bluuebunny/crossref_metadata_2025 huggingface dataset:
Viral load monitoring practices and correlates of viral non-suppression among children and young adolescents living with HIV in level five hospitals in Kiambu county, Kenya
Authors: Gachoka Lilian N. , Njoroge Anne
Published: June 2024

Background

HIV has been a major global public health issue among children and young adolescents living with HIV (CYALHIV), their viral suppression rates being lower compared to adults. Follow up through viral load monitoring may influence their health outcomes.

Objective

In a cross-sectional study we determined viral load monitoring practices and correlates of viral non-suppression of all CYALHIV in three level five hospitals in Kiambu county, Kenya

Methods

We abstracted data from electronic and paper medical records. Multivariable log binomial regression was used to estimate prevalence ratios (PR) and assess correlates of non-suppression. Adherence to viral load testing guidelines was assessed. Viral non-suppression was defined as a VL >1000c/ml.

Results

Of the 252 CYALHIV, the median age was 11 (IQR: 7-13) years. Fourteen had non-suppression at last assessment. Correlates of non-suppression included having previously had TB [aPR=4.25; 95% CI=1.41-12.8; p=0.01], ART side effects [aPR=3.01; 95% CI=1.37-6.62 p=0.006] and having received enhanced adherence counselling [aPR =5.32; 95% CI=2.00-14.15; p=0.001]. Being on Dolutegravir was significantly associated with a lower likelihood of non-suppression (aPR=0.35; CI:0.15-0.85: p = 0.021). Timing of baseline VL tests improved through the years though there were gaps in routine VL monitoring and follow-up on unsuppressed results.

Conclusion

At most current VL, 14% children were non-suppressed, higher than the 5% UNAIDS 2030 target. Special strategies on assessing and addressing corelates of non-suppression are essential for ART programs. Routine VL monitoring as per the guidelines was suboptimal despite increased access to VL testing, suggesting other barriers to VL monitoring.
Nonlinear spatial integration allows the retina to detect the sign of defocus in natural scenes
Authors: Goethals Sarah , Louboutin Awen , Hamlaoui Samy , Quetu Tom , Virgili Samuele , Goldin Matias A. , Baranton Konogan , Marre Olivier
Published: June 2024

Eye growth is regulated by the visual input. Many studies suggest that the retina can detect if a visual image is focused in front or behind the back of the eye, and modulate eye growth to bring it back to focus. How can the retina distinguish between these two types of defocus? Here we simulated how eye optics transform natural images and recorded how the isolated retina responds to different types of simulated defocus. We found that some ganglion cell types could distinguish between an image focussed in front or behind the retina, by estimating spatial contrast. Aberrations in the eye optics made spatial contrast, but not luminance, a reliable cue to distinguish these two types of defocus. Our results suggest a mechanism for how the retina can estimate the sign of defocus and provide an explanation for several results aiming at mitigating strong myopia by slowing down eye growth.
Spatial and directional tuning of serial dependence for tracking eye movements
Authors: Goettker Alexander , Stewart Emma E.M.
Published: June 2024

An attractive influence of past sensory experience on current behaviour has been observed in many domains, such as for perceptual decisions and motor responses. However, it is unclear what sort of information is integrated across trials, and the limits of this integration, especially for oculomotor behavior. Here we provide a detailed and systematic investigation of the spatial and directional tuning of serial dependence for oculomotor tracking. In a series of experiments, we measured oculomotor responses to sequences of movements: the first movement (the prior) could move at different velocities (5 or 15 deg/s), and could additionally vary in its spatial location or direction relative to the following movement. The second movement (the probe) always moved at the same velocity (10 deg/s) and was constant across all experiments. We observed that eye velocity for the probe movement was faster when following the fast prior compared to following the slow prior, replicating attractive serial dependence. Importantly, this effect stayed consistent for distances of up to 30 deg between probe and prior, strongly suggesting a retinotopic coordinate frame. When we manipulated the direction of the prior, we observed that the strength of the serial dependence on eye velocity as well as eye direction was modulated by the relative angle between prior and probe. We observed stronger serial dependence for prior directions more similar to the probe direction. The strength of the effect on eye velocity and eye direction was correlated, suggesting a shared mechanism controlling these effects. Across all experiments, we observed that even when the prior moved in the opposite direction to the probe, there was a residual attractive effect. This suggests that serial dependence for oculomotor tracking consists of two components, one retinotopic, direction-tuned component and one more general component that is not direction-specific.
Three’s a crowd: The relationship among endoparasites, an epibiont and theirDaphniahost
Authors: Hirshberg Ofir , Ben-Ami Frida
Published: June 2024

