bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling the formation of the first two neutron star–black hole mergers, GW200105 and GW200115: metallicity, chirp masses, and merger remnant spins
Authors: Chattopadhyay Debatri , Stevenson Simon , Broekgaarden Floor , Antonini Fabio , Belczynski Krzysztof
Published: May 2022

The two neutron star–black hole mergers (GW200105 and GW200115) observed in gravitational waves by advanced LIGO and Virgo, mark the first ever discovery of such binaries in nature. We study these two neutron star–black hole systems through isolated binary evolution, using a grid of population synthesis models. Using both mass and spin observations (chirp mass, effective spin, and remnant spin) of the binaries, we probe their different possible formation channels in different metallicity environments. Our models only support LIGO data when assuming the black hole is non-spinning. Our results show a strong preference that GW200105 and GW200115 formed from stars with sub-solar metallicities Z ≲ 0.005. Only two metal-rich (Z = 0.02) models are in agreement with GW200115. We also find that chirp mass and remnant spins jointly aid in constraining the models, while the effective spin parameter does not add any further information. We also present the observable (i.e. post-selection effects) median values of spin and mass distribution from all our models, which may be used as a reference for future mergers. Further, we show that the remnant spin parameter distribution exhibits distinguishable features in different neutron star–black hole sub-populations. We find that non-spinning, first born black holes dominate significantly the merging neutron star–black hole population, ensuring electromagnetic counterparts to such mergers a rare affair.
Variable structure in the PDS 70 disc and uncertainties in radio-interferometric image restoration
Authors: Casassus Simon , Cárcamo Miguel
Published: May 2022

The compact mm-wavelength signal in the central cavity of the PDS 70 disc, revealed by deep ALMA observations, is aligned with unresolved H α emission, and is thought to stem from a circumplanetary disc (CPD) around PDS 70c. We revisit the available ALMA data on PDS 70c with alternative imaging strategies, and with special attention to uncertainties and to the impact of the so-called ‘JvM correction’, which is thought to improve the dynamic range of restored images. We also propose a procedure for the alignment and joint imaging of multi-epoch visibility data. We find that the JvM correction exaggerates the peak signal-to-noise of the data, by up to a factor of 10. In the case of PDS 70, we recover the detection of PDS 70c from the 2019 July data, but only at 8 σ. However, its non-detection in 2017 Dec. suggests that PDS 70c is variable by at least $42{{\ \rm per\ cent}} \pm 13{{\ \rm per\ cent}}$ over a 1.75 yr time-span, so similar to models of the H α variability. We also pick up fine structure in the inner disc, such that its peak is offset by ∼0${_{.}^{\prime\prime}}$04 from the disc centre. The inner disc is variable too, which we tentatively ascribe to Keplerian rotation as well as intrinsic morphological changes.
Chromosomal synapsis defects can trigger oocyte apoptosis without elevating numbers of persistent DNA breaks above wild-type levels
Authors: Ravindranathan Ramya , Raveendran Kavya , Papanikos Frantzeskos , San-Segundo Pedro A , Tóth Attila
Published: May 2022

Generation of haploid gametes depends on a modified version of homologous recombination in meiosis. Meiotic recombination is initiated by single-stranded DNA (ssDNA) ends originating from programmed DNA double-stranded breaks (DSBs) that are generated by the topoisomerase-related SPO11 enzyme. Meiotic recombination involves chromosomal synapsis, which enhances recombination-mediated DSB repair, and thus, crucially contributes to genome maintenance in meiocytes. Synapsis defects induce oocyte apoptosis ostensibly due to unrepaired DSBs that persist in asynaptic chromosomes. In mice, SPO11-deficient oocytes feature asynapsis, apoptosis and, surprisingly, numerous foci of the ssDNA-binding recombinase RAD51, indicative of DSBs of unknown origin. Hence, asynapsis is suggested to trigger apoptosis due to inefficient DSB repair even in mutants that lack programmed DSBs. By directly detecting ssDNAs, we discovered that RAD51 is an unreliable marker for DSBs in oocytes. Further, SPO11-deficient oocytes have fewer persistent ssDNAs than wild-type oocytes. These observations suggest that oocyte quality is safeguarded in mammals by a synapsis surveillance mechanism that can operate without persistent ssDNAs.
ExpressVis: a biologist-oriented interactive web server for exploring multi-omics data
Authors: Liu Xian , Xu Kaikun , Tao Xin , Yin Ronghua , Ren Guangming , Yu Miao , Li Changyan , Chen Hui , Zhao Ke , Xiang Shensi , Gao Huiying , Bo Xiaochen , Chang Cheng , Yang Xiaoming
Published: May 2022

