Miracle-dz/UniFAR-FTUs huggingface dataset:
Fundamental role of the retarded potential in the electrodynamics of superluminal sources: reply to comment

Neither Eq. (6.52) of Jackson [Classical Electrodynamics, 3rd ed. (Wiley, 1999)] nor Hannay's derivation of that equation in the preceding Comment [J. Opt. Soc. Am. A26, 2107 (2009)] is applicable to a source whose distribution pattern moves faster than light in vacuo with nonzero acceleration. It is assumed in Hannay's derivation that the retarded distribution of the density of any moving source will be smooth and differentiable if its rest-frame distribution is. By working out an explicit example of a rotating superluminal source with a bounded and smooth density profile, we show that this assumption is erroneous. The retarded distribution of a rotating source with a moderate superluminal speed is, in general, spread over three disjoint volumes (differing in shape from one another and from the volume occupied by the source in its rest frame) whose boundaries depend on the space-time position of the observer. Hannay overlooks the fact that the limits of integration in his expression for the retarded potential are not differentiable, as functions of the coordinates of the observer, when the distribution pattern of the source moves faster than light. These limits, which delineate the boundaries of the retarded distribution of the source, have divergent gradients at those points on the source boundary that approach the observer, along the radiation direction, with the speed of light at the retarded time. In the superluminal regime, derivatives of the integral representing the retarded potential are well defined only as generalized functions.
Mass Loss and Jet Outflow in the Orion Nebula Proplyd LV 2

We have obtained Hubble Space Telescope (HST) Space Telescope Imaging Spectrometer high-resolution spectra of the Orion proplyd LV 2 in the C III doublet at 1906.68 and 1908.73 Å. New images at the 6 cm wavelength with MERLIN complement earlier HST images at a similar spatial resolution. This object is one of the closest proplyds to θ1 Ori C, the source of the photoionizing and photoevaporating radiation. Combining the spectra with the HST images and detailed theoretical models has allowed a determination of the mass-loss rate as 8.2 × 10-7 M☉ yr-1 ±10%. This rate of mass loss is used to address the conundrum of the continued existence of proplyds. Even though they should be photoevaporated in only about 105 yr, there is no evidence for their destruction. It is concluded that the only explanation is that the age of θ1 Ori C is less than 105 yr. These spectra and previously unpublished ground-based spectra in [O III] also show the presence of a monopolar microjet, redshifted by about 100 km s-1 with respect to the systemic velocity. This jet is more visible in the 6 cm MERLIN images than in HST images, and this image together with the spectra are used to determine the flow parameters for the jet. Our spectra also include the stand-off shock that lies between LV 2 and θ1 Ori C. This is the result of the high-velocity wind coming from the hot star θ1 Ori C with the low-velocity wind coming from the proplyd. As expected, this shock is at rest with respect to the two objects.
The Purchase Behaviour Towards Consumer Goods During Economic Crisis – A Middle Eastern Perspective

Abstract The primary purpose of this study is to develop a realistic understanding of the factors that influence consumers’ purchase behaviour towards consumer goods in the middle east region during the economic crisis, by focusing on Oman. This study has used linear regression analysis to develop a clear idea of the factors that influence consumers’ purchase behaviour towards consumer goods during the economic crisis. This study has also used Sobel test, to conduct the mediation analysis. The data was collected using a standard five-point Likert scale-based questionnaire, from a sample of 122 individuals who have recently completed their bachelor’s program in one of the four major Higher Education Institutions (HEIs) in Oman. Unlike the popular belief, this study has found the elements of the marketing mix to not exert significant influence on consumers’ purchase behaviour towards consumer goods during the economic crisis. However, the results found cultural and social factors to exert useful influence on the consumers’ purchase behaviour towards consumer goods. The study recommends that organizations need to focus more on cultural compliance and societal acceptance of their offerings, than focusing on the traditional marketing mix. While helping the organizations manufacturing or marketing consumer goods in the middle east region during the economic crisis, this study would add more value and variety to the available literature. While the findings of this study could also be used by individuals dealing with consumer products in similar markets to redefine their product offerings, by taking the cultural and social issues into consideration, this study could act as a point of reference for future researchers. This study has provided a unique perspective related to the factors that drive consumers’ purchase behaviour towards consumer goods in the middle east region, during the economic crisis. These observations could also be generalized and used in other countries that have similar cultural and social affiliations.
Progress on one-dimensional zinc oxide nanomaterials based photonic devices

