bluuebunny/crossref_metadata_2025 huggingface dataset:
The sperm epigenome does not display recurrent epimutations in patients with severely impaired spermatogenesis
Authors: Leitão Elsa , Persio Sara Di , Laurentino Sandra , Wöste Marius , Dugas Martin , Kliesch Sabine , Neuhaus Nina , Horsthemke Bernhard
Published: February 2020

Background

In the past 15 years, numerous studies have described aberrant DNA methylation of imprinted genes (e.g.MESTandH19) in sperm of infertile patients, but the prevalence and genomic extent of abnormal methylation patterns have remained unknown.

Results

Using deep bisulfite sequencing (DBS), we screened swim-up sperm samples from 40 normozoospermic and 93 oligoasthenoteratozoospermic (OAT) patients forH19andMESTmethylation. Based on this screening, we defined three patient groups: normal controls (NC), abnormally methylated infertile (AMI; n=7) and normally methylated infertile (NMI; n=86). Whole genome bisulfite sequencing (WGBS) of five NC and five AMI samples revealed abnormal methylation levels of all 50 imprinting control regions in each AMI sample. To investigate whether this finding reflected epigenetic germ line mosaicism or the presence of residual somatic DNA, we made a genome-wide inventory of soma-germ cell specific DNA methylation. We found that >2,000 germ cell-specific genes are promoter-methylated in blood and that AMI samples had abnormal methylation levels at these genes, consistent with the presence of somatic cell DNA. The comparison between the five NC and six NMI samples revealed 19 differentially methylated regions (DMRs), none of which could be validated in an independent cohort of 40 men. Previous studies reported a higher incidence of epimutations at single CpG sites in the CTCF-binding region 6 ofH19in infertile patients. DBS analysis of this locus, however, revealed an association between DNA methylation levels and genotype (rs2071094), but not fertility phenotype.

Conclusions

Our results suggest that somatic DNA contamination and genetic variation confound methylation studies in sperm of infertile men. While we cannot exclude the existence of rare patients with slightly abnormal sperm methylation at non-recurrent CpG sites, the prevalence of aberrant methylation in swim-up purified sperm of infertile men has likely been overestimated, which is reassuring for patients undergoing assisted reproduction.
Voltage-gated calcium channel subunit α2δ-3 shapes light responses of mouse retinal ganglion cells mainly in low and moderate light levels
Authors: Seitter Hartwig , Sothilingam Vithiyanjali , Benkner Boris , Garrido Marina Garcia , Kling Alexandra , Pirone Antonella , Seeliger Mathias , Münch Thomas A.
Published: February 2020

Little is known about the function of the auxiliary α2δ subunits of voltage-gated calcium channels in the retina. We investigated the role of α2δ-3 (Cacna2d3) using a mouse in which α2δ-3 was knocked out by LacZ insertion. Behavior experiments indicated a normal optokinetic reflex in α2δ-3 knockout animals. Strong expression of α2δ-3 could be localized to horizontal cells using the LacZ-reporter, but horizontal cell mosaic and currents carried by horizontal cell voltage-gated calcium channels were unchanged by the α2δ-3 knockout.In vivoelectroretinography revealed unaffected photoreceptor activity and signal transmission to depolarizing bipolar cells. We recorded visual responses of retinal ganglion cells with multi-electrode arrays in scotopic to photopic luminance levels and found subtle changes in α2δ-3 knockout retinas. Spontaneous activity in OFF ganglion cells was elevated in all luminance levels. Differential response strength to high- and low-contrast Gaussian white noise was compressed in ON ganglion cells during mesopic ambient luminance and in OFF ganglion cells during scotopic and mesopic ambient luminances. In a subset of ON ganglion cells, we found a sharp increase in baseline spiking after the presentation of drifting gratings in scotopic luminance. This increase happened after gratings of different spatial properties in knockout compared to wild type retinas. In a subset of ON ganglion cells of the α2δ-3 knockout, we found altered delays in rebound-like spiking to full-field contrast steps in scotopic luminance. In conclusion, α2δ-3 seems to participate in shaping visual responses mostly within brightness regimes when rods or both rods and cones are active.
Amyloid aggregates accumulate in melanoma metastasis driving YAP mediated tumor progression
Authors: Matafora Vittoria , Farris Francesco , Restuccia Umberto , Tamburri Simone , Martano Giuseppe , Bernardelli Clara , Pisati Federica , Casagrande Francesca , Lazzari Luca , Marsoni Silvia , Bonoldi Emanuela , Bachi Angela
Published: February 2020

Melanoma progression is generally associated to increased Yes-associated protein (YAP) mediated transcription. Actually, mechanical signals from the extracellular matrix are sensed by YAP, which activates proliferative genes expression, promoting melanoma progression and drug resistance. Which and how extracellular signals induce mechanotransduction is not completely understood.

