bluuebunny/crossref_metadata_2025 huggingface dataset:
Dysbalance of ACE2 levels – a possible cause for severe COVID‐19 outcome in COPD
Authors: Fließer Elisabeth , Birnhuber Anna , Marsh Leigh M , Gschwandtner Elisabeth , Klepetko Walter , Olschewski Horst , Kwapiszewska Grazyna
Published: May 2021

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) poses a serious threat to healthcare systems worldwide. Binding of the virus to angiotensin‐converting enzyme 2 (ACE2) is an important step in the infection mechanism. However, it is unknown if ACE2 expression in patients with chronic lung diseases (CLDs), such as chronic obstructive pulmonary disease (COPD), idiopathic pulmonary arterial hypertension (IPAH), or pulmonary fibrosis (PF), is changed as compared to controls. We used lung samples from patients with COPD (n = 28), IPAH (n = 10), and PF (n = 10) as well as healthy control donor (n = 10) tissue samples to investigate the expression of ACE2 and related cofactors that might influence the course of SARS‐CoV‐2 infection. Expression levels of the ACE2 receptor, the putative receptor CD147/BSG, and the viral entry cofactors TMPRSS2 (transmembrane serine protease 2), EZR, and FURIN were determined by quantitative PCR and in open‐access RNA sequencing datasets. Immunohistochemical and single‐cell RNA sequencing (scRNAseq) analyses were used for localization and coexpression, respectively. Soluble ACE2 (sACE2) plasma levels were analyzed by enzyme‐linked immunosorbent assay. In COPD as compared to donor, IPAH, and PF lung tissue, gene expression of ACE2, TMPRSS2, and EZR was significantly elevated, but circulating sACE2 levels were significantly reduced in COPD and PF plasma compared to healthy control and IPAH plasma samples. Lung tissue expressions of FURIN and CD147/BSG were downregulated in COPD. None of these changes were associated with changes in pulmonary hemodynamics. Histological analysis revealed coexpression of ACE2, TMPRSS2, and Ezrin in bronchial regions and epithelial cells. This was confirmed by scRNAseq analysis. There were no significant expression changes of the analyzed molecules in the lung tissue of IPAH and idiopathic PF as compared to control. In conclusion, we reveal increased ACE2 and TMPRSS2 expression in lung tissue with a concomitant decrease of protective sACE2 in COPD patients. These changes represent the possible risk factors for an increased susceptibility of COPD patients to SARS‐CoV‐2 infection.
Variation in developmental rates is not linked to environmental unpredictability in annual killifishes
Authors: Rowiński Piotr K. , Sowersby Will , Näslund Joacim , Eckerström‐Liedholm Simon , Gotthard Karl , Rogell Björn
Published: May 2021

Comparative evidence suggests that adaptive plasticity may evolve as a response to predictable environmental variation. However, less attention has been placed on unpredictable environmental variation, which is considered to affect evolutionary trajectories by increasing phenotypic variation (or bet hedging). Here, we examine the occurrence of bet hedging in egg developmental rates in seven species of annual killifish that originate from a gradient of variation in precipitation rates, under three treatment incubation temperatures (21, 23, and 25°C). In the wild, these species survive regular and seasonal habitat desiccation, as dormant eggs buried in the soil. At the onset of the rainy season, embryos must be sufficiently developed in order to hatch and complete their life cycle. We found substantial differences among species in both the mean and variation of egg development rates, as well as species‐specific plastic responses to incubation temperature. Yet, there was no clear relationship between variation in egg development time and variation in precipitation rate (environmental predictability). The exact cause of these differences therefore remains enigmatic, possibly depending on differences in other natural environmental conditions in addition to precipitation predictability. Hence, if species‐specific variances are adaptive, the relationship between development and variation in precipitation is complex and does not diverge in accordance with simple linear relationships.
Utilization of four galactans by Bacteroides thetaiotaomicron A4 based on transcriptome
Authors: Li Song , Zhang Baojie , Hu Jielun , Zhong Yadong , Sun Yonggan , Nie Shaoping
Published: May 2021

The interaction between gut microbiota and polysaccharide is being paid more and more attention. Galactan is a kind of polysaccharide mainly composed of galactose, and it has been shown to play a significant role in regulating gut microbiota. Bacteroides thetaiotaomicron is considered as the best degrader of polysaccharides. The purpose of this paper was to investigate the utilization of four different galactans, including agarose, carrageenan, arabinogalactan, and glucofucogalactan, by our own isolated B. thetaiotaomicron A4. Samples of cultures grown on either four galactans groups or control groups were collected. The change of OD600, pH, and short‐chain fatty acids (SCFAs) during fermentation were determined, and growth curve and transcriptome of B. thetaiotaomicron A4 were studied. B. thetaiotaomicron A4 could utilize the four galactans and grew well on them, with carrageenan being most utilized, followed by arabinogalactan, glucofucogalactan, and agarose. SCFAs (mainly acetic acid and propionic acid) produced along with the decreased pH during fermentation. A large number of genes of B. thetaiotaomicron A4 were upregulated and functioned in different pathways during the degradation of the four galactans. The carbohydrate metabolism‐related pathways of B. thetaiotaomicron A4 were enriched after feeding the four galactans, although the specific pathways were different among four galactans groups. The different structural characteristics of four galactans required that B. thetaiotaomicron A4 could excrete corresponding enzymes to degrade them. These results help to understand the interaction between galactans and gut microbe.
An evaluation of assumptions underlying respondent‐driven sampling and the social contexts of sexual and gender minority youth participating in HIV clinical trials in the United States
Authors: Wirtz Andrea L. , Iyer Jessica R. , Brooks Durryle , Hailey‐Fair Kimberly , Galai Noya , Beyrer Chris , Celentano David , Arrington‐Sanders Renata ,   PUSH Study Group
Published: May 2021

