bluuebunny/crossref_metadata_2025 huggingface dataset:
Single cell mRNA signals reveal a distinct developmental state of KMT2A-rearranged infant B-cell acute lymphoblastic leukemia
Authors: Khabirova Eleonora , Jardine Laura , Coorens Tim H. H. , Webb Simone , Treger Taryn D. , Englebert Justin , Porter Tarryn , Prigmore Elena , Collord Grace , Piapi Alice , Teichmann Sarah , Inglott Sarah , Williams Owen , Heidenreich Olaf , Young Matthew D. , Straathof Karin , Bomken Simon , Bartram Jack , Haniffa Muzlifah , Behjati Sam
Published: December 2021

Infant B-cell acute lymphoblastic leukemia (B-ALL) has not followed the increasing trend towards cure seen in other childhood B-ALLs. The prognosis for infants with KMT2A gene fusions is especially poor, and the origins of this aggressive leukemia remain unknown. Here, we investigated the developmental state of KMT2A-rearranged infant B-ALL within hematopoietic hierarchies of human fetal bone marrow, using bulk mRNA meta-analysis of childhood leukemia and examination of single lymphoblast transcriptomes. KMT2A-rearranged infant B-ALL was uniquely dominated by an early lymphocyte precursor (ELP) state. Direct comparison of infant lymphoblasts with ELP cells distilled the core oncogenic transcriptome of cancer cells which harboured potentially targetable hybrid myeloid-lymphoid features. Overall our quantitative molecular analyses demonstrate a distinct developmental state of KMT2A-rearranged infant B-ALL.
Capturing the start point of the virus-cell interaction with high-speed 3D single-particle tracking
Authors: Johnson Courtney , Exell Jack , Lin Yuxin , Aguilar Jonathan , Welsher Kevin D.
Published: December 2021

The early stages of the virus-cell interaction have long evaded observation by existing microscopy methods due to the rapid diffusion of virions in the extracellular space and the large 3D cellular structures involved. Here we present an active-feedback single-particle tracking method with simultaneous volumetric imaging of the live cell environment to address this knowledge gap to present unprecedented detail to the extracellular phase of the infectious cycle. We report previously unobserved phenomena in the early stages of the virus-cell interaction, including skimming contact events at the millisecond timescale, orders of magnitude change in diffusion coefficient upon binding, and cylindrical and linear diffusion modes along cellular protrusions. Finally, we demonstrate how this new method can move single-particle tracking from simple monolayer culture towards more tissue-like conditions by tracking single virions in tightly packed epithelial cells. This multi-resolution method presents new opportunities for capturing fast, 3D processes in biological systems.

One-Sentence Summary

Active-feedback 3D single-particle tracking enables an unprecedented look at the early stages of virus-cell interactions.
Differential regulation of SHH signaling and the developmental control of species-specific jaw size through neural crest-mediated Gas1 expression
Authors: Vavrušová Zuzana , Chu Daniel B. , Nguyen An , Fish Jennifer L. , Schneider Richard A.
Published: December 2021

Developmental control of jaw size is crucial to prevent disease and facilitate evolution. We have shown that species-specific differences in jaw size are established by neural crest mesenchyme (NCM), which are the jaw progenitors that migrate into the mandibular primordia. NCM relies on multiple signaling molecules including Sonic Hedgehog (SHH) to mediate interactions with mandibular epithelium that facilitate outgrowth of the jaws. SHH signaling is known to promote outgrowth and so we tested if differential regulation of the SHH pathway can account for species-specific variation in mandibular primordia size. We analyze gene expression of SHH pathway members in duck, chick, and quail, and find higher transcriptional activation in the larger mandibular primordia of duck relative to those of chick and quail. We generate quail-duck chimeras and demonstrate that such activation is NCM-mediated. Gain- and loss-of-function experiments reveal a species-specific response to SHH signaling, with the targetGas1being most sensitive to manipulations.Gas1overexpression and knockdown in NCM alters cell number and/or mandibular primordia size. Our work suggests that NCM-mediated changes in SHH signaling may modulate jaw size during development, disease, and evolution.

Summary Statement

We have determined thatGas1, which is a component of the SHH signaling pathway, plays a key role in the development and evolution of jaw size.
Geographic Disparities and Determinants of COVID-19 Incidence Risk in the Greater St. Louis Area, Missouri
Authors: Das Praachi , Igoe Morganne , Lenhart Suzanne , Luong Lan , Lanzas Cristina , Lloyd Alun L. , Odoi Agricola
Published: December 2021

Background

Evidence suggests that the risk of Coronavirus Disease 2019 (COVID-19) varies geographically due to differences in population characteristics. Therefore, the objectives of this study were to identify: (a) geographic disparities of COVID-19 risk in the Greater St. Louis area of Missouri, USA; (b) predictors of the identified disparities.

