bluuebunny/crossref_metadata_2025 huggingface dataset:
A H3K9me2-Binding Protein AGDP3 Limits DNA Methylation and Transcriptional Gene Silencing in Arabidopsis
Authors: Zhou Xuelin , Wei Mengwei , Nie Wenfeng , Xi Yue , Du Xuan , Peng Li , Zheng Qijie , Tang Kai , Satheesh Viswanathan , Wang Yuhua , Luo Jinyan , Liu Rui , Yang Zhenlin , Zhong Yingli , An Guo-Yong , Zhu Jian-Kang , Du Jiamu , Lei Mingguang
Published: March 2021

DNA methylation is critical for tuning gene expression to prevent potentially deleterious gene-silencing. The Arabidopsis DNA glycosylase/lyase REPRESSOR OF SILENCING 1 (ROS1) initiates active DNA demethylation and is required for the prevention of DNA hypermethylation at thousands of genomic loci. However, the mechanism recruiting ROS1 to specific loci is not well understood. Here, we report the discovery of Arabidopsis AGENET Domain Containing Protein 3 (AGDP3) as a cellular factor required for ROS1-mediated DNA demethylation, and targets ROS1 to specific loci. We found that AGDP3 could bind to the H3K9me2 mark by its AGD12 cassette. The crystal structure of the AGDP3 AGD12 in complex with an H3K9me2 peptide reveals the molecular basis for the specific recognition, that the dimethylated H3K9 and unmodified H3K4 are specifically anchored into two different surface pockets. Interestingly, a histidine residue located in the methylysine binding aromatic cage enables AGDP3 pH-dependent H3K9me2 binding capacity. Considering the intracellular pH correlates with the histone acetylation status, our results provide the molecular mechanism for the regulation of ROS1 DNA demethylase by the gene silencing H3K9me2 mark and the potential crosstalk with active histone acetylation mark.
Short duration overnight cattle kraaling in natural rangelands: does time after kraal use affect their utilization by wildlife and above ground grass parameters?
Authors: Huruba Rangarirai , Nemera Servious , Ngute Faith , Sahomba Meshack , Mundy Peter J. , Sebata Allan , MacFadyen Duncan N.
Published: March 2021

Short duration overnight cattle kraaling in natural rangelands creates nutrients hotspots attractive to a diverse suite of large mammalian herbivores. However, few studies have determined the use of these sites by large mammalian herbivores. We determined the number of animal sightings per day from camera traps and used them as proxies for use of these newly created nutrient hotspots of varying ages (1, 2, 3 and 4 years) and surrounding vegetation. Six mammalian herbivores of different sizes belonging to three feeding guilds viz. grazers (Burchell’s zebra Equus quagga burchelli and warthog Phacochoerus africanus), mixed feeders (impala Aepyceros melampus and African savanna elephant Loxodonta africana africana) and browsers (northern giraffe Giraffa camelopardalis giraffa and greater kudu Tragelaphus strepsiceros) frequently used these nutrient hotspots. The number of sightings per day of mammalian herbivores was determined during three periods of the year (January – wet season; June – early dry season; October – late dry season) to ascertain their use of these nutrient hotspots. In addition, above ground grass biomass and height was measured and related to grazer sightings. Furthermore, we tested if repeated grazing in the newly created nutrient hotspots stimulated grass compensatory growth. All the mammalian herbivores used the newly created nutrient hotspots similarly throughout the year, with impala the most active users. Grazer and browser use of nutrient hotspots was not influenced by their age, while mixed feeders mostly used the one year old sites. Grazer use of nutrient hotspots was not influenced by aboveground grass biomass and height. Repeated clipping (proxy for grazing) resulted in compensatory aboveground grass biomass growth in nutrient hotspots. Impala benefited the most and zebra the least from the creation of nutrient hotspots in natural rangelands. We conclude that creation of nutrients hotspots through short duration overnight kraaling results in rangeland heterogeneity that improves availability of herbivore foraging sites.
Noradrenergic circuit control of non-REM sleep substates
Authors: Osorio-Forero Alejandro , Cardis Romain , Vantomme Gil , Guillaume-Gentil Aurélie , Katsioudi Georgia , Fernandez Laura M.J. , Lüthi Anita
Published: March 2021