Introduction

Respondent‐driven sampling (RDS) has been an effective sampling strategy for HIV research in many settings, but has had limited success among some youth in the United States. We evaluated a modified RDS approach for sampling Black and Latinx sexual and gender minority youth (BLSGMY) and explored how lived experiences and social contexts of BLSGMY youth may impact traditional RDS assumptions.

Methods

RDS was implemented in three US cities, Baltimore, Philadelphia and Washington DC, to engage BLSGMY aged 15 to 24 years in HIV prevention or care intervention trials. RDS was modified to include targeted seed recruitment from venues, Internet and health clinics, and provided options for electronic or paper coupons. Qualitative interviews were conducted among a sub‐sample of RDS participants to explore their experiences with RDS. Interviews were coded using RDS assumptions as an analytic framework.

Results

Between August 2017 and October 2019, 405 participants were enrolled, 1670 coupons were distributed, with 133 returned, yielding a 0.079 return rate. The maximum recruitment depth was four waves among seeds that propagated. Self‐reported median network size was 5 (IQR 2 to 10) and reduced to 3 (IQR 1 to 5) when asked how many peers were seen in the past 30 days. Qualitative interviews (n = 27) revealed that small social networks, peer trust and targeted referral of peers with certain characteristics challenged network, random recruitment, and reciprocity assumptions of RDS. HIV stigma and research hesitancy were barriers to participation and peer referral. Other situational factors, such as phone ownership and access to reliable transportation, reportedly created challenges for referred peers to participate in research.

Conclusions

Small social networks and varying relationships with peers among BLSGMY challenge assumptions that underlie traditional RDS. Modified RDS approaches, including those that incorporate social media, may support recruitment for community‐based research but may challenge assumptions of reciprocal relationships. Research hesitancy and situational barriers are relevant and must be addressed across any sampling method and study design that includes BLSGMY in the United States.
Organisational support and turnover intentions: A moderated mediation approach
Authors: Pahlevan Sharif Saeed , Bolt Ester Ellen Trees , Ahadzadeh Ashraf Sadat , Turner Jason James , Sharif Nia Hamid
Published: May 2021

Aim

The current study aims to examine the moderating role of psychological ownership in the process that translates organisational support into nurses’ turnover intentions through job satisfaction.

Design

A cross‐sectional research design was used to test the hypotheses.

Method

Using a purposive sampling 341 self‐completed survey data were collected from nurses working in two public hospitals in Iran. Structural equation modelling was used to analyse the data.

Result

The research revealed that organisational support and job satisfaction were negatively related to a healthcare professionals’ turnover intention. Moreover, job satisfaction mediated the negative relationship between organisational support and turnover intention. The research also revealed that psychological ownership strengthened the positive relationship between organisational support and job satisfaction.
Chemotaxonomy of Aster species from the Qinghai‐Tibetan Plateau based on metabolomics
Authors: Li Li , He Lili , Su Xueyan , Amu Hamamozhi , Li Jing , Zhang Zhifeng
Published: May 2021

Introduction

The genus Aster plants have been widely used for thousands of years in the Qinghai‐Tibetan Plateau for the clearing of heat, detoxification, and the treatment of seasonal pandemic diseases. Although the presence of several flavonoid compounds in Aster has been reported by previous studies, the diversity of secondary metabolites within and among species is relatively unknown.

Objective

The metabolite profile of one Aster species was systematically compared with those of other taxa to find potential chemotaxonomic markers, delimit species, and assess chemodiversity.

Method

Samples of the above‐ground parts of 11 Aster species were collected and their metabolites were analysed by ultra‐high performance liquid chromatography with photodiode array detection and quadrupole time‐of‐flight tandem mass spectrometry. Unsupervised principal component analysis, supervised orthogonal partial least‐squares discriminant analysis, heatmap analysis, and hierarchical cluster analysis were employed to analyse 95 representative samples from 11 Aster species and determine species‐specific chemical markers based on a metabolomics database.

Results

Six phenolic acids and flavonoids were detected and quantified in all Aster species, suggesting that these compounds may be common constituents in the Aster genus. Metabolite analysis showed terpenoid compounds to be potential chemical markers for interspecies differentiation. Ent‐kaurane‐type diterpenoid glycosides were the main class of compounds in all Aster species except for A. farreri, which mainly contained oleanane‐type pentacyclic triterpenoids. Diterpenoid glycosides were low‐content chemotaxonomic markers and were detected for the first time in Aster species from the Qinghai‐Tibetan Plateau.