Methods

Data on COVID-19 incidence and chronic disease hospitalizations were obtained from the Departments of Health and Missouri Hospital Association, respectively. Socioeconomic and demographic data were obtained from the 2018 American Community Survey while population mobility data were obtained from the SafeGraph website. Choropleth maps were used to identify geographic disparities of COVID-19 risk and its predictors at the ZIP Code Tabulation Area (ZCTA) spatial scale. Global negative binomial and local geographically weighted negative binomial models were used to identify predictors of ZCTA-level geographic disparities of COVID-19 risk.

Results

There were geographic disparities in COVID-19 risk. Risks tended to be higher in ZCTAs with high percentages of the population with a bachelor’s degree (p<0.0001) and obesity hospitalizations (p<0.0001). Conversely, risks tended to be lower in ZCTAs with high percentages of the population working in agriculture (p<0.0001). However, the association between agricultural occupation and COVID-19 risk was modified by per capita between ZCTA visits. Areas that had both high per capita between ZCTA visits and high percentages of the population employed in agriculture had high COVID-19 risks. The strength of association between agricultural occupation and COVID-19 risk varied by geographic location.

Conclusions

Geographic Information Systems, global and local models are useful for identifying geographic disparities and predictors of COVID-19 risk. Geographic disparities of COVID-19 risk exist in the St. Louis area and are explained by differences in sociodemographic factors, population movements, and obesity hospitalization risks. The latter is particularly concerning due to the growing prevalence of obesity and the known immunological impairments among obese individuals. Therefore, future studies need to focus on improving our understanding of the relationships between COVID-19 vaccination efficacy, obesity and waning of immunity among obese individuals so as to better guide vaccination regimens, reduce disparities and improve population health for all.
Adaptive tail-length evolution in deer mice is associated with differential Hoxd13 expression in early development
Authors: Kingsley Evan P. , Hager Emily R. , Lassance Jean-Marc , Turner Kyle M. , Harringmeyer Olivia S. , Kirby Christopher , Neugeboren Beverly I. , Hoekstra Hopi E.
Published: December 2021

Variation in the size and number of axial segments underlies much of the diversity in animal body plans. Here, we investigate the evolutionary, genetic, and developmental mechanisms driving tail-length differences between forest and prairie ecotypes of deer mice (Peromyscus maniculatus). We first show that long-tailed forest mice perform better in an arboreal locomotion assay, consistent with tails being important for balance during climbing. The long tails of these forest mice consist of both longer and more caudal vertebrae than prairie mice. Using quantitative genetics, we identify six genomic regions that contribute to differences in total tail length, three of which associate with vertebra length and the other three with vertebra number. For all six loci, the forest allele increases tail length, consistent with the cumulative effect of natural selection. Two of the genomic regions associated with variation in vertebra number contain Hox gene clusters. Of those, we find an allele-specific decrease in Hoxd13 expression in the embryonic tail bud of long-tailed forest mice, consistent with its role in axial elongation. Additionally, we find that forest embryos have more presomitic mesoderm than prairie embryos, and that this correlates with an increase in the number of neuromesodermal progenitors (NMPs), which are modulated by Hox13 paralogs. Together, these results suggest a role for Hoxd13 in the development of natural variation in adaptive morphology on a microevolutionary timescale.

HIGHLIGHTS

In deer mice, the long-tailed forest ecotype outperforms the short-tailed prairie ecotype in climbing, consistent with the tail’s role in balance.

Long tails are due to mutations on distinct chromosomes that affect either length or number of caudal vertebrae.

QTL mapping identifies Hox clusters, one gene of which – Hoxd13 – shows low allele-specific expression in the embryonic tail bud of forest mice.

Forest mouse embryos have a larger presomitic mesoderm (PSM), likely mediated by a larger progenitor population (NMPs) and lower Hoxd13 levels.
Determination of Slow-binding HDAC Inhibitor Potency and Subclass Selectivity
Authors: Moreno-Yruela Carlos , Olsen Christian A.
Published: December 2021

Histone deacetylases (HDACs) 1–3 regulate chromatin structure and gene expression. These three enzymes are targets for cancer chemotherapy and are studied for the treatment of immune disorders and neurodegeneration, but there is a lack of selective pharmacological tool compounds to unravel their individual roles. Potent inhibitors of HDACs 1–3 often display slow-binding kinetics, which causes a delay in inhibitor–enzyme equilibration and may affect assay readout. Here, we compare the potency and selectivity of slow-binding inhibitors measured by discontinuous and continuous assays. We find that entinostat, a clinical candidate, inhibits HDACs 1–3 by a two-step, slow-binding mechanism with lower potencies than previously reported. In addition, we show that RGFP966, commercialized as HDAC3-selective probe, is a slow-binding inhibitor with inhibitor constants of 57 nM, 31 nM, and 13 nM against HDACs 1–3, respectively. These data highlight a need for thorough kinetic investigation in the development of selective HDAC probes.

