Good pedagogical practice in the use of digital technology is advised to incorporate diverse teaching tools and assessment methods.

Originality/value

Examination of the concurrent effects of teaching and assessment on academic performance unveils significant variation in students' academic performance under different formats, which may be attributable to multiple reasons.
The aerodynamic effects of blade pitch angle on small horizontal axis wind turbines
Authors: Kaya Mehmet Numan , Uzol Oguz , Ingham Derek , Köse Faruk , Buyukzeren Riza
Published: May 2022

Purpose

The purpose of this paper is to thoroughly investigate the aerodynamic effects of blade pitch angle on small scaled horizontal axis wind turbines (HAWTs) using computational fluid dynamics (CFD) method to find out the sophisticated effects on the flow phenomena and power performance.

Design/methodology/approach

A small HAWT is used as a reference to validate the model and examine the aerodynamic effects. The blade pitch angle was varied between +2 and −6 degrees, angles which are critical for the reference wind turbine in terms of performance, and the CFD simulations were performed at different tip speed ratio values, λ = 2, 3, 4, 5, 6, 7, 9 and 10.5 to cover the effects in various conditions. Results are examined in two different aspects, namely, general performance and the flow physics.

Findings

The power performance varies significantly according to the tip speed ratio; the power coefficient increases up to a certain pitch angle at the design tip speed ratio (λ = 6); however, between λ = 2 and 4, the more the blade is pitched downwards, the larger is the power coefficient, the smaller is the thrust coefficient. Similarly, for tip speed ratios higher than λ = 8, the positive effect of the low pitch angles on the power coefficient at λ = 6 reverses. The flow separation location moves close to the leading edge at low tip speed ratios when the blade is pitched upwards and the also tip vortices become more intense. In conclusion, the pitch control can significantly contribute to the performance of small HAWTs depending on different conditions.

Originality/value

In the literature, only very little attention has been paid to the aerodynamic effects of pitch angle on HAWTs, and no such study is available about the effects on small HAWTs. The change of blade pitch angle was maintained at only one degree each time to capture even the smallest aerodynamic effects, and the results are presented in terms of the power performance and flow physics.
Why do consumers free ride? Investigating the effects of cognitive effort on postpurchase dissonance
Authors: Nosi Costanza , Zollo Lamberto , Rialti Riccardo , Ciappei Cristiano
Published: May 2022

Purpose

Building on the theoretical paradigms of consumer free-riding and cognitive dissonance, this study aims to evaluate whether consumers’ cognitive effort when making a purchase decision impacts upon the relationship between free-riding habits and postpurchase cognitive dissonance.

Design/methodology/approach

To explore the relationship between cross-channel free-riding, cognitive efforts and cognitive dissonance, a framework was conceptualized and empirically tested on a sample of 518 Italian consumers. Covariance-based structural equation modeling and bootstrapped mediation analysis was performed with the PROCESS macro.

Findings

Results show that the more cognitively involved a free-riding consumer is, the more he/she will experience postpurchase cognitive dissonance.

Originality/value

Modern consumers habitually finalize their purchase activities through multiple different channels. The abundance of e-commerce/online platforms does indeed offer consumers a plethora of alternatives to physical/offline stores. Hence, consumers have been seen to act as “free-riders.” It is becoming more and more common for consumers to seek information in physical stores and then purchase a product online more conveniently. This notwithstanding, it has emerged that free-riding consumers tend to experience cognitive dissonance – which is a sensation of emotional discomfort – after making their purchases. The causes of this phenomenon are yet to be fully unpacked.
Regenerative tourism: transforming mindsets, systems and practices
Authors: Dredge Dianne
Published: May 2022

Purpose

The purpose of this paper is to examine the mindset shift, systems change and boundary spanning practices needed to transition to a regenerative approach in tourism. The paper seeks to deliver concrete ways to shift thinking and transition to a regenerative paradigm.

Design/methodology/approach

This viewpoint paper defines regenerative tourism, explores its principles and the levers for driving transformational change in tourism. It outlines what a conscious approach to regenerative tourism entails and outlines working principles for regenerative tourism. The paper concludes by identifying five key areas for reflection that seek to challenge established thinking and practice.

Findings

The reinvention of tourism requires work in three key areas: systems change, mindset shift and practice. Three findings are summarised as: (1) Regenerative tourism requires a shift in social-ecological consciousness and depends on our capacity to evolve our thinking from “me” to “we” and to develop compassion, empathy and collaborative action. (2) Scientific management is inconsistent with the transition to regeneration. Tourism must be managed as a complex adaptive system and overcome the challenges of individualism, reductionism, separation and marketisation associated with scientific thinking. (3) Regenerative tourism requires a deeply engaged bottom-up approach that is place-based, community-centred and environment-focused.

Originality/value

This paper shares the reflections, working principles and recommendations of The Tourism CoLab and is based on 30 years of experience as a consultant, policy analyst, educator, researcher, professor and now as founder of two tourism social enterprises. With the luxury of reflection and the distance from higher education that many do not have, the author shares her approach to shifting mindsets and driving transformative change.