One promising approach towards understanding what makes sleep vulnerable in disease is to look at how wake-promoting mechanisms affect healthy sleep. Wake-promoting neuronal activity is inhibited during non-REM sleep (NREMS). However, many mammalian species, including humans, show recurrent moments of sleep fragility during which sensory reactivity is elevated. Wake-related neuronal activity could thus remain active in NREMS, but its roles in dynamic variations of sensory reactivity remain unknown. Here, we demonstrate that mouse NREMS is a brain state with recurrent fluctuations of the wake-promoting neurotransmitter noradrenaline on the ∼50-seconds time-scale. These fluctuations occurred around mean noradrenaline levels greater than the ones of quiet wakefulness, while they declined steeply in REMS. They coincided with a clustering of sleep spindle rhythms in the forebrain and with heart rate variations. We addressed the origins of these fluctuations by using closed-loop optogenetic locus coeruleus (LC) activation or inhibition timed to moments of low and high spindle activity during NREMS. We could suppress, lock or entrain sleep spindle clustering or heart rate variations, demonstrating that both fore- and hindbrain-projecting LC neurons show synchronized infraslow activity variations in natural NREMS. Noradrenergic modulation of thalamic but not cortical circuits was required for sleep spindle clustering and involved noradrenaline release into primary sensory and reticular thalamic nuclei that activated both α1- and β-adrenergic receptors to cause slowly decaying membrane depolarizations. Noradrenergic signaling by LC, primarily known for attention promotion in wakefulness, renders mammalian NREMS more ‘wake-like’ on the close-to-minute-time scale through sustaining thalamocortical and autonomic sensory arousability.
Estimating Ectopic Beat Probability with Simplified Statistical Models that Account for Experimental Uncertainty
Authors: Jin Qingchu , Greenstein Joseph L. , Winslow Raimond L.
Published: March 2021

Ectopic beats (EBs) are cellular arrhythmias that can trigger lethal arrhythmias. Simulations using biophysically-detailed cardiac myocyte models can reveal how model parameters influence the probability of these cellular arrhythmias, however such analyses can pose a huge computational burden. Here, we develop a simplified approach in which logistic regression models (LRMs) are used to define a mapping between the parameters of complex cell models and the probability of EBs (P(EB)). As an example, in this study, we build an LRM for P(EB) as a function of diastolic cytosolic Ca2+concentration ([Ca2+]i), sarcoplasmic reticulum (SR) Ca2+load, and kinetic parameters of the inward rectifier K+current (IK1) and ryanodine receptor (RyR). This approach, which we refer to as arrhythmia sensitivity analysis, allows for evaluation of the relationship between these arrhythmic event probabilities and their associated parameters. This LRM is also used to demonstrate how uncertainties in experimentally measured values determine the uncertainty in P(EB). In a study of the role of [Ca2+]SRuncertainty, we show a special property of the uncertainty in P(EB), where with increasing [Ca2+]SRuncertainty, P(EB) uncertainty first increases and then decreases. Lastly, we demonstrate that IK1suppression, at the level that occurs in heart failure myocytes, increases P(EB).

Author summary

An ectopic beat is an abnormal cellular electrical event which can trigger dangerous arrhythmias in the heart. Complex biophysical models of the cardiac myocyte can be used to reveal how cell properties affect the probability of ectopic beats. However, such analyses can pose a huge computational burden. We develop a simplified approach that enables a highly complex biophysical model to be reduced to a rather simple statistical model from which the functional relationship between myocyte model parameters and the probability of an ectopic beat is determined. We refer to this approach as arrhythmia sensitivity analysis. Given the efficiency of our approach, we also use it to demonstrate how uncertainties in experimentally measured myocyte model parameters determine the uncertainty in ectopic beat probability. We find that, with increasing model parameter uncertainty, the uncertainty in probability of ectopic beat first increases and then decreases. In general, our approach can efficiently analyze the relationship between cardiac myocyte parameters and the probability of ectopic beats and can be used to study how uncertainty of these cardiac myocyte parameters influences the ectopic beat probability.
Differential effects on neuromuscular physiology betweenSodloss-of-function mutation and paraquat-induced oxidative stress inDrosophila
Authors: Ueda Atsushi , Iyengar Atulya , Wu Chun-Fang
Published: March 2021

Oxidative stress is thought to be a major contributor to aging processes. Here, we report differential effects on neurotransmission caused by loss-of-function mutations ofSuperoxide dismutase(Sod) and by paraquat (PQ) feeding inDrosophila. We demonstrated alterations inSodmutants; the larval neuromuscular junction displayed supernumerary discharges and the adult giant-fiber escape pathway showed increased latency and poor response to repetitive high-frequency stimulation. Even though the concentrations used led to motor coordination defects and lethality, PQ feeding failed to reproduce such performance deficits in these larval and adult preparations, indicating mechanistic distinctions between genetic and pharmacological manipulation of oxidative stress.
Comparative phylogeography of the freshwater mussels of the southeastern United States: reconstructing historic drainages using molecular data
Authors: Small Scott T. , Wares John P.
Published: March 2021

Knowledge of species ages and their distribution enhance our understanding of processes that create and maintain species diversity at both local and regional levels. The largest family of freshwater mussels (Unionidae), reach their highest species diversity in drainages of the southeastern united states. By sequencing multiple loci from mussel species distributed throughout the drainages in this region, we attempt to uncover historical patterns of divergence and determine the role of vicariance events on the species formation in mussels and extend our hypothesis to freshwater animals in general. We analyzed 346 sequences from five genera encompassing 37 species. Species were sampled across 12 distinct drainages ending either in the Atlantic Ocean or the Gulf of Mexico. Overall the topologies of the different genera returned phylogenetic trees that were congruent with geographically contiguous drainages. The most common pattern was the grouping between the Atlantic slope and gulf coast drainages, however the Tennessee drainage was often the exception to this pattern grouping with the Atlantic slope. Most mussel species find a most recent common ancestor within a drainage before finding an ancestor between drainages. This supports the hypothesis of allopatric divergence followed by later burst of speciation within a drainage. Our estimated divergence times for the Atlantic-Gulf split agree with other studies estimating vicariance in fish species of the Atlantic and gulf coast.
Trio-binned genomes of the woodratsNeotoma bryantiandN. lepidareveal novel gene islands and rapid copy number evolution of xenobiotic metabolizing cytochrome p450 genes
Authors: Greenhalgh Robert , Holding Matthew L. , Orr Teri J. , Henderson James B. , Parchman Thomas L. , Matocq Marjorie D. , Shapiro Michael D. , Dearing M. Denise
Published: March 2021

