bluuebunny/crossref_metadata_2025 huggingface dataset:
Senescence: why and where selection gradients might not decline with age
Authors: Roper Mark , Capdevila Pol , Salguero-Gómez Roberto
Published: July 2021

Patterns of ageing across the tree of life are much more diverse than previously thought. Yet, we still do not adequately understand how, why and where across the tree of life a particular pattern of ageing will evolve. An ability to predict ageing patterns requires a firmer understanding of how and why different ecological and evolutionary factors alter the sensitivity of fitness to age-related changes in mortality and reproduction. From this understanding, we can ask why and where selection gradients might not decline with age. Here, we begin by summarizing the recent breadth of literature that is unearthing, empirically and theoretically, the mechanisms that drive variation in patters of senescence. We focus on the relevance of two key parameters, population structure and reproductive value, as key to understanding selection gradients, and therefore senescence. We discuss how growth form, individual trade-offs, stage structure and social interactions may all facilitate differing distributions of these two key parameters than those predicted by classical theory. We argue that these four key aspects can help us understand why patterns of negligible and negative senescence can actually be explained under the same evolutionary framework as classical senescence.
Killing conspecific adults in mammals
Authors: Gómez José María , Verdú Miguel , González-Megías Adela
Published: July 2021

Mammals kill both conspecific infants and adults. Whereas infanticide has been profusely studied, the killing of non-infants (adulticide) has seldom attracted the attention of researchers. Mammals kill conspecific adults by at least four, non-exclusive reasons: during intrasexual aggression for mating opportunities, to defend valuable resources, to protect their progeny and to prey upon conspecifics. In this study, we test which reason is most likely to explain male and female adulticide in mammals. For this, we recorded the presence of adulticide, the ecological and behavioural traits, and the phylogenetic relationship for more than 1000 species. Adulticide has been recorded in over 350 species from the most important Mammalian clades. Male adulticide was phylogenetically correlated with the presence of size dimorphism and intrasexually selected weapons. Female adulticide was phylogenetically associated with the occurrence of infanticide. These results indicate that the evolutionary pathways underlying the evolution of adulticide differ between sexes in mammals. Whereas males commit adulticide to increase breeding opportunities and to compete with other males for mating, females commit adulticide mainly to defend offspring from infanticidal conspecifics.
The human visual system preserves the hierarchy of two-dimensional pattern regularity
Authors: Kohler Peter J. , Clarke Alasdair D. F.
Published: July 2021

Symmetries are present at many scales in natural scenes. Humans and other animals are highly sensitive to visual symmetry, and symmetry contributes to numerous domains of visual perception. The four fundamental symmetries—reflection, rotation, translation and glide reflection—can be combined into exactly 17 distinct regular textures. Thesewallpaper groupsrepresent the complete set of symmetries in two-dimensional images. The current study seeks to provide a more comprehensive description of responses to symmetry in the human visual system, by collecting both brain imaging (steady-state visual evoked potentials measured using high-density EEG) and behavioural (symmetry detection thresholds) data using the entire set of wallpaper groups. This allows us to probe the hierarchy of complexity among wallpaper groups, in which simpler groups are subgroups of more complex ones. We find that both behaviour and brain activity preserve the hierarchy almost perfectly: subgroups consistently produce lower-amplitude symmetry-specific responses in visual cortex and require longer presentation durations to be reliably detected. These findings expand our understanding of symmetry perception by showing that the human brain encodes symmetries with a high level of precision and detail. This opens new avenues for research on how fine-grained representations of regular textures contribute to natural vision.
What's my age again? On the ambiguity of histology-based skeletochronology
Authors: Schucht Pia J. , Klein Nicole , Lambertz Markus
Published: July 2021

Histology-based skeletochronology is a widely used approach to determine the age of an individual, and is based on the assumption that temporal cessations or decelerations of bone growth lead to incremental growth marks (GM), reflecting annual cycles. We studied the reliability of histology-based skeletochronology in a variety of extant tetrapods by comparing two different approaches: petrographic ground sections versus stained microtomized sections. Each bone was cut into two corresponding halves at its growth centre in order to apply both approaches to one and the same sample. None of the samples unequivocally revealed the actual age of the specimens, but truly concerning is the fact that the majority of samples even led to conflicting age estimates between the two approaches. Although the microtomized sections tended to yield more GM and thus indicated an older age than the ground sections, the contrary also occurred. Such a pronounced ambiguity in skeletochronological data strongly challenges the value of the respective age determinations for both extant and extinct animals. We conclude that much more research on the fundamental methodological side of skeletochronology—especially regarding the general nature and microscopic recognition of GM—is required.
Variable tropical moisture and food availability underlie mixed winter space-use strategies in a migratory songbird
Authors: Stanley Calandra Q. , Dudash Michele R. , Ryder Thomas B. , Gregory Shriver W. , Marra Peter P.
Published: July 2021

