bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissolution of polydisperse ensembles of crystals in channels with a forced flow
Authors: Ivanov Alexander A. , Alexandrov Dmitri V. , Alexandrova Irina V.
Published: April 2020

A non-stationary integro-differential model describing the dissolution of polydisperse ensembles of crystals in channels filled with flowing liquid is analysed. The particle-size distribution function, the particle flux through an arbitrary cross-section of the channel, the particle concentration profile, as well as the disappearance intensity of particles are found analytically. It is shown that a nonlinear behaviour of solutions is completely defined by the source term of particles introduced into the channel. In particular, the model approximately describes the processes of dissolution and transport of drug microcrystals to the target sites in a living organism, taking into account complex dissolution kinetics of drug particles.

This article is part of the theme issue ‘Patterns in soft and biological matters’.
From nucleation and coarsening to coalescence in metastable liquids
Authors: Alexandrov Dmitri V. , Alexandrova Irina V.
Published: April 2020

The transition of a metastable liquid (supersaturated solution or supercooled melt) occurring from the intermediate stage (where the crystals nucleate and grow) to the concluding stage (where the larger particles evolve at the expense of the dissolution of smaller particles) is theoretically described, with allowance for various mass transfer mechanisms (reaction on the interface surface, volume diffusion, grain-boundary diffusion, diffusion along the dislocations) arising at the stage of Ostwald ripening (coalescence). The initial distribution function (its ‘tail’) for the concluding stage (forming as a result of the evolution of a particulate assemblage during the intermediate stage) is taken into account to determine the particle-size distribution function at the stage of Ostwald ripening. This modified distribution function essentially differs from the universal Lifshitz–Slyozov (LS) solutions for several mass transfer mechanisms. Namely, its maximum lies below and is shifted to the left in comparison with the LS asymptotic distribution function. In addition, the right branch of the particle-size distribution lies above and is shifted to the right of the LS blocking point. It is shown that the initial ‘tail’ of the particle-size distribution function completely determines its behaviour at the concluding stage of Ostwald ripening. The present theory agrees well with experimental data.

This article is part of the theme issue ‘Patterns in soft and biological matters’.
The effect of density changes on crystallization with a mushy layer
Authors: Nizovtseva Irina G. , Alexandrov Dmitri V.
Published: April 2020

A nonlinear problem with two moving boundaries of the phase transition, which describes the process of directional crystallization in the presence of a quasi-equilibrium two-phase layer, is solved analytically for the steady-state process. The exact analytical solution in a two-phase layer is found in a parametric form (the solid phase fraction plays the role of this parameter) with allowance for possible changes in the density of the liquid phase accordingly to a linearized equation of state and arbitrary value of the solid fraction at the boundary between the two-phase and solid layers. Namely, the solute concentration, temperature, solid fraction in the mushy layer, liquid and solid phases, mushy layer thickness and its velocity are found analytically. The theory under consideration is in good agreement with experimental data. The obtained solutions have great potential applications in analysing similar processes with a two-phase layer met in materials science, geophysics, biophysics and medical physics, where the directional crystallization processes with a quasi-equilibrium mushy layer can occur.

This article is part of the theme issue ‘Patterns in soft and biological matters’.
Thermoelectric magnetohydrodynamic control of melt pool dynamics and microstructure evolution in additive manufacturing
Authors: Kao A. , Gan T. , Tonry C. , Krastins I. , Pericleous K.
Published: April 2020

Large thermal gradients in the melt pool from rapid heating followed by rapid cooling in metal additive manufacturing generate large thermoelectric currents. Applying an external magnetic field to the process introduces fluid flow through thermoelectric magnetohydrodynamics. Convective transport of heat and mass can then modify the melt pool dynamics and alter microstructural evolution. As a novel technique, this shows great promise in controlling the process to improve quality and mitigate defect formation. However, there is very little knowledge within the scientific community on the fundamental principles of this physical phenomenon to support practical implementation. To address this multi-physics problem that couples the key phenomena of melting/solidification, electromagnetism, hydrodynamics, heat and mass transport, the lattice Boltzmann method for fluid dynamics was combined with a purpose-built code addressing solidification modelling and electromagnetics. The theoretical study presented here investigates the hydrodynamic mechanisms introduced by the magnetic field. The resulting steady-state solutions of modified melt pool shapes and thermal fields are then used to predict the microstructure evolution using a cellular automata-based grain growth model. The results clearly demonstrate that the hydrodynamic mechanisms and, therefore, microstructure characteristics are strongly dependent on magnetic field orientation.

This article is part of the theme issue ‘Patterns in soft and biological matters'.
Field-induced circulation flow in magnetic fluids
Authors: Musickhin Anton , Yu Zubarev Andrey , Raboisson-Michel Maxim , Verger-Dubois Gregory , Kuzhir Pavel
Published: April 2020

In this paper, we present results of a theoretical study of circulation flow in ferrofluids under the action of an alternating inhomogeneous magnetic field. The results show that the field with the amplitude of about 17 kA m
−1
and angular frequency 10 s
−1
can induce mesoscopic flow with a velocity amplitude of about 0.5 mm s
−1
. This mechanism can be used for intensification of drag delivery in blood vessels.