Table of Contents artwork
Reversable deformation of artificial cell colony for muscle behavior mimicry triggered by actin polymerization
Authors: Li Chao , Zhang Xiangxiang , Yang Boyu , Wei Feng , Ren Yongshuo , Mu Wei , Han Xiaojun
Published: December 2021

The mimicry of living tissues from artificial cells is beneficial to understanding the interaction mechanism among cells, as well as holding great potentials in the tissue engineering field. Self-powered artificial cells capable of reversible deformation are developed by encapsulating living mitochondria, actin proteins, and methylcellulose. Upon the addition of pyruvate molecules, the mitochondria produce ATP molecules as energy sources to trigger the polymerization of actin. ATP molecules were produced by mitochondria (2.76×1010/ml) with the concentrations of 35.8±3.2 µM, 158.2±19.3 µM and 200.7±20.1 μM by adding pyruvate molecules with the concentration of 3 μM, 12 μM and 21 μM, respectively. The reversible deformation of artificial cells is experienced with spindle shape resulting from the polymerization of actins to form filaments adjacent to the lipid bilayer, subsequently back to spherical shape resulting from the depolymerization of actin filaments upon laser irradiations. The linear colonies composed of these artificial cells exhibit collective contraction and relaxation behavior to mimic muscle tissues. At the stage of maximum contraction, the long axis of each GUV is in parallel to each other. All colonies are synchronized in the contraction phase. The deformation of each GUV in the colonies is influenced by its adjacent GUVs. The muscle-like artificial cell colonies paved the path to develop sustainably self-powered artificial tissues in the field of tissue engineering.
Process engineering of biopharmaceutical production in moss bioreactors via model-based description and evaluation of phytohormone impact
Authors: Ruiz-Molina Natalia , Parsons Juliana , Schroeder Sina , Posten Clemens , Reski Ralf , Decker Eva L.
Published: December 2021

The moss Physcomitrella is an interesting production host for recombinant biopharmaceuticals. Here we produced MFHR1, a synthetic complement regulator which has been proposed for the treatment of diseases associated to the complement system as part of human innate immunity. We studied the impact of different operation modes for the production process in 5 L stirred-tank photobioreactors. The total amount of recombinant protein was doubled by using fed-batch or batch compared to semi-continuous operation, although the maximum specific productivity (mg MFHR1/g FW) increased just by 35%. We proposed an unstructured kinetic model which fits accurately with the experimental data in batch and semi-continuous operation under autotrophic conditions with 2% CO2 enrichment. The model is able to predict recombinant protein production, nitrate uptake and biomass growth, which is useful for process control and optimization. We investigated strategies to further increase MFHR1 production. While mixotrophic and heterotrophic conditions decreased the MFHR1-specific productivity compared to autotrophic conditions, addition of the phytohormone auxin (NAA, 10 μM) to the medium enhanced it by 470% in shaken flasks and up to 230% and 260%, in batch and fed-batch bioreactors, respectively. Supporting this finding, the auxin-synthesis inhibitor L-Kynurenine (100 μM) decreased MFHR1 production significantly by 110% and 580% at day 7 and 18, respectively. Expression analysis revealed that the MFHR1 transgene, driven by the Physcomitrella actin5 (PpAct5) promoter, was upregulated 16 hours after NAA addition and remained enhanced over the whole process, whereas the auxin-responsive gene PpIAA1A was upregulated within the first two hours, indicating that the effect of auxin on PpAct5 promoter-driven expression is indirect. Furthermore, the day of NAA supplementation was crucial, leading to an up to 8-fold increase of MFHR1-specific productivity (0.82 mg MFHR1/ g fresh weight, 150 mg accumulated over 7 days) compared to the productivity reported previously. Our findings are likely to be applicable to other plant-based expression systems to increase biopharmaceutical production and yields.
All-optical imaging and patterned stimulation with a one-photon endoscope
Authors: Zhang Jinyong , Hughes Ryan N. , Kim Namsoo , Fallon Isabella P. , Bakhurin Konstantin , Kim Jiwon , Ulloa Severino Francesco Paolo , Yin Henry H.
Published: December 2021

While in vivo calcium imaging makes it possible to record activity in defined neuronal populations with cellular resolution, optogenetics allows selective manipulation of neural activity. Recently, these two tools have been combined to stimulate and record neural activity at the same time, but current approaches often rely on two-photon microscopes that are difficult to use in freely moving animals, or one-photon fiberscopes with benchtop-based digital micromirror devices that limit system portability. To address these limitations, we have developed a new integrated system combining a one-photon endoscope and a digital micromirror device for simultaneous calcium imaging and precise optogenetic photo-stimulation (Miniscope with All-optical Patterned Stimulation and Imaging, MAPSI). Using this system, we were able to successfully image striatal neurons from either the direct pathway or the indirect pathway while simultaneously activating any neuron of choice within the field of view or synthesizing arbitrary spatio-temporal patterns of photo-stimulation in freely moving mice. We could also select neurons based on their relationship with behavior and recreate the behavior by mimicking the natural neural activity with photo-stimulation. MAPSI thus provides a powerful tool for in vivo interrogation of neural circuit function.
Factors associated with COVID-19 vaccine hesitancy in Senegal: a mixed study
Authors: Ba Mouhamadou Faly , Faye Adama , Kane Babacar , Diallo Amadou Ibra , Junot Amandine , Gaye Ibrahima , Bonnet Emmanuel , Ridde Valéry
Published: December 2021

Introduction

The most effective way to control the COVID-19 pandemic in the long term is through vaccination. Two of the important components that can hinder it are vaccine hesitancy and vaccine refusal. This study, conducted before the arrival of the vaccines in Senegal, aims to assess and identify factors associated with hesitancy to the COVID-19 vaccine.