Conclusion

Chemotaxonomy and metabolomics were used to support the phylogenic relationships of the Aster genus.
Efficient homogeneously weighted dispersion control charts with an application to distillation process
Authors: Abbasi Saddam Akber , Nassar Sara Hussam , Aldosari Mashael Mohammed , Adeoti Olatunde A.
Published: May 2021

Monitoring disturbances in process dispersion using control chart is mostly based on the assumption that the quality characteristic follows normal distribution, which is not the case in many real‐life situations. This paper proposes a set of new dispersion charts based on the homogeneously weighted moving average (HWMA) scheme, for efficient detection of shifts in process standard deviation (σ). These charts are based on a variety of σ estimators and are investigated for normal as well as heavy tailed symmetric and skewed distributions. The shift detection ability of the charts is evaluated using different run length characteristics, such as average run length (ARL), extra quadratic loss (EQL), and relative ARL measures. The performance of the proposed HWMA control charts is also compared with the existing EWMA dispersion charts, using different design parameters. Furthermore, an illustrative example is presented to monitor the vapor pressure in a distillation process.
Law of large numbers for Betti numbers of homogeneous and spatially independent random simplicial complexes
Authors: Kanazawa Shu
Published: May 2021

The Linial–Meshulam complex model is a natural higher dimensional analog of the Erdős–Rényi graph model. In recent years, Linial and Peled established a limit theorem for Betti numbers of Linial–Meshulam complexes with an appropriate scaling of the underlying parameter. The present article aims to extend that result to more general random simplicial complex models. We introduce a class of homogeneous and spatially independent random simplicial complexes, including the Linial–Meshulam complex model and the random clique complex model as special cases, and we study the asymptotic behavior of their Betti numbers. Moreover, we obtain the convergence of the empirical spectral distributions of their Laplacians. A key element in the argument is the local weak convergence of simplicial complexes. Inspired by the work of Linial and Peled, we establish the local weak limit theorem for homogeneous and spatially independent random simplicial complexes.
Robust penalized M‐estimation for function‐on‐function linear regression
Authors: Cai Xiong , Xue Liugen , Cao Jiguo
Published: May 2021

Function‐on‐function linear regression is an essential tool in characterizing the linear relationship between a functional response and a functional predictor. However, most of the estimation methods for this model are based on the least‐squares procedure, which is sensitive to atypical observations. In this paper, we present a robust method for the function‐on‐function linear model using M‐estimation and penalized spline regression. A fast iterative algorithm is provided to compute the estimates. The efficiency of the proposed robust penalized M‐estimator is investigated with several simulation studies in comparison with the conventional method. We demonstrate the performance of the proposed robust method with two real data examples in a capital bike‐sharing study and a Hawaii ocean time‐series program.
The need for psychological, caregiver‐centered intervention in the time of COVID‐19
Authors: Ortelli Paola , Ferrazzoli Davide , Versace Viviana , Saltuari Leopold , Sebastianelli Luca
Published: May 2021

We focus attention on problems that are affecting the informal caregivers of patients with neurodegenerative disorders in the time of COVID‐19. The pandemic is increasing difficulties in the management of the frailest people and their isolation is actually even more tangible than it was in the past. The social restrictions and the lockdown of many activities are putting the system of care provided by informal caregivers on the edge of collapse. We incite the scientific community to face these concerns and provide clinicians clear indications for assisting and supporting caregivers in the care of their relatives during this period. We suggest that e‐health programs could become the ideal “environment” to favor the continuity of care for patients with neurodegenerative conditions and guarantee the required support to their caregivers, both directly in terms of psychological management and indirectly for helping them in disease management.
SPOWTT: Improving the safety and productivity of offshore wind technician transit
Authors: Earle Fiona , Huddlestone Jonathan , Williams Terry , Stock‐Williams Clym , van der Mijle‐Meijer Harald , de Vries Linda , van Heemst Hans , Hoogerwerf Erwin , Koomen Lenard , de Ridder Erik‐Jan , Serraris Jorrit‐Jan , Struijk Gijs , Stormonth‐Darling Andrew , Cline Jon , Jenkins Mark , dos Santos Joana Godinho , Coates Ian , Corrie Andrew , Moore George
Published: May 2021

This paper describes the SPOWTT project. The intention of this project was to understand how sailing by crew transfer vessel (CTVs) to offshore wind farms affects the mental and physical wellbeing of individuals on board. The focus was on quantifying this impact, understanding the key drivers, with an aim to ensuring personnel can arrive to the wind turbines in a fit state to work safely and effectively. Impacts looked at subjective state beyond simply vomiting. Key results include the ability now to predict vessel motions from given Metocean conditions and vessel designs. We also discovered that the impact of vessel motions on seasickness is different for different symptoms and is driven not only by vertical z‐axis accelerations but also by certain frequencies of motion in the y‐axis. Frequencies other than 0.16 Hz were found to be impactful, and x‐axis movements appeared to have a longer‐lasting effect on the day's work. Through the formulation of a new, evidence‐based understanding of seasickness, we have created an operational planning tool, designed to have a direct benefit on the safety and productivity of offshore wind farm operations.
Old yeasts, young beer—The industrial relevance of yeast chronological life span
Authors: Wauters Ruben , Britton Scott J. , Verstrepen Kevin J.
Published: May 2021