In the era of life-omics, huge amounts of multi-omics data have been generated and widely used in biomedical research. It is challenging for biologists with limited programming skills to obtain biological insights from multi-omics data. Thus, a biologist-oriented platform containing visualization functions is needed to make complex omics data digestible. Here, we propose an easy-to-use, interactive web server named ExpressVis. In ExpressVis, users can prepare datasets; perform differential expression analysis, clustering analysis, and survival analysis; and integrate expression data with protein–protein interaction networks and pathway maps. These analyses are organized into six modules. Users can use each module independently or use several modules interactively. ExpressVis displays analysis results in interactive figures and tables, and provides comprehensive interactive operations in each figure and table, between figures or tables in each module, and among different modules. It is freely accessible at https://omicsmining.ncpsb.org.cn/ExpressVis and does not require login. To test the performance of ExpressVis for multi-omics studies of clinical cohorts, we re-analyzed a published hepatocellular carcinoma dataset and reproduced their main findings, suggesting that ExpressVis is convenient enough to analyze multi-omics data. Based on its complete analysis processes and unique interactive operations, ExpressVis provides an easy-to-use solution for exploring multi-omics data.
Measuring Belief-dependent Preferences without Data on Beliefs
Authors: Bellemare Charles , Sebald Alexander
Published: May 2022

We derive bounds on the causal effect of belief-dependent preferences (reciprocity and guilt aversion) on choices in sequential two-player games without data on the (higher-order) beliefs of players. We show how informative bounds can be derived by exploiting a specific invariance property common to those preferences. We illustrate our approach by analysing data from an experiment conducted in Denmark. Our approach produces tight bounds on the causal effect of reciprocity in the games we consider. These bounds suggest there exists significant reciprocity in our population—a result also substantiated by the participants’ answers to a post-experimental questionnaire. On the other hand, our approach yields high implausible estimates of guilt aversion—participants would be willing, in some games, to pay at least three Danish crowns (DKK) to avoid letting others down by one DKK. We contrast our estimated bounds with point estimates obtained using data on stated higher-order beliefs, keeping all other aspects of the model unchanged. We find that point estimates fall within our estimated bounds, suggesting that elicited higher-order belief data in our experiment is weakly (if at all) affected by various reporting biases.
Effects of reducing the standardized ileal digestible lysine and tryptophan to lysine ratio to slow growth of finishing pigs
Authors: Tolosa Andres F , Tokach Mike D , Goodband Robert D , Woodworth Jason C , DeRouchey Joel M , Gebhardt Jordan T , Wolfe Matt L
Published: May 2022

The COVID-19 global pandemic greatly affected pork processing plants in the United States. These pork processing plants were forced to either temporarily close or operate at reduced capacity due to the increased number of health-related employee absences. Because finishing pigs could not be timely marketed, methods to reduce growth performance were required to keep pigs from becoming too heavy at slaughter weight. Therefore, our objective was to determine the extent that reducing dietary standardized ileal digestible (SID) Lys and tryptophan-to-lysine ratio (Trp:Lys) ratio would slow finishing pig average daily gain (ADG) in a commercial setting. A total of 1,080 finishing pigs (327 × 1050, PIC; initially 32.3 kg) were used in a 119-d growth trial. Pigs were allotted by initial body weight (BW) and randomly assigned to 1 of 4 dietary treatments in a completely randomized block design with 27 pigs per pen and 10 pens per treatment. Three dietary regimes were formulated to contain either 100%, 90%, or 80% of the estimated SID Lys requirement for pigs in this facility, with a SID Trp:Lys ratio of 19%, with the exception of the last dietary phase formulated to 17% SID Trp:Lys. Seven different dietary phases were fed. The SID Lys concentrations in the 100% diets were: 1.10%, 1.01%, 0.91%, 0.83%, 0.79%, 0.71%, or 0.67% SID Lys from 32 to 40, 40 to 51, 51 to 72, 72 to 85, 85 to 98, 98 to 112, and 112 to 130 kg, respectively. A fourth regime was formulated to 80% SID Lys with a SID Trp:Lys ratio of 16% (80–16% SID Trp:Lys) throughout all phases. Overall from d 0 to 119, ADG (linear, P < 0.001), final BW (linear, P < 0.001), and gain-to-feed (G:F) decreased (linear, P = 0.087) as SID Lys decreased from 100% to 80% of the estimated requirement. Pigs fed the 80–16% SID Trp:Lys diets had an additional decrease in ADG (P < 0.05) and G:F (P < 0.10) compared with pigs fed 80% of the SID Lys requirement with the normal Trp:Lys ratio. The reduction in SID Lys (from 100% to 80%) and reduction in SID Lys and Trp:Lys ratio resulted in an 8.6 and 11.7 kg, respectively, decrease in final BW compared with pigs fed Lys and Trp at the requirement (100%). This study provides alternatives for pork producers to reduce growth rate of finishing pigs.
Evaluation of increasing digestible threonine to lysine ratio in corn–soybean meal diets without and with distillers dried grains with solubles on growth performance of growing-finishing pigs
Authors: Tolosa Andres F , Tokach Mike D , Goodband Robert D , Woodworth Jason C , DeRouchey Joel M , Gebhardt Jordan T
Published: May 2022