This article is part of the theme issue ‘Patterns in soft and biological matters'.
Stochastic phenomena in pattern formation for distributed nonlinear systems
Authors: Kolinichenko A. P. , Pisarchik A. N. , Ryashko L. B.
Published: April 2020

We study a stochastic spatially extended population model with diffusion, where we find the coexistence of multiple non-homogeneous spatial structures in the areas of Turing instability. Transient processes of pattern generation are studied in detail. We also investigate the influence of random perturbations on the pattern formation. Scenarios of noise-induced pattern generation and stochastic transformations are studied using numerical simulations and modality analysis.

This article is part of the theme issue ‘Patterns in soft and biological matters’.
Role of particle clusters on the rheology of magneto-polymer fluids and gels
Authors: Suarez-Fernandez William R. , Scionti Giuseppe , Duran Juan D. G. , Zubarev Andrey Yu. , Lopez-Lopez Modesto T.
Published: April 2020

Even in the absence of cross-linking, at large enough concentration, long polymer strands have a strong influence on the rheology of aqueous systems. In this work, we show that solutions of medium molecular weight (120 000–190 000 g mol−1) alginate polymer retained a liquid-like behaviour even for concentrations as large as 20% w/v. On the contrary, solutions of alginate polymer of larger (and also polydisperse) molecular weight (up to 600 000 g mol−1) presented a gel-like behaviour already at concentrations of 7% w/v. We dispersed micrometre-sized iron particles at a concentration of 5% v/v in these solutions, which resulted in either stable magnetic fluids or gels, depending on the type of alginate polymer employed (medium or large molecular weight, respectively). These magneto-polymer composites presented a shear-thinning behaviour that allowed injection through a syringe and recovery of the original properties afterwards. More interestingly, application of a magnetic field resulted in the formation of particle clusters elongated along the field direction. The presence of these clusters intensely affected the rheology of the systems, allowing a reversible control of their stiffness. We finally developed theoretical modelling for the prediction of the magnetic-sensitive rheological properties of these magneto-polymer colloids.

This article is part of the theme issue ‘Patterns in soft and biological matters'.
Targeted patterning of magnetic microparticles in a polymer composite
Authors: Borin Dmitry
Published: April 2020

Structured and polymerized in a uniform external magnetic field, polymer composites based on magnetic soft microparticles are considered. Variations of magnetic field parameters and material composition provide a possibility of targeted micro-structural patterning of these composites. The influences of parameter variations on the resulting internal micro-structure of the low concentrated specimens are evaluated and visualized using optical microscopy and microcomputed tomography. The experimental findings are discussed in order to provide advanced possibilities of controlled patterning of soft magnetic materials. It is experimentally demonstrated that the final three-dimensional morphology of composite structure is determined mainly by the concentration of magnetic powder. The intensity of the applied magnetic field influences the rate of structuring of particles in initially viscous media and, therefore, may provide a potential opportunity to obtain non-ergodic microstructures when the matrix is polymerized before the particles have completed the structuring process. The results obtained can serve as a basis for further development of the engineering method of targeted patterning. The method is intended to obtain a material with the desired microstructure by selecting specific parameters of external stimuli and components of the composite.

This article is part of the theme issue ‘Patterns in soft and biological matters’.
Collective in-plane magnetization in a two-dimensional XY macrospin system within the framework of generalized Ott–Antonsen theory
Authors: Tyulkina Irina V. , Goldobin Denis S. , Klimenko Lyudmila S. , Poperechny Igor S. , Raikher Yuriy L.
Published: April 2020

The problem of magnetic transitions between the low-temperature (macrospin ordered) phases in two-dimensional XY arrays is addressed. The system is modelled as a plane structure of identical single-domain particles arranged in a square lattice and coupled by the magnetic dipole–dipole interaction; all the particles possess a strong easy-plane magnetic anisotropy. The basic state of the system in the considered temperature range is an antiferromagnetic (AF) stripe structure, where the macrospins (particle magnetic moments) are still involved in thermofluctuational motion: the superparamagnetic blocking
T

b

temperature is lower than that (
T
af
) of the AF transition. The description is based on the stochastic equations governing the dynamics of individual magnetic moments, where the interparticle interaction is added in the mean-field approximation. With the technique of a generalized Ott–Antonsen theory, the dynamics equations for the order parameters (including the macroscopic magnetization and the AF order parameter) and the partition function of the system are rigorously obtained and analysed. We show that inside the temperature interval of existence of the AF phase, a static external field tilted to the plane of the array is able to induce first-order phase transitions from AF to ferromagnetic state; the phase diagrams displaying stable and metastable regions of the system are presented.