Herein, by secretome studies, we revealed an extracellular accumulation of amyloidogenic proteins, i.e. premelanosome protein (PMEL), together with proteins that assist amyloids maturation into fibrils. Indeed, we confirmed the presence of amyloid-like aggregates similar to those detected in Alzheimer disease. These aggregates were enriched in metastatic cell lines as well as in human melanoma biopsies, compared to their primitive counterpart. Mechanistically, we proved that beta-secretase (BACE) regulates the maturation of these aggregates and that its inhibition hampers YAP activity. Moreover, recombinant PMEL fibrils induce per se mechanotransduction promoting YAP activation. Finally, BACE inhibition affects cell proliferation and increases drug sensitivity. These results highlight the importance of amyloids for melanoma survival and the potential of beta-secretase inhibitors as new therapeutic approach to metastatic melanoma.
A multimodal computational pipeline for 3D histology of the human brain
Authors: Mancini Matteo , Casamitjana Adrià , Peter Loic , Robinson Eleanor , Crampsie Shauna , Thomas David L. , Holton Janice L. , Jaunmuktane Zane , Iglesias Juan Eugenio
Published: February 2020

Ex vivoimaging enables analysis of the human brain at a level of detail that is not possiblein vivowith MRI. In particular, histology can be used to study brain tissue at the microscopic level, using a wide array of different stains that highlight different microanatomical features. Complementing MRI with histology has important applications inex vivoatlas building and in modeling the link between microstructure and macroscopic MR signal. However, histology requires sectioning tissue, hence distorting its 3D structure, particularly in larger human samples. Here, we present an open-source computational pipeline to produce 3D consistent histology reconstructions of the human brain. The pipeline relies on a volumetric MRI scan that serves as undistorted reference, and on an intermediate imaging modality (blockface photography) that bridges the gap between MRI and histology. We present results on 3D histology reconstruction of a whole human hemisphere.
Shedding light on the control of CatSper Ca2+channels by cAMP and chemicals used to probe cAMP signaling
Authors: Wang Tao , Young Samuel , Tüttelmann Frank , Röpke Albrecht , Krallmann Claudia , Kliesch Sabine , Zeng Xu-Hui , Brenker Christoph , Strünker Timo
Published: February 2020

The sperm-specific CatSper channel controls the influx of Ca2+into the flagellum and, thereby, the swimming behavior of sperm. A hallmark of human CatSper is its polymodal activation by membrane voltage, intracellular pH, and oviductal hormones. Whether CatSper is also activated by signaling pathways involving an increase of cAMP and ensuing activation of protein kinase A (PKA) is, however, a matter of controversy. Here, using kinetic ion-sensitive fluorimetry and patch-clamp recordings, we study transmembrane Ca2+flux and membrane currents in human sperm from healthy donors and from patients that lack functional CatSper channels. We show that human CatSper is neither activated by intracellular cAMP directly nor indirectly by the cAMP/PKA-signaling pathway. Moreover, we demonstrate that non-physiological concentrations of cAMP and membrane-permeable cAMP analogs used to mimic the action of intracellular cAMP activate human CatSper from the outside via a previously unknown extracellular cyclic nucleotide-binding site. Finally, we demonstrate that the effects of common PKA inhibitors on human CatSper rest on off-target drug actions on CatSper itself rather than on inhibition of PKA. We conclude that the concept of an intracellular cAMP/PKA-activation of CatSper is primarily based on unspecific effects of chemical probes used to interfere with cAMP signaling. Altogether, our findings solve several controversial issues, which has important bearings on future studies of cAMP and Ca2+signaling and the ligand-control of CatSper in sperm.
Accurate, scalable cohort variant calls using DeepVariant and GLnexus
Authors: Yun Taedong , Li Helen , Chang Pi-Chuan , Lin Michael F. , Carroll Andrew , McLean Cory Y.
Published: February 2020

Population-scale sequenced cohorts are foundational resources for genetic analyses, but processing raw reads into analysis-ready variants remains challenging. Here we introduce an open-source cohort variant-calling method using the highly-accurate caller DeepVariant and scalable merging tool GLnexus. We optimized callset quality based on benchmark samples and Mendelian consistency across many sample sizes and sequencing specifications, resulting in substantial quality improvements and cost savings over existing best practices. We further evaluated our pipeline in the 1000 Genomes Project (1KGP) samples, showing superior quality metrics and imputation performance. We publicly release the 1KGP callset to foster development of broad studies of genetic variation.
Long-read Individual-molecule Sequencing Reveals CRISPR-induced Genetic Heterogeneity in Human ESCs
Authors: Bi Chongwei , Wang Lin , Yuan Baolei , Zhou Xuan , Pang Yu , Li  , Wang Sheng , Gao Yuhong Xin , Huang Yanyi , Li Mo
Published: February 2020

Accurately quantifying the genetic heterogeneity of a cell population is essential to understanding of biological systems. We develop a universal method to label individual DNA molecules for analyzing diverse types of rare genetic variants, with frequency as low as 4×10−5, using short- or long-read sequencing. It enables base-resolution haplotype-resolved quantitative characterization of rare variants. It provides the first quantitative evidence of persistent nonrandom large deletions and insertions following DNA repair of double-strand breaks induced by CRISPR-Cas9 in human pluripotent stem cells.
Cell cycle-associated expression patterns predict gene function in mycobacteria
Authors: Bandekar Aditya C. , Subedi Sishir , Ioerger Thomas R. , Sassetti Christopher M.
Published: February 2020