Abstract One-dimensional nanostructures hold the most attractive and excellent physiochemical characteristics which exhibit the paramount influence on the fundamental and technological nanoelectronic as well as nanophotonic applications. In this review article, we present a detailed introduction to the diverse synthetic procedures which can be utilized for the fabrication of single-, planar- and three-dimensional ZnO nanostructures. More specifically, a thorough discussion regarding luminescence characteristics of the one-dimensional ZnO nanostructures is presented for ultraviolet and visible regions. We summarize the room temperature spontaneous emission and stimulated emission along with the interaction of the incident beam with material cavity to produce resonant optical modes and low-temperature time resolved photoluminescence studies. The most recent published results on the white light emitting diodes fabricated with the combination of ZnO nanotubes with p-GaN and ZnO nanorods with p-organic polymers on glass and disposable paper are discussed. Additionally, the significant results on optically and electrically pumped lasers are discussed; along with an overview on the future of ZnO nanostructures based photonic devices.
Quality of Soft Cheese made with Goat's Milk as Affected with the addition of Certain Essence

To change the aroma of goat's milk cheese which none preferred for most Egyptian consumer, white cheese was made from goat's milk mixed with various flavourings (cream, butter, Cheddar cheese, Edam cheese, Gouda cheese and Emmental cheese). Results indicated that there are no pronounced differences between control and other treatments for yield, acidity, pH, fat, salt TN and TVFA contents. Cheese made using cream and butter flavourings had slightly higher WSN and NPN values as compared with different samples. Sensory evaluation data showed that adding the above mentioned tastes didn't effect on color & appearance and body & texture of fresh cheese and during ripening period to 90 days whereas adding cream and butter tastes improved the flavour of goat's milk cheese.
Formation of thermal eddies during rf heating of plasma

Moderate power (approx.1 kW) excitation of lower hybrid waves in a linear plasma column is found to increase the reflectivity of the phased waveguide exciter and to change the vertical position of the resonance cone. Probing of the plasma near the mouth of the waveguide reveals that the increased reflection results from an undulation in the plasma surface. We present evidence that this surface distortion is driven by thermal eddies associated with asymmetrical electron heating.
Accommodation, interpersonal justice, and the turnover intentions of employees with disabilities

Abstract The number of employees with disabilities in the workforce is increasing and accommodations are essential to the work of many of these individuals. Prior research has explored perceptions of accommodation requests as well as coworkers’ and managers’ reactions to accommodations; yet, we know little about how employees with disabilities experience their own accommodations. We draw from the disability literature as well as contemporary justice and social exchange theory to develop and subsequently test a multilevel moderated mediation model on this subject. We test our hypotheses with data from 4,083 employees nested in 256 workgroups across two time points. We find support for our prediction that accommodation-focused interpersonal justice influences turnover intentions. The effect of these justice perceptions was mediated by workgroup openness to communication. Further, we find that representation of accommodated employees with disabilities at the workgroup level plays an important role in these relationships. We look beyond the technical aspects of accommodation with this research to highlight the social experience of accommodation as a central driver of employee perceptions and work outcomes.
Galaxy formation and the peaks formalism

A large N-body simulation is used to compare the galaxies found by tagging peaks in the linear density field with the haloes that actually form. A variety of filters on the density field are tried in order to improve this correspondence, but none seems to do particularly well. The correlation function and velocity dispersion of the tagged peaks and the actual haloes also do not correspond very well. These comparisons bring into question the results of any study of galaxy formation that assumes that galaxies form at peaks in the initial density field, or simulations of large-scale structure that use the high-peak model to determine the galaxy distribution
Automated microarray for single-cell sorting and collection of lymphocytes following HIV reactivation