This article is part of the theme issue ‘Patterns in soft and biological matters’.
Patterns in soft and biological matters
Authors: Alexandrov Dmitri V. , Zubarev Andrey Yu.
Published: April 2020

The issue is devoted to theoretical, computer and experimental studies of internal heterogeneous patterns, their morphology and evolution in various soft physical systems—organic and inorganic materials (e.g. alloys, polymers, cell cultures, biological tissues as well as metastable and composite materials). The importance of these studies is determined by the significant role of internal structures on the macroscopic properties and behaviour of natural and manufactured tissues and materials. Modern methods of computer modelling, statistical physics, heat and mass transfer, statistical hydrodynamics, nonlinear dynamics and experimental methods are presented and discussed. Non-equilibrium patterns which appear during macroscopic transport and hydrodynamic flow, chemical reactions, external physical fields (magnetic, electrical, thermal and hydrodynamic) and the impact of external noise on pattern evolution are the foci of this issue. Special attention is paid to pattern formation in biological systems (such as drug transport, hydrodynamic patterns in blood and pattern dynamics in protein and insulin crystals) and to the development of a scientific background for progressive methods of cancer and insult therapy (magnetic hyperthermia for cancer therapy; magnetically induced drug delivery in thrombosed blood vessels). The present issue includes works on pattern growth and their evolution in systems with complex internal structures, including stochastic dynamics, and the influence of internal structures on the external static, dynamic magnetic and mechanical properties of these systems.

This article is part of the theme issue ‘Patterns in soft and biological matters’.
Rapid, large-scale, and effective detection of COVID-19 via non-adaptive testing
Authors: Täufer Matthias
Published: April 2020

Pooling of samples can increase lab capacity when using Polymerase chain reaction (PCR) to detect diseases such as COVID-19. However, pool testing is typically performed via anadaptive testing strategywhich requires a feedback loop in the lab and at least two PCR runs to confirm positive results. This can cost precious time. We discuss a non-adaptive testing method where each sample is distributed in a prescribed manner over several pools, and which yields reliable results after one round of testing. More precisely, assuming knowledge about the overall incidence rate, we calculate explicit error bounds on the number of false positives which scale favourably with pool size and sample multiplicity. This allows for hugely streamlined PCR testing and cuts in detection times for a large-scale testing scenario. A viable consequence of this method could be real-time screening of entire communities, frontline healthcare workers and international flight passengers, for example, using the PCR machines currently in operation.
Eco-evolutionary dynamics of prior selfing rate promotes the coexistence without niche partitioning under reproductive interference
Authors: Katsuhara Koki R. , Tachiki Yuuya , Iritani Ryosuke , Ushimaru Atushi
Published: April 2020

When the two or more plants species share the same pollinators, pollinator-mediated reproductive interference make coexistence difficult. Recent studies suggested prior autonomous selfing mitigate reproductive interference, could enabling coexistence without pollination niche partitioning (pre-emptive selfing hypothesis). However, there are no studies to test whether evolution of prior selfing promote the coexistence, considering eco-evolutionary dynamics of population size, selfing rate and inbreeding depression.

To examine conditions that the evolution of prior selfing promote coexistence under mutual reproductive interference especially in the point of view for pollinator availability and dynamics of inbreeding depression, we constructed individual-based model in which two plant species compete against each other in the form of mutual reproductive interference and can evolve prior autonomous selfing rate. We expected that purging of deleterious mutations could cause evolutionary rescue because inferior species could rescue population density through the evolution of prior selfing if the strength of inbreeding depression decreases with an increase of population’s selfing rate.

Our simulation demonstrated that the evolution of prior selfing could promote the coexistence while reproductive interference caused competitive exclusion without evolution. We found that lower pollinator availability tended to prefer rapid evolutionary shift to higher prior selfing rate, it neutralizes the negative effect of reproductive interference, and population dynamics exhibit neutral random walk in both species. When the strength of inbreeding depression decreased with an increase in population’s selfing rate, moderate pollinator availability resulted in long-term coexistence in which relative-abundance-dependent selection on the prior selfing rate rescue population density of inferior species intermittently.

Synthesis. We showed that the evolution of prior selfing could increase population growth rate of inferior species and consequently enable the long-term coexistence with evolutionary rescue. This is the new mechanisms explaining co-evolutionary coexistence of closely related plant species without niche partitioning and consistent with recent studies reported that closely related mixed-mating species are sympatrically growing even under the mutual reproductive interference.
Development of a simple and accurate molecular tool forSpodoptera frugiperdaspecies identification using LAMP
Authors: Kim Juil , Nam Hwa Yeun , Kwon Min , Kim Hyun Ju , Yi Hwi-Jong , Haenniger Sabine , Unbehend Melanie , Heckel David G.
Published: April 2020

The fall armyworm,Spodoptera frugiperdais a native species in the Americas. However, nowadays it is one of the most serious invasive lepidopteran pests in African and Asian countries.S. frugiperdahas been spread very quickly after the first outbreak was reported in many countries. Based on mt genome sequence alignment,S. frugiperdaspecific sequence region was identified in tRNAs coding region between NADH dehydrogenase, ND3 and ND5. By using this unique region, species diagnostic primers were designed and applied in LAMP (lamp loop mediated isothermal amplification) assay as well as conventional PCR to identify the field-collected samples ofS. frugiperda. Optimal incubation condition of LAMP assay was 61°C for 90 minutes with 4 LAMP primers, and additional loop primer increased the amplification efficiency. Also, wide range of DNA concentration responded in LAMP assay and minimum detectable DNA concentration was 10 pg. This LAMP assay was also applied in DNA releasing technique from larval and adult sample, without DNA extraction, 95°C incubation for five minutes of the tissue sample. This new molecular diagnostic method is easy to use and accurate. It possibly applied in intensive field monitoring ofS. frugiperdaand its ecological studies.
Comparison of SARS-CoV-2 infections among 3 species of non-human primates
Authors: Lu Shuaiyao , Zhao Yuan , Yu Wenhai , Yang Yun , Gao Jiahong , Wang Junbin , Kuang Dexuan , Yang Mengli , Yang Jing , Ma Chunxia , Xu Jingwen , Qian Xingli , Li Haiyan , Zhao Siwen , Li Jingmei , Wang Haixuan , Long Haiting , Zhou Jingxian , Luo Fangyu , Ding Kaiyun , Wu Daoju , Zhang Yong , Dong Yinliang , Liu Yuqin , Zheng Yingqiu , Lin Xiaochen , Jiao Li , Zheng Huanying , Dai Qing , Sun Qiangmin , Hu Yunzhang , Ke Changwen , Liu Hongqi , Peng Xiaozhong
Published: April 2020