Much like other living organisms, yeast cells have a limited life span, in terms of both the maximal length of time a cell can stay alive (chronological life span) and the maximal number of cell divisions it can undergo (replicative life span). Over the past years, intensive research revealed that the life span of yeast depends on both the genetic background of the cells and environmental factors. Specifically, the presence of stress factors, reactive oxygen species, and the availability of nutrients profoundly impact life span, and signaling cascades involved in the response to these factors, including the target of rapamycin (TOR) and cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathways, play a central role. Interestingly, yeast life span also has direct implications for its use in industrial processes. In beer brewing, for example, the inoculation of finished beer with live yeast cells, a process called “bottle conditioning” helps improve the product's shelf life by clearing undesirable carbonyl compounds such as furfural and 2‐methylpropanal that cause staling. However, this effect depends on the reductive metabolism of living cells and is thus inherently limited by the cells' chronological life span. Here, we review the mechanisms underlying chronological life span in yeast. We also discuss how this insight connects to industrial observations and ultimately opens new routes towards superior industrial yeasts that can help improve a product's shelf life and thus contribute to a more sustainable industry.
Vector solitons for the (2 + 1)‐dimensional coupled nonlinear Schrödinger system in the Kerr nonlinear optical fiber
Authors: Sun Yan , Tian Bo , Qu Qi‐Xing , Chai Han‐Peng , Yuan Yu‐Qiang , Shan Wen‐Rui , Jiang Yan
Published: May 2021

Investigated in this paper is the (2 + 1)‐dimensional coupled nonlinear Schrödinger system, which describes the propagation of the optical soliton through the Kerr nonlinear fiber in which each component diffracts in two transverse dimensions. By virtue of the Kadomtsev‐Petviashvili hierarchy reduction, we obtain the bright, dark and mixed vector soliton solutions in terms of the Gramian. We investigate the vector solitons graphically: (1) Bright‐dark one solitons with one of the components being gray or black are shown. Bouncing, beating, oscillating and breathing effects which appear during the interactions between the bright‐dark two solitons are discussed, and those interactions are shape‐preserving; (2) Degenerate and non‐degenerate dark‐dark one solitons are presented. Interaction of the dark‐dark two solitons is discussed and the two solitons keep their amplitudes and velocities invariant except for some phase shifts during the interaction; (3) Bound‐state and complexes of the bright‐bright solitons are presented.
Four point functions in CFT’s with slightly broken higher spin symmetry
Authors: Silva Joao A.
Published: May 2021

Abstract

We compute spinning four point functions in the quasi-fermionic three dimensional conformal field theory with slightly broken higher spin symmetry at finite t’Hooft coupling. More concretely, we obtain a formula for $$ \left\langle {j}_s{j}_{\tilde{0}}{j}_{\tilde{0}}{j}_{\tilde{0}}\right\rangle $$

j
s

j

0
˜

j

0
˜

j

0
˜

, where js is a higher spin current and $$ {j}_{\tilde{0}} $$

j

0
˜

is the scalar single trace operator. Our procedure consists in writing a plausible ansatz in Mellin space and using crossing, pseudo-conservation and Regge boundedness to fix all undetermined coefficients. Our method can potentially be generalised to compute all spinning four point functions in these theories.
Effect of acoustic excitation on fiber-reinforced polypropylene and the influence on melt viscosity
Authors: Heinrich Michael , Decker Ricardo , Reindel Paul , Böttcher Katja , Roth-Panke Isabelle , Kroll Lothar
Published: May 2021

The paper describes a novel technological approach to influencing the rheological properties of thermoplastic materials exposed to acoustic energy. The flow behavior of polypropylene with different mass percentages of glass fibers is investigated in a parallel plate rheometer under high-frequency longitudinal excitation. The influence of oscillation frequency on the melt viscosity is explained by means of shear thinning criteria. The dependence of the oscillation shape using sinusoidal excitation on shear thinning as a function of different fiber reinforcement percentages is also investigated. A phenomenological view describes the mutually influencing parameters with regard to different material compositions and different excitation frequencies over the time course of the rheometric measurement. Interacting relationships are analyzed and discussed and the potential of the actuator system to influence the plastic melt is worked out. Based on this, a technological approach follows which describes the transfer of an oscillating mold surface to plastics processing methods, which, especially in the case of energy-intensive injection molding technology, leads to the expectation of possible resource efficiency in energy and material.
Survey of water proton longitudinal relaxation in liver in vivo
Authors: Waterton John Charles
Published: May 2021

Objective

To determine the variability, and preferred values, for normal liver longitudinal water proton relaxation rate R1 in the published literature.

Methods

Values of mean R1 and between-subject variance were obtained from literature searching. Weighted means were fitted to a heuristic and to a model.

Results

After exclusions, 116 publications (143 studies) remained, representing apparently normal liver in 3392 humans, 99 mice and 249 rats. Seventeen field strengths were included between 0.04 T and 9.4 T. Older studies tended to report higher between-subject coefficients of variation (CoV), but for studies published since 1992, the median between-subject CoV was 7.4%, and in half of those studies, measured R1 deviated from model by 8.0% or less.