Identifying environmental correlates driving space-use strategies can be critical for predicting population dynamics; however, such information can be difficult to attain for small mobile species such as migratory songbirds. We combined radio-telemetry and high-resolution GPS tracking to examine space-use strategies under different moisture gradients for wood thrush (Hylocichla mustelina). We explored the role moisture plays in driving food abundance and, in turn, space-use strategies at a wintering site in Belize across 3 years. Individuals occupying drier habitats experienced lower food abundance and poorer body condition. Using data from our radio-tracked study population and GPS tracking from across five breeding populations, we detected low rates of overwinter site persistence across the wood thrush wintering range. Contrary to expectations, individuals in wetter habitats were more likely to engage in permanent mid-winter relocations, up to 148 km. We suggest facultative movements are instead a condition-dependent strategy that enables wintering wood thrush to locate alternative habitat as food availability declines throughout the dry season. Increased aridity is predicted across the wintering range of wood thrush, and future research should delve deeper into understanding how moisture impacts within and between season space-use dynamics and its ultimate impact on the population dynamics of this declining species.
Evaluation of randomly amplified polymorphic DNA-polymerase chain
reaction method for the identification of eighteen lyophilized probiotics
commercially available
Authors: Lee Bo Som , Yang Soo-Yeon , Choi Boyoung , Lee Minjee , Ban O-Hyun , Yang Jungwoo , Jung Young Hoon
Published: July 2021

Identification of probiotics is crucial to ensure the quality of food products
manufactured at the industrial scale. Although various techniques have been
introduced for bacterial identification, randomly amplified polymorphic
DNA-polymerase chain reaction (RAPD-PCR) is generally accepted as a conventional
method for bacterial identification. In this study, RAPD-PCR method was
evaluated for the identification of eighteen commercial probiotic strains. In
results, cellular and product (lyophilized) forms of each probiotic strain were
successfully identified based on band intensities and size of the amplified
genes. Therefore, RAPD-PCR method may be applied for the identification of
lyophilized probiotics commercially available.
Evaluating discharges and readmissions using a COVID Virtual Ward model: a retrospective data study assessing patient outcomes and the likely staffing commitment
Authors: Gallier Suzy , Atkin Catherine , Reddy-Kolanu Vinay , Parekh Dhruv , Zou Xiaoxu , Evison Felicity , Ball Simon , Sapey Elizabeth
Published: July 2021

Background

COVID-19 has placed a catastrophic burden on acute hospitals. In an attempt to reduce admissions and enable safe early discharge, a COVID virtual ward (CVW) care pathway has been supported by NHS England. This includes discharging people who meet objective criteria based on acuity scores and oxygen saturations, with pulse oximeters and daily phone calls for up to 14 days. Observational studies have reported the safety of this system, but without describing the outcomes from usual care.

Methods

A retrospective study using routinely collected health data from all adults with a confirmed positive severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) swab result between 1st June 2020 and 31st Jan 2021 who attended the Emergency Department or Acute Medical Unit at QEHB, which does not have a CVW service. Criteria for CVW were applied using data from the first 24 hours of presentation to hospital and subsequent health outcomes were included for 28 days, including re-presentation, re-admission, ITU escalation and death. Results were compared to reported studies based in secondary care.

Results

During the study period, 26,127 patients presented to QEHB hospital. 2301 had a positive SARS-CoV-2 swab. Of these, 1730 (75.2%) did not meet the criteria for the CVW and 571 (24.8%) did. Of the 571, 325 (56.9%) were discharged home within 24 hours and 246 (43.1%) were admitted for 24 hours or longer. Those admitted were older, with increased co-morbidities, 80.9% required hospital-supported acute therapies after the first 24 hours and 10.6% died. Of the 325 discharged, 44 were readmitted (13.5%), 30 (9.2%) with COVID-related symptoms, 5 (1.5%) required ITU and 1 patient (0.3%) died. These results were comparable to published studies with a CVW service.

Discussion

In the current study, discharging patients without a CVW did not confer a greater risk of re-presentation, re-admission, ITU escalation or death. The majority of patients who remained in hospital despite meeting the CVW criteria did so for the provision of treatments or acute assessments. It remains uncertain whether a CVW delivers improvements in hard outcomes, and further research is needed.
HLA-dependent variation in SARS-CoV-2 CD8+ T cell cross-reactivity with human coronaviruses
Authors: Buckley Paul R. , Lee Chloe H. , Pinho Mariana Pereira , Babu Rosana Ottakandathil , Woo Jeongmin , Antanaviciute Agne , Simmons Alison , Ogg Graham , Koohy Hashem
Published: July 2021