Corn distillers dried grains with solubles (DDGS) is commonly available and often can lower diet cost for swine diets. This corn co-product is recognized to be a source of dietary insoluble fiber, which can not only increase the villous length of the gut mucosa but also increase intestinal production of mucin. Mucin structure, functions, and synthesis are correlated to Thr intake; consequently, the dietary Thr level may need to be increased when feeding an insoluble fiber source such as corn–DDGS. Thus, the objective of this study was to evaluate if feeding standardized ileal digestible (SID) Thr:Lys ratio at or above the estimated requirement in diets without and with DDGS would influence growth performance in finishing pigs. A total of 2,160 pigs (PIC 337 × 1,050; initially 35.1 ± 0.5 kg) were used in a 112-d growth trial. Pigs were randomly assigned to pens (27 pigs per pen) in a randomized complete block design by body weight (BW) with 20 replications per treatment. Pens of pigs were allotted to one of four dietary treatments that were arranged in a 2 × 2 factorial with main effects of dietary Thr level (normal vs. high) and DDGS (without or with). Treatment diets were formulated in four phases from 34 to 57, 57 to 79, 79 to 104, and 104 to 130 kg BW. Diets with high DDGS were formulated to include 40% DDGS in phases 1 and 2, 30% in phase 3, and 15% in phase 4. The normal Thr diets were formulated to contain 61%, 62%, 63%, and 65% SID Thr:Lys ratios for the four dietary phases, respectively. High Thr diets had SID Thr:Lys ratios of 67%, 68%, 69%, and 72%, respectively. There were no interactions (P > 0.10) observed in any phase or overall between Thr level and added DDGS. For the overall period (day 0 to 112), pigs fed diets without DDGS had increased (P < 0.001) average daily gain (ADG) but reduced (P < 0.001) average daily feed intake (ADFI), leading to increased (P < 0.001) feed efficiency (gain-to-feed ratio [G:F]). There was no evidence for difference (P > 0.10) between pigs fed diets formulated at normal or high SID Thr:Lys ratio. In summary, feeding high levels of DDGS decreased ADG and increased ADFI, which resulted in decreased G:F and lower final BW, regardless of the dietary SID Thr:Lys ratio level. In the current study, increasing the level of digestible Thr in a diet that contained a highly insoluble fiber source did not increase the growth performance of grow-finish pigs.
Disparities in Research during Plastic Surgery Training: How Can We Level the Playing Field?
Authors: Murphy Alexander I. , Mellia Joseph A. , Iaconetti Emma K. , Asadourian Paul A. , Diatta Fortunay , Klifto Kevin M. , Morris Martin P. , Broach Robyn B. , Fischer John P. , Butler Paris D.
Published: May 2022

Background:

Lack of female and ethnically underrepresented in medicine (UIM) surgeons remains concerning in academic plastic surgery. One barrier to inclusion may be unequal opportunity to publish research. This study evaluates the extent of this challenge for plastic surgery trainees and identifies potential solutions.

Methods:

Data were collected on academic plastic surgeons' research productivity during training. Bivariate analysis compared publication measures between genders and race/ethnicities at different training stages (pre-residency/residency/clinical fellowship). Multivariate analysis determined training experiences independently associated with increased research productivity.

Results:

Overall, women had fewer total publications than men during training (8.89 versus 12.46, P = 0.0394). Total publications were similar between genders before and during residency (P > 0.05 for both) but lower for women during fellowship (1.32 versus 2.48, P = 0.0042). Women had a similar number of first-author publications during training (3.97 versus 5.24, P = 0.1030) but fewer middle-author publications (4.70 versus 6.81, P = 0.0405). UIM and non-UIM individuals had similar productivity at all training stages and authorship positions (P > 0.05 for all). Research fellowship completion was associated with increased total, first-, and middle-author training publications (P < 0.001 for all).

Conclusions:

Less research productivity for female plastic surgery trainees may reflect a disparity in opportunity to publish. Fewer middle-author publications could indicate challenges with network-building in a predominately male field. Despite comparable research productivity during training relative to non- UIM individuals, UIM individuals remain underrepresented in academic plastic surgery. Creating research fellowships for targeting underrepresented groups could help overcome these challenges.
Does Dedicated Research Time During Residency Predict Resident Academic Productivity and a Future Academic Career?
Authors: Onyekaba Ginikanwa , Mauch Jaclyn T. , Barrero Carlos , Mellia Joseph A. , Diatta Fortunay , Card Elizabeth , Broach Robyn B. , Fischer John P.
Published: May 2022

Objective

Dedicated research time is a component of certain plastic surgery programs, and yet, there is limited research examining its impact on academic productivity and career outcomes. This study aimed to assess the effect of dedicated research time on the academic productivity of residents and the likelihood of pursuing an academic career.

Methods

We conducted a cross-sectional study that examined bibliometric indices of integrated plastic surgery residency graduates from 2010 to 2020. Academic productivity was determined by the number of peer-reviewed publications and h-index 1 year after residency graduation. Results were analyzed using descriptive statistics, χ2 test, t test, and logistic regression.

Results

Data on plastic surgery residency graduates were analyzed (N = 490 from 46 programs). The mean numbers of publications and h-index per research track graduate were 26.1 and 8.23, respectively. The mean numbers of publications and h-index per nonresearch track graduate were 15.9 and 5.97, respectively. After controlling for the University of Alabama research ranking through multilinear regression analysis, we found that pursuing dedicated research time was an independent predictor of increased h-index and publication output, although it did not predict an increased likelihood of pursuing an academic career.

