bluuebunny/crossref_metadata_2025 huggingface dataset:
Genome-wide screen identifies curli amyloid fibril as a bacterial component promoting host neurodegeneration
Authors: Wang Chenyin , Lau Chun Yin , Ma Fuqiang , Zheng Chaogu
Published: March 2021

Growing evidence indicate that gut microbiota play a critical role in regulating the progression of neurodegenerative diseases, such as Parkinson’s disease (PD). The molecular mechanism underlying such microbe-host interaction is unclear. In this study, by feedingC. elegansexpressing human α-syn withE. coliknockout mutants, we conducted a genome-wide screen to identify bacterial genes that promote host neurodegeneration. The screen yielded 38 genes that fall into several genetic pathways, including curli formation, lipopolysaccharide assembly, adenosylcobalamin biosynthesis among others. We then focused on the curli amyloid fibril and found that genetically deleting or pharmacologically inhibiting the curli major subunit CsgA inE. colireduced α-syn-induced neuronal death, restored mitochondrial health, and improved neuronal functions. CsgA secreted by the bacteria colocalized with α-syn inside neurons and promoted α-syn aggregation through cross-seeding. Similarly, curli also promoted neurodegeneration inC. elegansmodels of AD, ALS, and HD and in human neuroblastoma cells.
Mutations in a β-group of solute carrier gene are responsible for egg and eye coloration of thebrown egg 4(b-4) mutant in the silkworm,Bombyx mori
Authors: Tomihara Kenta , Satta Katsuya , Matsuzaki Shohei , Yoshitake Kazutoshi , Yamamoto Kimiko , Uchiyama Hironobu , Yajima Shunsuke , Futahashi Ryo , Katsuma Susumu , Osanai-Futahashi Mizuko , Kiuchi Takashi
Published: March 2021

Thebrown egg 4(b-4) is a recessive mutant in the silkworm (Bombyx mori), whose egg and adult compound eyes exhibit a reddish-brown color instead of normal purple and black, respectively. By double digest restriction-site associated DNA sequencing (ddRAD-seq) analysis, we narrowed down a region linked to theb-4phenotype to approximately 1.1 Mb that contains 69 predicted gene models. RNA-seq analysis in ab-4strain indicated that one of the candidate genes had a different transcription start site, which generates a short open reading frame. We also found that exon skipping was induced in the same gene due to an insertion of a transposable element in other twob-4mutant strains. This gene encoded a putative amino acid transporter that belongs to the β-group of solute carrier (SLC) family and is orthologous toDrosophilaeye color mutant gene,mahogany(mah). Accordingly, we named this geneBmmah. We performed CRISPR/Cas9-mediated gene knockout targetingBmmah. Several adult moths in generation 0 (G0) had totally or partially reddish-brown compound eyes. We also established threeBmmahknockout strains, all of which exhibit reddish-brown eggs and adult compound eyes. Furthermore, eggs from complementation crosses between theb-4mutants and theBmmahknockout mutants also exhibited reddish-brown color, which was similar to theb-4mutant eggs, indicating thatBmmahis responsible for theb-4phenotypes.

Highlight

Responsible region for thebrown egg 4(b-4) mutation was narrowed down by double digest restriction-site associated DNA sequencing (ddRAD-seq).

The gene structure was disrupted in one of the candidate genes,Bombyx mori mahogany(Bmmah), in theb-4mutant strains.

CRISPR/Cas9-mediated gene knockout and complementation test confirmed that theBmmahis responsible for theb-4phenotypes.

TheBmmahencoded a putative amino acid transporter that belongs to the β-group of solute carrier family.

TheBmmahgene is essential for normal colorization of eggs, compound eyes, and ganglions.

Graphical abstract
Microglial refinement of A-fibre projections in the postnatal spinal cord dorsal horn is required for normal maturation of dynamic touch
Authors: Xu Yajing , Koch Stephanie C. , Chamessian Alexander , He Qianru , Sundukova Mayya , Heppenstall Paul , Ji RuRong , Fitzgerald Maria , Beggs Simon
Published: March 2021

Sensory systems are shaped in postnatal life by the refinement of synaptic connections. In the dorsal horn of the spinal cord, sensory circuits undergo postnatal activity dependent reorganisation, including the retraction of primary afferent A-fibres from superficial to deeper laminae which is accompanied by decreases in cutaneous sensitivity. Here we show that microglia, the resident immune cells in the CNS, phagocytose A-fibre terminals in superficial laminae in the first weeks of life. Genetic perturbation of microglial engulfment at that time prevents the normal process of A-fibre retraction, resulting in increased sensitivity of dorsal horn cells to dynamic tactile cutaneous stimulation, and behavioural hypersensitivity to dynamic touch. Thus, functional microglia are necessary for normal postnatal development of dorsal horn sensory circuits. In the absence of microglial engulfment, superfluous A-fibre projections remain in the dorsal horn and the balance of sensory connectivity is disrupted, leading to lifelong hypersensitivity to dynamic touch.