In freshwater communities, organisms interact in a variety of ways, including predation, competition and parasitism. Parasites are ubiquitous, playing an important role in shaping freshwater communities. Endoparasites live within internal organs of their host, while ectoparasites, also known as epibionts, are confined to the external part of the host’s body. We conducted a series of experiments to examine the relationship between endoparasites and epibionts using the crustaceanDaphnia magnaas host, the rotiferBrachionus rubensas epibiont and three species of endoparasites. First, we tested host preference of the epibiont betweenDaphniainfected by endoparasites and uninfectedDaphnia. Epibiont were found to attach more to uninfectedDaphniathan toDaphniainfected by the yeastMetschnikowia bicuspidata.On the other hand, epibionts attached more toDaphniainfected by the microsporidiumHamiltosporidium tvaerminnensisthan to uninfectedDaphnia. Second, we examined the effect of epibionts on the infection ofDaphniaby endoparasites. Infection prevalence tended to be higher, though not significantly, in the presence of epibionts. For two of the endoparasites,M. bicuspidataandH. tvaerminnensis, infection intensity (i.e., parasite spore production) was higher in the presence of epibionts. The infection intensity ofM. bicuspidataand the bacteriumPasteuria ramosawas affected by the time of death of theDaphnia(i.e., virulence). Finally, we examined the effects of endoparasites and epibionts on the survival and offspring production of theDaphnia. Both host survival and offspring production were negatively affected by the endoparasites, while epibionts did not seem to affect the fitness of their host.
Prediction of phase separation propensities of disordered proteins from sequence
Authors: von Bülow Sören , Tesei Giulio , Lindorff-Larsen Kresten
Published: June 2024

Phase separation is thought to be one possible mechanism governing the selective cellular enrichment of biomolecular constituents for processes such as transcriptional activation, mRNA regulation, and immune signaling. Phase separation is mediated by multivalent interactions of biological macromolecules including intrinsically disordered proteins and regions (IDRs). Despite considerable advances in experiments, theory and simulations, the prediction of the thermodynamics of IDR phase behaviour remains challenging. We combined coarse-grained molecular dynamics simulations and active learning to develop a fast and accurate machine learning model to predict the free energy and saturation concentration for phase separation directly from sequence. We validate the model using both experimental and computational data. We apply our model to all 27,663 IDRs of chain length up to 800 residues in the human proteome and find that 1,420 of these (5%) are predicted to undergo homotypic phase separation with transfer free energies<−2kBT. We use our model to understand the relationship between single-chain compaction and phase separation, and find that changes from charge-to hydrophobicity-mediated interactions can break the symmetry between intra-and inter-molecular interactions. We also analyse the structural preferences at condensate interfaces and find substantial heterogeneity that is determined by the same sequence properties as phase separation. Our work refines the established rules governing the relationships between sequence features and phase separation propensities, and our prediction models will be useful for interpreting and designing cellular experiments on the role of phase separation, and for the design of IDRs with specific phase separation propensities.
Leveraging epigenetic signatures to determine the cell-type of origin from long read sequencing data
Authors: Hannon Eilis , Mill Jonathan
Published: June 2024

DNA methylation differs across tissue- and cell-types with important implications for the analysis of disease-associated differences in tissues such as blood. To uncover the biological processes affected by epigenetic dysregulation, it is essential for epigenetic studies to generate data from the appropriate cell-types. Here we propose a framework to do this computationally from long-read sequencing data, bypassing the need to isolate subtypes of cells experimentally. Using reference data for six common blood cell-types, we evaluate the potential of this approach for attributing reads to specific cells using sequencing data generated from whole blood. Our analyses show that cell-type can be accurately classified using small regions of the genome comparable in size to those generated by long-read sequencing platforms, although the accuracy of classification varies across different regions of the genome and between cell-types. We found that for approximately one third of the genome it is possible to accurately discriminate reads originating from lymphocytes and myeloid cells with the prediction of more specialised subtypes of blood cell-types also encouraging. Our approach provides an alternative computational method for generating cell-specific DNA methylation profiles for epigenetic epidemiology, accelerating our ability to reveal critical insights of the role of the epigenome in health and disease.
Live-cell imaging of circular and long non-coding RNAs associated to FUS pathological aggregates by Pepper fluorescent RNA
Authors: Vitiello Erika , Castagnetti Francesco , Stufera Mecarelli Lorenzo , D’Ambra Eleonora , Tollis Paolo , Ruocco Giancarlo , Laneve Pietro , Caffarelli Elisa , Mariani Davide , Bozzoni Irene
Published: June 2024

Lately, important advancements in visualizing RNAs in fixed and live cells have been achieved. While mRNA imaging techniques are well-established, the development of effective methods for studying non-coding RNAs (ncRNAs) in living cells are still challenging but necessary, as they cover a variety of function and of intracellular localization, including highly dynamic processes like phase-transition, still poorly studiedin vivo. Addressing this issue, we tagged two exemplary ncRNAs with the innovative fluorescent RNA (fRNA) Pepper. Specifically, we show circ-HDGFRP3 interaction with p-bodies, we recapitulate its recruitment in pathological FUS aggregates in a dynamic fashion and we super-resolve its distribution in such aggregates via Structured Illumination Microscopy. Moreover, we tracked the long non-coding RNA (lncRNA) nHOTAIRM1, a motor neurons-specific constituent of stress granules (SG), monitoring its behavior throughout the oxidative-stress response in physiological and pathological conditions. Overall, as fRNAs development advances, our work shows a successful use of Pepper for the monitoring of complex processes, as phase-transition, of paradigmatic molecules like circular RNAs (circRNAs) and lncRNAs with super-resolution potential in living mammalian cells.
Mosaic midbrain organoids: a new tool to study Progressive Supranuclear Palsy and advancing clinical neurology research
Authors: Parrotta Elvira Immacolata , Lucchino Valeria , Zannino Clara , Valente Desirèe , Scalise Stefania , Benedetto Giorgia Lucia , Iazzetta Maria Roberta , Talarico Mariagrazia , Conforti Francesco , Di Agostino Silvia , Fiorenzano Alessandro , Quattrone Aldo , Cuda Giovanni , Quattrone Andrea
Published: June 2024