Conclusions

Participating in dedicated research during residency increases academic productivity, irrespective of the residency program’s research rank. Given this finding, offering research years can help support the mission of fostering academic opportunities within plastic surgery.
Investigating Patient-Level Radiation Exposure in Hand and Wrist Fracture Surgery
Authors: Xu Wen , Christopher Adrienne N. , Hu Sophia , Steinberg David R. , Bozentka David J. , Lin Ines C.
Published: May 2022

Background

Although occupational exposure to radiation has been previously studied in the hand surgery literature, there is a paucity of studies looking at radiation exposure to the patient during fluoroscopy-guided hand surgery. We aimed to describe the level of radiation experienced by patients undergoing common hand and wrist fracture fixation and to identify risk factors for increased radiation exposure.

Methods

We performed a retrospective review of patients at a single institution who underwent fracture fixation of the hand, wrist, or forearm requiring mini c-arm fluoroscopic guidance from 2016 to 2020. Data points collected included patient demographics, procedural details, and indicators of radiation exposure including dose-area product (DAP), total intraoperative images, and total fluoroscopy time. Effective dose (ED) was calculated using DAP, field size, and a previously established conversion factor.

Results

The final sample included 361 patients with an average age of 46 years. Procedures included fixation of forearm fractures (3.3%), distal radius fractures (35.7%), metacarpal fractures (30.8%), and phalangeal fractures (30.2%). The median number of intraoperative images acquired was 36, median total fluoroscopy time was 43 seconds, median DAP was 4.8 cGycm2, and median ED was 0.13 μSv. Distal (metacarpal and phalangeal) fractures required more intraoperative images and longer total fluoroscopy time (49 images, 61 seconds) compared with proximal (forearm and distal radius) fractures (39 images, 47 seconds) (images, P = 0.004; exposure time, P = 0.004). However, distal fractures had a lower average ED compared with proximal fractures (0.15 vs 0.19 μSv, P = 0.020). When compared with open procedures, percutaneous procedures had higher DAPs (8.8 vs 4.9 cGycm2, P < 0.001), higher ED (0.22 vs 0.15 μSv, P < 0.001), more intraoperative images (65 vs 36 images, P < 0.001), and longer total fluoroscopy time (81.9 vs 44.4 seconds, P < 0.001).

Conclusions

Patient-level radiation exposure during fluoroscopy-guided hand and wrist procedures is low relative to other common imaging modalities, such as dental radiographs, chest x-rays, and computed tomography scans, and is comparable with less than a few hours of natural background radiation exposure, highlighting the overall safety of this important technology. Further study should be performed to establish reference ranges, which could lead to improved patient counseling and evidence-based guidelines on patient shielding.
Single-cell transcriptome analysis reveals evolutionarily conserved features during the transition from normal breast stromal cells to cancer-associated fibroblasts
Authors: Delgado Ana Paula , Nemajerova Alice , Nelson Brian J. , Rao Manisha , Li Jinyu , Marchenko Natalia , Preall Jonathan , Moll Ute M. , Egeblad Mikala , Powers Scott
Published: May 2022

To comprehend cancer-associated fibroblasts (CAFs) origins, single-cell RNA sequencing was conducted on normal and cancerous breast tissue from mice and humans. We found three conserved CAF subtypes, which based on GOterm analysis we designated as matrix CAFs-, chemokine CAFs, and contractile CAFs. Matrix and chemokine CAFs originated from resident fibroblasts, while contractile CAFs originated from normal pericytes. Both human and mouse CAFs displayed upregulated genes involved in extracellular matrix organization, cellular respiration, and cell migration. Key transcription factors in both species included NFKB1, SP1, TP53, and TWIST2. Trajectory inference suggested that in some cases a transitory state characterized by JUN expression precedes the maturation of CAFs. Computational analysis revealed a common mechanism for CAF education involving the overexpression of TGF-β, PDGF, TNF, and NOTCH-family ligands in different tumor microenvironment cell types, along with reciprocal overexpression of receptors in CAFs. These findings bolster and broaden current understandings of CAF genesis.
Endogenous retroviruses promote prion-like spreading of proteopathic seeds
Authors: Liu Shu , Heumüller Stefanie-Elisabeth , Hossinger André , Müller Stephan A. , Buravlova Oleksandra , Lichtenthaler Stefan F. , Denner Philip , Vorberg Ina M.
Published: May 2022

Endogenous retroviruses, remnants of viral germline infections, make up a substantial proportion of the mammalian genome. While usually epigenetically silenced, retroelements can become upregulated in neurodegenerative diseases associated with protein aggregation, such as amyotrophic lateral sclerosis and tauopathies. Here we demonstrate that spontaneous upregulation of endogenous retrovirus gene expression drastically affects the dissemination of protein aggregates between murine cells in culture. Viral glycoprotein Env mediates membrane association between donor and recipient cells and promotes the intercellular transfer of protein aggregates packaged into extracellular vesicles. Proteopathic seed spreading can be inhibited by neutralizing antibodies targeting Env as well as drugs inhibiting viral protein processing. Importantly, we show that also overexpression of a human endogenous retrovirus Env elevates intercellular spreading of pathological Tau. Our data highlight the potential influence of endogenous retroviral proteins on protein misfolding diseases and suggest that antiviral drugs could represent promising candidates for inhibiting protein aggregate spreading.
Effect of turbulence intensity on aerodynamic characteristics of extended trailing edge airfoil
Authors: Livya E. , Nadaraja Pillai S.
Published: May 2022

Purpose

This paper aims to study the extended trailing edge airfoil for a range of angle of attack at different intensities of turbulence.