Impact statement

Microglia phagocytose superfluous A-fibres in the superficial spinal dorsal horn during normal development, the disruption of which leads to long term aberrant dynamic touch processing and behaviour.
SAF-A promotes origin licensing and replication fork progression to ensure robust DNA replication
Authors: Connolly Caitlin , Takahashi Saori , Miura Hisashi , Hiratani Ichiro , Gilbert Nick , Donaldson Anne D. , Hiraga Shin-ichiro
Published: March 2021

The organisation of chromatin is closely intertwined with biological activities of chromosome domains, including transcription and DNA replication status. Scaffold attachment factor A (SAF-A), also known as Heteronuclear Ribonucleoprotein Protein U (HNRNPU), contributes to the formation of open chromatin structure. Here we demonstrate that SAF-A promotes the normal progression of DNA replication, and enables resumption of replication after inhibition. We report that cells depleted for SAF-A show reduced origin licensing in G1 phase, and consequently reduced origin activation frequency in S phase. Replication forks progress slowly in cells depleted for SAF-A, also contributing to reduced DNA synthesis rate. Single-cell replication timing analysis revealed that the boundaries between early- and late-replicating domains are blurred in cells depleted for SAF-A. Associated with these defects, SAF-A-depleted cells show elevated γH2A phosphorylation and tend to enter quiescence. Overall we find that SAF-A protein promotes robust DNA replication to ensure continuing cell proliferation.
Respiration, heartbeat, and conscious tactile perception
Authors: Grund Martin , Al Esra , Pabst Marc , Dabbagh Alice , Stephani Tilman , Nierhaus Till , Gaebler Michael , Villringer Arno
Published: March 2021

Previous studies have shown that timing of sensory stimulation during the cardiac cycle interacts with perception. Given the natural coupling of respiration and cardiac activity, we investigated here their joint effects on tactile perception. Forty-one healthy female and male human participants reported conscious perception of finger near-threshold electrical pulses (33% null trials) and decision confidence while electrocardiography, respiratory activity, and finger photoplethysmography were recorded. Participants adapted their respiratory cycle to expected stimulus onsets to preferentially occur during late inspiration / early expiration. This closely matched heart rate variation (sinus arrhythmia) across the respiratory cycle such that most frequent stimulation onsets occurred during the period of highest heart rate probably indicating highest alertness and cortical excitability. Tactile detection rate was highest during the first quadrant after expiration onset. Inter-individually, stronger respiratory phase-locking to the task was associated with higher detection rates. Regarding the cardiac cycle, we confirmed previous findings that tactile detection rate was higher during diastole than systole and newly specified its minimum at 250 - 300 ms after the R-peak corresponding to the pulse wave arrival in the finger. Expectation of stimulation induced a transient heart deceleration which was more pronounced for unconfident decision ratings. Inter-individually, stronger post-stimulus modulations of heart rate were linked to higher detection rates. In summary, we demonstrate how tuning to the respiratory cycle and integration of respiratory-cardiac signals are used to optimize performance of a tactile detection task.

Significance statement

Mechanistic studies on perception and cognition tend to focus on the brain neglecting contributions of the body. Here, we investigated how respiration and heartbeat influence tactile perception: Respiration phase-locking to expected stimulus onsets corresponds to highest heart rate (and presumably alertness/cortical excitability) and correlates with detection performance. Tactile detection varies across the heart cycle with a minimum when the pulse reaches the finger and a maximum in diastole. Taken together with our previous finding of unchanged early ERPs across the cardiac cycle we conclude that these effects are not a peripheral physiological artifact but a result of cognitive processes that model our body’s internal state, make predictions to guide behavior, and might also tune respiration to serve the task.
Introduction bias: Imbalance in species introductions may obscure the identification of traits associated with invasiveness
Authors: Palma Estibaliz , Yen Jian , Vesk Peter A. , Vilà Monserrat , Catford Jane A.
Published: March 2021

1

The introduction stage is usually overlooked in trait-based studies of invasiveness, implicitly assuming that species introductions are random. However, human activities promote the movement of specific types of species. Thus, species deliberately introduced for distinct purposes (e.g. gardening, forestry) or as contaminants of human commodities (e.g. stowaway) will likely show particular traits. If species with certain traits have been preferentially introduced (i.e. introduction bias), some traits may have been mistakenly linked to species’ invasion abilities due to their influence on introduction probability.

In this work, we propose a theoretical framework with different scenarios of introduction bias. The introduction scenarios are: (1)Random introduction, independent from traits; (2)Biologically biased introduction, following the worldwide distribution of the trait; and (3)Human biased introduction, following a theoretical introduction pathway that favours the introduction of species with high values of the trait. We evaluate how the introduced trait distributions in these scenarios may affect trait distributions in naturalized and invasive species pools under different hypothesized associations between traits and the probabilities of naturalization and invasion. The aim of this work is to identify situations where ignoring introduction bias may lead to spurious correlations being found between species’ traits and species’ ability to become naturalized or invasive.