Progressive supranuclear palsy (PSP) is a severe neurodegenerative disease pathologically characterized by intracellular tangles of hyperphosphorylated tau protein, widely distributed across the neocortex, basal ganglia, and midbrain. Developing effective drugs for PSP presents challenges due to its complex underpinning mechanism and the absence of robust human models that accurately recapitulate biochemical and pathological features of the disease phenotype. Brain organoids have recently emerged as a three-dimensional tissue culture platform to study brain development and pathology. Here, we present a novel induced pluripotent stem cell (iPSC)-derived mosaic midbrain organoid (mMOs) system from four patients with progressive supranuclear palsy-Richardson syndrome (PSP-RS), aimed at reproducing key molecular disease features while reducing variability across organoids derived from different iPSC donors. The PSP-RS 3D model exhibited accumulation of hyperphosphorylated tau protein, predominance of 4R-tau, increased GFAP-positive cells, and PSP-associated histological alterations compared to organoids derived from healthy donors. Pathologically, diseased mMOs showed typical neurofibrillary tangles and tufted-shaped astrocytes, and poorly branched processes of Tyrosine Hydroxylase-immunoreactive cells with thin terminal branches. Our results suggest that mMOs represent a valuable experimental model for PSP research and hold great promise for future identification of new therapeutic targets for progressive supranuclear palsy.
Medial amygdalar tau is associated with anxiety symptoms in preclinical Alzheimer’s disease
Authors: Li Joyce S , Tun Samantha M , Ficek-Tani Bronte , Xu Wanwan , Wang Selena , Horien Corey L , Toyonaga Takuya , Nuli Shreya S , Zeiss Caroline J , Powers Albert R , Zhao Yize , Mormino Elizabeth C , Fredericks Carolyn A
Published: June 2024

BACKGROUND

While the amygdala receives early tau deposition in Alzheimer’s disease (AD) and is involved in social and emotional processing, the relationship between amygdalar tau and early neuropsychiatric symptoms in AD is unknown. We sought to determine whether focal tau binding in the amygdala and abnormal amygdalar connectivity were detectable in a preclinical AD cohort and identify relationships between these and self-reported mood symptoms.

METHODS

We examined n=598 individuals (n=347 amyloid-positive (58% female), n=251 amyloid-negative (62% female); subset into tau PET and fMRI cohorts) from the A4 Study. In our tau PET cohort, we used amygdalar segmentations to examine representative nuclei from three functional divisions of the amygdala. We analyzed between-group differences in division-specific tau binding in the amygdala in preclinical AD. We conducted seed-based functional connectivity analyses from each division in the fMRI cohort. Finally, we conducted exploratory post-hoc correlation analyses between neuroimaging biomarkers of interest and anxiety and depression scores.

RESULTS

Amyloid-positive individuals demonstrated increased tau binding in medial and lateral amygdala (F(4, 442)=14.61,p=0.00045;F(4, 442)=5.83,p=0.024, respectively). Across amygdalar divisions, amyloid-positive individuals had relatively increased regional connectivity from amygdala to other temporal regions, insula, and orbitofrontal cortex. There was an interaction by amyloid group between tau binding in the medial and lateral amygdala and anxiety. Medial amygdala to retrosplenial connectivity negatively correlated with anxiety symptoms (rs=-0.103,p=0.015).

CONCLUSIONS

Our findings suggest that preclinical tau deposition in the amygdala may result in meaningful changes in functional connectivity which may predispose patients to mood symptoms.
Variation in relaxation of non-photochemical quenching between the founder genotypes of the soybean (Glycine max) nested association mapping population
Authors: Gotarkar Dhananjay , Digrado Anthony , Wang Yu , Doran Lynn , Blakey Bethany , Diers Brian W. , Eck Daniel J. , Burgess Steven J.
Published: June 2024

Improving the efficiency of crop photosynthesis has the potential to increase yields. Genetic manipulation showed photosynthesis can be improved by speeding up relaxation of photoprotective mechanisms during sun to shade transitions. However, it is unclear if natural variation in relaxation of non-photochemical quenching (NPQ) can be exploited in crop breeding programs. To address this issue, we measured six NPQ parameters in the 40 founder lines and common parent of a Soybean Nested Association Mapping (SoyNAM) panel over two field seasons in Illinois. NPQ parameters did not show consistently variable trends throughout development, and variation between sampling days suggests environmental impacts on NPQ which last more than 24 hours. 17 genotypes were found to show small but consistent differences in NPQ relaxation kinetics relative to a reference line providing a basis for future mapping studies. Finally, a soybean canopy model predicted available phenotypic variation could result in a 1.6% difference in carbon assimilation when comparing fastest and slowest relaxing NPQ values.