Pre-existing T cell immunity to SARS-CoV-2 in individuals without prior exposure to SARS-CoV-2 has been reported in several studies. While emerging evidence hints toward prior exposure to common-cold human coronaviruses (HCoV), the extent of- and conditions for-cross-protective immunity between SARS-CoV-2 and HCoVs remain open. Here, by leveraging a comprehensive pool of publicly available functionally evaluated SARS-CoV-2 peptides, we report 126 immunogenic SARS-CoV-2 peptides with high sequence similarity to 285 MHC-presented target peptides from at least one of four HCoV, thus providing a map describing the landscape of SARS-CoV-2 shared and private immunogenic peptides with functionally validated T cell responses. Using this map, we show that while SARS-CoV-2 immunogenic peptides in general exhibit higher level of dissimilarity to both self-proteome and -microbiomes, there exist several SARS-CoV-2 immunogenic peptides with high similarity to various human protein coding genes, some of which have been reported to have elevated expression in severe COVID-19 patients. We then combine our map with a SARS-CoV-2-specific TCR repertoire data from COVID-19 patients and healthy controls and show that whereas the public repertoire for the majority of convalescent patients are dominated by TCRs cognate to private SARS-CoV-2 peptides, for a subset of patients, more than 50% of their public repertoires that show reactivity to SARS-CoV-2, consist of TCRs cognate to shared SARS-CoV-2-HCoV peptides. Further analyses suggest that the skewed distribution of TCRs cognate to shared and private peptides in COVID-19 patients is likely to be HLA-dependent. Finally, by utilising the global prevalence of HLA alleles, we provide 10 peptides with known cognate TCRs that are conserved across SARS-CoV-2 and multiple human coronaviruses and are predicted to be recognised by a high proportion of the global population. Overall, our work indicates the potential for HCoV-SARS-CoV-2 reactive CD8+T cells, which is likely dependent on differences in HLA-coding genes among individuals. These findings may have important implications for COVID-19 heterogeneity and vaccine-induced immune responses as well as robustness of immunity to SARS-CoV-2 and its variants.
Quantification of spatial subclonal interactions enhancing the invasive phenotype of paediatric glioma
Authors: Tari Haider , Kessler Ketty , Trahearn Nicholas , Werner Benjamin , Vinci Maria , Jones Chris , Sottoriva Andrea
Published: July 2021

Intra-tumour heterogeneity is an intrinsic property of all cancers. In some cases, such variation can be maintained by interactions between tumour subclones with distinct molecular and phenotypic characteristics. In paediatric gliomas, interactions can take the form of enhanced invasive phenotype, a hallmark of these malignancies. However, subclonal interactions are hard to quantify and difficult to distinguish from spatial confounding factors and experimental bias. Here we combine spatial computational modelling of cellular interactions and invasion, with co-evolution experiments of clonally disassembled primary glioma lines derived at autopsy. We design a Bayesian inference framework to quantify spatial subclonal interactions between molecular and phenotypically distinct lineages with different patterns of invasion. We show how this approach could discriminate genuine subclonal interactions where one clone enhanced the invasive phenotype of another, from apparent interactions that were only due to the complex dynamics of subclones growing in space. This study provides a new approach for the identification and quantification of spatial subclonal interactions in cancer.
Joint interactions with humans may pose a higher risk of zoonotic outbreaks than interactions with conspecifics among wildlife populations at human-wildlife interfaces
Authors: Balasubramaniam Krishna N. , Aiempichitkijkarn Nalina , Kaburu Stefano S. K. , Marty Pascal R. , Beisner Brianne A. , Bliss-Moreau Eliza , Arlet Malgorzata E. , Atwill Edward , McCowan Brenda
Published: July 2021

Pandemics caused by wildlife-origin pathogens, like COVID-19, highlight the importance of understanding the ecology of zoonotic transmission and outbreaks among wildlife populations at human-wildlife interfaces. To-date, the relative effects of human-wildlife and wildlife-wildlife interactions on the likelihood of such outbreaks remain unclear.

In this study, we used social network analysis and epidemiological Susceptible Infected Recovered (SIR) models, to track zoonotic outbreaks through wild animals’ joint propensities to engage in social-ecological co-interactions with humans, and their social grooming interactions with conspecifics.

We collected behavioral and demographic data on 10 groups of macaques (Macacaspp.) living in (peri)urban environments across Asia. Outbreak sizes predicted by the SIR models were related to structural features of the social networks, and particular properties of individual animals’ connectivity within those networks.

Outbreak sizes were larger when the first-infected animal was highly central, in both types of networks. Across host-species, particularly for rhesus and bonnet macaques, the effects of network centrality on outbreak sizes were stronger through macaques’ human co-interaction networks compared to grooming networks.

Our findings, independent of pathogen-transmissibility, suggest that wildlife populations in the Anthropocene are vulnerable to zoonosis more so due to their propensities to aggregate around anthropogenic factors than their gregariousness with conspecifics. Thus, the costs of zoonotic outbreaks may outweigh the potential/perceived benefits of jointly interacting with humans to procure anthropogenic food. From One Health perspectives, animals that consistently interact with both humans and conspecifics across time and space are useful targets for disease spillover assessments and control.
Viral receptor profiles of masked palm civet revealed by single-cell transcriptomics
Authors: Chen Dongsheng , Ou Zhihua , Wang Haoyu , Zhang Yanan , Zhu Jiacheng , An Fuyu , Xu Jinqian , Ding Xiangning , Ding Peiwen , Luo Lihua , Wu Weiying , Qin Qiuyu , Wei Yanan , Zhao Wandong , Lv Zhiyuan , Lan Tianming , Li Meiling , Zhang Wensheng , Liu Huan , Hua Yan
Published: July 2021