Our framework strongly points to the need to evaluate the traits of species that have become naturalized or invasive along with the traits of species that have failed to do so in order to unravel any existing introduction bias that may confound the correlation between species’ traits and invasion success. Overlooking a possible introduction bias may lead to the overestimation of the correlation between the trait and the species’ invasion ability, especially in cases when the pool of introduced species shows extreme values of the trait distribution (as compared to a random introduction). Trait-based studies that deserve special attention to avoid undesired effects of introduction bias on their findings are: those that investigate naturalization using only the pool of naturalized species, and those studies that examine invasiveness by comparing invasive species with native species.
A synthetic tubular molecular transport system
Authors: Stömmer Pierre , Kiefer Henrik , Kopperger Enzo , Honemann Maximilian N. , Kube Massimo , Simmel Friedrich C. , Netz Roland R. , Dietz Hendrik
Published: March 2021

We report the bottom-up construction of a macromolecular transport system in which molecular pistons diffusively move through micrometer-long, hollow filaments. The pistons can cover micrometer distances in fractions of seconds. We built the system using multi-layer DNA origami and analyzed the structures of the components using transmission electron microscopy. We studied the motion of the pistons along the tubes using single-molecule fluorescence microscopy and performed Langevin simulations to reveal details of the free energy surface that directs the motions of the pistons. The tubular transport system achieves diffusivities and displacement ranges known so far only from natural molecular motors and realizes mobility improvements over five orders of magnitude compared to previous artificial random walker designs. Electric fields can also be employed to actively pull the pistons along the filaments, thereby realizing a nanoscale electric rail system. Our system presents a platform for artificial motors that move autonomously driven by chemical fuels and for performing nanotribology studies, and it could form a basis for future molecular transportation networks.
Single dose of amphetamine induces delayed subregional attenuation of striatal cholinergic interneuron activity
Authors: Ztaou Samira , Oh Soo Jung , Tepler Sophia , Fleury Sixtine , Matamales Miriam , Bertran-Gonzalez Jesus , Chuhma Nao , Rayport Stephen
Published: March 2021

Psychostimulants such as amphetamine target dopamine neuron synapses to engender drug-induced plasticity. While dopamine neurons modulate the activity of striatal cholinergic interneurons (ChIs) with regional heterogeneity, how amphetamine affects ChI activity has not been elucidated. Here, we applied quantitative fluorescence imaging approaches to map the dose-dependent effects of a single dose of amphetamine on ChI activity at 2.5 and 24 hours after injection across the mouse striatum using the activity-dependent marker phosphorylated ribosomal protein S6 (p-rpS6). We found that amphetamine did not induce neurotoxic effects on ChIs, as their distribution and morphology were not affected. While low- or high-dose amphetamine did not affect ChI activity after 2.5 hours, ChI activity was significantly reduced in all striatal subregions after 24 hours, with a dose-dependent effect in the nucleus accumbens. Thus, our findings suggest that a single dose of amphetamine has delayed regionally heterogeneous effects on ChI activity.

Significance statement

Using the activity dependent marker phosphorylated ribosomal protein S6 (p-rpS6), we mapped amphetamine effects on the activity of cholinergic interneurons (ChIs) across the striatum. Amphetamine caused a delayed attenuation of ChI activity in all striatal subregions, and a dose-dependent effect in the ventral striatum/nucleus accumbens, a critical site of psychostimulant action.
Modulation of pulsatile GnRH dynamics across the ovarian cycle: the role of glutamatergic transmission in the arcuate kisspeptin network
Authors: Voliotis Margaritis , Li Xiao Feng , De Burgh Ross , Lass Geffen , Ivanova Deyana , McIntyre Caitlin , O’Byrne Kevin T. , Tsaneva-Atanasova Krasimira
Published: March 2021

Pulsatile GnRH release is essential for normal reproductive function. Kisspeptin secreting neurons found in the arcuate nucleus, known as KNDy neurons for co-expressing neurokinin B, and dynorphin, drive pulsatile GnRH release. Furthermore, gonadal steroids regulate GnRH pulsatile dynamics across the ovarian cycle by altering KNDy neurons’ signalling properties. However, the precise mechanism of regulation remains mostly unknown. To better understand these mechanisms we start by perturbing the KNDy system at different stages of the estrous cycle using optogenetics. We find that optogenetic stimulation of KNDy neurons stimulates pulsatile GnRH/LH secretion in estrous mice but inhibits it in diestrous mice. These in-vivo results in combination with mathematical modelling suggest that the transition between estrus and diestrus is underpinned by well-orchestrated changes in neuropeptide signalling and in the excitability of the KNDy population controlled via glutamate signalling. Guided by model predictions, we show that blocking glutamate signalling in diestrous animals inhibits LH pulses, and that optic stimulation of the KNDy population mitigates this inhibition. In estrous mice, disruption of glutamate signalling inhibits pulses generated via sustained low-frequency optic stimulation of the KNDy population, supporting the idea that the level of network excitability is critical for pulse generation. Our results reconcile previous puzzling findings regarding the estradiol-dependent effect that several neuromodulators have on the GnRH pulse generator dynamics. Therefore, we anticipate our model to be a cornerstone for a more quantitative understanding of the pathways via which gonadal steroids regulate GnRH pulse generator dynamics. Finally, our results could inform useful repurposing of drugs targeting the glutamate system in reproductive therapy.
Thyroid Hormone Dependent Transcriptional Programming by TRβ Requires SWI/SNF Chromatin Remodelers
Authors: Gillis Noelle E. , Boyd Joseph R. , Tomczak Jennifer A. , Frietze Seth , Carr Frances E.
Published: March 2021