Design/methodology/approach

In this paper, an experimental study on NACA 0020 airfoil with thin extended trailing edge modification of amplitude of h = 0.1c, 0.2c and 0.3c at the Reynolds number of 2.14 × 105 are tested. The research was carried out for an angle of attack ranging from 0° = α = 35° for the turbulence intensity of 0.3%, 3%, 5%, 7% and 12%. From the experimental readings, the surface pressures are scanned using a Scanivalve (MPS2464) pressure scanner for a sampling frequency of 700 Hz. The scanned pressures are converted to aerodynamic force coefficient and the results are combined and discussed.

Findings

The airfoil with the extended trailing edge will convert the adverse pressure gradient to a plateau pressure zone, indicating the delayed flow separation. The CL value at higher turbulence intensity (TI = 12%) for the extended trailing edge over perform the base airfoil at the post-stall region. The maintenance of flow stability is observed from the spectral graph.

Practical implications

A thin elongated trailing edge attached to the conventional airfoil serves as a flow control device by delaying the stall and improving the lift characteristics. Additionally, extending the airfoil's trailing edge helps to manage the performance of the airfoil even at a high level of turbulence.

Originality/value

Distinct from existing studies, the presented results reveals how the extended trailing edge attached to the airfoil performs in the turbulence zone ranging from 0.3% to 12% of TI. The displayed pressure distribution explains the need for increasing trailing edge amplitude (h) and its impact on flow behaviour. The observation is that extended trailing edge airfoil bears to maintain the performance even at higher turbulence region.
Does attention mechanism possess the feature of human reading? A perspective of sentiment classification task
Authors: Zhao Lei , Zhang Yingyi , Zhang Chengzhi
Published: May 2022

Purpose

To understand the meaning of a sentence, humans can focus on important words in the sentence, which reflects our eyes staying on each word in different gaze time or times. Thus, some studies utilize eye-tracking values to optimize the attention mechanism in deep learning models. But these studies lack to explain the rationality of this approach. Whether the attention mechanism possesses this feature of human reading needs to be explored.

Design/methodology/approach

The authors conducted experiments on a sentiment classification task. Firstly, they obtained eye-tracking values from two open-source eye-tracking corpora to describe the feature of human reading. Then, the machine attention values of each sentence were learned from a sentiment classification model. Finally, a comparison was conducted to analyze machine attention values and eye-tracking values.

Findings

Through experiments, the authors found the attention mechanism can focus on important words, such as adjectives, adverbs and sentiment words, which are valuable for judging the sentiment of sentences on the sentiment classification task. It possesses the feature of human reading, focusing on important words in sentences when reading. Due to the insufficient learning of the attention mechanism, some words are wrongly focused. The eye-tracking values can help the attention mechanism correct this error and improve the model performance.

Originality/value

Our research not only provides a reasonable explanation for the study of using eye-tracking values to optimize the attention mechanism but also provides new inspiration for the interpretability of attention mechanism.
Modeling and forecasting United States oil production along with the social cost of carbon: conventional and unconventional oil
Authors: Kazemzadeh Emad , Ahmadi Shadmehri Mohammad Taher , Ebrahimi Salari Taghi , Salehnia Narges , Pooya Alireza
Published: May 2022

Purpose

The USA is one of the largest oil producers in the world. For this purpose, the authors model and predict the US conventional and unconventional oil production during the period 2000–2030.

Design/methodology/approach

In this research, the system dynamics (SD) model has been used. In this model, economic, technical, geopolitical, learning-by-doing and environmental (social costs of carbon) issues are considered.

Findings

The results of the simulation, after successfully passing the validation test, show that the US unconventional oil production rate under the optimistic scenario (high oil prices) in 2030 is about 12.62 million barrels/day (mb/day), under the medium oil price scenario is about 11.4 mb/day and under the pessimistic scenario (low oil price) is about 10.18 mb/day. The results of US conventional oil production forecasting under these three scenarios (high, medium and low oil prices) show oil production of 4.62, 4.26 and 3.91 mb/day, respectively.

Originality/value

The contribution of this study is important in several respects: First, by modeling SD that technical, economic, proven reserves and technology factors are considered, this paper models US conventional and unconventional oil production separately. In this modeling, nonlinear relationships and feedback loops are presented to better understand the relationships between variables. Second, given the importance of environmental issues, the modeling of social costs of CO2 emissions per barrel of oil is also presented and considered as a part of oil production costs. Third, conventional and unconventional US oil production by 2030 is forecast separately, the results of this study could help policymakers to develop unconventional oil and plan for energy self-sufficiency.
Dispersity, stability and tribology behavior of modified nanoserpentine in lubricating oil
Authors: Yan Yanhong , Yan Xiaocui , Yang Chengwen , Zhou Yanfei , Jia Zhining , Hao Caizhe
Published: May 2022

Purpose

The purpose of this study is to improve the dispersion of nanoserpentine modified with OA, KH550 and KH550/oleic acid in lubricating oil. The main aims are to analyze the influence of the dispersion and stability of nanoserpentine modified by different modifiers on the friction properties of lubricating oil.