COVID-19, caused by SARS-CoV-2 infection, has recently been announced as a pandemic all over the world. Plenty of diagnostic, preventive and therapeutic knowledges have been enriched from clinical studies since December 2019. However, animal models, particularly non-human primate models, are urgently needed for critical questions that could not be answered in clinical patients, evaluations of anti-viral drugs and vaccines. In this study, two families of non-human primates, Old world monkeys (12Macaca mulatta, 6Macaca fascicularis) and New world monkeys (6Callithrix jacchus), were experimentally inoculated with SARS-CoV-2. Clinical signs were recorded. Samples were collected for analysis of viral shedding, viremia and histopathological examination. Increased body temperature was observed in 100% (12/12)M. mulatta, 33.3% (2/6)M. fascicularisand none (0/6) ofC. jacchuspost inoculation of SARS-CoV-2. All ofM. mulattaandM. fascicularisshowed chest radiographic abnormality. Viral genomes were detected in nasal swabs, throat swabs, anal swabs and blood from all 3 species of monkeys. Viral shedding from upper respiratory samples reached the peak between day 6 and day 8 post inoculation. From necropsiedM. mulattaandM. fascicularis, the tissues showing virus positive were mainly lung, weasand, bronchus and spleen. No viral genome was seen in any of tissues from 2 necropsiedC. jacchus.Severe gross lesions and histopathological changes were observed in lung, heart and stomach of SARS-CoV-2 infected animals. In summary, we have established a NHP model for COVID-19, which could be used to evaluate drugs and vaccines, and investigate viral pathogenesis.M. mulattais the most susceptible to SARS-CoV-2 infection, followed byM. fascicularisandC. jacchus.

One Sentence Summary

M. mulattais the most susceptible to SARS-CoV-2 infection as compared toM. fascicularisandC. jacchus.
Symptom-level genetic modelling identifies novel risk loci and unravels the shared genetic architecture of anxiety and depression
Authors: Thorp Jackson G. , Campos Adrian I. , Grotzinger Andrew D. , Gerring Zachary , An Jiyuan , Ong Jue-Sheng , Wang Wei ,   23andMe Research Team, Shringarpure Suyash , Byrne Enda M. , MacGregor Stuart , Martin Nicholas G. , Medland Sarah E. , Middeldorp Christel M. , Derks Eske M.
Published: April 2020

Depression and anxiety are highly prevalent and comorbid psychiatric traits that cause considerable burden worldwide. Previous studies have revealed substantial genetic overlap between depression, anxiety, and a closely related personality trait – neuroticism. Here, we use factor analysis and genomic structural equation modelling (Genomic SEM) to investigate the genetic factor structure underlying 28 items assessing depression, anxiety and neuroticism. Symptoms of depression and anxiety loaded on two distinct, although genetically correlated factors, while neuroticism items were partitioned between them. We leveraged this factor structure to conduct multivariate genome-wide association analyses on latent factors of anxiety symptoms and depressive symptoms, using data from over 400,000 individuals in the UK Biobank. We identified 89 independent variants for the depressive factor (61 genomic loci, 29 novel) and 102 independent variants for the anxiety factor (73 loci, 71 novels). Of these variants, 72% and 78%, respectively, replicated in an independent 23andMe cohort of ∼1.9 million individuals with self-reported diagnosis of depression (634,037 cases) and anxiety (624,615 cases). A pairwise GWAS analysis revealed substantial genetic overlap between anxiety and depression but also showed trait-specific genetic influences; e.g. genomic regions specific to depressive symptoms were associated with hypertriglyceridemia, while regions specific to anxiety symptoms were linked to blood pressure phenotypes. The substantial genetic overlap between the two traits was further evidenced by a lack of trait-specificity in polygenic prediction of depressive and anxiety symptoms. Our results provide novel insight into the genetic architecture of depression and anxiety and comorbidity between them.
Acoustic regularities in infant-directed speech and song across cultures
Authors: Hilton Courtney B. , Moser Cody J. , Bertolo Mila , Lee-Rubin Harry , Amir Dorsa , Bainbridge Constance M. , Simson Jan , Knox Dean , Glowacki Luke , Alemu Elias , Galbarczyk Andrzej , Jasienska Grazyna , Ross Cody T. , Neff Mary Beth , Martin Alia , Cirelli Laura K. , Trehub Sandra E. , Song Jinqi , Kim Minju , Schachner Adena , Vardy Tom A. , Atkinson Quentin D. , Salenius Amanda , Andelin Jannik , Antfolk Jan , Madhivanan Purnima , Siddaiah Anand , Placek Caitlyn D. , Salali Gul Deniz , Keestra Sarai , Singh Manvir , Collins Scott A. , Patton John Q. , Scaff Camila , Stieglitz Jonathan , Cutipa Silvia Ccari , Moya Cristina , Sagar Rohan R. , Anyawire Mariamu , Mabulla Audax , Wood Brian M. , Krasnow Max M. , Mehr Samuel A.
Published: April 2020