While the major events in prokaryotic cell cycle progression are likely to be coordinated with transcriptional and metabolic changes, these processes remain poorly characterized. Unlike many rapidly-growing bacteria, DNA replication and cell division are temporally-resolved in mycobacteria, making these slow-growing organisms a potentially useful system to investigate the prokaryotic cell cycle. To determine if cell-cycle dependent gene regulation occurs in mycobacteria, we characterized the temporal changes in the transcriptome of synchronously replicating populations ofMycobacterium tuberculosis(Mtb). By enriching for genes that display a sinusoidal expression pattern, we discover 485 genes that oscillate with a period consistent with the cell cycle. During cytokinesis, the timing of gene induction could be used to predict the timing of gene function, as mRNA abundance was found to correlate with the order in which proteins were recruited to the developing septum. Similarly, the expression pattern of primary metabolic genes could be used to predict the relative importance of these pathways for different cell cycle processes. Pyrimidine synthetic genes peaked during DNA replication and their depletion caused a filamentation phenotype that phenocopied defects in this process. In contrast, the IMP dehydrogenaseguaB2dedicated to guanosine synthesis displayed the opposite expression pattern and its depletion perturbed septation. Together, these data imply obligate coordination between primary metabolism and cell division, and identify periodically regulated genes that can be related to specific cell biological functions.
Diverse homeostatic and immunomodulatory roles of immune cells in the developing mouse lung revealed at single cell resolution
Authors: Domingo-Gonzalez Racquel , Zanini Fabio , Che Xibing , Liu Min , Jones Robert C. , Swift Michael A. , Quake Stephen R. , Cornfield David N. , Alvira Cristina M.
Published: February 2020

At birth, the lungs experience a sudden transition from a pathogen-free, hypoxic, fluid-filled environment to a pathogen-rich, rhythmically distended air-liquid interface. While many studies focus on adult tissue, the heterogeneity of immune cells in the perinatal lung remains unexplored. Here, we combine single cell transcriptomics within situhybridization to present an atlas of the murine lung immune compartment during a critical period of lung development. We show that the late embryonic lung is dominated by specialized proliferative macrophages with a surprising physical interaction with the developing vasculature. These macrophages disappear after birth and are replaced by a complex and dynamic mixture of macrophage subtypes, dendritic cells, granulocytes, and lymphocytes. Detailed characterization of macrophage diversity revealed a precise orchestration of five distinct subpopulations across postnatal development to fill context-specific functions in tissue remodeling, angiogenesis, and immunity. These data both broaden the putative roles for immune cells in the developing lung and provide a framework for understanding how external insults alter immune cell phenotype during a period of rapid lung growth and heightened vulnerability.
FOXO Transcription Factors Activate Alternative Major Immediate Early Promoters to Induce Human Cytomegalovirus Reactivation
Authors: Hale Andrew E , Collins-McMillen Donna , Lenarcic Erik M , Kamil Jeremy P , Goodrum Felicia , Moorman Nathaniel J
Published: February 2020

A key step during viral reactivation from latency is the re-expression of viral genes. Hematopoietic progenitor cells (HPCs) support human cytomegalovirus (HCMV) latency, and their differentiation triggers cellular cues that drive reactivation. A key step during HCMV reactivation in latently infected HPCs is re-expression of viral genes. We recently determined that the major immediate early promoter (MIEP), which is primarily responsible for MIE gene expression during lytic replication, remains silent during reactivation. Instead, alternative promoters in the MIE locus are induced by reactivation stimuli. Here, we find that forkhead family (FOXO) transcription factors are critical for activation of alternative MIE promoters during HCMV reactivation, as mutating FOXO binding sites in alternative MIE promoters decreased HCMV IE gene expression upon reactivation and significantly decreased the production of infectious virus from latently infected primary CD34+HPCs. These findings establish a mechanistic link by which infected cells sense environmental cues to regulate latency and reactivation, and emphasize the role of contextual activation of alternative MIE promoters as the primary drivers of reactivation.