Civets are small mammals belonging to the family Viverridae. The masked palm civets (Paguma larvata) served as an intermediate host in the bat-to-human transmission of severe acute respiratory syndrome coronavirus (SARS-CoV) in 20031. Because of their unique role in the SARS outbreak, civets were suspected as a potential intermediate host of SARS-CoV-2, the etiological pathogen of the COVID-19 pandemic. Besides their susceptibility to coronaviruses, civets can also be infected by other viruses, such as canine distemper viruses2, parvoviruses3, influenza viruses4, etc. Regarding the ecological and economical role of civets, it is vital to evaluate the potential threats from different pathogens to these animals. Receptor binding is a necessary step for virus entry into host cells. Understanding the distribution of receptors of various viruses provides hints to their potential tissue tropisms. Herein, we characterized the cell atlas of five important organs (the frontal lobe, lung, liver, spleen and kidney) of masked palm civets (Paguma larvata) and described the expression profiles of receptor associated genes of 132 viruses from 25 families, including 16 viruses from 10 families reported before that can attack civets and 116 viruses with little infection record.
ASXL3 controls cortical neuron fate specification through extrinsic self-renewal pathways
Authors: McGrath BT , Wu P , Salvi S , Girgla N , Chen X , Zhu J , KC R , Tsan YC , Moccia A , Srivastava A , Zhou X , Bielas SL
Published: July 2021

During corticogenesis, transcription plasticity is fundamental to the restriction of neural progenitor cell (NPC) multipotency and production of cortical neuron heterogeneity. Human and mouse genetic studies have highlighted the role of Polycomb transcriptional regulation in this process.ASXL3, which encodes a component of the Polycomb repressive deubiquitination (PR-DUB) complex, has been identified as a high confidence autism spectrum disorder (ASD) risk gene. Genetic inactivation ofAsxl3,in a mouse model that carries a clinically relevantASXL3frameshift (Asxl3fs)variant, disrupts lateral expansion of NPCs and delays cortical neuron differentiation. Single-cell RNA sequencing analysis implicates Notch signaling, which alters the composition of excitatory neurons and fidelity of cortical layer deposition. Our data provides a new link between extrinsic signaling cues and intrinsic epigenetic regulation that together control the timing of cell fate programs. Furthermore, transcriptomic analysis revealed dysregulation of other known ASD risk genes indicating that a convergent developmental pathway is affected. Collectively our work provides important insights about developmental mechanisms that contribute to ASD neuropathology.
Tempo of degeneration across independently evolved non-recombining regions
Authors: Carpentier Fantin , Rodríguez de la Vega Ricardo C. , Jay Paul , Duhamel Marine , Shykoff Jacqui A. , Perlin Michael H. , Wallen R. Margaret , Hood Michael E. , Giraud Tatiana
Published: July 2021

Recombination is beneficial over the long term, allowing more effective selection. Despite long-term advantages of recombination, local recombination suppression can evolve and lead to genomic degeneration, in particular on sex chromosomes. Here, we investigated the tempo of degeneration in non-recombining regions, i.e., the function curve for the accumulation of deleterious mutations over time, leveraging on 22 independent events of recombination suppression identified on mating-type chromosomes of anther-smut fungi, including newly identified ones. Using previously available and newly generated high-quality genome assemblies of alternative mating types of 13 Microbotryum species, we estimated degeneration levels in terms of accumulation of non-optimal codons and non-synonymous substitutions in non-recombining regions. We found a reduced frequency of optimal codons in the non-recombining regions compared to autosomes, that was not due to less frequent GC-biased gene conversion or lower ancestral expression levels compared to recombining regions. The frequency of optimal codons rapidly decreased following recombination suppression and reached an asymptote after ca 3 Mya. The strength of purifying selection remained virtually constant at dN/dS = 0.55, i.e. at an intermediate level between purifying selection and neutral evolution. Accordingly, non-synonymous differences between mating-type chromosomes increased linearly with stratum age, at a rate of 0.015 per MY. We thus develop a method for disentangling effects of reduced selection efficacy from GC-biased gene conversion in the evolution of codon usage and we quantify the tempo of degeneration in non-recombining regions, which is important for our knowledge on genomic evolution and on the maintenance of regions without recombination.
Metabolic turnover and dynamics of modified ribonucleosides by 13C labeling
Authors: Gameiro Paulo A. , Encheva Vesela , Dos Santos Mariana Silva , MacRae James I , Ule Jernej
Published: July 2021