Significance Statement

Evidence suggests increasing the rate of relaxation of photoprotection can lead to improved biomass and yield. We compare photoprotection relaxation rates in 41 diverse soybean genotypes grown in the field, identifying lines with faster rates of relaxation, and predict a potential 1.6% difference in daily carbon assimilation which could contribute to improving soybean performance.
Excitability and synaptic transmission after vitrification of mouse corticohippocampal slices
Authors: German Alexander , Akdaş Enes Yağız
Published: June 2024

Cryopreservation of adult neural tissue is of considerable practical and theoretical interest. Utilizing 61% w/v ethylene glycol, we vitrified and rewarmed acute mouse corticohippocampal slices to evaluate field excitatory postsynaptic potentials (fEPSP) in the stratum radiatum of the CA1 region of the hippocampus. Our results demonstrate successfully recovered synaptic transmission, and high-frequency stimulation (HFS)-induced potentiation. However, we failed to induce a stable potentiation following HFS stimulation. Structural analysis post-vitrification revealed cellular alterations such as swelling and vacuolization, which likely contributed to the unstable potentiation. Despite high variability in results, this study highlights the potential of vitrification to partially preserve brain function.
Long-distance chronometric leveling with a portable optical clock
Authors: Grotti J. , Nosske I. , Koller S.B. , Herbers S. , Denker H. , Timmen L. , Vishnyakova G. , Grosche G. , Waterholter T. , Kuhl A. , Koke S. , Benkler E. , Giunta M. , Maisenbacher L. , Matveev A. , Dörscher S. , Schwarz R. , Al-Masoudi A. , Hänsch T.W. , Udem Th. , Holzwarth R. , Lisdat C.
Published: June 2024

We have measured the geopotential difference between two locations separated by 457 km by comparison of two optical lattice clocks via an interferometric fiber link, utilizing the gravitational redshift of the clock transition frequency. The 87Sr clocks have been compared side-by-side before and after one of the clocks was moved to the remote location. The chronometrically measured geopotential difference of 3918.1(2.6)m2s−2 agrees with an independent geodetic determination of 3915.88(0.30)m2s−2. The uncertainty of the chronometric geopotential difference is equivalent to an uncertainty of 27cm in height.

Published by the American Physical Society
2024
Investigation of spin excitations and charge order in bulk crystals of the infinite-layer nickelate
LaNiO2
Authors: Hayashida S. , Sundaramurthy V. , Puphal P. , Garcia-Fernandez M. , Zhou Ke-Jin , Fenk B. , Isobe M. , Minola M. , Wu Y.-M. , Suyolcu Y. E. , van Aken P. A. , Keimer B. , Hepting M.
Published: June 2024

Recent x-ray spectroscopic studies have revealed spin excitations and charge density waves in thin films of infinite-layer (IL) nickelates. However, clarifying whether the origin of these phenomena is intrinsic to the material class or attributable to impurity phases in the films has presented a major challenge. Here we utilize topotactic methods to synthesize bulk crystals of the IL nickelate LaNiO2 with crystallographically oriented surfaces. We examine these crystals using resonant inelastic x-ray scattering (RIXS) at the Ni L3-edge to elucidate the spin and charge correlations in the bulk of the material. While we detect the presence of prominent spin excitations in the crystals, fingerprints of charge order are absent at the ordering vectors identified in previous thin-film studies. These results contribute to the understanding of the bulk properties of LaNiO2 and establish topotactically synthesized crystals as viable complementary specimens for spectroscopic investigations.

Published by the American Physical Society
2024
Searching for weakly interacting sub-eV particles with a fiber interferometer in a strong magnetic field
Authors: Batllori Josep Maria , Gu Yikun , Horns Dieter , Maroudas Marios , Ulrichs Johannes
Published: June 2024

A novel table-top experiment is introduced to detect photon-axion conversion: WISP searches on a fiber interferometer (WISPFI). The setup consists of a Mach-Zehnder-type interferometer with a fiber placed inside an external magnetic field, where mixing occurs which is detected by measuring changes in amplitude. Hollow-core photonic crystal fibers (HC-PCF) will be used to achieve resonant mixing that is tuneable by regulating the gas pressure in the fiber. An unexplored axion mass-range (28 meV–100 meV) can be probed reaching the two-photon coupling expected for the QCD axion.