The forms of many species’ vocal signals are shaped by their functions1–15. In humans, a salient context of vocal signaling is infant care, as human infants are altricial16, 17. Humans often alter their vocalizations to produce “parentese”, speech and song produced for infants that differ acoustically from ordinary speech and song18–35in fashions that have been proposed to support parent-infant communication and infant language learning36–39; modulate infant affect33, 40–45; and/or coordinate communicative interactions with infants46–48. These theories predict a form-function link in infant-directed vocalizations, with consistent acoustic differences between infant-directed and adult-directed vocalizations across cultures. Some evidence supports this prediction23, 27, 28, 32, 49–52, but the limited generalizability of individual ethnographic reports and laboratory experiments53and small stimulus sets54, along with intriguing reports of counterexamples55–62, leave the question open. Here, we show that people alter the acoustic forms of their vocalizations in a consistent fashion across cultures when speaking or singing to infants. We collected 1,615 recordings of infant- and adult-directed singing and speech produced by 410 people living in 21 urban, rural, and small-scale societies, and analyzed their acoustic forms. We found cross-culturally robust regularities in the acoustics of infant-directed vocalizations, such that infant-directed speech and song were reliably classified from acoustic features found across the 21 societies studied. The acoustic profiles of infant-directedness differed across language and music, but in a consistent fashion worldwide. In a secondary analysis, we studied whether listeners are sensitive to these acoustic features, playing the recordings to 51,065 people recruited online, from many countries, who guessed whether each vocalization was infant-directed. Their intuitions were largely accurate, predictable in part by acoustic features of the recordings, and robust to the effects of linguistic relatedness between vocalizer and listener. By uniting rich cross-cultural data with computational methods, we show links between the production of vocalizations and cross-species principles of bioacoustics, informing hypotheses of the psychological functions and evolution of human communication.
Effect of protein structure on evolution of cotranslational folding
Authors: Zhao V. , Jacobs W. M. , Shakhnovich E. I.
Published: April 2020

Cotranslational folding is expected to occur when the folding speed of the nascent chain is faster than the translation speed of the ribosome, but it is difficult to predict which proteins cotranslationally fold. Here, we simulate evolution of model proteins to investigate how native structure influences evolution of cotranslational folding. We developed a model that connects protein folding during and after translation to cellular fitness. Model proteins evolved improved folding speed and stability, with proteins adopting one of two strategies for folding quickly. Low contact order proteins evolve to fold cotranslationally. Such proteins adopt native conformations early on during the translation process, with each subsequently translated residue establishing additional native contacts. On the other hand, high contact order proteins tend not to be stable in their native conformations until the full chain is nearly extruded. We also simulated evolution of slowly translating codons, finding that slowing translation at certain positions enhances cotranslational folding. Finally, we investigated real protein structures using a previously published dataset that identified evolutionarily conserved rare codons inE. coligenes and associated such codons with cotranslational folding intermediates. We found that protein substructures preceding conserved rare codons tend to have lower contact orders, in line with our finding that lower contact order proteins are more likely to fold cotranslationally. Our work shows how evolutionary selection pressure can cause proteins with local contact topologies to evolve cotranslational folding.

Statement of significance

Substantial evidence exists for proteins folding as they are translated by the ribosome. Here we developed a biologically intuitive evolutionary model to show that avoiding premature protein degradation can be a sufficient evolutionary force to drive evolution of cotranslational folding. Furthermore, we find that whether a protein’s native fold consists of more local or more nonlocal contacts affects whether cotranslational folding evolves. Proteins with local contact topologies are more likely to evolve cotranslational folding through nonsynonymous mutations that strengthen native contacts as well as through synonymous mutations that provide sufficient time for cotranslational folding intermediates to form.
Acoustic analysis and playback experiments do not support the taxonomic revision of the Central and Western Canary Islands subspecies of the Eurasian Stone-curlew (Burhinus o. distinctus)
Authors: Dragonetti Marco , Caprara Massimo , Rodríguez-Godoy Felipe , Barone Rubén , Cerdeña V. Rubén , Giunchi Dimitri
Published: April 2020

Capsule

Acoustic analysis does not support the elevation ofB. o. distinctusto full species.

Aims

To verify whether the vocal repertoires ofB. o. oedicnemusandB. o. distinctusshow biologically significant quantitative and qualitative differences.

Methods

Integration of acoustic analysis of some of the most frequently uttered call types recorded in Italy and in Canary Islands with playback experiments.