Tandem mass spectrometry (MS/MS) is an accurate tool to assess modified ribonucleosides and their dynamics in mammalian cells. Yet, MS/MS quantification of lowly abundant modifications in non-ribosomal RNAs is unreliable, and the dynamic features of various modifications poorly understood. We developed a 13C labeling approach, 13C-dynamods, to quantify the turnover of base modifications in newly transcribed RNA. This turnover-based approach helped to resolve mRNA from ncRNA modifications in purified RNA or free ribonucleosides, and showed the distinct kinetics of N6-methyladenosine (m62A) versus 7-methylguanosine (m7G) in polyA+-purified RNA. We uncovered that N6,N6-dimethyladenosine (m62A) exhibits a distinct turnover in small RNAs and free ribonucleosides when compared to the known m6 A-modified large rRNAs. Finally, combined measurements of turnover and abundance informed on the transcriptional versus posttranscriptional sensitivity of modified ncRNAs and mRNAs, respectively, to stress conditions. Thus, 13C-dynamods enables studies of origin of modified RNAs at steady-state and their dynamics under non-stationary conditions.
Discovery of nanobodies against SARS-CoV-2 and an uncommon neutralizing mechanism
Authors: Li Tingting , Zhou Bingjie , Luo Zhipu , Lai Yanling , Huang Suqiong , Zhou Yuanze , Gautam Anupriya , Bourgeau Salome , Wang Shurui , Bao Juan , Tan Jingquan , Lavillette Dimitri , Li Dianfan
Published: July 2021

SARS-CoV-2 and its variants continue to threaten public health. The virus recognizes the host cell by attaching its Spike receptor-binding domain (RBD) to the host receptor ACE2. Therefore, RBD is a primary target for neutralizing antibodies and vaccines. Here we report the isolation, and biological and structural characterization of two single-chain antibodies (nanobodies, DL4 and DL28) from RBD-immunized alpaca. Both nanobodies bind Spike with affinities that exceeded the detection limit (picomolar) of the biolayer interferometry assay and neutralize the original SARS-CoV- 2 strain with IC50of 0.086 μg mL-1(DL4) and 0.385 μg mL-1(DL28). DL4 and a more potent, rationally designed mutant, neutralizes the Alpha variant as potently as the original strain but only displays marginal activity against the Beta variant. By contrast, the neutralizing activity of DL28, when in the Fc-fused divalent form, was less affected by the mutations in the Beta variant (IC50of 0.414 μg mL-1for Alpha, 1.060 μg mL-1for Beta). Crystal structure studies reveal that DL4 blocks ACE2-binding by direct competition, while DL28 neutralizes SARS-CoV-2 by an uncommon mechanism through which DL28 distorts the receptor-binding motif in RBD and hence prevents ACE2-binding. Our work provides two neutralizing nanobodies for potential therapeutic development and reveals an uncommon mechanism to design and screen novel neutralizing antibodies against SARS-CoV-2.
Discovery of genes that modulate flavivirus replication in an interferon-dependent manner
Authors: Lesage Sarah , Chazal Maxime , Beauclair Guillaume , Batalie Damien , Couderc Elodie , Lescure Aurianne , Del Nery Elaine , Tangy Frédéric , Martin Annette , Manel Nicolas , Jouvenet Nolwenn
Published: July 2021

Establishment of the interferon (IFN)-mediated antiviral state provides a crucial initial line of defense against viral infection. Numerous genes that contribute to this antiviral state remain to be identified. Using a loss-of-function strategy, we screened an original library of 1156 siRNAs targeting 386 individual curated human genes in stimulated microglial cells infected with Zika virus (ZIKV), an emerging RNA virus that belongs to the flavivirus genus. The screen recovered twenty-one potential host proteins that modulate ZIKV replication in an IFN-dependent manner, including the previously known IFITM3 and LY6E. Further characterization contributed to delineate the spectrum of action of these genes towards other pathogenic RNA viruses, including Hepatitis C virus and SARS-CoV-2. Our data revealed that APOL3 acts as a proviral factor for ZIKV and several other related and unrelated RNA viruses. In addition, we showed that MTA2, a chromatin remodeling factor, possesses potent flavivirus-specific antiviral functions. Our work identified previously unrecognized genes that modulate the replication of RNA viruses in an IFN-dependent way, opening new perspectives to target weakness points in the life cycle of these viruses.
Hierarchical clustering optimizes the tradeoff between compositionality and expressivity of task structures for flexible reinforcement learning
Authors: Liu Rex G , Frank Michael J
Published: July 2021

A hallmark of human intelligence, but challenging for reinforcement learning (RL) agents, is the ability to compositionally generalise, that is, to recompose familiar knowledge components in novel ways to solve new problems. For instance, when navigating in a city, one needs to know the location of the destination and how to operate a vehicle to get there, whether it be pedalling a bike or operating a car. In RL, these correspond to the reward function and transition function, respectively. To compositionally generalize, these two components need to be transferable independently of each other: multiple modes of transport can reach the same goal, and any given mode can be used to reach multiple destinations. Yet there are also instances where it can be helpful to learn and transfer entire structures, jointly representing goals and transitions, particularly whenever these recur in natural tasks (e.g., given a suggestion to get ice cream, one might prefer to bike, even in new towns). Prior theoretical work has explored how, in model-based RL, agents can learn and generalize task components (transition and reward functions). But a satisfactory account for how a single agent can simultaneously satisfy the two competing demands is still lacking. Here, we propose a hierarchical RL agent that learns and transfers individual task components as well as entire structures (particular compositions of components) by inferring both through a non-parametric Bayesian model of the task. It maintains a factorised representation of task components through a hierarchical Dirichlet process, but it also represents different possible covariances between these components through a standard Dirichlet process. We validate our approach on a variety of navigation tasks covering a wide range of statistical correlations between task components and show that it can also improve generalisation and transfer in more complex, hierarchical tasks with goal/subgoal structures. Finally, we end with a discussion of our work including how this clustering algorithm could conceivably be implemented by cortico-striatal gating circuits in the brain.
Multi-Elemental Isotope And Analog Tracer Application To Measure Nutrient Uptake And Distribution In Malus × Domestica Borkh
Authors: Gomez Raquel , Kalcsits Lee
Published: July 2021