Published by the American Physical Society
2024
Constraining
f(R)
gravity using future galaxy cluster abundance and weak-lensing mass calibration datasets
Authors: Vogt Sophie M. L. , Bocquet Sebastian , Davies Christopher T. , Mohr Joseph J. , Schmidt Fabian
Published: June 2024

We present forecasts for constraints on the Hu and Sawicki f(R) modified gravity model using realistic mock data representative of future cluster and weak lensing surveys. We create mock thermal Sunyaev-Zel’dovich effect selected cluster samples for SPT-3G and CMB-S4 and the corresponding weak gravitational lensing data from next-generation weak-lensing (ngWL) surveys like Euclid and Rubin. We employ a state-of-the-art Bayesian likelihood approach that includes all observational effects and systematic uncertainties to obtain constraints on the f(R) gravity parameter log10|fR0|. In this analysis we vary the cosmological parameters [Ωm,Ωνh2,h,As,ns,log10|fR0|], which allows us to account for possible degeneracies between cosmological parameters and f(R) modified gravity. The analysis accounts for f(R) gravity via its effect on the halo mass function which is enhanced on cluster mass scales compared to the expectations within general relativity (GR). Assuming a fiducial GR model, the upcoming cluster dataset SPT−3G×ngWL is expected to obtain an upper limit of log10|fR0|<−5.95 at 95% credibility, which significantly improves upon the current best bounds. The CMB−S4×ngWL dataset is expected to improve this even further to log10|fR0|<−6.23. Furthermore, f(R) gravity models with log10|fR0|≥−6, which have larger numbers of clusters, would be distinguishable from GR with both datasets. We also report degeneracies between log10|fR0| and Ωm as well as σ8 for log10|fR0|>−6 and log10|fR0|>−5 respectively. Our forecasts indicate that future cluster abundance studies of f(R) gravity will enable substantially improved constraints that are competitive with other cosmological probes.

Published by the American Physical Society
2024
Nonlinear rigid-body quantization of Skyrmions
Authors: Gudnason Sven Bjarke
Published: June 2024

We consider rigid-body quantization of the Skyrmion in the most general four-derivative generalization of the Skyrme model with a potential giving pions a mass, as well as in a class of higher-order Skyrme models. We quantize the spin and isospin zero modes following the results of Pottinger and Rathske. Although one could hope that a one-parameter family of theories could provide a smaller spin contribution to the energy at some point in theory space—which would be welcome for Bogomol’nyi-Prasad-Sommerfield-type models, we find that the standard Skyrme model limit, with two time derivatives, gives rise to the smallest spin contribution to the energy. We speculate whether this tuning of the spin energy could be useful in the larger picture of quantizing vibrational and light massive modes of the Skyrmions. Finally, we establish a topological energy bound for the Pottinger-Rathske model with potential terms as well as new bounds for higher-order Skyrme models, with and without a potential.

Published by the American Physical Society
2024
Toward multiloop local renormalization within causal loop-tree duality
Authors: Ríos-Sánchez José , Sborlini German
Published: June 2024

Renormalization is a well-known technique to get rid of ultraviolet (UV) singularities. When relying on dimensional regularization, these become manifest as ε poles, allowing one to define counterterms with useful recursive properties. However, this procedure requires one to work at “integral level” and poses difficulties to achieve a smooth combination with seminumerical approaches. This article is devoted to the development of an integrand-level renormalization formalism, better suited for semi- or fully numerical calculations. Starting from the loop-tree duality, we keep the causal representations of the integrands of multiloop Feynman diagrams and explore their UV behavior. Then, we propose a strategy that allows one to build local counterterms, capable of rendering the expressions integrable in the high-energy limit and in four space-time dimensions. Our procedure was tested on diagrams up to three loops, and we found a remarkably smooth cancellation of divergences. The results of this work constitute a powerful step toward a fully local renormalization framework in quantum field theory.

Published by the American Physical Society
2024
Statistical mechanics from relational complex time with a pure state
Authors: Gemsheim Sebastian , Rost Jan M.
Published: June 2024

Thermodynamics and its quantum counterpart are traditionally described with statistical ensembles. Canonical typicality has related statistical mechanics for a system to ensembles of global energy eigenstates of a system and its environment, analyzing their cardinality. We show that the canonical density for a system emerges from a maximally entangled global state of system and environment through relational complex time evolution between system and environment without the need to maximize the entropy or to count states.

Published by the American Physical Society
2024
Determination of the Collins-Soper Kernel from Lattice QCD
Authors: Avkhadiev Artur , Shanahan Phiala E. , Wagman Michael L. , Zhao Yong
Published: June 2024

This Letter presents a determination of the quark Collins-Soper kernel, which relates transverse-momentum-dependent parton distributions (TMDs) at different rapidity scales, using lattice quantum chromodynamics (QCD). This is the first such determination with systematic control of quark mass, operator mixing, and discretization effects. Next-to-next-to-leading logarithmic matching is used to match lattice-calculable distributions to the corresponding TMDs. The continuum-extrapolated lattice QCD results are consistent with several recent phenomenological parametrizations of the Collins-Soper kernel and are precise enough to disfavor other parametrizations.