Significance

Human cytomegalovirus infection is lifelong and persistent. Periodic reactivation of cytomegalovirus poses serious disease risk for immune-compromised patients. A critical driver of reactivation is expression of viral genes from the major immediate early locus. Recent paradigm-shifting evidence shows that reactivation is driven from promoters distinct from those that drive replication in permissive cells. Understanding the contextual control of these promoters and how they specifically respond to cellular cues that drive reactivation is critical for establishing future therapies that prevent reactivation. Our findings mechanistically define a previously enigmatic relationship between differentiation and reactivation, and provide potential targets for therapeutic intervention to prevent HCMV reactivation and disease.
Ecological success of sexual and asexual reproductive strategies invading an environmentally unstable habitat
Authors: Silva Willian T.A.F. , Nyqvist Anna , Jonsson Per R. , Harding Karin C.
Published: February 2020

Many aspects of sexual and asexual reproduction have been studied empirically and theoretically. The differences between sexual and asexual reproduction within a species often lead to a biased geographical distribution of individuals with different reproductive strategies. While sexuals are more abundant in the core habitat, asexuals are often found in marginal habitats along the edge of the species distribution. This pattern, called geographic parthenogenesis, has been observed in many species but the mechanisms reponsible for generating it are poorly known. We used a quantitative approach using a metapopulation model to explore the ecological processes that can lead to geographic parthenogenesis and the invasion of new habitats by different reproductive strategies. We analyzed the Allee effect on sexual populations and the population sensitivity to environmental stress during the invasion of a marginal, unstable habitat to demonstrate that a complex interaction between the Allee effect, sensitivity to environmental stress and the environmental conditions can determine the relative success of competing reproductive strategies during the initial invasion and longterm establishment in the marginal habitat. We discuss our results in the light of previous empirical and theoretical studies.

Author Summary

Individuals can reproduce with or without sex. Very often, closely related species are distributed in a such a way that the sexually reproducing species is most frequently found in the core habitat while the asexually reproducing species is found on the edge of the habitat range. This biased distribution of reproductive strategies across a habitat range is called geographic parthenogenesis and has been observed in several species. While many processes have been proposed to explain such a pattern, a quantitative approach of the ecological processes was absent. We investigated important differences between sexual and asexual reproduction and how these differences affect the success of sexuals and asexuals invading a marginal, unstable environment. We showed that the relative frequency of each reproductive strategy in the marginal habitat depends on how much sexuals rely on population density to reproduce and how much asexuals are affected by environmental stress relative to sexuals. Our study presents a quantitative ecological explanation for geographic parthenogenesis and provides the conditions under which different distribution patterns can emerge.
Cell phone digital microscopy using an oil droplet
Authors: Szydlowski Nicole Anna , Jing Haoran , Alqashmi Mohamed , Hu Ying Samuel
Published: February 2020

We introduce an accessible imaging method using droplets of microscope immersion and consumer-grade oils and a cell phone camera. We found that oil droplets were more resistant to evaporation than water droplets. We characterized the transverse magnification of oil and water droplets using cell phone screens and a resolution target. We further harnessed the close refractive index of cooking oils to that of the immersion oil and demonstrated their use as lenses for cell phone microscopy. Our method enables stable droplet-based optical imaging without specialized setups or manufacturing processes.
The fly liquid-food electroshock assay (FLEA) reveals opposite roles for neuropeptide F in avoidance of bitterness and shock
Authors: Mishra Puskar , Yang Shany E. , Montgomery Austin B. , Reed Addison R. , Rodan Aylin R. , Rothenfluh Adrian
Published: February 2020

Proper regulation of feeding is important for an organism’s well-being and survival. Food intake inDrosophilacan be determined in a number of ways, including by measuring the time a fly’s proboscis interacts with a food source in the fly liquid-food interaction counter (FLIC). Here, we show that electrical current flowing through flies during this interaction is aversive and leads to a reduction in food intake. Based on the FLIC, we engineer a novel assay, the fly liquid-food electroshock assay (FLEA), which allows for current adjustments for each feeding well. Using the FLEA, we show that both external incentives as well as internal motivational state can serve as drivers for flies to overcome higher current (electric shock) to obtain superior food. Unlike similar assays in which bitterness is the aversive stimulus for the fly to overcome, we show that current perception is not discounted as flies become more food-deprived. The FLEA is therefore a novel assay to accurately measure incentive motivation inDrosophila.Using the FLEA, we also show that neuropeptide F is required for proper perception or processing of an electroshock, a novel function for this neuropeptide involved in processing of external and internal stimuli.

Significance Statement

Many neuropsychiatric disorders, such as depression or addiction, are associated with alterations in motivated behavior. Assays measuring incentive motivation determine how driven an organism is to attain a goal, like food, or how attractive an incentive is. These tests require the animal to put effort into obtaining the reward, which can include physical work or overcoming an aversive stimulus. Such assays forDrosophilafeeding have relied on flies overcoming bitterness to obtain their food. However, the perception of bitterness is discounted as flies become food deprived, confounding the interpretation. Here, we developed a novel assay that does not suffer from the same shortcomings and thus allows for more accurate assessments of incentive motivation in this widely used model organism.
HDAC6 Regulates Radiosensitivity of Non-Small Cell Lung Cancer by Promoting Degradation of Chk1
Authors: Moses Niko , Zhang Mu , Wu Jheng-Yu , Hu Chen , Xiang Shengyan , Malysa Agnes , Jang Hyejeong , Chen Wei , Bai Wenlong , Bepler Gerold , Zhang Xiaohong Mary
Published: February 2020