Transcriptional regulation in response to thyroid hormone (T3) is a dynamic and cell-type specific process that maintains cellular homeostasis and identity in all tissues. However, our understanding of the mechanisms of thyroid hormone receptor (TR) actions at the molecular level are actively being refined. We used an integrated genomics approach to profile and characterize the cistrome of TRβ, map changes in chromatin accessibility, and capture the transcriptomic changes in response to T3in normal thyroid cells. There are significant shifts in TRβ genomic occupancy in response to T3, which are associated with differential chromatin accessibility, and differential recruitment of SWI/SNF chromatin remodelers. We further demonstrate selective recruitment of BAF and PBAF SWI/SNF complexes to TRβ binding sites, revealing novel differential functions in regulating chromatin accessibility and gene expression. Our findings highlight three distinct modes of TRβ interaction with chromatin and coordination of coregulator activity.
Cold Adaptation Leads To Repolarization Gradients Development In The Rainbow Trout Heart
Authors: Vaykshnorayte Marina A. , Vityazev Vladimir A. , Azarov Jan E.
Published: March 2021

Introduction

Thermal adaptation in fish is accompanied by morphological and electrophysiological changes in the myocardium. Little is known regarding changes of spatiotemporal organization of ventricular excitation and repolarization processes with acclimatization. We aimed to evaluate transmural and apicobasal heterogeneity of depolarization and repolarization characteristics in the in-situ heart of rainbow trout in seasonal acclimatization.

Methods

The experiments were done in the summer-acclimatized (SA, 18°C, n=8) and winter-acclimatized (WA, 3°C, n=8) rainbow trout. 24 unipolar electrograms were recorded with plunge needle electrodes (eight lead terminals each) impaled into the ventricular wall. Activation time (AT), end of repolarization time (RT), and activation-repolarization interval (ARI, a surrogate for action potential duration) were determined as dV/dt min during QRS-complex, dV/dt max during T-wave, and RT-AT difference, respectively.

Results

The SA fish demonstrated relatively flat apicobasal and transmural AT and especially ARI profiles. In the WA animals, ATs and ARIs were longer as compared to SA animals (p≤0.001), ARIs were shorter in the compact layer than in the spongy layer (p≤0.050), and within the compact layer, the apical region had shorter ATs and longer ARIs as compared to the basal region (p≤0.050). In multiple linear regression analysis, ARI duration was associated with cardiac cycle duration and AT in SA and WA animals. The WA animals demonstrated additionally an independent association of ARIs with spatial localization across the ventricle.

Conclusion

Adaptation to cold conditions in rainbow trout was associated with a spatial ventricular remodeling leading to the development of repolarization gradients typically observed in mammalian myocardium.

SUMMARY STATEMENT

The study gives an example of thermal adaptation in fish realized at the level of spatiotemporal organization of myocardial depolarization and repolarization.
New insights into the allosteric effects of CO2and bicarbonate on crocodilian hemoglobin
Authors: Bautista Naim M. , Malte Hans , Natarajan Chandrasekhar , Wang Tobias , Storz Jay F. , Fago Angela
Published: March 2021

Crocodilians are unique among vertebrates in that their hemoglobin (Hb) O2binding is allosterically regulated by bicarbonate, which forms in the red blood cell upon hydration of CO2. Although known for decades, this remarkable mode of allosteric control has not yet been experimentally verified with direct evidence of bicarbonate binding to crocodilian Hb, probably because of confounding CO2-mediated effects. Here we provide the first quantitative analysis of the separate allosteric effects of CO2and bicarbonate on Hb of the spectacled caiman (Caiman crocodilus). Using thin-layer gas diffusion chamber and Tucker chamber techniques, we demonstrate that both CO2and bicarbonate bind to Hb with high affinity and strongly decrease Hb-O2saturation, and propose that both effectors bind to an unidentified positively charged site containing a reactive amino group in the low-O2affinity T conformation of the Hb. These results provide the first experimental evidence that bicarbonate binds directly to crocodilian Hb and promotes O2delivery independently of CO2. Using the gas-diffusion chamber, we observed similar effects in the Hbs of a phylogenetically diverse set of other caiman, alligator, and crocodile species, suggesting that the unique mode of allosteric regulation by CO2and bicarbonate evolved >80-100 million years ago in the common ancestor of crocodilians. Taken together, our results show a tight and unusual linkage between O2and CO2transport in the blood of crocodilians, where build-up of blood CO2and bicarbonate ions during breath-hold diving or digestion facilitates O2delivery, while Hb desaturation facilitates CO2transport as protein-bound CO2and bicarbonate.
Brain Iron Imaging Markers in the Presence of White Matter Hyperintensities
Authors: Murray Kyle D. , Tivarus Madalina E. , Schifitto Giovanni , Uddin Md Nasir , Zhong Jianhui
Published: March 2021

Purpose

To investigate the relationship between pathological brain iron deposition and white matter hyperintensities (WMHs) in cerebral small vessel disease (CSVD), via Monte Carlo simulations of magnetic susceptibility imaging and a novel imaging marker called the Expected Iron Coefficient (EIC).