Published by the American Physical Society
2024
Pillar data-acquisition strategies for cryo-electron tomography of beam-sensitive biological samples
Authors: Parkhurst James M. , Varslot Trond , Dumoux Maud , Siebert C. Alistair , Darrow Michele , Basham Mark , Kirkland Angus , Grange Michael , Evans Gwyndaf , Naismith James H.
Published: June 2024

For cryo-electron tomography (cryo-ET) of beam-sensitive biological specimens, a planar sample geometry is typically used. As the sample is tilted, the effective thickness of the sample along the direction of the electron beam increases and the signal-to-noise ratio concomitantly decreases, limiting the transfer of information at high tilt angles. In addition, the tilt range where data can be collected is limited by a combination of various sample-environment constraints, including the limited space in the objective lens pole piece and the possible use of fixed conductive braids to cool the specimen. Consequently, most tilt series are limited to a maximum of ±70°, leading to the presence of a missing wedge in Fourier space. The acquisition of cryo-ET data without a missing wedge, for example using a cylindrical sample geometry, is hence attractive for volumetric analysis of low-symmetry structures such as organelles or vesicles, lysis events, pore formation or filaments for which the missing information cannot be compensated by averaging techniques. Irrespective of the geometry, electron-beam damage to the specimen is an issue and the first images acquired will transfer more high-resolution information than those acquired last. There is also an inherent trade-off between higher sampling in Fourier space and avoiding beam damage to the sample. Finally, the necessity of using a sufficient electron fluence to align the tilt images means that this fluence needs to be fractionated across a small number of images; therefore, the order of data acquisition is also a factor to consider. Here, an n-helix tilt scheme is described and simulated which uses overlapping and interleaved tilt series to maximize the use of a pillar geometry, allowing the entire pillar volume to be reconstructed as a single unit. Three related tilt schemes are also evaluated that extend the continuous and classic dose-symmetric tilt schemes for cryo-ET to pillar samples to enable the collection of isotropic information across all spatial frequencies. A fourfold dose-symmetric scheme is proposed which provides a practical compromise between uniform information transfer and complexity of data acquisition.
Exploring consumers’ perception of stingless bee honey using projective techniques
Authors: de Souza Andressa Pedroso Carlotto , Leães Fernanda Leal , Danieli Gabriele , Ruaro Eduarda Letícia , Righi Eléia , Meirelles Rafael Narciso , Sant’Anna Voltaire
Published: June 2024

Purpose

The objective of this study was to evaluate Brazilian consumers’ perceptions of stingless bee honey and the drivers involved in this product choice.

Design/methodology/approach

Three projective techniques were applied to 480 consumers who answered a rating task about liking, health, sustainability, quality taste, and utilization as ingredients, fulfilled completion sentences, and performed a hard laddering task.

Findings

The results showed a significant increase in the expected liking and flavor, and consumers perceived stingless bee honey as more sustainable, of higher quality, and more beneficial to health. Health, sustainability, and taste are the main drivers of purchasing this type of honey, and consumers are aware that it costs a premium price. In the value chain involved in choosing stingless bee honey, the appreciation of native bees, flavor, nutritional value, medicinal properties, producer appreciation, and curiosity were strong aspects for choosing the product. These aspects lead consumers to feel good, have peace of mind, feel like protecting nature and planets, and longevity.

Originality/value

Honey is popular worldwide, but stingless bee honey has little information on how consumers perceive it and on the purchasing decision chain. The results of the present study provide important information to enhance the consumption of this product with social and environmental importance and the growing demand for natural products that replace refined sugars.
Exploring business and SDG discourse on X: topics, users and engagement
Authors: Ascencio Christine , Eramudugoda Randika
Published: June 2024

Purpose

This paper examines thematic discourses concerning business and the Sustainable Development Goals (SDGs) on X (formerly Twitter), aiming to uncover active user groups and evaluate engagement levels across various topics. The study also explores the engagement patterns among different user categories, ultimately seeking deeper insights into platform discourse regarding business and the SDGs.

Design/methodology/approach

Utilizing unsupervised machine learning technique Latent Dirichlet Allocation (LDA), we perform exploratory topic modeling on X data referencing business and the SDGs, generating 16 thematic clusters. Subsequently, we analyze user descriptions to categorize users involved in these discussions. Finally, we employ binomial logit models to assess the relationship between topics and engagement and chi-squared test to evaluate the relationship between users and topics.

Findings

The exploratory research identifies 16 business and SDG topics, while the analysis of users reveals 6 stakeholder groups contributing to these discussions. Business groups emerge as the most frequent contributors, posting on topics related to partnership, action advocacy, and economic outcomes. Topics about updates on progress and transformative initiatives garnered strongest support for engagement.

Originality/value

This research not only sheds light on the current state of business and SDG discourse on X, but also underscores the significance of engaging external stakeholders in driving positive social change globally.
A novel higher-order sliding mode control for DC-DC boost converter system in PMDC motor exploring mismatched disturbances
Authors: R Dhanasekar , Srinivasan Ganesh Kumar , Rivera Marco
Published: June 2024

Purpose

The purpose of this study is to stabilize the rotating speed of the permanent magnet direct current (PMDC) motor driven by a DC-DC boost converter under mismatched disturbances (i.e.) under varying load circumstances like constant, frictional, fan type, propeller and undefined torques.

Design/methodology/approach

This manuscript proposes a higher order sliding mode control to elevate the dynamic behavior of the speed controller and the robustness of the PMDC motor. A second order classical sliding surface and proportional-integral-derivative sliding surface (PIDSS) are designed and compared.

Findings

For the boost converter with PMDC motor, both simulation and experimentation are exploited. The prototype is built for an 18 W PMDC motor with field programmable gate arrays. The suggested sliding mode with second order improves the robustness of the arrangement under disturbances with a wide range of control. Both the simulation and experimental setup shows satisfactory results.