Plant nutrient uptake is critical to maintain an optimum balance between vegetative and reproductive growth and fruit quality. Nutrient imbalances, and more specifically the relationship of potassium, magnesium and nitrogen to calcium, can be critical for fruit quality in apple (Malus x domestica Borkh.). In perennial plants, it is difficult to conduct short-term experiments to measure plant uptake and distribution in response to either cultivar or treatment because of substantial preexisting nutrient pools already present. The use of isotopically labeled nitrogen, and nutrient analogs such as strontium and rubidium allow for the quantification of uptake and distribution that is often not possible with bulk mineral analysis. Here, the objective was to understand how scion genotype influences nutrient uptake and partitioning between aboveground and below ground parts of the tree. In this experiment, 10 atom% 15N, Strontium (Sr), and Rubidium (Rb) were applied to three different potted apple cultivars that were either treated with ABA 250 mg/L or 500 mg/L or an untreated control. After 70 days of growth, overall recovery rates of each tracer reflected the mobility of their nutrient analog. Strontium had an average tracer recovery rate of 3.9%, followed by 15N with 14.6% recovery and finally Rb with 15.1%. Independent of treatment, ‘Gala’ significantly absorbed more tracer followed by Granny Smith and Honeycrisp for Rb and Sr but not 15N. These results have implications in understanding the association between aboveground factors like transpiration and nutrient uptake and distribution in apple.
The relationship between the level of a corporation’s public disclosure of its managerial values and its level of organizational authenticity
Authors: Neher Alain , Wong Alfred , Miles Morgan P.
Published: July 2021

Purpose

This study aims to explore if corporations that publicly disclose more information about their managerial values are also more organizationally authentic in enacting these values.

Design/methodology/approach

A maturity model of managerial values is used that ordinally ranks a corporation’s level of managerial values enactment using corporate annual reports. The samples of corporations’ corporate reports are qualitatively content analyzed, and the outcomes are statistically tested.

Findings

The findings indicate that as an organization voluntarily discloses more information about its corporate values, it tends to be more likely to enact their espoused values, and their corporation’s level of organizational authenticity increases.

Originality/value

This study suggests an approach to benchmark a corporation’s level of organizational authenticity using public information, and by doing so, contributes to both policy and practice by offering a framework to compare organizational authenticity between public corporations by their sector, size or the age of the corporation.
Work environment and performance among nurses: a significant way to overcome violation of human rights in the health sector
Authors: Bhatti Mitho Khan , Soomro Bahadur Ali , Shah Naimatullah
Published: July 2021

Purpose

The study aims to purpose the role of the work environment (WE) towards employees’ performance (EP) in Pakistan’s health sector.

Design/methodology/approach

Data-wise, the study is cross-sectional and random sampling was used to glean the response from the trained health nurses in Pakistan. The survey questionnaire was used as a primary tool to collect the data. In total, 306 usable samples as used to infer the final consequences.

Findings

The structural equation modeling through AMOS 26.0 for windows resulted in a positive and significant effect of an organizational learning culture, supervisor support on EP. On the other hand, the impact of peer support on EP is not significant among the nurses in Pakistan.

Practical implications

The policymakers and planners in the health sector and government may address unemployment – are willing to join the health sector. Better performance through the WE would provide equity in health and would not violate fundamental human rights. This work may help human resource management bring advancement in organizational and social determinants of health equity and practical interventions to overwhelm health-care barriers.

Originality/value

The study overcomes the gaps in terms of the cross-sectional survey to measure nurses’ performance in Pakistan.
Analysis of lubrication and sealing performance on textured piston pair with multi-factor coupling
Authors: Quan Song , Guo Yong , Liu Xuedong , Chen Zhewu , Liu Yudi
Published: July 2021

Purpose

This paper aims to study the lubrication and sealing performance on the textured piston pair under the cross action of the shape and structure parameters. This paper further carries out the optimization design of low energy consumption hydraulic impact piston pair.

Design/methodology/approach

Based on the characteristics of the ring gap seal piston pair, the flow field analysis model of the whole film gap is established for its periodic treatment. The friction power loss of the piston pair is defined as the evaluation index of the lubrication performance and the leakage power loss as the evaluation index of the sealing performance. The orthogonal test design and CFD software were used to analyze the lubrication and sealing performance of the textured piston pair.