We previously discovered that HDAC6 regulates the DNA damage response via modulating the homeostasis of a DNA mismatch repair protein, MSH2, through HDAC6’s ubiquitin E3 ligase activity. Here, we have reported HDAC6’s second E3 ligase substrate, a critical cell cycle checkpoint protein, Chk1. We have found that HDAC6 and Chk1 directly interact, and that HDAC6 ubiquitinates Chk1in vivo. Typical Chk1 protein levels fluctuate, peaking at G2 and subsequently resolving via the ubiquitin-proteasome pathway. However, in HDAC6 knockdown cells, Chk1 is constitutively active and fails to resolve post-ionizing radiation (IR), leading to increased radiation sensitivity. Upon IR treatment, a greater proportion of HDAC6 knockdown cells accumulated at G2/M phase when compared with control cells. Depletion or inhibition of Chk1 in HDAC6 knockdown cells renders those cells radiosensitive, suggesting that persistently high level of Chk1 could lead cells to arrest at G2/M phase and eventually, apoptosis. Clinically, we found that high levels of phosphorylated Chk1 (p-Ser317) are associated with a better overall survival in a cohort of non-small cell lung cancer (NSCLC) patients, suggesting a link between active Chk1 and lung cancer development. Overall, our results highlight a novel mechanism of Chk1 regulation at the protein level, and a possible strategy for sensitizing NSCLC to radiation via inhibiting the activity of HDAC6’s E3 ligase.
Correlating nuclear morphology and external force with combined atomic force microscopy and light sheet imaging separates roles of chromatin and lamin A/C in nuclear mechanics
Authors: Hobson Chad M. , Kern Megan , O’Brien E. Timothy , Stephens Andrew D. , Falvo Michael R. , Superfine Richard
Published: February 2020

Nuclei are constantly under external stress – be it during migration through tight constrictions or compressive pressure by the actin cap – and the mechanical properties of nuclei govern their subsequent deformations. Both altered mechanical properties of nuclei and abnormal nuclear morphologies are hallmarks of a variety of disease states. Little work, however, has been done to link specific changes in nuclear shape to external forces. Here, we utilize a combined atomic force microscope and light sheet microscope (AFM-LS) to show SKOV3 nuclei exhibit a two-regime force response that correlates with changes in nuclear volume and surface area, allowing us to develop an empirical model of nuclear deformation. Our technique further decouples the roles of chromatin and lamin A/C in compression, showing they separately resist changes in nuclear volume and surface area respectively; this insight was not previously accessible by Hertzian analysis. A two-material finite element model supports our conclusions. We also observed that chromatin decompaction leads to lower nuclear curvature under compression, which is important for maintaining nuclear compartmentalization and function. The demonstrated link between specific types of nuclear morphological change and applied force will allow researchers to better understand the stress on nuclei throughout various biological processes.
Mapping short reads, faithfully
Authors: Zorita Eduard Valera , Cortini Ruggero , Filion Guillaume J.
Published: February 2020

Mapping is the process of finding the original location of a DNA read in a reference sequence, typically a genome. Short read mappers are software tools used in most applications that involve high-throughput sequencing. As such, they must be continuously improved to keep up with increasing needs. Modern mappers rely on seeding heuristics, making them fast but inexact. For lack of a method to compute the reliability of their own output, mappers have so far used approximations of variable quality. Here we focus on faithfulness, the capacity to provide accurate mapping confidence, and we devise a strategy to map short reads faithfully. The key is to estimate the repetitiveness of the target reference, which is the dominant factor for the reliability of the mapping process. This approach highlights the existence of a class of reads that can be mapped with unprecedented confidence. We exploit this strategy in a prototype mapper that is competitive with state-of-the-art mappers BWA-MEM and Bowtie2, with the benefit of faithfulness. The software is open-source and available for download athttps://github.com/gui11aume/mmp.
Recent bloom of filamentous algae in Lake Baikal is caused bySpirogyraLink., 1820 of local origin
Authors: Mincheva Elena , Peretolchina Tatiana , Triboy Tatyana , Bukin Yrij , Kravtsova Luybov , Fedotov Andrey , Sherbakov Dmitry
Published: February 2020

Molecular phylogeny inferred fromrbcL nucleotide sequences obtained from the single sterile filaments of green algae collected around the perimeter of Lake Baikal indicates the polyphyletic origin of the representatives of genusSpirogyraLink., 1820 inhabiting the lake. The common ancestor of all Baikal Spirogyra dates back at least to 20 MYA. This roughly coincides with the age of continuously existing freshwater body in the confines of current Baikal. The descendants of this node include both Baikal and non-Baikal species and thus suggesting a complex history of multiple emigrations and immigrations. There is at least one major lineage of the BaikalSpirogyrain the phylogeny descending uninterruptedly from the common ancestor of allSpirogyraspecies found so far in the lake. The likely explanation is its permanent presence in the ecosystem. All this allows us to hypothesize that the current bloom is a spectacular but natural response of the Baikal ecosystem to the increased pollution.
Internal water storage buffering maintains plant function under drought as described by a general hydraulic model
Authors: Kaner Avigail , Preisler Yakir , Grünzweig José M , Mau Yair
Published: February 2020