Design/methodology/approach

The nanoserpentine particles obtained by ball-milling were modified by silane coupling agent KH550, OA and KH550/OA, respectively. The dispersity and stability of nanoserpentine in base lubricating oil were characterized by the absorbance value method, centrifuge precipitation rate method and static observation method. The MMU-5G screen display friction and wear tester was used to evaluate the tribological properties of C45E4/C45E4 friction pairs in corresponding lubricating oils. The surface morphology of the friction pairs was observed by scanning electron microscopy and energy dispersive spectroscopy.

Findings

The results showed that the dispersity and stability of nanoserpentine particles in lubricating oil were best modified by OA, followed by the KH550/OA and finally, the KH550. Nanoserpentine particles modified with oleic acid showed optimum tribological properties as lubricant additives.

Originality/value

This study can improve the dispersion stability of nanoserpentine particles in lubricating oil, increasing the antiwear and antifriction performance of lubricating oil, which has great significance in economic and military aspects.
The influence of manufacturing contexts on additive manufacturing-enabled competitive capabilities
Authors: Khorram Niaki Mojtaba , Nonino Fabio , Tafakkori Keivan , Torabi S. Ali , Kazemian Iman
Published: May 2022

Purpose

This paper presents a contingency analysis of additive manufacturing's (AM) impacts, proposes a novel form of AM-enabled competitive capabilities and explores manufacturing contexts (including product-operation-organization-related factors) influencing those capabilities.

Design/methodology/approach

A theoretical model incorporating manufacturing competitive capabilities and contingency concepts is developed and validated using an empirical study on 105 manufacturing firms using AM. Structural equation modeling is applied for statistical data analysis.

Findings

The results indicate that the production volume and material type have contingency effects on AM-enabled product quality, cost reduction and green capabilities. Besides, it has been demonstrated that the degree of a country's economic development and the firm's experience have contingency impacts on AM's capabilities as well.

Research limitations/implications

The contextual settings employed in this study are limited. A future contingency analysis requires further exploration of other factors (e.g. different AM technologies or application sectors) through in-depth case studies. Future studies can also be built upon the proposed framework to generalize the model for analyzing other emerging manufacturing technologies.

Practical implications

Uncertainties around AM implementation and its consequences place the context of evaluation as an essential facet. The derived insights aid practitioners in aligning the firm's internal characteristics (i.e. manufacturing and organizational contexts) with AM's promising competitive capabilities.

Originality/value

The study is among the first analysis to empirically and rigorously establishes the contingency effects of manufacturing and organizational factors on competitive capabilities related to AM, using a representative sample of manufacturers spanning different countries, firm sizes and other investigated manufacturing contexts.
Employer and internal branding research: a bibliometric analysis of 25 years
Authors: Saini Gordhan K. , Lievens Filip , Srivastava Mukta
Published: May 2022

Purpose

In the past 25 years, employer and internal branding have grown significantly. Prior reviews tended to focus on either one of these domains. This study aims to map the intellectual structure of research on both employer branding and internal branding, thereby identifying impactful authors and journals, current and evolving themes and avenues for future research.

Design/methodology/approach

Using VOSviewer and Biblioshiny software packages, a bibliometric analysis of 739 articles was conducted using various methods such as citation analysis, bibliographic coupling, cluster analysis, keyword analysis and three-field plot. The Scopus results were further validated using 297 articles produced by the Web of Science data set. It ensured the robustness of the results and generalizability of the findings across bibliometric data sets.

Findings

The findings first report the impactful articles, authors and institutions of employer and internal branding research, along with popular keywords used in this area. Next, the analysis reveals four major clusters and seven subthemes (i.e. employer brand and job seekers, employer brand and employees, employer brand and international human resource management (HRM), third-party employer branding, internal branding – conceptualization/review, internal branding – antecedents and consequences, internal brand management). Early research focused more on “corporate brandings,” whereas current research deals more with “employer branding: antecedents and consequences,” “employer branding conceptualization/review,” and “internal branding” and its subthemes. The employer and internal branding clusters have evolved largely independent from each other. This study offers future research directions and practical implications per cluster.

Originality/value

To the best of the authors’ knowledge, this study is the first comprehensive bibliometric analysis of both employer and internal branding research.
Solar rooftop adoption among Indian households: a structural equation modeling analysis
Authors: Kumar Vikas , Kaushik Arun Kumar
Published: May 2022

Purpose

This study aims to examine factors influencing purchase intentions of households toward solar rooftops, using diffusion of innovation theory.

Design/methodology/approach

Six dimensions from the diffusion of innovation theory have been contemplated to assess households’ purchase intentions toward solar rooftops. Primary data was collected from 863 respondents by using a purposive sampling technique from different parts of India. The study used structural equation modeling analysis to examine the data.