Methods

A synthetic pathological model of a different number of impenetrable spheres at random locations was employed to represent pathological iron deposition. The diffusion process was simulated with a Monte Carlo method with adjustable parameters to manipulate sphere size, distribution, and extracellular properties. Quantitative susceptibility mapping (QSM) was performed in a clinical dataset to study CSVD to derive and evaluate QSM, R2*, the iron microenvironment coefficient (IMC), and EIC in the presence of WMHs.

Results

The simulations show that QSM signals increase in the presence of increased tissue iron, confirming that the EIC increases with pathology. Clinical results demonstrate that while QSM, R2*, and the IMC do not show differences in brain iron, the EIC does in the context of CSVD.

Conclusion

The EIC is more sensitive to subtle changes in brain iron deposition caused by pathology, even when QSM, R2*, and the IMC do not.
Structural modeling of the SARS-CoV-2 Spike/human ACE2 complex interface can identify high-affinity variants associated with increased transmissibility
Authors: Hark Gan Hin , Twaddle Alan , Marchand Benoit , Gunsalus Kristin C.
Published: March 2021

The COVID-19 pandemic has triggered concerns about the emergence of more infectious and pathogenic viral strains. As a public health measure, efficient screening methods are needed to determine the functional effects of new sequence variants. Here we show that structural modeling of SARS-CoV-2 Spike protein binding to the human ACE2 receptor, the first step in host-cell entry, predicts many novel variant combinations with enhanced binding affinities. By focusing on natural variants at the Spike-hACE2 interface and assessing over 700 mutant complexes, our analysis reveals that high-affinity Spike mutations (including N440K, S443A, G476S, E484R, G502P) tend to cluster near known human ACE2 recognition sites (K31 and K353). These Spike regions are conformationally flexible, allowing certain mutations to optimize interface interaction energies. Although most human ACE2 variants tend to weaken binding affinity, they can interact with Spike mutations to generate high-affinity double mutant complexes, suggesting variation in individual susceptibility to infection. Applying structural analysis to highly transmissible variants, we find that circulating point mutations S447N, E484K and N501Y form high-affinity complexes (~40% more than wild-type). By combining predicted affinities and available antibody escape data, we show that fast-spreading viral variants exploit combinatorial mutations possessing both enhanced affinity and antibody resistance, including S447N/E484K, E484K/N501Y and K417T/E484K/N501Y. Thus, three-dimensional modeling of the Spike/hACE2 complex predicts changes in structure and binding affinity that correlate with transmissibility and therefore can help inform future intervention strategies.
Species-specific developmental timing dictates expansion of the avian wing skeletal pattern
Authors: Stainton Holly , Towers Matthew
Published: March 2021

A fundamental question in biology is how species-specific rates of embryonic development are controlled in differently sized species. To address this problem, we compared wing development in the quail and the larger chick. We reveal that pattern formation (humerus to digits) is faster in the quail wing as determined by the earlier activation of 5’Hoxgenes, termination of developmental organisers (ShhandFgf8) and the laying down of the skeleton (Sox9). Using interspecies tissue grafts, we show that developmental timing can be reset during a critical window in which retinoic acid signalling is active. Accordingly, retinoic acid can switch developmental timing between the quail and chick, and also between the chick and the larger turkey. We show that the incremental growth rate is equivalent between all three species, suggesting that differences in the expansion of the skeletal pattern are governed primarily by the tempo of development. Our findings have implications for how development is timed both within and between different species.
TMPRSS2 inhibitor discovery facilitated through anin silicoand biochemical screening platform
Authors: Peiffer Amanda L. , Garlick Julie M. , Wu Yujin , Soellner Matthew B. , Brooks Charles L. , Mapp Anna K.
Published: March 2021

The COVID-19 pandemic has highlighted the need for new antiviral targets, as many of the currently approved drugs have proven ineffective against mitigating SARS-CoV-2 infections. The host transmembrane serine protease TMPRSS2 is a highly promising antiviral target, as it plays a direct role in priming the spike protein before viral entry occurs. Further, unlike other targets such as ACE2, TMPRSS2 has no known biological role. Here we utilize virtual screening to curate large libraries into a focused collection of potential inhibitors. Optimization of a recombinant expression and purification protocol for the TMPRSS2 peptidase domain facilitates subsequent biochemical screening and characterization of selected compounds from the curated collection in a kinetic assay. In doing so, we demonstrate that serine protease inhibitors camostat, nafamostat, and gabexate inhibit through a covalent mechanism. We further identify new non-covalent compounds as TMPRSS2 protease inhibitors, demonstrating the utility of a combined virtual and experimental screening campaign in rapid drug discovery efforts.
Environmental disclosure and firm efficiency: a study of Pakistani firms
Authors: Rahim Imad
Published: March 2021

Purpose

The purpose of this paper is to examine the effect of environmental disclosure on firm efficiency of the listed firms in Pakistan.