Methods

This study was an explanatory, sequential, mixed-methods design. We collected quantitative data from December 24, 2020, to January 16, 2021, and qualitative data from February 19 to March 30, 2021. We conducted a marginal quota sampling nationwide. We used a structured questionnaire to collect data for the quantitative phase and an interview guide with a telephone interview for the qualitative phase. We performed descriptive, bivariate, and multivariate analyses with R software version 4.0.5 for the quantitative phase; and performed manual content analyses for the qualitative phase.

Results

We surveyed 607 people for the quantitative phase, and interviewed 30 people for the qualitative phase. Individuals who hesitated or refused to be vaccinated represented 12.9% and 32.8%, respectively. Vaccine hesitancy was related to gender, living in large cities, having a poor attitude towards the vaccine, thinking that the vaccine would not help protect them from the virus, being influenced by people important to them, and lacking information from health professionals. Vaccine refusal was related to living in large cities, having a poor attitude towards the vaccine, thinking that the vaccine would not help protect them from the virus, thinking that the vaccine could endanger their health, trusting opinions of people who were important to them, and lacking information from health professionals.

Conclusion

The results of the study show that the factors associated with hesitancy and refusal to be vaccinated against COVID-19 are diverse and complex. Reducing them will help to ensure better vaccination coverage if the current challenges of vaccine accessibility are addressed. Therefore, governments and health authorities should intensify their efforts to promote vaccine confidence and reduce misinformation.
KNOWLEDGE, ATTITUDES AND PRACTICE AMONG HEALTHCARE WORKERS TOWARDS COVID-19 PREVENTIVE MEASURES AT WOMEN AND NEW-BORN HOSPITAL, UNIVERSITY TEACHING HOSPITAL, LUSAKA, ZAMBIA
Authors: Shampile Joyce Nambela , Lingenda Godfrey , Zambwe Mowa , Chipimo Peter J.
Published: December 2021

Objective

To assess the knowledge, attitude and Practices among healthcare workers towards covid-19 preventive measures at Women and New-born Hospital of the University Teaching Hospitals in Lusaka.

Methods

Cross-sectional study conducted at WNH-UTH, Lusaka. Convenient sample of 264 frontline healthcare workers responded to self-administered questionnaire to determine their knowledge, attitudes and practices on COVID-19 preventive measures.

Results

Majority (31.9%) of the respondents were aged 25 – 29 years. The study revealed that 63.4% had a good knowledge, 60.3% had positive attitudes and 59.9% had a good practice. Attitude was positively related with practice (r = 0.524, p < 0.001) and knowledge (r = 0.469; p < 0.001). Further, knowledge was positively correlated with practice (r = 0.51; p < 0.001). Bivariate analysis results showed that only high knowledge score (75.6%; p < 0.001) and high attitude score (77.6%; p < 0.001) was associated with an increase in good practice among healthcare workers towards Covid-19 preventive measures.

Conclusion

The study showed the need for continued assessment of Knowledge Attitude and Practice among healthcare workers towards Covid-19 preventive measures. It further showed the need of designing interventions aimed at encouraging sustained compliance to preventive measures among healthcare workers to prevent COVID-19 transmission.

ARTICLE SUMMARY

Strengths and Limitations

This study was conducted at Women and Newborn Hospital of the University of Zambia and described the Knowledge, Attitude and Practice among Healthcare workers towards Covid-109 preventive measures. The study showed the need for continued assessment of Knowledge Attitude and Practice among healthcare workers towards Covid-19 preventive measures. This study has the potential to yield significant benefits for the participants and the community at large. The study is reproducible and feasible with results which can be used in designing interventions aimed at encouraging use of preventive measures available to healthcare workers to prevent COVID-19 transmission.