The genomic architecture underlying the origins and maintenance of biodiversity is an increasingly accessible feature of species, due in large part to third-generation sequencing and novel analytical toolsets. Woodrats of the genusNeotomaprovide a unique opportunity to study how vertebrate herbivores respond to climate change, as two sister species (N. bryantiandN. lepida) independently achieved a major dietary feat – switching to the novel and toxic food source creosote bush (Larrea tridentata) – in the aftermath of a natural warming event. To better understand the genetic mechanisms underlying this ability, we employed a trio binning sequencing approach with aN. bryanti×N. lepidaF1hybrid, resulting in phased, chromosome-level, highly complete, haploid genome assemblies for each species from one individual. Using these new assemblies, we explored the genomic architecture of three cytochrome p450 subfamilies (2A, 2B, and 3A) that play key roles in the metabolism of naturally occurring toxic dietary compounds. We found that woodrats show expansions of all three p450 gene families, including the evolution of multiple novel gene islands within the 2B and 3A subfamilies. Our assemblies demonstrate that trio binning from an F1hybrid rodent effectively recovers parental genomes from species that diverged more than a million years ago. Turnover and novelty in detoxification gene islands in herbivores is widespread within distinct p450 subfamilies, and may have provided the crucial substrate for dietary adaptation during environmental change.
Mitochondrial variant enrichment from high-throughput single-cell RNA-seq resolves clonal populations
Authors: Miller Tyler E. , Lareau Caleb A. , Verga Julia A. , Ssozi Daniel , Ludwig Leif S. , Farran Chadi El , Griffin Gabriel K. , Lane Andrew A. , Bernstein Bradley E. , Sankaran Vijay G. , van Galen Peter
Published: March 2021

Reconstructing lineage relationships in complex tissues can reveal mechanisms underlying development and disease. Recent methods combine single-cell transcriptomics with mitochondrial DNA variant detection to establish lineage relationships in primary human cells, but are not scalable to interrogate complex tissues. To overcome this limitation, here we develop a technology for high-confidence detection of mitochondrial mutations from high-throughput single-cell RNA-sequencing. We use the new method to identify skewed immune cell expansions in primary human clonal hematopoiesis.
Segmentation of Tissues and Proliferating Cells in Light-Sheet Microscopy Images using Convolutional Neural Networks
Authors: Lo Vercio Lucas D. , Green Rebecca M. , Robertson Samuel , Guo Si Han , Dauter Andreas , Marchini Marta , Vidal-García Marta , Zhao Xiang , Marcucio Ralph S. , Hallgrímsson Benedikt , Forkert Nils D.
Published: March 2021

Background and Objective

A variety of genetic mutations are known to affect cell proliferation and apoptosis during organism development, leading to structural birth defects such as facial clefting. Yet, the mechanisms how these alterations influence the development of the face remain unclear. Cell proliferation and its relation to shape variation can be studied in high detail using Light-Sheet Microscopy (LSM) imaging across a range of developmental time points. However, the large number of LSM images captured at cellular resolution precludes manual analysis. Thus, the aim of this work was to develop and evaluate automatic methods to segment tissues and proliferating cells in these images in an accurate and efficient way.

Methods

We developed, trained, and evaluated convolutional neural networks (CNNs) for segmenting tissues, cells, and specifically proliferating cells in LSM datasets. We compared the automatically extracted tissue and cell annotations to corresponding manual segmentations for three specific applications: (i) tissue segmentation (neural ectoderm and mesenchyme) in nuclear-stained LSM images, (ii) cell segmentation in nuclear-stained LSM images, and (iii) segmentation of proliferating cells in Phospho-Histone H3 (PHH3)-stained LSM images.

Results

The automatic CNN-based tissue segmentation method achieved a macro-average F-score of 0.84 compared to a macro-average F-score of 0.89 comparing corresponding manual segmentations from two observers. The automatic cell segmentation method in nuclear-stained LSM images achieved an F-score of 0.57, while comparing the manual segmentations resulted in an F-score of 0.39. Finally, the automatic segmentation method of proliferating cells in the PHH3-stained LSM datasets achieved an F-score of 0.56 for the automated method, while comparing the manual segmentations resulted in an F-score of 0.45.