Design/methodology/approach

The study uses secondary sources such as sustainability reports, annual reports and company websites to collect the data. A sample of 46 large firms is selected based on market capitalization and listing on the KSE-100 index.

Findings

The results suggest that environmental disclosure plays a significant positive role in determining the efficiency of the listed firms. The robustness test also confirms these results.

Research limitations/implications

The study suggests that regulators should take appropriate steps for better and increase the firm's environmental disclosure. The number of sample firms restricts the generalization of results from this study. However, the results are consistent and can be validated using a large sample.

Practical implications

The study includes implications to develop strict guidelines on environmental disclosure in response to its positive effect on the efficiency of the firm.

Originality/value

The study contributes to the growing environmental and efficiency literature by providing empirical evidence from a developing country where there are no strict guidelines on environmental regulations. This study is one of the first to capture environmental disclosure and measure efficiency by employing the data envelopment analysis (DEA) method in developing markets.
Factors affecting decision-making in land valuation process using AHP: a case in the Philippines
Authors: Bencure Jannet C. , Tripathi Nitin K. , Miyazaki Hiroyuki , Ninsawat Sarawut , Kim Sohee Minsun
Published: March 2021

Purpose

The research aims to establish importance scheme of geospatial factors for land valuation activities that may serve as an eye-opener and aid the concerned government agencies in drafting land valuation policies and guidelines to achieve a sound land governance and administration. It specifically identifies and weighs geospatial valuation factors to establish their importance.

Design/methodology/approach

The research involves discussions and survey questionnaires given to land experts (i.e. appraisers, environmental planners, land economist, geodetic engineers and assessors) who indicated their opinions on influence of geospatial factors on land value. The analytic hierarchy process (AHP) is then used to weigh the factors in terms of its importance.

Findings

The result was then compared with the multiple regression analysis (MRA) taking into consideration the standardized regression coefficient of the 15 factors. The AHP method found out the major road accessibility and slope direction as the most and least influential factors, respectively, while surprisingly MRA found major road accessibility not significant at p < 0.05 level of significance.

Research limitations/implications

The research generally reflects the sub-urban type of study area; hence, inclusion of other road types such as express ways and subways and performing sensitivity analysis of AHP are suggested in future studies.

Practical implications

The findings of the study will provide information of concerned government agencies in improving valuation activities, as well as to update values regularly based on the geospatial factors.

Originality/value

To the best of the authors’ knowledge, this study is the first effort to rank geospatial factors with analytic hierarchy analytic process that further considered both their negative and positive influences on land value. The approach surmounts the flaw and shortcomings of empirical methods of identifying importance of factors.
The influence of board characteristics on environmental performance: evidence from East Asian manufacturing industries
Authors: Nguyen Linh-TX , Thanh Cuong-Le
Published: March 2021

Purpose

The purpose of this study is to examine the influence of board characteristics on environmental performance in manufacturing firms of the emerging East Asian markets. The authors adopt a triple perspective of environmental performance that focusses on three major environmental areas including resource reduction, emission reduction and product innovation.

Design/methodology/approach

The authors consider three main board characteristics, namely, board size, board independence and board leadership structure, and investigate their impacts on a multidimensional construct of environmental performance. Specifically, both linear and quadratic functions are applied to address a possibility of the non-linear relationship between board size and environmental performance. The authors use fixed-effects estimations on a sample of manufacturing firms in the emerging East Asian countries between 2011 and 2016.

Findings

The study explores an inverse U-shaped relationship between board size and environmental performance. The authors also reveal that manufacturing firms are more likely to have better environmental performance when the proportion of independent directors on board increases. However, the separation of CEO and board chair roles has no impact on environmental performance.

Practical implications

The findings have important implications by identifying the role of a board of directors in implementing environmental protection strategies and by providing a foundation for corporate efforts to enhance sustainable development.

Originality/value

The study provides complete understanding of environmental performance as a multidimensional construct and sheds light on the influence of board characteristics, especially the inverse U-shaped influence of board size, on environmental performance in the East Asian manufacturing industries.
Job demands-resources model, transformational leadership and organizational performance: a multilevel study
Authors: Katou Anastasia A. , Koupkas Michael , Triantafillidou Eleni
Published: March 2021

Purpose

The purpose of this paper is to integrate an extended by personal resource job demands-resources (JD-R) model in the relationship between transformational leadership and organizational performance. It is argued that the responsive, supportive and developmental leader's style will reduce employees' levels of burnout and increase their levels of work engagement and ultimately will increase organizational performance expressed by productivity, growth and creativity.

Design/methodology/approach

The hypotheses were tested among a national sample of 1,011 employees in 107 Greek public and private organizations operating within an environment of economic and financial crises. The operational model was tested using a multilevel structural equation modelling.

Findings

It appeared that job demands and work burnout and job resources and work engagement, serially and fully mediated the relationship between transformational leadership and organizational performance. Further, it is found that personal resources negatively and fully mediate the relationship between job resources and work burnout and positively and partially mediate the relationship between job resources and work engagement.

Research limitations/implications

Data were collected using a cross-sectional design, not allowing dynamic causal inferences.