A promising strategy to cure HIV infected individuals is to use latency reversing agents (LRAs) to reactivate latent viruses, followed by host clearance of infected reservoir cells. However, reactivation of latent proviruses within infected cells is heterogeneous and often incomplete. This fact limits strategies to cure HIV which may require complete elimination of viable virus from all cellular reservoirs. For this reason, understanding the mechanism(s) of reactivation of HIV within cellular reservoirs is critical to achieve therapeutic success. Methodologies enabling temporal tracking of single cells as they reactivate followed by sorting and molecular analysis of those cells are urgently needed. To this end, microraft arrays were adapted to image T-lymphocytes expressing mCherry under the control of the HIV long terminal repeat (LTR) promoter, in response to the application of various LRAs (prostratin, iBET151, and SAHA). In response to prostratin, iBET151, and SAHA, 30.5 %, 11.2 %, and 12.1 % percentage of cells respectively, reactivated similar to that observed in other experimental systems. The arrays enabled large numbers of single cells (>25,000) to be imaged over time. mCherry fluorescence quantification identified cell subpopulations with differing reactivation kinetics. Significant heterogeneity was observed at the single cell level between different LRAs in terms of time to reactivation, rate of mCherry fluorescence increase upon reactivation, and peak fluorescence attained. In response to prostratin, subpopulations of T lymphocytes with slow and fast reactivation kinetics were identified. Single T-lymphocytes that were either fast or slow reactivators were sorted, and single-cell RNA-sequencing was performed. Different genes associated with inflammation, immune activation, and cellular and viral transcription factors were found. These results advance our conceptual understanding of HIV reactivation dynamics at the single-cell level toward a cure for HIV.
Proteome encoded determinants of protein sorting into extracellular vesicles

Extracellular vesicles (EVs) are membranous structures released by cells into the extracellular space and are thought to be involved in cell-to-cell communication. While EVs and their cargo are promising biomarker candidates, protein sorting mechanisms of proteins to EVs remain unclear. In this study, we ask if it is possible to determine EV association based on the protein sequence. Additionally, we ask what the most important determinants are for EV association. We answer these questions with explainable AI models, using human proteome data from EV databases to train and validate the model. It is essential to correct the datasets for contaminants introduced by coarse EV isolation workflows and for experimental bias caused by mass spectrometry. In this study, we show that it is indeed possible to predict EV association from the protein sequence: a simple sequence-based model for predicting EV proteins achieved an area under the curve of 0.77±0.01, which increased further to 0.84±0.00 when incorporating curated post-translational modification (PTM) annotations. Feature analysis shows that EV associated proteins are stable, polar, and structured with low isoelectric point compared to non-EV proteins. PTM annotations emerged as the most important features for correct classification; specifically palmitoylation is one of the most prevalent EV sorting mechanisms for unique proteins. Palmitoylation and nitrosylation sites are especially prevalent in EV proteins that are determined by very strict isolation protocols, indicating they could potentially serve as quality control criteria for future studies. This computational study offers an effective sequence-based predictor of EV associated proteins with extensive characterisation of the human EV proteome that can explain for individual proteins which factors contribute to their EV association.
Comparing two ways of measuring the power of party members in simple majority voting games

We examine two approaches to the problem of mea- suring the voting power of individuals in a voting body with an a priori coalition structure by means of the Shapley-Shubik index. In order to analyze this question we apply games with a priori unions and composite games. We compare these two approaches basing on voting games with 100 voters and different coalition structures and present our conclusions.
Novel diversity of polar Cyanobacteria revealed by genome-resolved metagenomics

Benthic microbial mats dominated by Cyanobacteria are important features of polar lakes. Although culture-independent studies have provided important insights into the diversity of polar Cyanobacteria, only a handful of genomes have been sequenced to date. Here, we applied a genome-resolved metagenomics approach to data obtained from Arctic, sub-Antarctic and Antarctic microbial mats. We recovered 37 metagenome-assembled genomes (MAGs) of Cyanobacteria representing 17 distinct species, most of which are only distantly related to genomes that have been sequenced so far. These include (i) lineages that are common in polar microbial mats such as the filamentous taxa Pseudanabaena , Leptolyngbya , Microcoleus / Tychonema and Phormidium; (ii) the less common taxa Crinalium and Chamaesiphon ; (iii) an enigmatic Chroococcales lineage only distantly related to Microcystis ; and (iv) an early branching lineage in the order Gloeobacterales that is distributed across the cold biosphere, for which we propose the name Candidatus Sivonenia alaskensis. Our results show that genome-resolved metagenomics is a powerful tool for expanding our understanding of the diversity of Cyanobacteria, especially in understudied remote and extreme environments.
The effectiveness of selection in a species affects the direction of amino acid frequency evolution