Conclusions

The proposed automatic CNN-based framework for tissue and cell segmentation leads to results comparable to the inter-observer agreement, accelerating the LSM image analysis. The trained CNN models can also be applied for shape or morphological analysis of embryos, and more generally in other areas of cell biology.
A cross-cohort analysis of autosomal DNA methylation sex differences in the term placenta
Authors: Inkster Amy M. , Yuan Victor , Konwar Chaini , Matthews Allison M. , Brown Carolyn J. , Robinson Wendy P.
Published: March 2021

Background

Human placental DNA methylation (DNAme) data is a valuable resource for studying sex differences during gestation, as DNAme profiles after delivery reflect the cumulative effects of gene expression patterns and exposures across gestation. Here, we present an analysis of sex differences in autosomal patterns of DNAme in the uncomplicated term placenta (n=343) using the Illumina 450K array.

Results

Using a false discovery rate < 0.05 and a mean sex difference in DNAme beta value of > 0.10, we identified 162 autosomal CpG sites that were differentially methylated by sex, and that replicated in an independent cohort of samples (n=293). Several of these differentially methylated CpG sites were part of larger correlated regions of differential DNAme, and many also exhibited sex-specific DNAme variability. Although global DNAme levels did not differ by sex, the majority of significantly differentially methylated CpGs were more highly methylated in male placentae, the opposite of what is seen in differential methylation analyses of somatic tissues. Interestingly, patterns of autosomal DNAme at these significantly differentially methylated CpGs organized placental samples along a continuum, rather than into discrete male and female clusters, and sample position along the continuum was significantly associated with maternal age and newborn birthweight standard deviation.

Conclusions

Our results provide a comprehensive analysis of sex differences in autosomal DNAme in the term human placenta. We report a list of high-confidence autosomal sex-associated differentially methylated CpGs, and identify several key features of these loci that suggest their relevance to sex differences observed in normative and complicated pregnancies.
A low-cost, long-term underwater camera trap network coupled with deep residual learning image analysis
Authors: Bilodeau Stephanie M. , Schwartz Austin W. H. , Xu Binfeng , Pauca V. Paúl , Silman Miles R.
Published: March 2021

Abstract

Understanding long-term trends in marine ecosystems requires accurate and repeatable counts of fishes and other aquatic organisms on spatial and temporal scales that are difficult or impossible to achieve with diver-based surveys. Long-term, spatially distributed cameras, like those used in terrestrial camera trapping, have not been successfully applied in marine systems due to limitations of the aquatic environment.

Here, we develop methodology for a system of low-cost, long-term camera traps (DispersedEnvironmentAquaticCameras), deployable over large spatial scales in remote marine environments. We use machine learning to classify the large volume of images collected by the cameras. We present a case study of these combined techniques’ use by addressing fish movement and feeding behavior related to grazing halos, a well-documented benthic pattern in shallow tropical reefscapes.

Cameras proved able to function continuously underwater at deployed depths (up to 7 m, with later versions deployed to 40 m) with no maintenance or monitoring for over five months, and collected time-lapse images during daylight hours for a total of over 100,000 images. Our ResNet-50-based deep learning model achieved 92.5% overall accuracy in sorting images with and without fish, and diver surveys revealed that the camera images accurately represented local fish communities.

The cameras and machine learning classification represent the first successful method for broad-scale underwater camera trap deployment, and our case study demonstrates the cameras’ potential for addressing questions of marine animal behavior, distributions, and large-scale spatial patterns.
Sub-stoichiometric Hsp104 regulates the genesis and persistence of self-replicable amyloid seeds of a yeast prion protein
Authors: Mahapatra Sayanta , Sarbahi Anusha , Madhu Priyanka , Swasthi Hema M. , Mukhopadhyay Samrat
Published: March 2021

The prion-like self-perpetuating conformational conversion is involved in both transmissible neurodegenerative diseases and non-Mendelian inheritance traits. The transmissibility of amyloid-like aggregates is dependent on the stoichiometry of chaperones such as heat shock proteins. To provide the mechanistic underpinning of the generation and persistence of prefibrillar amyloid seeds that are critical for the prion-like propagation, we studied the effect of Hsp104 disaggregase on the assembly mechanism of a yeast prion determinant ofSaccharomyces cerevisiaeSup35. At low sub-stoichiometric concentrations, Hsp104 exhibits a dual role and considerably accelerates the formation of seeding-competent prefibrillar amyloids by shortening the lag phase but also prolongs their persistence by introducing unusual kinetic halts and delaying their conversion into matured fibers. Hsp104-mediated amyloid species comprise a more ordered packing and display an enhanced autocatalytic self-templating ability compare to amyloids formed without Hsp104. Our findings underscore the key functional and pathological roles of sub-stoichiometric chaperones in prion-like propagation.
A Scalable Screening ofE. coliStrains for Recombinant Protein Expression
Authors: Morão Luana G. , Manzine Lívia R. , Clementino Lívia Oliveira D. , Wrenger Carsten , Nascimento Alessandro S.
Published: March 2021