Findings

Results confirmed that the dimensions, namely, relative advantage, compatibility, complexity, innovations and observability, positively influence households’ purchase intentions of solar rooftops, except for the trialability dimension.

Research limitations/implications

Data for the study is based on a purposive sampling technique that restricts the representation of the whole population. There may be variance in public perception from place to place due to demographic and psychographic differences.

Practical implications

The present study would facilitate devising a roadmap to improve the quality of the environment. Policy planners, researchers and professionals would find the implications of this study helpful in developing critical strategies.

Originality/value

The research practically explores households’ intention to purchase solar rooftops by filling the gap in previous literature. Findings of the study can equip firms with several advantages. Through the present study, one gets to know that developed and developing economies have similar energy usage issues. Further, it empirically examines the applicability of diffusion of innovation theory in the solar rooftops context.
A vertical coupling dynamic analysis method and engineering application of vehicle–track–substructure based on forced vibration
Authors: Li Guolong , Gao Mangmang , Yang Jingjing , Wang Yunlu , Cao Xueming
Published: May 2022

Purpose

This study aims to propose a vertical coupling dynamic analysis method of vehicle–track–substructure based on forced vibration and use this method to analyze the influence on the dynamic response of track and vehicle caused by local fastener failure.

Design/methodology/approach

The track and substructure are decomposed into the rail subsystem and substructure subsystem, in which the rail subsystem is composed of two layers of nodes corresponding to the upper rail and the lower fastener. The rail is treated as a continuous beam with elastic discrete point supports, and spring-damping elements are used to simulate the constraints between rail and fastener. Forced displacement and forced velocity are used to deal with the effect of the substructure on the rail system, while the external load is used to deal with the reverse effect. The fastener failure is simulated with the methods that cancel the forced vibration transmission, namely take no account of the substructure–rail interaction at that position.

Findings

The dynamic characteristics of the infrastructure with local diseases can be accurately calculated by using the proposed method. Local fastener failure will slightly affect the vibration of substructure and carbody, but it will significantly intensify the vibration response between wheel and rail. The maximum vertical displacement and the maximum vertical vibration acceleration of rail is 2.94 times and 2.97 times the normal value, respectively, under the train speed of 350 km·h−1. At the same time, the maximum wheel–rail force and wheel load reduction rate increase by 22.0 and 50.2%, respectively, from the normal value.

Originality/value

This method can better reveal the local vibration conditions of the rail and easily simulate the influence of various defects on the dynamic response of the coupling system.
Integrating disaster resilience into green rating systems – a modification of the Sri Lankan green building rating tool
Authors: Abeysinghe Sonali , De Zoysa Chandula Jithmi , Siriwardana Chandana , Bandara Chaminda , Dissanayake Ranjith
Published: May 2022

Purpose

The purpose of the study is to mainstream the disaster risk reduction (DRR) and disaster resilience measures into the GreenSL® building rating system in Sri Lanka to demonstrate a more holistic approach in achieving sustainability with resilience.

Design/methodology/approach

First, a comprehensive literature review was carried out on green building practices and rating tools, natural hazards and DRR and global and local frameworks. Next, criteria were developed incorporating the disaster resilience aspects through eight expert committee meetings and included the rating tool in three levels. Finally, 11 green-certified buildings from the Green Building Council of Sri Lanka were reevaluated using the new disaster resilient GREENSL® rating system for built environment as a validation for the new tool and to analyze the new certification levels.

Findings

All the green-certified buildings in hazard-prone areas dropped their certification by one level while the buildings in nonhazard-prone areas remained in the certification after being evaluated by the new DRR-incorporated rating system, which recommends the use of new tool for the buildings in hazard-prone areas. But due to the rapid changes in climate and the unpredictable trends of natural hazards, the use of new DRR incorporated GREENSL® rating system for built environment for the certification of buildings is highly endorsed.

Originality/value

This is the first research study based on the GREENSL rating system. And it is the first effort to incorporate DRR aspects to any rating tool in Sri Lanka. The projects that were evaluated for the validation of the new tool are the actual projects which obtained green building certification. Also, it is apparent that this study has gone some way towards enhancing the understanding of blending the sustainability and resilience in rating systems for built environment.
HighMHCdiversity confers no advantage for phenotypic quality and reproductive performance in a wild bird
Authors: Pikus Ewa , Dunn Peter O. , Minias Piotr
Published: May 2022

Genes of the major histocompatibility complex (MHC) encode antigen‐binding molecules and are an integral part of the acquired immune response of vertebrates. In general, high individual MHC diversity is expected to increase fitness by broadening the spectrum of pathogens recognized by the immune system, in accordance with the heterozygote advantage mechanism. On the other hand, the optimality hypothesis assumes that individuals with optimal (intermediate), rather than maximum, diversity of the MHC will achieve the highest fitness because of inherent costs associated with expressing diverse MHC alleles.

Here, we tested for associations between individual diversity of the MHC class I and class II genes (binding antigens of intra‐ and extracellular pathogens respectively) and a range of fitness‐related traits (condition, ornament expression and reproduction) in an urban population of the Eurasian cootFulica atra.