Practical implications

Considering that the transformational leadership style reduces employees' levels of burnout and increases their levels of work engagement and accordingly improves organizational performance, organizations are well advised to encourage this leadership style.

Social implications

Transformational leadership by balancing job demands and job resources could have a positive impact on employee well-being.

Originality/value

The study, using multilevel testing, demonstrates that the extended JD-R model can be integrated into the transformational leadership– organizational performance relationship.
Contributions of entrepreneurial orientation in the use of agile methods in project management
Authors: Garcia Vanessa Mesquita Blas , Martens Cristina Dai Prá , Carvalho Rodrigo Baroni , Martens Mauro Luiz
Published: March 2021

Purpose

This paper aims to analyze the degree of contribution of the entrepreneurial orientation (EO) of organizations in the use of agile methods (AM) in project management.

Design/methodology/approach

A quantitative approach with the application of a survey with project professionals resulted in 206 valid answers. The data were analyzed using structural equation modeling and the method of partial least squares (PLS).

Findings

The results present empirical evidence of the significant contribution of EO in the use of AM in project management, confirming the main hypothesis of this study. This effect was not influenced by the control variables tested.

Research limitations/implications

This study contributes to the development of research on AM and minimizes the literature gap on the connection between entrepreneurship and AM. The results are limited to the sample. Studies with broader samples and different segments are suggested, as well as the contribution of each dimension of the EO to AM.

Practical implications

Innovativeness, risk-taking, proactiveness, autonomy and competitive aggressiveness (EO dimensions) can contribute to the use of AM and guide actions to develop these behaviors, pursuing better adherence to agile values and the use of AM in project management.

Originality/value

The originality of this study regarding the connection between EO and AM lies on the presentation of a theoretical model of this relationship and reduces the gap in this research field. Given the degree of EO contribution in AM (19.7%), there are other factors that affect the use of AM in project management that should be investigated.
2018 saw a sharp increase in air crash deaths: visualizing and evaluating risk
Authors: Anderson Joe , Williams Susan K.
Published: March 2021

Theoretical basis

Risk literacy matters for business students. A significant aspect of decision-making is accurately evaluating the risks involved in a decision. Research shows that many people are challenged to understand simple, health-relevant risk rates and probabilities. It also shows that many people are functionally innumerate, even educated people like doctors. While there is much academic work in health aimed at understanding how to communicate health risks to patients, an important personal area for business students, there are many industries and organizations where understanding risk is important for business students’ careers. This case provides opportunities for business students to practice these skills.

Research methodology

This is a secondary-data, compact case. The impetus for the case was a blog and the data gathered is primarily from Aviation Safety Net, Worldbank, Airlines.org, International Air Transport Association and Statista.com.

Case overview/synopsis

Coming across a blog headline, a professor is dismayed at the message: 2018 saw a sharp increase in air crash deaths. Questioning that the headline is appropriate and that the number of fatalities is an appropriate measure, the professor sets out to analyze airline safety data.

Complexity academic level

This case is intended for undergraduate or graduate students in an introductory business analytics course. The focus is on using and communicating risk rates and visualization.
Educator and dairy farmer: the psychological empowerment of entrepreneur V.G. Jayakrishnan
Authors: Shivarajan Sridevi
Published: March 2021

Theoretical basis

The psychological empowerment theory of intrinsic motivation is the primary theoretical basis for the case. Other theories discussed include personality theories and transformational leadership theory.

Research methodology

This is a field-researched case, based on face to face interviews with V.G. Jayakrishnan. The author also visited Jayakrishnan’s institution and attended an event there. The author also relied upon archival data in the form of newspaper reports: both print and video. The case is based on events before July 31, 2017.

Case overview/synopsis

This case examines how entrepreneur V.G. Jayakrishnan, between 1995–2017, set up two successful, yet distinct businesses, namely, ICD (Institute for Career Development), a leading banking test prepping center in Kerala, India and JK Farms, a state-of-the-art dairy farm. Jayakrishnan’s vision and ability to think far ahead of his competition led to ICD becoming one of the most successful banking test prep centers in Kerala, India. Similarly, Jayakrishnan’s vision of scientific dairy farming allowed him to set up the state of the art JK Farms. The case allows students to examine the concepts of intrinsic motivation and transformational leadership.

Complexity academic level

The case can be used both at the graduate and undergraduate levels. At the graduate level, it can be used at the beginning of any leadership class to foster discussion about intrinsic motivation and transformational leadership. At the undergraduate level, it would be better positioned at the middle of the organizational behavior course after the students have discussed the chapters on motivation, leadership and personality in principal textbooks (Colquitt, LePine and Wesson, McGraw Hill, 2018).
Local prey shortages drive foraging costs and breeding success in a declining seabird, the Atlantic puffin
Authors: Fayet Annette L. , Clucas Gemma V. , Anker‐Nilssen Tycho , Syposz Martyna , Hansen Erpur S.
Published: March 2021

As more and more species face anthropogenic threats, understanding the causes of population declines in vulnerable taxa is essential. However, long‐term datasets, ideal to identify lasting or indirect effects on fitness measures such as those caused by environmental factors, are not always available.