Structural biology projects are highly dependent on the large-scale expression of soluble protein and, for this purpose, heterologous expression using bacteria or yeast as host systems is usually employed. In this scenario, some of the parameters to be optimized include (i) those related to the protein construct, such as the use of a fusion protein, the choice of an N-terminus fusion/tag or a C-terminus fusion/tag; (ii) those related to the expression stage, such as the concentration and selection of inducer agent and temperature expression and (iii) the choice of the host system, which includes the selection of a prokaryotic or eukaryotic cell and the adoption of a strain. The optimization of some of the parameters related to protein expression, stage (ii), is straightforward. On the other hand, the determination of the most suitable parameters related to protein construction requires a new cycle of gene cloning, while the optimization of the host cell is less straightforward. Here, we evaluated a scalable approach for the screening of host cells for protein expression in a structural biology pipeline. We evaluated fourEscherichia colistrains looking for the best yield of soluble heterologous protein expression using the same strategy for protein construction and gene cloning and comparing it to our standard strain, Rosetta 2 (DE3). Using a liquid handling device (robot),E. colipT-GroE, Lemo21(DE3), Arctic Express (DE3), and Rosetta Gami 2 (DE3) strains were screened for the maximal yield of soluble heterologous protein recovery. For the genes used in this experiment, the Arctic Express (DE3) strain resulted in better yields of soluble heterologous proteins. We propose that screening of host cell/strain is feasible, even for smaller laboratories and the experiment as proposed can easily be scalable to a high-throughput approach.
Rewriting deficit storylines: the positioning of one fourth-grader as comics expert
Authors: Reid Stephanie Francesca , Moses Lindsey
Published: March 2021

Purpose

This study took place in an elementary English language arts classroom during a comics writers workshop unit and focused on one fourth-grade author. This paper aims to explain how a fourth-grade student receiving special education services positions himself and is positioned by others as an expert during a unit on comics. When students’ knowledge about multimodal composition is recognized and valued, the classroom community can become a place where students can author themselves into positions of power and authority.

Design/methodology/approach

Informed by sociocultural theory, social semiotics and positioning theory, the authors conducted a qualitative study to analyze the focal participant’s published comic, classroom interactions and interview data using open and in vivo coding systems.

Findings

The findings documented how the focal participant was positioned as an expert by others and how he positioned himself as an expert. The findings also explore how this fourth-grade comics expert left an authorial residue that extended beyond the boundaries of this particular comics unit, impacting his teachers and future iterations of the comics workshop.

Originality/value

Scholars have theorized multimodal approaches to reading and writing pedagogy as an equitable enterprise that values meaning-makers using a wide variety of semiotic resources. This study shows how incorporating an explicit multimodal composition opportunity allowed one fourth-grade author space to craft a comic and re-author traditional classroom positions of power.
Improving data quality for human-as-a-security-sensor. A process driven quality improvement approach for user-provided incident information
Authors: Vielberth Manfred , Englbrecht Ludwig , Pernul Günther
Published: March 2021

Purpose

In the past, people were usually seen as the weakest link in the IT security chain. However, this view has changed in recent years and people are no longer seen only as a problem, but also as part of the solution. In research, this change is reflected in the fact that people are enabled to report security incidents that they have detected. During this reporting process, however, it is important to ensure that the reports are submitted with the highest possible data quality. This paper aims to provide a process-driven quality improvement approach for human-as-a-security-sensor information.

Design/methodology/approach

This work builds upon existing approaches for structured reporting of security incidents. In the first step, relevant data quality dimensions and influencing factors are defined. Based on this, an approach for quality improvement is proposed. To demonstrate the feasibility of the approach, it is prototypically implemented and evaluated using an exemplary use case.

Findings

In this paper, a process-driven approach is proposed, which allows improving the data quality by analyzing the similarity of incidents. It is shown that this approach is feasible and leads to better data quality with real-world data.

Originality/value

The originality of the approach lies in the fact that data quality is already improved during the reporting of an incident. In addition, approaches from other areas, such as recommender systems, are applied innovatively to the area of the human-as-a-security-sensor.
Access to precision medicine in Thailand: a comparative study
Authors: Jirawutkornkul Nisita , Patikorn Chanthawat , Anantachoti Puree
Published: March 2021

Purpose

This study explored health insurance coverage of genetic testing and potential factors associated with precision medicine (PM) reimbursement in Thailand.

Design/methodology/approach

The study employed a targeted review method. Thirteen PMs were selected to represent four PM categories: targeted cancer therapy candidate, prediction of adverse drug reactions (ADRs), dose adjustment and cancer risk prediction. Content analysis was performed to compare access to PMs among three health insurance schemes in Thailand. The primary outcome of the study was evaluating PM test reimbursement status. Secondary outcomes included clinical practice guidelines, PMs statement in FDA-approved leaflet and economic evaluation.

Findings

Civil Servant Medical Benefits Scheme (CSMBS) provided more generous access to PM than Universal Coverage Scheme (UCS) and Social Security Scheme (SSS). Evidence of economic evaluations likely impacted the reimbursement decisions of SSS and UCS, while the information provided in FDA-approved leaflets seemed to impact the reimbursement decisions of CSMBS. Three health insurance schemes provided adequate access to PM tests for some cancer-targeted therapies, while gaps existed for access to PM tests for serious ADRs prevention, dose adjustment and cancer risk prediction.