The study was a cross-sectional study which limits our ability to make causal inferences. Further the study was conducted at only one hospital which is located in the capital city and so the findings cannot be generalized to HCW in other parts of Zambia.
De Novo Design of Immunoglobulin-like Domains
Authors: Chidyausiku Tamuka M. , Mendes Soraia R. , Klima Jason C. , Eckhard Ulrich , Houliston Scott , Nadal Marta , Roel-Touris Jorge , Guevara Tibisay , Haddox Hugh K. , Moyer Adam , Arrowsmith Cheryl H. , Gomis-Rüth F. Xavier , Baker David , Marcos Enrique
Published: December 2021

Antibodies and antibody derivatives such as nanobodies contain immunoglobulin-like (Ig) β-sandwich scaffolds which anchor the hypervariable antigen-binding loops and constitute the largest growing class of drugs. Current engineering strategies for this class of compounds rely on naturally existing Ig frameworks, which can be hard to modify and have limitations in manufacturability, designability and range of action. Here we develop design rules for the central feature of the Ig fold architecture – the non-local cross-β structure connecting the two β-sheets – and use these tode novodesign highly stable seven-stranded Ig domains, confirm their structures through X-ray crystallography, and show they can correctly scaffold functional loops. Our approach opens the door to the design of a new class of antibody-like scaffolds with tailored structures and superior biophysical properties.
Top-down contribution to motor network reorganization during action preparation
Authors: Pisoni Alberto , Bianco Valentina , Arrigoni Eleonora , Di Russo Francesco , Romero Lauro Leonor J.
Published: December 2021

BACKGROUND

It is unclear whether the Bereitschaftspotential (BP) recorded in humans during action preparation mirrors motor areas activation escalation, or if its early and late phases reflect the engagement of different functional networks.

OBJECTIVE

Here, we aimed at recording the TMS evoked-potentials (TEP) stimulating the supplementary motor area (SMA) to assess whether and how cortical excitability and functional connectivity of this region change as the BP increases. We hypothesize that, at later stages, the SMA functional network should become more connected to regions relevant for the implementation of the final motor plan.

METHODS

We performed TMS-EEG recordings on fourteen healthy subjects during the performance of a visuomotor Go/No-go task, eliciting and recording cortical activity and functional connectivity at -700 ms and -300 ms before the onset of visual stimuli over the SMA.

RESULTS

When approaching stimulus onset, and thus BP peak, the SMA increased its functional connectivity with movement-related structures in the gamma and alpha bands, indicating a regional top-down preparation to implement the motor act. Beta-band connectivity, instead, was maintained constant for the whole BP time-course, being potentially related to sustained attention required by the experimental task.

CONCLUSION

These findings reveal that the BP is not a mere result of increased activation of the SMA, but the functional networks in which this region is involved qualitatively changes over time, becoming more related to the execution of the motor act.
Terminal heterocyst differentiation in the Anabaena patA mutant as a result of post-transcriptional modifications and molecular leakage
Authors: Casanova-Ferrer Pau , Ares Saúl , Muñoz-García Javier
Published: December 2021

The Anabaena genus is a model organism of filamentous cyanobacteria whose vegetative cells can differentiate under nitrogen-limited conditions into a type of cell called heterocyst. These heterocysts lose the possibility to divide and are necessary for the colony because they can fix and share environmental nitrogen. In order to distribute the nitrogen efficiently, heterocysts are arranged to form a quasi-regular pattern whose features are maintained as the filament grows. Recent efforts have allowed advances in the understanding of the interactions and genetic mechanisms underlying this dynamic pattern. However, the main role of the patA and hetF genes are yet to be clarified; in particular, the patA mutant forms heterocysts almost exclusively in the terminal cells of the filament. In this work, we investigate the function of these genes and provide a theoretical model that explains how they interact within the broader genetic network, reproducing their knock-out phenotypes in several genetic backgrounds, including a nearly uniform concentration of HetR along the filament for the patA mutant. Our results suggest a role of hetF and patA in a post-transcriptional modification of HetR which is essential for its regulatory function. In addition, the existence of molecular leakage out of the filament in its boundary cells is enough to explain the preferential appearance of terminal heterocysts, without any need for a distinct regulatory pathway.

Author summary

Understanding multicellular pattern formation is key for the study of both natural and synthetic developmental processes. Arguably one of the simplest model systems for this is the filamentous cyanobacterium Anabaena, that in conditions of nitrogen deprivation undergoes a dynamical differentiation process that differentiates roughly one in every ten cells into nitrogen-fixing heterocysts, in a quasi-regular pattern that is maintained as the filament keeps growing. One of the most characteristic mutations affecting this process forms heterocysts mostly constrained to the terminal cells of the filament. We have used experimental observations to propose a mathematical model of heterocyst differentiation able to reproduce this striking phenotype. The model extends our understanding of the regulations in this pattern-forming system and makes several predictions on molecular interactions. Importantly, a key aspect is the boundary condition at the filament’s ends: inhibitors of differentiation should be able to leak out of the filament, or otherwise the terminal cells would not differentiate. This highlights, in a very clear example, the importance of considering physical constraints in developmental processes.
Aging impairs primary task resumption and attentional control processes following interruptions
Authors: Rösner Marlene , Zickerick Bianca , Sabo Melinda , Schneider Daniel
Published: December 2021