Originality/value

According to software-generated mathematical design and experimental findings, PIDSS exhibits excellent performance with respect to settling speed, steady-state error and peak overshoot.
For a bright future. Cuban nuclear engineers studying in late socialist Hungary
Authors: Szente-Varga Mónika
Published: June 2024

Purpose

This research aims to contribute to History of Education Studies as well as to New Cold War Studies, by examining a Reactor Technology Specialist Engineer program, launched in Hungary three times in the 1980s for Cuban nuclear engineers, graduates of the University of Havana.

Design/methodology/approach

The institutional setting, the content of the program, the teaching staff, the students, and the outcomes are studied. The factors that motivated the birth of this special program are examined, including the following areas; in what ways it was different from the courses in which foreign students participated in Hungary; what its strengths and weaknesses were; how we can learn from this past experience and what relevance it has for the present.

Findings

The analysis – carried out within the context of Cuban–Hungarian relations in the Cold War – demonstrates that these two satellite countries used the fields of science and education to widen their international possibilities and at the same time to reinforce their national interests by cooperating with each other.

Originality/value

The investigation is based on archival sources, university yearbooks and journals as well as contemporary Hungarian press. Written sources were complemented by interviews with Cuban students and Hungarian teaching staff, thus providing a personal perspective, balancing official views.
Understanding factors shaping engagement in remote internships: the role of institutional communication, faculty support and intern cynicism
Authors: Kakkar Shiva , Ghulyani Swati , Kuril Samvet , Chaudhuri Manosi
Published: June 2024

Purpose

This study aims to understand the factors that shape intern engagement in remote settings by investigating the relationship between faculty support, institutional communication, intern cynicism, professional efficacy and work engagement during remote internships.

Design/methodology/approach

Data were collected for a period of two years from 309 interns representing four prestigious business schools in India. The statistical analysis involved employing covariance-based modelling using AMOS 22 and the NCA package for R.

Findings

The study reveals that institutional communication plays a vital role in reducing intern cynicism and enhancing professional efficacy, ultimately leading to higher levels of engagement. However, faculty support was found to primarily address cynicism, without significantly bolstering intern’s professional efficacy. Further, faculty support plays a more important role in facilitating work engagement compared to institutional communication.

Research limitations/implications

The findings contribute to the Job Demands-Resources theory and efficacy literature by highlighting the distinct role of institutional factors in determining intern engagement. This study provides valuable insights into the mechanisms that shape intern engagement in remote settings.

Practical implications

The findings suggest that institutions should prioritize task-oriented communication practices, as this contributes to enhancing intern’s professional efficacy. Additionally, faculty members should focus on addressing intern cynicism through relationship-oriented communication strategies.

Originality/value

This study's originality lies in its examination of the underexplored domain of remote internships, providing actionable insights that can inform the development of interventions aimed at deepening engagement in remote internships.
Role of fashion-consciousness, health-awareness and environmental concerns on millennials’ usage of smartwatches
Authors: Gadge Srushti , Kasera Sneh , Yeravdekar Rajiv , Singh Ankit , Borlepawar Vivek
Published: June 2024

Purpose

This paper aims to understand the underlying motivations and factors that drive millennials to embrace smartwatches as fashionable accessories, health monitoring tools and eco-friendly alternatives.

Design/methodology/approach

In June–July 2022, a cross-sectional study was conducted, gathering 285 complete responses through an online survey using convenience sampling. These responses were then analyzed to obtain valuable insights using structural equation modeling.

Findings

This study’s findings confirm the mediation effect of fashion innovativeness on the relationship between subjective norms and attitudes toward smartwatch usage (b= 0.034, lower limit confidence interval (LLCI) = 0.007, upper limit confidence interval (ULCI) = 0.086,p= 0.015). In addition, it highlights the mediating role of healthology in the association between subjective norms and attitudes toward using smartwatches (b= 0.062, LLCI = 0.006, ULCI = 0.151,p= 0.029).

Research limitations/implications

This research has limitations in terms of sample representativeness, self-reported data, cultural and regional factors and technological advancement.

Practical implications

Understanding millennials’ motivations behind smartwatch usage has implications for marketers, designers and manufacturers in targeting this generation effectively. By highlighting smartwatches’ fashion-forward and health-conscious aspects, companies can appeal to millennials’ preferences and develop innovative features that align with their values.

Social implications

This study provides validation for the increased level of environmental concerns among millennials, emphasizing its substantial influence on their purchasing decisions when it comes to smartwatches. Furthermore, it highlights that health-consciousness holds greater significance than fashion-forwardness as a determining factor for consumers of smartwatches.

Originality/value

This pioneering study explores the adoption intentions of smartwatch usage, examining it from the unique perspectives of health theology and environmental concerns. By delving into these novel dimensions, the research fills a significant gap in the existing literature. It contributes to a deeper understanding of the factors influencing millennials’ decision-making processes when embracing smartwatches.
Probing the effect of displacement on electrical contact tribological behavior at the risk frequency of nuclear safety DCS equipment
Authors: Wang Dongwei , Li Faqiang , Zhao Yang , Wang Fanyu , Jiang Wei
Published: June 2024

Purpose

This paper aims to study the tribological characteristics of the electrical contact system under different displacement amplitudes.