Results

The vocal repertoires of the individuals belonging to the two subspecies were rather similar, but the quantitative analysis of acoustic parameters evidenced some differences between the considered populations. In particular, the three most used call types showed higher frequency and higher utterance rhythm forB. o. distinctusthan forB. o. eodicnemus. Playback experiments indicated that individuals from the nominate subspecies responded in the same way to the playback of calls of individuals belonging to both subspecies.

Conclusion

Acoustic analysis supports the distinctiveness of Stone-curlew populations from Central and Western Canary Islands, thus confirming the available morphological and genetic data. These results, however, do not suggest the elevation ofB. o. distinctusto full species.
In vitroandin silicoanalyses of the angiotensin-I converting enzyme inhibitory activity of peptides identified fromBellamya bengalensisprotein hydrolysates
Authors: Dey Tanmoy Kumar , Chatterjee Roshni , Roychoudhury Anadi , Paul Debjyoti , Mandal Rahul Shubhra , Roy Souvik , Dhar Pubali
Published: April 2020

The study focuses on identification of ACE-inhibitory peptides from the proteolytic digests of muscle protein ofBellamya bengalensisand its underlying mechanism. 120 min Alcalase-hydrolysates were ultrafiltered to isolate the small peptide fraction (<3kDa) andin vitroACE-inhibitory activity was analyzed. The IC50value of the 120 min hydrolysate ultafiltered fraction was found to be 86.74 ± 0.575 µg/mL, while the IC50of Lisinopril is 0.31 ± 0.07 µg/mL. This fraction was assessed in MALDI-ToF mass-spectrometer and five peptides were sequenced viade novosequencing. The ACE-inhibitory potential of the peptides have a positive correlation with the hydrophobicity of the amino acids. Synthetic analogue of the peptide (IC50value 8.52 ± 0.779 µg/mL) was used to understand the thermodynamics of the inhibition by checking the binding affinity of the peptide to ACE by Isothermal titration calorimetry compared with lisinopril, and further substantiated byin silicosite specific molecular docking study.
Estimation of cellularity in tumours treated with Neoadjuvant therapy: A comparison of Machine Learning algorithms
Authors: Ortega-Ruíz Mauricio Alberto , Karabağ Cefa , Garduño Victor García , Reyes-Aldasoro Constantino Carlos
Published: April 2020

This paper describes a method for residual tumour cellularity (TC) estimation in Neoadjuvant treatment (NAT) of advanced breast cancer. This is determined manually by visual inspection by a radiologist, then an automated computation will contribute to reduce time workload and increase precision and accuracy. TC is estimated as the ratio of tumour area by total image area estimated after the NAT. The method proposed computes TC by using machine learning techniques trained with information on morphological parameters of segmented nuclei in order to classify regions of the image as tumour or normal. The data is provided by the 2019 SPIE Breast challenge, which was proposed to develop automated TC computation algorithms. Three algorithms were implemented: Support Vector Machines, Nearest K-means and Adaptive Boosting (AdaBoost) decision trees. Performance based on accuracy is compared and evaluated and the best result was obtained with Support Vector Machines. Results obtained by the methods implemented were submitted during ongoing challenge with a maximum of 0.76 of prediction probability of success.
Isolated Nuclei Stiffen in Response to Low Intensity Vibration
Authors: Newberg J , Schimpf J , Woods K , Loisate S , Davis P H , Uzer G
Published: April 2020

The nucleus, central to all cellular activity, relies on both direct mechanical input and its molecular transducers to sense and respond to external stimuli. While it has been shown that isolated nuclei can adapt to applied forceex vivo, the mechanisms governing nuclear mechanoadaptation in response to physiologic forcesin vivoremain unclear. To investigate nuclear mechanoadaptation in cells, we developed an atomic force microscopy (AFM) based procedure to probe live nuclei isolated from mesenchymal stem cells (MSCs) following the application of low intensity vibration (LIV) to determine whether nuclear stiffness increases as a result of LIV. Results indicated that isolated nuclei were, on average, 30% softer than nuclei tested within intact MSCs prior to LIV. When the nucleus was isolated following LIV (0.7g, 90Hz, 20min) applied four times (4x) separated by 1h intervals, stiffness of isolated nuclei increased 75% compared to non-LIV controls. LIV-induced nuclear stiffening required functional Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, but was not accompanied by increased levels of the nuclear envelope proteins LaminA/C or Sun-2. While depleting LaminA/C or Sun-1&2 resulted in either a 47% or 39%increasedheterochromatin to nuclear area ratio in isolated nuclei, the heterochromatin to nuclear area ratio wasdecreasedby 25% in LIV-treated nuclei compared to controls, indicating LIV-induced changes in the chromatin structure. Overall, our findings indicate that increased apparent cell stiffness in response to exogenous mechanical challenge of MSCs in the form of LIV is in part retained by increased nuclear stiffness and changes in chromatin structure.
Evaluation of Neuropharmacological Effects of Different Chemical Extracts ofFlemingia Stricta(Roxb.) Leaves
Authors: Biozid Md. Shahrear , Alam Mohammad Nazmul , Abeden Md. Jainul , Rahman Md. Masudur , Islam Md. Rafikul
Published: April 2020

Background

Traditional preparation of the leaf ofFlemingia stricta(Fabaceae) Roxb., a medicinal plant of the Indian subcontinent, has been used for treatment of different diseases as herbal preparation. Our purpose was to analyze Neuropharmacological effects of different chemical extracts ofFlemingia strictaRoxb. as particular form of behavioral inhibition that occurs in response to novel environmental events.