Attentional selection of working memory content is impaired after an interruption. This effect was shown to increase with age. Here we investigate how electrophysiological mechanisms underlying attentional selection within working memory differ during primary task resumption between younger and older adults. Participants performed a working memory task, while being frequently interrupted with either a cognitively low- or high-demanding arithmetic task. Afterwards, a retrospective cue (retro-cue) indicated the working memory content required for later report. The detrimental effect of the interruption was evident in both age groups, but while younger adults were more strongly affected by a high-than by a low-demanding interruption, the performance deficit appeared independently of the cognitive requirements of the interruption task in older adults. A similar pattern was found regarding frontal-posterior connectivity in the theta frequency range, suggesting that aging decreases the ability to selectively maintain relevant information within working memory. The power of mid-frontal theta oscillations (4-7 Hz) featured a comparable effect of interruptions in both age groups. How-ever, posterior alpha power (8-14 Hz) following the retro-cue was more diminished by a preceding interruption in older adults. These results suggest an age-related deficit in the atten-tional selection and maintenance of primary task information following an interruption that appeared independent from the cognitive requirements of the interrupting task.
Cilia Directionality Reveals a Slow Reverse Movement of Principal Neurons for Positioning and Lamina Refinement in the Cerebral Cortex
Authors: Yang Juan , Mirhosseiniardakani Soheila , Qiu Liyan , Bicja Kostandina , Del Greco Abigail , Lin Kevin Jungkai , Lyon Mark , Chen Xuanmao
Published: December 2021

Currently little is known about neuronal positioning and the roles of primary cilia in postnatal neurodevelopment. We show that primary cilia of principal neurons undergo marked changes in positioning and orientation, concurrent with postnatal neuron positioning in the mouse cerebral cortex. Primary cilia of early- and late-born principal neurons in compact layers display opposite orientations, while neuronal primary cilia in loose laminae are predominantly oriented toward the pia. In contrast, astrocytes and interneurons, and neurons in nucleated brain regions do not display specific cilia directionality. We further discovered that the cell bodies of principal neurons in inside-out laminated regions spanning from the hippocampal CA1 region to neocortex undergo a slow “reverse movement” for postnatal positioning and lamina refinement. Further, selective disruption of cilia function in the forebrain leads to altered lamination and gyrification in the retrosplenial cortex (RSC) that is formed by reverse movement. Collectively, this study identifies reverse movement as a fundamental process for principal cell positioning that refines lamination in the cerebral cortex and casts light on the evolutionary transition from 3-layered allocortices to 6-layered neocortices.

Summary Statement

Guided by cilia directionality, we discovered that the somata of principal neurons in inside-out laminated regions undergo a slow but substantial reverse movement for postnatal cell positioning, which refines cortical layering.
Assessment of the residential Finnish wolf population combines DNA captures, citizen observations and mortality data using a Bayesian state-space model
Authors: Mäntyniemi Samu , Helle Inari , Kojola Ilpo
Published: December 2021

Assessment of the Finnish wolf population relies on multiple sources of information. This paper describes how Bayesian inference is used to pool the information contained in different data sets (point observations, non-invasive genetics, known mortalities) for the estimation of the number of territories occupied by family packs and pairs. The output of the assessment model is a joint probability distribution, which describes current knowledge about the number of wolves within each territory. The joint distribution can be used to derive probability distributions for the total number of wolves in all territories and for the pack status within each territory. Most of the data set comprises of both voluntary-provided point observations and DNA samples provided by volunteers and research personnel. The new method reduces the role of expert judgement in the assessment process, providing increased transparency and repeatability.
Striatal dopamine explains novelty-induced behavioral dynamics and individual variability in threat prediction
Authors: Akiti Korleki , Tsutsui-Kimura Iku , Xie Yudi , Mathis Alexander , Markowitz Jeffrey , Anyoha Rockwell , Datta Sandeep Robert , Mathis Mackenzie Weygandt , Uchida Naoshige , Watabe-Uchida Mitsuko
Published: December 2021

Animals exhibit diverse behavioral responses, such as exploration and avoidance, to novel cues in the environment. However, it remains unclear how dopamine neuron-related novelty responses influence behavior. Here, we characterized dynamics of novelty exploration using multi-point tracking (DeepLabCut) and behavioral segmentation (MoSeq). Novelty elicits a characteristic sequence of behavior, starting with investigatory approach and culminating in object engagement or avoidance. Dopamine in the tail of striatum (TS) suppresses engagement, and dopamine responses were predictive of individual variability in behavior. Behavioral dynamics and individual variability were explained by a novel reinforcement learning (RL) model of threat prediction, in which behavior arises from a novelty-induced initial threat prediction (akin to “shaping bonus”), and a threat prediction that is learned through dopamine-mediated threat prediction errors. These results uncover an algorithmic similarity between reward- and threat-related dopamine sub-systems.