Originality/value

This was the first study to explore the situation of access to PMs in Thailand. The evidence alerts public health insurance schemes to reconsider access to PMs. Development of health technology assessment guidelines for PM test reimbursement decisions should be prioritized.
Politics and new media in ex/communist states – the example of Montenegro
Authors: Scekic Radenko , Lakic Slobodan , Pejanovic Ana
Published: March 2021

Purpose

This study aims to explore the use of evolutionary and institutionalization models to understand the technical progression of sustainability in political organizations and their contribution to sustainable effectiveness. It describes the evolution of mass media, political marketing, in the organization’s strategy and design and the methods it is using to institutionalize this political and transition change.

Design/methodology/approach

The study describes models of sustainability evolution and political and technical change, in political and social life in transition state Montenegro.

Findings

Online and internet presentations of political programs, political blogs, sites that promote the national history and culture of the desired perception – the achievements have already risen in Montenegro in the first decade of the new millennium and beyond. Internet presentation of political subjects are reduced mainly to a brief presentation of history and of political parties, and mostly during the current election campaign, serving to inform the public about the program and promotion announcements.

Originality/value

The findings of this study will help senior executives with responsibility for transition states. The aim of this paper is to show the transformation of the media during the transition period from one political system to another. With the use of descriptive methodological postulates and numerous case studies. With a wealth of facts and examples, which contributes to the originality and value of the article. The significance and originality of this research and article is reflected in a comprehensive and multidisciplinary approach to the transition process and quantitative and qualitative development of the media.
Design and optimization of projection stereolithography additive manufacturing system with multi-pass scanning
Authors: Qin Qin , Huang Jigang , Yao Jin , Gao Wenxiang
Published: March 2021

Purpose

Scanning projection-based stereolithography (SPSL) is a powerful technology for additive manufacturing with high resolution as well as large building area. However, the surface quality of stitching boundary in an SPSL system has been rarely studied, and no positive settlement was proposed to address the poor stitching quality. This paper aims to propose an approach of multi-pass scanning and a compensation algorithm for multi-pass scanning process to address the issue of poor stitching quality in SPSL systems.

Design/methodology/approach

The process of multi-pass scanning is realized by scanning regions repeatedly, and the regions can be cured simultaneously because of the very short repeat exposure time and very fast scanning. Then, the poor stitching quality caused by the non-simultaneous curing can be eliminated. Also, a compensation algorithm is designed for multi-pass scanning to reduce the stitching errors. The validity of multi-pass scanning is verified by curing depth test, while the performance of multi-pass scanning as well as proposed compensation algorithm is demonstrated by comparing with that of a previous SPSL system.

Findings

The results lead to a conclusion that multi-pass scanning with its compensation algorithm is an effective approach to improve the stitching quality of an SPSL system.

Practical implications

This study can provide advice for researchers to achieve the satisfactory surface finish with SPSL technology.

Originality/value

The authors proposed a process of multi-pass scanning as well as a compensation algorithm for SPSL additive manufacturing (system to improve the stitching quality, which has rarely been studied in previous work.
Identifying the factors of social currency for social media marketing strategy
Authors: Mishra Yog , Singh Anurag
Published: March 2021

Purpose

Dynamism has been the key to the success and popularity of social media, and users always try to adapt to the available new changes. Continuous growth in the access and reach of social media in the past decade has enabled the users to make a calculative assessment of their social media usage. Social currency is a phenomenon that helps the customer in their evaluation of social media usage. However, this concept is still in its infancy phase, and there have been hitherto no studies to understand the influence of social currency dimensions on Indian users. This paper aims to study the dimensions of social currency for a better insight into social media usage of Indian customers.

Design/methodology/approach

Data were collected from 384 respondents from the biggest residential university in Varanasi through a structured questionnaire using the snowball sampling technique. Responses were taken on a seven-point Likert scale. Responses were analyzed by the factor analysis method using the maximum likelihood estimation model.

Findings

The result of this study empirically demonstrated that six dimensions, i.e. conversation, information, utility, affiliation, advocacy and identity, constitute the social currency of the user while browsing social media sites. It was also found that among the factors described above, advocacy emerged as the most influential dimension of social currency for Indian users, followed by identity and affiliation.

Practical implications

The findings have various managerial implications for the firms that want to have a significant social media presence. These findings can help marketers to design a tailored social media campaign for Indian users in an efficient manner by successfully incorporating the aforesaid social currency dimensions in their strategy.

Social implications

This study also reflects the societal impact of the dimensions of social currency on Indian users, as any change in the usage of social media can have a long-lasting effect on the mood of the people. The influence of the social currency dimension differs significantly in the context of Indian users compared to the existing literature, as they give more value to the behavioural aspect of the social currency (advocacy, identity and affiliation), strengthening the sense of belongings among the members.