Methods

In present study, the anxiogenic activity of crude extracts ofFlemingia strictaleaves was determined using standard animal behavioral models, such as hole cross and open field; Sedative property and anxiolytic potential were assessed by conducting thiopental sodium induced sleeping times tests and elevated plus maze test respectively.

Results

The crude extracts at both dose (200 and 400mg/kg) exhibited a significant (P<0.05, P<0.01) dose-dependent suppression of motor activity and exploratory activity of mice in both open field and hole cross test. In anxiolytic study, extracts displayed increased percentage of entry into open arm at the dose of 200 and 400mg/kg. Extracts produced a significant (P<0.05, P<0.01) increase in sleeping duration and reduction of onset of sleep compared to sodium thiopental at both doses (200 and 400mg/kg).

Conclusion

This study demonstrates that the treated extracts have significant central nervous system depressant effect. Further studies on the active constituent of the extract can provide approaches for therapeutic intervention.
Comparative morphological and transcriptomic analyses reveal novel chemosensory genes in the poultry red mite,Dermanyssus gallinaeand knockdown by RNA interference
Authors: Bhowmick Biswajit , Tang Yu , Lin Fang , Øines Øivind , Zhao Jianguo , Liao Chenghong , Ignell Rickard , Hansson Bill S. , Han Qian
Published: April 2020

Detection of chemical cues via chemosensory receptor proteins are essential for most animals, and underlies critical behaviors, including location and discrimination of food resources, identification of sexual partners and avoidance of predators. The current knowledge of how chemical cues are detected is based primarily on data acquired from studies on insects, while our understanding of the molecular basis for chemoreception in acari, mites in particular, remains limited. The poultry red mite (PRM),Dermanyssus gallinae, is one of the most important blood-feeding ectoparasites of poultry. Unlike other ectoparasites on animals, PRM feeds mainly at night. During daytime, these animals hide themselves in crevices around the poultry house. The diversity in habitat usage, as well as the demonstrated host finding and avoidance behaviors suggest that PRM relies on their sense of smell to orchestrate complex behavioral decisions. Comparative transcriptome analyses revealed the presence of candidate variant ionotropic receptors (IRs), odorant binding proteins (OBPs), niemann-pick proteins type C2 (NPC2) and sensory neuron membrane proteins (SNMPs). Some of these proteins were highly and differentially expressed in the forelegs of PRM. Rhodopsin-like G protein-coupled receptors (GPCRs) were also identified, while insect-specific odorant receptors (ORs) and odorant co-receptors (ORcos) were not detected. Furthermore, using scanning electron microscopy (SEM), the tarsomeres of all legs pairs were shown to be equipped with sensilla chaetica with or without tip pores, while wall-pored olfactory sensilla chaetica were restricted to the distal-most tarsomeres of the forelegs. Further, using the conserved odorant binding protein (OBP) as a test case, the results showed that RNA interference (RNAi) can be induced inD. gallinaechemosensory tissues. This study is the first to describe the presence of chemosensory genes in anyDermanyssidaefamily. It is also the first report of chemosensory gene knockdown by RNAi in any mite species and demonstrate that their diminutive size, less than 1 mm, is not a major impediment when applying gene knockdown approaches. Our findings make a significant step forward in understanding the chemosensory abilities ofD. gallinae.
Pen-strep influence macrophage mechanical property and mechano-response to microenvironment
Authors: Zhao Weikang , Hu Buwei , Zhang Xuexiang , Wang Pingping
Published: April 2020

Penicillin-streptomycin (Pen-strep) is a common antibiotic used to prevent bacterial infection in cell culture and clinical treatment. Current research found pen-strep increased macrophage modulus but limited influence on cell adhesion. Phalloidin statin image indicates pen-strep mediate cell morphology on different extracellular matrix coated surface. The roundness analyzes further illustrated pen-strep promote cell spread on PDMS rubber, type I collagen, laminin, poly amino acid, poly-RGD peptides. Finally, YAP-1 and TAZ upregulation and β1 integrin downregulation may be the causes of cell elasticity and mechano-response to extracellular matrix (ECM) change.
Water as a reactant in the differential expression of proteins in cancer
Authors: Dick Jeffrey M.
Published: April 2020

How the abundances of proteins are shaped by tumor microenvironments, such as hypoxic conditions and higher water content compared to normal tissues, is an important question for cancer biochemistry. Compositional analysis of more than 250 datasets for differentially expressed proteins compiled from the literature reveals a higher stoichiometric hydration state in multiple cancer types compared to normal tissue; this trend is also evident in pan-cancer transcriptomic and proteomic datasets from The Cancer Genome Atlas and Human Protein Atlas. These findings support the notion of a basic physicochemical link between increased water content in tumors and the patterns of gene and protein expression in cancer. The generally increased hydration state is juxtaposed with a wide spectrum of carbon oxidation states of differentially expressed proteins, which may be associated with different gene ages, host tissue properties and metabolic features of specific cancer types.
Socioeconomic inequalities across life and premature mortality from 1971 to 2016: findings from three British birth cohorts born in 1946, 1958, and 1970
Authors: Fluharty Meg E , Hardy Rebecca , Ploubidis George B. , Pongiglione Benedetta , Bann David
Published: April 2020

Introduction

Disadvantaged socioeconomic position (SEP) in early and adult life has been repeatedly associated with premature mortality. However, it is unclear whether these inequalities differ across time, nor if they are consistent across different SEP indicators.