Findings

The cross action of shape and structure factors has a great influence of the lubrication and sealing performance on the textured piston pair. Clearance and shape parameters have great influence on it, while seal length and depth diameter ratio have little influence. The sealing performance of conical textured piston pair is good, while the lubrication performance of square textured piston pair is good. The primary and secondary order of influence of shape and structure on energy consumption on piston pair is B (seal clearance) > C (texture shape) > D (area ratio) > A (seal length) > E (depth diameter ratio).

Originality/value

Breaking the defect of local optimization design on traditional piston pair structure, then find the matching relationship of structural parameters on textured piston pair. Further improve the lubrication and sealing performance of the piston pair, and provide reference for the global optimization design of the low energy consumption hydraulic impact piston pair.
A simulation-based binomial model for building development appraisal
Authors: Lawal Yarima Sallau , Ibrahim Aliyu Makarfi , Abubakar Mu'awiya , Ishaq Ziyadul Hassan , Sa'ad Mohammed Mustapha
Published: July 2021

Purpose

Building developments are often capital intensive, have a long payback period and many associated risks and uncertainties. This makes investments in building projects to be a big challenge. This study aims to develop a computerized simulation-based binomial model (CSBBM) for building investment appraisal with a view to improving the economic sustainability of proposed building projects.

Design/methodology/approach

Mathematical equations and algorithms were developed based on the binomial method (BM) of real options analysis and then implemented on a computer system. A hybrid algorithm that integrates Monte Carlo simulation (MCS) and BM was also developed. A real-life project was used to test the model. Sensitivity analysis was also conducted to explore the influence of input variables on development option value (DOV).

Findings

The test result shows that the model developed provides a better estimate of the value of an investment when compared with traditional net present value technique, which underestimate the value. Moreover, inflation rate (i) and rental value (Ri) are the most sensitive variables for DOV. An increase in i and Ri by just 5% causes a corresponding increase in DOV by 202% and 132%, respectively. While the least sensitive variable is the discount rate (r), as an increase in r by 5% causes a corresponding decrease in DOV by just 9%. The CSBBM is capable of determining the optimal time of development of buildings with an accuracy of 80.77%.

Practical implications

The hybrid model produces higher DOV than that of only the BM because MCS considers randomness in uncontrollable variables. Thus, building investment decision-makers should always use MCS to complement the BM in an investment analysis.

Originality/value

There is limited evidence on the use of this kind of hybrid model for determining DOV in practice.
Coordination of similar days and multi-objective posterior process to predict energy of transmission substation
Authors: Abdolrezaei Hassan , Siahkali Hassan , Olamaei Javad
Published: July 2021

Purpose

This paper aims to present a hybrid model to mid-term forecast the load of transmission substations based on the knowledge of expert site and multi-objective posterior framework. The main important challenges in load forecasting are the different behavior of load in specific days. Regular days, holidays and special holidays, days after a holidays and days of load shifting are characterized by abnormal load profiles. The knowledge of these days is verified by expert operators in regional dispatching centers.

Design/methodology/approach

In this paper, a hybrid model for power prediction of transmission substations based on the combination of similar day selection and multi-objective posterior technique has been proposed. In the first step, the important data for prediction is provided. Posterior method is used in the second step for prediction that it is based on kernel functions. A multi-objective optimization has been formulated with three type of output accuracy measurement function that it is solved by non-dominated sorting genetic technique II (NSGT-II) method. TOPSIS way is used to find the best point of Pareto.

Findings

The presented method has been tested in four scenarios for three different transmission stations, and the test results have been compared. The presented results indicate that the presentation method has better results and is robust to different load characteristics, which can be used for better forecasting of different stations for better planning of repairs and network operation.

Originality/value

The main contributions of this paper can be categorized as follows: A hybrid model based on similar days selection and multi-objective framework posterior is presented. Similar day selection is done by expert site that the day type and days with scheduled repair are considered. Hyperparameters of posterior process are found by NSGT-II based on TOPSIS method.
Effect of non-linear thermal radiation on the stagnation point flow of double diffusive free convection due to movingvertical plate
Authors: Nandeppanavar Mahantesh M. , M.C. Kemparaju , N. Raveendra
Published: July 2021

Purpose

This paper aims to find the influence of convective heat transfer, buoyancy proportions, nonlinear thermal radiation, Prandtl number, Rayleigh number and Schmidt number on velocity, temperature and concentration profiles.

Design/methodology/approach

This paper explores the heat and mass transfer of a stagnation point stream of free convective Casson fluid over a moving vertical plate with nonlinear thermal radiation and convective boundary restrictions. The governing PDEs of stream, heat and concentration profiles were reformed into an arrangement of nonlinear ODEs by using similarity transformation. This framework was then tackled numerically by applying forth-order RK shooting strategy.

Findings

Distribution of flow, velocity and temperature profiles for different values of governing parameters are analyzed.