Originality/value

This paper highlights, for the first time, the level of influence social currency dimensions have on Indian users, as there have been hitherto no studies to understand the influence of social currency dimensions on Indian users. Another significant contribution of this research is the empirical validation of the social currency determinants. Thus, this study may contribute to the social media strategy of the firm for Indian users by incorporating the social currency dimension, as discussed in the study.
Exploring the consequences of COVID-19 on tourist behaviors: perceived travel risk, animosity and intentions to travel
Authors: Abraham Villy , Bremser Kerstin , Carreno Mercedes , Crowley-Cyr Lynda , Moreno Maria
Published: March 2021

Purpose

This paper aims to report on the findings emerging from an international study focused on the COVID-19 pandemic impact on travel attitudes and behavioral intentions .

Design/methodology/approach

An online survey created with SurveyMonkey was distributed to a sample of 216 international travelers who were at least 18 years of age.

Findings

The findings suggest that attribution theory (locus of control) may account for international travel. Individuals attributing the spread of COVID-19 to their own countries (internal locus of control) are more likely to travel abroad. Statistically significant differences are observed between various generational cohorts concerning perceived travel risk, domestic and international travel.

Originality/value

The impact of a health crisis on domestic and international travels conceptualized in a single model is absent from the literature. The authors propose a model to account for the influence of pandemics on tourists’ attitudes and intentions to travel and whether attribution of blame influences travel destination choices (domestic or international).
Plant holobiont interactions mediated by the type VI secretion system and the membrane vesicles: promising tools for a greener agriculture
Authors: Borrero de Acuña José Manuel , Bernal Patricia
Published: March 2021

A deeper understanding of the complex relationship between plants and their microbiota is allowing researchers to appreciate a plethora of possibilities to improve crops using chemical‐free alternatives based on beneficial microorganisms. An increase in crop yield from the promotion of plant growth or even simultaneous protection of the plants from the attack of phytopathogens can be achieved in the presence of different plant‐associated microorganisms known as plant‐growth‐promoting rhizobacteria (PGPR) and biocontrol agents (BCAs), respectively. Thus, the study of the great diversity of plant‐microbe and microbe‐microbe interactions is an attention‐grabbing topic covering studies of interactions since the plant seed and through all developmental stages, from root to shoot. The intricate communication systems that plant holobionts co‐evolved has resulted in many different strategies and interplays between these organisms shaping the bacterial communities and the plant fitness simultaneously. Herein, we emphasize two understudied delivery systems existing in plant‐associated bacteria: the type VI secretion system (T6SS) and the membrane vesicles with a huge potential to boost a highly demanded and necessary green agriculture.
Spatial and temporal distribution of aerobic anoxygenic phototrophic bacteria: key functional groups in biological soil crusts
Authors: Tang Kai , Yuan Bo , Jia Lijuan , Pan Xin , Feng Fuying , Jin Ke
Published: March 2021

Several significant ecosystem services are performed by biological soil crusts (BSCs) in drylands, wherein photoautotrophic microorganisms are commonly critical contributors. However, aerobic anoxygenic phototrophic bacteria (AAnPB) are rarely reported in BSCs, despite being the second major branch of Earth's phototrophic microbes. Here, we collected different types of BSCs and their subsoils from temperate deserts, investigated distributions of AAnPB communities among BSCs using cultivation and high‐throughput sequencing approaches, predicted keystone species by co‐occurrence network analysis, and verified their effects on BSCs formation through microcosm experiments. The absolute abundances and diversity of AAnPB were higher in BSCs and were closely related with BSCs successional stages, as well as soil organic carbon contents. AAnPB communities in both BSCs and their subsoils were dominated by Proteobacteria and Alphaproteobacteria, specifically Acetobacteraceae, Rhodospirillaceae, Roseiflexaceae, Sphingomonadaceae and Caulobacteraceae families. Mean annual precipitation, pH and available nutrients were the primary factors that shaped AAnPB community structures. The predicted keystone species belonged to the families Acetobacteraceae, Rhodospirillaceae and Sphingomonadanceae. Microcosm experiments demonstrated that inoculation with strains from the three families greatly accelerated the formation and development of BSCs. These observations suggest that AAnPB are likely important functional groups in BSCs that significantly contribute to their formation and important ecosystem services.
The Long March Through Whitehall: A Comment on Lowe and Pemberton, The Official History of the British Civil Service, Volume II: 1982–1997
Authors: Theakston Kevin
Published: March 2021

The Thatcher‐Major ‘permanent revolution’ massively changed the British civil service and Whitehall. The political clout provided by strong prime ministerial backing was a key factor in sustaining the momentum of change over the 1980s and 1990s. The process of change developed piecemeal, in a step‐by‐step and, in some ways, even haphazard fashion, with ‘New Right’ ideology just one factor. Economic and financial constraints were important in driving and sustaining the Whitehall efficiency drives and managerial reforms of the period. Support from managerially minded insiders and skilful prime ministerial businessmen advisers brought in from outside were also crucial. In contrast, the Johnson government's approach to civil service reform may be self‐defeating if it creates too much instability and needless strife, rather than building on ideas and building up support at different levels from within Whitehall itself.
Simulating Hydrological Responses of Integrated Crop‐Livestock Systems under Future Climate Changes in an Agricultural Watershed
Authors: Bawa Arun , Pérez‐Gutiérrez Juan D. , Kumar Sandeep
Published: March 2021