Internal water storage is of crucial importance for plants under drought stress, allowing them to temporarily maintain transpiration higher than root-uptake flow, thus potentially keeping a positive carbon balance. A deep understanding of this adaptation is key for predicting the fate of ecosystems subjected to climate change-induced droughts of increasing intensity and duration. Using a minimalistic model, we derive predictions for how environmental drivers (atmospheric demand and soil water availability) interplay with the water storage, creating time lags between the flows in the plant, and granting the plant increased hydraulic safety margin protecting its xylem from embolism. We parametrize our model against transpiration and sap flow measurements in a semi-arid pine forest during seasonal drought. From the parametrized whole-stand traits, we derive a 3.7-hour time lag between transpiration and sap flow, and that 31% of daily transpiration comes directly from the plant's internal water storage, both corroborated by the measurements. Due to the model simplicity, our results are useful for interpreting, analyzing, and predicting the effects of the internal storage buffering from the individual plant to the ecosystem scale. Because internal storage produces survival-enhancing behavior in sub-daily time scales, it is an indispensable component for modeling ecosystems under drought stress.
Modelling phase imperfections in compound refractive lenses
Authors: Celestre Rafael , Berujon Sebastien , Roth Thomas , Sanchez del Rio Manuel , Barrett Raymond
Published: February 2020

A framework based on physical optics for simulating the effect of imperfect compound refractive lenses (CRLs) upon an X-ray beam is described, taking into account measured phase errors obtained from at-wavelength metrology. A CRL stack is modelled, with increasing complexity, as a single thin phase element, then as a more realistic compound element including absorption and thickness effects, and finally adding realistic optical imperfections to the CRL. Coherent and partially coherent simulations using Synchrotron Radiation Workshop (SRW) are used to evaluate the different models, the effects of the phase errors and to check the validity of the design equations and suitability of the figures of merit.
Multiple Bragg reflection by a thick mosaic crystal. Corrigendum
Authors: Wuttke Joachim
Published: February 2020

An inconsistent approximation in Wuttke [Acta Cryst. (2014), A70, 429–440] is corrected. Section 3.5 on the polar angle random walk is withdrawn.
2,2′-[Methylenebis(sulfanediyl)]bis(pyridine 1-oxide)
Authors: Siegel David J. , Howarth Alexis N. , Traver Joseph R. , Hillesheim Patrick C. , Zeller Matthias , Mirjafari Arsalan
Published: February 2020

The title compound, C11H10N2O2S2, crystallizes with one complete molecule in the asymmetric unit. In the crystal, weak hydrogen bonding is observed between the N-oxide moieties and several C—H units.
Putting employees at the centre of sustainable HRM: a review, map and research agenda
Authors: Richards James
Published: February 2020

Purpose

Currently, sustainable HRM is largely an employer-driven exercise based on raising employee productivity. The purpose of the article is to expand this position by fully mapping out sustainable HRM and placing employees at the centre of such practices. A further purpose is to provide a research agenda suited to a wider take on sustainable HRM.

Design/methodology/approach

The article centres on an analytical review of extant sustainable HRM literature, plus an analytical review of wider literature considering further ways to sustain employment.

Findings

Employee-centred sustainable HRM goes far beyond what is accounted for in the extant HRM literature. The new map accounts for wider parties to sustainable HRM, including trade unions and self-organised employees. An extensive research agenda is a further key output from the study.

Research limitations/implications

The article is based on a literature review. Follow-up empirical research is required to test out aspects of the new map, as well as address research gaps identified by the review.

Practical implications

The findings have practical implications for HRM and occupational health practitioners, line managers, built environment and ergonomics specialists, governments, trade unions and workplace activists. A key practical implication is the potential to create micro-forms of corporatism, where wider political structures are absent, to foster employee-centred forms of sustainable HRM.

Originality/value

The article is novel in terms of drawing on a wide range of incongruous literature and synthesising the literature into a new map and an extensive research agenda.
Managerial skills and performance in small businesses: the mediating role of organizational climate
Authors: Mehralian Gholamhossein , Peikanpour Mohammad , Rangchian Maryam , Aghakhani Hamed
Published: February 2020

Purpose

The purpose of this paper is to develop a conceptual model to determine whether organizational climate (OC) mediates the effect of managerial skills (MSs) on business performance in small businesses, such as pharmacies.

Design/methodology/approach

The model proposed in this research was tested using separate questionnaires specifically designed for managers, employees and clients. The data set consists of responses from 301 managers, 470 clients and 328 employees from community pharmacies in Tehran, capital of Iran, which were analyzed using structural equation modeling.

Findings

Although the results indicated no significant direct relationship between MSs and pharmacy performance (PP), they also confirmed that having a context-appropriate set of MSs can positively affect PP via the mediating effect of OC.