Discussion

The within-study between-subject CoV incorporates repeatability error and true between-subject variation. Between-study variation also incorporates between-population variation, together with bias from interactions between methodology and physiology. While quantitative relaxometry ultimately requires validation with phantoms and analysis of propagation of errors, this survey allows investigators to compare their own R1 and variability values with the range of existing literature.
A Social-Ecological Approach to Understanding Adolescent Sexting Behavior
Authors: Hunter Simon C. , Russell Kirsten , Pagani Stefania , Munro Lindsey , Pimenta Sofia M. , Marín-López Inmaculada , Hong Jun Sung , Knifton Lee
Published: May 2021

This study examined the extent to which active and passive sexting behaviors are associated with family-, school-, peer-, and romantic-level variables. Young people (N = 3,322; 49.1% female, 48.3% male, 2.6% other) aged 11 to 15 years old (M = 12.84,SD = 0.89) took part, and all attended mainstream secondary schools in Scotland. Participants completed self-report measures of school connectedness, parental love and support, perceived susceptibility to peer- and romantic-pressure (e.g., to display behaviors just to impress others), and their involvement in active and passive sexting. The importance of both school- and family-level factors was evident, though perceived romantic-pressure had the largest effect. However, neither school- nor family-level variables were moderated by either perceived romantic-pressure or perceived peer-pressure. Efforts to reduce sexting or increase its safety should primarily seek to tackle young people’s ability to respond effectively to romantic-pressure. It may also be helpful to develop school connectedness and to help families provide support that is constructive and not intrusive.
Jacobi Ensemble, Hurwitz Numbers and Wilson Polynomials
Authors: Gisonni Massimo , Grava Tamara , Ruzza Giulio
Published: May 2021

We express the topological expansion of the Jacobi Unitary Ensemble in terms of triple monotone Hurwitz numbers. This completes the combinatorial interpretation of the topological expansion of the classical unitary invariant matrix ensembles. We also provide effective formulæ for generating functions of multipoint correlators of the Jacobi Unitary Ensemble in terms of Wilson polynomials, generalizing the known relations between one point correlators and Wilson polynomials.
Democratic societies defeat (COVID-19) disasters by boosting shared knowledge
Authors: Martignon Laura , Mousavi Shabnam , Engel Joachim
Published: May 2021

Preparing people for dealing with hazards, diseases and disasters requires teaching them statistics, and ideally doing so by means of good representation formats in a dynamic fashion. Translating these dynamics to simple communication is what governments need from scientists.
Numerical investigation of injection parameters and piston bowl geometries on emission and thermal performance of DI diesel engine
Authors: Rizvi Ikhtedar Husain , Gupta Rajesh
Published: May 2021

Tightening noose on engine emission norms compelled manufacturers globally to design engines with low emission specially NOx and soot without compromising their performance. Amongst various parameters, shape of piston bowls, injection pressure and nozzle diameter are known to have significant influence over the thermal performance and emission emanating from the engine. This paper investigates the combined effect of fuel injection parameters such as pressure at which fuel is injected and the injection nozzle size along with shape of piston bowl on engine emission and performance. Numerical simulation is carried out using one cylinder naturally aspirated diesel engine using AVL FIRE commercial code. Three geometries of piston bowls with different tumble and swirl characteristics are considered while maintaining the volume of piston bowl, compression ratio, engine speed and fuel injected mass constant along with equal number of variations for injection nozzle size and pressures for this analysis. The investigation corroborates that high swirl and large turbulence kinetic energy (TKE) are crucial for better combustion. TKE and equivalence ratio also increased as the injection pressure increases during the injection period, hence, enhances combustion and reduces soot formation. Increase in nozzle diameter produces higher TKE and equivalence ratio, while CO and soot emission are found to be decreasing and NOx formation to be increasing. Further, optimization is carried out for twenty-seven cases created by combining fuel injection parameters and piston bowl geometries. The case D2H1P1 (H1 = 0.2 mm, P1 = 200 bar) found to be an optimum case because of its lowest emission level with slightly better performance.
The Uneven Age of Speed: Caravans, Technology, and Mobility in the Late Ottoman and Post-Ottoman Middle East
Authors: Pétriat Philippe
Published: May 2021

This article explores the way overland mobility was transformed in the late 19th and early 20th centuries, during “the age of speed.” Beyond the already well-known caravan-to-car story, it argues that slow means of transportation such as caravans kept their own rationale and were instrumental in producing an economic geography that proved resilient in the face of the celebrated steam- or fuel-motorized means of accelerated mobility. Adopting the caravan traders and travelers’ vantage and foregrounding their life stories offer new insights on the way rail and automobility were experienced and adopted in the post-Ottoman Middle East. Such experiences cast a different light on the global rechanneling process affecting the circulation of persons and merchandise across the region during the interwar period. Exploring the resilience of caravans in an uneven age of speed does not only illuminate the transnational geographies underpinned by the overlapping networks of both slower and faster mobilities. It also helps to understand the many dimensions of their gradual albeit very uneven demise.
The historical and contemporary status of the sea otter Enhydra lutris population on Urup Island, southern Kuril Islands
Authors: Popov Igor , Scopin Alexey
Published: May 2021