Highlights

Novelty-induced behaviors are analyzed using modern machine-learning methods

Novelty induces risk assessment which develops into engagement or avoidance

Dopamine in the tail of striatum correlates with individual behavioral variability

Reinforcement learning with shaping bonus and uncertainty explains the data
Report of the Executive Committee for 2020
Authors: Ashcroft A. T.
Published: December 2021

The report of the Executive Committee for 2020 is presented.
Examining relational social ontologies of disaster resilience: lived experiences from India, Indonesia, Nepal, Chile and Andean territories
Authors: Meriläinen Eija , Joseph Jacquleen , Jauhola Marjaana , Yadav Punam , Romo-Murphy Eila , Marin Juliette , Gadhavi Shyam
Published: December 2021

Purpose

The neoliberal resilience discourse and its critiques both contribute to its hegemony, obscuring alternative discourses in the context of risk and uncertainties. Drawing from the “ontology of potentiality”, the authors suggest reclaiming “resilience” through situated accounts of the connected and relational every day from the global south. To explore alternate possibilities, the authors draw attention to the social ontology of disaster resilience that foregrounds relationality, intersectionality and situated knowledge.

Design/methodology/approach

Quilting together the field work experiences in India, Indonesia, Nepal, Chile and Andean territories, the authors interrogate the social ontologies and politics of resilience in disaster studies in these contexts through six vignettes. Quilting, as a research methodology, weaves together various individual fragments involving their specific materialities, situated knowledge, layered temporalities, affects and memories. The authors’ six vignettes discuss the use, politicisation and resistance to resilience in the aftermath of disasters.

Findings

While the pieces do not try to bring out a single “truth”, the authors argue that firstly, the vignettes provide non-Western conceptualisations of resilience, and attempts to provincialise externally imposed notions of resilience. Secondly, they draw attention to social ontology of resilience as the examples underscores the intersubjectivity of disaster experiences, the relational reaching out to communities and significant others.

Originality/value

Drawing from in-depth research conducted in six disaster contexts by seven scholars from South Asia, South America and Northern Europe, the authors embrace pluralist situated knowledge, and cross-cultural/language co-authoring. Thus, the co-authored piece contributes to diversifying disaster studies scholarship methodologically.
Gender gaps in opportunity-driven entrepreneurship: the impact of human and social capital
Authors: Chen Hong , Lee Byung Hee , Alymkulova Asylgul
Published: December 2021

Purpose

The purpose of this study is to investigate gender gaps in opportunity-driven entrepreneurship and illuminate the underlying mechanism of why women are less likely to create ventures in order to take advantage of the opportunity than men.

Design/methodology/approach

By drawing on human/social capital theory and expanding extant gender-related entrepreneurship literature, this study addresses how human and social capital mediates the relationship between gender and opportunity-driven entrepreneurship. A sample of 115,367 individuals across 62 countries drawn from the Global Entrepreneurship Monitor of 2016 was examined using multilevel logistic regression and Karlson-Holm-Breen (KHB) mediation analysis.

Findings

Findings of this study demonstrate that women’s lack of entrepreneurial relevant knowledge and skills, intrapreneurship experience as well as social networks with other entrepreneurs contribute to women’s less likelihood of engaging in opportunity-driven entrepreneurship than their male counterparts.

Originality/value

Compared to previous research mainly investigating macro-level determinants, this study further explores the explanatory factors affecting gender gaps in opportunity-driven entrepreneurship from the individual level. The findings provide an implication for public policy and give a direction to rethinking how to promote opportunity-driven entrepreneurship, especially for that led by women.
Associated probabilities aggregations in multistage investment decision-making
Authors: Sirbiladze Gia , Garg Harish , Khutsishvili Irina , Ghvaberidze Bezhan , Midodashvili Bidzina
Published: December 2021

Purpose

The attributes that influence the selection of applicants and the relevant crediting decisions are naturally distinguished by interactions and interdependencies. A new method of possibilistic discrimination analysis (MPDA) was developed for the second stage to address this phenomenon. The method generates positive and negative discrimination measures for each alternative applicant in relation to a particular attribute. The obtained discrimination pair reflects the interaction of attributes and represents intuitionistic fuzzy numbers (IFNs). For the aggregation of applicant's discrimination intuitionistic fuzzy assessments (with respect to attributes), new intuitionistic aggregation operators, such as AsP-IFOWA and AsP-IFOWG, are defined and studied. The new operators are certain extensions of the well-known Choquet integral and Yager OWA operators. The extensions, in contrast to the Choquet aggregation, take into account all possible interactions of the attributes by introducing associated probabilities of a fuzzy measure.

Design/methodology/approach

For optimal planning of investments distribution and decreasing of credit risks, it is crucial to have selected projects ranked within deeply detailed investment model. To achieve this, a new approach developed in this article involves three stages. The first stage is to reduce a possibly large number of applicants for credit, and here, the method of expertons is used. At the second stage, a model of improved decisions is built, which reduces the risks of decision making. In this model, as it is in multi-attribute decision-making (MADM) + multi-objective decision-making (MODM), expert evaluations are presented in terms of utility, gain, and more. At the third stage, the authors construct the bi-criteria discrete intuitionistic fuzzy optimization problem for making the most profitable investment portfolio with new criterion: 1) Maximization of total ranking index of selected applicants' group and classical criterion and 2) Maximization of total profit of selected applicants' group.