Originality/value

This is the first study investigating how MSs improve performance in retail pharmacies. Although this research focuses specifically on small businesses in the pharmaceutical industry, it nevertheless contributes to the literature by showing the importance of OC.
The platform economy as a working opportunity for older people
Authors: Berde Éva , Tőkés László
Published: February 2020

Purpose

The purpose of this paper is to show that gig jobs could be considered an alternative way, albeit not the very best, to give work opportunities to older people. This could offset the continuously decreasing income from the pay-as-you-go pension system, which remains the main source of income for older Hungarians.

Design/methodology/approach

The paper reviews the most important aspects of employment of older people and highlights the digital divide which still restricts their participation in the labor market. The paper analyzes data from the Hungarian carpooling company Oszkár and compares it with official statistical data from the Hungarian labor market, focusing on the dynamics of the employment of older persons.

Findings

The findings show that the alienation of older workers from the gig economy is just transitory, and that an increasing proportion of older gig workers can be anticipated.

Research limitations/implications

Compiling data on the gig economy faces a number of obstacles, as enterprises are disincentivized from revealing all their data.

Social implications

Older people are more likely to be employed in lower-quality jobs, such as own-account self-employed. They are also increasingly more likely to become gig workers.

Originality/value

The paper articulates the importance of remaining active as one ages and moreover challenges the traditional belief that gig jobs mainly offer opportunities to the younger generations.
Contraceptive discontinuation in Egypt as fertility returns to its 2000 level
Authors: Khalifa Mona , Hussein Wafaa Abdel Aziz , Metwally Soha
Published: February 2020

Purpose

The similarity of family planning (FP) indicators from EDHS2014 to that of EDHS2000 is alarming for policymakers and researchers who consider it as an echo of the past and a threat, which the FP programme has to face to prevent its progression. In 2000, the total fertility rate (TFR) was 3.5, the contraceptive prevalence rate was 56.1% and the discontinuation rate was 29.5%. In 2014, these indicators were 3.5, 58.5 and 30.1%, respectively. Although the change in the all method discontinuation rate is not large, it is a result of great changes in the method specific discontinuation rates, which was masked by changes in the contraceptive method mix. This study aims to present a comparison between contraceptive discontinuation rates in 2000, 2008 and 2014, discuss the reasons for discontinuation by methods and background characteristics of women and calculate the impact of eliminating discontinuation for reasons related to method and service provision on fertility.

Design/methodology/approach

Single/multiple decrement life tables were applied to the calendar data of the EDHS2008 and EDHS2014, to examine various net rates of contraceptive discontinuation by reasons and the status after discontinuation. The TFR estimated in the absence of method failure and abandonment while in need of births occurred within 24 months after discontinuation using installed Stata command tfr2.

Findings

The study estimates the impact of discontinuation on the TFR in 2014 to be an increase of about 20%. The TFR of 3.5 would have been only 2.8 if discontinuation due to method failure and method/service-related reasons were eliminated. Improvement regarding discontinuation behaviour is evident by increased switching, from 43.6 to 54.3% and the drop in the proportion of abandoning use while in need from 56.4 to 45.7%. Differentials suggest that discontinuation is expected to increase among vulnerable groups as desired fertility continues to rise. The increase in the share of “desire to become pregnant” – as a reason for discontinuation is a recent trend observed during the period between EDHS2008 and EDHS2014 and is recognised as a challenge by the national population strategy.

Originality/value

This study confirms that contraceptive discontinuation is an important part of the overall fertility increase observed by EDHS2014. The rising trend of increased desired family size and the shift away from using the intra uterine device may be considered as major challenges facing the FP programme in Egypt.
Product design matters, but is it enough? Consumers’ responses to product design and environment congruence
Authors: Naderi Ehsan , Naderi Iman , Balakrishnan Bimal
Published: February 2020

Purpose

This study aims to investigate the combined effects of product design and environment congruence on consumers’ aesthetic, affective and behavioral responses.

Design/methodology/approach

Two lab experiments with a 2 (high-level design cues vs low-level design cues) × 2 (congruent environment vs non-congruent environment) between-subjects design were conducted to test the hypotheses. The experimental stimuli (product: digital camera; environment: product display in a retail environment) were presented in a 3D simulation environment using a large TV (Experiment 1) and a stereoscopic virtual reality headset.

Findings

The results support the notion that product design cues elicit more positive aesthetic and affective responses. Environment congruence, on the other hand, plays a moderating role; product design cues elicit more favorable consumer responses in a congruent environment. In contrast, no such effect was found in a non-congruent environment.

Practical implications

Creating a congruent environment is only effective for well-designed products. In contrast, for products with low-level design elements, the congruence of promotional environment is not instrumental and may not elicit more favorable responses. Hence, such products can simply be presented in a generic display, especially considering the significant costs associated with designing, building and setting up a congruent display.