Originality/value

The original results are depicted in terms of plots.
Migrant entrepreneurs from an advanced economy in a developing country: the case of Korean entrepreneurs in Malaysia
Authors: Abd Hamid Hamizah , Everett André M.
Published: July 2021

Purpose

This study aims to explore the co-ethnic relations of migrant entrepreneurs (MEs) from advanced economies in a developing country, specifically in the context of co-ethnic ties among Korean migrant entrepreneurs (KMEs) operating business ventures in Malaysia.

Design/methodology/approach

This research is outlined by an embeddedness view and uses a qualitative approach using a single case study design.

Findings

For KMEs, in-group co-ethnic ties are mobilised in a relatively more structured manner coalescing personal and entrepreneurial endeavours, particularly demonstrating the dynamics of co-ethnic ties and the home country’s development levels. The findings lead to a model of migrant entrepreneurship for MEs from a more developed nation.

Originality/value

The theoretical value of this study lies in its clarification of the role of in-group ties in the setting of changing economic development levels and migration. Practice-wise, the findings on the adoption of co-ethnic ties that span formal, informal and transnational boundaries may inform migrants who are considering opportunities in less developed host countries, and assist stakeholders in developing policies concerning migrant communities and their ventures.
When artificial intelligence meets the hospitality and tourism industry: an assessment framework to inform theory and management
Authors: Huang Arthur , Chao Ying , de la Mora Velasco Efrén , Bilgihan Anil , Wei Wei
Published: July 2021

Purpose

This study reviews existing research and current applications of artificial intelligence (AI) in the hospitality and tourism industry. It further proposes a new evaluation framework to inform the susceptibility of AI adoptions.

Design/methodology/approach

This is a synthesis and evaluation study that qualitatively summarizes and presents findings on AI applications in the hospitality and tourism industry. Current AI applications are rated using a seven-dimensional framework based on Rogers' (2003) diffusion theory.

Findings

AI adoption susceptibility in the hospitality and tourism industry varies based on the type of AI. Search/booking engines, virtual agents and chatbots rank high in the adoption susceptibility.

Research limitations/implications

This study bridges innovation diffusion theoretical underpinnings and AI applications. The findings support researchers, developers and managers in evaluating the adoption susceptibility of AI technologies in the hospitality and tourism industry.

Originality/value

This paper is among the few that focus on assessing AI adoption susceptibility in the hospitality and tourism industry. This paper develops a theory-based framework for systematically evaluating AI innovations in hospitality and tourism.
Thematic analysis of hijab fashion from Muslim clothing retailers perspective
Authors: Hassan Siti Hasnah , Ara Husna
Published: July 2021

Purpose

The desire to find a new look of expressing the Muslim identity in society has led to a renewal of Muslim women’s interest in fashion. This allows fashion players to make trendy clothing and expand their business to meet the rising needs of Muslim women. Thus, this study aims to explore the concept of hijab fashion from the perspective of Islamic clothing retailers in Malaysia.

Design/methodology/approach

Data for this study were collected qualitatively using semi-structured interviews and analysed using a deductive thematic analysis.

Findings

This exploratory study describes hijab fashion as a representation of clothing for ideal contemporary Muslim women that enhances the beauty in Islamic outfits from the perspective of Islamic clothing retailers. Hijab fashion has emerged as a modern form of the modest dress code in accordance with Islamic guidelines representing the hijaber identity. It is not just a veil to cover the awrah but also represents the impression of fashionableness and modernity, reflecting the self-image, trendy style and personality representing the true ideal Muslim women, who are known as Muslimah.

Research limitations/implications

The sample and findings are based exclusively on the perception of retailers directly involved in Malaysia’s Islamic fashion business.

Practical implications

The findings from this study benefit the fashion retailers, Islamic fashion industry players and policymakers by highlighting the importance of providing appropriate products and services concerning the growth of Muslim consumer market and their spending behaviour.

Originality/value

The findings offer a new perspective on the nature of the phenomenon of hijaber fashion as a symbol of the modern Muslim woman from the viewpoint of Islamic fashion practitioners.
Fair value accounting from the users’ perspective: an experiment on how financial analysts rely on fair value estimates in their decisions
Authors: Allini Alessandra , Spanò Rosanna , Du Ning , Ronen Joshua
Published: July 2021

Purpose

The current paper aims to understand whether fair value accounting (FVA) affects analysts’ loan approval decisions and default risk judgments.

Design/methodology/approach

This study focusses on three issues: unrealized gain or loss resulting from FV measurement recognized in other comprehensive income (OCI), recognition of assets at FV or historical cost and the disclosure or non-disclosure of the FV of collateral assets. It uses an experiment carried out with a sample of 29 CFA analysts.

Findings

The results show that all three issues have a significant effect on analysts’ judgment and decision-making in processing FV estimates.

Originality/value

The paper extends knowledge on how financial analysts perceive FV estimates and disclosure and may help the accounting standard boards assess the challenges facing analysts when they apply professional judgments in interpreting FV measurements and disclosures. Moreover, it offers fresh views to the debate on the decision usefulness of FVA, particularly relevant in the post-implementation review of IFRS 13.