We describe the population of the Еndangered sea otter Enhydra lutris on Urup Island, one of the main wildlife refuges in the southern Kuril Islands of Russia. We reviewed historical and local reports of the sea otter, identified its habitat around the island, and surveyed the coastal waters of the island in 2019. Sea otters were numerous on Urup Island in the past but were hunted excessively and almost exterminated by the 1950s. Since then, sea otter populations have increased, and as the island is almost uninhabited we expected otters to be numerous. This was not the case, and we estimated the total population to be 363 ± SE 126 individuals. Our observation of two skinned carcasses on the shore suggests the low numbers are a result of poaching for the illegal fur trade. The case of Urup Island demonstrates that sea otters require active conservation, as even on a remote island they remain threatened. Establishment of protected areas would be an effective conservation measure for this species, although the suppression of demand for sea otter fur is of the greatest importance.
The interferon-stimulated exosomal hACE2 potently inhibits SARS-CoV-2 replication through competitively blocking the virus entry
Authors: Zhang Junsong , Huang Feng , Xia Baijin , Yuan Yaochang , Yu Fei , Wang Guanwen , Chen Qianyu , Wang Qian , Li Yuzhuang , Li Rong , Song Zheng , Pan Ting , Chen Jingliang , Lu Gen , Zhang Hui
Published: May 2021

Since the outbreak of coronavirus disease 2019 (COVID-19), it has become a global pandemic. The spike (S) protein of etiologic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specifically recognizes human angiotensin-converting enzyme 2 (hACE2) as its receptor, which is recently identified as an interferon (IFN)-stimulated gene. Here, we find that hACE2 exists on the surface of exosomes released by different cell types, and the expression of exosomal hACE2 is increased by IFNα/β treatment. In particular, exosomal hACE2 can specifically block the cell entry of SARS-CoV-2, subsequently inhibit the replication of SARS-CoV-2 in vitro and ex vivo. Our findings have indicated that IFN is able to upregulate a viral receptor on the exosomes which competitively block the virus entry, exhibiting a potential antiviral strategy.
Molecular mechanism of cell ferroptosis and research progress in regulation of ferroptosis by noncoding RNAs in tumor cells
Authors: Xie Bumin , Guo Yuan
Published: May 2021

Ferroptosis is a newly identified form of nonapoptotic regulated cell death characterized by iron-dependent accumulation of lipid reactive oxygen species. Morphologically and biochemically different from known types of cell death and apoptosis, ferroptosis promotes nervous system diseases, renal failure, ischemia–reperfusion injury, and the treatment of tumors. It could be induced by several mechanisms, including inhibition of glutathione peroxidase 4, lack of cysteine, and peroxidation of polyunsaturated fatty acids, but could be inhibited by iron chelators, lipophilic antioxidants, and some specific inhibitors. Ferroptosis is found to be closely related to the tumorigenesis, invasion, and metastasis of tumors. Noncoding RNAs (ncRNAs), including long noncoding RNAs (lncRNAs), microRNAs, and circular RNAs, do not encode proteins. NcRNAs are found to be capable of regulating the molecular mechanism of ferroptosis in tumor cells post transcription. Ferroptosis provides a new method for cancer treatment. Although several studies have confirmed the important role of ferroptosis in cancer treatment, its specific affecting mechanism is unclear. Here we reviewed the molecular mechanism of ferroptosis in tumor cells and the relationship between ferroptosis and the three important ncRNAs.
Reconstruction of ancient microbial genomes from the human gut
Authors: Wibowo Marsha C. , Yang Zhen , Borry Maxime , Hübner Alexander , Huang Kun D. , Tierney Braden T. , Zimmerman Samuel , Barajas-Olmos Francisco , Contreras-Cubas Cecilia , García-Ortiz Humberto , Martínez-Hernández Angélica , Luber Jacob M. , Kirstahler Philipp , Blohm Tre , Smiley Francis E. , Arnold Richard , Ballal Sonia A. , Pamp Sünje Johanna , Russ Julia , Maixner Frank , Rota-Stabelli Omar , Segata Nicola , Reinhard Karl , Orozco Lorena , Warinner Christina , Snow Meradeth , LeBlanc Steven , Kostic Aleksandar D.
Published: May 2021

Loss of gut microbial diversity1–6in industrial populations is associated with chronic diseases7, underscoring the importance of studying our ancestral gut microbiome. However, relatively little is known about the composition of pre-industrial gut microbiomes. Here we performed a large-scale de novo assembly of microbial genomes from palaeofaeces. From eight authenticated human palaeofaeces samples (1,000–2,000 years old) with well-preserved DNA from southwestern USA and Mexico, we reconstructed 498 medium- and high-quality microbial genomes. Among the 181 genomes with the strongest evidence of being ancient and of human gut origin, 39% represent previously undescribed species-level genome bins. Tip dating suggests an approximate diversification timeline for the key human symbiontMethanobrevibacter smithii. In comparison to 789 present-day human gut microbiome samples from eight countries, the palaeofaeces samples are more similar to non-industrialized than industrialized human gut microbiomes. Functional profiling of the palaeofaeces samples reveals a markedly lower abundance of antibiotic-resistance and mucin-degrading genes, as well as enrichment of mobile genetic elements relative to industrial gut microbiomes. This study facilitates the discovery and characterization of previously undescribed gut microorganisms from ancient microbiomes and the investigation of the evolutionary history of the human gut microbiota through genome reconstruction from palaeofaeces.
Symmetrically dimethylated histone H3R2 promotes global transcription during minor zygotic genome activation in mouse pronuclei
Authors: Morita Kohtaro , Hatanaka Yuki , Ihashi Shunya , Asano Masahide , Miyamoto Kei , Matsumoto Kazuya
Published: May 2021