Originality/value

Despite the empirical findings supporting the significant role of product design and environment congruence on consumers’ perceptual and behavioral responses, there is a paucity of research on the combined effect of these two factors. The present investigation is an attempt to fill this gap and challenges the generalizations made in previous research suggesting that a product’s environment must be aligned with the design elements embedded in the product.
Authentic leadership and meaningfulness at work
Authors: Chaudhary Richa
Published: February 2020

Purpose

This study aims to examine whether, how, and when authentic leadership shapes followers' perceptions of meaningfulness at work. Using authentic leadership theory, we posit that authentic leadership leads to more favorable perceptions of Corporate Social Responsibility (CSR), which, in turn, results in enhanced experiences of meaningfulness at work. In addition to studying authentic leadership as a driver of CSR perceptions, and hence meaningfulness, we also examine if followers' attributions of self-centered motives to organizational engagement in CSR moderates the above relationship.

Design/methodology/approach

In all, 368 employees from Indian IT industry participated in the survey. Data were analyzed usingProcess(Hayes 2013) in SPSS.

Findings

Results supported the hypothesized moderated mediation model by revealing that attribution of self-centered motives undermines the positive impact of authentic leadership on CSR perceptions, and, subsequently, meaningfulness.

Practical implications

By presenting CSR as a source of meaningfulness at work, this study establishes CSR as an important tool for fostering employee well-being. The internal corporate communication should emphasize how CSR activities of the organization represent core organizational values and organization’s genuine concern for the society.

Originality/value

The study adds to the leadership literature and integrates it with a divergent discipline of CSR by signifying the role of authentic leadership in the CSR process. By presenting a refined analysis of CSR in a developing country, this research expands the understanding of the expression of CSR in markets outside the developed core.
Additively manufactured textiles and parametric modelling by generative algorithms in orthopaedic applications
Authors: Ricotta Vito , Campbell Robert Ian , Ingrassia Tommaso , Nigrelli Vincenzo
Published: February 2020

Purpose

The purpose of this paper is to implement a new process aimed at the design and production of orthopaedic devices fully manufacturable by additive manufacturing (AM). In this context, the use of generative algorithms for parametric modelling of additively manufactured textiles (AMTs) also has been investigated, and new modelling solutions have been proposed.

Design/methodology/approach

A new method for the design of customised elbow orthoses has been implemented. In particular, to better customise the elbow orthosis, a generative algorithm for parametric modelling and creation of a flexible structure, typical of an AMT, has been developed.

Findings

To test the developed modelling algorithm, a case study based on the design and production of an elbow orthosis made by selective laser sintering was investigated. The obtained results have demonstrated that the implemented algorithm overcomes many drawbacks typical of the traditional computer aided design (CAD) modelling approaches. The parametric CAD model of the orthosis obtained through the new approach is characterised by a flexible structure with no deformations or mismatches and has been effectively used to produce the prototype through AM technologies.

Originality/value

The obtained results present innovative elements of originality in the CAD modelling sector, which can contribute to solving problems related to modelling for AM in different application fields.
The history of academic research in marketing and its implications for the future
Authors: Ratchford Brian T.
Published: February 2020

Purpose

The purpose of this study is to determine what the history of research in marketing implies for the reaction of the field to recent developments in technology due to the internet and associated developments.

Design/methodology/approach

This paper examines the introduction of new research topics over 10-year intervals from 1960 to the present. These provide the basic body of knowledge that drives the field at the present time.

Findings

While researchers have always borrowed techniques, they have refined them to make them applicable to marketing problems. Moreover, the field has always responded to new developments in technology, such as more powerful computers, scanners and scanner data, and the internet with a flurry of research that applies the technologies.

Research limitations/implications

Marketing will adapt to changes brought on by the internet, increased computer power and big data. While the field faces competition for other disciplines, its established body of knowledge about solving marketing problems gives it a unique advantage.

Originality/value

This paper traces the history of academic marketing from 1960 to the present to show how major changes in the field responded to changes in computer power and technology. It also derives implications for the future from this analysis.
Progress in microencapsulation of probiotics: A review
Authors: Yao Mingfei , Xie Jiaojiao , Du Hengjun , McClements David Julian , Xiao Hang , Li Lanjuan
Published: February 2020

The potential health benefits of probiotics may not be realized because of the substantial reduction in their viability during food storage and gastrointestinal transit. Microencapsulation can be used to enhance the resistance of probiotics to unfavorable conditions. A range of oral delivery systems has been developed to increase the level of probiotics reaching the colon including embedding and coating systems. This review introduces emerging strategies for the microencapsulation of probiotics and highlights the key mechanisms of their stress–tolerance properties. Recent in vitro and in vivo models for evaluation of the efficiency of probiotic delivery systems are also reviewed. Encapsulation technologies are required to maintain the viability of probiotics during storage and within the human gut so as to increase their ability to colonize the colon. These technologies work by protecting the probiotics from harsh environmental conditions, as well as increasing their mucoadhesive properties. Typically, the probiotics are either embedded inside or coated with food‐grade materials such as biopolymers or lipids. In some cases, additional components may be coencapsulated to enhance their viability such as nutrients or protective agents. The importance of having suitable in vitro and in vivo models to evaluate the efficiency of probiotic delivery systems is also emphasized.