Nearly neutral theory predicts that the effectiveness of natural selection will vary with species’ neutral genetic diversity, or effective population size (Ne). This relationship allows comparisons among species with different effective population sizes to reveal subtle selective preferences for a variety of traits. We investigate one such trait – amino acid composition – and find that the effectiveness of selection, measured as the Codon Adaptation Index of Species (CAIS), can predict amino acid frequencies across vertebrates. In addition to amino acid frequency (an evolutionary outcome), we also measure amino acid flux (an evolutionary process) on the branches separating mouse and rat, and compare it to flux on the branches separating human and chimpanzee. We decompose flux into a shared component that reflects a variety of universal artifacts, and a species-specific component capturing any effects of Ne. The shared component of flux is correlated with structural disorder propensity. The species component is correlated with selective preference as measured by CAIS, i.e., the two methods agree on which amino acids are preferred under more effective selection, with the CAIS method providing higher statistical resolution, and producing a correlation with random peptide fitness effects. Within highly exchangeable pairs of amino acids, arginine is strongly preferred over lysine, and valine over isoleucine. Interestingly, these preferences match how thermophiles tend to differ from mesophilic relatives, as expected from theories of marginal protein stability at mutation-selection-drift balance.
Verification of nucleotide sequence reagent identities in original publications in high impact factor cancer research journals

Human gene research studies that describe wrongly identified nucleotide sequence reagents have been mostly identified in journals of low to moderate impact factor, where unreliable findings could be considered to have limited influence on future research. This study examined whether papers describing wrongly identified nucleotide sequences are also published in high impact factor cancer research journals. We manually verified nucleotide sequence identities in original Molecular Cancer articles published in 2014, 2016, 2018 and 2020, including nucleotide sequence reagents that were claimed to target circRNAs. Using keywords identified in problematic 2018 and 2020 Molecular Cancer papers, we also verified nucleotide sequence identities in 2020 Oncogene papers that studied miRNA(s) and/or circRNA(s). Overall, 3.8% (253/6,647) and 4.3% (50/1,165) nucleotide sequences that were verified in Molecular Cancer and Oncogene papers, respectively, were found to be wrongly identified. These wrongly identified nucleotide sequences were distributed across 18% (92/500) original Molecular Cancer papers, including 38% Molecular Cancer papers from 2020, and 40% (21/52) selected Oncogene papers from 2020. Original papers with wrongly identified nucleotide sequences were therefore unexpectedly frequent in two high impact factor cancer research journals, highlighting the risks of employing journal impact factors or citations as proxies for research quality.
Membrane free-energy landscapes derived from atomistic dynamics explain nonuniversal cholesterol-induced stiffening

All lipid membranes have inherent morphological preferences and resist deformation. Yet adaptations in membrane shape can and do occur at multiple length scales. While this plasticity is crucial for cellular physiology, the factors controlling the morphological energetics of lipid bilayers and the dominant mechanisms of membrane remodeling remain unclear. An ongoing debate regarding the universality of the stiffening effect of cholesterol underscores the challenges facing this field, both experimentally and theoretically, even for simple lipid mixtures. On the computational side, we have argued that enhanced- sampling all-atom molecular dynamics simulations are uniquely suited for quantification of membrane conformational energetics, not only because they minimize a-priori assumptions, but also because they permit analysis of bilayers in deformed states. To showcase this approach, we examine reported inconsistencies between alternative experimental measurements of bending moduli for cholesterol-enriched membranes. Specifically, we analyze lipid bilayers with different chain saturation, and compute free-energy landscapes for curvature deformations distributed over areas from ∼5 to ∼60 nm2. These enhanced simulations, totaling over 100 microseconds of sampling time, enable us to directly quantify both bending and tilt moduli, and to dissect the contributing factors and molecular mechanisms of curvature generation at each length scale. Our results show that cholesterol effects are lipid-specific, in agreement with giantvesicle measurements, and explain why experiments probing nanometer scale lipid dynamics diverge. In summary, we demonstrate that quantitative structure-mechanics relationships can now be established for heterogenous membranes, paving the way for addressing open fundamental questions in cell membrane mechanics. Significance Elucidating the energetics and mechanisms of membrane remodeling is an essential step towards understanding cell physiology. This problem is challenging, however, because membrane bending involves both large-scale and atomic-level dynamics, which are difficult to measure simultaneously. A recent controversy regarding the stiffening effect of cholesterol, which is ubiquitous in animal cells, illustrates this challenge. We show how enhanced molecular-dynamics simulations can bridge this length-scale gap and reconcile seemingly incongruent observations. This approach facilitates a conceptual connection between lipid chemistry and membrane mechanics, thereby providing a solid basis for future research on remodeling phenomena, such as in membrane trafficking or viral infection.