Paternal genome reprogramming, such as protamine–histone exchange and global DNA demethylation, is crucial for the development of fertilised embryos. Previously, our study showed that one of histone arginine methylation, asymmetrically dimethylated histone H3R17 (H3R17me2a), is necessary for epigenetic reprogramming in the mouse paternal genome. However, roles of histone arginine methylation in reprogramming after fertilisation are still poorly understood. Here, we report that H3R2me2s promotes global transcription at the 1-cell stage, referred to as minor zygotic genome activation (ZGA). The inhibition of H3R2me2s by expressing a histone H3.3 mutant H3.3R2A prevented embryonic development from the 2-cell to 4-cell stages and significantly reduced global RNA synthesis and RNA polymerase II (Pol II) activity. Consistent with this result, the expression levels of MuERV-L as minor ZGA transcripts were decreased by forced expression of H3.3R2A. Furthermore, treatment with an inhibitor and co-injection of siRNA to PRMT5 and PRMT7 also resulted in the attenuation of transcriptional activities with reduction of H3R2me2s in the pronuclei of zygotes. Interestingly, impairment of H3K4 methylation by expression of H3.3K4M resulted in a decrease of H3R2me2s in male pronuclei. Our findings suggest that H3R2me2s together with H3K4 methylation is involved in global transcription during minor ZGA in mice.
Glassy carbon microelectrode arrays enable voltage-peak separated simultaneous detection of dopamine and serotonin using fast scan cyclic voltammetry
Authors: Castagnola Elisa , Thongpang Sanitta , Hirabayashi Mieko , Nava Giorgio , Nimbalkar Surabhi , Nguyen Tri , Lara Sandra , Oyawale Alexis , Bunnell James , Moritz Chet , Kassegne Sam
Published: May 2021

Glassy carbon (GC) microelectrode arrays can simultaneously discriminate the reduction and oxidation peaks of dopamine and serotonin at low concentrations (10–200 nM). They demonstrated fast electron transfer kinetics and good fouling properties.
Ant-nest-like Cu2−xSe@C with biomimetic channels boosts the cycling performance for lithium storage
Authors: Luo Wanshu , Cao Meng , Pan Hanqing , Wang Qingqing , Ma Yinglan , Wang Chao , Wang Ying , Gu Yingqiu , Zhang Lei
Published: May 2021

The ant-nest-like Cu2−xSe@C, composed of interconnected Cu2−xSe channels with amorphous carbon, can deliver a capacity of 879 mA h g−1 after 2500 cycles at 10.0 A g−1.
Nitrate reduction to ammonium: from CuO defect engineering to waste NOx-to-NH3economic feasibility
Authors: Daiyan Rahman , Tran-Phu Thanh , Kumar Priyank , Iputera Kevin , Tong Zizheng , Leverett Joshua , Khan Muhammad Haider Ali , Asghar Esmailpour Ali , Jalili Ali , Lim Maggie , Tricoli Antonio , Liu Ru-Shi , Lu Xunyu , Lovell Emma , Amal Rose
Published: May 2021

Critical to the feasibility of electrochemical reduction of waste NOx(NOxRR), as a sustainable pathway and to close the NOxcycle for the emerging NH3economy, is the requirement of inexpensive, scalable and selective catalysts that can generate NH4+with high yield, as indicated by our economic modelling.
Adsorption dynamics of thermoresponsive microgels with incorporated short oligo(ethylene glycol) chains at the oil–water interface
Authors: Dan Abhijit , Agnihotri Priyanshi , Bochenek Steffen , Richtering Walter
Published: May 2021

We report the effect of short OEG chains on the adsorption behaviour of thermoresponsive PNIPAM-based functional microgels at the oil–water interface at temperatures below and above the volume phase transition temperature of microgels.
Analysis on voltage characteristics of distribution network considering rolling mill load and Research on control measures
Authors: Wang Aihua , Zhang Xiaotong , Shi Zhenyu , Wang Shunjiang , Li Dianyang
Published: May 2021

In view of the voltage fluctuation and flicker of distribution network caused by rolling mill type typical load in some distribution networks and the reduction of power quality of power grid, it is necessary to analyze the voltage characteristics of distribution network, and adopt an effective governance measure to suppress harmonics in distribution network and improve power quality of power grid. The mathematical models of several typical loads corrected based on the measured data are established, and the influence radiation range of the corrected rolling mill load model on the distribution network voltage is analyzed, and a SVC (static var compensator) governance measure with SOGI phase-locked strategy is adopted for governance. Finally, combined with the actual operation parameters of a substation of State Grid, the power system simulation model is built by using simulation software, and the effectiveness of the governance measures adopted in this paper is verified by simulation analysis.
Numerical Simulation Based on Heat Transfer Enhancement of Supercritical Fluid in Micro-Fin Tube
Authors: Chen Peng-Fei , Chen Kang , Wang Xiao , Wen Long
Published: May 2021