Findings

The example gives the Pareto fronts obtained by both new operators, the Choquet integral and Yager OWA operators also well-known TOPSIS approach, for selecting applicants and awarding credits. For a fuzzy measure, the possibility measure defined on the expert evaluations of attributes is taken.

Originality/value

The comparative analysis identifies the applicants who will receive the funding sequentially based on crediting resources and their requirements. It has become apparent that the use of the new criterion has given more credibility to applicants in making optimal credit decisions in the environment of extended new operators, where the phenomenon of interaction of all attributes was also taken into account.
Visual analysis of global research trends in social bots based on bibliometrics
Authors: Chen Xiujuan , Gao Shanbing , Zhang Xue
Published: December 2021

Purpose

In order to further advance the research of social bots, based on the latest research trends and in line with international research frontiers, it is necessary to understand the global research situation in social bots.

Design/methodology/approach

Choosing Web of Science™ Core Collections as the data sources for searching social bots research literature, this paper visually analyzes the processed items and explores the overall research progress and trends of social bots from multiple perspectives of the characteristics of publication output, major academic communities and active research topics of social bots by the method of bibliometrics.

Findings

The findings offer insights into research trends pertaining to social bots and some of the gaps are also identified. It is recommended to further expand the research objects of social bots in the future, not only focus on Twitter platform and strengthen the research of social bot real-time detection methods and the discussion of the legal and ethical issues of social bots.

Originality/value

Most of the existing reviews are all for the detection methods and techniques of social bots. Unlike the above reviews, this study is a systematic literature review, through the method of quantitative analysis, comprehensively sort out the research output in social bots and shows the latest research trends in this area and suggests some research indirections that need to be focused in the future. The findings will provide references for subsequent scholars to research on social bots.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/OIR-06-2021-0336.
Tropicalization unlocks novel trophic pathways and enhances secondary productivity in temperate reefs
Authors: Pessarrodona Albert , Vergés Adriana , Bosch Néstor E. , Bell Sahira , Smith Shannen , Sgarlatta María P. , Wernberg Thomas
Published: December 2021

The structure of ecological communities is rapidly changing across the globe due to climate‐mediated shifts in species distributions, with novel ecosystem states emerging as new species become dominant. While it is clear that such changes restructure habitat properties and their associated assemblages, how new nutritional resources and consumers may affect the ecosystem trophic structure and energetic dynamics remains poorly resolved.

Here, we investigate how the reconfiguration of tropicalized reefs—that is, temperate ecosystems receiving an influx of tropical species—affects the availability of nutritional resources and energy flow through herbivore‐based trophic pathways. To do so, we quantified changes in algal and detrital resources along a tropicalization gradient in eastern Australia. We also estimated energy flow towards herbivorous fishes by quantifying their standing biomass (kg/ha), productivity (kg ha−1 day−1), and biomass turnover (% day−1), using an individual‐level modelling approach that combines estimates of fish growth rates and mortality.

Along the gradient, tropicalized reefs had relatively higher amounts of palatable algal turfs and detrital particulates compared to non‐tropicalized sites. Feeding intensity by herbivorous fishes was also c. 400 times higher on tropicalized reefs, with tropical turf‐cropping surgeon fishes being responsible for >98% of the feeding rates.

Turf‐driven trophic pathways underpinned virtual all (>99%) of the biomass produced by tropical fishes, which contributed up to 63% of the total herbivorous fish standing biomass and 86% of the productivity despite only representing 35% of the abundance. Turfs also fuelled most of the secondary productivity of tropical fishes on tropicalized reefs across Australia's western tropical–temperate transition zone, although their overall productivity was ~5 times lower. This is possibly due to turfs there containing elevated sediment loads, which dilute the nutritional quality of turf‐based resources, as well as other differences in the biogeographical context.

We propose that algal turfs are central drivers of ecosystem energetic shifts on temperate reefs as they become tropicalized because they support novel algal and detrital trophic pathways that enhance secondary productivity and biomass turnover. Our results also suggest that turf characteristics such as organic content or sediment load may emerge as increasingly important drivers of energy flow in temperate locations where turfs dominate benthic cover.

A free Plain Language Summary can be found within the Supporting Information of this article.
(Re)Thinking think tanks in the age of policy labs: The rise of knowledge‐based policy influence organisations
Authors: Wellstead Adam M. , Howlett Michael
Published: December 2021

The idea of ‘think tanks’ is one of the oldest in the policy sciences. Although the topic has been studied for decades, recent works dealing with advocacy groups, policy and behavioural insight labs and into the activities of think tanks themselves have led to discontent with the definitions used in the field, and especially with the way the term may obfuscate rather than clarify important distinctions between the different kinds of knowledge‐based policy influence organisations (KBPIO) operating in the contemporary policy landscape. In this paper, we examine the traditional and current definitions of think tanks utilised in the discipline and point out their weaknesses. We then develop a new framework to better capture the variation in the kinds of knowledge‐based organisations which operate in many sectors.