Contrary to our expectation, we found that high within‐individual allelic diversity of MHC genes (both class I and II) was associated with poorer condition (lower blood haemoglobin concentrations), weaker expression of the putative ornament (smaller frontal shield), later onset of breeding and smaller clutches. An analysis of functional MHC allele clusters (supertypes) provided further support for negative associations of MHC diversity with phenotypic quality and reproductive performance, but most of these relationships could not be explained by the presence of specific maladaptive supertypes. Finally, we found little empirical support for the optimality hypothesis in the Eurasian coot.

Our results suggest that the costs of high MHC diversity outweighed any benefits associated with broad MHC repertoire, which could be driven by depauperate pathogen diversity in an urban landscape. To the best of our knowledge, this is one of the first studies providing consistent evidence for negative associations of MHC diversity with a range of fitness‐related traits in a natural avian population.
Competition mediates understorey species range shifts under climate change
Authors: Sanczuk Pieter , De Lombaerde Emiel , Haesen Stef , Van Meerbeek Koenraad , Luoto Miska , Van der Veken Bas , Van Beek Eric , Hermy Martin , Verheyen Kris , Vangansbeke Pieter , De Frenne Pieter
Published: May 2022

Biological communities are reshuffling owing to species range shifts in response to climate change. This process inherently leads to novel assemblages of interacting species. Yet, how climatic change and local dynamics in biotic interactions jointly affect range shifts is still poorly understood.

We combine a unique long‐term transplant competition‐exclusion experiment with species distribution models (SDMs) to test the effects of biotic interactions on understorey species range shifts under climate change in European temperate forests. Using a time series of 18 years of individual‐level demographic data of four common understorey plant species transplanted beyond their cold range edge to plots with and without interspecific competition, we built integral projection models (IPMs) and analysed the effects of competition on five key vital rates and population growth (λ). We assessed the results of the transplant experiment in the context of the modelled species' current and future potential distributions.

We find that species' population performances in the transplant experiment decreased with lower predicted habitat suitability from the SDMs. The population performance at the transplant sites was mediated by biotic interactions with the local plant community: for two species with intermediate levels of predicted habitat suitability at the transplant sites, competition effects could explicitly differentiate between net population growth (λ > 1) or shrinkage (λ < 1).

Synthesis. Our findings contest the long‐standing idea that at cold range edges, mainly abiotic factors structure species' distributions. We conclude that biotic interactions, through acting on local population dynamics, may impact species distributions at the continental scale. Hence, predicting climate‐change impacts on biodiversity redistributions ultimately requires us to also integrate dynamics in biotic interactions.
Response‐guided long‐term treatment of chronic hepatitis D patients with bulevirtide—results of a “real world” study
Authors: Jachs Mathias , Schwarz Caroline , Panzer Marlene , Binter Teresa , Aberle Stephan W. , Hartl Lukas , Dax Kristina , Aigner Elmar , Stättermayer Albert F. , Munda Petra , Graziadei Ivo , Holzmann Heidemarie , Trauner Michael , Zoller Heinz , Gschwantler Michael , Mandorfer Mattias , Reiberger Thomas , Ferenci Peter
Published: May 2022

Background and Aim

Bulevirtide (BLV) blocks the uptake of the hepatitis D virus (HDV) into hepatocytes via the sodium/bile acid cotransporter NTCP. BLV was conditionally approved by the EMA but real‐life data on BLV efficacy are limited.

Methods

Patients were treated with BLV monotherapy. Patients who did not achieve further decreases in HDV‐RNA after 24 weeks were offered PEG‐IFN as an add‐on therapy in a response‐guided manner.

Results

Twenty‐three patients (m: 10, f: 13; mean age: 47.9 years, cirrhosis: 16; median ALT: 71 IU/ml; median HDV‐RNA: 2.1 × 105copies/ml) started BLV monotherapy (2 mg/day: 22; 10 mg/day: 1). Twenty‐two completed ≥24 weeks of treatment (24–137 weeks): Ten (45%) were classified as BLV responders at week 24. BLV was stopped in two patients with >6 months HDV‐RNA undetectability, but both became HDV‐RNA positive again. One patient was transplanted at week 25. One patient terminated treatment because of side effects at week 60. Ten patients are still on BLV monotherapy. Adding PEG‐IFN in eight patients induced an HDV‐RNA decrease in all (1.29 ± 0.19 [SD] log within 12 weeks). HDV‐RNA decreased by >2log or became undetectable in 45%(10/22), 55%(11/20), 65% (13/20) and 69% (9/13); and ALT levels normalised in 64% (14/22), 85% (17/20), 90% (18/20) and in 92% (12/13) patients at weeks 24, 36, 48 and 60, respectively. Portal pressure decreased in 40% (2/5) of patients undergoing repeated measurement under BLV therapy.

Conclusion

Long‐term BLV monotherapy is safe and effectively decreases HDV‐RNA and ALT—even in patients with cirrhosis. The optimal duration of BLV treatment alone or in combination with PEG‐IFN remains to be established. An algorithm for a response‐guided BLV treatment approach is proposed.