Methods

British birth cohorts born in 1946, 1958 and 1970 were used, and multiple SEP indicators in early and adult life were examined. Deaths were identified via national statistics or notifications. Cox proportional hazard models were used to estimate associations between SEP indicators and mortality risk—from 26-43 (n=40,784), 26-58 (n=35,431), and 26-70 years (n=5,353).

Results

More disadvantaged SEP was associated with higher mortality risk—magnitudes of association were similar across cohort and each SEP indicator. For example, hazards ratios (95% CI) between 26-43 years comparing lowest to highest father’s social class were 2.74 (1.02—7.32) in 1946c, 1.66 (1.03—2.69) in 1958c, and 1.94 (1.20—3.15) in 1970c. Childhood social class, adult social class, and housing tenure were each independently associated with mortality risk.

Conclusions

Socioeconomic circumstances in early and adult life appear to have had persisting associations with premature mortality from 1971—2016. This reaffirms the need to address socioeconomic factors across life to reduce inequalities in survival to older age.
New approximations, and policy implications, from a delayed dynamic model of a fast pandemic
Authors: Vyasarayani C. P. , Chatterjee Anindya
Published: April 2020

We study an SEIQR (Susceptible-Exposed-Infectious-Quarantined-Recovered) model for an infectious disease, with time delays for latency and an asymptomatic phase. For fast pandemics where nobody has prior immunity and everyone has immunity after recovery, the SEIQR model decouples into two nonlinear delay differential equations (DDEs) with five parameters. One parameter is set to unity by scaling time. The subcase of perfect quarantining and zero self-recovery before quarantine, with two free parameters, is examined first. The method of multiple scales yields a hyperbolic tangent solution; and a long-wave approximation yields a first order ordinary differential equation (ODE). With imperfect quarantining and nonzero self-recovery, the long-wave approximation is a second order ODE. These three approximations each capture the full outbreak, from infinitesimal initiation to final saturation. Low-dimensional dynamics in the DDEs is demonstrated using a six state non-delayed reduced order model obtained by Galerkin projection. Numerical solutions from the reduced order model match the DDE over a range of parameter choices and initial conditions. Finally, stability analysis and numerics show how correctly executed time-varying social distancing, within the present model, can cut the number of affected people by almost half. Alternatively, faster detection followed by near-certain quarantining can potentially be even more effective.
Comparison of different exit scenarios from the lock-down for COVID-19 epidemic in the UK and assessing uncertainty of the predictions
Authors: Zhigljavsky Anatoly , Whitaker Roger , Fesenko Ivan , Kremnizer Kobi , Noonan Jack
Published: April 2020

We model further development of the COVID-19 epidemic in the UK given the current data and assuming different scenarios of handling the epidemic. In this research, we further extend the stochastic model suggested in [1] and incorporate in it all available to us knowledge about parameters characterising the behaviour of the virus and the illness induced by it. The models we use are flexible, comprehensive, fast to run and allow us to incorporate the following:

time-dependent strategies of handling the epidemic;

spatial heterogeneity of the population and heterogeneity of development of epidemic in different areas;

special characteristics of particular groups of people, especially people with specific medical pre-histories and elderly.

Standard epidemiological models such as SIR and many of its modifications are not flexible enough and hence are not precise enough in the studies that requires the use of the features above. Decision-makers get serious benefits from using better and more flexible models as they can avoid of nuanced lock-downs, better plan the exit strategy based on local population data, different stages of the epidemic in different areas, making specific recommendations to specific groups of people; all this resulting in a lesser impact on economy, improved forecasts of regional demand upon NHS allowing for intelligent resource allocation.

In this work, we investigate the sensitivity of the model to all its parameters while considering several realistic scenarios of what is likely to happen with the dynamics of the epidemic after the lock-down, which has started on March 23, is lifted.

The main findings from this research are the following

very little gain, in terms of the projected hospital bed occupancy and expected numbers of death, of continuing the lock-down beyond April 13, provided the isolation of older and vulnerable people continues and the public carries on some level of isolation in the next 2-3 months, see Section 3.1;

in agreement with [1], isolation of the group of vulnerable people during the next 2-3 months should be one of the main priorities, see Section 3.2;

it is of high importance that the whole population carries on some level of isolation in the next 2-3 months, see Section 3.5;

the timing of the current lock-down seems to be very sensible in areas like London where the epidemic has started to pick up by March 23; in such areas the second wave of epidemic is not expected, see figures in Sections 2.2 and 3;

the epidemic should almost completely finish in July, no global second wave should be expected, except areas where the first wave is almost absent, see Section 3.4.