With the application of supercritical fluid heat transfer equipment in industrial fields such as solar thermal power generation, chemical industry, aerospace, etc., studying the heat transfer characteristics of supercritical fluid in micro-fin tubes has become a key theoretical basis for the development of micro-fin low-resistance heat transfer enhancement technology. In view of micro-fin tubes with different fin shapes, this paper took into account thermophysical properties of nitrogen under supercritical conditions and completed a numerical simulation study on the heat transfer process of nitrogen in 2 mm micro-fin tubes under supercritical pressure. The temperature field distribution of supercritical nitrogen in the micro-fin tube was analyzed, and the turbulent flow mechanism of the micro-fin was studied. It was found that micro-fin could increase the heat exchange area, destroy the boundary layer, and improve the heat transfer coefficient. This paper took comprehensive heat transfer performance evaluation factor PEC to compare the influence of different fin shapes on heat transfer enhancement performance of the heat exchange unit. It was found that the comprehensive heat transfer factor of the square straight micro-fin tube was about 1.22 times that of the smooth round tube, and PEC of the triangular straight micro tube was about 1.08 times that of the smooth tube. The results suggest that square straight micro-fin tube has significantly superior heat transfer performance than smooth round tube and triangular straight micro-fin tube.
Research on Energy Industry Strategy Based on Intelligent Digital Upgrading
Authors: Zhang Zhongpeng , Feng Lei , Zheng Zhengbing , Wang Guibao
Published: May 2021

The global energy supply and demand are constantly changing, and toward the leapfrog development of digital energy. How to further accelerate the pace of energy digital transformation is the direction that many scholars have been exploring. Starting from the background of international energy strategy, this article analyzes and researches new products of energy strategy digitization, energy data center intelligence and digital energy strategy, and then discusses the development trend and significance of intelligence in the future energy field. It aims to use digital technology and intelligent concepts to promote the in-depth integration of energy and modern information technology, promote the transformation of energy production management and marketing models, and reshape the energy industry chain, supply chain and value chain to promote the drawing of an intelligent blueprint in the energy field.
Research on Optimal Design and Control Method of Integrated Energy System Based on Improved Cloud Adaptive Particle Swarm
Authors: Ye Peng , Yang Shuo , Sun Feng , Zhang Mingli , Zhang Na
Published: May 2021

In order to rationally design the capacity of each energy coupling unit of the integrated energy system, effectively coordinate and optimize the control of the integrated energy system equipment. This paper proposes an improved cloud adaptive particle swarm algorithm design control method. First, three busbars and multi-energy coupling equipment models based on electric, thermal, and gas loads are established, and then the model has better global optimization capabilities and defenses. Then, an improved cloud adaptive particle swarm algorithm with better global optimization capabilities and anti-premature convergence characteristics is used to optimize the annual economic optimization model established to meet the power balance constraints of each bus and energy coupling equipment. Finally, under the conditions of output constraints and system energy purchase constraints, taking a typical park as an example, the simulation verifies the effectiveness of the method proposed in this paper in the optimization design and control operation of the integrated energy system.
Research on the application of 3D printing and BIM technology in the direction of bridges
Authors: Jiang Zonglin
Published: May 2021

Due to the multi-purpose and multi-collaboration nature of BIM technology, it makes the application of BIM not only the presentation of the structural model, but also the related construction progress and the embodiment of the construction process. It is this multi-functional use that makes BIM technology popular in the industry. 3D printing technology, on the other hand, when used in the field of engineering and construction, mainly prints out parts or all of the structure, and also ensures accuracy and speed. Linking the two will make the future of the related industry in a sudden development. Based on this, this paper will conduct an in-depth study on the application of 3D printing and BIM technology in the direction of bridges, aiming to promote the integration of the civil engineering field with the intelligent manufacturing scene and lay a solid foundation for the construction of modern society.
The effectiveness of Social Security Incentive Mechanism to promote the development of the Health Industry of Traditional Chinese Medicine
Authors: Ye Huali , Li Jun
Published: May 2021

On the basis of field research, this paper uses AHP and fuzzy comprehensive evaluation method to study the effectiveness of Chinese social security incentive mechanism in promoting the development of Chinese medicine health industry. The results show that the effectiveness of Chinese medicine health industry social security incentive mechanism is not enough. The government should strengthen the construction of Chinese Medicine health industry social security incentive mechanism and attach importance to relevant policies In order to realize the modernization of Chinese medicine health industry as soon as possible.
Research on Maritime Emergency Material Dispatch Based on Beetle Antennae Search Algorithm
Authors: Jiang Hongzheng , Zhu Yuzhu
Published: May 2021

The research on dispatching of emergency supplies for maritime emergencies is the key to improve the use efficiency of marine emergency resources and the success rate of search and rescue. In view of the characteristics of emergency accidents at sea, in this paper, a material scheduling model with the shortest time is built for multi-accident points, multi-ship dispatching and multi-material supply points, and the optimal material scheduling scheme is obtained. The step-size updating coefficient eta is introduced into the variable step-size optimization search algorithm ( BAS ), so that the step-size decreases with the depth of optimization, which improves the searching precision and accuracy of the search algorithm. The simulation experiment verifies that this algorithm can solve the optimization scheme of material scheduling quickly and efficiently.