Design/methodology/approach

First, the risk frequency of real nuclear safety distributed control system (DCS) equipment is evaluated. Subsequently, a reciprocating friction test device which is characterized by a ball-on-flat configuration is established, and a series of current-carrying tribological tests are carried out at this risk frequency.

Findings

At risk frequency and larger displacement amplitude, the friction coefficient visibly rises. The reliability of the electrical contact system declines as amplitude increases. The wear morphology analysis shows that the wear rate increases significantly and the degree of interface wear intensifies at a larger amplitude. The wear area occupied by the third body layer increases sharply, and the appearance of plateaus on the surface leads to the increase of friction coefficient and contact resistance. EDS analysis suggests that oxygen elements progressively arise in the third layer as a result of increased air exposure brought on by larger displacement amplitude.

Originality/value

Results are significant for recognizing the tribological properties of electrical connectors in nuclear power control systems.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0098/
The impact of IT use on supply chain coordination: the moderating role of environmental uncertainty
Authors: Yang Lu , Huo Baofeng , Ye Yuxiao
Published: June 2024

Purpose

This study aims to empirically test the direct effects of three types of information technology (IT) use on three dimensions of supply chain coordination (SCC). It further explores the spillover effects of IT use on coordination beyond its domain across the SC. Besides, this study probes into the moderating effects of environmental uncertainty (EU).

Design/methodology/approach

Structural equation modelling (SEM) is used to examine data collected from 202 firms in Hong Kong. Furthermore, multi-group SEM analysis with a series of invariance tests was used to test the moderating effects of EU.

Findings

Internal, supplier and customer IT use have direct effects on internal, supplier and customer coordination, respectively. Besides, IT use generates forward spillover effects beyond its domain along the forward physical flow in an SC. EU positively moderates the relationships between external IT use and SCC but does not shape the effectiveness of internal IT use in enhancing SCC. Moreover, under a high EU, the spillover effects of IT use on coordination can be intensified. Besides, the spillover effects further expand to benefit coordination on a larger scale of the SC under a high EU.

Originality/value

This study contributes by revealing that in addition to direct effects, IT use in a specific domain could generate spillover effects on coordination beyond its domain throughout an SC. More importantly, it contributes by explaining the difference in the effectiveness of IT use under different levels of EU using multi-group SEM analysis.
Knowledge work productivity in an activity-based workplace: a comparative analysis
Authors: Palvalin Miikka
Published: June 2024

Purpose

The purpose of this paper was to extend the current knowledge on the impacts of activity-based workplaces (ABWs) on productivity in knowledge work. It offers more background information that is needed to properly evaluate ABWs’ suitability for different organisations. In the results section, ABWs are compared to the cellular and open-plan office types.

Design/methodology/approach

This study was conducted using a survey method with 5,841 respondents. The data were collected between 2015 and 2019 from 32 public-sector organisations.

Findings

The findings of this paper reveal that ABWs offer clear advantages over the other office types but requires careful design and well-implemented solutions. The superiority between ABWs and cellular offices also depends on workers’ profiles and needs and is not for everyone.

Practical implications

For practitioners, this paper offers valuable information to compare the three office types: ABW, cellular and open-plan. It also highlights the importance of careful planning and good implementation, which are both essential to making the ABW environment productive for employees. Finally, this paper clearly provides evidence that ABWs and open-plan offices differ in their facilities and productivity.

Originality/value

This paper included a unique and large sample with open variables, which are fairly rare in ABW-related papers. It also provides evidence that ABWs, when implemented correctly, seem to be an excellent option for some work profiles.
Analysis to increase sharia credit card users: study in four cities in Indonesia
Authors: Indrajaya Sonny , Chan Syafrizal , Setyaningrum Retno Purwani
Published: June 2024

Purpose

The purpose of this study is to examine the effect and influence of perceived usefulness and perceived ease of use on knowledge sharing to improve and use Islamic credit cards.

Design/methodology/approach

Structural equation modeling was used in the analysis of the data collected from 160 respondents in four cities in Jakarta, Indonesia, using an online survey.

Findings

This study analyzes the effect of perceived usefulness and perceived ease of use on knowledge management, and also analyzes the effect of increasing knowledge management in increasing Islamic credit card users, as well as the role of knowledge management as mediation.

Research limitations/implications

This study only examines Islamic credit cards by looking at the contribution of the role of perceived usefulness and perceived ease of use knowledge management that are felt by users and prospective users of Islamic credit cards.

Practical implications

The results of this study highlight the need for Islamic banks to provide and increase knowledge to understand and know well about Islamic credit cards, which can increase intentions to become new users.

Originality/value

This research provides additional knowledge on Islamic credit cards, commonly referred to as bithaqah al-l’timan, as a means of payment and cash withdrawals in accordance with applicable regulations with reference to Islamic principles and policies by providing convenience, security and comfort for credit card users and for bank customers. Sharia banking can also grow the sharia economy, which currently Indonesia is still far behind.