Here we use a single year but multi‐population approach on populations with contrasting demographic trends to identify possible drivers and mechanisms of seabird population changes in the north‐east Atlantic, using the Atlantic puffin, a declining species, as a model system.

We combine miniature GPS trackers with camera traps and DNA metabarcoding techniques on four populations across the puffins’ main breeding range to provide the most comprehensive study of the species' foraging ecology to date.

We find that puffins use a dual foraging tactic combining short and long foraging trips in all four populations, but declining populations in southern Iceland and north‐west Norway have much greater foraging ranges, which require more (costly) flight, as well as lower chick‐provisioning frequencies, and a more diverse but likely less energy‐dense diet, than stable populations in northern Iceland and Wales.

Together, our findings suggest that the poor productivity of declining puffin populations in the north‐east Atlantic is driven by breeding adults being forced to forage far from the colony, presumably because of low prey availability near colonies, possibly amplified by intraspecific competition. Our results provide valuable information for the conservation of this and other important North‐Atlantic species and highlight the potential of multi‐population approaches to answer important questions about the ecological drivers of population trends.
Targeting autophagy in neurodegenerative diseases: From molecular mechanisms to clinical therapeutics
Authors: Ajoolabady Amir , Aslkhodapasandhokmabad Hamid , Henninger Nils , Demillard Laurie J. , Nikanfar Masoud , Nourazarian Alireza , Ren Jun
Published: March 2021

Many neurodegenerative diseases are associated with pathological aggregation of proteins in neurons. Autophagy is a natural self‐cannibalization process that can act as a powerful mechanism to remove aged and damaged organelles as well as protein aggregates. It has been shown that promoting autophagy can attenuate or delay neurodegeneration by removing protein aggregates. In this paper, we will review the role of autophagy in Alzheimer's disease (AD), Parkinson's Disease (PD), and Huntington's Disease (HD) and discuss opportunities and challenges of targeting autophagy as a potential therapeutic avenue for treatment of these common neurodegenerative diseases.
Nonprofit Entrepreneurial Orientation in the Context of Cross‐Sector Collaboration
Authors: Al‐Tabbaa Omar , Ciulli Francesca , Kolk Ans
Published: March 2021

Triggered by budgetary challenges and growing awareness of social needs, recent years have seen increasing entrepreneurial behaviour in the nonprofit sector, of which collaboration with for‐profit organizations is a case in point. Yet, while extant research has extensively studied the entrepreneurial orientation (EO) of for‐profit organizations, scant attention has been paid to its manifestations in the cross‐sector collaboration context and from the nonprofit perspective, even though numerous nonprofit organizations’ idiosyncrasies point to the need for a reconceptualization of the EO dimensions in that domain. Thus, taking the nonprofit perspective, our research aims to explore the dynamics and nature of EO in the context of nonprofit–business collaboration (NBC), examining how the EO core dimensions manifest themselves when nonprofit organizations (NPOs) proactively engage in NBC. We unpack the meaning of EO through two complementary empirical studies. Our work nuances the rather overlooked entrepreneurial posture of so‐called ‘active‐in‐collaboration’ NPOs, exposes new meanings of collaborative EO dimensions (relational proactiveness, relational innovativeness and relational risk management), discusses their underpinning mechanisms and suggests promising areas for further research and implications for practice.
Diagnostic yield and safety of biopsy guided by electromagnetic navigation bronchoscopy for high‐risk pulmonary nodules
Authors: Oh Ju Hyun , Choi Chang‐Min , Kim Seulgi , Kim Woo Sung , Hwang Hee Sang , Jang Se Jin , Oh Sang Young , Kim Mi Young , Lee Jae Cheol , Ji Wonjun
Published: March 2021

Background

Electromagnetic navigation bronchoscopy (ENB) is a useful method to obtain tissue for peripheral lung nodules. We aimed to understand the diagnostic yield and safety profile in high‐risk pulmonary nodules that cannot be accessed by percutaneous transthoracic needle biopsy.

Methods

In this single‐center retrospective study, we reviewed patients who underwent ENB for high‐risk pulmonary nodules. All procedures were performed under moderate sedation using intravenous midazolam and fentanyl.

Results

A total of 100 pulmonary nodules in 90 patients were subjected to ENB between October 2018 and May 2020. The median age of the study population was 66 (59–73). The mean diameter of the lung nodules was 27.9 mm. The diagnostic yield of ENB‐guided biopsy was 53.0%. Although the nodule size (odds ratio: 1.055, p = 0.007) and positive bronchus sign (odds ratio: 2.918, p = 0.020) were associated with the diagnostic yield during univariate analysis, nodule size was the only independent variable on the multivariable analysis. Interestingly, the diagnostic yield showed an upward trend after 60 cases, from 45%–65%. Procedure‐related complications were reported in 16 cases; among these, pneumothorax occurred in three cases, and four cases experienced moderate bleeding. No instance of major bleeding or death was linked to ENB‐guided biopsy.

Conclusion

ENB‐guided biopsy for high‐risk pulmonary nodules demonstrated an acceptable diagnostic yield and good safety profile. Moreover, the diagnostic yield was associated with nodule size and procedure experience.