Land use land cover (LULC) and climate are the determinant factors for the soil water balance. The combined effect of LULC and climate change is of great importance for effective water resources planning and management. This study assessed the hydrological impact of long‐term implementation of integrated crop‐livestock (ICL) system with the projected climate scenarios on water yield using the Soil and Water Assessment Tool model over two time periods (i.e., near future [2021–2050] and far future [2070–2099]). This study was conducted in three phases over Skunk Creek watershed (SCW), South Dakota. In phase I, the impact of long‐term ICL system implementation (1976–2005; 30 years) on soil hydrology was evaluated. Phase II and phase III evaluated the impacts of projected climate changes under existing land cover and ICL system, respectively. Outcomes of phase I showed a significant decrease in water yield and surface runoff. Phase II showed the susceptibility of SCW to extreme events such as floods and waterlogging during spring, and droughts during summers under the projected climate changes. Phase III showed the reduction in water yield and surface runoff due to the ICL system and minimizing the induced detrimental impacts only due to climate change. This study provides a perspective on the possible impacts of the ICL system to mitigate the hydrological alteration due to climate change.
Satellite‐Based Drought Reporting on the Navajo Nation
Authors: McCullum A.J.K. , McClellan C. , Daudert B. , Huntington J. , Green R. , Ly V. , Marley A.R.G. , Tulley N.R. , Morton C. , Hegewisch K.C. , Abatzoglou J.T. , McEvoy D.
Published: March 2021

In data scarce regions of the world, co‐produced management tools that combine remote sensing, modeled, and in situ data provide the information needed to support ground‐based monitoring systems for improved water and natural resource management. On the Navajo Nation (N.N.), in the Four Corners of the southwestern United States, there is a need for data‐driven management of water resources as the region is prone to water scarcity and emergency drought declarations, which have become more common under a changing climate. The current tools used by the N.N. Department of Water Resources largely lack the spatial detail, consistent measurements, and political and administrative information specific to their needs for determining appropriate response actions. The Drought Severity Evaluation Tool (DSET), a cloud‐based web application that harnesses the capabilities of Google Earth Engine, is a user‐friendly tool that pairs remotely sensed, modeled, and in situ data on the N.N. The DSET computing capabilities include on‐the‐fly generation of regional to field scale maps, time series figures, and reporting metrics that can assist in drought emergency declarations and the assistance to local communities through the subsequent allocation of relief dollars across the N.N. to the regions that need it most.
Stereotactic body radiation therapy for an octogenarian with pulmonary carcinosarcoma
Authors: Huang Wei‐Lun , Huang Yu‐Ling , Kao Chieh‐Ni , Liu Yu‐Wei
Published: March 2021

Pulmonary carcinosarcoma is a rare lung tumor accounting for <1% of primary lung cancers, characterized by biphasic components with both carcinomatous and sarcomatous mesenchymal features. This report describes a case of pulmonary carcinosarcoma in an octogenarian who was treated with stereotactic body radiation therapy (SBRT) and whose therapeutic response was sustained for 2 years. Along with other treatment modalities, SBRT might be considered for the treatment of medically inoperable localized stage pulmonary carcinosarcoma.
Sex differences in cholinergic circuits and behavioral disruptions following chronic ethanol exposure with and without thiamine deficiency
Authors: Kipp Brian T. , Nunes Polliana T. , Savage Lisa M.
Published: March 2021

Background

Few studies have investigated differences in the vulnerabilities of males and females to alcohol use disorder and alcohol‐related brain damage (ARBD). According to epidemiological and clinical findings, females appear to be more sensitive to the effects of alcohol and thiamine deficiency and have a worse prognosis in recovery from neurocognitive deficits compared with males. This study aimed to characterize the effects of chronic ethanol (EtOH) toxicity and thiamine deficiency across the sexes using rodent models.

Methods

Male and female Sprague Dawley rats were assigned to chronic forced EtOH treatment (CET), pyrithiamine‐induced thiamine deficiency (PTD), combined CET‐PTD, or pair‐fed (PF) control treatment conditions. Following treatments, spatial working memory was assessed during a spontaneous alternation task while measuring acetylcholine (ACh) in the prefrontal cortex (PFC) and the hippocampus (HPC). The animals also underwent an operant‐based attentional set‐shifting task (ASST) for the analysis of behavioral flexibility.

Results

Female and male rats did not differ in terms of EtOH consumption; however, the CET and CET‐PTD‐treated female rats had lower BECs than male rats. Compared with the PF group, the CET, PTD, and CET‐PTD groups exhibited spatial working memory impairments with corresponding reductions in ACh efflux in the PFC and HPC. The ASST revealed that CET‐PTD‐treated males and females displayed impairments marked by increased latency to make decisions. Thalamic shrinkage was prominent only in the CET‐PTD and PTD treatment conditions, but no sex‐specific effects were observed.

Conclusions

Although the CET and CET‐PTD‐treated females had lower BECs than the males, they demonstrated similar cognitive impairments. These results provide evidence that female rats experience behavioral and neurochemical disruptions at lower levels of alcohol exposure than males and that chronic EtOH and thiamine deficiencies produce a unique behavioral profile.